Scripps Research Scientists Identify Molecular Switch Driving Chronic Brain Inflammation in Alzheimer’s Patients

Scripps Research scientists find that blocking the S-nitrosylation of the STING protein reduces brain inflammation and protects nerve cell connections.

By: AXL Media

Published: Apr 25, 2026, 9:51 AM EDT

Source: Information for this report was sourced from EurekAlert!

A New Molecular Target in the Fight Against Dementia

Scientists at Scripps Research have pinpointed a specific molecular switch that drives the chronic immune overactivation responsible for brain damage in Alzheimer's disease. According to the study published in Cell Chemical Biology, the research focuses on a protein named STING, which usually serves as an early-warning system for the immune system. In the brains of those suffering from the condition, this protein undergoes a chemical modification called S-nitrosylation, or SNO. Dr. Stuart Lipton, the senior author and a clinical neurologist, explained that this reaction involves a molecule related to nitric oxide binding to the protein, effectively turning a protective mechanism into a source of localized destruction.

The Role of Environmental Toxins and Aging in Brain Decay

The chemical reaction that disrupts these proteins is not a random occurrence but is often triggered by external and biological stressors. According to the research team, factors such as advanced age, neuroinflammation, and exposure to environmental pollutants like wildfire smoke or air pollution can initiate the SNO process. This modification creates what Dr. Lipton describes as a "SNO-STORM," a cascade of protein dysfunction that has been linked not only to Alzheimer's but also to Parkinson's disease and various cancers. By identifying the exact location of this reaction on the STING protein at cysteine 148, the researchers have found a way to potentially halt the inflammatory cycle without disabling the entire immune system.

Pinpointing the Mechanics of Immune Overactivation

Collaborating with mass spectrometry expert Professor John Yates III, the researchers discovered that when the specific building block cysteine 148 is modified, the STING protein clusters into large, harmful complexes. These clusters were found in high concentrations within postmortem brain tissue from human patients and in lab-grown immune cells. According to the findings, the typical protein clumps associated with Alzheimer's, such as amyloid-beta, are capable of triggering this S-nitrosylation reaction themselves. This suggests that the disease progresses through a self-sustaining cycle where initial protein buildup drives inflammation, which in turn generates more nitric oxide and further modifies the STING protein.