Ye Ziwei[The Epoch Times, June 13, 2022](Compiled and reported by Epoch Times reporter Li Shaowei) Previous research suggested thatAlzheimer’s diseaseThe main feature of (Alzheimer’s) – the accumulation of protein plaques outside the cell caused byNeuronscells are damaged.A new study finds that it turns out that cells are damaged first after the disease, and causeamyloidproduced from the inside of the cell.
Alzheimer’s diseaseIt’s a type of dementia. For the past few decades, scientists have assumed that beta appears on the outside of brain cellsamyloidAccumulated plaque is the first sign of Alzheimer’s disease. These accumulated plaques then damage the functioning of the brain’s nerves. A new study by the NYU Grossman School of Medicine and the Nathan Kline Institute challenges this notion.
Analyzing brain cells from mice with Alzheimer’s disease, the new study found that amyloid deposits are actually produced inside the cells and accumulate before spreading to the outside of the cells.
The researchers found that lysosomes in mouse brain cells lost their normal function, resulting in the inability of various substances in brain cells to metabolize normally, resulting in protein accumulation. Lysosomes are intracellular vesicle structures filled with acidic enzymes responsible for breaking down, removing and recycling metabolites for the normal daily functioning of brain cells. Lysosomes are also responsible for breaking down and cleaning up discarded cellular parts after normal cell death.
The study found that in mice with the disease, acid activity in the lysosomes of brain cells decreased. The researchers observed that lysosomes in some brain cells swelled and filled with autophagic vacuole. Autophagic vacuoles are filled with garbage that cannot be broken down normally, and they contain early forms of beta amyloid.
in the most damagedNeuronsSeen inside the cell, these autophagic vesicles cluster around the nucleus, forming a “flower”-like pattern that bulges out from the outer cell membrane.
“Our study is the first to attribute the neuronal damage seen in Alzheimer’s disease to lysosomes inside cells, beta amyloids,” said Ju-Hyun Lee, one of the principal investigators. This is where the protein-like protein first appeared.”
“Previous theories mainly attributed the symptoms of Alzheimer’s disease to damage to brain cells caused by the accumulation of beta amyloid outside the cells, but did not take into account what happened before and within neurons,” Lee said. Case.”
Co-investigator Ralph Nixon said: “The new evidence seen in this study fundamentally changes our understanding of how Alzheimer’s disease develops. This may also explain why so many trials have been None of the treatments designed to clear amyloid plaques can stop the disease from progressing because cells are damaged before amyloid plaques build up outside the cells.”
“Our study suggests that future therapies should focus on restoring lysosomal function and rebalancing acidity levels within the cells of brain neurons,” Nixon said.
According to the National Institute on Aging, there are more than 6 million people with dementia in the United States, most of them over the age of 65. The patient’s cognition, memory and thinking ability continue to decline, and the severely ill can’t take care of themselves.
The study was published June 2 in the journal Nature Neuroscience. ◇
Responsible editor: Ye Ziwei