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Gao Z, Zhang J, Wei L, Yang X, Zhang Y, Cheng B, Yang Z, Gao W, Song C, Miao W, Williams K, Liu C, Xu Q, Chang Y, Gao Y. The Protective Effects of Imperatorin on Acetaminophen Overdose-Induced Acute Liver Injury. Oxid Med Cell Longev 2020; 2020:8026838. [PMID: 32454943 PMCID: PMC7243017 DOI: 10.1155/2020/8026838] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 12/23/2019] [Accepted: 12/28/2019] [Indexed: 12/11/2022]
Abstract
Acetaminophen (APAP) toxicity leads to severe acute liver injury (ALI) by inducing excessive oxidative stress, inflammatory response, and hepatocyte apoptosis. Imperatorin (IMP) is a furanocoumarin from Angelica dahurica, which has antioxidant and anti-inflammatory effects. However, its potential to ameliorate ALI is unknown. In this study, APAP-treated genetic knockout of Farnesoid X receptor (FXR) and Sirtuin 1 (SIRT1) mice were used for research. The results revealed that IMP could improve the severity of liver injury and inhibit the increase of proinflammatory cytokines, oxidative damage, and apoptosis induced by overdose APAP in an FXR-dependent manner. We also found that IMP enhanced the activation and translocation of FXR by increasing the expression of SIRT1 and the phosphorylation of AMPK. Besides, single administration of IMP at 4 h after APAP injection can also improve necrotic areas and serum transaminase, indicating that IMP have both preventive and therapeutic effects. Taken together, it is the first time to demonstrate that IMP exerts protective effects against APAP overdose-induced hepatotoxicity by stimulating the SIRT1-FXR pathway. These findings suggest that IMP is a potential therapeutic candidate for ALI, offering promise for the treatment of hepatotoxicity associated with APAP overdose.
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Affiliation(s)
- Zhao Gao
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, China
- Guangdong Institute of Sports Science, Guangzhou, China
| | - Jiecheng Zhang
- Department of Surgery, The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, China
| | - Li Wei
- The Second Clinical Medical College, Guangzhou University of Traditional Chinese Medicine, Guangzhou, China
| | - Xingping Yang
- The First Affiliated Hospital of Guangdong Pharmaceutical University, Guangzhou, China
| | - Yuan Zhang
- Guangdong Institute of Sports Science, Guangzhou, China
| | - Bo Cheng
- Science and Technology Innovation Center, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Zehong Yang
- Science and Technology Innovation Center, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Weihang Gao
- Science and Technology Innovation Center, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Chunhui Song
- Science and Technology Innovation Center, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Wei Miao
- Science and Technology Innovation Center, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Kevin Williams
- Division of Hypothalamic Research, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Changhui Liu
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Qin Xu
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Yongsheng Chang
- Tianjin Key Laboratory of Cellular and Molecular Immunology, Key Laboratory of Immune Micro-Environment and Disease (Ministry of Education), Department of Physiology and Pathophysiology, Tianjin Medical University, Tianjin, China
| | - Yong Gao
- The First Affiliated Hospital of Guangdong Pharmaceutical University, Guangzhou, China
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2
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Ferrell JM, Pathak P, Boehme S, Gilliland T, Chiang JYL. Deficiency of Both Farnesoid X Receptor and Takeda G Protein-Coupled Receptor 5 Exacerbated Liver Fibrosis in Mice. Hepatology 2019; 70:955-970. [PMID: 30664797 PMCID: PMC6642864 DOI: 10.1002/hep.30513] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 01/07/2019] [Indexed: 12/30/2022]
Abstract
Activation of the nuclear bile acid receptor farnesoid X receptor (FXR) protects against hepatic inflammation and injury, while Takeda G protein-coupled receptor 5 (TGR5) promotes adipose tissue browning and energy metabolism. Here, we examined the physiological and metabolic effects of the deficiency of these two bile acid receptors on hepatic metabolism and injury in mice. Fxr/Tgr5 double knockout mice (DKO) were generated for metabolic phenotyping. Male DKO mice fed a chow diet had reduced liver lipid levels but increased serum cholesterol levels. Liver cholesterol 7α-hydroxylase (Cyp7a1) activity and sterol 12α-hydroxylase mRNA levels were induced, while ileum FXR target genes were suppressed in DKO mice compared to wild-type (WT) mice. Bile acid pool size was increased in DKO mice, with increased taurocholic acid and decreased tauromuricholic acids. RNA sequencing analysis of the liver transcriptome revealed that bile acid synthesis and fibrosis gene expression levels are increased in chow-fed DKO mice compared to WT mice and that the top regulated pathways are involved in steroid/cholesterol biosynthesis, liver cirrhosis, and connective tissue disease. Cholestyramine treatment further induced Cyp7a1 mRNA and protein in DKO mice and increased bile acid pool size, while cholic acid also induced Cyp7a1 in DKO mice, suggesting impaired bile acid feedback regulation. A Western diet containing 0.2% cholesterol increased oxidative stress and markers of liver fibrosis but not hepatic steatosis in DKO mice. Conclusion: FXR and TGR5 play critical roles in protecting the liver from inflammation and fibrosis, and deficiency of both of these bile acid receptors in mice increased cholic acid synthesis and the bile acid pool, liver fibrosis, and inflammation; FXR and TGR5 DKO mice may be a model for liver fibrosis.
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Affiliation(s)
- Jessica M Ferrell
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH
| | - Preeti Pathak
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH
| | - Shannon Boehme
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH
| | - Tricia Gilliland
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH
| | - John Y L Chiang
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH
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3
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Amador A, Campbell S, Kazantzis M, Lan G, Burris TP, Solt LA. Distinct roles for REV-ERBα and REV-ERBβ in oxidative capacity and mitochondrial biogenesis in skeletal muscle. PLoS One 2018; 13:e0196787. [PMID: 29723273 PMCID: PMC5933789 DOI: 10.1371/journal.pone.0196787] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 04/19/2018] [Indexed: 12/19/2022] Open
Abstract
The nuclear receptors REV-ERBα and REV-ERBβ have been demonstrated to be core members of the circadian clock and participate in the regulation of a diverse set of metabolic functions. Due to their overlapping tissue expression patterns and gene expression profiles, REV-ERBβ is thought to be redundant to REV-ERBα. Recent work has highlighted REV-ERBα's role in the regulation of skeletal muscle oxidative capacity and mitochondrial biogenesis. Considering the similarity between the REV-ERBs and the hypothesized overlap in function, we sought to determine whether REV-ERBβ-deficiency presented with a similar skeletal muscle phenotype as REV-ERBα-deficiency. Ectopic overexpression in C2C12 cells demonstrated that REV-ERBβ drives mitochondrial biogenesis and the expression of genes involved in fatty acid oxidation. Intriguingly, knock down of REV-ERBβ in C2C12 cultures also resulted in mitochondrial biogenesis and increased expression of genes involved in fatty acid β-oxidation. To determine whether these effects occurred in vivo, we examined REV-ERBβ-deficient mice and observed a similar increase in expression of genes involved in mitochondrial biogenesis and fatty acid β-oxidation. Consistent with these results, REV-ERBβ-deficient mice exhibited an altered metabolic phenotype compared to wild-type littermate controls when measured by indirect calorimetry. This likely compensated for the increased food consumption that occurred, possibly aiding in the maintenance of their weight over time. Since feeding behaviors are a direct circadian output, this study suggests that REV-ERBβ may have more subtle effects on circadian behaviors than originally identified. Furthermore, these data implicate REV-ERBβ in the control of skeletal muscle metabolism and energy expenditure and suggest that development of REV-ERBα versus REV-ERBβ selective ligands may have therapeutic utility in the treatment of metabolic syndrome.
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MESH Headings
- Animals
- Body Weight
- Calorimetry, Indirect
- Cell Line
- Circadian Rhythm/genetics
- Circadian Rhythm/physiology
- Energy Metabolism/genetics
- Energy Metabolism/physiology
- Fatty Acids/metabolism
- Feeding Behavior/physiology
- Female
- Gene Expression Regulation
- Male
- Mice
- Mice, Knockout
- Mitochondria, Muscle/physiology
- Muscle, Skeletal/metabolism
- Nuclear Receptor Subfamily 1, Group D, Member 1/antagonists & inhibitors
- Nuclear Receptor Subfamily 1, Group D, Member 1/deficiency
- Nuclear Receptor Subfamily 1, Group D, Member 1/genetics
- Nuclear Receptor Subfamily 1, Group D, Member 1/physiology
- Organelle Biogenesis
- Oxidation-Reduction
- Oxidative Phosphorylation
- RNA Interference
- RNA, Small Interfering/genetics
- Receptors, Cytoplasmic and Nuclear/antagonists & inhibitors
- Receptors, Cytoplasmic and Nuclear/deficiency
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/physiology
- Repressor Proteins/antagonists & inhibitors
- Repressor Proteins/deficiency
- Repressor Proteins/genetics
- Repressor Proteins/physiology
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Affiliation(s)
- Ariadna Amador
- Kellogg School of Science and Technology, The Scripps Research Institute, Jupiter, Florida, United States of America
| | - Sean Campbell
- Department of Immunology and Microbiology, The Scripps Research Institute, Jupiter, Florida, United States of America
| | - Melissa Kazantzis
- Metabolic Core, The Scripps Research Institute, Jupiter, Florida, United States of America
| | - Gary Lan
- Department of Immunology and Microbiology, The Scripps Research Institute, Jupiter, Florida, United States of America
| | - Thomas P. Burris
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, St. Louis, Missouri, United States of America
| | - Laura A. Solt
- Department of Immunology and Microbiology, The Scripps Research Institute, Jupiter, Florida, United States of America
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, Florida, United States of America
- * E-mail:
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Hause F, Schlote D, Simm A, Hoffmann K, Santos AN. Accumulation of glycated proteins suggesting premature ageing in lamin B receptor deficient mice. Biogerontology 2018; 19:95-100. [PMID: 29081010 DOI: 10.1007/s10522-017-9733-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 10/19/2017] [Indexed: 01/01/2023]
Abstract
Accumulation of advanced glycation end products (AGEs) is accompanied by increased free radical activity which contributes to ageing and the development or worsening of degenerative diseases. Apart from other physiological factors, AGEs are also an important biomarker for premature ageing. Here we report protein modifications (glycation) in a mouse model of lamin B receptor deficient ic J /ic J mice displaying skin defects similar to those of classical progeria. Therefore, we analysed AGE-modifications in protein extracts from various tissues of ic J /ic J mice. Our results demonstrated that pentosidine as well as argpyrimidine were increased in ic J /ic J mice indicating a modification specific increase in biomarkers of ageing, especially derived from glycolysis dependent methylglyoxal. Furthermore, the expression of AGE-preventing enzymes (Glo1, Fn3k) differed between ic J /ic J and control mice. The results indicate that not only lamin A but also the lamin B receptor may be involved in ageing processes.
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Affiliation(s)
- Frank Hause
- Institute for Human Genetics, Martin Luther University of Halle-Wittenberg, 06112, Halle, Germany
| | - Dietmar Schlote
- Institute for Human Genetics, Martin Luther University of Halle-Wittenberg, 06112, Halle, Germany.
| | - Andreas Simm
- Clinic for Cardiac und Thoracic Surgery, Martin Luther University of Halle-Wittenberg, 06097, Halle, Germany
| | - Katrin Hoffmann
- Institute for Human Genetics, Martin Luther University of Halle-Wittenberg, 06112, Halle, Germany
| | - Alexander Navarrete Santos
- Clinic for Cardiac und Thoracic Surgery, Martin Luther University of Halle-Wittenberg, 06097, Halle, Germany
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5
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Dubois-Chevalier J, Dubois V, Dehondt H, Mazrooei P, Mazuy C, Sérandour AA, Gheeraert C, Guillaume P, Baugé E, Derudas B, Hennuyer N, Paumelle R, Marot G, Carroll JS, Lupien M, Staels B, Lefebvre P, Eeckhoute J. The logic of transcriptional regulator recruitment architecture at cis-regulatory modules controlling liver functions. Genome Res 2017; 27:985-996. [PMID: 28400425 PMCID: PMC5453331 DOI: 10.1101/gr.217075.116] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 04/05/2017] [Indexed: 02/06/2023]
Abstract
Control of gene transcription relies on concomitant regulation by multiple transcriptional regulators (TRs). However, how recruitment of a myriad of TRs is orchestrated at cis-regulatory modules (CRMs) to account for coregulation of specific biological pathways is only partially understood. Here, we have used mouse liver CRMs involved in regulatory activities of the hepatic TR, NR1H4 (FXR; farnesoid X receptor), as our model system to tackle this question. Using integrative cistromic, epigenomic, transcriptomic, and interactomic analyses, we reveal a logical organization where trans-regulatory modules (TRMs), which consist of subsets of preferentially and coordinately corecruited TRs, assemble into hierarchical combinations at hepatic CRMs. Different combinations of TRMs add to a core TRM, broadly found across the whole landscape of CRMs, to discriminate promoters from enhancers. These combinations also specify distinct sets of CRM differentially organized along the genome and involved in regulation of either housekeeping/cellular maintenance genes or liver-specific functions. In addition to these TRMs which we define as obligatory, we show that facultative TRMs, such as one comprising core circadian TRs, are further recruited to selective subsets of CRMs to modulate their activities. TRMs transcend TR classification into ubiquitous versus liver-identity factors, as well as TR grouping into functional families. Hence, hierarchical superimpositions of obligatory and facultative TRMs bring about independent transcriptional regulatory inputs defining different sets of CRMs with logical connection to regulation of specific gene sets and biological pathways. Altogether, our study reveals novel principles of concerted transcriptional regulation by multiple TRs at CRMs.
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Affiliation(s)
- Julie Dubois-Chevalier
- Université Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000 Lille, France
| | - Vanessa Dubois
- Université Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000 Lille, France
| | - Hélène Dehondt
- Université Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000 Lille, France
| | - Parisa Mazrooei
- The Princess Margaret Cancer Centre, University Health Network, Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 1L7, Canada
| | - Claire Mazuy
- Université Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000 Lille, France
| | - Aurélien A Sérandour
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge CB2 0RE, United Kingdom
| | - Céline Gheeraert
- Université Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000 Lille, France
| | - Penderia Guillaume
- Université Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000 Lille, France
| | - Eric Baugé
- Université Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000 Lille, France
| | - Bruno Derudas
- Université Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000 Lille, France
| | - Nathalie Hennuyer
- Université Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000 Lille, France
| | - Réjane Paumelle
- Université Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000 Lille, France
| | - Guillemette Marot
- Université Lille, MODAL Team, Inria Lille-Nord Europe, 59650 Villeneuve-d'Ascq, France
| | - Jason S Carroll
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge CB2 0RE, United Kingdom
| | - Mathieu Lupien
- The Princess Margaret Cancer Centre, University Health Network, Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 1L7, Canada
| | - Bart Staels
- Université Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000 Lille, France
| | - Philippe Lefebvre
- Université Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000 Lille, France
| | - Jérôme Eeckhoute
- Université Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000 Lille, France
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6
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Honke N, Shaabani N, Hardt C, Krings C, Häussinger D, Lang PA, Lang KS, Keitel V. Farnesoid X Receptor in Mice Prevents Severe Liver Immunopathology During Lymphocytic Choriomeningitis Virus Infection. Cell Physiol Biochem 2017; 41:323-338. [PMID: 28214859 DOI: 10.1159/000456168] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 12/20/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Bile acids (BAs) are steroid molecules that are synthesized in the liver. In addition to their important role as a surfactant in solubilizing lipids and promoting the absorption of lipids in the gastrointestinal tract, they act as inflammagens. The role of BAs and their receptor farnesoid X receptor (FXR) during viral infection has not been studied in detail. METHODS By using FXR-deficient mice, we investigated the role of bile acid receptor FXR during infection with lymphocytic choriomeningitis virus (LCMV). The importance of FXR in inducing IFN-I and monocytes proliferation were investigated and viral titers and T cell exhaustion were analyzed at different time points. RESULTS This study shows that controlled levels of BAs activate FXR in hepatocytes and FXR in response upregulates the production of type I interferon. In turn, FXR maintains BAs within a balanced range to inhibit their toxic effects. The absence of FXR results in high levels of BAs, which inhibit the proliferation of monocytes and result in a defect in viral elimination, consequently leading to T cell exhaustion. CONCLUSION We found that FXR contributes to IFN-I production in hepatocytes and balances BA levels to inhibit their toxic effects on monocytes.
