The protein phosphatase activity of PTEN is essential for regulating neural stem cell differentiation.

Jingwen Lyu,Xiuya Yu,Zilong Qiu,Jingjing Zhou,Lingjie He,Wenhao Zhou,Guoqiang Cheng,Cheng Cheng,Tianlin Cheng,Zhifang Chen

doi:10.1186/s13041-015-0114-1

Abstract

BackgroundThe tumor suppressor gene Phosphatase and tensin homolog (PTEN) is highly expressed in neural progenitor cells (NPCs) and plays an important role in development of the central nervous system. As a dual-specificity phosphatase, the loss of PTEN phosphatase activity has been linked to various diseases.ResultsHere we report that the protein phosphatase activity of Pten is critical for regulating differentiation of neural progenitor cells. First we found that deletion of Pten promotes neuronal differentiation. To determine whether the protein or lipid phosphatase activity is required for regulating neuronal differentiation, we generated phosphatase domain-specific Pten mutations. Interestingly, only expression of protein phosphatase-deficient mutant Y138L could mimic the effect of knocking down Pten, suggesting the protein phosphatase of Pten is critical for regulating NPC differentiation. Importantly, we showed that the wild-type and lipid phosphatase mutant (G129E) forms of Pten are able to rescue neuronal differentiation in Pten knockout NPCs, but mutants containing protein phosphatase mutant cannot. We further found that Pten-dependent dephosphorylation of CREB is critical for neuronal differentiation.ConclusionOur data indicate that the protein phosphatase activity of PTEN is critical for regulating differentiation of NSCs during cortical development.Electronic supplementary materialThe online version of this article (doi:10.1186/s13041-015-0114-1) contains supplementary material, which is available to authorized users.

Highlights

The tumor suppressor gene Phosphatase and tensin homolog (PTEN) is highly expressed in neural progenitor cells (NPCs) and plays an important role in development of the central nervous system
Pten-deficient neural stem cells (NSCs) differentiate precociously into neurons To evaluate the function of Pten in embryonic NSCs, the fate of neurospheres derived from PtenloxP/loxP embryos at E12.5 and maintained under proliferating culture conditions was examined
We found that wild-type CAMP response element-binding protein (CREB), but not S133A mutant, could rescue the abnormal neuronal differentiation caused by PTEN deletion, Figure 3 RNAi-resistant PTEN rescues the effect of PTEN knockdown. (A) Schematic illustration of lentiviral-based PTEN wild type, G129E, Y138L rescue constructs. (B) 293 T cells were transfected with vector, HA-PTEN-WT, HA-PTEN-WT-rescue, HA-PTEN-G129E-rescue, HA-PTEN-Y138L-rescue resulted in the expression of a 55 kDa band corresponding to the PTEN protein, as seen by western blotting. (C) The data show the Tuj1 positive cells in control, PTEN RNAi, PTEN RNAi + HA-PTEN-(WT, G129E, Y138L)-rescue conditions respectively. (D) NSCs transduced with green fluorescent protein (GFP), PTEN RNAi, or PTEN RNAi + HA-PTEN-(WT, G129E, Y138L)-rescue constructs were labeled with an antibody against the neuronal marker Tuj1

Summary

Introduction

The tumor suppressor gene Phosphatase and tensin homolog (PTEN) is highly expressed in neural progenitor cells (NPCs) and plays an important role in development of the central nervous system. Embryonic Pten null mice have enlarged brains [7,8,18], while Pten deletion in adult mice enhanced NSC proliferation and differentiation into neurons, suppressed cell death, and resulted in an increased cell size [5,6,7,8]. Despite these observations, the Pten deletion mouse model has not provided a clear insight into the role or mechanism of PTEN function in NSCs during embryonic development

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Conclusion