Effects of Doxycycline on Production of Growth Factors and Matrix Metalloproteinases in Pulmonary Fibrosis

• Published in: Respiration Vol. 81; no. 5; pp. 420 - 430
• Main Authors: Fujita, Hanako, Sakamoto, Noriho, Ishimatsu, Yuji, Kakugawa, Tomoyuki, Hara, Shintaro, Hara, Atsuko, Amenomori, Misato, Ishimoto, Hiroshi, Nagata, Towako, Mukae, Hiroshi, Kohno, Shigeru
• Format: Journal Article
• Language: English
• Published: Basel, Switzerland Karger 01.04.2011; S. Karger AG
• Subjects: Animals; Anti-Bacterial Agents - pharmacology; Antibacterial agents; Antibiotics. Antiinfectious agents. Antiparasitic agents; Basic Science Investigations; Biological and medical sciences; Blotting, Western; Cell Line; Collagen Type I - drug effects; Collagen Type I - metabolism; Connective Tissue Growth Factor - drug effects; Connective Tissue Growth Factor - metabolism; Doxycycline - pharmacology; Electrophoresis, Polyacrylamide Gel; Enzyme-Linked Immunosorbent Assay; Epithelial Cells - metabolism; Immunohistochemistry; Intercellular Signaling Peptides and Proteins - metabolism; Lung - pathology; Male; Matrix Metalloproteinase 2 - drug effects; Matrix Metalloproteinase 2 - metabolism; Matrix Metalloproteinases - drug effects; Matrix Metalloproteinases - metabolism; Medical sciences; Mice; Mice, Inbred ICR; Pharmacology. Drug treatments; Phosphorylation; Platelet-Derived Growth Factor - drug effects; Platelet-Derived Growth Factor - metabolism; Pneumology; Proteins; Pulmonary Alveoli - cytology; Pulmonary Fibrosis - drug therapy; Pulmonary Fibrosis - metabolism; Pulmonary Fibrosis - pathology; Respiration; Respiratory diseases; Respiratory system; Respiratory system : syndromes and miscellaneous diseases; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - metabolism; Signal Transduction - physiology; Smad Proteins - physiology; Transforming Growth Factor beta1 - pharmacology; Connective tissue growth factor; Smad; Epithelial mesenchymal transition; Fibroblast; Alveolar epithelial cells; Lung disease; Respiratory disease; Antibiotic; Pulmonary fibrosis; Doxycycline; Metalloproteinase; Antibacterial agent; Growth factor; Pneumology
• ISSN: 0025-7931; 1423-0356
• DOI: 10.1159/000324080

Background: Idiopathic pulmonary fibrosis (IPF) is characterized by progressive fibrosis and a poor prognosis. Alveolar epithelial cells (AECs) are considered to play important roles by releasing growth factors and matrix metalloproteinases (MMPs) and by being involved in epithelial mesenchymal transition in IPF. Doxycycline hydrochloride (DOXY), an inhibitor of MMPs, attenuates pulmonary fibrosis in models and in patients with IPF; however, the mechanism of this action remains obscure. Objectives: The present study investigated the effect of DOXY on growth factors and MMP production in AECs. Methods: Bleomycin (BL)-induced murine pulmonary fibrosis was treated with DOXY and examined by pathological and immunohistochemical staining. The human alveolar epithelial cell line A549 was stimulated with transforming growth factor (TGF)-β1 and incubated with DOXY, and then the expression of growth factors, MMPs, and collagen type I was evaluated at the mRNA and protein levels. We also evaluated the effects of DOXY on the TGF-β1-induced Smad signaling pathway. Results: DOXY reduced fibrosis scores and the production of collagen type I, connective tissue growth factor (CTGF), and TGF-β1 in BL models. DOXY inhibited the mRNA expression of MMP-2, MPP-9, CTGF, and collagen type I as well as the production of MMP-2 and platelet-derived growth factor-AA protein induced in A549 cells by TGF-β1 but not by Smad2 and Smad3 phosphorylation. We did not find a similar effect of DOXY in normal lung fibroblasts. Conclusions: Our results suggest that DOXY could be useful for attenuating pulmonary fibrosis through the inhibition of growth factors and MMP production in AECs.