vnewjay

An advance in stem cell research could one day give hope to patients in need of bone marrow transplants or blood transfusions, scientists have said.

Edinburgh experts used blood stem cells from mice to mimic how humans produce the stem cells and found they were able to multiply them by 150 times.

They hope their findings will lead to efficient production of blood stem cells in the laboratory.

They could then multiply in the body to renew a patient's blood supply.

The body generates billions of blood cells every day, which are produced by blood stem cells in the bone marrow tissue.

These include red blood cells, which deliver oxygen to different organs, and white blood cells, such as lymphocytes and macrophages, which play an important role in the body's immune system.

But high doses of chemotherapy given to patients with cancers, such as leukaemia and lymphoma, can destroy bone marrow.

Scientists in Edinburgh hope their research could benefit cancer patients or people with disorders of the blood system, if they can succeed in generating human blood stem cells in a laboratory.

Blood stem cells could also be transplanted into patients who have genetic blood diseases or have lost blood as a result of accidents or surgery - potentially reducing pressure on blood donor supplies.

Prof Alexander Medvinsky, of Edinburgh University's medical research council centre for regenerative medicine, said the success of the research on blood stem cells from mice was a "very strong step forward".

Healthy body

But he cautioned that any clinical application of the findings remained a long way off and many problems would have to be overcome before that point.

He said: "Blood stem cells can give rise to all different types of blood cells, that all have their own role to play in keeping the body healthy.

"While we are still a long way off from being able to grow blood stem cells that could be used to treat patients, this is a step forward in the right direction.

"We hope that understanding further the mechanisms of how blood stem cells are generated in the body will one day enable us to efficiently produce blood stem cells for needs of patients."

Prof Medvinsky said he hoped to begin research on human blood stem cells later in the year, helped by funding from the Leukaemia Research Fund.

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Extensive Hematopoietic Stem Cell Generation in the AGM Region via Maturation of VE-Cadherin+CD45+ Pre-Definitive HSCs

Elucidating the mechanisms underlying hematopoietic stem cell (HSC) specification and expansion in the embryo has been hampered by the lack of analytical cell culture systems that recapitulate in vivo development. Here, we describe an ex vivo model that facilitates a rapid and robust emergence of multipotent long-term repopulating HSCs in the embryonic AGM region. Because this method includes a cell dissociation step prior to reconstruction of a three-dimensional functional tissue and preserves both stromal and hematopoietic elements, it allowed us to identify the direct ancestry of the rapidly expanding HSC pool. We demonstrate that extensive generation of definitive HSCs in the AGM occurs predominantly through the acquisition of stem characteristics by the VE-cadherin+CD45+ population.

http://www.cellstemcell.com/cont ... highlight=Medvinsky