Hypoxia inducible factor 1α promotes interleukin-1 receptor antagonist expression during hepatic ischemia-reperfusion injury

Figure 6 Hypoxia-inducible factor transcriptionally upregulates interleukin-1 receptor antagonist expression. A: Luciferase assay for the wild-type promoter (-2113/+143) of interleukin-1 receptor antagonist (Il1ra) in AML12 cells; B: Luciferase assay for the wild-type promoter of Il1ra in AML12 cells upon hypoxia; C: Luciferase assay for wild-type and truncated promoters of Il1ra in AML12 cells upon hypoxia; D: Luciferase assay for wild-type (-2113/+143) and HRE-mutated promoters of Il1ra upon hypoxia; E: Chromatin immunoprecipitation assay for hypoxia-inducible factor (HIF)-1α binding to HRE sites upon hypoxia; F and G: Quantitative polymerase chain reaction analysis for the recruitment of HIF-1α to the endogenous Il1ra promoter in AML12 cells upon hypoxia. Indicated P-values were calculated using two-tailed unpaired Student’s t-tests. Data are presented as the mean ± SEM. Data are representative of independent experiments. ^nsP > 0.05, ^aP < 0.01, ^bP < 0.001. Hypo: Hypoxia; IS: Ischemia; HIF: Hypoxia-inducible factor; IL-1ra: Interleukin-1 receptor antagonist; IgG: Immunoglobulin G.