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Regulation of ABC transporters by hypoxia in HK‐2 human proximal tubule epithelial cells
Author(s) -
Chung Git,
Brown Colin Douglas
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.1099.6
Subject(s) - blot , microbiology and biotechnology , cell culture , hypoxia (environmental) , messenger rna , transporter , atp binding cassette transporter , chemistry , multidrug resistance associated protein 2 , kidney , biology , biochemistry , endocrinology , gene , genetics , organic chemistry , oxygen
Hypoxia‐inducible factor‐1 (HIF‐1), a transcription factor that is stabilised during hypoxia, may influence the expression of ABC transporters in the kidney. The aim of this study was to use a proximal tubule epithelial cell line (HK‐2) as a kidney model to determine changes in ABC transporters at an mRNA and functional level when HK‐2 cells were exposed to a hypoxia‐mimetic compound, desferrioxamine (DFO). Western Blots were used to determine changes in protein levels of HIF‐1 between DFO treated and untreated HK‐2 cells. A qPCR approach was used to determine mRNA expression of ABC transporters in DFO treated and untreated HK‐2 cells. The functional expression of ABC transporters in HK‐2 cells was determined using Hoechst 33342 and CMFDA dye efflux assays. Western blots of HIF‐1 protein showed significantly increased expression in HK‐2 cells treated with DFO compared with untreated cells. The mRNA expression profiles of MDR1, MRP1 and MRP3 showed an up‐regulation fold change of 1.63, 2.04 and 1.58 respectively in DFO treated HK‐2 cells compared to untreated cells. The magnitudes of the fluorescence of retained Hoechst 33342 and CMFDA dyes were significantly lower in DFO treated HK‐2 cells compared to untreated cells (P<0.01). These results provide evidence to support the hypothesis that HIF‐1, stabilised with DFO, influences the regulation of ABC transporters in the kidney.