Alzheimer’s disease, an irreversible form of dementia, is considered the world’s most common neurodegenerative disease.
The prime risk factor for Alzheimer’s is age, although it remains unclear why. It is known that the insulating layer around nerve cells in the brain, named myelin, degenerates with age.
Researchers at the Max Planck Institute (MPI) for Multidisciplinary Sciences in Göttingen have now shown that such defective myelin actively promotes disease-related changes in Alzheimer’s.
Slowing down age-related myelin damage could open up new ways to prevent the disease or delay its progression in the future.
What was I about to do? Where did I put the keys? When was that appointment again? It starts with slight memory lapses, followed by increasing problems to orient, to follow conversations, to articulate, or to perform simple tasks.
In the final phase, patients are most often care-dependent. Alzheimer’s disease progresses gradually and mainly affects the elderly. The risk of developing Alzheimer’s doubles every five years after the age of 65.
Signs of aging in the brain
“The underlying mechanisms that explain the correlation between age and Alzheimer’s disease have not yet been elucidated,” says Klaus-Armin Nave, director at the MPI for Multidisciplinary Sciences.
With his team of the Department of Neurogenetics, he investigates the function of myelin, the lipid-rich insulating layer of the brain’s nerve cell fibers. Myelin ensures the rapid communication between nerve cells and supports their metabolism.
“Intact myelin is critical for normal brain function. We have shown that age-related changes in myelin promote pathological changes in Alzheimer’s disease,” Nave says.
In a new study now published in the journal Nature, the scientists explored the possible role of age-related myelin degradation in the development of Alzheimer’s. Their work focused on a typical feature of the disease.
“Alzheimer’s is characterized by the deposition of certain proteins in the brain, the so-called amyloid beta peptides, or Aꞵ peptides for short,” states Constanze Depp, one of the study’s two first authors.
“The Aꞵ peptides clump together to form amyloid plaques. In Alzheimer’s patients, these plaques form many years and even decades before the first symptoms appear.” In the course of the disease, nerve cells finally die irreversibly and the transmission of information in the brain is disturbed.
Using imaging and biochemical methods, the scientists examined and compared different mouse models of Alzheimer’s in which amyloid plaques occur in a similar way to those in Alzheimer’s patients.
For the first time, however, they studied Alzheimer’s mice that additionally had myelin defects, which also occur in the human brain at an advanced age.
Ting Sun, second first author of the study, describes the results: “We saw that myelin degradation accelerates the deposition of amyloid plaques in the mice’ brains. The defective myelin stresses the nerve fibers, causing them to swell and produce more Aꞵ peptides.”
Overwhelmed immune cells
At the same time, the myelin defects attract the attention of the brain’s immune cells called microglia.
“These cells are very vigilant and monitor the brain for any sign of impairment. They can pick up and destroy substances, such as dead cells or cellular components,” Depp adds.
Normally, microglia detect and eliminate amyloid plaques, keeping the buildup at bay. However, when microglia are confronted with both defective myelin and amyloid plaques, they primarily remove the myelin remnants while the plaques continue to accumulate.
The researchers suspect that the microglia are ‘distracted’ or overwhelmed by the myelin damage, and thus cannot respond properly to plaques.
The results of the study show, for the first time, that defective myelin in the aging brain increases the risk of Aꞵ peptide deposition.
“We hope this will lead to new therapies. If we succeeded in slowing down age-related myelin damage, this could also prevent or slow down Alzheimer’s disease,” Nave says.

News
Most Plastic in the Ocean Is Invisible—And Deadly
Nanoplastics—particles smaller than a human hair—can pass through cell walls and enter the food web. New research suggest 27 million metric tons of nanoplastics are spread across just the top layer of the North [...]
Repurposed drugs could calm the immune system’s response to nanomedicine
An international study led by researchers at the University of Colorado Anschutz Medical Campus has identified a promising strategy to enhance the safety of nanomedicines, advanced therapies often used in cancer and vaccine treatments, [...]
