Molecular cloning of canalicular multispecific organic anion transporter defective in EHBR

1997 ◽  
Vol 272 (1) ◽  
pp. G16-G22 ◽  
Author(s):  
K. Ito ◽  
H. Suzuki ◽  
T. Hirohashi ◽  
K. Kume ◽  
T. Shimizu ◽  
...  
Keyword(s):  
Amino Acid ◽  
Stop Codon ◽  
Organic Anion ◽  
Amino Acid Level ◽  
Premature Stop Codon ◽  
Autosomal Recessive Inheritance ◽  
Organic Anions ◽  
Organic Anion Transporter ◽  
Sprague Dawley ◽  
Anion Transporter

Several organic anions are excreted into the bile via a canalicular multispecific organic anion transporter (cMOAT), which is hereditarily defective in mutant rats, such as the Eisai hyperbilirubinemic rat (EHBR) and TR- rat. In the present study, we cloned cMOAT from the Sprague-Dawley rat liver cDNA library based on the homology with human multidrug resistance-associated protein (hMRP). cMOAT was encoded by 4,623-base pair (bp) cDNA with a homology of 53.0 and 46.3% with hMRP at the cDNA and deduced amino acid level, respectively. The deduced amino acid sequence was the same as that cloned in Wistar rats (C. C. Paulusma, P. J. Bosma, G. J. Zaman, C. T. Bakker, M. Otter, G. L. Sceffer, P. Borst, and R. P. Oude Elferink. Science Wash. DC 271: 1126, 1996) except for four amino acid substitutions. By screening the library, three kinds of cDNA species for cMOAT with the same open reading frame and different 3'-untranslated region lengths (0.2, 1.5, and 3.5 kbp) were isolated. The Northern blot analysis of poly(A)+ RNA from the liver revealed that the expression of plural bands (approximately 5, 6, and 8 kb) was defective in EHBR, and this may be due to the presence of these cDNA species. Expression of cMOAT was observed almost exclusively in the liver and to a lesser extent in the duodenum, kidney, and jejunum. Reverse transcription-polymerase chain reaction (RT-PCR) and subsequent sequence analysis of EHBR liver, kidney, duodenum, and jejunum revealed that 1-bp replacement from G to A at nucleotide 2564 resulted in the introduction of the premature stop codon in all tissues examined. This mutation was different from that observed in TR (C. C. Paulusma, P. J. Bosma, G. J. Zaman, C. T. Bakker, M. Otter, G. L. Sceffer, P. Borst, and R. P. Oude Elferink. Science Wash. DC 271: 1126, 1996). Because EHBR and TR- are allelic mutants and both strains exhibit an autosomal recessive inheritance in the biliary excretion of organic anions it was concluded that the impaired expression of this particular protein is related to the pathogenesis of hyperbilirubinemia in the mutant animals.

scholarly journals Olfactory mucosa-expressed organic anion transporter, Oat6, manifests high affinity interactions with odorant organic anions

2006 ◽  
Vol 351 (4) ◽  
pp. 872-876 ◽  
Author(s):  
Gregory Kaler ◽  
David M. Truong ◽  
Derina E. Sweeney ◽  
Darren W. Logan ◽  
Megha Nagle ◽  
...  
Keyword(s):  
Organic Anion ◽  
Organic Anions ◽  
Olfactory Mucosa ◽  
Organic Anion Transporter ◽  
High Affinity ◽  
Anion Transporter

scholarly journals Identification of an Alternative Glycyrrhizin Metabolite Causing Liquorice-Induced Pseudohyperaldosteronism and the Development of ELISA System to Detect the Predictive Biomarker

2021 ◽  
Vol 12 ◽  
Author(s):  
Kan'ichiro Ishiuchi ◽  
Osamu Morinaga ◽  
Tetsuhiro Yoshino ◽  
Miaki Mitamura ◽  
Asuka Hirasawa ◽  
...  
Keyword(s):  
Serum Concentration ◽  
Immunosorbent Assay ◽  
Organic Anion ◽  
Predictive Biomarker ◽  
Organic Anion Transporter ◽  
Enzyme Linked Immunosorbent Assay ◽  
Sprague Dawley ◽  
Elisa System ◽  
Anion Transporter ◽  
Pharmacologically Active

