Scripps Research Scientists Discover Molecular STING Switch Driving Chronic Neuroinflammation in Alzheimer’s Disease Patients

Scientists pinpoint a molecular "SNO" switch on the STING protein that drives Alzheimer's brain damage, opening a new path for targeted neuroprotection.

By: AXL Media

Published: Apr 25, 2026, 4:26 AM EDT

Source: Information for this report was sourced from Scripps Research Institute

The Discovery of a Pathological Immune Trigger

A team at Scripps Research has pinpointed a specific molecular mechanism responsible for the chronic neuroinflammation that characterizes Alzheimer’s disease. The study, published in Cell Chemical Biology, focuses on a protein called STING, which typically serves as an early-warning system for the brain's immune defense. However, in the presence of Alzheimer’s, researchers discovered that STING undergoes a chemical modification called S-nitrosylation, or SNO. This reaction involving sulfur, oxygen, and nitrogen causes the protein to become hyperactive, leading to sustained inflammation that destroys the delicate connections between neurons. Senior author Stuart Lipton noted that blocking this switch protects the very brain cell connections lost to the disease.

Unraveling the Decades-Long Mystery of S-nitrosylation

The S-nitrosylation process was first discovered by Lipton over thirty years ago and involves a nitric oxide related molecule binding to a cysteine amino acid. This chemical alteration, which Lipton describes as a "SNO-STORM," can be accelerated by a combination of aging, neuroinflammation, and environmental toxins such as wildfire smoke or air pollution. While the modification has previously been linked to various conditions including cancer and Parkinson’s, this latest research provides the first clear evidence of its role in driving the inflammatory cycle of Alzheimer’s. By pinpointing cysteine 148 as the specific site of this reaction, the team has turned a broad biological process into a concrete target for drug development.

Evidence of Inflammation Across Human and Animal Models

The research team, utilizing advanced mass spectrometry, confirmed the presence of SNO-STING across multiple platforms, including postmortem brain tissue from human Alzheimer’s patients. The same pathological markers were observed in human stem cell-derived models and brain immune cells exposed to toxic proteins like amyloid-beta and alpha-synuclein. These findings suggest that the protein clumps synonymous with Alzheimer’s effectively trigger the S-nitrosylation reaction themselves. This creates a self-perpetuating cycle where initial protein buildup leads to inflammation, which produces more nitric oxide, further activating STING and worsening the damage to brain tissue.