Variability in hepatic expression of organic anion transporter 7/SLC22A9, a novel pravastatin uptake transporter: impact of genetic and regulatory factors
Abstract:
Human organic anion transporter 7 (OAT7, SLC22A9) is a hepatic transport protein poorly characterized so far. We therefore sought to identify novel OAT7 substrates and factors contributing to variable hepatic OAT7 expression. Using OAT7-expressing cells, pravastatin was identified as a substrate. Hepatic SLC22A9/OAT7 mRNA and protein expression varied 28-fold and 15-fold, respectively, in 126 Caucasian liver samples. Twenty-four variants in SLC22A9 were genotyped, including three rare missense variants (rs377211288, rs61742518, rs146027075), which occurred only heterozygously. No variant significantly affected hepatic SLC22A9/OAT7 expression. The three missense variants, however, showed functional consequences when expressed in vitro. Hepatic nuclear factor 4-alpha (HNF4alpha) emerged as a major transcriptional regulator of SLC22A9 by a series of in silico and in vitro analyses. In conclusion, pravastatin is the first identified OAT7 drug substrate. Substantial inter-individual variability in hepatic OAT7 expression, majorly driven by HNF4alpha, may contribute to pravastatin drug disposition and might affect response.The Pharmacogenomics Journal advance online publication, 4 August 2015; doi:10.1038/tpj.2015.55.
Projects: G2: Clinical Translation to Non-Invasive Volunteer Setting, G3: Clinical Translation to Pharmaceutical Drug Development
Pharmacogenomics J
Pharmacogenomics J. 2015 Aug 4. doi: 10.1038/tpj.2015.55.
5th Aug 2015
A. Emami Riedmaier, O. Burk, B. A. van Eijck, E. Schaeffeler, K. Klein, S. Fehr, S. Biskup, S. Muller, S. Winter, U. M. Zanger, M. Schwab, A. T. Nies
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- Created: 17th Dec 2015 at 11:49
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