Molecular And Phenotypic Blueprint Of Human Hematopoiesis Links Proliferation Stress To Stem Cell Aging
Our bodies rely on special cells, called hematopoietic stem cells, to continuously produce all types of blood cells, from oxygen-carrying red blood cells to infection-fighting white blood cells. As we age, the ability of these vital stem cells to function properly declines, leading to issues like a skewed production towards certain immune cells and a reduced capacity to regenerate blood.
A recent comprehensive study investigated how human blood stem cells change from youth to old age. Researchers meticulously analyzed these cells, looking at their characteristics, gene activity, and how well they functioned.
They discovered that while the total number of primitive blood stem cells remains relatively stable throughout life, the overall production of various blood cells decreases with age, particularly for red blood cells and certain immune cells. A key finding was that aged stem cells struggle with differentiation (specializing into different blood cell types), show problems with their cell cycle (the process of cell division), and are less able to handle “proliferation stress” – the strain caused by rapid cell division. This stress leads to DNA damage and causes the cells to develop characteristics of senescence, a state where cells stop dividing and can contribute to aging-related problems.
Remarkably, when young human blood stem cells were intentionally put under this kind of proliferative stress, they began to show many of the same age-related declines observed in naturally aged stem cells. This suggests that the stress of constant cell division is a major factor driving the aging of our blood-producing system. Understanding this link could open new avenues for therapies aimed at maintaining healthy blood production as we get older.
Source: link to paper