A team of scientists have found clearer evidence of how damaging proteins associated with Alzheimer’s disease attack human brain cells and destroy surrounding tissue.
In one of the first studies of its kind, looking at human brain cells grown in mouse brains, researchers have identified a key mechanism that could be a potential therapeutic target for a disease that affects millions of people for which there is no known cure.
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In an article for the journal Cell Stem Cell, the scientists describe experiments on human brain immune cells that were injected into the brains of specially bred immunodeficient mice, creating what they called the human-mouse illusion.
They detailed what happened to the brain’s specialized immune cells known as microglia after these cells were exposed to tau proteins, the damaging chemicals thought to be linked to Alzheimer’s and other severe human brain diseases.
“In this study, we used a newly developed mock mouse brain model that was injected with human cells and allowed to grow, develop and mature with their respective functions in the brain of a “living mouse.” This provided an unprecedented opportunity to investigate the role of human microglia in the brain, as well as the cognitive impairment seen in Alzheimer’s disease and Down’s syndrome, a genetic disease with a high risk of developing Alzheimer’s disease.”
By studying the process in a human-mouse brain chimera, the scientists were able to observe and analyze, with samples taken at different stages, a cellular attack in the brain that had been largely elusive until now.
At autopsy, scientists were able to examine the brains of people who died of Alzheimer’s disease and saw remnants of tau proteins, cellular changes, and some other possible causal factors.
The illusion of a human and mouse brain allowed the Rutgers team to extract and see human cells in the actual process of destruction.
Notably, the mice in the study were specifically bred to be immunocompromised so that they could receive transplanted human cells without rejection due to natural immune defenses. Immunodeficient mice were injected with human microglia and then tau proteins associated with the development of brain diseases.
“Because microglia are one of the first cells to respond when something goes wrong in the brain, we think the changes we’ve seen are important,” said Mengmen Chen, postdoctoral fellow in the Department of Cell Biology and neuroscience at Rutgers University and lead author of the study. study. .
Genetic analyzes have also shown that genes involved in interferon signaling are turned on during an attack, indicating an important area that future therapies should target.
Source: Medical Express