Researchers have identified a brain messenger protein, Arc, that plays a role in spreading toxic Tau proteins between neurons in mice. The study, published in the journal Cell, suggests that targeting this mechanism could prevent Alzheimer's disease from advancing.
Mechanism of Tau protein spread
Alzheimer's disease is characterized by the buildup of toxic Tau protein which destroys neurons. As these proteins spread to different brain regions, symptoms worsen. According to Jason Shepherd, a professor of neurobiology at University of Utah Health and senior author on the study, identifying this new way to potentially stop progression is an exciting development.
Role of Arc in transport
The research team found that Arc normally acts as a messenger by traveling in microscopic bubbles called extracellular vesicles (EVs) to carry information between cells. However, toxic Tau can attach to Arc to travel from sick neurons to healthy ones. Mitali Tyagi, a postdoctoral research associate at Washington University in St. Louis who conducted the research while at the University of Utah Health, described Tau tangles as glue monsters that can break into smaller seeds to corrupt new neurons.
Impact of removing Arc protein
In mouse models lacking the Arc protein, researchers observed that the transfer of Tau was severely reduced and almost gone. However, removing Arc also caused sick cells to die faster because Tau became trapped inside the neurons at toxic levels.
Implications for human Alzheimer's research
While the research was conducted in mice, the team found that human brain tissue also contains EVs with both Arc and Tau, suggesting a similar process may occur in humans. Jason Shepherd noted that while it is too early to claim a treatment is being developed, the findings could open new avenues for therapy.
Potential future therapeutic strategies
A potential future strategy involves blocking toxic Tau-containing vesicles mid-flight before they can infect healthy cells, which might prevent further cognitive decline and damage.
