Genetic mutations have been frequently studied due to their associations with diseases such as cancer, but very little is known about mutations which happen in people who are healthy. So in studying the healthy blood cells of an elderly woman, age 115, researchers located in New York discovered she had over 400 mutations, but found that her body had ‘tolerated’ them for lack of a better term.
The super-centenarian woman passed away in 2005 and was the oldest person in the world at that time. She was also most likely the oldest person that ever donated her body to science.
Hendrikje van Andel-Schipper was born in 1890 and was reported to have enjoyed very good cognition and a circulatory system free of disease up until her death.
Scientists stated that the elderly woman was down to only two stem cells at the time of her death and they were having to fuel two-thirds of the white blood cells in her body. This meant that basically each stem cell she had started her long life with had burned out.
It is believed that due to the fact that van Andel-Schipper had lost all her stem cells down to just two seems to show that mortality is indeed capped. It also means that researchers might be able to find ways to eradicate such a cap.
The investigation started when the researchers began to study substantial clues about life endurance for the rest of the human species. Human blood continually is refilled with what is known as hematopoietic stem cells. They remain inside bone marrow. Such cells divide to create various kinds of blood cells which include white blood cells.
However the division of cells can be prone to mistakes and ones that end up dividing the most are more probable to cultivate genetic mutations. There have been over hundreds of mutations discovered in individuals who have cancers of the blood such as acute myeloid leukemia, but it remains unclear if white blood cells considered healthy also contain such mutations.
The mutations that showed up in healthy white blood cells have come to be called somatic mutations because they are not passed on to any children, and seem to be well accepted by the body and do not lead to any type of disease.
Scientists studied the length of the telomeres, or the repetitive structures located at the ends of chromosomes which protect them. After someone is born, telomeres start to shorten with every cell division.
The telomeres of white blood cells were much shorter than the telomeres inside the brain of the 115-year-old. This shows that cells might have died due to stem cell exhaustion and may have reached their limit of being able to divide.
All this is due to genetic mutations and their associations with diseases such as cancer, but very little has been known about mutations which happen in people who are healthy. So in studying the healthy blood cells of the elderly woman, researchers located in New York discovered she had over 400 mutations, but found that her body had ‘tolerated’ them and she lived a very long life.
By Kimberly Ruble
All Voices News