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Poss, Kenneth Daniel

Overview:

Modeling disease in zebrafish
Genetic approaches to organ regeneration
Cardiac regeneration
Appendage regeneration
Developmental biology

Positions:

James B. Duke Professor of Cell Biology

Cell Biology
School of Medicine

Professor of Cell Biology

Cell Biology
School of Medicine

Professor in Medicine

Medicine, Cardiology
School of Medicine

Professor of Biology

Biology
Trinity College of Arts & Sciences

Member of the Duke Cancer Institute

Duke Cancer Institute
School of Medicine

Education:

Ph.D. 1998

Ph.D. — Massachusetts Institute of Technology

Research Fellow,

University of Utah

Postdoctoral Fellow, Cardiology

Children's Hospital

News:

Grants:

Multidisciplinary Heart and Vascular Diseases

Administered By
Medicine, Cardiology
AwardedBy
National Institutes of Health
Role
Mentor
Start Date
July 01, 1975
End Date
March 31, 2021

Eliciting heart regeneration through cardiomyocyte division

Administered By
Cell Biology
AwardedBy
Fondation Leducq
Role
Principal Investigator
Start Date
January 01, 2016
End Date
December 31, 2020

Identification and application of regulatory elements for heart regeneration

Administered By
Cell Biology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
December 15, 2016
End Date
November 30, 2020

Genetics Training Grant

Administered By
Basic Science Departments
AwardedBy
National Institutes of Health
Role
Mentor
Start Date
September 01, 1979
End Date
June 30, 2020

Organization and Function of Cellular Structure

Administered By
Basic Science Departments
AwardedBy
National Institutes of Health
Role
Mentor
Start Date
July 01, 1975
End Date
June 30, 2020

Mechanisms protecting cell surface integrity in giant vacuolated cells of the notochord

Administered By
Cell Biology
AwardedBy
National Institutes of Health
Role
Co-Sponsor
Start Date
June 01, 2017
End Date
May 31, 2020

Interdisciplinary Training Program in Lung Disease

Administered By
Medicine, Pulmonary, Allergy, and Critical Care Medicine
AwardedBy
National Institutes of Health
Role
Preceptor
Start Date
July 01, 2009
End Date
March 31, 2020

Regulation of the Epicardial Injury Response During Heart Regeneration in Zebrafish

Administered By
Cell Biology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
January 01, 2016
End Date
December 31, 2019

Role of Developmental Signaling Pathways in Tuberculosis Pathogenesis

Administered By
Molecular Genetics and Microbiology
AwardedBy
National Institutes of Health
Role
Collaborating Investigator
Start Date
February 01, 2017
End Date
January 31, 2019

Regulation of glial bridging during spinal cord regeneration in zebrafish

Administered By
Cell Biology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
December 01, 2016
End Date
November 30, 2018

Biomarkers of Heart Regeneration

Administered By
Medicine, Cardiology
AwardedBy
National Institutes of Health
Role
Mentor
Start Date
August 02, 2013
End Date
July 31, 2018

Dissecting the directional regeneration of ventricular epicardium

Administered By
Cell Biology
AwardedBy
American Heart Association
Role
Principal Investigator
Start Date
July 01, 2015
End Date
June 30, 2018

Regulation of Appendage Regeneration in Zebrafish

Administered By
Cell Biology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
July 01, 2014
End Date
June 30, 2018

Regulation of Myocardial Regeneration in Zebrafish

Administered By
Cell Biology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
August 01, 2005
End Date
April 30, 2018

Duke Research Training Program for Pediatricians

Administered By
Pediatrics, Infectious Diseases
AwardedBy
National Institutes of Health
Role
Training Faculty
Start Date
July 01, 2002
End Date
April 30, 2018

Center for Molecular & Cellular Studies of Ped Disease

Administered By
Pediatrics
AwardedBy
National Institutes of Health
Role
Mentor
Start Date
April 11, 2003
End Date
November 30, 2017

Training Program in Developmental and Stem Cell Biology

Administered By
Basic Science Departments
AwardedBy
National Institutes of Health
Role
Mentor
Start Date
May 01, 2001
End Date
October 31, 2017

Medical Scientist Training Program

Administered By
School of Medicine
AwardedBy
National Institutes of Health
Role
Mentor
Start Date
July 01, 1997
End Date
June 30, 2017

Serial Block Face Scanning Electron Microscope

Administered By
Pathology
AwardedBy
National Institutes of Health
Role
Minor User
Start Date
June 01, 2016
End Date
May 31, 2017

Regulation of cardiomyocyte proliferation dynamics during zebrafish heart development

Administered By
Cell Biology
AwardedBy
March of Dimes
Role
Principal Investigator
Start Date
June 01, 2014
End Date
May 31, 2017

Lightsheet Imaging System

Administered By
Biology
AwardedBy
National Institutes of Health
Role
Major User
Start Date
March 15, 2016
End Date
March 14, 2017

CHROMATIN REGULATORY EVENTS UNDERLYING ZEBRAFISH HEART REGENERATION

Administered By
Cell Biology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
February 01, 2014
End Date
January 31, 2017

Vegf Signaling and Cardiac Chamber Morphogenesis in Zebrafish

Administered By
Cell Biology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
January 01, 2015
End Date
December 31, 2016

Regeneration Next Initiative Annual Retreat

Administered By
Cell Biology
AwardedBy
North Carolina Biotechnology Center
Role
Principal Investigator
Start Date
October 01, 2016
End Date
October 31, 2016

Dissecting the directional regeneration of ventricular epicardium

Administered By
Cell Biology
AwardedBy
American Heart Association
Role
Principal Investigator
Start Date
July 01, 2015
End Date
October 31, 2016

Mechanisms of Neuregulin 1 in Heart Regeneration

Administered By
Surgery
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
September 30, 2015
End Date
September 29, 2016

2016 Weinstein Cardiovascular Development and Regeneration Conference

Administered By
Cell Biology
AwardedBy
March of Dimes
Role
Principal Investigator
Start Date
March 01, 2016
End Date
August 31, 2016

2016 Weinstein Cardiovascular Development and Regeneration Conference Organizing Committee

Administered By
Cell Biology
AwardedBy
The Company of Biologists
Role
Principal Investigator
Start Date
October 26, 2015
End Date
August 31, 2016

Visualizing and dissecting epicardial regeneration in zebrafish

Administered By
Cell Biology
AwardedBy
American Heart Association
Role
Principal Investigator
Start Date
July 01, 2014
End Date
June 30, 2016

Multidisciplinary Neonatal Training Grant

Administered By
Pediatrics, Neonatology
AwardedBy
National Institutes of Health
Role
Mentor
Start Date
April 01, 2010
End Date
June 30, 2015

Identifying mechanisms of heart regeneration

Administered By
Cell Biology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
August 01, 2011
End Date
July 31, 2014
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Awards:

Ruth and A. Morris Williams Prize in Basic Research. Duke University School of Medicine.

Type
School
Awarded By
Duke University School of Medicine
Date
January 01, 2011

Early Career Scientist. Howard Hughes Medical Institute.

Type
National
Awarded By
Howard Hughes Medical Institute
Date
January 01, 2009

Pew Scholars in the Biomedical Sciences. Pew Charitable Trusts, The.

Type
National
Awarded By
Pew Charitable Trusts, The
Date
January 01, 2006

Publications:

Ligament versus bone cell identity in the zebrafish hyoid skeleton is regulated by mef2ca.

Heightened phenotypic variation among mutant animals is a well-known, but poorly understood phenomenon. One hypothetical mechanism accounting for mutant phenotypic variation is progenitor cells variably choosing between two alternative fates during development. Zebrafish mef2cab1086 mutants develop tremendously variable ectopic bone in their hyoid craniofacial skeleton. Here, we report evidence that a key component of this phenotype is variable fate switching from ligament to bone. We discover that a 'track' of tissue prone to become bone cells is a previously undescribed ligament. Fate-switch variability is heritable, and comparing mutant strains selectively bred to high and low penetrance revealed differential mef2ca mutant transcript expression between high and low penetrance strains. Consistent with this, experimental manipulation of mef2ca mutant transcripts modifies the penetrance of the fate switch. Furthermore, we discovered a transposable element that resides immediately upstream of the mef2ca locus and is differentially DNA methylated in the two strains, correlating with differential mef2ca expression. We propose that variable transposon epigenetic silencing underlies the variable mef2ca mutant bone phenotype, and could be a widespread mechanism of phenotypic variability in animals.

Authors
Nichols, JT; Blanco-Sánchez, B; Brooks, EP; Parthasarathy, R; Dowd, J; Subramanian, A; Nachtrab, G; Poss, KD; Schilling, TF; Kimmel, CB
MLA Citation
Nichols, JT, Blanco-Sánchez, B, Brooks, EP, Parthasarathy, R, Dowd, J, Subramanian, A, Nachtrab, G, Poss, KD, Schilling, TF, and Kimmel, CB. "Ligament versus bone cell identity in the zebrafish hyoid skeleton is regulated by mef2ca." Development (Cambridge, England) 143.23 (December 2016): 4430-4440.
PMID
27789622
Source
epmc
Published In
Development (Cambridge)
Volume
143
Issue
23
Publish Date
2016
Start Page
4430
End Page
4440

Live Monitoring of Blastemal Cell Contributions during Appendage Regeneration.

The blastema is a mass of progenitor cells that enables regeneration of amputated salamander limbs or fish fins. Methodology to label and track blastemal cell progeny has been deficient, restricting our understanding of appendage regeneration. Here, we created a system for clonal analysis and quantitative imaging of hundreds of blastemal cells and their respective progeny in living adult zebrafish undergoing fin regeneration. Amputation stimulates resident cells within a limited recruitment zone to reset proximodistal (PD) positional information and assemble the blastema. Within the newly formed blastema, the spatial coordinates of connective tissue progenitors are predictive of their ultimate contributions to regenerated skeletal structures, indicating early development of an approximate PD pre-pattern. Calcineurin regulates size recovery by controlling the average number of progeny divisions without disrupting this pre-pattern. Our longitudinal clonal analyses of regenerating zebrafish fins provide evidence that connective tissue progenitors are rapidly organized into a scalable blueprint of lost structures.

Authors
Tornini, VA; Puliafito, A; Slota, LA; Thompson, JD; Nachtrab, G; Kaushik, A-L; Kapsimali, M; Primo, L; Di Talia, S; Poss, KD
MLA Citation
Tornini, VA, Puliafito, A, Slota, LA, Thompson, JD, Nachtrab, G, Kaushik, A-L, Kapsimali, M, Primo, L, Di Talia, S, and Poss, KD. "Live Monitoring of Blastemal Cell Contributions during Appendage Regeneration." Current biology : CB 26.22 (November 3, 2016): 2981-2991.
PMID
27839971
Source
epmc
Published In
Current Biology
Volume
26
Issue
22
Publish Date
2016
Start Page
2981
End Page
2991
DOI
10.1016/j.cub.2016.08.072

Injury-induced ctgfa directs glial bridging and spinal cord regeneration in zebrafish.

Unlike mammals, zebrafish efficiently regenerate functional nervous system tissue after major spinal cord injury. Whereas glial scarring presents a roadblock for mammalian spinal cord repair, glial cells in zebrafish form a bridge across severed spinal cord tissue and facilitate regeneration. We performed a genome-wide profiling screen for secreted factors that are up-regulated during zebrafish spinal cord regeneration. We found that connective tissue growth factor a (ctgfa) is induced in and around glial cells that participate in initial bridging events. Mutations in ctgfa disrupted spinal cord repair, and transgenic ctgfa overexpression or local delivery of human CTGF recombinant protein accelerated bridging and functional regeneration. Our study reveals that CTGF is necessary and sufficient to stimulate glial bridging and natural spinal cord regeneration.

Authors
Mokalled, MH; Patra, C; Dickson, AL; Endo, T; Stainier, DYR; Poss, KD
MLA Citation
Mokalled, MH, Patra, C, Dickson, AL, Endo, T, Stainier, DYR, and Poss, KD. "Injury-induced ctgfa directs glial bridging and spinal cord regeneration in zebrafish." Science (New York, N.Y.) 354.6312 (November 2016): 630-634.
PMID
27811277
Source
epmc
Published In
Science
Volume
354
Issue
6312
Publish Date
2016
Start Page
630
End Page
634

Monitoring Tissue Regeneration at Single-Cell Resolution.

For tissue regeneration researchers, seeing is believing. Here, we consider advances in genetic tools, imaging platforms, and quantification capabilities that are turning previously unattainable goals, like in toto capture of cellular and subcellular behaviors in regenerating tissues, into reality.

Authors
Di Talia, S; Poss, KD
MLA Citation
Di Talia, S, and Poss, KD. "Monitoring Tissue Regeneration at Single-Cell Resolution." Cell stem cell 19.4 (October 2016): 428-431.
PMID
27716522
Source
epmc
Published In
Cell Stem Cell
Volume
19
Issue
4
Publish Date
2016
Start Page
428
End Page
431
DOI
10.1016/j.stem.2016.09.007

Multicolor mapping of the cardiomyocyte proliferation dynamics that construct the atrium.

The orchestrated division of cardiomyocytes assembles heart chambers of distinct morphology. To understand the structural divergence of the cardiac chambers, we determined the contributions of individual embryonic cardiomyocytes to the atrium in zebrafish by multicolor fate-mapping and we compare our analysis to the established proliferation dynamics of ventricular cardiomyocytes. We find that most atrial cardiomyocytes become rod-shaped in the second week of life, generating a single-muscle-cell-thick myocardial wall with a striking webbed morphology. Inner pectinate myofibers form mainly by direct branching, unlike delamination events that create ventricular trabeculae. Thus, muscle clones assembling the atrial chamber can extend from wall to lumen. As zebrafish mature, atrial wall cardiomyocytes proliferate laterally to generate cohesive patches of diverse shapes and sizes, frequently with dominant clones that comprise 20-30% of the wall area. A subpopulation of cardiomyocytes that transiently express atrial myosin heavy chain (amhc) contributes substantially to specific regions of the ventricle, suggesting an unappreciated level of plasticity during chamber formation. Our findings reveal proliferation dynamics and fate decisions of cardiomyocytes that produce the distinct architecture of the atrium.

Authors
Foglia, MJ; Cao, J; Tornini, VA; Poss, KD
MLA Citation
Foglia, MJ, Cao, J, Tornini, VA, and Poss, KD. "Multicolor mapping of the cardiomyocyte proliferation dynamics that construct the atrium." Development (Cambridge, England) 143.10 (May 2016): 1688-1696.
PMID
26989176
Source
epmc
Published In
Development (Cambridge)
Volume
143
Issue
10
Publish Date
2016
Start Page
1688
End Page
1696
DOI
10.1242/dev.136606

Explant culture of adult zebrafish hearts for epicardial regeneration studies.

Here we describe how to culture adult zebrafish hearts as explants and study the regeneration of epicardial tissue ex vivo, as a means to identify therapeutic targets for heart disease. Uninjured or injured adult hearts are excised, washed and cultured in an incubator with gentle agitation. Heart explants can be prepared within 2 h, and they can be maintained in culture for 30 d or longer. If explants are prepared from appropriate transgenic lines, dynamic behaviors of epicardial cells can be monitored by live imaging using stereofluorescence microscopy. We also describe ex vivo procedures for genetic ablation of the epicardium, cell proliferation assays, tissue grafts and bead grafts. Basic cell culture and surgical skills are required to carry out this protocol. Unlike existing protocols for culturing isolated zebrafish epicardial cells on matrices, procedures described here maintain epicardial cells on an intact cardiac surface, thereby better supporting in vivo cell behaviors. Our protocols complement and extend in vivo studies of heart regeneration.

Authors
Cao, J; Poss, KD
MLA Citation
Cao, J, and Poss, KD. "Explant culture of adult zebrafish hearts for epicardial regeneration studies." Nature protocols 11.5 (May 2016): 872-881.
PMID
27055096
Source
epmc
Published In
Nature Protocols
Volume
11
Issue
5
Publish Date
2016
Start Page
872
End Page
881
DOI
10.1038/nprot.2016.049

Accessories to Limb Regeneration.

In a recent issue of Nature, Nacu et al. (2016) identified FGF and HH ligands as interacting molecular influences that are necessary and sufficient to induce the formation of supernumerary limbs from blastemal tissue in axolotl salamanders.

Authors
Han, Y; Poss, KD
MLA Citation
Han, Y, and Poss, KD. "Accessories to Limb Regeneration." Developmental cell 37.4 (May 2016): 297-298.
PMID
27219058
Source
epmc
Published In
Developmental Cell
Volume
37
Issue
4
Publish Date
2016
Start Page
297
End Page
298
DOI
10.1016/j.devcel.2016.05.007

Modulation of tissue repair by regeneration enhancer elements.

How tissue regeneration programs are triggered by injury has received limited research attention. Here we investigate the existence of enhancer regulatory elements that are activated in regenerating tissue. Transcriptomic analyses reveal that leptin b (lepb) is highly induced in regenerating hearts and fins of zebrafish. Epigenetic profiling identified a short DNA sequence element upstream and distal to lepb that acquires open chromatin marks during regeneration and enables injury-dependent expression from minimal promoters. This element could activate expression in injured neonatal mouse tissues and was divisible into tissue-specific modules sufficient for expression in regenerating zebrafish fins or hearts. Simple enhancer-effector transgenes employing lepb-linked sequences upstream of pro- or anti-regenerative factors controlled the efficacy of regeneration in zebrafish. Our findings provide evidence for 'tissue regeneration enhancer elements' (TREEs) that trigger gene expression in injury sites and can be engineered to modulate the regenerative potential of vertebrate organs.

Authors
Kang, J; Hu, J; Karra, R; Dickson, AL; Tornini, VA; Nachtrab, G; Gemberling, M; Goldman, JA; Black, BL; Poss, KD
MLA Citation
Kang, J, Hu, J, Karra, R, Dickson, AL, Tornini, VA, Nachtrab, G, Gemberling, M, Goldman, JA, Black, BL, and Poss, KD. "Modulation of tissue repair by regeneration enhancer elements." Nature 532.7598 (April 6, 2016): 201-206.
PMID
27049946
Source
epmc
Published In
Nature
Volume
532
Issue
7598
Publish Date
2016
Start Page
201
End Page
206
DOI
10.1038/nature17644

Building and re-building the heart by cardiomyocyte proliferation.

