Why do we suddenly become frail in the 70s? Scientists unlock cellular secret

Scientists have for the first time looked at the process of ageing to understand why we become so frail in the 70s.


Photo: The team studied the production of blood cells from the bone marrow, analysing the cells of 10 individuals. (Photo: Pixabay)

Researchers have for the first time tapped into the hidden secrets of ageing that leads to dramatic changes in the 70s. They discovered how genetic mutations accumulated slowly over a lifetime lead to dramatic changes in blood formation after 70.

Looking into the process at a cellular level, the researchers have uncovered how genetic changes that accumulate slowly in blood stem cells throughout life are the culprits. The findings could pave way for new and enhanced therapies for people in old age and medical treatments.

The study published in the journal Nature states that ageing is likely to be caused by the accumulation of multiple types of damage to our cells over time, with one theory being that the build-up of somatic mutations causes cells to progressively lose functional reserve.

Somatic mutation is the process by which all human cells acquire genetic changes throughout life.

Led by researchers from Cambridge, the team studied the production of blood cells from the bone marrow, analysing the cells of 10 individuals ranging from newborns to the elderly. They sequenced the whole genomes of 3,579 blood stem cells and were able to identify all the somatic mutations contained in each cell.

Researchers have the exciting task to figure out how these newly discovered mutations affect blood function in the elderly. (Photo: Pixabay)

The team then used this data to reconstruct the “family trees” of each person’s blood stem cells, showing, for the first time, an unbiased view of the relationships among blood cells and how these relationships change across the human lifespan.

“We’ve shown, for the first time, how steadily accumulating mutations throughout life lead to a catastrophic and inevitable change in blood cell populations after the age of 70,” Dr. Peter Campbell, senior researcher on the study said in a statement.

Researchers are hopeful that this model may well apply to other organ systems too. “These selfish clones with driver mutations expanding with age in many other tissues of the body we know this can increase cancer risk, but it could also be contributing to other functional changes associated with ageing,” Dr. Campbell added.

Researchers found that these blood cells changed dramatically after the age of 70 years. The production of blood cells in adults aged under 65 came from 20,000 to 200,000 stem cells, each of which contributed in roughly equal amounts.

“The team’s findings led them to propose a new model in which age-associated changes in blood production come from somatic mutations causing ‘selfish’ stem cells to dominate the bone marrow in the elderly,” the Wellcome-MRC Cambridge Stem Cell Institute said in a release.



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