Scientists have reversed a condition in rats that causes blood vessels in the brain to narrow, a discovery which could lead to a new treatment for dementia and stroke in humans.
Known as cerebral small vessel disease (SVD), the condition cuts off blood supply to brain tissue. This causes damage that can lead to dementia and stroke as well as worsen Alzheimer’s disease.
It was previously unclear how brain cells are damaged by the changes in small blood vessels in the brain, which occur with SVD.
In a new study, researchers at MRC Centre for Regenerative Medicine and the UK Dementia Research Institute at the University of Edinburgh discovered that SVD occurs when cells that line small blood vessels in the brain, known as endothelial cells, begin to dysfunction and release a toxic protein in the brain. This substance stops the production of the myelin sheath, a protective layer surrounding brain cells which helps nerve cells send and receive messages, and leads to brain damage.
The team then treated rats with drugs to stop endothelial cell dysfunction. Tests showed that the treatment reversed SVD symptoms and prevented brain damage in the rats.
SVD is responsible for nearly half of all cases of dementia in the UK and accounts for one in five cases of stroke. The team say their findings, published on Wednesday in the journal Science Translational Medicine, could offer a potential new therapeutic approach for patients.
“This important research helps us understand why small vessel disease happens, providing a direct link between small blood vessels and changes in the brain that are linked to dementia,” Professor Anna Williams, from the University of Edinburgh’s MRC Centre for Regenerative Medicine, said in a statement. “It also shows that these changes may be reversible, which paves the way for potential treatments.”
The team said further research is needed to determine whether the treatment is successful once the disease is “firmly established” and if it can reverse dementia symptoms.
There are an estimated 47 million people living with dementia worldwide. These figures are expected to double every 20 years, with dementia affecting over 115 million people by 2050. In the UK, around 850,000 people suffer from dementia, with costs totalling £26 billion each year.
Although additional studies are necessary before trials in humans could begin, experts were optimistic about the study’s results.
“The findings highlight a promising direction for research into treatments that could limit the damaging effects of blood vessel changes and help keep nerve cells functioning for longer,” said Dr Sara Imarisio, head of research at Alzheimer’s Research UK, which funded the study. “There are currently no drugs that slow down or stop Alzheimer’s disease and no treatments to help people living with vascular dementia.”