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7
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de Vries EM, Lammers LA, Achterbergh R, Klümpen HJ, Mathot RAA, Boelen A, Romijn JA. Fasting-Induced Changes in Hepatic P450 Mediated Drug Metabolism Are Largely Independent of the Constitutive Androstane Receptor CAR. PLoS One 2016; 11:e0159552. [PMID: 27434302 PMCID: PMC4951123 DOI: 10.1371/journal.pone.0159552] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 07/04/2016] [Indexed: 12/25/2022] Open
Abstract
Introduction Hepatic drug metabolism by cytochrome P450 enzymes is altered by the nutritional status of patients. The expression of P450 enzymes is partly regulated by the constitutive androstane receptor (CAR). Fasting regulates the expression of both P450 enzymes and CAR and affects hepatic drug clearance. We hypothesized that the fasting-induced alterations in P450 mediated drug clearance are mediated by CAR. Methods To investigate this we used a drug cocktail validated in humans consisting of five widely prescribed drugs as probes for specific P450 enzymes: caffeine (CYP1A2), metoprolol (CYP2D6), omeprazole (CYP2C19), midazolam (CYP3A4) and s-warfarin (CYP2C9). This cocktail was administered to wild type (WT, C57Bl/6) mice or mice deficient for CAR (CAR-/-) that were either fed ad libitum or fasted for 24 hours. Blood was sampled at predefined intervals and drug concentrations were measured as well as hepatic mRNA expression of homologous/orthologous P450 enzymes (Cyp1a2, Cyp2d22, Cyp3a11, Cyp2c37, Cyp2c38 and Cyp2c65). Results Fasting decreased Cyp1a2 and Cyp2d22 expression and increased Cyp3a11 and Cyp2c38 expression in both WT and CAR-/- mice. The decrease in Cyp1a2 was diminished in CAR-/- in comparison with WT mice. Basal Cyp2c37 expression was lower in CAR-/- compared to WT mice. Fasting decreased the clearance of all drugs tested in both WT and CAR-/- mice. The absence of CAR was associated with an decrease in the clearance of omeprazole, metoprolol and midazolam in fed mice. The fasting-induced reduction in clearance of s-warfarin was greater in WT than in CAR-/-. The changes in drug clearance correlated with the expression pattern of the specific P450 enzymes in case of Cyp1a2-caffeine and Cyp2c37-omeprazole. Conclusion We conclude that CAR is important for hepatic clearance of several widely prescribed drugs metabolized by P450 enzymes. However the fasting-induced alterations in P450 mediated drug clearance are largely independent of CAR.
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Affiliation(s)
- E. M. de Vries
- Department of Medicine, Academic Medical Center, Meibergdreef 9, 1105 AZ, Amsterdam, the Netherlands
- * E-mail:
| | - L. A. Lammers
- Department of Hospital Pharmacy, Academic Medical Center, Meibergdreef 9, 1105 AZ, Amsterdam, the Netherlands
| | - R. Achterbergh
- Department of Medical Oncology, Academic Medical Center, Meibergdreef 9, 1105 AZ, Amsterdam, the Netherlands
| | - H-J Klümpen
- Department of Medical Oncology, Academic Medical Center, Meibergdreef 9, 1105 AZ, Amsterdam, the Netherlands
| | - R. A. A. Mathot
- Department of Hospital Pharmacy, Academic Medical Center, Meibergdreef 9, 1105 AZ, Amsterdam, the Netherlands
| | - A. Boelen
- Department of Endocrinology and Metabolism, Academic Medical Center, Meibergdreef 9, 1105 AZ, Amsterdam, the Netherlands
| | - J. A. Romijn
- Department of Medicine, Academic Medical Center, Meibergdreef 9, 1105 AZ, Amsterdam, the Netherlands
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8
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Mochida K, Oikawa Y, Kimura Y, Kirisako H, Hirano H, Ohsumi Y, Nakatogawa H. Receptor-mediated selective autophagy degrades the endoplasmic reticulum and the nucleus. Nature 2015; 522:359-62. [PMID: 26040717 DOI: 10.1038/nature14506] [Citation(s) in RCA: 448] [Impact Index Per Article: 49.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 04/29/2015] [Indexed: 12/19/2022]
Abstract
Macroautophagy (hereafter referred to as autophagy) degrades various intracellular constituents to regulate a wide range of cellular functions, and is also closely linked to several human diseases. In selective autophagy, receptor proteins recognize degradation targets and direct their sequestration by double-membrane vesicles called autophagosomes, which transport them into lysosomes or vacuoles. Although recent studies have shown that selective autophagy is involved in quality/quantity control of some organelles, including mitochondria and peroxisomes, it remains unclear how extensively it contributes to cellular organelle homeostasis. Here we describe selective autophagy of the endoplasmic reticulum (ER) and nucleus in the yeast Saccharomyces cerevisiae. We identify two novel proteins, Atg39 and Atg40, as receptors specific to these pathways. Atg39 localizes to the perinuclear ER (or the nuclear envelope) and induces autophagic sequestration of part of the nucleus. Atg40 is enriched in the cortical and cytoplasmic ER, and loads these ER subdomains into autophagosomes. Atg39-dependent autophagy of the perinuclear ER/nucleus is required for cell survival under nitrogen-deprivation conditions. Atg40 is probably the functional counterpart of FAM134B, an autophagy receptor for the ER in mammals that has been implicated in sensory neuropathy. Our results provide fundamental insight into the pathophysiological roles and mechanisms of 'ER-phagy' and 'nucleophagy' in other organisms.
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Affiliation(s)
- Keisuke Mochida
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Yu Oikawa
- Frontier Research Center, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Yayoi Kimura
- Advanced Medical Research Center, Yokohama City University, Yokohama 236-0004, Japan
| | - Hiromi Kirisako
- 1] Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama 226-8503, Japan [2] CREST, Japan Science and Technology Agency, Saitama 332-0012, Japan
| | - Hisashi Hirano
- Advanced Medical Research Center, Yokohama City University, Yokohama 236-0004, Japan
| | - Yoshinori Ohsumi
- Frontier Research Center, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Hitoshi Nakatogawa
- 1] Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama 226-8503, Japan [2] CREST, Japan Science and Technology Agency, Saitama 332-0012, Japan
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Tsuchiya H, da Costa KA, Lee S, Renga B, Jaeschke H, Yang Z, Orena SJ, Goedken MJ, Zhang Y, Kong B, Lebofsky M, Rudraiah S, Smalling R, Guo G, Fiorucci S, Zeisel SH, Wang L. Interactions Between Nuclear Receptor SHP and FOXA1 Maintain Oscillatory Homocysteine Homeostasis in Mice. Gastroenterology 2015; 148:1012-1023.e14. [PMID: 25701738 PMCID: PMC4409521 DOI: 10.1053/j.gastro.2015.01.045] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 01/27/2015] [Accepted: 01/30/2015] [Indexed: 12/18/2022]
Abstract
BACKGROUND & AIMS Hyperhomocysteinemia is often associated with liver and metabolic diseases. We studied nuclear receptors that mediate oscillatory control of homocysteine homeostasis in mice. METHODS We studied mice with disruptions in Nr0b2 (called small heterodimer partner [SHP]-null mice), betaine-homocysteine S-methyltransferase (Bhmt), or both genes (BHMT-null/SHP-null mice), along with mice with wild-type copies of these genes (controls). Hyperhomocysteinemia was induced by feeding mice alcohol (National Institute on Alcohol Abuse and Alcoholism binge model) or chow diets along with water containing 0.18% DL-homocysteine. Some mice were placed on diets containing cholic acid (1%) or cholestyramine (2%) or high-fat diets (60%). Serum and livers were collected during a 24-hour light-dark cycle and analyzed by RNA-seq, metabolomic, and quantitative polymerase chain reaction, immunoblot, and chromatin immunoprecipitation assays. RESULTS SHP-null mice had altered timing in expression of genes that regulate homocysteine metabolism compared with control mice. Oscillatory production of S-adenosylmethionine, betaine, choline, phosphocholine, glyceophosphocholine, cystathionine, cysteine, hydrogen sulfide, glutathione disulfide, and glutathione, differed between SHP-null mice and control mice. SHP inhibited transcriptional activation of Bhmt and cystathionine γ-lyase by FOXA1. Expression of Bhmt and cystathionine γ-lyase was decreased when mice were fed cholic acid but increased when they were placed on diets containing cholestyramine or high-fat content. Diets containing ethanol or homocysteine induced hyperhomocysteinemia and glucose intolerance in control, but not SHP-null, mice. In BHMT-null and BHMT-null/SHP-null mice fed a control liquid, lipid vacuoles were observed in livers. Ethanol feeding induced accumulation of macrovesicular lipid vacuoles to the greatest extent in BHMT-null and BHMT-null/SHP-null mice. CONCLUSIONS Disruption of Shp in mice alters timing of expression of genes that regulate homocysteine metabolism and the liver responses to ethanol and homocysteine. SHP inhibits the transcriptional activation of Bhmt and cystathionine γ-lyase by FOXA1.
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Affiliation(s)
- Hiroyuki Tsuchiya
- Department of Medicine, University of Utah School of Medicine, Salt Lake City, Utah
| | - Kerry-Ann da Costa
- Nutrition Research Institute, Department of Nutrition, University of North Carolina at Chapel Hill, North Carolina
| | - Sangmin Lee
- Department of Physiology and Neurobiology and The Institute for Systems Genomics, University of Connecticut, Storrs, Connecticut
| | - Barbara Renga
- Dipartimento di Scienze Chirurgiche e Biomediche, University of Perugia, Perugia, Italy
| | - Hartmut Jaeschke
- Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, Kansas
| | - Zhihong Yang
- Department of Physiology and Neurobiology and The Institute for Systems Genomics, University of Connecticut, Storrs, Connecticut; Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut
| | - Stephen J Orena
- Nutrition Research Institute, Department of Nutrition, University of North Carolina at Chapel Hill, North Carolina
| | | | - Yuxia Zhang
- Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, Kansas
| | - Bo Kong
- Department of Pharmacology and Toxicology of School of Pharmacy, Rutgers University, Piscataway, New Jersey
| | - Margitta Lebofsky
- Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, Kansas
| | - Swetha Rudraiah
- Department of Physiology and Neurobiology and The Institute for Systems Genomics, University of Connecticut, Storrs, Connecticut
| | - Rana Smalling
- Department of Medicine, University of Utah School of Medicine, Salt Lake City, Utah
| | - Grace Guo
- Department of Pharmacology and Toxicology of School of Pharmacy, Rutgers University, Piscataway, New Jersey
| | - Stefano Fiorucci
- Dipartimento di Scienze Chirurgiche e Biomediche, University of Perugia, Perugia, Italy
| | - Steven H Zeisel
- Nutrition Research Institute, Department of Nutrition, University of North Carolina at Chapel Hill, North Carolina
| | - Li Wang
- Department of Physiology and Neurobiology and The Institute for Systems Genomics, University of Connecticut, Storrs, Connecticut; Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut; Department of Internal Medicine, Section of Digestive Diseases, Yale University, New Haven, Connecticut.
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10
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Ahlemeyer B, Vogt JF, Michel V, Hahn-Kohlberger P, Baumgart-Vogt E. Microporation is an efficient method for siRNA-induced knockdown of PEX5 in HepG2 cells: evaluation of the transfection efficiency, the PEX5 mRNA and protein levels and induction of peroxisomal deficiency. Histochem Cell Biol 2014; 142:577-91. [PMID: 25224142 DOI: 10.1007/s00418-014-1254-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/14/2014] [Indexed: 11/26/2022]
Abstract
The pathomechanism of peroxisomal biogenesis disorders (PBDs), a group of inherited autosomal recessive diseases with mutations of peroxin (PEX) genes, is not yet fully understood. Therefore, several knockout models, e.g., the PEX5 knockout mouse, have been generated exhibiting a complete loss of peroxisomal function. In this study, we wanted to knockdown PEX5 using the siRNA technology (1) to mimic milder forms of PBDs in which the mutated peroxin has some residual function and (2) to analyze the cellular consequences of a reduction of the PEX5 protein without adaption during the development as it is the case in a knockout animal. First, we tried to optimize the transfection of the hepatoma cell line HepG2 with PEX5 siRNA using different commercially available liposomal and non-liposomal transfection reagents (Lipofectamine(®) 2000, FuGENE 6, HiPerFect(®), INTERFERin™, RiboJuice™) as well as microporation using the Neon™ Transfection system. Microporation was found to be superior to the transfection reagents with respect to the transfection efficiency (100 vs. 0-70%), to the reduction of PEX5 mRNA (by 90 vs. 0-50%) and PEX5 protein levels (by 70 vs. 0-50%). Interestingly, we detected that a part of the cleaved PEX5 mRNA still existed as 3' fragment (15%) 24 h after microporation. Using microporation, we further analyzed whether the reduced PEX5 protein level impaired peroxisomal function. We indeed detected a reduced targeting of SKL-tagged proteins into peroxisomes as well as an increased oxidative stress as found in PBD patients and respective knockout mouse models. Knockdown of the PEX5 protein and functional consequences were at a maximum 48 h after microporation. Thereafter, the PEX5 protein was resynthesized, which may allow the temporal analysis of the loss as well as the reconstitution of peroxisomes in the future. In conclusion, we propose microporation as an efficient and reproducible method to transfect HepG2 cells with PEX5 siRNA. We succeeded to transiently knockdown PEX5 mRNA and its protein level leading to functional consequences similar as observed in peroxisome deficiencies.
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Affiliation(s)
- Barbara Ahlemeyer
- Division of Medical Cell Biology, Institute for Anatomy and Cell Biology, Justus Liebig University, Aulweg 123, 35385, Giessen, Germany,
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11
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Swennes AG, Sheh A, Parry NMA, Muthupalani S, Lertpiriyapong K, García A, Fox JG. Helicobacter hepaticus infection promotes hepatitis and preneoplastic foci in farnesoid X receptor (FXR) deficient mice. PLoS One 2014; 9:e106764. [PMID: 25184625 PMCID: PMC4153687 DOI: 10.1371/journal.pone.0106764] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 08/08/2014] [Indexed: 11/19/2022] Open
Abstract
Farnesoid X receptor (FXR) is a nuclear receptor that regulates bile acid metabolism and transport. Mice lacking expression of FXR (FXR KO) have a high incidence of foci of cellular alterations (FCA) and liver tumors. Here, we report that Helicobacter hepaticus infection is necessary for the development of increased hepatitis scores and FCA in previously Helicobacter-free FXR KO mice. FXR KO and wild-type (WT) mice were sham-treated or orally inoculated with H. hepaticus. At 12 months post-infection, mice were euthanized and liver pathology, gene expression, and the cecal microbiome were analyzed. H. hepaticus induced significant increases hepatitis scores and FCA numbers in FXR KO mice (P<0.01 and P<0.05, respectively). H. hepaticus altered the beta diversity of cecal microbiome in both WT and FXR KO mice compared to uninfected mice (P<0.05). Significant upregulation of β-catenin, Rela, Slc10a1, Tlr2, Nos2, Vdr, and Cyp3a11 was observed in all FXR KO mice compared to controls (P<0.05). Importantly, H. hepaticus and FXR deficiency were necessary to significantly upregulate Cyp2b10 (P<0.01). FXR deficiency was also a potent modulator of the cecal microbiota, as observed by a strong decrease in alpha diversity. A significant decrease in Firmicutes, particularly members of the order Clostridiales, was observed in FXR KO mice (P<0.05 and FDR<5%, ANOVA). While FXR deficiency strongly affects expression of genes related to immunity and bile acid metabolism, as well as the composition of the microbiome; however, its deficiency was not able to produce significant histopathological changes in the absence of H. hepaticus infection.
