Treatment With Glycogen Synthase Kinase 3ß Inhibitor Decreases Apoptotic and Autophagic Reactions in Rat Rotator Cuff Tears.

BACKGROUND: Apoptosis and autophagy are known to be correlated with the extent of damage in torn rotator cuffs, and there is no biological evidence for self-recovery or healing of the rotator cuff tear. PURPOSE: To establish in a rat model of partial- and full-thickness rotator cuff tears how a glycogen synthase kinase 3ß (GSK-3ß) inhibitor affects the expression of apoptotic and autophagic markers. STUDY DESIGN: Controlled laboratory study. METHODS: Twelve-week-old Sprague Dawley rats were divided into 3 groups (n = 16 per group). Group 1 acted as the control, with no treatment; group 2 received partial-thickness (right side) and full-thickness (left side) rotator cuff tears only; and group 3 received the same rotator cuff injuries, with GSK-3ß inhibitor injected afterward. The tendons from each group were harvested 42 days after surgery. Evaluation of gene expression, immunohistochemistry, and TUNEL staining (terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling) were performed for the following markers: caspases 3, 8, and 9 as well as Bcl-2 (B-cell lymphoma 2); BAX (Bcl-2-associated X protein); beclin 1; p53; and GSK-3ß; which represented apoptotic and autophagic reactions. Statistical analysis was performed using 1-way analysis of variance. RESULTS: In the group 2 rats with partial- and full-thickness tears, there were significant increases in the mRNA levels (fold changes) of all 8 markers as compared with group 1 (control). All these increased markers showed significant downregulation by the GSK-3ß inhibitor in partial-thickness tears. However, the response to the GSK-3ß inhibitor in full-thickness tears was not as prominent as in partial-thickness tears. The number of TUNEL-positive cells in group 2 (partial, 35.08% ± 1.625% [mean ± SE]; full, 46.92% ± 1.319%) was significantly higher than in group 1 (18.02% ± 1.036%; P < .01) and group 3 (partial, 28.04% ± 2.607% [P < .01]; full, 38.97% ± 2.772% [P < .01]), and immunohistochemistry revealed increased expression of all the markers in group 2 as compared with control. CONCLUSION: The apoptotic and autophagic activity induced in a rat model of an acute rotator cuff tear was downregulated after treatment with a GSK-3ß inhibitor, particularly with partial-thickness rotator cuff tears. CLINICAL RELEVANCE: A GSK-3ß inhibitor may be able to modulate deterioration in a torn rotator cuff.

Comparison of Gene Expression of Inflammation- and Fibrosis-Related Factors Between the Anterior and Posterior Capsule in Patients With Rotator Cuff Tear and Shoulder Stiffness.

BACKGROUND: Arthroscopic capsular release is an effective treatment for refractory shoulder stiffness, yet there are no basic studies that can explain the extent of the release. PURPOSE: This study aimed to compare the genetic expression of inflammation- and fibrosis-related factors between the anterior and posterior capsules in patients with shoulder stiffness and rotator cuff tear. STUDY DESIGN: Descriptive laboratory study. METHODS: Enrolled in this study were 35 patients who underwent arthroscopic capsular release for shoulder stiffness along with the rotator cuff repair. Anterior and posterior glenohumeral joint capsular tissues were obtained during the capsular release. For the control tissue, anterior capsule was obtained from 40 patients without stiffness who underwent arthroscopic rotator cuff repair. The gene expression of collagen types I and III, fibronectin, extracellular matrix, basic fibroblast growth factor, transforming growth factor-ß, connective tissue growth factor, matrix metalloproteinase (MMP)-1, MMP-2, MMP-9, tissue inhibitor of metalloproteinase (TIMP)-1, TIMP-2, intercellular adhesion molecule 1, interleukin 1, and tumor necrotizing factor-α were analyzed using real-time reverse transcription polymerase chain reaction. Differences in gene expression between the anterior capsule, the posterior capsule, and the control tissue were compared with the Kruskal-Wallis test. RESULTS: The expression levels of collagen types I and III were significantly higher in the anterior capsule with stiffness com (pared with both the posterior capsule with stiffness (P = .010 for both) and the control (P = .038 and .010, respectively). The levels of fibronectin, MMP-2, and MMP-9 in the anterior capsule were significantly higher than in both the posterior capsule (P = .013, .003, and .006, respectively) and the control (P = .014, .003, and .005, respectively). CONCLUSION: Genetic analysis of the shoulder capsule revealed that more fibrogenic processes occur in the anterior capsule compared with the posterior capsule in patients with shoulder stiffness. CLINICAL RELEVANCE: Capsular release for shoulder stiffness should be more focused on the anterior capsule than on the posterior capsule.

