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Hollenback D, Hambruch E, Fink G, Birkel M, Schulz A, Hornberger M, Liu K, Staiger KM, Krol HD, Deuschle U, Steeneck C, Kinzel O, Liles JT, Budas G, Watkins WJ, Kremoser C. Development of Cilofexor, an intestinally-biased Farnesoid X Receptor agonist, for the treatment of fatty liver disease. J Pharmacol Exp Ther 2024:JPET-AR-2023-001900. [PMID: 38409114 DOI: 10.1124/jpet.123.001900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 01/17/2024] [Accepted: 02/06/2024] [Indexed: 02/28/2024] Open
Abstract
The farnesoid X receptor (FXR) is a nuclear receptor that controls bile acid, lipid, and cholesterol metabolism. FXR-targeted drugs have shown promise in late-stage clinical trials for non-alcoholic steatohepatitis. Herein, we used clinical results from our first non-steroidal FXR agonist, Px-102 (4-[2-[2-chloro-4-[[5-cyclopropyl-3-(2,6-dichlorophenyl)-4-isoxazolyl]methoxy]phenyl]cyclopropyl] benzoic acid), to develop cilofexor, a potent, non-steroidal FXR agonist with a more manageable safety profile. Px-102 demonstrated the anticipated pharmacodynamic (PD) effects in healthy volunteers but caused a 2-fold increase in alanine aminotransferase (ALT) activity and changes in cholesterol levels. These data guided development of a high fat diet mouse model to screen FXR agonists based on ALT and cholesterol changes. Cilofexor was identified to elicit only minor changes in these parameters. The differing effects of cilofexor and Px-102 on ALT/cholesterol in the model could not be explained by potency or specificity, and we hypothesized that the relative contribution of intestinal and liver FXR activation may be responsible. Gene expression analysis from rodent studies revealed that cilofexor, but not Px-102, had a bias for FXR transcriptional activity in the intestine compared to the liver. Fluorescent imaging in hepatoma cells demonstrated similar subcellular localization for cilofexor and Px-102, but cilofexor was more rapidly washed out, consistent with a lower membrane residence time contributing to reduced hepatic transcriptional effects. Cilofexor demonstrated antisteatotic and antifibrotic efficacy in rodent models and antisteatotic efficacy in a monkey model, with the anticipated PD and a manageable safety profile in human phase I studies. Significance Statement FXR (farnesoid X receptor) agonists have shown promise in treating non-alcoholic steatohepatitis and other liver diseases in the clinic, but balancing efficacy with undesired side effects has been difficult. Here, we examined the preclinical and clinical effects of the first-generation FXR agonist, Px-102 (4-[2-[2-chloro-4-[[5-cyclopropyl-3-(2,6-dichlorophenyl)-4-isoxazolyl]methoxy]phenyl]cyclopropyl] benzoic acid), to enable the selection of an analog, cilofexor, with unique properties that reduced side effects yet maintained efficacy. Cilofexor is one of few remaining FXR agonists in clinical development.
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Affiliation(s)
| | | | - Gero Fink
- Biology, Phenex Pharmceuticals, Germany
| | | | | | | | - Kathy Liu
- Biology, Gilead Sciences, Inc, United States
| | | | | | | | | | | | | | - Grant Budas
- Biology, Gilead Sciences, Inc, United States
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Miyazaki-Anzai S, Masuda M, Shiozaki Y, Keenan AL, Chonchol M, Kremoser C, Miyazaki M. Free Deoxycholic Acid Exacerbates Vascular Calcification in CKD through ER Stress-Mediated ATF4 Activation. Kidney360 2021; 2:857-868. [PMID: 34423309 PMCID: PMC8378801 DOI: 10.34067/kid.0007502020] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Our metabolome approach found that levels of circulating, free deoxycholic acid (DCA) is associated with the severity of vascular calcification in patients with CKD. However, it is not known whether DCA directly causes vascular calcification in CKD. METHODS Using various chemicals and animal and cell culture models, we investigated whether the modulation of DCA levels influences vascular calcification in CKD. RESULTS CKD increased levels of DCA in mice and humans by decreasing urinary DCA excretion. Treatment of cultured VSMCs with DCA but no other bile acids (BAs) induced vascular calcification and osteogenic differentiation through endoplasmic reticulum (ER) stress-mediated activating transcription factor-4 (ATF4) activation. Treatment of mice with Farnesoid X receptor (FXR)-specific agonists selectively reduced levels of circulating cholic acid-derived BAs, such as DCA, protecting from CKD-dependent medial calcification and atherosclerotic calcification. Reciprocal FXR deficiency and DCA treatment induced vascular calcification by increasing levels of circulating DCA and activating the ER stress response. CONCLUSIONS This study demonstrates that DCA plays a causative role in regulating CKD-dependent vascular diseases through ER stress-mediated ATF4 activation.
