Experimental Study Of Nuciferine Promoting Autophagy And Inhibiting Macrophage Foaming Through PI3K/Akt/mTOR Pathway

AIM:To observe the effect of nuciferine(Nuciferin,NUF)on macrophage foaming and explore its possible molecular mechanism.METHODS:1.Human mononuclear macrophage cell line THP-1,was induced by oxidized low density lipoprotein(oxidizedlowdensitylipoprotein,OXLDL)to establish foam cell model in vitro,and treated with 5,10 and 20 ? mol / L nuciferine at the same time.2.Oil red O staining,total cholesterol content were used to evaluate the effect of nuciferine on formation of foam cell.3.Detecting the effect of nuciferine on autophagy: Western blot was used to detect the expression of LC3 B and P62 proteins,laser scanning confocal microscope was used to detect autophagy flow and transmission electron microscopy was used to detect the number of autophagosomes.4.In order to study whether the effect of nuciferine on the formation of foam cells by regulating autophagy,the autophagy inhibitor 3-methyladenine(3-MA)was used to inhibit autophagy.5.In order to observe the effect of nuciferine on the PI3K/Akt /mTOR pathway,the expression levels of Akt,mTOR,p-Akt and pmTOR proteins were detected by western blot.RESULTS:1.Compared with the control group,the intracellular lipid deposition and the content of total cholesterol in OX-LDL model group increased significantly(P < 0.001).Lipid droplets could be seen under electron microscope,indicating that the foam cell model was established successfully.2.Compared with the OX-LDL model group,the intracellular lipid deposition and the content of total cholesterol in the nuciferine group decreased significantly(P < 0.05),suggesting that nuciferine can inhibit the foaming of macrophages.3.Compared with the control group and OX-LDL model group,the expression of autophagy-related protein LC3II/LC3 I in nuciferine group increased significantly(P < 0.002),p62 decreased significantly(P < 0.001),autophagy body increased(P < 0.001),suggesting that nuciferine can promote autophagy.4.After the autophagy inhibitor 3-MA treatment,the intracellular lipid deposition and the content of total cholesterol increased significantly compared with the nuciferine group(P < 0.0001),which was similar to that of the model group,which proved that nuciferine inhibited cell foaming by promoting autophagy.5.Compared with the control group and OX-LDL model group,nuciferine significantly decreased the protein expression of p-mTOR and p-Akt(P < 0.05).CONCLUSION:Nuciferine may promote autophagy by inhibiting the PI3K/AKT/ mTOR pathway,reduce intracellular lipid deposition and total cholesterol content,and reduce the formation of foam cell.