Hair follicle stem cells, which boost hair growth, can prolong their life by switching their metabolic state.
In a new study, researchers found that a protein called Rictor holds a key role in the process.
The research was conducted by a team in Helsinki and Cologne, Germany.
Ultraviolet radiation and other environmental factors damage our skin and other tissues every day, with the body continuously removing and renewing the damaged tissue.
On average, humans shed daily 500 million cells and a quantity of hairs weighing a total of 1.5 grams.
The dead material is replaced by stem cells that promote tissue growth. Tissue function is dependent on the activity and health of these stem cells, as impaired activity results in the aging of the tissues.
Although the critical role of stem cells in aging is established, little is known about the mechanisms that regulate the long-term maintenance of these important cells.
The hair follicle with its well-understood functions and clearly identifiable stem cells were a perfect model system to study this important question.
At the end of hair follicles’ regenerative cycle, the moment a new hair is created, stem cells return to their specific location and resume a quiescent state.
The key finding in the study is that this return to the stem cell state requires a change in the cells’ metabolic state.
They switch from glutamine-based metabolism and cellular respiration to glycolysis, a shift triggered by signaling induced by a protein called Rictor, in response to the low oxygen concentration in the tissue.
Correspondingly, the team demonstrated that the absence of the Rictor protein impaired the reversibility of the stem cells, initiating slow exhaustion of the stem cells and hair loss caused by aging.
The research group created a genetic mouse model to study the function of the Rictor protein, observing that hair follicle regeneration and cycle were significantly delayed in mice lacking the protein.
Aging mice suffering from Rictor deficiency showed a gradual decrease in their stem cell, resulting in loss of hair.
The team says further research will now be conducted to examine how these preclinical findings could be utilized in human stem cell biology and potentially also in drug therapies that would protect hair follicles from aging.
In other words, the mechanisms identified in the study could possibly be used to prevent hair loss.
One author of the study is Sara Wickstrom.
The study is published in the Cell Metabolism journal.
Copyright © 2020 Knowridge Science Report. All rights reserved.
