Fig. 4

Iguratimod inhibits PKC activity and EGR1 expression. a, b PCA showed the global gene expression profiles (a) and the volcano plot showed the differentially expressed genes (b) of the RNA-seq data derived from vehicle (DMSO) or 10 μM iguratimod-treated activated human B cells (n = 3). c, d GSEA identified the immunoglobulin complex pathway (c), and PKC pathway (d) was inhibited by iguratimod in activated human B cells. e PKC activity was decreased upon iguratimod treatment in stimulated human B cells (n = 3). f Heatmap showed the expressions of key TFs in ASC differentiation and B cell identity from the RNA-seq data derived from vehicle (DMSO) or 10 μM iguratimod-treated activated human B cells (n = 3). g, h EGR1 expressions were shown by RPKM plots (g) or qRT-PCR plots (h) (n = 3, for g and h). i Western blot showed the suppression of EGR1 in activated human B cells by iguratimod at different time points. One representative experiment out of 3 was shown. j A proposed work model for the regulation of plasma cell differentiation by iguratimod via inhibiting PKC and EGR1. Dotted line indicates that PKC may additionally regulate plasma cell differentiation by EGR1-independent pathway. Data were expressed as mean ± SEM (e) and analyzed by one-way ANOVA with Bonferroni correction for multiple comparisons (e) or paired Student’s t test (g, h). *P < 0.05, ***P < 0.001. RPKM, reads per kilobase of exon per million mapped sequence reads