Abstract 225: Coordinated Transcriptome and Cell State Dynamics of Non-myocytes in Heart Regeneration

2020 ◽  
Vol 127 (Suppl_1) ◽  
Author(s):  
Hong Ma ◽  
Ziqing Liu ◽  
Yuchen Yang ◽  
Dong Feng ◽  
Yanhan Dong ◽  
...  
Keyword(s):  
Cardiac Regeneration ◽  
Cell Types ◽  
Multiple Time ◽  
Heart Regeneration ◽  
Cardiomyocyte Proliferation ◽  
Cellular Functions ◽  
Molecular Features ◽  
Functional Dynamics ◽  
Cell Diversity ◽  
Multiple Time Points

Cardiac regeneration occurs primarily through proliferation of existing cardiomyocytes, yet the regenerative response also involves complex interactions between distinct cardiac cell types including not only cardiomyocytes, but also non-cardiomyocytes (nonCMs). However, the subpopulations, distinguishing molecular features, cellular functions, and intercellular interactions of nonCMs in heart regeneration remain largely unexplored. Using the LIGER algorithm, we assembled an atlas of cell states from 61,977 individual nonCM scRNA-seq profiles isolated at multiple time points during heart regeneration in both wildtype and mutant fish. This analysis revealed extensive nonCM cell diversity, including multiple macrophage, fibroblast and endothelial subpopulations with unique spatiotemporal distributions and cooperative interactions during the process of cardiac regeneration. Genetic and pharmacological perturbation of macrophage functional dynamics compromised interactions among nonCM subpopulations, reduced cardiomyocyte proliferation, and caused defective cardiac regeneration. Furthermore, we developed a computational algorithm called Topologizer to map the topological relationships and dynamics of nonCMs during heart regeneration. We uncovered dynamic transitions between macrophage functional states and identified factors involved in mRNA processing and transcriptional regulation associated with the transition. Together, our single-cell transcriptomic analysis of nonCMs during cardiac regeneration provides a blueprint for interrogating the molecular and cellular basis of cardiac regeneration.

scholarly journals Polyploid cardiomyocytes: implications for heart regeneration

Development ◽  
2021 ◽  
Vol 148 (14) ◽  
Author(s):  
Anna Kirillova ◽  
Lu Han ◽  
Honghai Liu ◽  
Bernhard Kühn
Keyword(s):  
Cellular Proliferation ◽  
Cardiac Regeneration ◽  
Cell Types ◽  
Heart Regeneration ◽  
Cardiomyocyte Proliferation ◽  
Form And Function ◽  
Differentiated Cells ◽  
New Findings ◽  
Polyploid Cells ◽  
And Function

ABSTRACT Terminally differentiated cells are generally thought to have arrived at their final form and function. Many terminally differentiated cell types are polyploid, i.e. they have multiple copies of the normally diploid genome. Mammalian heart muscle cells, termed cardiomyocytes, are one such example of polyploid cells. Terminally differentiated cardiomyocytes are bi- or multi-nucleated, or have polyploid nuclei. Recent mechanistic studies of polyploid cardiomyocytes indicate that they can limit cellular proliferation and, hence, heart regeneration. In this short Spotlight, we present the mechanisms generating bi- and multi-nucleated cardiomyocytes, and the mechanisms generating polyploid nuclei. Our aim is to develop hypotheses about how these mechanisms might relate to cardiomyocyte proliferation and cardiac regeneration. We also discuss how these new findings could be applied to advance cardiac regeneration research, and how they relate to studies of other polyploid cells, such as cancer cells.

scholarly journals Zebrafish cardiac regeneration—looking beyond cardiomyocytes to a complex microenvironment

2020 ◽  
Author(s):  
Rebecca Ryan ◽  
Bethany R. Moyse ◽  
Rebecca J. Richardson
Keyword(s):  
Cardiac Injury ◽  
Cell Communication ◽  
Cardiac Regeneration ◽  
Cell Types ◽  
Regenerative Process ◽  
Heart Regeneration ◽  
Cardiomyocyte Proliferation ◽  
Underlying Mechanisms ◽  
Different Cell Types

