Scientists have discovered that a brain protein called Menin may play a role in aging. In mice, lower Menin levels were linked to age-related issues such as inflammation, memory loss, weaker bones, and thinner skin. When Menin was restored in older mice, some of these effects were partially reversed. Additionally, an amino acid called D-serine improved memory in the animals. These findings, published in the journal PLOS Biology in March 2023, were led by Lige Leng from Xiamen University in China. The study suggests that Menin might be a new target for research on healthy aging, potentially linking brain inflammation and metabolism to the aging process across the body. The researchers focused on the hypothalamus, a small brain region that helps regulate metabolism and other vital functions. It also appears to influence how the body ages. As inflammation increases in this area, it can lead to changes in both the brain and other body tissues. Earlier work by Leng and colleagues showed that Menin helps control inflammation in the hypothalamus, raising the question of whether its decline might contribute to aging. The study found that Menin levels dropped in certain neurons within the ventromedial hypothalamus, a region involved in metabolism, but not in other brain support cells. This indicated that the decline was specific to certain cells rather than a general loss in the brain region. To test if Menin loss could actually drive aging, the researchers created genetically modified mice where Menin could be selectively removed. Lower Menin levels in younger mice led to increased inflammation in the hypothalamus and symptoms of aging, such as thinner bones, thinner skin, and cognitive decline. Menin also influenced a chemical pathway that supports communication between brain cells. Mice with less Menin had lower levels of D-serine, an amino acid important for learning and memory. This suggests that Menin affects both brain inflammation and the chemistry needed for proper brain signaling. When researchers restored Menin levels in older mice by delivering the Menin gene to the hypothalamus, the animals showed improvements in skin thickness, bone mass, and cognitive performance. These effects were accompanied by higher D-serine levels in the hippocampus, a brain region crucial for learning and memory. Restoring Menin also extended the lifespan of the mice. A separate experiment tested D-serine supplements, which improved cognitive performance but did not reverse broader aging effects. This highlights that while D-serine may help cognition, it does not fully restore aging-related changes. Subsequent research has explored related mechanisms, but these findings are not yet direct confirmation of the Menin aging pathway. A 2024 study in the Journal of Physiology and Biochemistry found that a compound called itaconate increased Menin levels in brain cells and reduced inflammation. However, this was a cell study, not a test in whole animals. Another study from 2024 showed that communication between the hypothalamus and other body tissues, such as fat, can influence aging. Interventions that supported this communication increased activity and lifespan in mice, but through a different molecular pathway than Menin. A 2025 study by the Allen Institute found that certain brain cells near the hypothalamus were especially sensitive to aging. These cells showed signs of reduced function and increased immune activity. While this study did not test treatments, it emphasized the importance of the hypothalamus in aging research. Later work complicated the role of D-serine in aging, showing that in a model of Alzheimer’s disease, increasing D-serine could worsen some symptoms. This suggests that the effects of D-serine may depend on the specific disease context. Research on D-serine in humans is limited. A small 2016 study found that a single dose improved one type of memory test in older adults, but did not show lasting benefits or safety for long-term use. While these findings are intriguing, they do not yet support D-serine as a treatment for aging in humans. The Menin research highlights the potential of targeting brain signals to influence aging but leaves many questions unanswered, such as the causes of Menin decline and the long-term effects of any interventions. For now, the findings point to an experimental pathway worth exploring, rather than a proven treatment for aging.