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Kjølbye LR, Sørensen L, Yan J, Berglund NA, Ferkinghoff-Borg J, Robinson CV, Schiøtt B. Lipid Modulation of a Class B GPCR: Elucidating the Modulatory Role of PI(4,5)P 2 Lipids. J Chem Inf Model 2022; 62:6788-6802. [PMID: 36036575 DOI: 10.1021/acs.jcim.2c00635] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) lipids have been shown to stabilize an active conformation of class A G-protein coupled receptors (GPCRs) through a conserved binding site, not present in class B GPCRs. For class B GPCRs, previous molecular dynamics (MD) simulation studies have shown PI(4,5)P2 interacting with the Glucagon receptor (GCGR), which constitutes an important target for diabetes and obesity therapeutics. In this work, we applied MD simulations supported by native mass spectrometry (nMS) to study lipid interactions with GCGR. We demonstrate how tail composition plays a role in modulating the binding of PI(4,5)P2 lipids to GCGR. Specifically, we find the PI(4,5)P2 lipids to have a higher affinity toward the inactive conformation of GCGR. Interestingly, we find that in contrast to class A GPCRs, PI(4,5)P2 appear to stabilize the inactive conformation of GCGR through a binding site conserved across class B GPCRs but absent in class A GPCRs. This suggests differences in the regulatory function of PI(4,5)P2 between class A and class B GPCRs.
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Affiliation(s)
- Lisbeth R Kjølbye
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark.,Novo Nordisk A/S, Novo Nordisk Park 1, 2760 Måløv, Denmark
| | - Lars Sørensen
- Novo Nordisk A/S, Novo Nordisk Park 1, 2760 Måløv, Denmark
| | - Jun Yan
- Novo Nordisk A/S, Novo Nordisk Park 1, 2760 Måløv, Denmark
| | - Nils A Berglund
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
| | | | - Carol V Robinson
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Birgit Schiøtt
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark.,Interdisciplinary Nanoscience Center, Aarhus University, Gustav Wieds vej 14, 8000 Aarhus C, Denmark
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2
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Toussaint MJ, De Wit MM, Blaauboer BJ, Nederbragt H. Phenobarbital pretreatment in vivo and in vitro and the effect of hepatotoxicity of d-galactosamine in rat hepatocytes in culture. Toxicol In Vitro 2012; 8:1129-37. [PMID: 20693081 DOI: 10.1016/0887-2333(94)90254-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/1993] [Revised: 02/02/1994] [Indexed: 11/30/2022]
Abstract
Galactosamine (GalN) is a known hepatotoxic compound, acting by depletion of uracil nucleotides. The relation between an active cytochrome P-450 system (CYP) and the hepatotoxicity of GalN was studied in rat hepatocytes that were pretreated with phenobarbital (PB) in vivo or in vitro. A 24-hr in vitro pretreatment of cultured hepatocytes with PB resulted in a significant decrease in GalN toxicity as measured by lactate dehydrogenase (LDH) leakage. Furthermore, GalN treatment resulted in an increase in the activity of the PB-induced forms of CYP (namely CYP 2B1/2) as measured by 7-pentoxyresorufin O-depentylase (PROD) activity. This increase was not found after GalN treatment of microsomes. GalN had no effect on the concentration of the apoenzymes. GalN administration to hepatocytes of in vivo PB-pretreated rats resulted in a similar effect of GalN on the activity of the CYP enzymes but PB in vivo had no effect on GalN toxicity. These results suggest that GalN treatment may result in a significant increase in the specific activity of CYP 2B1/2 enzymes (PROD), without an obvious increase in the amount of PB-induced apoenzymes. This phenomenon was measurable only in intact cells. No direct relation is assumed between the activity of the CYP apoenzymes and the decrease in GalN toxicity after PB treatment. The toxicity of Galn was inhibited by PB treatment in vitro.
