Alzheimer’s: 200+ Hidden Proteins Linked to Disease
Beyond Amyloids: Unlocking New Avenues in Alzheimer’s Research
For decades, teh narrative of Alzheimer’s disease research has been largely defined by the well-known culprits: A-beta and tau amyloids.These sticky protein aggregates, capable of damaging neurons and impairing brain function, have been the primary focus of scientific inquiry.Though, a groundbreaking new study from Johns Hopkins University suggests that these prominent plaques may not be the sole drivers of age-related cognitive decline.
Researchers have identified over 200 types of misfolded proteins in rats that could be intricately linked to the cognitive impairments associated with aging. This discovery holds immense promise for identifying novel therapeutic targets and developing treatments for the millions of individuals over 65 grappling with Alzheimer’s, dementia, and other memory-robbing conditions that erode independence.
“Amyloids are the buildup of misshapen proteins. They’re big and ugly and easy to see under the microscope, so it makes sense that they catch our attention,” explains Stephen Fried, an assistant professor of chemistry and protein scientist at Johns hopkins. “But we’re seeing hundreds of proteins misfolding in ways that don’t clump together in an amyloid and yet still seem to impact how the brain functions. Our research is showing that amyloids are just the tip of the iceberg.”
Published on July 11 in Science Advances, the study aimed to pinpoint the molecular distinctions between aging brains that remain cognitively sharp and those experiencing decline. Fried and his team meticulously examined 17 two-year-old rats from the same colony. Seven of these rats performed poorly on memory and problem-solving tests, indicating cognitive impairment, while ten performed comparably to much younger, six-month-old rats.
The researchers then quantified over 2,500 protein types within the hippocampus, a brain region critical for spatial learning and memory. This advanced analysis allowed scientists, for the first time, to assess the folding status of individual proteins across a broad spectrum. This enabled them to differentiate between proteins that misfold generally with aging and those that specifically misfold in cognitively impaired rats.
The findings revealed that more than 200 proteins were misfolded in the cognitively impaired rats, while maintaining their correct shapes in their cognitively healthy counterparts. The researchers posit that a notable portion of these misfolded proteins are likely contributing to cognitive decline.
misfolded proteins are inherently dysfunctional, unable to perform essential cellular tasks.Cells possess a natural surveillance system designed to identify and eliminate these aberrant proteins. Previously, the scientific consensus held that misfolded proteins, particularly A-beta and tau, were only detrimental when they aggregated into amyloids.
“We think there are a lot of proteins that can be misfolded, not form amyloids, and still be problematic,” Fried states. “And that suggests these misfolded proteins have ways of escaping this surveillance system in the cell.”
The precise mechanisms by which these misfolded proteins evade cellular security remain an intriguing mystery. the Johns Hopkins team plans to further investigate these misfolded proteins using high-resolution microscopy to gain a more granular understanding of their molecular deformities.
“A lot of us have experienced a loved one or a relative who has become less capable of doing those everyday tasks that require cognitive abilities,” Fried reflects. “understanding what’s physically going on in the brain could led to better treatments and preventive measures.” This pioneering research opens exciting new avenues, shifting the focus beyond the established amyloid hypothesis and offering a more extensive view of the complex molecular landscape underlying cognitive aging.