The adult human heart does not regenerate significant amounts of lost tissue after injury. Rather than making new, functional muscle, human hearts are prone to scarring and hypertrophy, which can often lead to fatal arrhythmias and heart failure. The most-cited basis of this ineffective cardiac regeneration in mammals is the low proliferative capacity of adult cardiomyocytes. However, mammalian cardiomyocytes can avidly proliferate during fetal and neonatal development, and both adult zebrafish and neonatal mice can regenerate cardiac muscle after injury, suggesting that latent regenerative potential exists. Dissecting the cellular and molecular mechanisms that promote cardiomyocyte proliferation throughout life, deciphering why proliferative capacity normally dissipates in adult mammals, and deriving means to boost this capacity are primary goals in cardiovascular research. Here, we review our current understanding of how cardiomyocyte proliferation is regulated during heart development and regeneration.

Authors
Foglia, MJ; Poss, KD
MLA Citation
Foglia, MJ, and Poss, KD. "Building and re-building the heart by cardiomyocyte proliferation." Development (Cambridge, England) 143.5 (March 2016): 729-740. (Review)
PMID
26932668
Source
epmc
Published In
Development (Cambridge)
Volume
143
Issue
5
Publish Date
2016
Start Page
729
End Page
740
DOI
10.1242/dev.132910

Multicolor Cell Barcoding Technology for Long-Term Surveillance of Epithelial Regeneration in Zebrafish.

Current fate mapping and imaging platforms are limited in their ability to capture dynamic behaviors of epithelial cells. To deconstruct regenerating adult epithelial tissue at single-cell resolution, we created a multicolor system, skinbow, that barcodes the superficial epithelial cell (SEC) population of zebrafish skin with dozens of distinguishable tags. With image analysis to directly segment and simultaneously track hundreds of SECs in vivo over entire surface lifetimes, we readily quantified the orchestration of cell emergence, growth, repositioning, and loss under homeostatic conditions and after exfoliation or appendage amputation. We employed skinbow-based imaging in conjunction with a live reporter of epithelial stem cell cycle activity and as an instrument to evaluate the effects of reactive oxygen species on SEC behavior during epithelial regeneration. Our findings introduce a platform for large-scale, quantitative in vivo imaging of regenerating skin and reveal unanticipated collective dynamism in epithelial cell size, mobility, and interactions.

Authors
Chen, C-H; Puliafito, A; Cox, BD; Primo, L; Fang, Y; Di Talia, S; Poss, KD
MLA Citation
Chen, C-H, Puliafito, A, Cox, BD, Primo, L, Fang, Y, Di Talia, S, and Poss, KD. "Multicolor Cell Barcoding Technology for Long-Term Surveillance of Epithelial Regeneration in Zebrafish." Developmental cell 36.6 (March 2016): 668-680.
PMID
27003938
Source
epmc
Published In
Developmental Cell
Volume
36
Issue
6
Publish Date
2016
Start Page
668
End Page
680
DOI
10.1016/j.devcel.2016.02.017

Single epicardial cell transcriptome sequencing identifies Caveolin 1 as an essential factor in zebrafish heart regeneration.

In contrast to mammals, adult zebrafish have a high capacity to regenerate damaged or lost myocardium through proliferation of cardiomyocytes spared from damage. The epicardial sheet covering the heart is activated by injury and aids muscle regeneration through paracrine effects and as a multipotent cell source, and has received recent attention as a target in cardiac repair strategies. Although it is recognized that epicardium is required for muscle regeneration and itself has high regenerative potential, the extent of cellular heterogeneity within epicardial tissue is largely unexplored. Here, we performed transcriptome analysis on dozens of epicardial lineage cells purified from zebrafish harboring a transgenic reporter for the pan-epicardial gene tcf21. Hierarchical clustering analysis suggested the presence of at least three epicardial cell subsets defined by expression signatures. We validated many new pan-epicardial and epicardial markers by alternative expression assays. Additionally, we explored the function of the scaffolding protein and main component of caveolae, caveolin 1 (cav1), which was present in each epicardial subset. In BAC transgenic zebrafish, cav1 regulatory sequences drove strong expression in ostensibly all epicardial cells and in coronary vascular endothelial cells. Moreover, cav1 mutant zebrafish generated by genome editing showed grossly normal heart development and adult cardiac anatomy, but displayed profound defects in injury-induced cardiomyocyte proliferation and heart regeneration. Our study defines a new platform for the discovery of epicardial lineage markers, genetic tools, and mechanisms of heart regeneration.

Authors
Cao, J; Navis, A; Cox, BD; Dickson, AL; Gemberling, M; Karra, R; Bagnat, M; Poss, KD
MLA Citation
Cao, J, Navis, A, Cox, BD, Dickson, AL, Gemberling, M, Karra, R, Bagnat, M, and Poss, KD. "Single epicardial cell transcriptome sequencing identifies Caveolin 1 as an essential factor in zebrafish heart regeneration." Development (Cambridge, England) 143.2 (January 2016): 232-243.
PMID
26657776
Source
epmc
Published In
Development (Cambridge)
Volume
143
Issue
2
Publish Date
2016
Start Page
232
End Page
243
DOI
10.1242/dev.130534

Methodologies for Inducing Cardiac Injury and Assaying Regeneration in Adult Zebrafish.

The zebrafish has emerged as an important model organism for understanding the cellular and molecular mechanisms of tissue regeneration. Adult zebrafish efficiently replace cardiac muscle after partial resection of their ventricle, or after transgenic ablation of cardiomyocytes. Here, we describe methodology for inducing these injuries and assaying indicators of regeneration.

Authors
Wang, J; Poss, KD
MLA Citation
Wang, J, and Poss, KD. "Methodologies for Inducing Cardiac Injury and Assaying Regeneration in Adult Zebrafish." Methods in molecular biology (Clifton, N.J.) 1451 (January 2016): 225-235.
PMID
27464811
Source
epmc
Published In
Methods in molecular biology (Clifton, N.J.)
Volume
1451
Publish Date
2016
Start Page
225
End Page
235
DOI
10.1007/978-1-4939-3771-4_15

Myocardial NF-κB activation is essential for zebrafish heart regeneration.

Heart regeneration offers a novel therapeutic strategy for heart failure. Unlike mammals, lower vertebrates such as zebrafish mount a strong regenerative response following cardiac injury. Heart regeneration in zebrafish occurs by cardiomyocyte proliferation and reactivation of a cardiac developmental program, as evidenced by induction of gata4 regulatory sequences in regenerating cardiomyocytes. Although many of the cellular determinants of heart regeneration have been elucidated, how injury triggers a regenerative program through dedifferentiation and epicardial activation is a critical outstanding question. Here, we show that NF-κB signaling is induced in cardiomyocytes following injury. Myocardial inhibition of NF-κB activity blocks heart regeneration with pleiotropic effects, decreasing both cardiomyocyte proliferation and epicardial responses. Activation of gata4 regulatory sequences is also prevented by NF-κB signaling antagonism, suggesting an underlying defect in cardiomyocyte dedifferentiation. Our results implicate NF-κB signaling as a key node between cardiac injury and tissue regeneration.

Authors
Karra, R; Knecht, AK; Kikuchi, K; Poss, KD
MLA Citation
Karra, R, Knecht, AK, Kikuchi, K, and Poss, KD. "Myocardial NF-κB activation is essential for zebrafish heart regeneration." Proceedings of the National Academy of Sciences of the United States of America 112.43 (October 15, 2015): 13255-13260.
PMID
26472034
Source
epmc
Published In
Proceedings of the National Academy of Sciences of USA
Volume
112
Issue
43
Publish Date
2015
Start Page
13255
End Page
13260
DOI
10.1073/pnas.1511209112

Transient laminin beta 1a Induction Defines the Wound Epidermis during Zebrafish Fin Regeneration.

The first critical stage in salamander or teleost appendage regeneration is creation of a specialized epidermis that instructs growth from underlying stump tissue. Here, we performed a forward genetic screen for mutations that impair this process in amputated zebrafish fins. Positional cloning and complementation assays identified a temperature-sensitive allele of the ECM component laminin beta 1a (lamb1a) that blocks fin regeneration. lamb1a, but not its paralog lamb1b, is sharply induced in a subset of epithelial cells after fin amputation, where it is required to establish and maintain a polarized basal epithelial cell layer. These events facilitate expression of the morphogenetic factors shha and lef1, basolateral positioning of phosphorylated Igf1r, patterning of new osteoblasts, and regeneration of bone. By contrast, lamb1a function is dispensable for juvenile body growth, homeostatic adult tissue maintenance, repair of split fins, or renewal of genetically ablated osteoblasts. fgf20a mutations or transgenic Fgf receptor inhibition disrupt lamb1a expression, linking a central growth factor to epithelial maturation during regeneration. Our findings reveal transient induction of lamb1a in epithelial cells as a key, growth factor-guided step in formation of a signaling-competent regeneration epidermis.

Authors
Chen, C-H; Merriman, AF; Savage, J; Willer, J; Wahlig, T; Katsanis, N; Yin, VP; Poss, KD
MLA Citation
Chen, C-H, Merriman, AF, Savage, J, Willer, J, Wahlig, T, Katsanis, N, Yin, VP, and Poss, KD. "Transient laminin beta 1a Induction Defines the Wound Epidermis during Zebrafish Fin Regeneration." PLoS genetics 11.8 (August 25, 2015): e1005437-.
PMID
26305099
Source
epmc
Published In
PLoS genetics
Volume
11
Issue
8
Publish Date
2015
Start Page
e1005437
DOI
10.1371/journal.pgen.1005437

Nerves Regulate Cardiomyocyte Proliferation and Heart Regeneration.

Some organisms, such as adult zebrafish and newborn mice, have the capacity to regenerate heart tissue following injury. Unraveling the mechanisms of heart regeneration is fundamental to understanding why regeneration fails in adult humans. Numerous studies have revealed that nerves are crucial for organ regeneration, thus we aimed to determine whether nerves guide heart regeneration. Here, we show using transgenic zebrafish that inhibition of cardiac innervation leads to reduction of myocyte proliferation following injury. Specifically, pharmacological inhibition of cholinergic nerve function reduces cardiomyocyte proliferation in the injured hearts of both zebrafish and neonatal mice. Direct mechanical denervation impairs heart regeneration in neonatal mice, which was rescued by the administration of neuregulin 1 (NRG1) and nerve growth factor (NGF) recombinant proteins. Transcriptional analysis of mechanically denervated hearts revealed a blunted inflammatory and immune response following injury. These findings demonstrate that nerve function is required for both zebrafish and mouse heart regeneration.

Authors
Mahmoud, AI; O'Meara, CC; Gemberling, M; Zhao, L; Bryant, DM; Zheng, R; Gannon, JB; Cai, L; Choi, W-Y; Egnaczyk, GF; Burns, CE; Burns, CG; MacRae, CA; Poss, KD; Lee, RT
MLA Citation
Mahmoud, AI, O'Meara, CC, Gemberling, M, Zhao, L, Bryant, DM, Zheng, R, Gannon, JB, Cai, L, Choi, W-Y, Egnaczyk, GF, Burns, CE, Burns, CG, MacRae, CA, Poss, KD, and Lee, RT. "Nerves Regulate Cardiomyocyte Proliferation and Heart Regeneration." Developmental cell 34.4 (August 5, 2015): 387-399.
PMID
26256209
Source
epmc
Published In
Developmental Cell
Volume
34
Issue
4
Publish Date
2015
Start Page
387
End Page
399
DOI
10.1016/j.devcel.2015.06.017

Origin, Specification, and Plasticity of the Great Vessels of the Heart.

The pharyngeal arch arteries (PAAs) are a series of paired embryonic blood vessels that give rise to several major arteries that connect directly to the heart. During development, the PAAs emerge from nkx2.5-expressing mesodermal cells and connect the dorsal head vasculature to the outflow tract of the heart. Despite their central role in establishing the circulatory system, the embryonic origins of the PAA progenitors are only coarsely defined, and the factors that specify them and their regenerative potential are unclear. Using fate mapping and mutant analysis, we find that PAA progenitors are derived from the tcf21 and nkx2.5 double-positive head mesoderm and require these two transcription factors for their specification and survival. Unexpectedly, cell ablation shows that the tcf21+; nkx2.5+ PAA progenitors are not required for PAA formation. We find that this compensation is due to the replacement of ablated tcf21+; nkx2.5+ PAA cells by endothelial cells from the dorsal head vasculature. Together, these studies assign the embryonic origin of the great vessel progenitors to the interface between the pharyngeal and cardiac mesoderm, identify the transcription factor code required for their specification, and reveal an unexpected plasticity in the formation of the great vessels.

Authors
Nagelberg, D; Wang, J; Su, R; Torres-Vázquez, J; Targoff, KL; Poss, KD; Knaut, H
MLA Citation
Nagelberg, D, Wang, J, Su, R, Torres-Vázquez, J, Targoff, KL, Poss, KD, and Knaut, H. "Origin, Specification, and Plasticity of the Great Vessels of the Heart." Current biology : CB 25.16 (August 5, 2015): 2099-2110.
PMID
26255850
Source
epmc
Published In
Current Biology
Volume
25
Issue
16
Publish Date
2015
Start Page
2099
End Page
2110
DOI
10.1016/j.cub.2015.06.076

Myocardium and BMP signaling are required for endocardial differentiation.

Endocardial and myocardial progenitors originate in distinct regions of the anterior lateral plate mesoderm and migrate to the midline where they coalesce to form the cardiac tube. Endocardial progenitors acquire a molecular identity distinct from other vascular endothelial cells and initiate expression of specific genes such as nfatc1. Yet the molecular pathways and tissue interactions involved in establishing endocardial identity are poorly understood. The endocardium develops in tight association with cardiomyocytes. To test for a potential role of the myocardium in endocardial morphogenesis, we used two different zebrafish models deficient in cardiomyocytes: the hand2 mutant and a myocardial-specific genetic ablation method. We show that in hand2 mutants endocardial progenitors migrate to the midline but fail to assemble into a cardiac cone and do not express markers of differentiated endocardium. Endocardial differentiation defects were rescued by myocardial but not endocardial-specific expression of hand2. In metronidazole-treated myl7:nitroreductase embryos, myocardial cells were targeted for apoptosis, which resulted in the loss of endocardial nfatc1 expression. However, endocardial cells were present and retained expression of general vascular endothelial markers. We further identified bone morphogenetic protein (BMP) as a candidate myocardium-derived signal required for endocardial differentiation. Chemical and genetic inhibition of BMP signaling at the tailbud stage resulted in severe inhibition of endocardial differentiation while there was little effect on myocardial development. Heat-shock-induced bmp2b expression rescued endocardial nfatc1 expression in hand2 mutants and in myocardium-depleted embryos. Our results indicate that the myocardium is crucial for endocardial morphogenesis and differentiation, and identify BMP as a signal involved in endocardial differentiation.

Authors
Palencia-Desai, S; Rost, MS; Schumacher, JA; Ton, QV; Craig, MP; Baltrunaite, K; Koenig, AL; Wang, J; Poss, KD; Chi, NC; Stainier, DYR; Sumanas, S
MLA Citation
Palencia-Desai, S, Rost, MS, Schumacher, JA, Ton, QV, Craig, MP, Baltrunaite, K, Koenig, AL, Wang, J, Poss, KD, Chi, NC, Stainier, DYR, and Sumanas, S. "Myocardium and BMP signaling are required for endocardial differentiation." Development (Cambridge, England) 142.13 (July 2015): 2304-2315.
PMID
26092845
Source
epmc
Published In
Development (Cambridge)
Volume
142
Issue
13
Publish Date
2015
Start Page
2304
End Page
2315
DOI
10.1242/dev.118687

Epicardial regeneration is guided by cardiac outflow tract and Hedgehog signalling.

In response to cardiac damage, a mesothelial tissue layer enveloping the heart called the epicardium is activated to proliferate and accumulate at the injury site. Recent studies have implicated the epicardium in multiple aspects of cardiac repair: as a source of paracrine signals for cardiomyocyte survival or proliferation; a supply of perivascular cells and possibly other cell types such as cardiomyocytes; and as a mediator of inflammation. However, the biology and dynamism of the adult epicardium is poorly understood. To investigate this, we created a transgenic line to ablate the epicardial cell population in adult zebrafish. Here we find that genetic depletion of the epicardium after myocardial loss inhibits cardiomyocyte proliferation and delays muscle regeneration. The epicardium vigorously regenerates after its ablation, through proliferation and migration of spared epicardial cells as a sheet to cover the exposed ventricular surface in a wave from the chamber base towards its apex. By reconstituting epicardial regeneration ex vivo, we show that extirpation of the bulbous arteriosus-a distinct, smooth-muscle-rich tissue structure that distributes outflow from the ventricle-prevents epicardial regeneration. Conversely, experimental repositioning of the bulbous arteriosus by tissue recombination initiates epicardial regeneration and can govern its direction. Hedgehog (Hh) ligand is expressed in the bulbous arteriosus, and treatment with a Hh signalling antagonist arrests epicardial regeneration and blunts the epicardial response to muscle injury. Transplantation of Sonic hedgehog (Shh)-soaked beads at the ventricular base stimulates epicardial regeneration after bulbous arteriosus removal, indicating that Hh signalling can substitute for the influence of the outflow tract. Thus, the ventricular epicardium has pronounced regenerative capacity, regulated by the neighbouring cardiac outflow tract and Hh signalling. These findings extend our understanding of tissue interactions during regeneration and have implications for mobilizing epicardial cells for therapeutic heart repair.

Authors
Wang, J; Cao, J; Dickson, AL; Poss, KD
MLA Citation
Wang, J, Cao, J, Dickson, AL, and Poss, KD. "Epicardial regeneration is guided by cardiac outflow tract and Hedgehog signalling." Nature 522.7555 (June 2015): 226-230.
PMID
25938716
Source
epmc
Published In
Nature
Volume
522
Issue
7555
Publish Date
2015
Start Page
226
End Page
230
DOI
10.1038/nature14325

Back in Black.

In this issue of Developmental Cell, Iyengar and colleagues (2015) employ live imaging of melanocyte regeneration in adult zebrafish to define a bias in progenitor cell fates that enables both rapid pigment cell renewal and maintenance of regenerative capacity.

Authors
Kang, J; Karra, R; Poss, KD
MLA Citation
Kang, J, Karra, R, and Poss, KD. "Back in Black." Developmental cell 33.6 (June 2015): 623-624.
PMID
26102596
Source
epmc
Published In
Developmental Cell
Volume
33
Issue
6
Publish Date
2015
Start Page
623
End Page
624
DOI
10.1016/j.devcel.2015.06.001

Nrg1 is an injury-induced cardiomyocyte mitogen for the endogenous heart regeneration program in zebrafish.

