BACKGROUNDS:
To realize cardiac regeneration with human induced pluripotent stem cells (hiPSCs), efficient differentiation from hiPSCs to defined cardiac cell populations (cardiomyocytes [CMs]/ endothelial cells [ECs]/ vascular mural cells [MCs]), and transplantation technique for fair engraftment are required. Recently, we reported that mouse ES cell-derived cardiac tissue sheet transplantation to rat myocardial infarction (MI) model ameliorated cardiac function after MI (Stem Cells, in press). Here we tried to extend this technique to hiPSCs.
METHODS & RESULTS:
We have reported an efficient cardiomyocyte differentiation protocol based on a monolayer culture (PLoS One, 2011), in which cardiac troponin-T (cTnT)-positive CMs robustly appeared with 50-80% efficiency. In this study, we further modified the protocol to induce vascular cells (ECs/MCs) together with CMs by vascular endothelial cell growth factor supplementation, resulted in proportional differentiation of cTnT+-CMs (62.7±11.7% of total cells), VE-cadherin+-ECs (7.8±4.9%) and PDGFRb+-MCs (18.2±11.0%) at differentiation day 15 (n=12). Then, these cells were transferred onto temperature-responsive culture dishes (UpCell dishes; CellSeed, Tokyo, Japan) to form cardiac tissue sheets including defined cardiac populations. After 4 days of culture, we successfully collected self-pulsating cardiac tissue sheets with 7.0×10
5
±2.3 (n=12) of cells consisted of CMs (46.9±15.9% of total cells), ECs (4.1±3.7%), and MCs (22.5±15.7%). Three-layered hiPSC-derived cardiac sheets were transplanted to a MI model of athymic rat heart one week after MI. In transplantation group, echocardiogram showed a significant improvement of systolic function of left ventricle (fractional shortening: 22.6±5.0 vs 36.5±8.0%, p<0.001, n=20) and a decrease in akinetic length (20.8±9.7 vs 2.5±7.7%, p<0.001, n=20) (pre-treatment vs 4weeks after transplantation). We also succeeded in generation of larger sheets (1.6 inch diameter) with the same method.
CONCLUTIONS:
Transplantation of hiPSC-derived cardiac tissue sheets significantly ameliorates cardiac dysfunction after MI. Thus, we developed a valuable technological basis for hiPSC-based cardiac cell therapy.
Trichostatin A Enhances Differentiation of Human Induced Pluripotent Stem Cells to Cardiogenic Cells for Cardiac Tissue Engineering
