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Özvegy-Laczka C, Ungvári O, Bakos É. Fluorescence-based methods for studying activity and drug-drug interactions of hepatic solute carrier and ATP binding cassette proteins involved in ADME-Tox. Biochem Pharmacol 2023; 209:115448. [PMID: 36758706 DOI: 10.1016/j.bcp.2023.115448] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 01/31/2023] [Accepted: 02/01/2023] [Indexed: 02/11/2023]
Abstract
In humans, approximately 70% of drugs are eliminated through the liver. This process is governed by the concerted action of membrane transporters and metabolic enzymes. Transporters mediating hepatocellular uptake of drugs belong to the SLC (Solute carrier) superfamily of transporters. Drug efflux either toward the portal vein or into the bile is mainly mediated by active transporters of the ABC (ATP Binding Cassette) family. Alteration in the function and/or expression of liver transporters due to mutations, disease conditions, or co-administration of drugs or food components can result in altered pharmacokinetics. On the other hand, drugs or food components interacting with liver transporters may also interfere with liver function (e.g., bile acid homeostasis) and may even cause liver toxicity. Accordingly, certain transporters of the liver should be investigated already at an early stage of drug development. Most frequently radioactive probes are applied in these drug-transporter interaction tests. However, fluorescent probes are cost-effective and sensitive alternatives to radioligands, and are gaining wider application in drug-transporter interaction tests. In our review, we summarize our current understanding about hepatocyte ABC and SLC transporters affected by drug interactions. We provide an update of the available fluorescent and fluorogenic/activable probes applicable in in vitro or in vivo testing of these ABC and SLC transporters, including near-infrared transporter probes especially suitable for in vivo imaging. Furthermore, our review gives a comprehensive overview of the available fluorescence-based methods, not directly relying on the transport of the probe, suitable for the investigation of hepatic ABC or SLC-type drug transporters.
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Affiliation(s)
- Csilla Özvegy-Laczka
- Institute of Enzymology, RCNS, Eötvös Loránd Research Network, H-1117 Budapest, Magyar tudósok krt. 2., Hungary.
| | - Orsolya Ungvári
- Institute of Enzymology, RCNS, Eötvös Loránd Research Network, H-1117 Budapest, Magyar tudósok krt. 2., Hungary; Doctoral School of Biology, Institute of Biology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Éva Bakos
- Institute of Enzymology, RCNS, Eötvös Loránd Research Network, H-1117 Budapest, Magyar tudósok krt. 2., Hungary
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2
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Lu ZN, He HW, Zhang N. Advances in understanding the regulatory mechanism of organic solute transporter α-β. Life Sci 2022; 310:121109. [DOI: 10.1016/j.lfs.2022.121109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 10/09/2022] [Accepted: 10/17/2022] [Indexed: 11/07/2022]
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Pavlič R, Vidic S, Anko M, Knific T, Büdefeld T, Marton K, Sinreih M, Poschner S, Jäger W, Frković-Grazio S, Rižner TL. Altered Profile of E1-S Transporters in Endometrial Cancer: Lower Protein Levels of ABCG2 and OSTβ and Up-Regulation of SLCO1B3 Expression. Int J Mol Sci 2021; 22:3819. [PMID: 33917029 PMCID: PMC8067723 DOI: 10.3390/ijms22083819] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 03/31/2021] [Accepted: 04/01/2021] [Indexed: 11/16/2022] Open
Abstract
Endometrial cancer (EC) is associated with increased estrogen actions. Locally, estrogens can be formed from estrone-sulphate (E1-S) after cellular uptake by organic anion-transporting polypeptides (OATP) or organic anion transporters (OAT). Efflux of E1-S is enabled by ATP Binding Cassette transporters (ABC) and organic solute transporter (OST)αβ. Currently, 19 E1-S transporters are known but their roles in EC are not yet understood. Here, we analysed levels of E1-S transporters in Ishikawa (premenopausal EC), HEC-1-A (postmenopausal EC), HIEEC (control) cell lines, in EC tissue, examined metabolism of steroid precursor E1-S, studied effects of OATPs' inhibition and gene-silencing on E1-S uptake, and assessed associations between transporters and histopathological data. Results revealed enhanced E1-S metabolism in HEC-1-A versus Ishikawa which could be explained by higher levels of OATPs in HEC-1-A versus Ishikawa, especially 6.3-fold up-regulation of OATP1B3 (SLCO1B3), as also confirmed by immunocytochemical staining and gene silencing studies, lower ABCG2 expression and higher levels of sulfatase (STS). In EC versus adjacent control tissue the highest differences were seen for ABCG2 and SLC51B (OSTβ) which were 3.0-fold and 2.1-fold down-regulated, respectively. Immunohistochemistry confirmed lower levels of these two transporters in EC versus adjacent control tissue. Further analysis of histopathological data indicated that SLCO1B3 might be important for uptake of E1-S in tumours without lymphovascular invasion where it was 15.6-fold up-regulated as compared to adjacent control tissue. Our results clearly indicate the importance of E1-S transporters in EC pathophysiology and provide a base for further studies towards development of targeted treatment.
