title: Effect of acute lung injury on VLA-4 and CXCR4 expression in resident and circulating hematopoietic stem/progenitor cells.
abstract: BACKGROUND
  The effect of acute lung injury on adhesion molecule expression in hematopoietic stem/progenitor cells (HSPCs) is poorly understood.
  
  
  OBJECTIVE
  The aim of this study was to determine whether there is a relationship -between pulmonary inflammation, expression of VLA-4 (CD49d), LFA-1 (CD11a), L-selectin (CD62L), CXCR4, and chemotaxis in resident HSPCs, as well as the level of circulating HSPCs.
  
  
  METHODS
  Following intratracheal administration of a single LPS bolus in C57Bl/6 mice, the number of inflammatory cells, differential counts, and amounts of cytokines/ chemokines were studied in cytospins and bronchoalveolar lavage fluid (BALF) specimens. Expressions of adhesion -molecules and CXCR4 were analyzed in HSPCs by flow cytometry, as well as SDF-1-directed chemotaxis. Levels of HSPCs in the blood were studied in ungated and circulating subpopulations.
  
  
  RESULTS
  In coincidence with a peak of airway neutrophils, cytokine (IL-1β, TNF-α, and IL-6), chemokine (KC, MIP-2, and SDF-1) levels in BALF and the number of marrow HSPCs expressing CD49d and CXCR4 significantly increased at 48 h. The number of CD49d- and CXCR4-positive HSPCs dropped at 72 h. The HSPC subset comprising bigger cells behaved the same for CD49d. Chemotaxis of the marrow HSPC subset of bigger cells was higher in LPS-treated animals than in controls at 72 h. Finally, we could detect a significant decrease in circulating Sca-1(+) cells in the mononuclear population at 72 h in LPS-treated mice.
  
  
  CONCLUSIONS
  Our data provide evidence for a temporal relationship between pulmonary inflammation, CD49d and CXCR4 expression fluctuation in resident HSPCs, and the level of circulating HSPCs.
authors.affiliation: Department of Clinical and Experimental Sciences, University of Foggia, Foggia, Italy.
authors.forename: Teresa
authors.initials: T
authors.lastname: Trotta
authors.forename: Sante
authors.initials: S
authors.lastname: Di Gioia
authors.forename: Donatella
authors.initials: D
authors.lastname: Piro
authors.forename: Silvia
authors.initials: S
authors.lastname: Lepore
authors.forename: Santina
authors.initials: S
authors.lastname: Cantatore
authors.forename: Chiara
authors.initials: C
authors.lastname: Porro
authors.forename: Stefano
authors.initials: S
authors.lastname: Castellani
authors.forename: Antonio
authors.initials: A
authors.lastname: Petrella
authors.forename: Francesca
authors.initials: F
authors.lastname: Fortunato
authors.forename: Angela B
authors.initials: AB
authors.lastname: Maffione
authors.forename: Massimo
authors.initials: M
authors.lastname: Conese
mesh_terms: D055371:Acute Lung Injury / Q000378:metabolism*; D000818:Animals; D000950:Antigens, Ly / Q000378:metabolism; D054377:Chemokine CXCL12 / Q000097:blood; D002633:Chemotaxis; D006412:Hematopoietic Stem Cells / Q000378:metabolism*; D039041:Integrin alpha4beta1 / Q000378:metabolism*; D008070:Lipopolysaccharides; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D019718:Receptors, CXCR4 / Q000378:metabolism*
chemical_list: D000950:Antigens, Ly; C514936:CXCR4 protein, mouse; D054377:Chemokine CXCL12; C515256:Cxcl12 protein, mouse; D039041:Integrin alpha4beta1; D008070:Lipopolysaccharides; C074650:Ly6a protein, mouse; D008565:Membrane Proteins; D019718:Receptors, CXCR4