Effect of Particulate Matter in Atopic Dermatitis through HDACs and Filaggrin Alteration.

Atopic dermatitis (AD) is a skin condition that can be exacerbated by particulate matter (PM). The primary causes of AD are believed to be impairments in the skin barrier, such as filaggrin (FLG) abnormalities. Although there is substantial evidence for genetic factors contributing to AD, it is challenging to attribute the disease's predisposition solely to genetics. We hypothesize that PM may induce epigenetic modifications in AD, impacting FLG expression. Here, we assessed histone deacetylases (HDACs) and FLG levels under AD conditions with or without exposure to PM using qRT-PCR, western blotting, and immunofluorescence. Additionally, we observed changes in these molecules when co-treated with the HDAC inhibitor, trichostatin A (TSA). FLG levels tended to decrease when PM or IL-4/13 were given individually, and a further decrease upon IL-4/13 and PM cotreatment. Interestingly, HDAC3 and HDAC6 are increased when they were both given PM10 and IL-4/13 co-treatment compared to IL-4/13 treatment alone. FLG levels exhibited a significant restoration and the levels of HDACs were changed when treated with TSA than with IL-4/13 or IL-4/13+PM co-treatment. We found changes in FLG and HDACs in the AD-like in vivo model and in this model with PM. Our findings suggest that PM can induce epigenetic alterations in AD. Treatment with TSA ameliorates these effects on FLG expression, indicating its potential as a novel therapeutic approach for AD.