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Affiliation(s)
- M J Toussaint
- Department of Veterinary Pathology, Utrecht University, POB 80.158, 3508 TD Utrecht, The Netherlands
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3
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Gonzalez E, van Liempd S, Conde-Vancells J, Gutierrez-de Juan V, Perez-Cormenzana M, Mayo R, Berisa A, Alonso C, Marquez CA, Barr J, Lu SC, Mato JM, Falcon-Perez JM. Serum UPLC-MS/MS metabolic profiling in an experimental model for acute-liver injury reveals potential biomarkers for hepatotoxicity. Metabolomics 2011; 8:997-1011. [PMID: 23139648 PMCID: PMC3490499 DOI: 10.1007/s11306-011-0329-9] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
A key interest in clinical diagnosis and pharmaceutical industry is to have a repertoire of noninvasive biomarkers to-individually or in combination-be able to infer or predict the degree of liver injury caused by pathological conditions or drugs. Metabolomics-a comprehensive study of global metabolites-has become a highly sensitive and powerful tool for biomarker discovery thanks to recent technological advances. An ultra-performance liquid chromatography/time-of-flight tandem mass spectrometry (UPLC/TOF MS/MS)-based metabolomics approach was employed to investigate sera from galactosamine-treated rats to find potential biomarkers for acute liver injury. Hepatic damage was quantified by determining serum transaminase activity and in situ liver histological lesions. Principal component analysis in combination with coefficient of correlation analysis was used for biomarker selection and identification. According to the data, serum levels of several metabolites including glucose, amino acids, and membrane lipids were significantly modified, some of them showing a high correlation with the degree of liver damage determined by histological examination of the livers. In conclusion, this study supports that UPLC-MS/MS based serum metabolomics in experimental animal models could be a powerful approach to search for biomarkers for drug- or disease-induced liver injury.
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Affiliation(s)
- Esperanza Gonzalez
- Metabolomics Unit, CIC bioGUNE, CIBERehd, Bizkaia Technology Park, 48160 Derio, Bizkaia, Spain
| | - Sebastiaan van Liempd
- Metabolomics Platform, CIC bioGUNE, CIBERehd, Bizkaia Technology Park, 48160 Derio, Bizkaia, Spain
| | - Javier Conde-Vancells
- Metabolomics Unit, CIC bioGUNE, CIBERehd, Bizkaia Technology Park, 48160 Derio, Bizkaia, Spain
| | | | | | - Rebeca Mayo
- OWL Genomics, Bizkaia Technology Park, 48160 Derio, Bizkaia, Spain
| | - Agustin Berisa
- R&D and Innovation Department, FAES FARMA S.A., 48940 Leioa, Bizkaia, Spain
| | - Cristina Alonso
- OWL Genomics, Bizkaia Technology Park, 48160 Derio, Bizkaia, Spain
| | | | - Jonathan Barr
- OWL Genomics, Bizkaia Technology Park, 48160 Derio, Bizkaia, Spain
| | - Shelly C. Lu
- Division of Gastrointestinal and Liver Diseases, Keck School of Medicine, University Southern California, Los Angeles, CA 90033, USA
| | - Jose M. Mato
- Metabolomics Unit, CIC bioGUNE, CIBERehd, Bizkaia Technology Park, 48160 Derio, Bizkaia, Spain
| | - Juan M. Falcon-Perez
- Metabolomics Unit, CIC bioGUNE, CIBERehd, Bizkaia Technology Park, 48160 Derio, Bizkaia, Spain, IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain
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4
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Bollard ME, Xu J, Purcell W, Griffin JL, Quirk C, Holmes E, Nicholson JK. Metabolic profiling of the effects of D-galactosamine in liver spheroids using (1)H NMR and MAS-NMR spectroscopy. Chem Res Toxicol 2002; 15:1351-9. [PMID: 12437325 DOI: 10.1021/tx025571e] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We report here the combined application of (1)H magic angle spinning (MAS) and high-resolution NMR spectroscopy and pattern recognition methods to study the effects of a model toxin (D-galactosamine) in liver spheroid cultures. (1)H NMR spectra of metabolic profiles of spheroids showed closer similarities to intact liver spectra than those of isolated hepatocytes, suggesting their superiority as an in vitro model system. Batches of spheroids were prepared from male Sprague Dawley rat livers and incubated in control hepatocyte medium or medium containing D-galactosamine (4 or 20 mM) for 4 or 24 h. Intact spheroids were packed into rotors and analyzed using MAS-NMR spectroscopy or homogenized and analyzed using conventional (1)H NMR spectroscopy. Principal components analysis, (PCA), of the NMR data revealed separation of control and D-galactosamine-treated spheroids based on changes in the concentrations of the triglycerides and elevations in cholesterol and esters. The absence of cholesterol in hepatocytes and the relative under-representation of the lipid resonances offer an important advantage of spheroids over hepatocytes for the (1)H NMR studies of fatty liver. Orthogonal signal correction (OSC) was used as a data filter to remove non-dose-dependent variation from the NMR spectra, improving the classification of treated spheroids and controls. This work shows that useful metabolic information can be obtained on drug toxicity by the use of combined MAS-NMR and high-resolution NMR of liver spheroids and that such studies may enhance the validation of in vitro techniques against in vivo models for metabolic profiling.
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Affiliation(s)
- Mary E Bollard
- Biological Chemistry, Biomedical Sciences Division, Imperial College of Science, Technology, and Medicine, University of London, Sir Alexander Fleming Building, South Kensington, UK.
