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

Ae-Ri Ji,Shin Yong Moon,Seung-Yup Ku,Myung Soo Cho,Sun Kyung Oh,Young Min Choi,Yong Jin Kim,Seok Hyun Kim,Yoon Young Kim

doi:10.3858/emm.2010.42.3.018

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.

Highlights

Human embryonic stem cells have a common characteristic; hESCs are capable of generating identical daughter cells by unlimited cell divisions and differentiating into all cell types (Carpenter et al, 2004)
buthionine sulfoximine (BSO) which inhibits intracellular glutathione and enriches the level of reactive oxygen species (ROS) was used for ROS induction in hESCs and generated ROS were detected by dichloroflurescein diacetate (DCF-DA) staining
We have described the biological effects of ROS on hESC differentiation, into mesendodermal lineages

Summary

Introduction

Human embryonic stem cells (hESCs) have a common characteristic; hESCs are capable of generating identical daughter cells by unlimited cell divisions and differentiating into all cell types (Carpenter et al, 2004). This ability of hESCs has been shown to be dependent on the intrinsic regulators and the extracellular environment niche. ROS generated at low-to-moderate concentrations act as signaling molecules that are involved in signal transduction-mediated biological effects in cells. Such effects of ROS are related to differences in the concentrations of ROS (Valko et al, 2007)

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