Clinical Medicine and Hepatology Unit, University Campus Bio-Medico of Rome, Rome, Italy.
Mod Pathol. 2012 Apr;25(4):576-89. doi: 10.1038/modpathol.2011.197. Epub 2011 Dec 16.
Notwithstanding numerous evidences implicating toll-like receptor-4 (TLR4) in the pathogenesis of chronic hepatitis C virus (HCV) infection, the localization and level of TLR4 expression in the liver of patients with hepatitis C have never been investigated. We aimed to evaluate, by means of immunohistochemistry and real-time PCR (rt-PCR), hepatic TLR4 expression in patients with chronic HCV infection. Fifty patients who had undergone liver biopsy and 11 patients transplanted because of chronic HCV infection, and 12 controls free of liver disease, were included in the study. Each case was analyzed by immunohistochemistry for TLR4, α-smooth muscle actin and cytokeratin-7 (CK-7), and a subgroup of patients and all controls by rt-PCR for TLR4. Immunohistochemistry for α-smooth muscle actin was used to derive a score of activation of hepatic stellate cells and portal/septal myofibroblasts, while immunohistochemistry for CK-7 was used to evaluate and count hepatic progenitor cells, interlobular bile ducts and intermediate hepatocytes. In patients, the parenchymal elements responsible for the highest TLR4 level of expression were hepatic progenitor cells and biliary epithelial cells of interlobular bile ducts. Double-labeling experiments between anti-TLR4 and anti-CK7, anti-CD133, anti-CD44, anti-neural cell adhesion molecule, anti-epithelial cell adhesion molecule and anti-sex determining region Y-box 9, confirmed these findings. TLR4-positive hepatic progenitor cells and interlobular bile ducts were significantly correlated with the stage of liver disease (P<0.001), the grade of inflammation (P<0.001), and the activity of portal/septal myofibroblasts (P<0.001). rt-PCR study confirmed an increased TLR4 expression in the 26 patients analyzed with respect to controls (P<0.001). TLR4 expression positively correlated with fibrosis (P<0.05) and inflammation (P<0.05). The present results suggest that TLR4 expression by hepatic progenitor cells and biliary epithelial cells contributes to the progression of liver damage in the course of chronic HCV-related infection.
尽管有大量证据表明 Toll 样受体 4（TLR4）参与慢性丙型肝炎病毒（HCV）感染的发病机制，但 HCV 感染患者肝脏中 TLR4 的定位和表达水平从未被研究过。我们旨在通过免疫组织化学和实时 PCR（rt-PCR）评估慢性 HCV 感染患者肝脏 TLR4 的表达。本研究纳入了 50 例接受肝活检的患者和 11 例因慢性 HCV 感染而接受移植的患者，以及 12 例无肝病的对照者。对每个病例进行 TLR4、α-平滑肌肌动蛋白和细胞角蛋白-7（CK-7）的免疫组织化学分析，并对部分患者和所有对照者进行 TLR4 的 rt-PCR。用α-平滑肌肌动蛋白的免疫组织化学来评估肝星状细胞和门/间隔肌纤维母细胞的激活评分，而用 CK-7 的免疫组织化学来评估和计数肝祖细胞、小叶间胆管和中间肝细胞。在患者中，表达 TLR4 水平最高的实质成分是肝祖细胞和小叶间胆管的胆管上皮细胞。抗-TLR4 与抗-CK7、抗-CD133、抗-CD44、抗神经细胞黏附分子、抗上皮细胞黏附分子和抗性别决定区 Y 框 9 的双标记实验证实了这一发现。TLR4 阳性肝祖细胞和小叶间胆管与肝病的分期（P<0.001）、炎症的程度（P<0.001）和门/间隔肌纤维母细胞的活性（P<0.001）显著相关。对 26 例分析患者的 rt-PCR 研究证实 TLR4 的表达较对照组增加（P<0.001）。TLR4 的表达与纤维化（P<0.05）和炎症（P<0.05）呈正相关。本研究结果表明，肝祖细胞和胆管上皮细胞的 TLR4 表达有助于慢性 HCV 相关感染过程中肝损伤的进展。
