Acid ceramidase ASAH1 is a key regulator of epidermal ceramide levels and composition.

ABSTRACT: Maintenance of appropriate ceramide levels and composition in the stratum corneum of the epidermis is essential for skin barrier function. Although ceramide homeostasis is regulated by both synthesis and degradation, the extent of ceramide degradation in the epidermis, as well as the ceramidase responsible for this degradation, has thus far remained unclear. Here, we found that the acid ceramidase ASAH1 is strongly expressed in differentiated human keratinocytes. To investigate its role, we generated ASAH1 KO cells using immortalized human keratinocytes and analyzed their ceramide levels. Under differentiation conditions, ASAH1 KO keratinocytes exhibited a marked accumulation of ceramide classes composed of sphingosine (S) or dihydrosphingosine (dS) and nonhydroxy fatty acid (N) (ceramides

SUBMITTER: Nobumoto W 

PROVIDER: S-EPMC12907855 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature