雷公藤红素通过抑制Toll样受体4/核转录因子-κB炎症通路减轻脓毒症诱导的大鼠急性肺损伤

Celastrol alleviates sepsis-induced acute lung injury in rats by inhibiting the Toll-like receptor 4/nuclear factor-κB inflammatory pathway

目的探讨雷公藤红素(celastrol)在脓毒症大鼠急性肺损伤(ALI)中的保护作用及机制。方法按随机数字表法将24只雄性SD大鼠分为正常对照组(Con组)、假手术组(Sham组)、盲肠结扎穿孔术(CLP)致脓毒症ALI模型组(CLP组)和雷公藤红素干预组(CLP+celastrol组,术前1 h经腹腔给予雷公藤红素2 mg/kg),每组6只。术后24 h取大鼠腹主动脉血进行血气分析,随后处死大鼠取肺组织,计算肺湿/干质量比值(W/D);光镜下观察肺组织病理特点并进行肺组织病理评分;采用酶联免疫吸附试验(ELISA)检测肺组织中Toll样受体4(TLR4)、白细胞介素(IL-6、IL-10)、细胞质及细胞核内核转录因子-κB(NF-κB)的蛋白含量。结果Con组与Sham组动脉血氧分压(PaO_(2))、肺W/D比值、肺组织病理评分及肺组织炎性因子蛋白含量相当。与Con组比较,CLP组PaO_(2)明显下降〔mmHg(1 mmHg=0.133 kPa):60.33±2.01比109.20±2.99〕,肺W/D比值及肺组织病理评分明显升高〔肺W/D比值:4.44±0.05比3.27±0.04,肺组织病理评分(分):10.67±0.42比0.50±0.22〕,肺组织TLR4、IL-6、IL-10及细胞核内NF-κB蛋白含量明显升高〔TLR4(pg/L):21.87±0.66比3.27±0.09,IL-6(ng/L):861.10±8.28比120.30±3.91,IL-10(ng/L):212.40±2.57比41.73±1.02,细胞核NF-κB(ng/L):707.70±16.82比403.30±7.46〕,细胞质内NF-κB蛋白含量明显下降(ng/L:213.70±8.67比408.30±8.71),差异均有统计学意义(均P<0.05)。与CLP组比较,CLP+celastrol组PaO_(2)明显升高(mmHg:76.83±3.21比60.33±2.01),肺W/D比值、肺组织病理评分明显下降〔肺W/D比值:3.82±0.03比4.44±0.05,肺组织病理评分(分):5.00±0.37比10.67±0.42〕,肺组织TLR4、IL-6和细胞核NF-κB蛋白含量明显下降〔TLR4(pg/L):7.57±0.21比21.87±0.66,IL-6(ng/L):380.90±6.55比861.10±8.28,细胞核NF-κB(ng/L):533.80±9.42比707.70±16.82〕,细胞质NF-κB蛋白含量明显增加(ng/L:342.70±14.96比213.70±8.67),差异均有统计学意义(均P<0.05),而肺组织IL-10蛋白含量相当,差异无统计学意义(ng/L:210.50±3.16比212.40±2.57,P>0.05)。结论雷公藤红素可能通过抑制TLR4/NF-κB炎症通路,调节炎性因子的表达和释放,从而减轻脓毒症诱导的大鼠ALI。

Objective To investigate the protective effect and mechanism of celastrol in acute lung injury(ALI)of septic rats.Methods According to random number table,24 male Sprague-Dawley(SD)rats were divided into control group(Con group),Sham operation group(Sham group),sepsis-induced ALI group by cecal ligation and perforation(CLP group)and celastrol intervention group(CLP+celastrol group,2 mg/kg intraperitoneal administration 1 hour before surgery),6 rats in each group.The abdominal aortic blood of the rats was collected for blood gas analysis 24 hours after the surgery,and then the rats were sacrificed and the lung tissues were taken to calculate the lung wet/dry weight ratio(W/D).The pathological characteristics of lung tissues were observed under light microscope and calculated the lung injury score.The protein levels of Toll-like receptor 4(TLR4),interleukins(IL-6,IL-10),and nuclear factor-κB(NF-κB)of cytoplasm and nucleus in lung tissues were detected by enzyme linked immunosorbent assay(ELISA).Results The partial arterial oxygen pressure(PaO_(2)),lung W/D ratio,lung injury score and the protein levels of inflammatory factor in lung tissues had no differences between Con group and Sham group.Compared with the Con group,PaO_(2)in the CLP group was significantly decreased[mmHg(1 mmHg=0.133 kPa):60.33±2.01 vs.109.20±2.99],the lung W/D ratio and lung injury score were significantly increased(lung W/D ratio:4.44±0.05 vs.3.27±0.04,lung injury score:10.67±0.42 vs.0.50±0.22),and the protein levels of TLR4,IL-6,IL-10 and the nucleus NF-κB in the lung tissues were significantly increased[TLR4(pg/L):21.87±0.66 vs.3.27±0.09,IL-6(ng/L):861.10±8.28 vs.120.30±3.91,IL-10(ng/L):212.40±2.57 vs.41.73±1.02,nuclear NF-κB(ng/L):707.70±16.82 vs.403.30±7.46],but the protein level of cytoplasm NF-κB was significantly decreased(ng/L:213.70±8.67 vs.408.30±8.71),with statistically significant differences(all P<0.05).Compared with the CLP group,PaO_(2)in CLP+celastrol group was significantly increased(mmHg:76.83±3.21 vs.60.33±2.01),the lung W/D ratio and lung injury score were significantly decreased(lung W/D ratio:3.82±0.03 vs.4.44±0.05,lung injury score:5.00±0.37 vs.10.67±0.42),and the protein levels of TLR4,IL-6,IL-10 and nucleus NF-κB in the lung tissue were significantly decreased[TLR4(pg/L):7.57±0.21 vs.21.87±0.66,IL-6(ng/L):380.90±6.55 vs.861.10±8.28,nuclear NF-κB(ng/L):533.80±9.42 vs.707.70±16.82],and the protein level of cytoplasm NF-κB was significantly increased(ng/L:342.70±14.96 vs.213.70±8.67),with statistically significant differences(all P<0.05),while the protein level of IL-10 in lung tissues had no significant difference(ng/L:210.50±3.16 vs.212.40±2.57,P>0.05).Conclusion Celastrol may regulate the expression and release of inflammatory factors by inhibiting the TLR4/NF-κB pathway,thereby alleviating the ALI induced by sepsis in rats.