Browsing by Author "Chen, Simin"

Heart disease is the principal cause of death in humans. Stem cell-based therapy for heart regeneration has long been seen as a potential application since the heart lacks adequate intrinsic regenerative potential. In the cardiovascular field, clinical trials have already been carried out by implantation of both bone marrow-derived stem cells and cardiac resident progenitor cells derived from the adult heart tissue into the injured myocardium to restore the functionality of the heart after damage. However, before a robust stem and progenitor cell-based therapy for cardiovascular diseases can be applied in the clinical setting, more research is necessary to generate sufficient quantities of functional cardiomyocytes from stem cells and to understand behavior of cardiomyocytes upon transplantation. A comprehensive understanding of the developmental processes involved in cardiogenesis might support further investigations in more efficient cell-based regeneration therapies. This review discusses the molecular aspects of cardiogenesis during early development and links the insights with the in vitro generation of cardiac progenitor cells as well as functional cardiomyocytes. Furthermore, we discuss the advantages of cardiac progenitor cells and cardiomyocytes derived from pluripotent stem cells, cardiac resident stem cells in regenerative applications to cope with the damaged heart.

Induced pluripotent stem cells (iPSCs) provide a unique opportunity for the generation of patient-specific cells for use in disease modelling, drug screening, and regenerative medicine. The aim of this study was to compare human-induced pluripotent stem cells (hiPSCs) derived from different somatic cell sources regarding their generation efficiency and cardiac differentiation potential, and functionalities of cardiomyocytes. We generated hiPSCs from hair keratinocytes, bone marrow mesenchymal stem cells (MSCs), and skin fibroblasts by using two different virus systems. We show that MSCs and fibroblasts are more easily reprogrammed than keratinocytes. This corresponds to higher methylation levels of minimal promoter regions of the OCT4 and NANOG genes in keratinocytes than in MSCs and fibroblasts. The success rate and reprogramming efficiency was significantly higher by using the STEMCCA system than the OSNL system. All analysed hiPSCs are pluripotent and show phenotypical characteristics similar to human embryonic stem cells. We studied the cardiac differentiation efficiency of generated hiPSC lines (n 24) and found that MSC-derived hiPSCs exhibited a significantly higher efficiency to spontaneously differentiate into beating cardiomyocytes when compared with keratinocyte-, and fibroblast-derived hiPSCs. There was no significant difference in the functionalities of the cardiomyocytes derived from hiPSCs with different origins, showing the presence of pacemaker-, atrial-, ventricular- and Purkinje-like cardiomyocytes, and exhibiting rhythmic Ca-2 transients and Ca-2 sparks in hiPSC-derived cardiomyocytes. Furthermore, spontaneously and synchronously beating and force-developing engineered heart tissues were generated. Human-induced pluripotent stem cells can be reprogrammed from all three somatic cell types, but with different efficiency. All analysed iPSCs can differentiate into cardiomyocytes, and the functionalities of cardiomyocytes derived from different cell origins are similar. However, MSC-derived hiPSCs revealed a higher cardiac differentiation efficiency than keratinocyte- and fibroblast-derived hiPSCs.