From brain training apps to botox, many people will try anything to turn back the clock.
But a new study suggests that the key to slowing the aging process could lie with certain cells in our immune system called myeloid cells.
These cells play a critical role in fighting infection and cleaning up debris, but they often go into overdrive as we age and cause chronic inflammation.
The research indicates that turning off these cells can ‘age’ the brain and delay the onset of a variety of conditions, including heart disease, Alzheimer’s disease, cancer and vulnerability.
While the findings are at a very early stage, the researchers hope they can help drug manufacturers develop a compound to slow aging.
Research indicates that turning off myeloid cells can ‘age’ the brain and delay the onset of a variety of conditions, including heart disease, Alzheimer’s disease, cancer and frailty (stock image)
In the study, Stanford Medicine researchers studied myeloid cells in aged mice, as well as myeloid cells in cultures of people over the age of 65 and under 35.
Myeloid cells are found in the brain, circulatory system, and peripheral tissues, where they play an essential role in clearing dead cells, providing nutrients to other cells, and keeping an eye out for invading pathogens.
However, as we age, our myeloid cells begin to malfunction, damaging innocent tissues.
In the study, the researchers blocked the interaction of a hormone called PGE2 and a receptor on myeloid cells in the mice and human cells in culture.
Amazingly, this was enough to restore youthful metabolism and restore age-related mental decline in old mice.
Professor Katrin Andreasson, professor of neurology and neurological sciences and senior author of the study, explained, “If you modify the immune system, you can age the brain.”
PGE2 is a hormone that belongs to a group known as prostaglandins and does many different things in the body, depending on the cells it binds to.
For example, when PGE2 binds to a receptor called EP2 on myeloid cells, it starts inflammatory activity in the cells.
Myeloid cells are found in the brain, circulatory system, and peripheral tissues, where they play an essential role in clearing dead cells, providing nutrients to other cells, and keeping an eye out for invading pathogens. However, as we age, our myeloid cells begin to dysfunction, causing damage to innocent tissues in the process
In the study, the researchers found that the cells of older mice and older people had much higher numbers of EP2 on their surface and also produced more PGE2.
Unfortunately, because the hormone binds to these receptors, it leads to an increase in inflammation, damaging innocent tissues.
Professor Andreasson explained: ‘This powerful path stimulates aging. And it can be switched back. ‘
Using two compounds, the researchers blocked PGE2’s ability to bind to EP2 and were able to reverse this inflammation and age-related cognitive decline.
In fact, older mice were able to perform just as well on memory and spatial navigation tests as young mice.
Of particular interest was one of the two compounds, which proved to be effective even though it does not cross the blood-brain barrier.
According to the team, this suggests that resetting myeloid cells outside of the brain can have a huge effect on what is happening in the brain.
Unfortunately, the compounds are not approved for human use and have potentially toxic side effects, the researchers said.
However, the team hopes they can provide a roadmap for drug manufacturers to develop a secure compound that can be given to humans.