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Liu Z, Bai T, Liu B, Yu L. MulStack: An ensemble learning prediction model of multilabel mRNA subcellular localization. Comput Biol Med 2024; 175:108289. [PMID: 38688123 DOI: 10.1016/j.compbiomed.2024.108289] [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: 01/28/2024] [Revised: 02/28/2024] [Accepted: 03/12/2024] [Indexed: 05/02/2024]
Abstract
Subcellular localization of mRNA is related to protein synthesis, cell polarity, cell movement and other biological regulation mechanisms. The distribution of mRNAs in subcellulars is similar to that of proteins, and most mRNAs are distributed in multiple subcellulars. Recently, some computational methods have been designed to predict the subcellular localization of mRNA. However, these methods only employed a sin-gle level of mRNA features and did not employ the position encoding of nucleotides in mRNA. In this paper, an ensemble learning prediction model is proposed, named MulStack, which is based on random forest and deep learning for multilabel mRNA subcellular localization. The proposed method employs two levels of mRNA features, including sequence-level and residue-level features, and position encoding is employed for the first time in the field of subcellular localization of mRNA. Random forest is employed to learn mRNA sequence-level feature, deep learning is employed to learn mRNA sequence-level feature and mRNA residue-level combined with position encoding. And the outputs of random forest and deep learning model will be weighted sum as the prediction probability. Compared with existing methods, the results show that MulStack is the best in the localization of the nucleus, cytosol and exosome. In addition, position weight matrices (PWMs) are extracted by convolutional neural networks (CNNs) that can be matched with known RNA binding protein motifs. Gene ontology (GO) enrichment analysis shows biological processes, molecular functions and cellular components of mRNA genes. The prediction web server of MulStack is freely accessible at http://bliulab.net/MulStack.
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Affiliation(s)
- Ziqi Liu
- School of Computer Science and Technology, Xidian University, Xian, 710075, China.
| | - Tao Bai
- School of Mathematics & Computer Science, Yan'an University, Shaanxi, 716000, China; School of Computer Science and Technology, Beijing Institute of Technology, Beijing, 100081, China; Advanced Research Institute of Multidisciplinary Science, Beijing Institute of Technology, Beijing, 100081, China.
| | - Bin Liu
- School of Computer Science and Technology, Beijing Institute of Technology, Beijing, 100081, China; Advanced Research Institute of Multidisciplinary Science, Beijing Institute of Technology, Beijing, 100081, China.
| | - Liang Yu
- School of Computer Science and Technology, Xidian University, Xian, 710075, China.
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2
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Lu ZN, He HW, Zhang N. Advances in understanding the regulatory mechanism of organic solute transporter α-β. Life Sci 2022; 310:121109. [DOI: 10.1016/j.lfs.2022.121109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 10/09/2022] [Accepted: 10/17/2022] [Indexed: 11/07/2022]
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3
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Saran C, Fu D, Ho H, Klein A, Fallon JK, Honkakoski P, Brouwer KLR. A novel differentiated HuH-7 cell model to examine bile acid metabolism, transport and cholestatic hepatotoxicity. Sci Rep 2022; 12:14333. [PMID: 35995956 PMCID: PMC9395349 DOI: 10.1038/s41598-022-18174-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Accepted: 08/05/2022] [Indexed: 11/09/2022] Open
Abstract
Hepatic cell lines serve as economical and reproducible alternatives for primary human hepatocytes. However, the utility of hepatic cell lines to examine bile acid homeostasis and cholestatic toxicity is limited due to abnormal expression and function of bile acid-metabolizing enzymes, transporters, and the absence of canalicular formation. We discovered that culturing HuH-7 human hepatoma cells with dexamethasone (DEX) and 0.5% dimethyl sulfoxide (DMSO) for two weeks, with Matrigel overlay after one week, resulted in a shorter and improved differentiation process. These culture conditions increased the expression and function of the major bile acid uptake and efflux transporters, sodium taurocholate co-transporting polypeptide (NTCP) and the bile salt export pump (BSEP), respectively, in two-week cultures of HuH-7 cells. This in vitro model was further characterized for expression and function of bile acid-metabolizing enzymes, transporters, and cellular bile acids. Differentiated HuH-7 cells displayed a marked shift in bile acid composition and induction of cytochrome P450 (CYP) 7A1, CYP8B1, CYP3A4, and bile acid-CoA: amino acid N-acyltransferase (BAAT) mRNAs compared to control. Inhibition of taurocholate uptake and excretion after a 24-h treatment with prototypical cholestatic drugs suggests that differentiated HuH-7 cells are a suitable model to examine cholestatic hepatotoxicity.
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Affiliation(s)
- Chitra Saran
- Department of Pharmacology, UNC School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA
| | - Dong Fu
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA
| | - Henry Ho
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA
| | - Abigail Klein
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA
| | - John K Fallon
- Division of Pharmacoengineering and Molecular Pharmaceutics, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA
| | - Paavo Honkakoski
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA.,School of Pharmacy, University of Eastern Finland, Kuopio, Finland
| | - Kim L R Brouwer
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA.
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4
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Wang HH, Portincasa P, Liu M, Wang DQH. Genetic Analysis of ABCB4 Mutations and Variants Related to the Pathogenesis and Pathophysiology of Low Phospholipid-Associated Cholelithiasis. Genes (Basel) 2022; 13:1047. [PMID: 35741809 PMCID: PMC9222727 DOI: 10.3390/genes13061047] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 06/08/2022] [Indexed: 12/28/2022] Open
Abstract
Clinical studies have revealed that the ABCB4 gene encodes the phospholipid transporter on the canalicular membrane of hepatocytes, and its mutations and variants are the genetic basis of low phospholipid-associated cholelithiasis (LPAC), a rare type of gallstone disease caused by a single-gene mutation or variation. The main features of LPAC include a reduction or deficiency of phospholipids in bile, symptomatic cholelithiasis at <40 years of age, intrahepatic sludge and microlithiasis, mild chronic cholestasis, a high cholesterol/phospholipid ratio in bile, and recurrence of biliary symptoms after cholecystectomy. Needle-like cholesterol crystals, putatively “anhydrous” cholesterol crystallization at low phospholipid concentrations in model and native bile, are characterized in ABCB4 knockout mice, a unique animal model for LPAC. Gallbladder bile with only trace amounts of phospholipids in these mice is supersaturated with cholesterol, with lipid composition plotting in the left two-phase zone of the ternary phase diagram, consistent with “anhydrous” cholesterol crystallization. In this review, we summarize the molecular biology and physiological functions of ABCB4 and comprehensively discuss the latest advances in the genetic analysis of ABCB4 mutations and variations and their roles in the pathogenesis and pathophysiology of LPAC in humans, based on the results from clinical studies and mouse experiments. To date, approximately 158 distinct LPAC-causing ABCB4 mutations and variants in humans have been reported in the literature, indicating that it is a monogenic risk factor for LPAC. The elucidation of the ABCB4 function in the liver, the identification of ABCB4 mutations and variants in LPAC patients, and the exploration of gene therapy for ABCB4 deficiency in animal models can help us to better understand the cellular, molecular, and genetic mechanisms underlying the onset of the disease, and will pave the way for early diagnosis and prevention of susceptible subjects and effective intervention for LPAC in patients.
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Affiliation(s)
- Helen H. Wang
- Department of Medicine and Genetics, Division of Gastroenterology and Liver Diseases, Marion Bessin Liver Research Center, Einstein-Mount Sinai Diabetes Research Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA;
| | - Piero Portincasa
- Department of Biomedical Sciences and Human Oncology, Clinica Medica “A. Murri”, University of Bari Medical School, 70124 Bari, Italy;
| | - Min Liu
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45237, USA;
| | - David Q.-H. Wang
- Department of Medicine and Genetics, Division of Gastroenterology and Liver Diseases, Marion Bessin Liver Research Center, Einstein-Mount Sinai Diabetes Research Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA;
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5
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Frias-Soler RC, Kelsey NA, Villarín Pildaín L, Wink M, Bairlein F. Transcriptome signature changes in the liver of a migratory passerine. Genomics 2022; 114:110283. [PMID: 35143886 DOI: 10.1016/j.ygeno.2022.110283] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 12/13/2021] [Accepted: 01/31/2022] [Indexed: 12/01/2022]
Abstract
The liver plays a principal role in avian migration. Here, we characterised the liver transcriptome of a long-distance migrant, the Northern Wheatear (Oenanthe oenanthe), sampled at different migratory stages, looking for molecular processes linked with adaptations to migration. The analysis of the differentially expressed genes suggested changes in the periods of the circadian rhythm, variation in the proportion of cells in G1/S cell-cycle stages and the putative polyploidization of this cell population. This may explain the dramatic increment in the liver's metabolic capacities towards migration. Additionally, genes involved in anti-oxidative stress, detoxification and innate immune responses, lipid metabolism, inflammation and angiogenesis were regulated. Lipophagy and lipid catabolism were active at all migratory stages and increased towards the fattening and fat periods, explaining the relevance of lipolysis in controlling steatosis and maintaining liver health. Our study clears the way for future functional studies regarding long-distance avian migration.
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Affiliation(s)
- Roberto Carlos Frias-Soler
- Institute of Avian Research, An der Vogelwarte 21, 26386 Wilhelmshaven, Germany; Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Im Neuenheimer Feld 364, 69120 Heidelberg, Germany.
| | - Natalie A Kelsey
- Institute of Avian Research, An der Vogelwarte 21, 26386 Wilhelmshaven, Germany.
| | - Lilian Villarín Pildaín
- Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Im Neuenheimer Feld 364, 69120 Heidelberg, Germany
| | - Michael Wink
- Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Im Neuenheimer Feld 364, 69120 Heidelberg, Germany.
| | - Franz Bairlein
- Institute of Avian Research, An der Vogelwarte 21, 26386 Wilhelmshaven, Germany; Max Planck Institute of Animal Behavior, Am Obstberg 1, 78315 Radolfzell, Germany.
