Summary: | Objective: Fatty acid oxidation in macrophages is thought to regulate inflammatory status and insulin-sensitivity. An important unanswered question in this field is whether carnitine acetyl-transferase (CrAT) that regulates fatty acid oxidation and mitochondrial acetyl-CoA balance is required to integrate nutrient stress sensing to inflammatory response in macrophages. Methods: Mice with myeloid lineage-specific Crat deletion were subjected to several metabolic stressors, including high-fat diet-induced obesity, fasting, and LPS-induced endotoxemia. Their metabolic homeostasis was compared to that of Crat-sufficient littermate controls. Inflammatory potential of Crat-deficient and Crat-sufficient macrophages were measured both in vitro and in vivo. Results: Our studies revealed that ablation of CrAT in myeloid lineage cells did not impact glucose homeostasis, insulin-action, adipose tissue leukocytosis, and inflammation when animals were confronted with a variety of metabolic stressors, including high-fat diet, fasting, or LPS-induced acute endotoxemia. Conclusions: These findings demonstrate that unlike muscle cells, substrate switch mechanisms that control macrophage energy metabolism and mitochondrial short-chain acyl-CoA pools during nutrient stress are controlled by pathways that are not solely reliant on CrAT. Author Video: Author Video Watch what authors say about their articles Keywords: Macrophage, Adipose tissue, Inflammation, Carnitine acyltransferase
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