Loss of Keratin 10 Is Accompanied by Increased Sebocyte Proliferation and Differentiation

The study provided strong evidence that the targeted deletion of keratin 10 (K10) in mice led to increased proliferation and differentiation of sebocytes, the cells in sebaceous glands. This change was not associated with the induction of proliferation-associated keratins K6, K16, and K17. K10−/− mice exhibited accelerated sebaceous gland cell turnover and increased secretion of sebum, including wax esters, triglycerides, and cholesterol esters. Additionally, levels of major epidermal lipids such as ceramides and cholesterol were elevated, while glycosylceramides and sphingomyelin were reduced, without changes in sphingolipid biosynthesis. The amount of Cer(OS) bound to the cornified envelope, as well as loricrin and involucrin levels, remained unchanged. The study concluded that the altered composition of the suprabasal intermediate filament cytoskeleton in K10−/− mice promoted the differentiation of epidermal stem cells towards the sebocyte lineage.