Elevated p53 Activities Restrict Differentiation Potential of MicroRNA-Deficient Pluripotent Stem Cells

Stem Cell Reports. 2017 Nov 14;9(5):1604-1617. doi: 10.1016/j.stemcr.2017.10.006.

Abstract

Pluripotent stem cells (PSCs) deficient for microRNAs (miRNAs), such as Dgcr8-/- or Dicer-/- embryonic stem cells (ESCs), contain no mature miRNA and cannot differentiate into somatic cells. How miRNA deficiency causes differentiation defects remains poorly understood. Here, we report that miR-302 is sufficient to enable neural differentiation of differentiation-incompetent Dgcr8-/- ESCs. Our data showed that miR-302 directly suppresses the tumor suppressor p53, which is modestly upregulated in Dgcr8-/- ESCs and serves as a barrier restricting neural differentiation. We demonstrated that direct inactivation of p53 by SV40 large T antigen, a short hairpin RNA against Trp53, or genetic ablation of Trp53 in Dgcr8-/- PSCs enables neural differentiation, while activation of p53 by the MDM2 inhibitor nutlin-3a in wild-type ESCs inhibits neural differentiation. Together, we demonstrate that a major function of miRNAs in neural differentiation is suppression of p53 and that modest activation of p53 blocks neural differentiation of miRNA-deficient PSCs.

Keywords: Dgcr8; apoptosis; differentiation; miR-302; microRNA; neural differentiation; nutlin-3a; p53; pluripotent stem cells.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cells, Cultured
  • Mice
  • MicroRNAs / genetics*
  • MicroRNAs / metabolism
  • Neural Stem Cells / cytology
  • Neural Stem Cells / metabolism
  • Neurogenesis*
  • Pluripotent Stem Cells / cytology
  • Pluripotent Stem Cells / metabolism*
  • RNA-Binding Proteins / genetics
  • Ribonuclease III / genetics
  • Tumor Suppressor Protein p53 / genetics
  • Tumor Suppressor Protein p53 / metabolism*

Substances

  • Dgcr8 protein, mouse
  • MIRN302 microRNA, mouse
  • MicroRNAs
  • RNA-Binding Proteins
  • Tumor Suppressor Protein p53
  • Ribonuclease III