Fig. 4: HIF1α promotes glycolysis following adipocyte GLS depletion.
From: Reduced adipocyte glutaminase activity promotes energy expenditure and metabolic health
a, Heatmap of HIF1α target genes altered in siGLS versus siC treated human adipocytes (three replicates per condition). b, Effects of CB-839 in human adipocytes on protein levels of HIF1α. Effects of eta-ketoglutarate (EtaKG) or the HIF1α inhibitor VI (Inhib. VI) are shown (repeated twice). c, Illustration of how alpha-ketoglutarate (α-KG) degrades HIF1α through prolyl hydroxylase domain (PHD) proteins. d, Relative levels of α-KG in siGLS (n = 7) versus siC (n = 6) human adipocytes (repeated twice). Data were compared using Student’s t-test. e, Normalized (norm.) basal ECAR during glycostress tests in siC or siGLS human adipocytes treated with EtaKG (11 replicates per condition, repeated twice). Data were compared using two-way analysis of variance (ANOVA) and Tukey’s post hoc test. f, Normalized basal ECAR rate during glycostress tests in siC or siGLS human adipocytes treated with the HIF1α inhibitor VI (12 replicates per condition, repeated twice). Data were compared using two-way ANOVA and Tukey’s post hoc test. g, Normalized OCR in siC or siGLS human adipocytes treated with or without the HIF1α inhibitor VI (left) (six replicates per condition, repeated two times). Data were compared for basal respiration and maximal respiratory capacity using two-way ANOVA and Tukey’s post hoc test (right). h, Lactate secretion in human adipocytes transfected with siC (n = 7) or siGLS (n = 7) (left) or treated with DMSO (n = 6) or CB-839 (n = 7) (right). Data were compared using Student’s t-test (repeated more than three times). i,j, Representative western blots of total and phosphorylated protein levels of p38 MAPK, CREB and ATF2 in human adipocytes transfected with siC or siGLS (i) or incubated with DMSO or BPTES (j, repeated twice). Proteins from the same experiment were loaded on four different gels in parallel for i,j. k, Representative western blots of total and phosphorylated protein levels of p38 MAPK, ATF2 as well as ETC proteins in human adipocytes incubated with or without lactate (for 30 min) and the p38 MAPK inhibitor SB203580 (pretreatment for 2.5 h) (repeated twice), Proteins from the same experiment were loaded on five different gels in parallel. l, Representative western blot showing the ETC and GLS protein levels in siC or siGLS human adipocytes treated with or without the p38 MAPK inhibitor SB203580 (experiment repeated twice). m, Model of how inhibition of glutaminolysis drives a metabolic reprograming promoting adipocyte thermogenesis. Data d–h show mean ± s.e.m. Relevant P values are shown. c,m, Created with BioRender.com.