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5
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Rotundo RF, Vincent PA, McKeown-Longo PJ, Blumenstock FA, Saba TM. Hepatic fibronectin matrix turnover in rats: involvement of the asialoglycoprotein receptor. Am J Physiol Gastrointest Liver Physiol 2000; 277:G1189-99. [PMID: 10600816 DOI: 10.1152/ajpgi.1999.277.6.g1189] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
Abstract
Fibronectin (Fn) is a major adhesive protein found in the hepatic extracellular matrix (ECM). In adult rats, the in vivo turnover of plasma Fn (pFn) incorporated into the liver ECM is relatively rapid, i.e., <24 h, but the regulation of its turnover has not been defined. We previously reported that cellular Fn (cFn) and enzymatically desialylated plasma Fn (aFn), both of which have a high density of exposed terminal galactose residues, rapidly interact with hepatic asialoglycoprotein receptors (ASGP-R) in association with their plasma clearance after intravenous infusion. With the use of adult male rats (250-350 g) and measurement of the deoxycholate (DOC)-insoluble (125)I-labeled Fn in the liver, we determined whether the ASGP-R system can also influence the hepatic matrix retention of various forms of Fn. There was a rapid deposition of (125)I-pFn, (125)I-aFn, and (125)I-cFn into the liver ECM after their intravenous injection. Although (125)I-pFn was slowly lost from the liver matrix over 24 h, more than 90% of the incorporated (125)I-aFn and (125)I-cFn was cleared within 4 h (P < 0.01). Intravenous infusion of excess nonlabeled asialofetuin to competitively inhibit the hepatic ASGP-R delayed the rapid turnover of both aFn and cFn already incorporated within the ECM of the liver. ECM retention of both (125)I-aFn and (125)I-cFn was also less than (125)I-pFn (P < 0.01) as determined in vitro using liver slices preloaded in vivo with either tracer form of Fn. The hepatic ASGP-R appears to participate in the turnover of aFn and cFn within the liver ECM, whereas a non-ASGP-R-associated endocytic pathway apparently influences the removal of normal pFn incorporated within the hepatic ECM, unless it becomes locally desialylated.
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Affiliation(s)
- R F Rotundo
- Department of Physiology and Cell Biology, Albany Medical College, Albany, New York 12208, USA
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6
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Rudi J, Schlenker T, Raedsch R, Waldherr R, Zorn M, Stremmel W. Effect of ursodeoxycholic acid on biochemical parameters, hepatocyte proliferation and liver histology in galactosamine hepatitis in the rat. RESEARCH IN EXPERIMENTAL MEDICINE. ZEITSCHRIFT FUR DIE GESAMTE EXPERIMENTELLE MEDIZIN EINSCHLIESSLICH EXPERIMENTELLER CHIRURGIE 1995; 195:309-15. [PMID: 8579639 DOI: 10.1007/bf02576801] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The effect of oral administration of ursodeoxycholic acid (UDCA) on biochemical parameters, liver histology and liver cell proliferation was investigated in rats with galactosamine hepatitis. Treatment with UDCA led to a decrease of aminotransferases, but did not show any significant changes in liver histology or liver cell proliferation. The improvement of liver enzymes without change of histology in this animal model of hepatitis following treatment with UDCA is in agreement with results obtained from clinical trials with UDCA in patients with chronic viral hepatitis.
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Affiliation(s)
- J Rudi
- Department of Medicine, University of Heidelberg, Germany
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7
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Yamamoto C, Mori S, Murakami K, Yoshino M. Effect of galactosamine-induced hepatitis on the aerobic and anaerobic metabolism of the rat exposed to high-altitude hypoxia. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. PART C, PHARMACOLOGY, TOXICOLOGY & ENDOCRINOLOGY 1995; 110:83-7. [PMID: 7749607 DOI: 10.1016/0742-8413(94)00068-l] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Galactosamine-induced hepatitis caused a marked increase in plasma lactate and pyruvate, but completely abolished the increase in ketone bodies in the rat exposed to an 8000 m simulated altitude. Plasma free fatty acid as the precursor of ketone bodies was higher in the galactosamine-treated rats during and after an exposure to 8000 m altitude. Treatment of the rat with galactosamine markedly reduced activities of citrate synthase, fumarase, glutamate dehydrogenase and fructose 1,6-bisphosphatase, but increased hexokinase and glucose 6-phosphate dehydrogenase in the liver. The effect of galactosamine-induced hepatitis on the energy metabolism can be explained by a reduction of mitochondrial oxidative enzymes and gluconeogenesis, and involves a shift of the aerobic metabolism to anaerobic glycolysis at high altitude.
