TLR2促进大鼠肾缺血再灌注损伤中的炎症反应和氧化应激

TLR2 Promotes Inflammatory Response and Oxidative Stress in Rat Renal Ischemia-Reperfusion Injury

目的:探究肾缺血再灌注损伤对Toll样受体2(Toll-like receptors 2,TLR2)信号路径的影响,以及TLR2在肾缺血灌注中的作用。方法:将21只Wistar大鼠随机分为假手术组(Sham)、肾缺血再灌注模型组(I/R)和T2.5处理组(T2.5)。缺血再灌注24小时后,采集心脏血和左肾组织。对肾组织进行病理学分析,采用试剂盒检测血清肌酐(Cr)和血尿素氮(BUN)水平,采用酶联免疫吸附试验(ELISA)和免疫印迹分析(Western blot)检测肾组织炎症和氧化应激变化。结果:与假手术组相比,模型组大鼠肾组织出现明显损伤,T2.5处理能有效改善肾组织损伤,差异具有统计学意义(P<0.05)。与假手术组相比,模型组大鼠血清Cr、BUN水平显著上升,而T2.5能显著抑制血清Cr、BUN升高、减轻肾损伤(P<0.05)。与假手术组相比,模型组大鼠肾组织TLR2、TLR4相对表达量显著上升,T2.5能显著抑制肾组织TLR2、TLR4的升高,调节TLR信号通路(P<0.05)。与假手术组相比,模型组大鼠的NF-k B表达及磷酸化水平显著上升(P<0.05),T2.5能够显著下调I/R大鼠的NF-kB磷酸化水平(P<0.05),对NF-kB的表达则无明显影响(P>0.05)。与假手术组相比,模型组大鼠肾组织中促炎因子IL-6、IL-1β和TNF-α的浓度均显著上升(P<0.05),T2.5能通过显著下调IL-6和IL-1β水平来改善I/R大鼠的炎症水平(P<0.05),但对TNF-α的水平无明显影响(P>0.05)。与假手术组相比,模型组大鼠的SOD活力显著下降,T2.5能显著逆转该下降趋势(P<0.05);而模型组大鼠的MDA活力显著上升(P<0.05),T2.5处理对I/R大鼠的MDA活力无明显影响(P>0.05)。结论:TLR2在缺血再灌注损伤中促进了炎症反应和氧化应激,其机制与激活TLR信号路径,促进NF-kB磷酸化,进一步调节促炎因子的释放和抗氧化酶的活性有关。

Objective: To explore the effects of renal ischemia-reperfusion injury(RIRI) on the TLR2 signaling pathway and the role of TLR2 in RIRI. Methods: Twenty-one Wistar rats were randomly divided into sham operation group(Sham), renal ischemia reperfusion model group(I/R) and T2.5 treatment group(T2.5). After 24 hours of ischemia-reperfusion, heart blood and left kidney tissue were collected. Pathological analysis of renal tissue was observed, and serum creatinine(Cr) and blood urea nitrogen(BUN) were detected by kit. Inflammation and oxidative stress of renal tissue were detected by enzyme-linked immunosorbent assay(ELISA) and Western blot analysis. Results: Compared with the sham group, the renal tissue of the model group showed obvious damage, and the renal structure of the T2.5 group performed well, the difference was statistically significant(P<0.05). Compared with the sham group, the Serum Cr and BUN levels significantly increased in the I/R group, while T2.5 inhibited that increase of serum Cr and BUN and reduced renal damage of I/R rats(P<0.05). Compared with the sham group, the relative expression of TLR2 and TLR4 significantly increased in the renal tissue of the I/R group, while T2.5 regulated TLR signaling pathway by inhibiting that increase of TLR2, TLR4 in injured renal tissue(P<0.05).Compared with the sham group, the expression of NF-kB and its phosphorylation both significantly increased in the I/R group(P<0.05).T2.5 significantly down-regulated the phosphorylation of NF-k B in I/R rats(P<0.05), while had no significant effect on NF-kB expression(P>0.05). Compared with the sham group, the concentrations of pro-inflammatory factors IL-6, IL-1β and TNF-α significantly increased in the renal tissue of I/R group(P<0.05). T2.5 can promote the inflammation of I/R rats by down-regulating IL-6 and IL-1β levels(P<0.05), while had no significant effect on TNF-α level(P>0.05). Compared with the sham group, the SOD activity significantly decreased in the I/R group, T2.5 significantly reversed this decreasing by upregulating SOD activity(P<0.05). MDA activity in the I/R group was significantly increased than sham group(P<0.05), while T2.5 had no significant effect on MDA activity in I/R rats(P>0.05). Conclusions: TLR2 promotes inflammatory response and oxidative stress in ischemia-reperfusion injury by activating TLR signaling pathway,up-regulating the phosphorylation of NF-κB, further regulating the release of pro-inflammatory factor and activity of antioxidant enzymes.