Gene Expression Analysis by Quantitative Real-Time Reverse Transcriptase-Polymerase Chain Reaction of Glenohumeral Joint Synoviumin in Primary Frozen Shoulders

Background: Primary frozen shoulder is a condition characterized by painful and limited active and passive range of motion. Although the etiology is still uncertain, synovial fibrosis and adhesion were shown in glenohumeral joints of frozen shoulders. The messenger RNA expressions of three isoforms for hyaluronan synthase and of cytokines correlating with fibrosis and adhesion were analyzed for the synovium of glenohumeral joints in frozen shoulders to find possible molecular marker(s) correlated with pathogenesis of the disease.

Methods: Synovium from the upper border of the subscapularis muscle tendon in the glenohumeral joint was obtained from 10 primary frozen shoulders and 8 healthy control donors. The messenger RNA expressions were analyzed by real-time reverse transcriptase-polymerase chain reaction after isolation of the total messenger RNA from the collected synovia. Statistical analyses were done using the Mann Whitney U test.

Results: The messenger RNA expressions of three isoforms of hyaluronan synthase, which produce high molecular weight hyaluronan, in synovium of frozen shoulders were significantly lower than those in the control synovium (p<0.01). The messenger RNA expressions of interleukin-8 and interferon-γ, which induce angiogenesis or fibrosis, were significantly greater than those in control samples (p<0.01).

Conclusion: Decreased messenger RNA expressions of hyaluronan synthase isoforms and/or increased expressions of messenger RNAs for interleukin-8 and interferon-γ may correlate with the pathogenesis of frozen shoulder.