101
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Preliminary structure-activity relationship on theonellasterol, a new chemotype of FXR antagonist, from the marine sponge Theonella swinhoei. Mar Drugs 2012. [PMID: 23203270 PMCID: PMC3509528 DOI: 10.3390/md10112448] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Using theonellasterol as a novel FXR antagonist hit, we prepared a series of semi-synthetic derivatives in order to gain insight into the structural requirements for exhibiting antagonistic activity. These derivatives are characterized by modification at the exocyclic carbon-carbon double bond at C-4 and at the hydroxyl group at C-3 and were prepared from theonellasterol using simple reactions. Pharmacological investigation showed that the introduction of a hydroxyl group at C-4 as well as the oxidation at C-3 with or without concomitant modification at the exomethylene functionality preserve the ability of theonellasterol to inhibit FXR transactivation caused by CDCA. Docking analysis showed that the placement of these molecules in the FXR-LBD is well stabilized when on ring A functional groups, able to form hydrogen bonds and π interactions, are present.
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102
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Fujino T, Takeuchi A, Maruko-Ohtake A, Ohtake Y, Satoh J, Kobayashi T, Tanaka T, Ito H, Sakamaki R, Kashimura R, Ando K, Nishimaki-Mogami T, Ohkubo Y, Kitamura N, Sato R, Kikugawa K, Hayakawa M. Critical role of farnesoid X receptor for hepatocellular carcinoma cell proliferation. J Biochem 2012; 152:577-86. [PMID: 22969091 DOI: 10.1093/jb/mvs101] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Farnesoid X receptor (FXR), a pivotal factor maintaining bile acid homeostasis, has been recently shown to be a critical factor required for liver regeneration. The elucidation of the mechanism how FXR controls the proliferation of hepatocellular carcinoma cells is useful to establish the therapy for liver cancer. Here, we show that FXR plays a crucial role in the proliferation of human hepatocellular carcinoma cell line, HepG2, Huh7 and HLE. The treatment of HepG2 with FXR siRNA elevates the level of p16/INK4a expression resulting in the inhibition of cell proliferation. By contrast, FXR activation reduces p16/INK4a expression and stimulates the cell proliferation. The ectopic expression of the active form of Ras that causes strong activation of extracellular signal-regulated kinase (ERK) leads to the decrease in FXR expression, suggesting that FXR expression is negatively regulated via Ras/ERK pathway. The elevation of p16/INK4a expression and the inhibition of cell proliferation by FXR knockdown are also observed in Huh7 and HLE. In this study, we have suggested a novel mechanism by which hepatocellular carcinoma cell proliferation is regulated: FXR stimulates cell proliferation by suppressing the p16/INK4a expression, whereas Ras/ERK pathway down-regulates the FXR expression, leading to the suppressed cell proliferation in hepatocellular carcinoma cell lines.
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Affiliation(s)
- Tomofumi Fujino
- School of Pharmacy, Tokyo University of Pharmacy and Life Science, Tokyo, Japan.
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103
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Abstract
Non-alcoholic steatohepatitis (NASH) has a prevalence of 1% in Western countries. Its causes as well as its medical treatment are, to date, still debated. Recently, studies of agents suggested to have antiapoptotic, insulin-sensitizing or anti-inflammatory effects in patients with NASH have been conducted, one of which is ursodeoxycholic acid (UDCA), a tertiary bile acid. Between 1994 and 2008, four prospective randomized, double-blind, placebo-controlled studies of the treatment of NASH with UDCA were conducted. The first study, by Lindor et al., compared the impact of 13-15 mg/kg/day of UDCA to a placebo. The second study by Dufour et al. had an additional third arm that administered combination therapy with UDCA and vitamin E. The third and fourth studies by Leuschner et al. and by Ratziu et al. evaluated high doses of UDCA at 25-35 mg/kg/day, and used liver biopsies and serum liver enzyme levels to evaluate the impact of UDCA. With the exception of Ratziu et al.'s study, which was lacking a second liver biopsy, none of these studies showed any significant differences in the treatment of NASH with UDCA compared with a placebo. However, Dufour et al. did observe a significant improvement of NASH with the combination (UDCA/VitE) vs placebo therapy, whereas UDCA monotherapy was not effective in the treatment of NASH. Nevertheless, the effects of other bile acids and combination therapies need to be explored.
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Affiliation(s)
- Fabia Liechti
- University Clinic for Visceral Surgery and Medicine, Inselspital, University of Berne, 3010 Bern Switzerland
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104
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Farnesoid X receptor: from medicinal chemistry to clinical applications. Future Med Chem 2012; 4:877-91. [PMID: 22571613 DOI: 10.4155/fmc.12.41] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The farnesoid X receptor (FXR) is a bile sensor that acts in coordination with other nuclear receptors to regulate essential steps in bile acid uptake, metabolism and excretion. In addition, FXR is an ancillary receptor involved in lipid and glucose homeostasis. Steroidal and non-steroidal FXR ligands are currently available. Both groups have shown limitations in the preclinical studies regarding absorption, metabolism, specificity of target and intrinsic toxicity. FXR ligands endowed with agonistic activity are under development for the treatment of cholestatic liver diseases, including primary biliary cirrhosis and metabolic disorders linked to insulin resistance. Despite the fact that results from preclinical models are encouraging, targeting FXR holds potential for side effects (i.e., impaired cholesterol disposal and cholestasis). Thus, results from FXR gene-ablated mice and mice administered an FXR antagonist support a role for FXR antagonists or modulators (i.e., FXR agonists that selectively activate specific subsets of FXR target genes in a tissue) or co-regulator-specific manner.
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105
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Huang H, Yu Y, Gao Z, Zhang Y, Li C, Xu X, Jin H, Yan W, Ma R, Zhu J, Shen X, Jiang H, Chen L, Li J. Discovery and Optimization of 1,3,4-Trisubstituted-pyrazolone Derivatives as Novel, Potent, and Nonsteroidal Farnesoid X Receptor (FXR) Selective Antagonists. J Med Chem 2012; 55:7037-53. [DOI: 10.1021/jm3002718] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Huang Huang
- Shanghai Key
Laboratory of New Drug Design, School of Pharmacy, East China University
of Science and Technology, 130 Mei Long Road, Shanghai 200237, China
| | - Ying Yu
- Shanghai Key
Laboratory of New Drug Design, School of Pharmacy, East China University
of Science and Technology, 130 Mei Long Road, Shanghai 200237, China
| | - Zhenting Gao
- Shanghai Key
Laboratory of New Drug Design, School of Pharmacy, East China University
of Science and Technology, 130 Mei Long Road, Shanghai 200237, China
| | - Yong Zhang
- Department of Biochemistry, Zunyi Medical
College, 201 Dalian Road, Zunyi, Guizhou 563003, China
| | - Chenjing Li
- State Key Laboratory of Drug
Research, Shanghai Institute of Materia Medica, Chinese Academy of
Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, China
| | - Xing Xu
- State Key Laboratory of Drug
Research, Shanghai Institute of Materia Medica, Chinese Academy of
Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, China
| | - Hui Jin
- Shanghai Key
Laboratory of New Drug Design, School of Pharmacy, East China University
of Science and Technology, 130 Mei Long Road, Shanghai 200237, China
| | - Wenzhong Yan
- Shanghai Key
Laboratory of New Drug Design, School of Pharmacy, East China University
of Science and Technology, 130 Mei Long Road, Shanghai 200237, China
| | - Ruoqun Ma
- Shanghai Key
Laboratory of New Drug Design, School of Pharmacy, East China University
of Science and Technology, 130 Mei Long Road, Shanghai 200237, China
| | - Jin Zhu
- Shanghai Key
Laboratory of New Drug Design, School of Pharmacy, East China University
of Science and Technology, 130 Mei Long Road, Shanghai 200237, China
| | - Xu Shen
- Shanghai Key
Laboratory of New Drug Design, School of Pharmacy, East China University
of Science and Technology, 130 Mei Long Road, Shanghai 200237, China
- State Key Laboratory of Drug
Research, Shanghai Institute of Materia Medica, Chinese Academy of
Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, China
| | - Hualiang Jiang
- Shanghai Key
Laboratory of New Drug Design, School of Pharmacy, East China University
of Science and Technology, 130 Mei Long Road, Shanghai 200237, China
- State Key Laboratory of Drug
Research, Shanghai Institute of Materia Medica, Chinese Academy of
Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, China
| | - Lili Chen
- State Key Laboratory of Drug
Research, Shanghai Institute of Materia Medica, Chinese Academy of
Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, China
| | - Jian Li
- Shanghai Key
Laboratory of New Drug Design, School of Pharmacy, East China University
of Science and Technology, 130 Mei Long Road, Shanghai 200237, China
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106
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Ichikawa R, Takayama T, Yoneno K, Kamada N, Kitazume MT, Higuchi H, Matsuoka K, Watanabe M, Itoh H, Kanai T, Hisamatsu T, Hibi T. Bile acids induce monocyte differentiation toward interleukin-12 hypo-producing dendritic cells via a TGR5-dependent pathway. Immunology 2012; 136:153-62. [PMID: 22236403 DOI: 10.1111/j.1365-2567.2012.03554.x] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Dendritic cells (DCs) are known as antigen-presenting cells and play a central role in both innate and acquired immunity. Peripheral blood monocytes give rise to resident and recruited DCs in lymph nodes and non-lymphoid tissues. The ligands of nuclear hormone receptors can modulate DC differentiation and so influence various biological functions of DCs. The role of bile acids (BAs) as signalling molecules has recently become apparent, but the functional role of BAs in DC differentiation has not yet been elucidated. We show that DCs derived from human peripheral blood monocytes cultured with a BA produce lower levels of interleukin-12 (IL-12) and tumour necrosis factor-α in response to stimulation with commensal bacterial antigens. Stimulation through the nuclear receptor farnesoid X (FXR) did not affect the differentiation of DCs. However, DCs differentiated with the specific agonist for TGR5, a transmembrane BA receptor, showed an IL-12 hypo-producing phenotype. Expression of TGR5 could only be identified in monocytes and was rapidly down-regulated during monocyte differentiation to DCs. Stimulation with 8-bromoadenosine-cyclic AMP (8-Br-cAMP), which acts downstream of TGR5 signalling, also promoted differentiation into IL-12 hypo-producing DCs. These results indicate that BAs induce the differentiation of IL-12 hypo-producing DCs from monocytes via the TGR5-cAMP pathway.
