Heart and blood cells can be grown from reprogrammed mouse skin cells, report University of California, Los Angeles (UCLA) researchers in the journal Stem Cells. The researchers say this is the first demonstration that stem cells from reprogrammed skin can be used to generate three types of heart and blood cell, including beating heart tissue. These could theoretically be used to repair damage following disease or heart attack.
Skin cells are transformed into stem cells using a combination of genetic factors. UCLA researchers were among those to develop the technique last June. The cells, known as induced pluripotent stem (iPS) cells, resemble embryonic stem (ES) cells but do not require the use of human eggs or embryos in their development. A Canadian team previously generated beating heart tissue using embryonic stem cells.
Robb MacLellan and his team grew iPS cells on a protein matrix designed to promote the transition of stem cells into cardiovascular progenitors. These specialised cells were then treated under different conditions to direct development into three types of cardiovascular tissue: cardiomyocytes, or mature heart muscle cells that control heartbeat, endothelial cells, which form rudimentary blood vessels, and vascular smooth muscle cells, the specialized cells that line blood vessel walls. The cardiomyocytes began to beat once mature. 'I believe iPS cells address many of the shortcomings of human embryonic stem cells and are the future of regenerative medicine', said MacLellan, senior study author and associate professor of cardiology and physiology.
If iPS cell-derived cardiovascular tissues can be used to treat heart disease or damage, they could potentially allow personalised treatment following, for instance, a heart attack. A patient's own skin cells could provide iPS cells that in turn would be used to develop new heart tissue, which would be genetically matched to the patient thus avoiding immune rejection. '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 cells types found in the human heart', MacLellan said.
Work is underway at UCLA to determine whether the techniques established in mice can be used in humans. Although human applications of this research remain distant, it seems that iPS cells could provide regenerative treatment in future without the need for the controversial use of human eggs and embryos.
