Effect Of Curcumin On KIF16B-mediated Plasma Membrane Transport Of LDLR In Liver Cells

Objective: To analyze and explore the relationship between the effect of curcumin on LDLR expression with LDL uptake in hepatocytes and KIF16 B,a member of the kinesin family,hope to provide the theoretical support and scientific inspiration for clinical development of curcumin lipid-lowering drugs.Method: Liver HepG2 cells and liver LO2 cells were incubated in DMEM high glucose medium with 10% fetal bovine serum and cultured in vitro for 24 hours.The liver cells activity was measured by CCK8.The lipid contents of liver cells were observed by oil red O staining.The cholesterol levels of liver cells were detected by cholesterol test kit.The ability of the cells to uptake LDL was determined by Dil dye-labeled LDL co-incubated experiments.The protein expression of LDLR and KIF16 B in liver cells was analyzed by western blot.The co-localization of KIF16 B and LDLR in liver cells was detected by cellular immunofluorescence staining.The abundance of LDLR on the surface of liver cells was measured by flow cytometry.Results:1.The CCK8 results showed that the activity of liver HepG2 cells and liver LO2 cells did not change significantly when treated with curcumin at the concentration of 10 ?mol/L,20 ?mol/L,30 ?mol/L,40?mol/L,indicating that the curcumin concentration of 25 ?mol/L in previous experiments is suitable for this study.2.The oil red O staining results showed that the red lipid droplet content in the Rosavastatin group and the Curcumin group of the liver HepG2 cells and the liver LO2 cells were significantly increased than the Control group.3.The intracellular cholesterol content test results showed that compared with the Control group,the total cholesterol(TC)and free cholesterol(FC)levels in the Basal group of the liver HesG2 cells and the liver LO2 cells were decreased,while the TC and FC content in the Rosuvastatin group and Curcumin group were increased significantly.4.The cell uptake of Dil-LDL results showed that compared with the Control group,the red fluorescence of the Basal group was reduced in HepG2 cells,while the red fluorescence were significantly increased in the LPDS group,the Rosuvastatin group and the Curcumin group;In the LO2 cells,the red fluorescence were significantly reduced in the Basal group and the 25-HC group while increased in the LPDS group,the Rosuvastatin group and the Curcumin group compared with the Controlgroup.5.The western blot results showed that compared with the Control group in the liver HepG2 cells and liver LO2 cells,the protein expressions of LDLR and KIF16 B in the Basal group were not significantly different,while the levels of LDLR and KIF16 B proteins were significantly increased in the Rosuvastatin group and Curcumin group.6.The cell immunofluorescence staining results showed that compared with the Control group,the KIF16 B and LDLR fluorescence co-localization rates of the Basal group and the Rosuvastatin group did not change significantly in the liver HepG2 cells and liver LO2 cells,while the KIF16 B and LDLR fluorescence co-localization rates of the Curcumin group increased significantly.7.The flow cytometry results showed that compared with the Control group,the LDLR abundance on the cell membrane surface of the liver HepG2 cells was decreased in the Basal group,while significantly increased in the LPDS group,the Rosavastatin group and the Curcumin group;In the LO2 cells,the LDLR abundance on the cell membrane surface of the Rosavastatin group and the Curcumin group were increased compared with the Control group.Conclusion: The mechanism by which Curcumin increases LDLR protein expression and promotes LDL uptake of liver cells may be relatedto KIF16B-mediated LDLR transport to the plasma membrane.