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Affiliation(s)
- Riko Ichikawa
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan
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107
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De Marino S, Ummarino R, D'Auria MV, Chini MG, Bifulco G, D'Amore C, Renga B, Mencarelli A, Petek S, Fiorucci S, Zampella A. 4-Methylenesterols from Theonella swinhoei sponge are natural pregnane-X-receptor agonists and farnesoid-X-receptor antagonists that modulate innate immunity. Steroids 2012; 77:484-95. [PMID: 22285937 DOI: 10.1016/j.steroids.2012.01.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Revised: 01/09/2012] [Accepted: 01/10/2012] [Indexed: 01/01/2023]
Abstract
We report the isolation and the structural elucidation of a family of polyhydroxylated steroids from the marine sponge Theonella swinhoei. Decodification of interactions of these family with nuclear receptors shows that these steroids are potent agonists of human pregnane-X-receptor (PXR) and antagonists of human farnesoid-X-receptor (FXR) with the putative binding mode to nuclear receptors (NRs) obtained through docking experiments. By using monocytes isolated from transgenic mice harboring hPXR, we demonstrated that swinhosterol B counter-regulates induction of pro-inflammatory cytokines in a PXR-dependent manner. Exposure of CD4(+) T cells to swinhosterol B upregulates the expression of IL-10 causing a shift toward a T cells regulatory phenotype in a PXR dependent manner. These results pave the way to development of a dual PXR agonist/FXR antagonist with a robust immunomodulatory activity and endowed with the ability to modulate the expression of bile acid-regulated genes in the liver.
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MESH Headings
- Animals
- Binding Sites
- CD4-Positive T-Lymphocytes/drug effects
- CD4-Positive T-Lymphocytes/metabolism
- Cholesterol/analogs & derivatives
- Cholesterol/chemistry
- Cholesterol/isolation & purification
- Cholesterol/pharmacology
- Cytokines/genetics
- Cytokines/metabolism
- Gene Expression/drug effects
- Gene Expression Profiling
- Hep G2 Cells
- Humans
- Isomerism
- Liver/drug effects
- Liver/metabolism
- Liver/pathology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Models, Molecular
- Molecular Structure
- Monocytes/drug effects
- Monocytes/metabolism
- Pregnane X Receptor
- Protein Binding
- Protein Structure, Tertiary
- Receptors, Cytoplasmic and Nuclear/antagonists & inhibitors
- Receptors, Cytoplasmic and Nuclear/chemistry
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Steroid/agonists
- Receptors, Steroid/chemistry
- Receptors, Steroid/genetics
- Reverse Transcriptase Polymerase Chain Reaction
- Sterols/chemistry
- Sterols/isolation & purification
- Sterols/pharmacology
- T-Lymphocytes, Regulatory/drug effects
- T-Lymphocytes, Regulatory/metabolism
- Theonella/chemistry
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Affiliation(s)
- Simona De Marino
- Dipartimento di Chimica delle Sostanze Naturali, Università di Napoli "Federico II", Via D. Montesano 49, 80131 Napoli, Italy
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108
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Investigation of imatinib and other approved drugs as starting points for antidiabetic drug discovery with FXR modulating activity. Biochem Pharmacol 2012; 83:1674-81. [PMID: 22414727 DOI: 10.1016/j.bcp.2012.02.027] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Revised: 02/25/2012] [Accepted: 02/28/2012] [Indexed: 12/11/2022]
Abstract
A self-organizing map (SOM) is a virtual screening method used for correlation of molecular structure and potential biological activity on a certain target and offers a way to represent multi-dimensional data of large databases in a two-dimensional space. Large databases, for example the DrugBank database, provide information about biological activity and chemical structure of small molecules and are widely used in drug development for identification of new lead structures. The farnesoid X receptor (FXR) is a ligand activated transcription factor involved in key regulation mechanisms within glucose and lipid homeostasis. Although FXR became an established target in drug development for diseases associated with lipid, glucose or hepatic disorders during the last decade, none of the developed compounds have reached later phases of clinical development so far. We used a SOM trained with known FXR ligands to screen the DrugBank database for potential ligands for FXR. In this article, we report the successful identification of six approved drugs out of the Drugbank as FXR modulators (ketoconazole, pentamidine, dobutamine, imatinib, papaverine and montelukast) by using a SOM for screening of the DrugBank database. We show FXR modulation by selected compounds in a full length FXR transactivation assay and modulation of a FXR target gene by imatinib.
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109
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Neuschwander-Tetri BA. Farnesoid x receptor agonists: what they are and how they might be used in treating liver disease. Curr Gastroenterol Rep 2012; 14:55-62. [PMID: 22094889 DOI: 10.1007/s11894-011-0232-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The farnesoid X receptor (FXR) is a nuclear receptor expressed in the liver, small intestine, kidneys, and adrenals. In mouse liver, FXR is bound to thousands of genomic DNA binding sites. Conformational changes induced by bile acid binding to pre-bound FXR leads to increased expression of a variety of genes. These changes lead to decreased intracellular bile acid concentrations through multiple mechanisms including decreased bile acid synthesis from cholesterol, decreased hepatocellular uptake and increased secretion into bile. Activated FXR also modulates the expression of genes responsible for lipid and glucose metabolism. One of the other genes induced by activated FXR is a small heterodimeric partner (SHP), a protein that represses expression of specific genes. The effects of pharmacologically modulating FXR activation in humans is only beginning to be explored with the hopes of favorably altering lipid and glucose metabolism to address the vascular and metabolic complications of obesity and diabetes.
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Affiliation(s)
- Brent A Neuschwander-Tetri
- Division of Gastroenterology and Hepatology, Saint Louis University School of Medicine, St. Louis, MO 63110, USA.