Abstract The study of heart repair post-myocardial infarction has historically focused on the importance of cardiomyocyte proliferation as the major factor limiting adult mammalian heart regeneration. However, there is mounting evidence that a narrow focus on this one cell type discounts the importance of a complex cascade of cell–cell communication involving a whole host of different cell types. A major difficulty in the study of heart regeneration is the rarity of this process in adult animals, meaning a mammalian template for how this can be achieved is lacking. Here, we review the adult zebrafish as an ideal and unique model in which to study the underlying mechanisms and cell types required to attain complete heart regeneration following cardiac injury. We provide an introduction to the role of the cardiac microenvironment in the complex regenerative process and discuss some of the key advances using this in vivo vertebrate model that have recently increased our understanding of the vital roles of multiple different cell types. Due to the sheer number of exciting studies describing new and unexpected roles for inflammatory cell populations in cardiac regeneration, this review will pay particular attention to these important microenvironment participants.

scholarly journals Mechanistic basis of neonatal heart regeneration revealed by transcriptome and histone modification profiling

2019 ◽  
Vol 116 (37) ◽  
pp. 18455-18465 ◽  
Author(s):  
Zhaoning Wang ◽  
Miao Cui ◽  
Akansha M. Shah ◽  
Wenduo Ye ◽  
Wei Tan ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Rna Binding ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Cardiac Regeneration ◽  
Later Life ◽  
Heart Regeneration ◽  
Cardiomyocyte Proliferation ◽  
Neonatal Heart ◽  
Short Period

The adult mammalian heart has limited capacity for regeneration following injury, whereas the neonatal heart can readily regenerate within a short period after birth. To uncover the molecular mechanisms underlying neonatal heart regeneration, we compared the transcriptomes and epigenomes of regenerative and nonregenerative mouse hearts over a 7-d time period following myocardial infarction injury. By integrating gene expression profiles with histone marks associated with active or repressed chromatin, we identified transcriptional programs underlying neonatal heart regeneration, and the blockade to regeneration in later life. Our results reveal a unique immune response in regenerative hearts and a retained embryonic cardiogenic gene program that is active during neonatal heart regeneration. Among the unique immune factors and embryonic genes associated with cardiac regeneration, we identified Ccl24, which encodes a cytokine, and Igf2bp3, which encodes an RNA-binding protein, as previously unrecognized regulators of cardiomyocyte proliferation. Our data provide insights into the molecular basis of neonatal heart regeneration and identify genes that can be modulated to promote heart regeneration.

Cardiomyocyte proliferation in cardiac development and regeneration: a guide to methodologies and interpretations

2015 ◽  
Vol 309 (8) ◽  
pp. H1237-H1250 ◽  
Author(s):  
Marina Leone ◽  
Ajit Magadum ◽  
Felix B. Engel
Keyword(s):  
Cardiac Function ◽  
Molecular Mechanisms ◽  
Cardiac Development ◽  
Cardiac Regeneration ◽  
Experimental Medicine ◽  
Heart Regeneration ◽  
Cardiomyocyte Proliferation ◽  
Naturally Occurring ◽  
Ability To Regenerate ◽  
Zebrafish Heart

The newt and the zebrafish have the ability to regenerate many of their tissues and organs including the heart. Thus, a major goal in experimental medicine is to elucidate the molecular mechanisms underlying the regenerative capacity of these species. A wide variety of experiments have demonstrated that naturally occurring heart regeneration relies on cardiomyocyte proliferation. Thus, major efforts have been invested to induce proliferation of mammalian cardiomyocytes in order to improve cardiac function after injury or to protect the heart from further functional deterioration. In this review, we describe and analyze methods currently used to evaluate cardiomyocyte proliferation. In addition, we summarize the literature on naturally occurring heart regeneration. Our analysis highlights that newt and zebrafish heart regeneration relies on factors that are also utilized in cardiomyocyte proliferation during mammalian fetal development. Most of these factors have, however, failed to induce adult mammalian cardiomyocyte proliferation. Finally, our analysis of mammalian neonatal heart regeneration indicates experiments that could resolve conflicting results in the literature, such as binucleation assays and clonal analysis. Collectively, cardiac regeneration based on cardiomyocyte proliferation is a promising approach for improving adult human cardiac function after injury, but it is important to elucidate the mechanisms arresting mammalian cardiomyocyte proliferation after birth and to utilize better assays to determine formation of new muscle mass.

