title: Activation of heat shock response augments fibroblast growth factor-1 expression in wounded lung epithelium.
abstract: We previously showed that coincident exposure to heat shock (HS; 42°C for 2 h) and TNF-α synergistically induces apoptosis in mouse lung epithelium. We extended this work by analyzing HS effects on human lung epithelial responses to clinically relevant injury. Cotreatment with TNF-α and HS induced little caspase-3 and poly(ADP-ribose) polymerase cleavage in human small airway epithelial cells, A549 cells, and BEAS2B cells. Scratch wound closure rates almost doubled when A549 and BEAS2B cells and air-liquid interface cultures of human bronchial epithelial cells were heat shocked immediately after wounding. Microarray, qRT-PCR, and immunoblotting showed fibroblast growth factor 1 (FGF1) to be synergistically induced by HS and wounding. Enhanced FGF1 expression in HS/wounded A549 was blocked by inhibitors of p38 MAPK (SB203580) or HS factor (HSF)-1 (KNK-437) and in HSF1 knockout BEAS2B cells. PCR demonstrated FGF1 to be expressed from the two most distal promoters in wounded/HS cells. Wound closure in HS A549 and BEAS2B cells was reduced by FGF receptor-1/3 inhibition (SU-5402) or FGF1 depletion. Exogenous FGF1 accelerated A549 wound closure in the absence but not presence of HS. In the presence of exogenous FGF1, HS slowed wound closure, suggesting that it increases FGF1 expression but impairs FGF1-stimulated wound closure. Frozen sections from normal and idiopathic pulmonary fibrosis (IPF) lung were analyzed for FGF1 and HSP70 by immunofluorescence confocal microscopy and qRT-PCR. FGF1 and HSP70 mRNA levels were 7.5- and 5.9-fold higher in IPF than normal lung, and the proteins colocalized to fibroblastic foci in IPF lung. We conclude that HS signaling may have an important impact on gene expression contributing to lung injury, healing, and fibrosis.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland.|Critical Care Section, National Heart, Lung, Blood Institute, Bethesda, Maryland.
authors.forename: Rachel G
authors.initials: RG
authors.lastname: Scheraga
authors.affiliation: Department of Biology, Loyola University of Maryland, Baltimore, Maryland.
authors.forename: Christopher
authors.initials: C
authors.lastname: Thompson
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland.
authors.forename: Mohan E
authors.initials: ME
authors.lastname: Tulapurkar
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland.
authors.forename: Ashish C
authors.initials: AC
authors.lastname: Nagarsekar
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland.|Medicine and Research Services, Baltimore Veterans Affairs Medical Care System, Baltimore, Maryland.
authors.forename: Mark
authors.initials: M
authors.lastname: Cowan
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland.
authors.forename: Ratnakar
authors.initials: R
authors.lastname: Potla
authors.affiliation: Critical Care Section, National Heart, Lung, Blood Institute, Bethesda, Maryland.
authors.forename: Junfeng
authors.initials: J
authors.lastname: Sun
authors.affiliation: Critical Care Section, National Heart, Lung, Blood Institute, Bethesda, Maryland.
authors.forename: Rongman
authors.initials: R
authors.lastname: Cai
authors.affiliation: Critical Care Section, National Heart, Lung, Blood Institute, Bethesda, Maryland.
authors.forename: Carolea
authors.initials: C
authors.lastname: Logun
authors.affiliation: Critical Care Section, National Heart, Lung, Blood Institute, Bethesda, Maryland.
authors.forename: James
authors.initials: J
authors.lastname: Shelhamer
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland.|Medicine and Research Services, Baltimore Veterans Affairs Medical Care System, Baltimore, Maryland.
authors.forename: Nevins W
authors.initials: NW
authors.lastname: Todd
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland.|Medicine and Research Services, Baltimore Veterans Affairs Medical Care System, Baltimore, Maryland.
authors.forename: Ishwar S
authors.initials: IS
authors.lastname: Singh
authors.affiliation: Division of Rheumatology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland.|Medicine and Research Services, Baltimore Veterans Affairs Medical Care System, Baltimore, Maryland.
authors.forename: Irina G
authors.initials: IG
authors.lastname: Luzina
authors.affiliation: Division of Rheumatology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland.|Medicine and Research Services, Baltimore Veterans Affairs Medical Care System, Baltimore, Maryland.
authors.forename: Sergei P
authors.initials: SP
authors.lastname: Atamas
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland; jhasday@umaryland.edu.|Medicine and Research Services, Baltimore Veterans Affairs Medical Care System, Baltimore, Maryland.
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Hasday
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000235:genetics; D001665:Binding Sites; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism / Q000473:pathology; D004848:Epithelium / Q000378:metabolism* / Q000473:pathology*; D016220:Fibroblast Growth Factor 1 / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D000076249:Heat Shock Transcription Factors; D018869:Heat-Shock Response / Q000235:genetics; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000235:genetics; D008168:Lung / Q000378:metabolism / Q000473:pathology; D055370:Lung Injury / Q000235:genetics / Q000473:pathology*; D051379:Mice; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014945:Wound Healing / Q000235:genetics
chemical_list: D004268:DNA-Binding Proteins; D018840:HSP70 Heat-Shock Proteins; D000076249:Heat Shock Transcription Factors; D014157:Transcription Factors; D016220:Fibroblast Growth Factor 1
keywords: epithelial wound healing; fibroblast growth factor-1; heat shock; heat shock factor-1; idiopathic pulmonary fibrosis