Der Rückgang von Menin im Hypothalamus kann zur physiologischen Alterung beitragen und die Kognition, Knochenmasse, Hautdicke und Lebensdauer beeinflussen. Eine aktuelle Studie mit Mäusen legt nahe, dass eine einfache Nahrungsergänzung mit einer Aminosäure dazu beitragen kann, einige dieser altersbedingten Veränderungen zu mildern.
Der Verlust von Menin hilft, den Alterungsprozess anzukurbeln, und das Nahrungsergänzungsmittel kann ihn bei Mäusen umkehren.
Kognition, Knochenmasse, Hautdicke und Lebenserwartung sind alle von Menins Rückgang betroffen.
Laut einer neuen wissenschaftlichen Studie spielt der Rückgang des hypothalamischen Menins möglicherweise eine Schlüsselrolle beim Altern. Die Ergebnisse zeigen einen bisher unbekannten Treiber des physiologischen Alterns und legen die Supplementierung mit einer einfachen Aminosäure nahe[{” attribute=””>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 periphery.
Researchers find that the loss of a hypothalamic hormone helps drive the aging process, and a supplement can help reverse it in mice. Credit: Lige Leng, Ziqi Yuan and Jie Zhang, 2023, PLOS Biology, CC-BY 4.0
Recently, Leng and colleagues showed that Menin, a hypothalamic protein, is a key inhibitor of hypothalamic neuroinflammation, leading them to ask what role Menin may play in aging. Here, they observed that the level of Menin in the hypothalamus, but not astrocytes or microglia, 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, aging-related phenotypes including reductions in bone mass and skin thickness, cognitive decline, and modestly reduced lifespan.
Another change induced by loss of Menin was 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 loss of activity of an enzyme involved in its synthesis (which was in turn regulated by Menin).
Could reversing age-related Menin loss reverse signs of physiological aging? To test that, the authors delivered the gene for Menin into the hypothalamus of elderly (20-month-old) 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 hippocampus, a 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 the upstream processes that lead to its decline, and there is much to learn about the potential for exploiting this pathway, including how much phenotypic aging can be slowed, and for how long, and whether supplementation with D-serine may trigger other changes, yet to be discovered.
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.”
Leng adds, “Ventromedial hypothalamus (VMH) Menin signaling diminished in aged mice, which contributes to systemic aging phenotypes and cognitive deficits. The effects of Menin on aging are mediated by neuroinflammatory changes and metabolic pathway signaling, accompanied by serine deficiency in VMH, while restoration of Menin in VMH reversed aging-related phenotypes.”
Reference: “Hypothalamic Menin regulates systemic aging and cognitive decline” by Lige Leng, Ziqi Yuan, Xiao Su, Zhenlei Chen, Shangchen Yang, Meiqin Chen, Kai Zhuang, Hui Lin, Hao Sun, Huifang Li, Maoqiang Xue, Jun Xu, Jingqi Yan, Zhenyi Chen, Tifei Yuan and Jie Zhang, 16 March 2023, PLoS Biology.
DOI: 10.1371/journal.pbio.3002033