IL-8对角膜成纤维细胞胶原合成的影响

The Effect of IL-8 on Collagen Synthesis in Corneal Fibroblasts

促炎因子IL-8在圆锥角膜患者泪液中表达较高,但其作用机制尚不明确。胶原合成和降解异常是圆锥角膜的发病机制之一。通过探讨IL-8对正常角膜成纤维细胞胶原蛋白合成的影响及其分子机制,为进一步揭示圆锥角膜的发病机制提供参考。构建siRNA干扰体系,通过siRNA技术沉默角膜成纤维细胞中IL-8的表达;采用实时荧光定量PCR分析沉默IL-8后,促炎因子以及胶原合成和降解相关基因的表达变化;采用ELISA法检测总胶原的含量;采用明胶酶谱法检测MMP-2的活性;采用Western blot法检测沉默IL-8后相关信号途径关键蛋白的变化。结果发现:沉默IL-8表达后,角膜成纤维细胞总胶原含量及胶原合成基因(COL1A2,COL3A1,COL5A3,COL6A1)的表达显著升高,而胶原降解酶MMP-2的表达和活性下降;此外,沉默IL-8能够降低IL-6、IL-1β、VEGFA/VEGFR2基因和下游AKT、ERK1/2蛋白的表达。结果表明,IL-8调节角膜成纤维细胞中其他促炎因子及VEGF的表达,并通过PI3K/AKT、ERK信号通路负调控角膜成纤维细胞中胶原的合成,参与MMP-2介导的胶原降解过程。

IL-8 is highly expressed in tears of keratoconus patients,but its mechanism is still unclear.Abnormal collagen synthesis and degradation are one of the pathogenesis of keratoconus.In this study,the effect of IL-8 on collagen synthesis in corneal fibroblasts and its molecular mechanism were discussed to provide reference for clarifying the pathogenesis of keratoconus.siRNA interference system was established and the expression of IL-8 in corneal fibroblasts was silenced by siRNA.The expression changes of genes related to collagen synthesis and degradation as well as other pro-inflammatory factors after IL-8 silence were analyzed by real-time fluorescent quantitative PCR.The content of total collagen and the activity of MMP-2 were detected by ELISA and gelatin zymography,respectively.Western blot was used to analyze the expression changes of the key proteins of related signal pathway.The results show that the total collagen content and the expression of collagen synthesis genes(COL1A2,COL3A1,COL5A3 and COL6A1)increased significantly after IL-8 silencing,while the expression and activity of MMP-2 which participated in collagen degradation decreased.In addition,silencing IL-8 reduced the gene expression of IL-6,IL-1β,and VEGFA/VEGFR2,as well as the protein expression of AKT and ERK1/2 in downstream signal pathway.IL-8 regulated the expression of VEGF and other pro-inflammatory factors.It negatively regulated the collagen synthesis and participated in MMP-2 mediated collagen degradation in corneal fibroblasts through PI3K/AKT and ERK signaling pathways.