A protein called DAXX may protect the brain's immune cells from age-related changes and the inflammation that comes with them, according to a new study published in the journal Nature Neuroscience.
The researchers focused on microglia, immune cells that defend the brain, clear away damaged cells and help fight infection. As people age, microglia can change how they behave, becoming overactive and driving chronic inflammation in the brain.
What the mouse experiments showed
Experiments on mice found that DAXX levels in microglia decline with age. The protein normally helps keep certain stretches of DNA switched off, holding them in an inactive state.
When the researchers deliberately disabled DAXX in young mice, those DNA regions became active and the animals' microglia began behaving as they do during aging. The affected cells showed DNA damage and signs of cellular aging, and inflammation in the brain increased.
Evidence from human blood samples
The scientists said they found a similar inverse relationship between DAXX levels and the activity of these DNA regions when they analyzed blood samples from more than 3,000 people.
The study's authors suggested that preserving DAXX activity, and the ability of cells to keep these DNA regions under control, could be one way to protect the brain from age-related inflammation.
Background on microglia and aging
Microglia are the brain's resident immune cells and play a central role in clearing debris and responding to injury or infection. Chronic, low-grade inflammation driven by aging immune cells has been linked by researchers to a range of age-related brain conditions, which is why proteins that regulate microglial activity, such as DAXX, are of interest to scientists studying brain aging.
The report on DAXX follows other recent findings on brain health, including earlier research linking consumption of tomato paste to improved cognitive function, according to the source.
