1
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Liang T, Liu H, Li L, Huan R, Gui C. Human organic anion transporting polypeptide 1B3 (OATP1B3) is more heavily N-glycosylated than OATP1B1 in extracellular loops 2 and 5. Int J Biol Macromol 2024; 278:134748. [PMID: 39147348 DOI: 10.1016/j.ijbiomac.2024.134748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Revised: 07/25/2024] [Accepted: 08/09/2024] [Indexed: 08/17/2024]
Abstract
Human organic anion transporting polypeptide 1B3 (OATP1B3) and 1B1 are two liver-specific and highly homologous uptake transporters, whose structures consist of 12 transmembrane domains. The present study showed that OATP1B3 is more heavily N-glycosylated than OATP1B1 in extracellular loop 2 (EL2) and EL5. OATP1B3 has six N-glycosylation sites, namely N134, N145, N151, N445, N503, and N516, which is twice of that of OATP1B1. Single removal of individual N-glycans seems to have minimal influence on the surface expression and function of OATP1B3. However, simultaneous removal of all N-glycans will lead to OATP1B3's large retention in the endoplasmic reticulum and cellular degradation and thus significantly disrupts its surface expression. While N-glycosylation plays a crucial role in the surface expression of OATP1B3, it also has some effect on the transport function of OATP1B3 per se, which is not due to a decrease of substrate binding affinity but due to a reduced transporter's turnover number. Taken together, N-glycosylation is essential for normal surface expression and function of OATP1B3. Its disruption by some liver diseases such as NASH might alter the pharmacokinetic/pharmacodynamic properties of OATP1B3's substrate drugs.
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Affiliation(s)
- Ting Liang
- College of Pharmaceutical Sciences, Soochow University, 199 Renai Road, Suzhou Industrial Park, Suzhou, Jiangsu 215123, China
| | - Han Liu
- College of Pharmaceutical Sciences, Soochow University, 199 Renai Road, Suzhou Industrial Park, Suzhou, Jiangsu 215123, China
| | - Lanjing Li
- College of Pharmaceutical Sciences, Soochow University, 199 Renai Road, Suzhou Industrial Park, Suzhou, Jiangsu 215123, China
| | - Ru Huan
- College of Pharmaceutical Sciences, Soochow University, 199 Renai Road, Suzhou Industrial Park, Suzhou, Jiangsu 215123, China
| | - Chunshan Gui
- College of Pharmaceutical Sciences, Soochow University, 199 Renai Road, Suzhou Industrial Park, Suzhou, Jiangsu 215123, China.
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2
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Li Y, Liu H, Liang T, Han W, Bo Z, Qiu T, Li J, Xu M, Wang W, Yang S, Gui C. Importance of N-Glycosylation for the Expression and Function of Human Organic Anion Transporting Polypeptide 2B1. ACS Pharmacol Transl Sci 2023; 6:1347-1356. [PMID: 37854627 PMCID: PMC10580385 DOI: 10.1021/acsptsci.3c00076] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Indexed: 10/20/2023]
Abstract
Human organic anion transporting polypeptide 2B1 (OATP2B1) is a membrane transporter widely expressed in organs crucial for drug absorption and disposition such as the intestine, liver, and kidney. Evidence indicates that OATP2B1 is a glycoprotein. However, the sites of glycosylation and their contribution to the function and expression of OATP2B1 are largely unknown. In this study, by site-directed mutagenesis, we determined that two of four potential N-glycosylation sites in OATP2B1, N176 and N538, are indeed glycosylated. Functional studies revealed that the transport activities of mutants N176Q and N538Q were greatly reduced as compared to that of wild-type OATP2B1. However, the reduced activity was not due to the impairment of transport function per se but due to the decreased surface expression as the Km and normalized Vmax values of N176Q and N538Q were comparable to those of OATP2B1. Quantitative polymerase chain reaction (PCR) revealed that N176Q and N538Q mutations did not affect the expression of OATP2B1 at a transcriptional level. Immunofluorescence analysis showed that deglycosylated OATP2B1 was largely retained in the endoplasmic reticulum, which may activate the endoplasmic reticulum-associated degradation pathway, and the ubiquitin-proteasome system played a major role in the degradation of OATP2B1. Taken together, OATP2B1 is N-glycosylated, and N-glycosylation is essential for the surface expression of OATP2B1 but not critical for the transport function of OATP2B1 per se.
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Affiliation(s)
| | | | | | - Wanjun Han
- College of Pharmaceutical
Sciences, Soochow University, 199 Renai Road, Suzhou Industrial
Park, Suzhou, Jiangsu 215123, People’s
Republic of China
| | - Zheyue Bo
- College of Pharmaceutical
Sciences, Soochow University, 199 Renai Road, Suzhou Industrial
Park, Suzhou, Jiangsu 215123, People’s
Republic of China
| | - Tian Qiu
- College of Pharmaceutical
Sciences, Soochow University, 199 Renai Road, Suzhou Industrial
Park, Suzhou, Jiangsu 215123, People’s
Republic of China
| | - Jiawei Li
- College of Pharmaceutical
Sciences, Soochow University, 199 Renai Road, Suzhou Industrial
Park, Suzhou, Jiangsu 215123, People’s
Republic of China
| | - Mingming Xu
- College of Pharmaceutical
Sciences, Soochow University, 199 Renai Road, Suzhou Industrial
Park, Suzhou, Jiangsu 215123, People’s
Republic of China
| | - Weipeng Wang
- College of Pharmaceutical
Sciences, Soochow University, 199 Renai Road, Suzhou Industrial
Park, Suzhou, Jiangsu 215123, People’s
Republic of China
| | - Shuang Yang
- College of Pharmaceutical
Sciences, Soochow University, 199 Renai Road, Suzhou Industrial
Park, Suzhou, Jiangsu 215123, People’s
Republic of China
| | - Chunshan Gui
- College of Pharmaceutical
Sciences, Soochow University, 199 Renai Road, Suzhou Industrial
Park, Suzhou, Jiangsu 215123, People’s
Republic of China
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3
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Ouchida T, Maeda H, Akamatsu Y, Maeda M, Takamatsu S, Kondo J, Misaki R, Kamada Y, Ueda M, Ueda K, Miyoshi E. The specific core fucose-binding lectin Pholiota squarrosa lectin (PhoSL) inhibits hepatitis B virus infection in vitro. Sci Rep 2023; 13:6175. [PMID: 37061516 PMCID: PMC10105536 DOI: 10.1038/s41598-023-28572-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 01/20/2023] [Indexed: 04/17/2023] Open
Abstract
Glycosylation of proteins and lipids in viruses and their host cells is important for viral infection and is a target for antiviral therapy. Hepatitis B virus (HBV) is a major pathogen that causes acute and chronic hepatitis; it cannot be cured because of the persistence of its covalently closed circular DNA (cccDNA) in hepatocytes. Here we found that Pholiota squarrosa lectin (PhoSL), a lectin that specifically binds core fucose, bound to HBV particles and inhibited HBV infection of a modified human HepG2 cell line, HepG2-hNTCP-C4, that expresses an HBV receptor, sodium taurocholate cotransporting polypeptide. Knockout of fucosyltransferase 8, the enzyme responsible for core fucosylation and that aids receptor endocytosis, in HepG2-hNTCP-C4 cells reduced HBV infectivity, and PhoSL facilitated that reduction. PhoSL also blocked the activity of epidermal growth factor receptor, which usually enhances HBV infection. HBV particles bound to fluorescently labeled PhoSL internalized into HepG2-hNTCP-C4 cells, suggesting that PhoSL might inhibit HBV infection after internalization. As PhoSL reduced the formation of HBV cccDNA, a marker of chronic HBV infection, we suggest that PhoSL could impair processes from internalization to cccDNA formation. Our finding could lead to the development of new anti-HBV agents.
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Affiliation(s)
- Tsunenori Ouchida
- Department of Molecular Biochemistry and Clinical Investigation, Osaka University Graduate School of Medicine, 1-7 Yamada-Oka, Suita, Osaka, 565-0871, Japan
- Laboratory of Single Molecule Biology, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, 565-0871, Japan
| | - Haruka Maeda
- Department of Molecular Biochemistry and Clinical Investigation, Osaka University Graduate School of Medicine, 1-7 Yamada-Oka, Suita, Osaka, 565-0871, Japan
- Division of Virology, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, Suita, Osaka, 565-0871, Japan
| | - Yuka Akamatsu
- Department of Molecular Biochemistry and Clinical Investigation, Osaka University Graduate School of Medicine, 1-7 Yamada-Oka, Suita, Osaka, 565-0871, Japan
- Division of Virology, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, Suita, Osaka, 565-0871, Japan
| | - Megumi Maeda
- Department of Molecular Biochemistry and Clinical Investigation, Osaka University Graduate School of Medicine, 1-7 Yamada-Oka, Suita, Osaka, 565-0871, Japan
- Division of Virology, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, Suita, Osaka, 565-0871, Japan
| | - Shinji Takamatsu
- Department of Molecular Biochemistry and Clinical Investigation, Osaka University Graduate School of Medicine, 1-7 Yamada-Oka, Suita, Osaka, 565-0871, Japan
| | - Jumpei Kondo
- Department of Molecular Biochemistry and Clinical Investigation, Osaka University Graduate School of Medicine, 1-7 Yamada-Oka, Suita, Osaka, 565-0871, Japan
| | - Ryo Misaki
- Applied Microbiology Laboratory, International Center for Biotechnology, Osaka University, Suita, Osaka, 565-0871, Japan
| | - Yoshihiro Kamada
- Department of Advanced Metabolic Hepatology, Osaka University Graduate School of Medicine, Suita, Osaka, 565-0871, Japan
| | - Masahiro Ueda
- Laboratory of Single Molecule Biology, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, 565-0871, Japan
| | - Keiji Ueda
- Division of Virology, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, Suita, Osaka, 565-0871, Japan
| | - Eiji Miyoshi
- Department of Molecular Biochemistry and Clinical Investigation, Osaka University Graduate School of Medicine, 1-7 Yamada-Oka, Suita, Osaka, 565-0871, Japan.
