AIM: To observe the effect and mechanism of MicroRNA-34a on senescence and apoptosis of human lens epithelial cell line SRA01/04.

METHODS: MicroRNA-34a expression levels in ARC lens and transparent lens epithelial cells were detected by qRT-PCR. MicroRNA-34a mimics, MicroRNA-34a inhibitors and empty liposome(control group)were transfected into SRA01/04 cells by liposome transfection kit. Annexin V-FITC/PI double staining was used to detect the effect of MicroRNA-34a on the apoptosis of human lens cell line SRA01/04. The expression of Cdc42 and Rac1 protein was detected by western blot.

RESULTS: The expression level of MicroRNA-34a in anterior capsular tissue of transparent lens was significantly lower than that in ARC anterior capsular tissue(P<0.05). The positive rates of SA-β-gal in the MicroRNA-34a mimics group, the control group and the MicroRNA-34a inhibitors group were(87.56±2.34)%,(12.22±2.74)% and(3.45±0.45)%, respectively. The positive rates of SA-β-gal in the MicroRNA-34a mimics group was significantly higher than the control group, while the SA-β-gal positive rate in the MicroRNA-34a inhibitors group was significantly lower than that in the control group(P<0.05). The apoptosis rate of the MicroRNA-34a inhibitors group, control group and MicroRNA-34a mimics group were(5.87±1.22)%,(12.26±2.14)% and(29.45±3.12)%, respectively. The apoptosis rate of the MicroRNA-34a mimics group was significantly higher than that of the control group, while that of the MicroRNA-34a inhibitors group was significantly lower than that of the control group(P<0.05). The expressions of Cdc42 and Rac1 in the MicroRNA-34a mimics group were significantly higher than those in the control group(P<0.05), while the expressions of Cdc42 and Rac1 in the MicroRNA-34a inhibitors group were significantly lower than those in the control group(P<0.05).

CONCLUSION: MicroRNA-34a may promote the senescence and apoptosis of human lens epithelial cells by up-regulating Cdc42 and Rac1.