Heart regeneration is limited in adult mammals but occurs naturally in adult zebrafish through the activation of cardiomyocyte division. Several components of the cardiac injury microenvironment have been identified, yet no factor on its own is known to stimulate overt myocardial hyperplasia in a mature, uninjured animal. In this study, we find evidence that Neuregulin1 (Nrg1), previously shown to have mitogenic effects on mammalian cardiomyocytes, is sharply induced in perivascular cells after injury to the adult zebrafish heart. Inhibition of Erbb2, an Nrg1 co-receptor, disrupts cardiomyocyte proliferation in response to injury, whereas myocardial Nrg1 overexpression enhances this proliferation. In uninjured zebrafish, the reactivation of Nrg1 expression induces cardiomyocyte dedifferentiation, overt muscle hyperplasia, epicardial activation, increased vascularization, and causes cardiomegaly through persistent addition of wall myocardium. Our findings identify Nrg1 as a potent, induced mitogen for the endogenous adult heart regeneration program.

Authors
Gemberling, M; Karra, R; Dickson, AL; Poss, KD
MLA Citation
Gemberling, M, Karra, R, Dickson, AL, and Poss, KD. "Nrg1 is an injury-induced cardiomyocyte mitogen for the endogenous heart regeneration program in zebrafish." eLife 4 (April 2015).
Website
http://hdl.handle.net/10161/9718
PMID
25830562
Source
epmc
Published In
eLife
Volume
4
Publish Date
2015
DOI
10.7554/elife.05871

Hand2 elevates cardiomyocyte production during zebrafish heart development and regeneration.

Embryonic heart formation requires the production of an appropriate number of cardiomyocytes; likewise, cardiac regeneration following injury relies upon the recovery of lost cardiomyocytes. The basic helix-loop-helix (bHLH) transcription factor Hand2 has been implicated in promoting cardiomyocyte formation. It is unclear, however, whether Hand2 plays an instructive or permissive role during this process. Here, we find that overexpression of hand2 in the early zebrafish embryo is able to enhance cardiomyocyte production, resulting in an enlarged heart with a striking increase in the size of the outflow tract. Our evidence indicates that these increases are dependent on the interactions of Hand2 in multimeric complexes and are independent of direct DNA binding by Hand2. Proliferation assays reveal that hand2 can impact cardiomyocyte production by promoting division of late-differentiating cardiac progenitors within the second heart field. Additionally, our data suggest that hand2 can influence cardiomyocyte production by altering the patterning of the anterior lateral plate mesoderm, potentially favoring formation of the first heart field at the expense of hematopoietic and vascular lineages. The potency of hand2 during embryonic cardiogenesis suggested that hand2 could also impact cardiac regeneration in adult zebrafish; indeed, we find that overexpression of hand2 can augment the regenerative proliferation of cardiomyocytes in response to injury. Together, our studies demonstrate that hand2 can drive cardiomyocyte production in multiple contexts and through multiple mechanisms. These results contribute to our understanding of the potential origins of congenital heart disease and inform future strategies in regenerative medicine.

Authors
Schindler, YL; Garske, KM; Wang, J; Firulli, BA; Firulli, AB; Poss, KD; Yelon, D
MLA Citation
Schindler, YL, Garske, KM, Wang, J, Firulli, BA, Firulli, AB, Poss, KD, and Yelon, D. "Hand2 elevates cardiomyocyte production during zebrafish heart development and regeneration." Development (Cambridge, England) 141.16 (August 2014): 3112-3122.
PMID
25038045
Source
epmc
Published In
Development (Cambridge)
Volume
141
Issue
16
Publish Date
2014
Start Page
3112
End Page
3122
DOI
10.1242/dev.106336

Keeping at arm's length during regeneration.

Regeneration of a lost appendage in adult amphibians and fish is a remarkable feat of developmental patterning. Although the limb or fin may be years removed from its initial creation by an embryonic primordium, the blastema that emerges at the injury site fashions a close mimic of adult form. Central to understanding these events are revealing the cellular origins of new structures, how positional identity is maintained, and the determinants for completion. Each of these topics has been advanced recently, strengthening models for how complex tissue pattern is recalled in the adult context.

Authors
Tornini, VA; Poss, KD
MLA Citation
Tornini, VA, and Poss, KD. "Keeping at arm's length during regeneration." Developmental cell 29.2 (April 2014): 139-145. (Review)
PMID
24780734
Source
epmc
Published In
Developmental Cell
Volume
29
Issue
2
Publish Date
2014
Start Page
139
End Page
145
DOI
10.1016/j.devcel.2014.04.007

zebraflash transgenic lines for in vivo bioluminescence imaging of stem cells and regeneration in adult zebrafish.

The zebrafish has become a standard model system for stem cell and tissue regeneration research, based on powerful genetics, high tissue regenerative capacity and low maintenance costs. Yet, these studies can be challenged by current limitations of tissue visualization techniques in adult animals. Here we describe new imaging methodology and present several ubiquitous and tissue-specific luciferase-based transgenic lines, which we have termed zebraflash, that facilitate the assessment of regeneration and engraftment in freely moving adult zebrafish. We show that luciferase-based live imaging reliably estimates muscle quantity in an internal organ, the heart, and can longitudinally follow cardiac regeneration in individual animals after major injury. Furthermore, luciferase-based detection enables visualization and quantification of engraftment in live recipients of transplanted hematopoietic stem cell progeny, with advantages in sensitivity and gross spatial resolution over fluorescence detection. Our findings present a versatile resource for monitoring and dissecting vertebrate stem cell and regeneration biology.

Authors
Chen, C-H; Durand, E; Wang, J; Zon, LI; Poss, KD
MLA Citation
Chen, C-H, Durand, E, Wang, J, Zon, LI, and Poss, KD. "zebraflash transgenic lines for in vivo bioluminescence imaging of stem cells and regeneration in adult zebrafish." Development (Cambridge, England) 140.24 (December 2013): 4988-4997.
PMID
24198277
Source
epmc
Published In
Development (Cambridge)
Volume
140
Issue
24
Publish Date
2013
Start Page
4988
End Page
4997
DOI
10.1242/dev.102053

The zebrafish as a model for complex tissue regeneration

For centuries, philosophers and scientists have been fascinated by the principles and implications of regeneration in lower vertebrate species. Two features have made zebrafish an informative model system for determining mechanisms of regenerative events. First, they are highly regenerative, able to regrow amputated fins, as well as a lesioned brain, retina, spinal cord, heart, and other tissues. Second, they are amenable to both forward and reverse genetic approaches, with a research toolset regularly updated by an expanding community of zebrafish researchers. Zebrafish studies have helped identify new mechanistic underpinnings of regeneration in multiple tissues and, in some cases, have served as a guide for contemplating regenerative strategies in mammals. Here, we review the recent history of zebrafish as a genetic model system for understanding how and why tissue regeneration occurs. © 2013 Elsevier Ltd.

Authors
Gemberling, M; Bailey, TJ; Hyde, DR; Poss, KD
MLA Citation
Gemberling, M, Bailey, TJ, Hyde, DR, and Poss, KD. "The zebrafish as a model for complex tissue regeneration." Trends in Genetics 29.11 (November 1, 2013): 611-620. (Review)
Source
scopus
Published In
Trends in Genetics
Volume
29
Issue
11
Publish Date
2013
Start Page
611
End Page
620
DOI
10.1016/j.tig.2013.07.003

The zebrafish as a model for complex tissue regeneration.

For centuries, philosophers and scientists have been fascinated by the principles and implications of regeneration in lower vertebrate species. Two features have made zebrafish an informative model system for determining mechanisms of regenerative events. First, they are highly regenerative, able to regrow amputated fins, as well as a lesioned brain, retina, spinal cord, heart, and other tissues. Second, they are amenable to both forward and reverse genetic approaches, with a research toolset regularly updated by an expanding community of zebrafish researchers. Zebrafish studies have helped identify new mechanistic underpinnings of regeneration in multiple tissues and, in some cases, have served as a guide for contemplating regenerative strategies in mammals. Here, we review the recent history of zebrafish as a genetic model system for understanding how and why tissue regeneration occurs.

Authors
Gemberling, M; Bailey, TJ; Hyde, DR; Poss, KD
MLA Citation
Gemberling, M, Bailey, TJ, Hyde, DR, and Poss, KD. "The zebrafish as a model for complex tissue regeneration." Trends Genet 29.11 (November 2013): 611-620. (Review)
PMID
23927865
Source
pubmed
Published In
Trends in Genetics
Volume
29
Issue
11
Publish Date
2013
Start Page
611
End Page
620
DOI
10.1016/j.tig.2013.07.003

Local Dkk1 crosstalk from breeding ornaments impedes regeneration of injured male zebrafish fins.

Precise spatiotemporal regulation of signaling activators and inhibitors can help limit developmental crosstalk between neighboring tissues during morphogenesis, homeostasis, and regeneration. Here, we find that the secreted Wnt inhibitor Dkk1b is abundantly produced by dense regions of androgen-regulated epidermal tubercles (ETs) on the surfaces of adult male zebrafish pectoral fins. High-speed videos and amputation experiments reveal that pectoral fins and their ETs are used for male spawning. Formation and vigorous turnover of ETs involve Dkk1b induction and maintenance, whereas Dkk1b is typically restricted from the regeneration blastema after an amputation injury. When amputation occurs through a region containing ETs, a Dkk1b-enriched wound epidermis forms and blastema formation is disrupted, compromising regeneration. Thus, homeostatic signaling by key breeding ornaments can interfere with injury-activated tissue regeneration. Our findings help explain sexually dimorphic fin regeneration in zebrafish and have implications for how regenerative potential might decline as development progresses or during species evolution.

Authors
Kang, J; Nachtrab, G; Poss, KD
MLA Citation
Kang, J, Nachtrab, G, and Poss, KD. "Local Dkk1 crosstalk from breeding ornaments impedes regeneration of injured male zebrafish fins." Dev Cell 27.1 (October 14, 2013): 19-31.
PMID
24135229
Source
pubmed
Published In
Developmental Cell
Volume
27
Issue
1
Publish Date
2013
Start Page
19
End Page
31
DOI
10.1016/j.devcel.2013.08.015

Fibronectin is deposited by injury-activated epicardial cells and is necessary for zebrafish heart regeneration.

Unlike adult mammals, adult zebrafish vigorously regenerate lost heart muscle in response to injury. The epicardium, a mesothelial cell layer enveloping the myocardium, is activated to proliferate after cardiac injury and can contribute vascular support cells or provide mitogens to regenerating muscle. Here, we applied proteomics to identify secreted proteins that are associated with heart regeneration. We found that Fibronectin, a main component of the extracellular matrix, is induced and deposited after cardiac damage. In situ hybridization and transgenic reporter analyses indicated that expression of two fibronectin paralogues, fn1 and fn1b, are induced by injury in epicardial cells, while the itgb3 receptor is induced in cardiomyocytes near the injury site. fn1, the more dynamic of these paralogs, is induced chamber-wide within one day of injury before localizing epicardial Fn1 synthesis to the injury site. fn1 loss-of-function mutations disrupted zebrafish heart regeneration, as did induced expression of a dominant-negative Fibronectin cassette, defects that were not attributable to direct inhibition of cardiomyocyte proliferation. These findings reveal a new role for the epicardium in establishing an extracellular environment that supports heart regeneration.

Authors
Wang, J; Karra, R; Dickson, AL; Poss, KD
MLA Citation
Wang, J, Karra, R, Dickson, AL, and Poss, KD. "Fibronectin is deposited by injury-activated epicardial cells and is necessary for zebrafish heart regeneration." Developmental biology 382.2 (October 2013): 427-435.
PMID
23988577
Source
epmc
Published In
Developmental Biology
Volume
382
Issue
2
Publish Date
2013
Start Page
427
End Page
435
DOI
10.1016/j.ydbio.2013.08.012

Post-transcriptional regulation of myotube elongation and myogenesis by Hoi Polloi

Authors
Johnson, AN; Mokalled, MH; Valera, JM; Poss, KD; Olson, EN
MLA Citation
Johnson, AN, Mokalled, MH, Valera, JM, Poss, KD, and Olson, EN. "Post-transcriptional regulation of myotube elongation and myogenesis by Hoi Polloi." DEVELOPMENT 140.17 (September 1, 2013): 3645-3656.
PMID
23942517
Source
wos-lite
Published In
Development (Cambridge)
Volume
140
Issue
17
Publish Date
2013
Start Page
3645
End Page
3656
DOI
10.1242/dev.095596

Transcriptional components of anteroposterior positional information during zebrafish fin regeneration.

Many fish and salamander species regenerate amputated fins or limbs, restoring the size and shape of the original appendage. Regeneration requires that spared cells retain or recall information encoding pattern, a phenomenon termed positional memory. Few factors have been implicated in positional memory during vertebrate appendage regeneration. Here, we investigated potential regulators of anteroposterior (AP) pattern during fin regeneration in adult zebrafish. Sequence-based profiling from tissues along the AP axis of uninjured pectoral fins identified many genes with region-specific expression, several of which encoded transcription factors with known AP-specific expression or function in developing embryonic pectoral appendages. Transgenic reporter strains revealed that regulatory sequences of the transcription factor gene alx4a activated expression in fibroblasts and osteoblasts within anterior fin rays, whereas hand2 regulatory sequences activated expression in these same cell types within posterior rays. Transgenic overexpression of hand2 in all pectoral fin rays did not affect formation of the proliferative regeneration blastema, yet modified the lengths and widths of regenerating bones. Hand2 influenced the character of regenerated rays in part by elevation of the vitamin D-inactivating enzyme encoded by cyp24a1, contributing to region-specific regulation of bone metabolism. Systemic administration of vitamin D during regeneration partially rescued bone defects resulting from hand2 overexpression. Thus, bone-forming cells in a regenerating appendage maintain expression throughout life of transcription factor genes that can influence AP pattern, and differ across the AP axis in their expression signatures of these and other genes. These findings have implications for mechanisms of positional memory in vertebrate tissues.

Authors
Nachtrab, G; Kikuchi, K; Tornini, VA; Poss, KD
MLA Citation
Nachtrab, G, Kikuchi, K, Tornini, VA, and Poss, KD. "Transcriptional components of anteroposterior positional information during zebrafish fin regeneration." Development 140.18 (September 2013): 3754-3764.
PMID
23924636
Source
pubmed
Published In
Development (Cambridge)
Volume
140
Issue
18
Publish Date
2013
Start Page
3754
End Page
3764
DOI
10.1242/dev.098798

Translational profiling of cardiomyocytes identifies an early Jak1/Stat3 injury response required for zebrafish heart regeneration.

Certain lower vertebrates like zebrafish activate proliferation of spared cardiomyocytes after cardiac injury to regenerate lost heart muscle. Here, we used translating ribosome affinity purification to profile translating RNAs in zebrafish cardiomyocytes during heart regeneration. We identified dynamic induction of several Jak1/Stat3 pathway members following trauma, events accompanied by cytokine production. Transgenic Stat3 inhibition in cardiomyocytes restricted injury-induced proliferation and regeneration, but did not reduce cardiogenesis during animal growth. The secreted protein Rln3a was induced in a Stat3-dependent manner by injury, and exogenous Rln3 delivery during Stat3 inhibition stimulated cardiomyocyte proliferation. Our results identify an injury-specific cardiomyocyte program essential for heart regeneration.

Authors
Fang, Y; Gupta, V; Karra, R; Holdway, JE; Kikuchi, K; Poss, KD
MLA Citation
Fang, Y, Gupta, V, Karra, R, Holdway, JE, Kikuchi, K, and Poss, KD. "Translational profiling of cardiomyocytes identifies an early Jak1/Stat3 injury response required for zebrafish heart regeneration." Proc Natl Acad Sci U S A 110.33 (August 13, 2013): 13416-13421.
PMID
23901114
Source
pubmed
Published In
Proceedings of the National Academy of Sciences of USA
Volume
110
Issue
33
Publish Date
2013
Start Page
13416
End Page
13421
DOI
10.1073/pnas.1309810110

An injury-responsive gata4 program shapes the zebrafish cardiac ventricle.

A common principle of tissue regeneration is the reactivation of previously employed developmental programs. During zebrafish heart regeneration, cardiomyocytes in the cortical layer of the ventricle induce the transcription factor gene gata4 and proliferate to restore lost muscle. A dynamic cellular mechanism initially creates this cortical muscle in juvenile zebrafish, where a small number of internal cardiomyocytes breach the ventricular wall and expand upon its surface. Here, we find that emergent juvenile cortical cardiomyocytes induce expression of gata4 in a manner similar to during regeneration. Clonal analysis indicates that these cardiomyocytes make biased contributions to build the ventricular wall, whereas gata4(+) cardiomyocytes have little or no proliferation hierarchy during regeneration. Experimental microinjuries or conditions of rapid organismal growth stimulate production of ectopic gata4(+) cortical muscle, implicating biomechanical stress in morphogenesis of this tissue and revealing clonal plasticity. Induced transgenic inhibition defined an essential role for Gata4 activity in morphogenesis of the cortical layer and the preservation of normal cardiac function in growing juveniles, and again in adults during heart regeneration. Our experiments uncover an injury-responsive program that prevents heart failure in juveniles by fortifying the ventricular wall, one that is reiterated in adults to promote regeneration after cardiac damage.

Authors
Gupta, V; Gemberling, M; Karra, R; Rosenfeld, GE; Evans, T; Poss, KD
MLA Citation
Gupta, V, Gemberling, M, Karra, R, Rosenfeld, GE, Evans, T, and Poss, KD. "An injury-responsive gata4 program shapes the zebrafish cardiac ventricle." Curr Biol 23.13 (July 8, 2013): 1221-1227.
PMID
23791730
Source
pubmed
Published In
Current Biology
Volume
23
Issue
13
Publish Date
2013
Start Page
1221
End Page
1227
DOI
10.1016/j.cub.2013.05.028

Zebrafish second heart field development relies on progenitor specification in anterior lateral plate mesoderm and nkx2.5 function

Authors
Guner-Ataman, B; Paffett-Lugassy, N; Adams, MS; Nevis, KR; Jahangiri, L; Obregon, P; Kikuchi, K; Poss, KD; Burns, CE; Burns, CG
MLA Citation
Guner-Ataman, B, Paffett-Lugassy, N, Adams, MS, Nevis, KR, Jahangiri, L, Obregon, P, Kikuchi, K, Poss, KD, Burns, CE, and Burns, CG. "Zebrafish second heart field development relies on progenitor specification in anterior lateral plate mesoderm and nkx2.5 function." DEVELOPMENT 140.6 (March 2013): 1353-1363.
PMID
23444361
Source
wos-lite
Published In
Development (Cambridge)
Volume
140
Issue
6
Publish Date
2013
Start Page
1353
End Page
1363
DOI
10.1242/dev.088351

In vivo monitoring of cardiomyocyte proliferation to identify chemical modifiers of heart regeneration.

