Biochemical and Biophysical Research Communications, Vol.511, No.2, 330-335, 2019
Epidermal loss of phospholipase C delta 1 attenuates irritant contact dermatitis
Irritant contact dermatitis (ICD) is one of the most common inflammatory skin diseases caused by exposure to chemical irritants. Since chemical irritants primarily damage keratinocytes, these cells play a pivotal role in ICD. One of the phosphoinositide-metabolizing enzymes, phospholipase C (PLC) delta 1, is abundantly expressed in keratinocytes. However, the role of PLC delta 1 in ICD remains to be clarified. Here, we found that croton oil (CrO)-induced ear swelling, a feature of ICD, was attenuated in keratinocyte-specific PLC delta 1 knockout mice (PLC delta 1 cKO mice). Dendritic epidermal T cells (DETCs), which have a protective role against ICD, were activated in the epidermis of the PLC delta 1 cKO mice. In addition, the skin of CrO-treated PLC delta 1 cKO mice showed increased infiltration of Gr1(+)CD11b(+) myeloid cells. Of note, elimination of Gr1(+)CD11b(+) myeloid cells restored CrO-induced ear swelling in PLC delta 1 cKO mice to a similar level as that in control mice. Taken together, our results strongly suggest that epidermal loss of PLC delta 1 protects mice from ICD through induction of Gr1(+)CD11b(+) myeloid cells and activation of DETCs. (C) 2019 Elsevier Inc. All rights reserved.