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Affiliation(s)
- Renata Pavlič
- Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia; (R.P.); (S.V.); (M.A.); (T.K.); (T.B.); (K.M.); (M.S.)
| | - Suzana Vidic
- Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia; (R.P.); (S.V.); (M.A.); (T.K.); (T.B.); (K.M.); (M.S.)
| | - Maja Anko
- Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia; (R.P.); (S.V.); (M.A.); (T.K.); (T.B.); (K.M.); (M.S.)
| | - Tamara Knific
- Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia; (R.P.); (S.V.); (M.A.); (T.K.); (T.B.); (K.M.); (M.S.)
| | - Tomaž Büdefeld
- Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia; (R.P.); (S.V.); (M.A.); (T.K.); (T.B.); (K.M.); (M.S.)
| | - Kristina Marton
- Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia; (R.P.); (S.V.); (M.A.); (T.K.); (T.B.); (K.M.); (M.S.)
| | - Maša Sinreih
- Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia; (R.P.); (S.V.); (M.A.); (T.K.); (T.B.); (K.M.); (M.S.)
| | - Stefan Poschner
- Department of Pharmaceutical Chemistry, University of Vienna, 1090 Vienna, Austria; (S.P.); (W.J.)
| | - Walter Jäger
- Department of Pharmaceutical Chemistry, University of Vienna, 1090 Vienna, Austria; (S.P.); (W.J.)
| | - Snježana Frković-Grazio
- Department of Gynecological Pathology, Division of Gynaecology and Obstetrics, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia;
| | - Tea Lanišnik Rižner
- Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia; (R.P.); (S.V.); (M.A.); (T.K.); (T.B.); (K.M.); (M.S.)
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Fairweather SJ, Shah N, Brӧer S. Heteromeric Solute Carriers: Function, Structure, Pathology and Pharmacology. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 21:13-127. [PMID: 33052588 DOI: 10.1007/5584_2020_584] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Solute carriers form one of three major superfamilies of membrane transporters in humans, and include uniporters, exchangers and symporters. Following several decades of molecular characterisation, multiple solute carriers that form obligatory heteromers with unrelated subunits are emerging as a distinctive principle of membrane transporter assembly. Here we comprehensively review experimentally established heteromeric solute carriers: SLC3-SLC7 amino acid exchangers, SLC16 monocarboxylate/H+ symporters and basigin/embigin, SLC4A1 (AE1) and glycophorin A exchanger, SLC51 heteromer Ost α-Ost β uniporter, and SLC6 heteromeric symporters. The review covers the history of the heteromer discovery, transporter physiology, structure, disease associations and pharmacology - all with a focus on the heteromeric assembly. The cellular locations, requirements for complex formation, and the functional role of dimerization are extensively detailed, including analysis of the first complete heteromer structures, the SLC7-SLC3 family transporters LAT1-4F2hc, b0,+AT-rBAT and the SLC6 family heteromer B0AT1-ACE2. We present a systematic analysis of the structural and functional aspects of heteromeric solute carriers and conclude with common principles of their functional roles and structural architecture.
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Affiliation(s)
- Stephen J Fairweather
- Research School of Biology, Australian National University, Canberra, ACT, Australia. .,Resarch School of Chemistry, Australian National University, Canberra, ACT, Australia.
| | - Nishank Shah
- Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Stefan Brӧer
- Research School of Biology, Australian National University, Canberra, ACT, Australia.
