Researchers from Mass General Brigham and Washington University School of Medicine have identified xenon gas inhalation as a potential novel approach to combat Alzheimer's disease. Published in Science Translational Medicine, the study reveals that xenon gas suppresses neuroinflammation, reduces brain atrophy, and enhances protective neuronal states in mouse models of Alzheimer's. A Phase 1 clinical trial in healthy volunteers is slated to commence in early 2025.
The research addresses a critical need for effective Alzheimer's treatments, as current therapies primarily target amyloid plaques and tau tangles, with limited success. The team focused on xenon's ability to modulate microglia, the brain's primary immune cells, which play a crucial role in neurodegeneration.
Xenon's Impact on Microglia and Alzheimer's Pathology
In mouse models, inhaled xenon gas was found to penetrate the blood-brain barrier, directly influencing the fluid surrounding the brain. This resulted in reduced brain atrophy and neuroinflammation, along with improved nest-building behaviors, a marker of cognitive function. The gas also induced a protective microglial response, associated with clearing amyloid and improving cognition.
"It is a very novel discovery showing that simply inhaling an inert gas can have such a profound neuroprotective effect," said Oleg Butovsky, PhD, of the Ann Romney Center for Neurologic Diseases at Brigham and Women's Hospital. "One of the main limitations in the field of Alzheimer's disease research and treatment is that it is extremely difficult to design medications that can pass the blood-brain barrier—but Xenon gas does."
Study Details and Results
The study utilized mouse models expressing proteins characteristic of Alzheimer's, including tau and beta-amyloid. Mice exposed to xenon exhibited lower levels of these proteins. Additionally, mice with the APOE4 genetic variant, which elevates Alzheimer's risk, showed improved cognitive performance and reduced brain deterioration following xenon treatment.
David M. Holtzman, MD, from Washington University School of Medicine in St. Louis, noted, "It is exciting that in both animal models that model different aspects of Alzheimer's disease, amyloid pathology in one model and tau pathology in another model, that Xenon had protective effects in both situations."
Clinical Trial and Future Directions
Based on these promising results, the researchers have received FDA approval to initiate a Phase 1 trial to assess the safety of xenon gas in healthy volunteers. The trial will be conducted at Brigham and Women's Hospital.
The research team also plans to investigate the mechanisms by which xenon gas exerts its effects and explore its potential in treating other neurological conditions, such as multiple sclerosis, amyotrophic lateral sclerosis, and eye diseases involving neuronal loss. They are also developing technologies to enhance the efficiency and recyclability of xenon gas.
Howard Weiner, MD, co-director of the Ann Romney Center for Neurologic Diseases at BWH, stated, "If the clinical trial goes well, the opportunities for the use of Xenon gas are great. It could open the door to new treatments for helping patients with neurologic diseases."
