Neuroendocrinology of the Hair Follicle: Principles and Clinical Perspectives

The document from 2014 explores the neuroendocrinology of the human hair follicle (HF), revealing its role as a hormone-sensitive mini-organ involved in various biological processes such as growth, pigmentation, and energy metabolism. Key findings include the HF's expression of corticotropin-releasing hormone (CRH) and its receptors, the upregulation of proopiomelanocortin (POMC) transcription, and the presence of a peripheral hypothalamic-pituitary-adrenal (HPA) axis equivalent within the HF. Thyrotropin-releasing hormone (TRH) was identified as a stimulator of hair growth and pigmentation, while thyroid-stimulating hormone (TSH) and TRH were found to promote mitochondrial activity and regulate keratin expression. Prolactin (PRL) has dichotomous effects on hair growth, and the endocannabinoid system (ECS) controls mast cell biology. The document concludes that further research into HF neuroendocrinology could provide insights into general human neuroendocrinology and potential therapeutic targets, although the field is still in its early stages and requires more investigation.