title: Heme oxygenase modulates small intestine leukocyte adhesion following hindlimb ischemia/reperfusion by regulating the expression of intercellular adhesion molecule-1.
abstract: OBJECTIVE
  Heme oxygenase is the rate-limiting enzyme in the degradation of heme into carbon monoxide, iron, and bilirubin. Recent evidence suggests that the induction of heme oxygenase-1 is associated with potent anti-inflammatory properties. The objectives of this study were to determine the temporal, regional, and cellular distribution of heme oxygenase-1 within the small intestine and its role in modulating remote intestinal leukocyte recruitment following trauma induced by hindlimb ischemia/reperfusion.
  
  
  METHODS
  Randomized, controlled, prospective animal study.
  
  
  METHODS
  Hospital surgical research laboratory.
  
  
  METHODS
  Male C57BL/6 mice.
  
  
  METHODS
  Mice underwent 1 hr of bilateral hindlimb ischemia, followed by 3, 6, 12, or 24 hrs of reperfusion.
  
  
  RESULTS
  Heme oxygenase-1 messenger RNA, heme oxygenase-1 protein, and heme oxygenase activity were measured using reverse transcription polymerase chain reaction, Western blot, immunohistochemistry, and spectrophotometric assay, respectively. The jejunum was also exteriorized to quantify the flux of rolling and adherent leukocytes and R-Phycoerythrin conjugated intercellular adhesion molecule-1 monoclonal antibody fluorescence intensity in submucosal postcapillary venules with the use of intravital microscopy. Ischemia/reperfusion led to a significant increase in heme oxygenase-1 messenger RNA in the jejunum and ileum 3 hrs following limb reperfusion, with a subsequent increase in heme oxygenase-1 protein and heme oxygenase activity at 6 hrs. Ischemia/reperfusion also led to a significant 1.4-fold increase in leukocyte rolling, whereas inhibition of heme oxygenase via injection of tin protoporphyrin IX (20 micromol/kg intraperitoneally) resulted in a three-fold increase in leukocyte adhesion, compared with ischemia/reperfusion alone. This increase in adhesion was significantly reduced to baseline in mice treated with intercellular adhesion molecule-1 monoclonal antibody before heme oxygenase inhibition (40 microg/mouse), whereas inhibition of heme oxygenase activity following ischemia/reperfusion also led to a significant increase in R-Phycoerythrin intercellular adhesion molecule-1 monoclonal antibody fluorescence intensity.
  
  
  CONCLUSIONS
  Our data suggest that remote trauma induced by hindlimb ischemia/reperfusion leads to an increase in heme oxygenase activity within the small intestine, which modulates intercellular adhesion molecule-1 dependent intestinal leukocyte adhesion.
authors.affiliation: Medical Biophysics, University of Western Ontario, London, ON, USA.
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Scott
authors.forename: Daryl K
authors.initials: DK
authors.lastname: Gray
authors.forename: Aurelia
authors.initials: A
authors.lastname: Bihari
authors.forename: Amit
authors.initials: A
authors.lastname: Badhwar
authors.forename: Xuchen
authors.initials: X
authors.lastname: Zhang
authors.forename: Peiying
authors.initials: P
authors.lastname: Shan
authors.forename: Patty J
authors.initials: PJ
authors.lastname: Lee
authors.forename: Subrata
authors.initials: S
authors.lastname: Chakrabarti
authors.forename: Kenneth A
authors.initials: KA
authors.lastname: Harris
authors.forename: Richard F
authors.initials: RF
authors.lastname: Potter
mesh_terms: D000818:Animals; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D006419:Heme Oxygenase (Decyclizing) / Q000378:metabolism* / Q000502:physiology; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism*; D007421:Intestine, Small / Q000201:enzymology* / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D015427:Reperfusion Injury / Q000201:enzymology* / Q000378:metabolism; D014947:Wounds and Injuries / Q000201:enzymology* / Q000209:etiology / Q000378:metabolism
chemical_list: D015815:Cell Adhesion Molecules; D018799:Intercellular Adhesion Molecule-1; D006419:Heme Oxygenase (Decyclizing)