Yap is required for scar formation but not myocyte proliferation during heart regeneration in zebrafish

2018 ◽  
Vol 115 (3) ◽  
pp. 570-577 ◽  
Author(s):  
Michael A Flinn ◽  
Brooke E Jeffery ◽  
Caitlin C O’Meara ◽  
Brian A Link
Keyword(s):  
Heart Development ◽  
Critical Role ◽  
Scar Formation ◽  
Cardiac Cells ◽  
Mouse Heart ◽  
Heart Regeneration ◽  
Post Injury ◽  
Myocyte Proliferation ◽  
The Impact ◽  
Zebrafish Heart

Abstract Aims The Hippo signalling pathway regulates multiple cellular processes during organ development and maintenance by modulating activity of the transcriptional cofactor Yap. Core components of this pathway are required for neonatal mouse heart regeneration, however, investigations to date have typically focused on expression and activity in cardiomyocytes. Due to the regenerative capacity of zebrafish and the fact that global loss of Yap is not fully embryonic lethal in zebrafish, we leveraged a yap null mutant to investigate the impact of constitutive Yap deletion during zebrafish heart regeneration. Methods and results Following cryoinjury in adult hearts, myocyte proliferation was not decreased in yap mutants, contrary to expectations based on mouse data. Experiments in larval zebrafish (Danio rerio) revealed that deletion of either Yap or Taz had a modest effect on heart growth, reducing gross organ size, while their combined deletion was synergistic; thus, Yap and Taz share some overlapping roles in zebrafish heart development. Surprisingly, adult yap mutants exhibited decreased collagen composition at 7 days post-injury, suggesting a critical role for Yap in scar formation during heart regeneration. siRNA-mediated Yap knockdown in primary rat (Rattus norvegicus) cardiac cells revealed a fibroblast-specific role for Yap in controlling the expression of cytoskeletal and myofibroblast activation genes, as well as pro-inflammatory cyto/chemokines. Corroborating these RNAseq data, we observed increased macrophage infiltration in the scars of yap mutants at 7 days post-injury. Conclusion These results suggest that Yap deletion has minimal effect on myocyte proliferation in adults, but significantly influences scar formation and immune cell infiltration during zebrafish heart regeneration. Collectively, these data suggest an unexpected role for Yap in matrix formation and macrophage recruitment during heart regeneration.

scholarly journals Macrophages directly contribute collagen to scar formation during zebrafish heart regeneration and mouse heart repair

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Filipa C. Simões ◽  
Thomas J. Cahill ◽  
Amy Kenyon ◽  
Daria Gavriouchkina ◽  
Joaquim M. Vieira ◽  
...  
Keyword(s):  
Scar Formation ◽  
Mouse Heart ◽  
Heart Regeneration ◽  
Heart Repair ◽  
Zebrafish Heart

Abstract 82: Wnt11 Regulates Chamber Specific Neonatal Cardiomyocyte Proliferation During Perinatal Circulatory Transition

2017 ◽  
Vol 121 (suppl_1) ◽  
Author(s):  
Marlin Touma ◽  
Xuedong Kang ◽  
Fuying Gao ◽  
Yan Zhao ◽  
Reshma Biniwale ◽  
...  
Keyword(s):  
Heart Defects ◽  
Critical Role ◽  
Newborn Infants ◽  
R Package ◽  
Maturation Stage ◽  
Specific Gene ◽  
Mouse Heart ◽  
Cardiomyocyte Proliferation ◽  
Loss Of Function ◽  
Myocyte Proliferation

