Targeting of NADPH oxidase in vitro and in vivo suppresses fibroblast activation and experimental skin fibrosis

Dosoki H, Stegemann A, Taha M, Schnittler H, Luger TA, Schroeder K, Distler J, Kerkhoff C, Boehm M (2016)

Publication Type: Journal article

Publication year: 2016

Journal

Experimental Dermatology Wiley

DOI: 10.1111/exd.13180

Abstract

Although there is increasing evidence that oxidative stress is involved in collagen synthesis and myofibroblast activation the NADPH oxidase (Nox) system is incompletely investigated in the context of human dermal fibroblasts (HDFs) and skin fibrosis. Using the pan-Nox inhibitor diphenyleneiodonium (DPI) as an initial tool we show that gene expression of collagen type I, ?-smooth muscle actin (?-SMA) and fibronectin 1 is suppressed in HDFs. Detailed expression analysis of all Nox isoforms and adaptors revealed expression of RNA and protein expression of Nox4, p22(phox) , and Poldip2 but neither Nox1 nor Nox2. Nox4 could be immnolocalized to the endoplasmic reticulum. Importantly, TGF-?1 had a dose- and time-dependent upregulating effect on NADH activity and Nox4 gene expression in HDFs. Genetic silencing of Nox4 as demonstrated by siRNA in HDFs as well as in murine fibroblasts established from Nox4 knock-out mice confirmed that TGF-?1 -mediated collagen type I gene, ?-SMA and fibronectin 1 gene expression was Nox4-dependent. This TGF-?1 effect was mediated by Smad3 as shown by in silico promoter analysis, pharmacological inhibition, and gene silencing of Smad3. The relevance of these findings is highlighted in the bleomycin-induced scleroderma mouse model. DPI treatment attenuated skin fibrosis and myofibroblast activation. Moreover, Nox4 knock-down by siRNA reduced skin collagen synthesis, ?-SMA and fibronectin 1 expression in vivo. Finally, analyses of HDFs from patients with systemic sclerosis confirmed the expression of Nox4 and its adaptors whereas Nox1 and Nox2 were not detectable. Our findings indicate that Nox4 targeting is a promising future treatment for fibrotic skin diseases. This article is protected by copyright. All rights reserved.

Authors with CRIS profile

Jörg Distler Professur für Molekulare Mechanismen der Organfibrose

Involved external institutions

Westfälische Wilhelms-Universität (WWU) Münster DE Germany (DE) Universität Osnabrück DE Germany (DE) Goethe-Universität Frankfurt am Main DE Germany (DE)

How to cite

APA:

Dosoki, H., Stegemann, A., Taha, M., Schnittler, H., Luger, T.A., Schroeder, K.,... Boehm, M. (2016). Targeting of NADPH oxidase in vitro and in vivo suppresses fibroblast activation and experimental skin fibrosis. Experimental Dermatology. https://dx.doi.org/10.1111/exd.13180

MLA:

Dosoki, Heba, et al. "Targeting of NADPH oxidase in vitro and in vivo suppresses fibroblast activation and experimental skin fibrosis." Experimental Dermatology (2016).

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