Last year, during an aging conference in Manchester, a surprising conversation between Russian President Vladimir Putin and Chinese President Xi Jinping was inadvertently captured on a hot mic. The leaders discussed the potential for achieving immortality through advancements in biotechnology, specifically referencing the notion that young organs could be transplanted to prolong life. This idea, often associated with the “replacement” theory of longevity, has gained traction through experiments showing that young blood can rejuvenate older organisms, particularly in studies involving mice.
However, recent research challenges the feasibility of this concept. Investigations into heart transplants conducted at Brigham and Women’s Hospital in Boston reveal that transplanted organs, regardless of their donor’s age, tend to adopt the biological age of the recipient. This finding emphasizes the complexity of aging and raises questions about the effectiveness of using younger organs to reverse age-related deterioration. Jesse Poganik, a researcher involved in the study, highlighted the unexpected results from their experiments with mice, where young hearts seemed to age and vice versa.
The research team utilized three different “aging clocks” to assess the biological age of the mice’s tissues post-transplant. Contrary to expectations, the results indicated that the new hearts conformed to the recipient’s biological age within four to six months. While previous studies suggested that older organs could accelerate aging in younger recipients, Poganik’s findings indicate that the biological environment significantly influences organ behavior. Interestingly, the mice’s other organs remained unaffected by the transplant, indicating a disconnect between the transplanted heart’s aging process and the rest of the organism.
Data from human heart transplants corroborated these results, demonstrating that donor hearts quickly align their biological age with that of the recipient. The precise mechanisms behind this phenomenon remain unclear, but it is hypothesized that the recipient’s immune system may play a significant role. This complexity in aging suggests that while certain aspects of biological age may be reversible, a complete reversal remains a formidable challenge. Poganik hopes these insights will encourage the use of older donor organs, which are often discarded due to assumptions about their functionality. Ultimately, this research underscores the intricate nature of aging and the hurdles that remain in the quest for longevity.
Source: Young organs may not be a fountain of youth for recipients via MIT Technology Review