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6
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Ruan H, Lu Q, Wu J, Qin J, Sui M, Sun X, Shi Y, Luo J, Yang M. Hepatotoxicity of food-borne mycotoxins: molecular mechanism, anti-hepatotoxic medicines and target prediction. Crit Rev Food Sci Nutr 2021; 62:2281-2308. [PMID: 34346825 DOI: 10.1080/10408398.2021.1960794] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mycotoxins are metabolites produced by fungi. The widespread contamination of food and feed by mycotoxins is a global food safety problem and a serious threat to people's health. Most food-borne mycotoxins have strong hepatotoxicity. However, no effective methods have been found to prevent or treat Mycotoxin- Induced Liver Injury (MILI) in clinical and animal husbandry. In this paper, the molecular mechanisms and potential anti-MILI medicines of six food-borne MILI are reviewed, and their targets are predicted by network toxicology, which provides a theoretical basis for further study of the toxicity mechanism of MILI and the development of effective strategies to manage MILI-related health problems in the future and accelerate the development of food safety.
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Affiliation(s)
- Haonan Ruan
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Qian Lu
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Jiashuo Wu
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Jiaan Qin
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Ming Sui
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Xinqi Sun
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Yue Shi
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Jiaoyang Luo
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Meihua Yang
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
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7
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Identification of Accessible Hepatic Gene Signatures for Interindividual Variations in Nutrigenomic Response to Dietary Supplementation of Omega-3 Fatty Acids. Cells 2021; 10:cells10020467. [PMID: 33671567 PMCID: PMC7926558 DOI: 10.3390/cells10020467] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/15/2021] [Accepted: 02/17/2021] [Indexed: 12/29/2022] Open
Abstract
Dietary supplementation is a widely adapted strategy to maintain nutritional balance for improving health and preventing chronic diseases. Conflicting results in studies of similar design, however, suggest that there is substantial heterogenicity in individuals’ responses to nutrients, and personalized nutrition is required to achieve the maximum benefit of dietary supplementation. In recent years, nutrigenomics studies have been increasingly utilized to characterize the detailed genomic response to a specific nutrient, but it remains a daunting task to define the signatures responsible for interindividual variations to dietary supplements for tissues with limited accessibility. In this work, we used the hepatic response to omega-3 fatty acids as an example to probe such signatures. Through comprehensive analysis of nutrigenomic response to eicosapentaneoid acid (EPA) and/or docosahexaenoic acid (DHA) including both protein coding and long noncoding RNA (lncRNA) genes in human hepatocytes, we defined the EPA- and/or DHA-specific signature genes in hepatocytes. By analyzing gene expression variations in livers of healthy and relevant disease populations, we identified a set of protein coding and lncRNA signature genes whose responses to omega-3 fatty acid exhibit very high interindividual variabilities. The large variabilities of individual responses to omega-3 fatty acids were further validated in human hepatocytes from ten different donors. Finally, we profiled RNAs in exosomes isolated from the circulation of a liver-specific humanized mouse model, in which the humanized liver is the sole source of human RNAs, and confirmed the in vivo detectability of some signature genes, supporting their potential as biomarkers for nutrient response. Taken together, we have developed an efficient and practical procedure to identify nutrient-responsive gene signatures as well as accessible biomarkers for interindividual variations.
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8
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Hammer H, Schmidt F, Marx-Stoelting P, Pötz O, Braeuning A. Cross-species analysis of hepatic cytochrome P450 and transport protein expression. Arch Toxicol 2021; 95:117-133. [PMID: 33150952 PMCID: PMC7811513 DOI: 10.1007/s00204-020-02939-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 10/20/2020] [Indexed: 12/19/2022]
Abstract
Most drugs and xenobiotics are metabolized in the liver. Amongst others, different cytochrome P450 (CYP) enzymes catalyze the metabolic conversion of foreign compounds, and various transport proteins are engaged in the excretion of metabolites from the hepatocytes. Inter-species and inter-individual differences in the hepatic levels and activities of drug-metabolizing enzymes and transporters result from genetic as well as from environmental factors, and play a decisive role in determining the pharmacokinetic properties of a compound in a given test system. To allow for a meaningful comparison of results from metabolism studies, it is, therefore, of utmost importance to know about the specific metabolic properties of the test systems, especially about the levels of metabolic enzymes such as the CYPs. Using a targeted proteomics approach, we, therefore, compared the hepatic levels of important CYP enzymes and transporters in different experimental systems in vivo and in vitro, namely Wistar rats, C57/Bl6 mice, mice humanized for the two xeno-sensing receptors PXR (pregnane-X-receptor) and CAR (constitutive androstane receptor), mice with human hepatocyte-repopulated livers, human HepaRG hepatocarcinoma cells, primary human hepatocytes, and human liver biopsies. In addition, the effects of xenobiotic inducers of drug metabolism on CYP enzymes and transporters were analyzed in selected systems. This study for the first time presents a comprehensive overview of similarities and differences in important drug metabolism-related proteins among the different experimental models.
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Affiliation(s)
- Helen Hammer
- Signatope, Markwiesenstraße 55, 72770, Reutlingen, Germany
| | - Felix Schmidt
- Signatope, Markwiesenstraße 55, 72770, Reutlingen, Germany
| | - Philip Marx-Stoelting
- Department of Pesticides Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, 10589, Berlin, Germany
| | - Oliver Pötz
- Signatope, Markwiesenstraße 55, 72770, Reutlingen, Germany
| | - Albert Braeuning
- Department of Food Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, 10589, Berlin, Germany.
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9
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Xiong Q, Wu Y, Yang M, Wu G, Wang Y, Wang H, Feng J, Song L, Tong B, He G, Xu Y. Nr2e1 ablation impairs liver glucolipid metabolism and induces inflammation, high-fat diets amplify the damage. Biomed Pharmacother 2019; 120:109503. [DOI: 10.1016/j.biopha.2019.109503] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 09/17/2019] [Accepted: 09/26/2019] [Indexed: 02/08/2023] Open
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10
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Kurzawski M, Szeląg-Pieniek S, Łapczuk-Romańska J, Wrzesiński M, Sieńko J, Oswald S, Droździk M. The reference liver - ABC and SLC drug transporters in healthy donor and metastatic livers. Pharmacol Rep 2019; 71:738-745. [PMID: 31207436 DOI: 10.1016/j.pharep.2019.04.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 03/29/2019] [Accepted: 04/08/2019] [Indexed: 12/11/2022]
Abstract
BACKGROUND Analysis of results and conclusions in studies dedicated to pathology of the liver are usually based on comparison of pathological liver specimens and control/reference (considered as healthy) tissues. There are two main sources of the control liver samples used as the reference livers, i.e. deceased organ donor livers and non-tumorous tissue from metastatic livers, which are also applied for drug transporter investigations. However, no information has yet been published on drug transporters in these two major types of reference livers. METHODS We explored ABC (P-gp, MRP1, MRP2, MRP3, MRP4, BCRP, BSEP) and SLC (NTCP, MCT1, OCT1, OCT3, OAT2, OATP1B1, OATP1B3, OATP2B1) family transporters expression (qPCR) and protein abundance (LC-MS/MS) in healthy donors (n = 9) and metastatic (n = 13) livers. RESULTS The analysis of mRNA content revealed significant differences in ABCB11, ABCC1, ABCG2, SLC10A1, SLC16A1, SLCO1B1 and SLCO2B1 gene expression between livers from organ donors and patients who underwent surgical resection of metastatic tumors. The protein abundance of NTCP was significantly higher, whereas of P-gp significantly lower in non-tumorous tissues from metastatic livers. Greater inter-individual variability in protein abundance of all studied transporters in subjects with metastatic colon cancer was also observed. CONCLUSIONS The results suggest that final conclusions in liver pathology studies may depend on the reference liver tissue used, especially in gene expression studies.
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Affiliation(s)
- Mateusz Kurzawski
- Department of Experimental and Clinical Pharmacology, Pomeranian Medical University, Szczecin, Poland.
| | - Sylwia Szeląg-Pieniek
- Department of Experimental and Clinical Pharmacology, Pomeranian Medical University, Szczecin, Poland
| | - Joanna Łapczuk-Romańska
- Department of Experimental and Clinical Pharmacology, Pomeranian Medical University, Szczecin, Poland
| | - Maciej Wrzesiński
- Department of General and Transplantation Surgery, Marie Curie Regional Hospital, Szczecin, Poland
| | - Jerzy Sieńko
- Department of General and Transplantation Surgery, Pomeranian Medical University, Szczecin, Poland
| | - Stefan Oswald
- Department of Clinical Pharmacology, University Medicine of Greifswald, Greifswald, Germany
| | - Marek Droździk
- Department of Experimental and Clinical Pharmacology, Pomeranian Medical University, Szczecin, Poland
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Atilano-Roque A, Roda G, Fogueri U, Kiser JJ, Joy MS. Effect of Disease Pathologies on Transporter Expression and Function. J Clin Pharmacol 2017; 56 Suppl 7:S205-21. [PMID: 27385176 DOI: 10.1002/jcph.768] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 05/08/2016] [Accepted: 05/10/2016] [Indexed: 12/12/2022]
Abstract
Transporters are important determinants of drug absorption, distribution, and excretion. The clinical relevance of drug transporters in drug disposition and toxicology depends on their localization in liver, kidney, and brain. There has been growing evidence regarding the importance of disease status on alterations in metabolizing enzymes and transporter proteins. This review focuses on uptake and efflux transporter proteins in liver, kidney, and brain and discusses mechanisms of altered transporter expression and function secondary to disease.
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Affiliation(s)
- Amandla Atilano-Roque
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Aurora, CO, USA
| | - Gavriel Roda
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Aurora, CO, USA
| | - Uma Fogueri
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Aurora, CO, USA
| | - Jennifer J Kiser
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Aurora, CO, USA
| | - Melanie S Joy
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Aurora, CO, USA.,Division of Renal Diseases and Hypertension, University of Colorado School of Medicine, Aurora, CO, USA
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12
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Saeed A, Hoekstra M, Hoeke MO, Heegsma J, Faber KN. The interrelationship between bile acid and vitamin A homeostasis. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1862:496-512. [PMID: 28111285 DOI: 10.1016/j.bbalip.2017.01.007] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 01/04/2017] [Accepted: 01/18/2017] [Indexed: 12/12/2022]
Abstract
Vitamin A is a fat-soluble vitamin important for vision, reproduction, embryonic development, cell differentiation, epithelial barrier function and adequate immune responses. Efficient absorption of dietary vitamin A depends on the fat-solubilizing properties of bile acids. Bile acids are synthesized in the liver and maintained in an enterohepatic circulation. The liver is also the main storage site for vitamin A in the mammalian body, where an intimate collaboration between hepatocytes and hepatic stellate cells leads to the accumulation of retinyl esters in large cytoplasmic lipid droplet hepatic stellate cells. Chronic liver diseases are often characterized by disturbed bile acid and vitamin A homeostasis, where bile production is impaired and hepatic stellate cells lose their vitamin A in a transdifferentiation process to myofibroblasts, cells that produce excessive extracellular matrix proteins leading to fibrosis. Chronic liver diseases thus may lead to vitamin A deficiency. Recent data reveal an intricate crosstalk between vitamin A metabolites and bile acids, in part via the Retinoic Acid Receptor (RAR), Retinoid X Receptor (RXR) and the Farnesoid X Receptor (FXR), in maintaining vitamin A and bile acid homeostasis. Here, we provide an overview of the various levels of "communication" between vitamin A metabolites and bile acids and its relevance for the treatment of chronic liver diseases.
