Abstract: Objective To investigate the effects of hypoxia on the proliferation of trophoblast cell line HTR-8/SVneo cells and the protein expression of hypoxia inducer (HIF) -1α, vascular endothelial growth factor (VEGF), matrix metalloproteinase (MMP) -9 and tissue inhibitor of matrix metalloproteinase 1 (TIMP-1). Methods HTR-8/SVneo cells were treated with 0, 50, 100, 200, 400, 800, 1 000, 1 200 μmol/L CoCl2 to establish the chemical hypoxia model. The proliferation of HTR-8/SVneo cells was detected by CCK8 method after 24 h and 48 h culture at the above concentration. According to the results of CCK8 experiment, the hypoxic, medium and high concentration groups were determined. Western blot assay was used to detect changes of the protein expression levels of HIF-1α, VEGF, MMP-9 and TIMP-1 in HTR-8/ SVneo cells in the hypoxic, medium and high concentration groups. Results CCK8 experiment showed that hypoxia activated the proliferation of HTR-8/SVneo cells. After treatment with CoCl2 on HTR-8/SVneo cells for 48 hours, the OD value increased with the increase of concentration. Under the same CoCl 2 concentration, the OD value of 48 h was higher than that of 24 h. The 100, 200 and 400 μmol/ L CoCl2 were used as the low, medium and high concentration groups. After 48 hours, compared with the blank group, the expression levels of HIF-1α, MMP-9 protein in HTR-8/SVneo cells were upregulated in the low, medium and high concentration groups (P＜0.05). The ratio of MMP-9/TIMP-1 increased in a concentration dependent manner (P＜0.05). The protein expression of VEGF was upregulated in the hypoxia, medium and high concentration groups (P＜0.05). The expression level of TIMP-1 protein decreased in the low, medium and high CoCl2 groups, but it showed an increased trend with the increased CoCl2 concentrations. Conclusion Hypoxia can enhance the proliferation of HTR-8/SVneo cells, and the expression of VEGF and the ratio of MMP-9/TIMP-1 can be upregulated by HIF-1α.

Key words: hypoxia, cell proliferation, hypoxia-inducible factor 1, alpha subunit, matrix metalloproteinase 9, vascular endothelial growth factors, trophocyte