Figure 4. Impaired ω-O-acylceramide formation in PNPLA1-deficient epidermal explants and human primary keratinocytes.

Thin-layer chromatography (TLC, left panel) of ex vivo [1-¹⁴C] linoleic acid-labeled lipids from (a) epidermal explants of newborn wild-type and Pnpla1^−/− mice or (b) in vitro differentiated primary human keratinocytes derived from a healthy individual and a patient carrying a PNPLA1 nonsense mutation (c.391G>T) leading to a premature stop codon and truncated protein (p.Glu131*). TLC plates were exposed to PhosphorImager screens and obtained autoradiography signals were analyzed by a Storm scanner. Output images were adjusted for low signal intensities. Radioactivity contained in the ω-O-AcylCer bands was quantified by scintillation counting (right panel). Data are presented as means + SD (n = 4 mice or 3 independent culture dishes/genotype) and representative for three independent experiments. Statistically significant differences were determined by unpaired two-tailed Student’s t-test (***P < 0.001) between genotypes. ω-O-AcylCer, ω-O-acylceramide; ω-O-AcylGlcCer, ω-O-acylglucosylceramide; FA, fatty acid; non-OH-Cer, non-hydroxy ceramide; PNPLA1, patatin-like phospholipase domain-containing 1.