Effect of albumin on 14C-α-Methyl-d-Glucopyranoside uptake in primary cultured renal proximal tubule cells: Involvement of PLC, MAPK, and NF-κB

✍ Scribed by Ho Jae Han; Young Joon Oh; Yun Jung Lee

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 293 KB
• Volume: 202
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.20108

✦ Synopsis

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 ^14^C‐α‐methyl‐d‐glucopyranoside (α‐MG) uptake and its related signal molecules were examined in the primary cultured rabbit renal PTCs. BSA significantly increased uptake of α‐MG, a distinctive proximal tubule marker, as well as expression level of Na^+^/glucose cotransporters (SGLT1 and SGLT2) proteins. The BSA‐induced increase of α‐MG uptake was completely blocked by actinomycin D and cycloheximide. Neomycin or U 73122 (PLC inhibitors), BAPTA/AM or TMB‐8 (intracellular Ca^2+^ mobilization inhibitors) completely abolished BSA‐induced increase of α‐MG uptake. BSA significantly increased IP~s~ accumulation, but did not affect Ca^2+^ uptake. Effect of BSA on α‐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 H~2~O~2~ formation and α‐MG uptake. BSA activated NF‐κB translocation into nucleus. PDTC, SN50, and TLCK (NF‐κB inhibitors) also completely blocked BSA‐induced increase of α‐MG uptake, NF‐κB p65 and phospho IκB‐α activation. In conclusion, BSA stimulates α‐MG uptake and its action is partially correlated with PLC, MAPK, or NF‐κB signal molecules in primary cultured renal PTCs. © 2005 Wiley‐Liss, Inc.