MNSFβ Promotes the Proliferation and Migration of Human Extravillous Trophoblast Cells and the Villus Expression Level of MNSFβ Is Decreased in Recurrent Miscarriage Patients

Aims The invasion of extravillous trophoblast (EVT) cells into maternal decidua is essential for the establishment and maintenance of pregnancy. Derangement of EVT cell invasion might cause pregnancy complications including recurrent miscarriage (RM). We previously reported that deficiency of monoclonal nonspecific suppressor factor beta (MNSFβ) led to the early pregnancy failure in mice and the decidual MNSFβ expression level in RM patients was significantly decreased, but the underlying molecular mechanism of the role that MNSFβ played at the maternal-fetal interface remains unclear. Thus, in the present study, we determined effects of downregulated MNSFβ expression on human EVT cell activities. Methods The MNSFβ expression in first-trimester human decidual and placental villus tissues was detected, respectively, by immunofluorescence or immunohistochemical analyses. The MNSFβ expression level in the immortalized first-trimester human EVT cell line HTR8/SVneo was downregulated by transfecting the small interfering RNA against MNSFβ and upregulated by transfecting the recombinant pDsRed-MNSFβ plasmids. The proliferation, migration, invasion, and apoptosis activities of HTR8/SVneo cells were, respectively, determined by cytometry assay, scratch test, transwell assay, and FITC/PI staining. The expression levels of P53, RhoA, Bcl-2, Bax, and MMP-9 in HTR8/SVneo cells, as well as the expression levels of MNSFβ and RhoA in placental villi of RM patients and physically normal pregnant women (NP), were examined by Western blot analysis. Results MNSFβ protein signals were observed in first-trimester human villus and extravillous trophoblast cells. The downregulated MNSFβ expression significantly attenuated the proliferation, migration, and invasion abilities of HTR8/SVneo cells, accompanied with the obviously decreased expression levels of P53, RhoA, Bcl-2, Bax, and MMP-9, whereas the upregulated MNSFβ expression in HTR8/SVneo cells represented the inverse effects. Furthermore, expression levels of MNSFβ and RhoA in first-trimester human placental villus tissues of RM patients were significantly decreased compared to that of NP women. Conclusion These data suggested that MNSFβ promotes proliferation and migration of human EVT cells, probably via the P53 signaling pathway, and the deficiency of MNSFβ in placental villi might lead to early pregnancy loss by reducing proliferation and invasion activities of EVTs.