Effect of reduced alpha - cardiac actin 1 gene expression on embryonic cardiomyocytes H9C2 cell apoptosis of rats and its mechanism / 中华实用儿科临床杂志

ABSTRACT

Objective To explore the effect of reduced alpha - cardiac actin 1(ACTC1)gene expression on the rat embryonic cardiomyocytes H9C2 cell apoptosis and its mechanism. Methods The rat embryonic cardiomyocytes H9C2 cell was cultivated;the rat embryonic cardiomyocytes H9C2 cell was transfected with ACTC1 - small interfering RNA(siRNA),and at 24 h,48 h,72 h after transfection,the cells were collected for extraction and purification of RNA, the real - time quantitative PCR(qPCR)method was used to detect the expression level of ACTC1 gene;and the termi-nal deoxynucleotidyl transferase - mediated dUTP - biotin nick end labeling assay(TUNEL)method was used to ex-plore the effect of reduced ACTC1 gene expression on the rat embryonic cardiomyocytes H9C2 cell apoptosis. Western blot was used to detect the expression of Cyto C,cysteine - containing aspartate - specific proteases(Caspase)- 3, Caspase - 8,Caspase - 9,Bcl - 2 and Bax. Results The expression of ACTC1 mRNA detected by qPCR decreased compared with that of the scramble siRNA group in 24 h,48 h,72 h(0. 80 vs. 1. 00,0. 20 vs. 1. 00,0. 25 vs. 1. 00),and in the ACTC1 - siRNA group decreased significantly at 48 h,72 h,and the difference was statistically significant(t =4. 245,P < 0. 05);TUNEL positive cells rate significantly increased in the ACTC1 - siRNA group(80％)compared with that in the scramble siRNA group(20％),and the difference was statistically significant(P < 0. 05);Western blot also confirmed that the expression of Caspase - 3,Caspase - 9,Cyto C and Bax/ Bcl - 2 were accordingly increased (0. 91 ± 0. 12 vs. 0. 59 ± 0. 01,0. 48 ± 0. 09 vs. 0. 24 ± 0. 03,0. 92 ± 0. 03 vs. 0. 45 ± 0. 01,2. 25 ± 0. 26 vs. 1. 16 ± 0. 12),and the differences were statistically significant(t = 2. 821,7. 336,2. 420,0. 798,all P < 0. 05);but the expre-ssion of Caspase - 8 had no obvious change,and the difference was not statistically significant (P > 0. 05 ). Conclusions Reduced ACTC1 gene expression can induce the rat embryonic cardiomyocytes H9C2 cell apoptosis perhaps mainly through endogenous mitochondrial signal transduction pathways.