Expression of transforming growth factor beta and Smad signalling in ankylosing spondylitis / 中华风湿病学杂志

ABSTRACT

Objective To investigate the expression of transforming growth factor beta (TGF-β) and Smad signaling in ankylosing spondylitis (AS) and to explore their roles in the pathogenesis. Methods Fiftythree patients with AS were included in the study. In these 53 cases, 30 patients were performed computed tomography-guided needle biopsy in sacroiliac joint. Serum TGF-β_1 was determined by enzyme-linked immunosorbent assay (ELISA). Immunohistological studies were performed with the streptavidin-peroxidase conjugated methods to assess the expression of TGF-β_1, p-smad3 and Smad7 in sacroiliac joint tissue sample.One-way ANOVA, two independent samples t test and kolmogoorov-Simimov test were used to do statistical analysis. Results In 53 cases patients with AS, 20 cases were with high level Erythro-cyte sedimentation rate(ESR) and C-reactive protein (CRP), while those of the other 33 cases were normal. Serum average TGF-β_1level [ (15.9±5.6) ng/ml ], in patients with high level ESR/CRP [(5.4±5.8) ng/ml ] was significantly increased as compared to the controls and patients with normal ESR/CRP [(4.1±3.6) ng/ml] (P<0.05). There was no expression of TGF-β_1 could be detected in the pannus and bone marrow in SI joints tissue of 30 cases with AS, while decreased level of smad7 expression was detected. In addition, p-smad3 expression was found in the nuclear. Conclusion TGF-β_1 signaling may play an important role in the inflammatory erosion and cartilage fibrosis of sacrojlitis in AS.