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4
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Sugahara G, Ishida Y, Lee JJ, Li M, Tanaka Y, Eoh H, Higuchi Y, Saito T. Long-term cell fate and functional maintenance of human hepatocyte through stepwise culture configuration. FASEB J 2023; 37:e22750. [PMID: 36607308 PMCID: PMC9830592 DOI: 10.1096/fj.202201292rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 12/13/2022] [Accepted: 12/20/2022] [Indexed: 01/07/2023]
Abstract
Human hepatocyte culture system represents by far the most physiologically relevant model for our understanding of liver biology and diseases; however, its versatility has been limited due to the rapid and progressive loss of genuine characteristics, indicating the inadequacy of in vitro milieu for fate maintenance. This study, therefore, is designed to define environmental requirements necessary to sustain the homeostasis of terminally differentiated hepatocytes. Our study reveals that the supplementation of dimethyl sulfoxide (DMSO) is indispensable in mitigating fate deterioration and promoting adaptation to the in vitro environment, resulting in the restoration of tight cell-cell contact, cellular architecture, and polarity. The morphological recovery was overall accompanied by the restoration of hepatocyte marker gene expression, highlighting the interdependence between the cellular architecture and the maintenance of cell fate. However, beyond the recovery phase culture, DMSO supplementation is deemed detrimental due to the potent inhibitory effect on a multitude of hepatocyte functionalities while its withdrawal results in the loss of cell fate. In search of DMSO substitute, our screening of organic substances led to the identification of dimethyl sulfone (DMSO2), which supports the long-term maintenance of proper morphology, marker gene expression, and hepatocytic functions. Moreover, hepatocytes maintained DMSO2 exhibited clinically relevant toxicity in response to prolonged exposure to xenobiotics as well as alcohol. These observations suggest that the stepwise culture configuration consisting of the consecutive supplementation of DMSO and DMSO2 confers the microenvironment essential for the fate and functional maintenance of terminally differentiated human hepatocytes.
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Affiliation(s)
- Go Sugahara
- University of Southern California, Keck School of Medicine, Department of Medicine, Division of Gastrointestinal and Liver Diseases, Los Angeles, California, USA.,Research and Development Department, PhoenixBio, Co., Ltd, Kagamiyama, Higashi-Hiroshima, Hiroshima, Japan
| | - Yuji Ishida
- University of Southern California, Keck School of Medicine, Department of Medicine, Division of Gastrointestinal and Liver Diseases, Los Angeles, California, USA.,Research and Development Department, PhoenixBio, Co., Ltd, Kagamiyama, Higashi-Hiroshima, Hiroshima, Japan
| | - Jae Jin Lee
- University of Southern California, Keck School of Medicine, Department of Molecular Microbiology & Immunology, Los Angeles, California, USA
| | - Meng Li
- University of Southern California, Norris Medical Library, Bioinformatics Service Program, Los Angeles, California, USA
| | - Yasuhito Tanaka
- Department of Gastroenterology and Hepatology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Kumamoto, Japan
| | - Hyungjin Eoh
- University of Southern California, Keck School of Medicine, Department of Molecular Microbiology & Immunology, Los Angeles, California, USA
| | - Yusuke Higuchi
- Department of Molecular Medicine, Beckman Research Institute of City of Hope, Duarte, California, USA
| | - Takeshi Saito
- University of Southern California, Keck School of Medicine, Department of Medicine, Division of Gastrointestinal and Liver Diseases, Los Angeles, California, USA.,USC Research Center for Liver Diseases, Los Angeles, California, USA.,Corresponding author: Takeshi Saito, M.D., Ph.D., Associate Professor of Medicine, Molecular Microbiology & Immunology, and Pathology, USC Research Center for Liver Diseases, Division of Gastrointestinal and Liver Diseases, Keck School of Medicine of USC, University of Southern California, 2011 Zonal Avenue, HMR 801A, Los Angeles, CA 90033-9141, Phone: +1-323-442-2260, Fax:+1-323-442-5425,
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5
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Qin T, Wang Y, Nie J, Yu L, Zeng S. Oligomerization of the HBV/HDV functional receptor NTCP expressed in Sf9 insect cell. Biochim Biophys Acta Gen Subj 2022; 1866:130224. [DOI: 10.1016/j.bbagen.2022.130224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 08/01/2022] [Accepted: 08/02/2022] [Indexed: 10/31/2022]
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6
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Ruggiero MJ, Malhotra S, Fenton AW, Swint-Kruse L, Karanicolas J, Hagenbuch B. Structural Plasticity Is a Feature of Rheostat Positions in the Human Na +/Taurocholate Cotransporting Polypeptide (NTCP). Int J Mol Sci 2022; 23:ijms23063211. [PMID: 35328632 PMCID: PMC8954283 DOI: 10.3390/ijms23063211] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/11/2022] [Accepted: 03/15/2022] [Indexed: 02/05/2023] Open
Abstract
In the Na+/taurocholate cotransporting polypeptide (NTCP), the clinically relevant S267F polymorphism occurs at a "rheostat position". That is, amino acid substitutions at this position ("S267X") lead to a wide range of functional outcomes. This result was particularly striking because molecular models predicted the S267X side chains are buried, and thus, usually expected to be less tolerant of substitutions. To assess whether structural tolerance to buried substitutions is widespread in NTCP, here we used Rosetta to model all 19 potential substitutions at another 13 buried positions. Again, only subtle changes in the calculated stabilities and structures were predicted. Calculations were experimentally validated for 19 variants at codon 271 ("N271X"). Results showed near wildtype expression and rheostatic modulation of substrate transport, implicating N271 as a rheostat position. Notably, each N271X substitution showed a similar effect on the transport of three different substrates and thus did not alter substrate specificity. This differs from S267X, which altered both transport kinetics and specificity. As both transport and specificity may change during protein evolution, the recognition of such rheostat positions may be important for evolutionary studies. We further propose that the presence of rheostat positions is facilitated by local plasticity within the protein structure. Finally, we note that identifying rheostat positions may advance efforts to predict new biomedically relevant missense variants in NTCP and other membrane transport proteins.
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Affiliation(s)
- Melissa J. Ruggiero
- Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City, KS 66160, USA;
| | - Shipra Malhotra
- Program in Molecular Therapeutics, Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA 19111, USA; (S.M.); (J.K.)
| | - Aron W. Fenton
- Department of Biochemistry and Molecular Biology, The University of Kansas Medical Center, Kansas City, KS 66160, USA; (A.W.F.); (L.S.-K.)
| | - Liskin Swint-Kruse
- Department of Biochemistry and Molecular Biology, The University of Kansas Medical Center, Kansas City, KS 66160, USA; (A.W.F.); (L.S.-K.)
| | - John Karanicolas
- Program in Molecular Therapeutics, Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA 19111, USA; (S.M.); (J.K.)
| | - Bruno Hagenbuch
- Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City, KS 66160, USA;
- Correspondence:
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7
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Multitasking Na+/Taurocholate Cotransporting Polypeptide (NTCP) as a Drug Target for HBV Infection: From Protein Engineering to Drug Discovery. Biomedicines 2022; 10:biomedicines10010196. [PMID: 35052874 PMCID: PMC8773476 DOI: 10.3390/biomedicines10010196] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/10/2022] [Accepted: 01/13/2022] [Indexed: 02/05/2023] Open
Abstract
Hepatitis B virus (HBV) infections are among the major public health concerns worldwide with more than 250 million of chronically ill individuals. Many of them are additionally infected with the Hepatitis D virus, a satellite virus to HBV. Chronic infection frequently leads to serious liver diseases including cirrhosis and hepatocellular carcinoma, the most common type of liver cancer. Although current antiviral therapies can control HBV replication and slow down disease progress, there is an unmet medical need to identify therapies to cure this chronic infectious disease. Lately, a noteworthy progress in fighting against HBV has been made by identification of the high-affinity hepatic host receptor for HBV and HDV, namely Na+/taurocholate cotransporting polypeptide (NTCP, gene symbol SLC10A1). Next to its primary function as hepatic uptake transporter for bile acids, NTCP is essential for the cellular entry of HBV and HDV into hepatocytes. Due to this high-ranking discovery, NTCP has become a valuable target for drug development strategies for HBV/HDV-infected patients. In this review, we will focus on a newly predicted three-dimensional NTCP model that was generated using computational approaches and discuss its value in understanding the NTCP’s membrane topology, substrate and virus binding taking place in plasma membranes. We will review existing data on structural, functional, and biological consequences of amino acid residue changes and mutations that lead to loss of NTCP’s transport and virus receptor functions. Finally, we will discuss new directions for future investigations aiming at development of new NTCP-based HBV entry blockers that inhibit HBV tropism in human hepatocytes.
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8
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Kunst RF, Paulusma CC, van de Graaf SFJ. Insufficient evidence for NTCP activity in stellate cells. Gut 2021; 71:gutjnl-2021-326452. [PMID: 34911743 PMCID: PMC9484369 DOI: 10.1136/gutjnl-2021-326452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 11/29/2021] [Indexed: 12/08/2022]
Affiliation(s)
- Roni F Kunst
- Amsterdam Gastroenterology, Endocrinology, Metabolism, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Tytgat Institute and Department of Gastroenterology and Hepatology, Amsterdam UMC Locatie AMC, Amsterdam, North Holland, The Netherlands
| | - Coen C Paulusma
- Amsterdam Gastroenterology, Endocrinology, Metabolism, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Tytgat Institute and Department of Gastroenterology and Hepatology, Amsterdam UMC Locatie AMC, Amsterdam, North Holland, The Netherlands
| | - Stan F J van de Graaf
- Amsterdam Gastroenterology, Endocrinology, Metabolism, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Tytgat Institute and Department of Gastroenterology and Hepatology, Amsterdam UMC Locatie AMC, Amsterdam, North Holland, The Netherlands
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9
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Na+-Taurocholate Co-Transporting Polypeptide (NTCP) in Livers, Function, Expression Regulation, and Potential in Hepatitis B Treatment. LIVERS 2021. [DOI: 10.3390/livers1040019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Chronic hepatitis B virus (HBV) infection has become one of the leading causes of liver cirrhosis and hepatocellular carcinoma globally. The discovery of sodium taurocholate co-transporting polypeptide (NTCP), a solute carrier, as a key receptor for HBV and hepatitis D virus (HDV) has opened new avenues for HBV treatment. Additionally, it has led researchers to generate hepatoma cell lines (including HepG2-NTCP and Huh-7-NTCP) susceptible to HBV infection in vitro, hence, paving the way to develop and efficiently screen new and novel anti-HBV drugs. This review summarizes the history, function and critical findings regarding NTCP as a viral receptor for HBV/HDV, and it also discusses recently developed drugs targeting NTCP.
