Deletion of the <scp><i>Sox21</i></scp> gene drastically affects hair lipids

The study investigated the impact of Sox21 gene deletion on hair lipids. It was found that the deletion did not change the total levels and distribution of the cuticle-specific lipid 18-methyl eicosanoic acid (18-MEA), although its attachment to the cuticle surface was disrupted due to the loss of keratin-associated protein binding partners. While the overall ceramide (CER) levels remained similar between Sox21 +/+ and Sox21 −/− hairs, the composition of these lipids differed. Additionally, the deletion of the Sox21 gene led to an increase in cholesterol sulphate (CS) levels. The findings suggested that the biosynthesis process might be linked to cuticle keratinocyte maturation, as both CS and CERs are involved in keratinocyte differentiation.