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Gnanaguru G, Mackey A, Choi EY, Arta A, Rossato FA, Gero TW, Urquhart AJ, Scott DA, D'Amore PA, Ng YSE. Discovery of sterically-hindered phenol compounds with potent cytoprotective activities against ox-LDL-induced retinal pigment epithelial cell death as a potential pharmacotherapy. Free Radic Biol Med 2022; 178:360-368. [PMID: 34843917 PMCID: PMC8758799 DOI: 10.1016/j.freeradbiomed.2021.11.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 10/22/2021] [Accepted: 11/19/2021] [Indexed: 01/03/2023]
Abstract
Late-stage dry age-related macular degeneration (AMD) or geographic atrophy (GA) is an irreversible blinding condition characterized by degeneration of retinal pigment epithelium (RPE) and the associated photoreceptors. Clinical and genetic evidence supports a role for dysfunctional lipid processing and accumulation of harmful oxidized lipids in the pathogenesis of GA. Using an oxidized low-density lipoprotein (ox-LDL)-induced RPE death assay, we screened and identified sterically-hindered phenol compounds with potent protective activities for RPE. The phenol-containing PPARγ agonist, troglitazone, protected against ox-LDL-induced RPE cell death, whereas other more potent PPARγ agonists did not protect RPE cells. Knockdown of PPARγ did not affect the protective activity of troglitazone in RPE, confirming the protective function is not due to the thiazolidine (TZD) group of troglitazone. Prototypical hindered phenol trolox and its analogs potently protected against ox-LDL-induced RPE cell death whereas potent antioxidants without the phenol group failed to protect RPE. Hindered phenols preserved lysosomal integrity against ox-LDL-induced damage and FITC-labeled trolox was localized to the lysosomes in RPE cells. Analogs of trolox inhibited reactive oxygen species (ROS) formation induced by ox-LDL uptake in a dose-dependent fashion and were effective at sub-micromolar concentrations. Treatment with trolox analog 2,2,5,7,8-pentamethyl-6-chromanol (PMC) significantly induced the expression of the lysosomal protein NPC-1 and reduced intracellular cholesterol level upon ox-LDL uptake. Our data indicate that the lysosomal-localized hindered phenols are uniquely potent in protecting the RPE against the toxic effects of ox-LDL, and may represent a novel pharmacotherapy to preserve the vision in patients with GA.
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Affiliation(s)
- Gopalan Gnanaguru
- Harvard Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Boston, MA, USA
| | - Ashley Mackey
- Harvard Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Boston, MA, USA
| | - Eun Young Choi
- Harvard Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Boston, MA, USA
| | - Anthoula Arta
- Harvard Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Boston, MA, USA; Department of Health Technology, Institut for Sundhedsteknologi, Lyngby, Denmark
| | - Franco Aparecido Rossato
- Harvard Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Boston, MA, USA
| | - Thomas W Gero
- Department of Cancer Biology, Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA, 02215, USA
| | - Andrew J Urquhart
- Department of Health Technology, Institut for Sundhedsteknologi, Lyngby, Denmark
| | - David A Scott
- Department of Cancer Biology, Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA, 02215, USA
| | - Patricia A D'Amore
- Harvard Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Boston, MA, USA
| | - Yin Shan E Ng
- Harvard Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Boston, MA, USA.
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Cabrera-Reyes F, Parra-Ruiz C, Yuseff MI, Zanlungo S. Alterations in Lysosome Homeostasis in Lipid-Related Disorders: Impact on Metabolic Tissues and Immune Cells. Front Cell Dev Biol 2021; 9:790568. [PMID: 34957117 PMCID: PMC8703004 DOI: 10.3389/fcell.2021.790568] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 11/22/2021] [Indexed: 12/16/2022] Open
Abstract
Lipid-related disorders, which primarily affect metabolic tissues, including adipose tissue and the liver are associated with alterations in lysosome homeostasis. Obesity is one of the more prevalent diseases, which results in energy imbalance within metabolic tissues and lysosome dysfunction. Less frequent diseases include Niemann-Pick type C (NPC) and Gaucher diseases, both of which are known as Lysosomal Storage Diseases (LSDs), where lysosomal dysfunction within metabolic tissues remains to be fully characterized. Adipocytes and hepatocytes share common pathways involved in the lysosome-autophagic axis, which are regulated by the function of cathepsins and CD36, an immuno-metabolic receptor and display alterations in lipid diseases, and thereby impacting metabolic functions. In addition to intrinsic defects observed in metabolic tissues, cells of the immune system, such as B cells can infiltrate adipose and liver tissues, during metabolic imbalance favoring inflammation. Moreover, B cells rely on lysosomes to promote the processing and presentation of extracellular antigens and thus could also present lysosome dysfunction, consequently affecting such functions. On the other hand, growing evidence suggests that cells accumulating lipids display defective inter-organelle membrane contact sites (MCSs) established by lysosomes and other compartments, which contribute to metabolic dysfunctions at the cellular level. Overall, in this review we will discuss recent findings addressing common mechanisms that are involved in lysosome dysregulation in adipocytes and hepatocytes during obesity, NPC, and Gaucher diseases. We will discuss whether these mechanisms may modulate the function of B cells and how inter-organelle contacts, emerging as relevant cellular mechanisms in the control of lipid homeostasis, have an impact on these diseases.
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Affiliation(s)
- Fernanda Cabrera-Reyes
- Department of Cellular and Molecular Biology, Faculty of Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
- Department of Gastroenterology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Claudia Parra-Ruiz
- Department of Cellular and Molecular Biology, Faculty of Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
- Department of Gastroenterology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - María Isabel Yuseff
- Department of Cellular and Molecular Biology, Faculty of Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Silvana Zanlungo
- Department of Gastroenterology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
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Völkner C, Liedtke M, Untucht R, Hermann A, Frech MJ. Patient-Specific iPSC-Derived Neural Differentiated and Hepatocyte-like Cells, Carrying the Compound Heterozygous Mutation p.V1023Sfs*15/p.G992R, Present the "Variant" Biochemical Phenotype of Niemann-Pick Type C1 Disease. Int J Mol Sci 2021; 22:ijms222212184. [PMID: 34830064 PMCID: PMC8624182 DOI: 10.3390/ijms222212184] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 11/03/2021] [Accepted: 11/08/2021] [Indexed: 02/07/2023] Open
Abstract
Niemann–Pick disease type C1 (NP-C1) is a rare lysosomal storage disorder caused by autosomal recessive mutations in the NPC1 gene. Patients display a wide spectrum on the clinical as well as on the molecular level, wherein a so-called “variant” biochemical phenotype can be observed. Here, we report an in vitro analysis of fibroblasts obtained from an NP-C1 patient carrying the undescribed compound heterozygous mutation p.V1023Sfs*15/p.G992R. Since NP-C1 is a neurovisceral disease and the patient suffers from severe neurological as well as hepatic symptoms, we extended our study to neural differentiated and hepatocyte-like cells derived from patient-specific induced pluripotent stem cells. We detected slightly increased intracellular cholesterol levels compared to the control cell line in fibroblasts, neural differentiated and hepatocyte-like cells, suggesting a “variant” biochemical phenotype. Furthermore, the total NPC1 protein, as well as post-ER glycoforms of the NPC1 protein, tended to be reduced. In addition, colocalization analysis revealed a mild reduction of the NPC1 protein in the lysosomes. The patient was diagnosed with NP-C1 at the age of 34 years, after an initial misdiagnosis of schizophrenia. After years of mild and unspecific symptoms, such as difficulties in coordination and concentration, symptoms progressed and the patient finally presented with ataxia, dysarthria, dysphagia, vertical supranuclear gaze palsy, and hepatosplenomegaly. Genetic testing finally pointed towards an NP-C1 diagnosis, revealing the so-far undescribed compound heterozygous mutation p.V1023Sfs*15/p.G992R in the NPC1 gene. In light of these findings, this case provides support for the p.G992R mutation being causative for a “variant” biochemical phenotype leading to an adult-onset type of NP-C1 disease.
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Affiliation(s)
- Christin Völkner
- Translational Neurodegeneration Section “Albrecht Kossel”, Department of Neurology, University Medical Center Rostock, 18147 Rostock, Germany; (C.V.); (M.L.); (A.H.)
| | - Maik Liedtke
- Translational Neurodegeneration Section “Albrecht Kossel”, Department of Neurology, University Medical Center Rostock, 18147 Rostock, Germany; (C.V.); (M.L.); (A.H.)
| | - Robert Untucht
- Department of Neurology, University Hospital Carl Gustav Carus, Technische Universität Dresden, 01307 Dresden, Germany;
| | - Andreas Hermann
- Translational Neurodegeneration Section “Albrecht Kossel”, Department of Neurology, University Medical Center Rostock, 18147 Rostock, Germany; (C.V.); (M.L.); (A.H.)
- Center for Transdisciplinary Neurosciences Rostock (CTNR), University Medical Center Rostock, 18147 Rostock, Germany
- German Center for Neurodegenerative Diseases (DZNE) Rostock/Greifswald, 18147 Rostock, Germany
| | - Moritz J. Frech
- Translational Neurodegeneration Section “Albrecht Kossel”, Department of Neurology, University Medical Center Rostock, 18147 Rostock, Germany; (C.V.); (M.L.); (A.H.)
