1
|
Thuma TBT, Procopio RA, Jimenez HJ, Gunton KB, Pulido JS. Hypomorphic variants in inherited retinal and ocular diseases: A review of the literature with clinical cases. Surv Ophthalmol 2024; 69:337-348. [PMID: 38036193 DOI: 10.1016/j.survophthal.2023.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 11/17/2023] [Accepted: 11/20/2023] [Indexed: 12/02/2023]
Abstract
Hypomorphic variants decrease, but do not eliminate, gene function via a reduction in the amount of mRNA or protein product produced by a gene or by production of a gene product with reduced function. Many hypomorphic variants have been implicated in inherited retinal diseases (IRDs) and other genetic ocular conditions; however, there is heterogeneity in the use of the term "hypomorphic" in the scientific literature. We searched for all hypomorphic variants reported to cause IRDs and ocular disorders. We also discuss the presence of hypomorphic variants in the patient population of our ocular genetics department over the past decade. We propose that standardized criteria should be adopted for use of the term "hypomorphic" to describe gene variants to improve genetic counseling and patient care outcomes.
Collapse
Affiliation(s)
- Tobin B T Thuma
- Department of Pediatric Ophthalmology and Strabismus, Wills Eye Hospital, Philadelphia, PA, USA
| | | | - Hiram J Jimenez
- Vickie and Jack Farber Vision Research Center, Wills Eye Hospital, Philadelphia, PA, USA
| | - Kammi B Gunton
- Department of Pediatric Ophthalmology and Strabismus, Wills Eye Hospital, Philadelphia, PA, USA
| | - Jose S Pulido
- Vickie and Jack Farber Vision Research Center, Wills Eye Hospital, Philadelphia, PA, USA; Retina Service, Wills Eye Hospital, Philadelphia, PA, USA.
| |
Collapse
|
2
|
Karuntu JS, Klouwer FCC, Engelen M, Boon CJF. Systematic study of ophthalmological findings in 10 patients with PEX1-mediated Zellweger spectrum disorder. Ophthalmic Genet 2024:1-12. [PMID: 38664000 DOI: 10.1080/13816810.2024.2330389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 03/09/2024] [Indexed: 05/30/2024]
Abstract
PURPOSE This cross-sectional study describes the ophthalmological and general phenotype of 10 patients from six different families with a comparatively mild form of Zellweger spectrum disorder (ZSD), a rare peroxisomal disorder. METHODS Ophthalmological assessment included best-corrected visual acuity (BCVA), perimetry, microperimetry, ophthalmoscopy, fundus photography, spectral-domain optical coherence tomography (SD-OCT), and fundus autofluorescence (FAF) imaging. Medical records were reviewed for medical history and systemic manifestations of ZSD. RESULTS Nine patients were homozygous for c.2528 G > A (p.Gly843Asp) variants in PEX1 and one patient was compound heterozygous for c.2528 G>A (p.Gly843Asp) and c.2097_2098insT (p.Ile700TyrfsTer42) in PEX1. Median age was 22.6 years (interquartile range (IQR): 15.9 - 29.9 years) at the most recent examination, with a median symptom duration of 22.1 years. Symptom onset was variable with presentations of hearing loss (n = 7) or nyctalopia/reduced visual acuity (n = 3) at a median age of 6 months (IQR: 1.9-8.3 months). BCVA (median of 0.8 logMAR; IQR: 0.6-0.9 logMAR) remained stable over 10.8 years and all patients were hyperopic. Fundus examination revealed a variable retinitis pigmentosa (RP)-like phenotype with rounded hyperpigmentations as most prominent feature in six out of nine patients. Electroretinography, visual field measurements, and microperimetry further established the RP-like phenotype. Multimodal imaging revealed significant intraretinal fluid cavities on SD-OCT and a remarkable pattern of hyperautofluorescent abnormalities on FAF in all patients. CONCLUSION This study highlights the ophthalmological phenotype resembling RP with moderate to severe visual impairment in patients with mild ZSD. These findings can aid ophthalmologists in diagnosing, counselling, and managing patients with mild ZSD.
Collapse
Affiliation(s)
- Jessica S Karuntu
- Department of Ophthalmology, Leiden University Medical Center, Leiden, The Netherlands
| | - Femke C C Klouwer
- Department of Paediatric Neurology/Emma Children's Hospital, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Marc Engelen
- Department of Paediatric Neurology/Emma Children's Hospital, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Camiel J F Boon
- Department of Ophthalmology, Leiden University Medical Center, Leiden, The Netherlands
- Department of Ophthalmology, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| |
Collapse
|
3
|
Bremova-Ertl T, Hofmann J, Stucki J, Vossenkaul A, Gautschi M. Inborn Errors of Metabolism with Ataxia: Current and Future Treatment Options. Cells 2023; 12:2314. [PMID: 37759536 PMCID: PMC10527548 DOI: 10.3390/cells12182314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 09/09/2023] [Accepted: 09/15/2023] [Indexed: 09/29/2023] Open
Abstract
A number of hereditary ataxias are caused by inborn errors of metabolism (IEM), most of which are highly heterogeneous in their clinical presentation. Prompt diagnosis is important because disease-specific therapies may be available. In this review, we offer a comprehensive overview of metabolic ataxias summarized by disease, highlighting novel clinical trials and emerging therapies with a particular emphasis on first-in-human gene therapies. We present disease-specific treatments if they exist and review the current evidence for symptomatic treatments of these highly heterogeneous diseases (where cerebellar ataxia is part of their phenotype) that aim to improve the disease burden and enhance quality of life. In general, a multimodal and holistic approach to the treatment of cerebellar ataxia, irrespective of etiology, is necessary to offer the best medical care. Physical therapy and speech and occupational therapy are obligatory. Genetic counseling is essential for making informed decisions about family planning.
Collapse
Affiliation(s)
- Tatiana Bremova-Ertl
- Department of Neurology, University Hospital Bern (Inselspital) and University of Bern, 3010 Bern, Switzerland; (J.H.); (J.S.)
