LOX-1 is expressed in the adipose tissue of high-fat diet-induced obese mice in close association with MCP-1

LOX-1 is expressed in the adipose tissue of high-fat diet-induced obese mice in close association with MCP-1

Rieko Takanabe1, Koh Ono2, Yukiko Abe2, Hiromichi Wada1, Tomohide Takaya1, Noriko Satoh3, Akira Shimatsu1, Masatoshi Fujita4, Tatsuya Sawamura5, Koji Hasegawa1.

  1. Division of Translational Research, Kyoto Medical Center, National Hospital Organization, Kyoto, Japan.
  2. Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
  3. Division of Diabetic Research, Kyoto Medical Center, National Hospital Organization, Kyoto, Japan.
  4. Department of Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
  5. Department of Vascular Physiology, National Cardiovascular Center, Osaka, Japan.

第73回日本循環器学会学術集会 (大阪), 2009/03/21 (ポスター).

Abstract

Lectin-like oxidezed low-density lipoprotein (oxLDL) receptor-1 (LOX-1) is a receptor for oxidized LDL induced by inflammatory cytokines and oxidative stress. LOX-1 is strongly expressed in endothelial cells at early stages of atherosclerosis and suggested to be an inducer of a proinflammatory cytokine, monocyte chemoattractant protein (MCP-1). It has been recently reported that LOX-1 is expressed in adipocytes and that plasma soluble LOX-1 levels are increased in obese women. However, expression of LOX-1 in the adipose tissue of high-fat diet-induced obese mice and its significance in obesity are unknown. We fed C57BL/6 mice high-fat diet for eight weeks and examined LOX-1 mRNA levels in the mesenteric fat by RT-PCR. The levels were increased in mice fed high-fat diet compared to mice fed normal chow (2.3-fold, p < 0.05). The LOX-1 levels were correlated with plasma leptin levels (R = 0.785, p = 0.0001), body weight (R = 0.674, p = 0.0011) and mesenteric fat weight (R = 0.633, p = 0.0027). However, mRNA levels of LOX-1 did not correlated with those of aP2 and PPARγ, adipocyte differentiation markers. Notably, the LOX-1 levels were most closely correlated with MCP-1 levels (R = 0.905, p < 0.0001). These findings demonstrate that LOX-1 expression in the mouse adipose tissue is induced by high-fat diet in a close association with MCP-1 expression. The results also suggest that LOX-1, together with MCP-1, is involved in chronic inflammation of the adipose tissue in obesity.