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10
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Oswald A, Chakraborty A, Ni Y, Wettengel JM, Urban S, Protzer U. Concentration of Na +-taurocholate-cotransporting polypeptide expressed after in vitro-transcribed mRNA transfection determines susceptibility of hepatoma cells for hepatitis B virus. Sci Rep 2021; 11:19799. [PMID: 34611272 PMCID: PMC8492621 DOI: 10.1038/s41598-021-99263-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 09/21/2021] [Indexed: 02/07/2023] Open
Abstract
Infection of hepatocytes by hepatitis B virus (HBV) depends on surface expression of its receptor Na+-taurocholate-cotransporting polypeptide (NTCP), but sufficient NTCP expression is lacking in most cell lines. NTCP can be introduced by plasmid transfection or transduction by viral vectors to render cells permissive for HBV. However, transient transfection of hepatocyte-derived cell lines is inefficient, resulting in inhomogeneous protein expression and does not allow to adapt the level of NTCP expression. We therefore utilized in vitro transcribed mRNA to introduce NTCP into cells. Optimization using alternative cap structures and nucleotide modifications rendered mRNA transfection into different non-hepatic and hepatic cell lines very efficient. After transfection of mRNA, surface expression and functionality of NTCP was demonstrated by staining with an N-terminal HBV-preS peptide and bile acid uptake. Introduction of NTCP by mRNA transfection increased susceptibility of hepatoma cells to HBV in a dose-dependent manner. Transfection of NTCP mRNA into non-liver cells, in contrast, supported bile acid uptake but did still not render the cells permissive for HBV, demonstrating the requirement for additional host factors. Introduction of candidate host factors by mRNA transfection will allow for fast and convenient analysis of the viral life cycle using a transient, but reliable expression system.
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Affiliation(s)
- Andreas Oswald
- Institute of Virology, School of Medicine, Technical University of Munich/Helmholtz Zentrum München, Munich, Germany
| | - Anindita Chakraborty
- Institute of Virology, School of Medicine, Technical University of Munich/Helmholtz Zentrum München, Munich, Germany
| | - Yi Ni
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, Heidelberg, Germany
- German Center for Infection Research (DZIF), partner site Heidelberg, Heidelberg, Germany
| | - Jochen M Wettengel
- Institute of Virology, School of Medicine, Technical University of Munich/Helmholtz Zentrum München, Munich, Germany
| | - Stephan Urban
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, Heidelberg, Germany
- German Center for Infection Research (DZIF), partner site Heidelberg, Heidelberg, Germany
| | - Ulrike Protzer
- Institute of Virology, School of Medicine, Technical University of Munich/Helmholtz Zentrum München, Munich, Germany.
- German Center for Infection Research (DZIF), partner site Munich, Munich, Germany.
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11
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Basiglio CL, Crocenzi FA, Sánchez Pozzi EJ, Roma MG. Oxidative Stress and Localization Status of Hepatocellular Transporters: Impact on Bile Secretion and Role of Signaling Pathways. Antioxid Redox Signal 2021; 35:808-831. [PMID: 34293961 DOI: 10.1089/ars.2021.0021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Significance: Most hepatopathies are primarily or secondarily cholestatic in nature. Oxidative stress (OS) is a frequent trait among them, and impairs the machinery to generate bile by triggering endocytic internalization of hepatocellular transporters, thus causing cholestasis. This is critical, since it leads to accelerated transporter degradation, which could explain the common post-transcriptional downregulation of transporter expression in human cholestatic diseases. Recent Advances: The mechanisms involved in OS-induced hepatocellular transporter internalization are being revealed. Filamentous actin (F-actin) cytoskeleton disorganization and/or detachment of crosslinking actin proteins that afford transporter stability have been characterized as causal factors. Activation of redox-sensitive signaling pathways leading to changes in phosphorylation status of these structures is involved, including Ca2+-mediated activation of "classical" and "novel" protein kinase C (PKC) isoforms or redox-signaling cascades downstream of NADPH oxidase. Critical Issues: Despite the well-known occurrence of hepatocellular transporter internalization in human hepatopathies, the cholestatic implications of this phenomenon have been overlooked. Accordingly, no specific treatment has been established in the clinical practice for its prevention/reversion. Future Directions: We need to improve our knowledge on the pro-oxidant triggering factors and the multiple signaling pathways that mediate this oxidative injury in each cholestatic hepatopathy, so as to envisage tailor-made therapeutic strategies for each case. Meanwhile, administration of antioxidants or heme oxygenase-1 induction to elevate the hepatocellular levels of the endogenous scavenger bilirubin are promising alternatives that need to be re-evaluated and implemented. They may complement current treatments in cholestasis aimed to enhance transcriptional carrier expression, by providing membrane stability to the newly synthesized carriers. Antioxid. Redox Signal. 35, 808-831.
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Affiliation(s)
- Cecilia L Basiglio
- Instituto de Fisiología Experimental (IFISE), Facultad de Ciencias Bioquímicas y Farmacéuticas, CONICET, U.N.R., Rosario, Argentina
| | - Fernando A Crocenzi
- Instituto de Fisiología Experimental (IFISE), Facultad de Ciencias Bioquímicas y Farmacéuticas, CONICET, U.N.R., Rosario, Argentina
| | - Enrique J Sánchez Pozzi
- Instituto de Fisiología Experimental (IFISE), Facultad de Ciencias Bioquímicas y Farmacéuticas, CONICET, U.N.R., Rosario, Argentina
| | - Marcelo G Roma
- Instituto de Fisiología Experimental (IFISE), Facultad de Ciencias Bioquímicas y Farmacéuticas, CONICET, U.N.R., Rosario, Argentina
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12
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Ouchida T, Takamatsu S, Maeda M, Asuka T, Morita C, Kondo J, Ueda K, Miyoshi E. Challenges in the Application of Glyco-Technology to Hepatitis B Virus Therapy and Diagnosis. Viruses 2021; 13:v13091860. [PMID: 34578441 PMCID: PMC8473023 DOI: 10.3390/v13091860] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 09/13/2021] [Accepted: 09/14/2021] [Indexed: 01/05/2023] Open
Abstract
Hepatitis B virus (HBV) is a major pathogen that causes acute/chronic hepatitis. Continuous HBV infection can lead to the development of hepatocellular carcinoma (HCC). Although several different anti-HBV treatments are available for chronic hepatitis B patients, discontinuing these medications is difficult. Patients with chronic hepatitis B at high risk for HCC therefore require close observation. However, no suitable biomarkers for detecting high-risk groups for HCC exist, except for serum HBV-DNA, but a number of HCC biomarkers are used clinically, such as alpha-fetoprotein (AFP) and protein induced by vitamin K absence-II (PIVKA-II). Glycosylation is an important post-translational protein modification involved in many human pathologic conditions. HBV surface proteins contain various oligosaccharides, and several reports have described their biological functions. Inhibition of HBV glycosylation represents a potential novel anti-HBV therapy. It is thought that glycosylation of hepatocytes/hepatoma cells is also important for HBV infection, as it prevents HBV from infecting cells other than hepatocytes, even if the cells express the HBV receptor. In this review, we summarize considerable research regarding the relationship between HBV and glycosylation as it relates to the development of novel diagnostic tests and therapies for HBV.
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Affiliation(s)
- Tsunenori Ouchida
- Department of Molecular Biochemistry and Clinical Investigation, Osaka University Graduate School of Medicine, 1-7 Yamada-oka, Suita 565-0871, Japan; (T.O.); (S.T.); (M.M.); (T.A.); (C.M.); (J.K.)
| | - Shinji Takamatsu
- Department of Molecular Biochemistry and Clinical Investigation, Osaka University Graduate School of Medicine, 1-7 Yamada-oka, Suita 565-0871, Japan; (T.O.); (S.T.); (M.M.); (T.A.); (C.M.); (J.K.)
| | - Megumi Maeda
- Department of Molecular Biochemistry and Clinical Investigation, Osaka University Graduate School of Medicine, 1-7 Yamada-oka, Suita 565-0871, Japan; (T.O.); (S.T.); (M.M.); (T.A.); (C.M.); (J.K.)
| | - Tatsuya Asuka
- Department of Molecular Biochemistry and Clinical Investigation, Osaka University Graduate School of Medicine, 1-7 Yamada-oka, Suita 565-0871, Japan; (T.O.); (S.T.); (M.M.); (T.A.); (C.M.); (J.K.)
| | - Chiharu Morita
- Department of Molecular Biochemistry and Clinical Investigation, Osaka University Graduate School of Medicine, 1-7 Yamada-oka, Suita 565-0871, Japan; (T.O.); (S.T.); (M.M.); (T.A.); (C.M.); (J.K.)
- Department of Microbiology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita 565-0871, Japan;
| | - Jumpei Kondo
- Department of Molecular Biochemistry and Clinical Investigation, Osaka University Graduate School of Medicine, 1-7 Yamada-oka, Suita 565-0871, Japan; (T.O.); (S.T.); (M.M.); (T.A.); (C.M.); (J.K.)
| | - Keiji Ueda
- Department of Microbiology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita 565-0871, Japan;
| | - Eiji Miyoshi
- Department of Molecular Biochemistry and Clinical Investigation, Osaka University Graduate School of Medicine, 1-7 Yamada-oka, Suita 565-0871, Japan; (T.O.); (S.T.); (M.M.); (T.A.); (C.M.); (J.K.)
- Correspondence: ; Tel./Fax: +81-6-6879-2590
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13
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Appelman MD, Wettengel JM, Protzer U, Oude Elferink RPJ, van de Graaf SFJ. Molecular regulation of the hepatic bile acid uptake transporter and HBV entry receptor NTCP. Biochim Biophys Acta Mol Cell Biol Lipids 2021; 1866:158960. [PMID: 33932583 DOI: 10.1016/j.bbalip.2021.158960] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 04/06/2021] [Accepted: 04/26/2021] [Indexed: 12/18/2022]
Abstract
Transporters expressed by hepatocytes and enterocytes play a critical role in maintaining the enterohepatic circulation of bile acids. The sodium taurocholate cotransporting polypeptide (NTCP), exclusively expressed at the basolateral side of hepatocytes, mediates the uptake of conjugated bile acids. In conditions where bile flow is impaired (cholestasis), pharmacological inhibition of NTCP-mediated bile acid influx is suggested to reduce hepatocellular damage due to bile acid overload. Furthermore, NTCP has been shown to play an important role in hepatitis B virus (HBV) and hepatitis Delta virus (HDV) infection by functioning as receptor for viral entry into hepatocytes. This review provides a summary of current molecular insight into the regulation of NTCP expression at the plasma membrane, hepatic bile acid transport, and NTCP-mediated viral infection.
