1. Enhanced glycolysis and HIF-1α activation in adipose tissue macrophages sustains local and systemic interleukin-1β production in obesity
- Author
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Monika Sharma, Ravichandran Ramasamy, Tarik Hadi, Ludovic Boytard, Edward A. Fisher, Bhama Ramkhelawon, Susan Hutchison, Westley Spiro, Bo Yan, Lena Seifert, Russell Simon, Graeme J. Koelwyn, Mireille Ouimet, and Kathryn J. Moore
- Subjects
Adipose Tissue, White ,Adipose tissue macrophages ,Interleukin-1beta ,Palmitates ,lcsh:Medicine ,Adipose tissue ,Mice, Transgenic ,Inflammation ,Oxidative phosphorylation ,Intra-Abdominal Fat ,Diet, High-Fat ,Article ,Oxidative Phosphorylation ,Mice ,03 medical and health sciences ,0302 clinical medicine ,Bone Marrow ,medicine ,Animals ,Macrophage ,Glycolysis ,Obesity ,lcsh:Science ,Cells, Cultured ,030304 developmental biology ,0303 health sciences ,Multidisciplinary ,Chemistry ,Macrophages ,lcsh:R ,Hypoxia-Inducible Factor 1, alpha Subunit ,Cell Hypoxia ,Cell biology ,Mice, Inbred C57BL ,Mechanisms of disease ,Gene Expression Regulation ,Organ Specificity ,030220 oncology & carcinogenesis ,Saturated fatty acid ,lcsh:Q ,medicine.symptom ,Function (biology) - Abstract
During obesity, macrophages infiltrate the visceral adipose tissue and promote inflammation that contributes to type II diabetes. Evidence suggests that the rewiring of cellular metabolism can regulate macrophage function. However, the metabolic programs that characterize adipose tissue macrophages (ATM) in obesity are poorly defined. Here, we demonstrate that ATM from obese mice exhibit metabolic profiles characterized by elevated glycolysis and oxidative phosphorylation, distinct from ATM from lean mice. Increased activation of HIF-1α in ATM of obese visceral adipose tissue resulted in induction of IL-1β and genes in the glycolytic pathway. Using a hypoxia-tracer, we show that HIF-1α nuclear translocation occurred both in hypoxic and non-hypoxic ATM suggesting that both hypoxic and pseudohypoxic stimuli activate HIF-1α and its target genes in ATM during diet-induced obesity. Exposure of macrophages to the saturated fatty acid palmitate increased glycolysis and HIF-1α expression, which culminated in IL-1β induction thereby simulating pseudohypoxia. Using mice with macrophage-specific targeted deletion of HIF-1α, we demonstrate the critical role of HIF-1α-derived from macrophages in regulating ATM accumulation, and local and systemic IL-1β production, but not in modulating systemic metabolic responses. Collectively, our data identify enhanced glycolysis and HIF-1α activation as drivers of low-grade inflammation in obesity.
- Published
- 2020
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