Gene Expression and Biological Function of Pregnancy-Specific Glycoproteins

LÓPEZ-DÍAZ, F.; KORITSCHONER, N.; NORES, R.; PANZETTA-DUTARI, G.; PATRITO, L.C.; BOCCO, J.L.

Embu das Artes, San Pablo

Simposio; Ist Latin-American Symposium on Maternal-Fetal Interaction - Placenta: Clinical & Research (I-SLIMP); 2003

Sociedad Latinoamericana de Investigaciones Materno-Fetales y Placentarias

Pregnancy-specific Glycoproteins (PSGs) are the major placental proteins secreted by the syncitiotrophoblast, coded by 11 highly homologous genes. They have been demonstrated to induce the synthesis of anti-inflammatory cytokines such as IL-10 and TGF-B in monocytic cell lineages. Furthermore, we describe the effect of PSG1a in Arginase activity on human and murine monocytes, suggesting the participation of PSGs in immune system modulation at early steps in gestation through alternative monocyte activation. Transcriptional regulation of PSGs genes remains to be elucidated. However, several positive and negative regulatory regions have been described in our laboratory. We have just demonstrated that the ubiquitous transcription factor Sp1 is the major interacting protein with PSG5 gene core promoter element in placental cell extracts. Additionally, activation of PSG5 promoter by RXRa was demonstrated. RXRa showed a biphasic activity on PSG5 promoter activation, either enhancing Sp1-mediated activation or through the classical ligand-dependent pathway. Present data suggest a major role of the core promoter element of PSGs genes in the integration of several regulatory signals. The regulation of PSGs genes expression by retinoids and their receptors may contribute to explain how PSGs function is executed from early steps during pregnancy.