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Zheng J, Chen L, Schwake M, Silverman RB, Krainc D. Design and Synthesis of Potent Quinazolines as Selective β-Glucocerebrosidase Modulators. J Med Chem 2016; 59:8508-20. [PMID: 27598312 DOI: 10.1021/acs.jmedchem.6b00930] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Gaucher's disease is a common genetic disease caused by mutations in the β-glucocerebrosidase (GBA1) gene that have been also linked to increased risk of Parkinson's disease and Lewy body dementia. Stabilization of misfolded mutant β-glucocerebrosidase (GCase) represents an important therapeutic strategy in synucleinopathies. Here we report a novel class of GCase quinazoline inhibitors, obtained in a high throughput screening, with moderate potency against wild-type GCase. Rational design and a SAR study of this class of compounds led to a new series of quinazoline derivatives with single-digit nanomolar potency. These compounds were shown to selectively stabilize GCase when compared to other lysosomal enzymes and to increase N370S mutant GCase protein concentration and activity in cell assays. To the best of our knowledge, these molecules are the most potent noniminosugar GCase modulators to date that may prove useful for future mechanistic studies and therapeutic approaches in Gaucher's and Parkinson's diseases.
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Affiliation(s)
- Jianbin Zheng
- Department of Neurology, Northwestern University Feinberg School of Medicine , Chicago, Illinois 60611, United States.,Department of Chemistry, Department of Molecular Biosciences, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, and Center for Developmental Therapeutics, Northwestern University , Evanston, Illinois 60208-3113, United States
| | - Long Chen
- Department of Neurology, Northwestern University Feinberg School of Medicine , Chicago, Illinois 60611, United States
| | - Michael Schwake
- Department of Neurology, Northwestern University Feinberg School of Medicine , Chicago, Illinois 60611, United States
| | - Richard B Silverman
- Department of Chemistry, Department of Molecular Biosciences, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, and Center for Developmental Therapeutics, Northwestern University , Evanston, Illinois 60208-3113, United States
| | - Dimitri Krainc
- Department of Neurology, Northwestern University Feinberg School of Medicine , Chicago, Illinois 60611, United States
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Van Rossum A, Holsopple M. Enzyme Replacement or Substrate Reduction? A Review of Gaucher Disease Treatment Options. Hosp Pharm 2016; 51:553-63. [PMID: 27559188 DOI: 10.1310/hpj5107-553] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND Gaucher disease is a rare lysosomal storage disease resulting from a deficiency or reduced activity in the acid β-glucocosidase enzyme. Only 1 treatment option was available for 15 years, but several new treatment options have come to market since 2003. OBJECTIVE The article will detail the pathophysiology and review current therapies in the literature for all 3 major clinical types of Gaucher disease, with a focus on considerations for selecting therapy in type 1 disease. METHODS Extracted and summarized applicable studies and reviews from Cochrane Review, ClinicalTrials.gov, CINAHL, IPA, and PubMed. RESULTS Enzyme replacement therapy is preferred for the management of Gaucher disease. Current literature does not favor any enzyme replacement product over another. However, velaglucerase alfa and taliglucerase alfa theoretically have a lower risk of immunogenicity reactions compared with imiglucerase. Alternative treatments for type 1 disease include substrate reduction therapy; however, these treatments require evaluation of patient-specific variables (eg, genotype evaluation, renal function) and consideration of adverse effect and dosing profiles. Evaluation of current literature found no substrate reduction therapy is preferred over another. There are no approved therapies for type 2 and type 3 disease, but enzyme replacement therapy may be used with limited efficacy for symptom management. CONCLUSION Enzyme replacement therapy is preferred for treating type 1 Gaucher disease and substrate replacement therapy may be considered in patients who do not tolerate or cannot receive enzyme replacement therapy.
