Glycosyltransferases and glycosaminoglycans in bleomycin and transforming growth factor-β1-induced pulmonary fibrosis.

Abstract

Glycosaminoglycan (GAG) chains of proteoglycans (PGs) play important roles in fibrosis through cell-matrix interactions and growth factor binding in the extracellular matrix. We investigated the expression and regulation of PG core protein (versican) and key enzymes (xylosyltransferase [XT]-I, β1,3-glucuronosyltransferase [GlcAT]-I, chondroitin-4-sulfotransferase [C4ST]) implicated in synthesis and sulfation of GAGs in bleomycin (BLM) and adenovirus-transforming growth factor (TGF)-β1-induced lung fibrosis in rats. We also studied the role of GlcAT-I or TGF-β1 and the signaling pathways regulating PG-GAG production in primary lung fibroblasts isolated from saline- or BLM-instilled rats. The mRNA for XT-I, GlcAT-I, C4ST, and versican was increased in the lung 14 days after BLM injury. In vitro studies indicate that fibrotic lung fibroblasts (FLFs) expressed more XT-I, C4ST, and chondroitin sulfate (CS)-GAGs than did normal lung fibroblasts at baseline. TGF-β1 enhanced the expression of XT-I, C4ST-I, and versican in normal lung fibroblasts, whereas SB203580 or SB431542, by targeting p38 mitogen-activated protein kinase or TGF-β type-1 receptor/activin receptor-like kinase 5, respectively, attenuated the response to both TGF-β1 and FLFs on PG-GAG expression. Neutralizing anti-TGF-β1 antibody abrogated FLF-conditioned medium-stimulated expression of XT-I, GlcAT-I, versican, and CS-GAG. Forced expression of TGF-β1 in vivo enhanced versican, XT-I, GlcAT-I, and C4ST-I expression and PG-GAG deposition in rat lungs. Finally, induced expression of GlcAT-I gene in rat lung fibroblasts increased GAG synthesis by these cells. Together, our results provide new insights into the basis for increased PG-GAG deposition in lung fibrosis; inhibition of TGF-β1-mediated or fibrosis-induced PG-GAG production by activin receptor-like kinase 5/p38 inhibitors may contribute to antifibrotic activity.

• Authors: Narayanan Venkatesan, Kimitake Tsuchiya, Martin Kolb, Laszlo Farkas, Mustapha Bourhim, Mohamed Ouzzine, Mara S Ludwig
• Journal: American journal of respiratory cell and molecular biology (Am J Respir Cell Mol Biol) Vol. 50 Issue 3 Pg. 583-94 (Mar 2014) ISSN: 1535-4989 [Electronic] United States
• PMID: 24127863 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antibodies, Neutralizing
• Glycosaminoglycans
• Protein Kinase Inhibitors
• RNA, Messenger
• Receptors, Transforming Growth Factor beta
• Transforming Growth Factor beta1
• Vcan protein, rat
• Bleomycin
• Versicans
• Chondroitin Sulfates
• Glycosyltransferases
• glucuronyltransferase GlcAT-1
• Glucuronosyltransferase
• Pentosyltransferases
• UDP xylose-protein xylosyltransferase
• Protein Serine-Threonine Kinases
• p38 Mitogen-Activated Protein Kinases
• Receptor, Transforming Growth Factor-beta Type I
• Tgfbr1 protein, rat
• Sulfotransferases
• chondroitin 4-sulfotransferase

Topics

• Animals
• Antibodies, Neutralizing (pharmacology)
• Bleomycin
• Cells, Cultured
• Chondroitin Sulfates (metabolism)
• Disease Models, Animal
• Fibroblasts (enzymology, pathology)
• Gene Expression Regulation, Enzymologic
• Glucuronosyltransferase (metabolism)
• Glycosaminoglycans (genetics, metabolism)
• Glycosyltransferases (genetics, metabolism)
• Lung (drug effects, enzymology, pathology)
• Male
• Pentosyltransferases (metabolism)
• Protein Kinase Inhibitors (pharmacology)
• Protein Serine-Threonine Kinases (antagonists & inhibitors, metabolism)
• Pulmonary Fibrosis (chemically induced, enzymology, genetics, pathology, prevention & control)
• RNA, Messenger (metabolism)
• Rats
• Rats, Sprague-Dawley
• Receptor, Transforming Growth Factor-beta Type I
• Receptors, Transforming Growth Factor beta (antagonists & inhibitors, metabolism)
• Signal Transduction
• Sulfotransferases (metabolism)
• Time Factors
• Transfection
• Transforming Growth Factor beta1 (antagonists & inhibitors, genetics, metabolism)
• Up-Regulation
• Versicans (metabolism)
• p38 Mitogen-Activated Protein Kinases (antagonists & inhibitors, metabolism)