皮质酮抑制LPS诱导的小鼠巨噬细胞NLRP3表达及与XO的关系

目的:探讨皮质酮(CORT)对脂多糖(LPS)诱导的小鼠巨噬细胞核苷酸结合寡聚化结构域样受体蛋白3(NLRP3)表达的抑制作用及与黄嘌呤氧化酶(XO)的关系。方法:用LPS构建小鼠巨噬细胞RAW 264.7的炎症模型。运用不同浓度(0~900μg/L)的CORT处理巨噬细胞后提取细胞总蛋白,Western blot法检测细胞NLRP3和caspase-1的蛋白水平;按处理因素分组为:对照组、LPS组、LPS+CORT组和LPS+别嘌呤醇(allopurinol)组,分别于0、0.5、1、1.5和2 h提取细胞成分,运用real-time PCR和Western blot法检测细胞NLRP3和XO的m RNA和蛋白水平。结果:高于700μg/L的CORT可显著抑制LPS诱导的巨噬细胞中NLRP3的表达及caspase-1的活化(P0.05);与LPS组相比,LPS+CORT在下调LPS诱导的巨噬细胞NLRP3表达的同时抑制XO的表达(P0.05),LPS+allopurinol组巨噬细胞NLRP3的表达减少(P0.05)。结论:较高浓度的CORT能抑制LPS诱导的小鼠巨噬细胞NLRP3的表达,而CORT的抑制作用可能与其下调XO的表达水平有关。

Corticosterone inhibits LPS-induced expression of NLRP3 in mouse macrophages and its relation with XO

AIM: To investigate the inhibitory effect of corticosterone (CORT) on lipopolysaccharide (LPS)-induced expression of nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) and its relation with xanthine oxidase (XO). METHODS: An inflammatory model of mouse macrophage RAW 264.7 was established by stimulating with LPS. Total cellular protein was extracted after the macrophages were treated with CORT at different concentrations (0~900 μg/L). The protein levels of NLRP3 and caspase-1 were determined by Western blot. According to the treatments, the macrophages were divided into control group, LPS group, LPS+CORT group and LPS+allopurinol group. Cell components were extracted at 0, 0.5, 1, 1.5 and 2 h. The protein levels of NLRP3 and XO were determined by Western blot,and the mRNA expression of NLRP3 and XO was detected by real-time PCR. RESULTS: CORT at 700 μg/L and above significantly inhibited the expression of NLRP3 and the activation of caspase-1 in the macrophages induced by LPS (P<0.05). Compared with LPS group, the expression of NLRP3 and XO in LPS+CORT group was inhibited (P<0.05), and the expression of NLRP3 in LPS+allopurinol group was also reduced (P<0.05).CONCLUSION: High concentration of CORT inhibits the expression of NLRP3 in LPS-induced mouse macrophages, which is associated with XO. The inhibitory effect of CORT may be related to the reduction of XO expression.