TLR4及其信号通路在阻塞性黄疸肝脏损伤中作用的研究

目的 探讨TLR4及其信号通路在阻塞性黄疸中引起肝脏损伤的作用机制。方法 将60只SD大鼠（雌雄各半）随机分为阻塞性黄疸+多粘菌素B组（OJ+PMB组，n=15）、阻塞性黄疸组（OJ组，n=15）、假手术组（SO组，n=15）、空白对照组（CG组，n=15）。结扎胆总管建立阻塞性黄疸大鼠模型，并于术后7、14、21d采集标本，检测血清内毒素（LPS）、谷丙转氨酶（ALT）和总胆红素（TBI）含量，常规HE染色观察肝脏病变，ELISA法检测肝脏组织中TLR4蛋白表达和NF-kB P65活性，RT-PCR检测TLR4mRNA的表达情况 。结果 在同一时间点，OJ+PMB组、OJ组与SO组、CG组比较，血清内毒素、ALT、TBI和肝组织TLR4、NF-kB P65均明显升高（p＜0.01)。ALT与TLR4的变化呈明显正相关（r=0.875, p＜0.01），并且肝组织病理损伤也随肝组织中TLR4升高而逐渐加重。LPS与TLR4的变化呈正相关（r=0.848, p＜0.01)， TLR4与NF-kB p65的变化呈正相关（r=0.877, p＜0.01)，它们之间都存在明显的依存关系。21d时，OJ+PMB组与OJ组比较各血清学指标下降，差别有统计学意义（p＜0.01)，病理损伤减轻。结论 TLR4的表达可加重阻塞性黄疸肝脏的损伤，并可经LPS―TLR4―NF-kB信号转导通路发挥其作用；PMB有拮抗内毒素，减轻肝脏损伤作用。

Research on Effect of TLR4 and its Signaling Channel in Obstructive Jaundice Liver Injury

【Abstract】Objective: To probe the mechanism of effect of TLR4 and its signaling channel leading to obstructive jaundice liver injury. Methods: 60 SD rats (composed of male and female in equal) were divided into Obstructive Jaundice + Polymyxin B Group (OJ+PMB Group, n=15), Obstructive Jaundice Group (OJ Group, n=15), Sham-operated Group (SO Group, n=15), Blank Control Group (CG group, n=15). The obstructive-jaundice rat model was established by means of bile duct ligation, and 7, 14 and 21-day specimens were collected after operation, to test the contents of serum endotoxin (LPS), alanine aminotransferase (ALT) and total bilirubin (TBI), for observation of liver disease by means of routine HE stain, TLR4 protein expression and activity of NF-kB P65, as well as the expression of RT-PCR testing TLR4mRNA. Results: After compared with SO Group and CG Group of the same time point, endotoxin、ALT、TBI 、TLR4 and NF-kB P65 of OJ + PMB Group and OJ Group were significantly higher (p<0.01). Changes of ALT and TLR4 were of significant positive correlation (r=0.875, p<0.01), and liver tissues pathology gradually worsened with the increase of TLR4 in liver tissues. Changes of LPS and TLR4 were of positive correlation (r=0.848, p＜0.01), and changes of TLR4 and NF-kB P65 were of positive correlation and there were obvious dependencies between them. Various serum indicators were significant decreased after OJ+PMB Group compared with OJ Group in 21-day（p<0.01), pathological injury was alleviated. Conclusion: The expression of TLR4 can aggravate obstructive jaundice liver injury, which can play its role through LPS-TLR4-NF-kB signaling transduction channel; PMB had endotoxin, which can alleviate the liver injury.