Mature Heart Muscle Cells from Stem Cells

To-date, researchers have been able to differentiate human embryonic stem cells (hESC) into immature heart muscle cells. But these cells are unable to develop the robust internal structures—repeating sections of muscle cells called sarcomeres—that enable cardiomyocytes, mature heart muscle cells, to produce the contracting force that allows the heart to pump blood. Other cell components that allow heart muscle cells to communicate and work together also are less developed in immature cardiomyocytes. Wendy C. Crone, from the University of Wisconsin/Madison (Wisconsin, USA), and colleagues have utilized micropatterned substrates to successfully culture cardiomyocytes.  The substrate, patterned with a precisely sized series of channels, coaxes the growing cells to form the aligned and fibrous structure that is seen in mature heart tissue.  The study authors report that: “The seeded cells showed clear alignment with the features, dependent on the width rather than the overall aspect ratio of the features. This creation of highly-aligned cell aggregates with robust sarcomere structures holds great potential in advancing cell-based pharmacological studies, and will help researchers to understand the means by which [extracellular matrix] geometries can affect myofilament structure and maturation in hESC-derived cardiomyocytes.”