褪黑素抑制LPS诱导的脂肪细胞炎症反应及机制

Effect and Mechanism of Melatonin on Inflammatory Response of 3T3-L1 Adipocyte Induced by LPS

研究褪黑素对脂多糖(Lipopolysaccharide,LPS)诱导的3T3-L1脂肪细胞炎症反应的抑制作用及机制。体外培养3T3-L1前脂肪细胞并诱导成为成熟的脂肪细胞,用不同浓度的褪黑素(50、100、200μmol/L)处理2 h后,加入LPS(2μg/m L)诱导炎症反应,于LPS处理后不同时间,取细胞,qRT-PCR测定肿瘤坏死因子α(Tumor Necrosis Factor Alpha,TNF-α)和白介素6(Interleukin-6,IL-6)的表达情况,Western blot法测定各组总蛋白p-IκBα的表达情况。取上清液,酶联免疫吸附法(Enzyme linked immunosorbent assay,ELISA)检测TNF-α和IL-6的分泌情况。结果显示褪黑素显著抑制LPS诱导的3T3-L1脂肪细胞TNF-α和IL-6表达和分泌(P<0.05),呈现剂量效果依赖性;Western blot结果表明褪黑素显著抑制LPS诱导的脂肪细胞IκBα磷酸化(P<0.05)。这表明褪黑素通过降低LPS诱导的脂肪细胞IκBα磷酸化信号通路抑制脂肪细胞炎症反应。

This study aimed to explore the effect and mechanism of melatonin on inflammatory response of 3T3-L1 adipocyte induced by lipopolysaccharide（ LPS）. 3T3-L1 preadipocytes were cultured and induced to become mature adipose cells. Pretreated with different concentrations of melatonin for 2h,adipocytes were challenged with LPS（ 2 μg/m L）. After treatment with LPS for different time points,supernatant were harvested and enzyme linked immunosorbent assay（ ELISA） was used to detect the concentration of TNF-α and IL-6. qRT-PCRwere carried out to identify mRNA levels of TNF-α and IL-6. Western blot was used to assay p-IκBα. The results showed that 3T3-L1 adipocyte secreted TNF-α and IL-6 significantly after treatment with LPS. Melatoninsignificantly reduced TNF-α and IL-6 expression and secretion of3T3-L1 adipocyte induced by LPS in a dose-dependent manner. Western blot demonstrated that melatonin inhibited IκBαphosphorylation induced by LPS significantly. With these results,it was concluded that melatonin alleviated inflammatory response of 3T3-L1 adipocyte induced by LPS through inhibition of NF-κBsignal transduction.