Figure 5.

Involvement of the endocannabinoid receptor CB1 in the N-palmitoyl serinol (PS)-mediated stimulation of overall ceramide content. HaCaT KC were pretreated with IL-4 (50 ng/mL) for 20 h, followed by incubation with exogenous PS (25 μM) with or without CB1 inhibitor (AM-251, 10 μM) for 4 h. Total ceramide content was assessed by the LC-MS/MS system. Statistical significance was calculated using the unpaired Student’s t-test, and significance was defined as * p < 0.01 vs. vehicle control (or untreated control).