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110
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Chini MG, Jones CR, Zampella A, D’Auria MV, Renga B, Fiorucci S, Butts CP, Bifulco G. Quantitative NMR-Derived Interproton Distances Combined with Quantum Mechanical Calculations of 13C Chemical Shifts in the Stereochemical Determination of Conicasterol F, a Nuclear Receptor Ligand from Theonella swinhoei. J Org Chem 2012; 77:1489-96. [DOI: 10.1021/jo2023763] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Maria Giovanna Chini
- Dipartimento di Scienze Farmaceutiche
e Biomediche, Università di Salerno, via Ponte don Melillo, 84084 Fisciano (SA), Italy
| | - Catharine R. Jones
- Department of Chemistry, University of Bristol, Cantocks Close, BS8 1TS Bristol,
United Kingdom
| | - Angela Zampella
- Dipartimento
di Chimica delle
Sostanze Naturali, Università di Napoli “Federico II”, via D. Montesano 49, 80131 Napoli, Italy
| | - Maria Valeria D’Auria
- Dipartimento
di Chimica delle
Sostanze Naturali, Università di Napoli “Federico II”, via D. Montesano 49, 80131 Napoli, Italy
| | - Barbara Renga
- Dipartimento di Medicina Clinica
e Sperimentale, Università di Perugia, Nuova Facoltà di Medicina e Chirurgia, Via Gerardo Dottori
1 S. Andrea delle Fratte, 06132 Perugia, Italy
| | - Stefano Fiorucci
- Dipartimento di Medicina Clinica
e Sperimentale, Università di Perugia, Nuova Facoltà di Medicina e Chirurgia, Via Gerardo Dottori
1 S. Andrea delle Fratte, 06132 Perugia, Italy
| | - Craig P. Butts
- Department of Chemistry, University of Bristol, Cantocks Close, BS8 1TS Bristol,
United Kingdom
| | - Giuseppe Bifulco
- Dipartimento di Scienze Farmaceutiche
e Biomediche, Università di Salerno, via Ponte don Melillo, 84084 Fisciano (SA), Italy
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111
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112
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Nukitrangsan N, Okabe T, Toda T, Inafuku M, Iwasaki H, Oku H. Effect of Peucedanum japonicum Thunb Extract on High-fat Diet-induced Obesity and Gene Expression in Mice. J Oleo Sci 2012; 61:89-101. [DOI: 10.5650/jos.61.89] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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113
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Sepe V, Ummarino R, D'Auria MV, Chini MG, Bifulco G, Renga B, D'Amore C, Debitus C, Fiorucci S, Zampella A. Conicasterol E, a small heterodimer partner sparing farnesoid X receptor modulator endowed with a pregnane X receptor agonistic activity, from the marine sponge Theonella swinhoei. J Med Chem 2011; 55:84-93. [PMID: 22126372 DOI: 10.1021/jm201004p] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report the isolation and pharmacological characterization of conicasterol E isolated from the marine sponge Theonella swinhoei. Pharmacological characterization of this steroid in comparison to CDCA, a natural FXR ligand, and 6-ECDCA, a synthetic FXR agonist generated by an improved synthetic strategy, and rifaximin, a potent PXR agonist, demonstrated that conicasterol E is an FXR modulator endowed with PXR agonistic activity. Conicasterol E induces the expression of genes involved in bile acids detoxification without effect on the expression of small heterodimer partner (SHP), thus sparing the expression of genes involved in bile acids biosynthesis. The relative positioning in the ligand binding domain of FXR, explored through docking calculations, demonstrated a different spatial arrangement for conicasterol E and pointed to the presence of simultaneous and efficient interactions with the receptor. In summary, conicasterol E represents a FXR modulator and PXR agonist that might hold utility in treatment of liver disorders.
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Affiliation(s)
- Valentina Sepe
- Dipartimento di Chimica delle Sostanze Naturali, Università di Napoli "Federico II", Via D. Montesano 49, 80131 Napoli, Italy
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114
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Grienke U, Mihály-Bison J, Schuster D, Afonyushkin T, Binder M, Guan SH, Cheng CR, Wolber G, Stuppner H, Guo DA, Bochkov VN, Rollinger JM. Pharmacophore-based discovery of FXR-agonists. Part II: identification of bioactive triterpenes from Ganoderma lucidum. Bioorg Med Chem 2011; 19:6779-91. [PMID: 22014750 PMCID: PMC3254236 DOI: 10.1016/j.bmc.2011.09.039] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Revised: 09/15/2011] [Accepted: 09/21/2011] [Indexed: 01/06/2023]
Abstract
The farnesoid X receptor (FXR) belonging to the metabolic subfamily of nuclear receptors is a ligand-induced transcriptional activator. Its central function is the physiological maintenance of bile acid homeostasis including the regulation of glucose and lipid metabolism. Accessible structural information about its ligand-binding domain renders FXR an attractive target for in silico approaches. Integrated to natural product research these computational tools assist to find novel bioactive compounds showing beneficial effects in prevention and treatment of, for example, the metabolic syndrome, dyslipidemia, atherosclerosis, and type 2 diabetes. Virtual screening experiments of our in-house Chinese Herbal Medicine database with structure-based pharmacophore models, previously generated and validated, revealed mainly lanostane-type triterpenes of the TCM fungus Ganoderma lucidum Karst. as putative FXR ligands. To verify the prediction of the in silico approach, two Ganoderma fruit body extracts and compounds isolated thereof were pharmacologically investigated. Pronounced FXR-inducing effects were observed for the extracts at a concentration of 100 μg/mL. Intriguingly, five lanostanes out of 25 secondary metabolites from G. lucidum, that is, ergosterol peroxide (2), lucidumol A (11), ganoderic acid TR (12), ganodermanontriol (13), and ganoderiol F (14), dose-dependently induced FXR in the low micromolar range in a reporter gene assay. To rationalize the binding interactions, additional pharmacophore profiling and molecular docking studies were performed, which allowed establishing a first structure-activity relationship of the investigated triterpenes.
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Key Words
- cdca, chenodeoxycholic acid
- chm, 3d structural database of chinese herbal medicine
- dmem, dulbecco’s modified eagle’s medium
- fbs, fetal bovine serum
- fxr, farnesoid x receptor
- hek-293, human embryonic kidney-293
- pdb, protein data bank
- rxr, 9-cis-retionic acid receptor
- shp-1, small heterodimer partner 1
- vh, virtual hit
- farnesoid x receptor
- ganoderma lucidum
- lanostane triterpenes
- ganoderic acids
- molecular modeling
- virtual screening
- natural products
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Affiliation(s)
- Ulrike Grienke
- Institute of Pharmacy/Pharmacognosy and Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innrain 52c, 6020 Innsbruck, Austria
| | - Judit Mihály-Bison
- Center of Biomolecular Medicine and Pharmacology, Department of Vascular Biology and Thrombosis Research, Medical University of Vienna, Schwarzspanierstraße 17, 1090 Vienna, Austria
| | - Daniela Schuster
- Computer-Aided Molecular Design Group, Institute of Pharmacy/Pharmaceutical Chemistry and Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innrain 52c, 6020 Innsbruck, Austria
| | - Taras Afonyushkin
- Center of Biomolecular Medicine and Pharmacology, Department of Vascular Biology and Thrombosis Research, Medical University of Vienna, Schwarzspanierstraße 17, 1090 Vienna, Austria
| | - Markus Binder
- Center of Biomolecular Medicine and Pharmacology, Department of Vascular Biology and Thrombosis Research, Medical University of Vienna, Schwarzspanierstraße 17, 1090 Vienna, Austria
| | - Shu-hong Guan
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Zhang Jiang Hi-Tech Park, Pudong, 201203 Shanghai, China
| | - Chun-ru Cheng
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Zhang Jiang Hi-Tech Park, Pudong, 201203 Shanghai, China
| | - Gerhard Wolber
- Institute of Pharmacy/Pharmaceutical Chemistry, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195 Berlin, Germany
| | - Hermann Stuppner
- Institute of Pharmacy/Pharmacognosy and Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innrain 52c, 6020 Innsbruck, Austria
| | - De-an Guo
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Zhang Jiang Hi-Tech Park, Pudong, 201203 Shanghai, China
| | - Valery N. Bochkov
- Center of Biomolecular Medicine and Pharmacology, Department of Vascular Biology and Thrombosis Research, Medical University of Vienna, Schwarzspanierstraße 17, 1090 Vienna, Austria
| | - Judith M. Rollinger
- Institute of Pharmacy/Pharmacognosy and Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innrain 52c, 6020 Innsbruck, Austria
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115
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Bile acid signaling after an oral glucose tolerance test. Chem Phys Lipids 2011; 164:525-9. [DOI: 10.1016/j.chemphyslip.2011.05.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 04/28/2011] [Accepted: 05/10/2011] [Indexed: 01/16/2023]
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116
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Role of nuclear receptors for bile acid metabolism, bile secretion, cholestasis, and gallstone disease. Biochim Biophys Acta Mol Basis Dis 2011; 1812:867-78. [DOI: 10.1016/j.bbadis.2010.12.021] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Revised: 12/21/2010] [Accepted: 12/22/2010] [Indexed: 12/12/2022]
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117
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Abstract
Atherosclerosis is the leading cause of illness and death. Therapeutic strategies aimed at reducing cholesterol plasma levels have shown efficacy in either reducing progression of atherosclerotic plaques and atherosclerosis-related mortality. The farnesoid-X-receptor (FXR) is a member of metabolic nuclear receptors (NRs) superfamily activated by bile acids. In entero-hepatic tissues, FXR functions as a bile acid sensor regulating bile acid synthesis, detoxification and excretion. In the liver FXR induces the expression of an atypical NR, the small heterodimer partner, which subsequently inhibits the activity of hepatocyte nuclear factor 4α repressing the transcription of cholesterol 7a-hydroxylase, the critical regulatory gene in bile acid synthesis. In the intestine FXR induces the release of fibroblast growth factor 15 (FGF15) (or FGF19 in human), which activates hepatic FGF receptor 4 (FGFR4) signalling to inhibit bile acid synthesis. In rodents, FXR activation decreases bile acid synthesis and lipogenesis and increases lipoprotein clearance, and regulates glucose homeostasis by reducing liver gluconeogenesis. FXR exerts counter-regulatory effects on macrophages, vascular smooth muscle cells and endothelial cells. FXR deficiency in mice results in a pro-atherogenetic lipoproteins profile and insulin resistance but FXR−/– mice fail to develop any detectable plaques on high-fat diet. Synthetic FXR agonists protect against development of aortic plaques formation in murine models characterized by pro-atherogenetic lipoprotein profile and accelerated atherosclerosis, but reduce HDL levels. Because human and mouse lipoprotein metabolism is modulated by different regulatory pathways the potential drawbacks of FXR ligands on HDL and bile acid synthesis need to addressed in relevant clinical settings.
