Abstract
Objective: MicroRNA-221/222 is involved in the pathogenesis of intrahepatic cholestasis of pregnancy (ICP) to promote the apoptosis of placental bile acids through human trophoblastic cells. This study investigates the effects of miR-221/222 on proliferation, apoptosis and apoptosis-related proteins of human trophoblast HTR-8/SVneo (HTR-8 cells) to understand its role in promoting trophoblastic apoptosis. Methods: The experiment was divided into transfection group and negative control group. Transient transfection method was used in both groups. The transfection efficiency was detected by RT-QPCR after 48 h transfection. CCK-8 was used to detect the proliferation of HTR-8 cells and the apoptosis of HTR-8 cells were analyzed by flow cytometry. Western blot was used to detect the expression of B-cell Lymphoma 2 (Bcl-2) in HTR-8 cells. Data were compared with t-test. Results: The expression of miR-221/222 transfected group (25.43±0.80, 22.70±0.95) was increased significantly in the HTR-8 cells than that to negative control group (1.14±0.14, 1.58±0.14), and P value was < 0.01, the difference was statistically significant. The expression of Bcl-2 protein in mir-221/222 transfection group was (0.56 ± 0.03, 0.53 ± 0.03), and the protein expression was decreased compared with negative control group (0.72 ± 0.003, 0.76 ± 0.04). P value was < 0.05, the difference was statistically significant, and compared with the mir-221/222 negative control group (8.827 ± 0.48, 11.80 ± 0.45), cell apoptosis of mir-221/222 transfection group (42.53 ± 4.47, 24.09 ± 2.53) increased significantly, P value was < 0.01, and the difference was statistically significant. Proliferation rate in mir-221/222 transfection group was (0.82 ± 0.02, 0.74±0.01), and proliferation was inhibited, when compared with control group (1.15 ± 0.08, 1.06 ± 0.08), P value was < 0.05, and the difference was statistically significant. Conclusion: miR-221/222 may promote the apoptosis of human trophoblastic cells by down regulating the expression of apoptosis inhibitory protein bcl-2, leading to placental dysfunction and impairing the normal bile acid transport function of placenta. This mechanism may be involved in the occurrence and development of ICP.