American biologists have found that the FOXO3 gene protects brain stem cells from aging. The results of the study were published in the journal Nature Communications.
Scientists know that super-livers – people over 100 years old – share an unusual version of the gene that is responsible for the production of the FOXO3 protein. Researchers at Weill Cornell Medicine at Cornell University College of Medicine and Duke University have described how this gene affects the brain.
In 2018, Dr. Jihe Pike and his team discovered that brain cells in mice that lack the FOXO3 gene cannot cope with oxidative stress and die off. In a new study, researchers found that FOXO3 supports the brain’s regenerative capacity by halting stem cell division until the environment is favorable for the survival of new neurons.
Problems with the viability of brain cells may be due to inflammation, nutritional deficiencies, or radiation exposure. All of these conditions put additional stress on the brain. But oxidative stress has the biggest negative effect on brain cells. With it, harmful oxygen compounds accumulate in the body. This process was studied by researchers.
“Stem cells produce new brain cells needed for learning and memorization throughout life. If stem cells divide uncontrollably, they are depleted. The FOXO3 gene does its job by preventing stem cells from dividing until the stress passes, ”the scientists said.
They found that FOXO3 is directly modified by oxidative stress, and that modification sends the protein into the stem cell nucleus, where it turns on the stress response genes. The resulting reaction leads to a blockage of a nutrient called s-adenosylmethionine (SAM), which is needed by a protein called lamin to form a protective sheath around DNA in the stem cell nucleus. As a result, the DNA begins to leak out, the cell mistakes it for a viral infection, which triggers an immune response called the type I interferon response. One of the consequences of this response is that stem cells stop producing new neurons.
“Actually, that’s a good thing, because at this time, the environment is not ideal for newborn neurons. If new cells were exposed to such stressful conditions, they would be killed. It’s better for stem cells to stay dormant and wait until the stress is gone so they can start producing neurons later, ”Pike notes.
The results of the study explain why certain versions of the FOXO3 gene are associated with long and healthy lives – they help people maintain a good supply of brain stem cells. But scientists warn that it is too early to talk about the possibility of creating new methods of rejuvenation and treatment of brain diseases.
Earlier, on Feb.11, it was reported that naturally occurring phytonutrient compounds found in apples and other fruits promote the production of new brain cells, which helps improve memory and cognitive function. These are the conclusions reached by Australian and German scientists.