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Affiliation(s)
- Shinobu Miyazaki-Anzai
- Division of Renal Diseases, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Masashi Masuda
- Division of Renal Diseases, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Yuji Shiozaki
- Division of Renal Diseases, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Audrey L. Keenan
- Division of Renal Diseases, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Michel Chonchol
- Division of Renal Diseases, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | | | - Makoto Miyazaki
- Division of Renal Diseases, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado,Phenex Pharmaceuticals AG, Heidelberg, Germany
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Schwabl P, Hambruch E, Budas GR, Supper P, Burnet M, Liles JT, Birkel M, Brusilovskaya K, Königshofer P, Peck-Radosavljevic M, Watkins WJ, Trauner M, Breckenridge DG, Kremoser C, Reiberger T. The Non-Steroidal FXR Agonist Cilofexor Improves Portal Hypertension and Reduces Hepatic Fibrosis in a Rat NASH Model. Biomedicines 2021; 9:biomedicines9010060. [PMID: 33435509 PMCID: PMC7827357 DOI: 10.3390/biomedicines9010060] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 12/31/2020] [Accepted: 01/05/2021] [Indexed: 02/07/2023] Open
Abstract
Background: The farnesoid X receptor (FXR) influences hepatic metabolism, inflammation and liver fibrosis as key components of non-alcoholic steatohepatitis (NASH). We studied the effects of the non-steroidal FXR agonist cilofexor (formerly GS-9674) on portal pressure and fibrosis in experimental NASH. Methods: NASH was induced in Wistar rats using a choline-deficient high-fat diet plus intraperitoneal sodium nitrite injections. First, a dose-finding study was performed with 10 mg/kg and 30 mg/kg of cilofexor, focusing on histological readouts. Liver fibrosis was assessed by Picro-Sirius-Red, desmin staining and hepatic hydroxyproline content. Gene expression was determined by RT-PCR. In a subsequent hemodynamic study, rats received 30 mg/kg cilofexor with or without propranolol (25 mg/kg). Portal pressure, systemic hemodynamics and splanchnic blood flow were measured. Results: Cilofexor dose-dependently induced FXR target genes shp, cyp7a1 and fgf15 in hepatic and ileal tissues, paralleled by a dose-dependent reduction in liver fibrosis area (Picro-Sirius-Red) of −41% (10 mg/kg) and −69% (30 mg/kg), respectively. The 30 mg/kg cilofexor dose significantly reduced hepatic hydroxyproline content (−41%), expression of col1a1 (−37%) and pdgfr-β (−36%), as well as desmin area (−42%) in NASH rats. Importantly, cilofexor decreased portal pressure (11.9 ± 2.1 vs. 8.9 ± 2.2 mmHg; p = 0.020) without affecting splanchnic blood-flow or systemic hemodynamics. The addition of propranolol to cilofexor additionally reduced splanchnic inflow (−28%) but also mean arterial pressure (−25%) and heart rate (−37%). Conclusion: The non-steroidal FXR agonist cilofexor decreased portal hypertension and reduced liver fibrosis in NASH rats. While cilofexor seems to primarily decrease sinusoidal resistance in cirrhotic portal hypertension, the combination with propranolol additionally reduced mesenteric hyperperfusion.
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Affiliation(s)
- Philipp Schwabl
- Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, 1090 Vienna, Austria; (P.S.); (P.S.); (K.B.); (P.K.); (M.P.-R.); (M.T.)
- Vienna Hepatic Experimental Hemodynamic (HEPEX) Laboratory, Medical University of Vienna, 1090 Vienna, Austria
- Christian Doppler Lab for Portal Hypertension and Liver Fibrosis, Medical University of Vienna, 1090 Vienna, Austria
| | - Eva Hambruch
- Phenex Pharmaceuticals AG, 69123 Heidelberg, Germany; (E.H.); (M.B.); (C.K.)
| | - Grant R. Budas
- Gilead Sciences Inc., Foster City, CA 94404, USA; (G.R.B.); (J.T.L.); (W.J.W.); (D.G.B.)
| | - Paul Supper
- Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, 1090 Vienna, Austria; (P.S.); (P.S.); (K.B.); (P.K.); (M.P.-R.); (M.T.)
- Vienna Hepatic Experimental Hemodynamic (HEPEX) Laboratory, Medical University of Vienna, 1090 Vienna, Austria
| | | | - John T. Liles
- Gilead Sciences Inc., Foster City, CA 94404, USA; (G.R.B.); (J.T.L.); (W.J.W.); (D.G.B.)
| | - Manfred Birkel
- Phenex Pharmaceuticals AG, 69123 Heidelberg, Germany; (E.H.); (M.B.); (C.K.)
| | - Ksenia Brusilovskaya
- Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, 1090 Vienna, Austria; (P.S.); (P.S.); (K.B.); (P.K.); (M.P.-R.); (M.T.)
- Vienna Hepatic Experimental Hemodynamic (HEPEX) Laboratory, Medical University of Vienna, 1090 Vienna, Austria
- Christian Doppler Lab for Portal Hypertension and Liver Fibrosis, Medical University of Vienna, 1090 Vienna, Austria
| | - Philipp Königshofer
- Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, 1090 Vienna, Austria; (P.S.); (P.S.); (K.B.); (P.K.); (M.P.-R.); (M.T.)
- Vienna Hepatic Experimental Hemodynamic (HEPEX) Laboratory, Medical University of Vienna, 1090 Vienna, Austria
- Christian Doppler Lab for Portal Hypertension and Liver Fibrosis, Medical University of Vienna, 1090 Vienna, Austria
| | - Markus Peck-Radosavljevic
- Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, 1090 Vienna, Austria; (P.S.); (P.S.); (K.B.); (P.K.); (M.P.-R.); (M.T.)
- Vienna Hepatic Experimental Hemodynamic (HEPEX) Laboratory, Medical University of Vienna, 1090 Vienna, Austria
- Department of Internal Medicine and Gastroenterology (IMuG), Hepatology, Endocrinology, Rheumatology, and Nephrology with Centralized Emergency Service (ZAE), Klinikum Klagenfurt am Wörthersee, 9020 Klagenfurt, Austria
| | - William J. Watkins
- Gilead Sciences Inc., Foster City, CA 94404, USA; (G.R.B.); (J.T.L.); (W.J.W.); (D.G.B.)
| | - Michael Trauner
- Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, 1090 Vienna, Austria; (P.S.); (P.S.); (K.B.); (P.K.); (M.P.-R.); (M.T.)
| | - David G. Breckenridge
- Gilead Sciences Inc., Foster City, CA 94404, USA; (G.R.B.); (J.T.L.); (W.J.W.); (D.G.B.)
| | - Claus Kremoser
- Phenex Pharmaceuticals AG, 69123 Heidelberg, Germany; (E.H.); (M.B.); (C.K.)
| | - Thomas Reiberger
- Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, 1090 Vienna, Austria; (P.S.); (P.S.); (K.B.); (P.K.); (M.P.-R.); (M.T.)
