Iftakhar-E-Khuda I, Koide N, Hassan F, Noman A S M, Dagvadorj J, Tumurkhuu G, Naiki Y, Komatsu T, Yoshida T, Yokochi T
Department of Microbiology and Immunology, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan.
Clin Exp Immunol. 2009 Mar;155(3):552-8. doi: 10.1111/j.1365-2249.2008.03779.x.
U18666A is a cholesterol transport-inhibiting agent that is used widely to mimic Niemann-Pick type C disease. The effect of U18666A on tumour necrosis factor (TNF)-alpha production in mouse macrophage cell line, RAW 264.7 cells and peritoneal macrophages was examined. U18666A induced TNF-alpha mRNA expression 48 h after the treatment, and TNF-alpha production 48 and 72 h after stimulation in RAW 264.7 cells. U18666A accumulated intracellular free cholesterol in the culture of normal medium but not cholesterol-free medium. U18666A also induced reactive oxygen species (ROS) generation in normal medium but much less in cholesterol-free medium. Anti-oxidant N-acetyl-L-cysteine (NAC) abolished U18666A-induced TNF-alpha production. U18666A led to the phosphorylation of p38 mitogen-activated protein kinase 24 and 48 h after the stimulation and the p38 activation was inhibited in presence of cholesterol-free medium or NAC. A p38 inhibitor reduced U18666A-induced TNF-alpha production. Taken together, U18666A was suggested to induce TNF-alpha production in RAW 264.7 cells via free cholesterol accumulation-mediated ROS generation.
U18666A是一种胆固醇转运抑制剂，被广泛用于模拟尼曼-匹克C型疾病。研究了U18666A对小鼠巨噬细胞系RAW 264.7细胞和腹腔巨噬细胞中肿瘤坏死因子（TNF）-α产生的影响。U18666A在处理后48小时诱导TNF-α mRNA表达，并在RAW 264.7细胞刺激后48和72小时诱导TNF-α产生。U18666A在正常培养基培养中积累细胞内游离胆固醇，但在无胆固醇培养基中不积累。U18666A在正常培养基中也诱导活性氧（ROS）生成，但在无胆固醇培养基中生成量少得多。抗氧化剂N-乙酰-L-半胱氨酸（NAC）消除了U18666A诱导的TNF-α产生。U18666A在刺激后24和48小时导致p38丝裂原活化蛋白激酶磷酸化，并且在无胆固醇培养基或NAC存在下p38活化受到抑制。一种p38抑制剂减少了U18666A诱导的TNF-α产生。综上所述，提示U18666A通过游离胆固醇积累介导的ROS生成在RAW 264.7细胞中诱导TNF-α产生。
