A simple and non-genetic method for isolating highly pure heart muscle cells derived from stem cells is reported in this week's Nature Methods. The method will facilitate many studies that depend on pure populations of heart muscle cells, called cardiomyocytes.
Pluripotent stem cells can differentiate into several different cell types ― such as cardiomyocytes or neurons ― but the process is rarely one-hundred percent efficient. Therefore there is need for a methodology to purify the differentiated cells.
Keichi Fukuda and colleagues show that cardiomyocytes derived from mouse, marmoset and human embryonic stem cells, and also from mouse and human induced pluripotent stem cells, can be isolated to high purity. The scientists accomplished this by labeling the differentiated cells with a fluorescent dye that stains mitochondria and then collecting the cells that contained high levels of the dye. In contrast to existing methods, in which cardiomyocytes are isolated based on their expression of fluorescent markers, Fukuda and colleagues' method does not require genetic modification. The scientists note that this method of staining and sorting is successful in part because the cardiomyocytes have a high mitochondrial content.
Highly pure populations of cardiomyocytes can be used for a variety of basic studies on cardiac biology both in Petri dishes and in animals as well as for more applied studies such as drug screening.