- Center for Transdisciplinary Neurosciences Rostock (CTNR), University Medical Center Rostock, 18147 Rostock, Germany
- Correspondence:
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Meneses-Salas E, Garcia-Forn M, Castany-Pladevall C, Lu A, Fajardo A, Jose J, Wahba M, Bosch M, Pol A, Tebar F, Klein AD, Zanlungo S, Pérez-Navarro E, Grewal T, Enrich C, Rentero C. Lack of Annexin A6 Exacerbates Liver Dysfunction and Reduces Lifespan of Niemann-Pick Type C Protein-Deficient Mice. THE AMERICAN JOURNAL OF PATHOLOGY 2020; 191:475-486. [PMID: 33345999 DOI: 10.1016/j.ajpath.2020.12.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 11/25/2020] [Accepted: 12/09/2020] [Indexed: 12/12/2022]
Abstract
Niemann-Pick type C (NPC) disease is a lysosomal storage disorder characterized by cholesterol accumulation caused by loss-of-function mutations in the Npc1 gene. NPC disease primarily affects the brain, causing neuronal damage and affecting motor coordination. In addition, considerable liver malfunction in NPC disease is common. Recently, we found that the depletion of annexin A6 (ANXA6), which is most abundant in the liver and involved in cholesterol transport, ameliorated cholesterol accumulation in Npc1 mutant cells. To evaluate the potential contribution of ANXA6 in the progression of NPC disease, double-knockout mice (Npc1-/-/Anxa6-/-) were generated and examined for lifespan, neurologic and hepatic functions, as well as liver histology and ultrastructure. Interestingly, lack of ANXA6 in NPC1-deficient animals did not prevent the cerebellar degeneration phenotype, but further deteriorated their compromised hepatic functions and reduced their lifespan. Moreover, livers of Npc1-/-/Anxa6-/- mice contained a significantly elevated number of foam cells congesting the sinusoidal space, a feature commonly associated with inflammation. We hypothesize that ANXA6 deficiency in Npc1-/- mice not only does not reverse neurologic and motor dysfunction, but further worsens overall liver function, exacerbating hepatic failure in NPC disease.
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Affiliation(s)
- Elsa Meneses-Salas
- Unitat de Biologia Cel·lular, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain; Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Marta Garcia-Forn
- Institut de Neurociències, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Carla Castany-Pladevall
- Institut de Neurociències, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Albert Lu
- Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Institut de Neurociències, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain; Department of Biochemistry, Stanford University School of Medicine, Stanford, California
| | - Alba Fajardo
- Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Jaimy Jose
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia
| | - Mohamed Wahba
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia
| | - Marta Bosch
- Unitat de Biologia Cel·lular, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain; Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Albert Pol
- Unitat de Biologia Cel·lular, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain; Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Institució Catalana de Recerca i Estudis Avançats (ICREA), Universidad del Desarrollo, Clínica Alemana de Santiago, Chile
| | - Francesc Tebar
- Unitat de Biologia Cel·lular, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain; Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Andrés D Klein
- Centro de Genética y Genómica, Universidad del Desarrollo, Clínica Alemana de Santiago, Chile
| | - Silvana Zanlungo
- Departamento de Gastroenterología, Facultad de Medicina Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Esther Pérez-Navarro
- Institut de Neurociències, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Thomas Grewal
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia
| | - Carlos Enrich
- Unitat de Biologia Cel·lular, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain; Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
| | - Carles Rentero
- Unitat de Biologia Cel·lular, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain; Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
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5
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Magro Dos Reis I, Houben T, Oligschläger Y, Bücken L, Steinbusch H, Cassiman D, Lütjohann D, Westerterp M, Prickaerts J, Plat J, Shiri-Sverdlov R. Dietary plant stanol ester supplementation reduces peripheral symptoms in a mouse model of Niemann-Pick type C1 disease. J Lipid Res 2020; 61:830-839. [PMID: 32291331 PMCID: PMC7269767 DOI: 10.1194/jlr.ra120000632] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 03/23/2020] [Indexed: 11/20/2022] Open
Abstract
Niemann-Pick type C (NPC)1 disease is a rare genetic condition in which the function of the lysosomal cholesterol transporter NPC1 protein is impaired. Consequently, sphingolipids and cholesterol accumulate in lysosomes of all tissues, triggering a cascade of pathological events that culminate in severe systemic and neurological symptoms. Lysosomal cholesterol accumulation is also a key factor in the development of atherosclerosis and NASH. In these two metabolic diseases, the administration of plant stanol esters has been shown to ameliorate cellular cholesterol accumulation and inflammation. Given the overlap of pathological mechanisms among atherosclerosis, NASH, and NPC1 disease, we sought to investigate whether dietary supplementation with plant stanol esters improves the peripheral features of NPC1 disease. To this end, we used an NPC1 murine model featuring a Npc1-null allele (Npc1nih ), creating a dysfunctional NPC1 protein. Npc1nih mice were fed a 2% or 6% plant stanol ester-enriched diet over the course of 5 weeks. During this period, hepatic and blood lipid and inflammatory profiles were assessed. Npc1nih mice fed the plant stanol-enriched diet exhibited lower hepatic cholesterol accumulation, damage, and inflammation than regular chow-fed Npc1nih mice. Moreover, plant stanol consumption shifted circulating T-cells and monocytes in particular toward an anti-inflammatory profile. Overall, these effects were stronger following dietary supplementation with 6% stanols, suggesting a dose-dependent effect. The findings of our study highlight the potential use of plant stanols as an affordable complementary means to ameliorate disorders in hepatic and blood lipid metabolism and reduce inflammation in NPC1 disease.
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Affiliation(s)
- Inês Magro Dos Reis
- Department of Molecular Genetics, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, Maastricht, The Netherlands
| | - Tom Houben
- Department of Molecular Genetics, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, Maastricht, The Netherlands
| | - Yvonne Oligschläger
- Department of Molecular Genetics, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, Maastricht, The Netherlands
| | - Leoni Bücken
- Department of Molecular Genetics, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, Maastricht, The Netherlands
| | - Hellen Steinbusch
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - David Cassiman
- Liver Research Unit University of Leuven, Leuven, Belgium; Department of Gastroenterology-Hepatology and Metabolic Center, University Hospitals Leuven, Leuven, Belgium
| | - Dieter Lütjohann
- Institute of Clinical Chemistry and Clinical Pharmacology, Medical Faculty, University of Bonn, Bonn, Germany
| | - Marit Westerterp
- Department of Pediatrics, Section Molecular Genetics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Jos Prickaerts
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Jogchum Plat
- Department of Nutrition and Movement Sciences, School for Nutrition, Toxicology, and Metabolism, Maastricht University, Maastricht, The Netherlands
| | - Ronit Shiri-Sverdlov
- Department of Molecular Genetics, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, Maastricht, The Netherlands. mailto:
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Identification of Novel Pathways Associated with Patterned Cerebellar Purkinje Neuron Degeneration in Niemann-Pick Disease, Type C1. Int J Mol Sci 2019; 21:ijms21010292. [PMID: 31906248 PMCID: PMC6981888 DOI: 10.3390/ijms21010292] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 12/23/2019] [Accepted: 12/25/2019] [Indexed: 01/22/2023] Open
Abstract
Niemann-Pick disease, type C1 (NPC1) is a lysosomal disease characterized by progressive cerebellar ataxia. In NPC1, a defect in cholesterol transport leads to endolysosomal storage of cholesterol and decreased cholesterol bioavailability. Purkinje neurons are sensitive to the loss of NPC1 function. However, degeneration of Purkinje neurons is not uniform. They are typically lost in an anterior-to-posterior gradient with neurons in lobule X being resistant to neurodegeneration. To gain mechanistic insight into factors that protect or potentiate Purkinje neuron loss, we compared RNA expression in cerebellar lobules III, VI, and X from control and mutant mice. An unexpected finding was that the gene expression differences between lobules III/VI and X were more pronounced than those observed between mutant and control mice. Functional analysis of genes with anterior to posterior gene expression differences revealed an enrichment of genes related to neuronal cell survival within the posterior cerebellum. This finding is consistent with the observation, in multiple diseases, that posterior Purkinje neurons are, in general, resistant to neurodegeneration. To our knowledge, this is the first study to evaluate anterior to posterior transcriptome-wide changes in gene expression in the cerebellum. Our data can be used to not only explore potential pathological mechanisms in NPC1, but also to further understand cerebellar biology.
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Santiago-Mujica E, Flunkert S, Rabl R, Neddens J, Loeffler T, Hutter-Paier B. Hepatic and neuronal phenotype of NPC1 -/- mice. Heliyon 2019; 5:e01293. [PMID: 30923761 PMCID: PMC6423819 DOI: 10.1016/j.heliyon.2019.e01293] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 01/15/2019] [Accepted: 02/26/2019] [Indexed: 12/14/2022] Open
Abstract
Niemann-Pick type C disease (NPC) is a fatal autosomal recessive disorder characterized by a defect in the intracellular transport of lipoproteins leading to the accumulation of lipids in diverse tissues. A visceral and neuronal phenotype mimicking human NPC1 disease has been described in NPC1 mutant mice. These mice are by now the most widely used NPC1 rodent model to study NPC and developmental compounds against this devastating disease. Here we characterized NPC1-/- mice for their hepatic and neuronal phenotype to confirm the stability of the phenotype, provide a characterization of disease progression and pinpoint the age of robust phenotype onset. Animals of 4-10 weeks of age were analyzed for general health, motor deficits as well as hepatic and neuronal alterations with a special focus on cerebellar pathology. Our results show that NPC1-/- mice have a reduced general health at the age of 9-10 weeks. Robust motor deficits can be observed even earlier at 8 weeks of age. Hepatic changes included increased organ weight and cholesterol levels at 6 weeks of age accompanied by severely increased liver enzyme levels. Analysis of NPC1-/- brain pathology showed decreased cholesterol and increased Aβ levels in the hippocampus at the age of 6 weeks. Further analysis revealed a decrease of the cytokine IL-12p70 in the cerebellum along with a very early increase of astrocytosis. Hippocampal IL-12p70 levels were increased at the age of 6 weeks followed by increased activated microglia levels. By the age of 10 weeks, also cerebellar Aβ levels were increased along with strongly reduced Calbindin D-28k levels. Our results validate and summarize the progressive development of the hepatic and neuronal phenotype of NPC1-/- mice that starts with cerebellar astrocytosis, making this mouse model a valuable tool for the development of new compounds against NPC.