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Affiliation(s)
- Ali Saeed
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands; Institute of Molecular biology & Bio-technology, Bahauddin Zakariya University, Multan, Pakistan.
| | - Mark Hoekstra
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
| | - Martijn Oscar Hoeke
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
| | - Janette Heegsma
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands; Laboratory Medicine, Center for Liver, Digestive, and Metabolic Diseases, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
| | - Klaas Nico Faber
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
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13
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König A, Glebe D. Live Cell Imaging Confocal Microscopy Analysis of HBV Myr-PreS1 Peptide Binding and Uptake in NTCP-GFP Expressing HepG2 Cells. Methods Mol Biol 2017; 1540:27-36. [PMID: 27975305 DOI: 10.1007/978-1-4939-6700-1_3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
To obtain basic knowledge about specific molecular mechanisms involved in the entry of pathogens into cells is the basis for establishing pharmacologic substances blocking initial viral binding, infection, and subsequent viral spread. Lack of information about key cellular factors involved in the initial steps of HBV infection has hampered the characterization of HBV binding and entry for decades. However, recently, the liver-specific sodium-dependent taurocholate cotransporting polypeptide (NTCP) has been discovered as a functional receptor for HBV and HDV, thus opening the field for new concepts of basic binding and entry of HBV and HDV. Here, we describe practical issues of a basic in vitro assay system to examine kinetics and mechanisms of receptor-dependent HBV binding, uptake, and intracellular trafficking by live-cell imaging confocal microscopy. The assay system is comprised of HepG2 cells expressing a NTCP-GFP fusion-protein and chemically synthesized, fluorophore-labeled part of HBV surface protein, spanning the first N-terminal 48 amino acids of preS1 of the large hepatitis B virus surface protein.
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Affiliation(s)
- Alexander König
- Institute of Medical Virology, Justus Liebig University Giessen, National Reference Center for Hepatitis B and D Viruses, Biomedical Research Center Seltersberg, Schubertstr. 81, 35392, Giessen, Germany.,German Center for Infection Research (DZIF), partner site Giessen, Germany
| | - Dieter Glebe
- Institute of Medical Virology, Justus Liebig University Giessen, National Reference Center for Hepatitis B and D Viruses, Biomedical Research Center Seltersberg, Schubertstr. 81, 35392, Giessen, Germany. .,German Center for Infection Research (DZIF), partner site Giessen, Germany.
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Kosters A, Abebe DF, Felix JC, Dawson PA, Karpen SJ. Inflammation-associated upregulation of the sulfated steroid transporter Slc10a6 in mouse liver and macrophage cell lines. Hepatol Res 2016; 46:794-803. [PMID: 26510996 PMCID: PMC4851596 DOI: 10.1111/hepr.12609] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 09/28/2015] [Accepted: 10/14/2015] [Indexed: 12/12/2022]
Abstract
AIM Slc10a6, an incompletely characterized member of the SLC10A bile acid transporter family, was one of the most highly induced RNA transcripts identified in a screen for inflammation-responsive genes in mouse liver. This study aimed to elucidate a role for Slc10a6 in hepatic inflammation. METHODS Mice were treated with lipopolysaccharide (LPS; 2 mg/kg) or interleukin (IL)-1β (5 mg/kg) for various time points. Cells were treated with LPS (1 μg/mL) at various time points, with cell signaling inhibitors, nuclear receptor ligands and Slc10a6 substrates. All mRNA levels were determined by quantitative polymerase chain reaction. RESULTS Slc10a6 mRNA levels were upregulated in mouse liver at 2 h (7-fold), 4 h (100-fold) and 16 h (50-fold) after LPS treatment, and 35-fold by the cytokine IL-1β (4 h). Both absence of the nuclear receptor Fxr and pretreating mice with the synthetic retinoid X receptor-α ligand LG268 attenuated the LPS upregulation of Slc10a6 mRNA by 60-75%. In vitro, Slc10a6 mRNA was induced 30-fold by LPS in mouse RAW264.7 macrophages in a time-dependent manner (maximum at 8 h). The Slc10a6 substrate dehydroepiandrosterone sulfate (DHEAS) enhanced LPS induction of CCL5 mRNA, a pro-inflammatory chemokine, by 50% in RAW264.7 cells. This effect was abrogated in the presence of anti-inflammatory nuclear receptor ligands 9-cis-retinoic acid and dexamethasone. CONCLUSION Dramatic upregulation of Slc10a6 mRNA by LPS combined with enhanced LPS stimulation of CCL5 expression by the Slc10a6 substrate DHEAS in macrophages suggests that Slc10a6 function contributes to the hepatic inflammatory response.
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Affiliation(s)
- Astrid Kosters
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Emory University School of Medicine, Atlanta GA, 30322
| | - Demesew F. Abebe
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Emory University School of Medicine, Atlanta GA, 30322
| | - Julio C. Felix
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030
| | - Paul A. Dawson
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Emory University School of Medicine, Atlanta GA, 30322
| | - Saul J. Karpen
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Emory University School of Medicine, Atlanta GA, 30322
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15
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Shores NJ, Mendes-Corrêa MC, Maida I, Turner J, High KP, Babudieri S, Núñez M. Hepatic peroxisome proliferator-activated receptor γ and α-mRNA expression in HCV-infected adults is decreased by HIV co-infection and is also affected by ethnicity. Clinics (Sao Paulo) 2015; 70:790-6. [PMID: 26735218 PMCID: PMC4676314 DOI: 10.6061/clinics/2015(12)05] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2015] [Accepted: 10/20/2015] [Indexed: 01/12/2023] Open
Abstract
OBJECTIVE To determine peroxisome proliferator activated receptor α and γ mRNA expression in liver tissue of hepatitis C virus-infected patients with and without human immunodeficiency virus and its possible contribution to an acceleration of liver disease progression. METHODS We measured peroxisome proliferator-activated receptor α and γ mRNA expression by real-time polymerase chain reaction in liver tissues from 40 subjects infected only with hepatitis C virus, 36 subjects co-infected with hepatitis C virus and human immunodeficiency virus and 11 normal adults. RESULTS Hepatic mRNA expression of both peroxisome proliferator-activated receptors was significantly lower in hepatitis C virus-infected subjects with and without human immunodeficiency virus co-infection compared to the controls. Non-black race was also identified as a predictor of lower peroxisome receptor α and γ mRNA expression. Compared to subjects infected only with hepatitis C virus, liver peroxisome receptor γ mRNA expression was significantly lower in hepatitis C virus/human immunodeficiency virus-co-infected subjects (0.0092 in hepatitis C virus/human immunodeficiency virus-co-infection vs. 0.0120 in hepatitis C virus-only; p=0.004). Hepatic peroxisome receptor α mRNA expression in the hepatitis C virus-infected patients was lower in the presence of human immunodeficiency virus co-infection in non-black subjects (0.0769 vs. 0.1061; p=0.02), whereas the levels did not vary based on human immunodeficiency virus status among black subjects. CONCLUSION mRNA expression of both peroxisome proliferator-activated receptors is impaired in hepatitis C virus-infected liver and further reduced by human immunodeficiency virus co-infection, although the suppressive effects of the viruses are substantially mitigated in black patients.
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Affiliation(s)
- Nathan J Shores
- Wake Forest University Health Sciences, Department of Internal Medicine, Section on Infectious Diseases, Medical Center Boulevard, Winston Salem, NC, United States
- Charleston Gastroenterology Spec, Charleston/SC, United States
| | - Maria Cássia Mendes-Corrêa
- Faculdade de Medicina do ABC, Unidade de Referência em Doenças Infecciosas, Santo André/SP, Brazil
- Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Moléstias Infecciosas e Parasitárias, São Paulo/SP, Brazil
- Corresponding author: E-mail:
| | - Ivana Maida
- Università degli Studi Sassari, Istituto Malattie Infettive e Parassitarie, Sassari/SS, Italy
| | - JoLyn Turner
- Wake Forest University Health Sciences, Department of Internal Medicine, Section on Infectious Diseases, Medical Center Boulevard, Winston Salem, NC, United States
| | - Kevin P High
- Wake Forest University Health Sciences, Department of Internal Medicine, Section on Infectious Diseases, Medical Center Boulevard, Winston Salem, NC, United States
| | - Sergio Babudieri
- Università degli Studi Sassari, Istituto Malattie Infettive e Parassitarie, Sassari/SS, Italy
| | - Marina Núñez
- Wake Forest University Health Sciences, Department of Internal Medicine, Section on Infectious Diseases, Medical Center Boulevard, Winston Salem, NC, United States
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Gonzalez-Sanchez E, Firrincieli D, Housset C, Chignard N. Nuclear receptors in acute and chronic cholestasis. Dig Dis 2015; 33:357-66. [PMID: 26045270 DOI: 10.1159/000371688] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND Nuclear receptors (NRs) form a family of 48 members. NRs control hepatic processes such as bile acid homeostasis, lipid metabolism and mechanisms involved in fibrosis and inflammation. Due to their central role in the regulation of hepatoprotective mechanisms, NRs are promising therapeutic targets in cholestatic disorders. KEY MESSAGES NRs can be classified into five different physiological clusters. NRs from the 'bile acids and xenobiotic metabolism' and from the 'lipid metabolism and energy homeostasis' clusters are strongly expressed in the liver. Furthermore, NRs from these clusters, such as farnesoid X receptor α (FXRα), pregnane X receptor (PXR) and peroxisome proliferator-activated receptors (PPARs), have been associated with the pathogenesis and the progression of cholestasis. The latter observation is also true for vitamin D receptor (VDR), which is barely detectable in the whole liver, but has been linked to cholestatic diseases. Involvement of VDR in cholestasis is ascribed to a strong expression in nonparenchymal liver cells, such as biliary epithelial cells, Kupffer cells and hepatic stellate cells. Likewise, NRs from other physiological clusters with low hepatic expression, such as estrogen receptor α (ERα) or reverse-Erb α/β (REV-ERB α/β), may also control pathophysiological processes in cholestasis. CONCLUSIONS In this review, we will describe the impact of individual NRs on cholestasis. We will then discuss the potential role of these transcription factors as therapeutic targets.