- Center for Rare Diseases, University Hospital Bern (Inselspital) and University of Bern, 3010 Bern, Switzerland
| | - Jan Hofmann
- Department of Neurology, University Hospital Bern (Inselspital) and University of Bern, 3010 Bern, Switzerland; (J.H.); (J.S.)
| | - Janine Stucki
- Department of Neurology, University Hospital Bern (Inselspital) and University of Bern, 3010 Bern, Switzerland; (J.H.); (J.S.)
| | - Anja Vossenkaul
- Division of Pediatric Endocrinology, Diabetes and Metabolism, Department of Paediatrics, Inselspital, Bern University Hospital, University of Bern, 3010 Bern, Switzerland; (A.V.); (M.G.)
| | - Matthias Gautschi
- Division of Pediatric Endocrinology, Diabetes and Metabolism, Department of Paediatrics, Inselspital, Bern University Hospital, University of Bern, 3010 Bern, Switzerland; (A.V.); (M.G.)
- Institute of Clinical Chemistry, Inselspital, Bern University Hospital, University of Bern, 3010 Bern, Switzerland
| |
Collapse
|
4
|
Mohan S, Mayers M, Weaver M, Baudet H, De Biase I, Goldstein J, Mao R, McGlaughon J, Moser A, Pujol A, Suchy S, Yuzyuk T, Braverman NE. Evaluating the strength of evidence for genes implicated in peroxisomal disorders using the ClinGen clinical validity framework and providing updates to the peroxisomal disease nomenclature. Mol Genet Metab 2023; 139:107604. [PMID: 37236006 PMCID: PMC10484331 DOI: 10.1016/j.ymgme.2023.107604] [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: 01/07/2023] [Revised: 03/09/2023] [Accepted: 05/01/2023] [Indexed: 05/28/2023]
Abstract
Peroxisomal disorders are heterogeneous in nature, with phenotypic overlap that is indistinguishable without molecular testing. Newborn screening and gene sequencing for a panel of genes implicated in peroxisomal diseases are critical tools for the early and accurate detection of these disorders. It is therefore essential to evaluate the clinical validity of the genes included in sequencing panels for peroxisomal disorders. The Peroxisomal Gene Curation Expert Panel (GCEP) assessed genes frequently included on clinical peroxisomal testing panels using the Clinical Genome Resource (ClinGen) gene-disease validity curation framework and classified gene-disease relationships as Definitive, Strong, Moderate, Limited, Disputed, Refuted, or No Known Disease Relationship. Subsequent to gene curation, the GCEP made recommendations to update the disease nomenclature and ontology in the Monarch Disease Ontology (Mondo) database. Thirty-six genes were assessed for the strength of evidence supporting their role in peroxisomal disease, leading to 36 gene-disease relationships, after two genes were removed for their lack of a role in peroxisomal disease and two genes were curated for two different disease entities each. Of these, 23 were classified as Definitive (64%), one as Strong (3%), eight as Moderate (23%), two as Limited (5%), and two as No known disease relationship (5%). No contradictory evidence was found to classify any relationships as Disputed or Refuted. The gene-disease relationship curations are publicly available on the ClinGen website (https://clinicalgenome.org/affiliation/40049/). The changes to peroxisomal disease nomenclature are displayed on the Mondo website (http://purl.obolibrary.org/obo/MONDO_0019053). The Peroxisomal GCEP-curated gene-disease relationships will inform clinical and laboratory diagnostics and enhance molecular testing and reporting. As new data will emerge, the gene-disease classifications asserted by the Peroxisomal GCEP will be re-evaluated periodically.
Collapse
Affiliation(s)
- Shruthi Mohan
- Department of Genetics, School of Medicine, University of North Carolina at Chapel Hill, NC, USA
| | - Megan Mayers
- Department of Genetics, School of Medicine, University of North Carolina at Chapel Hill, NC, USA
| | - Meredith Weaver
- American College of Medical Genetics and Genomics, Bethesda, MD, USA
| | - Heather Baudet
- Department of Genetics, School of Medicine, University of North Carolina at Chapel Hill, NC, USA
| | | | - Jennifer Goldstein
- Department of Genetics, School of Medicine, University of North Carolina at Chapel Hill, NC, USA
| | - Rong Mao
- ARUP Laboratories, Salt Lake City, UT, USA
| | | | - Ann Moser
- Kennedy Krieger Institute, Baltimore, MD, USA
| | - Aurora Pujol
- Bellvitge Biomedical Research Institute (IDIBELL Instituto de Investigación Biomédica de Bellvitge), Barcelona, Spain
| | | | | | - Nancy E Braverman
- Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada.
| |
Collapse
|
5
|
Swinkels D, Baes M. The essential role of docosahexaenoic acid and its derivatives for retinal integrity. Pharmacol Ther 2023; 247:108440. [PMID: 37201739 DOI: 10.1016/j.pharmthera.2023.108440] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 05/08/2023] [Accepted: 05/15/2023] [Indexed: 05/20/2023]
Abstract
The fatty acid composition of photoreceptor outer segment (POS) phospholipids diverges from other membranes, being highly enriched in polyunsaturated fatty acids (PUFAs). The most abundant PUFA is docosahexaenoic acid (DHA, C22:6n-3), an omega-3 PUFA that amounts to over 50% of the POS phospholipid fatty acid side chains. Interestingly, DHA is the precursor of other bioactive lipids such as elongated PUFAs and oxygenated derivatives. In this review, we present the current view on metabolism, trafficking and function of DHA and very long chain polyunsaturated fatty acids (VLC-PUFAs) in the retina. New insights on pathological features generated from PUFA deficient mouse models with enzyme or transporter defects and corresponding patients are discussed. Not only the neural retina, but also abnormalities in the retinal pigment epithelium are considered. Furthermore, the potential involvement of PUFAs in more common retinal degeneration diseases such as diabetic retinopathy, retinitis pigmentosa and age-related macular degeneration are evaluated. Supplementation treatment strategies and their outcome are summarized.