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Coutinho MF, Santos JI, Alves S. Less Is More: Substrate Reduction Therapy for Lysosomal Storage Disorders. Int J Mol Sci 2016; 17:ijms17071065. [PMID: 27384562 PMCID: PMC4964441 DOI: 10.3390/ijms17071065] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 06/24/2016] [Accepted: 06/27/2016] [Indexed: 12/11/2022] Open
Abstract
Lysosomal storage diseases (LSDs) are a group of rare, life-threatening genetic disorders, usually caused by a dysfunction in one of the many enzymes responsible for intralysosomal digestion. Even though no cure is available for any LSD, a few treatment strategies do exist. Traditionally, efforts have been mainly targeting the functional loss of the enzyme, by injection of a recombinant formulation, in a process called enzyme replacement therapy (ERT), with no impact on neuropathology. This ineffectiveness, together with its high cost and lifelong dependence is amongst the main reasons why additional therapeutic approaches are being (and have to be) investigated: chaperone therapy; gene enhancement; gene therapy; and, alternatively, substrate reduction therapy (SRT), whose aim is to prevent storage not by correcting the original enzymatic defect but, instead, by decreasing the levels of biosynthesis of the accumulating substrate(s). Here we review the concept of substrate reduction, highlighting the major breakthroughs in the field and discussing the future of SRT, not only as a monotherapy but also, especially, as complementary approach for LSDs.
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Affiliation(s)
- Maria Francisca Coutinho
- Department of Human Genetics, Research and Development Unit, National Health Institute Doutor Ricardo Jorge, Rua Alexandre Herculano, 321 4000-055 Porto, Portugal.
| | - Juliana Inês Santos
- Department of Human Genetics, Research and Development Unit, National Health Institute Doutor Ricardo Jorge, Rua Alexandre Herculano, 321 4000-055 Porto, Portugal.
| | - Sandra Alves
- Department of Human Genetics, Research and Development Unit, National Health Institute Doutor Ricardo Jorge, Rua Alexandre Herculano, 321 4000-055 Porto, Portugal.
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Ward C, Martinez-Lopez N, Otten EG, Carroll B, Maetzel D, Singh R, Sarkar S, Korolchuk VI. Autophagy, lipophagy and lysosomal lipid storage disorders. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:269-84. [DOI: 10.1016/j.bbalip.2016.01.006] [Citation(s) in RCA: 165] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 01/07/2016] [Accepted: 01/12/2016] [Indexed: 12/30/2022]
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55
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Migdalska-Richards A, Schapira AHV. The relationship between glucocerebrosidase mutations and Parkinson disease. J Neurochem 2016; 139 Suppl 1:77-90. [PMID: 26860875 PMCID: PMC5111601 DOI: 10.1111/jnc.13385] [Citation(s) in RCA: 144] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 09/08/2015] [Accepted: 10/02/2015] [Indexed: 01/12/2023]
Abstract
Parkinson disease (PD) is the second most common neurodegenerative disorder after Alzheimer disease, whereas Gaucher disease (GD) is the most frequent lysosomal storage disorder caused by homozygous mutations in the glucocerebrosidase (GBA1) gene. Increased risk of developing PD has been observed in both GD patients and carriers. It has been estimated that GBA1 mutations confer a 20‐ to 30‐fold increased risk for the development of PD, and that at least 7–10% of PD patients have a GBA1 mutation. To date, mutations in the GBA1 gene constitute numerically the most important risk factor for PD. The type of PD associated with GBA1 mutations (PD‐GBA1) is almost identical to idiopathic PD, except for a slightly younger age of onset and a tendency to more cognitive impairment. Importantly, the pathology of PD‐GBA1 is identical to idiopathic PD, with nigral dopamine cell loss, Lewy bodies, and neurites containing alpha‐synuclein. The mechanism by which GBA1 mutations increase the risk for PD is still unknown. However, given that clinical manifestation and pathological findings in PD‐GBA1 patients are almost identical to those in idiopathic PD individuals, it is likely that, as in idiopathic PD, alpha‐synuclein accumulation, mitochondrial dysfunction, autophagic impairment, oxidative and endoplasmic reticulum stress may contribute to the development and progression of PD‐GBA1. Here, we review the GBA1 gene, its role in GD, and its link with PD.
The impact of glucocerebrosidase 1 (GBA1) mutations on functioning of endoplasmic reticulum (ER), lysosomes, and mitochondria. GBA1 mutations resulting in production of misfolded glucocerebrosidase (GCase) significantly affect the ER functioning. Misfolded GCase trapped in the ER leads to both an increase in the ubiquitin–proteasome system (UPS) and the ER stress. The presence of ER stress triggers the unfolded protein response (UPR) and/or endoplasmic reticulum‐associated degradation (ERAD). The prolonged activation of UPR and ERAD subsequently leads to increased apoptosis. The presence of misfolded GCase in the lysosomes together with a reduction in wild‐type GCase levels lead to a retardation of alpha‐synuclein degradation via chaperone‐mediated autophagy (CMA), which subsequently results in alpha‐synuclein accumulation and aggregation. Impaired lysosomal functioning also causes a decrease in the clearance of autophagosomes, and so their accumulation. GBA1 mutations perturb normal mitochondria functioning by increasing generation of free radical species (ROS) and decreasing adenosine triphosphate (ATP) production, oxygen consumption, and membrane potential. GBA1 mutations also lead to accumulation of dysfunctional and fragmented mitochondria.
