An inhibitor of NADPH oxidase-4 attenuates established pulmonary fibrosis in a rodent disease model.

Abstract

Idiopathic pulmonary fibrosis is a chronic progressive disease of increasing prevalence for which there is no effective therapy. Increased oxidative stress associated with an oxidant-antioxidant imbalance is thought to contribute to disease progression. NADPH oxidases (Nox) are a primary source of reactive oxygen species within the lung and cardiovascular system. We demonstrate that the Nox4 isoform is up-regulated in the lungs of patients with IPF and in a rodent model of bleomycin-induced pulmonary fibrosis and vascular remodeling. Nox4 is constitutively active, and therefore increased expression levels are likely to contribute to disease pathology. Using a small molecule Nox4/Nox1 inhibitor, we demonstrate that targeting Nox4 results in attenuation of an established fibrotic response, with reductions in gene transcripts for the extracellular matrix components collagen 1α1, collagen 3α1, and fibronectin and in principle pathway components associated with pulmonary fibrosis and hypoxia-mediated vascular remodeling: transforming growth factor (TGF)-β1, plasminogen activator inhibitor-1, hypoxia-inducible factor, and Nox4. TGF-β1 is a principle fibrotic mediator responsible for inducing up-regulation of profibrotic pathways associated with disease pathology. Using normal human lung-derived primary fibroblasts, we demonstrate that inhibition of Nox4 activity using a small molecule antagonist attenuates TGF-β1-mediated up-regulation in expression of profibrotic genes and inhibits the differentiation of fibroblast to myofibroblasts, that is associated with up-regulation in smooth muscle actin and acquisition of a contractile phenotype. These studies support the view that targeting Nox4 may provide a therapeutic approach for attenuating pulmonary fibrosis.

• Authors: Elizabeth R Jarman, Valerie S Khambata, Claire Cope, Peter Jones, Jan Roger, Li Yun Ye, Nicholas Duggan, Denise Head, Andrew Pearce, Neil J Press, Ben Bellenie, Bindi Sohal, Gabor Jarai
• Journal: American journal of respiratory cell and molecular biology (Am J Respir Cell Mol Biol) Vol. 50 Issue 1 Pg. 158-69 (Jan 2014) ISSN: 1535-4989 [Electronic] United States
• PMID: 23977848 (Publication Type: Journal Article)

Chemical References

• Actins
• Collagen Type I
• Collagen Type I, alpha 1 Chain
• Collagen Type III
• Enzyme Inhibitors
• Extracellular Matrix Proteins
• Fibronectins
• Small Molecule Libraries
• Transforming Growth Factor beta1
• NADPH Oxidase 4
• NADPH Oxidases
• NOX4 protein, human

Topics

• Actins (genetics, metabolism)
• Animals
• Cell Differentiation (drug effects, genetics)
• Cells, Cultured
• Collagen Type I (genetics, metabolism)
• Collagen Type I, alpha 1 Chain
• Collagen Type III (genetics, metabolism)
• Enzyme Inhibitors (pharmacology)
• Extracellular Matrix Proteins (genetics, metabolism)
• Fibroblasts (drug effects, metabolism, pathology)
• Fibronectins (genetics, metabolism)
• Humans
• Idiopathic Pulmonary Fibrosis (genetics, metabolism, pathology)
• Lung (drug effects, metabolism, pathology)
• Male
• Muscle, Smooth (drug effects, metabolism, pathology)
• Myofibroblasts (drug effects, metabolism, pathology)
• NADPH Oxidase 4
• NADPH Oxidases (antagonists & inhibitors, genetics, metabolism)
• Rats
• Rats, Sprague-Dawley
• Rodent Diseases (genetics, metabolism, pathology)
• Small Molecule Libraries (pharmacology)
• Transcription, Genetic (drug effects, genetics)
• Transforming Growth Factor beta1 (genetics, metabolism)
• Up-Regulation (drug effects, genetics)