Abstract
Metabolism of acetyl low density lipoprotein (Ac-LDL) and β-very low density lipoprotein (β-VLDL) was studied in macrophage cell lines; U-937, J774.1, and P388D1 to establish a system to detect atherogenic lipoproteins in disease states. J774 cell line degraded 125I Ac-LDL and incorporated 14C oleate into cholesterol ester in the presence of Ac-LDL, but other two cell lines and cultured human fibroblasts did not. All three cell lines and fibroblasts degraded 125I β-VLDL. 125I β-VLDL degradation was completely replaced with 160μg/ml native LDL in P388 and fibroblasts, but not in J774 and U-937 cell lines by even 500μg/ml LDL. 14C oleate was incorporated into cholesterol ester in all three macrophage cell lines and fibrobalsts in the presence of β-VLDL. J774 cells incorporated 14C oleate more than 10 folds in the presence of β-VLDL compared with in the presence of the same concentration of LDL, while P388 and fibroblasts incorporated oleate 4-5 folds. No cell line incorporated oleate in the presence of glycated LDL.
These results indicate that J774 may be an useful cell line to detect abnormal lipoproteins appearing in various disease states, and also suggest the presence of functionally specific receptor for β-VLDL in J774 cell lines.
