Researchers from the University of Leeds have found that carbon monoxide found naturally in our bodies could help protect against damage from Alzheimer’s proteins. Although fatal to people in large quantities, the study shows that the small amount of the gas present in our bodies may protect against the effects of the amyloid protein, a hallmark of Alzheimer’s disease. The research was funded by Alzheimer’s Research UK and Alzheimer’s Society with support from The Henry Smith Charity, and is published in the journal Cell Death and Disease.
Carbon monoxide is well-known as a toxic gas that can be harmful to humans, but it is also naturally produced within the body in small quantities, where it plays a number of important roles such as helping to regulate blood pressure. In the brain, carbon monoxide acts as a ‘chemical messenger’, helping nerve cells to communicate with each other. Previous research has shown that people with Alzheimer’s have increased amounts of carbon monoxide in the brain, but it’s unclear whether this increase is a cause of damage or a result of disease processes. The researchers at Leeds set out to understand what role carbon monoxide might play in the disease.
The team used nerve cells in a dish to test the effects of the toxic amyloid protein – a hallmark Alzheimer’s protein that builds in the brain and forms sticky clumps around nerve cells – and carbon monoxide. Initial results showed that when amyloid was added to the cells, around half of the cells died. However, when carbon monoxide was added, far fewer of the cells died, suggesting that the gas was able to prevent some of the damage caused by amyloid.
The researchers also sought to understand the mechanisms that may cause this protective effect. The team’s earlier research had suggested that amyloid may cause damage by activating an enzyme called AMPK, which is important for regulating the amount of energy available to cells. In the latest study, they found that carbon monoxide prevented amyloid from activating this enzyme.
Study co-author Dr Mark Dallas, who is now based at the University of Reading, said: “Although carbon monoxide is largely seen as a toxic gas, our cells contain the machinery to produce it at more manageable levels, and it plays an important role within the body. Our study builds on a body of work linking carbon monoxide to Alzheimer’s, and suggests that the increased amounts we see in people with the disease may be a result of a mechanism the brain uses to protect itself. We still need to fully understand carbon monoxide’s role in Alzheimer’s, but we hope this study will provide a new lead in the search for new treatments.”
Dr Simon Ridley, Head of Research at Alzheimer’s Research UK, said:
“These results shed new light on some of the complex processes that may occur in Alzheimer’s, and we’re delighted to have supported this study. Carbon monoxide produced from burning fuels is very dangerous for people, but this research suggests that when the gas is naturally produced within cells in tiny quantities, it may play a role in protecting brain cells. Continued investment in research is vital to ensure that results like these can be harnessed in the search for treatments to stop this devastating disease in its tracks.”
Dr Doug Brown, Director of Research and Development at Alzheimer’s Society said:
”Finding a way to protect brains cells from damage is top of the wish list for dementia research. Although this research is in the very early stages, it is promising to see that a chemical that is already made within our brains in small amounts could be helpful in the defence against Alzheimer’s disease. We will continue to fund research like this because only by understanding more about the complex causes of dementia will we be able to develop treatments to combat the condition.”