Fig. 5

Transcription factor STAT1 could directly upregulate IL-10 expression. A The shRNA and plasmic regulated STAT1 expression. B, C STAT1 regulated HIF-1α expression at transcription and protein levels. D, E STAT1 could also influence IL-10 expression at transcription and protein levels. F, G The promoter-luciferase reporter assay, showing that STAT1 directly promoted IL-10 expression but not HIF-1α. H The interaction of STAT1 with IL-10 shown using ChIP assays with control (IgG) or anti-STAT1 antibody. I Deletion and selective mutation analysis identified STAT1-responsive regions in the IL-10 promoter. Luciferase reporter plasmids containing serially truncated or mutated IL-10 promoter constructs were co-transfected with OE-STAT1 into NUGC3 cells, and relative luciferase activities were detected. The − 1811 ~ − 1821 sequence was the binding site