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Affiliation(s)
- Alton G. Swennes
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Alexander Sheh
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Nicola M. A. Parry
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Sureshkumar Muthupalani
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Kvin Lertpiriyapong
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Alexis García
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - James G. Fox
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- * E-mail:
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12
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da Silva TF, Eira J, Lopes AT, Malheiro AR, Sousa V, Luoma A, Avila RL, Wanders RJA, Just WW, Kirschner DA, Sousa MM, Brites P. Peripheral nervous system plasmalogens regulate Schwann cell differentiation and myelination. J Clin Invest 2014; 124:2560-70. [PMID: 24762439 DOI: 10.1172/jci72063] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Rhizomelic chondrodysplasia punctata (RCDP) is a developmental disorder characterized by hypotonia, cataracts, abnormal ossification, impaired motor development, and intellectual disability. The underlying etiology of RCDP is a deficiency in the biosynthesis of ether phospholipids, of which plasmalogens are the most abundant form in nervous tissue and myelin; however, the role of plasmalogens in the peripheral nervous system is poorly defined. Here, we used mouse models of RCDP and analyzed the consequence of plasmalogen deficiency in peripheral nerves. We determined that plasmalogens are crucial for Schwann cell development and differentiation and that plasmalogen defects impaired radial sorting, myelination, and myelin structure. Plasmalogen insufficiency resulted in defective protein kinase B (AKT) phosphorylation and subsequent signaling, causing overt activation of glycogen synthase kinase 3β (GSK3β) in nerves of mutant mice. Treatment with GSK3β inhibitors, lithium, or 4-benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione (TDZD-8) restored Schwann cell defects, effectively bypassing plasmalogen deficiency. Our results demonstrate the requirement of plasmalogens for the correct and timely differentiation of Schwann cells and for the process of myelination. In addition, these studies identify a mechanism by which the lack of a membrane phospholipid causes neuropathology, implicating plasmalogens as regulators of membrane and cell signaling.
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13
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Yao R, Yasuoka A, Kamei A, Ushiama S, Kitagawa Y, Rogi T, Shibata H, Abe K, Misaka T. Nuclear receptor-mediated alleviation of alcoholic fatty liver by polyphenols contained in alcoholic beverages. PLoS One 2014; 9:e87142. [PMID: 24498295 PMCID: PMC3911942 DOI: 10.1371/journal.pone.0087142] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Accepted: 12/18/2013] [Indexed: 12/22/2022] Open
Abstract
To elucidate the effect of the polyphenols contained in alcoholic beverages on the metabolic stress induced by ethanol consumption, four groups of mice were fed for five weeks on Lieber's diet with or without ethanol, with ethanol plus ellagic acid, and with ethanol plus trans-resveratrol. Alcoholic fatty liver was observed in the group fed the ethanol diet but not in those fed the ethanol plus polyphenol diets. Liver transcriptome analysis revealed that the addition of the polyphenols suppressed the expression of the genes related to cell stress that were up-regulated by ethanol alone. Conversely, the polyphenols up-regulated the genes involved in bile acid synthesis, unsaturated fatty acid elongation, and tetrahydrofolate synthesis that were down-regulated by ethanol alone. Because parts of these genes were known to be regulated by the constitutive androstane receptor (CAR), we performed the same experiment in the CAR-deficient mice. As a result, fatty liver was observed not only in the ethanol group but also with the ethanol plus polyphenol groups. In addition, there was no segregation of the gene expression profiles among these groups. These results provide a molecular basis for the prevention of alcohol-induced stress by the polyphenols in alcoholic beverages.
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Affiliation(s)
- Ruiqing Yao
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Akihito Yasuoka
- Department of Biological Engineering, Maebashi Institute of Technology, Maebashi-shi, Gunma, Japan
- Kanagawa Academy of Science and Technology, Takatsu-ku, Kawasaki-shi, Kanagawa, Japan
- * E-mail: (AY); (TM)
| | - Asuka Kamei
- Kanagawa Academy of Science and Technology, Takatsu-ku, Kawasaki-shi, Kanagawa, Japan
| | - Shota Ushiama
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Yoshinori Kitagawa
- Institute for Health Care Science, Suntory Wellness Ltd., Shimamoto-cho, Mishima-gun, Osaka, Japan
| | - Tomohiro Rogi
- Institute for Health Care Science, Suntory Wellness Ltd., Shimamoto-cho, Mishima-gun, Osaka, Japan
| | - Hiroshi Shibata
- Institute for Health Care Science, Suntory Wellness Ltd., Shimamoto-cho, Mishima-gun, Osaka, Japan
| | - Keiko Abe
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- Kanagawa Academy of Science and Technology, Takatsu-ku, Kawasaki-shi, Kanagawa, Japan
| | - Takumi Misaka
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- * E-mail: (AY); (TM)
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14
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Bjursell M, Wedin M, Admyre T, Hermansson M, Böttcher G, Göransson M, Lindén D, Bamberg K, Oscarsson J, Bohlooly-Y M. Ageing Fxr deficient mice develop increased energy expenditure, improved glucose control and liver damage resembling NASH. PLoS One 2013; 8:e64721. [PMID: 23700488 PMCID: PMC3659114 DOI: 10.1371/journal.pone.0064721] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Accepted: 04/17/2013] [Indexed: 12/17/2022] Open
Abstract
Nuclear receptor subfamily 1, group H, member 4 (Nr1h4, FXR) is a bile acid activated nuclear receptor mainly expressed in the liver, intestine, kidney and adrenal glands. Upon activation, the primary function is to suppress cholesterol 7 alpha-hydroxylase (Cyp7a1), the rate-limiting enzyme in the classic or neutral bile acid synthesis pathway. In the present study, a novel Fxr deficient mouse line was created and studied with respect to metabolism and liver function in ageing mice fed chow diet. The Fxr deficient mice were similar to wild type mice in terms of body weight, body composition, energy intake and expenditure as well as behaviours at a young age. However, from 15 weeks of age and onwards, the Fxr deficient mice had almost no body weight increase up to 39 weeks of age mainly because of lower body fat mass. The lower body weight gain was associated with increased energy expenditure that was not compensated by increased food intake. Fasting levels of glucose and insulin were lower and glucose tolerance was improved in old and lean Fxr deficient mice. However, the Fxr deficient mice displayed significantly increased liver weight, steatosis, hepatocyte ballooning degeneration and lobular inflammation together with elevated plasma levels of ALT, bilirubin and bile acids, findings compatible with non-alcoholic steatohepatitis (NASH) and cholestasis. In conclusion, ageing Fxr deficient mice display late onset leanness associated with elevated energy expenditure and improved glucose control but develop severe NASH-like liver pathology.
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15
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Kim MJ, Lee KJ, Hwang JY, Lee HS, Chio SH, Lim S, Jang HC, Park YJ. Loss of small heterodimer partner protects against atherosclerosis in apolipoprotein E-deficient mice. Endocr J 2013; 60:1171-7. [PMID: 23912975 DOI: 10.1507/endocrj.ej13-0212] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Small heterodimer partner (SHP) is involved in bile, lipid, and glucose metabolism. The aim of this study was to investigate the effect of SHP on the development of atherosclerosis. Apolipoprotein E knockout (ApoE-/-) mice were crossed with SHP knockout (SHP-/-) mice to generate double knockout (ApoE-/-SHP-/-) mice. ApoE-/- and ApoE-/-SHP-/- male mice were fed a western diet for 20 weeks. Body weight in ApoE-/-SHP-/) mice was significantly lower than that in ApoE-/- mice (37±1 g vs. 42±1 g, p<0.01). Loss of SHP in ApoE-/- mice decreased the size of adipocytes in white adipose tissue and reduced lipid accumulation in the liver. Glucose intolerance was improved in ApoE-/-SHP-/- mice as compared with ApoE-/- mice (p<0.01). There was no statistical difference in non-high density lipoprotein cholesterol levels between ApoE-/-SHP-/- mice and ApoE-/- mice despite an increase of cholesterol 7α-hydroxylase expression in the liver. The proportion of atherosclerotic lesions in the aorta was significantly lower in ApoE-/-SHP-/- mice than in ApoE-/- mice (2.8±2.0% vs. 9.1±1.9%, p<0.01). In conclusion, loss of SHP function can prevent atherosclerosis, and resistance to diet-induced obesity is the primary factor contributing to this protective effect.
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Affiliation(s)
- Min Joo Kim
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul 110-744, Republic of Korea
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16
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MESH Headings
- Adiposity/genetics
- Adiposity/physiology
- Animals
- Circadian Clocks/genetics
- Circadian Clocks/physiology
- Circadian Rhythm/genetics
- Circadian Rhythm/physiology
- Disease Models, Animal
- Energy Intake
- Energy Metabolism/physiology
- Homeostasis/physiology
- Humans
- Hypothalamus/physiology
- Lipid Metabolism/physiology
- Mice
- Mice, Knockout
- Models, Biological
- Nuclear Receptor Subfamily 1, Group D, Member 1/deficiency
- Nuclear Receptor Subfamily 1, Group D, Member 1/genetics
- Nuclear Receptor Subfamily 1, Group D, Member 1/physiology
- Obesity/etiology
- Obesity/physiopathology
- Receptors, Cytoplasmic and Nuclear/deficiency
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/physiology
- Repressor Proteins/deficiency
- Repressor Proteins/genetics
- Repressor Proteins/physiology
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17
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Li G, Thomas AM, Williams JA, Kong B, Liu J, Inaba Y, Xie W, Guo GL. Farnesoid X receptor induces murine scavenger receptor Class B type I via intron binding. PLoS One 2012; 7:e35895. [PMID: 22540009 PMCID: PMC3335076 DOI: 10.1371/journal.pone.0035895] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2012] [Accepted: 03/23/2012] [Indexed: 12/22/2022] Open
Abstract
Farnesoid X receptor (FXR) is a nuclear receptor and a key regulator of liver cholesterol and triglyceride homeostasis. Scavenger receptor class B type I (SR-BI) is critical for reverse cholesterol transport (RCT) by transporting high-density lipoprotein (HDL) into liver. FXR induces SR-BI, however, the underlying molecular mechanism of this induction is not known. The current study confirmed induction of SR-BI mRNA by activated FXR in mouse livers, a human hepatoma cell line, and primary human hepatocytes. Genome-wide FXR binding analysis in mouse livers identified 4 putative FXR response elements in the form of inverse repeat separated by one nucleotide (IR1) at the first intron and 1 IR1 at the downstream of the mouse Sr-bi gene. ChIP-qPCR analysis revealed FXR binding to only the intronic IR1s, but not the downstream one. Luciferase assays and site-directed mutagenesis further showed that 3 out of 4 IR1s were able to activate gene transcription. A 16-week high-fat diet (HFD) feeding in mice increased hepatic Sr-bi gene expression in a FXR-dependent manner. In addition, FXR bound to the 3 bona fide IR1s in vivo, which was increased following HFD feeding. Serum total and HDL cholesterol levels were increased in FXR knockout mice fed the HFD, compared to wild-type mice. In conclusion, the Sr-bi/SR-BI gene is confirmed as a FXR target gene in both mice and humans, and at least in mice, induction of Sr-bi by FXR is via binding to intronic IR1s. This study suggests that FXR may serve as a promising molecular target for increasing reverse cholesterol transport.
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MESH Headings
- Animals
- Base Sequence
- Cells, Cultured
- Cholesterol/metabolism
- Diet, High-Fat
- Female
- Hep G2 Cells
- Hepatocytes/drug effects
- Hepatocytes/metabolism
- Humans
- Introns
- Isoxazoles/pharmacology
- Lipoproteins, HDL/metabolism
- Liver/drug effects
- Liver/metabolism
- Mice
- Mice, Inbred C57BL
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- RNA, Messenger/metabolism
- Receptors, Cytoplasmic and Nuclear/deficiency
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/metabolism
- Scavenger Receptors, Class B/genetics
- Scavenger Receptors, Class B/metabolism
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Affiliation(s)
- Guodong Li
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas, United States of America
- Department of Abdominal Surgery, Cancer Treatment Center, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China
| | - Ann M. Thomas
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas, United States of America
| | - Jessica A. Williams
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas, United States of America
| | - Bo Kong
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas, United States of America
| | - Jie Liu
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas, United States of America
| | - Yuka Inaba
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Wen Xie
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Grace L. Guo
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas, United States of America
- * E-mail:
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18
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Prawitt J, Abdelkarim M, Stroeve JH, Popescu I, Duez H, Velagapudi VR, Dumont J, Bouchaert E, van Dijk TH, Lucas A, Dorchies E, Daoudi M, Lestavel S, Gonzalez FJ, Oresic M, Cariou B, Kuipers F, Caron S, Staels B. Farnesoid X receptor deficiency improves glucose homeostasis in mouse models of obesity. Diabetes 2011; 60:1861-71. [PMID: 21593203 PMCID: PMC3121443 DOI: 10.2337/db11-0030] [Citation(s) in RCA: 235] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
OBJECTIVE Bile acids (BA) participate in the maintenance of metabolic homeostasis acting through different signaling pathways. The nuclear BA receptor farnesoid X receptor (FXR) regulates pathways in BA, lipid, glucose, and energy metabolism, which become dysregulated in obesity. However, the role of FXR in obesity and associated complications, such as dyslipidemia and insulin resistance, has not been directly assessed. RESEARCH DESIGN AND METHODS Here, we evaluate the consequences of FXR deficiency on body weight development, lipid metabolism, and insulin resistance in murine models of genetic and diet-induced obesity. RESULTS FXR deficiency attenuated body weight gain and reduced adipose tissue mass in both models. Surprisingly, glucose homeostasis improved as a result of an enhanced glucose clearance and adipose tissue insulin sensitivity. In contrast, hepatic insulin sensitivity did not change, and liver steatosis aggravated as a result of the repression of β-oxidation genes. In agreement, liver-specific FXR deficiency did not protect from diet-induced obesity and insulin resistance, indicating a role for nonhepatic FXR in the control of glucose homeostasis in obesity. Decreasing elevated plasma BA concentrations in obese FXR-deficient mice by administration of the BA sequestrant colesevelam improved glucose homeostasis in a FXR-dependent manner, indicating that the observed improvements by FXR deficiency are not a result of indirect effects of altered BA metabolism. CONCLUSIONS Overall, FXR deficiency in obesity beneficially affects body weight development and glucose homeostasis.