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Key Words
- AAALAC, Association for Assessment and Accreditation of Laboratory Animal Care
- ALT, alanine aminotransferase
- ANOVA, Analysis of variance
- AOI, Area of interest
- AP, alkaline phosphatase
- APP, Amyloid Precursor Protein
- AST, aspartate aminotransferase
- CD45, cluster of differentiation 45
- CNS, central nervous system
- Cell biology
- DAPI, 4′,6-Diamidin-2-phenylindol
- GFAP, Glial fibrillary acidic protein
- IFN-γ, Interferon-gamma
- IL-10/12, Interleukin-10/12
- KC, keratinocyte chemoattractant
- MAP2, microtubuli-associated protein 2
- Molecular biology
- NPC, Niemann-Pick type C
- Neuroscience
- Physiology
- TNF-α, tumor necrosis factor-alpha
- WT, wildtype
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Lopez AM, Jones RD, Repa JJ, Turley SD. Niemann-Pick C1-deficient mice lacking sterol O-acyltransferase 2 have less hepatic cholesterol entrapment and improved liver function. Am J Physiol Gastrointest Liver Physiol 2018; 315:G454-G463. [PMID: 29878847 PMCID: PMC6230690 DOI: 10.1152/ajpgi.00124.2018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 05/31/2018] [Accepted: 06/01/2018] [Indexed: 01/31/2023]
Abstract
Cholesteryl esters are generated at multiple sites in the body by sterol O-acyltransferase (SOAT) 1 or SOAT2 in various cell types and lecithin cholesterol acyltransferase in plasma. Esterified cholesterol and triacylglycerol contained in lipoproteins cleared from the circulation via receptor-mediated or bulk-phase endocytosis are hydrolyzed by lysosomal acid lipase within the late endosomal/lysosomal (E/L) compartment. Then, through the successive actions of Niemann-Pick C (NPC) 2 and NPC 1, unesterified cholesterol (UC) is exported from the E/L compartment to the cytosol. Mutations in either NPC1 or NPC2 lead to continuing entrapment of UC in all organs, resulting in multisystem disease, which includes hepatic dysfunction and in some cases liver failure. These studies investigated primarily whether elimination of SOAT2 in NPC1-deficient mice impacted hepatic UC sequestration, inflammation, and transaminase activities. Measurements were made in 7-wk-old mice fed a low-cholesterol chow diet or one enriched with cholesterol starting 2 wk before study. In the chow-fed mice, NPC1:SOAT2 double knockouts, compared with their littermates lacking only NPC1, had 20% less liver mass, 28% lower hepatic UC concentrations, and plasma alanine aminotransferase and aspartate aminotransferase activities that were decreased by 48% and 36%, respectively. mRNA expression levels for several markers of inflammation were all significantly lower in the NPC1 mutants lacking SOAT2. The existence of a new class of potent and selective SOAT2 inhibitors provides an opportunity for exploring if suppression of this enzyme could potentially become an adjunctive therapy for liver disease in NPC1 deficiency. NEW & NOTEWORTHY In Niemann-Pick type C1 (NPC1) disease, the entrapment of unesterified cholesterol (UC) in the endosomal/lysosomal compartment of all cells causes multiorgan disease, including neurodegeneration, pulmonary dysfunction, and liver failure. Some of this sequestered UC entered cells initially in the esterified form. When sterol O-acyltransferase 2, a cholesterol esterifying enzyme present in enterocytes and hepatocytes, is eliminated in NPC1-deficient mice, there is a reduction in their hepatomegaly, hepatic UC content, and cellular injury.
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Affiliation(s)
- Adam M Lopez
- Department of Internal Medicine, University of Texas Southwestern Medical Center , Dallas, Texas
| | - Ryan D Jones
- Department of Physiology, University of Texas Southwestern Medical Center , Dallas, Texas
| | - Joyce J Repa
- Department of Internal Medicine, University of Texas Southwestern Medical Center , Dallas, Texas
- Department of Physiology, University of Texas Southwestern Medical Center , Dallas, Texas
| | - Stephen D Turley
- Department of Internal Medicine, University of Texas Southwestern Medical Center , Dallas, Texas
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Tobias F, Olson MT, Cologna SM. Mass spectrometry imaging of lipids: untargeted consensus spectra reveal spatial distributions in Niemann-Pick disease type C1. J Lipid Res 2018; 59:2446-2455. [PMID: 30266834 DOI: 10.1194/jlr.d086090] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Revised: 09/24/2018] [Indexed: 12/12/2022] Open
Abstract
Mass spectrometry imaging (MSI) is a tool to rapidly map the spatial location of analytes without the need for tagging or a reporter system. Niemann-Pick disease type C1 (NPC1) is a neurodegenerative, lysosomal storage disorder characterized by accumulation of unesterified cholesterol and sphingolipids in the endo-lysosomal system. Here, we use MSI to visualize lipids including cholesterol in cerebellar brain tissue from the NPC1 symptomatic mouse model and unaffected controls. To complement the imaging studies, a data-processing pipeline was developed to generate consensus mass spectra, thereby using both technical and biological image replicates to assess differences. The consensus spectra are used to determine true differences in lipid relative abundance; lipid distributions can be determined in an unbiased fashion without prior knowledge of location. We show the cerebellar distribution of gangliosides GM1, GM2, and GM3, including variants of lipid chain length. We also performed MALDI-MSI of cholesterol. Further analysis of lobules IV/V and X of the cerebellum gangliosides indicates regional differences. The specificity achieved highlights the power of MSI, and this new workflow demonstrates a universal approach for addressing reproducibility in imaging experiments applied to NPC1.
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Affiliation(s)
- Fernando Tobias
- Department of Chemistry University of Illinois at Chicago, Chicago, IL 60607
| | - Matthew T Olson
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Jacksonville, FL 32224
| | - Stephanie M Cologna
- Department of Chemistry University of Illinois at Chicago, Chicago, IL 60607 .,Laboratory of Integrative Neuroscience, University of Illinois at Chicago, Chicago, IL 60607
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10
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Lamri A, Pigeyre M, Garver WS, Meyre D. The Extending Spectrum of NPC1-Related Human Disorders: From Niemann-Pick C1 Disease to Obesity. Endocr Rev 2018; 39:192-220. [PMID: 29325023 PMCID: PMC5888214 DOI: 10.1210/er.2017-00176] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 01/02/2018] [Indexed: 12/22/2022]
Abstract
The Niemann-Pick type C1 (NPC1) protein regulates the transport of cholesterol and fatty acids from late endosomes/lysosomes and has a central role in maintaining lipid homeostasis. NPC1 loss-of-function mutations in humans cause NPC1 disease, a rare autosomal-recessive lipid-storage disorder characterized by progressive and lethal neurodegeneration, as well as liver and lung failure, due to cholesterol infiltration. In humans, genome-wide association studies and post-genome-wide association studies highlight the implication of common variants in NPC1 in adult-onset obesity, body fat mass, and type 2 diabetes. Heterozygous human carriers of rare loss-of-function coding variants in NPC1 display an increased risk of morbid adult obesity. These associations have been confirmed in mice models, showing an important interaction with high-fat diet. In this review, we describe the current state of knowledge for NPC1 variants in relationship to pleiotropic effects on metabolism. We provide evidence that NPC1 gene variations may predispose to common metabolic diseases by modulating steroid hormone synthesis and/or lipid homeostasis. We also propose several important directions of research to further define the complex roles of NPC1 in metabolism. This review emphasizes the contribution of NPC1 to obesity and its metabolic complications.
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Affiliation(s)
- Amel Lamri
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada
| | - Marie Pigeyre
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada.,INSERM 1190, European Genomics Institute for Diabetes, University of Lille, CHRU Lille, Lille, France
| | - William S Garver
- Department of Biochemistry and Molecular Biology, School of Medicine, University of New Mexico, Albuquerque, New Mexico
| | - David Meyre
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada.,Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
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11
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Marshall CA, Watkins-Chow DE, Palladino G, Deutsch G, Chandran K, Pavan WJ, Erickson RP. In Niemann-Pick C1 mouse models, glial-only expression of the normal gene extends survival much further than do changes in genetic background or treatment with hydroxypropyl-beta-cyclodextrin. Gene 2017; 643:117-123. [PMID: 29223359 DOI: 10.1016/j.gene.2017.12.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 12/01/2017] [Accepted: 12/06/2017] [Indexed: 11/19/2022]
Abstract
The Npc1nmf164 allele of Npc1 provides a mouse model for Niemann-Pick disease type C1 (NPC1), a genetic disease known to have a widely variable phenotype. The transfer of the Npc1nmf164 mutation from the C57BL/6J inbred strain to the BALB/cJ inbred strain increased the mean lifespan from 117.8days to 153.1days, confirming that the severity of the NPC1 phenotype is strongly influenced by genetic background. The transfer of another Npc1 allele, Npc1nih, to this background also extended survival of the homozygotes indicating that the modifying effect of BALB/cJ is not limited to a single allele of Npc1. The increased longevity due to the BALB/cJ background did not map to a previously mapped modifier on chromosome 19, indicating the presence of additional genes impacting disease severity. The previously studied Glial Fibrillary Acidic Protein promoter-Npc1 cDNA transgene (GFAP-Npc1) which only expresses NPC1 in astrocytes further extended the lifespan of Npc1nmf164 homozygotes on a BALB/cJ background (up to 600days). Hydroxypropyl-β-cyclodextrin (HPβCD) treatment, not previously tested in the Npc1nmf164 mutant, extended life in the Npc1nmf164 homozygotes but not the transgenic, Npc1nmf164 mice on the BALB/cJ background. In all cases, lack of weight gain and early cerebellar symptoms of loss of motor control were found. At termination, the one mouse sacrificed for histological studies showed severe, diffuse pulmonary alveolar proteinosis suggesting that pulmonary abnormalities in NPC1 mouse models are not unique to the Npc1nih allele.
