The embryonic patterning gene Dbx1 governs the survival of the auditory midbrain via Tcf7l2-Ap2δ transcriptional cascade

Cell Death Differ. 2023 Jun;30(6):1563-1574. doi: 10.1038/s41418-023-01165-6. Epub 2023 Apr 20.

Abstract

At the top of the midbrain is the inferior colliculus (IC), which functions as the major hub for processing auditory information. Despite the functional significance of neurons in the IC, our understanding of their formation is limited. In this study, we identify the embryonic patterning gene Dbx1 as a key molecular player that governs genetic programs for IC survival. We find that Dbx1 plays a critical role in preventing apoptotic cell death in postnatal IC by transcriptionally repressing c-Jun and pro-apoptotic BH3 only factors. Furthermore, by employing combined approaches, we uncover that Tcf7l2 functions downstream of Dbx1. Loss of Tcf7l2 function causes IC phenotypes with striking similarity to those of Dbx1 mutant mice, which include defective embryonic maturation and postnatal deletion of the IC. Finally, we demonstrate that the Dbx1-Tcf7l2 cascade functions upstream of Ap-2δ, which is essential for IC development and survival. Together, these results unravel a novel molecular mechanism for IC maintenance, which is indispensable for normal brain development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Homeodomain Proteins / metabolism
  • Inferior Colliculi* / metabolism
  • Mesencephalon* / metabolism
  • Mice
  • Neurons / metabolism
  • Transcription Factor 7-Like 2 Protein / metabolism
  • Transcription Factor AP-2 / genetics
  • Transcription Factor AP-2 / metabolism

Substances

  • Dbx1 protein, mouse
  • Homeodomain Proteins
  • Tcf7l2 protein, mouse
  • Transcription Factor 7-Like 2 Protein
  • Transcription Factor AP-2