High-throughput Sequencing Analysis Of Wnt Signaling Pathway Activated Oligodendrocytes And Downstream Target Genes Screening

Oligodendrocytes are one of most important glial cells in central nervous system,which form myelin sheath around axons and ensure the action potential between neurons travelling efficiently.And canonical Wnt signaling pathway and Wnt target genes have a great effect on oligodendrocyte development.However,the definition of Wnt target genes and their regulations on oligodendrocytes development are not thoroughly illustrated,and we are dedicated to screen for Wnt target genes which might be significant in regulating OLs development through high-throughput sequencing analysis.Therefore,we treated OPCs with BIO,a GSK3 inhibitor,to activate Wnt signaling pathway and promoted the entry of β-catenin(active)into the nucleus,and collected cells at the same stage for high-throughput sequencing analysis of RNA-Seq,β-catenin(active)and H3K27Ac ChIP-Seq,respectively.ROSE analysis showed that,β-catenin(active)did not mainly regulate downstream target genes through super-enhancers binding.In addition,11 nuclear transcription factors and chromatin remodelers directly activated by β-catenin(active)were screened and ranked by the rank product in BETA analysis,considering the rank order,we chose Brd7 as our target gene,for further study of its function in OLs development.In oli-neu cells,Brd7 inhibited Wnt activity,as a Wnt negative feedback target gene.And after overexpression and knockdown of Brd7 in rat OPCs in vitro,we found that Brd7 inhibited OPCs proliferation and promoted OLs differentiation and maturation,but did not affect cell apoptosis.Besides,we constructed Oligl-cre;Brd7fl/fl mice model with Brd7 selectively knocked out in OLs.Phenotypic analysis showed that Brd7 knockout significantly inhibited OLs differentiation and myelination in the corpus callosum and spinal cord,and promoted OPCs proliferation in corpus callosum in vivo,demonstrating that Brd7,as one of β-catenin(active)directly activated chromatin remodelers,promoted the development of OLs.