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Affiliation(s)
- Craig A Marshall
- Department of Pediatrics, University of Arizona College of Medicine, Tucson, AZ 85724-5073, United States
| | - Dawn E Watkins-Chow
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, United States
| | - Giampiero Palladino
- Department of Pediatrics, University of Arizona College of Medicine, Tucson, AZ 85724-5073, United States
| | - Gail Deutsch
- Department of Pathology, Seattle Children's Hospital, Seattle, WA, United States
| | - Keshav Chandran
- Department of Pediatrics, University of Arizona College of Medicine, Tucson, AZ 85724-5073, United States
| | - William J Pavan
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, United States
| | - Robert P Erickson
- Department of Pediatrics, University of Arizona College of Medicine, Tucson, AZ 85724-5073, United States.
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12
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Cairns R, Alvarez-Guaita A, Martínez-Saludes I, Wason SJ, Hanh J, Nagarajan SR, Hosseini-Beheshti E, Monastyrskaya K, Hoy AJ, Buechler C, Enrich C, Rentero C, Grewal T. Role of hepatic Annexin A6 in fatty acid-induced lipid droplet formation. Exp Cell Res 2017; 358:397-410. [PMID: 28712927 DOI: 10.1016/j.yexcr.2017.07.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 07/07/2017] [Accepted: 07/12/2017] [Indexed: 01/17/2023]
Abstract
Annexin A6 (AnxA6) has been implicated in the regulation of endo-/exocytic pathways, cholesterol transport, and the formation of multifactorial signaling complexes in many different cell types. More recently, AnxA6 has also been linked to triglyceride storage in adipocytes. Here we investigated the potential role of AnxA6 in fatty acid (FA) - induced lipid droplet (LD) formation in hepatocytes. AnxA6 was associated with LD from rat liver and HuH7 hepatocytes. In oleic acid (OA) -loaded HuH7 cells, substantial amounts of AnxA6 bound to LD in a Ca2+-independent manner. Remarkably, stable or transient AnxA6 overexpression in HuH7 cells led to elevated LD numbers/size and neutral lipid staining under control conditions as well as after OA loading compared to controls. In contrast, overexpression of AnxA1, AnxA2 and AnxA8 did not impact on OA-induced lipid accumulation. On the other hand, incubation of AnxA6-depleted HuH7 cells or primary hepatocytes from AnxA6 KO-mice with OA led to reduced FA accumulation and LD numbers. Furthermore, morphological analysis of liver sections from A6-KO mice revealed significantly lower LD numbers compared to wildtype animals. Interestingly, pharmacological inhibition of cytoplasmic phospholipase A2α (cPLA2α)-dependent LD formation was ineffective in AnxA6-depleted HuH7 cells. We conclude that cPLA2α-dependent pathways contribute to the novel regulatory role of hepatic AnxA6 in LD formation.
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Affiliation(s)
- Rose Cairns
- Faculty of Pharmacy, University of Sydney, Sydney, NSW 2006, Australia
| | - Anna Alvarez-Guaita
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain
| | - Inés Martínez-Saludes
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain
| | - Sundeep J Wason
- Faculty of Pharmacy, University of Sydney, Sydney, NSW 2006, Australia
| | - Jacky Hanh
- Faculty of Pharmacy, University of Sydney, Sydney, NSW 2006, Australia
| | - Shilpa R Nagarajan
- Discipline of Physiology, School of Medical Science & Bosch Institute; Sydney Medical School; Charles Perkins Centre, University of Sydney, Sydney, NSW 2006, Australia
| | - Elham Hosseini-Beheshti
- Discipline of Physiology, School of Medical Science & Bosch Institute; Sydney Medical School; Charles Perkins Centre, University of Sydney, Sydney, NSW 2006, Australia
| | - Katia Monastyrskaya
- Urology Research Laboratory, Department Clinical Research, University of Bern, 3010 Bern, Switzerland
| | - Andrew J Hoy
- Discipline of Physiology, School of Medical Science & Bosch Institute; Sydney Medical School; Charles Perkins Centre, University of Sydney, Sydney, NSW 2006, Australia
| | - Christa Buechler
- Department of Internal Medicine I, Regensburg University Hospital, 93042 Regensburg, Germany
| | - Carlos Enrich
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain
| | - Carles Rentero
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain.
| | - Thomas Grewal
- Faculty of Pharmacy, University of Sydney, Sydney, NSW 2006, Australia.
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13
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Characterization of cholesterol homeostasis in sphingosine-1-phosphate lyase-deficient fibroblasts reveals a Niemann-Pick disease type C-like phenotype with enhanced lysosomal Ca 2+ storage. Sci Rep 2017; 7:43575. [PMID: 28262793 PMCID: PMC5337937 DOI: 10.1038/srep43575] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 01/25/2017] [Indexed: 02/08/2023] Open
Abstract
Sphingosine-1-phosphate (S1P) lyase irreversibly cleaves S1P, thereby catalysing the ultimate step of sphingolipid degradation. We show here that embryonic fibroblasts from S1P lyase-deficient mice (Sgpl1−/−-MEFs), in which S1P and sphingosine accumulate, have features of Niemann-Pick disease type C (NPC) cells. In the presence of serum, overall cholesterol content was elevated in Sgpl1−/−-MEFs, due to upregulation of the LDL receptor and enhanced cholesterol uptake. Despite this, activation of sterol regulatory element-binding protein-2 was increased in Sgpl1−/−-MEFs, indicating a local lack of cholesterol at the ER. Indeed, free cholesterol was retained in NPC1-containing vesicles, which is a hallmark of NPC. Furthermore, upregulation of amyloid precursor protein in Sgpl1−/−-MEFs was mimicked by an NPC1 inhibitor in Sgpl1+/+-MEFs and reduced by overexpression of NPC1. Lysosomal pH was not altered by S1P lyase deficiency, similar to NPC. Interestingly, lysosomal Ca2+ content and bafilomycin A1-induced [Ca2+]i increases were enhanced in Sgpl1−/−-MEFs, contrary to NPC. These results show that both a primary defect in cholesterol trafficking and S1P lyase deficiency cause overlapping phenotypic alterations, and challenge the present view on the role of sphingosine in lysosomal Ca2+ homeostasis.
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14
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Munkacsi AB, Hammond N, Schneider RT, Senanayake DS, Higaki K, Lagutin K, Bloor SJ, Ory DS, Maue RA, Chen FW, Hernandez-Ono A, Dahlson N, Repa JJ, Ginsberg HN, Ioannou YA, Sturley SL. Normalization of Hepatic Homeostasis in the Npc1nmf164 Mouse Model of Niemann-Pick Type C Disease Treated with the Histone Deacetylase Inhibitor Vorinostat. J Biol Chem 2016; 292:4395-4410. [PMID: 28031458 DOI: 10.1074/jbc.m116.770578] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 12/21/2016] [Indexed: 12/31/2022] Open
Abstract
Niemann-Pick type C (NP-C) disease is a fatal genetic lipidosis for which there is no Food and Drug Administration (FDA)-approved therapy. Vorinostat, an FDA-approved inhibitor of histone deacetylases, ameliorates lysosomal lipid accumulation in cultured NP-C patient fibroblasts. To assess the therapeutic potential of histone deacetylase inhibition, we pursued these in vitro observations in two murine models of NP-C disease. Npc1nmf164 mice, which express a missense mutation in the Npc1 gene, were treated intraperitoneally, from weaning, with the maximum tolerated dose of vorinostat (150 mg/kg, 5 days/week). Disease progression was measured via gene expression, liver function and pathology, serum and tissue lipid levels, body weight, and life span. Transcriptome analyses of treated livers indicated multiple changes consistent with reversal of liver dysfunction that typifies NP-C disease. Significant improvements in liver pathology and function were achieved by this treatment regimen; however, NPC1 protein maturation and levels, disease progression, weight loss, and animal morbidity were not detectably altered. Vorinostat concentrations were >200 μm in the plasma compartment of treated animals but were almost 100-fold lower in brain tissue. Apolipoprotein B metabolism and the expression of key components of lipid homeostasis in primary hepatocytes from null (Npc1-/-) and missense (Npc1nmf164 ) mutant mice were altered by vorinostat treatment, consistent with a response by these cells independent of the status of the Npc1 locus. These results suggest that HDAC inhibitors have utility to treat visceral NP-C disease. However, it is clear that improved blood-brain barrier penetration will be required to alleviate the neurological symptoms of human NP-C disease.
