Deletion of the Sox21 Gene Drastically Affects Hair Lipids

The study investigated the impact of the Sox21 gene deletion on hair lipids in mice. It was found that in Sox21−/− mice, 18-methyleicosanoic acid (18-MEA) was present predominantly in its free form, unlike in wild-type mice where it existed in both free and bound forms. This suggested that while the synthesis of 18-MEA was unaffected, its binding via thioesterification was impaired due to the absence of proteins that typically bind to it. Additionally, the study observed changes in cholesterol sulphate (CS) and ceramide (CER) levels, with CS levels increasing 1.6-fold and variations in CER class compositions. These lipid alterations were linked to improper cuticle formation and might be associated with upregulation of peroxisome proliferator-activated receptors (PPARs). The findings suggested that SOX21 expression defects could contribute to hair loss, highlighting the gene's role in maintaining hair's chemical diffusion barrier, water-holding ability, and cell cohesion. Further research on SOX21 in humans could lead to new cosmetic technologies for hair care.