Hair follicle stem cells, which promote hair growth, can prolong their life by switching their metabolic state. In experiments conducted with mice, a research group active in Helsinki and Cologne, Germany, has demonstrated that a protein called Rictor holds a key role in the process.
New information on mechanisms that regulate stem cells
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 specialised 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 ageing of the tissues.
“Although the critical role of stem cells in ageing 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 was a perfect model system to study this important question,” says Sara Wickstrom.
Reduced metabolic flexibility in stem cells underlying hair loss
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 new 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,