姜黄素通过TLR-4/NF-κB信号通路减轻脓毒症相关的急性肠损伤

Curcumin alleviates sepsis-related acute intestinal injury through the TLR-4/NF-κB signaling pathway

目的探讨姜黄素(Cur)通过TLR-4/NF-κB信号通路对脓毒症大鼠急性肠损伤的保护作用。方法将100只雄性SD大鼠随机分成假手术组(sham)、模型组(Model)、姜黄素低剂量组(L-Cur,50 mg/kg)、姜黄素高剂量组(H-Cur,200 mg/kg),采用盲肠结扎穿刺(CLP)法建立大鼠脓毒症模型,并观察术后72 h存活率,同时收集术后24 h各组大鼠血液及小肠组织。HE染色观察小肠组织切片病理改变并进行Chui′s评分;ELISA检测血清中肿瘤坏死因子-α(TNF-α)、白介素6(IL-6)和白介素1β(IL-1β)表达水平;比色法测定小肠组织中一氧化氮(NO)、超氧化物歧化酶(SOD)、丙二醛(MDA)水平;Western blot检测小肠组织中紧密连接蛋白Claudin-1、ZO-1及TLR-4/NF-κB通路相关蛋白表达。结果与Model组比较,H-Cur组大鼠72 h生存率显著增高;与sham组比较,Model组大鼠肠黏膜显著受损(P<0.05),血清中炎症因子TNF-α、IL-6、IL-1β水平显著增加(P<0.05),小肠组织中NO水平、MDA含量显著增加(P<0.05),SOD活性显著下降(P<0.05),Claudin-1和ZO-1蛋白表达量显著下调(P<0.05),而TLR-4、MyD88蛋白及p-NF-κB p65(Ser536)水平显著上调(P<0.05);与Model组比较,;H-Cur组损伤程度显著减轻(P<0.05),血清中炎症因子TNF-α、IL-6、IL-1β水平显著降低(P<0.05),小肠组织中NO水平、MDA含量显著下降(P<0.05),SOD活性显著增加(P<0.05),Claudin-1和ZO-1蛋白表达量显著上调(P<0.05),而TLR-4、MyD88蛋白及p-NF-κB p65(Ser536)水平显著降低(P<0.05)。结论姜黄素可改善脓毒症大鼠急性肠损伤,其机制可能与其负反馈调控TLR4/NF-kB信号通路,抑制炎症及氧化应激损伤有关。

Objective To investigate the protective of curcumin(Cur)on sepsis rats with acute intestinal injury through the TLR-4/NF-κB signaling pathway.Methods 00 male SD rats were randomly divided into sham group,Model group,low-dose curcumin group(L-Cur,50 mg/kg),and high-dose curcumin group(H-Cur,200 mg/kg).The sepsis rat model was reproduced by cecal ligation and puncture(CLP),and the survival rate was observed for 72 h.At the same time,blood and small intestinal tissues were collected at 24 h.Pathological changes of small intestinal tissue sections were observed and chui′s score was performed.The levels of TNF-α,IL-6 and IL-1βin serum were detected by ELISA,and the contents of nitric oxide(NO),superoxide dismutase(SOD)and malondialdehyde(MDA)in small intestine were determined by colorimetry.Western blotting was performed to detect the expressions of tight-junction proteins as Claudin-1,ZO-1,and proteins involved in TLR-4/NF-κB pathway.Result Compared with the Model group,the 72 h survival rate in the H-Cur group was significantly increased.Compared with sham group,the damaged intestinal mucosa of Model group was significantly increased(P<0.05),the levels of TNF-α,IL-6,IL-1βin serum were significantly increased(P<0.05),the contents of NO and MDA were significantly increased(P<0.05),the activity of SOD was significantly decreased(P<0.05),The expression of Claudin-1 and ZO-1 was significantly down-regulated(P<0.05),while the levels of TLR-4,MyD88 and p-NF-B p65(Ser536)were significantly increased(P<0.05).Compared with Model group,the degree of injury in H-Cur group was significantly reduced(P<0.05),the levels of TNF-α,IL-6,IL-1βin serum were significantly decreased(P<0.05),the contents of NO and MDA were significantly decreased(P<0.05),the activity of SOD was significantly increased(P<0.05),The expression of Claudin-1 and ZO-1 was significantly up-regulated(P<0.05),while the levels of TLR-4,MyD88 and p-NF-B p65(Ser536)were significantly decreased(P<0.05).Conclusion Curcumin can improve acute intestinal injury in sepsis rats,and its mechanism may be related to its negative feedback in regulation of TLR4/NF-kB signal pathway,and inhibition of inflammation and oxidative stress injury.