AP-1 Regulates Chromatin Accessibility to Promote Sarcomere Disassembly and Cardiomyocyte Protrusion during Zebrafish Heart Regeneration
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ABSTRACT:
PROVIDER: PRJNA542058 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR9032270_1.fastq.gz | Fastqsanger.gz | |||
| SRR9032270_2.fastq.gz | Fastqsanger.gz | |||
| SRR9032280.fastq.gz | Fastqsanger.gz | |||
| SRR9032280_1.fastq.gz | Fastqsanger.gz | |||
| SRR9032280_2.fastq.gz | Fastqsanger.gz |
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Project description:The zebrafish has emerged as a powerful model to study cardiac regeneration; however, the mechanisms by which cardiomyocytes respond to damage by disassembling sarcomeres, proliferating, and repopulating the injured area remain unclear. Here, we show that AP-1 transcription factors play an essential role in regulating the cardiomyocyte response. Using ATAC-Seq, we first find that the cardiomyocyte chromatin accessibility landscape is dynamic following cryoinjury, and that AP-1 motifs are the most highly enriched in regions that gain accessibility during regeneration. Using a cardiomyocyte-specific dominant-negative approach, we show that AP-1 promotes cardiomyocyte proliferation as well as chromatin accessibility at genes regulating sarcomere disassembly and cardiomyocyte protrusion into the injured area. We further find distinct temporal requirements for AP-1 during cardiac regeneration. Altogether, these results indicate that AP-1 plays a key role in the cardiomyocyte response to injury by promoting chromatin accessibility changes, allowing the activation of gene expression programs that support regeneration.
2020-06-10 | GSE130940 | GEO
Project description:RationaleThe adult human heart is an organ with low regenerative potential. Heart failure following acute myocardial infarction is a leading cause of death due to the inability of cardiomyocytes to proliferate and replenish lost cardiac muscle. While the zebrafish has emerged as a powerful model to study endogenous cardiac regeneration, the molecular mechanisms by which cardiomyocytes respond to damage by disassembling sarcomeres, proliferating, and repopulating the injured area remain unclear. Furthermore, we are far from understanding the regulation of the chromatin landscape and epigenetic barriers that must be overcome for cardiac regeneration to occur.ObjectiveTo identify transcription factor regulators of the chromatin landscape, which promote cardiomyocyte regeneration in zebrafish, and investigate their function.Methods and resultsUsing the Assay for Transposase-Accessible Chromatin coupled to high-throughput sequencing (ATAC-Seq), we first find that the regenerating cardiomyocyte chromatin accessibility landscape undergoes extensive changes following cryoinjury, and that activator protein-1 (AP-1) binding sites are the most highly enriched motifs in regions that gain accessibility during cardiac regeneration. Furthermore, using bioinformatic and gene expression analyses, we find that the AP-1 response in regenerating adult zebrafish cardiomyocytes is largely different from the response in adult mammalian cardiomyocytes. Using a cardiomyocyte-specific dominant negative approach, we show that blocking AP-1 function leads to defects in cardiomyocyte proliferation as well as decreased chromatin accessibility at the fbxl22 and ilk loci, which regulate sarcomere disassembly and cardiomyocyte protrusion into the injured area, respectively. We further show that overexpression of the AP-1 family members Junb and Fosl1 can promote changes in mammalian cardiomyocyte behavior in vitro.ConclusionsAP-1 transcription factors play an essential role in the cardiomyocyte response to injury by regulating chromatin accessibility changes, thereby allowing the activation of gene expression programs that promote cardiomyocyte dedifferentiation, proliferation, and protrusion into the injured area.
| S-EPMC7274905 | biostudies-literature
Project description:Mammalian cardiomyocytes rapidly mature after birth, with hallmarks such as cell-cycle exit, binucleation, and metabolic switch to oxidative phosphorylation of lipids. The causes and transcriptional programs regulating cardiomyocyte maturation are not fully understood yet. Thus, we performed single cell RNA-seq of neonatal and postnatal day 7 rat hearts to identify the key factors for this process and found AP-1 as a key factor to regulate cardiomyocyte maturation. To find the mechanism of AP-1 during cardiomyocyte maturation, we performed RNA-seq analysis of neonatal rat ventricular cardiomyocytes and found Ap-1 promote cardiomyocyte maturation by regulating cardiomyocyte metabolism.