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Affiliation(s)
- Ester Gonzalez-Sanchez
- INSERM UMR_S 938, Centre de Recherche Saint-Antoine, and Sorbonne Universités, UPMC Université Paris 06, Paris, France
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Abstract
To date, the etiology and pathogenic underpinning of the progression of the most prevalent serious neonatal liver disease, biliary atresia, remains elusive. This disease presents as an aggressive form of neonatal cholestasis characterized by the destruction and obliteration of the extrahepatic bile ducts within the first few weeks of life and a rapid progression of biliary fibrosis, likely due to unremitting cholestasis and retention of biliary constituents including bile acids. In ∼5% of patients, biliary atresia is associated with laterality features, suggesting a genetic underpinning to a disease that begins soon after birth. However, biliary atresia does not occur within families and twins are discordant, indicating an absence of strict mendelian inheritance. Despite this, genes related to bile duct dysmorphogenesis/ciliopathies overlapping with features of biliary atresia in both humans and nonhuman model systems have been proposed. Taken together, strict genetic etiologies leading to a common pathway of a neonatal cholangiopathy resulting in biliary atresia remain elusive. Contributions from fibrogenesis- and inflammation-based studies suggest that early engagement of these pathways contributes to disease progression, but a recent double-blind study did not suggest any benefit from early use of corticosteroids. However, there are genetic contributions to the adaptation and response to cholangiopathies and cholestasis that may be present in certain populations that likely impact upon the response to hepatoportoenterostomy and subsequent biliary tract function. Studies utilizing next generation sequencing technologies (e.g., exome analysis) are ongoing in several laboratories around the world; they are expected to provide insights into genetic contributions to biliary atresia outcomes. Altogether, combinations of exome sequencing and large population studies are expected to reveal causative and modifying genes relevant to patients with biliary atresia as a means to provide therapeutic targets and potential opportunities for genetic screening.
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Affiliation(s)
- Anya Mezina
- Emory University School of Medicine, Atlanta, Ga., USA
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18
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Falguières T, Aït-Slimane T, Housset C, Maurice M. ABCB4: Insights from pathobiology into therapy. Clin Res Hepatol Gastroenterol 2014; 38:557-63. [PMID: 24953525 DOI: 10.1016/j.clinre.2014.03.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 02/25/2014] [Accepted: 03/05/2014] [Indexed: 02/04/2023]
Abstract
Adenosine triphosphate (ATP)-binding cassette, sub-family B, member 4 (ABCB4), also called multidrug resistance 3 (MDR3), is a member of the ATP-binding cassette transporter superfamily, which is localized at the canalicular membrane of hepatocytes, and mediates the translocation of phosphatidylcholine into bile. Phosphatidylcholine secretion is crucial to ensure solubilization of cholesterol into mixed micelles and to prevent bile acid toxicity towards hepatobiliary epithelia. Genetic defects of ABCB4 may cause progressive familial intrahepatic cholestasis type 3 (PFIC3), a rare autosomic recessive disease occurring early in childhood that may be lethal in the absence of liver transplantation, and other cholestatic or cholelithiasic diseases in heterozygous adults. Development of therapies for these conditions requires understanding of the biology of this transporter and how gene variations may cause disease. This review focuses on our current knowledge on the regulation of ABCB4 expression, trafficking and function, and presents recent advances in fundamental research with promising therapeutic perspectives.
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Affiliation(s)
- Thomas Falguières
- INSERM, UMR_S 938, CDR Saint-Antoine, 75012 Paris, France; UMR_S 938, CDR Saint-Antoine, Sorbonne Universités, UPMC - Université Paris-06, 75012 Paris, France
| | - Tounsia Aït-Slimane
- INSERM, UMR_S 938, CDR Saint-Antoine, 75012 Paris, France; UMR_S 938, CDR Saint-Antoine, Sorbonne Universités, UPMC - Université Paris-06, 75012 Paris, France
| | - Chantal Housset
- INSERM, UMR_S 938, CDR Saint-Antoine, 75012 Paris, France; UMR_S 938, CDR Saint-Antoine, Sorbonne Universités, UPMC - Université Paris-06, 75012 Paris, France; Service d'hépatologie, Centre Maladies Rares (CMR) Maladies Inflammatoires des Voies Biliaires, Hôpital Saint-Antoine, Assistance publique-Hôpitaux de Paris, 75012 Paris, France
| | - Michèle Maurice
- INSERM, UMR_S 938, CDR Saint-Antoine, 75012 Paris, France; UMR_S 938, CDR Saint-Antoine, Sorbonne Universités, UPMC - Université Paris-06, 75012 Paris, France.
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Quesnot N, Bucher S, Fromenty B, Robin MA. Modulation of metabolizing enzymes by bisphenol a in human and animal models. Chem Res Toxicol 2014; 27:1463-73. [PMID: 25142872 DOI: 10.1021/tx500087p] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Xenobiotics, such as contaminants and drugs, can be converted to potentially toxic reactive metabolites by phase 1 oxidizing enzymes. These metabolites are further detoxified by phase 2 conjugating enzymes and eliminated from cells by phase 3 transporters. Moreover, many of these xenobiotics are also able to induce or inhibit these enzymes, potentially modulating their own toxicity or that of other chemicals. The present review is focused on bisphenol A, a synthetic monomer used for many industrial applications and exhibiting xenoestrogen properties. The impact of this contaminant on all major classes of metabolizing enzymes (i.e., cytochromes P450, glutathione-S-transferases, sulfotransferases, UDP-glucuronyltransferases, and transporters) was reviewed, with a highlight on the modulation of cytochromes P450 involved in steroid metabolism. Interestingly, most of the studies reported in this review show that BPA is able to induce or inhibit metabolizing enzymes at high doses but also at doses compatible with human exposure.
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de Lima Toccafondo Vieira M, Tagliati CA. Hepatobiliary transporters in drug-induced cholestasis: a perspective on the current identifying tools. Expert Opin Drug Metab Toxicol 2014; 10:581-97. [PMID: 24588537 DOI: 10.1517/17425255.2014.884069] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
INTRODUCTION Impaired bile formation leads to the accumulation of cytotoxic bile salts in hepatocytes and, consequently, cholestasis and severe liver disease. Knowledge of the role of hepatobiliary transporters, especially the bile salt export pump (BSEP), in the pathogenesis of cholestasis is continuously increasing. AREAS COVERED This review provides an introduction into the role of these transport proteins in bile formation. It addresses the clinical relevance and pathophysiologic consequences of altered functions of these transporters by genetic mutations and drugs. In particular, the current practical aspects of identification and mitigation of drug candidates with liver liabilities employed during drug development, with an emphasis on preclinical screening for BSEP interaction, are discussed. EXPERT OPINION Within the potential pathogenetic mechanisms of acquired cholestasis, the inhibition of BSEP by drugs is well established. Interference of a new compound with BSEP transport activity should raise a warning sign to conduct follow-up experiments and to monitor liver function during clinical development. A combination of in vitro screening for transport interaction, in silico predicting models, and consideration of physicochemical and metabolic properties should lead to a more efficient screening of potential liver liability.
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Affiliation(s)
- Manuela de Lima Toccafondo Vieira
- Faculdade de Farmácia - UFMG, Departamento de Análises Clínicas e Toxicológicas, Av. Antônio Carlos, 6.627 - Pampulha, 31270-901 - Belo Horizonte - MG , Brazil +55 31 3547 3462 ;
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21
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A simple transcriptomic signature able to predict drug-induced hepatic steatosis. Arch Toxicol 2014; 88:967-82. [PMID: 24469900 DOI: 10.1007/s00204-014-1197-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 01/09/2014] [Indexed: 12/16/2022]
Abstract
It is estimated that only a few marketed drugs are able to directly induce liver steatosis. However, many other drugs may exacerbate or precipitate fatty liver in the presence of other risk factors or in patients prone to non-alcoholic fatty liver disease. On the other hand, current in vitro tests for drug-induced steatosis in preclinical research are scarce and not very sensitive or reproducible. In the present study, we have investigated the effect of well-characterized steatotic drugs on the expression profile of 47 transcription factors (TFs) in human hepatoma HepG2 cells and found that these drugs are able to up- and down-regulate a substantial number of these factors. Multivariate data analysis revealed a common TF signature for steatotic drugs, which consistently and significantly repressed FOXA1, HEX and SREBP1C in cultured cells. This signature was also observed in the livers of rats and in cultured human hepatocytes. Therefore, we selected these three TFs as predictive biomarkers for iatrogenic steatosis. With these biomarkers, a logistic regression analysis yielded a predictive model, which was able to correctly classify 92 % of drugs. The developed algorithm also predicted that ibuprofen, nifedipine and irinotecan are potential steatotic drugs, whereas troglitazone is not. In summary, this is a sensitive, specific and simple RT-PCR test that can be easily implemented in preclinical drug development to predict drug-induced steatosis. Our results also indicate that steatotic drugs affect expression of both common and specific subsets of TF and lipid metabolism genes, thus generating complex transcriptomic responses that cause or contribute to steatosis in hepatocytes.
