Gene expression of cardiac fibroblasts post-MI
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE111059 | GEO | 2018/02/24
REPOSITORIES: GEO
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Project description:In response to myocardial infarction (MI), quiescent cardiac fibroblasts differentiate into myofibroblasts mediating tissue repair in the infarcted area. One of the most widely accepted markers of myofibroblast differentiation is the expression of Acta2 which encodes smooth muscle alpha-actin (SMαA) that is assembled into stress fibers. However, the requirement of Acta2/ SMαA in the myofibroblast differentiation of cardiac fibroblasts and its role in post-MI cardiac repair remained largely unknown. To answer these questions, we generated a tamoxifen-inducible cardiac fibroblast-specific Acta2 knockout mouse line. Surprisingly, mice that lacked Acta2 in cardiac fibroblasts had a normal survival rate after MI. Moreover, Acta2 deletion did not affect the function or overall histology of infarcted hearts. No difference was detected in the proliferation, migration, or contractility between WT and Acta2-null cardiac myofibroblasts. It was identified that Acta2-null cardiac myofibroblasts had a normal total filamentous actin level and total actin level. Acta2 deletion caused a significant compensatory increase in the transcription level of non- Acta2 actin isoforms, especially Actg2 and Acta1, 2 other muscle actin isoforms. Moreover, in myofibroblasts the transcription levels of cytoplasmic actin isoforms were significantly higher than those of muscle actin isoforms. In addition, we found that myocardin-related transcription factor-A is critical for myofibroblast differentiation but is not required for the compensatory effects of non-Acta2 isoforms. In conclusion, the deletion of Acta2 does not prevent the myofibroblast differentiation of cardiac fibroblasts or affect the post-MI cardiac repair, and the increased expression and stress fiber formation of non-SMαA actin isoforms and the functional redundancy between actin isoforms are able to compensate for the loss of Acta2 in cardiac myofibroblasts.
2022-01-10 | GSE193163 | GEO
Project description:Repair of the infarcted heart requires TGFβ-Smad3 signaling in cardiac myofibroblasts. However, TGF-β-driven myofibroblast activation needs to be tightly regulated in order to prevent excessive fibrosis and adverse remodeling that may precipitate heart failure. We hypothesized that induction of the inhibitory Smad, Smad7 may restrain infarct myofibroblast activation, and we examined the molecular mechanisms of Smad7 actions. In a mouse model of non-reperfused infarction, Smad3 activation triggered Smad7 synthesis in β-SMA+ infarct myofibroblasts, but not in β-SMA-/PDGFRα+ fibroblasts. Myofibroblast-specific Smad7 loss increased heart failure-related mortality, worsened dysfunction, and accentuated fibrosis in the infarct border zone and in the papillary muscles. Smad7 attenuated myofibroblast activation and reduced synthesis of structural and matricellular extracellular matrix proteins. Smad7 actions on TGF-β cascades involved de-activation of Smad2/3 and non-Smad pathways, without any effects on TGF-β receptor activity. Unbiased transcriptomic and proteomic analysis identified receptor tyrosine kinase signaling as a major target of Smad7. Smad7 interacted with Erbb2 in a TGF-independent manner and restrained Erbb1/Erbb2 activation, suppressing fibroblast expression of fibrogenic proteases, integrins and CD44. Smad7 induction in myofibroblasts serves as an endogenous TGF-β-induced negative feedback mechanism that inhibits post-infarction fibrosis by restraining Smad-dependent and Smad-independent TGF-β responses, and by suppressing TGF-independent fibrogenic actions of Erbb2.
2021-11-11 | GSE185767 | GEO
Project description:In this study, we used a cardiac-specific, inducible expression system to activate YAP in adult mouse heart. Activation of YAP in adult heart promoted cardiomyocyte proliferation and did not deleteriously affect heart function. Furthermore, YAP activation after myocardial infarction (MI) preserved heart function and reduced infarct size. Using adeno-associated virus subtype 9 (AAV9) as a delivery vector, we expressed human YAP in the murine myocardium immediately after MI. We found that AAV9:hYAP significantly improved cardiac function and mouse survival. AAV9:hYAP did not exert its salutary effects by reducing cardiomyocyte apoptosis. Rather, we found that AAV9:hYAP stimulated adult cardiomyocyte proliferation. Gene expression profiling indicated that AAV9:hYAP stimulated cell cycle gene expression, enhanced TGFβ-signaling, and activated of components of the inflammatory response.Cardiac specific YAP activation after MI mitigated myocardial injury after MI, improved cardiac function and mouse survival. These findings suggest that therapeutic activation of hYAP or its downstream targets, potentially through AAV-mediated gene therapy, may be a strategy to improve outcome after MI. Three groups were involved in this study: sham group, AAV9:Luci+MI group and AAV9-YAP+MI group. Each group contained three biological replicates. The sham group had neither myocardial infarction nor AAV injection. The AAV9:Luci +MI(L for brief) group had myocardial infarction and injected with AAV9:Luic. The AAV9:hYAP+MI(YAP for brief) group had myocardial infarction and injected with AAV9:hYAP. 5 days after MI and AAV injection, the heart apexes were collected and the total RNA were isolated for microarray analysis.