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Affiliation(s)
- Monique D Appelman
- Tytgat Institute for Liver and Intestinal Research, Amsterdam University Medical Centers Amsterdam, the Netherlands; Amsterdam Gastroenterology, Endocrinology, Metabolism (AGEM), Amsterdam, the Netherlands
| | - Jochen M Wettengel
- Institute of Virology, Technische Universität München/Helmholtz Zentrum München, Munich, Germany
| | - Ulrike Protzer
- Institute of Virology, Technische Universität München/Helmholtz Zentrum München, Munich, Germany; German Center for Infection Research (DZIF), Munich partner site, Munich, Germany
| | - Ronald P J Oude Elferink
- Tytgat Institute for Liver and Intestinal Research, Amsterdam University Medical Centers Amsterdam, the Netherlands; Amsterdam Gastroenterology, Endocrinology, Metabolism (AGEM), Amsterdam, the Netherlands; Department of Gastroenterology and Hepatology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, the Netherlands
| | - Stan F J van de Graaf
- Tytgat Institute for Liver and Intestinal Research, Amsterdam University Medical Centers Amsterdam, the Netherlands; Amsterdam Gastroenterology, Endocrinology, Metabolism (AGEM), Amsterdam, the Netherlands; Department of Gastroenterology and Hepatology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, the Netherlands.
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14
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Palatini M, Müller SF, Lowjaga KAAT, Noppes S, Alber J, Lehmann F, Goldmann N, Glebe D, Geyer J. Mutational Analysis of the GXXXG/A Motifs in the Human Na +/Taurocholate Co-Transporting Polypeptide NTCP on Its Bile Acid Transport Function and Hepatitis B/D Virus Receptor Function. Front Mol Biosci 2021; 8:699443. [PMID: 34239896 PMCID: PMC8257933 DOI: 10.3389/fmolb.2021.699443] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 06/10/2021] [Indexed: 01/05/2023] Open
Abstract
Homodimerization is essential for plasma membrane sorting of the liver bile acid transporter NTCP and its function as Hepatitis B/D Virus (HBV/HDV) receptor. However, the protein domains involved in NTCP dimerization are unknown. NTCP bears two potential GXXXG/A dimerization motifs in its transmembrane domains (TMDs) 2 and 7. The present study aimed to analyze the role of these GXXXG/A motifs for the sorting, function, and dimerization of NTCP. The NTCP mutants G60LXXXA64L (TMD2), G233LXXXG237L (TMD7) and a double mutant were generated and analyzed for their interaction with wild-type NTCP using a membrane-based yeast-two hybrid system (MYTH) and co-immunoprecipitation (co-IP). In the MYTH system, the TMD2 and TMD7 mutants showed significantly lower interaction with the wild-type NTCP. In transfected HEK293 cells, membrane expression and bile acid transport activity were slightly reduced for the TMD2 mutant but were completely abolished for the TMD7 and the TMD2/7 mutants, while co-IP experiments still showed intact protein-protein interactions. Susceptibility for in vitro HBV infection in transfected HepG2 cells was reduced to 50% for the TMD2 mutant, while the TMD7 mutant was not susceptible for HBV infection at all. We conclude that the GXXXG/A motifs in TMD2 and even more pronounced in TMD7 are important for proper folding and sorting of NTCP, and so indirectly affect glycosylation, homodimerization, and bile acid transport of NTCP, as well as its HBV/HDV receptor function.
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Affiliation(s)
- Massimo Palatini
- Institute of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Justus Liebig University Giessen, Giessen, Germany
| | - Simon Franz Müller
- Institute of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Justus Liebig University Giessen, Giessen, Germany
| | | | - Saskia Noppes
- Institute of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Justus Liebig University Giessen, Giessen, Germany
| | - Jörg Alber
- Institute of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Justus Liebig University Giessen, Giessen, Germany
| | - Felix Lehmann
- Institute of Medical Virology, National Reference Center for Hepatitis B and D Viruses, Justus Liebig University Giessen, Giessen, Germany
| | - Nora Goldmann
- Institute of Medical Virology, National Reference Center for Hepatitis B and D Viruses, Justus Liebig University Giessen, Giessen, Germany
| | - Dieter Glebe
- Institute of Medical Virology, National Reference Center for Hepatitis B and D Viruses, Justus Liebig University Giessen, Giessen, Germany
| | - Joachim Geyer
- Institute of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Justus Liebig University Giessen, Giessen, Germany
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15
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In Vitro Infection with Hepatitis B Virus Using Differentiated Human Serum Culture of Huh7.5-NTCP Cells without Requiring Dimethyl Sulfoxide. Viruses 2021; 13:v13010097. [PMID: 33445753 PMCID: PMC7828204 DOI: 10.3390/v13010097] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 01/08/2021] [Accepted: 01/08/2021] [Indexed: 02/07/2023] Open
Abstract
An estimated two billion people worldwide have been infected with hepatitis B virus (HBV). Despite the high infectivity of HBV in vivo, a lack of easily infectable in vitro culture systems hinders studies of HBV. Overexpression of the sodium taurocholate co-transporting polypeptide (NTCP) bile acid transporter in hepatoma cells improved infection efficiency. We report here a hepatoma cell culture system that does not require dimethyl sulfoxide (DMSO) for HBV infection. We overexpressed NTCP in Huh7.5 cells and allowed these cells to differentiate in a medium supplemented with human serum (HS) instead of fetal bovine serum (FBS). We show that human serum culture enhanced HBV infection in Huh7.5-NTCP cells, e.g., in HS cultures, HBV pgRNA levels were increased by as much as 200-fold in comparison with FBS cultures and 19-fold in comparison with FBS+DMSO cultures. Human serum culture increased levels of hepatocyte differentiation markers, such as albumin secretion, in Huh7.5-NTCP cells to similar levels found in primary human hepatocytes. N-glycosylation of NTCP induced by culture in human serum may contribute to viral entry. Our study demonstrates an in vitro HBV infection of Huh7.5-NTCP cells without the use of potentially toxic DMSO.
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16
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Ruggiero MJ, Malhotra S, Fenton AW, Swint-Kruse L, Karanicolas J, Hagenbuch B. A clinically relevant polymorphism in the Na +/taurocholate cotransporting polypeptide (NTCP) occurs at a rheostat position. J Biol Chem 2020; 296:100047. [PMID: 33168628 PMCID: PMC7948949 DOI: 10.1074/jbc.ra120.014889] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 10/22/2020] [Accepted: 11/09/2020] [Indexed: 12/28/2022] Open
Abstract
Conventionally, most amino acid substitutions at “important” protein positions are expected to abolish function. However, in several soluble-globular proteins, we identified a class of nonconserved positions for which various substitutions produced progressive functional changes; we consider these evolutionary “rheostats”. Here, we report a strong rheostat position in the integral membrane protein, Na+/taurocholate (TCA) cotransporting polypeptide, at the site of a pharmacologically relevant polymorphism (S267F). Functional studies were performed for all 20 substitutions (S267X) with three substrates (TCA, estrone-3-sulfate, and rosuvastatin). The S267X set showed strong rheostatic effects on overall transport, and individual substitutions showed varied effects on transport kinetics (Km and Vmax) and substrate specificity. To assess protein stability, we measured surface expression and used the Rosetta software (https://www.rosettacommons.org) suite to model structure and stability changes of S267X. Although buried near the substrate-binding site, S267X substitutions were easily accommodated in the Na+/TCA cotransporting polypeptide structure model. Across the modest range of changes, calculated stabilities correlated with surface-expression differences, but neither parameter correlated with altered transport. Thus, substitutions at rheostat position 267 had wide-ranging effects on the phenotype of this integral membrane protein. We further propose that polymorphic positions in other proteins might be locations of rheostat positions.
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Affiliation(s)
- Melissa J Ruggiero
- Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Shipra Malhotra
- Program in Molecular Therapeutics, Fox Chase Cancer Center, Philadelphia, Pennsylvania, USA; Center for Computational Biology, University of Kansas, Lawrence, Kansas, USA
| | - Aron W Fenton
- Department of Biochemistry and Molecular Biology, The University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Liskin Swint-Kruse
- Department of Biochemistry and Molecular Biology, The University of Kansas Medical Center, Kansas City, Kansas, USA
| | - John Karanicolas
- Program in Molecular Therapeutics, Fox Chase Cancer Center, Philadelphia, Pennsylvania, USA
| | - Bruno Hagenbuch
- Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City, Kansas, USA.
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17
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Appelman MD, Robin MJ, Vogels EW, Wolzak C, Vos WG, Vos HR, Van Es RM, Burgering BM, Van de Graaf SF. The Lipid Raft Component Stomatin Interacts with the Na + Taurocholate Cotransporting Polypeptide (NTCP) and Modulates Bile Salt Uptake. Cells 2020; 9:cells9040986. [PMID: 32316189 PMCID: PMC7226988 DOI: 10.3390/cells9040986] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 04/13/2020] [Accepted: 04/14/2020] [Indexed: 12/15/2022] Open
Abstract
The sodium taurocholate cotransporting polypeptide (NTCP) is expressed at the basolateral membrane of hepatocytes, where it mediates the uptake of conjugated bile acids and forms the hepatocyte entry receptor for the hepatitis B and D virus. Here, we aimed to identify novel protein–protein interactions that could play a role in the regulation of NTCP. To this end, NTCP was precipitated from HA-tagged hNTCP-expressing HepG2 cells, and chloride channel CLIC-like 1 (CLCC1) and stomatin were identified as interacting proteins by mass spectrometry. Interaction was confirmed by co-immunoprecipitation. NTCP, CLCC1 and stomatin were found at the plasma membrane in lipid rafts, as demonstrated by a combination of immunofluorescence, cell surface biotinylation and isolation of detergent-resistant membranes. Neither CLCC1 overexpression nor its knockdown had an effect on NTCP function. However, both stomatin overexpression and knockdown increased NTCP-mediated taurocholate uptake while NTCP abundance at the plasma membrane was only increased in stomatin depleted cells. These findings identify stomatin as an interactor of NTCP and show that the interaction modulates bile salt transport.