scholarly journals Molecular regulation of myocardial proliferation and regeneration

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Lixia Zheng ◽  
Jianyong Du ◽  
Zihao Wang ◽  
Qinchao Zhou ◽  
Xiaojun Zhu ◽  
...  
Keyword(s):  
Recent Literature ◽  
Biological Process ◽  
Cardiac Regeneration ◽  
Molecular Regulation ◽  
Mouse Heart ◽  
Heart Regeneration ◽  
Cardiomyocyte Proliferation ◽  
Cellular Mechanisms ◽  
Concise Review ◽  
Complex Biological Process

AbstractHeart regeneration is a fascinating and complex biological process. Decades of intensive studies have revealed a sophisticated molecular network regulating cardiac regeneration in the zebrafish and neonatal mouse heart. Here, we review both the classical and recent literature on the molecular and cellular mechanisms underlying heart regeneration, with a particular focus on how injury triggers the cell-cycle re-entry of quiescent cardiomyocytes to replenish their massive loss after myocardial infarction or ventricular resection. We highlight several important signaling pathways for cardiomyocyte proliferation and propose a working model of how these injury-induced signals promote cardiomyocyte proliferation. Thus, this concise review provides up-to-date research progresses on heart regeneration for investigators in the field of regeneration biology.

scholarly journals Hormonal control of cardiac regenerative potential

2020 ◽  
Author(s):  
Alexander V. Amram ◽  
Stephen Cutie ◽  
Guo N. Huang
Keyword(s):  
Vitamin D ◽  
Thyroid Hormone ◽  
Thyroid Hormone Receptor ◽  
Cardiac Regeneration ◽  
Postnatal Period ◽  
Hormonal Control ◽  
Model Systems ◽  
Heart Regeneration ◽  
Cardiomyocyte Proliferation ◽  
Endocrine Signaling

Research conducted across phylogeny on cardiac regenerative responses following heart injury implicates endocrine signaling as a pivotal regulator of both cardiomyocyte proliferation and heart regeneration. Three prominently studied endocrine factors are thyroid hormone, vitamin D, and glucocorticoids, which canonically regulate gene expression through their respective nuclear receptors thyroid hormone receptor, vitamin D receptor, and glucocorticoid receptor. The main animal model systems of interest include humans, mice, and zebrafish, which vary in cardiac regenerative responses possibly due to the differential onsets and intensities of endocrine signaling levels throughout their embryonic to postnatal organismal development. Zebrafish and lower vertebrates tend to retain robust cardiac regenerative capacity into adulthood while mice and other higher vertebrates experience greatly diminished cardiac regenerative potential in their initial postnatal period that is sustained throughout adulthood. Here, we review recent progress in understanding how these three endocrine signaling pathways regulate cardiomyocyte proliferation and heart regeneration with a particular focus on the controversial findings that may arise from different assays, cellular-context, age, and species. Further investigating the role of each endocrine nuclear receptor in cardiac regeneration from an evolutionary perspective enables comparative studies between species in hopes of extrapolating the findings to novel therapies for human cardiovascular disease.