Adult mammalian cardiomyocytes have little capacity to proliferate in response to injury, a deficiency that underlies the poor regenerative ability of human hearts after myocardial infarction. By contrast, zebrafish regenerate heart muscle after trauma by inducing proliferation of spared cardiomyocytes, providing a model for identifying manipulations that block or enhance these events. Although direct genetic or chemical screens of heart regeneration in adult zebrafish present several challenges, zebrafish embryos are ideal for high-throughput screening. Here, to visualize cardiomyocyte proliferation events in live zebrafish embryos, we generated transgenic zebrafish lines that employ fluorescent ubiquitylation-based cell cycle indicator (FUCCI) technology. We then performed a chemical screen and identified several small molecules that increase or reduce cardiomyocyte proliferation during heart development. These compounds act via Hedgehog, Insulin-like growth factor or Transforming growth factor β signaling pathways. Direct examination of heart regeneration after mechanical or genetic ablation injuries indicated that these pathways are activated in regenerating cardiomyocytes and that they can be pharmacologically manipulated to inhibit or enhance cardiomyocyte proliferation during adult heart regeneration. Our findings describe a new screening system that identifies molecules and pathways with the potential to modify heart regeneration.

Authors
Choi, W-Y; Gemberling, M; Wang, J; Holdway, JE; Shen, M-C; Karlstrom, RO; Poss, KD
MLA Citation
Choi, W-Y, Gemberling, M, Wang, J, Holdway, JE, Shen, M-C, Karlstrom, RO, and Poss, KD. "In vivo monitoring of cardiomyocyte proliferation to identify chemical modifiers of heart regeneration." Development (Cambridge, England) 140.3 (February 2013): 660-666.
PMID
23293297
Source
epmc
Published In
Development (Cambridge)
Volume
140
Issue
3
Publish Date
2013
Start Page
660
End Page
666
DOI
10.1242/dev.088526

An injury-responsive gata4 program shapes the zebrafish cardiac ventricle

A common principle of tissue regeneration is the reactivation of previously employed developmental programs [1-3]. During zebrafish heart regeneration, cardiomyocytes in the cortical layer of the ventricle induce the transcription factor gene gata4 and proliferate to restore lost muscle [4-6]. A dynamic cellular mechanism initially creates this cortical muscle in juvenile zebrafish, where a small number of internal cardiomyocytes breach the ventricular wall and expand upon its surface [7]. Here, we find that emergent juvenile cortical cardiomyocytes induce expression of gata4 in a manner similar to during regeneration. Clonal analysis indicates that these cardiomyocytes make biased contributions to build the ventricular wall, whereas gata4+ cardiomyocytes have little or no proliferation hierarchy during regeneration. Experimental microinjuries or conditions of rapid organismal growth stimulate production of ectopic gata4+ cortical muscle, implicating biomechanical stress in morphogenesis of this tissue and revealing clonal plasticity. Induced transgenic inhibition defined an essential role for Gata4 activity in morphogenesis of the cortical layer and the preservation of normal cardiac function in growing juveniles, and again in adults during heart regeneration. Our experiments uncover an injury-responsive program that prevents heart failure in juveniles by fortifying the ventricular wall, one that is reiterated in adults to promote regeneration after cardiac damage. © 2013 Elsevier Ltd.

Authors
Gupta, V; Gemberling, M; Karra, R; Rosenfeld, GE; Evans, T; Poss, KD
MLA Citation
Gupta, V, Gemberling, M, Karra, R, Rosenfeld, GE, Evans, T, and Poss, KD. "An injury-responsive gata4 program shapes the zebrafish cardiac ventricle." Current Biology 23.13 (2013): 1221-1227.
Source
scival
Published In
Current Biology
Volume
23
Issue
13
Publish Date
2013
Start Page
1221
End Page
1227
DOI
10.1016/j.cub.2013.05.028

Toward a blueprint for regeneration.

Tissue regeneration has been studied for hundreds of years, yet remains one of the less understood topics in developmental biology. The recent Keystone Symposium on Mechanisms of Whole Organ Regeneration brought together biologists, clinicians and bioengineers representing an impressive breadth of model systems and perspectives. Members of the growing regeneration community discussed classic and new ideas on mechanisms of regeneration and how these can be applied to regenerative medicine.

Authors
Nachtrab, G; Poss, KD
MLA Citation
Nachtrab, G, and Poss, KD. "Toward a blueprint for regeneration." Development 139.15 (August 2012): 2639-2642.
PMID
22782718
Source
pubmed
Published In
Development (Cambridge)
Volume
139
Issue
15
Publish Date
2012
Start Page
2639
End Page
2642
DOI
10.1242/dev.080390

Regulation of zebrafish heart regeneration by miR-133.

Zebrafish regenerate cardiac muscle after severe injuries through the activation and proliferation of spared cardiomyocytes. Little is known about factors that control these events. Here we investigated the extent to which miRNAs regulate zebrafish heart regeneration. Microarray analysis identified many miRNAs with increased or reduced levels during regeneration. miR-133, a miRNA with known roles in cardiac development and disease, showed diminished expression during regeneration. Induced transgenic elevation of miR-133 levels after injury inhibited myocardial regeneration, while transgenic miR-133 depletion enhanced cardiomyocyte proliferation. Expression analyses indicated that cell cycle factors mps1, cdc37, and PA2G4, and cell junction components cx43 and cldn5, are miR-133 targets during regeneration. Using pharmacological inhibition and EGFP sensor interaction studies, we found that cx43 is a new miR-133 target and regeneration gene. Our results reveal dynamic regulation of miRNAs during heart regeneration, and indicate that miR-133 restricts injury-induced cardiomyocyte proliferation.

Authors
Yin, VP; Lepilina, A; Smith, A; Poss, KD
MLA Citation
Yin, VP, Lepilina, A, Smith, A, and Poss, KD. "Regulation of zebrafish heart regeneration by miR-133." Dev Biol 365.2 (May 15, 2012): 319-327.
PMID
22374218
Source
pubmed
Published In
Developmental Biology
Volume
365
Issue
2
Publish Date
2012
Start Page
319
End Page
327
DOI
10.1016/j.ydbio.2012.02.018

Clonally dominant cardiomyocytes direct heart morphogenesis.

As vertebrate embryos develop to adulthood, their organs undergo marked changes in size and tissue architecture. The heart acquires muscle mass and matures structurally to fulfil increasing circulatory needs, a process that is incompletely understood. Here we used multicolour clonal analysis to define the contributions of individual cardiomyocytes as the zebrafish heart undergoes morphogenesis from a primitive embryonic structure into its complex adult form. We find that the single-cardiomyocyte-thick wall of the juvenile ventricle forms by lateral expansion of several dozen cardiomyocytes into muscle patches of variable sizes and shapes. As juvenile zebrafish mature into adults, this structure becomes fully enveloped by a new lineage of cortical muscle. Adult cortical muscle originates from a small number of cardiomyocytes--an average of approximately eight per animal--that display clonal dominance reminiscent of stem cell populations. Cortical cardiomyocytes initially emerge from internal myofibres that in rare events breach the juvenile ventricular wall, and then expand over the surface. Our results illuminate the dynamic proliferative behaviours that generate adult cardiac structure, revealing clonal dominance as a key mechanism that shapes a vertebrate organ.

Authors
Gupta, V; Poss, KD
MLA Citation
Gupta, V, and Poss, KD. "Clonally dominant cardiomyocytes direct heart morphogenesis. (Published online)" Nature 484.7395 (April 25, 2012): 479-484.
PMID
22538609
Source
pubmed
Published In
Nature
Volume
484
Issue
7395
Publish Date
2012
Start Page
479
End Page
484
DOI
10.1038/nature11045

Regeneration of amputated zebrafish fin rays from de novo osteoblasts.

Determining the cellular source of new skeletal elements is critical for understanding appendage regeneration in amphibians and fish. Recent lineage-tracing studies indicated that zebrafish fin ray bone regenerates through the dedifferentiation and proliferation of spared osteoblasts, with limited if any contribution from other cell types. Here, we examined the requirement for this mechanism by using genetic ablation techniques to destroy virtually all skeletal osteoblasts in adult zebrafish fins. Animals survived this injury and restored the osteoblast population within 2 weeks. Moreover, amputated fins depleted of osteoblasts regenerated new fin ray structures at rates indistinguishable from fins possessing a resident osteoblast population. Inducible genetic fate mapping confirmed that new bone cells do not arise from dedifferentiated osteoblasts under these conditions. Our findings demonstrate diversity in the cellular origins of appendage bone and reveal that de novo osteoblasts can fully support the regeneration of amputated zebrafish fins.

Authors
Singh, SP; Holdway, JE; Poss, KD
MLA Citation
Singh, SP, Holdway, JE, and Poss, KD. "Regeneration of amputated zebrafish fin rays from de novo osteoblasts." Dev Cell 22.4 (April 17, 2012): 879-886.
PMID
22516203
Source
pubmed
Published In
Developmental Cell
Volume
22
Issue
4
Publish Date
2012
Start Page
879
End Page
886
DOI
10.1016/j.devcel.2012.03.006

III. Does heart regeneration occur?: B. Zebrafish heart regeneration

Authors
Major, RJ; Poss, KD
MLA Citation
Major, RJ, and Poss, KD. "III. Does heart regeneration occur?: B. Zebrafish heart regeneration." Heart Regeneration: Stem Cells and Beyond. January 1, 2012. 59-80.
Source
scopus
Publish Date
2012
Start Page
59
End Page
80
DOI
10.1142/9789814299817_0003

Cardiac regeneration.

The heart is a pump that is comprised of cardiac myocytes and other cell types and whose proper function is critical to quality of life. The ability to trigger regeneration of heart muscle following injury eludes adult mammals, a deficiency of great clinical impact. Major research efforts are attempting to change this through advances in cell therapy or activating endogenous regenerative mechanisms that exist only early in life. In contrast with mammals, lower vertebrates like zebrafish demonstrate an impressive natural capacity for cardiac regeneration throughout life. This review will cover recent progress in the field of heart regeneration with a focus on endogenous regenerative capacity and its potential manipulation.

Authors
Choi, WY; Poss, KD
MLA Citation
Choi, WY, and Poss, KD. "Cardiac regeneration." Curr Top Dev Biol 100 (2012): 319-344. (Review)
PMID
22449849
Source
pubmed
Published In
Current topics in developmental biology
Volume
100
Publish Date
2012
Start Page
319
End Page
344
DOI
10.1016/B978-0-12-387786-4.00010-5

Cardiac regenerative capacity and mechanisms

The heart holds the monumental yet monotonous task of maintaining circulation. Although cardiac function is critical to other organs and to life itself, mammals are not equipped with significant natural capacity to replace heart muscle that has been lost by injury. This deficiency plays a role in leaving millions worldwide vulnerable to heart failure each year. By contrast, certain other vertebrate species such as zebrafish are strikingly good at heart regeneration. A cellular and molecular understanding of endogenous regenerative mechanisms and advances in methodology to transplant cells together project a future in which cardiac muscle regeneration can be therapeutically stimulated in injured human hearts. This review focuses on what has been discovered recently about cardiac regenerative capacity and how natural mechanisms of heart regeneration in model systems are stimulated and maintained. Copyright © 2012 by Annual Reviews. All rights reserved.

Authors
Kikuchi, K; Poss, KD
MLA Citation
Kikuchi, K, and Poss, KD. "Cardiac regenerative capacity and mechanisms." Annual Review of Cell and Developmental Biology 28 (2012): 719-741.
PMID
23057748
Source
scival
Published In
Annual Review of Cell and Developmental Biology
Volume
28
Publish Date
2012
Start Page
719
End Page
741
DOI
10.1146/annurev-cellbio-101011-155739

A novel chemical screening strategy in zebrafish identifies common pathways in embryogenesis and rhabdomyosarcoma development

The zebrafish is a powerful genetic model that has only recently been used to dissect developmental pathways involved in oncogenesis. We hypothesized that operative pathways during embryogenesis would also be used for oncogenesis. In an effort to define RAS target genes during embryogenesis, gene expression was evaluated in Tg(hsp70-HRASG12V) zebrafish embryos subjected to heat shock. dusp6 was activated by RAS, and this was used as the basis for a chemical genetic screen to identify small molecules that interfere with RAS signaling during embryogenesis. A KRASG12D-induced zebrafish embryonal rhabdomyosarcoma was then used to assess the therapeutic effects of the small molecules. Two of these inhibitors, PD98059 and TPCK, had anti-tumor activity as single agents in both zebrafish embryonal rhabdomyosarcoma and a human cell line of rhabdomyosarcoma that harbored activated mutations in NRAS. PD98059 inhibited MEK1 whereas TPCK suppressed S6K1 activity; however, the combined treatment completely suppressed eIF4B phosphorylation and decreased translation initiation. Our work demonstrates that the activated pathways in RAS induction during embryogenesis are also important in oncogenesis and that inhibition of these pathways suppresses tumor growth. © 2013. Published by The Company of Biologists Ltd.

Authors
Le, X; Pugach, EK; Hettmer, S; Storer, NY; Liu, J; Wills, AA; DiBiase, A; Chen, EY; Ignatius, MS; Poss, KD; Wagers, AJ; Langenau, DM; Zon, LI
MLA Citation
Le, X, Pugach, EK, Hettmer, S, Storer, NY, Liu, J, Wills, AA, DiBiase, A, Chen, EY, Ignatius, MS, Poss, KD, Wagers, AJ, Langenau, DM, and Zon, LI. "A novel chemical screening strategy in zebrafish identifies common pathways in embryogenesis and rhabdomyosarcoma development." Development (Cambridge) 140.11 (2012): 2354-2364.
PMID
23615277
Source
scival
Published In
Development (Cambridge)
Volume
140
Issue
11
Publish Date
2012
Start Page
2354
End Page
2364
DOI
10.1242/dev.088427

Sexually dimorphic fin regeneration in zebrafish controlled by androgen/GSK3 signaling.

Certain fish and amphibians regenerate entire fins and limbs after amputation, whereas such potential is absent in birds and limited in mammals to digit tips [1, 2]. Additionally, regenerative success can change during life stages. Anuran tadpoles gradually lose the capacity to regenerate limbs [3, 4], and digit regeneration occurs more effectively in fetal mice and human children than adults [5-8]. Little is known about mechanisms that control regenerative capacity. Here, we identify an unexpected difference between male and female zebrafish in the regenerative potential of a major appendage. Males display regenerative defects in amputated pectoral fins, caused by impaired blastemal proliferation. This regenerative failure emerges after sexual maturity, is mimicked in androgen-treated females, and is suppressed in males by androgen receptor antagonism. Androgen signaling maintains expression of dkk1b and igfbp2a, which encode secreted inhibitors of Wnt and Igf signaling, respectively. Furthermore, the regulatory target of Wnts and Igfs, GSK3β, is inefficiently inactivated in male fin regenerates compared with females. Pharmacological inhibition of GSK3 in males increases blastemal proliferation and restores regenerative pattern. Our findings identify a natural sex bias in appendage regenerative capacity and indicate an underlying regulatory circuit in which androgen locally restricts key morphogenetic programs after amputation.

Authors
Nachtrab, G; Czerwinski, M; Poss, KD
MLA Citation
Nachtrab, G, Czerwinski, M, and Poss, KD. "Sexually dimorphic fin regeneration in zebrafish controlled by androgen/GSK3 signaling." Curr Biol 21.22 (November 22, 2011): 1912-1917.
PMID
22079110
Source
pubmed
Published In
Current Biology
Volume
21
Issue
22
Publish Date
2011
Start Page
1912
End Page
1917
DOI
10.1016/j.cub.2011.09.050

The regenerative capacity of zebrafish reverses cardiac failure caused by genetic cardiomyocyte depletion.

Natural models of heart regeneration in lower vertebrates such as zebrafish are based on invasive surgeries causing mechanical injuries that are limited in size. Here, we created a genetic cell ablation model in zebrafish that facilitates inducible destruction of a high percentage of cardiomyocytes. Cell-specific depletion of over 60% of the ventricular myocardium triggered signs of cardiac failure that were not observed after partial ventricular resection, including reduced animal exercise tolerance and sudden death in the setting of stressors. Massive myocardial loss activated robust cellular and molecular responses by endocardial, immune, epicardial and vascular cells. Destroyed cardiomyocytes fully regenerated within several days, restoring cardiac anatomy, physiology and performance. Regenerated muscle originated from spared cardiomyocytes that acquired ultrastructural and electrophysiological characteristics of de-differentiation and underwent vigorous proliferation. Our study indicates that genetic depletion of cardiomyocytes, even at levels so extreme as to elicit signs of cardiac failure, can be reversed by natural regenerative capacity in lower vertebrates such as zebrafish.

Authors
Wang, J; Panáková, D; Kikuchi, K; Holdway, JE; Gemberling, M; Burris, JS; Singh, SP; Dickson, AL; Lin, Y-F; Sabeh, MK; Werdich, AA; Yelon, D; Macrae, CA; Poss, KD
MLA Citation
Wang, J, Panáková, D, Kikuchi, K, Holdway, JE, Gemberling, M, Burris, JS, Singh, SP, Dickson, AL, Lin, Y-F, Sabeh, MK, Werdich, AA, Yelon, D, Macrae, CA, and Poss, KD. "The regenerative capacity of zebrafish reverses cardiac failure caused by genetic cardiomyocyte depletion." Development (Cambridge, England) 138.16 (August 2011): 3421-3430.
PMID
21752928
Source
epmc
Published In
Development (Cambridge)
Volume
138
Issue
16
Publish Date
2011
Start Page
3421
End Page
3430
DOI
10.1242/dev.068601

tcf21+ epicardial cells adopt non-myocardial fates during zebrafish heart development and regeneration.

Recent lineage-tracing studies have produced conflicting results about whether the epicardium is a source of cardiac muscle cells during heart development. Here, we examined the developmental potential of epicardial tissue in zebrafish during both embryonic development and injury-induced heart regeneration. We found that upstream sequences of the transcription factor gene tcf21 activated robust, epicardium-specific expression throughout development and regeneration. Cre recombinase-based, genetic fate-mapping of larval or adult tcf21(+) cells revealed contributions to perivascular cells, but not cardiomyocytes, during each form of cardiogenesis. Our findings indicate that natural epicardial fates are limited to non-myocardial cell types in zebrafish.

