Search results for "Organic Cation Transport Proteins"
showing 10 items of 21 documents
Loss of organic cation transporter 3 (Oct3) leads to enhanced proliferation and hepatocarcinogenesis
2017
// Johanna Vollmar 1 , Anja Lautem 2 , Ellen Closs 3 , Detlef Schuppan 4 , Yong Ook Kim 4 , Daniel Grimm 1 , Jens U. Marquardt 1 , Peter Fuchs 1 , Beate K. Straub 5 , Arno Schad 5 , Dirk Grundemann 6 , Jorn M. Schattenberg 1 , Nadine Gehrke 1 , Marcus A. Worns 1 , Jan Baumgart 7 , Peter R. Galle 1 and Tim Zimmermann 1 1 Department of Internal Medicine, Gastroenterology and Hepatology, University Medical Center, Johannes Gutenberg-University Mainz, Mainz, Germany 2 Department of Hepatobiliary and Transplantation Surgery, University Medical Center, Johannes Gutenberg-University Mainz, Mainz, Germany 3 Department of Pharmacology, University Medical Center, Johannes Gutenberg-University Mainz, …
Tetraspanin CD63 controls basolateral sorting of organic cation transporter 2 in renal proximal tubules.
2016
CD63 is a ubiquitously expressed member of the tetraspanin superfamily. Using a mating-based split-ubiquitin-yeast 2-hybrid system, pull-down experiments, total internal reflection fluorescence microscopy, Forster resonance energy transfer, and biotinylation assays, we found that CD63 interacts with human organic cation transporter 2 (hOCT2), which transports endogenous and exogenous substrates, such as neurotransmitters and drugs in several epithelial cells. CD63 overexpression affects cellular localization of hOCT2 expressed in human embryonic kidney (HEK)293 cells. Studies with CD63-knockout mice indicate that in renal proximal tubules, CD63 determines the insertion of the mouse ortholog…
Identification of the Tetraspanin CD9 as an Interaction Partner of Organic Cation Transporters 1 and 2
2019
Organic cation transporters (OCTs) are membrane proteins with relevant physiological (because they accept neurotransmitters as substrate) and pharmacological (because of their interaction with drugs) roles. The human OCTs hOCT1 (SLC22A1/hOCT1) and hOCT2 (SLC22A2/hOCT2) are highly expressed in hepatic (hOCT1) and in renal and neuronal tissue (hOCT2), suggesting a possible role in modulating neurotransmitter activity in the liver, kidney, and brain, and their clearance from the blood. Even though there are several data demonstrating that OCTs are regulated under various patho-physiological conditions, it remains largely unknown which proteins directly interact with OCTs and thereby influence …
Downregulation of organic cation transporter 1 (SLC22A1) is associated with tumor progression and reduced patient survival in human cholangiocellular…
2013
Cholangiocellular carcinoma (CCA) is a primary hepatic malignancy derived from cholangiocytes. The prognosis for CCA patients is very poor and conventional chemotherapy has been proven ineffective in improving long‑term patient survival rates. Organic cation transporters (OCTs) mediate the transport of a broad spectrum of endogenous substrates and the detoxification of xenobiotics. Moreover, OCTs are considered responsible for the responsiveness towards platinum‑based chemotherapies. Currently, there are no data available regarding the role of OCTs in CCA. Therefore, the aim of this study was to investigate the expression of OCT1 and OCT3 in CCA and the corresponding non-neoplastic tumor‑su…
Downregulation of organic cation transporters OCT1 (SLC22A1) and OCT3 (SLC22A3) in human hepatocellular carcinoma and their prognostic significance
2012
Abstract Background Organic cation transporters (OCT) are responsible for the uptake and intracellular inactivation of a broad spectrum of endogenous substrates and detoxification of xenobiotics and chemotherapeutics. The transporters became pharmaceutically interesting, because OCTs are determinants of the cytotoxicity of platin derivates and the transport activity has been shown to correlate with the sensitivity of tumors towards tyrosine kinase inhibitors. No data exist about the relevance of OCTs in hepatocellular carcinoma (HCC). Methods OCT1 (SLC22A1) and OCT3 (SLC22A3) mRNA expression was measured in primary human HCC and corresponding non neoplastic tumor surrounding tissue (TST) by…
Replication of interleukin 23 receptor and autophagy-related 16-like 1 association in adult- and pediatric-onset inflammatory bowel disease in Italy.