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22
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Sharvit E, Abramovitch S, Reif S, Bruck R. Amplified inhibition of stellate cell activation pathways by PPAR-γ, RAR and RXR agonists. PLoS One 2013; 8:e76541. [PMID: 24098526 PMCID: PMC3788137 DOI: 10.1371/journal.pone.0076541] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2013] [Accepted: 08/28/2013] [Indexed: 02/06/2023] Open
Abstract
Peroxisome proliferator activator receptors (PPAR) ligands such as 15-Δ12,13-prostaglandin L(2) [PJ] and all trans retinoic acid (ATRA) have been shown to inhibit the development of liver fibrosis. The role of ligands of retinoic X receptor (RXR) and its ligand, 9-cis, is less clear. The purpose of this study was to investigate the effects of combined treatment of the three ligends, PJ, ATRA and 9-cis, on key events during liver fibrosis in rat primary hepatic stellate cells (HSCs). We found that the anti-proliferative effect of the combined treatment of PJ, ATRA and 9-cis on HSCs was additive. Further experiments revealed that this inhibition was due to cell cycle arrest at the G0/G1 phase as demonstrated by FACS analysis. In addition, the combined treatment reduced cyclin D1 expression and increased p21 and p27 protein levels. Furthermore, we found that the three ligands down regulated the phosphorylation of mTOR and p70(S6K). The activation of HSCs was also inhibited by the three ligands as shown by inhibition of vitamin A lipid droplets depletion from HSCs. Studies using real time PCR and western blot analysis showed marked inhibition of collagen Iα1 and αSMA by the combination of the three ligands. These findings suggest that the combined use of PJ, ATRA and 9-cis causes inhibition of cell proliferation by cell cycle arrest and down-regulation of fibrotic markers to a greater extent compared to each of the ligands alone.
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Affiliation(s)
- Efrat Sharvit
- Institute of Gastroenterology and Liver Diseases, Tel Aviv Sourasky Medical Center, and Sackler Faculty of Medicine, Tel Aviv, Israel
- Pediatric Gastroenterology Unit, Dana Children’s Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shirley Abramovitch
- Pediatric Gastroenterology Unit, Dana Children’s Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Shimon Reif
- Institute of Gastroenterology and Liver Diseases, Tel Aviv Sourasky Medical Center, and Sackler Faculty of Medicine, Tel Aviv, Israel
- Pediatric Gastroenterology Unit, Dana Children’s Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Rafael Bruck
- Institute of Gastroenterology and Liver Diseases, Tel Aviv Sourasky Medical Center, and Sackler Faculty of Medicine, Tel Aviv, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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Nobili V, Svegliati-Baroni G, Alisi A, Miele L, Valenti L, Vajro P. A 360-degree overview of paediatric NAFLD: recent insights. J Hepatol 2013; 58:1218-29. [PMID: 23238106 DOI: 10.1016/j.jhep.2012.12.003] [Citation(s) in RCA: 125] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Revised: 11/14/2012] [Accepted: 12/04/2012] [Indexed: 02/08/2023]
Abstract
Non-alcoholic fatty liver disease (NAFLD) is a multi-faceted disorder, which ranges from simple steatosis to non-alcoholic steatohepatitis (NASH) with/without fibrosis. The effects of specific risk factors, such as obesity and sedentary lifestyle, on predisposing genetic settings eventually lead to the development of NAFLD in children. The complex interplay between genes and environment in NAFLD pathogenesis is sustained by multiple mechanisms that involve liver crosstalk with other organs and tissues, especially gut and adipose tissue. Unfortunately, natural history of paediatric NAFLD is lacking, and the etiopathogenesis is still in the process of being defined. Potential early predictors and suitable non-invasive diagnostic tools can be discovered based on the pathogenetic mechanisms and histological patterns. This will also help design novel treatments and a comprehensive and successful management strategy for patients. In this review, we discuss the recent advances made in genetics, etiopathogenesis, diagnosis, and therapeutic management of NAFLD, focusing especially on the obesity-related steatotic liver condition.
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Affiliation(s)
- Valerio Nobili
- Hepato-metabolic Disease Unit and Liver Research Unit, "Bambino Gesù" Children's Hospital, IRCCS, P.le S. Onofrio 4, 00165 Rome, Italy.
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Li Z, Kruijt JK, van der Sluis RJ, Van Berkel TJC, Hoekstra M. Nuclear receptor atlas of female mouse liver parenchymal, endothelial, and Kupffer cells. Physiol Genomics 2013; 45:268-75. [PMID: 23362145 DOI: 10.1152/physiolgenomics.00151.2012] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The liver consists of different cell types that together synchronize crucial roles in liver homeostasis. Since nuclear receptors constitute an important class of drug targets that are involved in a wide variety of physiological processes, we have composed the hepatic cell type-specific expression profile of nuclear receptors to uncover the pharmacological potential of liver-enriched nuclear receptors. Parenchymal liver cells (hepatocytes) and liver endothelial and Kupffer cells were isolated from virgin female C57BL/6 wild-type mice using collagenase perfusion and counterflow centrifugal elutriation. The hepatic expression pattern of 49 nuclear receptors was generated by real-time quantitative PCR using the NUclear Receptor Signaling Atlas (NURSA) program resources. Thirty-six nuclear receptors were expressed in total liver. FXR-α, EAR2, LXR-α, HNF4-α, and CAR were the most abundantly expressed nuclear receptors in liver parenchymal cells. In contrast, NUR77, COUP-TFII, LXR-α/β, FXR-α, and EAR2 were the most highly expressed nuclear receptors in endothelial and Kupffer cells. Interestingly, members of orphan receptor COUP-TF family showed a distinct expression pattern. EAR2 was highly and exclusively expressed in parenchymal cells, while COUP-TFII was moderately and exclusively expressed in endothelial and Kupffer cells. Of interest, the orphan receptor TR4 showed a similar expression pattern as the established lipid sensor PPAR-γ. In conclusion, our study provides the most complete quantitative assessment of the nuclear receptor distribution in liver reported to date. Our gene expression catalog suggests that orphan nuclear receptors such as COUP-TFII, EAR2, and TR4 may be of significant importance as novel targets for pharmaceutical interventions in liver.
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Affiliation(s)
- Zhaosha Li
- Division of Biopharmaceutics, Leiden Academic Centre for Drug Research, Leiden University, The Netherlands
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25
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Malek MA, Hoang MH, Jia Y, Lee JH, Jun HJ, Lee DH, Lee HJ, Lee C, Lee MK, Hwang BY, Lee SJ. Ombuin-3-O-β-D-glucopyranoside from Gynostemma pentaphyllum is a dual agonistic ligand of peroxisome proliferator-activated receptors α and δ/β. Biochem Biophys Res Commun 2012; 430:1322-8. [PMID: 23247028 DOI: 10.1016/j.bbrc.2012.12.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Accepted: 12/05/2012] [Indexed: 10/27/2022]
Abstract
We demonstrated that ombuin-3-O-β-D-glucopyranoside (ombuine), a flavonoid from Gynostemma pentaphyllum, is a dual agonist for peroxisome proliferator-activated receptors (PPARs) α and δ/β. Using surface plasmon resonance (SPR), time-resolved fluorescence resonance energy transfer (FRET) analyses, and reporter gene assays, we showed that ombuine bound directly to PPARα and δ/β but not to PPARγ or liver X receptors (LXRs). Cultured HepG2 hepatocytes stimulated with ombuine significantly reduced intracellular concentrations of triglyceride and cholesterol and downregulated the expression of lipogenic genes, including sterol regulatory element binding protein-1c (SREBP1c) and stearoyl-CoA desaturase-1 (SCD-1), with activation of PPARα and δ/β. Activation of LXRs by ombuine was confirmed by reporter gene assays, however, SPR and cell-based FRET assays showed no direct binding of ombuine to either of the LXRs suggesting LXR activation by ombuine may be operated via PPARα stimulation. Ombuine-stimulated macrophages showed significantly induced transcription of ATP binding cassette cholesterol transporter A1 (ABCA1) and G1 (ABCG1), the key genes in reverse cholesterol transport, which led to reduced cellular cholesterol concentrations. These results suggest that ombuine is a dual PPAR ligand for PPARα and δ/β with the ability to decrease lipid concentrations by reducing lipogenic gene expression in hepatocytes and inducing genes involved in cholesterol efflux in macrophages.
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Affiliation(s)
- Mastura Abd Malek
- Department of Biotechnology, Graduate School of Biotechnology, Korea University, Seoul 136-713, Republic of Korea
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Nuclear receptors in nonalcoholic Fatty liver disease. J Lipids 2012; 2012:139875. [PMID: 22187655 PMCID: PMC3236492 DOI: 10.1155/2012/139875] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Accepted: 09/14/2011] [Indexed: 01/03/2023] Open
Abstract
Nuclear receptors comprise a superfamily of ligand-activated transcription factors that are involved in important aspects of hepatic physiology and pathophysiology. There are about 48 nuclear receptors in the human. These nuclear receptors are regulators of many hepatic processes including hepatic lipid and glucose metabolism, bile acid homeostasis, drug detoxification, inflammation, regeneration, fibrosis, and tumor formation. Some of these receptors are sensitive to the levels of molecules that control lipid metabolism including fatty acids, oxysterols, and lipophilic molecules. These receptors direct such molecules to the transcriptional networks and may play roles in the pathogenesis and treatment of nonalcoholic fatty liver disease. Understanding the mechanisms underlying the involvement of nuclear receptors in the pathogenesis of nonalcoholic fatty liver disease may offer targets for the development of new treatments for this liver disease.
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Molecular Mechanisms Underlying the Link between Nuclear Receptor Function and Cholesterol Gallstone Formation. J Lipids 2011; 2012:547643. [PMID: 22132343 PMCID: PMC3206498 DOI: 10.1155/2012/547643] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Accepted: 08/10/2011] [Indexed: 12/23/2022] Open
Abstract
Cholesterol gallstone disease is highly prevalent in western countries, particularly in women and some specific ethnic groups. The formation of water-insoluble cholesterol crystals is due to a misbalance between the three major lipids present in the bile: cholesterol, bile salts, and phospholipids. Many proteins implicated in biliary lipid secretion in the liver are regulated by several transcription factors, including nuclear receptors LXR and FXR. Human and murine genetic, physiological, pathophysiological, and pharmacological evidence is consistent with the relevance of these nuclear receptors in gallstone formation. In addition, there is emerging data that also suggests a role for estrogen receptor ESR1 in abnormal cholesterol metabolism leading to gallstone disease. A better comprehension of the role of nuclear receptor function in gallstone formation may help to design new and more effective therapeutic strategies for this highly prevalent disease condition.
