Lu Q. Le, MD, PhD, the Kenneth E. Greer, MD, Professor and chair of the Department of Dermatology, and his lab published an exciting study titled “Transcription factor KROX20 marks epithelial stem cell ancestors for hair follicle formation” in the Journal of Clinical Investigation (JCI). The research, featured on the cover of JCI’s December 2, 2024 issue, uncovers epidermal stem cells required for hair formation and regeneration, which could point to new treatments for balding.
The primary function of the skin is to provide a barrier to maintain an internal environment that allows an organism to protect its DNA and reproduce it faithfully. The skin and its appendages, including hair, are also the defining characteristics of the human body appearance and thick, lustrous hair is associated with beauty and health. They undergo constant cellular turnover to replace the entire epidermis (top layer of the skin) every 28 days in human skin and reproduce new hairs to replace the shedding ones throughout life. Therefore, there must be resident stem cells in the skin to control this process. The quest to identify the identities of the involved stem cells and their niches regulating this homeostatic state has been the topic of considerable interest within the scientific community and the lay public as this knowledge is vital to understand skin and hair diseases.
In this study, Dr. Le’s lab identified the transcription factor KROX20 as a marker of a previously unidentified epidermal stem cell population that is indispensable for hair formation and regeneration. Using genetic labeling to perform comprehensive expression and cell lineage tracing analyses, they found that Krox20+ stem cells in the upper hair follicle migrate down to give rise to the stem cell reservoir and then the entire hair follicle and hair shaft. In vivo depletion of these skin stem cells arrests hair follicle morphogenesis leading to disruption of hair homeostasis, indicating that Krox20+ cells are hair stem cells in the skin, a finding that could lead to a possible treatment for balding.
Learn more about the Le Lab’s research.
Filed Under: Research