Function And Mechanism Of CD44v6 In Trophoblast Cells Of Recurrent Spontaneous Abortion

ObjectiveRecurrent Spontaneous Abortion(RSA)affects about 1 percent of the world’s fertile couples.Although a number of basic studies have elucidated its possible mechanism,about half of the causes of patients with recurrent abortion are still unknown.Due to its high incidence and low cure rate,many patients and families suffered a lot.The proliferation,migration and invasion of trophoblast cells play an important role in the establishment and maintenance of pregnancy.Damage to trophoblast cells is reported to be associated with recurrent abortion,but the underlying mechanism remains unknown.CD44 variant domain 6(CD44v6)is a transmembrane glycoprotein known to be expressed in placenta for decades.In this study,the expression and correlation of CD44v6 and Nuclear Factor NF kappa B in recurrent abortion were studied,and the effects of CD44v6 and NF expressed B pathway on the proliferation and invasion of trophoblast cells were studied,as well as the related mechanism of action,further clarifying the mechanism of action of CD44v6 on recurrent spontaneous abortion.MethodsThe study was conducted from March 2015 to March 2016 in the outpatient operation room of the Department of Gynaecology and Obstetrics of Renmin Hospital at Wuhan University.Patients who had at least two consecutive spontaneous abortions and were 7-10 weeks pregnant were allocated to the RSA group(n = 10),and the women with no history of spontaneous abortion and also with a gestation period of 7～10 weeks were enrolled into the control group(n = 10).All participants were non-smokers,not on medication,and had regular menstrual cycles.The expression levels of CD44v6 and NF κ B in the two groups were detected by immunohistochemistry.The trophoblast cells HTR-8/SVneo were cultured and divided into two groups:(1)the experimental group:transfection of CD44v6 specific siRNA into trophoblast cell line HTR-8/SVneo cells via LipofectamineTM 2000;(2)the negative control group:transfected empty vector into trophoblast cell line HTR-8/SVneo by LipofectamineTM 2000;(3)the blank control group:HTR-8/SVneo cells without liposome transfection.The expression levels of CD44v6 and NF κ B were detected after transfection,and the proliferation and invasion functions of trophoblast cells were detected by cloning formation assay and Transwell cell invasion experiment,what’s more,and the localization and quantification of CD44v6 and NF κ B were determined by immunofluorescence experiment.Results1.In patients with RSA,the expression of CD44v6 and NFκB decreased,and the abnormal regulation of CD44v6 and NFκB was related to RSA.2.Downregulation of CD44v6 in human trophoblast cells can lead to the decrease of the expression level of NFκB.3.Downregulation of CD44v6 in human trophoblast cells can result in decreased proliferation and invasion ability of trophoblast cells,and significantly reduce the nuclear aggregation of NFκB.ConclusionsCD44v6 may affect the proliferation and invasion of human trophoblast cells by regulating the expression and nuclear aggregation of NF κ B in human trophoblast cells,and eventually lead to RSA.