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Affiliation(s)
- C Yamamoto
- Department of Endocrinology and Metabolism, Nagoya University, Japan
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8
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Momchilova-Pankova AB, Markovska TT, Koumanov KS. Acyl-CoA synthetase activity depends on the phospholipid composition of rat liver plasma membranes. JOURNAL OF LIPID MEDIATORS AND CELL SIGNALLING 1995; 11:13-23. [PMID: 7728415 DOI: 10.1016/0929-7855(94)00024-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The dependence of acyl-CoA synthetase on the lipid composition of rat liver plasma membranes has been investigated. For this purpose the composition of the membranes was modified by incorporation of different phospholipids in the presence of partially purified lipid transfer proteins. Another approach to the modification of the membrane phospholipid composition was treatment with exogenous phospholipase C and subsequent enrichment with different phospholipids. The experiments performed in vitro indicated that the presence of certain phospholipids such as phosphatidylnositol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylserine was essential for the activation of long chain fatty acids by acyl-CoA synthetase. However, some differences were observed when oleate and palmitate were used as substrates. Sphingomyelin was found to inhibit this activity especially when oleic acid served as substrate. In addition, we tried to modify in vivo the membrane lipid composition by treatment with D-galactosamine, which is known to induce acute hepatitis and cause biochemical and biophysical alterations in liver membranes. The results thus obtained confirmed the idea that the augmentation of the membrane lipids and especially of PI, PE and PG was accompanied by acyl-CoA synthetase activation. The presence of two different enzymes, activating the saturated and unsaturated fatty acids is discussed.
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9
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Dwivedi Y, Rastogi R, Garg NK, Dhawan BN. Picroliv and its components kutkoside and picroside I protect liver against galactosamine-induced damage in rats. PHARMACOLOGY & TOXICOLOGY 1992; 71:383-7. [PMID: 1333078 DOI: 10.1111/j.1600-0773.1992.tb00566.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
D-Galactosamine (800 mg/kg, intraperitoneally) caused significant decrease in the activities of 5'-nucleotidase, glucose-6-phosphatase and cytochrome P450 and increase in activities of gamma-glutamyl transpeptidase, succinate dehydrogenase, acid phosphatase and acid ribonuclease in liver after 24 hr. The levels of RNA, protein and glycogen decreased while total lipids, phospholipids, cholesterol and lipid peroxides increased. It also increased the serum levels of transaminases, alkaline phosphatase and bilirubin while protein concentration decreased significantly. Oral administration of Picroliv (12 mg/kg/day for 7 days), a standardised iridoid glycoside fraction of Picrorhiza kurroa, significantly prevented the biochemical changes in liver and serum of galactosamine-toxicated rats. Kutkoside (12 mg/kg/day for 7 days) also protected against changes in most of the hepatic and serum constituents studied. Another iridoid glycoside from Picroliv, Picroside I, at the same dose level could only prevent toxicant-induced changes in acid phosphatase, phospholipids and lipid peroxides in liver and alkaline phosphatase in serum. Mixture of Picroside I and Kutkoside in the ratio of 1:1.5 at 12 mg/kg dose elicited lesser response than Picroliv.
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Affiliation(s)
- Y Dwivedi
- ICMR Centre for Advanced Pharmacological Research on Traditional Remedies, Central Drug Research Institute, Lucknow, India
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10
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Jonker AM, Dijkhuis FW, Kroese FG, Hardonk MJ, Grond J. Immunopathology of acute galactosamine hepatitis in rats. Hepatology 1990; 11:622-7. [PMID: 2328956 DOI: 10.1002/hep.1840110415] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Galactosamine hydrochloride induces liver disease in rats that morphologically resembles drug-induced hepatitis in man. In this study we analyzed the character of the inflammatory reaction following the toxic damage resulting from the administration of galactosamine hydrochloride using a broad panel of monoclonal antibodies to lymphocyte subsets and macrophages. Fat-storing cells were identified with a polyclonal anti-desmin antibody. Cellular proliferation was assessed by labeling S-phase cells with the thymidine analog bromodeoxyuridine. Injection of galactosamine hydrochloride was associated with conspicuous hepatocyte necrosis and parenchymal granulocyte influx in the first 24 hr. Thereafter, mononuclear inflammatory cells predominated, mainly T lymphocytes and macrophages, with maximal numbers at 48 hr. The majority of T lymphocytes were CD8-positive cells and were located in the portal tracts and parenchyma. CD4-positive T cells were scarce and confined to the portal tracts. Proliferation of fat-storing cells paralleled hepatocyte regeneration with maximal values after 48 to 72 hr. The temporal relationship between infiltrating mononuclear cells, mainly T lymphocytes of CD8 phenotype and macrophages, fat-storing cell proliferation and hepatic regeneration suggests pathophysiological interactions between these cell types in liver injury in the rat after galactosamine hydrochloride administration.
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Affiliation(s)
- A M Jonker
- Department of Pathology, University of Groningen, The Netherlands
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