Characterization and Enrichment of Cardiomyocytes Derived From Human Embryonic Stem Cells

Abstract

Abstract-Cell replacement therapy is a promising approach for the treatment of cardiac diseases, but is challenged by a limited supply of appropriate cells. We have investigated whether functional cardiomyocytes can be efficiently generated from human embryonic stem (hES) cells. Cardiomyocyte differentiation was evaluated using 3 parent (H1, H7, and H9) hES cell lines and 2 clonal (H9.1 and H9.2) hES cell lines. All cell lines examined differentiated into cardiomyocytes, even after long-term culture (50 passages or Ϸ260 population doublings). Upon differentiation, beating cells were observed after one week in differentiation conditions, increased in numbers with time, and could retain contractility for over 70 days. The beating cells expressed markers characteristic of cardiomyocytes, such as cardiac ␣-myosin heavy chain, cardiac troponin I and T, atrial natriuretic factor, and cardiac transcription factors GATA-4, Nkx2.5, and MEF-2. In addition, cardiomyocyte differentiation could be enhanced by treatment of cells with 5-aza-2Ј-deoxycytidine but not DMSO or retinoic acid. Furthermore, the differentiated cultures could be dissociated and enriched by Percoll density centrifugation to give a population containing 70% cardiomyocytes.

Gene Therapy for Cardiac Arrhythmias

“…Recent extensive developments in the understanding of embryonic stem cells (ESCs) and induced pluripotent stem cells have accelerated cell therapy for bradycardia. Since ESCs have the potential to differentiate into cardiomyocytes, 34,35 transplantation of ESC-derived pacemaker cells induced spontaneous ectopic beats. 36,37 …”

DNA hypermethylation in lung cancer is targeted at differentiation-associated genes

“…Based on these insights, we suspect that DNA methylation mechanistically contributes to the establishment of an early developmental, undifferentiated phenotype in cancer. It has been widely observed that DNA methyltransferase inhibitors induce differentiation (Xu et al, 2002;Yoon et al, 2006;Banerjee and Bacanamwo, 2010). The hypermethylation of differentiation-associated genes in lung cancer could also provide an explanation for the observed induction of differentiation in cells treated with DNA methyltransferase inhibitors.…”

Constraining the Pluripotent Fate of Human Embryonic Stem Cells for Tissue Engineering and Cell Therapy – The Turning Point of Cell-Based Regenerative Medicine

“…However, the nervous system and the heart are among the first tissue and organ systems formed from the cells of the ICM in embryogenesis. In fact, substantial neural and cardiac differentiation appears to occur at relatively early stages in embryonic stem cells cultivation under conditions that induce differentiation [22–26]. It is deducible that the specification of early embryonic neural and cardiac lineages may occur directly from the pluripotent hESCs, precede the germ layer formation, and subsequently influence lineage determination at later stages of the developmental continuum.…”

“…In hESC-differentiating multi-lineage aggregates (EBs), only a very small fraction of cells (< 4 %) spontaneously differentiate into cardiomyocytes [3,26]. Immune-selection, co-culturing, and morphogens have been used to isolate and enrich populations of immature cardiomyocytes from hESC-differentiating EBs [26,116–119]. Enriched hESC-derived cardiomyocytes could generate small grafts and function as the biological pacemaker in animal infarcted models [27].…”

“…Schematic comparison of well-controlled efficient cardiac lineage-specific differentiation of pluripotent hESCs maintained under the defined culture exclusively to a cardiomyocyte fate by small signal molecule induction [3,12–16,21] versus conventional cardiac differentiation approach using multi-lineage inclination of pluripotent cells through spontaneous germ layer induction [26,27,115–125]…”