With male pattern baldness, large (terminal) hairs convert into small (vellus) hairs. This is the negative effect of testosterone and DHT, a potent testosterone derivative, on hair follicle stem cells. Despite lack of visible hair growth, hair stem cells remain largely intact in the bald scalp skin!
Human hair loss conditions result from abnormalities in the so-called hair growth cycle, the recurrent process of hair production separated by periods of inactivity. Current anti-hair loss treatments modulate only part of this cyclic process e.g., Finasteride lengthens hair production phase leading to longer hairs, but it cannot activate re-entry of dormant hairs into new growth phase. Because of this, such treatments show extremely slow and incomplete recovery from hair loss, especially when the condition is advanced. Additionally, the efficacy of new hair regeneration via stem cell therapy or the so-called hair cloning was never conclusively demonstrated in the clinical settings. Inspired by the naturally occurring human condition of excessive hair growth, UCI researchers have discovered that re-entry of dormant hairs into active growth cycle can be efficiently stimulated when hairs are exposed to a specialized type of pigment-producing cell or to the signaling molecules that this type of cell actively makes. This suggests that either transplanting cells into the skin or simply injecting their bioactive molecules is sufficient to drive new hair growth on the scalp.
UCI scientists also found that hair growth-inducing effect of pigment-producing cells is potentiated by other naturally occurring cells derived from blood. Moreover, they investigated the profile of secreted signaling molecules and determined that a wide range of skin specific cells, beyond pigment producing cells, can be coaxed to make them due to shared profiles of secreted factors. Injecting a synthesized cocktail of signaling molecules in to an area with dormant hairs in vivo in animal model induced rapid new hair growth. Prospective plans involve testing these effects on human skin. Targeting a signaling pathway for naturally robust hair growth in humans presents a promising approach for treating hair loss conditions.
The hairy nevus is a common, benign birthmark where vellus hairs convert into the terminal hairs normally found on the scalp. UCI scientists believe that this occurs because of a protein signaling molecule that is produced by the hairy nevus and UCI has identified key proteins that they believe is responsible for the hair growth.
The way UCI scientists will Microinject hair-growth promoting molecules, derived from the hairy nevus birthmark, into the scalp skin affected by male pattern baldness. The hope is that these molecules will act as a signal to dormant stem cells (as it happens in the vellus hair follicles of the hairy nevus). It is hoped that this will result in vellus-to-terminal hair transformation and a cosmetically desirable hair growth restoration in the balding male