Kuniyasu Akihiko, Hayashi Shigeki, Nakayama Hitoshi
Department of Biofunctional Chemistry, Faculty of Pharmaceutical Sciences, Kumamoto University, 5-1 Ohe-Honmachi, Kumamoto 862-0973, Japan.
Biochem Biophys Res Commun. 2002 Jul 12;295(2):319-23. doi: 10.1016/s0006-291x(02)00666-6.
CD36 expressed on adipocytes is thought to function as a fatty acid transporter (FAT). Here we report that adipocytes can endocytose and lysosomally degrade OxLDL, mainly mediated by CD36. Mouse 3T3-L1 preadipocytes showed marked increase in uptake and degradation of (125)I-OxLDL during their differentiation to adipocytes. RT-PCR and immunoblot analysis indicated that expression of CD36 but not of scavenger receptor class A or macrosialin is required for the increase in uptake and degradation of (125)I-OxLDL in 3T3-L1 cells. An anti-CD36 antibody inhibited both uptake and degradation activities of (125)I-OxLDL up to 60%. These results strongly suggest that adipocytes may function as phagocytes like macrophages and that CD36 plays a novel role in adipose tissues.
脂肪细胞上表达的CD36被认为具有脂肪酸转运蛋白(FAT)的功能。在此我们报告,脂肪细胞能够通过内吞作用并在溶酶体中降解氧化型低密度脂蛋白(OxLDL),这一过程主要由CD36介导。小鼠3T3-L1前脂肪细胞在分化为脂肪细胞的过程中,对(125)I-OxLDL的摄取和降解显著增加。逆转录聚合酶链反应(RT-PCR)和免疫印迹分析表明,3T3-L1细胞中(125)I-OxLDL摄取和降解的增加需要CD36的表达,而不需要A类清道夫受体或巨唾液酸蛋白的表达。抗CD36抗体可将(125)I-OxLDL的摄取和降解活性抑制高达60%。这些结果有力地表明,脂肪细胞可能像巨噬细胞一样发挥吞噬细胞的功能,并且CD36在脂肪组织中发挥着新的作用。