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Abstract
The lysosomal storage disorders are hereditary metabolic disorders characterized by autosomal recessive inheritance, mainly caused by deficiency of an enzyme responsible for the intra-lysosomal breakdown of various substrates and products of cellular metabolism. This chapter examines the underlying defects, clinical manifestations, and provides context for the expected clinical outcome of various available therapy options employing enzyme replacement therapy, hematopoietic stem cell transplantation, substrate reduction, and enzyme enhancement therapies.
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Affiliation(s)
- Gregory M Pastores
- Department of Medicine (Clinical Genetics), National Center for Inherited Metabolic Disorders, Mater Misericordiae University Hospital, Dublin, Ireland; Department of Medicine (Genetics), University College of Dublin School of Medicine, Dublin, Ireland.
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2
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A molecular genetics view on Mucopolysaccharidosis Type II. MUTATION RESEARCH. REVIEWS IN MUTATION RESEARCH 2021; 788:108392. [PMID: 34893157 DOI: 10.1016/j.mrrev.2021.108392] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 06/03/2021] [Accepted: 08/05/2021] [Indexed: 02/07/2023]
Abstract
Mucopolysaccharidosis Type II (MPS II) is an X-linked recessive genetic disorder that primarily affects male patients. With an incidence of 1 in 100,000 male live births, the disease is one of the orphan diseases. MPS II symptoms are caused by mutations in the lysosomal iduronate-2-sulfatase (IDS) gene. The mutations cause a loss of enzymatic performance and result in the accumulation of glycosaminoglycans (GAGs), heparan sulfate and dermatan sulfate, which are no longer degradable. This inadvertent accumulation causes damage in multiple organs and leads either to a severe neurological course or to an attenuated course of the disease, although the exact relationship between mutation, extent of GAG accumulation and disease progression is not yet fully understood. This review is intended to present current diagnostic procedures and therapeutic interventions. In times when the genetic profile of patients plays an increasingly important role in the assessment of therapeutic success and future drug design, we chose to further elucidate the impact of genetic diversity within the IDS gene on disease phenotype and potential implications in current diagnosis, prognosis and therapy. We report recent advances in the structural biological elucidation of I2S enzyme that that promises to improve our future understanding of the molecular damage of the hundreds of IDS gene variants and will aid damage prediction of novel mutations in the future.
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3
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Piceatannol reduces resistance to statins in hypercholesterolemia by reducing PCSK9 expression through p300 acetyltransferase inhibition. Pharmacol Res 2020; 161:105205. [DOI: 10.1016/j.phrs.2020.105205] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 09/04/2020] [Accepted: 09/11/2020] [Indexed: 01/06/2023]
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4
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Anglès F, Hutt DM, Balch WE. HDAC inhibitors rescue multiple disease-causing CFTR variants. Hum Mol Genet 2020; 28:1982-2000. [PMID: 30753450 DOI: 10.1093/hmg/ddz026] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 12/21/2018] [Accepted: 01/16/2019] [Indexed: 12/14/2022] Open
Abstract
Understanding the role of the epigenome in protein-misfolding diseases remains a challenge in light of genetic diversity found in the world-wide population revealed by human genome sequencing efforts and the highly variable response of the disease population to therapeutics. An ever-growing body of evidence has shown that histone deacetylase (HDAC) inhibitors (HDACi) can have significant benefit in correcting protein-misfolding diseases that occur in response to both familial and somatic mutation. Cystic fibrosis (CF) is a familial autosomal recessive disease, caused by genetic diversity in the CF transmembrane conductance regulator (CFTR) gene, a cyclic Adenosine MonoPhosphate (cAMP)-dependent chloride channel expressed at the apical plasma membrane of epithelial cells in multiple tissues. The potential utility of HDACi in correcting the phenylalanine 508 deletion (F508del) CFTR variant as well as the over 2000 CF-associated variants remains controversial. To address this concern, we examined the impact of US Food and Drug Administration-approved HDACi on the trafficking and function of a panel of CFTR variants. Our data reveal that panobinostat (LBH-589) and romidepsin (FK-228) provide functional correction of Class II and III CFTR variants, restoring cell surface chloride channel activity in primary human bronchial epithelial cells. We further demonstrate a synergistic effect of these HDACi with Vx809, which can significantly restore channel activity for multiple CFTR variants. These data suggest that HDACi can serve to level the cellular playing field for correcting CF-causing mutations, a leveling effect that might also extend to other protein-misfolding diseases.
