title: Immunohistochemical and biochemical detection of low density lipoprotein receptors in cultured rat mesangial cells.
abstract: The expression of low density lipoprotein (LDL) receptors by cultured rat mesangial cells was demonstrated using immunohistochemical and biochemical methods. Using a mouse monoclonal anti-human LDL receptor antibody, the immunofluorescence technique was applied to cultured mesangial cells and showed granular staining. Immunoblotting analysis of the membrane fraction of cultured mesangial cells showed a single band with a protein of approximately 130,000 molecular weight. In addition, [125I]LDL binding and the uptake of [125I]LDL by cultured mesangial cells were studied. Binding and uptake both reached an equilibrium after about 30 min of incubation. A 50% reduction in [125I]LDL (20 micrograms protein/ml) binding and uptake occurred when unlabelled LDL was added to cultures at 20-40 micrograms protein/ml. Addition of high density lipoprotein without apoE to the culture medium did not induce competitive inhibition of [125I]LDL binding and uptake by mesangial cells. These findings suggest that cultured mesangial cells have the capacity to express an LDL receptor that regulates the cellular uptake of LDL.
authors.affiliation: First Department of Medicine, Teikyo University School of Medicine, Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Ito
authors.forename: M
authors.initials: M
authors.lastname: Chimata
authors.forename: M
authors.initials: M
authors.lastname: Oka
authors.forename: Y
authors.initials: Y
authors.lastname: Suzuki
authors.forename: N
authors.initials: N
authors.lastname: Hamada
authors.forename: M
authors.initials: M
authors.lastname: Fujimaki
authors.forename: K
authors.initials: K
authors.lastname: Oda
authors.forename: K
authors.initials: K
authors.lastname: Fujisawa
authors.forename: T
authors.initials: T
authors.lastname: Teramoto
authors.forename: K
authors.initials: K
authors.lastname: Nakamura
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D002478:Cells, Cultured; D004591:Electrophoresis, Polyacrylamide Gel; D005920:Glomerular Mesangium / Q000737:chemistry* / Q000166:cytology / Q000648:ultrastructure*; D015151:Immunoblotting; D007150:Immunohistochemistry; D007457:Iodine Radioisotopes; D008077:Lipoproteins, LDL / Q000378:metabolism / Q000493:pharmacokinetics; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D011973:Receptors, LDL / Q000032:analysis* / Q000378:metabolism; D013194:Staining and Labeling / Q000379:methods
chemical_list: D000911:Antibodies, Monoclonal; D007457:Iodine Radioisotopes; D008077:Lipoproteins, LDL; D011973:Receptors, LDL