Acute and long-term transcriptional responses in sulfur mustard-exposed SKH-1 hairless mouse skin

Abstract

Sulfur mustard (HD) ranks among the alkylating chemical warfare agents. Skin contact with HD produces an inflammatory response that evolves into separation at the epidermal-dermal junction conducting to blistering and epidermis necrosis. Up to now, current treatment strategies of HD burns have solely consisted in symptomatic management of skin damage. Therapeutic efficacy studies are still being conducted; classically using appropriate animal skin toxicity models. In order to substantiate the use of SKH-1 hairless mouse as an appropriate model for HD-induced skin lesions, we investigate the time-dependent quantitative gene expression of various selected transcripts associated to the dorsal skin exposure to HD saturated vapors. Using quantitative real time polymerase chain reaction (RT-qPCR), the expression of interleukins (IL-1β and IL-6), tumor necrosis factor (TNF)-α, macrophage inflammatory proteins (MIP)-2α (also called Cxcl2) and MIP-1αR (also called Ccr1), matrix metalloproteases (MMP-9 and MMP-2), laminin γ2 monomer (Lamc2) and keratin (K)1 was determined up to 21 days after HD challenge in order to allow enough time for wound repair to begin. Specific transcript RT-qPCR analysis demonstrated that IL-6, IL-1β, Ccr1, Cxcl2 mRNA levels increased as early as 6 h in HD-exposed skins and remained up-regulated over a 14-day period. Topical application of HD also significantly up-regulated MMP-9, TNF-α, and Lamc2 expression at specific time points. In contrast, MMP-2 mRNA levels remained unaffected by HD over the time-period considered, whereas that long-term study revealed that K1 mRNA level significantly increased only 21 days after HD challenge. Our study hereby provides first-hand evidence to substantiate a long period variation expression in the inflammatory cytokine, MMPs and structural components following cutaneous HD exposure in hairless mouse SKH-1. Our data credit the use of SKH-1 for investigating mechanisms of HD-induced skin toxicity and for the development of pharmacological countermeasures.

Time course of skin features and inflammatory biomarkers after liquid sulfur mustard exposure in SKH-1 hairless mice

“…Increases in MMP are of particular interest because of their ability to cleave basement membrane components and thus disrupt dermal/epidermal junction. This is clearly illustrated by animal studies demonstrating an increase expression of mRNA and/ or protein levels for MMP-9 in SM-exposed skin Dachir et al, 2010;Sabourin et al, 2002;Shakarjian et al, 2006;Vallet et al, 2012).…”

“…100 mg/kg, i. p.; Doléthal1, Vétoquinol, Lure, France), dorsal skin was collected and either fixed in 10% neutral buffered formalin or placed in RNAlater1 (Ambion, Austin, USA) as described earlier (CleryBarraud et al, 2012;Vallet et al, 2012).…”

“…This skin inflammation in response to SM exposure is controlled by an important regulation of a network of inflammatory mediators to recruit and activate inflammatory cells to the site of injury. Accordingly, several animal studies have documented an increased expression of interleukin (IL)-1a, IL-1b, IL-6, IL-8, tumor necrosis factor (TNF)-a, macrophage inflammatory proteins (MIP)-1a, MIP2a, MIP-1aR, granulocyte monocyte-colony stimulating factor (GM-CSF), cyclooxygenase-2 (COX2) and inducible nitric oxide synthase following vapor or liquid SM exposure (Nyska et al, 2001;Price et al, 2009;Ricketts et al, 2000;Sabourin et al, 2000Sabourin et al, , 2004Shakarjian et al, 2010;Vallet et al, 2012;Wormser et al, 2004Wormser et al, , 2005.…”

“…During the last years, the hairless mouse model stood out as the model of choice for studying the skin pathogenesis of SM Dorandeu et al, 2011;Joseph et al, 2011;Vallet et al, 2012) or its analogues the chloroethyl ethyl sulfide (CEES) (Jain et al, 2011a,b,b;Tewari-Singh et al, 2009) or the nitrogen mustard Jain et al, 2014;Tewari-Singh et al, 2013. Furthermore, it has been shown that the mouse ear model which is considered as the vesicant model for studying SM-induced inflammatory response and histopathological changes has altered reaction to SM-injury when compared to hairless mouse skin .…”

Sulfur mustard induced nuclear translocation of glyceraldehyde-3-phosphate-dehydrogenase (GAPDH)

“…The cellular response to SM includes increased protein expression and protein modifications that have been found both in vitro and in vivo [1,8].…”