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.

T3 receptor occupancy and T3 levels in plasma and cytosol during rat brain development

1990 ◽  
Vol 123 (1) ◽  
pp. 95-99 ◽  
Author(s):  
Beatriz Ferreiro ◽  
Rosa Pastor ◽  
Juan Bernal
Keyword(s):  
Thyroid Hormone ◽  
Rat Brain ◽  
Binding Sites ◽  
Thyroid Hormone Receptor ◽  
Receptor Occupancy ◽  
Postnatal Period ◽  
Brain Maturation ◽  
Oligodendrocyte Differentiation ◽  
Nuclear Extracts ◽  
Myelin Gene

Abstract. The concentration and occupancy of the thyroid hormone receptor have been measured in rat brain nuclear extracts at the end of the fetal period and during the postnatal period. Receptor occupancy attained maximal values at postnatal day 15 (52% of total receptor binding sites occupied by T3) and correlated with plasma and cytosol total and free T3. The values for these parameters showed greater differences throughout development than did receptor occupancy. From gestational day 21 to postnatal day 15, total T3 increased in plasma from 0.18 to 1 nmol/l and in cytosol from 1 to 7.5 pmol/l. Free T3 increased in plasma from 1.2 to 6 pmol/l and in cytosol from 8 to 59 pmol/l. Nuclear free T3, calculated on the basis of receptor occupancy, and Kd increased in parallel, from 39.8 to 107 pmol/l at the same ages. Values for nuclear free T3 were between 2 and 5 times those in cytosol and between 10 and 40 times those in plasma, suggesting the presence of a small free T3 gradient from plasma to the nucleus. All of the above changes take place during the critical period of oligodendrocyte differentiation and the start of myelin gene expression, suggesting that thyroid hormone influences these important events of brain maturation.

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 Vitamin D receptor-mediated control of Soggy, Wise, and Hairless gene expression in keratinocytes

2013 ◽  
Vol 220 (2) ◽  
pp. 165-178 ◽  
Author(s):  
Jui-Cheng Hsieh ◽  
Rudolf C Estess ◽  
Ichiro Kaneko ◽  
G Kerr Whitfield ◽  
Peter W Jurutka ◽  
...  
Keyword(s):  
Vitamin D ◽  
Thyroid Hormone ◽  
Vitamin D Receptor ◽  
Transcriptional Activation ◽  
Thyroid Hormone Receptor ◽  
Hair Cycle ◽  
Primary Human Keratinocytes ◽  
Hairless Gene ◽  
Responsive Element ◽  
Mammalian Hair

The vitamin D receptor (VDR), but not its hormonal ligand, 1,25-dihydroxyvitamin D3 (1,25D), is required for the progression of the mammalian hair cycle. We studied three genes relevant to hair cycle signaling, DKKL1 (Soggy), SOSTDC1 (Wise), and HR (Hairless), to determine whether their expression is regulated by VDR and/or its 1,25D ligand. DKKL1 mRNA was repressed 49–72% by 1,25D in primary human and CCD-1106 KERTr keratinocytes; a functional vitamin D responsive element (VDRE) was identified at −9590 bp in murine Soggy. Similarly, SOSTDC1 mRNA was repressed 41–59% by 1,25D in KERTr and primary human keratinocytes; a functional VDRE was located at −6215 bp in human Wise. In contrast, HR mRNA was upregulated 1.56- to 2.77-fold by 1,25D in primary human and KERTr keratinocytes; a VDRE (TGGTGAgtgAGGACA) consisting of an imperfect direct repeat separated by three nucleotides (DR3) was identified at −7269 bp in the human Hairless gene that mediated dramatic induction, even in the absence of 1,25D ligand. In parallel, a DR4 thyroid hormone responsive element, TGGTGAggccAGGACA, was identified at +1304 bp in the human HR gene that conferred tri-iodothyronine (T3)-independent transcriptional activation. Because the thyroid hormone receptor controls HR expression in the CNS, whereas VDR functions in concert with the HR corepressor specifically in skin, a model is proposed wherein unliganded VDR upregulates the expression of HR, the gene product of which acts as a downstream comodulator to feedback-repress DKKL1 and SOSTDC1, resulting in integration of bone morphogenic protein and Wnt signaling to drive the mammalian hair cycle and/or influencing epidermal function.

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 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.

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.

Abstract 17364: G-protein Signaling Regulation of the Hippo Pathway in Neonatal Heart Regeneration

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Masahide Sakabe ◽  
Aishlin Hassan ◽  
Mei Xin
Keyword(s):  
G Protein ◽  
Molecular Mechanisms ◽  
Hippo Pathway ◽  
Cardiac Injury ◽  
Cardiac Regeneration ◽  
Heart Regeneration ◽  
Cardiomyocyte Proliferation ◽  
Adult Age ◽  
Rhoa Activity ◽  
Β Blocker

Introduction: The regeneration potential in the adult mammalian heart is very limited due to the cessation of cardiomyocyte proliferation shortly after birth. Recent studies have revealed that changes after birth such as metabolic state, oxygen level, cardiomyocyte structure and maturity, immune system and polyploidy are among the factors contributing to the loss of the regenerative potential in the heart. The mechanisms that regulate the cardiac regenerative window are not well understood. Here we report that G-protein mediated signaling regulates Hippo-YAP in neonatal cardiomyocyte proliferation and heart regeneration through Rho activity. Hypothesis: Gas encoded by the Gnas gene, a downstream effector of beta-adrenergic receptor (βAR) inhibits cardiomyocyte proliferation via regulation of YAP activity. Methods: We pharmacologically inhibited the G protein coupled receptor mediated β adrenergic signaling with a β-blocker (metoprolol) at early postnatal stages, and genetically by deleting Gnas in the heart with αMHC-Cre. We accessed the cardiomyocyte proliferation, heart regeneration in these mice and elucidated molecular mechanisms. Results: We found that β-blocker enhanced cardiomyocyte proliferation and promoted cardiac regeneration post cardiac injury with improved cardiac function. Consistent with β-blocker treated mice, mice lacking Gnas in cardiomyocytes exhibited enlarged hearts with an increase in cardiomyocyte proliferation. RNA-seq analysis revealed that these cardiomyocytes maintained an immature status even at young-adult age. The genes associated with mitochondrial oxidative metabolism, the major energy source for mature cardiomyocytes, were downregulated. Moreover, YAP activity was upregulated in both cases. We also found that loss of Gαs function caused upregulation of RhoA activity, and inhibitor of Rho signaling pathway suppressed the YAP activity in cardiomyocytes. Conclusions: Our study reveals that Gαs negatively regulate cardiomyocyte proliferation and provides mechanistic insight for β-blocker treatment as a strategy for inducing cardiac dedifferentiation and proliferation in injured heart.

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