Collapse
Affiliation(s)
- Daniëlle Swinkels
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium
| | - Myriam Baes
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium.
| |
Collapse
|
6
|
Kocherlakota S, Swinkels D, Van Veldhoven PP, Baes M. Mouse Models to Study Peroxisomal Functions and Disorders: Overview, Caveats, and Recommendations. Methods Mol Biol 2023; 2643:469-500. [PMID: 36952207 DOI: 10.1007/978-1-0716-3048-8_34] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
During the last three decades many mouse lines were created or identified that are deficient in one or more peroxisomal functions. Different methodologies were applied to obtain global, hypomorph, cell type selective, inducible, and knockin mice. Whereas some models closely mimic pathologies in patients, others strongly deviate or no human counterpart has been reported. Often, mice, apparently endowed with a stronger transcriptional adaptation, have to be challenged with dietary additions or restrictions in order to trigger phenotypic changes. Depending on the inactivated peroxisomal protein, several approaches can be taken to validate the loss-of-function. Here, an overview is given of the available mouse models and their most important characteristics.
Collapse
Affiliation(s)
- Sai Kocherlakota
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Daniëlle Swinkels
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Paul P Van Veldhoven
- Laboratory of Peroxisome Biology and Intracellular Communication, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Myriam Baes
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium.
| |
Collapse
|
7
|
Mauriac SA, Peineau T, Zuberi A, Lutz C, Géléoc GSG. Loss of Pex1 in Inner Ear Hair Cells Contributes to Cochlear Synaptopathy and Hearing Loss. Cells 2022; 11:cells11243982. [PMID: 36552747 PMCID: PMC9777190 DOI: 10.3390/cells11243982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Revised: 12/04/2022] [Accepted: 12/06/2022] [Indexed: 12/13/2022] Open
Abstract
Peroxisome Biogenesis Disorders (PBD) and Zellweger syndrome spectrum disorders (ZSD) are rare genetic multisystem disorders that include hearing impairment and are associated with defects in peroxisome assembly, function, or both. Mutations in 13 peroxin (PEX) genes have been found to cause PBD-ZSD with ~70% of patients harboring mutations in PEX1. Limited research has focused on the impact of peroxisomal disorders on auditory function. As sensory hair cells are particularly vulnerable to metabolic changes, we hypothesize that mutations in PEX1 lead to oxidative stress affecting hair cells of the inner ear, subsequently resulting in hair cell degeneration and hearing loss. Global deletion of the Pex1 gene is neonatal lethal in mice, impairing any postnatal studies. To overcome this limitation, we created conditional knockout mice (cKO) using Gfi1Creor VGlut3Cre expressing mice crossed to floxed Pex1 mice to allow for selective deletion of Pex1 in the hair cells of the inner ear. We find that Pex1 excision in inner hair cells (IHCs) leads to progressive hearing loss associated with significant decrease in auditory brainstem responses (ABR), specifically ABR wave I amplitude, indicative of synaptic defects. Analysis of IHC synapses in cKO mice reveals a decrease in ribbon synapse volume and functional alterations in exocytosis. Concomitantly, we observe a decrease in peroxisomal number, indicative of oxidative stress imbalance. Taken together, these results suggest a critical function of Pex1 in development and maturation of IHC-spiral ganglion synapses and auditory function.
Collapse
Affiliation(s)
- Stephanie A. Mauriac
- Department of Otolaryngology, Boston Children’s Hospital, Boston, MA 02115, USA
- Kirby Neurobiology Center, Harvard Medical School, Boston, MA 02115, USA
| | - Thibault Peineau
- Department of Otolaryngology, Boston Children’s Hospital, Boston, MA 02115, USA
- Kirby Neurobiology Center, Harvard Medical School, Boston, MA 02115, USA
| | - Aamir Zuberi
- Rare Disease Translational Center, The Jackson Laboratory, Bar Harbor, ME 04609, USA
- Technology Evaluation and Development Research Laboratory, The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | - Cathleen Lutz
- Rare Disease Translational Center, The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | - Gwénaëlle S. G. Géléoc
- Department of Otolaryngology, Boston Children’s Hospital, Boston, MA 02115, USA
- Kirby Neurobiology Center, Harvard Medical School, Boston, MA 02115, USA
- Correspondence: ; Tel.: +1-617-919-4061
| |
Collapse
|
8
|
Cell Type-Selective Loss of Peroxisomal β-Oxidation Impairs Bipolar Cell but Not Photoreceptor Survival in the Retina. Cells 2022; 11:cells11010161. [PMID: 35011723 PMCID: PMC8750404 DOI: 10.3390/cells11010161] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 12/20/2021] [Accepted: 12/29/2021] [Indexed: 12/12/2022] Open
Abstract
Retinal degeneration is a common feature in peroxisomal disorders leading to blindness. Peroxisomes are present in the different cell types of the retina; however, their precise contribution to retinal integrity is still unclear. We previously showed that mice lacking the central peroxisomal β-oxidation enzyme, multifunctional protein 2 (MFP2), develop an early onset retinal decay including photoreceptor cell death. To decipher the function of peroxisomal β-oxidation in photoreceptors, we generated cell type selective Mfp2 knockout mice, using the Crx promotor targeting photoreceptors and bipolar cells. Surprisingly, Crx-Mfp2−/− mice maintained photoreceptor length and number until the age of 1 year. A negative electroretinogram was indicative of preserved photoreceptor phototransduction, but impaired downstream bipolar cell signaling from the age of 6 months. The photoreceptor ribbon synapse was affected, containing free-floating ribbons and vesicles with altered size and density. The bipolar cell interneurons sprouted into the ONL and died. Whereas docosahexaenoic acid levels were normal in the neural retina, levels of lipids containing very long chain polyunsaturated fatty acids were highly increased. Crx-Pex5−/− mice, in which all peroxisomal functions are inactivated in photoreceptors and bipolar cells, developed the same phenotype as Crx-Mfp2−/− mice. In conclusion, the early photoreceptor death in global Mfp2−/− mice is not driven cell autonomously. However, peroxisomal β-oxidation is essential for the integrity of photoreceptor ribbon synapses and of bipolar cells.