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Affiliation(s)
- Frédéric Anglès
- Department of Molecular Medicine, Scripps Research, North Torrey Pines Rd, La Jolla, CA, USA
| | - Darren M Hutt
- Department of Molecular Medicine, Scripps Research, North Torrey Pines Rd, La Jolla, CA, USA
| | - William E Balch
- Department of Molecular Medicine, Scripps Research, North Torrey Pines Rd, La Jolla, CA, USA.,Skaggs Institute of Chemical Biology, North Torrey Pines Rd, La Jolla, CA, USA
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5
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Bräuer AU, Kuhla A, Holzmann C, Wree A, Witt M. Current Challenges in Understanding the Cellular and Molecular Mechanisms in Niemann-Pick Disease Type C1. Int J Mol Sci 2019; 20:ijms20184392. [PMID: 31500175 PMCID: PMC6771135 DOI: 10.3390/ijms20184392] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 09/04/2019] [Accepted: 09/05/2019] [Indexed: 02/06/2023] Open
Abstract
Rare diseases are a heterogeneous group of very different clinical syndromes. Their most common causes are defects in the hereditary material, and they can therefore be passed on to descendants. Rare diseases become manifest in almost all organs and often have a systemic expressivity, i.e., they affect several organs simultaneously. An effective causal therapy is often not available and can only be developed when the underlying causes of the disease are understood. In this review, we focus on Niemann–Pick disease type C1 (NPC1), which is a rare lipid-storage disorder. Lipids, in particular phospholipids, are a major component of the cell membrane and play important roles in cellular functions, such as extracellular receptor signaling, intracellular second messengers and cellular pressure regulation. An excessive storage of fats, as seen in NPC1, can cause permanent damage to cells and tissues in the brain and peripheral nervous system, but also in other parts of the body. Here, we summarize the impact of NPC1 pathology on several organ systems, as revealed in experimental animal models and humans, and give an overview of current available treatment options.
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Affiliation(s)
- Anja U Bräuer
- Research Group Anatomy, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, D-26129 Oldenburg, Germany.
- Research Center for Neurosensory Science, Carl von Ossietzky University Oldenburg, D-26129 Oldenburg, Germany.
| | - Angela Kuhla
- Institute for Experimental Surgery, Rostock University Medical Center, Schillingallee 69a, 18057 Rostock, Germany.
- Center of Transdisciplinary Neuroscience Rostock, D-18147 Rostock, Germany.
| | - Carsten Holzmann
- Center of Transdisciplinary Neuroscience Rostock, D-18147 Rostock, Germany.
- Institute of Medical Genetics, Rostock University Medical Center, D-18057 Rostock, Germany.
| | - Andreas Wree
- Center of Transdisciplinary Neuroscience Rostock, D-18147 Rostock, Germany.
- Institute of Anatomy, Rostock University Medical Center, D-18057 Rostock, Germany.
| | - Martin Witt
- Center of Transdisciplinary Neuroscience Rostock, D-18147 Rostock, Germany.
- Institute of Anatomy, Rostock University Medical Center, D-18057 Rostock, Germany.
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6
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Hassan S, Sidransky E, Tayebi N. The role of epigenetics in lysosomal storage disorders: Uncharted territory. Mol Genet Metab 2017; 122:10-18. [PMID: 28918065 DOI: 10.1016/j.ymgme.2017.07.012] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 07/30/2017] [Accepted: 07/31/2017] [Indexed: 12/18/2022]
Abstract
The study of the contribution of epigenetic mechanisms, including DNA methylation, histone modifications, and microRNAs, to human disease has enhanced our understanding of different cellular processes and diseased states, as well as the effect of environmental factors on phenotypic outcomes. Epigenetic studies may be particularly relevant in evaluating the clinical heterogeneity observed in monogenic disorders. The lysosomal storage disorders are Mendelian disorders characterized by a wide spectrum of associated phenotypes, ranging from neonatal presentations to symptoms that develop in late adulthood. Some lack a tight genotype/phenotype correlation. While epigenetics may explain some of the discordant phenotypes encountered in patients with the same lysosomal storage disorder, especially among patients sharing the same genotype, to date, few studies have focused on these mechanisms. We review three common epigenetic mechanisms, DNA methylation, histone modifications, and microRNAs, and highlight their applications to phenotypic variation and therapeutics. Three specific lysosomal storage diseases, Gaucher disease, Fabry disease, and Niemann-Pick type C disease are presented as prototypical disorders with vast clinical heterogeneity that may be impacted by epigenetics. Our goal is to motivate researchers to consider epigenetics as a mechanism to explain the complexities of biological functions and pathologies of these rare disorders.
