THE ARISING · Longevity & Healthspan
Short-Lived mRNA Therapy Helped Mouse Hearts Repair After Heart Attack
The adult heart cannot replace the muscle cells it loses in a heart attack. A new study in mice, published in Nature Cardiovascular Research, reports that a brief burst of two proteins can get those cells dividing again and help the heart recover.
The evidence comes from mice. The researchers used transgenic mouse models and a prototype mRNA therapy. They report that Myc and cyclin T1 need to be switched on only transiently to drive heart muscle cells to proliferate. That led to repair of the heart muscle and functional recovery after a heart attack.
Myc is a protein that switches genes on and off. According to the paper, it is needed to restore tissue in several species that can regenerate. Adult mammalian heart muscle cells, by contrast, fail to divide after damage. Earlier work had shown that transgenic expression of Myc and cyclin T1 can push adult heart muscle cells to multiply and replace lost ones. The new study shows that the signal works when it is brief.
The therapy is a modified mRNA, a temporary set of instructions that cells read to make the two proteins. The authors describe it as a strategy for turning Myc and cyclin T1 co-expression into a way to regenerate the heart.
Further numbers come from the University of Cambridge, as reported by Medical Xpress. According to that coverage, mice given the therapy after a heart attack pumped about 10% more blood with each heartbeat than mice given a mock treatment. The gains were still present at 28 days and at 12 weeks, and the university reported no observed adverse effects in those mice. This does not establish long-term or human safety. The treatment is short-lived and localized, an approach designed to reduce the risk of overgrowth.
Next, according to the Cambridge team, come refinements to the treatment, then trials in larger animals and, after that, in people.