Source: Johns Hopkins Medicine
Date: August 21, 2012
Summary:
Johns Hopkins scientists have developed a reliable method to turn the clock back on blood cells, restoring them to a primitive stem cell state from which they can then develop into any other type of cell in the body. The work, described in the Aug. 8 issue of the journal Public Library of Science One (PLoS One), is "Chapter Two" in an ongoing effort to efficiently and consistently convert adult blood cells into stem cells that are highly qualified for clinical and research use in place of human embryonic stem cells, says Elias Zambidis, M.D., Ph.D., assistant professor of oncology and pediatrics at the Johns Hopkins Institute for Cell Engineering and the Kimmel Cancer Center.
For the new study, the Johns Hopkins team took cord blood cells, treated them with growth factors, and used plasmids to transfer four genes into them. They then delivered an electrical pulse to the cells, making tiny holes in the surface through which the plasmids could slip inside. Once inside, the plasmids triggered the cells to revert to a more primitive cell state. The scientific team next grew some of the treated cells in a dish alone, and some together with irradiated bone-marrow cells.
When scientists compared the cells grown using the blood cell method with iPS cells grown from hair cells and from skin cells, they found that the most superior iPS cells came from blood stem cells treated with just four genes and cultured with the bone marrow cells. These cells converted to a primitive stem cell state within seven to 14 days. Their techniques also were successful in experiments with blood cells from adult bone marrow and from circulating blood.
