Abstract 13454: Development of Functional Tissue-engineered Artificial Cardiac Construct using Human Induced Pluripotent Stem Cells; Optimizing the Cell Components to Mimic Cardiac Tissue
Background: Tissue-engineered artificial cardiac constructs (ACCs) derived from human induced pluripotent stem cells (hiPSCs) are promising for myocardial regenerative medicine and drug discovery. However, the appropriate ratio of cardiomyocytes (CMs) and non-CMs, which would substantially impact on functionality of the ACC, is poorly understood. We herein developed the well-functioning ACCs derived from hiPSCs, mimicking native cardiac tissue.
Methods: Cardiomyogenic differentiation was induced in hiPSCs to produce a mixed cell preparation including iPSC-CMs and non-CMs. The cell preparation was separated based on expression of the iPSC-CM specific marker, CD172, using a magnetic-activated cell sorting system to produce cell preparations with different ratios (25, 50, 70, and 90%) of iPSC-CMs, which were then prepared as scaffold-free constructs using thermoresponsive culture dishes.
Results: The CD172-sorted iPSC-CMs showed >90% positivity for cardiac troponin T, whereas the CD172-negative iPSC-non-CMs included CD31-, α-smooth muscle actin- or vimentin-positive cells. The ACC showed synchronized spontaneous beating when CMs constituted 50% or more of the total cells in the ACC. The electrical conduction velocity, assessed by a multi-electrode array, was positively related to the CM ratio in the ACCs and was 3.5±1.8, 8.6±2.8, and 16±5.0 cm/sec for CM ratios of 50, 70, and 90%, respectively. However, the ACC including 90% CMs failed to form a stable structure. Collagen type I and III were more abundantly expressed in the ACC including 25% and 50% CMs, whereas laminin alpha 2 and 4, major extra cellular matrix components of cardiac tissue, were more abundantly expressed in the ACC including 70% CMs, as assessed by quantitative PCR. In addition, the gene expression ratio of myosin light chain (MLC) 2v and MLC2a, an indicative ratio of myocyte maturation, was the highest in the ACC including 70% CMs. Moreover, expression of angiogenic factors, such as vascular endothelial growth factor, was highest in the ACC including 70% CMs.
Counclusions: The ACC composed of 70% CMs displayed greater stability and functionality compared to those of other ratios, indicating a possibility of optimal ACCs as a bio-cardiac support device or a tool for drug discovery.
Author Disclosures: H. Iseoka: None. S. Miyagawa: None. S. Fukushima: None. S. Masuda: None. N. Mochizuki-Oda: None. A. Saito: None. E. Ito: None. T. Ishikawa: None. J. Lee: None. Y. Sawa: None.
- © 2014 by American Heart Association, Inc.