血清淀粉样蛋白A信号通路调控角膜新生血管性疾病的机理研究

The pathogenesis of corneal neovascularization has always been concerned but is uncertain. In recent years the literature has showed that serum amyloid A protien-formyl peptide receptor like-1-matrix metalloproteinases signaling pathway plays an important role in development of tumor, arthritis and infectious diseases. But the signal pathway in corneal aspects has not been invertigated, only parts of the related factors in the expression of cornea cells. Our initial findings showed that all factors related the signal pathway expressed in the mouse cornea and its expression obviously changed during the different stages of corneal neovascularization, implying that the signal pathway may play an important role in the pathological process of corneal neovaseularization. This study will further investigate the signal pathway-related factor expression changes during the different stages of corneal neovascularization in mouse and in vitro culture in the corneal cells for external stimulation reaction. Application of RNA interference and transfection gene technology can inhibit or enhance a serum myloid A protein expression of the corneal cells so as to observe its influence on the biological characteristics and cornea corneal neovascularization process. Through the immunohistochemical and microarray assay technology ,the related mechanism will also be discussed. After the completion of the study, the scientific problems of corneal neovascularization pathological mechanism will be solved, to provide new targets for suppression of corneal neovascularization.

关于角膜新生血管的病理机制一直备受关注但尚无定论。近年来文献资料表明血清淀粉样蛋白A-甲酰肽类受体1-基质金属蛋白酶信号通路在肿瘤、关节炎、感染性疾病等病变过程中发挥着重要作用，但此信号通路在角膜方面尚无相关研究，仅有部分相关因子在角膜细胞中表达。我们前期的研究结果表明此信号通路相关因子均在小鼠角膜中表达并且其表达量在小鼠角膜新生血管病变过程中存在明显的变化，提示此信号通路在角膜新生血管病理过程中发挥重要作用。本课题将进一步研究在小鼠角膜新生血管模型的不同阶段及体外培养的角膜细胞在对外源性刺激信号反应过程中此信号通路相关因子的表达变化，以及应用干扰RNA、基因转染等技术抑制或增强血清淀粉样蛋白A的表达对角膜细胞的生物学特性和角膜新生血管病理过程的影响，并通过免疫组化、基因芯片技术等探讨相关机理。课题完成后将为解决角膜新生血管病理机理这一科学问题提供依据，为抑制角膜新生血管生长提供新的靶点。

关于角膜新生血管的病理机制一直备受关注但尚无定论。研究结果显示血清淀粉样蛋白A（serum amyloid A,Saa）及其受体甲酰肽受体2（formly peptide receptor 2,Fpr2）在小鼠角膜中表达并且其表达量在小鼠角膜新生血管病变过程中存在明显的变化，提示此Saa-Fpr2信号通路是否参与角膜新生血管的病理过程。通过Gene Expression Omnibus(GEO)及Pubmed数据库分析Saa-Fpr2信号通路可能参与的角膜新生血管及炎症的相关因子，发现Saa相关因子Saa1、Saa2、Saa3、Saa4中的Saa1和Saa3因子与角膜炎症及角膜新生血管关系较大。其受体有Fpr2、Cd36、Scarb1、Tlr2、Tlr4、P2ex7，其中Fpr2关于炎症方面研究较多，Saa诱导生成的Mpp分子主要有Mmp1a、Mmp1b、Mmp2、Mmp3、Mmp9、Mmp10、Mmp13，这些分子可能参与角膜炎症及角膜新生血管。分别用缝线法和碱烧伤法建立小鼠角膜新生血管模型，并通过RT-PCR、基因芯片、免疫组化及western blotting等技术研究Saa-Fpr2信号通路在角膜新生血管中表达变化。研究结果显示Saa-Fpr2信号通路中的Saa1、Saa3、其受体Fpr2、下游分子Mmp2、Mmp3参与角膜炎症及角膜新生血管提示Saa-Fpr2通路在角膜新生血管病理过程中发挥重要作用，对于进一步阐明角膜新生血管病理机制具有重要的意义，为抑制角膜新生血管生长提供新的靶点。