Abstract:Aim To study the role of dendritic cells (DC) with lectin-like oxidized low density lipoprotein receptor-1 (LOX-1) high expression in atherosclerosis in vitro and in vivo. Methods Western blot was used to examine the protein expression levels of LOX-1 in ox-LDL stimulated primary cultured bone marrow derived dendritic cells (BMDC) from C57 mice, flow cytometry was used to measure the ratio of LOX-1 high expression subsets and LOX-1 low expression subsets in BMDC, MACS was used to sort the two cell subsets with different LOX-1 expression and to observe the effects of ox-LDL on the ratio of two cell subsets and release of inflammatory factors. Results There were two different subsets of DC with high and low expression of LOX-1, the ratio of LOX-1high DC was increased after ox-LDL treatment. After the LOX-1high DC was stimulated by ox-LDL, the TNF-α and IL-1β mRNA was up-regulated (P<0.01), and the percentage of positive cells increased higher than that of negative cells. In hyperlipidemia model of C57 mice, total cholesterol levels were significantly increased after fed with high fat diet for 4,6 and 8 weeks. This was paralleled with an increase in DC number and in the ratio of LOX-1high DC and LOX-1low DC in the aorta from mice. Different concentrations of Dil-ox-LDL was used to stimulate DC2.4 cells, there was a concentration-dependent increase in the phagocytosis of Dil-ox-LDL by DC2.4 cells. Western blot showed that the LOX-1 expression in DC2.4 cells could be induced by ox-LDL at 20 mg/L and 40 mg/L. Conclusions Two DC subsets of LOX-1high DC and LOX-1low DC were found in the present study, and the levels of expression of inflammatory cytokines in LOX-1high DC subsets were significantly higher than LOX-1low DC subsets.In hyperlipidemia model of mice in vivo, the ratio of LOX-1high DC and LOX-1low DC was significantly increased in the aorta.In DC2.4 cells, ox-LDL could up-regulate LOX-1 expression.