白藜芦醇调节NLRP3炎性小体改善力竭运动大鼠肾组织炎症损伤

Resveratrol improves renal inflammatory injury in exhaustive exercise rats by regulating NOD-like receptor protein 3 inflammasome

目的 探讨白藜芦醇通过调节NOD样受体蛋白3(NOD-like receptor protein 3,NLRP3)炎性小体对力竭运动大鼠肾组织炎症损伤的改善作用。方法 将36只SD雄性大鼠按随机数字表法分为对照组(Con组,n=8)、白藜芦醇组(Rsv组,n=8)、力竭运动组(Ex组,n=10)和力竭运动+白藜芦醇组(Ex+Rsv组,n=10)。Ex组和Ex+Rsv组进行4周力竭跑台运动。Rsv组和Ex+Rsv组每天灌胃白藜芦醇,剂量为50 mg/kg。最后1次运动24 h后取材,分别取血、尿和肾组织以备检测,全自动分析仪检测血清肌酐(serum creatinine, Scr)、尿素氮(blood urea nitrogen, BUN)水平;ELISA检测尿中性粒细胞明胶酶相关脂质运载蛋白(neutrophil gelatinaseassociated lipocalin, NGAL)和肾损伤分子-1 (kidney injury molecule-1,KIM-1)以及肾组织IL-1β、IL-18、TNF-α、IL-6水平;HE染色观察肾组织形态结构变化;Western blot检测肾组织NLRP3、凋亡相关斑点样蛋白(apoptosis-associated speck-like protein, ASC)和cleaved caspase-1、IL-1β和IL-18蛋白表达;免疫荧光双染观察NLRP3和ASC在肾小管的共定位。结果 力竭运动组大鼠血清指标Scr及BUN、尿液指标KIM-1和NGAL水平均比对照组显著升高(P<0.01),肾组织HE染色显示存在肾组织损伤;力竭运动组大鼠肾组织NLRP3、ASC、cleaved caspase-1、IL-1β和IL-18蛋白表达均显著升高(P<0.01);白藜芦醇补充显著降低了力竭运动大鼠肾组织NLRP3炎性小体蛋白表达(P<0.05),改善其肾组织形态,降低肾组织炎症因子浓度(P<0.05)。结论 白藜芦醇可有效改善力竭运动大鼠肾组织炎症损伤,其机制可能与白藜芦醇抑制大鼠肾脏NLRP3炎性小体的过度激活有关。

Objective To explore the ameliorative effects of resveratrol on renal inflammation in rats after exhaustive exercise by regulating NOD-like receptor protein 3(NLRP3) inflammasome. Methods Thirty-six male SD rats were randomly divided into 4 groups: control group(Con, n=8), resveratrol group(Rsv, n=8), exhaustive exercise group(Ex, n=10), and exhaustive exercise+resveratrol group(Ex+Rsv, n=10), and the rats in the Ex and Ex+Rsv groups underwent 4 weeks of exhaustive treadmill exercise. The Rsv and Ex+Rsv groups were given resveratrol intragastrically at a dose of 50 mg/kg per day. The serum and urine samples as well as renal tissues of rats were collected in 24 h after the last training. The serum creatinine(Scr) and blood urea nitrogen(BUN) levels were detected by automatic analyzer;ELISA was used to determine the urine neutrophil gelatinase-associated lipocalin(NGAL), kidney injury molecule-1(KIM-1) and the contents of IL-1β, IL-18, TNF-α and IL-6 in renal tissues;The protein expression of NLRP3, apoptosis-associated speck-like protein(ASC), cleaved caspase-1, IL-1β and IL-18 were measured by Western blotting. In addition, the morphological and structural changes of renal tissue were observed with HE staining, and immunofluorescence staining was also performed to observe the co-localization of NLRP3 and ASC. Results The levels of Scr, BUN, NGAL and KIM-1 were significantly higer in the Ex group than the Con group(P<0.01). HE staining showed that renal injury was observed in the rats of Ex group, and the protein expression levels of NLRP3, ASC, cleaved caspase-1, IL-1β and IL-18 were all remarkably increased(P<0.01). However, resveratrol supplementation notably down-regulated the protein expression of NLRP3 inflammasome(P<0.05) and reduced the contents of inflammatory factors in renal tissues(P<0.05), and ameliorated pathological changes of renal tissues. Conclusions Resveratrol can effectively alleviate the inflammatory damage of renal tissue in rats after exhaustive exercise, and its mechanism may be related to its inhibiting NLRP3 inflammasome overactivation.