湿性年龄相关性黄斑变性患者外周血单个核细胞Toll样受体3的表达及意义

Expression and significance of toll-like receptors in peripheral blood mononuclear cells of patients with wet age-related macular degeneration

摘要:

目的：探索 Toll 样受体（toll-like receptors，TLRs）3/4在湿性年龄相关性黄斑变性（age-related macular degeneration，AMD）患者外周血单个核细胞（peripheral blood mononuclear cells，PBMCs）的表达及其意义。方法：25例湿性AMD患者和24例正常对照纳入本研究。患者与正常对照组均不患有糖尿病、冠心病、高血压等慢性疾病或免疫性疾病及与免疫相关的疾病。采用real-time PCR 的方法检测TLR3/4的基因水平的表达，流式细胞术检测 TLR3蛋白水平的表达。TLR3特定的配体PolyI∶C刺激后，ELISA检测白介素（interleukin，IL）-6、IL-8、单核细胞趋化蛋白1（monocyte chemotactic protein 1，MCP-1）的表达。结果：在PBMCs水平，AMD组TLR3在mRNA及蛋白水平表达均显著高于正常对照组，而TLR4的mRNA水平表达在2组之间无统计学差异。与对照组PBMCs相比，AMD组PBMCs IL-6及IL-8的表达明显升高，TLR3的配体PolyI∶C刺激后，AMD组PBMCs IL-6的表达显著增多，MCP-1、IL-8的表达在2组之间无统计学差异。结论：TLR3在AMD组表达上调，活化后可促进IL-6表达增多。由此推测TLR3信号通路可能通过促进促炎性细胞因子的表达在湿性AMD的发病发展中发挥着重要作用。

Abstract:

Objective：To investigate whether the toll-like receptors（TLRs） 3/4 are associated with wet form age-related macular de－generation（AMD）. Methods：Blood samples were collected from 25 wet AMD patients and 24 age-matched healthy controls. Peripher－al blood mononuclear cells（PBMCs） were isolated by Ficoll-Hypaque density gradient centrifugation. Expression of TLR3 and TLR4 mRNA was assessed by real-time PCR. TLR3 protein level was measured with flow cytometry. After stimulating PBMCs with specific ligands PolyI∶C，cytokines IL-6，IL-8 and MCP-1 protein productions were assessed. Results：TLR3 mRNA and protein expression was significantly higher in the PBMCs of wet AMD patients than those in controls. However，the differences of TLR4 mRNA expression between the two groups were not significant. The PBMCs of wet AMD patients produced more IL-6 protein than the controls in response to PolyI∶C，the ligand for TLR3. But there was no significant difference in MCP-1 production between wet AMD group and control group when stimulating PBMCs with PolyI∶C. Conclusion：Our data suggest that upregulation of TLR3 signal pathways maybe a critical link in the pathogenesis of wet AMD.