Collapse
|
9
|
Argyriou C, Polosa A, Song JY, Omri S, Steele B, Cécyre B, McDougald DS, Di Pietro E, Bouchard JF, Bennett J, Hacia JG, Lachapelle P, Braverman NE. AAV-mediated PEX1 gene augmentation improves visual function in the PEX1-Gly844Asp mouse model for mild Zellweger spectrum disorder. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2021; 23:225-240. [PMID: 34703844 PMCID: PMC8516995 DOI: 10.1016/j.omtm.2021.09.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 09/01/2021] [Indexed: 12/01/2022]
Abstract
Patients with Zellweger spectrum disorder (ZSD) commonly present with vision loss due to mutations in PEX genes required for peroxisome assembly and function. Here, we evaluate PEX1 retinal gene augmentation therapy in a mouse model of mild ZSD bearing the murine equivalent (PEX1-p[Gly844Asp]) of the most common human mutation. Experimental adeno-associated virus 8.cytomegalovirus.human PEX1.hemagglutinin (AAV8.CMV.HsPEX1.HA) and control AAV8.CMV.EGFP vectors were administered by subretinal injection in contralateral eyes of early (5-week-old)- or later (9-week-old)-stage retinopathy cohorts. HsPEX1.HA protein was expressed in the retina with no gross histologic side effects. Peroxisomal metabolic functions, assessed by retinal C26:0 lysophosphatidylcholine (lyso-PC) levels, were partially normalized after therapeutic vector treatment. Full-field flash electroretinogram (ffERG) analyses at 8 weeks post-injection showed a 2-fold improved retinal response in the therapeutic relative to control vector-injected eyes. ffERG improved by 1.6- to 2.5-fold in the therapeutic vector-injected eyes when each cohort reached 25 weeks of age. At 32 weeks of age, the average ffERG response was double in the therapeutic relative to control vector-injected eyes in both cohorts. Optomotor reflex analyses trended toward improvement. These proof-of-concept studies represent the first application of gene augmentation therapy to treat peroxisome biogenesis disorders and support the potential for retinal gene delivery to improve vision in these patients.
Collapse
Affiliation(s)
- Catherine Argyriou
- Department of Human Genetics, McGill University, Montreal, QC, Canada.,Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Anna Polosa
- Department of Ophthalmology & Visual Sciences, McGill University, Montreal, QC, Canada.,Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Ji Yun Song
- Center for Advanced Retinal and Ocular Therapeutics, F.M. Kirby Center for Molecular Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Samy Omri
- Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Bradford Steele
- Department of Biochemistry and Molecular Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Bruno Cécyre
- School of Optometry, Université de Montréal, Montreal, QC, Canada
| | - Devin S McDougald
- Center for Advanced Retinal and Ocular Therapeutics, F.M. Kirby Center for Molecular Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Erminia Di Pietro
- Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | | | - Jean Bennett
- Center for Advanced Retinal and Ocular Therapeutics, F.M. Kirby Center for Molecular Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Joseph G Hacia
- Department of Biochemistry and Molecular Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Pierre Lachapelle
- Department of Ophthalmology & Visual Sciences, McGill University, Montreal, QC, Canada.,Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Nancy E Braverman
- Department of Human Genetics, McGill University, Montreal, QC, Canada.,Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| |
Collapse
|
10
|
Sander CL, Sears AE, Pinto AF, Choi EH, Kahremany S, Gao F, Salom D, Jin H, Pardon E, Suh S, Dong Z, Steyaert J, Saghatelian A, Skowronska-Krawczyk D, Kiser PD, Palczewski K. Nano-scale resolution of native retinal rod disk membranes reveals differences in lipid composition. J Cell Biol 2021; 220:e202101063. [PMID: 34132745 PMCID: PMC8240855 DOI: 10.1083/jcb.202101063] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 04/26/2021] [Accepted: 05/18/2021] [Indexed: 02/07/2023] Open
Abstract
Photoreceptors rely on distinct membrane compartments to support their specialized function. Unlike protein localization, identification of critical differences in membrane content has not yet been expanded to lipids, due to the difficulty of isolating domain-specific samples. We have overcome this by using SMA to coimmunopurify membrane proteins and their native lipids from two regions of photoreceptor ROS disks. Each sample's copurified lipids were subjected to untargeted lipidomic and fatty acid analysis. Extensive differences between center (rhodopsin) and rim (ABCA4 and PRPH2/ROM1) samples included a lower PC to PE ratio and increased LC- and VLC-PUFAs in the center relative to the rim region, which was enriched in shorter, saturated FAs. The comparatively few differences between the two rim samples likely reflect specific protein-lipid interactions. High-resolution profiling of the ROS disk lipid composition gives new insights into how intricate membrane structure and protein activity are balanced within the ROS, and provides a model for future studies of other complex cellular structures.
Collapse
Affiliation(s)
- Christopher L. Sander
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA
| | - Avery E. Sears
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA
| | - Antonio F.M. Pinto
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute for Biological Studies, La Jolla, CA
| | - Elliot H. Choi
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA
| | - Shirin Kahremany
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA
| | - Fangyuan Gao
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA
| | - David Salom
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA
| | - Hui Jin
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH
| | - Els Pardon
- Vlaams Instituut voor Biotechnologie–Vrije Universiteit Brussel Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Brussels, Belgium
- Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Susie Suh
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA
| | - Zhiqian Dong
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA
| | - Jan Steyaert
- Vlaams Instituut voor Biotechnologie–Vrije Universiteit Brussel Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Brussels, Belgium
- Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Alan Saghatelian
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute for Biological Studies, La Jolla, CA
| | - Dorota Skowronska-Krawczyk
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA
| | - Philip D. Kiser
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA
- Research Service, VA Long Beach Healthcare System, Long Beach, CA
| | - Krzysztof Palczewski
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA
- Department of Chemistry, University of California, Irvine, Irvine, CA
| |
Collapse
|
11
|
Takashima S, Takemoto S, Toyoshi K, Ohba A, Shimozawa N. Zebrafish model of human Zellweger syndrome reveals organ-specific accumulation of distinct fatty acid species and widespread gene expression changes. Mol Genet Metab 2021; 133:307-323. [PMID: 34016526 DOI: 10.1016/j.ymgme.2021.05.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 05/04/2021] [Accepted: 05/04/2021] [Indexed: 11/24/2022]
Abstract
In Zellweger syndrome (ZS), lack of peroxisome function causes physiological and developmental abnormalities in many organs such as the brain, liver, muscles, and kidneys, but little is known about the exact pathogenic mechanism. By disrupting the zebrafish pex2 gene, we established a disease model for ZS and found that it exhibits pathological features and metabolic changes similar to those observed in human patients. By comprehensive analysis of the fatty acid profile, we found organ-specific accumulation and reduction of distinct fatty acid species, such as an accumulation of ultra-very-long-chain polyunsaturated fatty acids (ultra-VLC-PUFAs) in the brains of pex2 mutant fish. Transcriptome analysis using microarray also revealed mutant-specific gene expression changes that might lead to the symptoms, including reduction of crystallin, troponin, parvalbumin, and fatty acid metabolic genes. Our data indicated that the loss of peroxisomes results in widespread metabolic and gene expression changes beyond the causative peroxisomal function. These results suggest the genetic and metabolic basis of the pathology of this devastating human disease.