2021-12-01 | GSE182422 | GEO
Project description:AP-1 activation mediates postnatal cardiomyocyte maturation
| PRJNA756241 | ENA
Project description:Loss of myocardial mass in a neonatal rat cardiomyocyte culture is studied to determine whether there is a distinguishable cellular response based on the origin of mechano-signals. The approach herein compares the sarcomeric assembly and disassembly processes in heart cells by imposing mechano-signals at the interface with the extracellular matrix (extrinsic) and at the level of the myofilaments (intrinsic). Experiments compared the effects of imposed internal (inside/out) and external (outside/in) loading and unloading on modifications in neonatal rat cardiomyocytes. Unloading of the cellular substrate by myosin inhibition (1uM mavacamten), or cessation of cyclic strain (1 Hz, 10% strain) after preconditioning, led to significant disassembly of sarcomeric alpha-actinin by 6 hrs. In myosin inhibition, this was accompanied by redistribution of intracellular poly-ubiquitin K48 to the cellular periphery relative to the poly-ubiquitin K48 reservoir at the I-band. Moreover, loading and unloading of the cellular substrate led to a three-fold increase in post translational modifications (PTMs) when compared to the myosin-specific activation or inhibition. Specifically, phosphorylation increased with loading while ubiquitination increased with unloading, which may involve ERK1/2 and FAK activation. The identified PTMs, including ubiquitination, acetylation, and phosphorylation, are proposed to modify internal domains in alpha-actinin to increase its propensity to bind F-actin. These results demonstrate a link between mechanical feedback and sarcomere protein homeostasis via PTMs of alpha-actinin that exemplify how cardiomyocytes exhibit differential responses to the origin of force. The implications of sarcomere regulation governed by PTMs of alpha-actinin are discussed with respect to cardiac atrophy and heart failure.
2023-01-05 | MSV000091010 | MassIVE
Project description:The sarcomere is the muscle contractile unit, whose assembly and disassembly are intimately linked to changes in myofiber size and function. Mutations in sarcomeric proteins are common causes of myopathies, ranging from severe neonatal to adult-onset forms. Here, we identify HECTD1 as an E3 ubiquitin ligase necessary for sarcomere maintenance. We show that silencingHectd1 in myotubesreduces the levels of proteins critical for sarcomere integrity including a-actin, titin, troponins, tropomyosins, and several myosin heavy chain isoforms. We further establish that Hectd1 ubiquitylates and stabilizes the molecular chaperones KLHL40/41, that when dysfunctional destabilize nebulin and other sarcomere thin filament proteins (causing nemaline myopathy). Consequently, skeletal muscle-specific Hectd1 knockout mice (Hectd1 mKO) show progressive muscle weakness, exercise intolerance, and unresolved tissue remodeling. Molecular and histological analysis of Hectd1 mKO muscle revealed subsarcolemmal storage of the scaffold protein desmin, mitochondrial abnormalities, and severe sarcomere disorganization. This work uncovers Hectd1 as an E3 ligase critical for sarcomere assembly, and a novel diagnostic gene for myopathy with features of nemaline and desmin myopathy.
2024-07-26 | GSE272775 | GEO
Project description:Background: Negative-pressure wound therapy has become widely available in modern chronic wound cares. Accelerated keratinocyte (HaCaT cell) movements and decreased E-cadherin expressions induced by the applied negative pressure gradient of 125 mmHg (NP) have been reported in previous studies. However, the molecular mechanism for E-cadherin regulations under NP remains unexplored. We highlighted the signal transduction involved in NP-induced E-cadherin regulation for keratinocytes in the study. Results: Microarray results showed that catenin 1 (CTNND1) gene, the gene encoding the p120-catenin (p120ctn) in cell-cell junctions, was significantly (p = 0.0005) upregulated in HaCaT cells under NP for 12 hours in comparison with those at ambient pressure (AP). Cell fractionations and immunoblotting data showed that NP increased p120ctn phosphorylation, and resulted in p120ctn translocation from the plasma membrane to the cytoplasm. Fluorescent stains suggested that NP diminished the co-localization of p120ctn and E-cadherin on the plasma membrane. Similar phenomenon was also observed in the cells with overexpressed p120ctn at NP. Interestingly, overexpression of dN- p120ctn, a deletion mutant of p120ctn without the N-terminal phosphorylation sites, restored the adherens junctions (AJ) at NP. Knockdown of p120ctn with lentiviral small hairpin RNA not only diminished E-cadherin expressions but also accelerated cell movement at AP. Conclusions: Phosphorylation of p120ctn is endowed to respond rapidly to NP and contributes to the AJ disassembly. This NP-induced E-cadherin downregulation can possibly accelerate wound-healing process. Conclusions: Phosphorylation of p120ctn is endowed to respond rapidly to NP and contributes to the AJ disassembly. This NP-induced E-cadherin downregulation can possibly accelerate wound-healing process. HaCaT cells under negative pressure (NP) gradient of 125 mmHg for 12 hours in comparison with those at ambient pressure (AP) were tested for RNA extraction and hybridization on Affymetrix microarrays. The experiments have been biological replicated three times. The differential expression gene between NP and AP were selected and validated with qPCR method.
