Neural zinc finger protein Myt1 drives oligodendrocyte differentiation via repressing HDAC1-mediated histone deacetylation [ATAC-seq]

Members of the Myt (myelin transcription factor) family have been implicated in neuronal development. However, their in vivo roles in OL lineage development have not been systematically investigated. Here, we identified Myt1 transcription factor as a crucial regulator of oligodendrocyte differentiation in the developing central nervous system. Conventional knockout of Myt1 causes a remarkable delay in the initiation of OL differentiation, without affecting the generation and proliferation of OPCs. Conversely, hyperactivation of Myt1 induces precocious OL differentiation both in vitro and in vivo. Using a combination of RNA-seq and ChIP-seq analyses, we identified Nkx2.2 as a key target of Myt1 to switch on the OL differentiation program. Mechanistically, specific binding of Myt1 in the Nkx2.2 gene loci inhibits the nucleosomal histone deacetylation via hindering the HDAC1 repressor complex integrity and reducing the deacetylation activity of HDAC1. Additionally, we demonstrated that Myt1 functions downstream of Notch signaling pathway in controlling the timing of OL differentiation. Collectively, our data demonstrate that Myt1 is a major regulator of OL differentiation and provide insight into the epigenetic regulatory mechanisms under OL development. Myt1 is, therefore, a promising therapeutic target for enhancing the OL differentiation and myelination/remyelination during development or after demyelination insults. Overall design: In light of our findings that loss of Myt1 expression delayed OL differentiation, we sought to identify Myt1-regulated downstream target genes by RNA-sequencing (RNA-seq) in mouse P0 Myt1-/- and wild type spinal cords