miR-155对LPS诱导的角膜炎症免疫反应的调控作用及机制

Bacterial keratitis is the most common and serious corneal infectious disease that can lead to severe visual disability. Toll-like receptor (TLR) is the key factor to start and mediate inflammatory response of bacterial keratitis, and miR-155 is an important regulatory molecule for innate immune response.Our previous studies have found that TLR4 signaling pathway plays key role in Lipopolysaccharide(LPS)-induced immune response. However, the role of miR-155 in LPS-induced corneal inflammatory response is still unclear.In the present study, the effects of miR-155 overexpression on cell proliferation, apoptosis, cell cycle and migration will be evaluated in vitro. LPS-induced inflammatory factors and TLR4 signaling proteins after miR-155 upregulation or downregulation will be detected by ELISA and Western blot analysis. The specific protein inhibitors will be used to analyze key signaling pathways which mediate the role of miR-155 in innate immune response. The miR-155 sponge transgenetic C57BL/6J mice will be constructed and used for bacterial keratisis model. The inflammatory factors and TLR4 signaling proteins will be determined by RT-PCR and immunohistochemistry staining.The roles of miR-155 in LPS-induced corneal inflammatory and immune response are analyzed for from molecular, cellular and animal model levels, which will help us to elucidate the pathogenesis of bacterial keratitis and provides theoretical basis for target therapy.

细菌性角膜炎是当前发病率和致盲率最高的感染性角膜病。Toll样受体（TLR）是启动和介导细菌性角膜炎炎症反应的关键因子，而miR-155是调节炎症免疫反应的重要因子。我们前期证实TLR4介导LPS诱导的角膜炎症反应，但miR-155在LPS诱导的角膜炎症反应中的作用尚不明确。本课题拟体外检测miR-155对人角膜上皮细胞生物学功能的影响，采用ELISA和Western blot检测miR-155对LPS诱导的炎性因子和TLR4通路蛋白的影响。利用特异性阻断剂探寻介导miR-155炎症免疫调节作用的关键信号通路。构建miR-155 sponge转基因小鼠细菌性角膜炎模型，采用RT-PCR和免疫组化检测角膜组织炎性因子和TLR4通路蛋白的表达差异。从分子、细胞、整体水平分析miR-155对LPS诱导的角膜炎症免疫反应的调控作用及机制, 为阐明细菌性角膜炎的发病机制及指导靶向治疗提供理论基础。

细菌性角膜炎是当前发病率和致盲率最高的感染性角膜病。Toll样受体（TLR）是启动和介导细菌性角膜炎炎症反应的关键因子，而miR-155是调节炎症免疫反应的重要因子。我们前期证实TLR4介导LPS诱导的角膜炎症反应，但miR-155在LPS诱导的角膜炎症反应中的作用尚不明确。本课题通过体外和体内研究证实，miR-155通过TLR4-MyD8-TRAF6-NF-κB信号通路介导LPS诱导的角膜炎症反应，促进炎症因子IL-6，IL-8和TNF-α的表达。MiR-155的上调或下调不改变人角膜上皮细胞的细胞增殖和凋亡水平，但明显改变细胞迁移能力，并分别上调或下调MM2和MMP9的表达。体外研究还证实，LPS可上调miR-155的表达，并呈浓度依赖性上调。从分子、细胞、整体水平分析miR-155对LPS诱导的角膜炎症免疫反应的调控作用及机制, 为阐明细菌性角膜炎的发病机制及指导靶向治疗提供理论基础。