Up-regulated expression and activation of the. orphan chemokine receptor, CCRL2, in rheumatoid arthritis
Up-regulated expression and activation of the. orphan chemokine receptor, CCRL2, in rheumatoid arthritis
复制标题
DOI：
10.1002/art.20275
复制
发表时间：
2004-06-01
影响因子：
--
通讯作者：
Yoshimura, T
中科院分区：
文献类型：
--
作者：
Galligan, CL;Matsuyama, W;Yoshimura, T
Objective.风湿性关节炎（RA）是一种慢性炎症性疾病，其特征是细胞内流和关节结构破坏。趋化因子特征性地调节白细胞募集和活化。趋化因子（CC基序）受体样2（CCRL 2）是与其它CC趋化因子受体具有同源性的孤儿受体。我们进行了这项研究，以检查CCRL 2在RA中的表达，细胞因子的表达调节，以及一个假定的配体的来源，试图确定这种受体在炎症过程中的作用。免疫细胞化学法检测关节浸润白细胞CCRL 2的表达。体外研究使用北方和西方印迹法以及逆转录酶-聚合酶链反应评估了原代中性粒细胞中CCRL 2的表达。用逆转录病毒表达系统产生表达CCRL 2两种剪接变体（HEK/CCRL 2A或HEK/CCRL 2B）的HEK 293细胞，并使用48孔室检测其对RA患者滑液（SF）组分的迁移反应。5例RA患者的SF中所有浸润性中性粒细胞和部分巨噬细胞均表达CCRL 2。在体外研究的主要中性粒细胞显示，CCRL 2信使RNA（mRNA）迅速上调后，刺激脂多糖（1 μ g/ml）或肿瘤坏死因子（5 ng/ml）。CCRL 2A和CCRL 2B的mRNA在马槟榔刺激的中性粒细胞中表达。表达这些剪接变异体的细胞迁移响应RA SF的一部分。结论。类风湿关节炎患者滑膜中性粒细胞CCRL 2表达上调SF中存在的炎症产物激活该受体，表明CCRL 2是可能参与RA发病机制的功能性受体。
Objective. Rheumatoid arthritis (RA) is a chronic inflammatory condition characterized by a cellular influx and destruction of the joint architecture. Chemokines characteristically regulate leukocyte recruitment and activation. Chemokine (CC motif) receptor-like 2 (CCRL2) is an orphan receptor with homology to other CC chemokine receptors. We undertook this study to examine CCRL2 expression in RA, cytokine regulation of expression, and the source of a putative ligand in an attempt to determine the role of this receptor during inflammation.Methods. Expression of CCRL2 on joint-infiltrating leukocytes was examined by immunocytochemistry. In vitro studies evaluated CCRL2 expression in primary neutrophils using Northern and Western blotting and reverse transcriptase-polymerase chain reaction. HEK 293 cells expressing two splice variants of CCRL2 (HEK/CCRL2A or HEK/CCRL2B) were generated with a retroviral expression system, and their migration in response to fractions of synovial fluid (SF) from RA patients was examined using a 48-well chamber.Results. CCRL2 expression was observed on all infiltrating neutrophils and on some macrophages obtained from the SF of 5 RA patients. In vitro studies of primary neutrophils revealed that CCRL2 messenger RNA (mRNA) was rapidly up-regulated following stimulation with lipopolysaccharide (1 mug/ml) or tumor necrosis factor (5 ng/ml). The mRNA for both CCRL2A and CCRL2B were expressed in cytokine-stimulated neutrophils. Cells expressing either of these splice variants migrated in response to a fraction of RA SF.Conclusion. CCRL2 expression is up-regulated on synovial neutrophils of RA patients. Inflammatory products present in the SF activate this receptor, indicating that CCRL2 is a functional receptor that may be involved in the pathogenesis of RA.