Fig 2: PRDM1 targets SIRT2. a RT-qPCR determination of SIRT2 expression in 20 acute gouty arthritis samples and 34 healthy samples. b NAD+ levels in sh-/oe-PRDM1-treated cell culture medium. c Specific binding motifs of PRDM1 on the SIRT2 promoter obtained through JASPAR database analysis. d Prediction of binding sites between PRDM1 and SIRT2. e The relationship between PRDM1 and SIRT2 verified by dual-luciferase reporter gene assay. f The binding of PRDM1 to SIRT2 after MSU crystal stimulation verified by ChIP assay. *p < 0.05.

Fig 3: Expression of Prdm1 and Pax7 in E4 somite and limb cell cultures.As indicated, individual cultures, in this case a proliferating E4 hindlimb culture prior to myotube formation, were analyzed by double immunofluorescence for Prdm1 (A, Ab from Cell Signaling Technology) and the myoblast marker Pax7 (B). The myoblasts illustrated here all co-expressed Prdm1 and Pax7. C. Quantitative analysis of proliferating E4 cultures prior to myotube formation. Cultures were double immunostained for Prdm1 (Ab from Cell Signaling Technology) and Pax7 and staining patterns were quantified. Cells positive for both Pax7 and Prdm1 were the most abundant cell type in somitic (S), forelimb bud (F), and hindlimb bud (H) cultures (yellow bars). A small percentage of cells was positive for Pax7 but negative for Prdm1 (red bars). Some cells were also negative for Pax7 but positive for Prdm1 (green bars) or negative for both (gray bars). Bar = 10 µm.

Fig 4: Correlation of IL-21 receptor with Blimp-1 expression and effect on overall survival in human PDAC biopsies. Survival analysis of IL-21R and Blimp-1 expression. There was a non-significant trend towards shorter OS in PDAC patients with high IL-21R expression compared to patients with low IL-21R expression. PDAC patients expressing a high level of Blimp-1 had a significantly shorter survival compared to patients expressing a low level of Blimp-1. Survival was significantly shorter in patients with high IL-21 infiltrate compared to patients with low IL-21 infiltrate.

Fig 5: IL-21 upregulates Blimp-1 in an ERK-dependent manner. BxPC-3 and Panc-1 were incubated with IL-21 (10 and 25 ng/mL) for 24 h. (A) Treatment with IL-21 upregulates Blimp-1 expression. One of six independent experiments is shown. (B) Quantification of IL-21-dependent Blimp-1 upregulation (IL-21: 10 ng/mL). * P < 0.05. Wilcoxon rank-sum test. (C) ERK inhibitor prevents IL-21-dependent Blimp-1 upregulation. One of five independent experiments is shown.