Original Articles
Yi Wang, Lili Zhang, Minghui S
Abstract
To investigate the effects of Interleukin-1beta(IL-1β) on foam cell formation of THP-1 macrophages (Mфs). Human THP-1 monocytes were differentiated into macrophages by phorbol esters in vitro, then the macrophages were incubated with the absence of IL-1β and oxidized low density lipoprotein (ox-LDL) (control group), 10ng/ml IL-1β (IL-1β group), 100ug/ml ox-LDL (ox-LDL group) or 10ng/ml IL-1β and 100ug/ml ox-LDL (IL-ox-LDL group) for 24h. High performance liquid chomatography was used for qualitative and quantitative analysis of intracellular cholesterol and cholesteryl esters. Both light microscope with red oil O staining technique and transmission electron microscope were employed to observe the morphology of treated and controlled THP-1 cells. A large number of intracellular red oil O stained granules and lipid vacuoles were observed in ox-LDL group and IL-ox-LDL group, the contents of total cholesterol and cholesteryl esters were significantly higher than those of control group (P<0.05), and the contents of cholesteryl esters were higher than 50% of total cholesterol in both groups. However, only few intracellular red oil O stained granules and lipid vacuoles were observed in control group and IL-1β group, there was no significant difference in the contents of total cholesterol and cholesteryl esters between control group and IL-1βgroup (P>0.05), and the contents of cholesteryl esters were less than 50% of total cholesterol in both groups. IL-1β alone cannot make THP-1 cells into foam cells, indicating that inflammatory cytokines were not independently atherogenic.