A new study from Weill Cornell Medicine reveals that free radicals produced at specific sites in non-neuronal brain cells called astrocytes may drive dementia progression.
Published in Nature Metabolismon November 4, the research demonstrates that blocking this specific site can reduce brain inflammation and protect neurons, suggesting a novel therapeutic approach for neurodegenerative diseases including frontotemporal dementia and Alzheimer’s disease.
The study was co-led by Dr. Anna Or, associate professor of neuroscience in the Feil Family Brain and Mind Research Institute, and Dr. Adam Or, assistant professor of neuroscience research.
Novel Therapeutic Strategy
Researchers focused on mitochondria – the energy-producing structures within cells that generate molecules called reactive oxygen species (ROS) during metabolism. While ROS play important roles in cellular function at low levels, excessive production can be harmful.
“Decades of research have linked mitochondrial ROS to neurodegenerative disorders,” explained Dr. Adam Or. However, most antioxidant therapies have failed in clinical trials, likely because they cannot selectively block ROS at their source without disrupting cellular metabolism.
Technology Innovation: S3QEL Platform
Dr. Adam Or developed a unique drug discovery platform during his postdoctoral research that identified small molecules called S3QELs (“sequels”) capable of precisely inhibiting ROS production at a single mitochondrial site without affecting other mitochondrial functions.
The team targeted complex III, a site in oxidative metabolism that tends to push ROS out of mitochondria into the rest of the cell, where they are more likely to damage important cellular components.
Key Mechanistic Insights
Experiments showed that exposing astrocytes to disease-related factors – such as neuroinflammatory molecules or dementia-associated proteins like amyloid-beta – promoted ROS production in cellular mitochondria. S3QEL inhibition blocked most of this increase, while blocking other potential sources of cellular ROS proved ineffective.
The research also revealed that ROS oxidize certain immune and metabolic proteins associated with neurological diseases and affect the activity of thousands of genes, particularly those linked to brain inflammation and dementia.
In Vivo Validation
When researchers administered their S3QEL ROS inhibitor to mouse models of frontotemporal dementia, they found it reduced astrocyte activation, dampened neuroinflammation genes, and decreased tau modifications – even when treatment began long after the disease process started.
Long-term S3QEL treatment extended the mice’s lifespan, was well-tolerated, and produced no apparent side effects, which Dr. Anna Or attributes to its unique specificity. “The precision of these mechanisms hadn’t been appreciated before, particularly in brain cells,” she noted.
Clinical Translation and Future Directions
The team plans to collaborate with Dr. Subhash Sinha, a medicinal chemist and professor of neuroscience research, to develop these compounds into novel therapeutics.
Meanwhile, researchers will continue investigating how disease-related factors affect ROS production in the brain and examine whether genes associated with increased or decreased neurodegenerative disease risk affect ROS generation at specific mitochondrial sites. This research opens new possibilities for treating neurodegenerative disorders through targeted mitochondrial intervention.
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