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Affiliation(s)
- Andrew B Munkacsi
- From the School of Biological Sciences and .,Centre for Biodiscovery, Victoria University of Wellington, Wellington 6012, New Zealand
| | | | | | | | - Katsumi Higaki
- the Division of Functional Genomics, Research Center for Bioscience and Technology, Tottori University, Yonago 683-8503, Japan
| | | | | | - Daniel S Ory
- the Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Robert A Maue
- the Department of Physiology and Neurobiology and the Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755
| | - Fannie W Chen
- the Department of Genetics and Genomic Sciences, Mount Sinai School of Medicine, New York, New York 10029
| | | | - Nicole Dahlson
- the Departments of Physiology and Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390, and
| | - Joyce J Repa
- the Departments of Physiology and Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390, and
| | | | - Yiannis A Ioannou
- the Department of Genetics and Genomic Sciences, Mount Sinai School of Medicine, New York, New York 10029
| | - Stephen L Sturley
- the Department of Genetics and Development, Columbia University Medical Center, New York, New York 10032
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15
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Genetic and chemical correction of cholesterol accumulation and impaired autophagy in hepatic and neural cells derived from Niemann-Pick Type C patient-specific iPS cells. Stem Cell Reports 2014; 2:866-80. [PMID: 24936472 PMCID: PMC4050353 DOI: 10.1016/j.stemcr.2014.03.014] [Citation(s) in RCA: 159] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Revised: 03/25/2014] [Accepted: 03/31/2014] [Indexed: 12/17/2022] Open
Abstract
Niemann-Pick type C (NPC) disease is a fatal inherited lipid storage disorder causing severe neurodegeneration and liver dysfunction with only limited treatment options for patients. Loss of NPC1 function causes defects in cholesterol metabolism and has recently been implicated in deregulation of autophagy. Here, we report the generation of isogenic pairs of NPC patient-specific induced pluripotent stem cells (iPSCs) using transcription activator-like effector nucleases (TALENs). We observed decreased cell viability, cholesterol accumulation, and dysfunctional autophagic flux in NPC1-deficient human hepatic and neural cells. Genetic correction of a disease-causing mutation rescued these defects and directly linked NPC1 protein function to impaired cholesterol metabolism and autophagy. Screening for autophagy-inducing compounds in disease-affected human cells showed cell type specificity. Carbamazepine was found to be cytoprotective and effective in restoring the autophagy defects in both NPC1-deficient hepatic and neuronal cells and therefore may be a promising treatment option with overall benefit for NPC disease. Generation of Niemann-Pick type C (NPC) disease patient-specific iPSCs NPC1 hepatic and neuronal cells show defects in cholesterol and autophagic flux TALEN-mediated genetic correction rescues the cholesterol and autophagy defects Autophagy inducers can restore functional autophagy and increase cell viability
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16
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Vance JE, Karten B. Niemann-Pick C disease and mobilization of lysosomal cholesterol by cyclodextrin. J Lipid Res 2014; 55:1609-21. [PMID: 24664998 DOI: 10.1194/jlr.r047837] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Indexed: 12/31/2022] Open
Abstract
Niemann-Pick type C (NPC) disease is a lysosomal storage disease in which endocytosed cholesterol becomes sequestered in late endosomes/lysosomes (LEs/Ls) because of mutations in either the NPC1 or NPC2 gene. Mutations in either of these genes can lead to impaired functions of the NPC1 or NPC2 proteins and progressive neurodegeneration as well as liver and lung disease. NPC1 is a polytopic protein of the LE/L limiting membrane, whereas NPC2 is a soluble protein in the LE/L lumen. These two proteins act in tandem and promote the export of cholesterol from LEs/Ls. Consequently, a defect in either NPC1 or NPC2 causes cholesterol accumulation in LEs/Ls. In this review, we summarize the molecular mechanisms leading to NPC disease, particularly in the CNS. Recent exciting data on the mechanism by which the cholesterol-sequestering agent cyclodextrin can bypass the functions of NPC1 and NPC2 in the LEs/Ls, and mobilize cholesterol from LEs/Ls, will be highlighted. Moreover, the possible use of cyclodextrin as a valuable therapeutic agent for treatment of NPC patients will be considered.
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Affiliation(s)
- Jean E Vance
- The Group on Molecular and Cell Biology of Lipids and Department of Medicine, University of Alberta, Edmonton, AB, Canada
| | - Barbara Karten
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada
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17
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Ontogenic changes in lung cholesterol metabolism, lipid content, and histology in mice with Niemann-Pick type C disease. Biochim Biophys Acta Mol Cell Biol Lipids 2013; 1841:54-61. [PMID: 24076310 DOI: 10.1016/j.bbalip.2013.09.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 09/12/2013] [Accepted: 09/18/2013] [Indexed: 11/21/2022]
Abstract
Niemann-Pick Type C (NPC) disease is caused by a deficiency of either NPC1 or NPC2. Loss of function of either protein results in the progressive accumulation of unesterified cholesterol in every tissue leading to cell death and organ damage. Most literature on NPC disease focuses on neurological and liver manifestations. Pulmonary dysfunction is less well described. The present studies investigated how Npc1 deficiency impacts the absolute weight, lipid composition and histology of the lungs of Npc1(-/-) mice (Npc1(nih)) at different stages of the disease, and also quantitated changes in the rates of cholesterol and fatty acid synthesis in the lung over this same time span (8 to 70days of age). Similar measurements were made in Npc2(-/-) mice at 70days. All mice were of the BALB/c strain and were fed a basal rodent chow diet. Well before weaning, the lung weight, cholesterol and phospholipid (PL) content, and cholesterol synthesis rate were all elevated in the Npc1(-/-) mice and remained so at 70days of age. In contrast, lung triacylglycerol content was reduced while there was no change in lung fatty acid synthesis. Despite the elevated PL content, the composition of PL in the lungs of the Npc1(-/-) mice was unchanged. H&E staining revealed an age-related increase in the presence of lipid-laden macrophages in the alveoli of the lungs of the Npc1(-/-) mice starting as early as 28days. Similar metabolic and histologic changes were evident in the lungs of the Npc2(-/-) mice. Together these findings demonstrate an intrinsic lung pathology in NPC disease that is of early onset and worsens over time.
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18
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Lopez ME, Scott MP. Genetic dissection of a cell-autonomous neurodegenerative disorder: lessons learned from mouse models of Niemann-Pick disease type C. Dis Model Mech 2013; 6:1089-100. [PMID: 23907005 PMCID: PMC3759329 DOI: 10.1242/dmm.012385] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Understanding neurodegenerative disease progression and its treatment requires the systematic characterization and manipulation of relevant cell types and molecular pathways. The neurodegenerative lysosomal storage disorder Niemann-Pick disease type C (NPC) is highly amenable to genetic approaches that allow exploration of the disease biology at the organismal, cellular and molecular level. Although NPC is a rare disease, genetic analysis of the associated neuropathology promises to provide insight into the logic of disease neural circuitry, selective neuron vulnerability and neural-glial interactions. The ability to control the disorder cell-autonomously and in naturally occurring spontaneous animal models that recapitulate many aspects of the human disease allows for an unparalleled dissection of the disease neurobiology in vivo. Here, we review progress in mouse-model-based studies of NPC disease, specifically focusing on the subtype that is caused by a deficiency in NPC1, a sterol-binding late endosomal membrane protein involved in lipid trafficking. We also discuss recent findings and future directions in NPC disease research that are pertinent to understanding the cellular and molecular mechanisms underlying neurodegeneration in general.
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Affiliation(s)
- Manuel E Lopez
- Departments of Developmental Biology, Genetics, and Bioengineering, Howard Hughes Medical Institute, Stanford University School of Medicine, Clark Center W200, 318 Campus Drive, Stanford, CA 94305-5439, USA
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19
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Deficiency of a Niemann-Pick, type C1-related protein in toxoplasma is associated with multiple lipidoses and increased pathogenicity. PLoS Pathog 2011; 7:e1002410. [PMID: 22174676 PMCID: PMC3234224 DOI: 10.1371/journal.ppat.1002410] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Accepted: 10/16/2011] [Indexed: 02/07/2023] Open
Abstract
Several proteins that play key roles in cholesterol synthesis, regulation, trafficking and signaling are united by sharing the phylogenetically conserved 'sterol-sensing domain' (SSD). The intracellular parasite Toxoplasma possesses at least one gene coding for a protein containing the canonical SSD. We investigated the role of this protein to provide information on lipid regulatory mechanisms in the parasite. The protein sequence predicts an uncharacterized Niemann-Pick, type C1-related protein (NPC1) with significant identity to human NPC1, and it contains many residues implicated in human NPC disease. We named this NPC1-related protein, TgNCR1. Mammalian NPC1 localizes to endo-lysosomes and promotes the movement of sterols and sphingolipids across the membranes of these organelles. Miscoding patient mutations in NPC1 cause overloading of these lipids in endo-lysosomes. TgNCR1, however, lacks endosomal targeting signals, and localizes to flattened vesicles beneath the plasma membrane of Toxoplasma. When expressed in mammalian NPC1 mutant cells and properly addressed to endo-lysosomes, TgNCR1 restores cholesterol and GM1 clearance from these organelles. To clarify the role of TgNCR1 in the parasite, we genetically disrupted NCR1; mutant parasites were viable. Quantitative lipidomic analyses on the ΔNCR1 strain reveal normal cholesterol levels but an overaccumulation of several species of cholesteryl esters, sphingomyelins and ceramides. ΔNCR1 parasites are also characterized by abundant storage lipid bodies and long membranous tubules derived from their parasitophorous vacuoles. Interestingly, these mutants can generate multiple daughters per single mother cell at high frequencies, allowing fast replication in vitro, and they are slightly more virulent in mice than the parental strain. These data suggest that the ΔNCR1 strain has lost the ability to control the intracellular levels of several lipids, which subsequently results in the stimulation of lipid storage, membrane biosynthesis and parasite division. Based on these observations, we ascribe a role for TgNCR1 in lipid homeostasis in Toxoplasma.
