Extended Data Fig. 6: STAT3 modulates HIF1α expression and GSIS in β-cells.
From: β-Klotho promotes glycolysis and glucose-stimulated insulin secretion via GP130
a, Phosphorylation and expression levels of several kinases and transcription factors in islets isolated from 16-week-old male KlbF/F and KlbRIP mice as determined by immunoblotting (n = 4 mice for each group). b, Mouse MIN6 β-cells were infected with adenovirus encoding GFP (Adv-GFP) or Flag-tagged constitutively active STAT3 (Adv-STAT3c) at 100 MOI for 48 h, followed by examination of insulin secretion under 2.8 mM or 16.7 mM glucose conditions. The insulin secretion capacities were normalized to the cell protein concentration (n = 7 independent cultures). c, Mouse MIN6 β-cells were treated with the STAT3 inhibitor S3I-201 (200 μM) or PBS for 24 h, followed by immunoblotting analysis of p-STAT3, t-STAT3, HIF1α and Tubulin (left). The expression levels of HIF1α protein were quantified by densitometry analysis (right, n = 6 independent cultures). d, Basal (2.8 mM glucose) and high glucose (16.7 mM)-stimulated insulin secretion capacities were assessed in cells described in panel c (n = 7 independent cultures). e, ChIP assays with a rabbit anti-p-STAT3(Tyr705) polyclonal antibody were performed in islets isolated from 15-week-old male KlbF/F and KlbRIP mice using primers spanning to the SIE1 and SIE2 regions within the mouse Hif1α proximal promoters as described in Fig. 6e. The precipitated chromatin was quantified by real-time PCR and the relative fold change was calculated by normalizing to the genomic 36b4 gene (n = 8 mice for KlbF/F group, n = 9 mice for KlbRIP group). Data are presented as mean ± SEM. P values are derived from ordinary two-way ANOVA followed by Sidak’s multiple comparisons test (b, d, e), or two-tailed unpaired t-test (c).