Authors
Kikuchi, K; Gupta, V; Wang, J; Holdway, JE; Wills, AA; Fang, Y; Poss, KD
MLA Citation
Kikuchi, K, Gupta, V, Wang, J, Holdway, JE, Wills, AA, Fang, Y, and Poss, KD. "tcf21+ epicardial cells adopt non-myocardial fates during zebrafish heart development and regeneration." Development (Cambridge, England) 138.14 (July 2011): 2895-2902.
PMID
21653610
Source
epmc
Published In
Development (Cambridge)
Volume
138
Issue
14
Publish Date
2011
Start Page
2895
End Page
2902
DOI
10.1242/dev.067041

Restriction of hepatic competence by Fgf signaling.

Hepatic competence, or the ability to respond to hepatic-inducing signals, is regulated by a number of transcription factors broadly expressed in the endoderm. However, extrinsic signals might also regulate hepatic competence, as suggested by tissue explant studies. Here, we present genetic evidence that Fgf signaling regulates hepatic competence in zebrafish. We first show that the endoderm posterior to the liver-forming region retains hepatic competence: using transgenic lines that overexpress hepatic inducing signals following heat-shock, we found that at late somitogenesis stages Wnt8a, but not Bmp2b, overexpression could induce liver gene expression in pancreatic and intestinal bulb cells. These manipulations resulted in the appearance of ectopic hepatocytes in the intestinal bulb. Second, by overexpressing Wnt8a at various stages, we found that as embryos develop, the extent of the endodermal region retaining hepatic competence is gradually reduced. Most significantly, we found, using gain- and loss-of-function approaches, that Fgf10a signaling regulates this gradual reduction of the hepatic-competent domain. These data provide in vivo evidence that endodermal cells outside the liver-forming region retain hepatic competence and show that an extrinsic signal, Fgf10a, negatively regulates hepatic competence.

Authors
Shin, D; Lee, Y; Poss, KD; Stainier, DY
MLA Citation
Shin, D, Lee, Y, Poss, KD, and Stainier, DY. "Restriction of hepatic competence by Fgf signaling." Development 138.7 (April 2011): 1339-1348.
PMID
21385764
Source
pubmed
Published In
Development (Cambridge)
Volume
138
Issue
7
Publish Date
2011
Start Page
1339
End Page
1348
DOI
10.1242/dev.054395

Retinoic acid production by endocardium and epicardium is an injury response essential for zebrafish heart regeneration.

Zebrafish heart regeneration occurs through the activation of cardiomyocyte proliferation in areas of trauma. Here, we show that within 3 hr of ventricular injury, the entire endocardium undergoes morphological changes and induces expression of the retinoic acid (RA)-synthesizing enzyme raldh2. By one day posttrauma, raldh2 expression becomes localized to endocardial cells at the injury site, an area that is supplemented with raldh2-expressing epicardial cells as cardiogenesis begins. Induced transgenic inhibition of RA receptors or expression of an RA-degrading enzyme blocked regenerative cardiomyocyte proliferation. Injured hearts of the ancient fish Polypterus senegalus also induced and maintained robust endocardial and epicardial raldh2 expression coincident with cardiomyocyte proliferation, whereas poorly regenerative infarcted murine hearts did not. Our findings reveal that the endocardium is a dynamic, injury-responsive source of RA in zebrafish, and indicate key roles for endocardial and epicardial cells in targeting RA synthesis to damaged heart tissue and promoting cardiomyocyte proliferation.

Authors
Kikuchi, K; Holdway, JE; Major, RJ; Blum, N; Dahn, RD; Begemann, G; Poss, KD
MLA Citation
Kikuchi, K, Holdway, JE, Major, RJ, Blum, N, Dahn, RD, Begemann, G, and Poss, KD. "Retinoic acid production by endocardium and epicardium is an injury response essential for zebrafish heart regeneration." Dev Cell 20.3 (March 15, 2011): 397-404.
PMID
21397850
Source
pubmed
Published In
Developmental Cell
Volume
20
Issue
3
Publish Date
2011
Start Page
397
End Page
404

FGF signaling regulates rod photoreceptor cell maintenance and regeneration in zebrafish

Fgf signaling is required for many biological processes involving the regulation of cell proliferation and maintenance, including embryonic patterning, tissue homeostasis, wound healing, and cancer progression. Although the function of Fgf signaling is suggested in several different regeneration models, including appendage regeneration in amphibians and fin and heart regeneration in zebrafish, it has not yet been studied during zebrafish photoreceptor cell regeneration. Here we demonstrate that intravitreal injections of FGF-2 induced rod precursor cell proliferation and photoreceptor cell neuroprotection during intense light damage. Using the dominant-negative Tg(hsp70:. dn-fgfr1) transgenic line, we found that Fgf signaling was required for homeostasis of rod, but not cone, photoreceptors. Even though fgfr1 is expressed in both rod and cone photoreceptors, we found that Fgf signaling differentially affected the regeneration of cone and rod photoreceptors in the light-damaged retina, with the dominant-negative hsp70:. dn-fgfr1 transgene significantly repressing rod photoreceptor regeneration without affecting cone photoreceptors. These data suggest that rod photoreceptor homeostasis and regeneration is Fgf-dependent and that rod and cone photoreceptors in adult zebrafish are regulated by different signaling pathways. © 2011 Elsevier Ltd.

Authors
Qin, Z; Kidd, AR; Thomas, JL; Poss, KD; Hyde, DR; Raymond, PA; Thummel, R
MLA Citation
Qin, Z, Kidd, AR, Thomas, JL, Poss, KD, Hyde, DR, Raymond, PA, and Thummel, R. "FGF signaling regulates rod photoreceptor cell maintenance and regeneration in zebrafish." Experimental Eye Research 93.5 (2011): 726-734.
PMID
21945172
Source
scival
Published In
Experimental Eye Research
Volume
93
Issue
5
Publish Date
2011
Start Page
726
End Page
734
DOI
10.1016/j.exer.2011.09.003

A dual role for ErbB2 signaling in cardiac trabeculation.

Cardiac trabeculation is a crucial morphogenetic process by which clusters of ventricular cardiomyocytes extrude and expand into the cardiac jelly to form sheet-like projections. Although it has been suggested that cardiac trabeculae enhance cardiac contractility and intra-ventricular conduction, their exact function in heart development has not been directly addressed. We found that in zebrafish erbb2 mutants, which we show completely lack cardiac trabeculae, cardiac function is significantly compromised, with mutant hearts exhibiting decreased fractional shortening and an immature conduction pattern. To begin to elucidate the cellular mechanisms of ErbB2 function in cardiac trabeculation, we analyzed erbb2 mutant hearts more closely and found that loss of ErbB2 activity resulted in a complete absence of cardiomyocyte proliferation during trabeculation stages. In addition, based on data obtained from proliferation, lineage tracing and transplantation studies, we propose that cardiac trabeculation is initiated by directional cardiomyocyte migration rather than oriented cell division, and that ErbB2 cell-autonomously regulates this process.

Authors
Liu, J; Bressan, M; Hassel, D; Huisken, J; Staudt, D; Kikuchi, K; Poss, KD; Mikawa, T; Stainier, DY
MLA Citation
Liu, J, Bressan, M, Hassel, D, Huisken, J, Staudt, D, Kikuchi, K, Poss, KD, Mikawa, T, and Stainier, DY. "A dual role for ErbB2 signaling in cardiac trabeculation." Development 137.22 (November 2010): 3867-3875.
Website
http://hdl.handle.net/10161/4177
PMID
20978078
Source
pubmed
Published In
Development (Cambridge)
Volume
137
Issue
22
Publish Date
2010
Start Page
3867
End Page
3875
DOI
10.1242/dev.053736

Advances in understanding tissue regenerative capacity and mechanisms in animals.

Questions about how and why tissue regeneration occurs have captured the attention of countless biologists, biomedical engineers and clinicians. Regenerative capacity differs greatly across organs and organisms, and a range of model systems that use different regenerative strategies and that offer different technical advantages have been studied to understand regeneration. Making use of this range of systems and approaches, recent advances have allowed progress to be made in understanding several key issues that are common to natural regenerative events. These issues include: the determination of regenerative capacity; the importance of stem cells, dedifferentiation and transdifferentiation; how regenerative signals are initiated and targeted; and the mechanisms that control regenerative proliferation and patterning.

Authors
Poss, KD
MLA Citation
Poss, KD. "Advances in understanding tissue regenerative capacity and mechanisms in animals." Nat Rev Genet 11.10 (October 2010): 710-722. (Review)
PMID
20838411
Source
pubmed
Published In
Nature Reviews Genetics
Volume
11
Issue
10
Publish Date
2010
Start Page
710
End Page
722
DOI
10.1038/nrg2879

Ras controls melanocyte expansion during zebrafish fin stripe regeneration.

Regenerative medicine for complex tissues like limbs will require the provision or activation of precursors for different cell types, in the correct number, and with the appropriate instructions. These strategies can be guided by what is learned from spectacular events of natural limb or fin regeneration in urodele amphibians and teleost fish. Following zebrafish fin amputation, melanocyte stripes faithfully regenerate in tandem with complex fin structures. Distinct populations of melanocyte precursors emerge and differentiate to pigment regenerating fins, yet the regulation of their proliferation and patterning is incompletely understood. Here, we found that transgenic increases in active Ras dose-dependently hyperpigmented regenerating zebrafish fins. Lineage tracing and marker analysis indicated that increases in active Ras stimulated the in situ amplification of undifferentiated melanocyte precursors expressing mitfa and kita. Active Ras also hyperpigmented early fin regenerates of kita mutants, which are normally devoid of primary regeneration melanocytes, suppressing defects in precursor function and survival. By contrast, this protocol had no noticeable impact on pigmentation by secondary regulatory melanocyte precursors in late-stage kita regenerates. Our results provide evidence that Ras activity levels control the repopulation and expansion of adult melanocyte precursors after tissue loss, enabling the recovery of patterned melanocyte stripes during zebrafish appendage regeneration.

Authors
Lee, Y; Nachtrab, G; Klinsawat, PW; Hami, D; Poss, KD
MLA Citation
Lee, Y, Nachtrab, G, Klinsawat, PW, Hami, D, and Poss, KD. "Ras controls melanocyte expansion during zebrafish fin stripe regeneration." Dis Model Mech 3.7-8 (July 2010): 496-503.
Website
http://hdl.handle.net/10161/4181
PMID
20483996
Source
pubmed
Published In
Disease models & mechanisms
Volume
3
Issue
7-8
Publish Date
2010
Start Page
496
End Page
503
DOI
10.1242/dmm.004515

Hand2 regulates extracellular matrix remodeling essential for gut-looping morphogenesis in zebrafish.

Extracellular matrix (ECM) remodeling is critical for organogenesis, yet its molecular regulation is poorly understood. In zebrafish, asymmetric migration of the epithelial lateral plate mesoderm (LPM) displaces the gut leftward, allowing correct placement of the liver and pancreas. To observe LPM migration at cellular resolution, we transgenically expressed EGFP under the control of the regulatory sequences of the bHLH transcription factor gene hand2. We found that laminin is distributed along the LPM/gut boundary during gut looping, and that it appears to become diminished by the migrating hand2-expressing cells. Laminin diminishment is necessary for LPM migration and is dependent on matrix metalloproteinase (MMP) activity. Loss of Hand2 function causes reduced MMP activity and prolonged laminin deposition at the LPM/gut boundary, leading to failed asymmetric LPM migration and gut looping. Our study reveals an unexpected role for Hand2, a key regulator of cell specification and differentiation, in modulating ECM remodeling during organogenesis.

Authors
Yin, C; Kikuchi, K; Hochgreb, T; Poss, KD; Stainier, DY
MLA Citation
Yin, C, Kikuchi, K, Hochgreb, T, Poss, KD, and Stainier, DY. "Hand2 regulates extracellular matrix remodeling essential for gut-looping morphogenesis in zebrafish." Dev Cell 18.6 (June 15, 2010): 973-984.
PMID
20627079
Source
pubmed
Published In
Developmental Cell
Volume
18
Issue
6
Publish Date
2010
Start Page
973
End Page
984
DOI
10.1016/j.devcel.2010.05.009

Primary contribution to zebrafish heart regeneration by gata4(+) cardiomyocytes.

Recent studies indicate that mammals, including humans, maintain some capacity to renew cardiomyocytes throughout postnatal life. Yet, there is little or no significant cardiac muscle regeneration after an injury such as acute myocardial infarction. By contrast, zebrafish efficiently regenerate lost cardiac muscle, providing a model for understanding how natural heart regeneration may be blocked or enhanced. In the absence of lineage-tracing technology applicable to adult zebrafish, the cellular origins of newly regenerated cardiac muscle have remained unclear. Using new genetic fate-mapping approaches, here we identify a population of cardiomyocytes that become activated after resection of the ventricular apex and contribute prominently to cardiac muscle regeneration. Through the use of a transgenic reporter strain, we found that cardiomyocytes throughout the subepicardial ventricular layer trigger expression of the embryonic cardiogenesis gene gata4 within a week of trauma, before expression localizes to proliferating cardiomyocytes surrounding and within the injury site. Cre-recombinase-based lineage-tracing of cells expressing gata4 before evident regeneration, or of cells expressing the contractile gene cmlc2 before injury, each labelled most cardiac muscle in the ensuing regenerate. By optical voltage mapping of surface myocardium in whole ventricles, we found that electrical conduction is re-established between existing and regenerated cardiomyocytes between 2 and 4 weeks post-injury. After injury and prolonged fibroblast growth factor receptor inhibition to arrest cardiac regeneration and enable scar formation, experimental release of the signalling block led to gata4 expression and morphological improvement of the injured ventricular wall without loss of scar tissue. Our results indicate that electrically coupled cardiac muscle regenerates after resection injury, primarily through activation and expansion of cardiomyocyte populations. These findings have implications for promoting regeneration of the injured human heart.

Authors
Kikuchi, K; Holdway, JE; Werdich, AA; Anderson, RM; Fang, Y; Egnaczyk, GF; Evans, T; Macrae, CA; Stainier, DY; Poss, KD
MLA Citation
Kikuchi, K, Holdway, JE, Werdich, AA, Anderson, RM, Fang, Y, Egnaczyk, GF, Evans, T, Macrae, CA, Stainier, DY, and Poss, KD. "Primary contribution to zebrafish heart regeneration by gata4(+) cardiomyocytes." Nature 464.7288 (March 25, 2010): 601-605.
PMID
20336144
Source
pubmed
Published In
Nature
Volume
464
Issue
7288
Publish Date
2010
Start Page
601
End Page
605
DOI
10.1038/nature08804

Neuronal regulation of the spatial patterning of neurogenesis.

Precise regulation of neurogenesis is achieved in specific regions of the vertebrate nervous system by formation of distinct neurogenic and nonneurogenic zones. We have investigated how neurogenesis becomes confined to zones adjacent to rhombomere boundaries in the zebrafish hindbrain. The nonneurogenic zone at segment centers comprises a distinct progenitor population that expresses fibroblast growth factor (fgfr) 2, erm, sox9b, and the retinoic acid degrading enzyme, cyp26b1. FGF receptor activation upregulates expression of these genes and inhibits neurogenesis in segment centers. Cyp26 activity is a key effector inhibiting neuronal differentiation, suggesting antagonistic interactions with retinoid signaling. We identify the critical FGF ligand, fgf20a, which is expressed by specific neurons located in the mantle region at the center of segments, adjacent to the nonneurogenic zone. Fgf20a mutants have ectopic neurogenesis and lack the segment center progenitor population. Our findings reveal how signaling from neurons induces formation of a nonneurogenic zone of neural progenitors.

Authors
Gonzalez-Quevedo, R; Lee, Y; Poss, KD; Wilkinson, DG
MLA Citation
Gonzalez-Quevedo, R, Lee, Y, Poss, KD, and Wilkinson, DG. "Neuronal regulation of the spatial patterning of neurogenesis." Dev Cell 18.1 (January 19, 2010): 136-147.
PMID
20152184
Source
pubmed
Published In
Developmental Cell
Volume
18
Issue
1
Publish Date
2010
Start Page
136
End Page
147
DOI
10.1016/j.devcel.2009.11.010

Cardiac Regeneration in the Zebrafish Model System

This chapter reviews what is known about mechanisms of heart regeneration in zebrafish. In addition to addressing "how" regeneration occurs, it will touch on questions of "why." That is, why is the capacity for natural heart regeneration limited to nonmammalian species? Unlike mammals, zebrafish have the capacity to regenerate cardiac muscle removed by mechanical injury. They do so by stimulating the creation of new cardiomyocytes at the injury site, and by restricting scar formation. Research has essentially just begun to dissect the underlying mechanisms. Initial findings indicate that the regenerating heart establishes a field of cardiac progenitors, much like the embryonic heart field, as a source of new, proliferative cardiomyocytes. Regenerative cardiogenesis then proceeds in a wave of progenitor cell seeding, cardiomyocyte differentiation, and proliferation. Concomitantly, the epicardial cell layer that surrounds the myocardium proper responds to injury by expressing embryonic epicardial markers and proliferating. Then, in a process of epithelial-to-mesenchymal transition reminiscent of embryonic epicardial cells, the wound and regenerating muscle become populated by invading epicardial-derived cells. These epithelial-to-mesenchymal transition events, and the neovascularization that accompanies them, require the Fgf signaling pathway, ostensibly with Fgf ligands synthesized in injured/regenerating muscle recruiting epicardial-derived cells that express Fgf receptors. These events point to an intricate orchestration of different cardiac cell types to carry out regeneration in the injured zebrafish heart. © 2010 Elsevier Inc. All rights reserved.

Authors
Poss, K
MLA Citation
Poss, K. "Cardiac Regeneration in the Zebrafish Model System." Heart Development and Regeneration (2010): 839-853.
Source
scival
Published In
Heart Development and Regeneration
Publish Date
2010
Start Page
839
End Page
853
DOI
10.1016/B978-0-12-381332-9.00040-2

Maintenance of blastemal proliferation by functionally diverse epidermis in regenerating zebrafish fins.

Appendage regeneration in salamanders and fish occurs through formation and maintenance of a mass of progenitor tissue called the blastema. A dedicated epidermis overlays the blastema and is required for its proliferation and patterning, yet this interaction is poorly understood. Here, we identified molecularly and functionally distinct compartments within the basal epidermal layer during zebrafish fin regeneration. Proximal epidermal subtypes express the transcription factor lef1 and the blastemal mitogen shh, while distal subtypes express the Fgf target gene pea3 and wnt5b, an inhibitor of blastemal proliferation. Ectopic overexpression of wnt5b reduced shh expression, while pharmacologic introduction of a Hh pathway agonist partially rescued blastemal proliferation during wnt5b overexpression. Loss- and gain-of-function approaches indicate that Fgf signaling promotes shh expression in proximal epidermis, while Fgf/Ras signaling restricts shh expression from distal epidermis through induction of pea3 expression and maintenance of wnt5b. Thus, the fin wound epidermis spatially confines Hh signaling through the activity of Fgf and Wnt pathways, impacting blastemal proliferation during regenerative outgrowth.

