Heme oxygenase-1 upregulation protects against intestinal ischemia/reperfusion injury: a laboratory based study.
OBJECTIVE
Tissue damage caused by ischemia/reperfusion injury (IRI) of the intestine may lead to organ dysfunction in several clinical conditions, and is associated with increased incidence of chronic rejection after transplantation. Heme oxygenase-1 (HO-1) is a stress-inducible protein capable of modulating inflammation, oxidative stress, and cell death. The aim of the present study was to assess the effects of HO-1 upregulation on intestinal IRI.


METHODS
Lewis rats (seven groups, n=6 each) underwent intestinal warm ischemia induced by clamping the superior mesenteric artery and by ligating the inferior mesenteric artery for 60 min. After 120 or 240 min of reperfusion, tissue samples were collected for analysis. Cobalt protoporphyrin (CoPP) was administered IP at 10 or 20mg/kg 24h before IRI, to induce HO-1 upregulation. Control animals received vehicle alone. Tissue injury measurements included the following: histological changes, tissue myeloperoxidase (MPO) activity, nitrate/nitrite levels, and IL-6 levels.


RESULTS
A significant HO-1 upregulation was demonstrated in pre-treated animals (p<0.05, 95% CI: -0.84 to -0.05). Intestinal IL-6 mRNA expression levels were significantly reduced in animals treated with CoPP 20mg/kg after 240 min of IRI (p<0.05, 95% CI: 0.09-2.25). Significant reduction in MPO activity and NO products was observed in treated animals when compared to controls (p<0.01, 95% CI: 0.07-0.24 and p<0.01, 95% CI: 5.58-12.75, respectively).


CONCLUSIONS
Induction of HO-1 by CoPP administration before IRI was resulted in a significant reduction of intestinal tissue injury. Developing strategies to induce HO-1 upregulation before surgery will be important to reduce IRI in the clinical setting.
Wasserberg
Nir
N
Department of Surgery, University of Miami School of Medicine, Miami, FL 33136, United States. nwasserberg@surgery.usc.edu <nwasserberg@surgery.usc.edu>
Pileggi
Antonello
A
Salgar
Shashikumar K
SK
Ruiz
Phillip
P
Ricordi
Camillo
C
Inverardi
Luca
L
Tzakis
Andreas G
AG
D000704:Analysis of Variance; D000818:Animals; D015153:Blotting, Western; D051547:Heme Oxygenase-1 / Q000096:biosynthesis*; D015850:Interleukin-6 / Q000032:analysis; D007422:Intestines / Q000098:blood supply* / Q000503:physiopathology; D008297:Male; D008638:Mesenteric Arteries; D009569:Nitric Oxide / Q000032:analysis; D009195:Peroxidase / Q000032:analysis; D011524:Protoporphyrins / Q000494:pharmacology; D051381:Rats; D011917:Rats, Inbred Lew; D015427:Reperfusion Injury / Q000503:physiopathology / Q000517:prevention & control*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015854:Up-Regulation
D015850:Interleukin-6; D011524:Protoporphyrins; D009569:Nitric Oxide; C007095:cobaltiprotoporphyrin; D009195:Peroxidase; D051547:Heme Oxygenase-1