Propylthiouracil prevents cutaneous and pulmonary fibrosis in the reactive oxygen species murine model of systemic sclerosis
Authors: Gianluca Bagnato
Maurizio Cinquegrani
Domenica Altavilla
Donatella Sangari
Natasha Irrera
Alessandra Bitto
Gianfilippo Bagnato
Francesco Squadrito
Antonino Saitta
Marco Atteritano
William Roberts
Gabriele Pizzino
Journal: Arthritis research & therapy (2013)
Discipline: CLINICAL MEDICINE
Keywords: Cellular redox state; fibrosis; systemic sclerosis; thyroid abnormalities; propylthiouracil

Abstract:  Introduction: Recent advances suggest that the cellular redox state may play a significant role in the progression of fibrosis in systemic sclerosis (SSc). Another, and as yet poorly accounted for, feature of SSc is its overlap with thyroid abnormalities. Previous reports demonstrate that hypothyroidism reduces oxidant stress. The aim of this study was therefore to evaluate the effect of propylthiouracil (PTU), and of the hypothyroidism induced by it, on the development of cutaneous and pulmonary fibrosis in the oxidant stress murine model of SSc. Methods: Chronic oxidant stress SSc was induced in BALB/c mice by daily subcutaneous injections of hypochlorous acid (HOCl) for 6 weeks. Mice (n = 25) were randomized into three arms: HOCl (n = 10), HOCl plus PTU (n = 10) or vehicle alone (n = 5). PTU administration was initiated 30 minutes after HOCl subcutaneous injection and continued daily for 6 weeks. Skin and lung fibrosis were evaluated by histologic methods. Immunohistochemical staining for alpha-smooth muscle actin (α-SMA) in cutaneous and pulmonary tissues was performed to evaluate myofibroblast differentiation. Lung and skin concentrations of vascular endothelial growth factor (VEGF), extracellular signal-related kinase (ERK), rat sarcoma protein (Ras), Ras homolog gene family (Rho), and transforming growth factor (TGF) β were analyzed by Western blot. Results: Injections of HOCl induced cutaneous and lung fibrosis in BALB/c mice. PTU treatment prevented both dermal and pulmonary fibrosis. Myofibroblast differentiation was also inhibited by PTU in the skin and lung. The increase in cutaneous and pulmonary expression of VEGF, ERK, Ras, and Rho in mice treated with HOCl was significantly prevented in mice co-administered with PTU. Conclusions: PTU, probably through its direct effect on reactive oxygen species or indirectly through thyroid function inhibition, prevents the development of cutaneous and pulmonary fibrosis by blocking the activation of the Ras-ERK pathway in the oxidant-stress animal model of SSc. 

Retracted: No

PubPeer comments:
 Fig 5A-5F Western Blot analysis appears to contain repeated (or very similar) elements. I did not look elsewhere in the paper. *** ![file] , 
 Figure 3 appears to have an image which overlaps. Perhaps this explains the authors apparent reluctance to respond. I will contact journal momentarily. *** ![file] ![file] , 
 Here is a better illustration of the problems in Figure 5A, 5B and 6A, 6B. Potential splicing indicated by magenta arrows. Control bands seem constructed from repeated portions of bands, then rotated 180-degrees to represent controls from 2 different experiments. Oh, and the RHO band seems to be the same after flipping vertically (orange). Regardless of the cause of the issue, or the availability of the raw data, this seems very obvious and very problematic. *** ![file] , 
 #2 I did inform the journal in May of 2021 and sent a follow up inquiry in April 2022. In 2021, got this: u201dWe will investigate the concerns raised and take any action as appropriate.u201d , 
 #3 The actin bands in Figure 5B here (from **lung** tissue) not only are ALL the same within this blot, they are also the same bands used in Figure 5B of [Bagnato et al. 2013 Rheumatology](http: pubpeer.com publications B443BADB2B7AC7C0D7E083F5E26531) (a paper with its own serious issues already) which was about **skin** tissue. ![file] , 
 #5 There was an erratum published in 2014, however it does not address any of the issues discussed here. Link: https: arthritis-research.biomedcentral.com articles 10.1186 ar4534 ,