Hachicha M, Rathanaswami P, Schall T J, McColl S R
Centre de Recherche en Inflammation, Université Laval, Ste. Foy, Quebec, Canada.
Arthritis Rheum. 1993 Jan;36(1):26-34. doi: 10.1002/art.1780360106.
Since local secretion of chemotactic factors could contribute substantially to the homing of monocytes to the rheumatoid synovium, we investigated the ability of type B, or "fibroblast-like," synoviocytes isolated from the synovial tissue of patients with rheumatoid arthritis to synthesize and secrete the novel cytokine monocyte chemotactic protein 1 (MCP-1).
Synthesis and secretion of MCP-1 was determined by immunoprecipitation following metabolic labeling of MCP-1 with 35S-cysteine. MCP-1 gene regulation was assessed by Northern blot analysis.
Unstimulated type B synoviocytes released little or no MCP-1, although low levels of MCP-1 messenger RNA (mRNA) were detected. However, incubation of these cells with tumor necrosis factor alpha (TNF alpha) resulted in a time- and dose-dependent release of MCP-1 into the supernatant, and expression of MCP-1 mRNA. Use of cycloheximide and actinomycin D confirmed that TNF alpha was inducing MCP-1 expression at both the transcriptional and translational levels. Treatment of the synoviocytes with interferon-gamma (IFN gamma) also stimulated an increase in both the steady-state levels of MCP-1 mRNA, as well as MCP-1 protein synthesis and secretion. In addition, TNF alpha and IFN gamma in combination exerted a synergistic effect on both MCP-1 mRNA accumulation and protein secretion.
These studies demonstrate that the MCP-1 gene is regulated by TNF alpha and IFN gamma in type B synoviocytes and indicate that these cells may play an important role in the recruitment of inflammatory cells to the rheumatoid synovial environment, via the production of novel chemotactic cytokines such as MCP-1.
由于趋化因子的局部分泌可能在很大程度上促使单核细胞归巢至类风湿性滑膜，我们研究了从类风湿性关节炎患者滑膜组织中分离出的B型（或“成纤维细胞样”）滑膜细胞合成和分泌新型细胞因子单核细胞趋化蛋白1（MCP-1）的能力。
在用35S-半胱氨酸对MCP-1进行代谢标记后，通过免疫沉淀法测定MCP-1的合成和分泌。通过Northern印迹分析评估MCP-1基因调控。
未受刺激的B型滑膜细胞释放很少或不释放MCP-1，尽管检测到低水平的MCP-1信使核糖核酸（mRNA）。然而，将这些细胞与肿瘤坏死因子α（TNFα）一起孵育导致MCP-1呈时间和剂量依赖性释放到上清液中，并使MCP-1 mRNA表达。使用放线菌酮和放线菌素D证实TNFα在转录和翻译水平均诱导MCP-1表达。用干扰素-γ（IFNγ）处理滑膜细胞也刺激了MCP-1 mRNA的稳态水平以及MCP-1蛋白合成和分泌的增加。此外，TNFα和IFNγ联合对MCP-1 mRNA积累和蛋白分泌发挥协同作用。
这些研究表明，MCP-1基因在B型滑膜细胞中受TNFα和IFNγ调控，并表明这些细胞可能通过产生诸如MCP-1等新型趋化细胞因子，在将炎性细胞募集至类风湿性滑膜环境中发挥重要作用。
