Neuronal maturation defect in induced pluripotent stem cells from patients with Rett syndrome

Proc Natl Acad Sci U S A. 2011 Aug 23;108(34):14169-74. doi: 10.1073/pnas.1018979108. Epub 2011 Aug 1.

Abstract

Rett syndrome (RTT) is one of the most prevalent female neurodevelopmental disorders that cause severe mental retardation. Mutations in methyl CpG binding protein 2 (MeCP2) are mainly responsible for RTT. Patients with classical RTT exhibit normal development until age 6-18 mo, at which point they become symptomatic and display loss of language and motor skills, purposeful hand movements, and normal head growth. Murine genetic models and postmortem human brains have been used to study the disease and enable the molecular dissection of RTT. In this work, we applied a recently developed reprogramming approach to generate a novel in vitro human RTT model. Induced pluripotent stem cells (iPSCs) were derived from RTT fibroblasts by overexpressing the reprogramming factors OCT4, SOX2, KLF4, and MYC. Intriguingly, whereas some iPSCs maintained X chromosome inactivation, in others the X chromosome was reactivated. Thus, iPSCs were isolated that retained a single active X chromosome expressing either mutant or WT MeCP2, as well as iPSCs with reactivated X chromosomes expressing both mutant and WT MeCP2. When these cells underwent neuronal differentiation, the mutant monoallelic or biallelelic RTT-iPSCs displayed a defect in neuronal maturation consistent with RTT phenotypes. Our in vitro model of RTT is an important tool allowing the further investigation of the pathophysiology of RTT and the development of the curative therapeutics.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Amino Acid Sequence
  • Base Sequence
  • Biomarkers / metabolism
  • Cell Differentiation* / genetics
  • Child
  • Child, Preschool
  • Chromosomes, Human, X / genetics
  • Embryonic Stem Cells / metabolism
  • Female
  • Fibroblasts / metabolism
  • Fibroblasts / pathology
  • Gene Expression Regulation
  • Humans
  • Induced Pluripotent Stem Cells / metabolism
  • Induced Pluripotent Stem Cells / pathology*
  • Methyl-CpG-Binding Protein 2 / chemistry
  • Methyl-CpG-Binding Protein 2 / genetics
  • Methyl-CpG-Binding Protein 2 / metabolism
  • Molecular Sequence Data
  • Neurons / metabolism
  • Neurons / pathology*
  • Rett Syndrome / genetics
  • Rett Syndrome / pathology*
  • X Chromosome Inactivation / genetics

Substances

  • Biomarkers
  • Methyl-CpG-Binding Protein 2