title: Bleomycin increases neutrophil adhesion to human vascular endothelial cells independently of upregulation of ICAM-1 and E-selectin.
abstract: Bleomycin-induced lung disease is a serious complication of therapy characterized by alveolar injury, cytokine release, inflammatory cell recruitment, and eventually pulmonary fibrosis. The mechanisms underlying bleomycin-induced pulmonary fibrosis may be relevant to other progressive scarring diseases of the lungs. Pulmonary vascular endothelial cells are critically involved in immune cell extravasation at sites of injury through adhesion molecule expression and cytokine release. We sought to determine the effects of bleomycin on adhesion molecule expression and cytokine release by pulmonary vascular endothelial cells, and their functional relevance to inflammatory cell recruitment.
  
  
  
  The effects of pharmacologically relevant concentrations of bleomycin on adhesion molecule expression and cytokine release by human vascular endothelial cells in vitro were studied by flow cytometry, quantitative polymerase chain reaction, and enzyme-linked immunosorbent assay. A flow chamber model was used to assess the functional consequences on adhesion of flowing human neutrophils to endothelial cell monolayers.
  
  
  
  Bleomycin increased intercellular adhesion molecule 1 (ICAM-1; CD54), vascular cell adhesion molecule (VCAM-1; CD106), and E-selectin (CD62E) expression, and increased monocyte chemoattractant protein (MCP-1) and interleukin (IL-8) release by endothelial cells. Increases in protein expression were accompanied by increased mRNA transcription. In contrast, there was no direct effect of bleomycin on the profibrotic cytokines transforming growth factor-beta (TGF-β), platelet-derived growth factor-BB (PDGF-BB), or endothelin-1. Under flow conditions, endothelial cells exposed to bleomycin supported increased neutrophil adhesion which was independent of ICAM-1 or E-selectin.
  
  
  
  Our findings demonstrate that bleomycin promotes endothelial-mediated inflammation and neutrophil adhesion. These mechanisms may contribute to the development of pulmonary fibrosis by supporting immune cell recruitment in the lungs.
authors: a Academic Respiratory Medicine, Centre for Cardiovascular and Metabolic Research, Hull York Medical School, Castle Hill Hospital , Cottingham , United Kingdom.
authors: James D
authors: JD
authors: Williamson
authors: a Academic Respiratory Medicine, Centre for Cardiovascular and Metabolic Research, Hull York Medical School, Castle Hill Hospital , Cottingham , United Kingdom.
authors: Laura R
authors: LR
authors: Sadofsky
authors: a Academic Respiratory Medicine, Centre for Cardiovascular and Metabolic Research, Hull York Medical School, Castle Hill Hospital , Cottingham , United Kingdom.
authors: Michael G
authors: MG
authors: Crooks
authors: b School of Biological, Biomedical & Environmental Sciences, University of Hull , Hull , United Kingdom.
authors: John
authors: J
authors: Greenman
authors: a Academic Respiratory Medicine, Centre for Cardiovascular and Metabolic Research, Hull York Medical School, Castle Hill Hospital , Cottingham , United Kingdom.
authors: Simon P
authors: SP
authors: Hart
mesh_terms: D001761:Bleomycin / Q000494:pharmacology*; D002448:Cell Adhesion / Q000187:drug effects*; D002460:Cell Line; D019040:E-Selectin / Q000096:biosynthesis; D042783:Endothelial Cells / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007249:Inflammation; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis; D009504:Neutrophils / Q000378:metabolism*; D011658:Pulmonary Fibrosis; D015854:Up-Regulation
chemical_list: D019040:E-Selectin; D001761:Bleomycin; D018799:Intercellular Adhesion Molecule-1
keywords: bleomycin; cell adhesion; endothelium; neutrophil; pulmonary fibrosis