MeCP2-regulated miRNAs control early human neurogenesis through differential effects on ERK and AKT signaling

Mol Psychiatry. 2018 Apr;23(4):1051-1065. doi: 10.1038/mp.2017.86. Epub 2017 Apr 25.

Abstract

Rett syndrome (RTT) is an X-linked, neurodevelopmental disorder caused primarily by mutations in the methyl-CpG-binding protein 2 (MECP2) gene, which encodes a multifunctional epigenetic regulator with known links to a wide spectrum of neuropsychiatric disorders. Although postnatal functions of MeCP2 have been thoroughly investigated, its role in prenatal brain development remains poorly understood. Given the well-established importance of microRNAs (miRNAs) in neurogenesis, we employed isogenic human RTT patient-derived induced pluripotent stem cell (iPSC) and MeCP2 short hairpin RNA knockdown approaches to identify novel MeCP2-regulated miRNAs enriched during early human neuronal development. Focusing on the most dysregulated miRNAs, we found miR-199 and miR-214 to be increased during early brain development and to differentially regulate extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase and protein kinase B (PKB/AKT) signaling. In parallel, we characterized the effects on human neurogenesis and neuronal differentiation brought about by MeCP2 deficiency using both monolayer and three-dimensional (cerebral organoid) patient-derived and MeCP2-deficient neuronal culture models. Inhibiting miR-199 or miR-214 expression in iPSC-derived neural progenitors deficient in MeCP2 restored AKT and ERK activation, respectively, and ameliorated the observed alterations in neuronal differentiation. Moreover, overexpression of miR-199 or miR-214 in the wild-type mouse embryonic brains was sufficient to disturb neurogenesis and neuronal migration in a similar manner to Mecp2 knockdown. Taken together, our data support a novel miRNA-mediated pathway downstream of MeCP2 that influences neurogenesis via interactions with central molecular hubs linked to autism spectrum disorders.

Publication types

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

MeSH terms

  • Animals
  • Brain / embryology
  • Brain / metabolism
  • Cell Differentiation / genetics
  • Cell Line
  • Extracellular Signal-Regulated MAP Kinases / metabolism
  • Female
  • Humans
  • Induced Pluripotent Stem Cells / cytology
  • Induced Pluripotent Stem Cells / metabolism
  • MAP Kinase Signaling System*
  • Male
  • Methyl-CpG-Binding Protein 2 / genetics
  • Methyl-CpG-Binding Protein 2 / metabolism*
  • Mice
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • Neurogenesis / genetics
  • Neurogenesis / physiology*
  • Neurons / metabolism
  • Proto-Oncogene Proteins c-akt / metabolism
  • RNA, Small Interfering / genetics
  • Rett Syndrome / genetics
  • Rett Syndrome / metabolism
  • Rett Syndrome / pathology
  • Signal Transduction

Substances

  • MECP2 protein, human
  • MIRN214 microRNA, human
  • Mecp2 protein, mouse
  • Methyl-CpG-Binding Protein 2
  • MicroRNAs
  • RNA, Small Interfering
  • mirn199 microRNA, human
  • Proto-Oncogene Proteins c-akt
  • Extracellular Signal-Regulated MAP Kinases