Background: Fetal to neonatal transition of heart involves major changes in cardiomyocytes (CMC) including proliferative capacity. However, the chamber specific CMC proliferation programs of remain poorly understood. Elucidating the mechanisms involved is critical to develop chamber specific therapies for newborn infants with single ventricle physiology and other congenital heart defects (CHDs). Methods: Transcriptomes of mouse left ventricle (LV) and right ventricle (RV) were analyzed by RNA-seq at postnatal days 0 (P0), P3 and P7. R package and Ingenuity suite were used for weighted gene co-expression network analysis (WGCNA) and gene ontology studies. Mechanistic analysis was conducted using gain and loss of function approaches. Results: Mouse neonatal cardiac transcriptome was mostly affected by developmental stage. WGCNA revealed 5 LV and 8 RV modules that were significantly correlated with maturation stage and highly preserved between both ventricles at P0 and P7. In contrast, P3 specific gene modules exhibited the largest chamber specific variations in cell signaling, involving proliferation in LV and Wnt signaling molecules, including Wnt11, in RV. Importantly, Wnt11 expression significantly decreased in cyanotic CHDs phenotypes and correlated with O2 saturation levels in hypoxemic infants with Tetralogy of Fallot (TOF). Notably, Perinatal hypoxia treatment in mice suppressed Wnt11 expression, induced CMC proliferation, downregulated Rb1 expression and enhanced Rb1 phosphorylation more robustly in RV vs. LV. Remarkably, Wnt11 inactivation was sufficient to induce myocyte proliferation in perinatal mouse heart and reduced Rb1 expression and phosphorylation in primary neonatal CMC. Importantly, downregulated Wnt11 in hypoxemic TOF infantile heart was also associated with Rb1 suppression and inversely correlated with proliferation marker Plk1 in human. Conclusion: Using integrated systems genomic and functional biology analyses of perinatal cardiac transcriptome, we revealed a previously uncharacterized function for Wnt11 in chamber specific growth and cyanotic CHD. Reduction of Wnt11 expression by hypoxia plays a critical role in neonatal CMC proliferation via modulating Rb1 expression and activity.

scholarly journals H2S Protects against Cardiac Cell Hypertrophy through Regulation of Selenoproteins

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Adam Greasley ◽  
Yanjie Zhang ◽  
Bo Wu ◽  
Yanxi Pei ◽  
Nelson Belzile ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cardiac Hypertrophy ◽  
Critical Role ◽  
Thioredoxin Reductase ◽  
Cardiac Cells ◽  
Keshan Disease ◽  
Mouse Heart ◽  
Cardiac Cell ◽  
Cell Hypertrophy ◽  
Expression Of Genes

Cardiac hypertrophy is defined as the enlargement of the cardiac myocytes, leading to improper nourishment and oxygen supply due to the increased functional demand. This increased stress on the cardiac system commonly leads to myocardial infarction, contributing to 85% of all cardiac-related deaths. Cystathionine gamma-lyase- (CSE-) derived H2S is a novel gasotransmitter and plays a critical role in the preservation of cardiac functions. Selenocysteine lyase (SCLY) has been identified to produce H2Se, the selenium homologue of H2S. Deficiency of selenium is often found in Keshan disease, a congestive cardiomyopathy. The interaction of H2S and H2Se in cardiac cell hypertrophy has not been explored. In this study, cell viability was evaluated with a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Oxidative stress and cell size were observed through immunostaining. The expression of genes was determined by real-time PCR and western blot. Here, we demonstrated that incubation of rat cardiac cells (H9C2) with H2O2 lead to increased oxidative stress and cell surface area, which were significantly attenuated by pretreatment of either H2S or H2Se. H2S incubation induced SCLY/H2Se signaling, which next caused higher expressions and activities of selenoproteins, including glutathione peroxidase and thioredoxin reductase. Furthermore, deficiency of CSE inhibited the expressions of SCLY and selenoprotein P in mouse heart tissues. We also found that both H2S and H2Se stimulated Nrf2-targeted downstream genes. These data suggests that H2S protects against cardiac hypertrophy through enhancement of a group of antioxidant proteins.

scholarly journals Developmental and Regenerative Biology of Cardiomyocytes

2021 ◽  
Author(s):  
Angeliki Daiou ◽  
Katerina Petalidou ◽  
Georgios Siokatas ◽  
Eleftherios I. Papadopoulos ◽  
Konstantinos E. Hatzistergos
Keyword(s):  
Developmental Biology ◽  
Current Knowledge ◽  
Heart Diseases ◽  
Clinical Stage ◽  
Critical Role ◽  
Mouse Heart ◽  
Heart Regeneration ◽  
Adult Zebrafish ◽  
Mammalian Embryo ◽  
Metabolic Remodeling

The current progress and challenges in understanding the molecular and cellular mechanisms of cardiomyocyte embryonic development and regeneration are reviewed in our present work. Three major topics are critically discussed: how do cardiomyocytes form in the embryo? What is the adult origin of the cells that regenerate cardiomyocytes in animal models with adult heart regeneration capabilities? Can the promise of therapeutic cardiomyocyte regeneration be realized in humans? In the first topic, we highlight current advancements in understanding the developmental biology of cardiomyocytes, with emphasis on the regulative capabilities of the early embryo during specification and allocation of the cardiomyoblasts that produce the primordial heart. We further emphasize on trabecular cardiomyocyte development from late cardiomyoblasts, neural crest cells and primordial cardiomyocytes, and their critical role on the clonal growth of the compact/septal and cortical cardiomyocyte layers in the mammalian embryo and adult zebrafish, respectively. In the second topic, we focus on the reactivation of the cortical or trabecular compaction programs as hallmarks of cardiomyocyte regenerative cells during adult zebrafish and neonatal mouse heart regeneration, respectively, and underscore the metabolic remodeling that commonly drives cardiomyocyte regeneration in these organisms. Finally, we discuss the status of preclinical and clinical-stage therapeutics for cardiomyocyte regeneration, with particular emphasis on gene therapy, as well as adult and pluripotent stem cell-based cellular cardiomyoplasty approaches. In summary, our article provides a bird’s-eye view on the current knowledge and potential pitfalls in the field of developmental biology-guided regenerative medicine strategies for the treatment of heart diseases.

