Induced pluripotent stem cells: fibroblasts are optional
Embryonic stem cells can be obtained from blood cellsDmitry Safin, "Kompyulenta"
A group of scientists from the USA managed to reprogram cells contained in human peripheral blood and turn them into complete functional analogues of embryonic stem cells (ESCs).
"Using blood samples, which are usually not difficult to select, to obtain pluripotent stem cells is one of the easiest ways to perform this kind of surgery, which in the future will allow each person to provide a set of their own stem cells," said the study's lead author George Q. Daley from the Howard Hughes Medical Institute.
To create induced pluripotent stem (iPS) cells, scientists used CD34+ cells (hemocytoblasts, precursors of all types of blood cells) isolated from the blood of a 26-year-old man. In order to increase the total number of CD34+, they were aged in the presence of growth factors for six days. In the process of cultivation, scientists by transduction introduced into CD34+ cells the so–called reprogramming factors - genes, the expression of which is observed in ESCs. Two weeks later, the appearance of colonies of cells resembling ESCs in physical parameters was registered. Having studied their markers (characteristic combinations of proteins), the authors came to the conclusion that they are identical in functional characteristics to iPS cells.
Under laboratory conditions, such iPS cells quickly formed embryoid bodies - clusters from which cells of almost any type can develop. In order to test how the "reprogrammed" cells would behave in a living organism, scientists injected them into immunodeficient mice. After some time, the formation of teratomas consisting of well-differentiated tissues (derivatives of all three germ leaves) was recorded.
"My colleagues have indicated a new type of available programmable cells that will undoubtedly be analyzed in many research laboratories around the world," says Professor Grover C. Bagby of the Oregon Health and Science University (USA), who was not involved in the work, with confidence. "These discoveries will help determine what potential iPS cells have."
The full version of the report will be published in the journal Blood, published by the American Hematology Society.
Prepared based on the materials of EurekAlert!.
Portal "Eternal youth" www.vechnayamolodost.ru22.04.2009