Expression of Pregnancy-Specific Glycoproteins in in vitro differentiation systems

R. NORES; S. ANGELETTI; S. CAMOLOTTO; L. PATRITO; G. PANZETTA-DUTARI

Santiago

Simposio; II Latin-American Symposium on Fetal-Maternal Interaction and Placenta: From Basic to Clinical Research (II-SLIMP) and XIX Annual Meeting of the Chilean Society of Physiological Sciences; 2005

Chilean Society of Physiological Sciences

Human pregnancy-specific glycoproteins (PSGs) are encoded by 11 highly similar and transcriptionally active genes, essential for the maintenance of gestation. High levels of PSGs biosynthesis are restricted to the placenta syncytiotrophoblast (STB), and only very low levels are found in other cell types, such as the choriocarcinoma Jeg3 cell line. This cell line can be induced to mimic a syncytialization process, which is accompanied by the secretion of trophoblast specific differentiation markers, such as hCG. The purpose of this work was to analyze the expression of PSGs proteins and transcripts in cytotrophoblast (CTB) and Jeg3 differentiation systems. Isolated CTB cells were differentiated to STB by incubating during 72 hs in KGM media supplemented with EGF and 10 % FBS. Besides, Jeg3 and PSG-non-expressing COS7 cultures were daily treated for 5 days with 1 µM MTX. In vitro differentiated STB, but not isolated CTB cells, and MTX-differentiated Jeg3, but not COS7 cells, expressed high levels of PSG that were detected by western blot, semi-quantitative RT-PCR and immunocytochemistry. PSG transcripts and proteins follow a similar expression pattern in normal human trophoblast and choriocarcinoma Jeg3 cells differentiation systems. In addition, the present results indicate that PSGs are early biochemical markers of trophoblast differentiation preceding morphological differentiation in both systems. Supported by CONICET, FONCyT and SECyT-UNC.