The limitations of renal epithelial cell line HK-2 as a model of drug transporter expression and function in the proximal tubule
- 27 September 2012
- journal article
- research article
- Published by Springer Nature in Pflügers Archiv - European Journal of Physiology
- Vol. 464 (6), 601-611
- https://doi.org/10.1007/s00424-012-1163-2
Abstract
Acquiring a mechanistic understanding of the processes underlying the renal clearance of drug molecules in man has been hampered by a lack of robust in vitro models of human proximal tubules. Several human renal epithelial cell lines derived from the renal cortex are available, but few have been characterised in detail in terms of transporter expression. This includes the HK-2 proximal tubule cell line, which has been used extensively as a model of nephrotoxicity. The aim of this study was to investigate the expression and function of drug transporters in HK-2 cells and their suitability as an in vitro model of the human proximal tubule. qPCR showed no mRNA expression of the SLC22 transporter family (OAT1, OAT3, OCT2) in HK-2 cells compared to renal cortex samples. In contrast, SLC16A1 (MCT1), which is important in the uptake of monocarboxylates, and SLCO4C1 (OATP4C1) were expressed in HK-2 cells. The functional expression of these transporters was confirmed by uptake studies using radiolabelled prototypic substrates dl-lactate and digoxin, respectively. The mRNA expression of apical membrane efflux transporters ABCB1 (MDR1) and several members of the ABCC family (multidrug resistance proteins, MRPs) was shown by qPCR. ABCG1 (BCRP) was not detected. The efflux of Hoechst 33342, a substrate for MDR1, was blocked by MDR1 inhibitor cyclosporin A, suggesting the functional expression of this transporter. Similarly, the efflux of the MRP-specific fluorescent dye glutathione methylfluorescein was inhibited by the MRP inhibitor MK571. Taken together, the results of this study suggest that HK-2 cells are of limited value as an in vitro model of drug transporter expression in the human proximal tubule.Keywords
This publication has 40 references indexed in Scilit:
- Novel conditionally immortalized human proximal tubule cell line expressing functional influx and efflux transportersCell and tissue research, 2009
- Characterisation of human tubular cell monolayers as a model of proximal tubular xenobiotic handlingToxicology and Applied Pharmacology, 2008
- The breast cancer resistance protein transporter ABCG2 is expressed in the human kidney proximal tubule apical membraneKidney International, 2008
- Compound profiling for ABCC2 (MRP2) using a fluorescent microplate assay systemEuropean Journal of Pharmaceutics and Biopharmaceutics, 2007
- Cloning and functional characterization of human SMCT2 (SLC5A12) and expression pattern of the transporter in kidneyBiochimica et Biophysica Acta (BBA) - Biomembranes, 2007
- Influence of Different Chemicals on MDR-1 P-Glycoprotein Expression and Activity in the HK-2 Proximal Tubular Cell LineToxicology and Applied Pharmacology, 2002
- Molecular Cloning and Characterization of Two Novel Human Renal Organic Anion Transporters (hOAT1 and hOAT3)Biochemical and Biophysical Research Communications, 1999
- The Leukotriene LTD4 Receptor Antagonist Mk571 Specifically Modulates MRP Associated Multidrug ResistanceBiochemical and Biophysical Research Communications, 1995
- HK-2: An immortalized proximal tubule epithelial cell line from normal adult human kidneyKidney International, 1994
- A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye bindingAnalytical Biochemistry, 1976