枯否细胞通过释放细胞因子抑制全氟壬酸诱导的肝过氧化物酶体增殖物激活受体α表达。
Kupffer cells suppress perfluorononanoic acid-induced hepatic peroxisome proliferator-activated receptor α expression by releasing cytokines.
机构信息
Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China.
出版信息
Arch Toxicol. 2012 Oct;86(10):1515-25. doi: 10.1007/s00204-012-0877-4. Epub 2012 May 31.
Kupffer cells (KCs) have been demonstrated to play a role in the regulation of intra-hepatic lipid metabolism through the synthesis and secretion of biologically active products. The involvement of KCs in the disturbance of lipid metabolism that induced by perfluorononanoic acid (PFNA), a known agonist of the peroxisome proliferator-activated receptor alpha (PPARα), was investigated in this study. Rats were exposed to PFNA or PFNA combined with gadolinium chloride, an inhibitor of KCs, for 14 days. PFNA exposure dose-dependently increased absolute and relative liver weights, induced triglyceride accumulation, up-regulated the expression of both SERBP-1c and PPARα, and stimulated the release of TNFα and IL-1β. Inactivation of KCs markedly lowered TNFα and IL-1β level, enhanced PFNA-induced expression of PPARα and its target genes, and reduced liver triglyceride levels. In vitro, PFNA-induced expression of PPARα in primary cultured hepatocytes was suppressed by recombinant rat TNFα and IL-1β. However, inhibition of the NF-κB pathway prevented this. Transient transfection and promoter analysis further revealed that these two cytokines and NF-κB were coordinately involved in the suppression of PPARα promoter activity. Our data demonstrate that TNFα and IL-1β released from KCs following PFNA exposure can suppress the expression of PPARα via NF-κB pathway, which partially contribute to the evident accumulation of triglycerides in rat liver.
库普弗细胞 (KCs) 通过合成和分泌具有生物活性的产物,在调节肝内脂质代谢中发挥作用。本研究探讨了库普弗细胞是否参与了全氟壬酸 (PFNA) 引起的脂质代谢紊乱,PFNA 是过氧化物酶体增殖物激活受体α (PPARα) 的已知激动剂。大鼠暴露于 PFNA 或 PFNA 与镧系元素氯化钆(一种库普弗细胞抑制剂)联合 14 天。PFNA 暴露剂量依赖性地增加了肝重的绝对值和相对值,诱导甘油三酯积累,上调 SERBP-1c 和 PPARα 的表达,并刺激 TNFα 和 IL-1β 的释放。KCs 失活显著降低了 TNFα 和 IL-1β 水平,增强了 PFNA 诱导的 PPARα 及其靶基因的表达,并降低了肝甘油三酯水平。在体外,PFNA 诱导原代培养肝细胞中 PPARα 的表达被重组大鼠 TNFα 和 IL-1β 抑制。然而,NF-κB 通路的抑制阻止了这种情况。瞬时转染和启动子分析进一步表明,这两种细胞因子和 NF-κB 共同参与了 PPARα 启动子活性的抑制。我们的数据表明,PFNA 暴露后从 KCs 释放的 TNFα 和 IL-1β 可以通过 NF-κB 通路抑制 PPARα 的表达,这部分导致大鼠肝甘油三酯的明显积累。