# Heart Transplantation

Jesse Poganik's team at Harvard grafted hearts from young, middle-aged and old mice into mice of all three age groups and measured DNA methylation across roughly 320,000 genomic regions, finding that grafted hearts shifted their biological age toward the recipient; the same effect appeared in biopsy samples from 11 historical heart transplants at Brigham and Women's Hospital with large donor-recipient age gaps, while some functional measures such as heart rate, posterior wall thickness and exercise capacity tracked recipient age rather than donor age.

Jesse Poganik's team at Harvard grafted hearts from young, middle-aged and old mice into mice of all three age groups and measured DNA methylation across roughly 320,000 genomic regions, finding that grafted hearts shifted their biological age toward the recipient; the same effect appeared in biopsy samples from 11 historical heart transplants at Brigham and Women's Hospital with large donor-recipient age gaps, while some functional measures such as heart rate, posterior wall thickness and exercise capacity tracked recipient age rather than donor age.