2014-05-26 | E-GEOD-54612 | biostudies-arrayexpress
Project description:To assess the pathophysiological of genetic depletion of Yap and Wwtr1 in myofibroblasts following myocardial infarction, we utilized a Cre-lox system whereby the inducible Periostin promoter is leveraged to deplete both Yap and Wwtr1 from myofibroblasts in mice. Following myocardial infarction, myofibroblast depletion of both Yap and Wwtr1 significantly improves cardiac function after injury as compared to injured controls. Here, we have performed single cell RNA sequencing of interstitial cardiac cells 7 days post myocardial infarction to assess differentially express genes within cardiac fibroblasts and immune cell populations.
2023-02-27 | GSE204712 | GEO
Project description:Objectives: To investigate the role of ALKBH5 in fibroblasts during post-myocardial infarction (MI) repair. Background: N6-methyladenosine (m6A) mRNA modification has been shown to play an important role in cardiovascular diseases. The RNA demethylase, AlkB homolog 5 (ALKBH5), is an m6A "eraser" that is responsible for decreased m6A methylation. However, its role in cardiac fibroblasts during the post-MI healing process remains elusive. Methods: MI was mimicked by permanent left anterior descending artery ligation in global ALKBH5-knockout, ALKBH5-knockin, and fibroblast-specific ALKBH5-knockout mice to study the function of ALKBH5 during post-MI collagen repair. Methylated RNA immunoprecipitation sequencing was performed to explore potential ALKBH5 targets. Results: Dramatic alterations in ALKBH5 expression were observed during the early stage post-MI and in hypoxic fibroblasts. Global ALKBH5 knockin reduced infarct size and improved cardiac function after MI. The global and fibroblast-specific ALKBH5-knockout mice both exhibited low survival rates along with poor collagen repair, impaired cardiac function, and cardiac rupture. Both in vivo and in vitro ALKBH5 loss led to impaired fibroblast activation and decreased collagen deposition. Additionally, hypoxia, but not TGF-β1 or Ang II, upregulated ALKBH5 expression in myofibroblasts in a HIF-1α-dependent transcriptional manner. Mechanistically, ALKBH5 promoted the stability of ErbB4 mRNA and the degradation of ST14 mRNA via m6A demethylation. Fibroblast-specific ErbB4 overexpression ameliorated the impaired fibroblast-to-myofibroblast transformation and poor post-MI repair due to ALKBH5 knockout. Conclusions: Fibroblast ALKBH5 positively regulates post-MI healing via post-transcriptional modification and stabilization of ErbB4 mRNA in an m6A-dependent manner. Targeting ALKBH5/ERBB4 may be a potential therapeutic option for post-MI cardiac rupture.
2023-10-01 | GSE226415 | GEO
Project description:In this study, we used a cardiac-specific, inducible expression system to activate YAP in adult mouse heart. Activation of YAP in adult heart promoted cardiomyocyte proliferation and did not deleteriously affect heart function. Furthermore, YAP activation after myocardial infarction (MI) preserved heart function and reduced infarct size. Using adeno-associated virus subtype 9 (AAV9) as a delivery vector, we expressed human YAP in the murine myocardium immediately after MI. We found that AAV9:hYAP significantly improved cardiac function and mouse survival. AAV9:hYAP did not exert its salutary effects by reducing cardiomyocyte apoptosis. Rather, we found that AAV9:hYAP stimulated adult cardiomyocyte proliferation. Gene expression profiling indicated that AAV9:hYAP stimulated cell cycle gene expression, enhanced TGFβ-signaling, and activated of components of the inflammatory response.Cardiac specific YAP activation after MI mitigated myocardial injury after MI, improved cardiac function and mouse survival. These findings suggest that therapeutic activation of hYAP or its downstream targets, potentially through AAV-mediated gene therapy, may be a strategy to improve outcome after MI.
