title: Role of CXCL5 in leukocyte recruitment to the lungs during secondhand smoke exposure.
abstract: Chronic obstructive pulmonary disease (COPD) is the third leading cause of mortality in the United States. The major cause of COPD is cigarette smoking. Extensive leukocyte influx into the lungs, mediated by chemokines, is a critical event leading to COPD. Although both resident and myeloid cells secrete chemokines in response to inflammatory stimuli, little is known about the role of epithelial-derived chemokines, such as CXC chemokine ligand (CXCL)5, in the pathogenesis of cigarette smoke-induced inflammation. To explore the role of CXCL5, we generated CXCL5 gene-deficient mice and exposed them to secondhand smoke (SHS) for 5 hours/day for 5 days/week up to 3 weeks (subacute exposure). We observed a reduced recruitment of leukocytes to the lungs of CXCL5(-/-) mice compared with their wild-type (WT) counterparts, and noted that macrophages comprised the predominant leukocytes recruited to the lungs. Irradiation experiments performed on CXCL5(-/-) or WT mice transplanted with WT or CXCL5(-/-) bone marrow revealed that resident but not hematopoietic cell-driven CXCL5 is important for mediating SHS-induced lung inflammation. Interestingly, we observed a significant reduction of monocyte chemotactic protein-1 (MCP-1/CC chemokine ligand 2) concentrations in the lungs of CXCL5(-/-) mice. The instillation of recombinant MCP-1 in CXCL5(-/-) mice reversed macrophage recruitment. Our results also show the reduced activation of NF-κB/p65 in the lungs, as well as the attenuated activation of C-Jun N-terminal kinase, p42/44, and p38 mitogen-activated protein kinases and the expression of intercellular adhesion molecule-1 in the lungs of SHS-exposed CXCL5(-/-) mice. Our findings suggest an important role for CXCL5 in augmenting leukocyte recruitment in SHS-induced lung inflammation, and provide novel insights into CXCL5-driven pathogenesis.
authors.affiliation: Laboratory of Lung Biology, Department of Pathobiological Sciences, Louisiana State University, Baton Rouge, 70803, USA.
authors.forename: Gayathriy
authors.initials: G
authors.lastname: Balamayooran
authors.forename: Sanjay
authors.initials: S
authors.lastname: Batra
authors.forename: Shanshan
authors.initials: S
authors.lastname: Cai
authors.forename: Junjie
authors.initials: J
authors.lastname: Mei
authors.forename: G Scott
authors.initials: GS
authors.lastname: Worthen
authors.forename: Arthur L
authors.initials: AL
authors.lastname: Penn
authors.forename: Samithamby
authors.initials: S
authors.lastname: Jeyaseelan
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells; D018932:Chemokine CCL2 / Q000096:biosynthesis; D054365:Chemokine CXCL5 / Q000235:genetics / Q000378:metabolism*; D018844:Cyclin-Dependent Kinases / Q000096:biosynthesis; D004781:Environmental Exposure; D005260:Female; D007249:Inflammation / Q000276:immunology / Q000473:pathology; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis; D048031:JNK Mitogen-Activated Protein Kinases / Q000096:biosynthesis; D007962:Leukocytes / Q000276:immunology*; D008168:Lung / Q000276:immunology* / Q000378:metabolism*; D008264:Macrophages / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010446:Peptide Fragments / Q000096:biosynthesis; D029424:Pulmonary Disease, Chronic Obstructive / Q000276:immunology; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*; D051996:Transcription Factor RelA / Q000096:biosynthesis; D014157:Transcription Factors; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis; D048051:p38 Mitogen-Activated Protein Kinases / Q000096:biosynthesis; D000095043:Cyclin-Dependent Kinase-Activating Kinase
chemical_list: D018932:Chemokine CCL2; D054365:Chemokine CXCL5; C094739:Cxcl5 protein, mouse; D010446:Peptide Fragments; C498144:Rela protein, mouse; D014028:Tobacco Smoke Pollution; D051996:Transcription Factor RelA; D014157:Transcription Factors; D016159:Tumor Suppressor Protein p53; C503486:WDR77 protein, mouse; D018799:Intercellular Adhesion Molecule-1; D018844:Cyclin-Dependent Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D000095043:Cyclin-Dependent Kinase-Activating Kinase