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Affiliation(s)
- Andrea Mencarelli
- Dipartimento di Medicina Clinica e Sperimentale, Università Degli Studi di Perugia, Perugia, Italy
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118
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Lian F, Wang Y, Chen J, Xu H, Yang X, Liang L, Zhan Z, Ye Y, Chen M. Activation of farnesoid X receptor attenuates liver injury in systemic lupus erythematosus. Rheumatol Int 2011; 32:1705-10. [PMID: 21431940 DOI: 10.1007/s00296-011-1874-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2010] [Accepted: 02/18/2011] [Indexed: 10/18/2022]
Abstract
To investigate the expression and effect of farnesoid X receptor (FXR) on systemic lupus erythematosus (SLE) liver dysfunction and indicate its hepatoprotective role and the immunomodulatory property. mRNA and protein levels of FXR were determined on the liver specimens of SLE patients with liver injury as well as MRL/lpr rodent models. The FXR agonist chenodeoxycholic acid (CDCA) was administrated to MRL/lpr mice and the control BALB/C with concanavalin A (ConA)-induced liver injury. Blood samples were taken 0, 4, 8, 12, 16, and 24 h after ConA injection for the detection of serum ALT, AST, IFN-γ, TNF-α, and IL-6. FXR was down-regulated at both mRNA and protein levels in the liver specimens of SLE patients with liver injury as well as MRL/lpr mice. MRL/lpr was more susceptible to ConA than BALB/C indicated by significantly higher levels of aminotransferase and inflammatory cytokines. Activation of FXR by CDCA significantly reduced aminotransferase and inflammatory cytokines IFN-γ, TNF-α, and IL-6 caused by ConA injection in MRL/lpr mice. FXR was down-regulated in SLE patients as well as MRL/lpr lupus models with liver dysfunction. FXR activation ameliorated liver injury and suppressed inflammatory cytokines, thereby showing its protective function in SLE. Our findings raised the promising potential target for the treatment of SLE liver injury.
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Affiliation(s)
- Fan Lian
- Department of Rheumatology and Clinical Immunology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
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119
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Gardmo C, Tamburro A, Modica S, Moschetta A. Proteomics for the discovery of nuclear bile acid receptor FXR targets. Biochim Biophys Acta Mol Basis Dis 2011; 1812:836-41. [PMID: 21439373 PMCID: PMC3117992 DOI: 10.1016/j.bbadis.2011.03.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2010] [Revised: 02/23/2011] [Accepted: 03/15/2011] [Indexed: 01/24/2023]
Abstract
Nuclear receptors (NRs) are important pharmacological targets for a number of diseases, including cancer and metabolic disorders. To unmask the direct role of NR function it is fundamental to find the NR targets. During the last few years several NRs have been shown to affect microRNA expression, thereby modulating protein levels. The farnesoid X receptor (FXR), the main regulator of bile acid (BA) homeostasis, also regulates cholesterol, lipid and glucose metabolism. Here we used, for the first time, a proteomics approach on mice treated with a FXR ligand to find novel hepatic FXR targets. Nineteen spots with a more than two-fold difference in protein amounts were found by 2D-DIGE and 20 proteins were identified by MALDI-TOF MS as putative novel FXR targets. The most striking feature of the protein list was the great number of mitochondrial proteins, indicating a substantial impact of FXR activation on mitochondrial function in the liver. To examine if the differences found in the proteomics assay reflected differences at the mRNA level, a microarray assay was generated on hepatic samples from wild type and FXR−/− mice treated with a FXR ligand and compared to vehicle treatment. At least six proteins were shown to be regulated only at a post-transcriptional level. In conclusion, our study provides the impetus to include proteomic analysis for the identification of novel targets of transcription factors, such as NRs. This article is part of a Special Issue entitled: Translating nuclear receptors from health to disease.
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Affiliation(s)
- Cissi Gardmo
- Department of Translational Pharmacology, Consorzio Mario Negri Sud, Santa Maria Imbaro (CH), 66030, Italy.
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120
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Režen T. The impact of cholesterol and its metabolites on drug metabolism. Expert Opin Drug Metab Toxicol 2011; 7:387-98. [PMID: 21320036 DOI: 10.1517/17425255.2011.558083] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
INTRODUCTION Global prevalence of Western-type diet has increased in the last decades resulting in occurrence of certain chronic diseases. This type of diet is also linked to high-cholesterol intake and increase in blood cholesterol. Many of the molecular mechanisms of dealing with increased levels of cholesterol and its metabolites have been elucidated in animal models and humans. It is also evident that cholesterol metabolism is closely connected to drug metabolism. Cholesterol/bile acids and drugs share many transporters, enzymes and regulatory proteins which are key points in the crosstalk. AREAS COVERED This review presents an overview of the effect of cholesterol and its metabolites on drug metabolism with special emphasis on species-specific differences. The article focuses on the role of nuclear receptors farnesoid X receptor, vitamin D receptor and liver X receptor in the regulation of drug metabolism genes and the role of cholesterol biosynthesis intermediates, oxysterols and bile acids in the induction of drug metabolism through pregnane X receptor. EXPERT OPINION Studies show that the regulation of drug metabolism by sterols is multileveled. Many species-dependent differences were observed which hinder the transfer of findings from model animals to humans. As of now, there is little evidence available for cholesterol impact on drug metabolism in vivo in humans. There is also the need to confirm the results obtained in animal models and in vitro analyses in human cells but this is very difficult given the current lack of tools.
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Affiliation(s)
- Tadeja Režen
- Faculty of Medicine, University of Ljubljana, Institute of Biochemistry, Vrazov Trg 2, SI-1000 Ljubljana, Slovenia.
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121
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Sepe V, Bifulco G, Renga B, D'Amore C, Fiorucci S, Zampella A. Discovery of sulfated sterols from marine invertebrates as a new class of marine natural antagonists of farnesoid-X-receptor. J Med Chem 2011; 54:1314-20. [PMID: 21309576 DOI: 10.1021/jm101336m] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
We report the biochemical characterization of sulfated polyhydroxysterols isolated from marine invertebrates as potent antagonists of farnesoid-X-receptor (FXR), a ligand-regulated transcription factor involved in the regulation of lipid and glucose homeostasis in mammals. Molecular characterization of a library of sulfated polyhydroxysteroids resulted in the identification of a first FXR antagonist. In contrast to partial antagonists, this compound was endowed with an antagonistic activity on the expression of a subset of FXR-regulated genes in liver cells and abrogated the release of nuclear coreceptor from the promoter of these genes. The putative binding mode to FXR, obtained through docking calculations, suggested the crucial role played by the bent shape of the molecule as well as the presence of one hydroxyl group in its side chain. This compound is a major tool to explore the effect of FXR inhibition in pharmacological settings.
