title: Altered protein expression in neutrophils of calves treated with dexamethasone.
abstract: The effect of glucocorticoid treatment on protein expression in bovine neutrophils was examined with a proteomic approach to address the mechanisms by which stress alters neutrophil function and predisposes to bacterial pneumonia in cattle. Calves 6 to 8 mo old were treated with dexamethasone (0.1 mg/kg), neutrophils were isolated 24 h later, and whole-cell lysates were examined by 2-dimensional electrophoresis. Differentially expressed protein spots were identified by peptide mass fingerprinting. The antimicrobial protein lactotransferrin was detected at increased amounts in the neutrophils of the dexamethasone-treated calves. Proteins detected at reduced amounts in the neutrophils of the dexamethasone-treated calves included annexin 1, phosphoglycerate mutase, Na(+) - K+ ATPase, and cathelicidin 1. These findings identify glucocorticoid-induced changes in the levels of neutrophil proteins involved in host defense, inflammation, and cellular metabolism and suggest additional mechanisms by which glucocorticoids affect neutrophil function.
authors.affiliation: Department of Pathobiology, University of Guelph, Guelph, Ontario N1G 2W1.
authors.forename: Jennifer D
authors.initials: JD
authors.lastname: Beveridge
authors.forename: Gordon B
authors.initials: GB
authors.lastname: Mitchell
authors.forename: Dyanne
authors.initials: D
authors.lastname: Brewer
authors.forename: Mary Ellen
authors.initials: ME
authors.lastname: Clark
authors.forename: Jeff L
authors.initials: JL
authors.lastname: Caswell
mesh_terms: D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D003907:Dexamethasone / Q000494:pharmacology*; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods / Q000662:veterinary; D015870:Gene Expression / Q000187:drug effects*; D005938:Glucocorticoids / Q000494:pharmacology; D007958:Leukocyte Count / Q000662:veterinary; D008297:Male; D009504:Neutrophils / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D011506:Proteins / Q000302:isolation & purification / Q000378:metabolism*; D040901:Proteomics / Q000379:methods; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods / Q000662:veterinary
chemical_list: D005938:Glucocorticoids; D011506:Proteins; D003907:Dexamethasone