title: Expression and inhibition of matrix metalloproteinase (MMP)-8, MMP-9 and MMP-12 in early colonic anastomotic repair.
abstract: OBJECTIVE
  Submucosal collagen is paramount for colonic anastomotic integrity. Matrix metalloproteinases (MMPs) mediate collagen degradation that increases the risk of wound dehiscence. Although broad-spectrum MMP inhibitors are beneficial for anastomotic strength, they can cause adverse reactions. Knowledge of specific MMPs responsible for the weakening of anastomoses can be used to optimise MMP inhibition therapy. We aimed to quantify transcript and protein levels of multiple MMPs in colonic anastomoses and evaluate the effect of inhibiting the MMPs that displayed the highest expression levels on anastomotic repair.
  
  
  METHODS
  Left-sided colonic anastomoses were made in male Sprague-Dawley rats. After 3 days when biomechanical strength is lowest, MMP mRNA and protein levels were measured by quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assays and gelatin zymography. The effects of the MMP-8, MMP-9 and MMP-12 synthetic inhibitor AZD3342 was also studied.
  
  
  RESULTS
  MMP-8, MMP-9 and MMP-12 gene and protein expression increased profoundly (p < 0.01), and MMP-13 mRNA and MMP-2 mRNA and protein modestly (p < 0.001) in the anastomoses. MMP-3 mRNA levels were not up-regulated significantly compared with adjacent uninjured colon. Increased anastomotic MMP-12 levels paralleled macrophage infiltration by immunohistochemical analyses. AZD3342 (50 mg/kg) treatment increased the anastomotic breaking strength by 29% (p = 0.015) day 3 compared with vehicle. Improved anastomotic strength was not accompanied with alterations of type I or type III procollagen mRNA but was possibly due to inhibition of the concerted digestive action on the existent submucosal collagens by the targeted MMPs.
  
  
  CONCLUSIONS
  The present findings justify the concept of selective MMP inhibition to enhance anastomotic strength in colon.
authors.affiliation: Department of Surgery K, Bispebjerg Hospital, Bispebjerg Bakke 23, DK 2400 Copenhagen NV, Denmark. krarup75@gmail.com
authors.forename: Peter-Martin
authors.initials: PM
authors.lastname: Krarup
authors.forename: Mikkel
authors.initials: M
authors.lastname: Eld
authors.forename: Katja
authors.initials: K
authors.lastname: Heinemeier
authors.forename: Lars Nannestad
authors.initials: LN
authors.lastname: Jorgensen
authors.forename: Mark Berner
authors.initials: MB
authors.lastname: Hansen
authors.forename: Magnus S
authors.initials: MS
authors.lastname: Ågren
mesh_terms: D000714:Anastomosis, Surgical; D000818:Animals; D003094:Collagen / Q000096:biosynthesis; D003106:Colon / Q000201:enzymology* / Q000473:pathology / Q000601:surgery*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D008297:Male; D053508:Matrix Metalloproteinase 12 / Q000235:genetics / Q000378:metabolism*; D020784:Matrix Metalloproteinase 8 / Q000235:genetics / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism*; D061965:Matrix Metalloproteinase Inhibitors / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D014945:Wound Healing / Q000187:drug effects / Q000235:genetics
chemical_list: D061965:Matrix Metalloproteinase Inhibitors; D003094:Collagen; D020784:Matrix Metalloproteinase 8; D020780:Matrix Metalloproteinase 9; D053508:Matrix Metalloproteinase 12