转化生长因子β2在发育性髋关节发育不良患儿关节囊的分布和表达

Distribution and expression of TGF-β_2 in the capsule of children with developmental dysplasia of the hip

目的探讨发育性髋关节发育不良(DDH)患儿和非DDH儿童TGF-β2在关节囊的免疫组化分布规律与水平差异,并比较TGF-β2在mRNA水平的表达差异,以探索髋关节松弛的原因。方法选取性别相同、年龄相近的8对DDH(发育性髋关节脱位)患儿与非DDH儿童进行配对研究,采用S-P法免疫组化技术和半定量RT-PCR技术检测关节囊中TGF-β2的分布规律与水平差异,以及mRNA水平的差异。结果分泌TGF-β2的成纤维细胞于贴近关节侧的滑膜层呈强阳性表达,内部纤维层阳性表达细胞稀疏,强度减弱。DDH组与对照组配对比较,纤维层中有阳性成纤维细胞百分比及局部染色的灰度值较对照组明显减少,差异有统计学意义,P<0.01。DDH组关节囊TGFβ2mRNA的表达较对照组减少,差异有统计学意义,P<0.05。结论 DDH患儿的髋关节松弛很可能与关节囊中TGF-β2的分布减少和表达异常有关。

Objective This study examined the distribution and expression of transforming growth factor-β2（TGF-β2）in the hip capsule of children with developmental dysplasia（dislocation）of the hip（DDH）and non-DDH children in order to investigate the roles of TGF-β2 in hip joint laxity.Methods Eight children with DDH and eight age-and gender-matched non-DDH children（control group）were enrolled.The immunohistochemical technique（S-P method）was used to examine the distribution and content of TGF-β2 in the hip capsule.Semiquantitative RT-PCR method was used to detect mRNA expression of TGF-β2 in the hip capsule.The quantitative analysis of TGF-β2 was performed by professional image software.Results A high expression of TGF-β2 was observed in the synovial layer with fibroblast regularly arranged parallel to the joint surface.There was decreased expression of TGF-β2 in the fibrous layer of the capsule.The percentage of positive fibroblasts and the gray-scale density in the fibrous layer in the DDH group were significantly lower than those in the control group（P〈0.01）.TGF-β2 mRNA expression in the DDH group decreased compared with that in the control group（P〈0.05）.Conclusions The decreased TGF-β2 in distribution,content and mRNA expression in the hip capsule might contribute to hip joint laxity in children with DDH.