title: Increased IL-1beta expression and myofibroblast recruitment in subacromial bursa is associated with rotator cuff lesions with shoulder stiffness.
abstract: We evaluated whether proinflammatory cytokine expression and myofibroblast recruitment in subacromial bursa was linked to rotator cuff lesions with shoulder stiffness. We analyzed expressions of IL-1beta, IL-6, and TNF-alpha in subacromial bursa and joint fluid collected from 14 patients with cuff tears with stiffness as a study group (Group I) and 14 patients with rotator cuff tears without shoulder stiffness as a control group (Group II) using real-time RT-PCR, immunohistochemistry, and ELISA. Myofibroblast apoptosis in subacromial bursa was analyzed using terminal deoxynucleotidyl transferase -mediated deoxyuridine triphosphate-biotin nick end-labeling (TUNEL) and alpha-smooth muscle actin immunofluorescence staining. Shoulder function was evaluated using the Constant score. Group I had higher mRNA expression (p < 0.001) and immunoreactivities (p < 0.001) of IL-1beta. They also had higher levels of IL-1beta, IL-6, and TNF-alpha in joint fluid. Increased IL-1beta mRNA expression in the subacromial bursa and IL-1beta levels in joint fluid were correlated with a preoperative deficit in shoulder motion (p < 0.001) and preoperative Constant scores (p < 0.001). Immunofluorescence observations showed that Group I subjects had more myofibroblasts (p < 0.001) than Group II. In Group II, a significant correlation was found between apoptotic myofibroblasts and total myofibroblasts (p = 0.002), but not in Group I (p = 0.510). Increased expression of IL-1beta and myofibroblast recruitment in the subacromial bursa in rotator cuff lesions are linked to shoulder stiffness.
authors.affiliation: Department of Orthopaedic Surgery, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Taiwan, Republic of China. kojy@adm.cgmh.org.tw
authors.forename: Jih-Yang
authors.initials: JY
authors.lastname: Ko
authors.forename: Feng-Sheng
authors.initials: FS
authors.lastname: Wang
authors.forename: Hsuan-Ying
authors.initials: HY
authors.lastname: Huang
authors.forename: Ching-Jen
authors.initials: CJ
authors.lastname: Wang
authors.forename: Shin-Ling
authors.initials: SL
authors.lastname: Tseng
authors.forename: Chin
authors.initials: C
authors.lastname: Hsu
mesh_terms: D000173:Acromioclavicular Joint; D000368:Aged; D017209:Apoptosis / Q000276:immunology; D002061:Bursa, Synovial / Q000276:immunology* / Q000473:pathology*; D005260:Female; D005347:Fibroblasts / Q000473:pathology*; D005455:Fluorescent Antibody Technique; D015870:Gene Expression / Q000276:immunology; D006801:Humans; D020287:In Situ Nick-End Labeling; D053583:Interleukin-1beta / Q000235:genetics* / Q000378:metabolism; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000378:metabolism; D017006:Rotator Cuff / Q000276:immunology / Q000473:pathology; D000070636:Rotator Cuff Injuries; D013582:Synovial Fluid / Q000276:immunology / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism
chemical_list: D053583:Interleukin-1beta; D015850:Interleukin-6; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha