Damaged Protein May Indicate Alzheimer's in Healthy Adults
Elevated levels of a damaged protein called P-tau231 in the cerebrospinal fluid of currently healthy adults may be an early biomarker of future development of Alzheimer's disease. This discovery could be an important diagnostic tool in identifying Alzheimer's disease before symptoms become apparent.
In a normally functioning brain, tau proteins are the building blocks of a structure (microtubule) that helps transport nutrients and other essential substances across nerve cells. Abnormalities in tau proteins cause the microtubules to collapse and the proteins to stick together. The brains of people who have Alzheimer’s disease are characterized by the accumulation of such damaged tau proteins, which form neurofibrillary tangles.
The Alzheimer's Association estimates that 5.3 million Americans have this form of dementia, and that Alzheimer’s and other dementias triple the healthcare costs for Americans age 65 and older. Although there are several drugs approved by the Food and Drug Administration for treatment of Alzheimer’s, none of them can effectively slow or stop the progression of brain cell deterioration.
Researchers at New York University School of Medicine found that elevated levels of a specific tau protein, phosphorylated tau231 (P-tau231) in cerebrospinal fluid of healthy adults may be an early indicator of Alzheimer’s disease. This discovery is the first time scientists have shown that elevated levels of P-tau231 in normal adults can predict future memory loss and brain atrophy.
To arrive at their conclusion, the investigators evaluated 57 cognitively normal older adults and examined the relationships between their baseline cerebrospinal fluid biomarkers, longitudinal memory performance, and longitudinal measures of the medial temporal lobe gray matter using magnetic resonance imaging (MRI). Previous research shows that the medial temporal lobe is the most susceptible area of the brain in the early stages of Alzheimer’s disease.
The subjects were evaluated again two years later, and the scientists found that 20 of the 57 adults showed a decline in memory performance. Among this group of 20 individuals, the researchers discovered that they had higher baseline levels of P-tau231 and more atrophy in the medial temporal lobe. The study’s authors concluded that elevated levels of P-tau231 can predict a decline in memory and atrophy of the medial temporal lobe.
Mony de Leon, EdD, professor in the Department of Psychiatry and director of the Center for Brain Health at the Center of Excellence on Brain Aging at NYU School of Medicine, noted that “Identifying people at risk for Alzheimer’s disease is the necessary first step in developing preventive therapies.” Discovery that the damaged protein P-tau231 may predict development of Alzheimer’s disease in healthy adults can be valuable in future studies of the cause and treatment of the disease.
NYU School of Medicine