SHP-1 Arrests Mouse Early Embryo Development through Downregulation of Nanog by Dephosphorylation of STAT3

Songna Yin,Haibo Wu,Yan Zhang,Juan Du,Xinying Wu,Yong Zhang,Jiaxing Lv,Maria Cristina Vinci

doi:10.1371/journal.pone.0086330

Abstract

Src-homology protein tyrosine phosphatase-1 (SHP-1) is a protein tyrosine phosphatase that is implicated in the regulation of growth, differentiation, survival, apoptosis and proliferation of hematopoietic cells and other cell types. Here, we found that SHP-1 is involved in regulation of early embryonic development. Embryos overexpressing SHP-1 were mainly arrested at the 8-cell stage, and Nanog mRNA expression was first observed in the morulae that showed down-regulation of SHP-1. These results suggested an antagonistic relationship between SHP-1 and Nanog during early embryonic development. Next, the specific mechanism was examined in mouse F9 embryonal carcinoma cells. We confirmed that signal transducer and activator of transcription 3 (STAT3) was a substrate for SHP-1 by co-immunoprecipitation. Using overexpression and knockdown strategies, we found that SHP-1 participated in regulation of Nanog expression. Furthermore, site mutation of STAT3 was performed to confirm that SHP-1 was responsible for rapid STAT3 dephosphorylation and a decrease of Nanog expression in F9 cells. These findings suggest that SHP-1 plays a crucial role during early embryonic development. Thus, SHP-1 may function as a key regulator for Nanog that specifically demarcates the nascent epiblast, coincident with the domain of X chromosome reprogramming.

Highlights

Src-homology protein tyrosine phosphatase-1 (SHP-1) is a cytokine-inducible SH2-containing protein
We found that in signal transducer and activator of transcription 3 (STAT3) knocked down F9 cells, Nanog promoter activity was reduced to 50% when overexpressed SHP-1 (Fig. 5D); Nanog promoter activity was reduced to 42% when SHP-1 was knocked down (Fig. 5E)
With overexpression of STAT3 (Y750F), knockdown of SHP1 up-regulated Nanog and overexpression of SHP-1 inhibited the expression of Nanog

Summary

Introduction

Src-homology protein tyrosine phosphatase-1 (SHP-1) is a cytokine-inducible SH2-containing protein. It has been implicated in the regulation of multiple signaling pathways involved in cell growth, differentiation, survival and apoptosis [1,2]. SHP-1 is a non-receptor phosphatase that negatively regulates cytokine signaling and tyrosine kinase receptors, and functionally interacts with numerous proteins through SH2-mediated association with the phosphorylated tyrosine subunit [3]. Down-regulation of Nanog during the implantation stage is consistent with the intimate association with restricted expression to the epiblast [8]. Nanog is critical for the early inner cell mass to mature into the pluripotent epiblast [9]. We describe the mechanism of SHP-1 signaling through STAT3 following stimulation, which decreases Nanog expression by blocking STAT3 activation in F9 cells

Methods

Results

Conclusion