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Affiliation(s)
- Shahzeb Hassan
- Medical Genetics Branch, NHGRI, NIH, Bethesda, MD, United States
| | - Ellen Sidransky
- Medical Genetics Branch, NHGRI, NIH, Bethesda, MD, United States.
| | - Nahid Tayebi
- Medical Genetics Branch, NHGRI, NIH, Bethesda, MD, United States
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7
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Sung EA, Yu KR, Shin JH, Seo Y, Kim HS, Koog MG, Kang I, Kim JJ, Lee BC, Shin TH, Lee JY, Lee S, Kang TW, Choi SW, Kang KS. Generation of patient specific human neural stem cells from Niemann-Pick disease type C patient-derived fibroblasts. Oncotarget 2017; 8:85428-85441. [PMID: 29156730 PMCID: PMC5689620 DOI: 10.18632/oncotarget.19976] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 07/18/2017] [Indexed: 12/13/2022] Open
Abstract
Niemann-Pick disease type C (NPC) is a neurodegenerative and lysosomal lipid storage disorder, characterized by the abnormal accumulation of unesterified cholesterol and glycolipids, which is caused by mutations in the NPC1 genes. Here, we report the generation of human induced neural stem cells from NPC patient-derived fibroblasts (NPC-iNSCs) using only two reprogramming factors SOX2 and HMGA2 without going through the pluripotent state. NPC-iNSCs were stably expandable and differentiated into neurons, astrocytes, and oligodendrocytes. However, NPC-iNSCs displayed defects in self-renewal and neuronal differentiation accompanied by cholesterol accumulation, suggesting that NPC-iNSCs retain the main features of NPC. This study revealed that the cholesterol accumulation and the impairments in self-renewal and neuronal differentiation in NPC-iNSCs were significantly improved by valproic acid. Additionally, we demonstrated that the inhibition of cholesterol transportation by U18666A in WT-iNSCs mimicked the impaired self-renewal and neuronal differentiation of NPC-iNSCs, indicating that the regulation of cholesterol homeostasis is a crucial determinant for the neurodegenerative features of NPC. Taken together, these findings suggest that NPC-iNSCs can serve as an unlimited source of neural cells for pathological study or drug screening in a patient specific manner. Furthermore, this direct conversion technology might be extensively applicable for other human neurodegenerative diseases.
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Affiliation(s)
- Eun-Ah Sung
- Adult Stem Cell Research Center, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea.,Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea
| | - Kyung-Rok Yu
- Adult Stem Cell Research Center, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea.,Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea.,Current/Present address: Hematology Branch, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ji-Hee Shin
- Adult Stem Cell Research Center, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea.,Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea
| | - Yoojin Seo
- Adult Stem Cell Research Center, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea.,Current/Present address: Biomedical Research Institute, Pusan National University Hospital, Busan 49241, Republic of Korea.,Current/Present address: Pusan National University School of Medicine, Busan 49241, Republic of Korea
| | - Hyung-Sik Kim
- Adult Stem Cell Research Center, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea.,Current/Present address: Biomedical Research Institute, Pusan National University Hospital, Busan 49241, Republic of Korea.,Current/Present address: Pusan National University School of Medicine, Busan 49241, Republic of Korea
| | - Myung Guen Koog
- Adult Stem Cell Research Center, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea.,Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea
| | - Insung Kang
- Adult Stem Cell Research Center, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea.,Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea
| | - Jae-Jun Kim
- Adult Stem Cell Research Center, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea.,Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea
| | - Byung-Chul Lee
- Adult Stem Cell Research Center, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea.,Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea
| | - Tae-Hoon Shin
- Adult Stem Cell Research Center, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea.,Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea
| | - Jin Young Lee
- Adult Stem Cell Research Center, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea.,Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea
| | - Seunghee Lee
- Adult Stem Cell Research Center, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea.,Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea.,Institute for Stem Cell and Regenerative Medicine in Kangstem Biotech, Biomedical Science Building, Seoul National University, Seoul 08826, Republic of Korea
| | - Tae-Wook Kang