Collapse
Affiliation(s)
- Shigeo Takashima
- Division of Genomics Research, Life Science Research Center, Gifu University, Gifu, Japan; Institute for Glyco-core Research (iGCORE), Gifu University, Gifu, Japan; United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Gifu, Japan.
| | - Shoko Takemoto
- Division of Genomics Research, Life Science Research Center, Gifu University, Gifu, Japan
| | - Kayoko Toyoshi
- Division of Genomics Research, Life Science Research Center, Gifu University, Gifu, Japan
| | - Akiko Ohba
- Division of Genomics Research, Life Science Research Center, Gifu University, Gifu, Japan
| | - Nobuyuki Shimozawa
- Division of Genomics Research, Life Science Research Center, Gifu University, Gifu, Japan; Institute for Glyco-core Research (iGCORE), Gifu University, Gifu, Japan; United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Gifu, Japan
| |
Collapse
|
12
|
Mechanisms and Functions of Pexophagy in Mammalian Cells. Cells 2021; 10:cells10051094. [PMID: 34063724 PMCID: PMC8147788 DOI: 10.3390/cells10051094] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 04/28/2021] [Accepted: 05/01/2021] [Indexed: 12/17/2022] Open
Abstract
Peroxisomes play essential roles in diverse cellular metabolism functions, and their dynamic homeostasis is maintained through the coordination of peroxisome biogenesis and turnover. Pexophagy, selective autophagic degradation of peroxisomes, is a major mechanism for removing damaged and/or superfluous peroxisomes. Dysregulation of pexophagy impairs the physiological functions of peroxisomes and contributes to the progression of many human diseases. However, the mechanisms and functions of pexophagy in mammalian cells remain largely unknown compared to those in yeast. This review focuses on mammalian pexophagy and aims to advance the understanding of the roles of pexophagy in human health and diseases. Increasing evidence shows that ubiquitination can serve as a signal for pexophagy, and ubiquitin-binding receptors, substrates, and E3 ligases/deubiquitinases involved in pexophagy have been described. Alternatively, pexophagy can be achieved in a ubiquitin-independent manner. We discuss the mechanisms of these ubiquitin-dependent and ubiquitin-independent pexophagy pathways and summarize several inducible conditions currently used to study pexophagy. We highlight several roles of pexophagy in human health and how its dysregulation may contribute to diseases.
Collapse
|
13
|
Baldwin HA, Wang C, Kanfer G, Shah HV, Velayos-Baeza A, Dulovic-Mahlow M, Brüggemann N, Anding A, Baehrecke EH, Maric D, Prinz WA, Youle RJ. VPS13D promotes peroxisome biogenesis. J Cell Biol 2021; 220:212018. [PMID: 33891012 PMCID: PMC8077185 DOI: 10.1083/jcb.202001188] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Revised: 01/20/2021] [Accepted: 03/03/2021] [Indexed: 12/19/2022] Open
Abstract
The VPS13 gene family consists of VPS13A–D in mammals. Although all four genes have been linked to human diseases, their cellular functions are poorly understood, particularly those of VPS13D. We generated and characterized knockouts of each VPS13 gene in HeLa cells. Among the individual knockouts, only VPS13D-KO cells exhibit abnormal mitochondrial morphology. Additionally, VPS13D loss leads to either partial or complete peroxisome loss in several transformed cell lines and in fibroblasts derived from a VPS13D mutation–carrying patient with recessive spinocerebellar ataxia. Our data show that VPS13D regulates peroxisome biogenesis.
Collapse
Affiliation(s)
- Heather A Baldwin
- Biochemistry Section, Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD.,Cell, Molecular, Developmental Biology and Biophysics Doctoral Program, Johns Hopkins University, Baltimore, MD
| | - Chunxin Wang
- Biochemistry Section, Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
| | - Gil Kanfer
- Biochemistry Section, Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
| | - Hetal V Shah
- Biochemistry Section, Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD.,Program in Neuroscience & Cognitive Science, University of Maryland, College Park, MD
| | | | | | - Norbert Brüggemann
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany.,Department of Neurology, University of Lübeck, Lübeck, Germany
| | - Allyson Anding
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA
| | - Eric H Baehrecke
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA
| | - Dragan Maric
- National Institute of Neurological Disorders and Stroke Flow Cytometry Core Facility, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
| | - William A Prinz
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD
| | - Richard J Youle
- Biochemistry Section, Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
| |
Collapse
|
14
|
Das Y, Swinkels D, Baes M. Peroxisomal Disorders and Their Mouse Models Point to Essential Roles of Peroxisomes for Retinal Integrity. Int J Mol Sci 2021; 22:ijms22084101. [PMID: 33921065 PMCID: PMC8071455 DOI: 10.3390/ijms22084101] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 04/12/2021] [Accepted: 04/13/2021] [Indexed: 12/31/2022] Open
Abstract
Peroxisomes are multifunctional organelles, well known for their role in cellular lipid homeostasis. Their importance is highlighted by the life-threatening diseases caused by peroxisomal dysfunction. Importantly, most patients suffering from peroxisomal biogenesis disorders, even those with a milder disease course, present with a number of ocular symptoms, including retinopathy. Patients with a selective defect in either peroxisomal α- or β-oxidation or ether lipid synthesis also suffer from vision problems. In this review, we thoroughly discuss the ophthalmological pathology in peroxisomal disorder patients and, where possible, the corresponding animal models, with a special emphasis on the retina. In addition, we attempt to link the observed retinal phenotype to the underlying biochemical alterations. It appears that the retinal pathology is highly variable and the lack of histopathological descriptions in patients hampers the translation of the findings in the mouse models. Furthermore, it becomes clear that there are still large gaps in the current knowledge on the contribution of the different metabolic disturbances to the retinopathy, but branched chain fatty acid accumulation and impaired retinal PUFA homeostasis are likely important factors.
