The Expression Of Galectin-1and Its Regulatory Molecules In The Process Of Trophoblast Stem Cell Proliferation And Differentiation

Background:Trophoblastic proliferation and differentiation in an orderly manner play an important role in the process of embryonic implantation, placentation and maintenance of early pregnancy. Previous study showed that embryo implantation failure and early pregnancy loss (EPL) are related with poor trophoblastic proliferation and differentiation. Our previous proteomics study on human EPL chronic tissues found that Galectin-1(Gal-1) was significantly downregulated in trophoblast cells of EPL compared with the controls, which may suggestthat Gal-1plays an important role in early placental development and has a critical function in maintenance of pregnancy. We used TSC to study mechanisms of trophoblast cells in maintenance of pregnancy.Objective:The experiment is to evaluate the expression of Gal-1and related molecules during the process of trophoblastic proliferation and differentiation by using mouse trophoblast stem cells(TSC) model. The aim of this study is to reveal the pathogenesis of EPL, and find possible cellular and molecular treatment target. Materials and methods:TSC was cultured and induced to differentiate. QRT-PCR method was to detect the expression of markers in TSC proliferation and differentiation. Gal-1expression profile during the process of stem cell proliferation and differentiation was detected in mRNA and protein levels. Bisulfite sequencing method was used to detect promoter methylation levels of Gal-1in this state.Results:1. Gal-1expression of differentiated TSC was significantly upregulated at3-5days.2. Frequency of Gal-1promoter methylation decreased during differentiation. The frequency is about1.4%at Stem cell state, and then gradually declines to the lowest about0on the fifth day of differentiation, followed by increasing to1%.3. The expression and promoter methylation frequency of Gal-1were negatively correlated during the TSC differentiation process, Gal-1expression increased to a peak on the fifth day, while methylation frequency dropped to the lowest point.4. The expression of P-catenin, the key factor of cell fusion, and Gal-1was negatively correlated.Conclusion:1. The expression of Gal-1is significantly increased during TSC differentiation, which may be a role during TSC differentiation and fusion.2. The expression of Gal-1is relevant to the methylation of promoter.3. Gal-1may interact with β-catenin during differentiation and fusion of TSC.