A conserved molecular logic for neurogenesis to gliogenesis switch in the cerebral cortex

Proc Natl Acad Sci U S A. 2024 May 14;121(20):e2321711121. doi: 10.1073/pnas.2321711121. Epub 2024 May 7.

Abstract

During development, neural stem cells in the cerebral cortex, also known as radial glial cells (RGCs), generate excitatory neurons, followed by production of cortical macroglia and inhibitory neurons that migrate to the olfactory bulb (OB). Understanding the mechanisms for this lineage switch is fundamental for unraveling how proper numbers of diverse neuronal and glial cell types are controlled. We and others recently showed that Sonic Hedgehog (Shh) signaling promotes the cortical RGC lineage switch to generate cortical oligodendrocytes and OB interneurons. During this process, cortical RGCs generate intermediate progenitor cells that express critical gliogenesis genes Ascl1, Egfr, and Olig2. The increased Ascl1 expression and appearance of Egfr+ and Olig2+ cortical progenitors are concurrent with the switch from excitatory neurogenesis to gliogenesis and OB interneuron neurogenesis in the cortex. While Shh signaling promotes Olig2 expression in the developing spinal cord, the exact mechanism for this transcriptional regulation is not known. Furthermore, the transcriptional regulation of Olig2 and Egfr has not been explored. Here, we show that in cortical progenitor cells, multiple regulatory programs, including Pax6 and Gli3, prevent precocious expression of Olig2, a gene essential for production of cortical oligodendrocytes and astrocytes. We identify multiple enhancers that control Olig2 expression in cortical progenitors and show that the mechanisms for regulating Olig2 expression are conserved between the mouse and human. Our study reveals evolutionarily conserved regulatory logic controlling the lineage switch of cortical neural stem cells.

Keywords: Olig2; enhancer; gliogenesis; lineage switch; neurogenesis.

Publication types

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

MeSH terms

  • Animals
  • Basic Helix-Loop-Helix Transcription Factors* / genetics
  • Basic Helix-Loop-Helix Transcription Factors* / metabolism
  • Cell Lineage
  • Cerebral Cortex* / cytology
  • Cerebral Cortex* / metabolism
  • ErbB Receptors* / genetics
  • ErbB Receptors* / metabolism
  • Eye Proteins / genetics
  • Eye Proteins / metabolism
  • Gene Expression Regulation, Developmental
  • Hedgehog Proteins* / genetics
  • Hedgehog Proteins* / metabolism
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism
  • Humans
  • Mice
  • Nerve Tissue Proteins* / genetics
  • Nerve Tissue Proteins* / metabolism
  • Neural Stem Cells* / cytology
  • Neural Stem Cells* / metabolism
  • Neurogenesis* / physiology
  • Neuroglia / cytology
  • Neuroglia / metabolism
  • Olfactory Bulb / cytology
  • Olfactory Bulb / metabolism
  • Oligodendrocyte Transcription Factor 2* / genetics
  • Oligodendrocyte Transcription Factor 2* / metabolism
  • PAX6 Transcription Factor* / genetics
  • PAX6 Transcription Factor* / metabolism
  • Paired Box Transcription Factors / genetics
  • Paired Box Transcription Factors / metabolism
  • Repressor Proteins / genetics
  • Repressor Proteins / metabolism
  • Signal Transduction
  • Zinc Finger Protein Gli3 / genetics
  • Zinc Finger Protein Gli3 / metabolism

Substances

  • Basic Helix-Loop-Helix Transcription Factors
  • ErbB Receptors
  • Oligodendrocyte Transcription Factor 2
  • Nerve Tissue Proteins
  • Hedgehog Proteins
  • PAX6 Transcription Factor
  • Ascl1 protein, mouse
  • Olig2 protein, mouse
  • Pax6 protein, mouse
  • Homeodomain Proteins
  • Zinc Finger Protein Gli3
  • Eye Proteins
  • Repressor Proteins
  • Paired Box Transcription Factors
  • EGFR protein, mouse
  • Gli3 protein, mouse
  • Shh protein, mouse
  • PAX6 protein, human