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Affiliation(s)
- Janne Prawitt
- University of Lille Nord de France, INSERM UMR1011; UDSL; Institut Pasteur de Lille, Lille, France
| | - Mouaadh Abdelkarim
- University of Lille Nord de France, INSERM UMR1011; UDSL; Institut Pasteur de Lille, Lille, France
| | - Johanna H.M. Stroeve
- Center for Liver, Digestive and Metabolic Diseases, Laboratory of Pediatrics, University Medical Center Groningen, Groningen, the Netherlands
| | - Iuliana Popescu
- University of Lille Nord de France, INSERM UMR1011; UDSL; Institut Pasteur de Lille, Lille, France
| | - Helene Duez
- University of Lille Nord de France, INSERM UMR1011; UDSL; Institut Pasteur de Lille, Lille, France
| | | | - Julie Dumont
- University of Lille Nord de France, INSERM UMR1011; UDSL; Institut Pasteur de Lille, Lille, France
| | - Emmanuel Bouchaert
- University of Lille Nord de France, INSERM UMR1011; UDSL; Institut Pasteur de Lille, Lille, France
| | - Theo H. van Dijk
- Center for Liver, Digestive and Metabolic Diseases, Laboratory of Pediatrics, University Medical Center Groningen, Groningen, the Netherlands
| | - Anthony Lucas
- University of Lille Nord de France, INSERM UMR1011; UDSL; Institut Pasteur de Lille, Lille, France
| | - Emilie Dorchies
- University of Lille Nord de France, INSERM UMR1011; UDSL; Institut Pasteur de Lille, Lille, France
| | - Mehdi Daoudi
- University of Lille Nord de France, INSERM UMR1011; UDSL; Institut Pasteur de Lille, Lille, France
| | - Sophie Lestavel
- University of Lille Nord de France, INSERM UMR1011; UDSL; Institut Pasteur de Lille, Lille, France
| | - Frank J. Gonzalez
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| | - Matej Oresic
- VTT Technical Research Centre of Finland, Espoo, Finland
| | - Bertrand Cariou
- University of Lille Nord de France, INSERM UMR1011; UDSL; Institut Pasteur de Lille, Lille, France
- INSERM U915; Faculty of Medicine, University of Nantes, Thorax Institute; Clinic of Endocrinology, University Hospital Center Nantes, Nantes, France
| | - Folkert Kuipers
- Center for Liver, Digestive and Metabolic Diseases, Laboratory of Pediatrics, University Medical Center Groningen, Groningen, the Netherlands
| | - Sandrine Caron
- University of Lille Nord de France, INSERM UMR1011; UDSL; Institut Pasteur de Lille, Lille, France
| | - Bart Staels
- University of Lille Nord de France, INSERM UMR1011; UDSL; Institut Pasteur de Lille, Lille, France
- Corresponding author: Bart Staels,
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19
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Zhang YKJ, Guo GL, Klaassen CD. Diurnal variations of mouse plasma and hepatic bile acid concentrations as well as expression of biosynthetic enzymes and transporters. PLoS One 2011; 6:e16683. [PMID: 21346810 PMCID: PMC3035620 DOI: 10.1371/journal.pone.0016683] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Accepted: 12/31/2010] [Indexed: 12/30/2022] Open
Abstract
Background Diurnal fluctuation of bile acid (BA) concentrations in the enterohepatic system of mammals has been known for a long time. Recently, BAs have been recognized as signaling molecules beyond their well-established roles in dietary lipid absorption and cholesterol homeostasis. Methods and Results The current study depicted diurnal variations of individual BAs detected by ultra-performance liquid chromatography/mass spectrometry (UPLC/MS) in serum and livers collected from C57BL/6 mice fed a regular chow or a chow containing cholestyramine (resin). Circadian rhythms of mRNA of vital BA-related nuclear receptors, enzymes, and transporters in livers and ilea were determined in control- and resin-fed mice, as well as in farnesoid X receptor (FXR) null mice. The circadian profiles of BAs showed enhanced bacterial dehydroxylation during the fasting phase and efficient hepatic reconjugation of BAs in the fed phase. The resin removed more than 90% of BAs with β-hydroxy groups, such as muricholic acids and ursodeoxycholic acid, from serum and livers, but did not exert as significant influence on CA and CDCA in both compartments. Both resin-fed and FXR-null mouse models indicate that BAs regulate their own biosynthesis through the FXR-regulated ileal fibroblast growth factor 15. BA flux also influences the daily mRNA levels of multiple BA transporters. Conclusion BA concentration and composition exhibit circadian variations in mouse liver and serum, which influences the circadian rhythms of BA metabolizing genes in liver and ileum. The diurnal variations of BAs appear to serve as a signal that coordinates daily nutrient metabolism in mammals.
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Affiliation(s)
- Yu-Kun Jennifer Zhang
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas, United States of America
| | - Grace L. Guo
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas, United States of America
| | - Curtis D. Klaassen
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas, United States of America
- * E-mail:
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20
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Anakk S, Watanabe M, Ochsner SA, McKenna NJ, Finegold MJ, Moore DD. Combined deletion of Fxr and Shp in mice induces Cyp17a1 and results in juvenile onset cholestasis. J Clin Invest 2011; 121:86-95. [PMID: 21123943 PMCID: PMC3007143 DOI: 10.1172/jci42846] [Citation(s) in RCA: 89] [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: 08/13/2010] [Accepted: 10/13/2010] [Indexed: 12/17/2022] Open
Abstract
Bile acid homeostasis is tightly regulated via a feedback loop operated by the nuclear receptors farnesoid X receptor (FXR) and small heterodimer partner (SHP). Contrary to current models, which place FXR upstream of SHP in a linear regulatory pathway, here we show that the phenotypic consequences in mice of the combined loss of both receptors are much more severe than the relatively modest impact of the loss of either Fxr or Shp alone. Fxr-/-Shp-/- mice exhibited cholestasis and liver injury as early as 3 weeks of age, and this was linked to the dysregulation of bile acid homeostatic genes, particularly cytochrome P450, family 7, subfamily a, polypeptide 1 (Cyp7a1). In addition, double-knockout mice showed misregulation of genes in the C21 steroid biosynthesis pathway, with strong induction of cytochrome P450, family 17, subfamily a, polypeptide 1 (Cyp17a1), resulting in elevated serum levels of its enzymatic product 17-hydroxyprogesterone (17-OHP). Treatment of WT mice with 17-OHP was sufficient to induce liver injury that reproduced many of the histopathological features observed in the double-knockout mice. Therefore, our data indicate a pathologic role for increased production of 17-hydroxy steroid metabolites in liver injury and suggest that Fxr-/-Shp-/- mice could provide a model for juvenile onset cholestasis.
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Affiliation(s)
- Sayeepriyadarshini Anakk
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, USA.
Department of Internal Medicine, School of Medicine, Keio University, Shinjuku-ku, Tokyo, Japan.
Department of Pathology, Baylor College of Medicine, Houston, Texas, USA
| | - Mitsuhiro Watanabe
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, USA.
Department of Internal Medicine, School of Medicine, Keio University, Shinjuku-ku, Tokyo, Japan.
Department of Pathology, Baylor College of Medicine, Houston, Texas, USA
| | - Scott A. Ochsner
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, USA.
Department of Internal Medicine, School of Medicine, Keio University, Shinjuku-ku, Tokyo, Japan.
Department of Pathology, Baylor College of Medicine, Houston, Texas, USA
| | - Neil J. McKenna
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, USA.
Department of Internal Medicine, School of Medicine, Keio University, Shinjuku-ku, Tokyo, Japan.
Department of Pathology, Baylor College of Medicine, Houston, Texas, USA
| | - Milton J. Finegold
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, USA.
Department of Internal Medicine, School of Medicine, Keio University, Shinjuku-ku, Tokyo, Japan.
Department of Pathology, Baylor College of Medicine, Houston, Texas, USA
| | - David D. Moore
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, USA.
Department of Internal Medicine, School of Medicine, Keio University, Shinjuku-ku, Tokyo, Japan.
Department of Pathology, Baylor College of Medicine, Houston, Texas, USA
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21
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Wang XX, Jiang T, Shen Y, Caldas Y, Miyazaki-Anzai S, Santamaria H, Urbanek C, Solis N, Scherzer P, Lewis L, Gonzalez FJ, Adorini L, Pruzanski M, Kopp JB, Verlander JW, Levi M. Diabetic nephropathy is accelerated by farnesoid X receptor deficiency and inhibited by farnesoid X receptor activation in a type 1 diabetes model. Diabetes 2010; 59:2916-27. [PMID: 20699418 PMCID: PMC2963551 DOI: 10.2337/db10-0019] [Citation(s) in RCA: 136] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
OBJECTIVE The pathogenesis of diabetic nephropathy is complex and involves activation of multiple pathways leading to kidney damage. An important role for altered lipid metabolism via sterol regulatory element binding proteins (SREBPs) has been recently recognized in diabetic kidney disease. Our previous studies have shown that the farnesoid X receptor (FXR), a bile acid-activated nuclear hormone receptor, modulates renal SREBP-1 expression. The purpose of the present study was then to determine if FXR deficiency accelerates type 1 diabetic nephropathy in part by further stimulation of SREBPs and related pathways, and conversely, if a selective FXR agonist can prevent the development of type 1 diabetic nephropathy. RESEARCH DESIGN AND METHODS Insulin deficiency and hyperglycemia were induced with streptozotocin (STZ) in C57BL/6 FXR KO mice. Progress of renal injury was compared with nephropathy-resistant wild-type C57BL/6 mice given STZ. DBA/2J mice with STZ-induced hyperglycemia were treated with the selective FXR agonist INT-747 for 12 weeks. To accelerate disease progression, all mice were placed on the Western diet after hyperglycemia development. RESULTS The present study demonstrates accelerated renal injury in diabetic FXR KO mice. In contrast, treatment with the FXR agonist INT-747 improves renal injury by decreasing proteinuria, glomerulosclerosis, and tubulointerstitial fibrosis, and modulating renal lipid metabolism, macrophage infiltration, and renal expression of SREBPs, profibrotic growth factors, and oxidative stress enzymes in the diabetic DBA/2J strain. CONCLUSIONS Our findings indicate a critical role for FXR in the development of diabetic nephropathy and show that FXR activation prevents nephropathy in type 1 diabetes.
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MESH Headings
- Animals
- Crosses, Genetic
- DNA Primers
- Diabetes Mellitus, Experimental/pathology
- Diabetes Mellitus, Experimental/physiopathology
- Diabetes Mellitus, Type 1/pathology
- Diabetes Mellitus, Type 1/physiopathology
- Diabetic Nephropathies/pathology
- Diabetic Nephropathies/physiopathology
- Diabetic Nephropathies/prevention & control
- Female
- Foam Cells/pathology
- Kidney/pathology
- Kidney/physiopathology
- Kidney Glomerulus/pathology
- Macrophages/pathology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Inbred DBA
- Mice, Knockout
- Polymerase Chain Reaction
- Receptors, Cytoplasmic and Nuclear/deficiency
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/physiology
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Affiliation(s)
- Xiaoxin X. Wang
- Department of Medicine, University of Colorado Denver, and the VA Medical Center, Aurora, Colorado
| | - Tao Jiang
- Department of Medicine, University of Colorado Denver, and the VA Medical Center, Aurora, Colorado
| | - Yan Shen
- Department of Medicine, University of Colorado Denver, and the VA Medical Center, Aurora, Colorado
| | - Yupanqui Caldas
- Department of Medicine, University of Colorado Denver, and the VA Medical Center, Aurora, Colorado
| | - Shinobu Miyazaki-Anzai
- Department of Medicine, University of Colorado Denver, and the VA Medical Center, Aurora, Colorado
| | - Hannah Santamaria
- Department of Medicine, University of Colorado Denver, and the VA Medical Center, Aurora, Colorado
| | - Cydney Urbanek
- Department of Medicine, University of Colorado Denver, and the VA Medical Center, Aurora, Colorado
| | - Nathaniel Solis
- Department of Medicine, University of Colorado Denver, and the VA Medical Center, Aurora, Colorado
| | - Pnina Scherzer
- Nephrology and Hypertension Services, Hadassah University Hospital, Jerusalem, Israel
| | - Linda Lewis
- Department of Medicine, University of Colorado Denver, and the VA Medical Center, Aurora, Colorado
| | - Frank J. Gonzalez
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| | | | | | - Jeffrey B. Kopp
- Kidney Disease Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Jill W. Verlander
- Department of Medicine, Division of Nephrology, Hypertension, and Transplantation, University of Florida, Gainesville, Florida
| | - Moshe Levi
- Department of Medicine, University of Colorado Denver, and the VA Medical Center, Aurora, Colorado
- Corresponding author: Moshe Levi,
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22
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Cai SY, He H, Nguyen T, Mennone A, Boyer JL. Retinoic acid represses CYP7A1 expression in human hepatocytes and HepG2 cells by FXR/RXR-dependent and independent mechanisms. J Lipid Res 2010; 51:2265-74. [PMID: 20338915 PMCID: PMC2903807 DOI: 10.1194/jlr.m005546] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Cholesterol 7alpha-hydroxylase (CYP7A1) plays a key role in maintaining lipid and bile salt homeostasis as it is the rate-limiting enzyme converting cholesterol to bile acids. Deficiency of CYP7A1 leads to hyperlipidemia in man and mouse. Hyperlipidemia is often seen in patients when treated with high-dose retinoic acid (RA), but the molecular mechanisms remain elusive. Our present study revealed that CYP7A1 mRNA expression is greatly repressed by RA in both human hepatocytes and HepG2 cells where increased fibroblast growth factor 19 (FGF19) and small heterodimer partner (SHP) expressions were also observed, suggesting farnesoid X receptor (FXR) and retinoid X receptor (RXR) were activated. Promoter reporter assays demonstrate that all-trans RA (atRA) specifically activated FXR/RXR. However, detailed molecular analyses indicate that this activation is through RXR, whose ligand is 9-cis RA. Knocking down of FXR or RXRalpha by small interference RNA (siRNA) in human hepatocytes increased CYP7A1 basal expression, but the repressive effect of atRA persisted, suggesting there are also FXR/RXR-independent mechanisms mediating atRA repression of CYP7A1 expression. Chromatin immunoprecipitation (ChIP) assay and cell transfection results indicate that PGC-1alpha plays a role in the FXR/RXR-independent mechanism. Our findings may provide a potential explanation for hyperlipidemic side effects observed in some patients treated with high-dose RA.
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Affiliation(s)
- Shi-Ying Cai
- Department of Internal Medicine and Yale Liver Center, Yale University School of Medicine, New Haven, CT 06520
| | | | | | | | - James L. Boyer
- Department of Internal Medicine and Yale Liver Center, Yale University School of Medicine, New Haven, CT 06520
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23
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Braverman N, Zhang R, Chen L, Nimmo G, Scheper S, Tran T, Chaudhury R, Moser A, Steinberg S. A Pex7 hypomorphic mouse model for plasmalogen deficiency affecting the lens and skeleton. Mol Genet Metab 2010; 99:408-16. [PMID: 20060764 PMCID: PMC2839039 DOI: 10.1016/j.ymgme.2009.12.005] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Revised: 12/04/2009] [Accepted: 12/04/2009] [Indexed: 02/01/2023]
Abstract
Rhizomelic chondrodysplasia punctata type 1 is a peroxisome biogenesis disorder with the clinical features of rhizomelia, abnormal epiphyseal calcifications, congenital cataracts, and profound growth and developmental delays. It is a rare autosomal recessive disorder, caused by defects in the peroxisome receptor, PEX7. The pathology results from a deficiency of plasmalogens, a critical class of ether phospholipids whose functions are largely unknown. To study plasmalogens in an animal model, avoid early mortality and facilitate therapeutic investigations in this disease, we engineered a hypomorphic mouse model in which Pex7 transcript levels are reduced to less than 5% of wild type. These mice are born in expected ratios, are fertile and have a normal life span. However, they are petite and develop early cataracts. Further investigations showed delayed endochondral ossification and abnormalities in lens fibers. The biochemical features of reduced Pex7 function were reproduced in this model, including tissue plasmalogen deficiency, phytanic acid accumulation, reduced import of Pex7 ligands and consequent defects in plasmalogen biosynthesis and phytanic acid oxidation. Dietary supplementation with batyl alcohol, a plasmalogen precursor, recovered ether phospholipids in blood, but did not alter the clinical phenotype. The relatively mild phenotype of these mice mimics patients with milder PEX7 defects, and highlights the skeleton and lens as sensitive markers of plasmalogen deficiency. The role of plasmalogens in the normal function of these tissues at various ages can now be studied and additional therapeutic interventions tested in this model.
