Researchers have discovered a new way to limit the damage caused to the heart by a heart attack – by regenerating the heart through the growth of lymphatic vessels.
The team from the University of Oxford in the UK identified that stimulating the growth of lymphatic vessels in mice using a protein called VEGF-C improved the healing process and the ability of the heart to pump blood around the body.
“We have shown that given the right stimulus after a heart attack there is a significant response from the lymphatic system which enhances the heart’s healing process and limits the damage left behind,” says lead researcher Prof. Paul Riley. “This significantly improved the pumping function of the heart.”
The lymphatic system is a network of tubes and nodes that are responsible for transporting white blood cells around the body to fight injury and infection and keep the body fluids in balance.
“Relatively little is known about the role of the lymphatic system in the heart,” says Prof. Peter Weissberg, Medical Director at the British Heart Foundation (BHF). “This research has shed new light on how lymphatic vessels develop and shows for the first time that they may play a significant role in the heart’s response to injury after a heart attack.”
Heart attacks, also known as myocardial infarctions, occur when there is a loss of blood supply to a heart muscle. These attacks can cause irreparable damage to the heart, leaving it vulnerable to heart failure.
In the US, someone has a heart attack every 34 seconds. According to the Centers for Disease Control and Prevention (CDC), about half of people who develop heart failure die within 5 years of diagnosis.
In their study, Prof. Riley and colleagues demonstrated that in mice, more lymphatic vessels begin growing in adult hearts following a heart attack. By stimulating further growth of these vessels with VEGF-C – previously studied in animals as a treatment for lymphoma – the damage caused by the heart attack was reduced and recovery was amplified.
The team hypothesize that the extra lymphatic vessels grow in order to transport immune cells away from the damaged heart muscle, reducing the level of inflammation in the area and helping it to repair itself.
“This has never been documented before and the implications of these findings, in mice, could be huge,” explains Prof. Riley. “By unravelling the mystery of how the lymphatic system develops and its role in heart repair we hope to find new ways to reduce the devastating impact of a heart attack.”
The study, published in Nature, also challenges pre-existing beliefs that lymphatic vessels grow from existing veins. The researchers found that, instead, new lymphatic vessels grow from specialist cells that also have an important role in the growth of blood vessels in embryos.
Lead author Dr. Linda Klotz from the University College London Institute of Child Health describes the findings as an exciting new step in regenerative medicine that unlocks the potential for researchers to help organs to heal themselves following traumatic events such as heart attacks.
“Our greater understanding of the way lymphatic vessels develop from multiple origins in a growing embryo will also have important implications for creating targeted therapies and for future lymphatic studies,” she states.
Recently, Medical News Today reported on a large international study that associated weak grip strength with an increased risk of heart attack, stroke and death from both cardiovascular and noncardiovascular diseases.