Article Impact Level: HIGH Data Quality: STRONG Summary of Circulation Research https://doi.org/10.1161/CIRCRESAHA.125.327486 Dr. Robert D. Hume et al.
Points
- Researchers demonstrated that human cardiomyocytes undergo mitosis in response to a heart attack which contradicts long standing beliefs that adult heart muscle damage is entirely permanent and incapable of repair.
- The study utilized pioneering living tissue samples collected from patients during bypass surgery to provide the first reliable evidence of intrinsic heart muscle regeneration in a living human clinical population.
- While heart attacks can destroy up to one third of the cells in the heart the discovery of regrowing muscle cells offers hope for developing therapies that amplify this response.
- Specific proteins previously linked to heart regeneration in rodent models were identified in human tissue which suggests a viable molecular pathway for translating regenerative cardiovascular treatments into standard clinical practice.
- Enhancing the heart’s natural ability to produce new muscle cells could eventually address the severe shortage of heart transplants by providing a biological method to reverse chronic and end stage failure.
Summary
This study investigated the intrinsic mitotic potential of human cardiomyocytes following myocardial infarction (MI), an event that can eliminate up to one-third of the heart’s functional cells. While heart muscle cells were traditionally believed to cease cell cycling shortly after birth, researchers utilized living “pre-mortem” tissue samples to demonstrate that adult cardiomyocytes can re-enter mitosis in response to ischemic injury. This discovery identifies a latent regenerative capacity in the human heart that was previously only confirmed in rodent models.
The research utilized a pioneering collection method to obtain living tissue from both diseased and non-diseased myocardial regions in patients undergoing bypass surgery. Molecular analysis revealed increased mitotic activity following MI, identifying several specific proteins involved in cardiac regeneration that were previously observed in mice. These findings confirm that while the heart remains scarred post-infarction, it possesses a natural, though currently insufficient, mechanism for muscle cell replacement.
Given the significant disparity between the 144,000 heart failure patients in Australia and the availability of only 115 annual heart transplants, these results provide a critical foundation for regenerative medicine. The identified mitotic proteins represent potential therapeutic targets to amplify the heart’s natural repair response. Future efforts will focus on developing pharmacological or biological interventions aimed at reversing heart failure by enhancing this intrinsic mitotic potential to replace lost myocardium and restore pumping function.
Link to the article: https://www.ahajournals.org/doi/10.1161/CIRCRESAHA.125.327486
References
Hume, R. D., Warwick, J., Shim, W. J., Malecki, C., Li, M., Seth, L., Harney, D., Dagher, J., Lum, T., Tierney, G., Cooper, W., Slaughter, E., Wang, X., Nguyen, L., Cole, L., Edelman, J., Rashid, F. N., Houlahan, C., Gao, A., … Lal, S. (2026). Human hearts intrinsically increase cardiomyocyte mitosis after myocardial infarction. Circulation Research, 138(2). https://doi.org/10.1161/CIRCRESAHA.125.327486