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Affiliation(s)
- Monique D. Appelman
- Amsterdam UMC, University of Amsterdam, Tytgat Institute for Liver and Intestinal Research, Amsterdam Gastroenterology, Endocrinology and Metabolism, 1105 BK Amsterdam, The Netherlands
| | - Marion J.D. Robin
- Amsterdam UMC, University of Amsterdam, Tytgat Institute for Liver and Intestinal Research, Amsterdam Gastroenterology, Endocrinology and Metabolism, 1105 BK Amsterdam, The Netherlands
| | - Esther W.M. Vogels
- Amsterdam UMC, University of Amsterdam, Tytgat Institute for Liver and Intestinal Research, Amsterdam Gastroenterology, Endocrinology and Metabolism, 1105 BK Amsterdam, The Netherlands
| | - Christie Wolzak
- Amsterdam UMC, University of Amsterdam, Tytgat Institute for Liver and Intestinal Research, Amsterdam Gastroenterology, Endocrinology and Metabolism, 1105 BK Amsterdam, The Netherlands
| | - Winnie G. Vos
- Amsterdam UMC, University of Amsterdam, Tytgat Institute for Liver and Intestinal Research, Amsterdam Gastroenterology, Endocrinology and Metabolism, 1105 BK Amsterdam, The Netherlands
| | - Harmjan R. Vos
- Center for Molecular Medicine, Molecular Cancer Research Section, University Medical Center, 3584 CX Utrecht, The Netherlands
| | - Robert M. Van Es
- Center for Molecular Medicine, Molecular Cancer Research Section, University Medical Center, 3584 CX Utrecht, The Netherlands
| | - Boudewijn M.T. Burgering
- Center for Molecular Medicine, Molecular Cancer Research Section, University Medical Center, 3584 CX Utrecht, The Netherlands
| | - Stan F.J. Van de Graaf
- Amsterdam UMC, University of Amsterdam, Tytgat Institute for Liver and Intestinal Research, Amsterdam Gastroenterology, Endocrinology and Metabolism, 1105 BK Amsterdam, The Netherlands
- Amsterdam UMC, Department of Gastroenterology and Hepatology, University of Amsterdam, Amsterdam Gastroenterology, Endocrinology and Metabolism, Amsterdam 1105 AZ, The Netherlands
- Correspondence:
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18
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Wang T, Nakagawa S, Miyake T, Setsu G, Kunisue S, Goto K, Hirasawa A, Okamura H, Yamaguchi Y, Doi M. Identification and functional characterisation of N-linked glycosylation of the orphan G protein-coupled receptor Gpr176. Sci Rep 2020; 10:4429. [PMID: 32157140 PMCID: PMC7064540 DOI: 10.1038/s41598-020-61370-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Accepted: 02/26/2020] [Indexed: 12/13/2022] Open
Abstract
G-protein-coupled receptors (GPCRs) are important drug targets with diverse therapeutic applications. However, there are still more than a hundred orphan GPCRs, whose protein functions and biochemical features remain unidentified. Gpr176 encodes a class-A orphan GPCR that has a role in circadian clock regulation in mouse hypothalamus and is also implicated in human breast cancer transcriptional response. Here we show that Gpr176 is N-glycosylated. Peptide-N-glycosidase treatment of mouse hypothalamus extracts revealed that endogenous Gpr176 undergoes N-glycosylation. Using a heterologous expression system, we show that N-glycosylation occurs at four conserved asparagine residues in the N-terminal region of Gpr176. Deficient N-glycosylation due to mutation of these residues reduced the protein expression of Gpr176. At the molecular function level, Gpr176 has constitutive, agonist-independent activity that leads to reduced cAMP synthesis. Although deficient N-glycosylation did not compromise this intrinsic activity, the resultant reduction in protein expression was accompanied by attenuation of cAMP-repressive activity in the cells. We also demonstrate that human GPR176 is N-glycosylated. Importantly, missense variations in the conserved N-glycosylation sites of human GPR176 (rs1473415441; rs761894953) affected N-glycosylation and thereby attenuated protein expression and cAMP-repressive activity in the cells. We show that N-glycosylation is a prerequisite for the efficient protein expression of functional Gpr176/GPR176.
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Affiliation(s)
- Tianyu Wang
- Department of Systems Biology, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyō-ku, Kyoto, 606-8501, Japan
| | - Shumpei Nakagawa
- Department of Systems Biology, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyō-ku, Kyoto, 606-8501, Japan
| | - Takahito Miyake
- Department of Systems Biology, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyō-ku, Kyoto, 606-8501, Japan
| | - Genzui Setsu
- Department of Systems Biology, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyō-ku, Kyoto, 606-8501, Japan
| | - Sumihiro Kunisue
- Department of Systems Biology, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyō-ku, Kyoto, 606-8501, Japan
| | - Kaoru Goto
- Department of Systems Biology, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyō-ku, Kyoto, 606-8501, Japan
| | - Akira Hirasawa
- Department of Genomic Drug Discovery Science, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyō-ku, Kyoto, 606-8501, Japan
| | - Hitoshi Okamura
- Department of Systems Biology, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyō-ku, Kyoto, 606-8501, Japan.,Laboratory of Molecular Brain Science, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyō-ku, Kyoto, 606-8501, Japan
| | - Yoshiaki Yamaguchi
- Department of Systems Biology, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyō-ku, Kyoto, 606-8501, Japan
| | - Masao Doi
- Department of Systems Biology, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyō-ku, Kyoto, 606-8501, Japan.
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19
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Hu Q, Zhang F, Duan L, Wang B, Ye Y, Li P, Li D, Yang S, Zhou L, Chen W. E-cadherin Plays a Role in Hepatitis B Virus Entry Through Affecting Glycosylated Sodium-Taurocholate Cotransporting Polypeptide Distribution. Front Cell Infect Microbiol 2020; 10:74. [PMID: 32175289 PMCID: PMC7056903 DOI: 10.3389/fcimb.2020.00074] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 02/13/2020] [Indexed: 12/12/2022] Open
Abstract
Hepatitis B virus (HBV) infection is a major cause of chronic liver disease and hepatocellular carcinoma. Current antiviral therapy does not effectively eradicate HBV and further investigations into the mechanisms of viral infection are needed to enable the development of new therapeutic agents. The sodium-taurocholate cotransporting polypeptide (NTCP) has been identified as a functional receptor for HBV entry in liver cells. However, the NTCP receptor is not sufficient for entry and other membrane proteins contribute to modulate HBV entry. This study seeks to understand how the NTCP functions in HBV entry. Herein we show that knockdown of the cell-cell adhesion molecule, E-cadherin significantly reduced infection by HBV particles and entry by HBV pseudoparticles in infected liver cells and cell lines. The glycosylated NTCP localizes to the plasma membrane through interaction with E- cadherin, which increases interaction with the preS1 portion of the Large HBV surface antigen. Our study contributes novel insights that advance knowledge of HBV infection at the level of host cell binding and viral entry.
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Affiliation(s)
- Qin Hu
- Department of Laboratory Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
- Key Laboratory of Laboratory Medical Diagnostics of Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Feifei Zhang
- Department of Laboratory Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Liang Duan
- Department of Laboratory Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Bo Wang
- Department of Laboratory Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yuanyuan Ye
- Department of Laboratory Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Pu Li
- Department of Laboratory Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Dandan Li
- Department of Laboratory Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Shengjun Yang
- Department of Laboratory Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Lan Zhou
- Key Laboratory of Laboratory Medical Diagnostics of Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Weixian Chen
- Department of Laboratory Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
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20
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Russell LE, Zhou Y, Lauschke VM, Kim RB. In Vitro Functional Characterization and in Silico Prediction of Rare Genetic Variation in the Bile Acid and Drug Transporter, Na+-Taurocholate Cotransporting Polypeptide (NTCP, SLC10A1). Mol Pharm 2020; 17:1170-1181. [DOI: 10.1021/acs.molpharmaceut.9b01200] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Laura E. Russell
- Department of Physiology & Pharmacology, Western University, Medical Sciences Building, Rm 216, N6A 5C1 London, Ontario, Canada
| | - Yitian Zhou
- Department of Physiology and Pharmacology, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Volker M. Lauschke
- Department of Physiology and Pharmacology, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Richard B. Kim
- Department of Physiology & Pharmacology, Western University, Medical Sciences Building, Rm 216, N6A 5C1 London, Ontario, Canada
- Division of Clinical Pharmacology, Department of Medicine, Western University, 339 Windermere Rd, N6A 5A5 London, Ontario, Canada
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21
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Yan Y, Allweiss L, Yang D, Kang J, Wang J, Qian X, Zhang T, Liu H, Wang L, Liu S, Sui J, Chen X, Dandri M, Zhao J, Lu F. Down-regulation of cell membrane localized NTCP expression in proliferating hepatocytes prevents hepatitis B virus infection. Emerg Microbes Infect 2019; 8:879-894. [PMID: 31179847 PMCID: PMC6567113 DOI: 10.1080/22221751.2019.1625728] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Hepatocyte proliferation could result in the loss of covalently closed circular DNA (cccDNA) and the emergence of cccDNA-cleared nascent hepatocytes, which appear refractory to hepatitis B virus (HBV) reinfection with unknown mechanism(s). Sodium taurocholate cotransporting polypeptide (NTCP) is the functional receptor for HBV entry. In this study, down-regulation of cell membrane localized NTCP expression in proliferating hepatocytes was found to prevent HBV infection in HepG2-NTCP-tet cells and in liver-humanized mice. In patients, lower NTCP protein expression was correlated well with higher levels of hepatocyte proliferation and less HBsAg expression in HBV-related focal nodular hyperplasia (FNH) tissues. Clinically, significantly lower NTCP protein expression was correlated with more active hepatocyte proliferation in CHB patients with severe active necroinflammation and better antiviral treatment outcome. Mechanistically, the activation of cell cycle regulatory genes p53, S-phase kinase-associated protein 2 (SKP2) and cyclin D1 during cell proliferation, as well as proliferative and inflammatory cytokine Interleukin-6 (IL-6) could transcriptionally down-regulate NTCP expression. From these aspects, we conclude that within the milieu of hepatocyte proliferation, down-regulation of cell membrane localized NTCP expression level renders nascent hepatocytes resistant to HBV reinfection. This may accelerate virus clearance during immune-mediated cell death and compensatory proliferation of survival hepatocytes.
