Inhibition of the formation of macrophage-derived foam cells and promotion of their migration ability by β-glucan

Abstract

Objective To investigate the effects of β-glucan on the formation and migration ability of macrophage-derived foam cells. Methods RAW264.7 macrophages were cultured and oxidized low-density lipoprotein (ox-LDL) induced them to transform to foam cells. Oil red O staining was used to observe the formation of macrophage-derived foam cells in three groups: control group, ox-LDL intervention group and β-glucan intervention group (incubated in β-glucan and ox-LDL respectively). Real-time quantitative PCR was used to detect the expression of inflammatory cytokines (TNF-α, IL-6, IL-10, TGF-β) and intracellular CC chemokine receptor 1 (CCR1), CCR2, CCR5, CCR7. Flow cytometry was used to determine the expression of cell surface CCR1 and CCR7. Moreover, TranswellTM migration assay was used to detect the chemotactic response to CC chemokine ligand 19 (CCL19) and CCL21, CCR7-ligands. Results The macrophages become dark red after stained by oil red O in ox-LDL group, while the color of macrophages in β-glucan group is lighter. Compared with the ox-LDL group, the production of TNF-α mRNA was significantly down-regulated (P<0.05) and the production of CCR7 mRNA was up-regulated in β-glucan group (P<0.05). Up-regulation of CCR7 expression significantly promoted the chemotactic response of foam cells to CCL19 and CCL21 (both P<0.05). Conclusions β-glucan could inhibit the formation of macrophage-derived foam cell, increase the production of CCR7 and promote the migration of macrophage-derived foam cells. Key words: Foam cells; Migration; bera-glucan; Atherosclerosis