Reactive oxygen species enhance differentiation of human embryonic stem cells into mesendodermal lineage

Abstract

Recently, reactive oxygen species (ROS) have been studied as a regulator of differentiation into specific cell types in embryonic stem cells (ESCs). However, ROS role in human ESCs (hESCs) is unknown because mouse ESCs have been used mainly for most studies. Herein we suggest that ROS generation may play a critical role in differentiation of hESCs; ROS enhances differentiation of hESCs into bi-potent mesendodermal cell lineage via ROS-involved signaling pathways. In ROS-inducing conditions, expression of pluripotency markers (Oct4, Tra 1-60, Nanog, and Sox2) of hESCs was decreased, while expression of mesodermal and endodermal markers was increased. Moreover, these differentiation events of hESCs in ROS-inducing conditions were decreased by free radical scavenger treatment. hESC-derived embryoid bodies (EBs) also showed similar differentiation patterns by ROS induction. In ROS-related signaling pathway, some of the MAPKs family members in hESCs were also affected by ROS induction. p38 MAPK and AKT (protein kinases B, PKB) were inactivated significantly by buthionine sulfoximine (BSO) treatment. JNK and ERK phosphorylation levels were increased at early time of BSO treatment but not at late time point. Moreover, MAPKs family-specific inhibitors could prevent the mesendodermal differentiation of hESCs by ROS induction. Our results demonstrate that stemness and differentiation of hESCs can be regulated by environmental factors such as ROS.

Differential resistance of human embryonic stem cells and somatic cell types to hydrogen peroxide-induced genotoxicity may be dependent on innate basal intracellular ROS levels

“…Hence, the observed higher resistance of undifferentiated hESC to oxidative stress and genotoxic stress compared to somatic cell types, as reported by our previous studies [5,6], could be due to lower innate basal intracellular levels of ROS within hESCs compared to somatic cell types. Our findings are consistent with previous studies which showed that ROS play crucial roles as secondary messengers during stem cell differentiation into various somatic lineages [10,11], so that an increase in ROS levels in differentiated stem cell progenies is therefore expected. Hirano and Tamae [12] and Kuboyama et al [13], also reported that undifferentiated embryonic stem cells were more resistant to DNA damage induced by the ROS -8-oxoguanine (which is known to generate GC-to-TA point mutations in genomic DNA), as compared to their differentiated progenies.…”

SIRT1 Deficiency Downregulates PTEN/JNK/FOXO1 Pathway to Block Reactive Oxygen Species-Induced Apoptosis in Mouse Embryonic Stem Cells

“…A low-level ROS pulse is required specifically for cardio and vascular differentiation from mES cells [5]. ROS also enhances spontaneous differentiation of human ES cells into mesendodermal cell lineage [47].…”

Potential for pharmacological manipulation of human embryonic stem cells

“…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). These studies are the first to demonstrate ROS-mediated differentiation in hESCs.…”

“…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.…”