The Effect Of Drp1 Inhibitor On Sodium Azide-Induced Myocardial Cell Injury And The Mechanism

Purpose:The mechanism of NaN₃-induced myocardial cell injury has not been fully understood although it has been related studied.Recent studies have shown that mitochondria fission protein dynamin-related protein 1（Drp1）play an important role in the process of mitochondria fission,and involve in the balance of mitochondria dynamics.Mitochondrial division inhibitor（Mdivi-1）,a kind of derivatives of quinazoline,could inhibit the function of Drp1.It has been reported that Mdivi-1 possesses a protective effect in the models of myocardial ischemia-reperfusion injury,acute kidney injury and brain injury by inhibiting mitochondria fission.However,there is no data available regarding whether Mdivi-1 has the similar effect on the myocardial cell injuryby NaN₃.Therefore,with the model of myocardial cell injury by NaN₃,this study observed the changes of cell survival,the expression of Drp1,mitochondrial injury and apoptosis,to find out the effect of Mdivi-1 on NaN₃-induced myocardial cell injury and its possible mechanism.Method:Rat embryonic ventricular myocardial H9c2 cells were exposed to NaN₃with or without Mdivi-1 pretreatment in vitro.Cell viability was measured by CCK-8 assay.The change of cell nuclear morphology was identified by the immunofluorescence staining DAPI.The mitochondrial membrane potential of cells was detected by fluorescence probe JC-1.The ATP contents were determined by ATP-dependent bioluminescence assay kit.Reactive oxygen species（ROS）was also assessed by means of DCFH-DA（a fluorescent probe）.In addition,the expression of Drp1 and apoptosis-related proteins Bcl-2,Bax was determined by western blot.Results:The viability of H9c2 cells was significantly decrased after NaN₃administration.Simultaneously,NaN₃ treatment caused collapse of nuclear shape,upregulation of Drp1 and Bax expression,downregulation of Bcl-2,as well as collapsed mitochondrial membrane potential（ΔΨm）,reduction of ATP contentand increasment of ROS production.Conversely,pretreatment with Mdivi-1 reversed all these results above.Conclusions:These results suggested that Drp1 inhibitors Mdivi-1 could attenuate myocardial cell injury induced by NaN₃,mainly related to regulation of cell survival and nuclear shape,mitochondrial membrane potential,ATP,ROS production and apoptosis,and then play a protective role in myocardial cells.