Integrity of the Untorn Articular-Sided Tendon in Bursal-Sided Partial-Thickness Rotator Cuff Tear: A Comparative Study of Apoptotic Activity in Torn and Untorn Layers.

BACKGROUND: Conversion to full-thickness tear in partial-thickness rotator cuff tears (PTRCTs) is based on the quality and thickness of the normal-looking untorn rotator cuff layer. However, whether the untorn tendon is a healthy tissue remains to be elucidated. PURPOSE: To compare the apoptotic gene expression of the untorn articular layer with the torn bursal layer in PTRCTs. STUDY DESIGN: Controlled laboratory study. METHODS: Tendon tissues were harvested from 20 patients undergoing arthroscopic surgery for partial-thickness rotator cuff repair. As a control group, the tissues were harvested during intramedullary nail fixation in 10 proximal humeral fractures. In the experimental group, the samples were harvested from 2 sites: the torn bursal-sided tendon and the untorn articular-sided tendon. Hematoxylin and eosin (H&E) staining was conducted for basic histological evaluation, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining was used to detect apoptosis of tissue cells. The expression of caspase 3, 8, and 9 was confirmed immunohistochemically. Western blot analysis was used to assay the caspase activities. RESULTS: In H&E staining, the direction of collagen bundles in untorn tendon was disoriented when compared with those of control tendon. However, the shape of the nuclei was not different, although the nuclei of the untorn tendon showed apoptosis in the TUNEL staining similar to those of the torn tendon. The immunohistochemical staining of caspase 3, 8, and 9 was increased concomitantly in untorn and torn tendons. All of the caspase activities in the untorn articular layer and torn bursal layer were significantly higher than in controls ( P < .05). However, no significant differences were found between the two layers ( P > .05). CONCLUSION: The study demonstrates that apoptotic gene expression is increased not only in the torn bursal layer but also in the untorn articular layer of PTRCTs. CLINICAL RELEVANCE: The untorn articular layer of PTRCTs is abnormal, which triggers postoperative pain and further rotator cuff tears. Therefore, treatment of the abnormal untorn articular layer is essential in bursal-sided PTRCTs.

Intercellular adhesion molecule-1 (ICAM-1, CD54) is increased in adhesive capsulitis.

BACKGROUND: The purpose of this study was to investigate the presence of intercellular adhesion molecule-1 (ICAM-1) in shoulders with adhesive capsulitis ("frozen shoulder"). METHODS: Glenohumeral capsular tissue was obtained from twenty-six patients (seventeen with adhesive capsulitis and nine controls), and ICAM-1 was evaluated with use of oligonucleotide arrays, real-time reverse transcription-polymerase chain reaction (RT-PCR), and immunohistochemistry. ICAM-1 was also evaluated in synovial fluid with use of western blotting (six patients with adhesive capsulitis and two controls) and in peripheral blood with use of an enzyme-linked immunosorbent assay (ELISA) (thirty-two patients with adhesive capsulitis, twenty with diabetes mellitus, and fourteen controls). The effect of ICAM-1 treatment on gene expression of cytokines related to inflammation and fibrosis was evaluated in cultured normal human synovial cells. RESULTS: The level of ICAM-1 was significantly greater in capsular tissue from the glenohumeral joint of patients with adhesive capsulitis compared with controls as measured by oligonucleotide array analysis (0.12 ± 0.01 compared with 0.09 ± 0.00 arbitrary units) (p = 0.001), real-time RT-PCR (1.70 ± 0.19 compared with 0.67 ± 0.24 arbitrary units) (p < 0.05), and immunohistochemical staining. ICAM-1 was also significantly increased in the synovial fluid of patients with adhesive capsulitis (1.70 ± 0.18 arbitrary units) compared with normal controls (0.48 ± 0.17) (p < 0.05) and in serum of patients with adhesive capsulitis (633.22 ± 59.14 ng/mL) and patients with diabetes mellitus (671.25 ± 27.08 ng/mL) compared with controls (359.86 ± 44.29 ng/mL) (p < 0.05). Gene expression of cytokines related to inflammation and fibrosis in synoviocytes cultured in vitro was greater after three days of treatment with ICAM-1 and with ICAM-1 with glucose compared with untreated cells. CONCLUSIONS: ICAM-1 was increased in patients with adhesive capsulitis, similar to the increase that has been reported in patients with diabetes mellitus.