scholarly journals Midkine-a regulates the formation of a fibrotic scar during zebrafish heart regeneration

2021 ◽  
Author(s):  
Dimitrios Grivas ◽  
Álvaro González-Rajal ◽  
José Luis de la Pompa
Keyword(s):  
Critical Role ◽  
Cardiac Injury ◽  
Transcriptional Analysis ◽  
Endothelial Cell Proliferation ◽  
Heart Regeneration ◽  
Knock Out ◽  
Tgfβ Signalling ◽  
Fibrotic Scar ◽  
Zebrafish Heart

AbstractThe adult zebrafish heart regenerates after injury, unlike the hearts of mammals. Heart cryoinjury triggers the formation of a fibrotic scar that gradually degrades, leading to regeneration. Midkine-a (Mdka) is a multifunctional cytokine that is activated after cardiac injury. Here, we investigated the role of mdka in zebrafish heart regeneration. We show that mdka expression is strongly induced at 1-day post cryoinjury (dpci) throughout the epicardium, whereas by 7 dpci expression has become restricted to epicardial cells covering the injured area. To study the role of mdka in heart regeneration, we generated mdka-knock out (KO) zebrafish strains. Analysis of injured hearts showed that loss of mdka decreased endothelial cell proliferation and resulted in a blockade of heart regeneration characterized by retention of a collagenous scar. Transcriptional analysis revealed increases in collagen transcription and TGFβ signalling activity. These results reveal a critical role for mdka in fibrosis regulation during heart regeneration.

scholarly journals Heterogeneous pdgfrβ+ cells regulate coronary vessel development and revascularization during heart regeneration

2021 ◽  
Author(s):  
Subir Kapuria ◽  
Haipeng Bai ◽  
Juancarlos Fierros ◽  
Ying Huang ◽  
Feiyang Ma ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Coronary Arteries ◽  
Heart Development ◽  
Coronary Vessel ◽  
Heart Regeneration ◽  
Atrioventricular Canal ◽  
Mural Cell ◽  
Mural Cells ◽  
Vessel Development ◽  
Zebrafish Heart

ABSTRACTEndothelial cells emerge from the atrioventricular canal (AVC) to form nascent coronary blood vessels in the juvenile zebrafish heart. We found that pdgfrβ is first expressed in the epicardium around the AVC and later becomes localized mainly in the mural cells. pdgfrβ mutant fish display severe defects in mural cell recruitment and coronary vessel development. pdgfrβ+ mural cells are heterogeneous and those associated with coronary arteries also express cxcl12b. Mural cells positive for both pdgfrβ and cxcl12b transgenic reporters had elevated expression of smooth muscle cell genes. Interestingly, these mural cells were associated with coronary arteries even in the absence of Pdgfrβ, although smooth muscle gene expression was downregulated in these cells. We found that pdgfrβ expression dynamically changes in the epicardium derived cells, which we found to be a heterogeneous population. mdka was identified as a gene upregulated in subpopulations of pdgfrβ+ cells during heart regeneration. However, pdgfrβ but not mdka mutants showed defects in heart regeneration. Our results demonstrated that pdgfrβ+ cells and Pdgfrβ signaling are essential for coronary development and heart regeneration.SUMMARY STATEMENTHeterogeneous pdgfrβ positive cells are present in developing and regenerating zebrafish hearts and are required for development of mural cells and their association with the nascent coronary vessels during zebrafish heart development and regeneration.

scholarly journals Mononuclear diploid cardiomyocytes support neonatal mouse heart regeneration in response to paracrine IGF2 signaling

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Hua Shen ◽  
Peiheng Gan ◽  
Kristy Wang ◽  
Ali Darehzereshki ◽  
Kai Wang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Insulin Receptor ◽  
Heart Development ◽  
Postnatal Period ◽  
Mouse Heart ◽  
Heart Regeneration ◽  
Newborn Mouse ◽  
Cell Cycle Entry ◽  
Additional Cell

