Visfatin in adipocytes is upregulated by hypoxia through HIF1α-dependent mechanism
- 作者：Katsumori Segawa ; Atsunori Fukuhara ; Naomi Hosogai ; Kentaro Morita ; Yosuke Okuno ; Masaki Tanaka ; Yasuhiko Nakagawa ; Shinji Kihara ; Tohru Funahashi ; Ryutaro Komuro et al.
- 关键词：Visfatin ; Hypoxia ; HIF1α ; Obesity ; Metabolic syndrome
- 刊名：Biochemical and Biophysical Research Communications
- 出版年：2006
- 期刊代码：159_0006291x
- 类别：bio
- 出版时间：27 October 2006
- 卷：349
- 期：3
- 页码：875-882
- 文件大小：310 K
摘要
Obesity is associated with metabolic disorders, such as insulin resistance. Visfatin is an adipose-derived secretory factor to exert insulin-mimetic effects. Plasma visfatin levels and mRNA levels of visfatin in adipose tissues are increased in obesity. However, the mechanism that mediates induction of visfatin mRNA in adipose tissue of obesity remains unknown. Recent studies have reported that fat tissue is hypoxia in obesity. In this study, we investigated the effects of hypoxia on mRNA expression of visfatin in adipocytes. Hypoxia increased visfatin mRNA expression. Desferoxamine and Cobaltous chloride, two hypoxia mimetic compounds, also increased visfatin mRNA levels. Dimethyloxallyl glycine, a stabilizer of hypoxia-inducible factor 1α (HIF1α), mimicked the hypoxia-mediated upregulation of visfatin, and YC1, an inhibitor of HIF1 cancelled the hypoxia-induced upregulation of visfatin mRNA. We identified two functional hypoxia responsive elements (HRE) in mouse visfatin promoter. Hypoxic treatment and overexpression of HIF1α increased the promoter activity, and mutation of the HRE blunted hypoxia-induced activation of visfatin promoter. Our results suggest that visfatin mRNA expression is upregulated in the fat tissue of obesity through the activation of HIF1α pathway due to hypoxia.