Albert Einstein College of Medicine in New York City scientists published a paper in Nature on July 26th that show neural stem cells slow and reverse the aging process in mice. The same team previously showed the hypothalamus region of the brain was involved in aging. Nonetheless, this new study revealed the particular source as being stem cells found in the hypothalamus.
The hypothalamus region of the brain is known to regulate key metabolic processes such as growth and development. In 2013, Dongsheng Cai, a neuroendocrinologist, and his team at the Albert Einstein College of Medicine showed the hypothalamus is also involved in regulating the aging process in mice. That was an important revelation, but exactly how the hypothalamus did this was unclear until now.
Neural Stem Cells, the Exact Factors Involved in the Aging Process
In this study, Dr. Cai’s team pinpointed specific stem cells in the hypothalamus because they found that those stem cells naturally decline over the mouse’s lifespan as they age.
“By old age—about two years of age in mice—most of those cells were gone,” says Dr. Cai.
They next developed mouse models that were missing these same specific stem cells and found their aging speed was accelerated. This was measured by analyzing tissue and changes in the mice’s muscle endurance, coordination, social behavior, and cognitive ability.
The next question they wanted to answer was whether adding the stem cells back could slow or reverse aging. So the researchers injected these hypothalamic stem cells back into the brains of the mice missing these stem cells. In doing so, they found that the stem cells did indeed slow and reverse aging.
Researchers consider that this effect was due to molecules called microRNAs that are released by the neural stem cells into the cerebrospinal fluid. The team extracted exosomes containing these microRNAs from the hypothalamic stem cells. It then injected them into the cerebrospinal fluid of normal middle-aged mice and the mouse models missing the hypothalamic stem cells. Aging slowed significantly in both groups.
These neural stem cells could lead be a major key to treating and slowing age-related diseases. Dr. Cai predicted that it might be important to administer such therapies in middle age before the effects of the disease are irreversible.
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