Fig 2: ANGPTL2-MAG induces Fyn-mediated signaling to enhance the differentiation of oligodendrocytes. A Gene Ontology (GO) analysis of the downregulated differentially expressed genes (DEGs) in the brains of Angptl2+/+ and Angptl2−/− mice at day 15 as determined by RNA sequencing (n = 3). B Enrichment score plots from GSEA related to the GO signature for myelin sheath and ensheathment of neurons (n = 3). FDR, false discovery rate; NES, normalized enrichment score. C Relative mRNA levels of potential candidates related to myelination markers, transcription factors, metabolic regulators and other genes in the brain tissues of Angptl2+/+ and Angptl2−/− mice at day 15 as measured by quantitative RT-PCR (n = 3). D Immunoblot analysis of MYRF and ANGPTL2 protein levels in the brain tissues of Angptl2+/+ and Angptl2−/− mice at day 5, day 15 and day 35. Ratio of MYRF/β-actin was quantified and normalized against Angptl2+/+, respectively. One representative experiment is shown. E–F Immunoblot analysis of MYRF protein levels in the brain tissues of Mag+/+ and Mag−/− mice (E) or Mag−/−Angptl2+/+ and Mag−/−Angptl2−/− mice (F) at day 5, day 15 and day 35. Ratio of MYRF/β-actin was quantified and normalized against Angptl2+/+, respectively. One representative experiment is shown. G–H MAG directly interacted with FYN, as detected by forward (G) or reverse (H) co-immunoprecipitation assays. CMV-MAG (full-length)-FC and pLVX-FYN-strepII plasmids were used in this experiment. One representative experiment is shown. I RSC96 cells with ectopic expression of MAG (full-length)-FLAG and FYN-StrepII were treated with ANGPTL2 proteins, followed by co-immunoprecipitation analysis to evaluate the changes in tyrosine phosphorylation levels of MAG and FYN using 4G10 and p-SRC (Tyr416) antibodies, respectively. The levels of immunoprecipitated protein were quantified and normalized against the control group, respectively. One representative experiment is shown. J RSC96 cells overexpressing FYN-StrepII or MAG (full-length)-FC were subjected to immunoblot analysis to determine MYRF protein levels. Ratio of MYRF/β-actin was quantified and normalized against negative control (empty vector), respectively. One representative experiment is shown. K Western blot analysis of the protein levels of P-SRC (Tyr416), Fyn and MBP in HCN cells 72 h after induction with IGF1 (100 ng/ml), with/without ANGPTL2-Flag (2 μg/ml) and AZD0530 (2 μM) as indicated. Ratios of P-SRC (Tyr416)/β-actin, Fyn/β-actin, MYRF/β-actin and MBP/β-actin were quantified and normalized against the control treated with IGF1 alone, respectively. One representative experiment is shown. L Schematic diagram of the working model for the role of ANGPTL2-MAG in oligodendrocytes differentiation, myelination and differentiation. (***p < 0. 001)