神经生长因子干扰TLR-NF-κB信号通路缓解角膜炎症反应的作用及其机制研究

Herpes simplex keratitis (HSK) is induced by the infection of herpes simplex virus-1 (HSV-1) with the characteristic of high incidence, disablement and recurrence rates. It was found that NGF could effectively treat HSK and prevent the relapse of the disease, whilst the detailed mechanisms remain unclear. Our previous studies showed that the expression profiles of miRNAs were significantly changed after HSV-1 infection, and these miRNAs mainly participate in NF-kB signaling pathway. In addition, NGF could significantly inhibit the inflammation responses of corneal epithelial cells induced by TLR activation, which was caused by virus infection. Considering our previous result that NGF has regulatory effect on miRNA profiles of corneal epithelial cells, therefore, we propose that miRNAs that related to NF-kB signaling pathway might be the key component in mediating the effect of NGF on ameliorating the corneal inflammation of HSK. In the current study, we will further investigate the influence of NGF on virus infection-related TLRs, as well as its following NF-kB signaling pathway. Additionally, we will explore the role of miRNAs that mediate the modulatory effect of NGF on HSK. Our study will provide new insights in the pathogenesis and treatment studies of HSK.

单纯疱疹病毒性角膜炎（HSK）是由HSV-1感染引起的角膜部炎症，预后差，治疗棘手。病理性的炎症反应是HSK致病的关键环节。临床研究表明NGF可有效治疗HSK及预防复发，但作用机制仍未明确。前期研究表明HSV-1感染后的角膜组织中与炎症通路调节因子NF-κB密切相关的miRNA表达显著变化；病毒感染可激活TLR，NGF对由此引发的炎症反应有明显的抑制作用；结合前期发现的NGF调控细胞增殖与其对miRNA的调控作用密切相关的实验结果，我们设想NF-κB信号通路相关miRNA可能是介导NGF缓解HSK角膜炎症反应的关键因素。本项目拟在此基础上研究NGF对病毒感染相关TLR及其下游NF-κB信号通路的影响；并进一步探索NGF抑制HSK的作用是否通过影响miRNA表达实现的。本研究将为NGF的临床使用提供进一步的理论依据，为明确角膜上皮细胞的抗病毒感染机制提供新的视角。

单纯疱疹病毒性角膜炎（HSK）是由HSV-1感染引起的角膜部炎症，预后差，治疗棘手。病理性的炎症反应是HSK致病的关键环节。临床研究表明NGF可有效治疗HSK及预防复发，但作用机制仍未明确。本研究通过TLR的特异性激动剂处理角膜上皮细胞，模拟病毒感染的病理过程，研究发现NGF对病毒感染相关的TLR3信号通路活化后引起的角膜炎症反应具有明显的抑制作用。NGF能显著抑制TLR3下游的关键信号通路NF-κB的激活，明显抑制转录因子p65入核；与此同时，NGF可有效清除炎症信号通路的重要第二信使ROS，并在一定程度上缓解TLR3激活诱导ROS激增而产生的细胞氧化损伤。另一方面，我们通过miRNA技术筛选到参与NGF缓解角膜炎症反应的关键miRNA，即miR-141-3p。与正常对照相比，miR-141-3p在HSK患者角膜中的表达明显下调；进一步研究发现NGF可以上调角膜上皮细胞中miR-141-3p表达，抑制NF-κB信号通路磷酸化，从而减少炎症因子IL-6、IL-8的分泌，缓解炎症反应。本项目进一步阐明了NGF缓解病毒感染相关炎症反应的分子机制，首次筛选并验证了NGF与下游NF-κB信号通路间起调控作用的关键miRNA。本研究为NGF的临床使用提供进一步的理论依据，为明确角膜上皮细胞的抗病毒感染机制提供新的视角。