Injury to the newborn mouse heart is efficiently regenerated, but this capacity is lost by one week after birth. We found that IGF2, an important mitogen in heart development, is required for neonatal heart regeneration. IGF2 originates from the endocardium/endothelium and is transduced in cardiomyocytes by the insulin receptor. Following injury on postnatal day 1, absence of IGF2 abolished injury-induced cell cycle entry during the early part of the first postnatal week. Consequently, regeneration failed despite the later presence of additional cell cycle-inducing activities 7 days following injury. Most cardiomyocytes transition from mononuclear diploid to polyploid during the first postnatal week. Regeneration was rescued in Igf2-deficient neonates in three different contexts that elevate the percentage of mononuclear diploid cardiomyocytes beyond postnatal day 7. Thus, IGF2 is a paracrine-acting mitogen for heart regeneration during the early postnatal period, and IGF2-deficiency unmasks the dependence of this process on proliferation-competent mononuclear diploid cardiomyocytes.

scholarly journals Midkine-a Regulates the Formation of a Fibrotic Scar During Zebrafish Heart Regeneration

2021 ◽  
Vol 9 ◽  
Author(s):  
Dimitrios Grivas ◽  
Álvaro González-Rajal ◽  
José Luis de la Pompa
Keyword(s):  
Critical Role ◽  
Cardiac Injury ◽  
Transcriptional Analysis ◽  
Endothelial Cell Proliferation ◽  
Heart Regeneration ◽  
Knock Out ◽  
Injured Area ◽  
Fibrotic Scar ◽  
Zebrafish Heart

Unlike the hearts of mammals, the adult zebrafish heart regenerates after injury. Heart cryoinjury in zebrafish triggers the formation of a fibrotic scar that gradually degrades, leading to regeneration. Midkine-a (Mdka) is a multifunctional cytokine that is activated after cardiac injury. Here, we investigated the role of mdka in zebrafish heart regeneration. We show that mdka expression was induced at 1-day post-cryoinjury (dpci) throughout the epicardial layer, whereas by 7 dpci expression had become restricted to the epicardial cells covering the injured area. To study the role of mdka in heart regeneration, we generated mdka-knock out (KO) zebrafish strains. Analysis of injured hearts showed that loss of mdka decreased endothelial cell proliferation and resulted in an arrest in heart regeneration characterized by retention of a collagenous scar. Transcriptional analysis revealed increases in collagen transcription and intense TGFβ signaling activity. These results reveal a critical role for mdka in fibrosis regulation during heart regeneration.

scholarly journals Microbiota Modulates Cardiac Transcriptional Responses to Intermittent Hypoxia and Hypercapnia

2021 ◽  
Vol 12 ◽  
Author(s):  
Dan Zhou ◽  
Jin Xue ◽  
Yukiko Miyamoto ◽  
Orit Poulsen ◽  
Lars Eckmann ◽  
...  
Keyword(s):  
Intermittent Hypoxia ◽  
Cardiovascular Response ◽  
Critical Role ◽  
Transcriptional Response ◽  
Mouse Heart ◽  
Transcriptional Responses ◽  
Germ Free ◽  
Cage System ◽  
Obstructive Sleep ◽  
The Impact

The microbiota plays a critical role in regulating organismal health and response to environmental stresses. Intermittent hypoxia and hypercapnia, a condition that represents the main hallmark of obstructive sleep apnea in humans, is known to induce significant alterations in the gut microbiome and metabolism, and promotes the progression of atherosclerosis in mouse models. To further understand the role of the microbiome in the cardiovascular response to intermittent hypoxia and hypercapnia, we developed a new rodent cage system that allows exposure of mice to controlled levels of O2 and CO2 under gnotobiotic conditions. Using this experimental setup, we determined the impact of the microbiome on the transcriptional response to intermittent hypoxia and hypercapnia in the left ventricle of the mouse heart. We identified significant changes in gene expression in both conventionally reared and germ-free mice. Following intermittent hypoxia and hypercapnia exposure, we detected 192 significant changes in conventionally reared mice (96 upregulated and 96 downregulated) and 161 significant changes (70 upregulated and 91 downregulated) in germ-free mice. Only 19 of these differentially expressed transcripts (∼10%) were common to conventionally reared and germ-free mice. Such distinct transcriptional responses imply that the host microbiota plays an important role in regulating the host transcriptional response to intermittent hypoxia and hypercapnia in the mouse heart.

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