Research reveals why mild brain injury can trigger Alzheimer’s
New research explains how a single mild brain injury can set off changes that increase the risk of Alzheimer’s disease.
The discovery points to a possible way to prevent the disorder by repairing the brain’s drainage system after head trauma.
Scientists found that traumatic brain injuries impair lymphatic vessels that connect the brain and the immune system.
These vessels in the brain’s protective membranes drain waste and help defend the brain.
The research, conducted at the University of Virginia School of Medicine, suggests traumatic brain injuries accelerate the build-up of harmful tau protein linked to Alzheimer’s.
In laboratory mice, a single mild head injury damaged the brain and triggered degeneration.
John Lukens, director of UVA’s Harrison Family Translational Research Center in Alzheimer’s and Neurodegenerative Diseases, said: “Our findings indicate that fixing brain drainage following head trauma can provide a much-needed strategy to limit the development of Alzheimer’s disease later in life.
“Our hope is that these discoveries will inspire the design of novel brain drainage-boosting therapeutics that can be deployed to accelerate recovery of the injured brain and limit the risk of developing Alzheimer’s disease.”
The researchers identified specific effects of mild traumatic brain injuries, including harmful changes in immune cells called macrophages (the brain’s clean-up cells).
In laboratory mice, intervention within 24 hours of injury helped protect brain health and restore lymphatic vessel function.
Scientists used a harmless, hollowed-out virus shell (a delivery vector) to carry VEGFC, a natural growth factor that helps lymphatic vessels grow and repair, into the brain’s protective membranes.
This treatment prevented the build-up of harmful tau protein.
Dr Ashley Bolte, a member of the research team, said: “This research builds on our understanding of some of the devastating long-term outcomes after brain injury and how they pertain to neurodegenerative disease.
“Traumatic brain injury is a condition where we have very few medical interventions currently, so a prospective therapeutic target is very exciting.”
Lukens added: “Traumatic brain injury has also been linked to multiple other neurodegenerative disorders, including ALS, Parkinson’s disease and chronic traumatic encephalopathy (CTE).
“Exploring whether recuperating brain drainage following head trauma is also effective in protecting against these other devastating neurodegenerative diseases will be an important future area of investigation for our lab and others.”