Authors
Lee, Y; Hami, D; De Val, S; Kagermeier-Schenk, B; Wills, AA; Black, BL; Weidinger, G; Poss, KD
MLA Citation
Lee, Y, Hami, D, De Val, S, Kagermeier-Schenk, B, Wills, AA, Black, BL, Weidinger, G, and Poss, KD. "Maintenance of blastemal proliferation by functionally diverse epidermis in regenerating zebrafish fins." Dev Biol 331.2 (July 15, 2009): 270-280.
PMID
19445916
Source
pubmed
Published In
Developmental Biology
Volume
331
Issue
2
Publish Date
2009
Start Page
270
End Page
280
DOI
10.1016/j.ydbio.2009.05.545

Feedback regulation of neurogenesis

Authors
Gonzalez-Quevedo, R; Sobieszczuk, DF; Poliakov, A; Lee, Y; Poss, KD; Wilkinson, DG
MLA Citation
Gonzalez-Quevedo, R, Sobieszczuk, DF, Poliakov, A, Lee, Y, Poss, KD, and Wilkinson, DG. "Feedback regulation of neurogenesis." DEVELOPMENTAL BIOLOGY 331.2 (July 15, 2009): 388-389.
Source
wos-lite
Published In
Developmental Biology
Volume
331
Issue
2
Publish Date
2009
Start Page
388
End Page
389
DOI
10.1016/j.ydbio.2009.05.020

Genetic DISC-section of regeneration in Drosophila.

Although regeneration has long fascinated biologists, it remains a challenging field of study with much yet to learn at the molecular level. In this issue of Developmental Cell, Smith-Bolton et al. introduce a genetic ablation system in Drosophila melanogaster with the potential for large-scale identification of new regulators of regeneration.

Authors
Nachtrab, G; Poss, KD
MLA Citation
Nachtrab, G, and Poss, KD. "Genetic DISC-section of regeneration in Drosophila." Dev Cell 16.6 (June 2009): 777-778.
PMID
19531347
Source
pubmed
Published In
Developmental Cell
Volume
16
Issue
6
Publish Date
2009
Start Page
777
End Page
778
DOI
10.1016/j.devcel.2009.05.015

Hoxb5b acts downstream of retinoic acid signaling in the forelimb field to restrict heart field potential in zebrafish.

How adjacent organ fields communicate during development is not understood. Here, we identify a mechanism in which signaling within the forelimb field restricts the potential of the neighboring heart field. In zebrafish embryos deficient in retinoic acid (RA) signaling, the pectoral fins (forelimbs) are lost while both chambers of the heart are enlarged. We provide evidence that both of these phenotypes are due to RA signaling acting directly within the forelimb field. hoxb5b, an RA-responsive gene expressed within the forelimb field, is required to restrict the number of atrial cells arising from the adjacent heart field, although its function is dispensable for forelimb formation. Together, these data indicate nonautonomous influences downstream of RA signaling that act to limit individual chamber size. Therefore, our results offer new perspectives on the mechanisms regulating organ size and the possible causes of congenital syndromes affecting both the heart and forelimb.

Authors
Waxman, JS; Keegan, BR; Roberts, RW; Poss, KD; Yelon, D
MLA Citation
Waxman, JS, Keegan, BR, Roberts, RW, Poss, KD, and Yelon, D. "Hoxb5b acts downstream of retinoic acid signaling in the forelimb field to restrict heart field potential in zebrafish." Dev Cell 15.6 (December 2008): 923-934.
PMID
19081079
Source
pubmed
Published In
Developmental Cell
Volume
15
Issue
6
Publish Date
2008
Start Page
923
End Page
934
DOI
10.1016/j.devcel.2008.09.009

Reiterative roles for FGF signaling in the establishment of size and proportion of the zebrafish heart.

Development of a functional organ requires the establishment of its proper size as well as the establishment of the relative proportions of its individual components. In the zebrafish heart, organ size and proportion depend heavily on the number of cells in each of its two major chambers, the ventricle and the atrium. Heart size and chamber proportionality are both affected in zebrafish fgf8 mutants. To determine when and how FGF signaling influences these characteristics, we examined the effect of temporally controlled pathway inhibition. During cardiac specification, reduction of FGF signaling inhibits formation of both ventricular and atrial cardiomyocytes, with a stronger impact on ventricular cells. After cardiomyocyte differentiation begins, reduction of FGF signaling can still result in a deficiency of ventricular cardiomyocytes. Consistent with two temporally distinct roles for FGF, we find that increased FGF signaling induces a cardiomyocyte surplus only before cardiac differentiation begins. Thus, FGF signaling first regulates heart size and chamber proportionality during cardiac specification and later refines ventricular proportion by regulating cell number after the onset of differentiation. Together, our data demonstrate that a single signaling pathway can act reiteratively to coordinate organ size and proportion.

Authors
Marques, SR; Lee, Y; Poss, KD; Yelon, D
MLA Citation
Marques, SR, Lee, Y, Poss, KD, and Yelon, D. "Reiterative roles for FGF signaling in the establishment of size and proportion of the zebrafish heart." Dev Biol 321.2 (September 15, 2008): 397-406.
PMID
18639539
Source
pubmed
Published In
Developmental Biology
Volume
321
Issue
2
Publish Date
2008
Start Page
397
End Page
406
DOI
10.1016/j.ydbio.2008.06.033

Fgfs control homeostatic regeneration in adult zebrafish fins.

Adult teleost fish and urodele amphibians possess a spectacular ability to regenerate amputated appendages, based on formation and maintenance of progenitor tissue called a blastema. Although injury-induced, or facultative, appendage regeneration has been studied extensively, the extent to which homeostatic regeneration maintains these structures has not been examined. Here, we found that transgenic inhibition of Fgf receptors in uninjured zebrafish caused severe atrophy of all fin types within 2 months, revealing a requirement for Fgfs to preserve dermal bone, joint structures and supporting tissues. Appendage maintenance involved low-level expression of markers of blastema-based regeneration, focused in distal structures displaying recurrent cell death and proliferation. Conditional mutations in the ligand Fgf20a and the kinase Mps1, factors crucial for regeneration of amputated fins, also caused rapid, progressive loss of fin structures in otherwise uninjured animals. Our experiments reveal that the facultative machinery that regenerates amputated teleost fins also has a surprisingly vigorous role in homeostatic regeneration.

Authors
Wills, AA; Kidd, AR; Lepilina, A; Poss, KD
MLA Citation
Wills, AA, Kidd, AR, Lepilina, A, and Poss, KD. "Fgfs control homeostatic regeneration in adult zebrafish fins." Development 135.18 (September 2008): 3063-3070.
PMID
18701543
Source
pubmed
Published In
Development (Cambridge)
Volume
135
Issue
18
Publish Date
2008
Start Page
3063
End Page
3070
DOI
10.1242/dev.024588

New regulators of vertebrate appendage regeneration.

Appendage regeneration is a complex and fascinating biological process exhibited in vertebrates by urodele amphibians and teleost fish. A current focus in the field is to identify new molecules that control formation and function of the regeneration blastema, a mass of proliferative mesenchyme that emerges after limb or fin amputation and serves as progenitor tissue for lost structures. Two studies published recently have illuminated new molecular regulators of blastemal proliferation. After amputation of a newt limb, the nerve sheath releases nAG, a blastemal mitogen that facilitates regeneration. In amputated zebrafish fins, regeneration is optimized through depletion of the microRNA miR-133, a mechanism that requires Fgf signaling. These discoveries establish research avenues that may impact the regenerative capacity of mammalian tissues.

Authors
Yin, VP; Poss, KD
MLA Citation
Yin, VP, and Poss, KD. "New regulators of vertebrate appendage regeneration." Curr Opin Genet Dev 18.4 (August 2008): 381-386. (Review)
PMID
18644447
Source
pubmed
Published In
Current Opinion in Genetics & Development
Volume
18
Issue
4
Publish Date
2008
Start Page
381
End Page
386
DOI
10.1016/j.gde.2008.06.008

Hoxb5b acts downstream of retinoic acid signaling in the forelimb field to restrict heart field potential in zebrafish

Authors
Waxman, JS; Keegan, BR; Roberts, RW; Poss, KD; Yelon, D
MLA Citation
Waxman, JS, Keegan, BR, Roberts, RW, Poss, KD, and Yelon, D. "Hoxb5b acts downstream of retinoic acid signaling in the forelimb field to restrict heart field potential in zebrafish." July 15, 2008.
Source
wos-lite
Published In
Developmental Biology
Volume
319
Issue
2
Publish Date
2008
Start Page
482
End Page
482
DOI
10.1016/j.ydbio.2008.05.060

Fgf-dependent depletion of microRNA-133 promotes appendage regeneration in zebrafish.

Appendage regeneration is defined by rapid changes in gene expression that achieve dramatic developmental effects, suggesting involvement of microRNAs (miRNAs). Here, we find dynamic regulation of many miRNAs during zebrafish fin regeneration. In particular, miR-133 levels are high in uninjured fins but low during regeneration. When regeneration was blocked by Fibroblast growth factor (Fgf) receptor inhibition, high miR-133 levels were quickly restored. Experimentally increasing amounts of miR-133 attenuated fin regeneration. Conversely, miR-133 antagonism during Fgf receptor inhibition accelerated regeneration through increased proliferation within the regeneration blastema. The Mps1 kinase, an established positive regulator of blastemal proliferation, is an in vivo target of miR-133. Our findings identify miRNA depletion as a new regulatory mechanism for complex tissue regeneration.

Authors
Yin, VP; Thomson, JM; Thummel, R; Hyde, DR; Hammond, SM; Poss, KD
MLA Citation
Yin, VP, Thomson, JM, Thummel, R, Hyde, DR, Hammond, SM, and Poss, KD. "Fgf-dependent depletion of microRNA-133 promotes appendage regeneration in zebrafish." Genes Dev 22.6 (March 15, 2008): 728-733.
PMID
18347091
Source
pubmed
Published In
Genes & development
Volume
22
Issue
6
Publish Date
2008
Start Page
728
End Page
733
DOI
10.1101/gad.1641808

Regulated addition of new myocardial and epicardial cells fosters homeostatic cardiac growth and maintenance in adult zebrafish.

The heart maintains structural and functional integrity during years of continual contraction, but the extent to which new cell creation participates in cardiac homeostasis is unclear. Here, we assessed cellular and molecular mechanisms of cardiac homeostasis in zebrafish, which display indeterminate growth and possess an unusual capacity to regenerate after acute cardiac injury. Lowering fish density in the aquarium triggered rapid animal growth and robust cardiomyocyte proliferation throughout the adult ventricle, greater than that observed during slow animal growth or size maintenance. Rapid animal growth also induced strong expression of the embryonic epicardial markers raldh2 (aldh1a2) and tbx18 in adult epicardial tissue. Pulse-chase dye labeling experiments revealed that the epicardium recurrently contributes cells to the ventricular wall, indicating an active homeostatic process. Inhibition of signaling by Fibroblast growth factors (Fgfs) decreased this epicardial supplementation of the ventricular wall in growing zebrafish, and led to spontaneous ventricular scarring in animals maintaining cardiac size. Our results demonstrate that the adult zebrafish ventricle grows and is maintained by cardiomyocyte hyperplasia, and that epicardial cells are added to the ventricle in an Fgf-dependent fashion to support homeostasis.

Authors
Wills, AA; Holdway, JE; Major, RJ; Poss, KD
MLA Citation
Wills, AA, Holdway, JE, Major, RJ, and Poss, KD. "Regulated addition of new myocardial and epicardial cells fosters homeostatic cardiac growth and maintenance in adult zebrafish." Development 135.1 (January 2008): 183-192.
PMID
18045840
Source
pubmed
Published In
Development (Cambridge)
Volume
135
Issue
1
Publish Date
2008
Start Page
183
End Page
192
DOI
10.1242/dev.010363

Cardiac progenitors during zebrafish heart regeneration

Authors
Kikuchi, K; Poss, KD
MLA Citation
Kikuchi, K, and Poss, KD. "Cardiac progenitors during zebrafish heart regeneration." August 31, 2007.
Source
wos-lite
Published In
Circulation Research
Volume
101
Issue
5
Publish Date
2007
Start Page
E57
End Page
E57

Bmp and Fgf signaling are essential for liver specification in zebrafish.

Based on data from in vitro tissue explant and ex vivo cell/bead implantation experiments, Bmp and Fgf signaling have been proposed to regulate hepatic specification. However, genetic evidence for this hypothesis has been lacking. Here, we provide in vivo genetic evidence that Bmp and Fgf signaling are essential for hepatic specification. We utilized transgenic zebrafish that overexpress dominant-negative forms of Bmp or Fgf receptors following heat-shock induction. These transgenes allow one to bypass the early embryonic requirements for Bmp and Fgf signaling, and also to completely block Bmp or Fgf signaling. We found that the expression of hhex and prox1, the earliest liver markers in zebrafish, was severely reduced in the liver region when Bmp or Fgf signaling was blocked just before hepatic specification. However, hhex and prox1 expression in adjacent endodermal and mesodermal tissues appeared unaffected by these manipulations. Additional genetic studies indicate that the endoderm maintains competence for Bmp-mediated hepatogenesis over an extended window of embryonic development. Altogether, these data provide the first genetic evidence that Bmp and Fgf signaling are essential for hepatic specification, and suggest that endodermal cells remain competent to differentiate into hepatocytes for longer than anticipated.

Authors
Shin, D; Shin, CH; Tucker, J; Ober, EA; Rentzsch, F; Poss, KD; Hammerschmidt, M; Mullins, MC; Stainier, DY
MLA Citation
Shin, D, Shin, CH, Tucker, J, Ober, EA, Rentzsch, F, Poss, KD, Hammerschmidt, M, Mullins, MC, and Stainier, DY. "Bmp and Fgf signaling are essential for liver specification in zebrafish." Development 134.11 (June 2007): 2041-2050.
PMID
17507405
Source
pubmed
Published In
Development (Cambridge)
Volume
134
Issue
11
Publish Date
2007
Start Page
2041
End Page
2050
DOI
10.1242/dev.000281

Specification of epibranchial placodes in zebrafish.

In all vertebrates, the neurogenic placodes are transient ectodermal thickenings that give rise to sensory neurons of the cranial ganglia. Epibranchial (EB) placodes generate neurons of the distal facial, glossopharyngeal and vagal ganglia, which convey sensation from the viscera, including pharyngeal endoderm structures, to the CNS. Recent studies have implicated signals from pharyngeal endoderm in the initiation of neurogenesis from EB placodes; however, the signals underlying the formation of placodes are unknown. Here, we show that zebrafish embryos mutant for fgf3 and fgf8 do not express early EB placode markers, including foxi1 and pax2a. Mosaic analysis demonstrates that placodal cells must directly receive Fgf signals during a specific crucial period of development. Transplantation experiments and mutant analysis reveal that cephalic mesoderm is the source of Fgf signals. Finally, both Fgf3 and Fgf8 are sufficient to induce foxi1-positive placodal precursors in wild-type as well as Fgf3-plus Fgf8-depleted embryos. We propose a model in which mesoderm-derived Fgf3 and Fgf8 signals establish both the EB placodes and the development of the pharyngeal endoderm, the subsequent interaction of which promotes neurogenesis. The coordinated interplay between craniofacial tissues would thus assure proper spatial and temporal interactions in the shaping of the vertebrate head.

Authors
Nechiporuk, A; Linbo, T; Poss, KD; Raible, DW
MLA Citation
Nechiporuk, A, Linbo, T, Poss, KD, and Raible, DW. "Specification of epibranchial placodes in zebrafish." Development 134.3 (February 2007): 611-623.
PMID
17215310
Source
pubmed
Published In
Development (Cambridge)
Volume
134
Issue
3
Publish Date
2007
Start Page
611
End Page
623
DOI
10.1242/dev.02749

Getting to the heart of regeneration in zebrafish.

A scientific and clinical prerogative of the 21st century is to stimulate the regenerative ability of the human heart. While the mammalian heart shows little or no natural regeneration in response to injury, certain non-mammalian vertebrates possess an elevated capacity for cardiac regeneration. Adult zebrafish restore ventricular muscle removed by surgical resection, events that involve little or no scarring. Recent studies have begun to reveal cellular and molecular mechanisms of this regenerative process that have exciting implications for human cardiac biology and disease.

Authors
Poss, KD
MLA Citation
Poss, KD. "Getting to the heart of regeneration in zebrafish." Semin Cell Dev Biol 18.1 (February 2007): 36-45. (Review)
PMID
17178459
Source
pubmed
Published In
Seminars in Cell and Developmental Biology
Volume
18
Issue
1
Publish Date
2007
Start Page
36
End Page
45
DOI
10.1016/j.semcdb.2006.11.009

Zebrafish Heart Regeneration as a Model for Cardiac Tissue Repair.

Heart disease remains the leading cause of mortality throughout the world. Mammals have an extremely limited capacity to repair lost or damaged heart tissue, thus encouraging biologists to seek out models for heart regeneration. Zebrafish exhibit a robust regenerative capacity in a variety of tissues including the fin, spinal cord, retina, and heart, making it the sole regenerative vertebrate organism currently amenable to genetic manipulation. Future studies will utilize functional approaches to tease apart zebrafish heart regeneration in hopes of unlocking our own regenerative potential.

Authors
Major, RJ; Poss, KD
MLA Citation
Major, RJ, and Poss, KD. "Zebrafish Heart Regeneration as a Model for Cardiac Tissue Repair." Drug Discov Today Dis Models 4.4 (2007): 219-225.
PMID
19081827
Source
pubmed
Published In
Drug Discov Today Dis Models
Volume
4
Issue
4
Publish Date
2007
Start Page
219
End Page
225
DOI
10.1016/j.ddmod.2007.09.002

A dynamic epicardial injury response supports progenitor cell activity during zebrafish heart regeneration.

Zebrafish possess a unique yet poorly understood capacity for cardiac regeneration. Here, we show that regeneration proceeds through two coordinated stages following resection of the ventricular apex. First a blastema is formed, comprised of progenitor cells that express precardiac markers, undergo differentiation, and proliferate. Second, epicardial tissue surrounding both cardiac chambers induces developmental markers and rapidly expands, creating a new epithelial cover for the exposed myocardium. A subpopulation of these epicardial cells undergoes epithelial-to-mesenchymal transition (EMT), invades the wound, and provides new vasculature to regenerating muscle. During regeneration, the ligand fgf17b is induced in myocardium, while receptors fgfr2 and fgfr4 are induced in adjacent epicardial-derived cells. When fibroblast growth factors (Fgf) signaling is experimentally blocked by expression of a dominant-negative Fgf receptor, epicardial EMT and coronary neovascularization fail, prematurely arresting regeneration. Our findings reveal injury responses by myocardial and epicardial tissues that collaborate in an Fgf-dependent manner to achieve cardiac regeneration.

