Mechanism of Resveratrol on autophagy mediated by Mst1/Sirt3 signaling pathway in diabetic cardiomyopathy

Objective:To observe the effects of resveratrol on myocardial cell injury and Mst1/Sirt3 signaling pathway mediated autophagy in type 2 diabetic mice. Methods:C57 BL/KSJ db/db mice were allocated to the normal control group,the model group,and the resveratrol group;C57 BL/KSJ db/m mice served as the melbine group,with 10 mice each. The resveratrol group and the melbine group were treated with resveratrol and metformin by gavage,respectively. The normal control group and the model group were treated with equal volume of normal saline by gavage,for 8 consecutive weeks. H & E staining,transmission electron microscopy and immunofluorescence were used to observe the pathological morphology,ultrastructure and apoptosis levels of myocardial tissues,respectively. RT-qPCR method was used to detect the expression levels of apoptosis genes Bax and Bcl-2 in myocardial tissues,and Western-blot method was used to detect the expression levels of autophagy proteins(LC3 and p62),Mst1 and Sirt3 proteins in myocardial tissue. Results:Compared with the model group,resveratrol can significantly reduce the body weight,blood glucose level and serum CK and LDH levels of db/db mice,and the differences were statistically significant(P<0.05;P<0.01). Meanwhile,after resveratrol treatment,myocardial inflammation score,apoptosis rate,Bax mRNA expression level and Bax/Bcl-2 ratio in myocardial tissue were significantly reduced,and Bcl-2 mRNA expression level was significantly increased,and the differences were statistically significant(P<0.01). In addition,compared with the model group,the expression level of p62 and p-Mst1 protein in the myocardial tissue of the resveratrol group was significantly reduced,and the expression level of Sirt3 protein and the ratio of LC3Ⅱ/LC3Ⅰ were significantly increased,and the differences were statistically significant(P<0.01). Conclusion:Resveratrol promotes the autophagy level of cardiomyocytes by activating the Mst1/Sirt3 signaling pathway and inhibits cardiomyocyte apoptosis to play a protective role in diabetic cardiomyopathy.

Resveratrol ameliorates diabetic myocardial injury through HSF1-mediated ferroptosis

Objective:To observe the effect of resveratrol on the injury of diabetic cardiomyocytes and its effect on HSF1 mediated iron death.Methods:the diabetic cardiomyopathy model was established by high glucose induced H9c2,and H9c2 was exposed to normal glucose concentration as a control.Then the intervention was performed with the corresponding drugs.The cell proliferation level was detected by CCK8 method,the concentrations of LDH,SOD,MDA and iron ions were detected by kit method,and the expression levels of HSF1,apoptotic proteins(Bax and Bcl-2)and iron death marker proteins(ACSL4,GPX4 and SLC7A11)were detected by Western blot;Results:compared with the blank group,the cell activity,SOD activity,the expression of HSF1,Bcl-2,GPX4 and SLC7A11 protein in the model group decreased significantly,and the LDH activity,MDA content,Bax and ACSL4 protein expression,Bax/Bcl-2 ratio and Fe^(2+)content increased significantly(P<0.01).Compared with the model group,the activity of H9c2 cells,the activity of SOD,the expression of HSF1,Bcl-2,GPX4 and SLC7A11 protein increased significantly,and the activity of LDH,the content of MDA,the expression of Bax and ACSL4 protein,the ratio of Bax/Bcl-2 and the content of Fe^(2+)decreased significantly in the resveratrol group(P<0.01).After the intervention,the activity of H9c2 cells,the activity of SOD,the expression of HSF1,Bcl-2,GPX4 and SLC7A11 protein decreased significantly,and the activity of LDH,the content of MDA,the expression of Bax and ACSL4 protein,the ratio of Bax/Bcl-2 and the content of Fe^(2+)increased significantly in si-hsf1 group(P<0.01);Conclusion:resveratrol can inhibit cell iron death and improve high glucose induced cardiomyocyte injury by up regulating the expression of HSF1.

Mechanism of hesperidin improving myocardial ischemia/reperfusion injury in type 2 diabetic rats through SIRT1/Nrf2/HO-1 signaling pathway

Objective:To observe the protective effect of hesperidin on myocardial ischemia/reperfusion injury in type 2 diabetes mellitus and its effect on SIRT1/Nrf2/HO-1 signaling pathway.Methods:50 Sprague-Dawley(SD)rats were randomly assigned to the normal control group(NC),model group,ischemia-reperfusion group(IR),hesperidin group,SIRT1 inhibitor group and hesperidin plus SIRT1 inhibitor group.In addition to NC,the rats in the remaining groups were replicated by intraperitoneal of high-fat diet combined with injection of streptozotocin for type 2 diabetic rats.After then,the myocardial ischemia/reperfusion injury(MIRI)rat model was established by LAd for 30 minutes with 2 hours reperfusion.He staining was used to observe the pathological changes of myocardial tissue,and the levels of serum LDH,CK-MB and SOD,GSH and MDA in myocardial tissue were detected by kit methods,and the expression abundance of related proteins in 4-HNE and SIRT1/Nrf2/HO-1 signal pathway were detected by immunohistochemistry and Western blot;Results:Hesperidin could significantly inhibit cardiomyocyte necrosis and inflammatory cell infiltration,reduce LDH activity,CK-MB and MDA level,and increase SOD activity,GSH and 4-HNE level,the differences were statistically significant when compared with IR group(P<0.01).In addition,compared with the ischemia-reperfusion group,the expressions of SIRT1,Nrf2 and HO-1 proteins in hesperidin group were significantly up-regulated,the differences were statistically significant(P<0.01);Conclusion:Hesperidin inhibits oxidative stress by activating SIRT1/Nrf2/HO-1 signaling pathway,and play a protective effect of myocardial ischemia reperfusion injury in diabetic rats.