OSAKA — Researchers at The University of Osaka reported that simultaneous administration of five therapeutic mRNAs reduced heart tissue damage and improved heart function in a mouse model of heart attack. The treatment also increased survival rates compared to untreated mice.
The study, set to be published in Small Science, used polymer-based mRNA carriers known as polyplex nanomicelles to deliver mRNAs encoding five different proteins important for tissue recovery directly to the hearts of mice with heart failure. Treated mice exhibited improved heart contraction, thicker heart walls, and better blood movement through the heart.
After a heart attack, heart failure can develop due to inflammation, scarring of heart tissue, death of heart cells, and reduced blood flow to the heart tissue. The study demonstrates that treating heart tissue with multiple mRNAs involved in repairing various signs of damage can effectively address the multifaceted nature of heart failure after a heart attack.
"The fact that a heart attack causes such complex damage to the heart makes it difficult to treat," says Kazuma Handa, lead author of the study. "Conventional treatments that only target one of these types of damage are typically not effective."
Keiji Itaka, senior author, explained the therapeutic effects observed in the study. "The results were very positive." He added, "Delivering the five-mRNA cargo to the damaged heart tissue promoted the formation of new blood vessels, inhibited scar tissue formation, increased tissue repair, and decreased the rate of heart cell death." The results could serve as the foundation for a new generation of treatments for heart failure and help establish mRNA-based medicine as a new pillar of regenerative medicine.