Project description:Aims: Cardiac fibroblasts (CFs) play a crucial role in cardiac remodelling, which is a common cause of heart failure (HF). However, the molecular mechanisms underlying the fibroblast-to-myofibroblast transition remain largely unknown. Foxm1 is well known in various cardiopulmonary pathologies. However, Foxm1-driven CF activation in the progression of cardiac remodelling to HF remains to be investigated. Methods: Changes in Foxm1 expression were assessed in samples from patients with HF and mice with transverse aortic constriction (TAC)-induced cardiac remodelling. Pharmacologic antagonist FDI-6 was used to explore the effects of Foxm1 inhibition on post-TAC outcomes. Tcf21-Cre and PostnMCM were used to evaluate Foxm1 loss- and gain-of-function in CFs and myofibroblasts, respectively. Cardiac function and remodelling were examined by echocardiography and histological analysis. Foxm1 downstream target genes were identified by mass spectrometry (MS) and transcriptomic analysis. Post-translational regulation was evaluated by in vitro chromatin immunoprecipitation, co-immunoprecipitation, and ubiquitination assays. Pharmacological inhibition of Usp10 or knockout of p38γ in vivo verified the signalling pathway by which Foxm1 regulated cardiac remodelling. Results: Foxm1 was upregulated in human HF samples as well as in the mouse cardiac remodelling model. CFs were the primary cell type responsible for Foxm1 upregulation. Foxm1 pharmacological inhibition or genetic knockout in CFs or myofibroblasts significantly attenuated TAC-induced cardiac remodelling and HF. Conversely, conditional overexpression of Foxm1 in CFs or myofibroblasts resulted in more severe pathological cardiac remodelling and dysfunction. Combined RNA-sequencing and MS analysis revealed that Foxm1 promoted Usp10 expression by binding to its promoter. Usp10 interacted with p38γ, resulting in p38γ deubiquitination and thus inﬂuencing the downstream p38 mitogen-activated protein kinase (MAPK) signalling pathway. Pharmacological inhibition of Usp10 or genetic knockout of p38γ ameliorated the exacerbated TAC-induced cardiac remodelling in mice with myofibroblast-specific Foxm1 overexpression. Conclusion: Our findings reveal an essential role of Foxm1 in CF activation during cardiac remodelling. These results suggest that targeting the Foxm1/Usp10/p38γ MAPK axis may represent a new potential therapeutic strategy against pathological cardiac remodelling and HF.

Project description:Purpose: Heart failure (HF) is a leading cause of morbidity and mortality worldwide, and it is characterized by cardiac hypertrophy and fibrosis. However, effective treatments are not available to block cardiac fibrosis after cardiac hypertrophy. The QiShenYiQi pill (QSYQ) is an effective treatment for chronic HF. However, the underlying mechanism remains unclear. Methods: In the present study, a pressure overload-induced cardiac hypertrophy model was established in rats by inducing ascending aortic stenosis for 4 weeks. QSYQ was administered for 6 weeks, and its effects on cardiac fibrosis, myocardial apoptosis, RP S19 release, macrophage polarization, TGF-β1 production, and TGF-β1/Smad signaling were analyzed. In vitro studies using H9C2, Raw264.7, and RDF cell models were performed to confirm the in vivo study findings and evaluate the contribution to the observed effects of the main ingredients of QSYQ, namely, astragaloside IV, notoginsenoside R1, 3,4-dihydroxyl-phenyl lactic acid, and Dalbergia odorifera T. C. Chen oil. The role of four-and-a-half LIM domains protein 2 (FHL2) in cardiac fibrosis and QSYQ's effects were assessed by small interfering RNAs (siRNAs). Results: QSYQ ameliorated cardiac fibrosis after pressure overload-induced cardiac hypertrophy and attenuated cardiomyocyte apoptosis, low FHL2 expression, and TGF-β1 release by the injured myocardium. QSYQ also inhibited the following: release of RP S19 from the injured myocardium, activation of C5a receptors in monocytes, polarization of macrophages, and release of TGF-β1. Moreover, QSYQ downregulated TGF-βR-II expression induced by TGF-β1 in fibroblasts and inhibited Smad protein activation and collagen release and deposition. Conclusion: The results showed that QSYQ inhibited myocardial fibrosis after pressure overload, which was mediated by RP S19-TGF-β1 signaling and decreased FHL2, thus providing support for QSYQ as a promising therapy for blocking myocardial fibrosis.

Dataset Information

MiR-21-Dependent Macrophage-to-Fibroblast Signaling Determines the Cardiac Response to Pressure Overload.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets