Mayo Clinic researchers have made a groundbreaking discovery linking blood-brain barrier dysfunction to Alzheimer’s disease, which could pave the way for new diagnostic tools and treatments.
In a significant breakthrough, researchers at the Mayo Clinic and their international collaborators have identified unique molecular signatures in the blood-brain barrier linked to Alzheimer’s disease. Published in Nature Communications, the study could lead to revolutionary advances in diagnosing and treating the debilitating condition that affects millions of people worldwide.
“These signatures have high potential to become novel biomarkers that capture brain changes in Alzheimer’s disease,” Nilüfer Ertekin-Taner, the study’s senior author and chair of the Department of Neuroscience at Mayo Clinic and leader of the Genetics of Alzheimer’s Disease and Endophenotypes Laboratory at Mayo Clinic in Florida, said in a news release.
The blood-brain barrier, a critical network of vessels and tissues, shields the brain from harmful substances in the blood. Disruptions in this protective barrier have long been associated with Alzheimer’s, but pinpointing specific molecular changes has been elusive.
The research team delved into brain tissue from 12 individuals diagnosed with Alzheimer’s disease and 12 healthy controls, utilizing the Mayo Clinic Brain Bank and various published datasets. This extensive analysis covered thousands of cells across more than six different brain regions, making it one of the most thorough examinations of blood-brain barrier dysfunction in Alzheimer’s to date.
By focusing on brain vascular cells, particularly the interaction between pericytes and astrocytes which are crucial for maintaining the blood-brain barrier, researchers uncovered altered communication mediated by molecules VEGFA and SMAD3. VEGFA promotes blood vessel growth, while SMAD3 is integral in cellular response mechanisms. The study indicated that higher VEGFA levels corresponded to lower SMAD3 levels, which were validated through cellular and zebrafish models.
Importantly, Alzheimer’s donors with higher blood SMAD3 levels exhibited less vascular damage and better clinical outcomes. This suggests a potential for SMAD3 as a biomarker and therapeutic target.
The potential implications of these findings could provide much-needed hope for developing effective treatments for Alzheimer’s, which currently lacks a cure.
Moving forward, researchers aim to explore how brain SMAD3 levels correspond to those in the blood and investigate additional molecules involved in blood-brain barrier maintenance.
“This useful and productive work helps us better understand the specific mechanisms that play a role in the blood-brain barrier breakdown and other possible vascular changes in people with Alzheimer’s,” says Heather M. Snyder, vice president of medical and scientific relations at Alzheimer’s Association, said in the news release. “Understanding the biology that influences and impacts disease progression is essential to uncovering new avenues for novel therapies and tools to detect the earliest stages of the disease.”