Researchers have discovered a new mechanism for aging, and taking a simple nutritional supplement may be able to stop it!
According to a new scientific study, the decline of a Menin, a protein present in the hypothalamus, may play a key role in aging. The findings reveal a previously unknown driver of physiological aging and suggest that supplementation with a simple amino acid may mitigate some age-related changes. The research, by Lige Leng of Xiamen University, Xiamen, China, and colleagues, was published on March 16th in the open-access journal PLOS Biology.
The hypothalamus has been recognized as a key mediator of physiological aging through an increase in the process of neuroinflammatory signaling over time. In turn, inflammation promotes multiple age-related processes, both in the brain and the body.
Leng and his colleagues showed that Menin is a key inhibitor of hypothalamic neuroinflammation, leading them to ask what role Menin may play in aging.
They observed that the level of Menin in the hypothalamus declines with age. To explore this decline, they created conditional knockout mice, in which Menin activity could be inhibited.
They found that reduction of Menin in younger mice led to an increase in hypothalamic neuroinflammation and other “aging-related” conditions, including reductions in bone mass and skin thickness, cognitive decline, and modestly reduced lifespan.
Another change observed by the scientists induced by Menin decline was also a decline in levels of the amino acid D-serine, known to be a neurotransmitter and sometimes used as a dietary supplement found in soybeans, eggs, fish, and nuts.
The authors showed this decline was due to the loss of activity of an enzyme involved in its synthesis –which was, in turn, regulated by Menin. The relationship suggests that supplementing with D-serine could help maintain Menin levels in the brain, thereby slowing aging.
To test that possibility, the authors delivered the gene for Menin into the hypothalamus of elderly mice. Thirty days later, they found improved skin thickness and bone mass, along with better learning, cognition, and balance, which correlated with an increase in D-serine within the central brain region important for learning and memory. Remarkably, similar benefits on cognition, though not on the peripheral signs of aging, could be induced by three weeks of dietary supplementation with D-serine.
There is much left to be learned about Menin’s role in aging, including how much aging can be slowed, and for how long, and whether supplementation with D-serine.
Nonetheless, Leng said, “We speculate that the decline of Menin expression in the hypothalamus with age may be one of the driving factors of aging, and Menin may be the key protein connecting the genetic, inflammatory, and metabolic factors of aging. D-serine is a potentially promising therapeutic for cognitive decline.”