2014-05-26 | GSE54612 | GEO
Project description:Background. Accumulation of extracellular matrix in the myocardium attenuates cardiac contractile function, and predisposes to arrhythmias and sudden cardiac death. Connective tissue growth factor (CTGF) is a matricellular protein that has been shown to promote development of cardiac fibrosis. Objectives. To investigate for the potential of CTGF monoclonal antibody (CTGF mAb) in protecting from development of cardiac fibrosis following myocardial infarction (MI), and to evaluate its effect during infarct repair and acute cardiac ischemia-reperfusion (I/R) injury. Methods. Mice were subjected to MI or to I/R injury and treated with either control IgG or CTGF mAb. Cultured human cardiac fibroblasts were used to investigate the signalling mechanisms modulated by CTGF mAb. Results. Treatment with CTGF mAb for four days from day three after MI improved survival, attenuated infarct expansion, and resulted in better preserved left ventricular (LV) systolic function. CTGF mAb therapy for six weeks from day seven after MI reduced the MI-induced increase in cardiomyocyte size, heart weight to body weight ratio and remote LV fibrosis. RNA sequencing analysis of LV samples showed that CTGF mAb induced expression of cardiac repair/developmental genes and normalized the MI-induced increase in expression of inflammatory/profibrotic genes. CTGF mAb induced c-Jun N-terminal kinase (JNK) phosphorylation in vivo and in vitro, and inhibition of JNK abrogated the reduced collagen production in CTGF mAb treated fibroblasts. Conclusions. Treatment with CTGF mAb induces expression of cardiac repair/developmental genes and inhibits expression of inflammatory/pro-fibrotic genes in MI hearts providing benefit during post-MI cardiac repair and reducing post-MI cardiac fibrosis.
2019-04-02 | GSE129134 | GEO
Project description:Neuregulin-1 (NRG-1) is a paracrine factor critical for cardiac development. We have been examining whether the recombinant NRG-1β isoform known as glial growth factor 2 (GGF2) has therapeutic potential for heart failure. In both small and large animals after experimental myocardial infarction (MI) we have found that GGF2 treatment improves myocardial function and limits progressive myocardial remodeling. To understand potential mechanisms for this effect, we compared gene expression in swine by microarray analysis. We used microarrays to compared th the global gene expression underlying the efficacy of GGF2 treatment for heart injury. Left ventricular tissue remote from the site of infarct was collected from each of 8 animals (3 untreated controls, 3 low dose GGF2-treated and 2 high dose GGF2-treated) and processed for gene expression microarray analysis using Affymetrix porcine genome GeneChips.
2014-06-21 | E-GEOD-48255 | biostudies-arrayexpress
Project description:After skin injury fibroblasts migrate into the wound and transform into contractile extracellular matrix-producing myofibroblasts to promote skin repair. Persistent activation of myofibroblasts can cause excessive fibrotic reactions, but the underlying mechanisms are not fully understood. We used SMA-GFP transgenic mice to study myofibroblast recruitment and activation in skin wounds. Myofibroblasts were initially recruited to wounds three days post injury reached a maximum after seven days and subsequently declined. Expression profiling showed that 1749 genes were differentially expressed in sorted myofibroblasts from wounds seven days post injury. GO-Term analysis associated most of these genes with the extracellular region and cell periphery including upregulated genes encoding for ECM proteins, integrins and focal adhesion proteins and a specific set of growth factors, cytokines and chemokines promoting the healing response. In contrast, cell adhesion molecules involved in cell-cell interaction were downregulated. Novel genes not yet known to be expressed in myofibroblast were found. Hence, this first characterization of a myofibroblast specific expression network at the peak of granulation tissue formation in situ provides important insights into myofibroblast activation in skin wounds and identifies novel target genes to control excessive ECM deposition during fibrotic reactions.
2017-12-30 | GSE95786 | GEO
Project description:Fibrotic scarring drives the progression of heart failure after myocardial infarction (MI). Therefore, the development of specific treatment regimens to counteract fibrosis is of high clinical relevance. The transcription factor SOX9 functions as an important regulator during embryogenesis, but recent data point towards an additional causal role in organ fibrosis. We show here that SOX9 is upregulated in the scar after MI in mice. Fibroblast specific deletion of Sox9 ameliorated MI-induced left ventricular dysfunction, dilatation and myocardial scarring in vivo. Unexpectedly, deletion of Sox9 also potently eliminated persisting leukocyte infiltration of the scar in the chronic phase after MI. RNA-sequencing from the infarct scar revealed that Sox9 deletion in fibroblasts resulted in strongly downregulated expression of genes related to extracellular matrix, proteolysis and inflammation. Importantly, Sox9 deletion in isolated cardiac fibroblasts in vitro similarly affected gene expression as in the cardiac scar and prevented their activation and myofibroblast differentiation. Together, our data demonstrate that fibroblast SOX9 functions as a master regulator of cardiac fibrosis and inflammation and might constitute a novel therapeutic target during MI.
2019-07-25 | GSE132265 | GEO