Megalin/Cubilin-mediated Uptake of FITC-labeled IgG by OK Kidney Epithelial Cells
スポンサーリンク
概要
- 論文の詳細を見る
In this paper, we characterize the uptake mechanism of fluorescein isothiocyanate-labeled human immunoglobulin G (FITC-hIgG) in opossum kidney (OK) epithelial cells, which have been shown to express megalin and cubilin. Confocal immunofluorescence microscopy showed the punctate expression of the neonatal Fc receptor FcRn in the cytoplasm, but not on the cell surface membrane. Temperature- and energy-dependent uptake of FITC-hIgG was observed at pH 7.4 but not at pH 6.0, indicating that the internalization of FITC-hIgG might not be due to FcRn, which has a binding affinity for IgG under acidic conditions. Under physiological pH conditions, human and bovine serum γ-globulin decreased FITC-hIgG uptake in a concentration-dependent manner. In addition, FITC-hIgG uptake was inhibited by various megalin and/or cubilin ligands including albumin, cytochrome c, transferrin and gentamicin. Endosomal acidification inhibitors (bafilomycin A1 and chloroquine) significantly decreased the uptake of FITC-hIgG. Clathrin-dependent endocytosis inhibitors (phenylarsine oxide and chlorpromazine) decreased FITC-hIgG uptake. Potassium depletion and hypertonicity, conditions known to inhibit clathrin-dependent endocytosis, also decreased FITC-hIgG uptake. In contrast, caveolin-dependent endocytosis inhibitors (nystatin and methyl-β-cyclodextrin) did not decrease, but rather increased the uptake of FITC-hIgG. These observations suggest that the internalization of FITC-hIgG in OK cells might be, at least in part, due to megalin/cubilin-mediated, clathrin-dependent endocytosis.
- 日本薬物動態学会の論文
日本薬物動態学会 | 論文
- COMPETITIVE DISPLACEMENT OF SERUM PROTEIN BINDING TO REGULATE PHARMACOKINETICS OF A CEREBRAL BLOOD FLOW RADIOPHARMACEUTICAL
- Studies on the Metabolic Fate of Felodipine. (IV). Identification of New Metabolites of Felodipine in Rat.
- Metabolic Fate of Pergolide Mesylate. (2): Absorption, Distribution, Excretion of 14C-Pergolide Mesylate in Rats after Repeated Administration.
- Studies on the Metabolic Fate of 3H-TJN-101. (III): Absorption, Distribution and Excretion after Multiple Oral Administration to Rats.
- Studies on the Pharmacokinetics of Perindopril Erbumine in Rats. (1): Plasma Level Profile, Distribution, Metabolism and Excretion after Single Oral Administration.