Faulty Cell Cleanup in the Brain Could Contribute to Alzheimer's, Study Shows

An international study published in Nature Neuroscience suggests deficient clearing of dysfunctional mitochondria in the brain could play a central role in the development of Alzheimer's disease, reports ScienceAlert . "When the cleaning system does not work properly, there will be an accumulation of defective mitochondria in the brain cells," says Vilhelm Bohr from the U.S. Center for Healthy Aging and National Institutes of Health. "And this may be really dangerous." Analysis of post-mortem tissue samples taken from the hippocampus of deceased persons with Alzheimer's revealed more undersized and faulty mitochondria, as well as a large amount of AMP-activated protein kinase, a chemical that triggers the degradation of mitochondria so they can be broken down and removed. The researchers cultured Alzheimer's brain tissue and measured amounts and activity of proteins associated with mitochondria clearance. They then used Caenorhabditis elegans worms engineered to reflect Alzheimer's-like physiology and function, demonstrating the role of various proteins in locking up the mitophagy process so they could to reverse the condition's effects. Concentrations of beta amyloid plaques declined with the defective microchondria's cleansing, while the chemical changes to tau proteins that induce tangling also lessened.