- Vienna Hepatic Experimental Hemodynamic (HEPEX) Laboratory, Medical University of Vienna, 1090 Vienna, Austria
- Christian Doppler Lab for Portal Hypertension and Liver Fibrosis, Medical University of Vienna, 1090 Vienna, Austria
- Ludwig Boltzmann Institute for Rare and Undiagnosed Diseases (LBI-RUD), 1090 Vienna, Austria
- CeMM Research Center for Molecular Medicine, The Austrian Academy of Sciences, 1090 Vienna, Austria
- Correspondence: ; Tel.: +43-1-40400-47410
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Abstract
FXR agonists have demonstrated very promising clinical results in the treatment of liver disorders such as primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC), and nonalcoholic steatohepatitis (NASH). NASH, in particular, is one of the last uncharted white territories in the pharma landscape, and there is a huge medical need and a large potential pharmaceutical market for a NASH pharmacotherapy. Clinical efficacy superior to most other treatment options was shown by FXR agonists such as obeticholic acid (OCA) as they improved various metabolic features including liver steatosis as well as liver inflammation and fibrosis. But OCA's clinical success comes with some major liabilities such as pruritus, high-density lipoprotein cholesterol (HDLc) lowering, low-density lipoprotein cholesterol (LDLc) increase, and a potential for drug-induced liver toxicity. Some of these effects can be attributed to on-target effects exerted by FXR, but with others it is not clear whether it is FXR- or OCA-related. Therefore a quest for novel, proprietary FXR agonists is ongoing with the aim to increase FXR potency and selectivity over other proteins and to overcome at least some of the OCA-associated clinical side effects through an improved pharmacology. In this chapter we will discuss the historical and ongoing efforts in the identification and development of nonsteroidal, which largely means non-bile acid-type, FXR agonists for clinical use.
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Affiliation(s)
- Christian Gege
- Phenex Pharmaceuticals AG, Drug Discovery Research, Heidelberg, Germany
| | - Eva Hambruch
- Phenex Pharmaceuticals AG, Drug Discovery Research, Heidelberg, Germany
| | - Nina Hambruch
- Phenex Pharmaceuticals AG, Drug Discovery Research, Heidelberg, Germany
| | - Olaf Kinzel
- Phenex Pharmaceuticals AG, Drug Discovery Research, Heidelberg, Germany
| | - Claus Kremoser
- Phenex Pharmaceuticals AG, Drug Discovery Research, Heidelberg, Germany.
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Paalvast Y, Zhou E, Mulder N, Koehorst M, Boverhof R, Willems van Dijk K, Rensen P, Kuivenhoven J, Kremoser C, Wang Y, Kuipers F, Groen A, de Boer J. FXR activation normalizes dyslipidemia and alleviates obesity in western-type diet–fed APOE*3-Leiden.CETP transgenic mice. Atherosclerosis 2018. [DOI: 10.1016/j.atherosclerosis.2018.06.914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Worthmann A, John C, Rühlemann MC, Baguhl M, Heinsen FA, Schaltenberg N, Heine M, Schlein C, Evangelakos I, Mineo C, Fischer M, Dandri M, Kremoser C, Scheja L, Franke A, Shaul PW, Heeren J. Cold-induced conversion of cholesterol to bile acids in mice shapes the gut microbiome and promotes adaptive thermogenesis. Nat Med 2017; 23:839-849. [PMID: 28604703 DOI: 10.1038/nm.4357] [Citation(s) in RCA: 196] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 05/17/2017] [Indexed: 12/12/2022]
Abstract
Adaptive thermogenesis is an energy-demanding process that is mediated by cold-activated beige and brown adipocytes, and it entails increased uptake of carbohydrates, as well as lipoprotein-derived triglycerides and cholesterol, into these thermogenic cells. Here we report that cold exposure in mice triggers a metabolic program that orchestrates lipoprotein processing in brown adipose tissue (BAT) and hepatic conversion of cholesterol to bile acids via the alternative synthesis pathway. This process is dependent on hepatic induction of cytochrome P450, family 7, subfamily b, polypeptide 1 (CYP7B1) and results in increased plasma levels, as well as fecal excretion, of bile acids that is accompanied by distinct changes in gut microbiota and increased heat production. Genetic and pharmacological interventions that targeted the synthesis and biliary excretion of bile acids prevented the rise in fecal bile acid excretion, changed the bacterial composition of the gut and modulated thermogenic responses. These results identify bile acids as important metabolic effectors under conditions of sustained BAT activation and highlight the relevance of cholesterol metabolism by the host for diet-induced changes of the gut microbiota and energy metabolism.
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Affiliation(s)
- Anna Worthmann
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Clara John
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Malte C Rühlemann
- Institute of Clinical Molecular Biology, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Miriam Baguhl
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Femke-Anouska Heinsen
- Institute of Clinical Molecular Biology, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Nicola Schaltenberg
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Markus Heine
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christian Schlein
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ioannis Evangelakos
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Chieko Mineo
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Markus Fischer
- Institute of Food Chemistry, University of Hamburg, Hamburg, Germany
| | - Maura Dandri
- Department of Internal Medicine I, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Ludger Scheja
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Andre Franke
- Institute of Clinical Molecular Biology, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Philip W Shaul
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Joerg Heeren
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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de Boer JF, Schonewille M, Boesjes M, Wolters H, Bloks VW, Bos T, van Dijk TH, Jurdzinski A, Boverhof R, Wolters JC, Kuivenhoven JA, van Deursen JM, Oude Elferink RPJ, Moschetta A, Kremoser C, Verkade HJ, Kuipers F, Groen AK. Intestinal Farnesoid X Receptor Controls Transintestinal Cholesterol Excretion in Mice. Gastroenterology 2017; 152:1126-1138.e6. [PMID: 28065787 DOI: 10.1053/j.gastro.2016.12.037] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 12/03/2016] [Accepted: 12/23/2016] [Indexed: 01/17/2023]
Abstract
BACKGROUND & AIMS The role of the intestine in the maintenance of cholesterol homeostasis increasingly is recognized. Fecal excretion of cholesterol is the last step in the atheroprotective reverse cholesterol transport pathway, to which biliary and transintestinal cholesterol excretion (TICE) contribute. The mechanisms controlling the flux of cholesterol through the TICE pathway, however, are poorly understood. We aimed to identify mechanisms that regulate and stimulate TICE. METHODS We performed studies with C57Bl/6J mice, as well as with mice with intestine-specific knockout of the farnesoid X receptor (FXR), mice that express an FXR transgene specifically in the intestine, and ABCG8-knockout mice. Mice were fed a control diet or a diet supplemented with the FXR agonist PX20606, with or without the cholesterol absorption inhibitor ezetimibe. Some mice with intestine-specific knockout of FXR were given daily injections of fibroblast growth factor (FGF)19. To determine fractional cholesterol absorption, mice were given intravenous injections of cholesterol D5 and oral cholesterol D7. Mice were given 13C-acetate in drinking water for measurement of cholesterol synthesis. Bile cannulations were performed and biliary cholesterol secretion rates were assessed. In a separate set of experiments, bile ducts of male Wistar rats were exteriorized, allowing replacement of endogenous bile by a model bile. RESULTS In mice, we found TICE to be regulated by intestinal FXR via induction of its target gene Fgf15 (FGF19 in rats and human beings). Stimulation of this pathway caused mice to excrete up to 60% of their total cholesterol content each day. PX20606 and FGF19 each increased the ratio of muricholate:cholate in bile, inducing a more hydrophilic bile salt pool. The altered bile salt pool stimulated robust secretion of cholesterol into the intestinal lumen via the sterol-exporting heterodimer adenosine triphosphate binding cassette subfamily G member 5/8 (ABCG5/G8). Of note, the increase in TICE induced by PX20606 was independent of changes in cholesterol absorption. CONCLUSIONS Hydrophilicity of the bile salt pool, controlled by FXR and FGF15/19, is an important determinant of cholesterol removal via TICE. Strategies that alter bile salt pool composition might be developed for the prevention of cardiovascular disease. Transcript profiling: http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?token=irsrayeohfcntqx&acc=GSE74101.