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Affiliation(s)
- Ying Yan
- a State Key Laboratory of Natural and Biomimetic Drugs, Department of Microbiology and Infectious Disease Center, School of Basic Medical Sciences , Peking University Health Science Center , Beijing , People's Republic of China
| | - Lena Allweiss
- b Department of Medicine, Center for Internal Medicine , University Medical Center Hamburg-Eppendorf , Hamburg , Germany
| | - Danli Yang
- a State Key Laboratory of Natural and Biomimetic Drugs, Department of Microbiology and Infectious Disease Center, School of Basic Medical Sciences , Peking University Health Science Center , Beijing , People's Republic of China
| | - Jingting Kang
- c Institute of Basic Medical Sciences Chinese Academy of Medical Sciences , School of Basic Medicine Peking Union Medical College , Beijing , People's Republic of China
| | - Jianwen Wang
- a State Key Laboratory of Natural and Biomimetic Drugs, Department of Microbiology and Infectious Disease Center, School of Basic Medical Sciences , Peking University Health Science Center , Beijing , People's Republic of China
| | - Xiangjun Qian
- a State Key Laboratory of Natural and Biomimetic Drugs, Department of Microbiology and Infectious Disease Center, School of Basic Medical Sciences , Peking University Health Science Center , Beijing , People's Republic of China
| | - Ting Zhang
- a State Key Laboratory of Natural and Biomimetic Drugs, Department of Microbiology and Infectious Disease Center, School of Basic Medical Sciences , Peking University Health Science Center , Beijing , People's Republic of China
| | - Hui Liu
- a State Key Laboratory of Natural and Biomimetic Drugs, Department of Microbiology and Infectious Disease Center, School of Basic Medical Sciences , Peking University Health Science Center , Beijing , People's Republic of China
| | - Lu Wang
- a State Key Laboratory of Natural and Biomimetic Drugs, Department of Microbiology and Infectious Disease Center, School of Basic Medical Sciences , Peking University Health Science Center , Beijing , People's Republic of China
| | - Shuhong Liu
- d Department of Pathology and Hepatology , The 5th Medical Centre, Chinese PLA General Hospital , Beijing , People's Republic of China
| | - Jianhua Sui
- e Biologics Research Center , National Institute of Biological Sciences , Beijing , People's Republic of China
| | - Xiangmei Chen
- a State Key Laboratory of Natural and Biomimetic Drugs, Department of Microbiology and Infectious Disease Center, School of Basic Medical Sciences , Peking University Health Science Center , Beijing , People's Republic of China
| | - Maura Dandri
- b Department of Medicine, Center for Internal Medicine , University Medical Center Hamburg-Eppendorf , Hamburg , Germany.,f German Center for Infection Research (DZIF) , Hamburg-Lübeck-Borstel-Riems Partner Site , Hamburg , Germany
| | - Jingmin Zhao
- d Department of Pathology and Hepatology , The 5th Medical Centre, Chinese PLA General Hospital , Beijing , People's Republic of China
| | - Fengmin Lu
- a State Key Laboratory of Natural and Biomimetic Drugs, Department of Microbiology and Infectious Disease Center, School of Basic Medical Sciences , Peking University Health Science Center , Beijing , People's Republic of China
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Donkers JM, Appelman MD, van de Graaf SFJ. Mechanistic insights into the inhibition of NTCP by myrcludex B. JHEP Rep 2019; 1:278-285. [PMID: 32039379 PMCID: PMC7001544 DOI: 10.1016/j.jhepr.2019.07.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 07/18/2019] [Accepted: 07/19/2019] [Indexed: 02/06/2023] Open
Abstract
Background & aims The sodium taurocholate co-transporting polypeptide (NTCP) is the entry receptor for the hepatitis B and delta virus (HBV/HDV) and the main hepatic uptake transporter of conjugated bile acids. Myrcludex B, a synthetic peptide mimicking the NTCP-binding domain of HBV, blocks HBV/HDV infection and inhibits NTCP-mediated bile acid uptake. In humans this increases systemic bile acid levels, which remain elevated for hours even after Myrcludex B is cleared from the circulation. Here, we investigated the dynamics of Myrcludex B-induced NTCP-mediated bile acid transport inhibition in mice and if/how the duration of this effect relates to NTCP protein turnover. Methods Plasma bile acids were determined in Myrcludex B-treated OATP1a/1b-deficient mice. In vitro, plasma membrane-resident NTCP was labeled with biotin or fluorescein isothiocyanate (FITC)-labeled Myrcludex B and traced in time using hNTCP-overexpressing U2OS cells. Förster resonance energy transfer by fluorescent lifetime imaging microscopy was used to investigate whether Myrcludex B can transfer to newly synthesized NTCP. Results Conjugated bile salt levels in plasma peaked 4 h after subcutaneous Myrcludex B administration. After 24 h, plasma bile salt levels were completely normalized, in line with restored NTCP-mediated bile acid transport in vitro. Biotin-labeled NTCP disappeared faster than Myrcludex B-FITC, with almost 40% of FITC signal remaining after 24 h. FITC fluorescence lifetime was strongly decreased upon expression of DY547-labeled acyl carrier protein-tagged NTCP, demonstrating transfer of pre-bound Myrcludex B-FITC to newly formed NTCP. Conclusions The dynamics of NTCP protein turnover and Myrcludex B-induced plasma bile salt elevations are similar, suggesting that the Myrcludex B:NTCP interaction is very long-lived. Nevertheless, Myrcludex B is not completely degraded together with NTCP and can transfer to newly synthesized NTCP. Lay summary The experimental drug Myrcludex B binds the sodium taurocholate co-transporting polypeptide (NTCP), the viral entry receptor for the hepatitis B and D virus (HBV/HDV), and thereby prevents infection, but also inhibits hepatic bile salt uptake leading to transiently elevated bile salt levels. This study describes that while the normalization of plasma bile salt levels likely depends on the protein turnover rate of NTCP, Myrcludex B partly escapes co-degradation with NTCP by transferring from one NTCP molecule to another. This is of importance to the HBV/HDV research field as it provides a potential explanation for the distinct kinetics and dose-dependence of Myrcludex B’s effects on viral infection versus bile salt transport. Myrcludex B-induced plasma bile salt elevations coincide with NTCP protein turnover. NTCP-bound Myrcludex B can transfer from one NTCP molecule to another. Transfer to newly synthesized NTCP might extend the inhibitory potential of Myrcludex B. 50% occupation of NTCP by Myrcludex B is not enough to block bile acid transport.
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Affiliation(s)
- Joanne M Donkers
- Amsterdam UMC, University of Amsterdam, Tytgat Institute for Liver and Intestinal Research, Amsterdam Gastroenterology and Metabolism, Amsterdam, the Netherlands
| | - Monique D Appelman
- Amsterdam UMC, University of Amsterdam, Tytgat Institute for Liver and Intestinal Research, Amsterdam Gastroenterology and Metabolism, Amsterdam, the Netherlands
| | - Stan F J van de Graaf
- Amsterdam UMC, University of Amsterdam, Tytgat Institute for Liver and Intestinal Research, Amsterdam Gastroenterology and Metabolism, Amsterdam, the Netherlands.,Amsterdam UMC, University of Amsterdam, Department of Gastroenterology and Hepatology, Amsterdam Gastroenterology and Metabolism, Amsterdam, the Netherlands
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23
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Ueda Y, Gu W, Dansako H, Nishitsuji H, Satoh S, Shimotohno K, Kato N. A new hepatoma cell line exhibiting high susceptibility to hepatitis B virus infection. Biochem Biophys Res Commun 2019; 515:156-162. [PMID: 31133379 DOI: 10.1016/j.bbrc.2019.05.126] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 05/19/2019] [Indexed: 12/14/2022]
Abstract
Hepatitis B virus (HBV) infection, which increases the risk of cirrhosis and hepatocellular carcinoma and requires lifelong treatment, has become a major global health problem. However, host factors essential to the HBV life cycle are still unclear, and the development of new drugs is needed. Cells derived from the human hepatoma cell line HepG2 and engineered to overexpress sodium taurocholate cotransporting polypeptide (NTCP: a receptor for HBV), termed HepG2/NTCP cells, are widely used as the cell-based HBV infection and replication systems for HBV research. We recently found that human hepatoma cell line Li23-derived cells overexpressing NTCP (A8 cells subcloned from Li23 cells), whose gene expression profile was distinct from that of HepG2/NTCP cells, were also sensitive to HBV infection. However, the HBV susceptibility of A8 cells was around 1/100 that of HepG2/NTCP cells. Since we considered that plural cell assay systems will be needed for the objective evaluation of anti-HBV reagents, as we previously demonstrated in hepatitis C virus research, we here attempted to develop a new Li23 cell-derived assay system equivalent to that using HepG2/NTCP cells. By repeated subcloning of A8 cells, we successfully established a new cell line (A8.15.78.10) exhibiting high HBV susceptibility equal to that of HepG2/NTCP cells. Characterization of A8.15.78.10 cells revealed that the increase of HBV susceptibility was correlated with increases in the protein and glycosylation levels of NTCP, and with decreased expression of STING, a factor contributing to innate immunity. Finally, we performed a comparative evaluation of HBV entry inhibitors (cyclosporin A and rosiglitazone) by an HBV/secNL reporter assay using A8.15.78.10 cells or HepG2/NTCP cells. The results confirmed that cyclosporin A exhibited anti-HBV activity in both cell lines, as previously reported. However, we found that rosiglitazone did not show the anti-HBV activity in A8.15.78.10 cells, although it worked in HepG2/NTCP cells as previously reported. This suggested that the difference in anti-HBV activity between cyclosporin A and rosiglitazone was due to the different types of cells used for the assay. In conclusion, plural assay systems using different types of cells are required for the objective and impartial evaluation of anti-HBV reagents.
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Affiliation(s)
- Youki Ueda
- Department of Tumor Virology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan
| | - Weilin Gu
- Department of Tumor Virology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan
| | - Hiromichi Dansako
- Department of Tumor Virology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan
| | - Hironori Nishitsuji
- Research Center for Hepatitis and Immunology, National Center for Global Health and Medicine, 1-7-1 Kohnodai, Ichikawa, Chiba, 272-8575, Japan
| | - Shinya Satoh
- Department of Tumor Virology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan
| | - Kunitada Shimotohno
- Research Center for Hepatitis and Immunology, National Center for Global Health and Medicine, 1-7-1 Kohnodai, Ichikawa, Chiba, 272-8575, Japan
| | - Nobuyuki Kato
- Department of Tumor Virology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan.
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24
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Roma MG, Barosso IR, Miszczuk GS, Crocenzi FA, Pozzi EJS. Dynamic Localization of Hepatocellular Transporters: Role in Biliary Excretion and Impairment in Cholestasis. Curr Med Chem 2019; 26:1113-1154. [DOI: 10.2174/0929867325666171205153204] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 09/06/2017] [Accepted: 09/07/2017] [Indexed: 12/25/2022]
Abstract
Bile flow generation is driven by the vectorial transfer of osmotically active compounds from sinusoidal blood into a confined space, the bile canaliculus. Hence, localization of hepatocellular transporters relevant to bile formation is crucial for bile secretion. Hepatocellular transporters are localized either in the plasma membrane or in recycling endosomes, from where they can be relocated to the plasma membrane on demand, or endocytosed when the demand decreases. The balance between endocytic internalization/ exocytic targeting to/from this recycling compartment is therefore the main determinant of the hepatic capability to generate bile, and to dispose endo- and xenobiotics. Furthermore, the exacerbated endocytic internalization is a common pathomechanisms in both experimental and human cholestasis; this results in bile secretory failure and, eventually, posttranslational transporter downregulation by increased degradation. This review summarizes the proposed structural mechanisms accounting for this pathological condition (e.g., alteration of function, localization or expression of F-actin or F-actin/transporter cross-linking proteins, and switch to membrane microdomains where they can be readily endocytosed), and the mediators implicated (e.g., triggering of “cholestatic” signaling transduction pathways). Lastly, we discussed the efficacy to counteract the cholestatic failure induced by transporter internalization of a number of therapeutic experimental approaches based upon the use of compounds that trigger exocytic targetting of canalicular transporters (e.g., cAMP, tauroursodeoxycholate). This therapeutics may complement treatments aimed to transcriptionally improve transporter expression, by affording proper localization and membrane stability to the de novo synthesized transporters.
