After the age of 65 years, three in ten men experience androgenetic alopecia (or baldness). In general, we often see a loss of hair density with age, both in men and in women. However, science has long looked into the phenomenon of age-related hair loss, both to understand its origin and to treat it. Focusing on stem cells seems to offer the best hope for a cure, based on numerous studies.
The hair transplant procedure is indeed an expensive and invasive procedure. As for drugs, finasteride used for androgenetic alopecia in men can induce side effects such as loss of libido and erectile dysfunction while minoxidil can cause hypertrichosis. Today, therefore, researchers seem to be looking more at alternative solutions, and in particular by focusing on stem cells.
For decades, researchers have always focused on keratinocytes, cells that make up the epidermis and integuments (body hair, hair, etc.). However, as part of a study conducted by the University of Calgary (Canada), the team of researchers focused on a small cell group present in hair follicles and in skin stem cells. :fibroblasts. And according to them, these fibroblasts are the main cause of age-related hair loss.
By studying the sparse coat of elderly mice, they noticed that fibroblast stem cells had lost their regenerative function or were malfunctioning. “There weren’t enough of them to regenerate fibroblasts. As a result, the fibroblasts and hair follicles began to miniaturize and were no longer able to produce hair,” explains Biernaskie, head of the research team.
Fibroblasts are important because they send messages to keratinocytes to force them to divide, and in so doing, orchestrate the growth cycles of hair follicles allowing the production of new hairs. When the fibroblasts become scarce, the “signal” then becomes too weak to reach the keratinocytes and maintain the process of capillary growth. For Jeff Biernaskie: “if we want one day to succeed in preventing hair loss or to re-grow those which are already falling, we must work to preserve the function of these stem cells which are in the hair follicles”.
This finding may help guide future research into hair loss more precisely. Scientists at the University of Calgary are particularly hoping to find a way to prevent this degeneration by blocking certain genetic mutations that occur directly in stem cells in fibroblasts.
They also believe that this will have broader implications. Indeed, Wisoo Shin, lead author of the study, points out that similar fibroblasts are found in most of our organs, maintaining their integrity and promoting tissue regeneration. Finding a way to promote self-renewal to produce new functional fibroblasts into old age therefore also offers hope that we can treat certain injuries and help the skin to regenerate.