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Affiliation(s)
- Jan Freark de Boer
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
| | - Marleen Schonewille
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Marije Boesjes
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Henk Wolters
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Vincent W Bloks
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Trijnie Bos
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Theo H van Dijk
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Angelika Jurdzinski
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Renze Boverhof
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Justina C Wolters
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Jan A Kuivenhoven
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Jan M van Deursen
- Department of Pediatric and Adolescent Medicine, Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Ronald P J Oude Elferink
- Tytgat Institute for Liver and Intestinal Research, Department of Hepatology and Gastroenterology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Antonio Moschetta
- Department of Interdisciplinary Medicine, University of Bari, IRCCS Istituto Tumori "Giovanni Paolo II," Bari, Italy
| | | | - Henkjan J Verkade
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Folkert Kuipers
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Albert K Groen
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
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Schwabl P, Hambruch E, Seeland BA, Hayden H, Wagner M, Garnys L, Strobel B, Schubert TL, Riedl F, Mitteregger D, Burnet M, Starlinger P, Oberhuber G, Deuschle U, Rohr-Udilova N, Podesser BK, Peck-Radosavljevic M, Reiberger T, Kremoser C, Trauner M. The FXR agonist PX20606 ameliorates portal hypertension by targeting vascular remodelling and sinusoidal dysfunction. J Hepatol 2017; 66:724-733. [PMID: 27993716 DOI: 10.1016/j.jhep.2016.12.005] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Revised: 11/27/2016] [Accepted: 12/07/2016] [Indexed: 02/06/2023]
Abstract
BACKGROUND & AIMS Steroidal farnesoid X receptor (FXR) agonists demonstrated potent anti-fibrotic activities and lowered portal hypertension in experimental models. The impact of the novel non-steroidal and selective FXR agonist PX20606 on portal hypertension and fibrosis was explored in this study. METHODS In experimental models of non-cirrhotic (partial portal vein ligation, PPVL, 7days) and cirrhotic (carbon tetrachloride, CCl4, 14weeks) portal hypertension, PX20606 (PX,10mg/kg) or the steroidal FXR agonist obeticholic acid (OCA,10mg/kg) were gavaged. We then measured portal pressure, intrahepatic vascular resistance, liver fibrosis and bacterial translocation. RESULTS PX decreased portal pressure in non-cirrhotic PPVL (12.6±1.7 vs. 10.4±1.1mmHg; p=0.020) and cirrhotic CCl4 (15.2±0.5 vs. 11.8±0.4mmHg; p=0.001) rats. In PPVL animals, we observed less bacterial translocation (-36%; p=0.041), a decrease in lipopolysaccharide binding protein (-30%; p=0.024) and splanchnic tumour necrosis factor α levels (-39%; p=0.044) after PX treatment. In CCl4 rats, PX decreased fibrotic Sirius Red area (-43%; p=0.005), hepatic hydroxyproline (-66%; p<0.001), and expression of profibrogenic proteins (Col1a1, α smooth muscle actin, transforming growth factor β). CCl4-PX rats had significantly lower transaminase levels and reduced hepatic macrophage infiltration. Moreover, PX induced sinusoidal vasodilation (upregulation of cystathionase, dimethylaminohydrolase (DDAH)1, endothelial nitric oxide synthase (eNOS), GTP-cyclohydrolase1) and reduced intrahepatic vasoconstriction (downregulation of endothelin-1, p-Moesin). In cirrhosis, PX improved endothelial dysfunction (decreased von-Willebrand factor) and normalized overexpression of vascular endothelial growth factor, platelet-derived growth factor and angiopoietins. While short-term 3-day PX treatment reduced portal pressure (-14%; p=0.041) by restoring endothelial function, 14week PX therapy additionally inhibited sinusoidal remodelling and decreased portal pressure to a greater extent (-22%; p=0.001). In human liver sinusoidal endothelial cells, PX increased eNOS and DDAH expression. CONCLUSIONS The non-steroidal FXR agonist PX20606 ameliorates portal hypertension by reducing liver fibrosis, vascular remodelling and sinusoidal dysfunction. LAY SUMMARY The novel drug PX20606 activates the bile acid receptor FXR and shows beneficial effects in experimental liver cirrhosis: In the liver, it reduces scarring and inflammation, and also widens blood vessels. Thus, PX20606 leads to an improved blood flow through the liver and decreases hypertension of the portal vein. Additionally, PX20606 improves the altered intestinal barrier and decreases bacterial migration from the gut.
