Expression of P53, Bcl-2, Bax, and JNK-1 in Relation to the Apoptosis of the Ruptured Rotator Cuff Tendon / 대한정형외과연구학회지

ABSTRACT

PURPOSE: The causes of rotator cuff tendon tear were excessive overuse, aging process and impingement syndrome and a lot of research of these factors have been performed. But molecular study of cuff tear or apoptosis of rotator cuff tenocyte is not done until now. In this study, the apoptosis level and apoptosis-related gene expression were investigated in the specimens from the torn margin of a rotator cuff tear, and compared with those from normal portion. MATERIALS AND METHODS: Among patients who underwent arthroscopic shoulder surgery between April 2008 to August 2008, 15 patients with complete rotator cuff tear was investigated. These were 10 men and 5 women. The age were from 48 years to 76 years old (average 61.5 years). The contol group were 2 patients with intact subscapularis tendon. Patients with impingement syndrome, partial tear or tendinitis were excluded from the design of the study. Tendon specimen in the tear margin of supraspinatus or infraspinatus tendon was evaluated using Hematoxylin-Eosinophilic stain, TUNNEL assay and immunohistochemistry for p53, Bcl-2, Bax and JNK1 were performed. RESULTS: TUNNEL assay was positive in 5 cases of the 15 specimens. In these cases, 5.4% of the cells were positive. The apoptosis-related gene such as p53, Bcl-2, Bax and JNK-1, and tear size were evaluated. These correlations were evaluated using a correlation analysis of Spearman correlation analysis. Spearman correlation coefficient between apoptosis and bcl-2, and between apoptosis and p53 were 0.625 and 0.71, respectively. These p values were 0.01 and 0.003, respectively. Spearman correlation coefficient between p53 and tear size, and Bax and tear size were 0.58 and 0.76, respectively. These p values were 0.02 and <0.001, respectively. The apoptosis of control group in normal subscapular tendon is zero. CONCLUSION: The increased apopotic index was correlated with increased bcl-2 and p53 gene in Rotator cuff tear patients. The larger tear showed increased p53 and Bax gene expression. Further research in this area will need to reduce apoptosis in the development of the rotator cuff tear.