title: Effect of albumin on 14C-alpha-Methyl-D-Glucopyranoside uptake in primary cultured renal proximal tubule cells: involvement of PLC, MAPK, and NF-kappaB.
abstract: A growing body of evidence implicates albumin has an important regulatory function in renal proximal tubule cells (PTCs). In present study, the effect of bovine serum albumin (BSA) on 14C-alpha-methyl-D-glucopyranoside (alpha-MG) uptake and its related signal molecules were examined in the primary cultured rabbit renal PTCs. BSA significantly increased uptake of alpha-MG, a distinctive proximal tubule marker, as well as expression level of Na+/glucose cotransporters (SGLT1 and SGLT2) proteins. The BSA-induced increase of alpha-MG uptake was completely blocked by actinomycin D and cycloheximide. Neomycin or U 73122 (PLC inhibitors), BAPTA/AM or TMB-8 (intracellular Ca2+ mobilization inhibitors) completely abolished BSA-induced increase of alpha-MG uptake. BSA significantly increased IPs accumulation, but did not affect Ca2+ uptake. Effect of BSA on alpha-MG uptake was blocked by PD 98059, but did not SB 203580. BSA increased phosphorylation of p44/42 mitogen activated protein kinase (MAPK) in a time-dependent manner. NAC or catalase (antioxidants) significantly blocked BSA-induced increase of H2O2 formation and alpha-MG uptake. BSA activated NF-kappaB translocation into nucleus. PDTC, SN50, and TLCK (NF-kappaB inhibitors) also completely blocked BSA-induced increase of alpha-MG uptake, NF-kappaB p65 and phospho IkappaB-alpha activation. In conclusion, BSA stimulates alpha-MG uptake and its action is partially correlated with PLC, MAPK, or NF-kappaB signal molecules in primary cultured renal PTCs.
authors.affiliation: Department of Veterinary Physiology, College of Veterinary Medicine, Chonnam National University, Gwangju, Korea. hjhan@chonnam.ac.kr
authors.forename: Ho Jae
authors.initials: HJ
authors.lastname: Han
authors.forename: Young Joon
authors.initials: YJ
authors.lastname: Oh
authors.forename: Yun Jung
authors.initials: YJ
authors.lastname: Lee
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000187:drug effects / Q000502:physiology; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D002250:Carbon Radioisotopes; D002478:Cells, Cultured; D002614:Chelating Agents / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism; D020672:I-kappa B Proteins / Q000378:metabolism; D007687:Kidney Tubules, Proximal / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008757:Methylglucosides / Q000493:pharmacokinetics*; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011817:Rabbits; D012709:Serum Albumin / Q000378:metabolism* / Q000494:pharmacology; D012710:Serum Albumin, Bovine / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D010738:Type C Phospholipases / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology
chemical_list: D000975:Antioxidants; D002250:Carbon Radioisotopes; D002614:Chelating Agents; D004791:Enzyme Inhibitors; D020672:I-kappa B Proteins; D008757:Methylglucosides; D016328:NF-kappa B; D012709:Serum Albumin; D000072000:NF-KappaB Inhibitor alpha; D012710:Serum Albumin, Bovine; C027020:methylglucoside; D006861:Hydrogen Peroxide; D048052:Mitogen-Activated Protein Kinase 3; D010738:Type C Phospholipases