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Affiliation(s)
- Nancy Braverman
- Department of Human Genetics and Pediatrics, Montreal Children's Hospital Research Institute, McGill University, Montreal, QC, Canada.
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24
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Finkelstein D, Lamba V, Assem M, Rengelshausen J, Yasuda K, Strom S, Schuetz E. ADME transcriptome in Hispanic versus White donor livers: Evidence of a globally enhanced NR1I3 (CAR, constitutive androstane receptor) gene signature in Hispanics. Xenobiotica 2009; 36:989-1012. [PMID: 17118917 DOI: 10.1080/00498250600861769] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [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] [Indexed: 01/11/2023]
Abstract
Previous studies have found that, compared with Whites, Hispanic donor livers had elevated expression of CYP2 enzymes, gene products regulated by the constitutive androstane receptor (CAR). The objectives of the current study were to determine (1) the CAR activation signature in human liver (2) whether other drug detoxification (absorption, distribution, metabolism and excretion (ADME)) genes were differentially expressed in Hispanic versus White livers, and (3) the extent of overlap in the CAR and Hispanic liver transcriptomes. The CAR transcriptome (ADME genes differentially expressed following phenobarbital versus vehicle treatment of human hepatocytes) and the Hispanic liver transcriptome (ADME genes differentially expressed in Hispanic versus White livers) were identified using Affymetrix oligonucleotide arrays. Quantitative real-time polymerase chain reaction (PCR) was used to verify candidate genes in a larger sample size. Comparison of the CAR and Hispanic liver ADME transcriptomes revealed a significant association between the gene changes. Sixty-four per cent of the ADME genes induced more than twofold by phenobarbital were also induced in Hispanics, and 14% of the ADME genes repressed more than twofold by phenobarbital were repressed in Hispanics. In conclusion, compared with Whites, Hispanic donor livers have increased expression of many genes that are transcriptionally regulated by CAR. This result has practical implications to the drug treatment of Hispanic patients.
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Affiliation(s)
- D Finkelstein
- The Hartwell Center, St Jude Children's Research Hospital, Memphis, TN 38105, USA
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25
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Mouzat K, Volat F, Baron S, Alves G, Pommier AJC, Volle DH, Marceau G, DeHaze A, Déchelotte P, Duggavathi R, Caira F, Lobaccaro JMA. Absence of nuclear receptors for oxysterols liver X receptor induces ovarian hyperstimulation syndrome in mice. Endocrinology 2009; 150:3369-75. [PMID: 19325005 PMCID: PMC2703512 DOI: 10.1210/en.2008-1519] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Ovarian hyperstimulation syndrome is a frequent complication occurring during in vitro fertilization cycles. It is characterized by a massive ovarian enlargement associated with an accumulation of extra vascular fluid. Here we show that liver X receptor (LXR)-alpha and LXR-beta deficient mice present many clinical and biological signs of ovarian hyperstimulation syndrome: ovarian enlargement, hemorrhagic corpora lutea, increased ovarian vascular permeability, and elevated estradiol. Ovulation stimulation resulted in excessive ovarian response to exogenous gonadotropins because follicle number and estradiol production were higher in transgenic mice. LXR deficiency also leads to perturbations in general inflammatory status, associated with ovarian il-6 deregulation. Upon treatment with the synthetic LXR agonist T09101317, serum estradiol and expression of star and cyp11a1 genes were markedly increased in wild-type mice, showing that LXRs are key regulators of ovarian steroidogenesis. These results suggest that LXRs control the ovulation by regulating endocrine and vascular processes.
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Affiliation(s)
- Kevin Mouzat
- Unité Mixte de Recherche, Centre National de la Recherche Scientifique 6247, Clermont Université, Centre de Recherche en Nutrition Humaine d'Auvergne, 63177 Aubière Cedex, France
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26
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Abstract
Pelger-Huët anomaly (PHA), an autosomal dominant haematological trait is characterised by neutrophil nuclear hypolobulation and modified chromatin distribution. Mutations in the lamin B receptor gene, a member of the sterol reductase family have been identified as the underlying cause. Due to its asymptomatic nature or lack of observer familiarity, PHA is often overlooked. In this review, we give an overview of the main pathophysiological, clinical, morphological and functional aspects of PHA. Furthermore, we highlight the importance of a comprehensive approach to the assessment of this laminopathy.
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Affiliation(s)
- M M Speeckaert
- Departments of Internal Medicine, University Hospital Ghent, De Pintelaan 185, Gent, Belgium.
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27
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Duez H, Duhem C, Laitinen S, Patole PS, Abdelkarim M, Bois-Joyeux B, Danan JL, Staels B. Inhibition of adipocyte differentiation by RORalpha. FEBS Lett 2009; 583:2031-6. [PMID: 19450581 DOI: 10.1016/j.febslet.2009.05.019] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2009] [Revised: 04/27/2009] [Accepted: 05/08/2009] [Indexed: 01/27/2023]
Abstract
Here we show that gene expression of the nuclear receptor RORalpha is induced during adipogenesis, with RORalpha4 being the most abundantly expressed isoform in human and murine adipose tissue. Over-expression of RORalpha4 in 3T3-L1 cells impairs adipogenesis as shown by the decreased expression of adipogenic markers and lipid accumulation, accompanied by decreased free fatty acid and glucose uptake. By contrast, mouse embryonic fibroblasts from staggerer mice, which carry a mutation in the RORalpha gene, differentiate more efficiently into mature adipocytes compared to wild-type cells, a phenotype which is reversed by ectopic RORalpha4 restoration.
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MESH Headings
- 3T3-L1 Cells
- Adipocytes/cytology
- Adipocytes/metabolism
- Adipogenesis/genetics
- Adipogenesis/physiology
- Adult
- Animals
- Cell Differentiation/genetics
- Cell Differentiation/physiology
- Fatty Acids, Nonesterified/metabolism
- Gene Expression
- Glucose/metabolism
- Humans
- In Vitro Techniques
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Neurologic Mutants
- Nuclear Receptor Subfamily 1, Group F, Member 1
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, Cytoplasmic and Nuclear/deficiency
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/metabolism
- Recombinant Proteins/genetics
- Recombinant Proteins/metabolism
- Trans-Activators/deficiency
- Trans-Activators/genetics
- Trans-Activators/metabolism
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Affiliation(s)
- Hélène Duez
- Institut Pasteur de Lille, Département d'Athérosclérose, Lille F-59019, France
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28
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Abstract
The unique historical aspects of Pelger and Huet's discovery of the Pelger-Huet cell highlight the diagnostic challenge that this morphologic finding presents to the physician. Making the diagnosis of the benign autosomal dominant anomaly is complicated by the morphologically similar pseudo-Pelger-Huet cell, which can signify underlying myeloid dsyplasia. This article relates the history of the Pelger-Huet anomaly as well as describes the clinical significance and diagnostic workup for the finding of a Pelger-Huet cell on peripheral smear.
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Affiliation(s)
- John M Cunningham
- University of Minnesota Twin Cities, Medical School, Minneapolis, Minnesota 55455, USA.
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29
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Kong B, Luyendyk JP, Tawfik O, Guo GL. Farnesoid X receptor deficiency induces nonalcoholic steatohepatitis in low-density lipoprotein receptor-knockout mice fed a high-fat diet. J Pharmacol Exp Ther 2009; 328:116-22. [PMID: 18948497 PMCID: PMC2685903 DOI: 10.1124/jpet.108.144600] [Citation(s) in RCA: 146] [Impact Index Per Article: 9.7] [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: 08/07/2008] [Accepted: 10/22/2008] [Indexed: 12/23/2022] Open
Abstract
Nonalcoholic steatohepatitis (NASH) comprises dysregulation of lipid metabolism and inflammation. Identification of the various genetic and environmental susceptibility factors for NASH may provide novel treatments to limit inflammation and fibrosis in patients. This study utilized a mouse model of hypercholesterolemia, low-density lipoprotein receptor knockout (LDLr(-/-)) mice fed a high-fat diet for 5 months, to test the hypothesis that farnesoid X receptor (FXR) deficiency contributed to NASH development. Either the high-fat diet or FXR deficiency increased serum alanine aminotransferase activity, whereas only FXR deficiency increased bile acid and alkaline phosphatase levels. FXR deficiency and high-fat feeding increased serum cholesterol and triglycerides. Although high fat led to macrosteatosis and hepatocyte ballooning in livers of mice regardless of genotype, no inflammatory infiltrate was observed in the livers of LDLr(-/-) mice. In contrast, in the livers of LDLr(-/-)/FXR(-/-) mice, foci of inflammatory cells were observed occasionally when fed the control diet and were greatly increased when fed the high-fat diet. Consistent with enhanced inflammatory cells, hepatic levels of tumor necrosis factor alpha and intercellular adhesion molecule-1 mRNA were increased by the high-fat diet in LDLr(-/-)/FXR(-/-) mice. In agreement with elevated levels of procollagen 1 alpha 1 and TGF-beta mRNA, type 1 collagen protein levels were increased in livers of LDLr(-/-)/FXR(-/-) mice fed a high-fat diet. In conclusion, FXR deficiency induces pathologic manifestations required for NASH diagnosis in a mouse model of hypercholesterolemia, including macrosteatosis, hepatocyte ballooning, and inflammation, which suggest a combination of FXR deficiency and high-fat diet is a risk factor for NASH development, and activation of FXR may be a therapeutic intervention in the treatment of NASH.
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Affiliation(s)
- Bo Kong
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center. 3901 Rainbow Blvd., Kansas City, KS 66160, USA
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30
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Abstract
The farnesoid X receptor (FXR) is a nuclear receptor that plays key roles in hepatoprotection by maintaining the homeostasis of liver metabolism. FXR null mice display strong hepatic inflammation and develop spontaneous liver tumors. In this report, we demonstrate that FXR is a negative modulator of nuclear factor kappaB (NF-kappaB)-mediated hepatic inflammation. Activation of FXR by its agonist ligands inhibited the expression of inflammatory mediators in response to NF-kappaB activation in both HepG2 cells and primary hepatocytes cultured in vitro. In vivo, compared with wild-type controls, FXR(-/-) mice displayed elevated messenger RNA (mRNA) levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), interferon-inducible protein 10, and interferon-gamma in response to lipopolysaccharide (LPS). Examination of FXR(-/-) livers showed massive necroses and inflammation after treatment with LPS at a dose that does not induce significant liver damage or inflammation in wild-type mice. Moreover, transfection of a constitutively active FXR expression construct repressed the iNOS, COX-2, interferon-inducible protein 10 and interferon-gamma mRNA levels induced by LPS administration. FXR activation had no negative effects on NF-kappaB-activated antiapoptotic genes, suggesting that FXR selectively inhibits the NF-kappaB-mediated hepatic inflammatory response but maintains or even enhances the cell survival response. On the other hand, NF-kappaB activation suppressed FXR-mediated gene expression both in vitro and in vivo, indicating a negative crosstalk between the FXR and NF-kappaB signaling pathways. Our findings reveal that FXR is a negative mediator of hepatic inflammation, which may contribute to the critical roles of FXR in hepatoprotection and suppression of hepatocarcinogenesis.
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Affiliation(s)
- Yan-Dong Wang
- Department of Gene Regulation and Drug Discovery, Beckman Research Institute, City of Hope National Medical Center, Duarte, CA 91010, USA
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31
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Zwerger M, Herrmann H, Gaines P, Olins AL, Olins DE. Granulocytic nuclear differentiation of lamin B receptor-deficient mouse EPRO cells. Exp Hematol 2008; 36:977-87. [PMID: 18495328 PMCID: PMC2547467 DOI: 10.1016/j.exphem.2008.03.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2008] [Revised: 03/06/2008] [Accepted: 03/07/2008] [Indexed: 11/17/2022]
Abstract
OBJECTIVE Lamin B receptor (LBR) is an integral protein of the inner nuclear membrane. Recent studies have demonstrated that genetic deficiency of LBR during granulopoiesis results in hypolobulation of the mature neutrophil nucleus, as observed in human Pelger-Huët anomaly and mouse ichthyosis (ic). In this study, we utilized differentiated early promyelocytes (EPRO cells) that were derived from the bone marrow of homozygous and heterozygous ichthyosis mice to examine changes to the expression of nuclear envelope proteins and heterochromatin structure that result from deficient LBR expression. MATERIALS AND METHODS Wild-type (+/+), heterozygous (+/ic), and homozygous (ic/ic) granulocytic forms of EPRO cells were analyzed for the expression of multiple lamins and inner nuclear envelope proteins by immunostaining and immunoblotting techniques. The heterochromatin architecture was also examined by immunostaining for histone lysine methylation. RESULTS Wild-type (+/+) and heterozygous (+/ic) granulocytic forms revealed ring-shaped nuclei and contained LBR within the nuclear envelope; ic/ic granulocytes exhibited smaller ovoid nuclei devoid of LBR. The pericentric heterochromatin of undifferentiated and granulocytic ic/ic cells was condensed into larger spots and shifted away from the nuclear envelope, compared to +/+ and +/ic cell forms. Lamin A/C, which is normally not present in mature granulocytes, was significantly elevated in LBR-deficient EPRO cells. CONCLUSIONS Our observations suggest roles for LBR during granulopoiesis, which can involve augmenting nuclear membrane growth, facilitating compartmentalization of heterochromatin, and promoting downregulation of lamin A/C expression.
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Affiliation(s)
- Monika Zwerger
- B065, German Cancer Research Center, Heidelberg, D-69120, Germany
| | - Harald Herrmann
- B065, German Cancer Research Center, Heidelberg, D-69120, Germany
| | - Peter Gaines
- Department of Biological Sciences, University of Massachusetts Lowell, Lowell, MA 01854
| | - Ada L. Olins
- Department of Biology, Bowdoin College, Brunswick, ME 04101
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Gaines P, Tien CW, Olins AL, Olins DE, Shultz LD, Carney L, Berliner N. Mouse neutrophils lacking lamin B-receptor expression exhibit aberrant development and lack critical functional responses. Exp Hematol 2008; 36:965-76. [PMID: 18550262 PMCID: PMC2543941 DOI: 10.1016/j.exphem.2008.04.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2008] [Revised: 03/20/2008] [Accepted: 04/11/2008] [Indexed: 11/17/2022]
Abstract
OBJECTIVE The capacity of neutrophils to eradicate bacterial infections is dependent on normal development and activation of functional responses, which include chemotaxis and generation of oxygen radicals during the respiratory burst. A unique feature of the neutrophil is its highly lobulated nucleus, which is thought to facilitate chemotaxis, but may also play a role in other critical neutrophil functions. Nuclear lobulation is dependent on expression of the inner nuclear envelope protein, the lamin B receptor (LBR), mutations of which cause hypolobulated neutrophil nuclei in human Pelger-Huët anomaly and the "ichthyosis" (ic) phenotype in mice. In this study, we have investigated roles for LBR in mediating neutrophil development and activation of multiple neutrophil functions, including chemotaxis and the respiratory burst. MATERIALS AND METHODS A progenitor EML cell line was generated from an ic/ic mouse, and derived cells that lacked LBR expression were induced to mature neutrophils and then examined for abnormal morphology and functional responses. RESULTS Neutrophils derived from EML-ic/ic cells exhibited nuclear hypolobulation identical to that observed in ichthyosis mice. The ic/ic neutrophils also displayed abnormal chemotaxis, supporting the notion that nuclear segmentation augments neutrophil extravasation. Furthermore, promyelocytic forms of ic/ic cells displayed decreased proliferative responses and produced a deficient respiratory burst upon terminal maturation. CONCLUSIONS Our studies of promyelocytes that lack LBR expression have identified roles for LBR in regulating not only the morphologic maturation of the neutrophil nucleus, but also proliferative and functional responses that are critical to innate immunity.
