title: Increased matrix metalloprotease-3 gene expression in ruptured rotator cuff tendons is associated with postoperative tendon retear.
abstract: OBJECTIVE
  The role of matrix metalloproteases (MMPs) in ruptured rotator cuff tendons remains unknown. This study aimed to investigate the gene expression of MMPs in ruptured rotator cuff tendons and to compare their expression levels between patients with and without postoperative tendon retear.
  
  
  METHODS
  Twenty-four patients (a median age of 61 years: interquartile range, 55-66 years) with full-thickness rotator cuff tears were examined in this study. The marginal site of the ruptured tendon was harvested during surgery. The mRNA expression levels of collagen types I and III, MMP-1, MMP-3, MMP-7, MMP-9, MMP-13, tissue inhibitor of MMP (TIMP)-1, and TIMP-2 were analysed by real-time reverse transcription polymerase chain reaction. Postoperative retear was evaluated by magnetic resonance imaging at a minimum of 1 year following surgery.
  
  
  RESULTS
  The mRNA expression levels of MMP-3 and TIMP-1 in ruptured rotator cuff tendons were significantly increased in patients with postoperative retear (n = 6), compared with patients without retear (n = 18) (P = 0.04). For collagens, MMP-1, MMP-7, MMP-9, MMP-13, and TIMP-2, there were no significant differences in the mRNA expression levels in ruptured tendons between patients with and without retear.
  
  
  CONCLUSIONS
  These results suggest that, in addition to up-regulation of TIMP-1 gene expression, increased MMP-3 gene expression in ruptured rotator cuff tendons is associated with postoperative tendon retear. Thus, drug therapy specifically targeting MMP-3 after rotator cuff repair should be considered in the future.
authors.affiliation: Department of Orthopedic Surgery, Kurume University Medical Center, 155 Kokubu-machi, Kurume, Fukuoka, 839-0863, Japan. gomasa@med.kurume-u.ac.jp
authors.forename: Masafumi
authors.initials: M
authors.lastname: Gotoh
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Mitsui
authors.forename: Hideaki
authors.initials: H
authors.lastname: Shibata
authors.forename: Tetsu
authors.initials: T
authors.lastname: Yamada
authors.forename: Isao
authors.initials: I
authors.lastname: Shirachi
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Nakama
authors.forename: Takahiro
authors.initials: T
authors.lastname: Okawa
authors.forename: Fujio
authors.initials: F
authors.lastname: Higuchi
authors.forename: Kensei
authors.initials: K
authors.lastname: Nagata
mesh_terms: D000368:Aged; D024042:Collagen Type I / Q000235:genetics / Q000378:metabolism; D024061:Collagen Type III / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008279:Magnetic Resonance Imaging; D053505:Matrix Metalloproteinases, Secreted / Q000235:genetics* / Q000378:metabolism; D008875:Middle Aged; D011183:Postoperative Complications; D012333:RNA, Messenger / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D012008:Recurrence; D017006:Rotator Cuff / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D000070636:Rotator Cuff Injuries; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000235:genetics / Q000378:metabolism; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D024042:Collagen Type I; D024061:Collagen Type III; D012333:RNA, Messenger; C560823:TIMP2 protein, human; D019715:Tissue Inhibitor of Metalloproteinase-1; D019716:Tissue Inhibitor of Metalloproteinase-2; D053505:Matrix Metalloproteinases, Secreted