Blocking brain inflammation stops Alzheimer’s

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 6^th 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 shows narcolepsy medication modafinil will actually make you smart]

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.