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5
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Beaudoin JJ, Brouwer KLR, Malinen MM. Novel insights into the organic solute transporter alpha/beta, OSTα/β: From the bench to the bedside. Pharmacol Ther 2020; 211:107542. [PMID: 32247663 PMCID: PMC7480074 DOI: 10.1016/j.pharmthera.2020.107542] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 03/25/2020] [Indexed: 12/14/2022]
Abstract
Organic solute transporter alpha/beta (OSTα/β) is a heteromeric solute carrier protein that transports bile acids, steroid metabolites and drugs into and out of cells. OSTα/β protein is expressed in various tissues, but its expression is highest in the gastrointestinal tract where it facilitates the recirculation of bile acids from the gut to the liver. Previous studies established that OSTα/β is upregulated in liver tissue of patients with extrahepatic cholestasis, obstructive cholestasis, and primary biliary cholangitis (PBC), conditions that are characterized by elevated bile acid concentrations in the liver and/or systemic circulation. The discovery that OSTα/β is highly upregulated in the liver of patients with nonalcoholic steatohepatitis (NASH) further highlights the clinical relevance of this transporter because the incidence of NASH is increasing at an alarming rate with the obesity epidemic. Since OSTα/β is closely linked to the homeostasis of bile acids, and tightly regulated by the nuclear receptor farnesoid X receptor, OSTα/β is a potential drug target for treatment of cholestatic liver disease, and other bile acid-related metabolic disorders such as obesity and diabetes. Obeticholic acid, a semi-synthetic bile acid used to treat PBC, under review for the treatment of NASH, and in development for the treatment of other metabolic disorders, induces OSTα/β. Some drugs associated with hepatotoxicity inhibit OSTα/β, suggesting a possible role for OSTα/β in drug-induced liver injury (DILI). Furthermore, clinical cases of homozygous genetic defects in both OSTα/β subunits resulting in diarrhea and features of cholestasis have been reported. This review article has been compiled to comprehensively summarize the recent data emerging on OSTα/β, recapitulating the available literature on the structure-function and expression-function relationships of OSTα/β, the regulation of this important transporter, the interaction of drugs and other compounds with OSTα/β, and the comparison of OSTα/β with other solute carrier transporters as well as adenosine triphosphate-binding cassette transporters. Findings from basic to more clinically focused research efforts are described and discussed.
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Affiliation(s)
- James J Beaudoin
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Kim L R Brouwer
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
| | - Melina M Malinen
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Kuopio, Finland
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6
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Suga T, Yamaguchi H, Ogura J, Mano N. Characterization of conjugated and unconjugated bile acid transport via human organic solute transporter α/β. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:1023-1029. [DOI: 10.1016/j.bbamem.2019.03.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 03/01/2019] [Accepted: 03/04/2019] [Indexed: 01/03/2023]
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7
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Theiler-Schwetz V, Zaufel A, Schlager H, Obermayer-Pietsch B, Fickert P, Zollner G. Bile acids and glucocorticoid metabolism in health and disease. Biochim Biophys Acta Mol Basis Dis 2019; 1865:243-251. [DOI: 10.1016/j.bbadis.2018.08.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 07/18/2018] [Accepted: 08/01/2018] [Indexed: 12/12/2022]
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8
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Mertens KL, Kalsbeek A, Soeters MR, Eggink HM. Bile Acid Signaling Pathways from the Enterohepatic Circulation to the Central Nervous System. Front Neurosci 2017; 11:617. [PMID: 29163019 PMCID: PMC5681992 DOI: 10.3389/fnins.2017.00617] [Citation(s) in RCA: 173] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 10/23/2017] [Indexed: 12/14/2022] Open
Abstract
Bile acids are best known as detergents involved in the digestion of lipids. In addition, new data in the last decade have shown that bile acids also function as gut hormones capable of influencing metabolic processes via receptors such as FXR (farnesoid X receptor) and TGR5 (Takeda G protein-coupled receptor 5). These effects of bile acids are not restricted to the gastrointestinal tract, but can affect different tissues throughout the organism. It is still unclear whether these effects also involve signaling of bile acids to the central nervous system (CNS). Bile acid signaling to the CNS encompasses both direct and indirect pathways. Bile acids can act directly in the brain via central FXR and TGR5 signaling. In addition, there are two indirect pathways that involve intermediate agents released upon interaction with bile acids receptors in the gut. Activation of intestinal FXR and TGR5 receptors can result in the release of fibroblast growth factor 19 (FGF19) and glucagon-like peptide 1 (GLP-1), both capable of signaling to the CNS. We conclude that when plasma bile acids levels are high all three pathways may contribute in signal transmission to the CNS. However, under normal physiological circumstances, the indirect pathway involving GLP-1 may evoke the most substantial effect in the brain.