Collapse
|
15
|
Dahan N, Francisco T, Falter C, Rodrigues T, Kalel V, Kunze M, Hansen T, Schliebs W, Erdmann R. Current advances in the function and biogenesis of peroxisomes and their roles in health and disease. Histochem Cell Biol 2021; 155:513-524. [PMID: 33818645 PMCID: PMC8062356 DOI: 10.1007/s00418-021-01982-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/03/2021] [Indexed: 12/20/2022]
Affiliation(s)
- Noa Dahan
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Tania Francisco
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal
| | - Christian Falter
- Plant Biochemistry and Infection Biology, Institute of Plant Science and Microbiology, University of Hamburg, Hamburg, Germany
| | - Tony Rodrigues
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal
| | - Vishal Kalel
- Department System Biochemistry, Institute of Biochemistry and Pathobiochemistry, Medical Faculty, Ruhr-University of Bochum, Universitätstr.150, 44780, Bochum, Germany
| | - Markus Kunze
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090, Vienna, Austria
| | - Tobias Hansen
- Department System Biochemistry, Institute of Biochemistry and Pathobiochemistry, Medical Faculty, Ruhr-University of Bochum, Universitätstr.150, 44780, Bochum, Germany
| | - Wolfgang Schliebs
- Department System Biochemistry, Institute of Biochemistry and Pathobiochemistry, Medical Faculty, Ruhr-University of Bochum, Universitätstr.150, 44780, Bochum, Germany
| | - Ralf Erdmann
- Department System Biochemistry, Institute of Biochemistry and Pathobiochemistry, Medical Faculty, Ruhr-University of Bochum, Universitätstr.150, 44780, Bochum, Germany.
| |
Collapse
|
16
|
Park NY, Jo DS, Park SJ, Lee H, Bae JE, Hong Y, Kim JB, Kim YH, Park HJ, Choi JY, Lee HJ, Ryoo ZY, Lee HS, Kim JC, Lee EK, Cho DH. Depletion of HNRNPA1 induces peroxisomal autophagy by regulating PEX1 expression. Biochem Biophys Res Commun 2021; 545:69-74. [PMID: 33545634 DOI: 10.1016/j.bbrc.2021.01.083] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 01/24/2021] [Indexed: 11/27/2022]
Abstract
Peroxisomes play an essential role in cellular homeostasis by regulating lipid metabolism and the conversion of reactive oxygen species (ROS). Several peroxisomal proteins, known as peroxins (PEXs), control peroxisome biogenesis and degradation. Various mutations in the PEX genes are genetic causes for the development of inheritable peroxisomal-biogenesis disorders, such as Zellweger syndrome. Among the peroxins, PEX1 defects are the most common mutations in Zellweger syndrome. PEX1 is an AAA-ATPase that regulates the recycling of PEX5, which is essential for importing peroxisome matrix proteins. However, the post-transcriptional regulation of PEX1 is largely unknown. Here, we showed that heterogeneous nuclear ribonucleoprotein A1 (HNRNPA1) controls PEX1 expression. In addition, we found that depletion of HNRNPA1 induces autophagic degradation of peroxisome, which is blocked in ATG5-knockout cells. In addition, depletion of HNRNPA1 increased peroxisomal ROS levels. Inhibition of the generation of peroxisomal ROS by treatment with NAC significantly suppressed pexophagy in HNRNPA1-deficient cells. Taken together, our results suggest that depletion of HNRNPA1 increases peroxisomal ROS and pexophagy by downregulating PEX1 expression.
Collapse
Affiliation(s)
- Na Yeon Park
- School of Life Sciences, BK21 FOUR KNU Creative BioResearch Group, Kyungpook National University, Daegu, 41566, South Korea
| | - Doo Sin Jo
- School of Life Sciences, BK21 FOUR KNU Creative BioResearch Group, Kyungpook National University, Daegu, 41566, South Korea
| | - So Jung Park
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
| | - Heejin Lee
- Department of Biochemistry, College of Medicine, Catholic University of Korea, Seoul, 06591, South Korea
| | - Ji-Eun Bae
- Brain Science and Engineering Institute, Kyungpook National University, Daegu, 41566, South Korea
| | - Youlim Hong
- Department of Biochemistry, College of Medicine, Catholic University of Korea, Seoul, 06591, South Korea
| | - Joon Bum Kim
- School of Life Sciences, BK21 FOUR KNU Creative BioResearch Group, Kyungpook National University, Daegu, 41566, South Korea
| | - Yong Hwan Kim
- School of Life Sciences, BK21 FOUR KNU Creative BioResearch Group, Kyungpook National University, Daegu, 41566, South Korea
| | - Hyun Jun Park
- School of Life Sciences, BK21 FOUR KNU Creative BioResearch Group, Kyungpook National University, Daegu, 41566, South Korea
| | - Ji Yeon Choi
- School of Life Sciences, BK21 FOUR KNU Creative BioResearch Group, Kyungpook National University, Daegu, 41566, South Korea
| | - Ha Jung Lee
- School of Life Sciences, BK21 FOUR KNU Creative BioResearch Group, Kyungpook National University, Daegu, 41566, South Korea
| | - Zae Young Ryoo
- School of Life Sciences, BK21 FOUR KNU Creative BioResearch Group, Kyungpook National University, Daegu, 41566, South Korea
| | - Hyun-Shik Lee
- School of Life Sciences, BK21 FOUR KNU Creative BioResearch Group, Kyungpook National University, Daegu, 41566, South Korea
| | - Jin Cheon Kim
- Department of Surgery, University of Ulsan College of Medicine and Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, South Korea
| | - Eun Kyung Lee
- Department of Biochemistry, College of Medicine, Catholic University of Korea, Seoul, 06591, South Korea.
| | - Dong-Hyung Cho
- School of Life Sciences, BK21 FOUR KNU Creative BioResearch Group, Kyungpook National University, Daegu, 41566, South Korea.
