Dr Andrew Bahn
Department of Physiology
Otago School of Medical Sciences
University of Otago
PO Box 913
Fax: +64 3 479 7323
Member of Membrane & Ion Transport.
My main research topic is the renal organic anion transport. Organic anions (OA) are substances, which possess a negative charge under physiological conditions. This class of substances includes a wide array of endogenous as well as exogenous compounds such as neurotransmitter metabolites, urate or prostaglandins, anti-viral drugs, antibiotics, analgesics or ochratoxin A, to name just a few. The kidney is the organ that facilitates secretion of these substances into the urine. Transport proteins involved in the secretion process of OA are members of the so called solute carrier family 22A (SLC22A). In recent years I was involved in the cloning and functional characterisation of organic anion transporters (OAT) of the SLC22A family.
Urate is the end product of purine metabolism in higher primates and well known as the substance causing gout. It has come back into clinical focus because of new studies supporting its impact on cardiovascular and neurodegenerative diseases. Recently, we have demonstrated that transporters such as organic anion transporter 4 (OAT4) or OAT10 are not only capable of urate transport, but they are also involved in renal secretion of anti-hypertensive drugs such as diuretics (furosemide or torasemide) or thiazides (hydrochlorothiazide) and even the immunosuppressant cyclosporine A. We provided evidence that OAT4 as well as OAT10 exchange these drugs during secretion against urate and are consequently involved in the hyperuricemic effect of these commonly used diuretics, thiazides and cyclosporine A (Hagos et al. 2007a; Hagos et al. 2007b; Bahn et al. 2008).
Transporters currently known to play a significant role in determining urate plasma levels are URAT1, OAT4, ABCG2 and glucose transporter 9 (GLUT9). My main current interest is the post-transcriptional regulation of these urate transporters, especially GLUT9 in general and under different stress conditions.
- Organic anion transport
- Urate transport
- 2012 - 2013 Otago Medical Research Foundation (Laurenson grant) in collaboration with A/P Lisa Stamp (Christchurch)
- 2012 - 2013 The National Heart Foundation, Associate Investigator with Dr Regis Lamberts
- 2012 - 2013 University of Otago Research Grant
- 2012 - 2013 University of Otago Research Grant, Associate Investigator with Dr Regis Lamberts
- 2011 - 2013 Prostate Cancer Foundation New Zealand
- 2011 - 2012 Dean's Bequest funding
- 2010 - 2013 Health Research Council (HRC) emerging researcher first grant
- Dinour D, Bahn A, Ganon L, Ron R, Geifman-Holtzman O, Knecht A, Gafter U, Rachamimov R, Sela BA, Burckhardt G, Holtzman EJ. URAT1 mutations cause renal hypouricemia type 1 in Iraqi Jews. Nephrol Dial Transplant. 2011, 26(7):2175-81.
- Rödiger M., Zhang X., Ugele B., Gersdorff N., Wright SH, Burckhardt G., Bahn A. Organic Anion Transporter 3 (OAT3) and renal transport of the metal chelator 2,3-dimercapto-1-propanesulfonic acid (DMPS). Can J Physiol Pharmacol 2010, 88(2):141-6.
- Bakhiya N., Arlt V.M., Bahn A., Burckhardt G., Phillips D.H., Glatt H. Molecular evidence for an involvement of organic anion transporters (OATs) in aristolochic acid nephropathy. Toxicology. 2009 Oct 1;264(1-2):74-9.
- Bahn A., Hagos Y., Reuter S., Balen D., Brzica H., Krick W., Burckhardt B.C., Sabolic I., Burckhardt G. Identification of a new urate and high affinity nicotinate transporter - human Organic Anion Transporter 10 (hOAT10, SLC22A13). J Biol Chem. 2008;283(24):16332-41.
- Ugele B., Bahn A. and Rex-Haffner M. Functional differences in steroid sulphate uptake of Organic Anion Transporter 4 (OAT4) and Organic Anion Transporting Polypeptide 2B1 (OATP2B1). J Steroid Biochem Mol Biol. 2008 Jul;111(1-2):1-6.
- Sabolic I, Asif AR, Budach WE, Wanke C, Bahn A, Burckhardt G. Gender differences in kidney function. Pflügers Arch. 2007; 455:397-429.
- Hagos Y., Bahn A., Vormfelde S.V., Brockmöller J., Burckhardt G. Torasemide transport by organic anion transporters contributes to hyperuricemia. J Am Soc Nephrol. 2007; 18:3101-3109 (a).
- Hagos Y., Stein D., Ugele B., Burckhardt G., Bahn A. Human renal Organic-Anion-Transporter 4 (hOAT4) operates as an asymmetric urate transporter. J Am Soc Nephrol. 2007;18:430?439 (b).
- Ljubojevic M., Balen D., Breljak D., Kusan M., Anzai N., Bahn A., Burckhardt G., Sabolic I. Renal expression of organic anion transporter OAT2 in rats and mice is regulated by sex hormones. Am J Physiol Renal Physiol. 2007; 292:F361-72.
- Bakhiya N., Stephani M., Bahn A., Ugele B., Seidel A., Burckhardt G., Glatt H. Uptake of chemically reactive, DNA-damaging sulfuric acid esters into renal cells byhuman organic anion transporters. J Am Soc Nephrol. 2006; 17:1414-21.
- Kidney and Gastrointestinal Physiology
Physiology is the stepchild of medicine. That is why Cinderella often turns out the queen.