Diabetes 57:2992-2998, 2008 DOI: 10.2337/db08-0592 © 2008 by the American Diabetes Association
Oxidative Stress Regulates Adipocyte Apolipoprotein E and Suppresses Its Expression in Obesity
1 Department of Medicine, University of Illinois, Chicago, Illinois Corresponding author: Theodore Mazzone, tmazzone{at}uic.edu
OBJECTIVE—Endogenous expression of apolipoprotein E (apoE) has a significant impact on adipocyte lipid metabolism and is markedly suppressed in obesity. Adipose tissue oxidant stress is emerging as an important mediator of adipocyte dysfunction. These studies were undertaken to evaluate the role of oxidant stress for regulation of adipocyte apoE. RESEARCH DESIGN AND METHODS—ApoE gene and protein expression in 3T3-L1 adipocytes or mature adipocytes and adipose tissue from C57/BL6 mice was evaluated after induction of oxidant stress. The response of adipose tissue and adipocytes from obese compared with lean mice to antioxidants was also assessed.
RESULTS—Oxidant stress in 3T3-L1 cells or adipocytes and adipose tissue from lean mice significantly reduced apoE mRNA and protein level. Inclusion of an antioxidant eliminated this reduction. Oxidant stress was accompanied by activation of the nuclear factor- CONCLUSIONS—Oxidant stress significantly modulates adipose tissue and adipocyte apoE expression. Furthermore, oxidant stress contributes to suppression of adipocyte apoE in obesity. This suppression depends on interaction between adipose tissue stromovascular cells and adipocytes.
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