The role of metallothionein in a dinitrofluorobenzene-induced atopic dermatitis-like murine model

Atopic dermatitis (AD), one of the most common chronic eczematous skin disorders, is associated with cutaneous hyperactivity as a response to environmental triggers. Metallothionein (MT) plays a constitutive defensive role in the response to noxious stimuli. However, the role of MT in AD development is unclear. Using an AD-like murine model created by the topical application of 2.4-dinitrofluorobenzene, we studied the dynamic pattern of MT expression on AD development. AD-like lesions were evaluated based on the development of erythema, edema, exfoliation, scaling, increased thickness, and increased weight of lesional skin. These characteristics of AD-like lesions and thymic stromal lymphopoietin (TSLP) expression peaked at Day 1 of the establishment of our model and gradually alleviated over time. The MT expression in lesional skin was increased and peaked at Day 3. By immunostaining, increased expression of MT was translocated from the cytoplasm to the nucleus. MT-1/2 knockout (MT−/−) mice and wild type (MT+/+) mice were also used to evaluate the role of MT on AD. MT−/− mice had greater edema scores, thickness, lesional skin weight, as well as more CD4+ T cells, TSLP, superoxide dismutase, and NDUFAF1. These results suggest that MT may play a protective role against AD development, and that antioxidant and nuclear protective mechanisms may be involved.