Investigation of the mechanism of joint destruction in inflammatory process and the development of its prophyractic treatement by cellular and molecular biological approach

为探讨黏附分子(VLA-4、VLA-5)、基质金属蛋白酶(MMPs)及其组织抑制因子(TIMP)在类风湿关节炎(RA)滑膜中的定位，应用免疫组织化学方法对类风湿关节炎(RA)软骨-血管膜连接进行了研究。VLA-5在与细胞外软骨基质接触的滑膜细胞表面有较强的表达，提示VLA-5与构成基质的纤维连接蛋白的相互作用可能在类风湿滑膜血管疙瘩的形成和侵袭过程中起重要作用。基质金属蛋白酶-1和基质金属蛋白酶-3与VLA-5抗原在软骨-血管膜连接处均呈阳性表达，而TIMP-1的表达很弱。这些结果提示，软骨-血管膜连接处的基质金属蛋白酶和组织基质金属蛋白酶的失衡可能加速了血管疙瘩对关节软骨的侵袭，导致关节破坏。本研究还检测了炎症刺激对培养的滑膜成纤维细胞黏附分子表达的调节作用，以阐明通过抑制黏附分子的表达及其功能来抑制类风湿关节炎关节破坏的可能性。炎性细胞因子如白介素1β增加了人巨噬细胞系U-937细胞对RA滑膜成纤维细胞的黏附。炎症细胞因子刺激后，黏附分子1CAM-1、VCAM-1表达增强，而VLA-5表达稳定。这些结果提示，炎症刺激对VLA-5的影响不是很大，在调节黏附分子表达和细胞黏附方面，抗体直接抑制VLA-5的功能可能是RA治疗所必需的。

In order to examine the localization of adhesion molecule (VLA-4, VLA-5), matrix metalloproteinase (MMP) and tissue inhibitor of matrix metalloproteinase (TIMP) in rheumatoid synovium, the cartilage-pannusjunction in rheumatoid arthritis (RA) were explored immunohistochemically. VLA-5 is strongly expressed on the cell surface of synovial cells contacting extracellular cartilage matrix, which is suggesting that interaction of VLA-5 and fibronectin constituting the matrix might be important in pannus formation and invasion in rheumatoid synovium. Both MMP-1 and MMP-3 are positively stained closed to the VLA-5 antigen in cartilage-pannusjunction, whereas the expression of TIMP-1 was very weak. These results may indicate that imbalance of MMP and TIMP in cartilage-pannus junction may accelerate the invasion of pannus on articular cartilage lead to joint destruction.Modulation of adhesion molecule expression on cultured synovial fibroblasts by inflammatory stimulation were also examined in order to elucidate the possibilities of the suppression of joint destruction in RA by inhibiting the expression of adhesion molecule and its function. Inflammatory cytokines such as interleukin-1β has augmented the cell attachment of human macrophage cell line U-937 to RA synovial fibroblasts. While the expression of adhesion molecules such as 1CAM-1 and VCAM-1 were enhanced by stimulation of inflammatory cytokines, the expression of VLA-5 has been stable. These results suggest that VLA-5 has not been influenced quantitively by inflammatory stimulation and functional inhibition of VLA-5 directly by antibodies might be necessary for the RA treatment in terms of the modulation of adhesion molecule expression and cell attachment.