五羟色胺再摄取抑制剂和干眼病发病通路的机制研究

Dry eye disease (DED) is one kind of common ophthalmological disease and has a close relationship with depression. DED can cause great pain of patients and heavy burden of medical system. In addition, there are many influencing factors of DED, and selective serotonin reuptake inhibitor (SSRI) would be mainly discussed as an influencing factor of DED in this study. SSRI is now the first choice in depression treatment, however there are quite a few depression patients taking SSRI who are suffering DED. This phenomenon drew ophthalmologists’ attention. Toll-like receptor 4 (TLR4) is a transmembrane protein receptor of innate immunity. The expression of proinflammatory cytokine increases when the TLR4 signaling pathway is activated, which proved to be the trigger of DED. We discovered the expression of TLR4 signaling pathway was upregulated in patients who had taken SSRI for a long period. Thus, with the support of references, we propose a hypothesis: in ocular surface, SSRI is able to increase the concentration of 5-Hydroxytryptamine (as known as serotonin, 5-HT), which upregulated the expression of TLR4 signaling pathway, and this induces DED. In order to elucidate the mechanism of SSRI inducing DED, we plan to conduct clinical trail and experiments of zoology and cytology by protocols in molecular biology. The results and conclusion of this study will be meaningful and instructive to drug section in dry eye patients with depression.

干眼病是眼科常见疾病，与抑郁症关系密切，可引起患者严重不适，造成医疗系统沉重疾病负担。此外干眼病的发病受到多种因素影响，本课题将着重讨论五羟色胺再摄取抑制剂（SSRI）的影响。SSRI是目前抑郁症治疗首选用药，然而使用SSRI药物患者中大量患有干眼病，这引起了临床医师关注。Toll样受体（TLR4）是生物固有免疫系统中的跨膜蛋白受体，TLR4信号通路激活后可以引起促炎细胞因子增加。促炎细胞因子表达增加被证实导致干眼病发生。本课题组在前期工作中发现长期使用SSRI患者眼表TLR4信号通路的表达上调。结合文献支持，本课题组提出SSRI类药物可能通过增加眼表五羟色胺（5-HT）浓度，上调眼表TLR4信号通路表达，进而导致患者干眼病发生的科学假说。本课题计划从临床、动物学及细胞学试验多个层面，结合分子生物学技术，阐明SSRI药物引起患者干眼病的发病机制。课题成果对指导干眼病患者抑郁用药有重要价值。

研究背景及目的：干眼病（Dye eye disease, DED）是一种常见的多因素炎症性疾病，可导致视觉障碍及慢性眼部不适。我们的研究主要目的在于评估五羟色胺再摄取抑制剂（selective serotonin reuptake inhibitors, SSRIs)在眼表的副作用。.方法：本研究课题通过人体、动物及细胞三个层面详细展开。首先第一部分入组同时患有干眼病及抑郁症的患者随机选择接受SSRI类治疗，同时另外20名患者接受安慰剂治疗。五羟色胺、炎症因子以及促凋亡蛋白的水平通过蛋白芯片、qRT-PCR以及ELISA等方法进行测量。此外，在第二部分，研究者还建立了小鼠的抑郁模型，对小鼠模型SSRIs使用3-6周。泪液生成、角膜上皮屏障功能受到评估。五羟色胺、炎症因子的水平通过qRT-PCR、免疫组化染色及ELISA的方法进行测量。而在最后第三部分，本课题组对人类角膜上皮细胞进行五羟色胺、HTR拮抗剂和/或NF-κB信号抑制剂的处理。炎症因子以及促凋亡蛋白的表达水平通过qRT-PCR、Western印迹分析和ELISA进行检测。细胞凋亡率通过流失细胞学进行测量。.结果：首先在临床患者中观察到，使用SSRI的患者组，其泪液五羟色胺水平更高，炎症以及眼表的细胞凋亡更显著。进而在小鼠的抑郁模型中，抑郁减少泪液分泌已经增加了IL-1b和TNF-a生成，然而五羟色胺，TLR2和TLR4的水平没有增加。最后，通过细胞学层面的研究，本研究组观察到SSRIs加重干眼，并干扰了角膜上皮的屏障。SSRIs是通过增加泪液五羟色胺的水平，从而促进眼表的炎症应答。此外，五羟色胺通过激活NF-κB信号通路，来导致角膜上皮细胞的炎症反应以及细胞凋亡。.结论及关键意义：SSRIs通过激活NF-κB通路来加重抑郁相关干眼。HTRs的拮抗剂或NF-κB信号通路抑制剂，是抑郁相关干眼的潜在治疗策略。这对于抑郁相关干眼患者在抑郁药物的选择也具有明确的提示价值。