HDAC1 and HDAC2 regulate oligodendrocyte differentiation by disrupting the β-catenin–TCF interaction

Abstract

Previous work has suggested that the histone deacetylase HDAC1 promotes and canonical Wnt signaling antagonizes oligodendrocyte differentiation. Here, Ye et al. show that HDAC1/2 directly interferes with canonical Wnt signaling in oligodendrocyte precursors by competing with β-catenin for interaction with the transcriptional co-factor TCF7L2. TCF7L2 itself is shown to be crucial for oligodendrocyte development. Oligodendrocyte development is regulated by the interaction of repressors and activators in a complex transcriptional network. We found that two histone-modifying enzymes, HDAC1 and HDAC2, were required for oligodendrocyte formation. Genetic deletion of both Hdac1 and Hdac2 in oligodendrocyte lineage cells resulted in stabilization and nuclear translocation of β-catenin, which negatively regulates oligodendrocyte development by repressing Olig2 expression. We further identified the oligodendrocyte-restricted transcription factor TCF7L2/TCF4 as a bipartite co-effector of β-catenin for regulating oligodendrocyte differentiation. Targeted disruption of Tcf7l2 in mice led to severe defects in oligodendrocyte maturation, whereas expression of its dominant-repressive form promoted precocious oligodendrocyte specification in developing chick neural tube. Transcriptional co-repressors HDAC1 and HDAC2 compete with β-catenin for TCF7L2 interaction to regulate downstream genes involved in oligodendrocyte differentiation. Thus, crosstalk between HDAC1/2 and the canonical Wnt signaling pathway mediated by TCF7L2 serves as a regulatory mechanism for oligodendrocyte differentiation.