The Role of Apoptosis-Inducing Factor on TNF-α Induced Apoptosis in Cultured Neonatal Rat Cardiontyocytes

Objective This study was designed to investigate the role of apoptosis-inducing factor on neonatal rat cardiomyocytes apoptosis induced by TNF-a,and to detect the effect of IL-10 on the apoptosis rate of cardio-myocytes apoptosis induced by TNF-α.Methods Neonatal rat cardiacmyocytes in primary culture were exposed to TNF-α( 100ng/ml)for 12 hours,18 hours,24 hours,TNF-α( 100ng/ml) for lohours pretreated by IL-10(50ng/ml) 1 hour,or IL-10(50ng/ml) for 19hours.Apoptotic cells were detected by flow cytometry and Hoechest 33258 dye; Western blot were used to determine the apoptosis-inducing factor protein expression.Results The apoptosis rate of cardiomyocytes increased in TNF-α 12 hours group than that of control[ Flow cytometry (5.08 ±0.79% ) vs ( 2.2± 0.77)% ,P <0.05],and reach the peak in TNF-α 18 hours group compared with control[ Flow cytometry(14.39± 2.31)%vs(2.2±0.77)%,P<0.01;Hoechst 33258 dyeing(18.936±2.791)% Vs(2.890± 1.326)% ,P< 0.01];also elevated in TNF-α 24 hours group vs control[Flow cytometry(4.61±0.84)% vs(2.2 ±0.77)% ,P< 0.05].AIF expression:Increased expression of AIF in the cells treated by TNF-α( 100 ng/ml) 12 hours,reached highest in TNF-α( 100 ng/ml) for 18 hours group and decreased in TNF-α( 100 ng/ml) 24 hours group compared with control;AIF expression is not decrease in TNF-α( 100 ng/ml) 18 hours pretreated by IL-10(50 ng/ml) for 1-hour group comparing with TNF-α( 100 ng/ml) 18hours group.Conclusion The study demonstrated that AIF contributed to TNF-α induced apoptosis of rat cardiomyocytes; IL-10 alleviated the apoptosis of rat cardiacmyocytes induced by TNF-α,and AIF may not its mechanism. Key words: Mice; Myocardium; Interleukin-10; Tumor necrosis factor; Apoptosis