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Affiliation(s)
- Peter Gaines
- University of Massachusetts Lowell, Department of Biological Sciences, Lowell, MA
| | - Chiung W. Tien
- University of Massachusetts Lowell, Department of Biological Sciences, Lowell, MA
| | - Ada L. Olins
- Bowdoin College, Biology Department, Brunswick, ME
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Repa JJ, Li H, Frank-Cannon TC, Valasek MA, Turley SD, Tansey MG, Dietschy JM. Liver X receptor activation enhances cholesterol loss from the brain, decreases neuroinflammation, and increases survival of the NPC1 mouse. J Neurosci 2007; 27:14470-80. [PMID: 18160655 PMCID: PMC6673433 DOI: 10.1523/jneurosci.4823-07.2007] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2007] [Revised: 11/16/2007] [Accepted: 11/16/2007] [Indexed: 11/21/2022] Open
Abstract
Although cholesterol is a major component of the CNS, there is little information on how or whether a change in sterol flux across the blood-brain barrier might alter neurodegeneration. In Niemann-Pick type C (NPC) disease, a mutation in NPC1 protein causes unesterified cholesterol to accumulate in the lysosomal compartment of every cell, including neurons and glia. Using the murine model of this disease, we used genetic and pharmacologic approaches in an attempt to alter cholesterol homeostasis across the CNS. Genetic deletion of the sterol transporters ATP-binding cassette transporter A1 (ABCA1) and low-density lipoprotein receptor in the NPC1 mouse did not affect sterol balance or longevity. However, deletion of the nuclear receptor, liver X receptor beta (LXRbeta), had an adverse effect on progression of the disease. We therefore tested the effects of increasing LXR activity by oral administration of a synthetic ligand for this transcription factor. Treatment with this LXR agonist increased cholesterol excretion out of brain from 17 to 49 microg per day, slowed neurodegeneration, and prolonged life. This agonist did not alter synthesis of cholesterol or expression of genes associated with the formation of 24(S)-hydroxycholesterol or neurosteroids such as CYP46A1, 3alphaHSD, and CYP11A1. However, levels of the sterol transporters ABCA1 and ATP-binding cassette transporter G1 were increased. Concomitantly, markers of neuroinflammation, CD14, MAC1, CD11c, and inducible nitric oxide synthase, were reduced, and microglia reverted from their amoeboid, active form to a ramified, resting configuration. Thus, LXR activation resulted in increased cholesterol excretion from the brain, decreased neuroinflammation, and deactivation of microglia to slow neurodegeneration and extend the lifespan of the NPC1 mouse.
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Affiliation(s)
- Joyce J. Repa
- Department of Internal Medicine, University of Texas Southwestern Medical School, Dallas, Texas 75390-9151, and
- Department of Physiology, University of Texas Southwestern Medical School, Dallas, Texas 75390-9077
| | - Hao Li
- Department of Internal Medicine, University of Texas Southwestern Medical School, Dallas, Texas 75390-9151, and
| | - Tamy C. Frank-Cannon
- Department of Physiology, University of Texas Southwestern Medical School, Dallas, Texas 75390-9077
| | - Mark A. Valasek
- Department of Physiology, University of Texas Southwestern Medical School, Dallas, Texas 75390-9077
| | - Stephen D. Turley
- Department of Internal Medicine, University of Texas Southwestern Medical School, Dallas, Texas 75390-9151, and
| | - Malú G. Tansey
- Department of Physiology, University of Texas Southwestern Medical School, Dallas, Texas 75390-9077
| | - John M. Dietschy
- Department of Internal Medicine, University of Texas Southwestern Medical School, Dallas, Texas 75390-9151, and
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Bradley MN, Hong C, Chen M, Joseph SB, Wilpitz DC, Wang X, Lusis AJ, Collins A, Hseuh WA, Collins JL, Tangirala RK, Tontonoz P. Ligand activation of LXR beta reverses atherosclerosis and cellular cholesterol overload in mice lacking LXR alpha and apoE. J Clin Invest 2007; 117:2337-46. [PMID: 17657314 PMCID: PMC1924496 DOI: 10.1172/jci31909] [Citation(s) in RCA: 222] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2007] [Accepted: 05/17/2007] [Indexed: 12/15/2022] Open
Abstract
Liver X receptors (LXRs) alpha and beta are transcriptional regulators of cholesterol homeostasis and potential targets for the development of antiatherosclerosis drugs. However, the specific roles of individual LXR isotypes in atherosclerosis and the pharmacological effects of synthetic agonists remain unclear. Previous work has shown that mice lacking LXRalpha accumulate cholesterol in the liver but not in peripheral tissues. In striking contrast, we demonstrate here that LXRalpha(-/-)apoE(-/-) mice exhibit extreme cholesterol accumulation in peripheral tissues, a dramatic increase in whole-body cholesterol burden, and accelerated atherosclerosis. The phenotype of these mice suggests that the level of LXR pathway activation in macrophages achieved by LXRbeta and endogenous ligand is unable to maintain homeostasis in the setting of hypercholesterolemia. Surprisingly, however, a highly efficacious synthetic agonist was able to compensate for the loss of LXRalpha. Treatment of LXRalpha(-/-)apoE(-/-) mice with synthetic LXR ligand ameliorates the cholesterol overload phenotype and reduces atherosclerosis. These observations indicate that LXRalpha has an essential role in maintaining peripheral cholesterol homeostasis in the context of hypercholesterolemia and provide in vivo support for drug development strategies targeting LXRbeta.
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Affiliation(s)
- Michelle N. Bradley
- Howard Hughes Medical Institute and Department of Pathology and Laboratory Medicine,
Department of Medicine and Department of Human Genetics, and
Division of Endocrinology, Department of Medicine, UCLA David Geffen School of Medicine, Los Angeles, California, USA.
Nuclear Receptor Discovery Research, GlaxoSmithKline, Research Triangle Park, North Carolina, USA
| | - Cynthia Hong
- Howard Hughes Medical Institute and Department of Pathology and Laboratory Medicine,
Department of Medicine and Department of Human Genetics, and
Division of Endocrinology, Department of Medicine, UCLA David Geffen School of Medicine, Los Angeles, California, USA.
Nuclear Receptor Discovery Research, GlaxoSmithKline, Research Triangle Park, North Carolina, USA
| | - Mingyi Chen
- Howard Hughes Medical Institute and Department of Pathology and Laboratory Medicine,
Department of Medicine and Department of Human Genetics, and
Division of Endocrinology, Department of Medicine, UCLA David Geffen School of Medicine, Los Angeles, California, USA.
Nuclear Receptor Discovery Research, GlaxoSmithKline, Research Triangle Park, North Carolina, USA
| | - Sean B. Joseph
- Howard Hughes Medical Institute and Department of Pathology and Laboratory Medicine,
Department of Medicine and Department of Human Genetics, and
Division of Endocrinology, Department of Medicine, UCLA David Geffen School of Medicine, Los Angeles, California, USA.
Nuclear Receptor Discovery Research, GlaxoSmithKline, Research Triangle Park, North Carolina, USA
| | - Damien C. Wilpitz
- Howard Hughes Medical Institute and Department of Pathology and Laboratory Medicine,
Department of Medicine and Department of Human Genetics, and
Division of Endocrinology, Department of Medicine, UCLA David Geffen School of Medicine, Los Angeles, California, USA.
Nuclear Receptor Discovery Research, GlaxoSmithKline, Research Triangle Park, North Carolina, USA
| | - Xuping Wang
- Howard Hughes Medical Institute and Department of Pathology and Laboratory Medicine,
Department of Medicine and Department of Human Genetics, and
Division of Endocrinology, Department of Medicine, UCLA David Geffen School of Medicine, Los Angeles, California, USA.
Nuclear Receptor Discovery Research, GlaxoSmithKline, Research Triangle Park, North Carolina, USA
| | - Aldons J. Lusis
- Howard Hughes Medical Institute and Department of Pathology and Laboratory Medicine,
Department of Medicine and Department of Human Genetics, and
Division of Endocrinology, Department of Medicine, UCLA David Geffen School of Medicine, Los Angeles, California, USA.
Nuclear Receptor Discovery Research, GlaxoSmithKline, Research Triangle Park, North Carolina, USA
| | - Allan Collins
- Howard Hughes Medical Institute and Department of Pathology and Laboratory Medicine,
Department of Medicine and Department of Human Genetics, and
Division of Endocrinology, Department of Medicine, UCLA David Geffen School of Medicine, Los Angeles, California, USA.
Nuclear Receptor Discovery Research, GlaxoSmithKline, Research Triangle Park, North Carolina, USA
| | - Willa A. Hseuh
- Howard Hughes Medical Institute and Department of Pathology and Laboratory Medicine,
Department of Medicine and Department of Human Genetics, and
Division of Endocrinology, Department of Medicine, UCLA David Geffen School of Medicine, Los Angeles, California, USA.
Nuclear Receptor Discovery Research, GlaxoSmithKline, Research Triangle Park, North Carolina, USA
| | - Jon L. Collins
- Howard Hughes Medical Institute and Department of Pathology and Laboratory Medicine,
Department of Medicine and Department of Human Genetics, and
Division of Endocrinology, Department of Medicine, UCLA David Geffen School of Medicine, Los Angeles, California, USA.
Nuclear Receptor Discovery Research, GlaxoSmithKline, Research Triangle Park, North Carolina, USA
| | - Rajendra K. Tangirala
- Howard Hughes Medical Institute and Department of Pathology and Laboratory Medicine,
Department of Medicine and Department of Human Genetics, and
Division of Endocrinology, Department of Medicine, UCLA David Geffen School of Medicine, Los Angeles, California, USA.
Nuclear Receptor Discovery Research, GlaxoSmithKline, Research Triangle Park, North Carolina, USA
| | - Peter Tontonoz
- Howard Hughes Medical Institute and Department of Pathology and Laboratory Medicine,
Department of Medicine and Department of Human Genetics, and
Division of Endocrinology, Department of Medicine, UCLA David Geffen School of Medicine, Los Angeles, California, USA.
Nuclear Receptor Discovery Research, GlaxoSmithKline, Research Triangle Park, North Carolina, USA
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Mataki C, Magnier BC, Houten SM, Annicotte JS, Argmann C, Thomas C, Overmars H, Kulik W, Metzger D, Auwerx J, Schoonjans K. Compromised intestinal lipid absorption in mice with a liver-specific deficiency of liver receptor homolog 1. Mol Cell Biol 2007; 27:8330-9. [PMID: 17908794 PMCID: PMC2169191 DOI: 10.1128/mcb.00852-07] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Bile acids (BAs) are water-soluble end products from cholesterol metabolism and are essential for efficient absorption of dietary lipids. By using targeted somatic mutagenesis of the nuclear receptor liver receptor homolog 1 (LRH-1) in mouse hepatocytes, we demonstrate here that LRH-1 critically regulates the physicochemical properties of BAs. The absence of LRH-1 and subsequent deficiency of Cyp8b1 eliminate the production of cholic acid and its amino acid conjugate taurocholic acid and increase the relative amounts of less amphipathic BA species. Intriguingly, while the expression of Cyp8b1 is almost extinguished in the livers of mice that lack LRH-1, the expression of the rate-limiting enzyme of BA synthesis, i.e., Cyp7a1, remains unchanged. The profound remodeling of the BA composition significantly reduces the efficacy of intestinal absorption of lipids and reuptake of BAs and facilitates the removal of lipids from the body. Our studies unequivocally demonstrate a pivotal role for LRH-1 in determining the composition of BAs, which, in turn has major consequences on whole-body lipid homeostasis.
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Affiliation(s)
- Chikage Mataki
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP, 67404 Illkirch, France
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Abstract
AIM To investigate the roles of liver X receptors (LXR) in the lipid composition and gene expression regulation in the murine caput epididymidis. LXR are nuclear receptors for oxysterols, molecules derived from cholesterol metabolism that are present in mammals as two isoforms: LXRalpha, which is more specifically expressed in lipid-metabolising tissues, such as liver, adipose and steroidogenic tissues, and macrophages, whereas LXRbeta is ubiquitous. Their importance in reproductive physiology has been sustained by the fact that male mice in which the function of both LXR has been disrupted have fertility disturbances starting at the age of 5 months, leading to complete sterility by the age of 9 months. These defects are associated with epididymal epithelial degeneration in caput segments one and two, and with a sperm midpiece fragility, leading to the presence of isolated sperm heads and flagella when luminal contents are recovered from the cauda epididymidis. METHODS The lipid composition of the caput epididymidis of wild-type and LXR-deficient mice was assessed using oil red O staining on tissue cryosections and lipid extraction followed by high performance liquid chromatography or gas chromatography. Gene expression was checked by quantitative real time polymerase chain reaction. RESULTS Using LXR-deficient mice, we showed an alteration of the lipid composition of the caput epididymidis as well as a significantly decreased expression of the genes encoding SREBP1c, SCD1 and SCD2, involved in fatty acid metabolism. CONCLUSION Altogether, these results show that LXR are important regulators of epididymal function, and play a critical role in the lipid maturation processes occurring during sperm epididymal maturation.
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Affiliation(s)
- Fabrice Saez
- Laboratoire Epididyme et Maturation des Gamètes, Centre de Recherche en Nutrition Humaine d'Auvergne, Université Blaise-Pascal, UMR CNRS 6547, Aubière Cedex, France.
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Hernandez JP, Huang W, Chapman LM, Chua S, Moore DD, Baldwin WS. The environmental estrogen, nonylphenol, activates the constitutive androstane receptor. Toxicol Sci 2007; 98:416-26. [PMID: 17483497 PMCID: PMC1995745 DOI: 10.1093/toxsci/kfm107] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Nonylphenol (NP) and its parent compounds, the nonylphenol ethoxylates are some of the most prevalent chemicals found in U.S. waterways. NP is also resistant to biodegradation and is a known environmental estrogen, which makes NP a chemical of concern. Our data show that NP also activates the constitutive androstane receptor (CAR), an orphan nuclear receptor important in the induction of detoxification enzymes, including the P450s. Transactivation assays demonstrate that NP increases murine CAR (mCAR) transcriptional activity, and NP treatment can overcome the inhibitory effects of the inverse agonist, androstanol, on mCAR activation. Treatment of wild-type (CAR +/+) mice with NP at 50 or 75 mg/kg/day increases Cyp2b protein expression in a dose-dependent manner as demonstrated by Western blotting, and was confirmed by quantitative reverse transcription-PCR of Cyp2b10 transcript levels. CAR-null (CAR -/-) mice show no increased expression of Cyp2b following NP treatment, indicating that CAR is required for NP-mediated Cyp2b induction. In addition, NP increases the translocation of CAR into the nucleus, which is the key step in the commencement of CAR's transcriptional activity. NP also induced CYP2B6 in primary human hepatocytes, and increased Cyp2b10 messenger RNA and protein expression in humanized CAR mice, indicating that NP is an activator of human CAR as well. In conclusion, NP is a CAR activator, and this was demonstrated in vitro with transactivation assays and in vivo with transgenic CAR mouse models.