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Affiliation(s)
- Valentina Sepe
- Dipartimento di Chimica delle Sostanze Naturali, Università di Napoli Federico II, via D Montesano 49, 80131 Napoli, Italy
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122
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Nuclear receptor PXR, transcriptional circuits and metabolic relevance. Biochim Biophys Acta Mol Basis Dis 2011; 1812:956-63. [PMID: 21295138 DOI: 10.1016/j.bbadis.2011.01.014] [Citation(s) in RCA: 162] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Revised: 01/25/2011] [Accepted: 01/26/2011] [Indexed: 12/14/2022]
Abstract
The pregnane X receptor (PXR, NR1I2) is a ligand activated transcription factor that belongs to the nuclear hormone receptor (NR) superfamily. PXR is highly expressed in the liver and intestine, but low levels of expression have also been found in many other tissues. PXR plays an integral role in xenobiotic and endobiotic metabolism by regulating the expression of drug-metabolizing enzymes and transporters, as well as genes implicated in the metabolism of endobiotics. PXR exerts its transcriptional regulation by binding to its DNA response elements as a heterodimer with the retinoid X receptor (RXR) and recruitment of a host of coactivators. The biological and physiological implications of PXR activation are broad, ranging from drug metabolism and drug-drug interactions to the homeostasis of numerous endobiotics, such as glucose, lipids, steroids, bile acids, bilirubin, retinoic acid, and bone minerals. The purpose of this article is to provide an overview on the transcriptional circuits and metabolic relevance controlled by PXR. This article is part of a Special Issue entitled: Translating Nuclear Receptors from Health to Disease.
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123
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SHP-dependent and -independent induction of peroxisome proliferator-activated receptor-γ by the bile acid sensor farnesoid X receptor counter-regulates the pro-inflammatory phenotype of liver myofibroblasts. Inflamm Res 2011; 60:577-87. [PMID: 21279417 DOI: 10.1007/s00011-010-0306-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Revised: 12/20/2010] [Accepted: 12/23/2010] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVE The regulation of hepatic stellate cells (HSCs) by bacterial lipopolysaccharide (LPS) represents a recently-discovered and novel mechanism for hepatic injury and fibrosis. Stimulation of HSCs with LPS results in a rapid and marked induction of interleukin (IL)1β, IL6 and tumor necrosis factor α. These events lead to the development of the activated phenotype in the HSCs associated with fibrosis and inflammation in the injured liver. We have previously demonstrated that farnesoid X receptor (FXR) activation increases transcription of rat peroxisome proliferator-activated receptor-γ (PPARγ) gene in HSCs. We aimed at evaluating the molecular mechanism of the transcriptional regulation of the PPARγ gene by FXR. METHODS Real-time PCR, ELISA, transactivations, EMSA and ChIP experiments were performed in HSC-T6 cells, in primary HSCs, in HEK293T cells and in CCl(4)-treated rats. RESULTS In vivo and in vitro activation of FXR downregulates cytokines and collagen(α)1 while inducing PPARγ and small heterodimer partner (SHP). NUBIScan analysis of rat PPARγ promoter revealed the presence of a putative FXR response element. Cotransfection with FXR/retinoic acid receptor significantly enhanced chenodeoxycholic acid-induced luciferase activity. EMSA experiments demonstrated that FXR was able to bind to an inverted repeat-1 sequence and ChIP experiments confirmed that FXR is recruited on the PPARγ promoter. CONCLUSION The present study provides a molecular basis for the physiological cross-talk between FXR and PPARγ pathways in HSCs.
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Choi H, Hwang H, Chin J, Kim E, Lee J, Nam SJ, Lee BC, Rho BJ, Kang H. Tuberatolides, potent FXR antagonists from the Korean marine tunicate Botryllus tuberatus. JOURNAL OF NATURAL PRODUCTS 2011; 74:90-4. [PMID: 21142112 DOI: 10.1021/np100489u] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
One isoprenoid, tuberatolide A (1), meroterpenoids tuberatolide B (2) and 2'-epi-tuberatolide B (3), and the known meroterpenoids yezoquinolide (4), (R)-sargachromenol (5), and (S)-sargachromenol (6) were isolated from the Korean marine tunicate Botryllus tuberatus. The structures of these compounds were elucidated by NMR, MS, and CD spectroscopic analyses. These terpenoids antagonized the chenodeoxycholic acid (CDCA)-activated human farnesoid X receptor (hFXR) in a cell-based co-transfection assay with IC(50) values as low as 1.5 μM without significant effect on steroid receptors. Furthermore, they released the co-activator peptide from the CDCA-bound hFXR ligand binding domain in cell-free surface plasmon resonance experiments.
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Affiliation(s)
- Hyukjae Choi
- Center for Marine Natural Products and Drug Discovery, School of Earth and Environmental Sciences, Seoul National University, NS-80, 151-747, Seoul, Korea
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125
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Regulation of FXR transcriptional activity in health and disease: Emerging roles of FXR cofactors and post-translational modifications. Biochim Biophys Acta Mol Basis Dis 2010; 1812:842-50. [PMID: 21130162 DOI: 10.1016/j.bbadis.2010.11.011] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Revised: 11/18/2010] [Accepted: 11/22/2010] [Indexed: 12/26/2022]
Abstract
Abnormally elevated lipid and glucose levels due to the disruption of metabolic homeostasis play causative roles in the development of metabolic diseases. A cluster of metabolic conditions, including dyslipidemia, abdominal obesity, and insulin resistance, is referred to as metabolic syndrome, which has been increasing globally at an alarming rate. The primary nuclear bile acid receptor, Farnesoid X Receptor (FXR, NR1H4), plays important roles in controlling lipid and glucose levels by regulating expression of target genes in response to bile acid signaling in enterohepatic tissues. In this review, I discuss how signal-dependent FXR transcriptional activity is dynamically regulated under normal physiological conditions and how it is dysregulated in metabolic disease states. I focus on the emerging roles of post-translational modifications (PTMs) and transcriptional cofactors in modulating FXR transcriptional activity and pathways. Dysregulation of nuclear receptor transcriptional signaling due to aberrant PTMs and cofactor interactions are key determinants in the development of metabolic diseases. Therefore, targeting such abnormal PTMs and transcriptional cofactors of FXR in disease states may provide a new molecular strategy for development of pharmacological agents to treat metabolic syndrome. This article is part of a Special Issue entitled: Translating nuclear receptors from health to disease.
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Abstract
IMPORTANCE OF THE FIELD The farnesoid X receptor (FXR) is a key regulator of cholesterol homeostasis, triglyceride synthesis and lipogenesis. Given some patients' inability to tolerate existing medications, such as the statins, for cholesterol reduction, there is a pressing need for additional medicines to treat dyslipidemia. FXR agonists have emerged in discovery and preclinical efforts to show great potential for the treatment of these and other life-impairing and life-threatening conditions. AREAS COVERED IN THIS REVIEW Recent advances in the search for novel FXR modulators are reviewed, with a particular focus on patent applications and peer-reviewed publications disclosed in the past 5 years. WHAT THE READER WILL GAIN A total of 72 patent applications and peer-reviewed articles, containing 16 generic structure classes with nearly 5000 novel synthesized structures are reviewed. Where possible, the structure-activity relationship of these structure classes is surveyed, new insights into in vitro and in vivo efficacy of FXR agonists are disclosed, and potential new and promising therapeutic applications are revealed. TAKE HOME MESSAGE FXR agonists have proven their efficacy and safety in primates and have significant potential as therapeutic agents for the treatment of dyslipidemia and potentially an array of other disease areas.
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127
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Kim HY, Cho HK, Choi YH, Lee KS, Cheong J. Bile acids increase hepatitis B virus gene expression and inhibit interferon-α activity. FEBS J 2010; 277:2791-802. [DOI: 10.1111/j.1742-4658.2010.07695.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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128
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Chiang JYL. Hepatocyte nuclear factor 4alpha regulation of bile acid and drug metabolism. Expert Opin Drug Metab Toxicol 2010; 5:137-47. [PMID: 19239393 DOI: 10.1517/17425250802707342] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The hepatocyte nuclear factor 4alpha (HNF4alpha) is a liver-enriched nuclear receptor that plays a critical role in early morphogenesis, fetal liver development, liver differentiation and metabolism. Human HNF4alpha gene mutations cause maturity on-set diabetes of the young type 1, an autosomal dominant non-insulin-dependent diabetes mellitus. HNF4alpha is an orphan nuclear receptor because of which the endogenous ligand has not been firmly identified. The trans-activating activity of HNF4alpha is enhanced by interacting with co-activators and inhibited by corepressors. Recent studies have revealed that HNF4alpha plays a central role in regulation of bile acid metabolism in the liver. Bile acids are required for biliary excretion of cholesterol and metabolites, and intestinal absorption of fat, nutrients, drug and xenobiotics for transport and distribution to liver and other tissues. Bile acids are signaling molecules that activate nuclear receptors to control lipids and drug metabolism in the liver and intestine. Therefore, HNF4alpha plays a central role in coordinated regulation of bile acid and xenobiotics metabolism. Drugs that specifically activate HNF4alpha could be developed for treating metabolic diseases such as diabetes, dyslipidemia and cholestasis, as well as drug metabolism and detoxification.
