The accumulation of plaque inside the arteries can be an insidious condition with grave consequences that include blood clots and strokes, but luckily it does give off some tell-tale signs. Researchers in the UK have developed a new type of glowing probe that focuses on one of them, increasing its fluorescence in the presence of a key enzyme and possibly acting as an early warning sign for cardiovascular disease.
Known as atherosclerosis, the build-up of arterial plaque is a key driver of heart disease and stroke, and is in turn a leading cause of death in the Western world. One of the ways the condition can endanger human health is when the plaque actually breaks away from the artery walls, events known as intraplaque haemorrhages (IPHs), which can then restrict blood flow and lead to chronic disease or stroke.
The new probe, developed by scientists at Imperial College London, takes aim at an enzyme known as heme oxygenase-1 (HO-1), which is produced in large amounts as IPHs take hold. The probe consists of two compartments that transfer fluorescent molecules between one another – one "donor" component and an "acceptor" component.
But as the probe comes into contact with HO-1, the enzyme breaks a bond connecting these two compartments, and causes a build up of the fluorescent molecules in the donor compartment. This means that the probe glows up to six times more brightly in the presence of HO-1, as was demonstrated in lab tests using modified E. Coli cells, with the change in fluorescence able to be detected using spectroscopy.
“Current methods to detect IPH rely on hospital-based imaging techniques that are both time-consuming and expensive," says study author Professor James Leiper. "The current technology aims to produce a fast and sensitive diagnostic test that can be used at the time that a patient first presents with symptoms to allow early detection of IPH. Use of such a test would allow for more rapid treatment and improved outcomes for patients suffering from IPH.”
The early proof-of-concept is promising, but such a clinical test is still a ways off. The scientists will next carry out further studies involving mammal and human cells, with hopes that the probe could one day also enable long-term tracking of cardiovascular health.
"The probes could also provide real-time analysis of the underpinning biological processes involved in vascular disease, providing new insights and potentially new ways to track the progress of chronic disease," says study co-lead Dr Joe Boyle.
The research was published in the Journal of the American Chemical Society.
Source: Imperial College London
