Protection effect of dapagliflozin on the myocardium of septic mice by activating the AMPK/mTOR autophagy pathway

Xia Fenfen; Zhong Ying; Ding Ruilin; Zhang Yuanhua; Wang Xiaojie; Yan Zhonghan; Shi Xuemei; Peng Qing

doi:10.3969/j.issn.1002-1949.2024.08.006

Abstract：Objective To explore the effect and mechanism of dapagliflozin(Dapa)on sepsis-induced myocardial damage.Methods Random allocation was performed to assign male C57BL/6J mice into various groups including control group,LPS group,LPS+Dapa group,LPS+Dapa+Compound C(adenylate activated protein kinase inhibitor)group,and LPS+Dapa+3-MA(3-methyladenine)group,with 6 mice in each group.LPS+Dapa group,LPS+Dapa+Compound C group and LPS+Dapa+3-MA group were pretreated with dapagliflozin(10 mg/kg)once a day by gavage for one week.Compounds C and 3-MA were used to inhibit the activation and autophagy of adenosine monophosphate-activated protein kinase(AMPK),respectively.On the 7th day,septic cardiomyopathy was induced by administering lipopolysaccharide(LPS)in mice.Cardiac function was assessed through echocardiography,hematoxylin-eosin staining and LC3 immunofluorescence staining.The phenotype of autophagy-related proteins were evaluated by using immunofluorescence and Western blot.The phenotype of macrophages proteins were evaluated by using enzyme-linked immunosorbent assay(ELISA),Western blot and RT-qPCR.The expression of AMPK and mTOR were evaluated by Western blot.Results Compared to the control group,the mice in LPS group exhibited significant differences in cardiac function and myocardium,such as disorganized,hypertrophic and ruptured myocardial cells,the increase of myocardial injury markers and inflammatory factors.The dapagliflozin demonstrated a significant amelioration in cardiac function and myocardial pathological changes in mice,concomitant with a reduction in the levels of myocardial injury markers and inflammatory factors.The Western blot results showed that the LPS group had a slight increase in Arg-land LC3 Ⅱ/LC3 Ⅰ ratio compared to the control group,a significant increase in iNOS and p-mTOR,and the decrease of p62 and p-AMPK expression were observed(P＜0.05).Compared to the group treated with LPS alone,the LPS+Dapa group showed a significant increase in the expression of Arg-1 and p-AMPK.Additionally,there was a further enhancement in LC3 Ⅱ/LC3 Ⅰ levels,while iNOS,p-mTOR and p62 expression exhibited a decrease(P＜0.05).Immunofluorescence analysis provided the evidences for supporting the notion that dapagliflozin can promote the expression of LC3 Ⅱ.The results of Arg-1 and iNOS gene were consistent with the protein expression(P＜0.05).In the above results,adding 3-MA or Compound C to the LPS+Dapa group can reverse the effect of dapagliflozin.Conclusions In septic mice,dapagliflozin has the potential to mitigate myocardial damage by potentially enhancing the AMPK/mTOR autophagy pathway and diminishing inflammatory response,and macrophage phenotype may also be involved.