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Affiliation(s)
- Marcelo G. Roma
- Instituto de Fisiologia Experimental (IFISE) - Facultad de Ciencias Bioquimicas y Farmaceuticas (CONICET - U.N.R.), S2002LRL, Rosario, Argentina
| | - Ismael R. Barosso
- Instituto de Fisiologia Experimental (IFISE) - Facultad de Ciencias Bioquimicas y Farmaceuticas (CONICET - U.N.R.), S2002LRL, Rosario, Argentina
| | - Gisel S. Miszczuk
- Instituto de Fisiologia Experimental (IFISE) - Facultad de Ciencias Bioquimicas y Farmaceuticas (CONICET - U.N.R.), S2002LRL, Rosario, Argentina
| | - Fernando A. Crocenzi
- Instituto de Fisiologia Experimental (IFISE) - Facultad de Ciencias Bioquimicas y Farmaceuticas (CONICET - U.N.R.), S2002LRL, Rosario, Argentina
| | - Enrique J. Sánchez Pozzi
- Instituto de Fisiologia Experimental (IFISE) - Facultad de Ciencias Bioquimicas y Farmaceuticas (CONICET - U.N.R.), S2002LRL, Rosario, Argentina
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25
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Hepatitis B virus genome recycling and de novo secondary infection events maintain stable cccDNA levels. J Hepatol 2018; 69:1231-1241. [PMID: 30142426 PMCID: PMC7611400 DOI: 10.1016/j.jhep.2018.08.012] [Citation(s) in RCA: 134] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 08/05/2018] [Accepted: 08/08/2018] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS Several steps in the HBV life cycle remain obscure because of a lack of robust in vitro infection models. These steps include particle entry, formation and maintenance of covalently closed circular (ccc) DNA, kinetics of gene expression and viral transmission routes. This study aimed to investigate infection kinetics and cccDNA dynamics during long-term culture. METHODS We selected a highly permissive HepG2-NTCP-K7 cell clone engineered to express sodium taurocholate co-transporting polypeptide (NTCP) that supports the full HBV life cycle. We characterized the replication kinetics and dynamics of HBV over six weeks of infection. RESULTS HBV infection kinetics showed a slow infection process. Nuclear cccDNA was only detected 24 h post-infection and increased until 3 days post-infection (dpi). Viral RNAs increased from 3 dpi reaching a plateau at 6 dpi. HBV protein levels followed similar kinetics with HBx levels reaching a plateau first. cccDNA levels modestly increased throughout the 45-day study period with 5-12 copies per infected cell. Newly produced relaxed circular DNA within capsids was reimported into the nucleus and replenished the cccDNA pool. In addition to intracellular recycling of HBV genomes, secondary de novo infection events resulted in cccDNA formation. Inhibition of relaxed circular DNA formation by nucleoside analogue treatment of infected cells enabled us to measure cccDNA dynamics. HBV cccDNA decayed slowly with a half-life of about 40 days. CONCLUSIONS After a slow infection process, HBV maintains a stable cccDNA pool by intracellular recycling of HBV genomes and via secondary infection. Our results provide important insights into the dynamics of HBV infection and support the future design and evaluation of new antiviral agents. LAY SUMMARY Using a unique hepatocellular model system designed to support viral growth, we demonstrate that hepatitis B virus (HBV) has remarkably slow infection kinetics. Establishment of the episomal transcription template and the persistent form of the virus, so called covalently closed circular DNA, as well as viral transcription and protein expression all take a long time. Once established, HBV maintains a stable pool of covalently closed circular DNA via intracellular recycling of HBV genomes and through infection of naïve cells by newly formed virions.
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26
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Robin MJD, Appelman MD, Vos HR, van Es RM, Paton JC, Paton AW, Burgering B, Fickert P, Heijmans J, van de Graaf SFJ. Calnexin Depletion by Endoplasmic Reticulum Stress During Cholestasis Inhibits the Na +-Taurocholate Cotransporting Polypeptide. Hepatol Commun 2018; 2:1550-1566. [PMID: 30556041 PMCID: PMC6287483 DOI: 10.1002/hep4.1262] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 09/03/2018] [Indexed: 12/18/2022] Open
Abstract
Cholestasis‐induced accumulation of bile acids in the liver leads to farnesoid X receptor (FXR)‐mediated transcriptional down‐regulation of the bile acid importer Na+‐taurocholate cotransporting protein (NTCP) and to induction of endoplasmic reticulum (ER) stress. However, whether ER stress affects bile acid uptake is largely unknown. Here, we investigated the role of ER stress on the regulation and function of the bile acid transporter NTCP. ER stress was induced using thapsigargin or subtilase cytotoxin in human osteosarcoma (U2OS) and human hepatocellular carcinoma (HepG2) cells stably expressing NTCP. Cellular bile acid uptake was determined using radiolabeled taurocholate (TCA). NTCP plasma membrane expression was determined by cell surface biotinylation. Mice received a single injection of thapsigargin, and effects of ER stress on NTCP messenger RNA (mRNA) and protein were measured by reverse‐transcription polymerase chain reaction (RT‐PCR) and western blot analysis. Effects of cholestasis on NTCP and ER stress were assessed in response to 3, 5‐diethoxycarbonyl‐1, 4‐dihydrocollidine (DDC) feeding or bile duct ligation in FXR–/– mice after 7 or 3 days, respectively. Novel NTCP‐interacting proteins were identified by mass spectrometry (MS), interaction verified, and assessed by co‐immunoprecipitation and TCA uptake for functional relevance in relation to ER stress. ER stress induction strongly reduced NTCP protein expression, plasma membrane abundance, and NTCP‐mediated bile acid uptake. This was not controlled by FXR or through a single unfolded protein response (UPR) pathway but mainly depended on the interaction of NTCP with calnexin, an ER chaperone. In mice, expression of both NTCP and calnexin was reduced by thapsigargin or cholestasis‐induced ER stress. Calnexin down‐regulation in vitro recapitulated the effect of ER stress on NTCP. Conclusion: ER stress‐induced down‐regulation of calnexin provides an additional mechanism to dampen NTCP‐mediated bile acid uptake and protect hepatocytes against bile acid overload during cholestasis.
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Affiliation(s)
- Marion J D Robin
- Amsterdam UMC University of Amsterdam, Tytgat Institute for Liver and Intestinal Research, Amsterdam Gastroenterology and Metabolism Amsterdam the Netherlands
| | - Monique D Appelman
- Amsterdam UMC University of Amsterdam, Tytgat Institute for Liver and Intestinal Research, Amsterdam Gastroenterology and Metabolism Amsterdam the Netherlands
| | - Harmjan R Vos
- Center for Molecular Medicine, Molecular Cancer Research Section University Medical Center Utrecht the Netherlands
| | - Robert M van Es
- Center for Molecular Medicine, Molecular Cancer Research Section University Medical Center Utrecht the Netherlands
| | - James C Paton
- Research Centre for Infectious Diseases, Department of Molecular and Cellular Biology University of Adelaide Adelaide Australia
| | - Adrienne W Paton
- Research Centre for Infectious Diseases, Department of Molecular and Cellular Biology University of Adelaide Adelaide Australia
| | - Boudewijn Burgering
- Center for Molecular Medicine, Molecular Cancer Research Section University Medical Center Utrecht the Netherlands
| | - Peter Fickert
- Division of Gastroenterology and Hepatology, Department of Internal Medicine Medical University of Graz Graz Austria
| | - Jarom Heijmans
- Amsterdam UMC, University of Amsterdam Department of Gastroenterology and Hepatology, Amsterdam Gastroenterology and Metabolism Amsterdam the Netherlands
| | - Stan F J van de Graaf
- Amsterdam UMC University of Amsterdam, Tytgat Institute for Liver and Intestinal Research, Amsterdam Gastroenterology and Metabolism Amsterdam the Netherlands.,Amsterdam UMC, University of Amsterdam Department of Gastroenterology and Hepatology, Amsterdam Gastroenterology and Metabolism Amsterdam the Netherlands
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27
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Lee J, Zong L, Krotow A, Qin Y, Jia L, Zhang J, Tong S, Li J. N-Linked Glycosylation Is Not Essential for Sodium Taurocholate Cotransporting Polypeptide To Mediate Hepatitis B Virus Infection In Vitro. J Virol 2018; 92:e00732-18. [PMID: 29793953 PMCID: PMC6052319 DOI: 10.1128/jvi.00732-18] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 05/14/2018] [Indexed: 01/05/2023] Open
Abstract
Sodium taurocholate cotransporting polypeptide (NTCP) has been identified as a hepatitis B virus (HBV) receptor, and its overexpression in HepG2 cell lines leads to efficient secretion of hepatitis B e antigen (HBeAg) following challenge with a large dose of cell culture-derived HBV (cHBV) particles. However, NTCP-reconstituted HepG2 cells are inefficiently infected by patient serum-derived HBV (sHBV) and release very little hepatitis B surface antigen (HBsAg) following cHBV infection, unlike differentiated HepaRG cells, which are naturally susceptible to both cHBV and sHBV particles. Here, we investigated whether NTCP could explain the different behaviors of the two cell types. Endogenous NTCP protein from differentiated HepaRG cells was unglycosylated despite wild-type coding sequence. HepaRG cells stably transfected with an epitope-tagged NTCP expression construct displayed higher sHBV but not cHBV susceptibility than cells transfected with the null mutant. Tagged NTCP introduced to both HepG2 and HepaRG cells was glycosylated, with N5 and N11 being sites of N-linked glycosylation. Mutating N5, N11, or both did not alter cell surface availability of NTCP or its subcellular localization, with both the singly glycosylated and nonglycosylated forms still capable of mediating cHBV infection in HepG2 cells. In conclusion, nonglycosylated NTCP is expressed by differentiated HepaRG cells and capable of mediating cHBV infection in HepG2 cells, but it cannot explain differential susceptibility of HepaRG and HepG2/NTCP cells to cHBV versus sHBV infection and different HBsAg/HBeAg ratios following cHBV infection. The responsible host factor(s) remains to be identified.IMPORTANCE HBV can infect differentiated HepaRG cells and also HepG2 cells overexpressing NTCP, the currently accepted HBV receptor. However, HepG2/NTCP cells remain poorly susceptible to patient serum-derived HBV particles and release very little hepatitis B surface antigen following infection by cell culture-derived HBV. We found differentiated HepaRG cells expressed nonglycosylated NTCP despite a wild-type coding sequence. NTCP introduced to HepG2 cells was glycosylated at two N-linked glycosylation sites, but mutating either or both sites failed to prevent infection by cell culture-derived HBV or to confer susceptibility to serum-derived HBV. Overexpressing NTCP in HepRG cells did not increase infection by cell culture-derived HBV or distort the ratio between the two viral antigens. These findings suggest that host factors unique to HepaRG cells are required for efficient infection by serum-derived HBV, and factors other than NTCP contribute to balanced viral antigen production following infection by cell culture-derived HBV.
