Expression of MTA1 in preeclamptic placental tissue and its effects on trophoblast function

Abstract

Objective·To investigate the expression of metastasis-associated protein 1 (MTA1) in placental tissues of preeclampsia (PE) patients and its impact on trophoblast cell function.Methods·Placental specimens were collected from pregnant women with PE (PE group, 20 cases) patients and healthy pregnant women as controls (control group, 35 cases). Western blotting and immunofluorescent double staining were performed to analyze the expression changes of MTA1. The human first-trimester placental trophoblast cell line HTR8/SVneo was cultured, and the cell migration ability was assessed through wound healing assay. The cell invasion ability was detected using Transwell invasion assay. Under hypoxic conditions simulating the invasion of extravillous trophoblasts into the uterus, quantitative real-time polymerase chain reaction (qRT-PCR) was performed to analyze the mRNA expression of hypoxia-induced matrix metalloproteinases (MMP-2 and MMP-9), thus assessing their secretion levels. An extravillous trophoblast explant model was constructed to assess the overall villus outgrowth capacity of the explants. Immunohistochemistry (IHC) was performed to confirm the presence of the endothelial marker CD31 for placental angiogenesis analysis in mice. Fifteen Mta1-/- female mice and fifteen wild-type C57 female mice were mated with wild-type male C57 mice for fertility testing.Results·Western blotting revealed significantly decreased expression of MTA1 protein in placental tissues of the PE group compared to the control group. Immunofluorescent double staining showed that MTA1 was mainly localized in the nuclei of trophoblast cells. The wound healing assay demonstrated that HTR8/SVneo with stable MTA1 knockdown exhibited weaker cell migration ability compared to the control group (P=0.002). The Transwell invasion assay demonstrated a marked decrease in invasiveness in MTA1-knockdown cells, significantly lower than the control group (P=0.015). Hypoxia-induced expression levels of matrix metalloproteinases MMP-2 and MMP-9 were significantly reduced (P=0.020, P=0.003). After MTA1 knockdown, the overall villus outgrowth capacity of the explants was decreased compared to the control group (P=0.003). IHC results showed that CD31 expression in the placenta of Mta1-/- female mice was significantly lower than that of wild-type female mice (P=0.004). The litter size of Mta1-/- female mice was significantly reduced (P=0.000).Conclusion·The expression level of MTA1 is closely related to PE. Endogenous MTA1 may be involved in trophoblast invasion into the endometrium and villous capillary remodeling.

Keywords

• preeclampsia (pe)
• metastasis-associated protein 1 (mta1)
• extravillous trophoblast (evt)