Mechanism of NETosis Regulating Cardiomyocyte Autophagy to Promote Acute Myocardial Infarction in Mice / 医学研究杂志

ABSTRACT

Objective To explore the correlation between acute myocardial infarction(AMI)and neutrophil extracellular traps-os-is(NETosis)in the regulation of cardiomyocyte autophagy in mice.Methods The mouse model of AMI was established in C57BL/6mice by ligation of the left anterior descending coronary artery.Mouse primary cardiomyocytes were treated with oxygen glucose deprivation(OGD)to build an in vitro model of cardiomyocyte injury.Neutrophils were treated with PMA(NETosis inducer)/DNas Ⅰ(NETosis in-hibitor),the supernatant was taken to treat OGD-induced cardiomyocytes,and rapamycin(Rap)was used to treat OGD-induced car-diomyocytes.The myocardial infarction area was detected by TTC staining;serum cTnI level was detected by enzyme-linked immunoad-sordent assay(ELISA);cardiomyocytes apoptosis was detected by TUNEL staining;NETosis marker levels in neutrophil supernatant were detected by ELISA,and related protein expression levels were detected by Western blot.Results TTC staining showed that compared with the sham-operated group,the myocardial infarction area of the mice in the model group was significantly increased,the level of cTnI in serum was significantly increased(P<0.05),the apoptosis of cardiomyocytes was increased,and the levels of Beclin-1 and LC3-Ⅱ/LC3-Ⅰ were significantly increased,the p62 protein expression level was significantly decreased.Compared with the control group,the expression levels of apoptosis and cleaved caspase-3 were significantly increased under OGD conditions(P<0.05).Compared with the control group,the levels of NETosis markers MPO-DNA,MPO,and NE in the neutrophil supernatant in the PMA group were signifi-cantly increased;compared with the PMA-treated group the apoptosis level of cardiomyocytes in the PMA + DNas Ⅰ group was signifi-cantly decreased;the levels of Beclin-1 and LC3-Ⅱ/LC3-Ⅰwere significantly decreased,and the protein expression level of p62 was significantly increased;compared with the PMA + DNas Ⅰ group,Rap treatment could enhance the levels of Beclin-1 and LC3-Ⅱ/LC3-Ⅰ,and inhibit the level of p62(P<0.05).It also significantly reversed the decrease in apoptosis induced by PMA + DNas Ⅰ.Conclusion Neutrophil NETosis can promote AMI in mice by regulating cardiomyocyte autophagy,which can provide a new direction and theoretical basis for the research and development of therapeutic drugs for AMI.