Menu
Understanding role of stem cells in hair growth
Stem cells
Stem cells are believed to play a vital role in aging. As stem cells age, they lose their ability to renew the body’s tissues and organs. Over time, they stop dividing and eventually die. This decline in numbers is known as stem cell exhaustion. However, the process isn’t well understood.
The hair follicle is an ideal system to examine stem cell populations during aging. Stem cells in a compartment of the hair follicle called the bulge give rise to hair. When hair falls out, it can be replaced by new hair generated by the remaining stem cells. Permanent hair loss was thought to occur when most of these stem cells were damaged or died.
To understand how stem cells are depleted with age in live animals, a team led by Dr. Rui Yi of Northwestern University studied how hair follicle stem cells behave in aging mice. Their work was funded by NIH’s National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institute of General Medical Sciences (NIGMS), and National Cancer Institute (NCI). The results were published in Nature Aging on October 4, 2021.
The team observed the growth of individual hair follicles in the ear using laser light that penetrates deep into tissue. They labeled hair follicle stem cells with florescent proteins to track their development in young and old mice. The laser excites the fluorescent tags, which then emit light that can be observed under a microscope. Time-lapse images were periodically collected when mice were sedated and then analyzed on a computer. The researchers studied hundreds of hair follicles in young and old mice. For one study, they tracked 78 hair follicles over 16 days or more to monitor their behaviors over time.The results show that hair follicle stem cells escape from the bulge into surrounding tissue. This depletes the reserve of hair follicle stem cells, resulting in thinning hair and balding.stem cells may help by re-triggering the growth and reproduction of cells in an area of the body that was formerly too old or damaged to do so on its own. By reintroducing such cells to the scalp, physicians and aestheticians can help clients rediscover their formerly thick, lustrous hair.
The hair follicle is an ideal system to examine stem cell populations during aging. Stem cells in a compartment of the hair follicle called the bulge give rise to hair. When hair falls out, it can be replaced by new hair generated by the remaining stem cells. Permanent hair loss was thought to occur when most of these stem cells were damaged or died.
To understand how stem cells are depleted with age in live animals, a team led by Dr. Rui Yi of Northwestern University studied how hair follicle stem cells behave in aging mice. Their work was funded by NIH’s National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institute of General Medical Sciences (NIGMS), and National Cancer Institute (NCI). The results were published in Nature Aging on October 4, 2021.
The team observed the growth of individual hair follicles in the ear using laser light that penetrates deep into tissue. They labeled hair follicle stem cells with florescent proteins to track their development in young and old mice. The laser excites the fluorescent tags, which then emit light that can be observed under a microscope. Time-lapse images were periodically collected when mice were sedated and then analyzed on a computer. The researchers studied hundreds of hair follicles in young and old mice. For one study, they tracked 78 hair follicles over 16 days or more to monitor their behaviors over time.The results show that hair follicle stem cells escape from the bulge into surrounding tissue. This depletes the reserve of hair follicle stem cells, resulting in thinning hair and balding.stem cells may help by re-triggering the growth and reproduction of cells in an area of the body that was formerly too old or damaged to do so on its own. By reintroducing such cells to the scalp, physicians and aestheticians can help clients rediscover their formerly thick, lustrous hair.