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Affiliation(s)
- Kim L Mertens
- Master's Program in Biomedical Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Andries Kalsbeek
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands.,Laboratory of Endocrinology, Department Clinical Chemistry, Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands.,Department of Hypothalamic Integration Mechanisms, Netherlands Institute for Neuroscience, Amsterdam, Netherlands
| | - Maarten R Soeters
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Hannah M Eggink
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands.,Department of Hypothalamic Integration Mechanisms, Netherlands Institute for Neuroscience, Amsterdam, Netherlands
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9
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Yuan ZQ, Li KW. Role of farnesoid X receptor in cholestasis. J Dig Dis 2016; 17:501-509. [PMID: 27383832 DOI: 10.1111/1751-2980.12378] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 06/23/2016] [Accepted: 07/03/2016] [Indexed: 12/11/2022]
Abstract
The nuclear receptor farnesoid X receptor (FXR) plays an important role in physiological bile acid synthesis, secretion and transport. Defects of FXR regulation in these processes can cause cholestasis and subsequent pathological changes. FXR regulates the synthesis and uptake of bile acid via enzymes. It also increases bile acid solubility and elimination by promoting conjugation reactions and exports pump expression in cholestasis. The changes in bile acid transporters are involved in cholestasis, which can result from the mutations of transporter genes or acquired dysfunction of transport systems, such as inflammation-induced intrahepatic cholestasis. The modulation function of FXR in extrahepatic cholestasis is not identical to that in intrahepatic cholestasis, but the discrepancy may be reduced over time. In extrahepatic cholestasis, increasing biliary pressure can induce bile duct proliferation and bile infarcts, but the absence of FXR may ameliorate them. This review provides an update on the function of FXR in the regulation of bile acid metabolism, its role in the pathophysiological process of cholestasis and the therapeutic use of FXR agonists.
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Affiliation(s)
- Zhi Qing Yuan
- Department of Biliary-Pancreatic Surgery, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Ke Wei Li
- Department of Biliary-Pancreatic Surgery, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China.
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10
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Nelson JE, Roth CL, Wilson L, Yates K, Aouizerat B, Morgan–Stevenson V, Whalen E, Hoofnagle A, Mason M, Gersuk V, Yeh MM, Kowdley KV. Vitamin D Deficiency Is Associated With Increased Risk of Non-alcoholic Steatohepatitis in Adults With Non-alcoholic Fatty Liver Disease: Possible Role for MAPK and NF-κB? Am J Gastroenterol 2016; 111:852-63. [PMID: 27002799 PMCID: PMC5361650 DOI: 10.1038/ajg.2016.51] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 02/01/2016] [Indexed: 01/10/2023]
Abstract
OBJECTIVES The objective of this study was to determine the relationship of serum vitamin D deficiency (VDD) to histologic features of non-alcoholic fatty liver disease (NAFLD), and associated demographic, clinical, laboratory, and transcriptomic data in the well-characterized Non-alcoholic Steatohepatitis Clinical Research Network (NASH CRN) cohort. METHODS Serum vitamin D 25(OH)D (VD) was quantified by liquid chromatography-tandem mass spectrometry in 190 adults (>18 years) with biopsy-proven NAFLD. Subjects were categorized according to their level of VD as either sufficient (>30 ng/ml), insufficient (≥20≤30 ng/ml), or deficient (VDD; <20 ng/ml). Multivariable logistic regression was used to investigate the association of VDD and the presence of definite NASH and individual histological features of NAFLD after adjusting for age, sex, race, body mass index, alanine aminotransferase, and diabetes status. Hepatic transcriptomic data was compared between VDD and non-VDD subjects. RESULTS VDD was present in 55% of subjects and was independently associated with definitive NASH (odds ratio (OR) 3.15, 95% confidence interval (CI), 1.62-6.15, P=0.001), increased lobular inflammation (OR=1.98, 95% CI, 1.08-3.61, P=0.026), more ballooning (OR=2.38, 95% CI, 1.32-4.30, P=0.004), and the presence of fibrosis (OR=2.32, 95% CI, 1.13-4.77, P=0.022). There was a significant inverse relationship between lower levels of serum resistin and increased VD level category (P=0.013). The KRT10, SEMA3B, SNORD3C, ARSD, and IGKV4-1 genes were differentially expressed (false discovery rate <0.05) between VDD and non-VDD subjects. Gene ontology and pathway analysis suggest activation of the mitogen-activated protein kinase and nuclear factor-κB pathways in VDD NAFLD subjects. CONCLUSIONS VDD is prevalent among US adult NAFLD patients and is independently associated with a definitive diagnosis of NASH and increased histological severity. Novel associations in proinflammatory pathways were identified, which suggest the mechanism for VDD in the pathogenesis of NASH and support dietary and/or lifestyle modifications to increase vitamin D levels in these patients.