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Min G. Estrogen modulates transactivations of SXR-mediated liver X receptor response element and CAR-mediated phenobarbital response element in HepG2 cells. Exp Mol Med 2011; 42:731-8. [PMID: 20871212 DOI: 10.3858/emm.2010.42.11.074] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
The nuclear receptors, steroid and xenobiotic receptor (SXR) and constitutive androstane receptor (CAR) play important functions in mediating lipid and drug metabolism in the liver. The present study demonstrates modulatory actions of estrogen in transactivations of SXR-mediated liver X receptor response element (LXRE) and CAR-mediated phenobarbital response element (PBRU). When human estrogen receptor (hERα) and SXR were exogenously expressed, treatment with either rifampicin or corticosterone promoted significantly the SXR-mediated transactivation of LXRE reporter gene in HepG2. However, combined treatment with estrogen plus either rifampicin or corticosterone resulted in less than 50% of the mean values of the transactivation by rifampicin or corticosterone alone. Thus, it is suggested that estrogen may repress the SXR-mediated transactivation of LXRE via functional cross-talk between ER and SXR. The CAR-mediated transactivation of PBRU was stimulated by hERa in the absence of estrogen. However, the potentiation by CAR agonist, TCPOBOP, was significantly repressed by moxestrol in the presence of ER. Thus, ER may play both stimulatory and inhibitory roles in modulating CAR-mediated transactivation of PBRU depending on the presence of their ligands. In summary, this study demonstrates that estrogen modulates transcriptional activity of SXR and CAR in mediating transactivation of LXRE and PBRU, respectively, of the nuclear receptor target genes through functional cross-talk between ER and the corresponding nuclear receptors.
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Affiliation(s)
- Gyesik Min
- Department of Pharmaceutical Engineering, Jinju National University, Jinju 660-758, Korea.
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Abstract
PURPOSE OF REVIEW This review will provide an overview of the role of nuclear receptors in bile acid homeostasis with a focus on the farnesoid X receptor (FXR) and its potential therapeutic use in cholestatic liver diseases. RECENT FINDINGS Nuclear receptors have emerged as important mediators of a variety of metabolic and transport functions involving the liver. The role of FXR, in particular, has come to light because of its important role in bile acid homeostasis. The use of potent FXR ligands has recently been shown to offer potentially important therapeutic benefits in patients with primary biliary cirrhosis, an important cholestatic liver disease of adults. This recent finding has now opened the door for future therapeutic trials for use of FXR agonists such as obeticholic acid for the treatment of chronic cholestatic liver diseases. SUMMARY Further understanding of the role of farnesoid X receptor agonists and the potential role of ligands in animal models of other forms of cholestasis will be important to set the stage for future applications to human disease.
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Kacevska M, Downes MR, Sharma R, Evans RM, Clarke SJ, Liddle C, Robertson GR. Extrahepatic cancer suppresses nuclear receptor-regulated drug metabolism. Clin Cancer Res 2011; 17:3170-80. [PMID: 21498392 DOI: 10.1158/1078-0432.ccr-10-3289] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
PURPOSE To determine the mechanisms by which tumors situated in extrahepatic sites can cause profound changes in hepatic drug clearance, contributing to altered drug response and chemotherapy resistance. EXPERIMENTAL DESIGN We studied in wild-type or transgenic CYP3A4 reporter mice implanted with the murine Engelbreth-Holm-Swarm sarcoma changes in nuclear receptor and hepatic transcription factor expression and/or function, particularly related to CYP3A gene regulation. RESULTS Repression of hepatic CYP3A induction was dramatic and associated with reduced levels of C/EBPβ isoforms, impaired pregnane X receptor, and constitutive androstane receptor function. Unexpectedly, extrahepatic tumors strongly reduced nuclear accumulation of retinoid X receptor alpha (RXRα) in hepatocytes, providing a potential explanation for impaired function of nuclear receptors that rely on RXRα dimerization. Profiling revealed 38 nuclear receptors were expressed in liver with 14 showing between 1.5- and four-fold reduction in expression in livers of tumor-bearing animals, including Car, Trβ, Lxrβ, Pparα, Errα/β, Reverbα/β, and Shp. Altered Pparα and γ induction of target genes provided additional evidence of perturbed hepatic metabolic control elicited by extrahepatic tumors. CONCLUSIONS Extrahepatic malignancy can affect hepatic drug metabolism by nuclear receptor relocalization and decreased receptor expression and function. These findings could aid the design of intervention strategies to normalize drug clearance and metabolic pathways in cancer patients at risk of chemotherapy-induced toxicity or cancer cachexia.
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Affiliation(s)
- Marina Kacevska
- Storr Liver Unit, Westmead Millennium Institute, University of Sydney, Westmead, New South Wales, Australia
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31
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Trauner M, Halilbasic E. Nuclear receptors as new perspective for the management of liver diseases. Gastroenterology 2011; 140:1120-1125.e1-12. [PMID: 21334334 DOI: 10.1053/j.gastro.2011.02.044] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Nuclear receptors (NRs) are ligand-activated transcription factors that act as sensors for a broad range of natural and synthetic ligands and regulate several key hepatic functions including bile acid homeostasis, bile secretion, lipid and glucose metabolism, as well as drug deposition. Moreover, NRs control hepatic inflammation, regeneration, fibrosis, and tumor formation. Therefore, NRs are key for understanding the pathogenesis and pathophysiology of a wide range of hepatic disorders. Finally, targeting NRs and their alterations offers exciting new perspectives for the treatment of liver diseases.
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Affiliation(s)
- Michael Trauner
- Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Austria.
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32
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Wagner M, Zollner G, Trauner M. Nuclear receptors in liver disease. Hepatology 2011; 53:1023-34. [PMID: 21319202 DOI: 10.1002/hep.24148] [Citation(s) in RCA: 211] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Accepted: 12/16/2010] [Indexed: 12/24/2022]
Abstract
Nuclear receptors are ligand-activated transcriptional regulators of several key aspects of hepatic physiology and pathophysiology. As such, nuclear receptors control a large variety of metabolic processes including hepatic lipid metabolism, drug disposition, bile acid homeostasis, as well as liver regeneration, inflammation, fibrosis, cell differentiation, and tumor formation. Derangements of nuclear receptor regulation and genetic variants may contribute to the pathogenesis and progression of liver diseases. This places nuclear receptors into the frontline for novel therapeutic approaches for a broad range of hepatic disorders and diseases including cholestatic and fatty liver disease, drug hepatotoxicity, viral hepatitis, liver fibrosis, and cancer.
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Affiliation(s)
- Martin Wagner
- Laboratory of Experimental and Molecular Hepatology, Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Austria
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33
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Ooi JP, Kuroyanagi M, Sulaiman SF, Muhammad TST, Tan ML. Andrographolide and 14-Deoxy-11, 12-Didehydroandrographolide inhibit cytochrome P450s in HepG2 hepatoma cells. Life Sci 2011; 88:447-54. [DOI: 10.1016/j.lfs.2010.12.019] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Revised: 12/08/2010] [Accepted: 12/14/2010] [Indexed: 12/23/2022]
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Abstract
Hepatobiliary transport systems are essential for the uptake and excretion of a variety of compounds including bile acids. Disruption and dysregulation of this excretory pathway result in cholestasis, leading to the intrahepatic accumulation of bile acids and other toxic compounds with progression of liver pathology. Cholestasis induced by inflammation is a common complication in patients with extrahepatic infections or inflammatory processes, generally referred to as sepsis-associated cholestasis. Microbial products, including endotoxin, induce signaling pathways within hepatocytes either directly, or through activation of proinflammatory cytokines, leading to rapid and profound reductions in bile flow. The expression and function of key hepatobiliary transporters are suppressed in response to inflammatory signaling. These proinflammatory signaling cascades lead to repressed expression and activity of a large number of nuclear transcriptional regulators, many of which are essential for maintenance of hepatobiliary transporter gene expression. Interestingly, recently discovered molecular crosstalk between bile acid activated nuclear receptors and proinflammatory nuclear mediators may provide new means of understanding adaptive processes within liver. Inflammation-induced cholestasis and the effects of retained molecules in cholestasis on inflammatory signals are interwoven in the liver, providing potential opportunities for research and therapeutics.
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Zollner G, Wagner M, Trauner M. Nuclear receptors as drug targets in cholestasis and drug-induced hepatotoxicity. Pharmacol Ther 2010; 126:228-43. [PMID: 20388526 DOI: 10.1016/j.pharmthera.2010.03.005] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2010] [Accepted: 03/24/2010] [Indexed: 01/04/2023]
Abstract
Nuclear receptors are key regulators of various processes including reproduction, development, and metabolism of xeno- and endobiotics such as bile acids and drugs. Research in the last two decades provided researchers and clinicians with a detailed understanding of the regulation of these processes and, most importantly, also prompted the development of novel drugs specifically targeting nuclear receptors for the treatment of a variety of diseases. Some nuclear receptor agonists are already used in daily clinical practice but many more are currently designed or tested for the treatment of diabetes, dyslipidemia, fatty liver disease, cancer, drug hepatotoxicity and cholestasis. The hydrophilic bile acid ursodeoxycholic acid is currently the only available drug to treat cholestasis but its efficacy is limited. Therefore, development of novel treatments represents a major goal for both pharmaceutical industry and academic researchers. Targeting nuclear receptors in cholestasis is an intriguing approach since these receptors are critically involved in regulation of bile acid homeostasis. This review will discuss the general role of nuclear receptors in regulation of transporters and other enzymes maintaining bile acid homeostasis and will review the role of individual receptors as therapeutic targets. In addition, the central role of nuclear receptors and other transcription factors such as the aryl hydrocarbon receptor (AhR) and the nuclear factor-E2-related factor (Nrf2) in mediating drug disposition and their potential therapeutic role in drug-induced liver disease will be covered.
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Affiliation(s)
- Gernot Zollner
- Laboratory of Experimental and Molecular Hepatology, Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University Graz, Auenbruggerplatz 15, A-8036 Graz, Austria
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Arrese M, Karpen SJ. Nuclear receptors, inflammation, and liver disease: insights for cholestatic and fatty liver diseases. Clin Pharmacol Ther 2010; 87:473-8. [PMID: 20200515 DOI: 10.1038/clpt.2010.2] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors are players of substantial relevance in the regulation of hepatic gene expression. NRs direct normal physiology and metabolism, adaptations to liver disease, and responses to inflammation and toxins.They also contribute to the regenerative response. In this review, we summarize currently available experimental and clinical data, focusing on the role of NRs in cholestasis and nonalcoholic fatty liver disease (NAFLD). We also highlight the potential of NRs as targets for safe and effective therapeutic interventions.
