Role of lncRNA MEG3 in Regulating Autophagy Mediated by mTOR in Diabetic Cardiomyopathy
Objective To explore the role of lncRNA MEG3 in regulating mTOR mediated autophagy in diabetic cardiomyopathy(DCM).Methods A C57BL/6 DCM mouse model was established.The normal group and DCM group were set up.Cardiac ultrasound and Masson staining were used to detect the changes of the functional and structure of the left atrium.The expression level of lncRNA MEG3 in mouse myocardial tissue was detected by real-time quantitative polymerase chain reaction(RT-qPCR),and the expression level of p62,LC3-Ⅱ,Beclin1,p-mTOR and mTOR were detected by Western blot.Myocardial cells of C57BL/6mouse were isolated,and high glucose induced myocardial cell damage.The cells were transfected with si-NC and si-MEG3 and treated with high glucose,the normal,high glucose,high glucose+si-NC and high glucose+si-MEG3 groups were set up.The expression level of lncRNA MEG3 was detect by RT-qPCR.The expression levels of p62,LC3-Ⅱ,Beclin1,p-mTOR,mTOR,p-ERK and ERK were detected by Western blot.The myocardial cell injury was detected by CCK-8、LDH、ROS、GSH-Px kits.Results Abnormal cardiac function was observed in DCM mouse.Compared with the normal group,the expression level of p62 in cardiomyocytes of DCM group was signifi-cantly increased,the expression levels of LC3-Ⅱ and Beclin1 were significantly decreased,and the expression level of p-mTOR was in-creased.In the cell experiment,the expression level of p62 in cardiomyocytes induced by high glucose was significantly higher than that in the normal group.The expression levels of LC3-Ⅱ and Beclin1 were significantly decreased,and the expression levels of p-mTOR and p-ERK were increased;the cell viability and GSH-Px activity were decreased.The LDH and ROS activities were significantly in-creased.After downregulating lncRNA MEG3,the changes of autophagy related proteins and cell damage indexes in the high glucose+si-MEG3 group were reversed.Conclusion Down-regulation of lncRNA MEG3 inhibits the activation of ERK/mTOR signaling path-way,and the autophagy induced by high glucose can be restored.The myocardial damage of diabetes mellitus can be alleviated.
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