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Affiliation(s)
- James E. Nelson
- Benaroya Research Institute at Virginia Mason Medical Center,
Seattle WA
| | | | - Laura Wilson
- Johns Hopkins Bloomberg School of Public Health, Dept of
Epidemiology, Baltimore, MD
| | - Kathie Yates
- Johns Hopkins Bloomberg School of Public Health, Dept of
Epidemiology, Baltimore, MD
| | - Bradley Aouizerat
- Department of Physiological Nursing, University of California at San
Francisco, San Francisco, CA
- Institute for Human Genetics, University of California at San
Francisco, San Francisco, CA
| | | | - Elizabeth Whalen
- Benaroya Research Institute at Virginia Mason Medical Center,
Seattle WA
| | - Andrew Hoofnagle
- Departments of Laboratory Medicine and Medicine, University of
Washington, Seattle, WA
| | - Michael Mason
- Benaroya Research Institute at Virginia Mason Medical Center,
Seattle WA
| | - Vivian Gersuk
- Benaroya Research Institute at Virginia Mason Medical Center,
Seattle WA
| | - Matthew M. Yeh
- Department of Pathology, University of Washington School of
Medicine, Seattle WA
| | - Kris V. Kowdley
- Benaroya Research Institute at Virginia Mason Medical Center,
Seattle WA
- Liver Care Network, Swedish Medical Center, Seattle, WA
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Zheng X, Chen T, Zhao A, Wang X, Xie G, Huang F, Liu J, Zhao Q, Wang S, Wang C, Zhou M, Panee J, He Z, Jia W. The Brain Metabolome of Male Rats across the Lifespan. Sci Rep 2016; 6:24125. [PMID: 27063670 PMCID: PMC4827083 DOI: 10.1038/srep24125] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 03/16/2016] [Indexed: 12/14/2022] Open
Abstract
Comprehensive and accurate characterization of brain metabolome is fundamental to brain science, but has been hindered by technical limitations. We profiled the brain metabolome in male Wistar rats at different ages (day 1 to week 111) using high-sensitivity and high-resolution mass spectrometry. Totally 380 metabolites were identified and 232 of them were quantitated. Compared with anatomical regions, age had a greater effect on variations in the brain metabolome. Lipids, fatty acids and amino acids accounted for the largest proportions of the brain metabolome, and their concentrations varied across the lifespan. The levels of polyunsaturated fatty acids were higher in infancy (week 1 to week 3) compared with later ages, and the ratio of omega-6 to omega-3 fatty acids increased in the aged brain (week 56 to week 111). Importantly, a panel of 20 bile acids were quantitatively measured, most of which have not previously been documented in the brain metabolome. This study extends the breadth of the mammalian brain metabolome as well as our knowledge of functional brain development, both of which are critically important to move the brain science forward.
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Affiliation(s)
- Xiaojiao Zheng
- Shanghai Key Laboratory of Diabetes Mellitus and Center for Translational Medicine, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China
| | - Tianlu Chen
- Shanghai Key Laboratory of Diabetes Mellitus and Center for Translational Medicine, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China
| | - Aihua Zhao
- Shanghai Key Laboratory of Diabetes Mellitus and Center for Translational Medicine, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China
| | - Xiaoyan Wang
- Ministry of Education Key Laboratory of Systems Biomedicine, Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Guoxiang Xie
- University of Hawaii Cancer Center, Honolulu 96813, USA
| | - Fengjie Huang
- Shanghai Key Laboratory of Diabetes Mellitus and Center for Translational Medicine, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China
| | - Jiajian Liu
- Shanghai Key Laboratory of Diabetes Mellitus and Center for Translational Medicine, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China
| | - Qing Zhao
- Shanghai Key Laboratory of Diabetes Mellitus and Center for Translational Medicine, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China
| | - Shouli Wang
- Shanghai Key Laboratory of Diabetes Mellitus and Center for Translational Medicine, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China
| | - Chongchong Wang
- Ministry of Education Key Laboratory of Systems Biomedicine, Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Mingmei Zhou
- Center for Chinese Medical Therapy and Systems Biology, E-Institute, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Jun Panee
- University of Hawaii Cancer Center, Honolulu 96813, USA
| | - Zhigang He
- F. M. Kirby Neurobiology Center, Children's Hospital, and Department of Neurology, Harvard Medical School, Boston, MA 02115, USA
| | - Wei Jia
- Shanghai Key Laboratory of Diabetes Mellitus and Center for Translational Medicine, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China.,University of Hawaii Cancer Center, Honolulu 96813, USA.,Center for Chinese Medical Therapy and Systems Biology, E-Institute, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
