Changes in the Phenotype and Metabolism of Peritoneal Macrophages in Mucin-2 Knockout Mice and Partial Restoration of Their Functions In Vitro After L-Fucose Treatment.

In the development of inflammatory bowel disease (IBD), peritoneal macrophages contribute to the resident intestinal macrophage pool. Previous studies have demonstrated that oral administration of L-fucose exerts an immunomodulatory effect and repolarizes the peritoneal macrophages in vivo in mice. In this study, we analyzed the phenotype and metabolic profile of the peritoneal macrophages from mice, as well as the effect of L-fucose on the metabolic and morphological characteristics of these macrophages in vitro. The investigation utilized flow cytometry, quantitative PCR (qPCR), measurement of the intracellular ATP and Ca concentrations, an analysis of mitochondrial respiration and membrane potential, and transmission electron microscopy (TEM) for ultrastructural evaluations. The mice exhibited lower intracellular ATP and Ca levels in their peritoneal macrophages, a higher percentage of stellate macrophages, and an increased oxygen consumption rate (OCR), combined with a higher percentage of mitochondria displaying an abnormal ultrastructure. Additionally, there was a five-fold increase in condensed mitochondria compared to their level in C57BL/6 mice. The number of CD209 peritoneal macrophages was reduced three-fold, while the number of M1-like cells increased two-fold in the mice. L-fucose treatment enhanced ATP production and reduced the expression of the , , and genes, which may suggest a reduction in pro-inflammatory factor production and a shift in the differentiation of peritoneal macrophages towards the M2 phenotype.