Increased deposition of chondroitin/dermatan sulfate glycosaminoglycan and upregulation of beta1,3-glucuronosyltransferase I in pulmonary fibrosis.
Fiche publication
Date publication
février 2011
Auteurs
Membres identifiés du Cancéropôle Est :
Dr OUZZINE Mohamed
Tous les auteurs :
Venkatesan N, Ouzzine M, Kolb M, Netter P, Ludwig MS
Lien Pubmed
Résumé
Pulmonary fibrosis (PF) is characterized by increased deposition of proteoglycans (PGs), in particular core proteins. Glycosaminoglycans (GAGs) are key players in tissue repair and fibrosis, and we investigated whether PF is associated with changes in the expression and structure of GAGs as well as in the expression of beta1,3-glucuronosyltransferase I (GlcAT-I), a rate-limiting enzyme in GAG synthesis. Lung biopsies from idiopathic pulmonary fibrosis (IPF) patients and lung tissue from a rat model of bleomycin (BLM)-induced PF were immunostained for chondroitin sulfated-GAGs and GlcAT-I expression. Alterations in disaccharide composition and sulfation of chondroitin/dermatan sulfate (CS/DS) were evaluated by fluorophore-assisted carbohydrate electrophoresis (FACE) in BLM rats. Lung fibroblasts isolated from control (saline-instilled) or BLM rat lungs were assessed for GAG structure and GlcAT-I expression. Disaccharide analysis showed that 4- and 6-sulfated disaccharides were increased in the lungs and lung fibroblasts obtained from fibrotic rats compared with controls. Fibrotic lung fibroblasts and transforming growth factor-beta(1) (TGF-beta(1))-treated normal lung fibroblasts expressed increased amounts of hyaluronan and 4- and 6-sulfated chondroitin, and neutralizing anti-TGF-beta(1) antibody diminished the same. TGF-beta(1) upregulated GlcAT-I and versican expression in lung fibroblasts, and signaling through TGF-beta type I receptor/p38 MAPK was required for TGF-beta(1)-mediated GlcAT-I and CS-GAG expression in fibroblasts. Our data show for the first time increased expression of CS-GAGs and GlcAT-I in IPF, fibrotic rat lungs, and fibrotic lung fibroblasts. These data suggest that alterations of sulfation isomers of CS/DS and upregulation of GlcAT-I contribute to the pathological PG-GAG accumulation in PF.
Référence
Am J Physiol Lung Cell Mol Physiol. 2011 Feb;300(2):L191-203