Brain's 'security system' linked to Alzheimer's, obesity

Imagine a tiny security system guarding your brain, keeping out nasties and letting in goodness. This vital blood-brain barrier is crucial for overall health. But when it goes wrong, it's linked to a whole host of serious conditions like Alzheimer's, chronic pain, and even obesity. Now, a team of scientists are unravelling its mysteries.

Unlocking the brain's secret shield

Researchers at Johns Hopkins University are digging deep into how diseases disrupt the blood-brain barrier. This complex interface controls what gets into our brains and what stays out.

Peter Searson, who is leading the team, explained: "The blood-brain barrier is a security system that enables the brain to function in a tightly controlled biochemical environment."

He added that this "specialised barrier is essential for overall brain health."

From Alzheimer's to obesity – a common link?

Disruption to this barrier is increasingly seen as a key factor in a surprising number of conditions. These include Alzheimer's disease, obesity, chronic pain, traumatic brain injury (TBI), and multiple sclerosis.

In less severe cases, molecules from the blood can leak into the brain. But more serious disruptions can lead to microbleeds and haemorrhage.

Searson's lab uses tissue-engineered models, built with human stem cells, to mimic the brain's tiny blood vessels. They study how stress affects the barrier.

"We are deconvoluting how stress causes blood-brain barrier disruption," Searson said.

Normal ageing also causes low levels of barrier disruption. The team hopes their work could lead to new treatments to slow ageing in blood vessels and prevent age-related neurodegenerative diseases.

The challenge of treatment

One of the biggest hurdles in treating brain diseases is simply getting drugs past this robust barrier.

"Because the blood-brain barrier is so effective, apart from a few very small molecules, it's almost impossible to get drugs into the brain," Searson explained.

He added: "A major challenge in treating diseases of the brain is getting drugs across the blood-brain barrier."

His lab's models have already been used to test new ways of delivering drugs or genes to the brain.

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