Involvement of transcription factor NR2F2 in human trophoblast differentiation.
BACKGROUND
During the in vitro differentiation of human villous cytotrophoblast (CTB) cells to a syncytiotrophoblast (STB) phenotype, mRNA levels for the nuclear hormone receptor NR2F2 (ARP-1, COUP-TFII) increase rapidly, reaching a peak at day 1 of differentiation that is 8.8-fold greater than that in undifferentiated CTB cells. To examine whether NR2F2 is involved in the regulation of villous CTB cell differentiation, studies were performed to determine whether NR2F2 regulates the expression of TFAP2A (AP-2alpha), a transcription factor that is critical for the terminal differentiation of these cells to a STB phenotype.
Overexpression of NR2F2 in primary cultures of human CTB cells and JEG-3 human choriocarcinoma cells induced dose-dependent increases in TFAP2A promoter activity. Conversely, siRNA mediated silencing of the NR2F2 gene in villous CTB undergoing spontaneous differentiation blocked the induction of the mRNAs for TFAP2A and several STB cell specific marker genes, including human placental lactogen (hPL), pregnancy specific glycoprotein 1 (PSG1) and corticotropin releasing hormone (CRH) by 51-59%. The induction of TFAP2A promoter activity by NR2F2 was potentiated by the nuclear hormone receptors retinoic acid receptor alpha (RARA) and retinoid X receptor alpha (RXRA).


CONCLUSIONS
Taken together, these results strongly suggest that NR2F2 is involved in villous CTB cell differentiation and that NR2F2 acts, at least in part, by directly activating TFAP2A gene expression and by potentiating the transactivation of TFAP2A by RARA and RXRA.
Hubert
Michael A
MA
Department of Pediatrics, University of Cincinnati, Cincinnati, Ohio, United States of America.
Sherritt
Susan L
SL
Bachurski
Cindy J
CJ
Handwerger
Stuart
S
D051837:COUP Transcription Factor II / Q000235:genetics*; D002454:Cell Differentiation / Q000235:genetics*; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D020869:Gene Expression Profiling; D006801:Humans; D011401:Promoter Regions, Genetic / Q000235:genetics; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018168:Receptors, Retinoic Acid / Q000235:genetics; D000072482:Retinoic Acid Receptor alpha; D047490:Retinoid X Receptor alpha / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D050656:Transcription Factor AP-2 / Q000235:genetics; D014162:Transfection; D014327:Trophoblasts / Q000166:cytology / Q000378:metabolism*
D051837:COUP Transcription Factor II; D012333:RNA, Messenger; D018168:Receptors, Retinoic Acid; D000072482:Retinoic Acid Receptor alpha; D047490:Retinoid X Receptor alpha; D050656:Transcription Factor AP-2; C000607071:RARA protein, human; C493673:TFAP2A protein, human; C095569:NR2F2 protein, human