Distribution and expression of TGF-β2 in the capsule of children with developmental dysplasia of the hip

Abstract:

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.［Chin J Contemp Pediatr, 2010, 12 (8):641-644］