This article is part of a special issue on Parkinson disease.
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56
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Boutin M, Sun Y, Shacka JJ, Auray-Blais C. Tandem Mass Spectrometry Multiplex Analysis of Glucosylceramide and Galactosylceramide Isoforms in Brain Tissues at Different Stages of Parkinson Disease. Anal Chem 2016; 88:1856-63. [PMID: 26735924 DOI: 10.1021/acs.analchem.5b04227] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Previous studies demonstrated that Parkinson disease (PD) is associated with a decreased activity of the glucocerebrosidase (GCase) enzyme in brain tissues. The objective of this study was to determine if GCase deficiency is associated with the accumulation of its glucosylceramide (GluCer) substrate in PD brain tissues. An ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed, optimized, and validated for the multiplex analysis of GluCer isoforms (C18:0, C20:0, C22:0, C24:1, and C24:0) in brain tissue samples. These molecules were chromatographically separated from their isobaric galactosylceramide (GalCer) counterparts using normal phase chromatography. The analysis was performed by tandem mass spectrometry in the multiple reaction monitoring (MRM) acquisition mode. Limits of detection ranging from 0.4 to 1.1 nmol/g brain tissue were established for the different GluCer isoforms analyzed. For the first time, GluCer isoform levels were analyzed in temporal cortex brain tissue samples from 26 PD patients who were divided into three PD disease stages (IIa, III, and IV) according to the Unified Staging System for Lewy Body Disorders. These specimens were compared with brain tissue samples from 12 controls and 6 patients with Incidental Lewy Body Disease. No significant GluCer concentration differences were observed between the 5 sample groups. The GluCer isoform levels were also normalized with their matching GalCer isoforms. The normalized results showed a trend for GluCer levels which increased with PD severity. However, the differences observed between the groups were not significant, owing likely to the high standard deviations measured.
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Affiliation(s)
- Michel Boutin
- Division of Medical Genetics, Department of Pediatrics, Centre de Recherche-CHUS, Faculty of Medicine and Health Sciences, Université de Sherbrooke , 3001, 12th Avenue North, Sherbrooke, Quebec, Canada , J1H 5N4
| | - Ying Sun
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center , R Building Room1401, 3333 Burnet Avenue, Cincinnati, Ohio 45229, United States
| | - John J Shacka
- Department of Pathology, Molecular and Cellular Pathology Division, University of Alabama at Birmingham , 1670 University Boulevard, VH G019H, Birmingham, Alabama 35294, United States.,Birmingham VA Medical Center , Birmingham, Alabama 35233, United States
| | - Christiane Auray-Blais
- Division of Medical Genetics, Department of Pediatrics, Centre de Recherche-CHUS, Faculty of Medicine and Health Sciences, Université de Sherbrooke , 3001, 12th Avenue North, Sherbrooke, Quebec, Canada , J1H 5N4
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Bosch ME, Kielian T. Neuroinflammatory paradigms in lysosomal storage diseases. Front Neurosci 2015; 9:417. [PMID: 26578874 PMCID: PMC4627351 DOI: 10.3389/fnins.2015.00417] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 10/15/2015] [Indexed: 01/02/2023] Open
Abstract
Lysosomal storage diseases (LSDs) include approximately 70 distinct disorders that collectively account for 14% of all inherited metabolic diseases. LSDs are caused by mutations in various enzymes/proteins that disrupt lysosomal function, which impairs macromolecule degradation following endosome-lysosome and phagosome-lysosome fusion and autophagy, ultimately disrupting cellular homeostasis. LSDs are pathologically typified by lysosomal inclusions composed of a heterogeneous mixture of various proteins and lipids that can be found throughout the body. However, in many cases the CNS is dramatically affected, which may result from heightened neuronal vulnerability based on their post-mitotic state. Besides intrinsic neuronal defects, another emerging factor common to many LSDs is neuroinflammation, which may negatively impact neuronal survival and contribute to neurodegeneration. Microglial and astrocyte activation is a hallmark of many LSDs that affect the CNS, which often precedes and predicts regions where eventual neuron loss will occur. However, the timing, intensity, and duration of neuroinflammation may ultimately dictate the impact on CNS homeostasis. For example, a transient inflammatory response following CNS insult/injury can be neuroprotective, as glial cells attempt to remove the insult and provide trophic support to neurons. However, chronic inflammation, as seen in several LSDs, can promote neurodegeneration by creating a neurotoxic environment due to elevated levels of cytokines, chemokines, and pro-apoptotic molecules. Although neuroinflammation has been reported in several LSDs, the cellular basis and mechanisms responsible for eliciting neuroinflammatory pathways are just beginning to be defined. This review highlights the role of neuroinflammation in select LSDs and its potential contribution to neuron loss.