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20
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Ulatowski L, Parker R, Davidson C, Yanjanin N, Kelley TJ, Corey D, Atkinson J, Porter F, Arai H, Walkley SU, Manor D. Altered vitamin E status in Niemann-Pick type C disease. J Lipid Res 2011; 52:1400-10. [PMID: 21550990 DOI: 10.1194/jlr.m015560] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Vitamin E (α-tocopherol) is the major lipid-soluble antioxidant in many species. Niemann-Pick type C (NPC) disease is a lysosomal storage disorder caused by mutations in the NPC1 or NPC2 gene, which regulates lipid transport through the endocytic pathway. NPC disease is characterized by massive intracellular accumulation of unesterified cholesterol and other lipids in lysosomal vesicles. We examined the roles that NPC1/2 proteins play in the intracellular trafficking of tocopherol. Reduction of NPC1 or NPC2 expression or function in cultured cells caused a marked lysosomal accumulation of vitamin E in cultured cells. In vivo, tocopherol significantly accumulated in murine Npc1-null and Npc2-null livers, Npc2-null cerebella, and Npc1-null cerebral cortices. Plasma tocopherol levels were within the normal range in Npc1-null and Npc2-null mice, and in plasma samples from human NPC patients. The binding affinity of tocopherol to the purified sterol-binding domain of NPC1 and to purified NPC2 was significantly weaker than that of cholesterol (measurements kindly performed by R. Infante, University of Texas Southwestern Medical Center, Dallas, TX). Taken together, our observations indicate that functionality of NPC1/2 proteins is necessary for proper bioavailability of vitamin E and that the NPC pathology might involve tissue-specific perturbations of vitamin E status.
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Affiliation(s)
- L Ulatowski
- Department of Nutrition, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
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21
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Jelinek D, Millward V, Birdi A, Trouard TP, Heidenreich RA, Garver WS. Npc1 haploinsufficiency promotes weight gain and metabolic features associated with insulin resistance. Hum Mol Genet 2010; 20:312-21. [PMID: 21036943 DOI: 10.1093/hmg/ddq466] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
A recent population-based genome-wide association study has revealed that the Niemann-Pick C1 (NPC1) gene is associated with early-onset and morbid adult obesity. Concurrently, our candidate gene-based mouse growth study performed using the BALB/cJ NPC1 mouse model (Npc1) with decreased Npc1 gene dosage independently supported these results by suggesting an Npc1 gene-diet interaction in relation to early-onset weight gain. To further investigate the Npc1 gene in relation to weight gain and metabolic features associated with insulin resistance, we interbred BALB/cJ Npc1(+/-) mice with wild-type C57BL/6J mice, the latter mouse strain commonly used to study aspects of diet-induced obesity and insulin resistance. This breeding produced a hybrid (BALB/cJ-C57BL/6J) Npc1(+/-) mouse model with increased susceptibility to weight gain and insulin resistance. The results from our study indicated that these Npc1(+/-) mice were susceptible to increased weight gain characterized by increased whole body and abdominal adiposity, adipocyte hypertrophy and hepatic steatosis in the absence of hyperphagia. Moreover, these Npc1(+/-) mice developed abnormal metabolic features characterized by impaired fasting glucose, glucose intolerance, hyperinsulinemia, hyperleptinemia and dyslipidemia marked by an increased concentration of cholesterol and triacylglycerol associated with low-density lipoprotein and high-density lipoprotein. The overall results are consistent with a unique Npc1 gene-diet interaction that promotes both weight gain and metabolic features associated with insulin resistance. Therefore, the NPC1 gene now represents a previously unrecognized gene involved in maintaining energy and metabolic homeostasis that will contribute to our understanding concerning the current global epidemic of obesity and type 2 diabetes mellitus.
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Affiliation(s)
- David Jelinek
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, 1 University of New Mexico, Albuquerque, NM, USA
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Vincent M, Sayre NL, Graham MJ, Crooke RM, Shealy DJ, Liscum L. Evaluation of an anti-tumor necrosis factor therapeutic in a mouse model of Niemann-Pick C liver disease. PLoS One 2010; 5:e12941. [PMID: 20886067 PMCID: PMC2944848 DOI: 10.1371/journal.pone.0012941] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2010] [Accepted: 08/31/2010] [Indexed: 12/02/2022] Open
Abstract
Background Niemann-Pick type C (NPC) disease is a lysosomal storage disease characterized by the accumulation of cholesterol and glycosphingolipids. The majority of NPC patients die in their teen years due to progressive neurodegeneration; however, half of NPC patients also suffer from cholestasis, prolonged jaundice, and hepatosplenomegaly. We previously showed that a key mediator of NPC liver disease is tumor necrosis factor (TNF) α, which is involved in both proinflammatory and apoptotic signaling cascades. In this study, we tested the hypothesis that blocking TNF action with an anti-TNF monoclonal antibody (CNTO5048) will slow the progression of NPC liver disease. Methodology/Principal Findings Treatment of wild-type C57BL/6 mice with NPC1-specific antisense oligonucleotides led to knockdown of NPC1 protein expression in the liver. This caused classical symptoms of NPC liver disease, including hepatic cholesterol accumulation, hepatomegaly, elevated serum liver enzymes, and lipid laden macrophage accumulation. In addition, there was a significant increase in the number of apoptotic cells and a proliferation of stellate cells. Concurrent treatment of NPC1 knockdown mice with anti-TNF had no effect on the primary lipid storage or accumulation of lipid-laden macrophages. However, anti-TNF treatment slightly blunted the increase in hepatic apoptosis and stellate cell activation that was seen with NPC1 knockdown. Conclusions/Significance Current therapeutic options for NPC disease are limited. Our results provide proof of principle that pharmacologically blocking the TNF-α inflammatory cascade can slightly reduce certain markers of NPC disease. Small molecule inhibitors of TNF that penetrate tissues and cross the blood-brain barrier may prove even more beneficial.
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Affiliation(s)
- Melanie Vincent
- Department of Physiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Naomi L. Sayre
- Department of Physiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Mark J. Graham
- Cardiovascular Disease Antisense Drug Discovery, Isis Pharmaceuticals, Inc, Carlsbad, California, United States of America
| | - Rosanne M. Crooke
- Cardiovascular Disease Antisense Drug Discovery, Isis Pharmaceuticals, Inc, Carlsbad, California, United States of America
| | - David J. Shealy
- Centocor Research and Development, Inc., Radnor, Pennsylvania, United States of America
| | - Laura Liscum
- Department of Physiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- * E-mail:
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Uronen RL, Lundmark P, Orho-Melander M, Jauhiainen M, Larsson K, Siegbahn A, Wallentin L, Zethelius B, Melander O, Syvänen AC, Ikonen E. Niemann-Pick C1 modulates hepatic triglyceride metabolism and its genetic variation contributes to serum triglyceride levels. Arterioscler Thromb Vasc Biol 2010; 30:1614-20. [PMID: 20489167 DOI: 10.1161/atvbaha.110.207191] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE To study how Niemann-Pick disease type C1 (NPC1) influences hepatic triacylglycerol (TG) metabolism and to determine whether this is reflected in circulating lipid levels. METHODS AND RESULTS In Npc1(-/-) mice, the hepatic cholesterol content is increased but the TG content is decreased. We investigated lipid metabolism in Npc1(-/-) mouse hepatocytes and the association of NPC1 single-nucleotide polymorphisms with circulating TGs in humans. TGs were reduced in Npc1(-/-) mouse serum and hepatocytes. In Npc1(-/-) hepatocytes, the incorporation of [3H]oleic acid and [3H]acetate into TG was decreased, but shunting of oleic acid- or acetate-derived [3H]carbons into cholesterol was increased. Inhibition of cholesterol synthesis normalized TG synthesis, content, and secretion in Npc1(-/-) hepatocytes, suggesting increased hepatic cholesterol neogenesis as a cause for the reduced TG content and secretion. We found a significant association between serum TG levels and 5 common NPC1 single-nucleotide polymorphisms in a cohort of 1053 men, with the lowest P=8.7 x 10(-4) for the single-nucleotide polymorphism rs1429934. The association between the rs1429934 A allele and higher TG levels was replicated in 2 additional cohorts, which included 8041 individuals. CONCLUSIONS This study provides evidence of the following: (1) in mice, loss of NPC1 function reduces hepatocyte TG content and secretion by increasing the metabolic flux of carbons into cholesterol synthesis; and (2) common variation in NPC1 contributes to serum TG levels in humans.
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Peake KB, Vance JE. Defective cholesterol trafficking in Niemann-Pick C-deficient cells. FEBS Lett 2010; 584:2731-9. [PMID: 20416299 DOI: 10.1016/j.febslet.2010.04.047] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2010] [Revised: 04/15/2010] [Accepted: 04/16/2010] [Indexed: 11/29/2022]
Abstract
Pathways of intracellular cholesterol trafficking are poorly understood at the molecular level. Mutations in Niemann-Pick C (NPC) proteins, NPC1 and NPC2, however, have led to insights into the mechanism by which endocytosed cholesterol is exported from late endosomes/lysosomes (LE/L). Mutations in NPC1, a multi-spanning membrane protein of LE/L, or mutations in NPC2, a soluble luminal protein of LE/L, cause the neurodegenerative disorder NPC disease. This review focuses on data supporting a model in which movement of cholesterol out of LE/L is mediated by the sequential action of the two NPC proteins. We also discuss potential therapies for NPC disease, including evidence that treatment of NPC-deficient mice with the cholesterol-binding compound, cyclodextrin, markedly attenuates neurodegeneration, and increases life-span, of NPC1-deficient mice.
