Comparative analyses on expression of galectins1-4, 7-10 and 12 in first trimester placenta, decidua and isolated trophoblast cells in vitro

INTRODUCTION: Galectins are members of the mammalian β-galactoside-binding proteins, which recognize Galβ1-4GlcNAc sequences of several cell surface oligosaccharides. Plenty of galectins are already described in human tissue, especially in placenta. Here, gal-1-4, 7-10 and gal-12 were investigated systematically in trophoblast and decidua cells of first trimester placentas.

MATERIAL AND METHODS: Within this study, 15 first trimester placentas after induced abortion (7th-14th week of gestation) were examined with immunohistology and immunofluorescence based on a scoring system. Moreover, isolated and cultivated trophoblast cells from the first trimester were analyzed and evaluated for expression of gal-1-4, gal-7-10 and gal-12 at mRNA and protein level with real-time RT-Polymerase chain Reaction/PCR (Taq-Man). Double immuno-fluorescence with trophoblast specific markers identified galectin expressing cells at the feto-maternal interface.

RESULTS: We could detect immunohistochemical staining of galectins 1-4, 7-10 and 12 in first trimester placenta: all examined galectins were found in the Cytotrophoblast (CTB) and syncytiotrophoblast (SCT). Gal-1, -2, -3, -4, -7, -8, -9, -10 and -12 were identified in extravillous trophoblast cells (EVT) in immunohistology and immunoflourescence. The expression of gal-1, -9, -10, and gal-12 increased after 96h incubation in vitro without stimulation at mRNA level, while gal-2, -3, -4, -7 and -8 were decreased.

DISCUSSION AND CONCLUSION: This study describes a systematic analysis of the expression of gal-1-4, gal-7-10 and gal-12 in first trimester placentas and isolated trophoblast cells. Expression levels at mRNA level and the change within 96h cultivation in vitro indicate a possible influence on syncytium building of trophoblast cell on expression of galectins. Therefore, an interaction of galectins in vitro in syncytium building is possible.