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Affiliation(s)
- M Arrese
- Department of Gastroenterology, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
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Karpen SJ, Trauner M. The new therapeutic frontier--nuclear receptors and the liver. J Hepatol 2010; 52:455-62. [PMID: 20133000 DOI: 10.1016/j.jhep.2009.12.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2009] [Revised: 09/20/2009] [Accepted: 10/09/2009] [Indexed: 02/07/2023]
Abstract
A joint EASL/AASLD Monothematic Conference on 'Nuclear Receptors and Liver Disease' was held from February 27th to March 1st, 2009, in Vienna, Austria, to discuss the latest advances at the forefront of basic and clinical nuclear receptor research and its potential implications for liver diseases. This article reports the highlights of the conference and summarizes the main conclusions emphasizing the relevance for clinical and experimental hepatology. The confluence of nuclear receptors as central transcriptional regulators, acting as sensors and adaptors to many of the small molecules present in the intracellular milieu of all the cells of the liver, provides a current framework to address a broader physiological understanding of the liver. The next stage will be the design and testing of safe and effective therapeutics.
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Affiliation(s)
- Saul J Karpen
- Department of Pediatrics, Division of Pediatric Gastroenterology, Hepatology, and Nutrition, Texas Children's Liver Center, Baylor College of Medicine, Pediatrics/Liver Center, One Baylor Plaza, Houston, TX 77030, USA
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Caccia S, Garattini S, Pasina L, Nobili A. Predicting the clinical relevance of drug interactions from pre-approval studies. Drug Saf 2009; 32:1017-39. [PMID: 19810775 DOI: 10.2165/11316630-000000000-00000] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Drug interactions (DIs) may result in adverse drug events that could be prevented, but in many cases the available information on potential DIs is not easily transferable to clinical practice. The majority of studies date from preclinical or premarketing phases, using animals or human-derived sources that may not accurately reflect the growing clinical complexity of high-risk populations, such as the elderly, women, children, patients with chronic disease, polytherapy and impaired organ functions. Thus, at the time of approval of a new drug the information in the summary of product characteristics refers to potential DIs, but lacks specific management recommendations and is of limited clinical utility. Therefore, we set out to review in vitro and in vivo methods to predict and quantify potential DIs, to see whether these studies could help the physician tackle daily problems of the assessment and choice of combined drug therapies, and to propose, from a clinical point of view, how premarketing studies could be improved so as to help the physician at the patient's bedside. Preclinical and premarketing study design needs to be improved to make information easily accessible and clinically transferable. Studies should also take into account appropriate sample size, duration, co-morbidity, number of coadministered drugs, within- and between-subject variability, specific at-risk populations and/or drugs with a relatively narrow therapeutic window, and clinical endpoints. After premarketing development in situations where there is potential high risk of serious adverse events, specific phase IV studies (and/or active pharmacovigilance studies) should be required to monitor and quantitatively assess their clinical impact.
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Affiliation(s)
- Silvio Caccia
- Laboratory of Drug Metabolism, 'Mario Negri' Institute for Pharmacological Research, Milan, Italy
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39
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Kosters A, White DD, Sun H, Thevananther S, Karpen SJ. Redundant roles for cJun-N-terminal kinase 1 and 2 in interleukin-1beta-mediated reduction and modification of murine hepatic nuclear retinoid X receptor alpha. J Hepatol 2009; 51:898-908. [PMID: 19767119 PMCID: PMC2818213 DOI: 10.1016/j.jhep.2009.06.029] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Revised: 05/29/2009] [Accepted: 06/23/2009] [Indexed: 01/28/2023]
Abstract
BACKGROUND/AIMS Retinoid X receptor alpha (RXRalpha), the heterodimeric partner for multiple nuclear receptors (NRs), was shown to be an essential target for inflammation-induced cJun-N-terminal kinase (JNK) signaling in vitro. This study aimed to explore the role of hepatic JNK signaling and its effects on nuclear RXRalpha levels downstream of interleukin-1beta (IL-1beta) in vivo. METHODS Effects of IL-1beta on hepatic NR-dependent gene expression, nuclear RXRalpha levels, and roles for individual JNK isoforms were studied in wild-type, Jnk1(-/-), and Jnk2(-/-) mice and in primary hepatocytes of each genotype. RESULTS IL-1beta administration showed a time-dependent reduction in expression of the hepatic NR-dependent genes Ntcp, Cyp7a1, Cyp8b1, Abcg5, Mrp2, and Mrp3. IL-1beta treatment for 1h activated JNK and resulted in both post-translational modification and reduction of nuclear RXRalpha. In wild-type primary hepatocytes, IL-1beta modified and reduced nuclear RXRalpha levels time dependently, which was prevented by chemical inhibition of JNK as well as by inhibition of proteasomal degradation. Individual absence of either JNK1 or JNK2 did not significantly influence the reduction or modification of hepatic nuclear RXRalpha by IL-1beta both in vivo and in primary hepatocytes. CONCLUSIONS Functional redundancy exists for JNK1 and JNK2 in IL-1beta-mediated alterations of hepatic nuclear RXRalpha levels, stressing the importance of this pathway in mediating the hepatic response to inflammation.
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Affiliation(s)
- Astrid Kosters
- Texas Children's Liver Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
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40
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Elfaki DAH, Bjornsson E, Lindor KD. Review article: nuclear receptors and liver disease--current understanding and new therapeutic implications. Aliment Pharmacol Ther 2009; 30:816-25. [PMID: 19706148 DOI: 10.1111/j.1365-2036.2009.04104.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND The important role of nuclear receptors and their contribution to liver function in both physiological and pathological conditions has come to attention in recent years and has advanced our understanding of several liver diseases. These findings led to the introduction of targeting nuclear receptors as treatment strategies for various liver diseases. AIMS To review the new insights brought by the study of nuclear receptors to our understanding of the molecular basis of various liver diseases, and to summarize some of the recent studies that evaluated the efficacy of targeting nuclear receptor as a new approach in treating liver diseases. METHODS Review of articles, using PubMed and article references. RESULTS Nuclear receptor ligands in patients with liver diseases have been associated with a variety of toxicities. Some clinical results have not met the expectations predicted from animal experiments. Mechanistic explanations at the molecular level are needed for preventing toxicity and improving outcomes from nuclear receptor ligands. CONCLUSION The use of various nuclear receptor ligands in liver diseases is a promising approach that can benefit many patients suffering from these devastating diseases. However, we are far from a full understanding of the molecular mechanisms by which these receptors work.
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Affiliation(s)
- D A H Elfaki
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN 55901, USA
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Poupon R. [Cholestasis and cholestatic liver diseases]. GASTROENTEROLOGIE CLINIQUE ET BIOLOGIQUE 2009; 33:778-788. [PMID: 19556086 DOI: 10.1016/j.gcb.2009.04.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The main determinant of bile formation is an osmotic filtration process resulting from active transport of bile acids and other osmotic solutes (glutathion). Most of the membrane transporters ensuring bile formation have now been identified. The expression of these membrane transporters is regulated through transcriptional and post-traductional mechanisms. Transcriptional regulation is under the control of nuclear receptors activated by ligands such as bile acids, which act as endogenous steroids synthesized from cholesterol in hepatocytes. Cholestatic liver diseases comprise genetic diseases resulting from the complex interaction between genetic and environmental factors. Monogenic cholestatic diseases recently identified illustrate the key role of membrane transporters in biliary function. Bile acids and inflammatory mediators are potent modulators of transporters and nuclear receptor genes and thus trigger an adaptative response to cholestasis. The extent of this adaptative response could explain the compelling phenotypic variability of cholestatic diseases in childhood and adults. The first-line medical treatment is currently ursodeoxycholic acid and in case of failure of this medical treatment, liver transplantation is required. Recent progress in the molecular pathogenesis of bile formation and cholestatic liver diseases is expected to provide the design of drugs targeted to the molecular abnormalities typical of cholestatic diseases.
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Affiliation(s)
- R Poupon
- Service d'Hépatologie, Centre de Références des Maladies Inflammatoires des Voies Biliaires, Hôpital Saint-Antoine, Assistance Publique-Hôpitaux de Paris, 75571 Paris cedex 12, France.
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Zollner G, Trauner M. Nuclear receptors as therapeutic targets in cholestatic liver diseases. Br J Pharmacol 2009; 156:7-27. [PMID: 19133988 DOI: 10.1111/j.1476-5381.2008.00030.x] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Cholestasis results in intrahepatic accumulation of cytotoxic bile acids, which cause liver damage ultimately leading to biliary fibrosis and cirrhosis. Cholestatic liver injury is counteracted by a variety of adaptive hepatoprotective mechanisms including alterations in bile acid transport, synthesis and detoxification. The underlying molecular mechanisms are mediated mainly at a transcriptional level via a complex network involving nuclear receptors including the farnesoid X receptor, pregnane X receptor, vitamin D receptor and constitutive androstane receptor, which target overlapping, although not identical, sets of genes. Because the intrinsic adaptive response to bile acids cannot fully prevent liver injury in cholestasis, therapeutic targeting of these receptors via specific and potent agonists may further enhance the hepatic defence against toxic bile acids. Activation of these receptors results in repression of bile acid synthesis, induction of phases I and II bile acid hydroxylation and conjugation and stimulation of alternative bile acid export while limiting hepatocellular bile acid import. Furthermore, the use of nuclear receptor ligands may not only influence bile acid transport and metabolism but may also directly target hepatic fibrogenesis and inflammation. Many drugs already used to treat cholestasis and its complications such as pruritus (e.g. ursodeoxycholic acid, rifampicin, fibrates) may act via activation of nuclear receptors. More specific and potent nuclear receptor ligands are currently being developed. This article will review the current knowledge on nuclear receptors and their potential role in the treatment of cholestatic liver diseases.