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Affiliation(s)
- Philipp Schwabl
- Div. of Gastroenterology and Hepatology, Dept. of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Eva Hambruch
- Phenex Pharmaceuticals, Waldhofer Strasse 104, 69123 Heidelberg, Germany
| | - Berit A Seeland
- Div. of Gastroenterology and Hepatology, Dept. of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Hubert Hayden
- Div. of Gastroenterology and Hepatology, Dept. of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Michael Wagner
- Div. of Gastroenterology and Hepatology, Dept. of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Lukas Garnys
- Div. of Gastroenterology and Hepatology, Dept. of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Bastian Strobel
- Div. of Gastroenterology and Hepatology, Dept. of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Tim-Lukas Schubert
- Div. of Gastroenterology and Hepatology, Dept. of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Florian Riedl
- Div. of Gastroenterology and Hepatology, Dept. of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Dieter Mitteregger
- Vienna Medical Innovation Center (VMIC), Group Practice LABORS.at, Vienna, Austria
| | - Michael Burnet
- Synovo GmbH, Paul-Ehrlich-Str. 15, 72076 Tübingen, Germany
| | | | - Georg Oberhuber
- Dept. of Pathology, Medical University of Vienna, Vienna, Austria
| | - Ulrich Deuschle
- Phenex Pharmaceuticals, Waldhofer Strasse 104, 69123 Heidelberg, Germany
| | - Nataliya Rohr-Udilova
- Div. of Gastroenterology and Hepatology, Dept. of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Bruno K Podesser
- Dept. of Biomedical Research, Medical University of Vienna, Vienna, Austria
| | - Markus Peck-Radosavljevic
- Div. of Gastroenterology and Hepatology, Dept. of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Thomas Reiberger
- Div. of Gastroenterology and Hepatology, Dept. of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Claus Kremoser
- Phenex Pharmaceuticals, Waldhofer Strasse 104, 69123 Heidelberg, Germany
| | - Michael Trauner
- Div. of Gastroenterology and Hepatology, Dept. of Internal Medicine III, Medical University of Vienna, Vienna, Austria.
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10
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Hambruch E, Kinzel O, Kremoser C. On the Pharmacology of Farnesoid X Receptor Agonists: Give me an “A”, Like in “Acid”. Nuclear Receptor Research 2016. [DOI: 10.11131/2016/101207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Affiliation(s)
- Eva Hambruch
- Phenex Pharmaceuticals AG, Waldhofer Str. 104, 69123 Heidelberg, Germany
| | - Olaf Kinzel
- Phenex Pharmaceuticals AG, Waldhofer Str. 104, 69123 Heidelberg, Germany
| | - Claus Kremoser
- Phenex Pharmaceuticals AG, Waldhofer Str. 104, 69123 Heidelberg, Germany
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11
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De Boer JF, Schonewille M, Boesjes M, Wolters H, Bloks VW, Bos T, Van Dijk TH, Jurdzinski A, Boverhof R, Van Deursen JM, Oude Elferink RP, Moschetta A, Kremoser C, Verkade HJ, Kuipers F, Groen AK. Abstract 424: Transintestinal Cholesterol Excretion Can Drive Massive Cholesterol Elimination in Mice. Arterioscler Thromb Vasc Biol 2016. [DOI: 10.1161/atvb.36.suppl_1.424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
High plasma cholesterol levels increase the risk of cardiovascular disease (CVD). Transintestinal Cholesterol Excretion (TICE) is a recently emerged pathway of cholesterol removal and has the potential to lower plasma cholesterol levels and confer protection against CVD. Under control conditions, TICE accounts for about 30% of fecal cholesterol loss in mice. Using a panel of knock-out and transgenic mice as well as pharmacological manipulations we show that in mice TICE is regulated by intestinal activation of the Farnesoid X Receptor (FXR), via its target Fibroblast Growth Factor 15/19 (FGF15/19). Activation of FXR by the agonist PX20606 (PX) resulted in a >10-fold increased fecal cholesterol excretion as well as TICE and 40% reduced plasma cholesterol levels. The induction of fecal cholesterol excretion and TICE was absent in PX-treated intestine-specific FXR-null mice but was regained when those mice were co-treated with FGF19. Moreover, FGF19 treatment alone was sufficient to induce fecal cholesterol loss to a similar extend as was observed in PX-treated wild-type mice. PX treatment resulted in an increased muricholate/cholate-ratio and thereby induced a more hydrophilic bile salt pool. Not surprisingly, cholesterol absorption was reduced in PX-treated mice. However, experiments in which mice were co-treated with PX and the cholesterol absorption inhibitor ezetimibe revealed that the stimulating effect of PX on fecal neutral sterol excretion and TICE were completely independent of differences in cholesterol absorption. Of note, treatment of mice with a combination of PX and ezetimibe stimulated fecal cholesterol loss and TICE so strongly that those mice lost about 60% of their entire estimated body cholesterol content each day. The stimulation of fecal cholesterol loss and TICE by PX and PX/ezetimibe treatment was severely blunted in Abcg8-KO mice and this could not be restored by hepatic reintroduction of Abcg8, indicating a decisive role for intestinal ABCG5/G8 in PX-induced fecal cholesterol loss and TICE. Our data strongly suggest that hydrophilic bile acids stimulate ABCG5/G8 activity in the intestine, leading to an increased flux of cholesterol from the body into the intestinal lumen that is subsequently excreted with the feces.