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MESH Headings
- Adult
- Aged
- Animals
- Aryl Hydrocarbon Hydroxylases/biosynthesis
- Cell Line, Tumor
- Constitutive Androstane Receptor
- Cytochrome P-450 CYP2B6
- Cytochrome P450 Family 2
- Endocrine Disruptors/toxicity
- Estrogens/toxicity
- Female
- Hepatocytes/drug effects
- Hepatocytes/enzymology
- Humans
- Liver/drug effects
- Liver/enzymology
- Mice
- Mice, Transgenic
- Middle Aged
- Muscle Relaxants, Central/pharmacology
- Oxidoreductases, N-Demethylating/biosynthesis
- Phenols/toxicity
- Pregnane X Receptor
- Rats
- Receptors, Cytoplasmic and Nuclear/agonists
- Receptors, Cytoplasmic and Nuclear/deficiency
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/metabolism
- Receptors, Steroid/genetics
- Receptors, Steroid/metabolism
- Steroid Hydroxylases/biosynthesis
- Transcription Factors/agonists
- Transcription Factors/deficiency
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Transcriptional Activation/drug effects
- Zoxazolamine/pharmacology
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Affiliation(s)
- Juan P Hernandez
- Biological Sciences, The University of Texas at El Paso, El Paso, Texas 79968, USA
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39
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Hernandez JP, Huang W, Chapman LM, Chua S, Moore DD, Baldwin WS. The environmental estrogen, nonylphenol, activates the constitutive androstane receptor. Toxicol Sci 2007; 98:416-426. [PMID: 17483497 DOI: 10.1017/s1368980009991996.validation] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2023] Open
Abstract
Nonylphenol (NP) and its parent compounds, the nonylphenol ethoxylates are some of the most prevalent chemicals found in U.S. waterways. NP is also resistant to biodegradation and is a known environmental estrogen, which makes NP a chemical of concern. Our data show that NP also activates the constitutive androstane receptor (CAR), an orphan nuclear receptor important in the induction of detoxification enzymes, including the P450s. Transactivation assays demonstrate that NP increases murine CAR (mCAR) transcriptional activity, and NP treatment can overcome the inhibitory effects of the inverse agonist, androstanol, on mCAR activation. Treatment of wild-type (CAR +/+) mice with NP at 50 or 75 mg/kg/day increases Cyp2b protein expression in a dose-dependent manner as demonstrated by Western blotting, and was confirmed by quantitative reverse transcription-PCR of Cyp2b10 transcript levels. CAR-null (CAR -/-) mice show no increased expression of Cyp2b following NP treatment, indicating that CAR is required for NP-mediated Cyp2b induction. In addition, NP increases the translocation of CAR into the nucleus, which is the key step in the commencement of CAR's transcriptional activity. NP also induced CYP2B6 in primary human hepatocytes, and increased Cyp2b10 messenger RNA and protein expression in humanized CAR mice, indicating that NP is an activator of human CAR as well. In conclusion, NP is a CAR activator, and this was demonstrated in vitro with transactivation assays and in vivo with transgenic CAR mouse models.
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MESH Headings
- Adult
- Aged
- Animals
- Aryl Hydrocarbon Hydroxylases/biosynthesis
- Cell Line, Tumor
- Constitutive Androstane Receptor
- Cytochrome P-450 CYP2B6
- Cytochrome P450 Family 2
- Endocrine Disruptors/toxicity
- Estrogens/toxicity
- Female
- Hepatocytes/drug effects
- Hepatocytes/enzymology
- Humans
- Liver/drug effects
- Liver/enzymology
- Mice
- Mice, Transgenic
- Middle Aged
- Muscle Relaxants, Central/pharmacology
- Oxidoreductases, N-Demethylating/biosynthesis
- Phenols/toxicity
- Pregnane X Receptor
- Rats
- Receptors, Cytoplasmic and Nuclear/agonists
- Receptors, Cytoplasmic and Nuclear/deficiency
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/metabolism
- Receptors, Steroid/genetics
- Receptors, Steroid/metabolism
- Steroid Hydroxylases/biosynthesis
- Transcription Factors/agonists
- Transcription Factors/deficiency
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Transcriptional Activation/drug effects
- Zoxazolamine/pharmacology
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Affiliation(s)
- Juan P Hernandez
- Biological Sciences, The University of Texas at El Paso, El Paso, Texas 79968, USA
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Kang HS, Angers M, Beak JY, Wu X, Gimble JM, Wada T, Xie W, Collins JB, Grissom SF, Jetten AM. Gene expression profiling reveals a regulatory role for ROR alpha and ROR gamma in phase I and phase II metabolism. Physiol Genomics 2007; 31:281-94. [PMID: 17666523 DOI: 10.1152/physiolgenomics.00098.2007] [Citation(s) in RCA: 155] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Retinoid-related orphan receptors alpha (ROR alpha) and gamma (ROR gamma) are both expressed in liver; however, their physiological functions in this tissue have not yet been clearly defined. The ROR alpha1 and ROR gamma 1 isoforms, but not ROR alpha 4, show an oscillatory pattern of expression during circadian rhythm. To obtain insight into the physiological functions of ROR receptors in liver, we analyzed the gene expression profiles of livers from WT, ROR alpha-deficient staggerer (sg) mice (ROR alpha(sg/sg)), ROR gamma(-/-), and ROR alpha(sg/sg)ROR gamma(-/-) double knockout (DKO) mice by microarray analysis. DKO mice were generated to study functional redundancy between ROR alpha and ROR gamma. These analyses demonstrated that ROR alpha and ROR gamma affect the expression of a number of genes. ROR alpha and ROR gamma are particularly important in the regulation of genes encoding several phase I and phase II metabolic enzymes, including several 3beta-hydroxysteroid dehydrogenases, cytochrome P450 enzymes, and sulfotransferases. In addition, our results indicate that ROR alpha and ROR gamma each affect the expression of a specific set of genes but also exhibit functional redundancy. Our study shows that ROR alpha and ROR gamma receptors influence the regulation of several metabolic pathways, including those involved in the metabolism of steroids, bile acids, and xenobiotics, suggesting that RORs are important in the control of metabolic homeostasis.
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MESH Headings
- Animals
- Bile Acids and Salts/metabolism
- Cells, Cultured/metabolism
- Circadian Rhythm/genetics
- Cytochrome P-450 Enzyme System/metabolism
- Female
- Gene Expression Profiling
- Hepatocytes/metabolism
- Lipid Metabolism/genetics
- Liver/metabolism
- Metabolic Networks and Pathways/genetics
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Neurologic Mutants
- Nuclear Receptor Subfamily 1, Group F, Member 1
- Nuclear Receptor Subfamily 1, Group F, Member 3
- Receptors, Cytoplasmic and Nuclear/deficiency
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/physiology
- Receptors, Retinoic Acid/deficiency
- Receptors, Retinoic Acid/genetics
- Receptors, Retinoic Acid/physiology
- Receptors, Thyroid Hormone/deficiency
- Receptors, Thyroid Hormone/genetics
- Receptors, Thyroid Hormone/physiology
- Recombinant Fusion Proteins/metabolism
- Steroids/metabolism
- Trans-Activators/deficiency
- Trans-Activators/genetics
- Trans-Activators/physiology
- Transfection
- Xenobiotics/metabolism
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Affiliation(s)
- Hong Soon Kang
- Cell Biology Section, National Institutes of Health, Research Triangle Park, North Carolina 27709, USA
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Ogawa-Goto K, Tanaka K, Ueno T, Tanaka K, Kurata T, Sata T, Irie S. p180 is involved in the interaction between the endoplasmic reticulum and microtubules through a novel microtubule-binding and bundling domain. Mol Biol Cell 2007; 18:3741-51. [PMID: 17634287 PMCID: PMC1995732 DOI: 10.1091/mbc.e06-12-1125] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [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: 11/11/2022] Open
Abstract
p180 was originally reported as a ribosome-binding protein on the rough endoplasmic reticulum membrane, although its precise role in animal cells has not yet been elucidated. Here, we characterized a new function of human p180 as a microtubule-binding and -modulating protein. Overexpression of p180 in mammalian cells induced an elongated morphology and enhanced acetylated microtubules. Consistently, electron microscopic analysis clearly revealed microtubule bundles in p180-overexpressing cells. Targeted depletion of endogenous p180 by small interfering RNAs led to aberrant patterns of microtubules and endoplasmic reticulum in mammalian cells, suggesting a specific interaction between p180 and microtubules. In vitro sedimentation assays using recombinant polypeptides revealed that p180 bound to microtubules directly and possessed a novel microtubule-binding domain (designated MTB-1). MTB-1 consists of a predicted coiled-coil region and repeat domain, and strongly promoted bundle formation both in vitro and in vivo when expressed alone. Overexpression of p180 induced acetylated microtubules in cultured cells in an MTB-1-dependent manner. Thus, our data suggest that p180 mediates interactions between the endoplasmic reticulum and microtubules mainly through the novel microtubule-binding and -bundling domain MTB-1.
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Affiliation(s)
- Kiyoko Ogawa-Goto
- Department of Pathology, National Institute of Infectious Diseases, Shinjuku, Tokyo 162-8640, Japan.
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Traves PG, Hortelano S, Zeini M, Chao TH, Lam T, Neuteboom ST, Theodorakis EA, Palladino MA, Castrillo A, Bosca L. Selective activation of liver X receptors by acanthoic acid-related diterpenes. Mol Pharmacol 2007; 71:1545-53. [PMID: 17329499 DOI: 10.1124/mol.106.031906] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [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: 02/05/2023] Open
Abstract
Terpenoids constitute a large family of natural steroids that are widely distributed in plants and insects. We investigated the effects of a series of diterpenes structurally related to acanthoic acid in macrophage functions. We found that diterpenes with different substitutions at the C4 position in ring A are potent activators of liver X receptors (LXRalpha and LXRbeta) in both macrophage cell lines from human and mouse origin and primary murine macrophages. Activation of LXR by these diterpenes was evaluated in transient transfection assays and gene expression analysis of known LXR-target genes, including the cholesterol transporters ABCA1 and ABCG1, the sterol regulatory element-binding protein 1c, and the apoptosis inhibitor of macrophages (Spalpha). Moreover, active diterpenes greatly stimulated cholesterol efflux from macrophages. It is interesting that these diterpenes antagonize inflammatory gene expression mainly through LXR-dependent mechanisms, indicating that these compounds can activate both LXR activation and repression functions. Stimulation of macrophages with acanthoic acid diterpenes induced LXR-target gene expression and cholesterol efflux to similar levels observed with synthetic agonists 3-[3-[N-(2-chloro-3-trifluoromethylbenzyl)-(2,2-diphenylethyl)-amino]propyloxy]phenylacetic acid hydrochloride (GW3965) and N-(2,2,2-trifluoroethyl)-N-[4-[2,2,2-trifluoro-1-hydroxy-1-(trifluoromethyl)-ethyl]phenyl]-benzenesulfonamide [T1317 (T0901317)]. These effects observed in gene expression were deficient in macrophages lacking both LXR isoforms (LXRalpha,beta(-/-)). These results show the ability of certain acanthoic acid diterpenes to activate efficiently both LXRs and suggest that these compounds can exert beneficial effects from a cardiovascular standpoint through LXR-dependent mechanisms.
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Affiliation(s)
- Paqui G Traves
- Centro Nacional de Investigaciones Cardiovasculares and Instituto de Investigaciones Biomédicas Alberto Sols, Madrid, Spain
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43
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Matsukuma KE, Wang L, Bennett MK, Osborne TF. A key role for orphan nuclear receptor liver receptor homologue-1 in activation of fatty acid synthase promoter by liver X receptor. J Biol Chem 2007; 282:20164-71. [PMID: 17522048 DOI: 10.1074/jbc.m702895200] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [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] [Indexed: 11/06/2022] Open
Abstract
Liver X receptor (LXR) activates fatty acid synthase (FAS) gene expression through binding to a DR-4 element in the promoter. We show that a distinct nuclear receptor half-site 21 bases downstream of the DR-4 element is also critical for the response of FAS to LXR but is not involved in LXR binding to DNA. This half-site specifically binds liver receptor homologue-1 (LRH-1) in vitro and in vivo, and we show LRH-1 is required for maximal LXR responsiveness of the endogenous FAS gene as well as from promoter reporter constructs. We also demonstrate that LRH-1 stimulation of the FAS LXR response is blocked by the addition of small heterodimer partner (SHP) and that FAS mRNA is overexpressed in SHP knock-out animals, providing evidence that FAS is an in vivo target of SHP repression. Taken together, these findings identify the first direct lipogenic gene target of LRH-1/SHP repression and provide a mechanistic explanation for bile acid repression of FAS and lipogenesis recently reported by others.
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Affiliation(s)
- Karen E Matsukuma
- Department of Molecular Biology and Biochemistry, School of Biological Sciences and Center for Diabetes Research and Treatment, University of California, Irvine, CA 92697-3900, USA
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44
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Mullican SE, Zhang S, Konopleva M, Ruvolo V, Andreeff M, Milbrandt J, Conneely OM. Abrogation of nuclear receptors Nr4a3 and Nr4a1 leads to development of acute myeloid leukemia. Nat Med 2007; 13:730-5. [PMID: 17515897 DOI: 10.1038/nm1579] [Citation(s) in RCA: 237] [Impact Index Per Article: 13.9] [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: 12/20/2006] [Accepted: 03/20/2007] [Indexed: 12/27/2022]
Abstract
Nur77 (NR4A1) and Nor-1 (NR4A3) are highly homologous orphan nuclear receptors that regulate the transcription of overlapping target genes. The transcriptional activity of both proteins is regulated in a ligand-independent manner by cell- and stimulus-specific gene induction and protein phosphorylation. Nor-1 and Nur77 have been implicated in a variety of cellular processes, including the transduction of hormonal, inflammatory, mitogenic, apoptotic and differentiative signals. Cellular responses to these proteins suggest that they may function as homeostatic regulators of proliferation, apoptosis and differentiation, and thus may regulate cellular susceptibility to tumorigenesis. Their physiological functions, however, remain poorly understood. Here we describe a previously unsuspected function of Nor-1 and Nur77-as critical tumor suppressors of myeloid leukemogenesis. The abrogation of these proteins in mice led to rapidly lethal acute myeloid leukemia (AML), involving abnormal expansion of hematopoietic stem cells (HSCs) and myeloid progenitors, decreased expression of the AP-1 transcription factors JunB and c-Jun and defective extrinsic apoptotic (Fas-L and TRAIL) signaling. We found that downregulation of NR4A3 ( NOR-1 ) and NR4A1 ( NUR77 ) was a common feature in leukemic blasts from human AML patients, irrespective of karyotype. Thus Nor-1 and Nur77 may provide potential targets for therapeutic intervention in AML.
