8 results on '"Annett, Kuehne"'
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2. In vitro validation of an in vivo phenotyping drug cocktail for major drug transporters in humans
- Author
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Chih-hsuan Hsin, Annett Kuehne, Yi Gu, Gabriele Jedlitschky, Yohannes Hagos, Dirk Gründemann, and Uwe Fuhr
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Pharmaceutical Science - Published
- 2023
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3. Functional and Pharmacological Comparison of Human and Mouse Na+/Taurocholate Cotransporting Polypeptide (NTCP)
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Mladen V. Tzvetkov, Yohannes Hagos, Juergen Brockmoeller, Joachim Geyer, Saskia Floerl, and Annett Kuehne
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0301 basic medicine ,SLC10A1 ,biology ,Transporter ,Pharmacology ,Biochemistry ,3. Good health ,Analytical Chemistry ,Transport protein ,03 medical and health sciences ,chemistry.chemical_compound ,Benzbromarone ,030104 developmental biology ,0302 clinical medicine ,Pharmacokinetics ,chemistry ,Estrone sulfate ,030220 oncology & carcinogenesis ,medicine ,biology.protein ,Molecular Medicine ,IC50 ,Biotechnology ,Fluvastatin ,medicine.drug - Abstract
The Na+/taurocholate cotransporting polypeptide (NTCP) is located in the basolateral membrane of hepatocytes, where it transports bile acids from the portal blood back into hepatocytes. Furthermore, NTCP has a role for the hepatic transport of some drugs. Extrapolation of drug transport data from rodents to humans is not always possible, because species differences in the expression level, localization, affinity, and substrate selectivity of relevant transport proteins must be considered. In the present study, a functional comparison of human NTCP (hNTCP) and mouse Ntcp (mNtcp) showed similar Km values of 67 ± 10 µM and 104 ± 9 µM for the probe substrate estrone-3-sulfate as well as of 258 ± 42 µM and 199 ± 13 µM for the drug rosuvastatin, respectively. IC50 values for the probe inhibitor cyclosporine A were 3.1 ± 0.3 µM for hNTCP and 1.6 ± 0.4 µM for mNtcp. In a drug and pesticide inhibitory screening on both transporters, 4 of the 15 tested drugs (cyclosporine A, benzbromarone, MK571, and fluvastatin) showed high inhibitory potency, but only slight inhibition was observed for the 13 tested pesticides. Among these compounds, only four drugs and three pesticides showed significant differences in their inhibition pattern on hNTCP and mNtcp. Most pronounced was the difference for benzbromarone with a fivefold higher IC50 for mNtcp (27 ± 10 µM) than for hNTCP (5.5 ± 0.6 µM).In conclusion, we found a strong correlation between the transport kinetics and inhibition pattern among hNTCP and mNtcp. However, specific compounds, such as benzbromarone, showed clear species differences. Such species differences have to be considered when pharmacokinetic data are transferred from rodent to humans.
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- 2021
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4. Investigations with Drugs and Pesticides Revealed New Species- and Substrate-Dependent Inhibition by Elacridar and Imazalil in Human and Mouse Organic Cation Transporter OCT2
- Author
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Annett Kuehne, Saskia Floerl, and Yohannes Hagos
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Inorganic Chemistry ,Organic Chemistry ,General Medicine ,Physical and Theoretical Chemistry ,SLC22 ,OCT2 ,species differences ,drugs ,pesticides ,elacridar and imazalil ,Molecular Biology ,Spectroscopy ,Catalysis ,Computer Science Applications - Abstract
Multiple drugs are used to treat various indications as well as pesticides that are ingested unintentionally and enter the bloodstream. The residence time or bioavailability of these substances in circulation depends on several mechanisms, such as drug–drug interaction (DDI), drug–pesticide interaction, metabolizing enzymes and the hepatic and renal transport systems, involved in the elimination of the compounds from the body. One of these transporters is the Organic Cation Transporter 2 (OCT2) member of the solute carrier(SLC22) transporter family. OCT2 is highly expressed in the proximal tubule epithelial cells in human and mouse kidney, where it mediates the uptake of endogenous organic cations as well as numerous drugs and xenobiotics, and contributes to the first step of