The muscle cells that line the blood vessels have long been known to multi-task. While their main function is pumping blood through the body, they are also involved in ‘patching up’ injuries in the blood vessels. Overzealous switching of these cells from the ‘pumping’ to the ‘repair’ mode can lead to atherosclerosis, resulting in the formation of ‘plaques’ in the blood vessels that block the blood flow.
Using state-of-the art genomics technologies, an interdisciplinary team of researchers based in Cambridge and London has caught a tiny number of vascular muscle cells in mouse blood vessels in the act of switching and described their molecular properties. The researchers used an innovative methodology known as single-cell RNA-sequencing, which allows them to track the activity of most genes in the genome in hundreds of individual vascular muscle cells.
Their findings, published in Nature Communications, could pave the way for detecting the ‘switching’ cells in humans, potentially enabling the diagnosis and treatment of atherosclerosis at a very early stage in the future.
Atherosclerosis can lead to potentially serious cardiovascular diseases such as heart attack and stroke. Although there are currently no treatments that reverse atherosclerosis, lifestyle interventions such as improved diet and increased exercise can reduce the risk of the condition worsening; early detection can minimise this risk.
“We knew that although these cells in healthy tissues look similar to each other, they are actually quite a mixed bag at the molecular level,” explains Dr Helle Jørgensen, a group leader at the University of Cambridge’s Division of Cardiovascular Medicine, who co-directed the study. “However, when we got the results, a very small number of cells in the vessel really stood out. These cells lost the activity of typical muscle cell genes to various degrees, and instead expressed a gene called Sca1 that is best known to mark stem cells, the body’s ‘master cells’.”
The ability to detect the activity (or ‘expression’) of thousands of genes in parallel in these newly-discovered cells has been a game-changer, say the researchers.
Image: Blood clot forming in arterial plaque
Credit: Annie Cavanagh
Reproduced courtesy of the University of Cambridge