Fig. 3

Uric acid activates the JAK2/STAT3 pathway to regulate HMGCS2 expression. A, B AC16 cells were treated with uric acid (0, 100, 200, or 400 mg/L) for 24 h. Western blotting was used to determine the levels of P-JAK2, T-JAK2, P-STAT3, and T-STAT3, and representative western blot images (A) and the corresponding statistical analysis (B) (n = 5/group) are presented in the figure. C Quantification of the IL-6 mRNA level (n = 5/group). D Quantification of the IL-6R mRNA level (n = 6/group). E Quantification of the GP130 mRNA level (n = 3/group). F–H The effects of various concentrations of sIL-6R on the activation of STAT3 induced by uric acid (400 mg/L). AC16 cells were cotreated with uric acid (400 mg/L) and sIL-6R (0, 5, or 50 ng/ml) for 24 h. Representative western blot images (F) and quantification (n = 5/group) of P-STAT3 (G) and STAT3 (H) are shown in the figure. I, J STAT3 motif (I) and STAT3-binding site (J) in the HMGCS2 promoter. K HEK-293 cells were transfected with a STAT3-overexpressing plasmid, a wild-type (WT) HMGCS2 promoter or a mutant (MT) HMGCS2 promoter plasmid for 48 h. Luciferase activity was measured via a dual-luciferase assay to detect the combined effects of STAT3 and the HMGCS2 promoter in HEK-293 cells (n = 5/group). L, O AC16 cells were individually transfected with the control plasmid, wild-type STAT3 plasmid (STAT3 WT), Y705D mutant STAT3 (STAT3 Y705D), or Y705 F mutant STAT3 (STAT3 Y705 F) for 48 h, and representative western blot images (A) and corresponding statistical analysis (M-O) (n = 3/group) are presented in the figure (n = 3/group). The data represent the means ± S.E.M.s. *p < 0.05 vs the indicated group