Authors
Lepilina, A; Coon, AN; Kikuchi, K; Holdway, JE; Roberts, RW; Burns, CG; Poss, KD
MLA Citation
Lepilina, A, Coon, AN, Kikuchi, K, Holdway, JE, Roberts, RW, Burns, CG, and Poss, KD. "A dynamic epicardial injury response supports progenitor cell activity during zebrafish heart regeneration." Cell 127.3 (November 3, 2006): 607-619.
PMID
17081981
Source
pubmed
Published In
Cell
Volume
127
Issue
3
Publish Date
2006
Start Page
607
End Page
619
DOI
10.1016/j.cell.2006.08.052

Fgf signaling instructs position-dependent growth rate during zebrafish fin regeneration.

During appendage regeneration in urodeles and teleosts, tissue replacement is precisely regulated such that only the appropriate structures are recovered, a phenomenon referred to as positional memory. It is believed that there exists, or is quickly established after amputation, a dynamic gradient of positional information along the proximodistal (PD) axis of the appendage that assigns region-specific instructions to injured tissue. These instructions specify the amount of tissue to regenerate, as well as the rate at which regenerative growth is to occur. A striking theme among many species is that the rate of regeneration is more rapid in proximally amputated appendages compared with distal amputations. However, the underlying molecular regulation is unclear. Here, we identify position-dependent differences in the rate of growth during zebrafish caudal fin regeneration. These growth rates correlate with position-dependent differences in blastemal length, mitotic index and expression of the Fgf target genes mkp3, sef and spry4. To address whether PD differences in amounts of Fgf signaling are responsible for position-dependent blastemal function, we have generated transgenic fish in which Fgf receptor activity can be experimentally manipulated. We find that the level of Fgf signaling exhibits strict control over target gene expression, blastemal proliferation and regenerative growth rate. Our results demonstrate that Fgf signaling defines position-dependent blastemal properties and growth rates for the regenerating zebrafish appendage.

Authors
Lee, Y; Grill, S; Sanchez, A; Murphy-Ryan, M; Poss, KD
MLA Citation
Lee, Y, Grill, S, Sanchez, A, Murphy-Ryan, M, and Poss, KD. "Fgf signaling instructs position-dependent growth rate during zebrafish fin regeneration." Development 132.23 (December 2005): 5173-5183.
PMID
16251209
Source
pubmed
Published In
Development (Cambridge)
Volume
132
Issue
23
Publish Date
2005
Start Page
5173
End Page
5183
DOI
10.1242/dev.02101

A proximodistal gradient of Fgf signaling defines position-dependent rates of zebrafish fin regeneration.

Authors
Lee, Y; Grill, S; Murphy-Ryan, M; Poss, KD
MLA Citation
Lee, Y, Grill, S, Murphy-Ryan, M, and Poss, KD. "A proximodistal gradient of Fgf signaling defines position-dependent rates of zebrafish fin regeneration." July 15, 2005.
Source
wos-lite
Published In
Developmental Biology
Volume
283
Issue
2
Publish Date
2005
Start Page
642
End Page
642

A zebrafish model of germ cell aneuploidy.

The high frequency of chromosomal nondisjunction in human germ cells impacts society in many ways. Yet, the etiology of chromosome disorders remains unclear. Using a zebrafish strain with a hypomorphic mutation in the kinase Mps1, a genetic association between reduced germ cell mitotic checkpoint activity and aneuploid progeny was recently established. This work highlights the exquisite sensitivity of vertebrate germ cells to disruptions in Mps1 function and mitotic checkpoint activity. In addition, it introduces the zebrafish as a promising tool with which to further investigate the origins of aneuploidy.

Authors
Poss, KD
MLA Citation
Poss, KD. "A zebrafish model of germ cell aneuploidy." Cell Cycle 3.10 (October 2004): 1225-1226.
PMID
15467466
Source
pubmed
Published In
Cell Cycle
Volume
3
Issue
10
Publish Date
2004
Start Page
1225
End Page
1226
DOI
10.4161/cc.3.10.1170

Germ cell aneuploidy in zebrafish with mutations in the mitotic checkpoint gene mps1.

Aneuploidy, resulting from chromosome missegregation during meiosis, is a major cause of human infertility and birth defects. However, its molecular basis remains incompletely understood. Here we have identified a spectrum of chromosome anomalies in embryos of zebrafish homozygous for a hypomorphic mutation in Mps1, a kinase required for the mitotic checkpoint. These aneuploidies are caused by meiotic error and result in severe developmental defects. Our results reveal Mps1 as a critical regulator of chromosome number in zebrafish, and demonstrate how slight genetic perturbation of a mitotic checkpoint factor can dramatically reduce the fidelity of chromosome segregation during vertebrate meiosis.

Authors
Poss, KD; Nechiporuk, A; Stringer, KF; Lee, C; Keating, MT
MLA Citation
Poss, KD, Nechiporuk, A, Stringer, KF, Lee, C, and Keating, MT. "Germ cell aneuploidy in zebrafish with mutations in the mitotic checkpoint gene mps1." Genes Dev 18.13 (July 1, 2004): 1527-1532.
PMID
15231734
Source
pubmed
Published In
Genes & development
Volume
18
Issue
13
Publish Date
2004
Start Page
1527
End Page
1532
DOI
10.1101/gad.1182604

Transplantation and in vivo imaging of multilineage engraftment in zebrafish bloodless mutants.

The zebrafish is firmly established as a genetic model for the study of vertebrate blood development. Here we have characterized the blood-forming system of adult zebrafish. Each major blood lineage can be isolated by flow cytometry, and with these lineal profiles, defects in zebrafish blood mutants can be quantified. We developed hematopoietic cell transplantation to study cell autonomy of mutant gene function and to establish a hematopoietic stem cell assay. Hematopoietic cell transplantation can rescue multilineage hematopoiesis in embryonic lethal gata1-/- mutants for over 6 months. Direct visualization of fluorescent donor cells in embryonic recipients allows engraftment and homing events to be imaged in real time. These results provide a cellular context in which to study the genetics of hematopoiesis.

Authors
Traver, D; Paw, BH; Poss, KD; Penberthy, WT; Lin, S; Zon, LI
MLA Citation
Traver, D, Paw, BH, Poss, KD, Penberthy, WT, Lin, S, and Zon, LI. "Transplantation and in vivo imaging of multilineage engraftment in zebrafish bloodless mutants." Nat Immunol 4.12 (December 2003): 1238-1246.
PMID
14608381
Source
pubmed
Published In
Nature Immunology
Volume
4
Issue
12
Publish Date
2003
Start Page
1238
End Page
1246
DOI
10.1038/ni1007

Positional cloning of a temperature-sensitive mutant emmental reveals a role for sly1 during cell proliferation in zebrafish fin regeneration.

Here, we used classical genetics in zebrafish to identify temperature-sensitive mutants in caudal fin regeneration. Gross morphological, histological, and molecular analyses revealed that one of these strains, emmental (emm), failed to form a functional regeneration blastema. Inhibition of emm function by heat treatment during regenerative outgrowth rapidly blocked regeneration. This block was associated with reduced proliferation in the proximal blastema and expansion of the nonproliferative distal blastemal zone. Positional cloning revealed that the emm phenotype is caused by a mutation in the orthologue of yeast sly1, a gene product involved in protein trafficking. sly1 is upregulated in the newly formed blastema as well as during regenerative outgrowth. Thus, sly1 is essential for blastemal organization and proliferation during two stages of fin regeneration.

Authors
Nechiporuk, A; Poss, KD; Johnson, SL; Keating, MT
MLA Citation
Nechiporuk, A, Poss, KD, Johnson, SL, and Keating, MT. "Positional cloning of a temperature-sensitive mutant emmental reveals a role for sly1 during cell proliferation in zebrafish fin regeneration." Dev Biol 258.2 (June 15, 2003): 291-306.
PMID
12798289
Source
pubmed
Published In
Developmental Biology
Volume
258
Issue
2
Publish Date
2003
Start Page
291
End Page
306

Tales of regeneration in zebrafish.

Complex tissue regeneration involves exquisitely coordinated proliferation and patterning of adult cells after severe injury or amputation. Certain lower vertebrates such as urodele amphibians and teleost fish have a greater capacity for regeneration than mammals. However, little is known about molecular mechanisms of regeneration, and cellular mechanisms are incompletely defined. To address this deficiency, we and others have focused on the zebrafish model system. Several helpful tools and reagents are available for use with zebrafish, including the potential for genetic approaches to regeneration. Recent studies have shed light on the remarkable ability of zebrafish to regenerate fins.

Authors
Poss, KD; Keating, MT; Nechiporuk, A
MLA Citation
Poss, KD, Keating, MT, and Nechiporuk, A. "Tales of regeneration in zebrafish." Dev Dyn 226.2 (February 2003): 202-210. (Review)
PMID
12557199
Source
pubmed
Published In
Developmental Dynamics
Volume
226
Issue
2
Publish Date
2003
Start Page
202
End Page
210
DOI
10.1002/dvdy.10220

Changes in gravitational force induce alterations in gene expression that can be monitored in the live, developing zebrafish heart.

Little is known about the effect of microgravity on gene expression, particularly in vivo during embryonic development. Using transgenic zebrafish that express the gfp gene under the influence of a beta-actin promoter, we examined the affect of simulated-microgravity on GFP expression in the heart. Zebrafish embryos, at the 18-20 somite-stage, were exposed to simulated-microgravity for 24 hours. The intensity of GFP fluorescence associated with the heart was then determined using fluorescence microscopy. Our measurements indicated that simulated-microgravity induced a 23.9% increase in GFP-associated fluorescence in the heart. In contrast, the caudal notochord showed a 17.5% increase and the embryo as a whole showed only an 8.5% increase in GFP-associated fluorescence. This suggests that there are specific effects on the heart causing the more dramatic increase. These studies indicate that microgravity can influence gene expression and demonstrate the usefulness of this in vivo model of 'reporter-gene' expression for studying the effects of microgravity.

Authors
Gillette-Ferguson, I; Ferguson, DG; Poss, KD; Moorman, SJ
MLA Citation
Gillette-Ferguson, I, Ferguson, DG, Poss, KD, and Moorman, SJ. "Changes in gravitational force induce alterations in gene expression that can be monitored in the live, developing zebrafish heart." Adv Space Res 32.8 (2003): 1641-1646.
PMID
15002421
Source
pubmed
Published In
Advances in Space Research
Volume
32
Issue
8
Publish Date
2003
Start Page
1641
End Page
1646

Heart regeneration in zebrafish.

Cardiac injury in mammals and amphibians typically leads to scarring, with minimal regeneration of heart muscle. Here, we demonstrate histologically that zebrafish fully regenerate hearts within 2 months of 20% ventricular resection. Regeneration occurs through robust proliferation of cardiomyocytes localized at the leading epicardial edge of the new myocardium. The hearts of zebrafish with mutations in the Mps1 mitotic checkpoint kinase, a critical cell cycle regulator, failed to regenerate and formed scars. Thus, injury-induced cardiomyocyte proliferation in zebrafish can overcome scar formation, allowing cardiac muscle regeneration. These findings indicate that zebrafish will be useful for genetically dissecting the molecular mechanisms of cardiac regeneration.

Authors
Poss, KD; Wilson, LG; Keating, MT
MLA Citation
Poss, KD, Wilson, LG, and Keating, MT. "Heart regeneration in zebrafish." Science 298.5601 (December 13, 2002): 2188-2190.
PMID
12481136
Source
pubmed
Published In
Science
Volume
298
Issue
5601
Publish Date
2002
Start Page
2188
End Page
2190
DOI
10.1126/science.1077857

Mps1 defines a proximal blastemal proliferative compartment essential for zebrafish fin regeneration.

One possible reason why regeneration remains enigmatic is that the dominant organisms used for studying regeneration are not amenable to genetic approaches. We mutagenized zebrafish and screened for temperature-sensitive defects in adult fin regeneration. The nightcap mutant showed a defect in fin regeneration that was first apparent at the onset of regenerative outgrowth. Positional cloning revealed that nightcap encodes the zebrafish orthologue of mps1, a kinase required for the mitotic checkpoint. mps1 expression was specifically induced in the proximal regeneration blastema, a group of cells that normally proliferate intensely during outgrowth. The nightcap mutation caused severe defects in these cells. However, msxb-expressing blastemal cells immediately distal to this proliferative region did not induce mps1 and were retained in mutants. These results indicate that the proximal blastema comprises an essential subpopulation of the fin regenerate defined by the induction and function of Mps1. Furthermore, we show that molecular mechanisms of complex tissue regeneration can now be dissected using zebrafish genetics.

Authors
Poss, KD; Nechiporuk, A; Hillam, AM; Johnson, SL; Keating, MT
MLA Citation
Poss, KD, Nechiporuk, A, Hillam, AM, Johnson, SL, and Keating, MT. "Mps1 defines a proximal blastemal proliferative compartment essential for zebrafish fin regeneration." Development 129.22 (November 2002): 5141-5149.
PMID
12399306
Source
pubmed
Published In
Development (Cambridge)
Volume
129
Issue
22
Publish Date
2002
Start Page
5141
End Page
5149

Induction of lef1 during zebrafish fin regeneration

Because the transcription factor Lef1 is important for development of several vertebrate organs but has not been investigated for involvement in epimorphic regeneration, we examined its expression during regeneration of amputated adult zebrafish caudal fins. We found that lef1 is markedly up-regulated in the newly formed wound epidermis of the fin regenerate and is maintained in the basal epidermal layer during formation of the regeneration blastema. During regenerative outgrowth, lef1 expression is strongest in epidermal cells adjacent to newly aligned scleroblasts that secrete bone matrix, while it is low or undetectable in epidermis adjacent to mesenchymal areas with either mature bone or proliferative distal blastema cells. This localization is similar to that of the putative fin ray patterning signal Shh. In addition, brief treatments of fin regenerates with retinoic acid of the synthetic Fgfr1 inhibitor SU5402 down-regulate epidermal lef1, similar to their effects on shh. These results suggest a role for Lef1 in scleroblast alignment analogous to that proposed for Shh. Other Wnt signaling pathway members wnt3a, wnt5, and β-catenin are also expressed in the fin regenerate. Our data suggest that Lef1 has specific roles in inducing and patterning vertebrate regenerating tissue. (C) 2000 Wiley-Liss, Inc.

Authors
Poss, KD; Shen, J; Keating, MT
MLA Citation
Poss, KD, Shen, J, and Keating, MT. "Induction of lef1 during zebrafish fin regeneration." Developmental Dynamics 219.2 (October 24, 2000): 282-286.
Source
scopus
Published In
Developmental Dynamics
Volume
219
Issue
2
Publish Date
2000
Start Page
282
End Page
286
DOI
10.1002/1097-0177(2000)9999:9999<::AID-DVDY1045>3.0.CO;2-C

Induction of lef1 during zebrafish fin regeneration.

Because the transcription factor Lef1 is important for development of several vertebrate organs but has not been investigated for involvement in epimorphic regeneration, we examined its expression during regeneration of amputated adult zebrafish caudal fins. We found that lef1 is markedly up-regulated in the newly formed wound epidermis of the fin regenerate and is maintained in the basal epidermal layer during formation of the regeneration blastema. During regenerative outgrowth, lef1 expression is strongest in epidermal cells adjacent to newly aligned scleroblasts that secrete bone matrix, while it is low or undetectable in epidermis adjacent to mesenchymal areas with either mature bone or proliferative distal blastema cells. This localization is similar to that of the putative fin ray patterning signal Shh. In addition, brief treatments of fin regenerates with retinoic acid or the synthetic Fgfr1 inhibitor SU5402 down-regulate epidermal lef1, similar to their effects on shh. These results suggest a role for Lef1 in scleroblast alignment analogous to that proposed for Shh. Other Wnt signaling pathway members wnt3a, wnt5, and beta-catenin are also expressed in the fin regenerate. Our data suggest that Lef1 has specific roles in inducing and patterning vertebrate regenerating tissue.

Authors
Poss, KD; Shen, J; Keating, MT
MLA Citation
Poss, KD, Shen, J, and Keating, MT. "Induction of lef1 during zebrafish fin regeneration." Dev Dyn 219.2 (October 2000): 282-286.
PMID
11002347
Source
pubmed
Published In
Developmental Dynamics
Volume
219
Issue
2
Publish Date
2000
Start Page
282
End Page
286
DOI
10.1002/1097-0177(2000)9999:9999<::AID-DVDY1045>3.0.CO;2-C

Roles for Fgf signaling during zebrafish fin regeneration.

Following amputation of a urodele limb or teleost fin, the formation of a blastema is a crucial step in facilitating subsequent regeneration. Using the zebrafish caudal fin regeneration model, we have examined the hypothesis that fibroblast growth factors (Fgfs) initiate blastema formation from fin mesenchyme. We find that fibroblast growth factor receptor 1 (fgfr1) is expressed in mesenchymal cells underlying the wound epidermis during blastema formation and in distal blastemal tissue during regenerative outgrowth. fgfr1 transcripts colocalize with those of msxb and msxc, putative markers for undifferentiated, proliferating cells. A zebrafish Fgf member, designated wfgf, is expressed in the regeneration epidermis during outgrowth. Furthermore, we show that a specific inhibitor of Fgfr1 applied immediately following fin amputation blocks blastema formation, without obvious effects on wound healing. This inhibitor blocks the proliferation of blastemal cells and the onset of msx gene transcription. Inhibition of Fgf signaling during ongoing fin regeneration prevents further outgrowth while downregulating the established expression of blastemal msx genes and epidermal sonic hedgehog. Our findings indicate that zebrafish fin blastema formation and regenerative outgrowth require Fgf signaling.

Authors
Poss, KD; Shen, J; Nechiporuk, A; McMahon, G; Thisse, B; Thisse, C; Keating, MT
MLA Citation
Poss, KD, Shen, J, Nechiporuk, A, McMahon, G, Thisse, B, Thisse, C, and Keating, MT. "Roles for Fgf signaling during zebrafish fin regeneration." Dev Biol 222.2 (June 15, 2000): 347-358.
PMID
10837124
Source
pubmed
Published In
Developmental Biology
Volume
222
Issue
2
Publish Date
2000
Start Page
347
End Page
358
DOI
10.1006/dbio.2000.9722

The indispensability of heme oxygenase-1 in protecting against acute heme protein-induced toxicity in vivo.