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MESH Headings
- Acute Disease
- Animals
- Blast Crisis/genetics
- Blast Crisis/pathology
- DNA-Binding Proteins/antagonists & inhibitors
- DNA-Binding Proteins/biosynthesis
- DNA-Binding Proteins/deficiency
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/physiology
- Down-Regulation/genetics
- Humans
- Leukemia, Myeloid/genetics
- Leukemia, Myeloid/metabolism
- Leukemia, Myeloid/pathology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Nerve Tissue Proteins/deficiency
- Nerve Tissue Proteins/genetics
- Nerve Tissue Proteins/physiology
- Nuclear Receptor Subfamily 4, Group A, Member 1
- Receptors, Cytoplasmic and Nuclear/antagonists & inhibitors
- Receptors, Cytoplasmic and Nuclear/biosynthesis
- Receptors, Cytoplasmic and Nuclear/deficiency
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/physiology
- Receptors, Steroid/antagonists & inhibitors
- Receptors, Steroid/biosynthesis
- Receptors, Steroid/deficiency
- Receptors, Steroid/genetics
- Receptors, Steroid/physiology
- Receptors, Thyroid Hormone/antagonists & inhibitors
- Receptors, Thyroid Hormone/biosynthesis
- Receptors, Thyroid Hormone/deficiency
- Receptors, Thyroid Hormone/genetics
- Receptors, Thyroid Hormone/physiology
- Transcription Factors/antagonists & inhibitors
- Transcription Factors/biosynthesis
- Transcription Factors/deficiency
- Transcription Factors/genetics
- Transcription Factors/physiology
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Affiliation(s)
- Shannon E Mullican
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
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45
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Cowin AJ, Adams DH, Strudwick XL, Chan H, Hooper JA, Sander GR, Rayner TE, Matthaei KI, Powell BC, Campbell HD. Flightless I deficiency enhances wound repair by increasing cell migration and proliferation. J Pathol 2007; 211:572-581. [PMID: 17326236 DOI: 10.1002/path.2143] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.7] [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: 11/10/2022]
Abstract
Wound healing disorders are a therapeutic problem of increasing clinical importance involving substantial morbidity, mortality, and rising health costs. Our studies investigating flightless I (FliI), a highly conserved actin-remodelling protein, now reveal that FliI is an important regulator of wound repair whose manipulation may lead to enhanced wound outcomes. We demonstrate that FliI-deficient + /- mice are characterized by improved wound healing with increased epithelial migration and enhanced wound contraction. In contrast, FliI-overexpressing mice have significantly impaired wound healing with larger less contracted wounds and reduced cellular proliferation. We show that FliI is secreted in response to wounding and that topical application of antibodies raised against the leucine-rich repeat domain of the FliI protein (FliL) significantly improves wound repair. These studies reveal that FliI affects wound repair via mechanisms involving cell migration and proliferation and that FliI might represent an effective novel therapeutic factor to improve conditions in which wound healing is impaired.
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Affiliation(s)
- A J Cowin
- Child Health Research Institute, 72 King William Road, North Adelaide, South Australia
- Department of Paediatrics, University of Adelaide, South Australia
- School of Pharmacy and Medical Sciences, University of South Australia, Australia
| | - D H Adams
- Child Health Research Institute, 72 King William Road, North Adelaide, South Australia
| | - X L Strudwick
- Child Health Research Institute, 72 King William Road, North Adelaide, South Australia
| | - H Chan
- Child Health Research Institute, 72 King William Road, North Adelaide, South Australia
| | - J A Hooper
- Molecular Genetics and Evolution Group and Centre for the Molecular Genetics of Development, Research School of Biological Sciences, Australian National University, Canberra, ACT, Australia
| | - G R Sander
- Child Health Research Institute, 72 King William Road, North Adelaide, South Australia
- Department of Paediatrics, University of Adelaide, South Australia
| | - T E Rayner
- Child Health Research Institute, 72 King William Road, North Adelaide, South Australia
| | - K I Matthaei
- Division of Molecular Bioscience, The John Curtin School of Medical Research, Canberra, ACT, Australia
| | - B C Powell
- Child Health Research Institute, 72 King William Road, North Adelaide, South Australia
- Department of Paediatrics, University of Adelaide, South Australia
- School of Pharmacy and Medical Sciences, University of South Australia, Australia
| | - H D Campbell
- Molecular Genetics and Evolution Group and Centre for the Molecular Genetics of Development, Research School of Biological Sciences, Australian National University, Canberra, ACT, Australia
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46
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Ricketts ML, Boekschoten MV, Kreeft AJ, Hooiveld GJEJ, Moen CJA, Müller M, Frants RR, Kasanmoentalib S, Post SM, Princen HMG, Porter JG, Katan MB, Hofker MH, Moore DD. The cholesterol-raising factor from coffee beans, cafestol, as an agonist ligand for the farnesoid and pregnane X receptors. Mol Endocrinol 2007; 21:1603-16. [PMID: 17456796 DOI: 10.1210/me.2007-0133] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.2] [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] [Indexed: 02/08/2023] Open
Abstract
Cafestol, a diterpene present in unfiltered coffee brews such as Scandinavian boiled, Turkish, and cafetière coffee, is the most potent cholesterol-elevating compound known in the human diet. Several genes involved in cholesterol homeostasis have previously been shown to be targets of cafestol, including cholesterol 7alpha-hydroxylase (CYP7A1), the rate-limiting enzyme in bile acid biosynthesis. We have examined the mechanism by which cafestol elevates serum lipid levels. Changes in several lipid parameters were observed in cafestol-treated APOE3Leiden mice, including a significant increase in serum triglyceride levels. Microarray analysis of these mice identified alterations in hepatic expression of genes involved in lipid metabolism and detoxification, many of which are regulated by the nuclear hormone receptors farnesoid X receptor (FXR) and pregnane X receptor (PXR). Further studies demonstrate that cafestol is an agonist ligand for FXR and PXR, and that cafestol down-regulates expression of the bile acid homeostatic genes CYP7A1, sterol 12alpha-hydroxylase, and Na(+)-taurocholate cotransporting polypeptide in the liver of wild-type but not FXR null mice. Cafestol did not affect genes known to be up-regulated by FXR in the liver of wild-type mice, but did increase expression of the positive FXR-target genes intestinal bile acid-binding protein and fibroblast growth factor 15 (FGF15) in the intestine. Because FGF15 has recently been shown to function in an enterohepatic regulatory pathway to repress liver expression of bile acid homeostatic genes, its direct induction in the gut may account for indirect effects of cafestol on liver gene expression. PXR-dependent gene regulation of cytochrome P450 3A11 and other targets by cafestol was also only seen in the intestine. Using a double FXR/PXR knockout mouse model, we found that both receptors contribute to the cafestol-dependent induction of intestinal FGF15 gene expression. In conclusion, cafestol acts as an agonist ligand for both FXR and PXR, and this may contribute to its impact on cholesterol homeostasis.
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MESH Headings
- Animals
- Apolipoprotein E3/genetics
- Cholesterol 7-alpha-Hydroxylase/genetics
- Coffee/chemistry
- DNA-Binding Proteins/agonists
- DNA-Binding Proteins/deficiency
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/metabolism
- Diterpenes/adverse effects
- Diterpenes/metabolism
- Diterpenes/pharmacology
- Female
- Fibroblast Growth Factors/genetics
- Humans
- Hypercholesterolemia/chemically induced
- In Vitro Techniques
- Ligands
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Transgenic
- Models, Biological
- Pregnane X Receptor
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, Cytoplasmic and Nuclear/agonists
- Receptors, Cytoplasmic and Nuclear/deficiency
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/metabolism
- Receptors, Steroid/agonists
- Receptors, Steroid/deficiency
- Receptors, Steroid/genetics
- Receptors, Steroid/metabolism
- Transcription Factors/agonists
- Transcription Factors/deficiency
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Transcriptional Activation/drug effects
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Affiliation(s)
- Marie-Louise Ricketts
- Department of Molecular and Cellular Biology, Baylor College of Medicine, BCM 130, One Baylor Plaza, Houston, Texas 77030, USA.
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47
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Friebe A, Mergia E, Dangel O, Lange A, Koesling D. Fatal gastrointestinal obstruction and hypertension in mice lacking nitric oxide-sensitive guanylyl cyclase. Proc Natl Acad Sci U S A 2007; 104:7699-704. [PMID: 17452643 PMCID: PMC1863512 DOI: 10.1073/pnas.0609778104] [Citation(s) in RCA: 188] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The signaling molecule nitric oxide (NO), first described as endothelium-derived relaxing factor (EDRF), acts as physiological activator of NO-sensitive guanylyl cyclase (NO-GC) in the cardiovascular, gastrointestinal, and nervous systems. Besides NO-GC, other NO targets have been proposed; however, their particular contribution still remains unclear. Here, we generated mice deficient for the beta1 subunit of NO-GC, which resulted in complete loss of the enzyme. GC-KO mice have a life span of 3-4 weeks but then die because of intestinal dysmotility; however, they can be rescued by feeding them a fiber-free diet. Apparently, NO-GC is absolutely vital for the maintenance of normal peristalsis of the gut. GC-KO mice show a pronounced increase in blood pressure, underlining the importance of NO in the regulation of smooth muscle tone in vivo. The lack of an NO effect on aortic relaxation and platelet aggregation confirms NO-GC as the only NO target regulating these two functions, excluding cGMP-independent mechanisms. Our knockout model completely disrupts the NO/cGMP signaling cascade and provides evidence for the unique role of NO-GC as NO receptor.
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Affiliation(s)
- Andreas Friebe
- Institut für Pharmakologie und Toxikologie, Medizinische Fakultät, Ruhr-Universität Bochum, 44780 Bochum, Germany.
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48
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Lee KW, Cobb LJ, Paharkova-Vatchkova V, Liu B, Milbrandt J, Cohen P. Contribution of the orphan nuclear receptor Nur77 to the apoptotic action of IGFBP-3. Carcinogenesis 2007; 28:1653-8. [PMID: 17434920 DOI: 10.1093/carcin/bgm088] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [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] [Indexed: 11/14/2022] Open
Abstract
Tumor suppression by insulin-like growth factor-binding protein-3 (IGFBP-3) has been demonstrated to occur via insulin-like growth factor-dependent and -independent mechanisms in vitro and in vivo. We have recently described IGFBP-3-induced mitochondrial translocation of the nuclear receptors RXRalpha/Nur77 in the induction of prostate cancer (CaP) cell apoptosis. Herein, we demonstrate that IGFBP-3 and Nur77 associate in the cytoplasmic compartment in 22RV1 CaP cells. Nur77 is a major component of IGFBP-3-induced apoptosis as shown by utilizing mouse embryonic fibroblasts (MEFs) derived from Nur77 wild-type and knockout (KO) mice. However, dose-response experiments revealed that a small component of IGFBP-3-induced apoptosis is Nur77 independent. Reintroduction of Nur77 into Nur77 KO MEFs restores full responsiveness to IGFBP-3. IGFBP-3 induces phosphorylation of Jun N-terminal kinase and inhibition of Akt phosphorylation and activity, which have been associated with Nur77 translocation. Finally, IGFBP-3 administration to CaP xenografts on SCID mice induced apoptosis and translocated Nur77 out of the nucleus. Taken together, our results verify an important role for the orphan nuclear receptor Nur77 in the apoptotic actions of IGFBP-3.
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MESH Headings
- Animals
- Apoptosis/physiology
- Cell Line, Tumor
- DNA-Binding Proteins/deficiency
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/metabolism
- DNA-Binding Proteins/physiology
- Fibroblasts/cytology
- Fibroblasts/enzymology
- Fibroblasts/metabolism
- Humans
- Insulin-Like Growth Factor Binding Protein 3
- Insulin-Like Growth Factor Binding Proteins/metabolism
- Insulin-Like Growth Factor Binding Proteins/physiology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, SCID
- Nuclear Receptor Subfamily 4, Group A, Member 1
- Prostatic Neoplasms/metabolism
- Prostatic Neoplasms/pathology
- Protein Binding/physiology
- Protein Transport/physiology
- Receptors, Cytoplasmic and Nuclear/deficiency
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/metabolism
- Receptors, Cytoplasmic and Nuclear/physiology
- Receptors, Steroid/deficiency
- Receptors, Steroid/genetics
- Receptors, Steroid/metabolism
- Receptors, Steroid/physiology
- Subcellular Fractions/metabolism
- Transcription Factors/deficiency
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Transcription Factors/physiology
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Affiliation(s)
- Kuk-Wha Lee
- Division of Pediatric Endocrinology, Mattel Children's Hospital at University of California at Los Angeles, David Geffen School of Medicine, 10833 Le Conte Avenue, MDCC 22-315, Los Angeles, CA 90095, USA.
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49
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Labelle-Dumais C, Paré JF, Bélanger L, Farookhi R, Dufort D. Impaired progesterone production in Nr5a2+/- mice leads to a reduction in female reproductive function. Biol Reprod 2007; 77:217-25. [PMID: 17409375 DOI: 10.1095/biolreprod.106.059121] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [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: 01/13/2023] Open
Abstract
NR5A2 is an orphan nuclear receptor involved in cholesterol metabolism and embryogenesis. The high level of expression of NR5A2 in the ovary and its involvement in the regulation of steroidogenic gene expression also suggest a role for this transcription factor in female reproductive function. In vivo evidence for a role for NR5A2 in fertility, however, is still lacking. In order to address this possibility, we used Nr5a2+/- mice to demonstrate that heterozygosity for a null mutation of Nr5a2 leads to a decreased fertility in females. Our results indicate that although Nr5a2+/- mice display normal follicular development, ovulation, and estrogen production, they exhibit altered luteal function. More specifically, we show that the reduced reproductive ability of Nr5a2+/- females arises from a reduction in circulating progesterone concentrations and can be rescued by exogenous progesterone supplementation. This study therefore provides the first in vivo evidence for a role of NR5A2 in reproductive function and steroidogenesis.
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Affiliation(s)
- Cassandre Labelle-Dumais
- Division of Experimental Medicine, Department of Obstetrics and Gynecology, McGill University, RVH, Montreal, Québec, Canada H3A 1A1
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50
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Krysko O, Hulshagen L, Janssen A, Schütz G, Klein R, De Bruycker M, Espeel M, Gressens P, Baes M. Neocortical and cerebellar developmental abnormalities in conditions of selective elimination of peroxisomes from brain or from liver. J Neurosci Res 2007; 85:58-72. [PMID: 17075904 DOI: 10.1002/jnr.21097] [Citation(s) in RCA: 66] [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: 01/06/2023]
Abstract
Defects in the formation of the cerebral cortex and the cerebellum are a prominent feature of the peroxisome biogenesis disorder Zellweger syndrome and in mouse models for this disease. The aim of the present study was to investigate the impact of liver and brain peroxisomes on neurodevelopment by analyzing mice with tissue-selective elimination of peroxisomes. To this end, Pex5-loxP mice were bred with albumin/alpha-fetoprotein (Alfp)-Cre and nestin (Nes)-Cre mice. Local elimination of peroxisomes from the brain in Nes-Pex5 knockout mice caused a delay of cortical neuronal migration and of the formation of cerebellar folia and fissures. Migration of granule cells from the external granular layer was retarded, as was the polarization and branching of Purkinje cells, resulting in a less complex branching pattern and a smaller dendritic tree at P21. The Alfp-Pex5 knockout mice were affected differently, displaying a partial arrest of neuronal migration in the cerebral neopallium in the postnatal period despite of the incomplete elimination of peroxisomes from liver during embryonic development. Major abnormalities were seen in the formation of the cerebellum of these liver knockout mice, including hypotrophy, impaired foliation, a delay of granule cell migration, increased cell death, and stunted Purkinje cell arborization. In conclusion, these data demonstrate that absence of peroxisomal function both from liver and brain impairs cortical neuronal migration and maturation of the cerebellum, but different pathogenic mechanisms might be involved.
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Affiliation(s)
- Olga Krysko
- Laboratory for Cell Metabolism, K.U. Leuven, Leuven, Belgium
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