• Contributed by Mary Metkus

The Key to Immortality?

It’s no secret that modern society is obsessed with stopping the aging process. People get their grey hairs dyed, their tummies tucked, and even botox injected in their faces. While we may not be able to actually slow the aging process of our bodies, we spend countless amounts of money trying look younger than we are, and deluding ourselves into thinking that age does not apply to us. People crave eternal youth, and although the title of this post is a bit misleading, I regret to inform you that the coveted elixir of life is still yet to be discovered. However, recent research has found a way to effectively slow aging in mice, our mammalian brethren.

According to a study published by Zhang, et. al. in Nature on August 3, hypothalamic stem cells, a type of stem cell found in the brain, can slow the aging process, both physically and mentally. The hypothalamus is a region in the brain that has been shown to be involved in aging, inflammation, and memory, among other functions. The stem cells residing there decline as mice grow older, potentially having a role in the decline of mental and physiological function associated with aging. When researchers used methods to destroy the cells prematurely in mice, the mice seemed to age faster, declining in memory, muscle strength, and coordination. The researchers also tested the opposite effect by taking hypothalamic stem cells from infant mice and injecting them into the brains of middle aged mice. They found that those mice seemed to age slower, with better cognitive and physical function than untreated mice of the same age. The injected mice also lived 10% longer than untreated mice.

Zhang, et. al. also found that these hypothalamic stem cells secrete microRNAs, fragments of RNA which helps to regulate gene expression. These microRNAs are found to be secreted into the cerebrospinal fluid around the brain and spinal cord. The levels of these microRNAs in the cerebrospinal fluid decline with age, similar to the decline of the hypothalamic stem cells with age. When researchers injected these microRNAs into the brains of middle aged mice, cognitive decline and muscle degeneration were slowed.

So, somehow these stem cells in the hypothalamus are preventing aging, and it appear to be in part by secreting microRNAs that regulate gene expression. It would be interesting to delve more into the link of these stem cells to other physiological mechanisms of aging in the nervous system, such as their role in memory, and cell death. Other interesting directions could be to further investigate the role of the microRNAs in the aging process. Maybe they could be regulating the production of cell death proteins, or other genes that cause harm to our cells. While it’s not exactly a magic elixir of life, it is still pretty promising. These findings could be used in developing potential anti-aging therapies in humans, perhaps even in treating neurodegenerative disorders like Alzheimer’s. However, until more is done to understand these stem cells and their mechanistic role in aging, I would keep that next botox appointment just to be safe.