Fig 2: c-MYC Positively Regulates the Expression of BATF3. (A) Construction of c-MYC Lentivirus. (B) Representative GFP Fluorescence Graph of c-MYC Lentivirus After Transfection of HEK293T Cells. (C, D) Relative Expression Levels of c-MYC and BATF3 mRNA After c-MYC Overexpression (C) and Knockdown (D) (n = 3). (E, H) Protein Expression Levels of c-MYC and BATF3 After c-MYC Overexpression (E, F) and Knockdown (G, H) (n = 3). (I) Relative Expression Levels of Canonical c-MYC Downstream Target Genes mRNA After c-MYC Overexpression and Knockdown (n = 3). (J–M) Protein Expression Levels of Canonical c-MYC Downstream Target Genes After c-MYC Overexpression (J–K) and Knockdown (L-M) (n = 3). *, P < 0. 05, **, P < 0. 01, ***, P < 0. 001.

Fig 3: Relative mRNA expression of BATF3 and candidate transcription factors in PBMCs. Relative mRNA levels of (A) BATF3, (B) c-MYC, (C) EGR1, (D) EGR2, and (E) EGR3 in PBMCs from children with T1DM and healthy controls (n = 30). Data are presented as relative expression levels. *, P < 0.05, **, P < 0.01; ns, not significant.

Fig 4: c-MYC binds 1–2 kb upstream of the BATF3 transcription start site. (A, B) Construction of c-MYC overexpression plasmids (A) and BATF3 promoter luciferase plasmids (B). (C) c-MYC binding motif and predicted binding sites on the BATF3 promoter. (D) Relative luciferase activity in HEK293T cells co-transfected with plasmids with or without the BATF3 promoter and MYC overexpression. (E) Relative fluorescence activity of HEK293T cells co-transduced with different BATF3 promoter truncations and c-MYC. **, P < 0. 01, ***, P < 0. 001, ns, not significant.

Fig 5: c-MYC is a key transcription factor potentially regulating BATF3 in pediatric T1DM. (A) Volcano plot and (B) hierarchical clustering heatmap of differentially expressed genes (DEGs) between children with T1DM and healthy controls in the GSE9006 PBMC microarray dataset (T1DM, n = 43; controls, n = 24). DEGs were defined as FDR < 0.05 and |log₂FC| > 0.5. (C) GO enrichment and (D) KEGG pathway enrichment analyses of DEGs identified from GSE9006. (E) Protein–protein interaction (PPI) network of DEGs constructed using the STRING database (parameters as described in Methods). (F) Venn diagram showing the intersection between predicted BATF3 transcription factors and transcription factors derived from the GSE9006 DEG list (predicted using AnimalTFDB4 and JASPAR based on the BATF3 promoter sequence).