Stem cell development dependent on blood flow
Two studies have indicated that it is the physical force of a heart beat which triggers blood stem cells to produce new blood cells.
Hematopoietic stem cells (HSCs) are the cells in bone marrow and embryos which are able to produce any type of blood cell. In blood disorders such as leukaemia, if scientists are able to isolate a few of these cells and encourage them to produce blood cells in the lab, it could be revolutionary, as patients would no longer require bone marrow transplants from a matched donor.
A team working on zebrafish screened over 2,500 chemicals to study their effects on HSC production. They saw that chemicals which enhanced the blood flow caused an increase in HSCs. Further tests indicated that nitric oxide (NO) was responsible for regulating the HSC development, and could be the mechanism by which the body converts the physical forces into chemical signals. However, it was clear that without the physical force of circulation, the HSCs were unable to develop.
The other team extracted HSCs from mice embryos. They then used a device to propel fluid over these cells to look at how the stress of friction produced by the flow of the fluid affected blood cell formation. They found that the force of the blood flow promoted blood cell formation and increased colonies of HSCs.
The aim of studies such as these are to develop a way to coax stem cells into producing blood forming cells in the lab, which could then be used in the treatment of blood disorders.