SOX2 Is Regulated Differently from NANOG and OCT4 in Human Embryonic Stem Cells during Early Differentiation Initiated with Sodium Butyrate

Ade Kallas,Annika Trei,Toivo Maimets,Martin Pook

doi:10.1155/2014/298163

Abstract

Transcription factors NANOG, OCT4, and SOX2 regulate self-renewal and pluripotency in human embryonic stem (hES) cells; however, their expression profiles during early differentiation of hES cells are unclear. In this study, we used multiparameter flow cytometric assay to detect all three transcription factors (NANOG, OCT4, and SOX2) simultaneously at single cell level and monitored the changes in their expression during early differentiation towards endodermal lineage (induced by sodium butyrate). We observed at least four distinct populations of hES cells, characterized by specific expression patterns of NANOG, OCT4, and SOX2 and differentiation markers. Our results show that a single cell can express both differentiation and pluripotency markers at the same time, indicating a gradual mode of developmental transition in these cells. Notably, distinct regulation of SOX2 during early differentiation events was detected, highlighting the potential importance of this transcription factor for self-renewal of hES cells during differentiation.

Highlights

The differentiation potential of human embryonic stem cells and human induced pluripotent stem cells is a subject of great interest in basic and clinical research
We assessed the coexpression of transcription factors NANOG, OCT4, and SOX2 in pluripotent human embryonic stem (hES)
The coexpression of NANOG, OCT4, and SOX2 was detected in 91% of cells, demonstrating that during regular culture of hESC a small subpopulation of cells expressed SOX2 and SSEA-3, but not NANOG and OCT4

Summary

Introduction

The differentiation potential of human embryonic stem (hES) cells and human induced pluripotent stem (hiPS) cells is a subject of great interest in basic and clinical research. Small changes in the level of OCT4 can force pluripotent stem cells to differentiate into cells that express markers of endoderm, mesoderm, or extraembryonic lineages such as trophectoderm-like cells [11, 12]. Knockdown of SOX2 in hES cells promotes differentiation into trophectoderm-like cells [13], while overexpression of SOX2 induces differentiation to trophectoderm [14]. It is currently unclear how hES cells maintain the expression of these key transcription factors within the narrow limits that permit continuation of the undifferentiated state. In order to begin investigating this, we undertook an analysis of expression of NANOG, OCT4, and SOX2 at the single cell level at pluripotency and during induced differentiation or commitment

Methods

Results

Discussion

Conclusion