Expression and transcriptional regulation of individual pregnancy-specific glycoprotein genes in differentiating trophoblast cells

CAMOLOTTO, SOLEDAD; RACCA, ANA; RENA, VIVIANA; NORES, RODRIGO; PATRITO, LUIS; GENTI-RAIMONDI, SUSANA; PANZETTA-DUTARI, GRACIELA

PLACENTA

W B SAUNDERS CO LTD

Año: 2010 p. 912 - 921

0143-4004

Human pregnancy-specific glycoproteins (PSGs) are the major placental polypeptides encoded by eleven highly conserved genes. Low PSG levels have been associated with complicated pregnancies. However, expression of each PSG gene and their regulation during cytotrophoblast cell differentiation remain poorly explored. Herein, we analyze the expression of five PSG genes and demonstrate that they are almost undetectable in undifferentiated trophoblast, but are all transcribed in differentiated cells. Among them, PSG1, PSG3 and PSG5 genes achieve high mRNA levels, while PSG7 and PSG9 are poorly expressed. In addition, total PSG proteins and transcripts markedly increase during trophoblast differentiation, preceding morphological syncytialization and βhCG mRNA synthesis. The 5´ regulatory region contributes to the transcriptional control of PSG genes induction in trophoblast cells undergoing differentiation. This responsive region in PSG3 maps within a 130 bp promoter sequence, overlapping the transcription start site. Present findings provide novel data for understanding the control of PSG gene expression and demonstrate that their proteins and transcripts represent early markers of trophoblast differentiation. Understanding the molecular events involved in their expression may give insights into both physiological and pathophysiological processes during trophoblast differentiation into syncytium.