Not only is our biological age different from our chronological age, but it varies from organ to organ. Understanding why and how could be a Longevity game-changer.
A certain liver transplant has received a lot of coverage on Twitter recently; a 93-year-old liver, with a parasite-related cyst was transplanted as a last resort into a 19-year-old woman. The recipient is still alive and went on to have a healthy baby after the operation. The liver in question has just celebrated its 100th birthday.
Longevity.Technology: Last week we described a research paper that suggests where you live could be as important in determining your lifespan as your genetics. There are even more variables at play when the fact that our organs could all have different rates of aging.
In understanding why aging rates vary across different organs, transplant data is a good place to start. A study by the researchers at the Institute of Ageing and Chronic Disease, University of Liverpool and the Biogerontology Research Foundation, University of Oxford, found that, as might be expected, transplants from older donors had a lower success rate than transplants involving chronologically younger organs [1].
But the research also highlighted some interesting differences, depending on the organ being transplanted. The success rate with hearts and pancreases decreased after the donor hit 40, but with lungs, not until 65. Corneas seem to be the most robust transplant, as the age of the donor appears to have little or no effect on the success of surgery [2].
“We’ve wondered for some time if it might be possible to simply rewind the aging clock without inducing pluripotency. Now we’ve found that, by tightly controlling the duration of the exposure to these protein factors, we can promote rejuvenation in multiple human cell types.”
Vasculature can often be an obstacle in transplant and the team did note this: “It is logical to think that age-related changes in vasculature and microvasculature of the different organs must be a significant factor contributing to their age-related dysfunction [3].” As 3D-bioprinting improves, improvements to organs in vivo might prolong their life as well as improving transplant rates.
There has also been success in rejuvenating cells using Yamanaka factors, a group of protein transcription factors that play a vital role in the creation of induced pluripotent stem cells (cells that have the ability to become any cell in the body).
Lead researcher on that study, Dr Vittorio Sebastiano said: “We’ve wondered for some time if it might be possible to simply rewind the aging clock without inducing pluripotency. Now we’ve found that, by tightly controlling the duration of the exposure to these protein factors, we can promote rejuvenation in multiple human cell types [4].”
Research into Yamanaka factors might result in successful therapies that are able to restore failing organs on an as-needed basis, or preventative organ treatments that ensure healthy organs are kept in top condition.
Organ health and lifespan is also tied to lifestyle and living environment; as Dr Richard Siow, director of ageing research at King’s College London, says: “A very good example is the lungs and pollution. Lungs are more aged in the city, or in high pollution environments …
What we eat and how we eat it, how we sleep and when we sleep – all these things can impact our organs in varying ways that we don’t fully understand [5].
[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6123500/
[2] Ibid
[3] Ibid
[4] https://www.eurekalert.org/pub_releases/2020-03/sm-ohc032220.php
[5] https://www.bbc.com/future/article/20200625-the-woman-with-a-100-year-old-liver