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Affiliation(s)
- Megan E. Bosch
- Departments of Pharmacology and Experimental Neuroscience, University of Nebraska Medical CenterOmaha, NE, USA
| | - Tammy Kielian
- Pathology and Microbiology, University of Nebraska Medical CenterOmaha, NE, USA
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58
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Shaaltiel Y, Gingis-Velitski S, Tzaban S, Fiks N, Tekoah Y, Aviezer D. Plant-based oral delivery of β-glucocerebrosidase as an enzyme replacement therapy for Gaucher's disease. PLANT BIOTECHNOLOGY JOURNAL 2015; 13:1033-40. [PMID: 25828481 DOI: 10.1111/pbi.12366] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Revised: 02/10/2015] [Accepted: 02/24/2015] [Indexed: 06/04/2023]
Abstract
Gaucher's disease (GD), a lysosomal storage disorder caused by mutations in the gene encoding glucocerebrosidase (GCD), is currently treated by enzyme replacement therapy (ERT) using recombinant GCD that is administered intravenously every 2 weeks. However, intravenous administration includes discomfort or pain and might cause local and systemic infections that may lead to low patient compliance. An orally administered drug has the potential to alleviate these problems. In this study, we describe the potential use of plant cells as a vehicle for the oral delivery of recombinant human GCD (prGCD) expressed in carrot cells. The in vitro results demonstrate that the plant cells protect the recombinant protein in the gastric fluids and may enable absorption into the blood. Feeding experiments, with rat and pig as model animals, using carrot cells containing prGCD, show that active recombinant prGCD was found in the digestive tract and blood system and reached both, liver and spleen, the target organs in GD. These results demonstrate that the oral administration of proteins encapsulated in plant cells is feasible. Specifically, carrot cells containing recombinant human prGCD can be used as an oral delivery system and are a feasible alternative to intravenous administration of ERT for GD.
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Affiliation(s)
| | | | | | - Nadia Fiks
- Protalix Biotherapeutics, Carmiel, Israel
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59
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Espejo-Mojica ÁJ, Alméciga-Díaz CJ, Rodríguez A, Mosquera Á, Díaz D, Beltrán L, Díaz S, Pimentel N, Moreno J, Sánchez J, Sánchez OF, Córdoba H, Poutou-Piñales RA, Barrera LA. Human recombinant lysosomal enzymes produced in microorganisms. Mol Genet Metab 2015; 116:13-23. [PMID: 26071627 DOI: 10.1016/j.ymgme.2015.06.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 06/03/2015] [Accepted: 06/04/2015] [Indexed: 12/30/2022]
Abstract
Lysosomal storage diseases (LSDs) are caused by accumulation of partially degraded substrates within the lysosome, as a result of a function loss of a lysosomal protein. Recombinant lysosomal proteins are usually produced in mammalian cells, based on their capacity to carry out post-translational modifications similar to those observed in human native proteins. However, during the last years, a growing number of studies have shown the possibility to produce active forms of lysosomal proteins in other expression systems, such as plants and microorganisms. In this paper, we review the production and characterization of human lysosomal proteins, deficient in several LSDs, which have been produced in microorganisms. For this purpose, Escherichia coli, Saccharomyces cerevisiae, Pichia pastoris, Yarrowia lipolytica, and Ogataea minuta have been used as expression systems. The recombinant lysosomal proteins expressed in these hosts have shown similar substrate specificities, and temperature and pH stability profiles to those produced in mammalian cells. In addition, pre-clinical results have shown that recombinant lysosomal enzymes produced in microorganisms can be taken-up by cells and reduce the substrate accumulated within the lysosome. Recently, metabolic engineering in yeasts has allowed the production of lysosomal enzymes with tailored N-glycosylations, while progresses in E. coli N-glycosylations offer a potential platform to improve the production of these recombinant lysosomal enzymes. In summary, microorganisms represent convenient platform for the production of recombinant lysosomal proteins for biochemical and physicochemical characterization, as well as for the development of ERT for LSD.
