大黄通过调控紧密连接蛋白治疗大鼠脓毒症

Therapeutic Effect of Rhei Radix et Rhizoma on Septic Rats Via Regulating Tight Junction Protein

目的:探究大黄治疗脓毒症大鼠的分子机制。方法:100只Wistar大鼠随机分为假手术组,模型组,大黄高、中、低剂量组(150,100,50 mg·kg^(-1)),除假手术组只暴露盲肠,不进行结扎与穿孔,其余各组采用盲肠结扎法制作大鼠脓毒症模型,记录各组大鼠死亡情况,采用细菌16S rRNA实时荧光定量聚合酶链式反应(q PCR)检测大鼠结肠及肠系膜淋巴结、血液中金黄色葡萄球菌及大肠埃希菌数量,采用q PCR和蛋白质免疫印迹(Western blot)法检测大鼠结肠紧密连接蛋白紧密连接相关蛋白-1(ZO-1)和闭锁蛋白(Occludin)水平。结果:与假手术组比较,脓毒症模型组大鼠病死率最高,不同标本的金黄色葡萄球菌及大肠埃希菌检出率和数量明显升高,ZO-1和Occludin mRNA及蛋白表达明显降低(P<0.01);与模型组比较,大黄高、中剂量组大鼠病死率降低,大鼠不同标本的上述两细菌检出率和数量有所减低,细菌移位情况减少,大鼠结肠的ZO-1和Occludin mRNA及蛋白表达明显升高(P<0.05,P<0.01)。结论:大黄可调控结肠紧密连接蛋白表达保护肠黏膜屏障,从而抑制脓毒症大鼠细菌移位治疗脓毒症。

Objective： To investigate the molecular mechanism of Rhei Radix et Rhizoma on septic rats.Method： Totally 100 Wistar rats were randomly divided into sham-operation group,model group,Rhei Radix et Rhizoma high dose,middle dose and low dose groups（ 150,100,50 mg·kg^-1）. The rats in sham-operation group only exposed the cecum,without ligation and perforation; and the rats in other groups received cecum ligation method to establish rat sepsis models. The mortality of rats was recorded in various groups. The number of colon and mesenteric lymph nodes,Staphylococcus aureus and Escherichia coli in blood was detected by bacterial 16 S rRNA Real-time fluorescence quantitative polymerase chain reaction（ q PCR）. The levels of zonula occludens-1（ ZO-1） and Occludin were detected by q PCR and Western blot. Result： As compared with the sham-operation group,the mortality was the highest in septic model group,the detectable rate and number of S. aureus and E. coli in the samples of septic model group were significantly increased,while ZO-1 and Occludin mRNA and protein expression levels were significantly decreased（ P 〈0. 01）. As compared with the model group,the mortality was deceased in Rhei Radix et Rhizoma high dose and middle dose groups; the detectable rate and number of S. aureus and E. coli in the samples of these two groups were decreased,bacterial translocation was reduced,ZO-1 and Occludin mRNA and protein expression levels in rat colon were significantly increased（ P 〈0. 05,P 〈0. 01）.Conclusion： Rhei Radix et Rhizoma can regulate the expression of tight junction protein to protect the intestinal mucosal barrier and inhibit bacterial translocation in septic rats.