Relevance of Syndecan-1 in the Trophoblastic BeWo Cell Syncytialization

Problem To investigate the role of syndecan-1 in the differentiation of the BeWo cells into syncytiotrophoblast. Method of study BeWo cells were stimulated with forskolin to form syncytia, and the expression of syndecan-1, desmoplakin I+II, human chorionic gonadotrophin (hCG) and angiogenesis-associated factors was analyzed. Syndecan-1 was silenced by siRNA to evaluate its involvement in the forskolin-mediated syncytia formation. Results Treatment of the BeWo cells with forskolin led to a significant increase in the syncytia formation. It was associated with an increase in the expression of syndecan-1 with a concomitant decrease in the expression of desmoplakin I+II. Forskolin treatment of the BeWo cells also led to an increase in the secretion of soluble endoglin, whereas no change was observed in the soluble fms-like tyrosine kinase-1. Silencing of the syndecan-1 expression in BeWo cells led to a significant decrease in cell fusion both in the presence and in the absence of forskolin. It was associated with a significant decrease in hCG level in the conditioned medium. Conclusion Syndecan-1 is up-regulated in BeWo cells during differentiation and its silencing inhibits syncytialization and thus could be a useful biomarker for syncytiotrophoblast formation.