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Affiliation(s)
- Ángela J Espejo-Mojica
- Institute for the Study of Inborn Errors of Metabolism, School of Sciences, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Carlos J Alméciga-Díaz
- Institute for the Study of Inborn Errors of Metabolism, School of Sciences, Pontificia Universidad Javeriana, Bogotá, Colombia.
| | - Alexander Rodríguez
- Institute for the Study of Inborn Errors of Metabolism, School of Sciences, Pontificia Universidad Javeriana, Bogotá, Colombia; Chemical Department, School of Science, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Ángela Mosquera
- Institute for the Study of Inborn Errors of Metabolism, School of Sciences, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Dennis Díaz
- Institute for the Study of Inborn Errors of Metabolism, School of Sciences, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Laura Beltrán
- Institute for the Study of Inborn Errors of Metabolism, School of Sciences, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Sergio Díaz
- Institute for the Study of Inborn Errors of Metabolism, School of Sciences, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Natalia Pimentel
- Institute for the Study of Inborn Errors of Metabolism, School of Sciences, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Jefferson Moreno
- Institute for the Study of Inborn Errors of Metabolism, School of Sciences, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Jhonnathan Sánchez
- Institute for the Study of Inborn Errors of Metabolism, School of Sciences, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Oscar F Sánchez
- School of Chemical Engineering, Purdue University, West Lafayette, IN, USA
| | - Henry Córdoba
- Chemical Department, School of Science, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Raúl A Poutou-Piñales
- Laboratorio de Biotecnología Molecular, Grupo de Biotecnología Ambiental e Industrial (GBAI), School of Sciences, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Luis A Barrera
- Institute for the Study of Inborn Errors of Metabolism, School of Sciences, Pontificia Universidad Javeriana, Bogotá, Colombia
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Abstract
Eliglustat [Cerdelga™ (US, EU)], a small-molecule oral glucosylceramide analogue that inhibits the enzyme glucosylceramide synthase has been developed by Genzyme Corporation (a subsidiary of Sanofi) for the treatment of Gaucher disease type 1 in adults. Inhibition of this enzyme reduces the accumulation of the lipid glucosylceramide in the liver, spleen, bone marrow and other organs. Eliglustat received its first global approval in this indication in the US, for use in treatment-naïve and treatment-experienced adult patients. It is also under regulatory review in the EU and Japan. This article summarizes the milestones in the development of eliglustat leading to this first approval for Gaucher disease type 1.
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Affiliation(s)
- Raewyn M Poole
- Springer, Private Bag 65901, Mairangi Bay 0754, Auckland, New Zealand,
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61
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Yip VLM, Hawcutt DB, Pirmohamed M. Pharmacogenetic Markers of Drug Efficacy and Toxicity. Clin Pharmacol Ther 2015; 98:61-70. [PMID: 25870137 DOI: 10.1002/cpt.135] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 04/08/2015] [Indexed: 12/23/2022]
Abstract
The action of a drug is dictated by its pharmacokinetic and pharmacodynamics properties, both of which can vary in different individuals because of environmental and genetic factors. Pharmacogenetics, the study of genetic factors determining drug response, has the potential to improve clinical outcomes through targeting therapies, individualizing dosing, preventing adverse drug reactions, and potentially rescuing previously failed therapies. Although there have been significant advances in pharmacogenetics over the last decade, only a few have been translated into clinical practice. However, with new rapid genotyping technologies, regulatory modernization, novel clinical trial designs, systems approaches, and integration of pharmacogenetic data into decision support systems, there is hope that pharmacogenetics, as an important component of the overall drive towards personalized medicine, will advance more quickly in the future. There will continue to be a need for collaboration between centers all over the world, and multisector working, capitalizing on the current data revolution.
