In a recent study, scientists have found a novel cause of Alzheimer's disease. Prevailing theories suggest that plaques in the brain cause neurodegeneration andcould cause dementia. Now the new research results show that the cells' slowed ability to clean themselves could be a risk factor.
Autophagy of cells found as a possible cause of Alzheimer's
Along with signs of dementia, doctors make a definitive Alzheimer's diagnosis when they find a combination of two things in the brain: amyloid plaques and neurofibrillary tangles. The plaques are a collection of amyloid, while the tangles are mostly made of a protein called tau. Around 20% of people have the plaques but no signs of dementia or Alzheimer's disease. This makes it appear that the plaques themselves are not the cause, according to the study authors. Therefore, they investigated whether the tau protein could reveal more about the mechanism behind the development of dementia. For this project, researchers scanned all proteins in donated brain samples. Those with brain reconstruction but without dementia had normal tau, while an opposite form of tau was found in those who developed plaques or tangles as well as dementia.
Most proteins in the body have a half-life of less than 48 hours. However, if the protein hangs out for too long, certain amino acids can convert to the reverse isomer. In general, the process of clearing used or defective proteins from cells, known as autophagy, slows down in people over 65. Fortunately, scientists are already testing drugs to improve the process of autophagy. Some candidates include existing medications approved for cardiovascular disease. This could help speed up the approval process. Autophagy can also be induced by fasting. When cells run out of proteins from an individual's diet, they fill the gap by recycling proteins already present in the cells. Exercise also increases the process of so-called cell cleansing. After the authorsthis studyHaving found the slowing of autophagy as an underlying cause of Alzheimer's, potential drug therapies against neurodegenerative diseases could help.