| |
Collapse
|
17
|
Characterizing the phospholipid composition of six edible sea cucumbers by NPLC-Triple TOF-MS/MS. J Food Compost Anal 2020. [DOI: 10.1016/j.jfca.2020.103626] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
|
18
|
Demaret T, Roumain M, Ambroise J, Evraerts J, Ravau J, Bouzin C, Bearzatto B, Gala JL, Stepman H, Marie S, Vincent MF, Muccioli GG, Najimi M, Sokal EM. Longitudinal study of Pex1-G844D NMRI mouse model: A robust pre-clinical model for mild Zellweger spectrum disorder. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165900. [PMID: 32693164 DOI: 10.1016/j.bbadis.2020.165900] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 06/27/2020] [Accepted: 07/15/2020] [Indexed: 12/11/2022]
Abstract
Zellweger spectrum disorders (ZSD) are inborn errors of metabolism caused by mutations in PEX genes that lead to peroxisomal biogenesis disorder (PBD). No validated treatment is able to modify the dismal progression of the disease. ZSD mouse models used to develop therapeutic approaches are limited by poor survival and breeding restrictions. To overcome these limitations, we backcrossed the hypomorphic Pex1 p.G844D allele to NMRI background. NMRI mouse breeding restored an autosomal recessive Mendelian inheritance pattern and delivered twice larger litters. Mice were longitudinally phenotyped up to 6 months of age to make this model suitable for therapeutic interventions. ZSD mice exhibited growth retardation and relative hepatomegaly associated to progressive hepatocyte hypertrophy. Biochemical studies associated with RNA sequencing deciphered ZSD liver glycogen metabolism alterations. Affected fibroblasts displayed classical immunofluorescence pattern and biochemical alterations associated with PBD. Plasma and liver showed very long-chain fatty acids, specific oxysterols and C27 bile acids intermediates elevation in ZSD mice along with a specific urine organic acid profile. With ageing, C26 fatty acid and phytanic acid levels tended to normalize in ZSD mice, as described in patients reaching adulthood. In conclusion, our mouse model recapitulates a mild ZSD phenotype and is suitable for liver-targeted therapies evaluation.
Collapse
Affiliation(s)
- Tanguy Demaret
- Laboratoire d'Hépatologie Pédiatrique et Thérapie Cellulaire, Unité PEDI, Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain (UCLouvain), 1200 Brussels, Belgium.
| | - Martin Roumain
- Bioanalysis and Pharmacology of Bioactive Lipids Research Group (BPBL), Louvain Drug Research Institute (LDRI), Université Catholique de Louvain (UCLouvain), 1200 Brussels, Belgium.
| | - Jérôme Ambroise
- Center for Applied Molecular Technologies (CTMA), Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain (UCLouvain), 1200 Brussels, Belgium.
| | - Jonathan Evraerts
- Laboratoire d'Hépatologie Pédiatrique et Thérapie Cellulaire, Unité PEDI, Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain (UCLouvain), 1200 Brussels, Belgium.
| | - Joachim Ravau
- Laboratoire d'Hépatologie Pédiatrique et Thérapie Cellulaire, Unité PEDI, Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain (UCLouvain), 1200 Brussels, Belgium.
| | - Caroline Bouzin
- IREC Imaging Platform (2IP), Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain (UCLouvain), 1200 Brussels, Belgium.
| | - Bertrand Bearzatto
- Center for Applied Molecular Technologies (CTMA), Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain (UCLouvain), 1200 Brussels, Belgium.
| | - Jean-Luc Gala
- Center for Applied Molecular Technologies (CTMA), Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain (UCLouvain), 1200 Brussels, Belgium.
| | - Hedwig Stepman
- Department of Laboratory Medicine, Ghent University Hospital, 9000 Ghent, Belgium.
| | - Sandrine Marie
- Department of Laboratory Medicine, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain (UCLouvain), 1200 Brussels, Belgium.
| | - Marie-Françoise Vincent
- Department of Laboratory Medicine, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain (UCLouvain), 1200 Brussels, Belgium.
| | - Giulio G Muccioli
- Bioanalysis and Pharmacology of Bioactive Lipids Research Group (BPBL), Louvain Drug Research Institute (LDRI), Université Catholique de Louvain (UCLouvain), 1200 Brussels, Belgium.
| | - Mustapha Najimi
- Laboratoire d'Hépatologie Pédiatrique et Thérapie Cellulaire, Unité PEDI, Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain (UCLouvain), 1200 Brussels, Belgium.
| | - Etienne M Sokal
- Laboratoire d'Hépatologie Pédiatrique et Thérapie Cellulaire, Unité PEDI, Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain (UCLouvain), 1200 Brussels, Belgium.
| |
Collapse
|
19
|
Hepatocyte-specific deletion of peroxisomal protein PEX13 results in disrupted iron homeostasis. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165882. [PMID: 32565019 DOI: 10.1016/j.bbadis.2020.165882] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 05/11/2020] [Accepted: 06/16/2020] [Indexed: 12/31/2022]
Abstract
Peroxisomes are organelles, abundant in the liver, involved in a variety of cellular functions, including fatty acid metabolism, plasmalogen synthesis and metabolism of reactive oxygen species. Several inherited disorders are associated with peroxisomal dysfunction; increasingly many are associated with hepatic pathologies. The liver plays a principal role in regulation of iron metabolism. In this study we examined the possibility of a relationship between iron homeostasis and peroxisomal integrity. We examined the effect of deleting Pex13 in mouse liver on systemic iron homeostasis. We also used siRNA-mediated knock-down of PEX13 in a human hepatoma cell line (HepG2/C3A) to elucidate the mechanisms of PEX13-mediated regulation of hepcidin. We demonstrate that transgenic mice lacking hepatocyte Pex13 have defects in systemic iron homeostasis. The ablation of Pex13 expression in hepatocytes leads to a significant reduction in hepatic hepcidin levels. Our results also demonstrate that a deficiency of PEX13 gene expression in HepG2/C3A cells leads to decreased hepcidin expression, which is mediated through an increase in the signalling protein SMAD7, and endoplasmic reticulum (ER) stress. This study identifies a novel role for a protein involved in maintaining peroxisomal integrity and function in iron homeostasis. Loss of Pex13, a protein important for peroxisomal function, in hepatocytes leads to a significant increase in ER stress, which if unresolved, can affect liver function. The results from this study have implications for the management of patients with peroxisomal disorders and the liver-related complications they may develop.