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Affiliation(s)
- V L M Yip
- Departments of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, UK.,Royal Liverpool University Hospital, Liverpool, UK
| | - D B Hawcutt
- Women and Child Health Institute of Translational Medicine, University of Liverpool, Liverpool, UK.,Alder Hey Children's Hospital, Liverpool, UK
| | - M Pirmohamed
- Departments of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, UK.,Royal Liverpool University Hospital, Liverpool, UK
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Sayson B, Popurs MAM, Lafek M, Berkow R, Stockler-Ipsiroglu S, van Karnebeek CDM. Retrospective analysis supports algorithm as efficient diagnostic approach to treatable intellectual developmental disabilities. Mol Genet Metab 2015; 115:1-9. [PMID: 25801009 DOI: 10.1016/j.ymgme.2015.03.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 03/02/2015] [Accepted: 03/02/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND Intellectual developmental disorders (IDD(1)), characterized by a significant impairment in cognitive function and behavior, affect 2.5% of the population and are associated with considerable morbidity and healthcare costs. Inborn errors of metabolism (IEM) currently constitute the largest group of genetic defects presenting with IDD, which are amenable to causal therapy. Recently, we created an evidence-based 2-tiered diagnostic protocol (TIDE protocol); the first tier is a 'screening step' applied in all patients, comprising routinely performed, wide available metabolic tests in blood and urine, while second-tier tests are more specific and based on the patient's phenotype. The protocol is supported by an app (www.treatable-ID.org). OBJECTIVE To retrospectively examine the cost- and time-effectiveness of the TIDE protocol in patients identified with a treatable IEM at the British Columbia Children's Hospital. METHODS We searched the database for all IDD patients diagnosed with a treatable IEM, during the period 2000-2009 in our academic institution. Data regarding the patient's clinical phenotype, IEM, diagnostic tests and interval were collected. Total costs and time intervals associated with all testing and physician consultations actually performed were calculated and compared to the model of the TIDE protocol. RESULTS Thirty-one patients (16 males) were diagnosed with treatable IDD during the period 2000-2009. For those identifiable via the 1st tier (n=20), the average cost savings would have been $311.17 CAD, and for those diagnosed via a second-tier test (n=11) $340.14 CAD. Significant diagnostic delay (mean 9 months; range 1-29 months) could have been avoided in 9 patients with first-tier diagnoses, had the TIDE protocol been used. For those with second-tier treatable IDD, diagnoses could have been more rapidly achieved with the use of the Treatable IDD app allowing for specific searches based on signs and symptoms. CONCLUSION The TIDE protocol for treatable forms of IDD appears effective reducing diagnostic delay and unnecessary costs. Larger prospective studies, currently underway, are needed to prove that standard screening for treatable conditions in patients with IDD is time- and cost-effective, and most importantly will preserve brain function by timely diagnosis enabling initiation of causal therapy.
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Affiliation(s)
- Bryan Sayson
- Division of Pediatric Neurology, BC Children's Hospital, Vancouver, Canada; Department of Pediatrics, BC Children's Hospital, Vancouver, Canada; Treatable Intellectual Disability Endeavour in British Columbia, Vancouver, Canada; University of British Columbia, Vancouver, Canada
| | - Marioara Angela Moisa Popurs
- Department of Pediatrics, BC Children's Hospital, Vancouver, Canada; Treatable Intellectual Disability Endeavour in British Columbia, Vancouver, Canada; Division of Biochemical Diseases, BC Children's Hospital, Vancouver, Canada
| | - Mirafe Lafek
- Department of Pediatrics, BC Children's Hospital, Vancouver, Canada; Treatable Intellectual Disability Endeavour in British Columbia, Vancouver, Canada; Division of Biochemical Diseases, BC Children's Hospital, Vancouver, Canada
| | - Ruth Berkow
- Treatable Intellectual Disability Endeavour in British Columbia, Vancouver, Canada
| | - Sylvia Stockler-Ipsiroglu
- Department of Pediatrics, BC Children's Hospital, Vancouver, Canada; Treatable Intellectual Disability Endeavour in British Columbia, Vancouver, Canada; Division of Biochemical Diseases, BC Children's Hospital, Vancouver, Canada; Child and Family Research Institute, Vancouver, Canada; University of British Columbia, Vancouver, Canada
| | - Clara D M van Karnebeek
- Department of Pediatrics, BC Children's Hospital, Vancouver, Canada; Treatable Intellectual Disability Endeavour in British Columbia, Vancouver, Canada; Division of Biochemical Diseases, BC Children's Hospital, Vancouver, Canada; Child and Family Research Institute, Vancouver, Canada; University of British Columbia, Vancouver, Canada; Centre for Molecular Medicine and Therapeutics, Vancouver, Canada.
