From the philosopher’s stone to the fountain of youth, many myths have spawned around the desire to stop aging in its tracks. Modern biomedical science is helping to uncover some anti-aging strategies, among them a molecule known as nicotinamide (NAM), a form of vitamin B3. NAM is known particularly for its beneficial effects on skin appearance.
“NAM reduces sallowness and wrinkles, and more recently has been shown to prevent some skin cancers,” explained Sophie Bellanger, Principal Investigator at the Skin Research Institute of Singapore (SRIS), A*STAR, adding that “until recently we knew very little about the pathways underlying its anti-aging properties.”
Now, Bellanger and her team have shown that NAM works by helping stem cells in the skin retain their unique properties. The research was carried out in partnership with Procter & Gamble.
While most cells in the body are specialized, stem cells maintain the ability to proliferate and differentiate to renew tissues, making them vital to the body’s self-repair mechanisms. To see what effects NAM had on human skin stem cells, the researchers isolated primary cells from the epidermis of healthy donors and grew them with or without NAM in the lab.
They found that skin stem cells deprived of NAM progressively differentiated into specialized skin cells as they grew over weeks, losing their stemness properties. On the other hand, skin stem cells supplied with constant high NAM levels continued to multiply without becoming specialized, thus retaining their initial flexible state over time.
Bellanger and her team thus wondered if the effect of NAM on stemness maintenance was due to its conversion to nicotinamide adenine dinucleotide (NAD), which helps the cell to process sources of energy. Indeed, stem cells which were chemically stripped of NAD dramatically slowed down their glucose metabolism and massively differentiated after only 48 hours, while also displaying signs of cellular aging, otherwise known as senescence.
“The ability of NAM to control the fate of skin stem cells has several important implications,” noted Bellanger. “As an immediate application, stem cell culturing is used to grow skin grafts for severe burn patients, and using NAM to prevent stem cell loss could increase the success rate of this therapy.”
Ultimately, stem cell loss might be related to aging throughout the human body and not just the skin. “Control of stem cell fate by NAM could be ubiquitous, extending to other organs. This pinpoints NAM as a promising compound to delay loss of stem cells throughout a wide range of tissues, and therefore fight aging throughout the whole body,” Bellanger concluded.
The A*STAR-affiliated researcher contributing to this research is from the Skin Research Institute of Singapore (SRIS).