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Affiliation(s)
- Kyle B Peake
- Group on the Molecular and Cell Biology of Lipids, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
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25
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Rutledge AC, Su Q, Adeli K. Apolipoprotein B100 biogenesis: a complex array of intracellular mechanisms regulating folding, stability, and lipoprotein assemblyThis paper is one of a selection of papers published in this special issue entitled “Canadian Society of Biochemistry, Molecular & Cellular Biology 52nd Annual Meeting — Protein Folding: Principles and Diseases” and has undergone the Journal's usual peer review process. Biochem Cell Biol 2010; 88:251-67. [DOI: 10.1139/o09-168] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Apolipoprotein B100 (apoB) is a large amphipathic lipid-binding protein that is synthesized by hepatocytes and used to assemble and stabilize very low density lipoproteins (VLDL). It may have been derived through evolution from other lipid-associating proteins such as microsomal triglyceride transfer protein or vitellogenin. The correct folding of apoB requires assistance from chaperone proteins in co-translational lipidation, disulfide bond formation, and glycosylation. Any impairment in these processes results in co-translational targeting of the misfolded apoB molecule for proteasomal degradation. In fact, most of the regulation of apoB production is mediated by intracellular degradation. ApoB that misfolds post-translationally, perhaps as a result of oxidative stress, may be eliminated through autophagy. This review focuses on the proposed pentapartite domain structure of apoB, the role that each domain plays in the binding of lipid species and regulation of apoB synthesis, and the process of VLDL assembly. The factors involved in the recognition, ubiquitination, and proteasomal delivery of defective apoB molecules are also discussed.
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Affiliation(s)
- Angela C. Rutledge
- Molecular Structure and Function Program, Research Institute, The Hospital for Sick Children, Room 3652, 555 University Ave., Toronto, ON M5G 1X8, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Medical Sciences Building, Room 6243, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | - Qiaozhu Su
- Molecular Structure and Function Program, Research Institute, The Hospital for Sick Children, Room 3652, 555 University Ave., Toronto, ON M5G 1X8, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Medical Sciences Building, Room 6243, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | - Khosrow Adeli
- Molecular Structure and Function Program, Research Institute, The Hospital for Sick Children, Room 3652, 555 University Ave., Toronto, ON M5G 1X8, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Medical Sciences Building, Room 6243, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
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26
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Garver WS, Jelinek D, Meaney FJ, Flynn J, Pettit KM, Shepherd G, Heidenreich RA, Vockley CMW, Castro G, Francis GA. The National Niemann-Pick Type C1 Disease Database: correlation of lipid profiles, mutations, and biochemical phenotypes. J Lipid Res 2010; 51:406-15. [PMID: 19744920 PMCID: PMC2803243 DOI: 10.1194/jlr.p000331] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2009] [Revised: 09/09/2009] [Indexed: 12/17/2022] Open
Abstract
Niemann-Pick type C1 disease (NPC1) is an autosomal recessive lysosomal storage disorder characterized by neonatal jaundice, hepatosplenomegaly, and progressive neurodegeneration. The present study provides the lipid profiles, mutations, and corresponding associations with the biochemical phenotype obtained from NPC1 patients who participated in the National NPC1 Disease Database. Lipid profiles were obtained from 34 patients (39%) in the survey and demonstrated significantly reduced plasma LDL cholesterol (LDL-C) and increased plasma triglycerides in the majority of patients. Reduced plasma HDL cholesterol (HDL-C) was the most consistent lipoprotein abnormality found in male and female NPC1 patients across age groups and occurred independent of changes in plasma triglycerides. A subset of 19 patients for whom the biochemical severity of known NPC1 mutations could be correlated with their lipid profile showed a strong inverse correlation between plasma HDL-C and severity of the biochemical phenotype. Gene mutations were available for 52 patients (59%) in the survey, including 52 different mutations and five novel mutations (Y628C, P887L, I923V, A1151T, and 3741_3744delACTC). Together, these findings provide novel information regarding the plasma lipoprotein changes and mutations in NPC1 disease, and suggest plasma HDL-C represents a potential biomarker of NPC1 disease severity.
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Affiliation(s)
- William S. Garver
- Department of Pediatrics, University of Arizona, 1501 N. Campbell Avenue, Tucson, AZ 85724-5037
| | - David Jelinek
- Department of Pediatrics, University of Arizona, 1501 N. Campbell Avenue, Tucson, AZ 85724-5037
| | - F. John Meaney
- Department of Pediatrics, University of Arizona, 1501 N. Campbell Avenue, Tucson, AZ 85724-5037
| | - James Flynn
- Department of Pediatrics, University of Arizona, 1501 N. Campbell Avenue, Tucson, AZ 85724-5037
| | - Kathleen M. Pettit
- Department of Pediatrics, University of Arizona, 1501 N. Campbell Avenue, Tucson, AZ 85724-5037
| | - Glen Shepherd
- Ara Parseghian Medical Research Foundation, 3530 E. Campo Abierto, Suite 105, Tucson, AZ 85718-3327
| | - Randall A. Heidenreich
- Department of Pediatrics, University of New Mexico, 1 University of New Mexico, Albuquerque, NM 87131-0001
| | - Cate M. Walsh Vockley
- National Niemann-Pick Disease Foundation and Medical Genetics, Children's Hospital of Pittsburgh, 45th StreetPenn Avenue, Pittsburgh, PA 15201
| | - Graciela Castro
- Department of Medicine, University of British Columbia James Hogg Research Centre, St. Paul's Hospital, 1081 Burrard Street, Vancouver, British Columbia, Canada V6Z 1Y6
| | - Gordon A. Francis
- Department of Medicine, University of British Columbia James Hogg Research Centre, St. Paul's Hospital, 1081 Burrard Street, Vancouver, British Columbia, Canada V6Z 1Y6
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27
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Walkley SU, Vanier MT. Secondary lipid accumulation in lysosomal disease. BIOCHIMICA ET BIOPHYSICA ACTA 2009; 1793:726-36. [PMID: 19111580 PMCID: PMC4382014 DOI: 10.1016/j.bbamcr.2008.11.014] [Citation(s) in RCA: 159] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2008] [Revised: 11/11/2008] [Accepted: 11/28/2008] [Indexed: 01/22/2023]
Abstract
Lysosomal diseases are inherited metabolic disorders caused by defects in a wide spectrum of lysosomal and a few non-lysosomal proteins. In most cases a single type of primary storage material is identified, which has been used to name and classify the disorders: hence the terms sphingolipidoses, gangliosidoses, mucopolysaccharidoses, glycoproteinoses, and so forth. In addition to this primary storage, however, a host of secondary storage products can also be identified, more often than not having no direct link to the primary protein defect. Lipids - glycosphingolipids and phospholipids, as well as cholesterol - are the most ubiquitous and best studied of these secondary storage materials. While in the past typically considered nonspecific and nonconsequential features of these diseases, newer studies suggest direct links between secondary storage and disease pathogenesis and support the view that understanding all aspects of this sequestration process will provide important insights into the cell biology and treatment of lysosomal disease.
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Affiliation(s)
- Steven U Walkley
- Dominick P. Purpura Department of Neuroscience, Rose F. Kennedy Center, Albert Einstein College of Medicine, 1410 Pelham Parkway South, Bronx, NY, USA.
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28
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Karten B, Peake KB, Vance JE. Mechanisms and consequences of impaired lipid trafficking in Niemann-Pick type C1-deficient mammalian cells. Biochim Biophys Acta Mol Cell Biol Lipids 2009; 1791:659-70. [PMID: 19416638 DOI: 10.1016/j.bbalip.2009.01.025] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2008] [Accepted: 01/20/2009] [Indexed: 11/18/2022]
Abstract
Niemann-Pick C disease is a fatal progressive neurodegenerative disorder caused in 95% of cases by mutations in the NPC1 gene; the remaining 5% of cases result from mutations in the NPC2 gene. The major biochemical manifestation of NPC1 deficiency is an abnormal sequestration of lipids, including cholesterol and glycosphingolipids, in late endosomes/lysosomes (LE/L) of all cells. In this review, we summarize the current knowledge of the NPC1 protein in mammalian cells with particular focus on how defects in NPC1 alter lipid trafficking and neuronal functions. NPC1 is a protein of LE/L and is predicted to contain thirteen transmembrane domains, five of which constitute a sterol-sensing domain. The precise function of NPC1, and the mechanism by which NPC1 and NPC2 (both cholesterol binding proteins) act together to promote the movement of cholesterol and other lipids out of the LE/L, have not yet been established. Recent evidence suggests that the sequestration of cholesterol in LE/L of cells of the brain (neurons and glial cells) contributes to the widespread death and dysfunction of neurons in the brain. Potential therapies include treatments that promote the removal of cholesterol and glycosphingolipids from LE/L. Currently, the most promising approach for extending life-span and improving the quality of life for NPC patients is a combination of several treatments each of which individually modestly slows disease progression.