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Affiliation(s)
- John Y L Chiang
- Northeastern Ohio Universities Colleges of Medicine and Pharmacy, Department of Integrative Medical Sciences, Rootstown, Ohio 44272, USA.
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129
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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: 67] [Impact Index Per Article: 4.8] [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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130
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Lee J, Padhye A, Sharma A, Song G, Miao J, Mo YY, Wang L, Kemper JK. A pathway involving farnesoid X receptor and small heterodimer partner positively regulates hepatic sirtuin 1 levels via microRNA-34a inhibition. J Biol Chem 2010; 285:12604-11. [PMID: 20185821 DOI: 10.1074/jbc.m109.094524] [Citation(s) in RCA: 208] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Sirtuin 1 (SIRT1) is a NAD-dependent deacetylase that is critically involved in diverse cellular processes including metabolic disease, cancer, and possibly aging. Despite extensive studies on SIRT1 function, how SIRT1 levels are regulated remains relatively unknown. Here, we report that the nuclear bile acid receptor farnesoid X receptor (FXR) inhibits microRNA-34a (miR-34a) in the liver, which results in a positive regulation of SIRT1 levels. Activation of FXR by the synthetic agonist GW4064 decreases hepatic miR-34a levels in normal mice, and consistently, hepatic miR-34a levels are elevated in FXR-null mice. FXR induces expression of small heterodimer partner (SHP), an orphan nuclear receptor and transcriptional corepressor, which in turn results in repression of p53, a key activator of the miR-34a gene, by inhibiting p53 occupancy at the promoter. MiR-34a decreased SIRT1 levels by binding to the 3'-untranslated region of SIRT1 mRNA, and adenovirus-mediated overexpression of miR-34a substantially decreased SIRT1 protein levels in mouse liver. Remarkably, miR-34a levels were elevated, and SIRT1 protein levels were reduced in diet-induced obese mice, and FXR activation in these mice reversed the miR-34a and SIRT1 levels, indicating an intriguing link among FXR activation, decreased miR-34a, and subsequently, increased SIRT1 levels. Our study demonstrates an unexpected role of the FXR/SHP pathway in controlling SIRT1 levels via miR-34a inhibition and that elevated miR-34a levels in obese mice contribute to decreased SIRT1 levels. Manipulation of this regulatory network may be useful for treating diseases of aging, such as metabolic disease and cancer.
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Affiliation(s)
- Jiyoung Lee
- Department of Molecular and Integrative Physiology, University of Illinois, Urbana-Champaign, Illinois 61801, USA
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Grade CVC, Salerno MS, Schubert FR, Dietrich S, Alvares LE. An evolutionarily conserved Myostatin proximal promoter/enhancer confers basal levels of transcription and spatial specificity in vivo. Dev Genes Evol 2010; 219:497-508. [DOI: 10.1007/s00427-009-0312-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2009] [Accepted: 12/02/2009] [Indexed: 12/21/2022]
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132
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Zhang Y. Farnesoid X receptor-Acting through bile acids to treat metabolic disorders. DRUG FUTURE 2010; 35:635-642. [PMID: 24465082 DOI: 10.1358/dof.2010.035.08.1520865] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Farnesoid X receptor (FXR) is a member of the nuclear receptor superfamily and plays an important role in maintaining bile acid, lipid and glucose homeostasis. Bile acids are endogenous ligands for FXR. However, bile acids may also activate pathways independent of FXR. The development of specific FXR agonists has provided important insights into the role of FXR in metabolism. Recent data have demonstrated that FXR is a therapeutic target for treatment of certain metabolic disorders. This review will focus on recent advances in the role of FXR in metabolic disease.
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Affiliation(s)
- Yanqiao Zhang
- Department of Integrative Medical Sciences Northeastern Ohio Universities College of Medicine 4209 State Route 44 Rootstown, OH 44272
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133
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Fiorucci S, Cipriani S, Baldelli F, Mencarelli A. Bile acid-activated receptors in the treatment of dyslipidemia and related disorders. Prog Lipid Res 2009; 49:171-85. [PMID: 19932133 DOI: 10.1016/j.plipres.2009.11.001] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2009] [Revised: 11/05/2009] [Accepted: 11/09/2009] [Indexed: 12/11/2022]
Abstract
Dyslipidemia is a metabolic disorder that constitutes a major risk factor for cardiovascular diseases and stroke and is often associated with diabetes mellitus and atherosclerosis. In recent years a number of ligand-activated receptors have been found to exert a role in integrating essential steps of lipid and glucose metabolism. Bile acid-activated receptors are a defined subset of nuclear and G-protein coupled receptors mainly expressed in entero-hepatic tissues for which bile acids function as signaling molecules. Primary bile acids (chenodeoxycholic acid and cholic acid) are physiological ligands/activators of farnesoid-X-receptor (FXR), pregnane-X-receptor (PXR) and constitutive androstane receptor (CAR), while litocholic acid is a ligand for the Vitamin D receptor (VDR) and the G-protein coupled receptor TGR5. Despite FXR demonstrates a high selectivity for bile acids, PXR and CAR are relatively promiscuous receptors integrating lipid homeostasis with xenobiotic metabolism. FXR, PXR, CAR and TGR exert synergistic activities in regulating lipid and glucose homeostasis and energy expenditure and liver and peripheral insulin sensitivity. Ligands for these receptors hold promise in the treatment of dyslipidemic conditions as revealed by results of a number of preclinical models but carry a defined risk for potential side effects.
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Affiliation(s)
- Stefano Fiorucci
- Dipartimento di Medicina Clinica e Sperimentale, Università Degli Studi di Perugia, Perugia, Italy.
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134
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Mansell JP, Shorez D, Farrar D, Nowghani M. Lithocholate--a promising non-calcaemic calcitriol surrogate for promoting human osteoblast maturation upon biomaterials. Steroids 2009; 74:963-70. [PMID: 19646460 DOI: 10.1016/j.steroids.2009.07.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2008] [Revised: 05/19/2009] [Accepted: 07/20/2009] [Indexed: 11/17/2022]
Abstract
BACKGROUND AND AIMS Calcitriol, an active vitamin D metabolite, has a limited application in bone repair because of its undesirable hypercalcaemic action. However it has emerged that lithocholic acid (LCA) is a non-calcaemic vitamin D receptor ligand but whether this steroid can support osteoblast maturation has not been reported. Using the human osteoblast cell line, MG63, we explored the potential of LCA and LCA derivatives to secure osteoblast maturation. RESULTS The co-stimulation of cells with LCA, LCA acetate or LCA acetate methyl ester (0.5-5 microM) and lysophosphatidic acid (LPA, 20 microM) resulted in clear, synergistic increases in MG63 maturation that was both time and dose dependent. Cells grown upon both titanium and hydroxyapatite, two widely used implant materials, responded well to co-treatment with LCA acetate (5 microM) and LPA (20 microM) as demonstrated by stark, synergistic increases in ALP activity. Evidence of activator protein-1 (AP-1) stimulation by LCA acetate (30 microM) was demonstrated using an AP-1 luciferase reporter assay. Synergistic increases in ALP activity, and therefore osteoblast maturation, were observed for MG63 cells co-stimulated with LCA acetate (5 microM) and either epidermal growth factor (10 ng/ml) or transforming growth factor-beta (10 ng/ml). Ligands acting on either the farnesoid X receptor or pregnane X receptor could not substitute for the action of LCA acetate on MG63 maturation. CONCLUSIONS Lithocholate is able to act as a calcitriol surrogate in generating mature osteoblasts. Given that LCA is non-calcaemic it is likely to find an application in bone repair/regeneration by aiding matrix calcification at implant sites.
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Affiliation(s)
- Jason Peter Mansell
- Department of Oral & Dental Science, University of Bristol Dental School, Lower Maudlin Street, Bristol, BS1 2LY, UK.
