Diabetes 53:2757-2766, 2004 © 2004 by the American Diabetes Association, Inc. CCAAT/Enhancer Binding Protein and Nuclear Factor-Y Regulate Adiponectin Gene Expression in Adipose Tissue
1 Department of Biochemistry and Molecular Biology, Institute of Genetic Science, Seoul, Korea Adiponectin is one of the adipokines secreted by adipocytes and regulates energy homeostasis associated with insulin sensitivity, suggesting a possibility of nutritional regulation of adiponectin gene expression. In this study, we showed that the transcription of adiponectin gene was induced 46 h after refeeding of mice. Also, differentiated 3T3-L1 adipocytes that were treated with high glucose expressed significantly increased adiponectin mRNA. Promoter analysis using nuclear extracts from white adipose tissue revealed that CCAAT/enhancer binding protein (C/EBP) and nuclear factor-Y (NF-Y) bound on the 117/73 region of the adiponectin promoter. This region was critical for the activity of the adiponectin promoter as the deletion or mutation of this region markedly diminished the promoter activity to a basal level. Furthermore, the C/EBP binding increased in both refed animal and high glucose-treated 3T3-L1 adipocytes in an electrophoretic mobility shift assay, suggesting that C/EBP is responsible for the dietary response of the adiponectin gene expression. Chromatin immunoprecipitation studies demonstrated the binding of C/EBP and NF-Y in both mouse and differentiated 3T3-L1 adipocytes and also that C/EBP binding increased in response to high glucose. These findings demonstrated that C/EBP and NF-Y are critical for the regulation of the adiponectin expression in response to nutrients and in the course of adipocyte differentiation.
Address correspondence and reprint requests to Jae-woo Kim, MD, PhD, Department of BiochemistryMolecular Biology, Yonsei University College of Medicine, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-752, Korea. E-mail: japol13{at}yumc.yonsei.ac.kr
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