Transient receptor potential channels in hair follicle biology: physiological significance and translational relevance

Transient receptor potential (TRP) channels are a family of versatile ion channels that act as sensor for a wide range of chemical and physical stimuli. These cation-permeable channels are widely expressed in various tissues and play pivotal roles in numerous biologic processes. Studies have demonstrated that six specific TRP channels -TRPV1, TRPV3, TRPV4, TRPM5, TRPML1 and TRPML3 - are actively involved in hair follicle (HF) cell proliferation, modulation of hair growth-related signalling pathways, regulation of hair cycle progression, and control of hair growth and pigmentation in humans and mice. This review summarizes the distribution profiles and functional roles of TRP channels in HF biology. Based on findings from ex vivo cultured human HFs and murine models, this review also provides an overview of TRP channel agonists and antagonists implicated in hair disorders. Furthermore, we highlight the therapeutic potential of selectively targeting these channels for treating hair loss. A deeper understanding of their regulatory mechanisms may provide novel strategies for managing hair diseases and facilitate the development of more effective targeted therapies.