Abstract:

Objective To explore the role of transforming growth factor (TFG)-β and matrix metalloproteinases（MMPs）in the development of frozen shoulder. Methods Twenty-four patients who underwent shoulder arthroscopy were included, and were divided into frozen shoulder group (n=12) and control group (n=12; n=2 for shoulder instability, n=5 for rotator cuff tear and n=5 for subacromial impingement). Joint capsule tissues at the rotator cuff interval were obtained, and the expression of TGF-β, MMP-1, MMP-2, MMP-3, MMP-9 and MMP-12 mRNA and protein was detected by Real-time PCR and Western blotting, respectively. Results The expression of TGF-β mRNA in frozen shoulder group and control group was 3.36×10⁴±2.18×10³ and 1.85×10⁴±3.31×10³, respectively, the expression of TGF-β protein was 1.55±0.33 and 1.13±0.21, respectively, and there were significant differences between these two groups （P<0.05）. The expression of MMP1, MMP2, MMP3, MMP9 and MMP12 mRNA and protein in frozen shoulder group was significantly higher than that in control group（P<0.05）. Conclusion The higher expression of TGF-β and MMPs in joint capsule of frozen shoulder may be associated with the development of frozen shoulder.

Key words: frozen shoulder, transforming growth factor-β, metalloproteinases, fibrosis