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Affiliation(s)
- Jan F De Boer
- Dept of Pediatrics, Univ Med Cntr Groningen, Groningen, Netherlands
| | | | - Marije Boesjes
- Dept of Pediatrics, Univ Med Cntr Groningen, Groningen, Netherlands
| | - Henk Wolters
- Dept of Pediatrics, Univ Med Cntr Groningen, Groningen, Netherlands
| | - Vincent W Bloks
- Dept of Pediatrics, Univ Med Cntr Groningen, Groningen, Netherlands
| | - Trijnie Bos
- Dept of Pediatrics, Univ Med Cntr Groningen, Groningen, Netherlands
| | - Theo H Van Dijk
- Dept of Pediatrics, Univ Med Cntr Groningen, Groningen, Netherlands
| | | | - Renze Boverhof
- Dept of Pediatrics, Univ Med Cntr Groningen, Groningen, Netherlands
| | - Jan M Van Deursen
- Dept of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN
| | - Ronald P Oude Elferink
- Tytgat Institute for Liver and Intestinal Rsch, Academic Med Cntr, Amsterdam, Netherlands
| | | | - Claus Kremoser
- Phenex, Phenex Pharmaceuticals AG, Ludwigshafen, Germany
| | | | - Folkert Kuipers
- Dept of Pediatrics, Univ Med Cntr Groningen, Groningen, Netherlands
| | - Albert K Groen
- Dept of Pediatrics, Univ Med Cntr Groningen, Groningen, Netherlands
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12
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Gege C, Kinzel O, Steeneck C, Schulz A, Kremoser C. Knocking on FXR's door: the "hammerhead"-structure series of FXR agonists - amphiphilic isoxazoles with potent in vitro and in vivo activities. Curr Top Med Chem 2015; 14:2143-58. [PMID: 25388536 DOI: 10.2174/1568026614666141112094430] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 09/29/2014] [Accepted: 10/02/2014] [Indexed: 11/22/2022]
Abstract
The Farnesoid X Receptor (FXR) was recently validated in clinical studies using the bile acid analogue Obeticholic Acid (OCA) as an attractive drug target for liver diseases such as Primary Biliary Cirrhosis (PBC) or Non-alcoholic Steatohepatitis (NASH). OCA, however, turned out to induce cholesterol- related side effects upon prolonged treatment and it shows bile acid like pharmacokinetics. The quest for synthetic non-steroidal FXR agonists with general drug likeliness and improved pharmacokinetic and - dynamic properties has started more than a decade ago: The first non-steroidal and selective FXR agonist with decent submicromolar potency, GW4064, was patented in 1998 and published in 2000. Since then, many pharmaceutical companies have taken GW4064 as a structural template for their efforts in identifying novel patentable FXR agonists with the GW-derived trisubstituted isoxazole general structure. However, so far only one compound out of these different series has made it into the early stages of clinical development: The Px-102/Px-104 from Phenex is currently tested in a phase IIa study in patients with Non-Alcoholic Fatty Liver Disease (NAFLD). In this review we try to summarize from the patent and scientific literature the attempts to improve the GW4064 structure into different directions. Furthermore, we suggest directions for further improvements of this special class of synthetic FXR agonists which all display the typical "hammerhead"-conformation in the FXR ligand binding pocket that provides the basis for their impressive in vitro and in vivo potencies.
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Affiliation(s)
| | | | | | | | - Claus Kremoser
- Phenex Pharmaceuticals AG, Waldhofer Str. 104, 69123 Heidelberg, Germany.
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13
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Deuschle U, Birkel M, Hambruch E, Hornberger M, Kinzel O, Perović-Ottstadt S, Schulz A, Hahn U, Burnet M, Kremoser C. The nuclear bile acid receptor FXR controls the liver derived tumor suppressor histidine-rich glycoprotein. Int J Cancer 2014; 136:2693-704. [PMID: 25363753 DOI: 10.1002/ijc.29312] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Accepted: 10/16/2014] [Indexed: 12/19/2022]
Abstract
The nuclear bile acid receptor Farnesoid X receptor (FXR) is strongly expressed in liver and intestine, controls bile acid and lipid homeostasis and exerts tumor-protective functions in liver and intestine. Histidine-rich glycoprotein (HRG) is an abundant plasma protein produced by the liver with the proposed function as a pattern recognition molecule involved in the clearance of immune complexes, necrotic cells and pathogens, the modulation of angiogenesis, the normalization of deranged endothelial vessel structure in tumors and tumor suppression. FXR recognition sequences were identified within a human HRG promoter fragment that mediated FXR/FXR-agonist dependent reporter gene activity in vitro. We show that HRG is a novel transcriptional target gene of FXR in human hepatoma cells, human upcyte® primary hepatocytes and 3D human liver microtissues in vitro and in mouse liver in vivo. Prolonged administration of the potent nonsteroidal FXR agonist PX20606 increases HRG levels in mouse plasma. Finally, daily oral administration of this FXR agonist for seven days resulted in a significant increase of HRG levels in the plasma of healthy human male volunteers during a clinical Phase I safety study. HRG might serve as a surrogate marker indicative of liver-specific FXR activation in future human clinical studies. Furthermore, potent FXR agonists might be beneficial in serious health conditions where HRG is reduced, for example, in hepatocellular carcinoma but also other solid cancers, liver failure, sepsis and pre-eclampsia.
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Affiliation(s)
- Ulrich Deuschle
- Phenex Pharmaceuticals AG, Waldhofer Str. 104, 69123, Heidelberg, Germany
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14
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Schonewille M, de Boer J, Boesjes M, Wolters H, Verkade H, Tietge U, Kremoser C, Groen A. Combination treatment of the novel pharmacological fxr-compound px20606 and ezetimibe leads to massively increased neutral sterols excretion in mice. Atherosclerosis 2014. [DOI: 10.1016/j.atherosclerosis.2014.05.535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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15
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Podszun MC, Grebenstein N, Spruss A, Schlueter T, Kremoser C, Bergheim I, Frank J. Dietary α-tocopherol and atorvastatin reduce high-fat-induced lipid accumulation and down-regulate CD36 protein in the liver of guinea pigs. J Nutr Biochem 2014; 25:573-9. [PMID: 24725433 DOI: 10.1016/j.jnutbio.2014.01.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 01/15/2014] [Accepted: 01/20/2014] [Indexed: 12/21/2022]
Abstract
The increased uptake and storage of lipids in the liver are important features of steatotic liver diseases. The fatty acid translocase/scavenger receptor cluster of differentiation (CD)36 facilitates the hepatic uptake of lipids. We investigated if RRR-α-tocopherol (αT) alone or in combination with atorvastatin (ATV) is capable of preventing hepatic lipid accumulation via down-regulation of CD36. To this end, Dunkin Hartley guinea pigs were fed a control diet (5% fat); or a high-fat control diet (21% fat, 0.15% cholesterol); or a high-fat control diet fortified with αT (250 mg/kg diet), ATV (300 mg/kg diet) or both ATV+αT for 6 weeks. Hepatic triacylglycerols, hepatic protein and mRNA expression of CD36 as well as the mRNA expression of the controlling nuclear receptors LXRα, PXR and PPARγ were determined. Animals fed the high-fat control diet accumulated significantly more triacylglycerols in the liver than control animals. This was significantly reduced by ATV and numerically by αT and ATV+αT. Hepatic CD36 protein concentrations were significantly higher in the high-fat than in the control group, and both αT and ATV reduced CD36 expression to the level observed in the control group. However, no synergistic effect of the combined treatment was observed. Neither CD36 mRNA nor that of the nuclear receptors (LXRα, PXR and PPARγ) differed between groups, suggesting a posttranslational regulatory mechanism. Our results indicate that orally administered ATV and αT individually, but not synergistically, prevent diet-induced lipid accumulation in the liver of guinea pigs by down-regulation of hepatic CD36 protein.
