MATR3 regulates METTL3-Mediated m6A modification of MSI2 mRNA to activate the Wnt/β-Catenin pathway, exacerbating myocardial fibrosis and atrial fibrillation
摘要
To investigate the role and molecular mechanisms of the RNA-binding protein MATR3 in myocardial fibrosis of atrial fibrillation (AF). Expression of MATR3 and MSI2 in AF patients was analyzed using GEO datasets (GSE79768, GSE14975, GSE31821). Human atrial fibroblasts (HAFs) induced by Angiotensin II (Ang-II) were used as an in vitro cellular model of myocardial fibrosis. Expression and interactions of MATR3, METTL3, and MSI2 were validated by qRT-PCR and Western blot. The binding between MATR3 and METTL3 was confirmed by co-immunoprecipitation (Co-IP). The m6A modification level of MSI2 mRNA was detected by methylated RNA immunoprecipitation (MeRIP-qPCR). Cell proliferation, migration, and fibrotic phenotypes were evaluated by CCK-8, EdU, scratch, and Transwell assays, as well as detection of fibrosis markers. An Ang-II-induced mouse model of atrial fibrosis was constructed, and the in vivo effects of MATR3 were verified by HE staining, Masson’s trichrome staining, and molecular detection. Analysis of GEO datasets showed that both MATR3 and MSI2 were highly expressed in AF patients. Ang-II treatment significantly upregulated the expression of MATR3 in HAFs, while knockdown of MATR3 inhibited Ang-II-induced proliferation, migration, and pro-fibrotic phenotypic changes in HAFs (reducing the expression of α-SMA, collagen I/III). Mechanistically, MATR3 interacted endogenously with METTL3 and stabilized the METTL3 protein by inhibiting proteasomal degradation. METTL3 mediated the m6A modification of MSI2 mRNA, enhancing its stability and promoting its expression. MSI2 exerted a pro-fibrotic effect by activating the Wnt/β-Catenin pathway. In vivo experiments confirmed that silencing MATR3 downregulated the expression of METTL3 and MSI2, inhibited the activation of the Wnt pathway, and alleviated Ang-II-induced atrial fibrosis in mice. MATR3 promotes myocardial fibrosis and exacerbates AF by regulating METTL3-mediated m6A modification of MSI2 mRNA to activate the Wnt/β-Catenin pathway. Targeting MATR3 may represent a potential therapeutic strategy for AF.