Dystroglycan expression in human placenta: Basement membrane localization and subunit distribution change between the first and third trimester

Objectives: This study describes the distribution of dystroglycan (DG) in human placenta, membranes, and uterine decidua. Study design: Dystroglycan expression was characterized by Western blotting, immunohistochemistry, and immunofluorescence microscopy using human tissues and cultured cells. Results: Both α-DG and β-DG are expressed in the term syncytiotrophoblast, and α-DG is localized to the basement membrane. In first-trimester chorionic villi, α-DG and β-DG are localized to the periphery of the cytotrophoblast. Expression varies in term fetal membranes. α-Dystroglycan is not detectable in choriocarcinoma cells or HTR cells, but β-DG is present in both normal and cleaved forms. Conclusion: Dystroglycan is expressed at high levels in human trophoblasts, and localization of the α- and β-subunits varies with gestational age and trophoblast differentiation. Because DG expression inversely correlates with invasiveness in many cancers, its pattern of expression in trophoblasts suggests a possible function in inhibition of placental invasion.