Scientists have long known that the brain has its own immune system. This system helps protect the brain from infections and damage. It works by using special immune cells that detect danger and respond quickly.
However, in Alzheimer’s disease, this system does not behave in a healthy way. Instead of protecting the brain, it becomes overactive and causes long-lasting inflammation.
This ongoing inflammation can damage the connections between brain cells. These connections, called synapses, are very important for memory, learning, and thinking. When synapses are lost, people begin to experience the symptoms of Alzheimer’s disease, such as memory loss and confusion.
A new study from Scripps Research, published in Cell Chemical Biology on April 23, 2026, has discovered an important clue about why this harmful inflammation happens. The researchers identified a “molecular switch” that controls this process. This switch involves a protein called STING.
STING is normally part of the body’s early warning system. It helps detect threats, such as viruses, and activates the immune response. In a healthy situation, this is very helpful. But in Alzheimer’s disease, the researchers found that STING becomes overactive.
The reason for this overactivity is a chemical change called S-nitrosylation. This is a process where a small molecule related to nitric oxide attaches to a protein and changes how it works. In this case, the change happens at a specific part of the STING protein, known as cysteine 148.
When STING is modified in this way, it forms clusters and becomes highly active. This leads to increased inflammation in the brain. The researchers found high levels of this modified form, called SNO-STING, in brain tissue from people with Alzheimer’s. They also observed it in human brain cells grown in the lab and in mice with the disease.
The study also showed that proteins linked to Alzheimer’s, such as amyloid-beta and alpha-synuclein, can trigger this chemical change. This suggests a harmful cycle. First, these proteins build up in the brain. Then they trigger inflammation, which produces nitric oxide. This leads to more S-nitrosylation of STING, causing even more inflammation.
To test their idea, the researchers created a modified version of the STING protein that could not undergo this chemical change. When this version was used in mice with Alzheimer’s, the results were very encouraging. The mice showed less brain inflammation, and importantly, their synapses were protected.
Protecting synapses is very important because it is closely linked to maintaining memory and thinking abilities. This means that targeting this molecular switch could help slow down or prevent cognitive decline.
Another important finding is that this approach does not completely shut down the immune system. The normal protective function of STING remains active. Only the harmful overactivation is reduced. This makes it a promising target for future treatments.
However, this study was done in laboratory models and mice, not in humans. While the results are exciting, more research is needed to confirm whether the same effects will be seen in people. Clinical trials will be necessary before any new treatments become available.
Overall, this study provides a new understanding of how inflammation develops in Alzheimer’s disease. It highlights the importance of looking at specific molecular changes rather than broad immune suppression.
In conclusion, the findings suggest that targeting the S-nitrosylation of STING could be a new way to reduce harmful brain inflammation and protect brain function. While still in early stages, this research offers hope for future therapies that could slow or prevent Alzheimer’s disease.
If you care about Alzheimer’s, please read studies about the likely cause of Alzheimer’s disease , and new non-drug treatment that could help prevent Alzheimer’s.
For more health information, please see recent studies about diet that may help prevent Alzheimer’s, and results showing some dementia cases could be prevented by changing these 12 things.
Source: Scripps Research.