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Affiliation(s)
- Maren C Podszun
- Institute of Biological Chemistry and Nutrition, University of Hohenheim, D-70599 Stuttgart, Germany
| | - Nadine Grebenstein
- Institute of Biological Chemistry and Nutrition, University of Hohenheim, D-70599 Stuttgart, Germany
| | - Astrid Spruss
- Institute of Nutrition, University of Jena, D-07743 Jena, Germany
| | | | | | - Ina Bergheim
- Institute of Nutrition, University of Jena, D-07743 Jena, Germany
| | - Jan Frank
- Institute of Biological Chemistry and Nutrition, University of Hohenheim, D-70599 Stuttgart, Germany.
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16
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Hambruch E, Miyazaki-Anzai S, Hahn U, Matysik S, Boettcher A, Perović-Ottstadt S, Schlüter T, Kinzel O, Krol HD, Deuschle U, Burnet M, Levi M, Schmitz G, Miyazaki M, Kremoser C. Synthetic farnesoid X receptor agonists induce high-density lipoprotein-mediated transhepatic cholesterol efflux in mice and monkeys and prevent atherosclerosis in cholesteryl ester transfer protein transgenic low-density lipoprotein receptor (-/-) mice. J Pharmacol Exp Ther 2012; 343:556-67. [PMID: 22918042 PMCID: PMC11047796 DOI: 10.1124/jpet.112.196519] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Accepted: 08/22/2012] [Indexed: 01/03/2023] Open
Abstract
Farnesoid X receptor (FXR), a bile acid-activated nuclear hormone receptor, plays an important role in the regulation of cholesterol and more specifically high-density lipoprotein (HDL) homeostasis. Activation of FXR is reported to lead to both pro- and anti-atherosclerotic effects. In the present study we analyzed the impact of different FXR agonists on cholesterol homeostasis, plasma lipoprotein profiles, and transhepatic cholesterol efflux in C57BL/6J mice and cynomolgus monkeys and atherosclerosis development in cholesteryl ester transfer protein transgenic (CETPtg) low-density lipoprotein receptor (LDLR) (-/-) mice. In C57BL/6J mice on a high-fat diet the synthetic FXR agonists isopropyl 3-(3,4-difluorobenzoyl)-1,1-dimethyl-1,2,3,6-tetrahydroazepino[4,5-b]indole-5-carboxylate (FXR-450) and 4-[2-[2-chloro-4-[[5-cyclopropyl-3-(2,6-dichlorophenyl)-4-isoxazolyl]methoxy]phenyl]cyclopropyl]benzoic acid (PX20606) demonstrated potent plasma cholesterol-lowering activity that affected all lipoprotein species, whereas 3-[2-[2-chloro-4-[[3-(2,6-dichlorophenyl)-5-(1-methylethyl)-4-isoxazolyl]methoxy]phenyl]ethenyl]benzoic acid (GW4064) and 6-ethyl chenodeoxycholic acid (6-ECDCA) showed only limited effects. In FXR wild-type mice, but not FXR(-/-) mice, the more efficacious FXR agonists increased fecal cholesterol excretion and reduced intestinal cholesterol (re)uptake. In CETPtg-LDLR(-/-) mice PX20606 potently lowered total cholesterol and, despite the observed HDL cholesterol (HDLc) reduction, caused a highly significant decrease in atherosclerotic plaque size. In normolipidemic cynomolgus monkeys PX20606 and 6-ECDCA both reduced total cholesterol, and PX20606 specifically lowered HDL(2c) but not HDL(3c) or apolipoprotein A1. That pharmacological FXR activation specifically affects this cholesterol-rich HDL(2) subclass is a new and highly interesting finding and sheds new light on FXR-dependent HDLc lowering, which has been perceived as a major limitation for the clinical development of FXR agonists.
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17
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Kremoser C, Albers M, Burris TP, Deuschle U, Koegl M. Panning for SNuRMs: using cofactor profiling for the rational discovery of selective nuclear receptor modulators. Drug Discov Today 2007; 12:860-9. [DOI: 10.1016/j.drudis.2007.07.025] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2007] [Revised: 07/20/2007] [Accepted: 07/23/2007] [Indexed: 01/20/2023]
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18
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Albers M, Blume B, Schlueter T, Wright MB, Kober I, Kremoser C, Deuschle U, Koegl M. A novel principle for partial agonism of liver X receptor ligands. Competitive recruitment of activators and repressors. J Biol Chem 2005; 281:4920-30. [PMID: 16354658 DOI: 10.1074/jbc.m510101200] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Partial, selective activation of nuclear receptors is a central issue in molecular endocrinology but only partly understood. Using LXRs as an example, we show here that purely agonistic ligands can be clearly and quantitatively differentiated from partial agonists by the cofactor interactions they induce. Although a pure agonist induces a conformation that is incompatible with the binding of repressors, partial agonists such as GW3965 induce a state where the interaction not only with coactivators, but also corepressors is clearly enhanced over the unliganded state. The activities of the natural ligand 22(R)-hydroxycholesterol and of a novel quinazolinone ligand, LN6500 can be further differentiated from GW3965 and T0901317 by their weaker induction of coactivator binding. Using biochemical and cell-based assays, we show that the natural ligand of LXR is a comparably weak partial agonist. As predicted, we find that a change in the coactivator to corepressor ratio in the cell will affect NCoR recruiting compounds more dramatically than NCoR-dissociating compounds. Our data show how competitive binding of coactivators and corepressors can explain the tissue-specific behavior of partial agonists and open up new routes to a rational design of partial agonists for LXRs.