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12
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van Dijk R, Kremer AE, Smit W, van den Elzen B, van Gulik T, Gouma D, Lameris JS, Bikker H, Enemuo V, Stokkers PCF, Feist M, Bosma P, Jansen PLM, Beuers U. Characterization and treatment of persistent hepatocellular secretory failure. Liver Int 2015; 35:1478-88. [PMID: 24905729 DOI: 10.1111/liv.12603] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 05/18/2014] [Indexed: 01/04/2023]
Abstract
BACKGROUND & AIMS Hepatocellular secretory failure induced by drugs, toxins or transient biliary obstruction may sometimes persist for months after removal of the initiating factor and may then be fatal without liver transplantation. We characterized patients with severe persistent hepatocellular secretory failure (PHSF) and treated them with the pregnane X receptor (PXR) agonist, rifampicin. We also studied the effect of rifampicin on PXR-dependent expression of genes involved in biotransformation and secretion in vitro. METHODS Thirteen patients (age 18-81 years, 6 male) with hepatocellular secretory failure that persisted after removal of the inducing factor (drugs/toxin: 9) or biliary obstruction (4) were identified over 6 years. Six of these patients were screened for ATP8B1 or ABCB11 mutations. All were treated with rifampicin (300 mg daily) for 1-10 weeks. Expression of genes involved in biotransformation and secretion was determined by rtPCR in human hepatocytes and intestinal cells incubated with rifampicin (10 μmol/L). RESULTS Serum bilirubin of patients with PHSF ranged from 264 to 755 μmol/L. Normal γGT was found in 10/13 patients of whom 3/6 tested positive for ATP8B1/ABCB11 mutations. Serum bilirubin declined to <33 μmol/L after 1-10 weeks of rifampicin treatment. In vitro, rifampicin PXR-dependently upregulated biotransformation phase 1 (CYP3A4), phase 2 (UGT1A1) and phase 3 (MRP2) enzymes/carriers as well as the basolateral bile salt exporter OSTβ. CONCLUSION Persistent hepatocellular secretory failure may develop in carriers of transporter gene mutations. In severe cases, rifampicin may represent an effective therapeutic option of PHSF. PXR-dependent induction of CYP3A4, UGT1A1, MRP2 and OSTβ could contribute to the anticholestatic effect of rifampicin in PHSF.
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Affiliation(s)
- Remco van Dijk
- Department of Gastroenterology & Hepatology and Tytgat Institute for Liver and Intestinal Research, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
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Baghdasaryan A, Chiba P, Trauner M. Clinical application of transcriptional activators of bile salt transporters. Mol Aspects Med 2014; 37:57-76. [PMID: 24333169 PMCID: PMC4045202 DOI: 10.1016/j.mam.2013.12.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 11/21/2013] [Accepted: 12/01/2013] [Indexed: 02/07/2023]
Abstract
Hepatobiliary bile salt (BS) transporters are critical determinants of BS homeostasis controlling intracellular concentrations of BSs and their enterohepatic circulation. Genetic or acquired dysfunction of specific transport systems causes intrahepatic and systemic retention of potentially cytotoxic BSs, which, in high concentrations, may disturb integrity of cell membranes and subcellular organelles resulting in cell death, inflammation and fibrosis. Transcriptional regulation of canalicular BS efflux through bile salt export pump (BSEP), basolateral elimination through organic solute transporters alpha and beta (OSTα/OSTβ) as well as inhibition of hepatocellular BS uptake through basolateral Na(+)-taurocholate cotransporting polypeptide (NTCP) represent critical steps in protection from hepatocellular BS overload and can be targeted therapeutically. In this article, we review the potential clinical implications of the major BS transporters BSEP, OSTα/OSTβ and NTCP in the pathogenesis of hereditary and acquired cholestatic syndromes, provide an overview on transcriptional control of these transporters by the key regulatory nuclear receptors and discuss the potential therapeutic role of novel transcriptional activators of BS transporters in cholestasis.
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Affiliation(s)
- Anna Baghdasaryan
- Hans Popper Laboratory of Molecular Hepatology, Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Austria; Laboratory of Experimental and Molecular Hepatology, Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Austria
| | - Peter Chiba
- Institute of Medical Chemistry, Medical University of Vienna, Austria
| | - Michael Trauner
- Hans Popper Laboratory of Molecular Hepatology, Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Austria.
