Researchers have identified a new mechanism that may contribute to the accumulation of tau protein in the brain, a feature commonly seen in Alzheimer's disease. The study, published March 5 in Cell Press Blue, focused on tanycytes—specialized non-neuronal cells located mainly in the third ventricle of the brain.
Tanycytes are known for their role in transferring metabolic signals between the blood and cerebrospinal fluid (CSF), which helps maintain communication within the brain and body. In this research, scientists aimed to understand how these cells might help clear toxic molecules like tau from the brain.
The team discovered that tanycytes move harmful substances out of the CSF and into the bloodstream for removal. When this process is disrupted, tau can build up within the brain. "Surprisingly, we were able to show in rodent and cellular models not only that tanycytes were indeed involved in clearing tau but also that tanycytes in the brains of human Alzheimer's patients were fragmented and had changes in gene expression related to this shuttle function," Prevot says.
The researchers suggest that targeting tanycyte function could offer new ways to maintain brain health and prevent neurodegeneration. However, they caution there are significant challenges ahead. These include a lack of effective animal models for Alzheimer’s disease and a need for larger patient groups with more long-term data to better understand how tanycyte dysfunction leads to tau buildup.
"Our findings provide the first evidence for structural and functional alterations in these little-known but key brain cells in human disease," says Prevot.
This research received support from organizations including the European Research Council, National Institutes of Health, Fondation pour la Recherche Médicale, and Fondation NRJ for Neuroscience-Institut de France.