2008
AIM: To investigate gene variants in a large Italian inflammatory bowel disease (IBD) cohort, and to analyze the correlation of sub-phenotypes (including age at diagnosis) and epistatic interaction with other IBD genes. METHODS: Total of 763 patients with Crohn's disease (CD, 189 diagnosed at age < 19 years), 843 with ulcerative colitis (UC, 179 diagnosed < 19 years), 749 healthy controls, and 546 healthy parents (273 trios) were included in the study. The rs2241880 [autophagy-related 16-like 1 (ATG16L1)], rs11209026 and rs7517847 [interleukin 23 receptor (IL23R)], rs2066844, rs2066845, rs2066847 (CARD15), rs1050152 (OCTN1), and rs2631367 (OCTN2) gene variants were genotyped. RESULTS: The f…
Functional characterization of ORCTL2--an organic cation transporter expressed in the renal proximal tubules.
1998
AbstractChromosome 11p15.5 harbors a gene or genes involved in Beckwith-Wiedemann syndrome that confer(s) susceptibility to Wilms' tumor, rhabdomyosarcoma, and hepatoblastoma. We have previously identified a transcript at 11p15.5 which encodes a putative membrane transport protein, designated organic cation transporter-like 2 (ORCTL2), that shares homology with tetracycline resistance proteins and bacterial multidrug resistance proteins. In this report, we have investigated the transport properties of ORCTL2 and show that this protein can confer resistance to chloroquine and quinidine when overexpressed in bacteria. Immunohistochemistry analyses performed with anti-ORCTL2 polyc.onal antibod…
Intestinal drug efflux: formulation and food effects
2001
The intestine, primarily regarded as an absorptive organ, is also prepared for the elimination of certain organic acids, bases and neutral compounds depending on their affinity to intestinal carrier systems. Several of the transport systems known to mediate efflux in the major clearing organs--liver and kidney--are also expressed in the intestine. Examples of secretory transporters in the intestine are P-glycoprotein, members of the multidrug resistance associated protein family, breast cancer resistance protein, organic cation transporters and members of the organic anion polypeptide family. In this communication, the P-glycoprotein mediated intestinal secretion of talinolol, a model compo…
Deletion of organic cation transporter Oct3 promotes hepatic fibrosis via upregulation of TGFβ
2019
Organic cation transporters (OCT) are responsible for the intracellular uptake and detoxification of a broad spectrum of endogenous and exogenous substrates. OCTs are downregulated in cholestasis, fibrosis, and hepatocellular carcinoma, but the underlying molecular mechanisms and downstream effects of OCT deletion are unknown. Oct3-knockout ( Oct3−/−; FVB.Slc22a3tm10pb) and wild-type (WT; FVB) mice were subject to escalating doses of carbon tetrachloride (CCl4) or thioacetamide (TAA) for 6 wk to induce advanced parenchymal liver fibrosis. Secondary biliary fibrosis was generated by bile duct ligation. Liver fibrosis was assessed by hydroxyproline determination, quantitative Sirius red morp…
Regulation of organic anion transporters in a new rat model of acute and chronic cholangitis resembling human primary sclerosing cholangitis
2002
Primary sclerosing cholangitis (PSC) is a cholestatic liver disease of unknown etiology. Although the primary defect affects cholangiocytes, cholestatic injury of hepatocytes may promote further liver damage. Since down-regulation of hepatocellular organic anion transporters is implicated in the molecular pathogenesis of cholestasis, expression of these transporters was determined in a novel rat model, which closely resembles human PSC.Hepatic protein and mRNA expression of basolateral (Ntcp, Oatp1, 2 and 4) and canalicular (Mrp2, Bsep) organic anion transporters were analyzed 1, 4 and 12 weeks after induction of experimental PSC by 2,4,6-trinitrobenzenesulfonic acid (TNBS).Specific down-re…