Two studies in zebrafish demonstrate that regeneration of cardiac tissue does not rely on activation of stem cells and may point to new approaches for regenerating heart muscle in individuals who survive myocardial infarction.
Investigators at Duke University Medical School in Durham, NC, showed that cardiomyocytes expressing the cardiogenesis gene gata4 (revealed by green fluorescence) proliferated and helped replace damaged cardiac cells. They also found that the cardiomyocytes helped renew scarred tissue, which occurs in humans after heart muscle dies during myocardial infarction (Kikuchi K et al. Nature. 2010;464:601-605).
Friedrich MJ. Heart Repair. JAMA. 2010;303(17):1686. doi:10.1001/jama.2010.526