title: Libby amphibole-induced mesothelial cell autoantibodies bind to surface plasminogen and alter collagen matrix remodeling.
abstract: Lamellar pleural thickening (LPT) is a fibrotic disease induced by exposure to Libby amphibole (LA) asbestos that causes widespread scarring around the lung, resulting in deterioration of pulmonary function. Investigating the effects of autoantibodies to mesothelial cells (MCAA) present in the study populations has been a major part of the effort to understand the mechanism of pathogenesis. It has been shown in vitro that human mesothelial cells (Met5a) exposed to MCAA increase collagen deposition into the extracellular matrix (ECM). In this study, we sought to further elucidate how MCAA drive increased collagen deposition by identifying the protein targets bound by MCAA on the cellular surface using biotinylation to label and isolate surface proteins. Isolated surface protein fractions were identified as containing MCAA targets using ELISA The fractions that demonstrated binding by MCAA were then analyzed by tandem mass spectrometry (MS/MS) and MASCOT analysis. The most promising result from the MASCOT analysis, plasminogen (PLG), was tested for MCAA binding using purified human PLG in an ELISA We report that serum containing MCAA bound at an optical density (OD) 3 times greater than that of controls, and LA-exposed subjects had a high frequency of positive tests for anti-PLG autoantibodies. This work implicates the involvement of the plasminogen/plasmin system in the mechanism of excess collagen deposition in Met5a cells exposed to MCAA Elucidating this mechanism could contribute to the understanding of LPT.
authors: Department of Biological Sciences, Idaho State University, Pocatello, Idaho.
authors: Robert
authors: R
authors: Hanson
authors: Department of Chemistry, Idaho State University, Pocatello, Idaho.
authors: Caryn
authors: C
authors: Evilia
authors: Department of Biological Sciences, Idaho State University, Pocatello, Idaho.
authors: John
authors: J
authors: Gilmer
authors: Department of Biological Sciences, Idaho State University, Pocatello, Idaho.
authors: Linda
authors: L
authors: Woods
authors: Center for Asbestos Related Diseases, Libby, Montana.
authors: Brad
authors: B
authors: Black
authors: Department of Thoracic Surgery, Icahn School of Medicine at Mt Sinai, New York City, New York.
authors: Raja
authors: R
authors: Flores
authors: Department of Biological Sciences, Idaho State University, Pocatello, Idaho Department of Thoracic Surgery, Icahn School of Medicine at Mt Sinai, New York City, New York pfaujean@isu.edu.
authors: Jean C
authors: JC
authors: Pfau
mesh_terms: D000368:Aged; D017636:Asbestos, Amphibole / Q000009:adverse effects / Q000378:metabolism*; D001323:Autoantibodies / Q000378:metabolism*; D002478:Cells, Cultured; D003094:Collagen / Q000276:immunology* / Q000378:metabolism; D004848:Epithelium / Q000276:immunology* / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010958:Plasminogen / Q000276:immunology* / Q000378:metabolism; D060066:Protein Interaction Maps
chemical_list: D017636:Asbestos, Amphibole; D001323:Autoantibodies; D010958:Plasminogen; D003094:Collagen
keywords: Asbestos; Libby amphibole; autoimmunity; collagen; plasminogen; pleural fibrosis; proteomics