title: pH dependence of neutrophil-endothelial cell adhesion and adhesion molecule expression.
abstract: Neutrophil adhesion to the vascular endothelium is enhanced during tissue ischemia and/or inflammation, conditions that are associated with tissue acidosis. This study examined the effects of hypercarbic acidosis (10 or 20% CO2) and of hypocarbic alkalosis (0% CO2) on human neutrophil CD18 and human aortic endothelial cell intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin expression quantified by flow cytometry. Acidosis with 20% CO2 for 4 h decreased ICAM-1 to 60.6 +/- 9.7% of control. In contrast, alkalosis with 0% CO2 for 4 h enhanced ICAM-1 expression to 143.8 +/- 10.1% of control. There was no pH dependence of VCAM-1 or E-selectin expression. Tumor necrosis factor-alpha (TNF-alpha; 10 ng/ml) increased endothelial ICAM-1, E-selectin, and VCAM-1; under these conditions, acidosis with 20% CO2 blunted both ICAM-1 and E-selectin surface expression compared with 5% CO2-, TNF-alpha-treated cells. Hypercarbic acidosis with 20% CO2 increased neutrophil CD18 expression and enhanced neutrophil adhesion. This latter effect was inhibited by neutrophil pretreatment with an anti-CD18 monoclonal antibody. In contrast, when only endothelial cells were preincubated with the hypercarbic buffer, neutrophil adhesion diminished to 55.6 +/- 7.8% of control. The results suggest that acidosis generated during tissue ischemia/inflammation may induce CD18-mediated neutrophil adhesion despite a decrease in ICAM-1 expression.
authors.affiliation: Laboratory of Cardiovascular Science, Gerontology Research Center, National Institute on Aging, National Institutes of Health, Baltimore, Maryland.
authors.forename: C V
authors.initials: CV
authors.lastname: Serrano
authors.forename: A
authors.initials: A
authors.lastname: Fraticelli
authors.forename: R
authors.initials: R
authors.lastname: Paniccia
authors.forename: A
authors.initials: A
authors.lastname: Teti
authors.forename: B
authors.initials: B
authors.lastname: Noble
authors.forename: S
authors.initials: S
authors.lastname: Corda
authors.forename: T
authors.initials: T
authors.lastname: Faraggiana
authors.forename: R C
authors.initials: RC
authors.lastname: Ziegelstein
authors.forename: J L
authors.initials: JL
authors.lastname: Zweier
authors.forename: M C
authors.initials: MC
authors.lastname: Capogrossi
mesh_terms: D002448:Cell Adhesion; D015815:Cell Adhesion Molecules / Q000096:biosynthesis*; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology / Q000502:physiology*; D005434:Flow Cytometry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009504:Neutrophils / Q000166:cytology / Q000502:physiology*
chemical_list: D015815:Cell Adhesion Molecules