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63
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Rauch JN, Gestwicki JE. Rehabilitating mutant GCase. ACTA ACUST UNITED AC 2015; 21:919-20. [PMID: 25126987 DOI: 10.1016/j.chembiol.2014.07.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Gaucher's disease is a hereditary deficiency of the enzyme β-glucocerebrosidase (GCase) that is most commonly treated by enzyme replacement therapy. In this issue of Chemistry & Biology, Tan and colleagues search for alternative ways to rehabilitate mutant GCase by understanding how it interacts with the proteostasis network.
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Affiliation(s)
- Jennifer N Rauch
- Department of Pharmaceutical Chemistry, Institute for Neurodegenerative Disease, University of California at San Francisco, 675 Nelson Rising Lane, San Francisco, CA 94158, USA
| | - Jason E Gestwicki
- Department of Pharmaceutical Chemistry, Institute for Neurodegenerative Disease, University of California at San Francisco, 675 Nelson Rising Lane, San Francisco, CA 94158, USA.
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Abstract
Progressive myoclonic epilepsies are a group of disorders characterised by a relentlessly progressive disease course until death; treatment-resistant epilepsy is just a part of the phenotype. This umbrella term encompasses many diverse conditions, ranging from Lafora body disease to Gaucher's disease. These diseases as a group are important because of a generally poor response to antiepileptic medication, an overall poor prognosis and inheritance risks to siblings or offspring (where there is a proven genetic cause). A correct diagnosis also helps patients and their families to accept and understand the nature of their disease, even if incurable. Here, we discuss the phenotypes of these disorders and summarise the relevant specific investigations to identify the underlying cause.
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Affiliation(s)
- Naveed Malek
- Department of Neurology, Institute of Neurological Sciences, Southern General Hospital, Glasgow, UK
| | - William Stewart
- Department of Neuropathology, Institute of Neurological Sciences, Southern General Hospital, Glasgow, UK
| | - John Greene
- Department of Neurology, Institute of Neurological Sciences, Southern General Hospital, Glasgow, UK
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Götze T, Blessing H, Grillhösl C, Gerner P, Hoerning A. Neonatal Cholestasis - Differential Diagnoses, Current Diagnostic Procedures, and Treatment. Front Pediatr 2015; 3:43. [PMID: 26137452 PMCID: PMC4470262 DOI: 10.3389/fped.2015.00043] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2014] [Accepted: 04/29/2015] [Indexed: 12/18/2022] Open
Abstract
Cholestatic jaundice in early infancy is a complex diagnostic problem. Misdiagnosis of cholestasis as physiologic jaundice delays the identification of severe liver diseases. In the majority of infants, prolonged physiologic jaundice represent benign cases of breast milk jaundice, but few among them are masked and caused by neonatal cholestasis (NC) that requires a prompt diagnosis and treatment. Therefore, a prolonged neonatal jaundice, longer than 2 weeks after birth, must always be investigated because an early diagnosis is essential for appropriate management. To rapidly identify the cases with cholestatic jaundice, the conjugated bilirubin needs to be determined in any infant presenting with prolonged jaundice at 14 days of age with or without depigmented stool. Once NC is confirmed, a systematic approach is the key to reliably achieve the diagnosis in order to promptly initiate the specific, and in many cases, life-saving therapy. This strategy is most important to promptly identify and treat infants with biliary atresia, the most common cause of NC, as this requires a hepatoportoenterostomy as soon as possible. Here, we provide a detailed work-up approach including initial treatment recommendations and a clinically oriented overview of possible differential diagnoses in order to facilitate the early recognition and a timely diagnosis of cholestasis. This approach warrants a broad spectrum of diagnostic procedures and investigations including new methods that are described in this review.