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135
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Mencarelli A, Renga B, Migliorati M, Cipriani S, Distrutti E, Santucci L, Fiorucci S. The bile acid sensor farnesoid X receptor is a modulator of liver immunity in a rodent model of acute hepatitis. THE JOURNAL OF IMMUNOLOGY 2009; 183:6657-66. [PMID: 19880446 DOI: 10.4049/jimmunol.0901347] [Citation(s) in RCA: 120] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Immune-mediated liver diseases including autoimmune and viral hepatitis are a major health problem worldwide. In this study, we report that activation of the farnesoid X receptor (FXR), a member of the ligand-activated nuclear receptor superfamily and bile sensor highly expressed in the liver, attenuates liver injury in a model of autoimmune hepatitis induced by Con A. We found that FXR gene ablation results in a time-dependent increase of liver expression (up to 20-fold in a 9-mo-old mouse) of osteopontin, a NKT cell-derived extracellular matrix protein and immunoregulatory cytokine. In comparison to wild-type, FXR(-/-) mice are more susceptible to Con A-induced hepatitis and react to Con A administration by an unregulated production of osteopontin. Administering wild-type mice with a synthetic FXR agonist attenuated Con A-induced liver damage and liver expression of the osteopontin gene. By in vitro studies, we found that FXR is expressed by primarily isolated NKT cells and its ablation favors ostepontin production in response to Con A. Chromatin immunoprecipitation assay and coimmunoprecipitation experiments demonstrate that the short heterodimer partner (SHP), a nuclear receptor and FXR target, was expressed by NKT cell hybridomas and increased in response to FXR activation. FXR activates SHP that interacts with and inhibits c-Jun binding to the osteopontin promoter. These data indicate that in NKT cells, FXR activation causes a SHP-mediated inhibition of osteopontin production. These data support the notion that the bile acid sensor FXR regulates the activation of liver NKT cells.
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Affiliation(s)
- Andrea Mencarelli
- Dipartimento di Medicina Clinica e Sperimentale, University of Perugia, Perugia, Italy
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136
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Vavassori P, Mencarelli A, Renga B, Distrutti E, Fiorucci S. The bile acid receptor FXR is a modulator of intestinal innate immunity. THE JOURNAL OF IMMUNOLOGY 2009; 183:6251-61. [PMID: 19864602 DOI: 10.4049/jimmunol.0803978] [Citation(s) in RCA: 447] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The farnesoid X receptor (FXR) is a bile acid-regulated nuclear receptor expressed in enterohepatic tissues. In this study we investigated whether FXR is expressed by cells of innate immunity and regulates inflammation in animal models of colitis. Acute (7 days) and chronic (8 wk) colitis were induced in wild-type and FXR(-/-) mice by intrarectal administration of trinitrobenzensulfonic acid or by 7-day administration of 5% dextran sulfate in drinking water. The results of this experiment demonstrate that FXR is expressed by and exerts counterregulatory effects on cells of innate immunity. Exposure of LPS-activated macrophages to 6-ethyl chenodeoxycholic acid (6E-CDCA; INT-747) a synthetic FXR ligand, results in a reciprocal regulation of NF-kappaB dependent-genes (TNF-alpha, IL-1beta, IL-6, COX-1, COX-2, and iNOS) and induction of SHP, a FXR-regulated gene. FXR activation stabilizes the nuclear corepressor NCoR on the NF-kappaB responsive element on the IL-1beta promoter. Colon inflammation in Crohn's disease patients and in rodent models of colitis is associated with a reduced expression of FXR mRNA. Using two rodent models of colon inflammation, we show that progression of these immune-mediated disorders is exacerbated in FXR(-/-) mice (p < 0.01). In vivo treatment with INT-747 attenuates organ injury and immune cell activation. FXR activation increased the colon expression of I-BABP, FXR, and SHP while reducing IL-1beta, IL-2, IL-6, TNF-alpha, and IFN-gamma mRNA expression and attenuating disease severity. In aggregate, these findings provide evidence that FXR is an essential component of a network of nuclear receptors that regulate intestinal innate immunity and homeostasis.
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Affiliation(s)
- Piero Vavassori
- Dipartimento di Medicina Clinica e Sperimentale, Università di Perugia, Perugia, Italy
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137
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Evans MJ, Gardell SJ. Farnesoid X receptor as a therapeutic target for dyslipidemia. ACTA ACUST UNITED AC 2009. [DOI: 10.2217/clp.09.51] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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138
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Cipriani S, Mencarelli A, Palladino G, Fiorucci S. FXR activation reverses insulin resistance and lipid abnormalities and protects against liver steatosis in Zucker (fa/fa) obese rats. J Lipid Res 2009; 51:771-84. [PMID: 19783811 DOI: 10.1194/jlr.m001602] [Citation(s) in RCA: 332] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The farnesoid X receptor (FXR) is a bile acid activated nuclear receptor. Zucker (fa/fa) rats, harboring a loss of function mutation of the leptin receptor, develop diabetes, insulin resistance, obesity, and liver steatosis. In this study, we investigated the effect of FXR activation by 6-ethyl-chenodeoxycholic acid, (6E-CDCA, 10 mg/kg) on insulin resistance and liver and muscle lipid metabolism in fa/fa rats and compared its activity with rosiglitazone (10 mg/kg) alone or in combination with 6E-CDCA (5 mg/kg each). In comparison to lean (fa/+), fa/fa rats on a normal diet developed insulin resistance and liver steatosis. FXR activation protected against body weight gain and liver and muscle fat deposition and reversed insulin resistance as assessed by insulin responsive substrate-1 phosphorylation on serine 312 in liver and muscles. Activation of FXR reduced liver expression of genes involved in fatty acid synthesis, lipogenesis, and gluconeogenesis. In the muscles, FXR treatment reduced free fatty acid synthesis. Rosiglitazone reduced blood insulin, glucose, triglyceride, free fatty acid, and cholesterol plasma levels but promoted body weight gain (20%) and liver fat deposition. FXR activation reduced high density lipoprotein plasma levels. In summary, FXR administration reversed insulin resistance and correct lipid metabolism abnormalities in an obesity animal model.
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Affiliation(s)
- Sabrina Cipriani
- Dipartimento di Medicina Clinica e Sperimentale, Università di Perugia, Via E. dal Pozzo, Perugia, Italy
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139
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Mann J, Mann DA. Transcriptional regulation of hepatic stellate cells. Adv Drug Deliv Rev 2009; 61:497-512. [PMID: 19393271 DOI: 10.1016/j.addr.2009.03.011] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2008] [Accepted: 03/10/2009] [Indexed: 02/08/2023]
Abstract
Hepatic stellate cell (HSC) activation is a process of cellular transdifferentiation in which, upon liver injury, the quiescent vitamin A storing perisinusoidal HSC is converted into a wound-healing myofibroblast and acquires potent pro-inflammatory and pro-fibrogenic activities. This remarkable phenotypic transformation is underpinned by changes in the expression of a vast number of genes. In this review we survey current knowledge of the transcription factors that either control HSC activation or which regulate specific fibrogenic functions of the activated HSC such as collagen expression, proliferation and resistance to apoptosis.
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140
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Li H, Shinde PB, Lee HJ, Yoo ES, Lee CO, Hong J, Choi SH, Jung JH. Bile acid derivatives from a sponge-associated bacterium Psychrobacter sp. Arch Pharm Res 2009; 32:857-62. [DOI: 10.1007/s12272-009-1607-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2009] [Revised: 05/25/2009] [Accepted: 06/09/2009] [Indexed: 11/24/2022]
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141
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Natalini B, Sardella R, Gioiello A, Carbone G, Dawgul M, Pellicciari R. Side-chain modified bile acids: chromatographic separation of 23-methyl epimers. J Sep Sci 2009; 32:2022-33. [DOI: 10.1002/jssc.200900080] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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142
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Renga B, Migliorati M, Mencarelli A, Fiorucci S. Reciprocal regulation of the bile acid-activated receptor FXR and the interferon-γ-STAT-1 pathway in macrophages. Biochim Biophys Acta Mol Basis Dis 2009; 1792:564-73. [DOI: 10.1016/j.bbadis.2009.04.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2008] [Revised: 04/11/2009] [Accepted: 04/15/2009] [Indexed: 01/04/2023]
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143
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Abstract
The farnesoid X receptor (FXR) is a member of ligand-activated nuclear receptor superfamily. FXR is a bile sensor and is part of a complex network of nuclear receptors that includes also the constitutive androstane receptor and the pregnane X receptor. These receptors act coordinately to regulate essential steps of bile acids and xenobiotics uptake, metabolism and excretion in hepatocytes, cholangiocytes and kidney cells. Preclinical models indicate that FXR agonists are effective in reducing liver injury in nonobstructive models of cholestasis. FXR ligands are currently under investigation for treating patients with early stage primary biliary cirrhosis. Although these ligands hold promise, evidence is growing that FXR activation could impair the expression/activity of basolateral transporters such as multidrug resistance protein 4 essential for basolateral secretion of bile constituents in the systemic circulation. Because FXR, pregnane X receptor and constitutive androstane receptor ligands interact with different target genes, it appear that a combination with pregnane X receptor, constitutive androstane receptor ligand/activator or both or ursodeoxycholic acid could prevent possible side-effects of FXR activation in severe cholestasis.
