The α7 Nicotinic Acetylcholine Receptor on Fibroblast-like Synoviocytes and in Synovial Tissue From Rheumatoid Arthritis Patients A Possible Role for a Key Neurotransmitter in Synovial Inflammation
The α7 Nicotinic Acetylcholine Receptor on Fibroblast-like Synoviocytes and in Synovial Tissue From Rheumatoid Arthritis Patients A Possible Role for a Key Neurotransmitter in Synovial Inflammation
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DOI：
10.1002/art.24470
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发表时间：
2009-05-01
影响因子：
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通讯作者：
Tak, Paul P.
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文献类型：
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作者：
van Maanen, Marjolein A.;Stoof, Susanne P.;Tak, Paul P.
Objective.最近的研究表明，神经递质作为炎症调节剂的重要作用。因此，本研究旨在探讨烟碱乙酰胆碱受体α 7亚单位（α 7 nAChR）在类风湿关节炎（RA）中的表达及其功能。通过筛选腺病毒短发夹RNA（Ad.shRNA）文库，鉴定了α 7 nAChR在成纤维细胞样滑膜细胞（FLS）中调节促炎细胞因子表达的潜在作用。α 7特异性抗体用于免疫组织化学，异硫氰酸荧光素标记的α-银环蛇毒素，其特异性结合α 7 nAChR，用于免疫荧光。FLS中的基因表达通过定量聚合酶链反应与特异性引物的α 7 nAChR。此外，我们分析了dup alpha 7（一种变体alpha 7转录本）的信使RNA（mRNA）表达。接下来，我们通过检测α 7特异性激动剂对活化FLS产生白细胞介素-6（IL-6）和IL-8的影响，研究了α 7 nAChR在RA FLS中的功能作用。使用Ad.shRNA文库对807个转录本进行筛选，结果显示特异性α 7 nAChR shRNA有效调节FLS中IL-8和基质金属蛋白酶的表达。α 7 nAChR在RA患者的炎症滑膜中表达，主要在内膜衬里层中。我们发现在培养的RA FLS中，α 7 nAChR在mRNA和蛋白水平均有表达。FLS也组成性表达dup α 7 mRNA。特异性α 7 nAChR激动剂可减少肿瘤坏死因子α诱导的FLS产生IL-6和IL-8。α 7 nAChR及其dup α 7变体在RA滑膜中表达，在调节炎症中可能发挥关键作用。靶向α 7 nAChR可能为治疗RA提供新的途径。
Objective. Recent studies have suggested an important role for neurotransmitters as modulators of inflammation. Therefore, we undertook this study to investigate the expression of the alpha 7 subunit of the nicotinic acetylcholine receptor (alpha 7nAChR) and its function in rheumatoid arthritis (RA).Methods. The potential role of the alpha 7nAChR in modulating proinflammatory cytokine expression in fibroblast-like synoviocytes (FLS) was identified by screening an adenoviral short hairpin RNA (Ad.shRNA) library. An alpha 7-specific antibody was used for immunohistochemistry, and fluorescein isothiocyanate-labeled alpha-bungarotoxin, which binds specifically to the alpha 7nAChR, was used for immunofluorescence. Gene expression in FLS was determined by quantitative polymerase chain reaction with primers specific for the alpha 7nAChR. In addition, we analyzed messenger RNA (mRNA) expression of dup alpha 7, a variant alpha 7 transcript. Next, we studied the functional role of the alpha 7nAChR in RA FLS by examining the effects of alpha 7-specific agonists on the production of interleukin-6 (IL-6) and IL-8 by activated FLS.Results. A screen using an Ad.shRNA library against 807 transcripts revealed that a specific alpha 7nAChR shRNA potently modulated IL-8 and matrix metalloproteinase expression in FLS. The alpha 7nAChR was expressed in the inflamed synovium from RA patients, predominantly in the intimal lining layer. We found alpha 7nAChR expression at both the mRNA and protein level in cultured RA FLS. FLS also constitutively expressed dup alpha 7 mRNA. Specific alpha 7nAChR agonists reduced tumor necrosis factor alpha-induced IL-6 and IL-8 production by FLS.Conclusion. The alpha 7nAChR and its dup alpha 7 variant are expressed in RA synovium, where they may play a critical role in regulating inflammation. Targeting the alpha 7nAChR could provide a novel antiinflammatory approach to the treatment of RA.