2015-12-31 | E-GEOD-70512 | biostudies-arrayexpress
Project description:Although mammals are thought to lose their capacity to regenerate heart muscle shortly after birth, embryonic and neonatal cardiomyocytes in mammals are hyperplastic. During proliferation these cells need to selectively disassemble their myofibrils for successful cytokinesis. The mechanism of sarcomere disassembly is, however, not understood. To study this, we performed a series of immunofluorescence studies of multiple sarcomeric proteins in proliferating neonatal rat ventricular myocytes and correlated these observations with biochemical changes at different cell cycle stages. During myocyte mitosis, α-actinin and titin were disassembled as early as prometaphase. α-actinin (representing the sarcomeric Z-disk) disassembly precedes that of titin (M-line), suggesting that titin disassembly occurs secondary to the collapse of the Z-disk. Sarcomere disassembly was concurrent with the dissolution of the nuclear envelope. Inhibitors of several intracellular proteases could not block the disassembly of α-actinin or titin. There was a dramatic increase in both cytosolic (soluble) and sarcomeric α-actinin during mitosis, and cytosolic α-actinin exhibited decreased phosphorylation compared to sarcomeric α-actinin. Inhibition of cyclin-dependent kinase 1 (CDK1) induced the quick reassembly of the sarcomere. Sarcomere dis- and re-assembly in cardiomyocyte mitosis is CDK1-dependent and features dynamic differential post-translational modifications of sarcomeric and cytosolic α-actinin.
| S-EPMC4467976 | biostudies-literature
Project description:Cardiac development relies on proper cardiomyocyte differentiation including expression and assembly of cell-type specific actomyosin subunits into a functional cardiac sarcomere. Control of this process involves not only promoting expression of cardiac sarcomere subunits but also repressing expression of non-cardiac myofibril paralogs. This level of transcriptional control requires broadly expressed multiprotein machines that modify and remodel the chromatin landscape to restrict transcription machinery access. Prominent among these is the Nucleosome Remodeling and Deacetylase (NuRD) complex, which includes the catalytic core subunit CHD4. Here, we demonstrate that direct CHD4-mediated repression of skeletal and smooth muscle myofibril isoforms is required for normal cardiac sarcomere formation, function, and embryonic survival early in gestation. Through transcriptomic and system genome-wide analyses of CHD4 localization, we identified novel CHD4 binding sites in smooth muscle myosin heavy chain, fast skeletal α-actin, and the fast skeletal troponin complex genes. We further demonstrate that in the absence of CHD4, cardiomyocytes in the developing heart form a hybrid muscle cell that contains cardiac, skeletal and smooth muscle myofibril components. These misexpressed paralogs intercalate into the nascent cardiac sarcomere to disrupt sarcomere formation and cause impaired cardiac function in utero. These results demonstrate the genomic and physiological requirements for CHD4 in mammalian cardiac development.
2018-05-15 | GSE109012 | GEO
Project description:Systemic hypertension increases cardiac workload and subsequently induces signaling networks in heart that underlie myocyte growth (hypertrophic response) through expansion of sarcomeres with the aim to increase contractility. However, conditions of increased workload can induce both adaptive and maladaptive growth of heart muscle. Previous studies implicate two members of the AP-1 transcription factor family, junD and fra-1, in regulation of heart growth during hypertrophic response. In this study, we investigate the function of the AP-1 transcription factors, c-jun and c-fos, in heart growth. Using pressure overload-induced cardiac hypertrophy in mice and targeted deletion of Jun or Fos in cardiomyocytes, we show that c-jun is required for adaptive cardiac hyphertrophy, while c-fos is dispensable in this context. c-jun promotes expression of sarcomere proteins and suppresses expression of extracellular matrix proteins. Capacity of cardiac muscle to contract depends on organization of principal thick and thin filaments, myosin and actin, within the sarcomere. In line with decreased expression of sarcomere-associated proteins, Jun-deficient cardiomyocytes present disarrangement of filaments in sarcomeres and actin cytoskeleton disorganization. Moreover, Jun-deficient hearts subjected to pressure overload display pronounced fibrosis and increased myocyte apoptosis finally resulting in dilated cardiomyopathy. In conclusion, c-jun but not c-fos is required to induce a transcriptional program aimed at adapting heart growth upon increased workload. Microarrays were used to identify specific genes that might be globally affected in the absence of c-jun in cardiomyocytes. Total RNA was extracted from the hearts of 10 weeks old Junf/f (n=2) and Jun delta mu (n=2) mice using TRIzol Reagent.
2013-09-19 | E-GEOD-47898 | biostudies-arrayexpress