MIT Technology Review is reporting that new research on transplanted hearts in mice and humans suggests donor organs quickly adopt the biological age of the person or animal that receives them, regardless of how young the donor was.
It said the findings, published online at bioRxiv, challenge the idea that young organs could rejuvenate older bodies. The outlet noted that the research follows renewed attention to longevity theories after a hot mic reportedly caught Russia's Vladimir Putin and China's Xi Jinping discussing the possibility of living forever through continuous organ transplantation.
According to MIT Technology Review, Jesse Poganik at Brigham and Women's Hospital in Boston and his colleagues performed heart transplants in mice, implanting a second heart in the neck so the new organ could be compared with the original. Young adult mice received hearts from middle-aged donors in some cases, while middle-aged mice received young hearts in others. Using molecular tools known as aging clocks, the team assessed the biological ages of the tissues.
The outlet said the transplanted hearts appeared to have adopted the biological age of the recipients between four and six months after surgery. Young hearts got older, and old hearts got younger. The team also found that the mice's blood and other organs, including their original hearts, seemed unaffected by the presence of the new heart.
MIT Technology Review said data from human heart transplants backed up the finding. Tissue samples stored for decades at Brigham and Women's showed that a new heart quickly adopts the biological age of the recipient no matter the donor's age.
It said researchers are unsure why this happens. João Pedro de Magalhães of the University of Birmingham, who was not involved in the study, suggested the recipient's immune system may play a role. Poganik suggested the effects of a young heart may be diluted by the rest of an older body, or that a single organ may not be enough to produce a measurable effect.
MIT Technology Review said Poganik hopes the finding will encourage surgeons to consider hearts from older donors, many of which are discarded over assumptions they will not function as well. It said the study also underscores how complex aging is, and that Poganik believes scientists are unlikely to find a way to completely reverse it.
Full Article: Young organs may not be a fountain of youth for recipients