To Örebro University

Macrophages play an essential role in lipid metabolism; however, the excessive uptake of modified lipids andcholesterol crystals (CC) leads to the formation of pro-inflammatory lipid-laden macrophages called foam cells.Since theα-1,6- andβ-1,3-D-glucans from the basidiome and the mycelium of the edible mushroomPleurotusalbidushave previously been shown to regulate macrophage function, these glucans were tested in macro-phage-like THP-1 cells previously exposed to acetylated low-density lipoproteins (acLDL) or CC. The glucansinhibited lipid-induced inflammation, but only theβ-1,3-D-glucan regulated both the NLRP3 inflammasome ac-tivation and the expression of genes involved on lipid efflux in acLDL- or CC-pretreated cells, thereby reducingfoam cell formation. In contrast, the twoα-1,6-glucans tested inhibited foam cell formation only in acLDL-pretreated cells and had no effect on the expression of the peroxisome proliferator-activated receptor gammaand liver X receptor alpha genes, suggesting that these glucans regulate lipid influx rather than lipid efflux.Thus,α-andβ-D-glucans differentially regulate lipid-induced inflammation and foam cell formation in macro-phage-like cells. Furthermore, results emphasize thatP. albidushas potential to be used as a functional food oras a source for the extraction of biologically-active glucans.