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Affiliation(s)
- Jiwon Lee
- Liver Research Center, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, Rhode Island, USA
| | - Li Zong
- Liver Research Center, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, Rhode Island, USA
- Molecular Virology Laboratory, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Alexander Krotow
- Liver Research Center, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, Rhode Island, USA
| | - Yanli Qin
- Department of Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, China
| | - Lucy Jia
- Liver Research Center, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, Rhode Island, USA
| | - Jiming Zhang
- Department of Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, China
| | - Shuping Tong
- Liver Research Center, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, Rhode Island, USA
- Molecular Virology Laboratory, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Jisu Li
- Liver Research Center, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, Rhode Island, USA
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28
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Abstract
Drug transporter proteins are critical to the distribution of a wide range of endogenous compounds and xenobiotics such as hormones, bile acids, peptides, lipids, sugars, and drugs. There are two classes of drug transporters- the solute carrier (SLC) transporters and ATP-binding cassette (ABC) transporters -which predominantly differ in the energy source utilized to transport substrates across a membrane barrier. Despite their hydrophobic nature and residence in the membrane bilayer, drug transporters have dynamic structures and adopt many conformations during the translocation process. Whereas there is significant literature evidence for the substrate specificity and structure-function relationship for clinically relevant drug transporters proteins, there is less of an understanding in the regulatory mechanisms that contribute to the functional expression of these proteins. Post-translational modifications have been shown to modulate drug transporter functional expression via a wide range of molecular mechanisms. These modifications commonly occur through the addition of a functional group (e.g. phosphorylation), a small protein (e.g. ubiquitination), sugar chains (e.g. glycosylation), or lipids (e.g. palmitoylation) on solvent accessible amino acid residues. These covalent additions often occur as a result of a signaling cascade and may be reversible depending on the type of modification and the intended fate of the signaling event. Here, we review the significant role in which post-translational modifications contribute to the dynamic regulation and functional consequences of SLC and ABC drug transporters and highlight recent progress in understanding their roles in transporter structure, function, and regulation.
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Affiliation(s)
- Lindsay C Czuba
- Department of Pharmaceutical Sciences, University of Maryland, 20 Penn Street, Baltimore, MD 21201, USA
| | | | - Peter W Swaan
- Department of Pharmaceutical Sciences, University of Maryland, 20 Penn Street, Baltimore, MD 21201, USA.
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29
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Adam AAA, van der Mark VA, Donkers JM, Wildenberg ME, Oude Elferink RPJ, Chamuleau RAFM, Hoekstra R. A practice-changing culture method relying on shaking substantially increases mitochondrial energy metabolism and functionality of human liver cell lines. PLoS One 2018; 13:e0193664. [PMID: 29672606 PMCID: PMC5908182 DOI: 10.1371/journal.pone.0193664] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 02/15/2018] [Indexed: 12/22/2022] Open
Abstract
Practice-changing culturing techniques of hepatocytes are highly required to increase their differentiation. Previously, we found that human liver cell lines HepaRG and C3A acquire higher functionality and increased mitochondrial biogenesis when cultured in the AMC-Bioartificial liver (BAL). Dynamic medium flow (DMF) is one of the major contributors to this stimulatory effect. Recently, we found that DMF-culturing by shaking of HepaRG monolayers resulted in higher mitochondrial biogenesis. Here we further investigated the effect of DMF-culturing on energy metabolism and hepatic functionality of HepaRG and C3A monolayers. HepaRG and C3A DMF-monolayers were incubated with orbital shaking at 60 rpm during the differentiation phase, while control monolayers were maintained statically. Subsequently, energy metabolism and hepatic functionality were compared between static and DMF-cultures. DMF-culturing of HepaRG cells substantially increased hepatic differentiation; transcript levels of hepatic structural genes and hepatic transcription regulators were increased up to 15-fold (Cytochrome P450 3A4) and nuclear translocation of hepatic transcription factor CEBPα was stimulated. Accordingly, hepatic functions were positively affected, including ammonia elimination, urea production, bile acid production, and CYP3A4 activity. DMF-culturing shifted energy metabolism from aerobic glycolysis towards oxidative phosphorylation, as indicated by a decline in lactate production and glucose consumption, and an increase in oxygen consumption. Similarly, DMF-culturing increased mitochondrial energy metabolism and hepatic functionality of C3A cells. In conclusion, simple shaking of monolayer cultures substantially improves mitochondrial energy metabolism and hepatic differentiation of human liver cell lines. This practice-changing culture method may prove to prolong the in-vitro maintenance of primary hepatocytes and increase hepatic differentiation of stem cells.
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Affiliation(s)
- Aziza A. A. Adam
- Tytgat Institute for Liver and Intestinal Research, Academic Medical Center (AMC), University of Amsterdam, Amsterdam, The Netherlands
| | - Vincent A. van der Mark
- Tytgat Institute for Liver and Intestinal Research, Academic Medical Center (AMC), University of Amsterdam, Amsterdam, The Netherlands
- Experimental Surgical Laboratory, Academic Medical Center (AMC), University of Amsterdam, Amsterdam, The Netherlands
| | - Joanne M. Donkers
- Tytgat Institute for Liver and Intestinal Research, Academic Medical Center (AMC), University of Amsterdam, Amsterdam, The Netherlands
| | - Manon E. Wildenberg
- Tytgat Institute for Liver and Intestinal Research, Academic Medical Center (AMC), University of Amsterdam, Amsterdam, The Netherlands
- Department Of Gastroenterology and Hepatology, Academic Medical Center (AMC), University of Amsterdam, Amsterdam, The Netherlands
| | - Ronald P. J. Oude Elferink
- Tytgat Institute for Liver and Intestinal Research, Academic Medical Center (AMC), University of Amsterdam, Amsterdam, The Netherlands
| | - Robert A. F. M. Chamuleau
- Tytgat Institute for Liver and Intestinal Research, Academic Medical Center (AMC), University of Amsterdam, Amsterdam, The Netherlands
| | - Ruurdtje Hoekstra
- Tytgat Institute for Liver and Intestinal Research, Academic Medical Center (AMC), University of Amsterdam, Amsterdam, The Netherlands
- Experimental Surgical Laboratory, Academic Medical Center (AMC), University of Amsterdam, Amsterdam, The Netherlands
- * E-mail:
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30
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Sargiacomo C, El-Kehdy H, Pourcher G, Stieger B, Najimi M, Sokal E. Age-dependent glycosylation of the sodium taurocholate cotransporter polypeptide: From fetal to adult human livers. Hepatol Commun 2018; 2:693-702. [PMID: 29881821 PMCID: PMC5983131 DOI: 10.1002/hep4.1174] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 02/25/2018] [Accepted: 02/26/2018] [Indexed: 12/25/2022] Open
Abstract
Sodium taurocholate cotransporter polypeptide (NTCP), mainly expressed on the sinusoidal membrane of hepatocytes, is one of the major transporters responsible for liver bile acid (BA) re-uptake. NTCP transports conjugated BA from the blood into hepatocytes and is crucial for correct enterohepatic circulation. Studies have shown that insufficient hepatic clearance of BA correlates with elevated serum BA in infants younger than 1 year of age. In the current study, we investigated human NTCP messenger RNA and protein expression by using reverse-transcription quantitative polymerase chain reaction and immunoblotting in isolated and cryopreserved human hepatocytes from two different age groups, below and above 1 year of age. Here, we show that NTCP messenger RNA expression is not modulated whereas NTCP protein posttranslational glycosylation is modulated in an age-dependent manner. These results were confirmed by quantification analysis of NTCP 55-kDa N-glycosylated bands, which showed significantly less total NTCP protein in donors below 1 year of age compared to donors older than 1 year. NTCP tissue localization was also analyzed by means of immunofluorescence. This revealed that NTCP cellular localization in fetal samples was mainly perinuclear, suggesting that NTCP is not glycosylated, while its postnatal localization on the plasma membrane is age dependent compared to multidrug resistant protein 2, which is apical starting in fetal life. Conclusion: After birth, the NTCP age-dependent maturation process requires approximately 1 year to complete NTCP glycosylation in human hepatocytes. Therefore, NTCP late posttranslational glycosylation appears to be important for correct NTCP membrane localization, which might explain physiologic cholestasis in neonatal life and might play a central role for HBV infection after birth. (Hepatology Communications 2018;2:693-702).
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Affiliation(s)
- Camillo Sargiacomo
- Institute of Experimental and Clinical Research, Laboratory of Pediatric Hepatology and Cell Therapy Université Catholique de Louvain Brussels Belgium
| | - Hoda El-Kehdy
- Institute of Experimental and Clinical Research, Laboratory of Pediatric Hepatology and Cell Therapy Université Catholique de Louvain Brussels Belgium
| | - Guillaume Pourcher
- Department of Digestive Diseases, Institut Mutualiste Montsouris Paris Descartes University Paris France
| | - Bruno Stieger
- Department of Clinical Pharmacology and Toxicology University Hospital Zurich Zurich Switzerland
| | - Mustapha Najimi
- Institute of Experimental and Clinical Research, Laboratory of Pediatric Hepatology and Cell Therapy Université Catholique de Louvain Brussels Belgium
| | - Etienne Sokal
- Institute of Experimental and Clinical Research, Laboratory of Pediatric Hepatology and Cell Therapy Université Catholique de Louvain Brussels Belgium
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31
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Role of glycosylation in nucleating protein folding and stability. Biochem J 2017; 474:2333-2347. [PMID: 28673927 DOI: 10.1042/bcj20170111] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 04/14/2017] [Accepted: 04/19/2017] [Indexed: 12/17/2022]
Abstract
Glycosylation constitutes one of the most common, ubiquitous and complex forms of post-translational modification. It commences with the synthesis of the protein and plays a significant role in deciding its folded state, oligomerization and thus its function. Recent studies have demonstrated that N-linked glycans help proteins to fold as the stability and folding kinetics are altered with the removal of the glycans from them. Several studies have shown that it alters not only the thermodynamic stability but also the structural features of the folded proteins modulating their interactions and functions. Their inhibition and perturbations have been implicated in diseases from diabetes to degenerative disorders. The intent of this review is to provide insight into the recent advancements in the general understanding on the aspect of glycosylation driven stability of proteins that is imperative to their function and finally their role in health and disease states.
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