The role of stomatin in trophoblast cell differentiation

• Main Authors: Tung-Wei Chen, 陳同偉
• Other Authors: Chi-Hung Lin
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/70778819911311306556

博士 === 國立陽明大學 === 生醫光電研究所 === 104 === Placental trophoblast differentiation involves the continuous fusion of mononuclear cytotrophoblasts. However, except for syncytin, little is known about the detailed mechanism underlying trophoblast fusion. A previous study indicated that lipid rafts play an important role in HTLV-1 syncytium formation. To identify proteins that may be involved in placental trophoblast differentiation, we examined stomatin, an important lipid-raft protein that localizes to detergent-resistant membrane domains. The syncytium and human chorionic gonadotropin (β-hCG; a marker of placenta trophoblast differentiation) were visualized by immunofluorescence staining. We found that over-expression of stomatin in the non-fusogenic JEG-3 cell line caused syncytium formation and increased the fusion index of cells. Treating these cells with N6,2ʹ-O-dibutyryladenosine 3ʹ,5ʹ-cyclic monophosphate further increased cell fusion by stomatin. β-hCG was found in a few JEG-3 cells over-expressing stomatin at 48 h and its levels increased dramatically at 72 h along with the multi-nuclear syncytium. RNA interference was used to decrease stomatin expression in BeWo cells, a fusogenic human choriocarcinoma cell line. After knockdown for 72 h, stomatin levels decreased by almost 95%. The fusion indexes of control and stomatin knockdown cells at 72 h were 9.4 and 6.5%, respectively. Our data indicate that stomatin can trigger syncytium formation and upregulate β-hCG for cell fusion in non-fusogenic JEG-3 cells. Downregulation of stomatin slightly inhibited the fusion index of fusogenic BeWo cells. Thus, these data suggest that stomatin may play an important role in trophoblast differentiation.