Study identifies novel stem cell in blood and vessel formation

London, ON – July 20, 2004) – A study published today from the Krembil Centre for Stem Cell Biology at Robarts Research Institute has for the first time identified the specific precursor stem cell that give rise not only to the important cells lining our blood vessels but also the blood itself.

Robarts scientist Dr Mick Bhatia and his colleagues had demonstrated last year that human embryonic stem cells (hESCs) can make blood cells; and they and others have known for some time that there is a connection between the development of the blood and the formation of the vessels it flows through. Now, Dr Bhatia has traced the development of these interrelated systems back to a specific population of primitive endothelial-like cells in the lining of the earliest blood vessels. His findings are published today in the journal Immunity.

Understanding this common lineage of blood and cells comprising veins and arteries provides a powerful tool to test ideas about how these human precursor cells could potentially be transplanted to repair damaged tissue or organs, such as in cases of trauma or injury where vessels have been torn and major blood loss has occurred, or in cancer to "turn off" the formation of blood vessels that feed a growing tumour.

"We think we’ve identified a version of human blood precursors that may be the most potent of blood cells — the one that has the greatest developmental potential to promote repair of vessels as well as regeneration of the blood itself," explains Dr Bhatia, director of the Krembil Centre for Stem Cell Biology at Robarts. "This precursor cell provides an important new tool in our biological toolkit that can help us understand precisely how stem cells give rise to the tissues and organs of the body — and how we can harness that potential to minimize the damage of injury and disease."

Still, Dr Bhatia, who is also an associate professor of microbiology and immunology at The University of Western Ontario, stresses that much fundamental biology remains in stem cell research. Before new therapies can be developed, tested and safely used in humans, researchers continue to refine methods in identifying, purifying and verifying rare and elusive stem cells for study. They are also identifying what genes are important in the development and differentiation of these cells, what genes are linked to blood cancers, such as leukemias, and which particular growth factors can have a stimulating — or inhibiting — effect on stem cell development.