Abstract Objective To investigate what role the endothelial cells interfacing with blood components play in cholesterol metabolism. Methods Isotope labeling technique, Gas Chromatography/Mass Spectrometry and We...Abstract Objective To investigate what role the endothelial cells interfacing with blood components play in cholesterol metabolism. Methods Isotope labeling technique, Gas Chromatography/Mass Spectrometry and Western blotting were used to measure the presence of 27 oxygenated cholesterol in medium and the presence of sterol 27 hydroxylase in endothelium. Results When human endothelial cells were cultured in a medium containing fetal calf serum, there was a significant accumulation of 27 hydroxycholesterol and 3β hydroxy 5 cholesteneic acid, products of cholesterol metabolism, in the medium. The rate of formation of these products almost increased linearly with time of cultivation. After addition of 100 μg of extraneous cholesterol to the medium, the accumulation of 27 hydroxy cholesterol and 3β hydroxy 5 cholesteneic acid increased significantly. Addition of more cholesterol did not further increase the formation of 27 hydroxy cholesterol and caused a decrease in the formation of 3β hydroxy 5 cholesteneic acid. The presence of sterol 27 hydroxylase in the endothelium was demonstrated by Western blotting. Conclusion Cultured human endothelium from umbilical veins are able to convert exogenous cholesterol into 27 hydroxy cholesterol and 3β hydroxy 5 cholesteneic acid. furthermore, the cells are able to transport these products from the cells into the medium.展开更多
文摘Abstract Objective To investigate what role the endothelial cells interfacing with blood components play in cholesterol metabolism. Methods Isotope labeling technique, Gas Chromatography/Mass Spectrometry and Western blotting were used to measure the presence of 27 oxygenated cholesterol in medium and the presence of sterol 27 hydroxylase in endothelium. Results When human endothelial cells were cultured in a medium containing fetal calf serum, there was a significant accumulation of 27 hydroxycholesterol and 3β hydroxy 5 cholesteneic acid, products of cholesterol metabolism, in the medium. The rate of formation of these products almost increased linearly with time of cultivation. After addition of 100 μg of extraneous cholesterol to the medium, the accumulation of 27 hydroxy cholesterol and 3β hydroxy 5 cholesteneic acid increased significantly. Addition of more cholesterol did not further increase the formation of 27 hydroxy cholesterol and caused a decrease in the formation of 3β hydroxy 5 cholesteneic acid. The presence of sterol 27 hydroxylase in the endothelium was demonstrated by Western blotting. Conclusion Cultured human endothelium from umbilical veins are able to convert exogenous cholesterol into 27 hydroxy cholesterol and 3β hydroxy 5 cholesteneic acid. furthermore, the cells are able to transport these products from the cells into the medium.
