Redox signaling as a therapeutic target to inhibit myofibroblast activation in degenerative fibrotic disease.
Degenerative fibrotic diseases encompass numerous systemic and organ-specific disorders. Despite their associated significant morbidity and mortality, there is currently no effective antifibrotic treatment. Fibrosis is characterized by the development and persistence of myofibroblasts, whose unregulated deposition of extracellular matrix components disrupts signaling cascades and normal tissue architecture leading to organ failure and death. The profibrotic cytokine transforming growth factor beta (TGFβ) is considered the foremost inducer of fibrosis, driving myofibroblast differentiation in diverse tissues. This review summarizes recent in vitro and in vivo data demonstrating that TGF β-induced myofibroblast differentiation is driven by a prooxidant shift in redox homeostasis. Elevated NADPH oxidase 4 (NOX4)-derived hydrogen peroxide (H2O2) supported by concomitant decreases in nitric oxide (NO) signaling and reactive oxygen species scavengers are central factors in the molecular pathogenesis of fibrosis in numerous tissues and organs. Moreover, complex interplay between NOX4-derived H2O2 and NO signaling regulates myofibroblast differentiation. Restoring redox homeostasis via antioxidants or NOX4 inactivation as well as by enhancing NO signaling via activation of soluble guanylyl cyclases or inhibition of phosphodiesterases can inhibit and reverse myofibroblast differentiation. Thus, dysregulated redox signaling represents a potential therapeutic target for the treatment of wide variety of different degenerative fibrotic disorders.
Division of Experimental Urology, Department of Urology, Innsbruck Medical University, Anichstrasse 35, A-6020 Innsbruck, Austria.
Natalie
0000-0001-9326-8177
N
Sampson
Institute for Biomedical Aging Research, University of Innsbruck, 6020 Innsbruck, Austria.
Peter
P
Berger
Department of Internal Medicine III, Innsbruck Medical University, Anichstrasse 35, A-6020 Innsbruck, Austria.
Christoph
C
Zenzmaier
D002454:Cell Differentiation / Q000235:genetics; D005109:Extracellular Matrix / Q000378:metabolism; D005355:Fibrosis / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D058628:Myofibroblasts / Q000378:metabolism* / Q000473:pathology; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D010084:Oxidation-Reduction; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction; D053773:Transforming Growth Factor beta1 / Q000378:metabolism
D017382:Reactive Oxygen Species; D053773:Transforming Growth Factor beta1; D009569:Nitric Oxide; D006861:Hydrogen Peroxide; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases; C498910:NOX4 protein, human