A report in Science Express, an online advance publications section of the journal Science, shows that adult blood stem cells are not able to transform themselves into many other types of body tissue. To some, the findings indicate that adult stem cells do not have the same potential for use in treatments for disease and injury as embryonic stem cells do.
The researchers, from Stanford University, US, introduced adult blood stem cells into adult mice that had had their bone marrow removed by radiation and traced their development. They found that blood-making bone marrow cells were replenished, but that the stem cells 'had virtually no effect' on the regeneration of other types of cell in the mice, including brain, kidney, gut, liver, and muscle.
Amy Wagers, one of the authors of the study, said that out of the 'millions' of blood stem cells introduced to the mice, only one neuron cell was formed, and that only one in 70,000 blood stem cells transformed into a liver cell. This suggests, she said, that 'adult blood stem cells make only one thing - blood'. Making other types of cell from this type of stem cell 'is an extremely rare event', she added.