Advances in heart regeneration based on cardiomyocyte proliferation and regenerative potential of binucleated cardiomyocytes and polyploidization

2019 ◽  
Vol 133 (11) ◽  
pp. 1229-1253 ◽  
Author(s):  
Marina Leone ◽  
Felix B. Engel
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Relevant Literature ◽  
Cardiac Regeneration ◽  
Coronary Intervention ◽  
Cell Types ◽  
Proliferative Potential ◽  
Cardiomyocyte Proliferation ◽  
Post Injury ◽  
Great Achievement

Abstract One great achievement in medical practice is the reduction in acute mortality of myocardial infarction due to identifying risk factors, antiplatelet therapy, optimized hospitalization and acute percutaneous coronary intervention. Yet, the prevalence of heart failure is increasing presenting a major socio-economic burden. Thus, there is a great need for novel therapies that can reverse damage inflicted to the heart. In recent years, data have accumulated suggesting that induction of cardiomyocyte proliferation might be a future option for cardiac regeneration. Here, we review the relevant literature since September 2015 concluding that it remains a challenge to verify that a therapy induces indeed cardiomyocyte proliferation. Most importantly, it is unclear that the detected increase in cardiomyocyte cell cycle activity is required for an associated improved function. In addition, we review the literature regarding the evidence that binucleated and polyploid mononucleated cardiomyocytes can divide, and put this in context to other cell types. Our analysis shows that there is significant evidence that binucleated cardiomyocytes can divide. Yet, it remains elusive whether also polyploid mononucleated cardiomyocytes can divide, how efficient proliferation of binucleated cardiomyocytes can be induced, what mechanism regulates cell cycle progression in these cells, and what fate and physiological properties the daughter cells have. In summary, we propose to standardize and independently validate cardiac regeneration studies, encourage the field to study the proliferative potential of binucleated and polyploid mononucleated cardiomyocytes, and to determine whether induction of polyploidization can enhance cardiac function post-injury.

scholarly journals Polyploidy in Cardiomyocytes

2020 ◽  
Vol 126 (4) ◽  
pp. 552-565 ◽  
Author(s):  
Wouter Derks ◽  
Olaf Bergmann
Keyword(s):  
Cardiac Injury ◽  
Physiological Role ◽  
Cell Types ◽  
Cell Number ◽  
The Body ◽  
Cardiomyocyte Hypertrophy ◽  
Heart Regeneration ◽  
Cardiomyocyte Proliferation ◽  
Hypertrophic Growth

The hallmark of most cardiac diseases is the progressive loss of cardiomyocytes. In the perinatal period, cardiomyocytes still proliferate, and the heart shows the capacity to regenerate upon injury. In the adult heart, however, the actual rate of cardiomyocyte renewal is too low to efficiently counteract substantial cell loss caused by cardiac injury. In mammals, cardiac growth by cell number expansion changes to growth by cardiomyocyte enlargement soon after birth, coinciding with a period in which most cardiomyocytes increase their DNA content by multinucleation and nuclear polyploidization. Although cardiomyocyte hypertrophy is often associated with these processes, whether polyploidy is a prerequisite or a consequence of hypertrophic growth is unclear. Both the benefits of cardiomyocyte enlargement over proliferative growth of the heart and the physiological role of polyploidy in cardiomyocytes are enigmatic. Interestingly, hearts in animal species with substantial cardiac regenerative capacity dominantly comprise diploid cardiomyocytes, raising the hypothesis that cardiomyocyte polyploidy poses a barrier for cardiomyocyte proliferation and subsequent heart regeneration. On the contrary, there is also evidence for self-duplication of multinucleated myocytes, suggesting a more complex picture of polyploidy in heart regeneration. Polyploidy is not restricted to the heart but also occurs in other cell types in the body. In this review, we explore the biological relevance of polyploidy in different species and tissues to acquire insight into its specific role in cardiomyocytes. Furthermore, we speculate about the physiological role of polyploidy in cardiomyocytes and how this might relate to renewal and regeneration.

scholarly journals Heart regeneration: beyond new muscle and vessels

2021 ◽  
Author(s):  
Judy R Sayers ◽  
Paul R Riley
Keyword(s):  
Heart Development ◽  
Cell Function ◽  
Cell Types ◽  
Heart Regeneration ◽  
Cardiomyocyte Proliferation ◽  
Cardiovascular Tissue ◽  
Function Calls ◽  
Heart Muscle Cells ◽  
System Cell ◽  
Heart Injury

