Mice studies have shown that stem cells present in the hypothalamus, a region of the brain that produces hormones and other signalling chemicals, can reverse ageing. As per a study published in Nature, the stem cells release a molecule called microRNA, that regulate gene expression, into the cerebro-spinal fluid. These cells helped improve cognitive function and muscle strength in middle-aged mice. Many previous studies have postulated that the hypothalamus is involved in ageing given it regulates many functions such as inflammation and appetite. Researchers at the Albert Einstein College of Medicine in the US, led by Dongsheng Cai found that the stem cells present in the hypothalamus disappeared as the mice aged. Injected with viruses that destroy the cells, subject mice exhibited signs of ageing such as failing memory, decreased muscle strength, endurance and deteriorating coordination faster than untreated mice. The team then injected stem cells taken from new born mice into the hypothalamus of middle-aged mice, and these showed reinvigorated brain functioning as well as better muscle strength.
Cai and team are now trying to identify the specific microRNA, among the thousands of types produced, that are involved in ageing. They next hope to isolate and study it in non-human primates as a lead to study in humans. The ramifications, if the findings hold for humans as well, could be paradigm-shifting. From the potential they hold for treating progressive neurological disorders like dementia and Alzheimer’s to bringing metabolism back to the peak it reaches in young adults, the stem cells and the hypothalamus could reverse the ravages of time on the human body. Scientists are also interested to see if the microRNAs from the stem cells can pass into the blood stream, meaning they can reach other organs and parts of the body.