- Adult Stem Cell Research Center, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea.,Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea.,Institute for Stem Cell and Regenerative Medicine in Kangstem Biotech, Biomedical Science Building, Seoul National University, Seoul 08826, Republic of Korea
| | - Soon Won Choi
- Adult Stem Cell Research Center, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea.,Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea
| | - Kyung-Sun Kang
- Adult Stem Cell Research Center, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea.,Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea
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8
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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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9
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Ordoñez MP, Steele JW. Modeling Niemann Pick type C1 using human embryonic and induced pluripotent stem cells. Brain Res 2017; 1656:63-67. [PMID: 26972536 PMCID: PMC5018240 DOI: 10.1016/j.brainres.2016.03.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 03/02/2016] [Accepted: 03/07/2016] [Indexed: 11/16/2022]
Abstract
Data generated in Niemann Pick type C1 (NPC1) human embryonic and human induced pluripotent stem cell derived neurons complement on-going studies in animal models and provide the first example, in disease-relevant human cells, of processes that underlie preferential neuronal defects in a NPC1. Our work and that of other investigators in human neurons derived from stem cells highlight the importance of performing rigorous mechanistic studies in relevant cell types to guide drug discovery and therapeutic development, alongside of existing animal models. Through the use of human stem cell-derived models of disease, we can identify and discover or repurpose drugs that revert early events that lead to neuronal failure in NPC1. Together with the study of disease pathogenesis and efficacy of therapies in animal models, these strategies will fulfill the promise of stem cell technology in the development of new treatments for human diseases. This article is part of a Special Issue entitled SI: Exploiting human neurons.
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Affiliation(s)
- M Paulina Ordoñez
- Sanford Consortium for Regenerative Medicine, University of California, San Diego, La Jolla, CA 92037, United States; Department of Pediatric Gastroenterology, Hepatology, and Nutrition, University of California, San Diego, La Jolla, CA 92037, United States.
| | - John W Steele
- Sanford Consortium for Regenerative Medicine, University of California, San Diego, La Jolla, CA 92037, United States
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10
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Newton J, Hait NC, Maceyka M, Colaco A, Maczis M, Wassif CA, Cougnoux A, Porter FD, Milstien S, Platt N, Platt FM, Spiegel S. FTY720/fingolimod increases NPC1 and NPC2 expression and reduces cholesterol and sphingolipid accumulation in Niemann-Pick type C mutant fibroblasts. FASEB J 2017; 31:1719-1730. [PMID: 28082351 DOI: 10.1096/fj.201601041r] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 01/03/2017] [Indexed: 11/11/2022]
Abstract
Niemann-Pick type C (NPC) disease is a fatal neurodegenerative disorder caused by mutations in NPC1 or NPC2 with decreased functions leading to lysosomal accumulation of cholesterol and sphingolipids. FTY720/fingolimod, used for treatment of multiple sclerosis, is phosphorylated by nuclear sphingosine kinase 2, and its active phosphorylated form (FTY720-P) is an inhibitor of class I histone deacetylases. In this study, administration of clinically relevant doses of FTY720 to mice increased expression of NPC1 and -2 in brain and liver and decreased cholesterol in an SphK2-dependent manner. FTY720 greatly increased expression of NPC1 and -2 in human NPC1 mutant fibroblasts that correlated with formation of FTY720-P and significantly reduced the accumulation of cholesterol and glycosphingolipids. In agreement with this finding, FTY720 pretreatment of human NPC1 mutant fibroblasts restored transport of the cholera toxin B subunit, which binds ganglioside GM1, to the Golgi apparatus. Together, these findings suggest that FTY720 administration can ameliorate cholesterol and sphingolipid storage and trafficking defects in NPC1 mutant fibroblasts. Because neurodegeneration is the main clinical feature of NPC disease, and FTY720 accumulates in the CNS and has several advantages over available histone deacetylase inhibitors now in clinical trials, our work provides a potential opportunity for treatment of this incurable disease.-Newton, J., Hait, N. C., Maceyka, M., Colaco, A., Maczis, M., Wassif, C. A., Cougnoux, A., Porter, F. D., Milstien, S., Platt, N., Platt, F. M., Spiegel, S. FTY720/fingolimod increases NPC1 and NPC2 expression and reduces cholesterol and sphingolipid accumulation in Niemann-Pick type C mutant fibroblasts.