Nano-Enhanced Hydrogel Strategies for Cartilage Repair
A recent article in Engineering describes the development of a protein-based nanocomposite hydrogel designed to deliver two therapeutic agents—dexamethasone (Dex) and kartogenin (KGN)—to support cartilage repair. The hydrogel is engineered to modulate immune responses and promote [...]
New Cancer Drug Blocks Tumors Without Debilitating Side Effects
A new drug targets RAS-PI3Kα pathways without harmful side effects. It was developed using high-performance computing and AI. A new cancer drug candidate, developed through a collaboration between Lawrence Livermore National Laboratory (LLNL), BridgeBio Oncology [...]
Scientists Are Pretty Close to Replicating the First Thing That Ever Lived
For 400 million years, a leading hypothesis claims, Earth was an “RNA World,” meaning that life must’ve first replicated from RNA before the arrival of proteins and DNA. Unfortunately, scientists have failed to find [...]
Why ‘Peniaphobia’ Is Exploding Among Young People (And Why We Should Be Concerned)
An insidious illness is taking hold among a growing proportion of young people. Little known to the general public, peniaphobia—the fear of becoming poor—is gaining ground among teens and young adults. Discover the causes [...]
Team finds flawed data in recent study relevant to coronavirus antiviral development
The COVID pandemic illustrated how urgently we need antiviral medications capable of treating coronavirus infections. To aid this effort, researchers quickly homed in on part of SARS-CoV-2's molecular structure known as the NiRAN domain—an [...]
Drug-Coated Neural Implants Reduce Immune Rejection
Summary: A new study shows that coating neural prosthetic implants with the anti-inflammatory drug dexamethasone helps reduce the body’s immune response and scar tissue formation. This strategy enhances the long-term performance and stability of electrodes [...]
Scientists discover cancer-fighting bacteria that ‘soak up’ forever chemicals in the body
A family of healthy bacteria may help 'soak up' toxic forever chemicals in the body, warding off their cancerous effects. Forever chemicals, also known as PFAS (per- and polyfluoroalkyl substances), are toxic chemicals that [...]
Johns Hopkins Researchers Uncover a New Way To Kill Cancer Cells
A new study reveals that blocking ribosomal RNA production rewires cancer cell behavior and could help treat genetically unstable tumors. Researchers at the Johns Hopkins Kimmel Cancer Center and the Department of Radiation Oncology and Molecular [...]
AI matches doctors in mapping lung tumors for radiation therapy
In radiation therapy, precision can save lives. Oncologists must carefully map the size and location of a tumor before delivering high-dose radiation to destroy cancer cells while sparing healthy tissue. But this process, called [...]
Scientists Finally “See” Key Protein That Controls Inflammation
Researchers used advanced microscopy to uncover important protein structures. For the first time, two important protein structures in the human body are being visualized, thanks in part to cutting-edge technology at the University of [...]
AI tool detects 9 types of dementia from a single brain scan
Mayo Clinic researchers have developed a new artificial intelligence (AI) tool that helps clinicians identify brain activity patterns linked to nine types of dementia, including Alzheimer's disease, using a single, widely available scan—a transformative [...]
Is plastic packaging putting more than just food on your plate?
New research reveals that common food packaging and utensils can shed microscopic plastics into our food, prompting urgent calls for stricter testing and updated regulations to protect public health. Beyond microplastics: The analysis intentionally [...]
Aging Spreads Through the Bloodstream
Summary: New research reveals that aging isn’t just a local cellular process—it can spread throughout the body via the bloodstream. A redox-sensitive protein called ReHMGB1, secreted by senescent cells, was found to trigger aging features [...]
AI and nanomedicine find rare biomarkers for prostrate cancer and atherosclerosis
Imagine a stadium packed with 75,000 fans, all wearing green and white jerseys—except one person in a solid green shirt. Finding that person would be tough. That's how hard it is for scientists to [...]