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Affiliation(s)
- Michael Albers
- PheneX Pharmaceuticals AG, 67056 Ludwigshafen, Germany and Department of Vascular and Metabolic Diseases, F. Hoffmann-La Roche AG, 4070 Basel, Switzerland
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19
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Otte K, Kranz H, Kober I, Thompson P, Hoefer M, Haubold B, Remmel B, Voss H, Kaiser C, Albers M, Cheruvallath Z, Jackson D, Casari G, Koegl M, Pääbo S, Mous J, Kremoser C, Deuschle U. Identification of farnesoid X receptor beta as a novel mammalian nuclear receptor sensing lanosterol. Mol Cell Biol 2003; 23:864-72. [PMID: 12529392 PMCID: PMC140718 DOI: 10.1128/mcb.23.3.864-872.2003] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Nuclear receptors are ligand-modulated transcription factors. On the basis of the completed human genome sequence, this family was thought to contain 48 functional members. However, by mining human and mouse genomic sequences, we identified FXRbeta as a novel family member. It is a functional receptor in mice, rats, rabbits, and dogs but constitutes a pseudogene in humans and primates. Murine FXRbeta is widely coexpressed with FXR in embryonic and adult tissues. It heterodimerizes with RXRalpha and stimulates transcription through specific DNA response elements upon addition of 9-cis-retinoic acid. Finally, we identified lanosterol as a candidate endogenous ligand that induces coactivator recruitment and transcriptional activation by mFXRbeta. Lanosterol is an intermediate of cholesterol biosynthesis, which suggests a direct role in the control of cholesterol biosynthesis in nonprimates. The identification of FXRbeta as a novel functional receptor in nonprimate animals sheds new light on the species differences in cholesterol metabolism and has strong implications for the interpretation of genetic and pharmacological studies of FXR-directed physiologies and drug discovery programs.
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20
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Ciossek T, Monschau B, Kremoser C, Löschinger J, Lang S, Müller BK, Bonhoeffer F, Drescher U. Eph receptor-ligand interactions are necessary for guidance of retinal ganglion cell axons in vitro. Eur J Neurosci 1998; 10:1574-80. [PMID: 9751130 DOI: 10.1046/j.1460-9568.1998.00180.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Previous results of an in vitro guidance test, the stripe assay, have demonstrated the presence of a repulsive axon guidance activity for temporal retinal axons in the posterior part of the vertebrate optic tectum. Ephrin-A5 and Ephrin-A2 are ligands for the EphA subfamily of Eph receptor tyrosine kinases, which are expressed in overlapping gradients in the posterior part of the tectum. When recombinantly expressed, both proteins have been shown to guide retinal ganglion cell axons in the stripe assay. While these results suggest that Ephrin-A5 and Ephrin-A2 form part of the posterior repulsive guidance activity, they do not elucidate whether they are necessary components. Here we report that soluble forms of the ligands at nanomolar concentrations completely abolish this repulsive activity. Similar results were obtained with the soluble extracellular domain of EphA3, which is a receptor for Ephrin-A2 and Ephrin-A5, but not with the corresponding domain of EphB3, a receptor for the transmembrane class of Eph ligands. These experiments show that the repulsive axon guidance activity seen in the stripe assay is mediated by Ephrin-A ligands.
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Affiliation(s)
- T Ciossek
- Max-Planck-Institute for Developmental Biology, Department of Physical Biology, Tübingen, Germany
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21
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Monschau B, Kremoser C, Ohta K, Tanaka H, Kaneko T, Yamada T, Handwerker C, Hornberger MR, Löschinger J, Pasquale EB, Siever DA, Verderame MF, Müller BK, Bonhoeffer F, Drescher U. Shared and distinct functions of RAGS and ELF-1 in guiding retinal axons. EMBO J 1997; 16:1258-67. [PMID: 9135142 PMCID: PMC1169724 DOI: 10.1093/emboj/16.6.1258] [Citation(s) in RCA: 212] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Two ligands for Eph-related receptor tyrosine kinases, RAGS and ELF-1, have been implicated in the control of development of the retinotectal projection. Both molecules are expressed in overlapping gradients in the tectum, the target area of retinal ganglion cell axons. In two in vitro assays ELF-1 is shown to have a repellent axon guidance function for temporal, but apparently not for nasal axons. RAGS on the other hand is repellent for both types of axons, though to different degrees. Thus, RAGS and ELF-1 share some and differ in other properties. The biological activities of these molecules correlate with the strength of interaction with their receptors expressed on RGC axons. The meaning of these findings for guidance of retinal axons in the tectum is discussed.
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Affiliation(s)
- B Monschau
- Department of Physical Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany
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22
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Drescher U, Kremoser C, Handwerker C, Löschinger J, Noda M, Bonhoeffer F. In vitro guidance of retinal ganglion cell axons by RAGS, a 25 kDa tectal protein related to ligands for Eph receptor tyrosine kinases. Cell 1995; 82:359-70. [PMID: 7634326 DOI: 10.1016/0092-8674(95)90425-5] [Citation(s) in RCA: 718] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The results of previous in vitro experiments indicate that a glycosylphosphatidylinositol (GPI)-anchored protein may play an important role in the guidance of temporal retinal axons during the formation of the topographically ordered retinotectal projection. We have purified and cloned a GPI-anchored, 25 kDa glycoprotein that is a good candidate for a molecule involved in this process. During the time of innervation by retinal ganglion cells, this protein is gradedly expressed in the posterior part of the developing tectum. In two different in vitro assay systems, the recombinant protein induces growth cone collapse and repulsion of retinal ganglion cell axons. These phenomena are observed for axons of temporal as well as nasal origin, indicating that an additional activity may be necessary to confer the nasotemporal specificity observed in previous assays. We named the protein RAGS (for repulsive axon guidance signal). The sequence of RAGS shows significant homology to recently identified ligands for receptor tyrosine kinases of the Eph subfamily.
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Affiliation(s)
- U Drescher
- Max-Planck-Institute for Developmental Biology, Department of Physical Biology, Tübingen, Federal Republic of Germany
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