Molecular Mechanisms Underlying Ascl1-Mediated Astrocyte-to-Neuron Conversion

Stem Cell Reports. 2021 Mar 9;16(3):534-547. doi: 10.1016/j.stemcr.2021.01.006. Epub 2021 Feb 11.

Abstract

Direct neuronal reprogramming potentially provides valuable sources for cell-based therapies. Proneural gene Ascl1 converts astrocytes into induced neuronal (iN) cells efficiently both in vitro and in vivo. However, the underlying mechanisms are largely unknown. By combining RNA sequencing and chromatin immunoprecipitation followed by high-throughput sequencing, we found that the expression of 1,501 genes was markedly changed during the early stages of Ascl1-induced astrocyte-to-neuron conversion and that the regulatory regions of 107 differentially expressed genes were directly bound by ASCL1. Among Ascl1's direct targets, Klf10 regulates the neuritogenesis of iN cells at the early stage, Myt1 and Myt1l are critical for the electrophysiological maturation of iN cells, and Neurod4 and Chd7 are required for the efficient conversion of astrocytes into neurons. Together, this study provides more insights into understanding the molecular mechanisms underlying Ascl1-mediated astrocyte-to-neuron conversion and will be of value for the application of direct neuronal reprogramming.

Keywords: astrocyte-to-neuron conversion; chromo-helicase-DNA-binding protein 7 (Chd7); direct neuronal reprogramming; induced neuronal (iN) cells; molecular mechanisms; transcription factor Ascl1; transcription factor Klf10; transcription factor Myt1; transcription factor Myt1l; transcription factor Neurod4.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Astrocytes / physiology*
  • Basic Helix-Loop-Helix Transcription Factors / genetics
  • Basic Helix-Loop-Helix Transcription Factors / metabolism*
  • Cellular Reprogramming
  • Chromatin Immunoprecipitation Sequencing
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Early Growth Response Transcription Factors / genetics
  • Early Growth Response Transcription Factors / metabolism*
  • Gene Expression Regulation*
  • Gene Knockdown Techniques
  • HEK293 Cells
  • Humans
  • Kruppel-Like Transcription Factors / genetics
  • Kruppel-Like Transcription Factors / metabolism*
  • Mice
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism*
  • Neurons / physiology*
  • Sequence Analysis, RNA
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Transcriptome

Substances

  • Ascl1 protein, mouse
  • Basic Helix-Loop-Helix Transcription Factors
  • Chd7 protein, mouse
  • DNA-Binding Proteins
  • Early Growth Response Transcription Factors
  • KLF10 protein, mouse
  • Kruppel-Like Transcription Factors
  • Myt1 protein, mouse
  • Myt1l protein, mouse
  • Nerve Tissue Proteins
  • Neurod4 protein, mouse
  • Transcription Factors