Abstract The most striking consequence of a heart attack is the loss of billions of heart muscle cells, alongside damage to the associated vasculature. The lost cardiovascular tissue is replaced by scar formation, which is non-functional and results in pathological remodelling of the heart and ultimately heart failure. It is, therefore, unsurprising that the heart regeneration field has centred efforts to generate new muscle and blood vessels through targeting cardiomyocyte proliferation and angiogenesis following injury. However, combined insights from embryological studies and regenerative models, alongside the adoption of -omics technology, highlight the extensive heterogeneity of cell types within the forming or re-forming heart and the significant crosstalk arising from non-muscle and non-vessel cells. In this review, we focus on the roles of fibroblasts, immune, conduction system, and nervous system cell populations during heart development and we consider the latest evidence supporting a function for these diverse lineages in contributing to regeneration following heart injury. We suggest that the emerging picture of neurologically, immunologically, and electrically coupled cell function calls for a wider-ranging combinatorial approach to heart regeneration.

scholarly journals Ephrin-B1 blocks adult cardiomyocyte proliferation and heart regeneration

2019 ◽  
Author(s):  
Marie Cauquil ◽  
Céline Mias ◽  
Céline Guilbeau-Frugier ◽  
Clément Karsenty ◽  
Marie-Hélène Seguelas ◽  
...  
Keyword(s):  
Resting State ◽  
Cardiac Tissue ◽  
Hippo Pathway ◽  
Cardiac Regeneration ◽  
Mouse Heart ◽  
Heart Regeneration ◽  
Cardiomyocyte Proliferation ◽  
Postnatal Maturation

AbstractAimsDeciphering the innate mechanisms governing the blockade of proliferation in adult cardiomyocytes (CMs) is challenging for mammalian heart regeneration. Despite the exit of CMs from the cell cycle during the postnatal maturation period coincides with their morphological switch to a typical adult rod-shape, whether these two processes are connected is unknown. Here, we examined the role of ephrin-B1, a CM rod-shape stabilizer, in adult CM proliferation and cardiac regeneration.Methods and resultsTransgenic- or AAV9-based ephrin-B1 repression in adult mouse heart led to substantial proliferation of resident CMs and tissue regeneration to compensate for apex resection, myocardial infarction (MI) and senescence. Interestingly, in the resting state, CMs lacking ephrin-B1 did not constitutively proliferate, indicative of no major cardiac defects. However, they exhibited proliferation-competent signature, as indicated by higher mononucleated state and a dramatic decrease of miR-195 mitotic blocker, which can be mobilized under neuregulin-1 stimulation in vitro and in vivo. Mechanistically, the post-mitotic state of the adult CM relies on ephrin-B1 sequestering of inactive phospho-Yap1, the effector of the Hippo-pathway, at the lateral membrane. Hence, ephrin-B1 repression leads to phospho-Yap1 release in the cytosol but CM quiescence at resting state. Upon cardiac stresses (apectomy, MI, senescence), Yap1 could be activated and translocated to the nucleus to induce proliferation-gene expression and consequent CM proliferationConclusionsOur results identified ephrin-B1 as a new natural locker of adult CM proliferation and emphasize that targeting ephrin-B1 may prove a future promising approach in cardiac regenerative medicine for HF treatment.SignificanceThe mammalian adult heart is unable to regenerate due to the inability of cardiomyocytes (CMs) to proliferate and replace cardiac tissue lost. Exploiting CM-specific transgenic mice or AAV9-based gene therapy, this works identifies ephrin-B1, a specific rod-shape stabilizer of the adult CM, as a natural padlock of adult CM proliferation for compensatory adaptation to different cardiac stresses (apectomy, MI, senescence), thus emphasizing a new link between the adult CM morphology and their proliferation potential. Moreover, the study demonstrates proof-of-concept that targeting ephrin-B1 may be an innovative therapeutic approach for ischemic heart failure.

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