Organic Chemicals in Diesel Exhaust Particles Enhance Picryl Chloride-Induced Atopic Dermatitis in NC/Nga Mice

Abstract

Background: Diesel exhaust particles (DEP) have been reported to worsen allergic airway inflammation in mice. Recently, the organic chemical components of DEP (DEP-OC) were found to be important contributors to the aggravation of allergic airway inflammation in mice. The purpose of this study was to examine the effects of DEP-OC on atopic dermatitis (AD)-like skin lesions induced by picryl chloride (PiCl) in NC/Nga mice. Methods: DEP were extracted with benzene/ethanol, and the soluble organic fraction formed the DEP-OC. NC/Nga male mice received simultaneous application of DEP-OC and/or PiCl on their ears once a week for 9 or 3 weeks. We evaluated skin lesions by noting scaling, eruption, excoriation, erosion, hemorrhage, pathologic changes, production of cytokines, and IgE level in the serum. Results: PiCl application alone produced progressively severe AD-like skin lesions. The application of PiCl plus DEP-OC resulted in a marked worsening of skin lesions in the early stages of AD. Moreover, mast cell counts significantly increased in the subcutaneous tissue. Administration of PiCl combined with DEP-OC resulted in a greater increase in the local expression of interleukin-4, keratinocyte chemoattractant, and neutrophils in subcutaneous tissue compared with PiCl treatment alone. In contrast, the combination treatment produced lower levels of IFN-γ compared with PiCl treatment alone. Conclusions: DEP-OC application to the skin aggravated PiCl-induced AD. This aggravation may be due to activation of the Th2-associated immune responses by the organic chemicals in DEP.

Association between exposure to traffic-related air pollution and pediatric allergic diseases based on modeled air pollution concentrations and traffic measures in Seoul, Korea: a comparative analysis

“…One study investigated the effect of diesel exhaust particle (DEP); they also suggested that DEP was associated with atopic dermatitis in mouse models [47].…”

Impact of airborne particulate matter on skin: a systematic review from epidemiology to in vitro studies

“…In vivo, the activation of the inflammatory cascade was observed through activation of NF-κB signaling with a resulting increased expression of pro-inflammatory cytokines upon topical exposure to PM [121,122,169]. Additionally, an increase in epidermal thickness (i.e., an indicator for activation of the inflammatory cascade) and neutrophil infiltration was observed [121,168,179,226]. [233]…”

“…This indicates that PM can aggravate symptoms from skin diseases with an already existing disrupted skin barrier like AE, supporting the epidemiological evidence that airborne PM can aggravate AE symptoms. Moreover, in AE mice models, topical application with the soluble phase of diesel PM (e.g., PAHs), resulted in increased lesion formation and increased immunoglobulin E (IgE) levels [226].…”

Impact of Ambient Particulate Matter on the Skin’s Immune System

“…This effect suggests that PM is correlated with the symptoms of skin conditions, such as atopic eczema (AE), which has a disrupted skin barrier (24,83). Additionally, topical administration of the soluble PAHs from diesel fuel exacerbates lesion formation and increases immunoglobulin E levels in AE mouse models (84).…”

“…Acute epidermal thickening and dermal inflammation seen in skin with damaged barriers raises the possibility that PM 2.5 provokes an inflammatory reaction, leading to more skin damage (91). Repeated PM 2.5 application can cause severe dermal inflammation with mostly neutrophil infiltration, increasing the severity of inflammatory skin diseases (84,91).…”