Inflammation key to repairing injured hearts in mice

Directly injecting living or dead heart stem cells into injured hearts and surrounding injured tissue triggers acute inflammation and wound healing-like properties in mice, according to a new study in Nature.

Macrophages—an immune cell that engulf and digest cell debris at the site of injury—mediated the healing mechanism and provided a modest benefit to heart function after a heart attack. Zymosan—a substance designed to induce an immediate immune response—decreased scarring and a longer-lasting, although modest, benefit on injured tissue. The study was partly funded by NHLBI.