Tetraspanin CD151 is expressed in osteoarthritic cartilage and is involved in pericellular activation of pro-matrix metalloproteinase 7 in osteoarthritic chondrocytes
Tetraspanin CD151 is expressed in osteoarthritic cartilage and is involved in pericellular activation of pro-matrix metalloproteinase 7 in osteoarthritic chondrocytes
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DOI：
10.1002/art.22140
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发表时间：
2006-10-01
影响因子：
--
通讯作者：
Okada, Yasunori
中科院分区：
文献类型：
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作者：
Fujita, Yoshinari;Shiomi, Takayuki;Okada, Yasunori
Objective.基质金属蛋白酶7（matrix metalloproteinase 7，proMMP-7）在骨关节炎（osteoarthritic，OA）关节软骨中过表达，其激活后可降解多种细胞外基质（extracellular matrix，ECM）和非ECM分子，但其在软骨中的激活过程尚不清楚。本研究旨在探讨tetraspanin CD 151在OA软骨中的表达及其与proMMP-7活化的关系。采用逆转录-聚合酶链反应（RT-PCR）、实时荧光定量PCR、免疫组化、原位杂交和免疫印迹法检测关节软骨中CD 151的表达。用软骨细胞研究CD 151与proMMP-7的相互作用及proMMP-7的活化。RT-PCR显示CD 151信使RNA在所有OA软骨样品中表达，但仅在30%的正常对照软骨样品中表达。免疫组化和原位杂交结果表明，CD 151与proMMP-7共表达的软骨细胞，主要是在表浅和移行区的OA软骨。CD 151免疫反应性与软骨样本中的Mankin评分（r = 0.757，P < 0.0001 [n = 30]）和软骨细胞克隆化程度（r = 0.83，P < 0.0001 [n = 30]）直接相关。复合物CD 151和proMMP-7和他们的细胞膜上的共定位证明了免疫沉淀和双荧光免疫染色的OA软骨细胞。原位酶谱显示软骨细胞具有细胞周蛋白水解活性，MMP抑制剂、抗MMP-7抗体或抗CD 151抗体可消除这种活性。这些数据表明，CD 151在OA软骨中过表达，并表明CD 151在proMMP-7的细胞周活化中起作用，导致软骨破坏和/或软骨细胞克隆。
Objective. The proenzyme of matrix metalloproteinase 7 (proMMP-7), which can degrade various extracellular matrix (ECM) and non-ECM molecules after being activated, is overexpressed in osteoarthritic (OA) articular cartilage, but the process of its activation in the cartilage remains unknown. The present study was undertaken to investigate the expression of tetraspanin CD151 in OA cartilage and its involvement in proMMP-7 activation.Methods. The expression of CD151 in articular cartilage was examined by reverse transcription-polymerase chain reaction (RT-PCR), real-time PCR, immunohistochemistry, in situ hybridization, and immunoblotting. Chondrocytes were used to study the interaction between CD151 and proMMP-7, and activation of proMMP-7.Results. RT-PCR revealed expression of CD151 messenger RNA in all OA cartilage samples, but in only 30% of normal control cartilage samples. Immunohistochemistry and in situ hybridization findings indicated that CD151 was coexpressed with proMMP-7 in chondrocytes, mainly in the superficial and transitional zones of OA cartilage. CD151 immunoreactivity directly correlated with the Mankin score (r = 0.757, P < 0.0001 [n = 30]) and the degree of chondrocyte cloning (r = 0.83, P < 0.0001 [n = 30]) in the cartilage samples. Complexes CD151 and proMMP-7 and their colocalization on the cell membranes were demonstrated by immunoprecipitation and double fluorescence immunostaining of the OA chondrocytes. In situ zymography indicated that chondrocytes exhibit pericellular proteolytic activity, which was abolished by treatment with MMP inhibitors, anti-MMP-7 antibody, or anti-CD151 antibody.Conclusion. These data demonstrate that CD151 is overexpressed in OA cartilage and suggest that CD151 plays a role in the pericellular activation of proMMP-7, leading to cartilage destruction and/or chondrocyte cloning.