Scientists discover how aging is controlled by the brain

A team of researchers from the Albert Einstein College of Medicine have discovered that stem cells located in the hypothalamus can influence the rapidity of aging within the body. As these neural stem cells decrease in number, the aging process accelerates.

• A group of healthy mice were placed under observation for their neural stem cells.
• The number of these stem cells declined when the animals reached 10 months in age.
• A few of the middle-aged mice had their stem cells selectively disrupted, leading to those cells dying faster than normal and speeding up the aging of the mice.
• By contrast, injecting stem cells into normal mice and those whose stem cells had been destroyed showed marked improvements. Both groups of mice either had their aging slowed down or reversed.
• The researchers found that stem cells impact aging through the production of microRNAs (miRNAs). These molecules, which are released into cerebrospinal fluid through exosomes, have been shown to affect gene expression.
• Exosomes containing miRNAs were extracted from stem cells and injected into two groups of mice. Aging was greatly slowed down in animals from both groups, which in itself was measured through behavioral testing and tissue analyses.

The researchers then concluded that hypothalamic neural stem cells played a huge role in the aging process. Although a decline in their numbers could hasten aging, this loss was not irreversible. Moreover, repleneshing these cells could slow down and even overturn aging across the body.

Journal Reference:

Zhang Y, Kim MS, Jia B, Yan J, Zuniga-Hertz JP, Han, C. HYPOTHALAMIC STEM CELLS CONTROL AGEING SPEED PARTLY THROUGH EXOSOMAL MIRNAS. Nature, 2017; 548: 52-57. DOI: 10.1038/nature23282