89-OR: FGFR1/MAPKs/AP-1 Signaling Mediates Cardiomyopathy in Streptozotocin-Induced Type 1 Diabetes

Diabetic cardiomyopathy is a complex entity associated with multiple contributing mechanisms and consequent manifestations in the clinic. Emerging evidence implicates that increased activity of fibroblast growth factor receptor 1 (FGFR1) is required during induced cardiac damage and remodeling. However, little is known about the roles of FGFR1 on diabetic cardiomyopathy (DCM). We hypothesized that the high-concentration glucose (HG)/diabetes induced cardiac pathophysiological and malfunctional alterations are linked to the activation of FGFR1. We tested this hypothesis by challenging cultured cardiomyocytes with high-concentration glucose and myocardium of streptozotocin (STZ)-induced type 1 diabetic mice (T1D). This study indicated that FGFR1 phosphorylation was increased in myocardium of streptozotocin (STZ)-induced type 1 diabetic mice (T1D) and cultured cardiomyocytes to high-concentration glucose. The inactivation of FGFR1 by selective inhibitors AZD4547, neutralized the increased FGFR1 phosphorylation and significantly reduced myocardial structural and functional deficits in type 1 diabetic mice. In vitro, overexpression of FGFR1 by lentivirus-transfection aggravated HG-induced fibrosis and hypertrophy in cardiomyocytes. Blocking FGFR1 by AZD4547 or CRISPER-Cas9 knockout, HG-induced fibrosis and hypertrophy in cardiomyocytes were significantly decreased. Then, GSEA analysis of RNA-sequencing implied that collagen5a1(Col5a1) and periostin (Postn) were associated with fibrosis and myosin heavy chain 4/7/8/9 (Myh4/7/8/9) were associated with hypertrophy. Analysis by PASTAA database and confirmatory tests by inhibiting FGFR1 or MAPKs indicated that MAPKs/AP-1 plays a crucial role in FGkFR1-mediated cardiomyocyte injuries challenged by HG. These results reveal an unrecognized FGFR1/MAPKs/AP-1 signaling axis involved in the development and progression of DCM and suggest that AZD4547 might be a potential agent for treating DCM. Disclosure X. Chen: None. Y. Wang: None. F. Shen: None. Funding National Natural Science Foundation of China (81700335)