In a possible world first, scientists have found a way to direct stem cells to heart tissue, potentially revolutionising treatment for cardiovascular disease.
In Ireland, approximately 10,000 people die each year as a result of cardiovascular disease, making it the most common cause of death in the country. While a number of treatments are now available with varying results, one of the most promising candidates is stem cell treatment.
So far, trials have taken stem cells grown from a patient or donor and injected them into the patient’s heart to regenerate damaged tissue. However, while results have offered serious potential, stem cell distribution remains a major stumbling block. High blood flow in the heart combined with various ‘tissue sinks’, which circulating cells come into contact with, means the majority of the stem cells end up in the lungs and spleen.
Yet new hope is on the horizon as scientists from the University of Bristol revealed, in a possible world first, that they have found a way to direct stem cells to the heart tissue with significantly greater accuracy. This could radically improve the treatment of cardiovascular disease, they added.
‘Painting’ the outside of stem cells
Writing in Chemical Science, the researchers said they achieved this by finding a way to re-engineer the membranes of stem cells with a special protein so that they ‘home’ to heart tissue.
“We know that some bacterial cells contain properties that enable them to detect and home to diseased tissue. For example, the oral bacterial found in our mouths can occasionally cause strep throat,” said Dr Adam Perriman, the study’s lead author.
“If it enters the blood stream it can home to damaged tissue in the heart, causing infective endocarditis. Our aim was to replicate the homing ability of bacteria cells and apply it to stem cells.”
The researchers looked at how bacterial cells use a protein called an adhesin to guide their way to heart tissue. With this knowledge, they produced an artificial cell membrane-binding version of the protein that could be ‘painted’ on the outside of stem cells. Testing the treatment in a mouse, they were able to demonstrate it worked.
“Significantly, we show in a mouse model that the designer adhesin protein spontaneously inserts into the plasma membrane of the stem cells with no [cytotoxicity] and then directs the modified cells to the heart after transplant,” Perriman explained.
“To our knowledge, this is the first time that the targeting properties of infectious bacteria have been transferred to mammalian cells.”