Adipokine expression in brown and white adipocytes in response to hypoxia

作者:Wree A*; Mayer A; Westphal S; Beilfuss A; Canbay A; Schick R R; Gerken G; Vaupel P
来源:Journal of Endocrinological Investigation, 2012, 35(5): 522-527.
DOI:10.3275/7964

摘要

Backgroud: Adipose tissue has emerged as an important endocrine regulator by secreting hormones referred to as adipokines. Recent studies showed that adipose tissue considerably responds to hypoxia. Although the impact of white adipose tissue on regulative processes is established, the importance of brown adipose tissue in adults has emerged just recently. Methods: Brown (BA) and white adipocytes (WA) were cultured either in the presence of chemical hypoxia-mimetics or under hypoxic atmosphere of 1% oxygen. Expression of hypoxia-inducible factor 1 alpha (HIF-1 alpha) was assessed by western blot. The expression levels of several known HIF-1 alpha-regulated proteins [vascular endothelial growth factor (VEGF), leptin, adiponectin, and angiotensinogen (AGT)] were quantified. Results: Both chemical hypoxia-mimetics and physical hypoxia led to increased nuclear HIF-1 alpha expression and to decreased cytoplasmatic adiponectin in both cell types. In contrast, VEGF and AGT expression did not change upon hypoxic stimulation. Leptin was exclusively detectable in WA, while uncoupling-protein 1 (UCP-1) was expressed in BA only. Conclusions: WA and BA are sensitive to hypoxia, in which HIF-1 alpha expression is induced. Protein expression of adiponectin is hypoxia-dependent, whereas AGT, VEGF, leptin, and UCP-1 expression do not change secondary to hypoxia. (J. Endocrinol. Invest.

  • 出版日期2012-5