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Affiliation(s)
- Jason Newton
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
| | - Nitai C Hait
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
| | - Michael Maceyka
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
| | - Alexandria Colaco
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom; and
| | - Melissa Maczis
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
| | - Christopher A Wassif
- Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
| | - Antony Cougnoux
- Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
| | - Forbes D Porter
- Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
| | - Sheldon Milstien
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
| | - Nicholas Platt
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom; and
| | - Frances M Platt
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom; and
| | - Sarah Spiegel
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA;
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11
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Neuronal gene repression in Niemann-Pick type C models is mediated by the c-Abl/HDAC2 signaling pathway. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2015; 1859:269-79. [PMID: 26603102 DOI: 10.1016/j.bbagrm.2015.11.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 11/05/2015] [Accepted: 11/17/2015] [Indexed: 12/26/2022]
Abstract
BACKGROUND Niemann-Pick type C (NPC) disease is a fatal neurodegenerative disorder characterized by the accumulation of free cholesterol in lysosomes. There are currently no effective FDA-approved treatments for NPC, although in the last years the inhibition of histone deacetylases (HDACs) has emerged as a potential treatment for this disease. However, the molecular mechanisms that deregulate HDAC activity in NPC disease are unknown. Previously our group had shown that the proapoptotic tyrosine kinase c-Abl signaling is activated in NPC neurons. Here, we demonstrate that c-Abl activity increases HDAC2 levels inducing neuronal gene repression of key synaptic genes in NPC models. RESULTS Our data show that: i) HDAC2 levels and activity are increased in NPC neuronal models and in Npc1(-/-) mice; ii) inhibition of c-Abl or c-Abl deficiency prevents the increase of HDAC2 protein levels and activity in NPC neuronal models; iii) c-Abl inhibition decreases the levels of HDAC2 tyrosine phosphorylation; iv) treatment with methyl-β-cyclodextrin and vitamin E decreases the activation of the c-Abl/HDAC2 pathway in NPC neurons; v) in vivo treatment with two c-Abl inhibitors prevents the increase of HDAC2 protein levels in the brain of Npc1(-/-) mice; and vi) c-Abl inhibition prevents HDAC2 recruitment to the promoter of neuronal genes, triggering an increase in their expression. CONCLUSION Our data show the involvement of the c-Abl/HDAC2 signaling pathway in the regulation of neuronal gene expression in NPC neuronal models. Thus, inhibition of c-Abl could be a pharmacological target for preventing the deleterious effects of increased HDAC2 levels in NPC disease.
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12
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Akt activation increases cellular cholesterol by promoting the proteasomal degradation of Niemann-Pick C1. Biochem J 2015; 471:243-53. [PMID: 26283546 DOI: 10.1042/bj20150602] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 08/17/2015] [Indexed: 11/17/2022]
Abstract
Null mutations of the Niemann-Pick type C1 (NPC1) gene cause NPC disease, a lysosomal storage disorder characterized by cholesterol accumulation in late endosomes (LE) and lysosomes (Ly). Nascent or mutated NPC1 is degraded through the ubiquitin-proteasome pathway, but how NPC1 degradation is regulated remains currently unknown. In the present study, we demonstrated a link between NPC1 degradation and the Akt (protein kinase B)/mTOR [mammalian (or mechanistic) target of rapamycin] signalling pathway in cervical cancer cell lines. We provided evidence that activated Akt/mTOR pathway increased NPC1 degradation by ∼50% in C33A cells when compared with SiHa or HeLa cells. NPC1 degradation in C33A cells was reversed when Akt/mTOR activation was blocked by specific inhibitors or when mTORC1 (mTOR complex 1) was disrupted by regulatory associated protein of mTOR (Raptor) knockdown. Importantly, inhibition of the Akt/mTOR pathway led to decreased NPC1 ubiquitination in C33A cells, pointing to a role of Akt/mTOR in the proteasomal degradation of NPC1. Moreover, we found that NPC1 depletion in several cancer cell lines inhibited cell proliferation and migration. Our results uncover Akt as a key regulator of NPC1 degradation and link NPC1 to cancer cell proliferation and migration.
