"The End of Baldness? The Chemical Controlling Life and Death in Hair Follicles Identified"

Summary: Researchers discovered how the TGF-beta protein controls the process by which hair follicles, including stem cells, divide and form new cells or orchestrate apoptosis. The findings could provide new treatment options for baldness and therapies to speed up wound healing.

A single chemical is key to controlling when hair follicle cells divide, and when they die. This discovery could not only treat baldness, but ultimately speed wound healing because follicles are a source of stem cells.

Most cells in the human body have a specific form and function determined during embryonic development that does not change. For example, a blood cell cannot turn into a nerve cell, or vice versa. Stem cells, however, are like the blank tiles in a game of Scrabble; they can turn into other types of cells.

Their adaptability makes them useful for repairing damaged tissue or organs.
“In science fiction when characters heal quickly from injuries, the idea is that stem cells allowed it,” said UC Riverside mathematical biologist and study co-author Qixuan Wang.
“In real life, our new research gets us closer to understanding stem cell behavior, so that we can control it and promote wound healing,” Wang said. This research is detailed in a recent Biophysical Journal article.
The liver and stomach regenerate themselves in response to wounds. However, Wang’s team studied hair follicles because they’re the only organ in humans that regenerates automatically and periodically, even without injury.
The researchers 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 own death — eventually leading to the death of the whole hair follicle.

“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,” Wang said.
As with many chemicals, it is the amount that makes the difference. If the cell produces a certain quantity of TGF-beta, it activates cell division. Too much of it causes apoptosis.
No one is entirely sure why follicles kill themselves. Some hypotheses suggest it is an inherited trait from animals shedding fur to survive hot summer temperatures or trying to camouflage.
“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 cell and develop into a new follicle,” Wang said.
If scientists can determine more precisely the way TGF-beta activates cell division, and how the chemical communicates with other important genes, it might be possible to activate follicle stem cells and stimulate hair growth.
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 all over the world.  

“Potentially our work could offer something to help people suffering from a variety of problems,” Wang said.

CausticSymmetry wrote:J Cosmet Dermatol. 2022 Jul;21(7):2763-2773. doi: 10.1111/jocd.15081. Epub 2022 Jun 9.
Lagerstroemia indica extract regulates human hair dermal papilla cell growth and degeneration via modulation of β-catenin, Stat6, and TGF-β signaling pathway
Byung Hyun Kim 1, Myong Ki Kim 2, Bu Young Choi 1

Background: Lagerstroemia indica (L. indica) is reported to have diverse biological activities including anti-inflammatory, anti-cancer, neuro-regulatory, antidiabetic, and antioxidant activity.

Aims: The purpose of this study is to examine the potential of hair growth promotion and/or hair loss prevention by L. indica extract.

Patients/methods: The effects of L. indica on hair growth have been studied in human hair follicle dermal papillary (hHFDP) cells and follicular organ culture ex vivo by cell proliferation assay, PCR, western blot analysis, and reporter gene activity assay. Moreover, a clinical trial was conducted in healthy volunteers.

Results: Lagerstroemia indica significantly promoted the proliferation of hHFDP cells, which was associated with increased expression of TCF/LEF, VEGF, and Gli1 mRNA, and inhibition of STAT6 and Smad2 mRNA. Treatment with L. indica also increased the TCF/LEF reporter gene activity but downregulated the SBE- and STAT6-luciferase activities. The expression of total β-catenin, CDK4, and CDK2 were elevated, while that of STAT6 and SMAD2/3 was suppressed upon treatment with L. indica. In human hair follicles organ culture, L. indica significantly inhibited hair follicular degeneration. The clinical trial showed a statistically significant rise in total hair count in test group (n = 24) after 24 weeks of applying the hair tonic enriched with L. indica (141.46 ± 21.27 number/cm2 , p < 0.05).

Conclusion: We suggest that L. indica extract prevents hair loss as well as stimulate hair growth by regulating the Wnt-β-catenin, JAK3-STAT6, and TGF-β1-Smad signaling pathways, and may be further developed as a novel functional cosmetic for preventing hair loss.

Keywords: Lagerstroemia indica; IL-4-JAK3-STAT6; Wnt-β-catenin; hair growth; hair loss.