Human Hair Follicles Can Taste: Stimulation of the Bitter Taste Receptor TAS2R4 Inhibits Hair Growth Ex Vivo by Up-Regulating TGF-β2

The study "571 Human Hair Follicles can “Taste”: Stimulation of the Bitter Taste Receptor TAS2R4 Inhibits Hair Growth Ex Vivo by Up-Regulating TGF-β2" reveals that human scalp hair follicles express the bitter taste receptor, TAS2R4, which when activated by the sweet-tasting steviol-glycoside, rebaudioside A (Reb A), significantly inhibits the proliferation of hair matrix keratinocytes. This leads to premature hair follicle involution (catagen) ex vivo by increasing the expression of the key catagen-promoting growth factor, TGF-β2, and by stimulating TGF-β signaling-related pathways/target genes. The study confirms that hair growth inhibition by Reb A is mediated by TAS2R4 activation and mainly driven by TGF-β pathway activation. This research introduces taste receptors as chemosensory regulators of human organ/tissue remodeling and identifies a novel, drug-free strategy for the therapeutic inhibition of unwanted hair growth by topically applicable tastants, such as steviol-glycoside TAS2R4 agonists.