Inhibitory effect of Tanshinone Ⅱ A on the proliferation of human retinal pigment epithelial cells in hypoxia and its mechanism / 中华实验眼科杂志

ABSTRACT

Objective To investigate the effect of Tanshinone Ⅱ A on the proliferation and the signaling pathway of human retinal pigment epithelial (RPE) cells in hypoxia.Methods CoCl2(150 μ mol/L) was used to simulate hypoxic condition and the ARPE-19 cells cultured in vitro were divided into blank control group,hypoxia control group,Tanshinone Ⅱ A group and hypoxia-inducible factor-1αt (HIF-1 α) inhibitor group.The different doses of Tanshinone Ⅱ A were used to treat ARPE-19 for 24,48 and 72 hours,respectively.The inhibitory rate of cell proliferation of different groups were detected by MTT after 24,48 and 72 hours of administration cultured,and the apoptosis rate and the cell cycle distribution of cells in the hypoxia were analyzed by flow cytometry.Real-time PCR and Western blot were used to detect the expressions of mRNA and protein of HIF-1α and vascular endothelial growth factor (VEGF).Results MTT assay showed that Tanshinone Ⅱ A could inhibit the proliferation of ARPE-19 cells in a dose-and time-dependent manner,and the proliferation inhibitory rate gradually increased in the 1,5 and 10 mg/L Tanshinone Ⅱ A groups,with significant differences between any two groups (all at P＜0.05).Flow cytometry showed that the apoptosis rate of ARPE-19 in 1,5 and 10 mg/L Tanshinone Ⅱ A groups gradually increased with the elevation of Tanshinone Ⅱ A dosage,with significant differences between any two groups (all at P＜0.05).The cell proportion in the G0/G1 phase gradually increased,while the cell proportion in the S phase gradually decreased along with the elevation of Tanshinone Ⅱ A concentration,significant differences were obtained among the hypoxia control group,1,5 and 10 mg/L Tanshinone Ⅱ A groups (all at P＜0.05).RT-PCR and Western blot showed that the relative expression of VEGF mRNA,HIF-1 α and VEGF protein in the the blank control group,hypoxia control group,1,5 and 10 mg/L Tanshinone Ⅱ A groups and HIF-1α inhibitor group were significantly different (all at P＜0.05).The expression of VEGF mRNA,HIF-1α and VEGF protein decreased successively in the 1,5 and 10 mg/L Tanshinone Ⅱ A groups,with significant differences between them (all at P＜0.05).There were no significant differences between 10 mg/L Tanshinone Ⅱ A and the HIF-1 α inhibitor group of all the test indexes(all at P＞0.05).Conclusions Tanshinone Ⅱ A can inhibit the proliferation of RPE cells,induce apoptosis by arresting cells at G0/G1 phase.The mechanism is related to the suppression of HIF-1 α/VEGF signaling pathway.