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Affiliation(s)
- Barbara Karten
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada
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29
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Kristiana I, Yang H, Brown AJ. Different kinetics of cholesterol delivery to components of the cholesterol homeostatic machinery: implications for cholesterol trafficking to the endoplasmic reticulum. Biochim Biophys Acta Mol Cell Biol Lipids 2008; 1781:724-30. [PMID: 18838129 DOI: 10.1016/j.bbalip.2008.08.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2008] [Revised: 08/18/2008] [Accepted: 08/29/2008] [Indexed: 11/17/2022]
Abstract
Previously, using an oxysterol to induce cholesterol trafficking to the Endoplasmic Reticulum (ER), we reported a dissociation between cholesterol transport to two important cholesterol regulatory components in the ER: the cholesterol esterifying enzyme ACAT (Acyl CoA:Cholesterol Acyltransferase) and the membrane-bound transcription factor SREBP (Sterol Regulatory Element Binding Protein) (X. Du, Y.H. Pham and A.J. Brown, Effects of 25-hydroxycholesterol on cholesterol esterification and SREBP processing are dissociable: implications for cholesterol movement to the regulatory pool in the endoplasmic reticulum, J. Biol Chem. 279 (2004) 47010-47016). Here, we employed low-density lipoprotein (LDL) as a more physiologically-relevant mode of cholesterol delivery, and compared cholesterol transport to ACAT (determined by esterification) and SREBP (assessed by processing) in mutant Chinese Hamster Ovary cells that have cholesterol-trafficking defects (including Niemann-Pick type C). We showed clear differences in kinetics between the two, with impaired cholesterol trafficking to SREBP being resolved more rapidly than to ACAT. This is unlikely to be due to a reduced threshold of cholesterol sensed by the SREBP system relative to ACAT, since both responded to LDL-derived cholesterol within 2 h whereas the divergence observed between the two was prolonged (>20 h). Furthermore, ACAT inhibition did not expand the ER regulatory pool of cholesterol as judged by unaltered sensitivity of SREBP processing to LDL. Collectively, our data favor the contention that there are different cholesterol pools and/or transport pathways which feed ACAT and SREBP within the ER.
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Affiliation(s)
- Ika Kristiana
- BABS, School of Biotechnology and Biomolecular Sciences, Biosciences Building D26, University of New South Wales, Sydney, 2052, Australia
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30
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Abstract
PURPOSE OF REVIEW This review summarizes the role of phosphatidylcholine metabolism in plasma lipoprotein homeostasis. RECENT FINDINGS While it was previously known that phosphatidylcholine biosynthesis was required for normal hepatic VLDL secretion, recent studies have shown that both phosphatidylcholine biosynthetic pathways (the cytidine 5'-diphosphocholine and the phosphatidylethanolamine methylation pathways) are required. In addition, a requirement of acyl-coenzyme A synthetase 3, but not acyl-coenzyme A synthetase 1 or 4, for phosphatidylcholine synthesis and VLDL secretion is now documented. ABCA1 has been implicated in the transfer of phosphatidylcholine to apolipoproteinA-1 both during and after secretion of apolipoproteinA-1. Other studies have introduced the concept of reverse phosphatidylcholine transport in which both HDL and LDL supply phosphatidylcholine to the liver. An unexpected finding is that half of the phosphatidylcholine delivered to liver from lipoproteins is converted into triacylglycerol. SUMMARY The liver is both a donor of phosphatidylcholine during the assembly and secretion of lipoproteins as well as a recipient of phosphatidylcholine from plasma lipoproteins.
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Affiliation(s)
- Dennis E Vance
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada.
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31
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Bibliography. Current world literature. Lipid metabolism. Curr Opin Lipidol 2008; 19:314-21. [PMID: 18460925 DOI: 10.1097/mol.0b013e328303e27e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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32
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Rimkunas VM, Graham MJ, Crooke RM, Liscum L. In vivo antisense oligonucleotide reduction of NPC1 expression as a novel mouse model for Niemann Pick type C- associated liver disease. Hepatology 2008; 47:1504-12. [PMID: 18438776 PMCID: PMC2440313 DOI: 10.1002/hep.22327] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
UNLABELLED Niemann-Pick type C (NPC) is a fatal autosomal recessive lipidosis that is characterized by lysosomal storage of cholesterol and glycosphingolipids. Patients exhibit prolonged neonatal jaundice, hepatosplenomegaly, and progressive neurodegeneration that generally result in death by the teen years. Most clinical cases are caused by mutations in the NPC1 gene. Current mouse models of NPC are not well suited for studying the liver disease due to the rapidly progressing neurological disease. To facilitate study of NPC-associated liver dysfunction, we have developed a novel mouse model using antisense oligonucleotides to ablate NPC1 expression primarily in the liver. Here, we show that the NPC1 knockdown leads to a liver disease phenotype similar to that of patients with NPC and the NPC(nih) mouse model. Key features include hepatomegaly, lipid storage, elevated serum liver enzymes, and increased apoptosis. CONCLUSION This novel NPC1 antisense mouse model will allow delineation of the mechanism by which NPC1 dysfunction leads to liver cell death.
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Affiliation(s)
| | - Mark J. Graham
- Cardiovascular Disease Antisense Drug Discovery, Isis Pharmaceuticals Inc., Carlsbad, CA
| | - Rosanne M. Crooke
- Cardiovascular Disease Antisense Drug Discovery, Isis Pharmaceuticals Inc., Carlsbad, CA
| | - Laura Liscum
- Department of Physiology, Tufts University School of Medicine, Boston, MA
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Abstract
Cholesterol is an essential structural component in the cell membranes of most vertebrates. The biophysical properties of cholesterol and the enzymology of cholesterol metabolism provide the basis for how cells handle cholesterol and exchange it with one another. A tightly controlled--but only partially characterized--network of cellular signalling and lipid transfer systems orchestrates the functional compartmentalization of this lipid within and between organellar membranes. This largely dictates the exchange of cholesterol between tissues at the whole body level. Increased understanding of these processes and their integration at the organ systems level provides fundamental insights into the physiology of cholesterol trafficking.
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Affiliation(s)
- Elina Ikonen
- Institute of Biomedicine/Anatomy, University of Helsinki, Haartmaninkatu 8, University of Helsinki, Helsinki FI-00014, Finland.
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MacDonald MLE, Singaraja RR, Bissada N, Ruddle P, Watts R, Karasinska JM, Gibson WT, Fievet C, Vance JE, Staels B, Hayden MR. Absence of stearoyl-CoA desaturase-1 ameliorates features of the metabolic syndrome in LDLR-deficient mice. J Lipid Res 2007; 49:217-29. [PMID: 17960025 DOI: 10.1194/jlr.m700478-jlr200] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
A combination of the interrelated metabolic risk factors obesity, insulin resistance, dyslipidemia, and hypertension, often described as the "metabolic syndrome," is known to increase the risk of developing cardiovascular disease and diabetes. Stearoyl-coenzyme A desaturase (SCD) activity has been implicated in the metabolic syndrome, but detailed studies of the beneficial metabolic effects of SCD deficiency have been limited. Here, we show that absence of the Scd1 gene product reduces plasma triglycerides and reduces weight gain in severely hyperlipidemic low density lipoprotein receptor (LDLR)-deficient mice challenged with a Western diet. Absence of SCD1 also increases insulin sensitivity, as measured by intraperitoneal glucose and insulin tolerance testing. SCD1 deficiency dramatically reduces hepatic lipid accumulation while causing more modest reductions in plasma apolipoproteins, suggesting that in conditions of sustained hyperlipidemia, SCD1 functions primarily to mediate lipid stores. In addition, absence of SCD1 partially ameliorates the undesirable hypertriglyceridemic effect of antiatherogenic liver X receptor agonists. Our results demonstrate that constitutive reduction of SCD activity improves the metabolic phenotype of LDLR-deficient mice on a Western diet.
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Affiliation(s)
- Marcia L E MacDonald
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
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Wang MD, Franklin V, Sundaram M, Kiss RS, Ho K, Gallant M, Marcel YL. Differential Regulation of ATP Binding Cassette Protein A1 Expression and ApoA-I Lipidation by Niemann-Pick Type C1 in Murine Hepatocytes and Macrophages. J Biol Chem 2007; 282:22525-33. [PMID: 17553802 DOI: 10.1074/jbc.m700326200] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Niemann-Pick type C1 (Npc1) protein inactivation results in lipid accumulation in late endosomes and lysosomes, leading to a defect of ATP binding cassette protein A1 (Abca1)-mediated lipid efflux to apolipoprotein A-I (apoA-I) in macrophages and fibroblasts. However, the role of Npc1 in Abca1-mediated lipid efflux to apoA-I in hepatocytes, the major cells contributing to HDL formation, is still unknown. Here we show that, whereas lipid efflux to apoA-I in Npc1-null macrophages is impaired, the lipidation of endogenously synthesized apoA-I by low density lipoprotein-derived cholesterol or de novo synthesized cholesterol or phospholipids in Npc1-null hepatocytes is significantly increased by about 1-, 3-, and 8-fold, respectively. The increased cholesterol efflux reflects a major increase of Abca1 protein in Npc1-null hepatocytes, which contrasts with the decrease observed in Npc1-null macrophages. The increased Abca1 expression is largely post-transcriptional, because Abca1 mRNA is only slightly increased and Lxr alpha mRNA is not changed, and Lxr alpha target genes are reduced. This differs from the regulation of Abcg1 expression, which is up-regulated at both mRNA and protein levels in Npc1-null cells. Abca1 protein translation rate is higher in Npc1-null hepatocytes, compared with wild type hepatocytes as measured by [(35)S]methionine incorporation, whereas there is no difference for the degradation of newly synthesized Abca1 in these two types of hepatocytes. Cathepsin D, which we recently identified as a positive modulator of Abca1, is markedly increased at both mRNA and protein levels by Npc1 inactivation in hepatocytes but not in macrophages. Consistent with this, inhibition of cathepsin D with pepstatin A reduced the Abca1 protein level in both Npc1-inactivated and WT hepatocytes. Therefore, Abca1 expression is specifically regulated in hepatocytes, where Npc1 activity modulates cathepsin D expression and Abca1 protein translation rate.
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Affiliation(s)
- Ming-Dong Wang
- Lipoprotein and Atherosclerosis Research Group, University of Ottawa Heart Institute, Ottawa, Ontario K1Y 4W7, Canada
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