April 28, 2014
Unlocking The Secrets Of Death In A Long-Lived Individual’s Blood
Lawrence LeBlond for redOrbit.com - Your Universe Online
They say that only two things in life are certain: death and taxes. For the former, a new study of the blood of one of the world’s oldest women has offered clues to not only why death occurs, but may also unlock some of the secrets of longevity.Hendrikie van Andel-Schipper, who was born in 1890 and lived to the ripe old age of 115, was at the time of her death in 2005 the oldest person in the world. But as astonishing as that may seem, even more remarkable is that her health was impeccable and her cognition was crystal-clear. When van Andel-Schipper died, her body – at her and her family’s request – was donated to science to hopefully uncover the secrets of a long life.
Researchers, led by Henne Holstege of the VU University Medical Center in Amsterdam, the Netherlands, have now examined Andel-Schipper’s blood and other tissues to see how they were affected by age, according to a report by the NewScientist.
According to the NewScientist report, the researchers found that in the years leading up to her death, most of Andel-Schipper’s white blood cells originated from just two stem cells, indicating that most of her blood stem cells had been used up or died. The researchers also discovered her white blood cells had incredibly short telomeres – the protective caps on chromosomes that gradually degenerate as people age.
The study findings, published in the journal Genome Research, helps support the theory of stem cell exhaustion, which suggests that an individual’s lifespan may be limited by the cells’ ability to divide – ultimately, cell division does not last forever.
So, in essence, Andel-Schipper’s physical and mental health may have been well enough to continue her life for years, but because her stem cells had reached a state of exhaustion, her body gradually lost the capacity to keep regenerating vital tissues and cells, such as blood.
"It's estimated that we're born with around 20,000 blood stem cells, and at any one time, around 1,000 are simultaneously active to replenish blood," Holstege said in a statement, as cited by the NewScientist's Andy Coghlan. In Andel-Schipper’s case, only a couple were providing her body with much-needed blood.
Holstege noted, however, that the results raise the possibility of injecting aging bodies with youthful stem cells saved from earlier years in their life to potentially keep people living longer – that is if their bodies are healthy enough to do so.
"If I took a sample now and gave it back to myself when I'm older, I would have long telomeres again – although it might only be possible with blood, not other tissues," she said.
Holstege also noted that “mutations within the blood cells were harmless – all resulting from mistaken replication of DNA during van Andel-Schipper’s life as the “mother” blood stem cells multiplied to provide clones from which blood was repeatedly replenished.”
This is the first time patterns of lifetime “somatic” mutations have been observed in such an old, yet otherwise healthy, individual. The absence of mutations posing dangers of disease and cancer suggest that Andel-Schipper had a superior system for repairing – or perhaps aborting – cells with dangerous mutations.
Holstege next hopes to hunt down the clues in genes that protect against cognitive diseases, such as Alzheimer’s disease, by comparing Andel-Schipper’s DNA to that of people who die at a much younger age as a result of the disease.