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Affiliation(s)
- Gernot Zollner
- Laboratory of Experimental and Molecular Hepatology, Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria
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Martínez-Fernández P, Hierro L, Jara P, Alvarez L. Knockdown of ATP8B1 expression leads to specific downregulation of the bile acid sensor FXR in HepG2 cells: effect of the FXR agonist GW4064. Am J Physiol Gastrointest Liver Physiol 2009; 296:G1119-29. [PMID: 19228886 DOI: 10.1152/ajpgi.90371.2008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Farnesoid X receptor (FXR) is a bile acid-sensing nuclear receptor that controls bile acid homeostasis. It has been suggested that downregulation of FXR contributes to the pathogenesis of an inherited disorder of bile secretion caused by mutations in ATP8B1. We have investigated the relationship between ATP8B1 knockdown and FXR downregulation in the human hepatoblastoma cell line HepG2. Transfection of HepG2 cells with ATP8B1 small interfering RNA (siRNA) duplexes led to a 60% reduction in the endogenous levels of ATP8B1 mRNA and protein and a concomitant decrease in FXR mRNA and protein content, as well as in FXR phosphorylation. This decrease was accompanied by a marked reduction in mRNA levels of a subset of FXR targets, such as bile salt export pump (ABCB11), small heterodimer partner, and uridine 5'-diphosphate-glucuronosyltransferase. ATP8B1 inhibition specifically targeted FXR since mRNA expression of other prominent nuclear receptors, such as pregnane X receptor and constitutive androstane receptor, or liver-enriched transcription factors, such as hepatocyte nuclear factor 1alpha (HNF-1alpha) and HNF-4alpha, was not altered. The expression of other key genes involved in bile acid synthesis, detoxification, and transport also remained unchanged upon ATP8B1 knockdown. Supporting the specificity of the effect, siRNA-mediated silencing of ABCB11, whose defect is associated with another inherited disorder of bile secretion, did not affect FXR expression. Treatment with the synthetic FXR agonist GW4064 was able to partially neutralize ATP8B1 siRNA-mediated FXR downregulation and fully counteract inhibition of FXR target genes. Collectively these findings indicate that ATP8B1 knockdown specifically downregulates FXR, and this action can be circumvented by treatment with FXR agonists.
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Affiliation(s)
- Pilar Martínez-Fernández
- Research Unit, La Paz University Hospital-Fundación para la Investigación Biomédica del Hospital Universitario La Paz (FIBHULP), Madrid, Spain
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Takeyama Y, Uehara Y, Inomata S, Morihara D, Nishizawa S, Ueda SI, Matsumoto T, Tanaka T, Anan A, Nishimura H, Irie M, Iwata K, Shakado S, Sohda T, Sakisaka S. Alternative transporter pathways in patients with untreated early-stage and late-stage primary biliary cirrhosis. Liver Int 2009; 29:406-14. [PMID: 18662272 DOI: 10.1111/j.1478-3231.2008.01846.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND/AIMS The hepatic expression of bile acid transporters is altered in experimental cholestasis and it is unclear whether regulation exists in human cholestatic diseases. We investigated the expression of genes involved in bile acid detoxification, basolateral export and nuclear factor regulation in untreated primary biliary cirrhosis (PBC). METHODS Liver tissues were obtained from patients with early-stage and late-stage PBC. The hepatic expression levels of messenger RNAs were determined by the real-time reverse transcription polymerase chain reaction. RESULTS The hepatic expression of multidrug-resistance protein 4 messenger RNA was significantly upregulated in early-stage and late-stage PBC patients compared with controls. The hepatic expression of multidrug-resistance protein 2 and multidrug-resistance protein 3 messenger RNAs was significantly elevated only in early-stage PBC patients. The hepatic expression levels of farnesoid X receptor, fetoprotein transcription factor and constitutive androstane receptor mRNAs were correlated with those of multidrug-resistance protein 2, multidrug-resistance protein 3 and multidrug-resistance protein 4 respectively. CONCLUSIONS The hepatic expression of multidrug-resistance protein 4 was enhanced in patients with untreated PBC at all stages. However, the hepatic expression of multidrug-resistance protein 2 and multidrug-resistance protein 3 was enhanced only in early-stage patients. The lack of upregulation of these proteins might contribute to the progression of PBC.
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Affiliation(s)
- Yasuaki Takeyama
- Department of Gastroenterology and Medicine, Fukuoka University School of Medicine, Fukuoka, Japan
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Mulder J, Karpen SJ, Tietge UJF, Kuipers F. Nuclear receptors: mediators and modifiers of inflammation-induced cholestasis. FRONT BIOSCI-LANDMRK 2009; 14:2599-630. [PMID: 19273222 PMCID: PMC4085779 DOI: 10.2741/3400] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Inflammation-induced cholestasis (IIC) is a frequently occurring phenomenon. A central role in its pathogenesis is played by nuclear receptors (NRs). These ligand-activated transcription factors not only regulate basal expression of hepatobiliary transport systems, but also mediate adaptive responses to inflammation and possess anti-inflammatory characteristics. The latter two functions may be exploited in the search for new treatments for IIC as well as for cholestasis in general. Current knowledge of the pathogenesis of IIC and the dual role NRs in this process are reviewed. Special interest is given to the use of NRs as potential targets for intervention.
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Affiliation(s)
- Jaap Mulder
- Department of Pediatrics Center for Liver, Digestive and Metabolic Diseases, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
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Mottino AD, Catania VA. Hepatic drug transporters and nuclear receptors: Regulation by therapeutic agents. World J Gastroenterol 2008; 14:7068-74. [PMID: 19084913 PMCID: PMC2776836 DOI: 10.3748/wjg.14.7068] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The canalicular membrane represents the excretory pole of hepatocytes. Bile is an important route of elimination of potentially toxic endo- and xenobiotics (including drugs and toxins), mediated by the major canalicular transporters: multidrug resistance protein 1 (MDR1, ABCB1), also known as P-glycoprotein, multidrug resistance-associated protein 2 (MRP2, ABCC2), and the breast cancer resistance protein (BCRP, ABCG2). Their activities depend on regulation of expression and proper localization at the canalicular membrane, as regulated by transcriptional and post-transcriptional events, respectively. At transcriptional level, specific nuclear receptors (NR)s modulated by ligands, co-activators and co-repressors, mediate the physiological requirements of these transporters. This complex system is also responsible for alterations occurring in specific liver pathologies. We briefly describe the major Class II NRs, pregnane X receptor (PXR) and constitutive androstane receptor (CAR), and their role in regulating expression of multidrug resistance proteins. Several therapeutic agents regulate the expression of relevant drug transporters through activation/inactivation of these NRs. We provide some representative examples of the action of therapeutic agents modulating liver drug transporters, which in addition, involve CAR or PXR as mediators.
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Abstract
In recent years the discovery of a number of major transporter proteins expressed in the liver and intestine specifically involved in bile acid transport has led to improved understanding of bile acid homeostasis and the enterohepatic circulation. Sodium (Na(+))-dependent bile acid uptake from portal blood into the liver is mediated primarily by the Na(+) taurocholate co-transporting polypeptide (NTCP), while secretion across the canalicular membrane into the bile is carried out by the bile salt export pump (BSEP). In the ileum, absorption of bile acids from the lumen into epithelial cells is mediated by the apical Na(+) bile salt transporter (ASBT), whereas exit into portal blood across the basolateral membrane is mediated by the organic solute transporter alpha/beta (OSTalpha/beta) heterodimer. Regulation of transporter gene expression and function occurs at several different levels: in the nucleus, members of the nuclear receptor superfamily, regulated by bile acids and other ligands are primarily involved in controlling gene expression, while cell signalling events directly affect transporter function, and subcellular localization. Polymorphisms, dysfunction, and impaired adaptive responses of several of the bile acid transporters, e.g. BSEP and ASBT, results in liver and intestinal disease. Bile acid transporters are now understood to play central roles in driving bile flow, as well as adaptation to various pathological conditions, with complex regulation of activity and function in the nucleus, cytoplasm, and membrane.
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Affiliation(s)
- A Kosters
- Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
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Ghose R, Guo T, Haque N. Regulation of gene expression of hepatic drug metabolizing enzymes and transporters by the Toll-like receptor 2 ligand, lipoteichoic acid. Arch Biochem Biophys 2008; 481:123-30. [PMID: 18940178 DOI: 10.1016/j.abb.2008.10.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2008] [Revised: 09/29/2008] [Accepted: 10/06/2008] [Indexed: 01/07/2023]
Abstract
Expression of hepatic drug metabolizing enzymes (DMEs) is altered in infection and inflammation. However, the role of Gram+ve bacterial components and their receptor, Toll-like receptor (TLR) 2 in regulation of hepatic DMEs is unknown. Gene expression of DMEs is regulated by members of the nuclear receptor superfamily (PXR, CAR and RXRalpha). The TLR2 ligand, lipoteichoic acid (LTA) reduced RNA levels of CAR and its target genes, Cyp2b10, Cyp2a4 and Sultn in mouse liver ( approximately 60-80% reduction). Hepatic genes regulated by PXR and CAR, Cyp3a11 and Mrp2 were moderately reduced by LTA, along with approximately 50% reduction of PXR RNA and nuclear protein levels of RXRalpha. The effects of LTA were significantly attenuated by pre-treatment with the Kupffer cell inhibitor, gadolinium chloride, indicating that Kupffer cells contribute to LTA-mediated down-regulation of hepatic genes. These results indicate that treatment with Gram+ve bacterial components preferentially down-regulate CAR and its target genes in the liver.
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Affiliation(s)
- Romi Ghose
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, 1441 Moursund Street, Houston, TX 77030, USA.
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Marin JJG. How we have learned about the complexity of physiology, pathobiology and pharmacology of bile acids and biliary secretion. World J Gastroenterol 2008; 14:5617-9. [PMID: 18837076 PMCID: PMC2748194 DOI: 10.3748/wjg.14.5617] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
During the last decades the concept of bile secretion as merely a way to add detergent components to the intestinal mixture to facilitate fat digestion/absorption and to eliminate side products of heme metabolism has evolved considerably. In the series of mini-reviews that the World Journal of Gastroenterology is to publish in its section of “Highlight Topics”, we will intend to give a brief but updated overview of our knowledge in this field. This introductory letter is intended to thank all scientists who have contributed to the development of this area of knowledge in gastroenterology.
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Stahl S, Davies MR, Cook DI, Graham MJ. Nuclear hormone receptor-dependent regulation of hepatic transporters and their role in the adaptive response in cholestasis. Xenobiotica 2008; 38:725-77. [DOI: 10.1080/00498250802105593] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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