Effects Of Low-concentration Hydrogen Peroxide On Cardiomyocyte Autophagy And Its Mechanism

Objective: 1.Effects of low-concentration hydrogen peroxide on cardiomyocyte autophagy.2.Effects of low-concentration hydrogen peroxide on cardiomyocyte autophagy related protein Beclin1.3.Effects of antioxidants on autophagy in cardiac myocytes of rats in the early stage of pressure overload.Methods: Grouping: 1.H9C2 myocardial cell culture model:(1)the control group(2)10u M hydrogen peroxide intervention group 2.rat model of pressure overload:(1)sham-operation group(2)Abdominal aorta constriction(AAC)group(3)AAC+N-acetyl cysteine(NAC)group The expression of protein in myocardial cells was detected by Western Blotting.Results: In vitro experiment: H9C2 myocardial cell culture model,low concentration of H2O2(10umol/L)to intervene 72 h,control group(1±0.10)VS group 10umol/L(0.76±0.12),comparison between groups,P<0.05,showed that he expression of LC3II/I ratio was significantly decreased;when the low concentration of H2O2(10umol/ L)intervention,48 h the control group(1 ± 0.11)VS group 10umol/L(0.76 ± 0.08),comparison between groups,P<0.05,showed that the expression of Beclin1 was significantly decreased.In vivo experiment: The rat model of pressure overload,3 days after AAC,the weight of whole heart and left ventricular weight tended to increase,and NAC decreased the weight of heart.In the Western blotting method,sham group(1 ±0.10)VS group AAC(0.61 ±0.12),comparison between groups,P<0.05,showed that in the AAC group the expression of LC3II/I ratio was significantly decreased;group AAC(0.61 ±0.12)VS group AAC+NAC(1.01 ±0.10),comparison between groups,P<0.05,showed that in the AAC+NAC group the expression of LC3II/I ratio was significantly increased.sham group(1 + 0.08)VS group AAC(0.81 + 0.06),comparison between groups,P<0.05,showed that in the AAC group the expression of Beclin1 was significantly decreased,group AAC(0.81 + 0.06)VS group AAC+NAC(1.01 + 0.08),comparison between groups,P<0.05,showed that in the AAC+NAC group the expression of Beclin1 was significantly increased.Conclusions: 1.The autophagy of myocardial cells was decreased in a low-concentration hydrogen peroxide.2.In the early stage of pressure overload,the autophagy of myocardial cells was decreased.3.Antioxidants can inhibit the decrease of cardiomyocyte apoptosis that induced by pressure overload.