Beginning of The End For Alzheimer's?

Memory loss is one of the hallmarks of Alzheimer's disease.

But it may be possible to reverse the symptom, restoring 
people's memories, according to researchers.

Research published in the journal Brain suggests that a 
new approach using epigenetics – the study of chemical 
reactions and factors that influence genetics without
changing the DNA sequence, effectively switching genes on 
and off, had shown it was possible to reverse memory decline.

Scientists used mouse models carrying the gene mutations for 
familial Alzheimer's, where more than one member of a family 
had the disease, as well as post-mortem brain tissue from 
Alzheimer's patients.

She said a key reason for cognitive decline in Alzheimer's 
patients is the loss of glutamate receptors, which are critical 
to learning and short-term memory – itself the result of an 
epigenetic process known as repressive histone modification.

Scientists used epigenetics to try to reverse the effects of memory loss in Alzeimer's patients (Picture: Getty)

She said: "We found that in Alzheimer's disease, many 
subunits of glutamate receptors in the frontal cortex 
are downregulated, disrupting the excitatory signals, 
which impairs working memory."

By understanding that process, scientists could identify 
potential drugs that would reverse the process.

"Our study not only reveals the correlation between 
epigenetic changes and Alzheimer's, we also found we 
can correct the cognitive dysfunction by targeting the 
epigenetic enzymes to restore glutamate receptors," said 
Prof Yan.

"In this paper, we have not only identified the epigenetic 
factors that contribute to the memory loss, we also found 
ways to temporarily reverse them in an animal model of 
Alzheimer's Disease."

Researchers injected the Alzheimer's animals three times 
with compounds designed to inhibit the enzyme that controls 
repressive histone modification.

Prof Yan said: "When we gave the Alzheimer's animals this 
enzyme inhibitor, we saw the rescue of cognitive 
function confirmed through evaluations of recognition 
memory, spatial memory and working memory.

"We were quite surprised to see such dramatic cognitive 
improvement. At the same time, we saw the recovery of 
glutamate receptor expression and function in the frontal 
cortex."

Future studies will be needed for long-lasting results, 
Prof Yan said, but she said an epigenetic approach 
works well for brain disorders such as Alzheimer's 
because they allow the control of many genes rather 
than just one.

She added: "An epigenetic approach can correct a 
network of genes, which will collectively restore cells 
to their normal state and restore the complex brain function."