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13
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Meaney S. Epigenetic regulation of cholesterol homeostasis. Front Genet 2014; 5:311. [PMID: 25309573 PMCID: PMC4174035 DOI: 10.3389/fgene.2014.00311] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 08/20/2014] [Indexed: 01/15/2023] Open
Abstract
Although best known as a risk factor for cardiovascular disease, cholesterol is a vital component of all mammalian cells. In addition to key structural roles, cholesterol is a vital biochemical precursor for numerous biologically important compounds including oxysterols and bile acids, as well as acting as an activator of critical morphogenic systems (e.g., the Hedgehog system). A variety of sophisticated regulatory mechanisms interact to coordinate the overall level of cholesterol in cells, tissues and the entire organism. Accumulating evidence indicates that in additional to the more “traditional” regulatory schemes, cholesterol homeostasis is also under the control of epigenetic mechanisms such as histone acetylation and DNA methylation. The available evidence supporting a role for these mechanisms in the control of cholesterol synthesis, elimination, transport and storage are the focus of this review.
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Affiliation(s)
- Steve Meaney
- School of Biological Sciences, College of Sciences and Health, Dublin Institute of Technology Dublin, Ireland ; Environmental Sustainability and Health Institute, Dublin Institute of Technology Dublin, Ireland
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14
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Spincemaille P, Cammue BP, Thevissen K. Sphingolipids and mitochondrial function, lessons learned from yeast. MICROBIAL CELL (GRAZ, AUSTRIA) 2014; 1:210-224. [PMID: 28357246 PMCID: PMC5349154 DOI: 10.15698/mic2014.07.156] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Accepted: 06/10/2014] [Indexed: 01/22/2023]
Abstract
Mitochondrial dysfunction is a hallmark of several neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease, but also of cancer, diabetes and rare diseases such as Wilson's disease (WD) and Niemann Pick type C1 (NPC). Mitochondrial dysfunction underlying human pathologies has often been associated with an aberrant cellular sphingolipid metabolism. Sphingolipids (SLs) are important membrane constituents that also act as signaling molecules. The yeast Saccharomyces cerevisiae has been pivotal in unraveling mammalian SL metabolism, mainly due to the high degree of conservation of SL metabolic pathways. In this review we will first provide a brief overview of the major differences in SL metabolism between yeast and mammalian cells and the use of SL biosynthetic inhibitors to elucidate the contribution of specific parts of the SL metabolic pathway in response to for instance stress. Next, we will discuss recent findings in yeast SL research concerning a crucial signaling role for SLs in orchestrating mitochondrial function, and translate these findings to relevant disease settings such as WD and NPC. In summary, recent research shows that S. cerevisiae is an invaluable model to investigate SLs as signaling molecules in modulating mitochondrial function, but can also be used as a tool to further enhance our current knowledge on SLs and mitochondria in mammalian cells.
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Affiliation(s)
- Pieter Spincemaille
- Centre of Microbial and Plant Genetics (CMPG), KU Leuven,
Kasteelpark Arenberg 20, 3001 Heverlee, Belgium
| | - Bruno P. Cammue
- Centre of Microbial and Plant Genetics (CMPG), KU Leuven,
Kasteelpark Arenberg 20, 3001 Heverlee, Belgium
- Department of Plant Systems Biology, VIB, Technologiepark 927, 9052,
Ghent, Belgium
| | - Karin Thevissen
- Centre of Microbial and Plant Genetics (CMPG), KU Leuven,
Kasteelpark Arenberg 20, 3001 Heverlee, Belgium
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Abstract
OPINION STATEMENT Ataxia can originate from many genetic defects, but also from nongenetic causes. To be able to provide treatment, the first step is to establish the right diagnosis. Once the cause of the ataxia is defined, some specific treatments may be available. For example, the nongenetic ataxias that arise from vitamin deficiencies can improve following treatment. In most cases, however, therapies do not cure the disease and are purely symptomatic. Physiotherapy and occupational therapy are effective in all type of ataxias and often remain the most efficient treatment option for these patients to maximize their quality of life.
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