Metabolic and functional remodeling of colonic macrophages in response to high-fat diet-induced obesity
Ângela Castoldi, David E. Sanin, Nikki van Teijlingen Bakker, Cristhiane Fávero de Aguiar, Lauar de Brito Monteiro, Nisha Rana, Katarzyna M. Grzes, Agnieszka M. Kabat, Jonathan M. Curtis, Alanna M. Cameron, George Caputa, Tiago Antônio de Souza, Fabrício Oliveira Souto, Joerg M. Buescher, Joy Edwards-Hicks, Erika L. Pearce, Edward J. Pearce, Niels Olsen Saraiva Câmara
Abstract
Little is known about the effects of high-fat diet (HFD)-induced obesity on resident colonic lamina propria (LP) macrophages (LPMs) function and metabolism. Here, we report that obesity and diabetes resulted in increased macrophage infiltration in the colon. These macrophages exhibited the residency phenotype CX3CR1 hi MHCII hi and were CD4 - TIM4 - . During HFD, resident colonic LPM exhibited a lipid metabolism gene expression signature that overlapped that used to define lipid-associated macrophages (LAMs). Via single-cell RNA sequencing, we identified a sub-cluster of macrophages, increased in HFD, that were responsible for the LAM signature. Compared to other macrophages in the colon, these cells were characterized by elevated glycolysis, phagocytosis, and efferocytosis signatures. CX3CR1 hi MHCII hi colonic resident LPMs had fewer lipid droplets (LDs) and decreased triacylglycerol (TG) content compared to equivalent cells in lean mice and exhibited increased phagocytic capacity, suggesting that HFD induces adaptive responses in LPMs to limit bacterial translocation.