鼠尾草酸基于TLR4/NF-κB/NLRP3通路对脓毒血症所致急性肾损伤大鼠肾脏及血管内皮的保护作用

Protective effect of carnosic acid based on TLR4/NF-κB/NLRP3 pathway on kidney and vascular endothelium in rats with acute kidney injury induced by sepsis

目的 探讨鼠尾草酸对脓毒血症所致急性肾损伤(AKI)大鼠的肾脏和血管内皮的保护作用,并探讨其机制。方法 将50只SD雄性大鼠随机分为健康对照组、模型组、鼠尾草酸低剂量组(50 mg/kg)、鼠尾草酸中剂量组(100 mg/kg)和鼠尾草酸高剂量组(200 mg/kg),每组10只。除健康对照组外,给予其余4组采用盲肠结扎穿刺手术构建脓毒性急性肾损伤大鼠模型。术后3 d,给予鼠尾草酸低、中、高剂量组分别灌胃50 mg/kg、100 mg/kg、200 mg/kg鼠尾草酸,给予健康对照组和模型组等量生理盐水灌胃,均干预4周。采用HE染色法观察各组大鼠肾脏组织的病理学变化;比较各组大鼠血清肌酐和尿素氮水平,以及肾脏组织中核因子κB(NF-κB)、 NF-κB抑制蛋白(IκB)α、Toll样受体4(TLR4)、NOD样受体热蛋白结构域相关蛋白3(NLRP3)、血管性血友病因子(vWF)蛋白表达量。结果 与健康对照组相比,模型组的肾脏组织病理损伤评分,血清肌酐和尿素氮水平,以及肾组织中vWF、NF-κB、TLR4、NLRP3蛋白表达量均升高,而肾组织中IκBα蛋白表达量降低(均P<0.05)。与模型组比较,鼠尾草酸低、中、剂量组的肾脏组织病理损伤评分,血清肌酐和尿素氮水平,以及肾组织中vWF、NF-κB、TLR4、NLRP3蛋白表达量均降低,而肾组织中IκBα蛋白表达量均升高(均P<0.05)。在鼠尾草酸干预组中,肾脏组织病理损伤评分与血清肌酐和尿素氮水平的改善程度与鼠尾草酸浓度呈剂量依赖性(均P<0.05)。结论 鼠尾草酸对脓毒血症所致AKI模型大鼠具有较好的肾脏保护作用,其主要作用机制可能与改善血管内皮细胞损伤,抑制TLR4/NF-κB/NLRP3信号通路有关。

Objective To explore the protective effect of carnosic acid on kidney and vascular endothelium in rats with acute kidney injury induced by sepsis,and to investigate its mechanism.Methods Fifty male SD rats were randomly divided into healthy control group,model group,carnosic acid with low-dose group(50 mg/kg),carnosic acid with medium-dose group(100 mg/kg) or carnosic acid with high-dose group(200 mg/kg),with 10 rats in each group.Except for the healthy control group,cecal ligation and puncture surgery was performed to establish septic acute kidney injury rats model in the remaining 4 groups.After 3 days of surgery,intragastric administrations of carnosic acid with 50 mg/kg,100 mg/kg,and 200 mg/kg were given to the carnosic acid with low-,medium-,and high-dose groups,respectively,while intragastric administration of equivalent normal saline was given to the healthy control group and model group,for a 4-week intervention.The HE staining was used to observe pathological changes of rats′ renal tissues in various groups.The serum creatinine and urea nitrogen levels,as well as the expressions of nuclear factor kappa-B(NF-κB),inhibitor of NF-κB(IκB)α,Toll-like receptor 4(TLR4),NOD-like receptor thermal protein domain associated protein 3(NLRP3),von Willebrand factor(vWF) proteins in renal tissues were compared between various groups.Results Compared with the healthy control group,the model group exhibited an elevated score of pathological injury in renal tissues,and elevated levels of serum creatinine and urea nitrogen,as well as elevated expressions of vWF,NF-κB,TLR4,and NLRP3 proteins in renal tissues,whereas a decreased IκBα protein expression in renal tissues(all P<0.05).Compared with the model group,the carnosic acid with low-,medium-,and high-dose groups depicted a decreased score of pathological injury in renal tissues,and decreased levels of serum creatinine and urea nitrogen,as well as decreased expressions of vWF,NF-κB,TLR4,and NLRP3 proteins in renal tissues,while an elevated IκBα protein expression in renal tissues(all P<0.05).In the carnosic acid intervention group,the improvement of the pathological injury score in renal tissues,and serum creatinine and urea nitrogen levels were dose-dependent with carnosic acid concentrations(all P<0.05).Conclusion Carnosic acid has a good renal protective effect on sepsis-induced AKI model rats,and its main mechanism may be related to improving vascular endothelial cell injury and inhibiting TLR4/NF-κB/NLRP3 signaling pathway.