MiRNA-222 Affects Trophoblast Function By Regulating The Expression Of PTEN

【Objective】The study is conducted to investigate the effects of miR-222 on trophoblast functions including migration,invasion,proliferation,apoptosis and tube formation ability by regulating the expression of miR-222 in human trophoblast cell line(HTR-8/SVneo).To investigate the correlation between miR-222 and PTEN as well as its possible mechanism in the pathogenesis of preeclampsia.【Methods】HTR-8/SVneo was transfected with miR-222 mimic and miR-222 inhibitor to up-regulate or inhibit miR-222,and the negative control was transfected at the same time,then q RT-PCR was performed to detect the expression of miR-222.Transwell assay was used to detect the invasion and migration ability of transfected HTR-8/SVneo,the ability of cells to migrate after transfection was also determined by wound healing assay.Proliferation,cell cycle and apoptosis of transfected cells were measured by CCK8 assay and flow cytometry respectively,tube formation assay was conducted to evaluate angiogenesis ability.Then through the q RT-PCR to detect the expression of PTEN m RNA in transfected cells,the expression level of PTEN and apoptosis-related factor Caspase9 protein in transfected cells were detected by western blotting.Placenta and first-trimester villi were collected,the location and expression of PTEN in placenta and first-trimester villi were shown by immunohistochemistry.The expression of PTEN were detected by q RT-PCR and western blotting,meanwhile,the expression of miR-222 in the placenta was detected.【Results】Overexpression of miR-222 can enhance the invasion,migration,proliferation and tube formation ability of HTR-8/SVneo cells and weaken the cell apoptosis ability,while inhibition of miR-222 can weaken the invasion,migration,proliferation and tube formation ability of HTR-8/SVneo cells and enhance the apoptosis ability.After overexpression of miR-222,the m RNA and protein level of PTEN in HTR-8/SVneo cells decreased,while the expression of apoptosis-related factor Caspase9 protein also decreased.After inhibition of miR-222,the m RNA and protein expression of PTEN increased,while the expression of apoptosis-related factor Caspase9 protein also increased.PTEN was expressed in the placenta of normal and preeclampsia as well as first-trimester villus and located in the trophoblast cells.Compared with normal placenta,the expression of miR-222 in preeclamptic placenta decreased while the expression level of PTEN increased.【Conclusions】Overexpression of miR-222 can promote invasion,migration,proliferation and angiogenesis ability of HTR-8/SVneo cells and inhibit their apoptosis.However,the inhibition of miR-222 can weaken the invasion,migration,proliferation and angiogenesis ability of HTR-8/SVneo cells and promote their apoptosis,indicating that miR-222 has a regulatory effect on the biological function of trophoblast cells.Mi R-222 may regulate trophoblast by regulating the expression of PTEN,leading to placental dysfunction,which is a possible mechanism involved in the pathogenesis of preeclampsia.