Heme oxygenase (HO) is the rate limiting enzyme in the degradation of heme, and its isozyme, HO-1, may protect against tissue injury. One posited mechanism is the degradation of heme released from destabilized heme proteins. We demonstrate that HO-1 is a critical protectant against acute heme protein-induced toxicity in vivo. In the glycerol model of heme protein toxicity-one characterized by myolysis, hemolysis, and kidney damage-HO-1 is rapidly induced in the kidney of HO-1 +/+ mice as the latter sustain mild, reversible renal insufficiency without mortality. In stark contrast, after this insult, HO-1 -/- mice exhibit fulminant, irreversible renal failure and 100% mortality; HO-1 -/- mice do not express HO-1, and evince an eightfold increment in kidney heme content as compared to HO-1 +/+ mice. We also demonstrate directly the critical dependency on HO-1 in protecting against a specific heme protein, namely, hemoglobin: doses of hemoglobin which exert no nephrotoxicity or mortality in HO-1 +/+ mice, however, precipitate rapidly developing, acute renal failure and marked mortality in HO-1 -/- mice. We conclude that the induction of HO-1 is an indispensable response in protecting against acute heme protein toxicity in vivo.

Authors
Nath, KA; Haggard, JJ; Croatt, AJ; Grande, JP; Poss, KD; Alam, J
MLA Citation
Nath, KA, Haggard, JJ, Croatt, AJ, Grande, JP, Poss, KD, and Alam, J. "The indispensability of heme oxygenase-1 in protecting against acute heme protein-induced toxicity in vivo." Am J Pathol 156.5 (May 2000): 1527-1535.
PMID
10793064
Source
pubmed
Published In
The American journal of pathology
Volume
156
Issue
5
Publish Date
2000
Start Page
1527
End Page
1535
DOI
10.1016/S0002-9440(10)65024-9

Heme oxygenase-1 gene ablation or expression modulates cisplatin-induced renal tubular apoptosis

Heme oxygenase-1 (HO-1) is a 32-kDa microsomal enzyme that catalyzes the conversion of heme to biliverdin, releasing iron and carbon monoxide. Induction of HO-1 occurs as a protective response in cells/tissues exposed to a wide variety of oxidant stimuli. The chemotherapeutic effects of cis- diamminedichloroplatinum(II) (cisplatin), a commonly used anticancer drug, are limited by significant nephrotoxicity, which is characterized by varying degrees of renal tubular apoptosis and necrosis. The purpose of this study was to evaluate the functional significance of HO-1 expression in cisplatin- induced renal injury. Our studies demonstrate that transgenic mice deficient in HO-1 (-/-), develop more severe renal failure and have significantly greater renal injury compared with wild-type (+/+) mice treated with cisplatin. In vitro studies in human renal proximal tubule cells demonstrate that hemin, an inducer of HO-1, significantly attenuated cisplatin-induced apoptosis and necrosis, whereas inhibition of HO-1 enzyme activity reversed the cytoprotective effect. Overexpression of HO-1 resulted in a significant reduction in cisplatin-induced cytotoxicity. These studies provide a basis for future studies using targeted gene expression of HO-1 as a therapeutic and preventive modality in high-risk settings of acute renal failure.

Authors
Shiraishi, F; Curtis, LM; Truong, L; Poss, K; Visner, GA; Madsen, K; Nick, HS; Agarwal, A
MLA Citation
Shiraishi, F, Curtis, LM, Truong, L, Poss, K, Visner, GA, Madsen, K, Nick, HS, and Agarwal, A. "Heme oxygenase-1 gene ablation or expression modulates cisplatin-induced renal tubular apoptosis." American Journal of Physiology - Renal Physiology 278.5 47-5 (2000): F726-F736.
PMID
10807584
Source
scival
Published In
American journal of physiology. Renal physiology
Volume
278
Issue
5 47-5
Publish Date
2000
Start Page
F726
End Page
F736

Haem oxygenase-1 prevents cell death by regulating cellular iron.

Haem oxygenase-1 (HO1) is a heat-shock protein that is induced by stressful stimuli. Here we demonstrate a cytoprotective role for HO1: cell death produced by serum deprivation, staurosporine or etoposide is markedly accentuated in cells from mice with a targeted deletion of the HO1 gene, and greatly reduced in cells that overexpress HO1. Iron efflux from cells is augmented by HO1 transfection and reduced in HO1-deficient fibroblasts. Iron accumulation in HO1-deficient cells explains their death: iron chelators protect HO1-deficient fibroblasts from cell death. Thus, cytoprotection by HO1 is attributable to its augmentation of iron efflux, reflecting a role for HO1 in modulating intracellular iron levels and regulating cell viability.

Authors
Ferris, CD; Jaffrey, SR; Sawa, A; Takahashi, M; Brady, SD; Barrow, RK; Tysoe, SA; Wolosker, H; Barañano, DE; Doré, S; Poss, KD; Snyder, SH
MLA Citation
Ferris, CD, Jaffrey, SR, Sawa, A, Takahashi, M, Brady, SD, Barrow, RK, Tysoe, SA, Wolosker, H, Barañano, DE, Doré, S, Poss, KD, and Snyder, SH. "Haem oxygenase-1 prevents cell death by regulating cellular iron." Nat Cell Biol 1.3 (July 1999): 152-157.
PMID
10559901
Source
pubmed
Published In
Nature Cell Biology
Volume
1
Issue
3
Publish Date
1999
Start Page
152
End Page
157
DOI
10.1038/11072

Circadian locomotor rhythms in mice with targeted disruption of the gene for the carbon monoxide synthesizing enzyme, heme oxygenase-2

Carbon monoxide (CO), generated in neurons by the enzyme heme oxygenase- 2 (HO2), is postulated to be a gaseous signaling molecule in the mammalian brain. Because of the recent evidence suggesting an important role of another endogenously produced gas, nitric oxide (NO), in entrainment of circadian rhythms in mammals, we hypothesized that CO may also be involved in regulating these rhythms. Consistent with this idea, others have found a circadian rhythm of heme turnover and CO synthesis can be induced by bright light. Furthermore, HO2 is co-localized with guanylyl cyclase, the putative target of CO, throughout the brain, with high amounts of staining in the suprachiasmatic nucleus (SCN) of the hypothalamus. The goal of the present study was to evaluate the role of CO in photic entrainment in wild-type and HO2 deficient mice. HO2-/- mice did not display any abnormalities in circadian rhythmicity: Entrainment to a light-dark cycle, the ability to phase delay locomotor activity after a four hour phase shift in photoperiod, and the period of the free running rhythm (t) were similar between HO2-/- and wild-type mice. Taken together, these data suggest that CO does not play a major role in regulating circadian activity rhythms in mice.

Authors
Demas, GE; Kriegsfeld, LJ; Poss, KD; Tonegawa, S; Nelson, RJ
MLA Citation
Demas, GE, Kriegsfeld, LJ, Poss, KD, Tonegawa, S, and Nelson, RJ. "Circadian locomotor rhythms in mice with targeted disruption of the gene for the carbon monoxide synthesizing enzyme, heme oxygenase-2." Biological Rhythm Research 30.3 (1999): 282-289.
Source
scival
Published In
Biological Rhythm Research
Volume
30
Issue
3
Publish Date
1999
Start Page
282
End Page
289
DOI
10.1076/brhm.30.3.282.3053

Expression of heme oxygenase-1 can determine cardiac xenograft survival.

The rejection of concordant xenografts, such as mouse-to-rat cardiac xenografts, is very similar to the delayed rejection of porcine-to-primate discordant xenografts. In concordant models, this type of rejection is prevented by brief complement inhibition by cobra venom factor (CVF) and sustained T-cell immunosuppression by cyclosporin A (CyA). Mouse hearts that survive indefinitely in rats treated with CVF plus CyA express the anti-inflammatory gene heme oxygenase-1 (HO-1) in their endothelial cells and smooth muscle cells. The anti-inflammatory properties of HO-1 are thought to rely on the ability of this enzyme to degrade heme and generate bilirubin, free iron and carbon monoxide. Bilirubin is a potent anti-oxidant, free iron upregulates the transcription of the cytoprotective gene, ferritin, and carbon monoxide is thought to be essential in regulating vascular relaxation in a manner similar to nitric oxide. We show here that the expression of the HO-1 gene is functionally associated with xenograft survival, and that rapid expression of HO-1 in cardiac xenografts can be essential to ensure long-term xenograft survival.

Authors
Soares, MP; Lin, Y; Anrather, J; Csizmadia, E; Takigami, K; Sato, K; Grey, ST; Colvin, RB; Choi, AM; Poss, KD; Bach, FH
MLA Citation
Soares, MP, Lin, Y, Anrather, J, Csizmadia, E, Takigami, K, Sato, K, Grey, ST, Colvin, RB, Choi, AM, Poss, KD, and Bach, FH. "Expression of heme oxygenase-1 can determine cardiac xenograft survival." Nat Med 4.9 (September 1998): 1073-1077.
PMID
9734404
Source
pubmed
Published In
Nature Medicine
Volume
4
Issue
9
Publish Date
1998
Start Page
1073
End Page
1077
DOI
10.1038/2063

Oxygen toxicity and iron accumulation in the lungs of mice lacking heme oxygenase-2.

Heme oxygenase (HO) activity leads to accumulation of the antioxidant bilirubin, and degradation of the prooxidant heme. Moderate overexpression of the inducible form, HO-1, is associated with protection against oxidative injury. However, the role of HO-2 in oxidative stress has not been explored. We evaluated survival, indices of oxidative injury, and lung and HO expression in HO-2 null mutant mice exposed to > 95% O2 compared with wild-type controls. Similar basal levels of major lung antioxidants were observed, except that the knockouts had a twofold increase in total glutathione content. Despite increased HO-1 expression from HO-1 induction, knockout animals were sensitized to hyperoxia-induced oxidative injury and mortality, and also had significantly increased markers of oxidative injury before hyperoxic exposure. Furthermore, during hyperoxia, lung hemoproteins and iron content were significantly increased without increased ferritin, suggesting accumulation of available redox-active iron. These results demonstrate that the absence of HO-2 is associated with induction of HO-1 and increased oxygen toxicity in vivo, apparently due to accumulation of lung iron. These results suggest that HO-2 functions to augment the turnover of lung iron during oxidative stress, and that this function does not appear to be compensated for by induction of HO-1 in the knockouts.

Authors
Dennery, PA; Spitz, DR; Yang, G; Tatarov, A; Lee, CS; Shegog, ML; Poss, KD
MLA Citation
Dennery, PA, Spitz, DR, Yang, G, Tatarov, A, Lee, CS, Shegog, ML, and Poss, KD. "Oxygen toxicity and iron accumulation in the lungs of mice lacking heme oxygenase-2." J Clin Invest 101.5 (March 1, 1998): 1001-1011.
PMID
9486970
Source
pubmed
Published In
Journal of Clinical Investigation
Volume
101
Issue
5
Publish Date
1998
Start Page
1001
End Page
1011
DOI
10.1172/JCI448

Ejaculatory abnormalities in mice with targeted disruption of the gene for heme oxygenase-2.

Nitric oxide (NO) is well established as a neurotransmitter in the central and peripheral nervous systems. More recently, another gas, carbon monoxide (CO) has also been implicated in neurotransmission. In the nervous system CO is formed by a subtype of heme oxygenase (HO) designated HO2. HO2 is localized to discrete neuronal populations in the brain resembling localizations of soluble guanylyl cyclase, which is activated by CO. CO may also function in the peripheral autonomic nervous system, in conjunction with NO. The majority of ganglia in the myenteric plexus possess both HO2 and neuronal NO synthase (NOS). Defects in myenteric plexus neurotransmission occur both in mice with targeted deletion of genes for HO2 and neuronal NOS. HO2 also occurs in other autonomic ganglia including the petrosal, superior cervical and nodose ganglia. Neuronal NOS is localized to neurons regulating male reproductive behavior, such as penile erection, and NOS inhibitors prevent erection. Because of the other parallels between NO and CO, we speculated that CO may play a role in male reproductive behavior. In the present study we describe HO2 localization in neuronal structures regulating copulatory reflexes. Reflex activity of the bulbospongiosus muscle, which mediates ejaculation and ejaculatory behavior, is markedly diminished in mice with targeted deletion of the gene for HO2 (HO2-).

Authors
Burnett, AL; Johns, DG; Kriegsfeld, LJ; Klein, SL; Calvin, DC; Demas, GE; Schramm, LP; Tonegawa, S; Nelson, RJ; Snyder, SH; Poss, KD
MLA Citation
Burnett, AL, Johns, DG, Kriegsfeld, LJ, Klein, SL, Calvin, DC, Demas, GE, Schramm, LP, Tonegawa, S, Nelson, RJ, Snyder, SH, and Poss, KD. "Ejaculatory abnormalities in mice with targeted disruption of the gene for heme oxygenase-2." Nat Med 4.1 (January 1998): 84-87.
PMID
9427611
Source
pubmed
Published In
Nature Medicine
Volume
4
Issue
1
Publish Date
1998
Start Page
84
End Page
87

Targeted gene deletion of heme oxygenase 2 reveals neural role for carbon monoxide.

Neuronal nitric oxide synthase (nNOS) generates NO in neurons, and heme-oxygenase-2 (HO-2) synthesizes carbon monoxide (CO). We have evaluated the roles of NO and CO in intestinal neurotransmission using mice with targeted deletions of nNOS or HO-2. Immunohistochemical analysis demonstrated colocalization of nNOS and HO-2 in myenteric ganglia. Nonadrenergic noncholinergic relaxation and cyclic guanosine 3',5' monophosphate elevations evoked by electrical field stimulation were diminished markedly in both nNOSDelta/Delta and HO-2(Delta)/Delta mice. In wild-type mice, NOS inhibitors and HO inhibitors partially inhibited nonadrenergic noncholinergic relaxation. In nNOSDelta/Delta animals, NOS inhibitors selectively lost their efficacy, and HO inhibitors were inactive in HO-2(Delta)/Delta animals.

Authors
Zakhary, R; Poss, KD; Jaffrey, SR; Ferris, CD; Tonegawa, S; Snyder, SH
MLA Citation
Zakhary, R, Poss, KD, Jaffrey, SR, Ferris, CD, Tonegawa, S, and Snyder, SH. "Targeted gene deletion of heme oxygenase 2 reveals neural role for carbon monoxide." Proc Natl Acad Sci U S A 94.26 (December 23, 1997): 14848-14853.
PMID
9405702
Source
pubmed
Published In
Proceedings of the National Academy of Sciences of USA
Volume
94
Issue
26
Publish Date
1997
Start Page
14848
End Page
14853

Heme oxygenase 1 is required for mammalian iron reutilization.

The majority of iron for essential mammalian biological activities such as erythropoiesis is thought to be reutilized from cellular hemoproteins. Here, we generated mice lacking functional heme oxygenase 1 (Hmox1; EC 1.14.99.3), which catabolizes heme to biliverdin, carbon monoxide, and free iron, to assess its participation in iron homeostasis. Hmox1-deficient adult mice developed an anemia associated with abnormally low serum iron levels, yet accumulated hepatic and renal iron that contributed to macromolecular oxidative damage, tissue injury, and chronic inflammation. Our results indicate that Hmox1 has an important recycling role by facilitating the release of iron from hepatic and renal cells, and describe a mouse model of human iron metabolic disorders.

Authors
Poss, KD; Tonegawa, S
MLA Citation
Poss, KD, and Tonegawa, S. "Heme oxygenase 1 is required for mammalian iron reutilization." Proc Natl Acad Sci U S A 94.20 (September 30, 1997): 10919-10924.
PMID
9380735
Source
pubmed
Published In
Proceedings of the National Academy of Sciences of USA
Volume
94
Issue
20
Publish Date
1997
Start Page
10919
End Page
10924

Reduced stress defense in heme oxygenase 1-deficient cells.

Stressed mammalian cells up-regulate heme oxygenase 1 (Hmox1; EC 1.14.99.3), which catabolizes heme to biliverdin, carbon monoxide, and free iron. To assess the potential role of Hmox1 in cellular antioxidant defense, we analyzed the responses of cells from mice lacking functional Hmox1 to oxidative challenges. Cultured Hmox1(-/-) embryonic fibroblasts demonstrated high oxygen free radical production when exposed to hemin, hydrogen peroxide, paraquat, or cadmium chloride, and they were hypersensitive to cytotoxicity caused by hemin and hydrogen peroxide. Furthermore, young adult Hmox1(-/-) mice were vulnerable to mortality and hepatic necrosis when challenged with endotoxin. Our in vitro and in vivo results provide genetic evidence that up-regulation of Hmox1 serves as an adaptive mechanism to protect cells from oxidative damage during stress.

Authors
Poss, KD; Tonegawa, S
MLA Citation
Poss, KD, and Tonegawa, S. "Reduced stress defense in heme oxygenase 1-deficient cells." Proc Natl Acad Sci U S A 94.20 (September 30, 1997): 10925-10930.
PMID
9380736
Source
pubmed
Published In
Proceedings of the National Academy of Sciences of USA
Volume
94
Issue
20
Publish Date
1997
Start Page
10925
End Page
10930

Hippocampal long-term potentiation is normal in heme oxygenase-2 mutant mice.

We have generated mice deficient in HO-2, the major cerebral isoform of heme oxygenase, in order to assess the potential role of carbon monoxide as a retrograde messenger in hippocampal LTP. Cerebral HO catalytic activity was markedly reduced in the HO-2 mutant mice, yet no differences were found between wild types and mutants in gross neuroanatomical structure, in basal hippocampal synaptic transmission, or in the amount of potentiation produced by various LTP induction protocols. Furthermore, zinc protoporphyrin IX, an inhibitor of HO, had nearly identical inhibitory effects on LTP in wild-type and HO-2 mutant hippocampal slices. Our data indicate that carbon monoxide produced endogenously by HO is unlikely to be a neuromodulator required for LTP in the hippocampus.

Authors
Poss, KD; Thomas, MJ; Ebralidze, AK; O'Dell, TJ; Tonegawa, S
MLA Citation
Poss, KD, Thomas, MJ, Ebralidze, AK, O'Dell, TJ, and Tonegawa, S. "Hippocampal long-term potentiation is normal in heme oxygenase-2 mutant mice." Neuron 15.4 (October 1995): 867-873.
PMID
7576635
Source
pubmed
Published In
Neuron
Volume
15
Issue
4
Publish Date
1995
Start Page
867
End Page
873
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