TCDD-Induced Activation of Aryl Hydrocarbon Receptor Regulates the Skin Stem Cell Population

The study investigated the role of the environmental toxin TCDD in regulating the skin stem cell population through activation of the aryl hydrocarbon receptor (AHR). TCDD was found to potentially upregulate c-Myc via the EGFR-ERK pathway, leading to increased activation and differentiation of human epidermal stem cells (EPSCs) into keratinocytes. This process could result in the depletion of the epidermal stem cell compartment, contributing to the development of chloracne, characterized by hyperkeratosis and sebaceous gland metaplasia. The findings suggested that TCDD-induced AHR activation might cause increased epidermal stem cell turnover, mirroring the phenotype seen in c-Myc overexpressing transgenic mice.