Matrigel Mattress: A Method for the Generation of Single Contracting Human-Induced Pluripotent Stem Cell-Derived Cardiomyocytes
Rationale: The lack of measurable single cell contractility of human induced pluripotent stem cell-derived cardiac myocytes (hiPSC-CMs) currently limits the utility of hiPSC-CMs for evaluating contractile performance for both basic research and drug discovery.
Objective: To develop a culture method that rapidly generates contracting single hiPSC-CMs and allows quantification of cell shortening with standard equipment used for studying adult cardiac myocytes (CMs).
Methods and Results: Single hiPSC-CMs were cultured for 5 - 7 days on a 0.4 - 0.8 mm thick mattress of undiluted Matrigel ("mattress hiPSC-CM") and compared to hiPSC-CMs maintained on control substrate (<0.1 mm thick 1:60 diluted matrigel, "control hiPSC-CM"). Compared to control hiPSC-CM, mattress hiPSC-CMs had more rod-shape morphology and significantly increased sarcomere length. Contractile parameters of mattress hiPSC-CMs measured with video-based edge detection was comparable to that of freshly isolated adult rabbit ventricular CMs. Morphological and contractile properties of mattress hiPSC-CM were consistent across cryopreserved hiPSC-CMs generated independently at another institution. Unlike control hiPSC-CM, mattress hiPSC-CMs display robust contractile responses to positive inotropic agents such as myofilament calcium sensitizers. Mattress hiPSC-CMs exhibit molecular changes that include increased expression of the maturation marker cardiac troponin I and significantly increased action potential upstroke velocity due to a 2-fold increase in sodium current (INa).
Conclusions:The Matrigel mattress method enables the rapid generation of robustly contracting hiPSC-CMs and enhances maturation. This new method allows quantification of contractile performance at the single cell level, which should be valuable to disease modeling, drug discovery and preclinical cardiotoxicity testing.
- induced pluripotent stem cells
- stem cell
- excitation-contraction coupling
- cardiac function
- Received September 8, 2015.
- Revision received September 22, 2015.
- Accepted October 1, 2015.