STEM-CELL RESEARCHERS AT UCLA have grown functioning cardiac cells, using mouse-skin cells that had been reprogrammed into cells with the same unlimited properties as embryonic stem cells. The finding is the first to show that induced pluripotent stem cells, or iPS cells, which don’t involve the use of embryos or eggs, can be differentiated into the three types of cardiovascular cells needed to repair the heart and blood vessels.
The discovery could one day lead to clinical trials of new treatments for people who suffer heart attacks, have atherosclerosis or are in heart failure, says W. Robb MacLellan, M.D., a researcher at the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA and senior author of the study. Researchers also were able to differentiate the iPS cells into several types of blood cells, which may one day aid in treating blood diseases and in transplanting bone marrow.
The study, which was published online in the journal Stem Cells, follows a breakthrough last year in which UCLA stem-cell researchers were among several scientific teams that were the first to create iPS cells by reprogramming mouse-skin cells into cells resembling embryonic stem cells. Although iPS cells are believed to be very similar to embryonic stem cells, further study needs to be done to confirm their differentiation potential. Dr. MacLellan’s study proved that iPS cells can be induced into becoming cardiovascular cells, an important step in the confirmation process.
Studies are also under way at UCLA to determine if human iPS cells behave similarly to mouse cells. If they do, the time may come when a person could use his or her own skin cells to create individualized iPS cell lines to provide cells for cardiac repair and regeneration, Dr. MacLellan says.
“Our hope is that, based on this work in mice, we can show that similar cardiovascular progenitor cells can be found in human iPS cells and, using a similar strategy, that we can isolate the progenitor cells and differentiate them into the cell types found in the human heart,” Dr. MacLellan says.
(A) Undifferentiated induced-pluripotent stem (iPS) cell colonies; (B) iPS cell-derived embryoid body; iPS cell-derived cardiovascular progenitor cells differentiate into (C)hematopoietic cells (blood) and (D) show cardiovascular differentiation into endothelial cells (blood vessel, green) and cardiac myocytes (heart muscle, red).Photography: Courtesy of Dr. W. Robb Maclellan.