Myocardial infraction, more commonly known as a heart attack, leaves the heart muscle damaged and in need of repair. But sometimes the immune cells sent to repair the damage do more harm than good, which can lead to heart failure. A team from the University of Oxford has found a protein that could help solve this problem and create a better treatment.
Heart attacks occur when the flow of blood to the heart is blocked. This blockage can occur due to a buildup of fat, cholesterol and other substances in the arteries. This buildup forms a plaque which eventually breaks away causing a clot to form, the interrupted blood flow can then damage or destroy parts of the heart muscle as they are deprived of oxygen. The extent of the damage to the heart muscle depends on the size of the area supplied by the blocked artery and the time between injury and treatment. The damage heals by forming scar tissue and can take several weeks, immune cells work to clean up the dead and dying cells to stimulate cell repopulation and tissue renewal. While the body works to heal the heart, these immune cells can also cause further inflammation resulting in more damage, which can lead to heart failure.
A team from the University of Oxford, funded by the British Heart Foundation, have found a new treatment that can regenerate the heart after a heart attack in a way that prevents the onset of heart failure. Professor of Regenerative Medicine Paul Riley, who led the research, said "We now know that it's not enough to just get healing immune cells into the heart. We need to boost the routes that remove these immune cells once they've done their job, so that they don't start causing more harm and ultimately contribute to the long-term damage that leads to heart failure.” Utilizing a mouse model, they investigated the protein, VEGF-C, and its mechanism for improving the functional outcome post heart attack by inducing lymphatic vessel growth.
The study involved injecting VEGF-C into mice post heart attack and comparing with untreated mice. They found that VEGF-C treatment significantly reduced the amount of damage to heart muscle and resulted in almost full recovery of heart pumping function, while the untreated mice lost almost half of their heart function post heart attack. Use of VEGF-C also promoted growth of lymphatic vessels, the extra vessels allowed the immune cells to be cleared more quickly after they repaired and cleared dead/dying cells. By clearing the immune cells faster, they were not able to cause significant damage via inflammation, leading to overall better healing of the heart and recovery of heart function.
Future research will focuse on achieving the right balance of immune cells after a heart attack, the correct balance will allow for proper initial heart repair without inflammation, scarring or heart failure. "This research has allowed us to start a drug discovery programme to develop drugs to promote the growth of lymphatic vessels and quickly clear immune cells. We hope to get a treatment we could give to people after a heart attack within 5-10 years." said Paul Riley.
To read this study click here. . To learn more about heart attacks, signs and symptoms, and treatment see the video below!