CHICAGO, June 14 (Xinhua) -- Researchers at the University of Chicago (UChicago) have redeemed amyloid precursor protein (APP), a major cause of Alzheimer's disease, as an unlikely hero by uncovering its extended role in brain signaling that can prevent the development of Alzheimer's disease in mice.
In the study posted on the website of UChicago on Thursday, the researchers fashioned a sticky lipid anchor protein from natural APP, and injected this modified APP segment, called the mAICD, into mice.
These mice were genetically-engineered to be afflicted with aggressive Alzheimer's disease at a young age. Normally, they would have suffered from the advanced symptoms of the disease as young as six months old, equivalent to a young adult in humans.
After the injection, the researchers tested the mice's ability to form spatiotemporal memories. Equipped with a generous helping of mAICD, these mice successfully recalled or ignored objects and places previously explored.
On the other hand, the control mice with Alzheimer's who expressed a less interactive version of mAICD, did not recognize supposedly familiar objects and locations at all. They were already gripped by the jaws of the disease.
"When we looked at the mice with the mAICD, they became almost normal," said Angele Parent, an associate professor of neurobiology at UChicago. It was as if these mice had never showed signs of Alzheimer's.
This lipid anchor protein was able to keep Alzheimer's disease at bay in these mice, as long as its expression starts during the brain development stage.
For years, researchers have mainly paid attention to APP for the A-Beta segment encoded in the amino acid sequence, like a dormant monster waiting to be unleashed and erase memories. Now the researchers also know that by participating in complex nerve machinery, APP can stimulate the growth of new neurons and strengthen synaptic activity by triggering a series of events associated with memory consolidation.
The researchers are currently investigating the effects of the same mAICD intervention in the brains of adult mice already afflicted with Alzheimer's.
The study has been published in the journal Cell Reports.
