游离脂肪酸激活肾系膜细胞NLRP3炎症小体信号及氧化应激机制的探讨

Investigation of the activation of NLRP3 inflammasome signaling and the mechanism of oxidative stress induced by free fatty acids in renal mesangial cells of rats

目的:探讨NLRP3炎症小体在游离脂肪酸(free fatty acids,FFAs)诱导下的肾小球系膜细胞(HBZY-1)中的表达及氧化应激在其中的影响。方法:将HBZY-1细胞分为正常对照组、不同浓度棕榈酸组、高棕榈酸+N-乙酰半胱氨酸(N-acetylL-cysteine,NAC)组。各组细胞培养6、9、12 h后采用Western blotting和RT-PCR检测各组NLRP3、Caspase-1、IL-1β蛋白及m RNA表达,并同时观察NAC对各组蛋白及m RNA表达的影响。结果:棕榈酸刺激肾系膜细胞NLRP3炎症小体信号分子的表达变化:与对照组相比,不同作用浓度和时间的棕榈酸均可上调NLRP3、Caspase-1、IL-1β蛋白及m RNA表达(P<0.05),且呈浓度和时间依赖性。与单纯棕榈酸组相比,NAC预处理可阻止棕榈酸诱导的NLRP3、Caspase-1、IL-1β蛋白及m RNA表达上调(P<0.05)。结论:棕榈酸可通过氧化应激机制诱导系膜细胞NLRP3炎症小体信号的活化,参与糖尿病肾病炎症的发生。

Objective： To explore the expression of NLRP3 inflammasome induced by free fatty acids and the influence of oxidative stress in renal mesangial cells. Methods： Mesangial cells were randomly divided into the normal group（NC group）, different concentrations of palmitic acid group（HPA group） and the NAC intervention in high palmitic group（HPA＋NAC group）. Each group was cultured for 6, 9 and 12 h,then detected the expressions of NLRP3, Caspase-1, IL-1β protein and m RNA by Western blotting and RT-PCR,and the influence on the protein and m RNA expression of each group induced by NAC was observed. Results： Compared with normal group, the protein and m RNA level of NLRP3, Caspase-1 and IL-1β were upregulated induced by different concentrations palmitic acid for various times, in a dose and time-dependent manner（P〈0.05）. Compared with palmitic acid group, the expressions of NLRP3, Caspase-1 and IL-1β were decreased after pretreatment palmitic acid growp with NAC（P〈0.05）. Conclusion： Palmitic acid could induce the activation of NLRP3 inflammasome signaling in mesangial cells via reactive oxygen species and mediate inflammation in diabetic nephropathy.