Increased cellular ceramide accounts in part for UVB irradiation-induced apoptosis in
cultured human keratinocytes with concurrent increased glucosylceramide but not
sphingomyelin generation in these cells. Given that conversion of ceramide to non-apoptotic
metabolites such as sphingomyelin and glucosylceramide protects cells from ceramide-
induced apoptosis, we hypothesized that failed up-regulation of sphingomyelin generation
contributes to ceramide accumulation following UVB irradiation. Because both …