Feasibility, Safety, and Therapeutic Efficacy of Human Induced Pluripotent Stem Cell-Derived Cardiomyocyte Sheets in a Porcine Ischemic Cardiomyopathy Model

Abstract

Background-Human induced pluripotent stem cell-derived cardiomyocytes (hiPS-CMs) are a promising source of cells for regenerating myocardium. However, several issues, especially the large-scale preparation of hiPS-CMs and elimination of undifferentiated iPS cells, must be resolved before hiPS cells can be used clinically. The cell-sheet technique is one of the useful methods for transplanting large numbers of cells. We hypothesized that hiPS-CM-sheet transplantation would be feasible, safe, and therapeutically effective for the treatment of ischemic cardiomyopathy. Methods and Results-Human iPS cells were established by infecting human dermal fibroblasts with a retrovirus carryingOct3/4, Sox2, Klf4, and c-Myc. Cardiomyogenic differentiation was induced by WNT signaling molecules, yielding hiPS-CMs that were almost 90% positive for ␣-actinin, Nkx2.5, and cardiac troponin T. hiPS-CM sheets were created using thermoresponsive dishes and transplanted over the myocardial infarcts in a porcine model of ischemic cardiomyopathy induced by ameroid constriction of the left anterior descending coronary artery (nϭ6 for the iPS group receiving sheet transplantation and the sham-operated group; both groups received tacrolimus daily). Transplantation significantly improved cardiac performance and attenuated left ventricular remodeling. hiPS-CMs were detectable 8 weeks after transplantation, but very few survived long term. No teratoma formation was observed in animals that received hiPS-CM sheets. Conclusions-The culture system used yields a large number of highly pure hiPS-CMs, and hiPS-CM sheets could improve cardiac function after ischemic cardiomyopathy. This newly developed culture system and the hiPS-CM sheets may provide a basis for the clinical use of hiPS cells in cardiac regeneration therapy. Key Words: pluripotent stem cell Ⅲ regeneration therapy Ⅲ transplantation T he myocardium has limited regenerative capacity, and loss of myocardium due to myocardial infarction therefore leads to heart failure. Despite remarkable recent progress in medical and surgical treatments for heart failure, end-stage heart failure remains a leading cause of morbidity and mortality. 1 Therefore, the myocardium is one of the most important targets in regenerative medicine. Cell therapy has been introduced as a new treatment for heart failure. Clinical trials using bone marrow cells and myoblasts are underway; although these cells improve cardiac performance, chiefly through paracrine cytokine effects, they show limited differentiation into cardiomyocytes. 2 Induced pluripotent stem (iPS) cells were first generated by nuclear reprogramming of mouse fibroblasts in 2006, 3 and human iPS (hiPS) cells were established in 2007 by the transduction of defined factors. 4,5 The production of hiPS cells poses fewer legal and ethical issues than does the generation of human embryonic stem (ES) cells. In addition, recent studies have demonstrated methods for the highly efficient production from hiPS cells of cardiomyocytes with typical electrophysio...

Preclinical Studies for Induced Pluripotent Stem Cell-based Therapeutics

“…Recently, Templin et al (39) reported vascular differentiation and long-term engraftment of human iPSCs in a pig model of myocardial infarction. The use of human iPSC-derived cardiomyocyte sheets on temperature-sensitive polymers has been explored in the porcine ischemic model in an attempt to improve cell survival and engraftment (40). Additional technological improvements are required to obtain long-lasting therapeutic effects.…”

Scalable culture of human pluripotent stem cells in 3D

“…In this instance, the use of thermoreversible gel properties enables Lei and Schaffer (7) to simply change the temperature to quickly and efficiently extract cells from the gels without adversely affecting cell viability. The reversible use of the 3D hydrogel for hPSC growth is similar to the thermoreversible hydrogel surface-coating technologies pioneered by Okano and colleagues that are now being used to produce intact cell-sheet products for tissue-engineering applications (14).…”

Cardiac Repair Using Stem Cells Conditioned Media Based Therapy in a Rodent Model of Myocardial Infarction and Heart Failure

“…Additionally, adverse events including rhythm disturbances and teratoma/teratocarcinoma formation have been identified utilizing stem cell grafting techniques, hampering this methodology [29][30][31][32] .…”