Hair follicles are mini skin organs that undergo cyclic growth. Various signals regulate the hair follicles fate decisions jointly.

A new study reported the discovery of a single chemical that controls when hair follicle cells divide and when they die. This discovery is expected to treat baldness and accelerate wound healing because follicles are a source of stem cells.

The adaptability of the stem cells makes them helpful in repairing damaged tissue or organs.

UC Riverside mathematical biologist and study co-author Qixuan Wang said, “In science fiction, when characters heal quickly from injuries, the idea is that stem cells allowed it. In real life, our new research gets us closer to understanding stem cell behavior so that we can control it and promote wound healing.”

Scientists determined how a type of protein, TGF-beta, controls the process by which cells in hair follicles, including stem cells, divide and form new cells or orchestrate their death — eventually leading to the death of the whole hair follicle.

Cross section of a typical hair follicle
Cross section of a typical hair follicle. (Qixuan Wang/UCR)

Wang said, “TGF-beta has two opposite roles. It helps activate some hair follicle cells to produce new life, and later, it helps orchestrate apoptosis, the process of cell death.”

Nobody is certain as to why follicles destroy themselves. According to some theories, it is an inherited feature from animals that shed their fur to survive the hot summer months or to attempt and blend in.

Wang said, “Even when a hair follicle kills itself, it never kills its stem cell reservoir. When the surviving stem cells receive the signal to regenerate, they divide, make new cells, and develop into a new follicle.”

It may be possible to activate follicle stem cells and increase hair development if scientists can more accurately pinpoint how TGF-beta activates cell division and interacts with other crucial genes.

Wang said, “Because many animals, including humans, possess skin covered with hair, perfect wound healing would require regeneration of hair follicles. Being able to more precisely control levels of TGF-beta could also one-day cure baldness, which bothers millions of people worldwide.”

Journal Reference:

  1. Katherine Dinh, Qixuan Wang, et al. A probabilistic Boolean model on hair follicle cell fate regulation by TGF-β. Biophysical Journal. 2022; VOLUME 121, ISSUE 13, P2638-2652. DOI: 10.1016/j.bpj.2022.05.035