Researchers from the Tohoku University Graduate School of Medicine and Tohoku Medical Megabank Organization in Japan have discovered why air pollutants cause some people to be more susceptible to atopic dermatitis, a kind of skin inflammation. Their work was published in Nature Immunology.
While the correlation between air pollution and the prevalence and severity of atopic dermatitis is well-known, the underlying mechanism was not widely understood. AhR, a transcription factor activated by air pollutants, causes hypersensitivity to itch through the expression of the neurotrophic factor artemin, according to Dr. Masayuki Yamamoto, who led the research team with Drs. Takanori Hidaka and Eri Kobayashi.
“Scratching makes things worse because the skin barrier gets disrupted and sensitization to antigens is enhanced. That’s why some people are predisposed to atopic dermatitis,” said Yamamoto.
In human clinical samples, the researchers observed high levels of AhR activation and artemin expression in atopic dermatitis patients, but not in healthy individuals. This is also consistent with the findings in a similar study of mice, and further supports the notion that chronic activation of AhR is an important environmental factor causing atopic dermatitis.
Currently, steroid drugs are used as a symptomatic treatment for atopic dermatitis. However, in some cases, the itch remains. The research team believes that control of the itch is important and hopes that with the results of this study, new treatments using inhibitors of AhR and/or artemin can be found.
The article can be found at: Hidaka et al. (2016) The Aryl Hydrocarbon Receptor AhR Links Atopic Dermatitis and Air Pollution via Induction of the Neurotrophic Factor Artemin. Read more from Asian Scientist Magazine at: http://www.asianscientist.com/2016/11/in-the-lab/air-pollutants-atopic-dermatitis/