Liquorice is usually used as crude drug in traditional Japanese Kampo medicine and traditional Chinese medicine. Liquorice-containing glycyrrhizin (GL) can cause pseudohyperaldosteronism as a side effect. Previously, we identified 18β-glycyrrhetyl-3-O-sulfate (3) as a GL metabolite in Eisai hyperbilirubinuria rats (EHBRs) with the dysfunction of multidrug resistance-related protein (Mrp2). We speculated that 3 was associated with the onset of liquorice-induced pseudohyperaldosteronism, because it was mainly detected in serum of patients with suspected to have this condition. However, it is predicted that other metabolites might exist in the urine of EHBRs orally treated with glycyrrhetinic acid (GA). We explored other metabolites in the urine of EHBRs, and investigated the pharmacokinetic profiles of the new metabolite in EHBRs and normal Sprague-Dawley rats. We further analyzed the serum concentrations of the new metabolite in the patients of pseudohyperaldosteronism. Finally, we developed the analyzing method of these metabolites as a preventive biomarker for the onset of pseudohyperaldosteronism using an enzyme-linked immunosorbent assay (ELISA). We isolated a new GL metabolite, 18β-glycyrrhetyl-3-O-sulfate-30-O-glucuronide (4). Compound 4 significantly inhibited rat type-2 11β-hydroxysteroid dehydrogenase (11β-HSD2) and was a substrate of both organic anion transporter (OAT) 1 and OAT3. Compound 4 was also detected in the serum of patients with suspected pseudohyperaldosteronism at an approximately 10-fold lower concentrations than 3, and these concentrations were positively correlated. Compound 4 showed a lower serum concentration and weaker inhibitory titer on 11β-HSD2 than 3. We developed an enzyme-linked immunosorbent assay system using an anti-18β-glycyrrhetyl-3-O-glucuronide (3MGA) monoclonal antibody to measure the serum concentration of 3 to facilitate the measurement of biomarkers to predict the onset of pseudohyperaldosteronism. Although we found 4 as the secondary candidate causative agent, 3 could be the main potent preventive biomarker of liquorice-induced pseudohyperaldosteronism. Compound 3 was detected in serum at a higher concentration than GA and 4, implying that 3 may be a pharmacologically active ingredient mediating not only the development of pseudohyperaldosteronism but anti-inflammatory effects in humans administered GL or other liquorice-containing preparations.

Impact of the induced organic anion transporter 1 (Oat1) renal expression by furosemide on the pharmacokinetics of organic anions

Nephrology ◽  
2017 ◽  
Vol 22 (8) ◽  
pp. 642-648 ◽  
Author(s):  
María Julia Severin ◽  
María Herminia Hazelhoff ◽  
Romina Paula Bulacio ◽  
María Eugenia Mamprin ◽  
Anabel Brandoni ◽  
...  
Keyword(s):  
Organic Anion ◽  
Organic Anions ◽  
Organic Anion Transporter ◽  
Anion Transporter ◽  
Renal Expression

Molecular characterization of human and rat organic anion transporter OATP-D

2003 ◽  
Vol 285 (6) ◽  
pp. F1188-F1197 ◽  
Author(s):  
Hisanobu Adachi ◽  
Takehiro Suzuki ◽  
Michiaki Abe ◽  
Naoki Asano ◽  
Hiroya Mizutamari ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Sequence Homology ◽  
Organic Anion ◽  
Organic Anion Transporter ◽  
Prostaglandin E ◽  
Amino Acid Sequence Homology ◽  
Phylogenetic Tree Analysis ◽  
Anion Transporter

We have isolated and characterized a novel human and rat organic anion transporter subtype, OATP-D. The isolated cDNA from human brain encodes a polypeptide of 710 amino acids ( Mr 76,534) with 12 predicted transmembrane domains. The rat clone encodes 710 amino acids ( Mr 76,821) with 97.6% amino acid sequence homology with human OATP-D. Human and rat OATP-D have moderate amino acid sequence homology with LST-1/rlst-1, the rat oatp family, the prostaglandin transporter, and moat1/MOAT1/KIAA0880/OATP-B. Phylogenetic tree analysis revealed that OATP-D is branched in a different position from all known organic anion transporters. OATP-D transports prostaglandin E1 ( Km 48.5 nM), prostaglandin E2 ( Km 55.5 nM), and prostaglandin F2α, suggesting that, functionally, OATP-D encodes a protein that has similar characteristics to those of the prostaglandin transporter. Rat OATP-D also transports prostaglandins. The expression pattern of OATP-D mRNA was abundant mainly in the heart, testis, brain, and some cancer cells. Immunohistochemical analysis further revealed that rat OATP-D is widely expressed in the vascular, renal, and reproductive system at the protein level. These results suggest that OATP-D plays an important role in translocating prostaglandins in specialized tissues and cells.

