Experimental mRNA therapy promotes repair after heart attack damage

Researchers at the University of Cambridge have developed an experimental mRNA therapy that temporarily activates two proteins, Myc and Cyclin T1, inside heart muscle cells, prompting them to divide and repair damage after a heart attack. In a study published in Nature Cardiovascular Research, mice that received the treatment showed a stronger heartbeat and pumped around 10% more blood per beat than mice given a mock treatment, according to the Marietta Daily Journal and themercury.com. The improvement persisted when the animals were reassessed at 28 days and again at 12 weeks, and no adverse effects were observed, Medical Xpress reported. The therapy is delivered by direct injection into the heart shortly after injury and is designed to be short-lived and localized, reducing the risk of permanent genetic modification or uncontrolled cell growth.

Adult human hearts cannot regenerate lost muscle cells; after a heart attack up to one billion cardiomyocytes may be lost, leading to scarring, heart failure and death, the Marietta Daily Journal noted. Around 200,000 people in the U.K. are diagnosed with heart failure each year, and current treatments only slow disease progression without replacing lost tissue, the same outlet said. Dr. Catherine Wilson, associate professor at Cambridge's Department of Pharmacology and Gurdon Institute and co-senior author of the study, told Medical Xpress: "These are really exciting results. There's no cure for heart failure, and our treatment could potentially have a meaningful impact on the quality of life of millions of people around the world." She added: "We're not just treating the symptoms of heart failure — this approach could help the heart to repair itself."

Professor Bryan Williams, chief scientific and medical officer at the British Heart Foundation, which funded the work, called the research "an important step forward towards therapies which could help repair the damage to the heart following a heart attack," according to the Marietta Daily Journal. He said: "Getting the human heart to repair itself is the holy grail for cardiologists. The heart is easily repaired when we are babies in the womb, but our heart muscle cells lose the ability to regenerate and fix the heart shortly after we are born." The Cambridge team is now refining the treatment and plans further trials in larger animal models before any human studies, the Marietta Daily Journal and Medical Xpress reported.