Establishment of a Mouse Model for Porokeratosis Due to Mevalonate Diphosphate Decarboxylase Deficiency.

Introduction: Porokeratosis (PK) is an autoinflammatory keratinization disease (AIKD) characterized by circular or annular skin lesions with a hyperkeratotic rim, pathologically shown as the cornoid lamella. Four genes that cause PK are associated with the mevalonate (MV) pathway. In Chinese PK patients, mevalonate diphosphate decarboxylase (MVD) is the most common causative gene. The lack of an animal model has greatly limited research on PK pathogenesis.

Materials and methods: In this research, we constructed K14-CreER^T2-Mvd^fl/fl mice using the Cre-LoxP system to create a mouse model for in-depth studies of PK. The Epidermal Mvd gene was knocked out by intraperitoneal injection of Tamoxifen (TAM). Pathology, immunohistochemistry, RNA-seq, and Western Blot analysis were performed.

Results: Skin lesions appeared following Mvd deficiency, and pathological examination revealed the characteristic cornoid lamella, as well as cutaneous inflammation. Furthermore, we observed elevated levels of IL-17A and IL-1β, and a decreased Loricrin level in epidermal Mvd-deficient mice. Compared with the wild-type (WT) group, Mvd deficiency activated the expression of lipid metabolism-related proteins.

Conclusion: We developed the first mouse model for PK research, enabling further studies on disease development and treatment approaches.