One protein keeps Alzheimer inflammation switched on
Alzheimer’s brains are in a constant state of inflammation. But why doesn’t that inflammation switch off on its own?
Normally, brain cells respond to a danger signal, deal with it, and then close down the inflammatory pathway. In Alzheimer’s disease, that last step fails. Inflammation stays active and gradually damages the connections between nerve cells. The question was: what keeps the signal permanently on?
STING stuck in the active position
The answer the researchers found centers on a protein called STING. This protein normally plays a role in the cell’s defense system: it detects DNA in the wrong location, such as outside the nucleus, and then triggers an inflammatory signal. That is useful when a virus is present, but harmful when the system fails to shut down.
In Alzheimer’s brain tissue, STING was found to be chemically modified in a way that keeps the protein permanently active. That chemical modification is called acetylation: a small molecule attaches to the protein and changes its structure. This causes the inflammatory signal to keep firing continuously, even when there is no longer a direct threat.
A specific target for new treatments
This matters because it identifies a specific, potentially addressable mechanism. If researchers can find a way to block or reverse the acetylation of STING, it could reduce chronic inflammation without shutting down the entire brain immune system. That distinction is important: the brain’s immune system is also needed for normal functions.
The research gives scientists a concrete target. Clinical applications do not yet exist, but STING inhibitors are already being investigated for other conditions. That existing knowledge could accelerate their application in Alzheimer’s research.