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144
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Malaguarnera M, Di Rosa M, Nicoletti F, Malaguarnera L. Molecular mechanisms involved in NAFLD progression. J Mol Med (Berl) 2009; 87:679-95. [PMID: 19352614 DOI: 10.1007/s00109-009-0464-1] [Citation(s) in RCA: 208] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2008] [Revised: 02/26/2009] [Accepted: 03/18/2009] [Indexed: 02/06/2023]
Abstract
Non-alcoholic fatty liver disease (NAFLD) is an emerging metabolic-related disorder characterized by fatty infiltration of the liver in the absence of alcohol consumption. NAFLD ranges from simple steatosis to non-alcoholic steatohepatitis (NASH), which might progress to end-stage liver disease. This progression is related to the insulin resistance, which is strongly linked to the metabolic syndrome consisting of central obesity, diabetes mellitus, and hypertension. Earlier, the increased concentration of intracellular fatty acids within hepatocytes leads to steatosis. Subsequently, multifactorial complex interactions between nutritional factors, lifestyle, and genetic determinants promote necrosis, inflammation, fibrosis, and hepatocellular damage. Up to now, many studies have revealed the mechanism associated with insulin resistance, whereas the mechanisms related to the molecular components have been incompletely characterized. This review aims to assess the potential molecular mediators initiating and supporting the progression of NASH to establish precocious diagnosis and to plan more specific treatment for this disease.
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145
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Fujino T, Murakami K, Ozawa I, Minegishi Y, Kashimura R, Akita T, Saitou S, Atsumi T, Sato T, Ando K, Hara S, Kikugawa K, Hayakawa M. Hypoxia downregulates farnesoid X receptor via a hypoxia-inducible factor-independent but p38 mitogen-activated protein kinase-dependent pathway. FEBS J 2009; 276:1319-32. [DOI: 10.1111/j.1742-4658.2009.06867.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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146
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Ottow E, Weinmann H. Nuclear Receptors as Drug Targets: A Historical Perspective of Modern Drug Discovery. ACTA ACUST UNITED AC 2008. [DOI: 10.1002/9783527623297.ch1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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147
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Abstract
Type 2 diabetes and cardiovascular disease represent a serious threat to the health of the population worldwide. Although overall adiposity and particularly visceral adiposity are established risk factors for these diseases, in the recent years fatty liver emerged as an additional and independent factor. However, the pathophysiology of fat accumulation in the liver and the cross-talk of fatty liver with other tissues involved in metabolism in humans are not fully understood. Here we discuss the mechanisms involved in the pathogenesis of hepatic fat accumulation, particularly the roles of body fat distribution, nutrition, exercise, genetics, and gene-environment interaction. Furthermore, the effects of fatty liver on glucose and lipid metabolism, specifically via induction of subclinical inflammation and secretion of humoral factors, are highlighted. Finally, new aspects regarding the dissociation of fatty liver and insulin resistance are addressed.
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Affiliation(s)
- Norbert Stefan
- Department of Internal Medicine, Otfried-Müller-Strasse 10, D-72076 Tübingen, Germany
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148
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Battle MA, Bondow BJ, Iverson MA, Adams SJ, Jandacek RJ, Tso P, Duncan SA. GATA4 is essential for jejunal function in mice. Gastroenterology 2008; 135:1676-1686.e1. [PMID: 18812176 PMCID: PMC2844802 DOI: 10.1053/j.gastro.2008.07.074] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2008] [Revised: 07/01/2008] [Accepted: 07/17/2008] [Indexed: 12/23/2022]
Abstract
BACKGROUND & AIMS Although the zinc-finger transcription factor GATA4 has been implicated in regulating jejunal gene expression, the contribution of GATA4 in controlling jejunal physiology has not been addressed. METHODS We generated mice in which the Gata4 gene was specifically deleted in the small intestinal epithelium. Measurements of plasma cholesterol and phospholipids, intestinal absorption of dietary fat and cholesterol, and gene expression were performed on these animals. RESULTS Mice lacking GATA4 in the intestine displayed a dramatic block in their ability to absorb cholesterol and dietary fat. Comparison of the global gene expression profiles of control jejunum, control ileum, and GATA4 null jejunum by gene array analysis revealed that GATA4 null jejunum lost expression of 53% of the jejunal-specific gene set and gained expression of 47% of the set of genes unique to the ileum. These alterations in gene expression included a decrease in messenger RNAs (mRNAs) encoding lipid and cholesterol transporters as well as an increase in mRNAs encoding proteins involved in bile acid absorption. CONCLUSIONS Our data demonstrate that GATA4 is essential for jejunal function including fat and cholesterol absorption and confirm that GATA4 plays a pivotal role in determining jejunal vs ileal identity.
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Affiliation(s)
- Michele A. Battle
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Benjamin J. Bondow
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Moriah A. Iverson
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Scott J. Adams
- Department of Economics, University of Wisconsin Milwaukee, Milwaukee, Wisconsin, USA
| | - Ronald J. Jandacek
- Genome Research Institute, Department of Pathology, University of Cincinnati, Cincinnati, Ohio, USA
| | - Patrick Tso
- Genome Research Institute, Department of Pathology, University of Cincinnati, Cincinnati, Ohio, USA
| | - Stephen A. Duncan
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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149
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Anderson N, Borlak J. Molecular Mechanisms and Therapeutic Targets in Steatosis and Steatohepatitis. Pharmacol Rev 2008; 60:311-57. [DOI: 10.1124/pr.108.00001] [Citation(s) in RCA: 291] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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150
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Gyamfi MA, Tanaka Y, He L, Klaassen CD, Wan YJY. Hepatic effects of a methionine-choline-deficient diet in hepatocyte RXRalpha-null mice. Toxicol Appl Pharmacol 2008; 234:166-78. [PMID: 18952117 DOI: 10.1016/j.taap.2008.09.022] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2008] [Revised: 08/23/2008] [Accepted: 09/16/2008] [Indexed: 01/21/2023]
Abstract
Retinoid X receptor-alpha (RXRalpha) is an obligate partner for several nuclear hormone receptors that regulate important physiological processes in the liver. In this study the impact of hepatocyte RXRalpha deficiency on methionine and choline deficient (MCD) diet-induced steatosis, oxidative stress, inflammation, and hepatic transporters gene expression were examined. The mRNA of sterol regulatory element-binding protein (SREBP)-regulated genes, important for lipid synthesis, were not altered in wild type (WT) mice, but were increased 2.0- to 5.4-fold in hepatocyte RXRalpha-null (H-RXRalpha-null) mice fed a MCD diet for 14 days. Furthermore, hepatic mRNAs and proteins essential for fatty acid beta-oxidation were not altered in WT mice, but were decreased in the MCD diet-fed H-RXRalpha-null mice, resulting in increased hepatic free fatty acid levels. Cyp2e1 enzyme activity and lipid peroxide levels were induced only in MCD-fed WT mice. In contrast, hepatic mRNA levels of pro-inflammatory factors were increased only in H-RXRalpha-null mice fed the MCD diet. Hepatic uptake transporters Oatp1a1 and Oatp1b2 mRNA levels were decreased in WT mice fed the MCD diet, whereas the efflux transporter Mrp4 was increased. However, in the H-RXRalpha-null mice, the MCD diet only moderately decreased Oatp1a1 and induced both Oatp1a4 and Mrp4 gene expression. Whereas the MCD diet increased serum bile acid levels and alkaline phosphatase activity in both WT and H-RXRalpha-null mice, serum ALT levels were induced (2.9-fold) only in the H-RXRalpha-null mice. In conclusion, these data suggest a critical role for RXRalpha in hepatic fatty acid homeostasis and protection against MCD-induced hepatocyte injury.
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Affiliation(s)
- Maxwell Afari Gyamfi
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160-7417, USA
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