骨关节炎和类风湿性关节炎滑膜中IL-1受体拮抗剂三种同工型的表达及其生物学意义

白介素 1受体拮抗剂 (IL - 1Ra)以三种同工型的形式存在 ,即 17kDa的分泌型IL - 1Ra(sIL - 1Ra)、18kDa的细胞内IL - 1Ra(icIL - 1RaI)及 16kDa的细胞内IL - 1Ra(icIL - 1RaII)。本实验采用免疫组化和反转录PCR的方法 ,观察了IL - 1Ra的三种同工型在 3例骨关节炎 (OA)和 3例类风湿性关节炎 (RA)患者关节滑膜中的表达和分布情况。免疫组化结果显示OA和RA的滑膜中IL - 1Ra高度表达 ,主要集中在滑膜的衬里层细胞、炎症浸润细胞以及血管内皮细胞中 ;RT -PCR结果提示OA滑膜的三个标本中均只存在 16kDa的icIL - 1RaII型 ,而RA的三个滑膜标本中有两个存在IL - 1Ra的三种同工型 ,还有一个标本只存在 18kDa的icIL - 1RaI型。因此 ,OA和RA的滑膜中均高度表达IL -1Ra,但存在的形式和发挥作用的方式可能有所不同 ,推测与这两种疾病的发病机制有关。

The Expression and Biological Function of Three Kinds of IL-1 Receptor Antagonist Isoforms in Synovium from OA and RA

IL-1R antagonist exists as three well-characterized isoforms,17-kDa secretory IL-1Ra (sIL-1Ra) and 18-kDa intracellular IL-1Ra (icIL-1RaI) as well as 16-kDa intracellular IL-1Ra (icIL-1RaII).This experiment was aimed at investigating the expression and localization of the three isoforms of IL-1Ra gene in human synovium from patients with osteoarthritis (OA) and rheumatoid arthritis (RA).We assessed IL-1Ra mRNA and protein expression in articular synovium from 3 cases of OA individuals and 3 cases of RA individuals by using RT-PCR and immunohistochemistry staining method respectively.Immunohistochemistry staining showed that intense expression of IL-1Ra at protein level occurred in synovium from OA and RA,mostly focused on the sites of synovial lining cells,inflammatory inflitrating cells and endothelial cells.RT-PCR showed that only icIL-1Ra II exists in all 3 cases from OA,and all three isoforms occurred in 2 of 3 cases from RA as well as icIL-1RaI in 1 of 3 cases from RA.Our data indicated that IL-1Ra were highly expressed in synovium from OA and RA,but there may be somewhat difference in the existing mode and the functioning form.IL-1Ra may be related to the pathogenesis of the two diseases.