Molecular Physiology of Renal p-Aminohippurate Secretion

Physiology ◽  
2001 ◽  
Vol 16 (3) ◽  
pp. 114-118 ◽  
Author(s):  
Gerhard Burckhardt ◽  
Andrew Bahn ◽  
Natascha A. Wolff
Keyword(s):  
Organic Anion ◽  
Organic Anions ◽  
Proximal Tubules ◽  
Organic Anion Transporter ◽  
Molecular Physiology ◽  
Renal Proximal Tubules ◽  
Anion Transporter ◽  
Tubule Lumen ◽  
Tubule Cells ◽  
Species Specific

Renal proximal tubules secrete various organic anions, including drugs and p-aminohippurate (PAH). Uptake of PAH from blood into tubule cells occurs by exchange with intracellular α-ketoglutarate and is mediated by the organic anion transporter 1. PAH exit into tubule lumen is species specific and may involve ATP-independent and -dependent transporters.

Reduced folate derivatives are endogenous substrates for cMOAT in rats

1998 ◽  
Vol 275 (4) ◽  
pp. G789-G796 ◽  
Author(s):  
Hiroyuki Kusuhara ◽  
Yong-Hae Han ◽  
Minoru Shimoda ◽  
Eiichi Kokue ◽  
Hiroshi Suzuki ◽  
...  
Keyword(s):  
Biliary Excretion ◽  
Organic Anion ◽  
Membrane Vesicles ◽  
Organic Anion Transporter ◽  
Sprague Dawley ◽  
Anion Transporter ◽  
Bile Drainage ◽  
Endogenous Substrates

We examined the role of the canalicular multispecific organic anion transporter (cMOAT) in the biliary excretion of reduced folate derivatives in vivo and in vitro using normal [Sprague-Dawley rats (SDR)] and mutant [Eisai hyperbilirubinemic rats (EHBR)] rats whose cMOAT is hereditarily deficient. In vivo, the biliary excretion of endogenous tetrahydrofolate (H4PteGlu), 5-methyltetrahydrofolate (5-CH3-H4PteGlu), and 5,10-methylenetetrahydrofolate (5,10-CH2-H4PteGlu) in EHBR was reduced to 8.2%, 1.9%, and 5.5% of those in SDR, respectively, whereas that of 10-formyltetrahydrofolate (10-HCO-H4PteGlu) was detected only in SDR and not in EHBR. Bile drainage caused reduction of endogenous plasma folate concentrations in SDR but not in EHBR. In vitro, significant ATP-dependent uptake of3H-labeled 5-CH3-H4PteGlu into canalicular membrane vesicles was observed only in SDR. This ATP-dependent uptake was saturable with a Michaelis constant ( K m) value of 126 μM, which was comparable with its inhibitor constant ( K i) value of 121 μM for the ATP-dependent uptake of a typical cMOAT substrate, 2,4-dinitrophenyl- S-glutathione (DNP-SG). Vice versa, DNP-SG inhibited the uptake of 5-CH3-H4PteGlu with a K i of 35 μM, which was similar to its K m value. In addition, H4PteGlu and 5,10-CH2-H4PteGlu also inhibited the ATP-dependent uptake of DNP-SG. These results indicate that 5-CH3-H4PteGlu and other derivatives are transported via cMOAT. Therefore, reduced folate derivatives are the first endogenous substrates for cMOAT that do not contain glutathione, glucuronide, or sulfate moieties.

Molecular physiology of renal organic anion transporters

2006 ◽  
Vol 290 (2) ◽  
pp. F251-F261 ◽  
Author(s):  
Takashi Sekine ◽  
Hiroki Miyazaki ◽  
Hitoshi Endou
Keyword(s):  
Organic Anion ◽  
Organic Anions ◽  
Organic Anion Transporter ◽  
Transepithelial Transport ◽  
Gene Localization ◽  
Organic Anion Transporters ◽  
Molecular Physiology ◽  
Anion Transporters ◽  
Anion Transporter ◽  
Molecular Information

Recent advances in molecular biology have identified three organic anion transporter families: the organic anion transporter (OAT) family encoded by SLC22A, the organic anion transporting peptide (OATP) family encoded by SLC21A ( SLCO), and the multidrug resistance-associated protein (MRP) family encoded by ABCC. These families play critical roles in the transepithelial transport of organic anions in the kidneys as well as in other tissues such as the liver and brain. Among these families, the OAT family plays the central role in renal organic anion transport. Knowledge of these three families at the molecular level, such as substrate selectivity, tissue distribution, and gene localization, is rapidly increasing. In this review, we will give an overview of molecular information on renal organic anion transporters and describe recent topics such as the regulatory mechanisms and molecular physiology of urate transport. We will also discuss the physiological roles of each organic anion transporter in the light of the transepithelial transport of organic anions in the kidneys.

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