Involvement of lncR-30245 in Myocardial Infarction–Induced Cardiac Fibrosis Through Peroxisome Proliferator-Activated Receptor-γ–Mediated Connective Tissue Growth Factor Signalling Pathway

Long noncoding RNAs (lncRNAs) are emerging as important mediators of cardiac pathophysiology. The aim of the present study is to investigate the effects of lncR-30245, an lncRNA, on cardiac fibrogenesis and the underlying mechanism.Myocardial infarction (MI) and transforming growth factor (TGF)-β1 were used to induce fibrotic phenotypes. Cardiac fibrosis was detected by Masson's trichrome staining. Cardiac function was evaluated by echocardiography. Western blot, quantitative reverse transcription-polymerase chain reaction, and pharmacological approaches were used to investigate the role of lncR-30245 in cardiac fibrogenesis.Expression of lncR-30245 was significantly increased in MI hearts and TGF-β1-treated cardiac fibroblasts (CFs). LncR-30245 was mainly located in the cytoplasm. Overexpression of lncR-30245 promoted collagen production and CF proliferation. Knockdown of lncR-30245 significantly inhibited TGF-β1-induced collagen production and CF proliferation. LncR-30245 overexpression inhibited the antifibrotic role of peroxisome proliferator-activated receptor (PPAR)-γ and increased connective tissue growth factor (CTGF) expression, whereas lncR-30245 knockdown exerted the opposite effects. Rosiglitazone, a PPAR-γ agonist, significantly inhibited lncR-30245-induced CTGF upregulation and collagen production in CFs. In contrast, T0070907, a PPAR-γ antagonist, attenuated the inhibitory effects of lncR-30245 small interfering RNA (siRNA) on TGF-β1-induced CTGF expression and collagen production. LncR-30245 knockdown significantly enhanced ejection fraction and fractional shortening and attenuated cardiac fibrosis in MI mice.Our study indicates that the lncR-30245/PPAR-γ/CTGF pathway mediates MI-induced cardiac fibrosis and might be a therapeutic target for various cardiac diseases associated with fibrosis.