Resistance of fibrogenic responses to glucocorticoid and 2-methoxyestradiol in bleomycin-induced lung fibrosis in mice

• Published in: Canadian journal of physiology and pharmacology Vol. 85; no. 7; pp. 727 - 738
• Main Authors: LANGENBACH, Shenna Y, WHEATON, Ben J, FERNANDES, Darren J, JONES, Catherine, SUTHERLAND, Tara E, WRAITH, Bronwyn C, HARRIS, Trudi, SCHULIGA, Michael J, MCLEAN, Catriona, STEWART, Alastair G
• Format: Conference Proceeding Journal Article
• Language: English
• Published: Ottawa, ON National Research Council of Canada 01.07.2007; NRC Research Press
• Subjects: Airway Resistance - drug effects; Animal experimentation; Animals; Biological and medical sciences; Bleomycin - toxicity; Body Weight - drug effects; Bronchoalveolar Lavage Fluid - chemistry; Bronchoalveolar Lavage Fluid - cytology; Cell Adhesion Molecules - genetics; Corticosteroids; Cytokines - genetics; Drug Resistance; Estradiol - analogs & derivatives; Estradiol - pharmacology; Estradiol - therapeutic use; Fibrosis; Fundamental and applied biological sciences. Psychology; Gene Expression - drug effects; Glucocorticoids - pharmacology; Glucocorticoids - therapeutic use; Hydroxyproline - analysis; Lung - drug effects; Lung - metabolism; Lung - physiopathology; Lung Compliance - drug effects; Lungs; Matrix Metalloproteinases - genetics; Methylprednisolone; Methylprednisolone - pharmacology; Methylprednisolone - therapeutic use; Mice; Mice, Inbred C57BL; Organ Size - drug effects; Physiological aspects; Pulmonary Alveoli - drug effects; Pulmonary Alveoli - metabolism; Pulmonary Alveoli - pathology; Pulmonary Emphysema - chemically induced; Pulmonary Emphysema - drug therapy; Pulmonary Emphysema - metabolism; Pulmonary Fibrosis - chemically induced; Pulmonary Fibrosis - drug therapy; Pulmonary Fibrosis - metabolism; Reverse Transcriptase Polymerase Chain Reaction; Tissue Inhibitor of Metalloproteinases - genetics; Tubulin Modulators - pharmacology; Tubulin Modulators - therapeutic use; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Australia; Corticosteroid; Lung disease; Peptides; Respiratory disease; Steroid hormone; Hydroxyproline; Rodentia; Methylprednisolone; Glucocorticoid; Asthma; Vertebrata; Mammalia; Bleomycin; Pulmonary fibrosis; Mouse; Glycopeptide; Bronchus disease; Obstructive pulmonary disease
• ISSN: 0008-4212
• DOI: 10.1139/Y07-065

Bleomycin-induced lung fibrosis in mice reproduces some key features of pulmonary fibrosis in humans including alveolar inflammation, myofibroblast proliferation, and collagen deposition. Glucocorticoids have been used as first-line therapy for the treatment of lung fibrosis, although their clinical efficacy is equivocal. We examined the effect of the glucocorticoid, methylprednisolone (MP), and the estrogen metabolite, 2-methoxyestradiol (2MEO) on bleomycin-induced bronchoalveolar inflammation, fibrosis, and changes in lung function. The characterization of the time-course of the bleomycin-induced fibrosis indicated that lung dry mass and hydroxyproline content showed less variance than histopathological assessment of fibrosis. The bleomycin-induced increases in bronchoalveolar lavage (BAL) fluid cell number and protein levels were not significantly influenced by treatment with either MP (1 mg.(kg body mass)(-1).day(-1), i.p.) or 2MEO (50 mg.(kg body mass)(-1).day(-1), i.p.). Lung fibrosis, measured histopathologically or by hydroxyproline content, was not significantly influenced by either MP or 2MEO treatment, whereas the latter agent did reduce the increment in lung dry mass. The enlargement of alveolar airspaces and the decline in lung compliance were exacerbated by MP treatment. These data suggest that bleomycin-induced pulmonary fibrosis is resistant to inhibition by concurrent treatment with either glucocorticoids or 2MEO.