Effect of Human Donor Cell Source on Differentiation and Function of Cardiac Induced Pluripotent Stem Cells

Abstract

Background Human-induced pluripotent stem cells (iPSCs) are a potentially unlimited source for generation of cardiomyocytes (iPSC-CMs). However, current protocols for iPSC-CM derivation face a number of challenges, including variability in somatic cell sources and inconsistencies in cardiac differentiation efficiency. Objectives We aimed to assess the effect of epigenetic memory on differentiation and function of iPSC-CMs generated from somatic cell sources of cardiac versus non-cardiac origins. Methods Cardiac progenitor cells (CPCs) and skin fibroblasts from the same donors were reprogrammed into iPSCs and differentiated into iPSC-CMs via embryoid body and monolayer-based differentiation protocols. Results Differentiation efficiency was found to be higher in CPC-derived iPSC-CMs (CPC-iPSC-CMs) than in fibroblast-derived iPSC-CMs (Fib-iPSC-CMs). Gene expression analysis during cardiac differentiation demonstrated upregulation of cardiac transcription factors in CPC-iPSC-CMs, including NKX2-5, MESP1, ISL1, HAND2, MYOCD, MEF2C, and GATA4. Epigenetic assessment revealed higher methylation in the promoter region of NKX2-5 in Fib-iPSC-CMs compared to CPC-iPSC-CMs. Epigenetic differences were found to dissipate with increased cell passaging, and a battery of in vitro assays revealed no significant differences in their morphological and electrophysiological properties at early passage. Finally, cell delivery into small animal myocardial infarction (MI) model indicated that CPC-iPSC-CMs and Fib-iPSC-CMs possess comparable therapeutic capabilities in improving functional recovery in vivo. Conclusions This is the first study to compare differentiation of iPSC-CMs from human CPCs versus human fibroblasts from the same donors. We demonstrate that while epigenetic memory improves differentiation efficiency of cardiac versus non-cardiac somatic cell source in vitro, it does not contribute to improved functional outcome in vivo.

A Singular Role of IK1 Promoting the Development of Cardiac Automaticity during Cardiomyocyte Differentiation by IK1 –Induced Activation of Pacemaker Current

“…In our study, we found that I K1 -induced I f activation could regulate the automaticity of mouse and human ESC-CMs differentiated with two different methods, EB-differentiation and inductive co-culture, indicating a general role of I K1 -induced I f activation during the development of cardiac automaticity. This is consistent with previous finding that the epigenetic memory of cardiac somatic cell source does not influence the functional outcome of iPSC-differentiated CMs, while it improves cardiac differentiation efficiency 48 .…”

Epigenetic modification in congenital heart diseases by using stem cell technologies

“…Epigenetic memory has thus complicated study of the differentiation of iPS cells. In terms of this phenomenon, variable findings have been reported: some studies claimed that epigenetic memory accounted for only a small proportion of the variability [69,70] and disappeared after repeated passages [67,68] , while others reported that epigenetic memory remained [66] . Indeed, there are certain difficulties associated with the use of iPS cells, but they have fascinating features compared with ES cells, so they could be used as disease models.…”

“…When we differentiate iPS cells into a designed type of cell, it would be better to select iPS cells generated from that particular type of somatic cell. Some studies have proved the significant differences in differentiation potential among designed cells to differentiate into other types of cell [66][67][68] . In our experiments, we generated iPS cells from CPCs and differentiated them into cardiomyocytes [44] .…”

“…In contrast to the findings of Kim et al, Polo et al reported that the repeated passage of iPS cells eliminated their transcriptional, epigenetic, and functional differences among those with different original cell types. In addition, Sanchez-Freire et al generated iPS cells from CPCs and skin fibroblasts from the same donors and differentiated them into cardiomyocytes [68] . They showed that there were significantly higher rates of TNNT2-positive cells and beating EBs in the CPC-iPS-derived cardiomyocytes than in the fibroblast-iPS-derived ones.…”

BMP and WNT: the road to cardiomyocytes is paved with precise modulation

“…However, iPSCs have a number of benefits including their genetic match to an individual patient genotype. Importantly, iPSCs often display biased differentiation efficiency according to the lineage of source cells (5), including the cardiac lineage (6). In this respect, the results presented in this study open the question of whether cardiac propensity of iPSC lines is measurable in inherited responsiveness to BMP and WNT signaling cascades.…”