title: High-density lipoprotein increases the uptake of oxidized low density lipoprotein via PPARγ/CD36 pathway in inflammatory adipocytes.
abstract: OBJECTIVE
  Previous studies have demonstrated that the dysregulated-secretion of adipokines by adipocytes may contribute to obesity-associated atherosclerosis (As) and high density lipoprotein (HDL) may protect against atherogenesis through multiple pathways. This study was to explore the effect of HDL on the oxLDL uptake in inflammatory adipocytes stimulated by endotoxin lipopolysaccharide (LPS) and the possible mechanism.
  
  
  RESULTS
  3T3-L1 adipocytes were cultured and induced to differentiation and maturation. Acute inflammation in adipocytes was induced by LPS (100 ng/ml) for 6 hours. The adipocytes were pretreated with HDL in various concentrations (10, 50, 100 μg/ml) for 16 hours or with specific PPARγ antagonist (GW9662, 10 μM) or agonist (Rosiglitazone, 10 μM) for 30 min before administration of LPS. The results showed that LPS significantly increased the release of inflammation-related adipokines, such as monocyte chemoattractant protein-1 (MCP-1), plasminogen activator inhibitor 1 (PAI-1), tumor necrosis factor-alpha (TNF-α), interleukin (IL)-8 and IL-6, while decreasing the release of leptin and adiponectin. Meanwhile, LPS reduced the uptake and degradation of 125I-oxLDL, and down-regulated the expression of PPARγ and CD36. Pretreatment with HDL dose-dependently affected the release of IL-8 and IL-6 and the reduced uptake and degradation of oxLDL of adipocytes stimulated by LPS, accompanied with marked upregulation of PPARγ and CD36 expression. Pretreatment with GW9662 markedly inhibited the upregulation of CD36 expression mediated by HDL (100 μg/ml), while the effects of Rosiglitazone were opposite to GW9662.
  
  
  CONCLUSIONS
  HDL may increase oxLDL uptake of inflammatory adipocytes stimulated by LPS via upregulation of PPARγ/CD36 pathway, which may be a new mechanism of anti-atherosclerosis mediated by HDL.
authors: 1. Post-doctoral Mobile Stations for Basic Medicine, Institute of Cardiovascular Disease and Key Lab for Arteriosclerology of Hunan Province, University of South China, Hengyang, Hunan, 421001, China ; 2. Department of Cardiology, First People's Hospital of Chenzhou, Chenzhou, 423000, China ; 3. Department of Cardiology, The second Xiangya Hospital of Central South University, Changsha, 410011, China.
authors: Qiaoqing
authors: Q
authors: Zhong
authors: 3. Department of Cardiology, The second Xiangya Hospital of Central South University, Changsha, 410011, China.
authors: Shuiping
authors: S
authors: Zhao
authors: 3. Department of Cardiology, The second Xiangya Hospital of Central South University, Changsha, 410011, China.
authors: Bilian
authors: B
authors: Yu
authors: 4. Department of Cardiology, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510080, China.
authors: Xing
authors: X
authors: Wang
authors: 5. Department of Anesthesia and Critical Care, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
authors: Robina
authors: R
authors: Matyal
authors: 5. Department of Anesthesia and Critical Care, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
authors: Yunping
authors: Y
authors: Li
authors: 1. Post-doctoral Mobile Stations for Basic Medicine, Institute of Cardiovascular Disease and Key Lab for Arteriosclerology of Hunan Province, University of South China, Hengyang, Hunan, 421001, China.
authors: Zhisheng
authors: Z
authors: Jiang
mesh_terms: D016475:3T3 Cells; D017667:Adipocytes / Q000378:metabolism*; D054392:Adipokines / Q000378:metabolism; D000818:Animals; D018955:CD36 Antigens / Q000378:metabolism*; D015850:Interleukin-6 / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D008075:Lipoproteins, HDL / Q000378:metabolism / Q000502:physiology*; D008077:Lipoproteins, LDL / Q000378:metabolism; D053858:Metabolic Networks and Pathways; D051379:Mice; D010084:Oxidation-Reduction; D047495:PPAR gamma / Q000378:metabolism*
chemical_list: D054392:Adipokines; D018955:CD36 Antigens; D015850:Interleukin-6; D016209:Interleukin-8; D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D047495:PPAR gamma
keywords: Atherosclerosis; Inflammation; Lipopolysaccharide; Lipoprotein