The Effect And Mechanism Of SGLT2 Inhibitors On Alleviating Cardiac Remodeling By Regulating Autophagy

Background: Heart failure(HF)is the end stage of various cardiovascular diseases,and it is also one of the main causes of death in patients with cardiovascular diseases.According to statistics,approximately 64.3 million people worldwide suffer from HF.Cardiac remodeling is the central process in the development of HF.Sodium-glucose co-transporter 2(SGLT2)inhibitors inhibit the reabsorption of glucose in renal tubules,and reduce the mortality and readmission rate of HF patients regardless of presence or absence of diabetes.Clinical trials of SGLT2 inhibitors for the treatment of HF have made significant progress,but the specific mechanism of action of SGLT2 inhibitors in improving HF and whether they have a direct effect on the heart are still not well understood.SGLT2 inhibitors are a very promising class of drugs for the treatment of HF.Further clarifying their mechanism of action will not only help us to understand the pharmacology of SGLT2 inhibitors,but also help to open up new therapeutic fields and strategies.Aims: 1.To clarify the role of SGLT2 inhibitor dapagliflozin(DAPA)in alleviating cardiac remodeling,and RNA sequencing(RNA-seq)was performed to further clarify its possible mechanism of action.2.To explore the regulatory mechanism of autophagy in the effect of DAPA on improving cardiac remodeling.3.To reveal the molecular mechanism of DAPA improving cardiac remodeling by regulating autophagy.Methods: 1.A mice model of cardiac remodeling induced by transverse aortic constriction(TAC)was constructed.Echocardiography,hematoxylin-eosin staining,sirius red staining,immunofluorescence staining,and RT-q PCR were used to clarify the role of DAPA in improving cardiac remodeling.RNA-seq was also performed to clarify its possible mechanism.2.An Ang II-induced cardiomyocyte hypertrophy and extracellular matrix(ECM)deposition model was established using H9C2 cells and primary neonatal rat ventricular myocytes(NVRMs).RT-q PCR,western blot,immunofluorescence,and dual fluorescence-labeled LC3 B plasmid transfection of cardiomyocytes were performed.Autophagy inhibitor 3-MA and SIRT1 specific inhibitor EX527 were used to clarify the roles and mechanisms of autophagy and the SIRT1/PGC-1α signaling pathway in the improvement of cardiomyocyte hypertrophy and ECM deposition by SGLT2 inhibitor DAPA.3.A myocardial infarction(MI)-induced cardiac remodeling model was constructed.Echocardiography,hematoxylin-eosin staining,masson staining,immunofluorescence,immunohistochemistry,ELISA,RT-q PCR,and Western blot were performed.SIRT1 specific inhibitor EX527 was used to further clarify the roles and mechanisms of autophagy and the SIRT1/PGC-1α signaling pathway in the improvement of cardiac remodeling by SGLT2 inhibitor DAPA.4.Statistical analysis and graphing were performed using Graph Pad Prism 9.4software.P < 0.05 indicates a statistically significant difference.Results: 1.DAPA improved left ventricular function,cardiac hypertrophy,and cardiac fibrosis in mice after TAC surgery.RNA-seq indicated that DAPA is mainly involved in energy metabolism processes such as lipid metabolism and gluconeogenesis,and it also affects lysosomes and autophagosomes.The main related pathway is the SIRT1/PGC-1α signaling pathway.2.In vivo experiments showed that DAPA restored autophagic flux after TAC surgery.In vitro experiments found that DAPA alleviated Ang II-induced cardiomyocyte hypertrophy and ECM deposition,and improved the autophagy flux.The autophagy inhibitor 3-MA reversed the effect of DAPA on promoting autophagy and alleviating cardiomyocyte hypertrophy and ECM deposition.3.The TAC-induced cardiac remodeling model showed that DAPA activated the SIRT1/PGC-1α signaling pathway in mice after TAC surgery.In vitro experiments showed that DAPA pretreatment promoted the expression of SIRT1 and PGC-1αproteins in H9C2 cells.The SIRT1-specific inhibitor EX527 reversed the effect of DAPA on promoting the expression of SIRT1 and PGC-1α proteins,and also reversed the effect of DAPA on promoting autophagy and alleviating cardiomyocyte hypertrophy and ECM deposition.The MI-induced cardiac remodeling model showed that DAPA improved cardiac function,alleviated cardiac fibrotic scar formation,and reduced cardiomyocyte hypertrophy in the marginal zone of MI by regulating autophagy through the SIRT1/PGC-1α signaling pathway.Conclusion 1.SGLT2 inhibitor DAPA alleviates TAC-induced left ventricular dysfunction and cardiac remodeling.RNA-seq analysis suggests that DAPA is mainly involved in energy metabolism processes such as lipid metabolism and gluconeogenesis,and it also affects lysosomes and autophagosomes.The main related pathway is the SIRT1/PGC-1α signaling pathway.2.SGLT2 inhibitor DAPA alleviates cardiac remodeling in mice after TAC surgery and reduces Ang II-induced cardiomyocyte hypertrophy and ECM deposition by regulating autophagy.DAPA acts on the formation stage of autophagosomes to promote autophagy.3.SGLT2 inhibitor DAPA alleviates TAC-induced and MI-induced cardiac remodeling by regulating autophagy through the SIRT1/PGC-1α signaling pathway.In conclusion,autophagy flux and SIRT1/PGC1-α pathway are inhibited in TAC-induced and MI-induced cardiac remodeling.The SGLT2 inhibitor DAPA activates the SIRT1/PGC-1α signaling pathway to promote the formation of autophagosomes,restore autophagy flux,and thereby alleviates cardiac remodeling.