Researchers from the University of Southampton have
discovered that blocking the production of new immune cells in the brain can
help prevent the progression of Alzheimer’s disease. Experts described the
findings as “exciting” and said it could lead to new treatments for the
disease.
Researchers said their discovery added weight to evidence
that inflammation in the brain is what propels the disease. [Read more Drug
slows Alzheimer’s by boosting brain’s ‘garbage disposal’ system]
Until now most drugs used to treat dementia have targeted
amyloid plaques in the brain which are the hallmarks of Alzheimer's disease.
However, the new study, published in the journal Brain,
suggests that progression of the disease could be halted by targeting
inflammation in the brain, caused by a build-up of immune cells called
microglia.
Alzheimer's is a progressive neurodegenerative disease that slowly
destroys memory and cognitive skills, and eventually the ability to carry
out the simplest tasks. It is the most common cause of dementia, accounting for
about 60-70% of all dementia cases. Together with other forms of dementia,
Alzheimer’s affects 47.5 million people worldwide. The disease gives rise to 7.7
million new cases each year.
Alzheimer’s has been recently ranked as the 6th leading cause of death in
the United States. An estimated 5.7 million Americans of all ages have
Alzheimer’s, and by 2050 this number is projected to rise to closely 14
million.
Around 800,000 people in the UK are affected by the disease.
Age is one of the risk factors of Alzheimer’s. People over
the age of 70 are at a higher risk of developing Alzheimer’s. [স্বল্প
শর্করাযুক্ত খাদ্য তালিকায় আপনি কি খেতে পারেন?]
For their study, the researchers compared post-mortem brain
tissue samples from healthy people with the brains of people of the same age
with Alzheimer's disease. They found increased numbers of microglia in the tissue
samples of people with Alzheimer's disease compared with the tissue samples of
healthy people. Microglia is a type of cell that, among other things, helps
regulate immune responses like inflammation. Previous studies have also suggested
that these cells could play an important role.
Next, the scientists wanted to study microglia in mice. They
found that mice that were given an oral dose of inhibitor to block a receptor -
called CSF1R - responsible for the rise in microglia in their brains, had fewer
memory and behavioral problems, compared with untreated mice.
The drug also prevented the loss of communication points
between nerve cells in the brain which is commonly seen in people with
Alzheimer's. [Read more Research
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The scientists also discovered that the inhibitor did not
reduce microglia levels below the number needed for healthy immune function,
suggesting blocking CSF1R only eliminates excessive numbers of cells.
However, the treatment did not stop another well-known
feature of Alzheimer's disease - build-up of toxic amyloid protein clumps in
the animals’ brain.
"These findings are as close to evidence as we can get
to show that this particular pathway is active in the development of
Alzheimer's disease," said Dr. Diego Gomez-Nicola, lead author and
neuroscientist and researcher in biological sciences at Southampton.
Mark Dallas, a neuroscientist at Reading University, said
the discovery could explain why drugs designed to treat Alzheimer’s have so far
been unsuccessful. [Read more Is ghee healthier
than butter?]
“Excitingly, it does however highlight new avenues for
researchers to exploit and strengthens the case for targeting other cell types
within the brain in the fight against Alzheimer’s,” he added.
For the next step, scientists are planning to build on these
findings and work to find a safe drug to test in humans and see if blocking the
action of CSF1R has the same effect.
