Electrical stimulation of human embryonic stem cells: Cardiac differentiation and the generation of reactive oxygen species

Abstract

Exogenous electric fields have been implied in cardiac differentiation of mouse embryonic stem cells and the generation of reactive oxygen species (ROS). In this work, we explored the effects of electrical field stimulation on ROS generation and cardiogenesis in embryoid bodies (EBs) derived from human embryonic stem cells (hESC, line H13), using a custom-built electrical-stimulation bioreactor. Electrical properties of the bioreactor system were characterized by electrochemical impedance spectroscopy (EIS) and analysis of electrical currents. The effects of the electrode material (stainless steel, titanium-nitride coated titanium, titanium), length of stimulus (1 s and 90 s) and age of EBs at the onset of electrical stimulation (4 and 8 days) were investigated with respect to ROS generation. The amplitude of the applied electrical field was 1 V/mm. The highest rate of ROS generation was observed for stainless steel electrodes, for signal duration of 90 s, and 4-days old EBs. Notably, comparable ROS generation was achieved by incubation of EBs with 1 nM H2O2. Cardiac differentiation in these EBs was evidenced by spontaneous contractions, expression of Troponin T, and its sarcomeric organization. These results imply that electrical stimulation plays a role in cardiac differentiation of hESCs, through mechanisms associated with the intracellular generation of ROS.

The Combination of Electric Current and Copper Promotes Neuronal Differentiation of Adipose-Derived Stem Cells

“…High amounts of ROS can cause cell death and disrupt or inhibit gene expression but at lower levels ROS can increase the proliferation and differentiation by activating many signaling cascades and transcription factors 18,[37][38][39] . However, the actual effect of ROS in this stimulation setup still needs to be investigated.…”

Potential for pharmacological manipulation of human embryonic stem cells

“…This study found a link between the eicosanoid signalling pathway and pluripotency and several oxidized metabolites and the promotion of neuronal and cardiac differentiation. A previously mentioned study found that an increase in ROS, which would lead to an increase in oxidized metabolites, led to cardiac differentiation (Serena et al, 2009) and mesodermal/ endodermal differentiation (Ji et al, 2010). Oxygen tension may also affect differentiation (Chen et al, 2010b;Lim et al, 2011) as, similar to hESC culture, differentiation protocols do no tend to use physiological levels of oxygen, as is shown in the production of retinal progenitor cells (Bae et al, 2011), mesoderm and cardiac cells (Niebruegge et al, 2009), chondrocytes (Koay andAthanasiou, 2008) and functional endothelium (Prado-Lopez et al, 2010) from hESCs.…”

“…The effects of electrical field stimulation on ROS generation and cardiogenesis in EBs derived from hESCs have also been explored and, under optimal conditions, cardiac differentiation induced by EFS was observed to be similar to that after H 2O2 treatment (Serena et al, 2009). Further the growth of hESCs in ROS-inducing conditions (BSO treatment, which inhibits intracellular glutathione and enriches ROS levels) has been shown to induce an up-regulation in mesodermal and endodermal differentiation and this occurred through MAPK signalling (Ji et al, 2010).…”

Hydrogels for cardiac tissue engineering

“…For example, it was found that cardiac differentiation of human ESCs were promoted by applying electrical stimulation using a bioreactor. 82 In another study, it was demonstrated that uniaxial mechanical loading promoted the cardiomyocyte differentiation of human ESCs within 3D collagen hydrogels. 83 It was found that the application of mechanical stimulation enhanced cardiomyocyte alignment, hypertrophy, proliferation as well as the formation of sarcomeric bands.…”