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Affiliation(s)
- Thomas Götze
- Department for Pediatric and Adolescent Medicine, Friedrich-Alexander University of Erlangen-Nuremberg , Erlangen , Germany
| | - Holger Blessing
- Department for Pediatric and Adolescent Medicine, Friedrich-Alexander University of Erlangen-Nuremberg , Erlangen , Germany
| | - Christian Grillhösl
- Department for Pediatric and Adolescent Medicine, Friedrich-Alexander University of Erlangen-Nuremberg , Erlangen , Germany
| | - Patrick Gerner
- Department for Pediatric and Adolescent Medicine, Albert-Ludwigs-University Freiburg , Freiburg , Germany
| | - André Hoerning
- Department for Pediatric and Adolescent Medicine, Friedrich-Alexander University of Erlangen-Nuremberg , Erlangen , Germany
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Barnes S, Xu YH, Zhang W, Liou B, Setchell KDR, Bao L, Grabowski GA, Sun Y. Ubiquitous transgene expression of the glucosylceramide-synthesizing enzyme accelerates glucosylceramide accumulation and storage cells in a Gaucher disease mouse model. PLoS One 2014; 9:e116023. [PMID: 25551612 PMCID: PMC4281226 DOI: 10.1371/journal.pone.0116023] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 12/02/2014] [Indexed: 11/18/2022] Open
Abstract
Gaucher disease is a lysosomal storage disease caused by defective activity of acid β-glucosidase (GCase), which leads to the accumulation of its major substrates, glucosylceramide (GlcCer) and glucosylsphingosine (GlcSph) in many cells. To modulate cellular substrate concentration in viable mouse models of Gaucher disease (Gba1 mutants), a novel mouse model was created with enhanced glycosphingolipid biosynthesis. This was accomplished by cross-breeding Gba1 mutant mice with mice expressing a transgene (GCStg) containing the mouse glucosylceramide synthase (GCS, Ugcg) cDNA driven by the ROSA promoter, yielding GCStg/Gba1 mice. The GCStg rescued Ugcg null mice from embryonic lethality. GCStg/Gba1 mice showed 2-3 fold increases in tissue GCS activity as well as accelerated GlcCer accumulation and the appearance of lipid-laden CD68 positive macrophages in visceral organs. Although GlcCer/GlcSph concentrations were elevated in the brain, there was no neurodegenerative phenotype up to 1 yr of age conceivably due to the greater residual GCase hydrolytic activity in the brains than in the visceral tissues of 9V/null mice. These studies provide 'proof of principle' for threshold substrate flux that modifies phenotypic development in Gaucher disease and other lysosomal storage diseases.
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Affiliation(s)
- Sonya Barnes
- The Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States of America
| | - You-Hai Xu
- The Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States of America
- The Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Wujuan Zhang
- The Division of Pathology and Laboratory Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States of America
| | - Benjamin Liou
- The Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States of America
| | - Kenneth D. R. Setchell
- The Division of Pathology and Laboratory Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States of America
- The Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Liming Bao
- Dartmouth-Hitchcock Medical Center, Geisel School of Medicine, Dartmouth College, Lebanon, New Hampshire, United States of America
| | - Gregory A. Grabowski
- The Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States of America
- Synageva BioPharma Corp., Lexington, Massachusetts, United States of America
| | - Ying Sun
- The Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States of America
- The Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
- * E-mail:
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Glucocerebrosidase inhibitors: future drugs for the treatment of Gaucher disease? Future Med Chem 2014; 6:975-8. [DOI: 10.4155/fmc.14.41] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
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Shayman JA, Larsen SD. The development and use of small molecule inhibitors of glycosphingolipid metabolism for lysosomal storage diseases. J Lipid Res 2014; 55:1215-25. [PMID: 24534703 DOI: 10.1194/jlr.r047167] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Glycosphingolipid (GSL) storage diseases have been the focus of efforts to develop small molecule therapeutics from design, experimental proof of concept studies, and clinical trials. Two primary alternative strategies that have been pursued include pharmacological chaperones and GSL synthase inhibitors. There are theoretical advantages and disadvantages to each of these approaches. Pharmacological chaperones are specific for an individual glycoside hydrolase and for the specific mutation present, but no candidate chaperone has been demonstrated to be effective for all mutations leading to a given disorder. Synthase inhibitors target single enzymes such as glucosylceramide synthase and inhibit the formation of multiple GSLs. A glycolipid synthase inhibitor could potentially be used to treat multiple diseases, but at the risk of lowering nontargeted cellular GSLs that are important for normal health. The basis for these strategies and specific examples of compounds that have led to clinical trials is the focus of this review.
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Affiliation(s)
- James A Shayman
- Department of Internal Medicine and Vahlteich Medicinal Chemistry Core, University of Michigan, Ann Arbor, MI 48109
| | - Scott D Larsen
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, MI 48109
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