renal clearance. In this study, we examined OCT2 on two subjects: First, the transferability of data from mouse to human, since mice are initially examined in the development of new drugs to assess the renal excretion of organic cations. Second, to what extent the choice of substrate affects the properties of an inhibitor. For this purpose, the functional properties of hOCT2 and mOct2 were validated under the same experimental conditions with the known substrates metformin and 1-Methyl-4-phenylpyridinium iodide (MPP). While hOCT2 and mOct2 showed very low affinities for metformin with Km values of 3.9 mM and 3.5 mM, the affinity of hOCT2 and mOct2 for MPP (62 and 40 µM) was 64- and 89-fold higher, respectively. For our positive control inhibitor decynium22, we determined the following IC50 values for hOCT2 and mOct2: 2.2 and 2.6 µM for metformin uptake, and 16 and 6.9 µM for MPP uptake. A correlation analysis of the inhibitory effects of 13 drugs and 9 pesticides on hOCT2- and mOct2-mediated transport of metformin showed a correlation coefficient R2 of 0.88, indicating good interspecies correlation. Nevertheless, the bioenhancer elacridar and the fungicide imazalil showed species-dependent inhibitory potentials. Concentration-dependent inhibition of hOCT2- and mOct2-mediated metformin uptake by elacridar showed IC50 values of 20 µM and 1.9 µM and by imazalil 4.7 µM and 0.58 µM, respectively. In conclusion, although our data show comparable species-independent interactions for most compounds, there can be large species–specific differences in the interactions of individual compounds, which should be considered when extrapolating data from mice to humans. Furthermore, a comparison of the inhibitory potential of elacridar and imazalil on metformin uptake with that on MPP uptake reveals substrate-dependent differences in hOCT2 and mOct2 for both inhibitors. Therefore, it might be useful to test two different substrates in inhibition studies.
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- 2022
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5. Functional characterization and comparison of human and mouse organic anion transporter 1 as drugs and pesticides uptake carrier
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Saskia, Floerl, Annett, Kuehne, and Yohannes, Hagos
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Mice ,Organic Anion Transport Protein 1 ,Animals ,Humans ,Membrane Transport Proteins ,Pharmaceutical Science ,Biological Transport ,Organic Anion Transporters, Sodium-Independent ,Pesticides ,Kidney - Abstract
The organic anion transporter 1 (OAT1) is mainly expressed in proximal tubule cells, where it mediates the renal uptake of endogenous and exogenous compounds. Thereby, it has enormous clinical relevance particularly in drug-drug interactions. The aim of the present in vitro study was to elucidate potential species dependent disparity of human and mouse OAT1 in handling of structural diverse drugs and pesticides. A basic functional comparison of the two transporters showed a similar time-dependent uptake of the substrate para-aminohippuric acid (PAH), the affinity (K
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- 2022
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6. Functional and Pharmacological Comparison of Human and Mouse Na
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Saskia, Floerl, Annett, Kuehne, Joachim, Geyer, Juergen, Brockmoeller, Mladen V, Tzvetkov, and Yohannes, Hagos
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Bile Acids and Salts ,Kinetics ,Mice ,Dose-Response Relationship, Drug ,Symporters ,Benzbromarone ,Hepatocytes ,Animals ,Humans ,Organic Anion Transporters, Sodium-Dependent ,Biological Transport ,Ion Channel Gating ,Cells, Cultured - Abstract
The Na
- Published
- 2021
7. Functional and Pharmacological Comparison of Human, Mouse, and Rat Organic Cation Transporter 1 toward Drug and Pesticide Interaction
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Annett Kuehne, Yohannes Hagos, and Saskia Floerl
