Researchers at St. Michael’s Hospital are one step closer to understanding why plaque bursts in coronary arteries and causes heart attacks.
The clue might be something called microRNA-145. MicroRNAs are short chains of bossy molecules that scientists are increasingly coming to realize control a wide variety of biological processes.
Dr. Subodh Verma, a cardiac surgeon at St. Michael’s, published a paper in the journal Circulation today, describing for the first time how microRNA-145 gene therapy can drastically reduce the severity and progression of atherosclerosis in mice.
In addition this approach appeared to make the atherosclerotic plaque more stable and less prone to burst.
Atherosclerosis, commonly called hardening of the arteries, is a condition in which fat, cholesterol and other substances build up in the walls of arteries and form hard structures called plaques. It is the leading cause of death in Canada.
Dr. Verma said most heart attacks occur when plaques rupture like a broken eggshell and release their contents into the artery. Researchers are therefore looking for ways to reduce the size of plaques and make them more stable.
One of the key questions is what causes the outer layer of the plaque to finally burst – a layer of smooth muscle cells known as the fibrous cap. These cells undergo “phenotypic transformation” in response to various stressful environments and cardiovascular risk factors, making them more likely to rupture and cause heart attacks. MicroRNA-145 is one of the factors that appear to play a critical role in preventing the transformation of vascular smooth muscle cells into rupture-prone cells.
In atherosclerosis-prone animals, microRNA-145-based gene therapy reduced the plaque size by approximately 50 per cent and increased the collagen content of the plaque and fibrous cap area by 40 to 50 per cent, indicating that this therapy can reduce plaque buildup and also make it less prone to rupture, the inciting event of heart attacks.
The researchers also found that in human atherosclerotic plaques, the amount of microRNA-145 was reduced compared to normal arteries that were free of plaque, providing supporting human insights to the animal study.
"Atherosclerosis continues to be the number one killer in modern societies and finding new ways to treat this problem are needed," said Dr. Verma.
Dr. Fina Lovren, a senior research associate at St Michael’s Hospital, carried out the experimental work on this project under the direction of Dr. Verma.
About St. Michael's HospitalSt. Michael’s Hospital provides compassionate care to all who enter its doors. The hospital also provides outstanding medical education to future health care professionals in more than 23 academic disciplines. Critical care and trauma, heart disease, neurosurgery, diabetes, cancer care, and care of the homeless are among the Hospital’s recognized areas of expertise. Through the Keenan Research Centre and the Li Ka Shing International Healthcare Education Center, which make up the Li Ka Shing Knowledge Institute, research and education at St. Michael’s Hospital are recognized and make an impact around the world. Founded in 1892, the hospital is fully affiliated with the University of Toronto.
Leslie Shepherd | EurekAlert!
The cytoskeleton of neurons has been found to be involved in Alzheimer's disease
18.01.2019 | University of the Basque Country
Bioinspired nanoscale drug delivery method developed by WSU, PNNL researchers
10.01.2019 | Washington State University
The scientific and political community alike stress the importance of German Antarctic research
Joint Press Release from the BMBF and AWI
The Antarctic is a frigid continent south of the Antarctic Circle, where researchers are the only inhabitants. Despite the hostile conditions, here the Alfred...
World first experiments on sensor that may revolutionise everything from medical devices to unmanned vehicles
The new sensor - capable of detecting vibrations of living cells - may revolutionise everything from medical devices to unmanned vehicles.
Dead and alive at the same time? Researchers at the Max Planck Institute of Quantum Optics have implemented Erwin Schrödinger’s paradoxical gedanken experiment employing an entangled atom-light state.
In 1935 Erwin Schrödinger formulated a thought experiment designed to capture the paradoxical nature of quantum physics. The crucial element of this gedanken...
Cellulose obtained from wood has amazing material properties. Empa researchers are now equipping the biodegradable material with additional functionalities to produce implants for cartilage diseases using 3D printing.
It all starts with an ear. Empa researcher Michael Hausmann removes the object shaped like a human ear from the 3D printer and explains:
The phenomenon of so-called superlubricity is known, but so far the explanation at the atomic level has been missing: for example, how does extremely low friction occur in bearings? Researchers from the Fraunhofer Institutes IWM and IWS jointly deciphered a universal mechanism of superlubricity for certain diamond-like carbon layers in combination with organic lubricants. Based on this knowledge, it is now possible to formulate design rules for supra lubricating layer-lubricant combinations. The results are presented in an article in Nature Communications, volume 10.
One of the most important prerequisites for sustainable and environmentally friendly mobility is minimizing friction. Research and industry have been dedicated...
16.01.2019 | Event News
14.01.2019 | Event News
12.12.2018 | Event News
18.01.2019 | Materials Sciences
18.01.2019 | Life Sciences
18.01.2019 | Health and Medicine