Upstream stimulatory factors regulate aortic preferentially expressed gene-1 expression in vascular smooth muscle cells.
The phenotypic modulation of vascular smooth muscle cells (VSMC) plays a central role in the pathogenesis of arteriosclerosis. Aortic preferentially expressed gene-1 (APEG-1), a VSMC-specific gene, is expressed highly in differentiated but not in dedifferentiated VSMC. Previously, we identified an E-box element in the mouse APEG-1 proximal promoter, which is essential for VSMC reporter activity. In this study, we investigated the role of upstream stimulatory factors (USF) in the regulation of APEG-1 transcription via this E-box element. By electrophoretic mobility shift assays, recombinant USF1 and USF2 homo- and heterodimers bound specifically to the APEG-1 E-box. Nuclear extracts prepared from primary cultures of rat aortic smooth muscle cells exhibited specific USF1 and USF2 binding to the APEG-1 E-box. To investigate the binding properties of USF during VSMC differentiation, nuclear extracts were prepared from the neural crest cell line, MONC-1, which differentiates into VSMC in culture. Maximal USF1 and USF2 protein levels and binding to the APEG-1 E-box occurred 3 h after the differentiation of MONC-1 cells was initiated. Co-transfection experiments demonstrated that dominant negative USF repressed APEG-1 promoter activity, and USF1, but not USF2, transactivated the APEG-1 promoter. Our studies demonstrate that USF factors contribute to the regulation of APEG-1 expression and may influence the differentiation of VSMC.
Chen
Y H
YH
Pulmonary and Critical Care and Cardiovascular Divisions, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, USA.
Layne
M D
MD
Watanabe
M
M
Yet
S F
SF
Perrella
M A
MA
D000818:Animals; D001011:Aorta / Q000378:metabolism*; D001013:Aorta, Thoracic / Q000166:cytology / Q000378:metabolism; D015152:Blotting, Northern; D015153:Blotting, Western; D002454:Cell Differentiation; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D004268:DNA-Binding Proteins; D019281:Dimerization; D004305:Dose-Response Relationship, Drug; D005786:Gene Expression Regulation; D005799:Genes, Dominant; D008156:Luciferases / Q000378:metabolism; D008297:Male; D009130:Muscle, Smooth / Q000166:cytology; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000378:metabolism*; D010641:Phenotype; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism*; D014158:Transcription, Genetic; D014162:Transfection; D051720:Upstream Stimulatory Factors
D004268:DNA-Binding Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; D051720:Upstream Stimulatory Factors; C497182:Usf1 protein, rat; C497187:Usf2 protein, rat; D008156:Luciferases