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0301 basic medicine ,species differences ,Rodent ,Pharmacology ,OCT1 ,drugs ,lcsh:Chemistry ,Mice ,0302 clinical medicine ,Drug Interactions ,lcsh:QH301-705.5 ,Spectroscopy ,media_common ,Organic cation transport proteins ,biology ,Chemistry ,General Medicine ,Computer Science Applications ,Transport protein ,030220 oncology & carcinogenesis ,Ketoconazole ,medicine.drug ,Drug ,media_common.quotation_subject ,Catalysis ,Clonidine ,Article ,Inorganic Chemistry ,03 medical and health sciences ,Species Specificity ,biology.animal ,medicine ,Animals ,Humans ,Physical and Theoretical Chemistry ,Molecular Biology ,SLC22A1 ,Organic Chemistry ,Substrate (chemistry) ,Transporter ,solute carrier (SLC) family ,pesticides ,Fungicides, Industrial ,Rats ,030104 developmental biology ,HEK293 Cells ,lcsh:Biology (General) ,lcsh:QD1-999 ,Verapamil ,biology.protein ,Catecholamine Plasma Membrane Transport Proteins - Abstract
Extrapolation from animal to human data is not always possible, because several essential factors, such as expression level, localization, as well as the substrate selectivity and affinity of relevant transport proteins, can differ between species. In this study, we examined the interactions of drugs and pesticides with the clinically relevant organic cation transporter hOCT1 (SLC22A1) in comparison to the orthologous transporters from mouse and rat. We determined Km-values (73 ±, 7, 36 ±, 13, and 57 ±, 5 µ, M) of human, mouse and rat OCT1 for the commonly used substrate 1-methyl-4-phenylpyridinium (MPP) and IC50-values of decynium22 (12.1 ±, 0.8, 5.3 ±, 0.4, and 10.5 ±, 0.4 µ, M). For the first time, we demonstrated the interaction of the cationic fungicides imazalil, azoxystrobin, prochloraz, and propamocarb with human and rodent OCT1. Drugs such as ketoconazole, clonidine, and verapamil showed substantial inhibitory potential to human, mouse, and rat OCT1 activity. A correlation analysis of hOCT1 versus mouse and rat orthologs revealed a strong functional correlation between the three species. In conclusion, this approach shows that transporter interaction data are in many cases transferable between rodents and humans, but potential species differences for other drugs and pesticides could not be excluded, though it is recommendable to perform functional comparisons of human and rodent transporters for new molecular entities.
- Published
- 2020
8. HNF4α Induced Chemosensitivity to Oxaliplatin and 5-FU Mediated by OCT1 and CNT3 in Renal Cell Carcinoma
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Gerhard Burckhardt, Annett Kuehne, Venkata V.V.R. Marada, Yohannes Hagos, Saskia Floerl, Maja Henjakovic, and Waja Wegner
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Organoplatinum Compounds ,Organic anion transporter 1 ,Pharmaceutical Science ,Antineoplastic Agents ,Pharmacology ,Real-Time Polymerase Chain Reaction ,chemistry.chemical_compound ,Downregulation and upregulation ,Cell Line, Tumor ,medicine ,Humans ,Carcinoma, Renal Cell ,Organic cation transport proteins ,biology ,Organic Cation Transporter 1 ,Membrane Transport Proteins ,Kidney Neoplasms ,Deoxyuridine ,Uridine ,Oxaliplatin ,Hepatocyte nuclear factors ,Hepatocyte Nuclear Factor 4 ,chemistry ,Apoptosis ,biology.protein ,Cancer research ,Fluorouracil ,medicine.drug - Abstract
Increased expression of transporters-mediating uptake of antineoplastic drugs could render renal cell carcinoma (RCC) more sensitive to chemotherapy. Here, we studied the effect of hepatocyte nuclear factor 4α (HNF4α) on the expression of selected uptake transporters in RCC lines. Organic cation transporters (OCTs) and organic anion transporters (OATs) mRNA levels in HNF4α-transfected RCCs were measured by real-time PCR. Expression of HNF4α, β-catenin, N-cadherin, and E-cadherin was detected by immunofluorescence. OCT1, OAT2, and concentrative nucleoside transporter 3 (CNT3) were tested using tritium-labeled substrates and an apoptosis assay. Most RCC did not express uptake transporters in the absence or presence of HNF4α. In RCCNG1 cells, HNF4α-expression increased the chemosensitivity to oxaliplatin and enhanced the accumulation of methyl-4-phenylpyridinium acetate, a model substrate for OCT1. Furthermore, HNF4α enhanced OAT2 mRNA and increased caspase-3 activity upon incubation with a purported OAT2 substrate, 5-fluorouracil (5-FU). However, functional OAT2 protein was not upregulated. CNT3 mRNA was significantly elevated by HNF4α. Inhibition of CNT3-mediated uridine uptake by 5-FU metabolite 5-fluoro-2'-deoxyuridine suggested the involvement of CNT3 in increased caspase-3 activity. Our data suggest that HNF4α increases the expression of OCT1 and CNT3 in RCCNG1 cells, thereby increasing the chemosensitivity of tumor cells to oxaliplatin and 5-FU.
- Published
- 2014
- Full Text
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