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Assa A, Vong L, Pinnell LJ, Avitzur N, Johnson-Henry KC, Sherman PM. Vitamin D deficiency promotes epithelial barrier dysfunction and intestinal inflammation. J Infect Dis 2014; 210:1296-305. [PMID: 24755435 DOI: 10.1093/infdis/jiu235] [Citation(s) in RCA: 146] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Vitamin D, an important modulator of the immune system, has been shown to protect mucosal barrier homeostasis. This study investigates the effects of vitamin D deficiency on infection-induced changes in intestinal epithelial barrier function in vitro and on Citrobacter rodentium-induced colitis in mice. METHODS Polarized epithelial Caco2-bbe cells were grown in medium with or without vitamin D and challenged with enterohemorrhagic Escherichia coli O157:H7. Barrier function and tight junction protein expression were assessed. Weaned C57BL/6 mice were fed either a vitamin D-sufficient or vitamin D-deficient diet and then infected with C. rodentium. Disease severity was assessed by histological analysis, intestinal permeability assay, measurement of inflammatory cytokine levels, and microbiome analysis. RESULTS 1,25(OH)2D3 altered E. coli O157:H7-induced reductions in transepithelial electrical resistance (P < .01), decreased permeability (P < .05), and preserved barrier integrity. Vitamin D-deficient mice challenged with C. rodentium demonstrated increased colonic hyperplasia and epithelial barrier dysfunction (P < .0001 and P < .05, respectively). Vitamin D deficiency resulted in an altered composition of the fecal microbiome both in the absence and presence of C. rodentium infection. CONCLUSIONS This study demonstrates that vitamin D is an important mediator of intestinal epithelial defenses against infectious agents. Vitamin D deficiency predisposes to more-severe intestinal injury in an infectious model of colitis.
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Affiliation(s)
- Amit Assa
- Cell Biology Program, Research Institute Department of Paediatrics, Hospital for Sick Children
| | - Linda Vong
- Cell Biology Program, Research Institute
| | | | | | | | - Philip M Sherman
- Cell Biology Program, Research Institute Department of Paediatrics, Hospital for Sick Children University of Toronto, Canada
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15
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Xu S, Sun AQ, Suchy FJ. A novel RARα/CAR-mediated mechanism for regulation of human organic solute transporter-β gene expression. Am J Physiol Gastrointest Liver Physiol 2014; 306:G154-62. [PMID: 24264050 PMCID: PMC3920074 DOI: 10.1152/ajpgi.00138.2013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Accepted: 11/16/2013] [Indexed: 01/31/2023]
Abstract
The organic solute transporter-α/β (OSTα/β) is a heteromeric transporter that is essential for bile acid and sterol disposition and for the enterohepatic circulation. To better understand the mechanism underlying OST gene regulation, the effects of retinoic acid (RA) on OSTα/β gene expression were investigated. The results show a dose-dependent induction of OSTβ but not OSTα expression in both Huh7 and HepG2 cells by RA treatment. A novel functional RA receptor response element (RARE; so-called DR5) in the promoter of OSTβ gene was identified. The interaction of RARα/RXRα with the RARE was verified by electrophoretic mobility shift and chromatin immunoprecipitation assays and its functional importance by hOSTβ promoter activation in luciferase reporter assays. The studies demonstrated that the RARE is also a constitutive androstane receptor (CAR) binding site for OSTβ gene regulation. These results suggest that OSTβ is a target of both FXR-mediated (by binding to IR-1 element) and RARα- and CAR-mediated (by binding to DR5 element) gene regulation pathways. In summary, this study has uncovered a novel RARE (DR5) element in the promoter of OSTβ that binds RARα or CAR heterodimerized with RXRα and appears to function synergistically with the IR-1 element to provide maximal induction of OSTβ in response to RA. These findings demonstrate a role for RARα and CAR in controlling OSTβ expression levels.
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Affiliation(s)
- Shuhua Xu
- Children's Hospital Colorado, Univ. of Colorado School of Medicine, 13123 E. 16th Ave., B065 Aurora, CO 80045.
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Borges K. Slc10A4 - what do we know about the function of this "secret ligand carrier" protein? Exp Neurol 2013; 248:258-61. [PMID: 23810836 DOI: 10.1016/j.expneurol.2013.06.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 06/13/2013] [Accepted: 06/15/2013] [Indexed: 12/27/2022]
Abstract
This commentary discusses the possible functions of a relatively newly described solute carrier protein, Slc10a4, in regards to a recent article by Zelano et al. (2013) published in the January issue of Experimental Neurology, 239, 73-81. Slc10a4 belongs to the sodium-bile acid cotransporter family (Slc10), but does not show plasma membrane transport activity of bile acids and related molecules. It is co-localized with synaptic vesicle transporters for acetylcholine and dopamine. In Slc10a4 lacking mice, Zelano et al. found increased excitability in hippocampal slices and in vivo responses to pilocarpine, but not kainate. These findings are critically examined here. This author speculates on the possible function of Slc10a4, but remains partial about "specific effects of Slc10a4 in cholinergic systems". It is hoped that approaches targeting human SLC10A4 can be discovered for potential clinical use in neurological disorders, such as Alzheimer's and Parkinson's disease, schizophrenia and addiction. Conversely, some side effects are expected due to peripheral Slc10a4 localization in sympathetic and parasympathetic nerves, as well as mast cells.
