title: Upstream stimulatory factor induces Nr5a1 and Shbg gene expression during the onset of rat Sertoli cell differentiation.
abstract: Within the testis, each Sertoli cell can support a finite number of developing germ cells. During development, the cessation of Sertoli cell proliferation and the onset of differentiation establish the final number of Sertoli cells and, thus, the total number of sperm that can be produced. The upstream stimulatory factors 1 and 2 (USF1 and USF2, respectively) differentially regulate numerous Sertoli cell genes during differentiation. To identify genes that are activated by USF proteins during differentiation, studies were conducted in Sertoli cells isolated from 5- and 11-day-old rats, representing proliferating and differentiating cells, respectively. Usf1 mRNA and USF1 protein levels were increased between 5 and 11 days after birth. In vitro studies revealed that USF1 and USF2 DNA-binding activity also increased at 11 days for the promoters of four potential target genes, Fshr, Gata4, Nr5a1, and Shbg. Chromatin immunoprecipitation assays confirmed that USF recruitment increased in vivo between 5 and 11 days after birth at the Fshr, Gata4, and Nr5a1 promoters. Expression of Nr5a1 and Shbg, but not of Fshr or Gata4, mRNAs was elevated in 11-day-old Sertoli cells compared with 5-day-old Sertoli cells. Transient transfection of USF1 and USF2 expression vectors up-regulated Nr5a1 and Shbg promoter activity. RNA interference assays demonstrated that USF1 and USF2 contribute to Nr5a1 and Shbg expression in differentiating cells. Together, these data indicate that increased USF levels induce the expression of Nr5a1 and Shbg during the differentiation of Sertoli cells, whereas Fshr and Gata4 expression is not altered by USF proteins during differentiation.
authors: Center for Research in Reproductive Physiology, Department of Obstetrics, Gynecology, and Reproduction Services, Magee Women's Research Institute, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA.
authors: Michelle A
authors: MA
authors: Wood
authors: Priya
authors: P
authors: Mukherjee
authors: Corey A
authors: CA
authors: Toocheck
authors: William H
authors: WH
authors: Walker
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002454:Cell Differentiation / Q000502:physiology*; D050991:GATA4 Transcription Factor / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D008297:Male; D023421:Models, Animal; D011401:Promoter Regions, Genetic / Q000502:physiology; D034622:RNA Interference; D051381:Rats; D017207:Rats, Sprague-Dawley; D011962:Receptors, FSH / Q000378:metabolism; D012708:Sertoli Cells / Q000166:cytology* / Q000502:physiology; D012738:Sex Hormone-Binding Globulin / Q000378:metabolism*; D054339:Steroidogenic Factor 1 / Q000378:metabolism*; D051720:Upstream Stimulatory Factors / Q000378:metabolism*
chemical_list: D050991:GATA4 Transcription Factor; C084365:Gata4 protein, rat; D011962:Receptors, FSH; D012738:Sex Hormone-Binding Globulin; D054339:Steroidogenic Factor 1; D051720:Upstream Stimulatory Factors; C497182:Usf1 protein, rat; C497187:Usf2 protein, rat; C515060:steroidogenic factor 1, rat