A study conducted by the University of Barcelona provides new evidence on the role of the glymphatic system, responsible for clearing waste from the brain, in neurodegenerative diseases. The study shows that patients with conditions such as Alzheimer's disease, frontotemporal lobar degeneration and amyotrophic lateral sclerosis (ALS) exhibit a higher accumulation of wasteosomes , small structures that act as waste containers , in key regions of the waste-clearance system. These results suggest that the brain's waste clearance system may be functioning poorly in these patients, which could lead to the accumulation of these structures and contribute to the progression of the disease.
According to researchers, understanding how the brain removes waste could be key to better understanding neurodegenerative diseases and, in the future, developing new prevention and treatment strategies.
The study, published in the journal Acta Neuropathologica Communications , was led by Professor Jordi Vilaplana, from the UB's Faculty of Pharmacy and Food Science, the Institute of Neurosciences (UBneuro) and the CIBER Area for Neurodegenerative Diseases (CIBERNED), together with Laura Molina-Porcel, a researcher at the Neurological Tissue Bank Biobank of the Hospital Clínic de Barcelona - August Pi i Sunyer Institute of Biomedical Research (Biobank HCB-IDIBAPS). Marta Riba and Raquel Alsina (UB-UBneuro-CIBERNED) are the first authors of a study in which researchers from the Universitat Politècnica de Catalunya and Qilimanjaro Quantum Tech also participated.
Brain waste in key regions
The researchers analysed brain samples from 185 donors, including people with Alzheimer's disease, amyotrophic lateral sclerosis and frontotemporal lobar degeneration, as well as individuals without a neurodegenerative disease. The aim was to determine whether patients exhibit differences in the number of wasteosomes, also known as corpora amylacea, and where these structures appear.
The results of the analysis show that wasteosomes repeatedly accumulate in specific regions of patients' brains, specifically in areas associated with the drainage pathways of the glymphatic system, and that their number is significantly higher in the brains of diseased donors. According to the researchers, this distribution reinforces the hypothesis that wasteosomes may act as indicators of chronic glymphatic system insufficiency , that is, that the system responsible for clearing waste from the brain does not function correctly over a prolonged period of time. This distribution is also independent of the distribution of the pathological proteins characteristic of each disease. "This finding is particularly relevant because it indicates that wasteosomes are not a local consequence of deposits of altered proteins, but rather reflect a common mechanism shared by different neurodegenerative diseases," the researchers explain.
In this context, the glymphatic system emerges as a potentially key element in understanding this shared mechanism. "When this system functions inefficiently, the brain's ability to eliminate altered proteins and other waste products is reduced, which could promote the accumulation of toxic substances and contribute both to the onset and progression of neurodegenerative diseases," the experts note.
