瞬时受体通道 M4与人膝关节软骨年龄变化及软骨破坏的关系

Correlation of transient receptor potential melastatin 4 （TRPM4） to human aging changes of articular cartilage and to cartilage damage

目的：探讨瞬时受体通道 M4（TRPM4）与人膝关节年龄变化及骨关节炎（OA）软骨破坏的相关性。方法选择2013年2月至2014年2月山西医科大学第二医院骨科外伤截肢正常关节软骨及 OA 患者30例。根据年龄分为20～29岁组，30～39岁组，40～49岁组，每组6例；根据 OA 患者膝关节置换关节软骨，软骨破坏轻组6例，软骨破坏重者6例。根据番红 O 结果评价膝关节退变程度，实时荧光定量聚合酶链反应法测定 TRPM4 mRNA 在基因水平的变化，免疫印迹法测定 TRPM4蛋白水平的表达，免疫荧光，免疫组化分析 TRPM4在关节软骨及细胞表面的分布。结果番红 O 显示，随着年龄的增加，关节软骨逐渐退变，OA 患者退变更明显。人关节软骨上存在 TRPM4蛋白通道。随着年龄的增加，各组正常软骨中 TRPM4 mRNA 和蛋白逐渐增加，差别有统计学意义（P〈0.05）。随着关节软骨破坏的加重，TRPM4在 mRNA 和蛋白显著增加，差别有统计学意义（P〈0.05）。正常软骨，年龄和 TRPM4蛋白表达量呈正相关（r=0.632，P〈0.01），OA软骨，TRPM4蛋白表达量和破坏程度正相关（r=0.714，P〈0.01）。免疫荧光显示，TRPM4主要位于软骨细胞膜上，免疫组化显示，TRPM4位于软骨浅层。结论人膝关节软骨中存在 TRPM4蛋白，其表达水平与人年龄正相关，与膝关节病变过程，软骨破坏程度相关。

Objective To explore Correlation of Transient receptor potential melastatin 4 （TRPM4） to human aging changes of articular cartilage and to cartilage damage. Methods Collect knee amputation trauma patients, divided according to age group 20 to 29 years, 30 to 39 age group, 40 to 49 age group, each six cases; collect OA articular cartilage knee replacement patients,six cases of mild cartilage damage group, six cases of severe cartilage damage. The degeneration of cartilage was evaluated by revised Safranin O. The TRPM4 mRNA was assessed by RT-PCR and the TRPM4 protein expression examined by western blot. Immunohistochemistry and immunofluorescence investigate the localization of TRPM4 within human articular cartilage and the cellular distribution. Results Safranin O show that with increasing age, the degeneration of articular cartilage gradually , OA patients are more obvious damaged. TRPM4 was expressed in human cartilage.With the growth of age and worsening cartilage damage,TRPM4 mRNA and protein expressions increased obviously in cartilage（P〈0.05）.In normal cartilage, human age and TRPM4 protein expression was positively correlated （r=0.632,P〈0.01）. The damage degree of cartilage was positively correlated with TRPM4 expression（r=0.714,P〈0.01）.TRPM4 mainly located in the cell membrane of superficial cartilage chondrocyte. Conclusion TRPM4 expression is correlated with the human age and the damage degree of knee joint OA.