Effects Of Nuciferine On The Expression Of SR-BI And Foam Formation Of Human THP-1 Derived Macrophage

Objective:1. To investigate the effect of ox-LDL on eholesterol accumulation and the expression of SR-BI in PMA-induced THP-1-derived macrophages.2. To investigate the effect of nuciferine on eholesterol influx and the expression of SR-BI in PMA-induced THP-1-derived macrophages. To probe the possible mechanism of anti-ASof nuciferine.Methods:1. Macrophages were derived from human monocyte lines THP-1 by PMA. Macrophages were coincubated with ox-LDL at various concentration (25mg/L,50mg/L,100mg/L) respectively for 24 hours into foam cells. THP-1 macrophages incubated without ox-LDL were the control groups. The course of the differentiation stimulated by ox-LDL from macrophages to foam cells was observed at microscope.Oil Red O staining was used to observe the intracellular lipid droplets. SR-BI mRNA level were detemrined by Sybr Green rt-PCR, protein level by western blot,respectively.2. Macrophages were derived from human monocyte lines THP-1 by PMA. THP-1 derived macrophages were incubated with ox-LDL (50mg/L) for 24 hours into foam cells.Then the foam cells were coincubated with nuciferine at various concentration (25mg/L,50mg/L, 100mg/L) respectively for 24 hours.THP-1 macrophages incubated without ox-LDL or nuciferine were the control groups. Oil Red O staining was used to observe the intracellular lipid droplets. SR-BI mRNA level were quantified by Sybr Green rt-PCR, protein level by western blot,respectively.Results:1. The changes of cellular characteristics in the course of the differentiation induced by PMA from monocyte lines THP-1 to macrophages were observed at microscope: from suspension to pasting wall:from round shape to ellipse,shuttle,irregular shape. The changes of cellular characteristics in the differentiation from macrophages into foam cells were showed by Oil red O staining: there were a load of lipid droplet.2. Results of part one : Oil red O staining showed that lipid droplets in ox-LDL groups were more than the control groups , and the intracellular droplets were minor with the presence of ox-LDL. The expression of both SR-BI mRNA and protein were decresed , and the degree of degression was correlated positively to the concentration of ox-LDL(P<0.01).3. Results of part two : Oil red O staining showed that lipid droplets in nuciferine groups were less than control groups , and the intracellular droplets were minor with the presence of nuciferine. The expression of both SR-BI mRNA and protein was incresed by nuciferine, and the degree of degression was correlated negetively to the concentration of nuciferine (P<0.01).Conclusion:1. Ox-LDL downregulates the expression of SR-BI in THP-1 derived macrophages ; increases the eholesterol accumulation , finally leading to the foam formation of THP-1 derived macrophage (P<0.01).2. Nuciferine upregulates the expression of SR-BI in THP-1 derived macrophages; decreases the eholesterol accumulation and increases the eholesterol influx, lessen the foam formation of THP-1 derived macrophage. We probe that this may be the possible mechanism of anti-atherosclerosis of nuciferine.