Fatty Acids at the Crossroads of Mitochondria Dynamics in Macrophages

Purpose of Review This review describes the current knowledge about lipid metabolism in macrophages, its relation to mitochondrial dynamics, and the consequences in macrophage behavior. Recent Findings Lipid droplet (LD) expansion is necessary for optimal macrophage inflammatory response, as M1 (pro-inflammatory) macrophages accumulate LDs within the cytoplasm as a response to leptin signaling. The broken tricarboxylic acid (TCA) cycle, a hallmark of M1 macrophage metabolism alongside fissioned mitochondria, generates accumulated citrate that feeds fatty acid synthesis (FAS), which supplies LDs with fatty acids. All of these pathways are connected in order to induce and maintain the M1 phenotype. Summary Macrophage profiles are closely related to their metabolism and mitochondrial network. Mitochondrial fission is linked with FAS in an essential mechanism for maintaining metabolic characteristics of M1 macrophages, in the context of LD expansion. While we do not know the full extent to which these factors interact, there are evident links between mitochondria dynamics and fatty acid metabolism in macrophage polarization which can be further explored.