Lipoprotein binding to cultured human hepatoma cells.
AUTOR(ES)
Krempler, F
RESUMO
Binding of various 125I-lipoproteins to hepatic receptors was studied on cultured human hepatoma cells (Hep G2). Chylomicrons, isolated from a chylothorax, chylomicron remnants, hypertriglyceridemic very low-density lipoproteins, normotriglyceridemic very low-density lipoproteins (NTG-VLDL), their remnants, low-density lipoproteins (LDL), and HDL-E (an Apo E-rich high-density lipoprotein isolated from the plasma of a patient with primary biliary cirrhosis) were bound by high-affinity receptors. Chylomicron remnants and HDL-E were bound with the highest affinity. The results, obtained from competitive binding experiments, are consistent with the existence of two distinct receptors on Hep G2 cells: (a) a remnant receptor capable of high-affinity binding of triglyceride-rich lipoproteins and HDL-E, but not of Apo E free LDL, and (b) a LDL receptor capable of high-affinity binding of LDL, NTG-VLDL, and HDL-E. Specific binding of Apo E-free LDL was completely abolished in the presence of 3 mM EDTA, indicating that binding to the LDL receptor is calcium dependent. Specific binding of chylomicron remnants was not inhibited by the presence of even 10 mM EDTA. Preincubation of the Hep G2 cells in lipoprotein-containing medium resulted in complete suppression of LDL receptors but did not affect the remnant receptors. Hep G2 cells seem to be a suitable model for the study of hepatic receptors for lipoprotein in man.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=442251Documentos Relacionados
- Binding of tissue plasminogen activator to cultured human endothelial cells.
- Binding of Escherichia coli S fimbriae to cultured human endothelial cells.
- Transfer of retinol-binding protein from HepG2 human hepatoma cells to cocultured rat stellate cells.
- Involvement of cell surface heparin sulfate in the binding of lipoprotein lipase to cultured bovine endothelial cells.
- Plasma triglycerides determine low density lipoprotein composition, physical properties, and cell-specific binding in cultured cells.