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Affiliation(s)
- Karin Borges
- Department of Pharmacology, School of Biomedical Sciences, The University of Queensland, Skerman Building 65, St Lucia QLD 4072, Australia.
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17
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Ballatori N, Christian WV, Wheeler SG, Hammond CL. The heteromeric organic solute transporter, OSTα-OSTβ/SLC51: a transporter for steroid-derived molecules. Mol Aspects Med 2013; 34:683-92. [PMID: 23506901 PMCID: PMC3827772 DOI: 10.1016/j.mam.2012.11.005] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Accepted: 08/20/2012] [Indexed: 12/12/2022]
Abstract
The organic solute transporter alpha-beta (OSTα-OSTβ) is one of the newest members of the solute carrier family, designated as SLC51, and arguably one of the most unique. The transporter is composed of two gene products encoded by SLC51A and SLC51B that heterodimerize to form the functional transporter complex. SLC51A encodes OSTα, a predicted 340-amino acid, 7-transmembrane (TM) domain protein, whereas SLC51B encodes OSTβ, a putative 128-amino acid, single-TM domain polypeptide. Heterodimerization of the two subunits increases the stability of the individual proteins, facilitates their post-translational modification, and is required for delivery of the functional transporter complex to the plasma membrane. There are no paralogues for SLC51A or SLC51B in any genome that has been examined. The transporter functions via a facilitated diffusion mechanism, and can mediate either efflux or uptake depending on the electrochemical gradient of its substrates. Overall, characterization of the transporter's substrate specificity, transport mechanism, tissue distribution, subcellular localization, and transcriptional regulation as well as the phenotype of the recently generated Slc51a-deficient mice have revealed that OSTα-OSTβ plays a central role in the transport of bile acids, conjugated steroids, and structurally-related molecules across the basolateral membrane of many epithelial cells. In particular, OSTα-OSTβ appears to be essential for intestinal bile acid absorption, and thus for dietary lipid absorption.
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Affiliation(s)
- Nazzareno Ballatori
- Department of Environmental Medicine, University of Rochester School of Medicine, Rochester, NY 14642, United States
| | - Whitney V. Christian
- Department of Environmental Medicine, University of Rochester School of Medicine, Rochester, NY 14642, United States
| | - Sadie G. Wheeler
- Department of Environmental Medicine, University of Rochester School of Medicine, Rochester, NY 14642, United States
| | - Christine L. Hammond
- Department of Environmental Medicine, University of Rochester School of Medicine, Rochester, NY 14642, United States
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Christian WV, Li N, Hinkle PM, Ballatori N. β-Subunit of the Ostα-Ostβ organic solute transporter is required not only for heterodimerization and trafficking but also for function. J Biol Chem 2012; 287:21233-43. [PMID: 22535958 PMCID: PMC3375545 DOI: 10.1074/jbc.m112.352245] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2012] [Revised: 04/09/2012] [Indexed: 12/29/2022] Open
Abstract
The organic solute transporter, Ost/Slc51, is composed of two distinct proteins that must heterodimerize to generate transport activity, but the role of the individual subunits in mediating transport activity is unknown. The present study identified regions in Ostβ required for heterodimerization with Ostα, trafficking of the Ostα-Ostβ complex to the plasma membrane, and bile acid transport activity in HEK293 cells. Bimolecular fluorescence complementation analysis revealed that a 25-amino acid peptide containing the Ostβ transmembrane (TM) domain heterodimerized with Ostα, although the resulting complex failed to reach the plasma membrane and generate cellular [(3)H]taurocholate transport activity. Deletion of the single TM domain of Ostβ abolished interaction with Ostα, demonstrating that the TM segment is necessary and sufficient for formation of a heteromeric complex with Ostα. Mutation of the highly conserved tryptophan-asparagine sequence within the TM domain of Ostβ to alanines did not prevent cell surface trafficking, but abolished transport activity. Removal of the N-terminal 27 amino acids of Ostβ resulted in a transporter complex that reached the plasma membrane and exhibited transport activity at 30 °C. Complete deletion of the C terminus of Ostβ abolished [(3)H]taurocholate transport activity, but reinsertion of two native arginines immediately C-terminal to the TM domain rescued this defect. These positively charged residues establish the correct N(exo)/C(cyt) topology of the peptide, in accordance with the positive inside rule. Together, the results demonstrate that Ostβ is required for both proper trafficking of Ostα and formation of the functional transport unit, and identify specific residues of Ostβ critical for these processes.
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Affiliation(s)
| | - Na Li
- From the Departments of Environmental Medicine and
| | - Patricia M. Hinkle
- Pharmacology and Physiology, University of Rochester School of Medicine, Rochester, New York 14642
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