title: Increased expression of epidermal fatty acid-binding protein by alveolar macrophages during acute rejection of rat lungs.
abstract: In the lung, epidermal fatty acid-binding protein (E-FABP) is expressed by alveolar macrophages (AM) and alveolar epithelial cells type II (AEII). E-FABP may regulate macrophage activation and is involved in the metabolism of surfactant phospholipids. As macrophage activation and surfactant dysfunction are associated with rejection, we hypothesize that E-FABP expression is changed during acute rejection of pulmonary grafts. Orthotopic left lung transplantations were performed in the Dark Agouti to Lewis and in the isogeneic Lewis to Lewis rat strain combinations. E-FABP expression was analyzed in the lung by immunohistochemistry, immunoblotting and quantitative reverse transcription-polymerase chain reaction (RT-PCR). Alveolar leukocytes obtained by bronchoalveolar lavage were analyzed by RT-PCR. Immunohistochemistry of isografts revealed strong E-FABP immunoreactivity in AEII and a moderate immunoreactivity in AM. In allografts undergoing acute rejection, AM exhibiting increased E-FABP immunoreactivity accumulated. Immunoblots revealed a single band at 15 kDa, which corresponds to the expected molecular mass of E-FABP. The levels of E-FABP mRNA were higher in allografts than in isografts and control lungs. Furthermore, alveolar leukocytes isolated by bronchoalveolar lavage from allografts displayed higher E-FABP mRNA expression levels than leukocytes from isografts and controls. In conclusion, we demonstrate for the first time upregulation of E-FABP expression in AM during severe inflammation.
authors.affiliation: Laboratory of Experimental Surgery, Department of General and Thoracic Surgery, University of Giessen Lung Center, Justus-Liebig-University Giessen, Giessen, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Holler
authors.forename: Anna
authors.initials: A
authors.lastname: Zakrzewicz
authors.forename: Holger
authors.initials: H
authors.lastname: Garn
authors.forename: Markus
authors.initials: M
authors.lastname: Hirschburger
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Kummer
authors.forename: Winfried
authors.initials: W
authors.lastname: Padberg
authors.forename: Veronika
authors.initials: V
authors.lastname: Grau
mesh_terms: D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology / Q000276:immunology; D005136:Eye Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D050556:Fatty Acid-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D006084:Graft Rejection / Q000276:immunology*; D007113:Immunity, Innate / Q000276:immunology; D015151:Immunoblotting; D007150:Immunohistochemistry; D016040:Lung Transplantation / Q000276:immunology*; D008262:Macrophage Activation / Q000276:immunology*; D016676:Macrophages, Alveolar / Q000276:immunology*; D008297:Male; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D011663:Pulmonary Surfactants / Q000276:immunology; D012313:RNA / Q000737:chemistry / Q000235:genetics; D051381:Rats; D011917:Rats, Inbred Lew; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018709:Statistics, Nonparametric
chemical_list: D005136:Eye Proteins; C107356:Fabp5 protein, rat; D050556:Fatty Acid-Binding Proteins; D009419:Nerve Tissue Proteins; D011663:Pulmonary Surfactants; D012313:RNA