JCI Insight (Feb 2023)

Acute high-fat diet impairs macrophage-supported intestinal damage resolution

  • Andrea A. Hill,
  • Myunghoo Kim,
  • Daniel F. Zegarra-Ruiz,
  • Lin-Chun Chang,
  • Kendra Norwood,
  • Adrien Assié,
  • Wan-Jung H. Wu,
  • Michael C. Renfroe,
  • Hyo Wong Song,
  • Angela M. Major,
  • Buck S. Samuel,
  • Joseph M. Hyser,
  • Randy S. Longman,
  • Gretchen E. Diehl

Journal volume & issue
Vol. 8, no. 3

Abstract

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Chronic exposure to high-fat diets (HFD) worsens intestinal disease pathology, but acute effects of HFD in tissue damage remain unclear. Here, we used short-term HFD feeding in a model of intestinal injury and found sustained damage with increased cecal dead neutrophil accumulation, along with dietary lipid accumulation. Neutrophil depletion rescued enhanced pathology. Macrophages from HFD-treated mice showed reduced capacity to engulf dead neutrophils. Macrophage clearance of dead neutrophils activates critical barrier repair and antiinflammatory pathways, including IL-10, which was lost after acute HFD feeding and intestinal injury. IL-10 overexpression restored intestinal repair after HFD feeding and intestinal injury. Macrophage exposure to lipids from the HFD prevented tethering and uptake of apoptotic cells and Il10 induction. Milk fat globule-EGF factor 8 (MFGE8) is a bridging molecule that facilitates macrophage uptake of dead cells. MFGE8 also facilitates lipid uptake, and we demonstrate that dietary lipids interfere with MFGE8-mediated macrophage apoptotic neutrophil uptake and subsequent Il10 production. Our findings demonstrate that HFD promotes intestinal pathology by interfering with macrophage clearance of dead neutrophils, leading to unresolved tissue damage.

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