Collapse
|
20
|
Collin GB, Gogna N, Chang B, Damkham N, Pinkney J, Hyde LF, Stone L, Naggert JK, Nishina PM, Krebs MP. Mouse Models of Inherited Retinal Degeneration with Photoreceptor Cell Loss. Cells 2020; 9:cells9040931. [PMID: 32290105 PMCID: PMC7227028 DOI: 10.3390/cells9040931] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 04/05/2020] [Accepted: 04/07/2020] [Indexed: 12/12/2022] Open
Abstract
Inherited retinal degeneration (RD) leads to the impairment or loss of vision in millions of individuals worldwide, most frequently due to the loss of photoreceptor (PR) cells. Animal models, particularly the laboratory mouse, have been used to understand the pathogenic mechanisms that underlie PR cell loss and to explore therapies that may prevent, delay, or reverse RD. Here, we reviewed entries in the Mouse Genome Informatics and PubMed databases to compile a comprehensive list of monogenic mouse models in which PR cell loss is demonstrated. The progression of PR cell loss with postnatal age was documented in mutant alleles of genes grouped by biological function. As anticipated, a wide range in the onset and rate of cell loss was observed among the reported models. The analysis underscored relationships between RD genes and ciliary function, transcription-coupled DNA damage repair, and cellular chloride homeostasis. Comparing the mouse gene list to human RD genes identified in the RetNet database revealed that mouse models are available for 40% of the known human diseases, suggesting opportunities for future research. This work may provide insight into the molecular players and pathways through which PR degenerative disease occurs and may be useful for planning translational studies.
Collapse
Affiliation(s)
- Gayle B. Collin
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Navdeep Gogna
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Bo Chang
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Nattaya Damkham
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
- Siriraj Center of Excellence for Stem Cell Research, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - Jai Pinkney
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Lillian F. Hyde
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Lisa Stone
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Jürgen K. Naggert
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Patsy M. Nishina
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
- Correspondence: (P.M.N.); (M.P.K.); Tel.: +1-207-2886-383 (P.M.N.); +1-207-2886-000 (M.P.K.)
| | - Mark P. Krebs
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
- Correspondence: (P.M.N.); (M.P.K.); Tel.: +1-207-2886-383 (P.M.N.); +1-207-2886-000 (M.P.K.)
| |
Collapse
|
21
|
Demaret T, Courtoy GE, Ravau J, Van Der Smissen P, Najimi M, Sokal EM. Accurate and live peroxisome biogenesis evaluation achieved by lentiviral expression of a green fluorescent protein fused to a peroxisome targeting signal 1. Histochem Cell Biol 2020; 153:295-306. [PMID: 32124009 DOI: 10.1007/s00418-020-01855-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/17/2020] [Indexed: 12/30/2022]
Abstract
Peroxisomes are ubiquitous organelles formed by peroxisome biogenesis (PB). During PB, peroxisomal matrix proteins harboring a peroxisome targeting signal (PTS) are imported inside peroxisomes by peroxins, encoded by PEX genes. Genetic alterations in PEX genes lead to a spectrum of incurable diseases called Zellweger spectrum disorders (ZSD). In vitro drug screening is part of the quest for a cure in ZSD by restoring PB in ZSD cell models. In vitro PB evaluation is commonly achieved by immunofluorescent staining or transient peroxisome fluorescent reporter expression. Both techniques have several drawbacks (cost, time-consuming technique, etc.) which we overcame by developing a third-generation lentiviral transfer plasmid expressing an enhanced green fluorescent protein fused to PTS1 (eGFP-PTS1). By eGFP-PTS1 lentiviral transduction, we quantified PB and peroxisome motility in ZSD and control mouse and human fibroblasts. We confirmed the stable eGFP-PTS1 expression along cell passages. eGFP signal analysis distinguished ZSD from control eGFP-PTS1-transduced cells. Live eGFP-PTS1 transduced cells imaging quantified peroxisomes motility. In conclusion, we developed a lentiviral transfer plasmid allowing stable eGFP-PTS1 expression to study PB (deposited on Addgene: #133282). This tool meets the needs for in vitro PB evaluation and ZSD drug discovery.
Collapse
Affiliation(s)
- Tanguy Demaret
- Laboratoire d'Hépatologie Pédiatrique et Thérapie Cellulaire, Unité PEDI, Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain (UCLouvain), 1200, Brussels, Belgium
| | - Guillaume E Courtoy
- IREC Imaging Platform (2IP), Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain (UCLouvain), 1200, Brussels, Belgium
| | - Joachim Ravau
- Laboratoire d'Hépatologie Pédiatrique et Thérapie Cellulaire, Unité PEDI, Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain (UCLouvain), 1200, Brussels, Belgium
| | - Patrick Van Der Smissen
- Platform for Imaging Cells and Tissues (PICT), de Duve Institute, Université Catholique de Louvain (UCLouvain), 1200, Brussels, Belgium
| | - Mustapha Najimi
- Laboratoire d'Hépatologie Pédiatrique et Thérapie Cellulaire, Unité PEDI, Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain (UCLouvain), 1200, Brussels, Belgium
| | - Etienne M Sokal
- Laboratoire d'Hépatologie Pédiatrique et Thérapie Cellulaire, Unité PEDI, Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain (UCLouvain), 1200, Brussels, Belgium.
| |
Collapse
|
22
|
Abe Y, Tamura S, Honsho M, Fujiki Y. A Mouse Model System to Study Peroxisomal Roles in Neurodegeneration of Peroxisome Biogenesis Disorders. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1299:119-143. [PMID: 33417212 DOI: 10.1007/978-3-030-60204-8_10] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Fourteen PEX genes are currently identified as genes responsible for peroxisome biogenesis disorders (PBDs). Patients with PBDs manifest as neurodegenerative symptoms such as neuronal migration defect and malformation of the cerebellum. To address molecular mechanisms underlying the pathogenesis of PBDs, mouse models for the PBDs have been generated by targeted disruption of Pex genes. Pathological phenotypes and metabolic abnormalities in Pex-knockout mice well resemble those of the patients with PBDs. The mice with tissue- or cell type-specific inactivation of Pex genes have also been established by using a Cre-loxP system. The genetically modified mice reveal that pathological phenotypes of PBDs are mediated by interorgan and intercellular communications. Despite the illustrations of detailed pathological phenotypes in the mutant mice, mechanistic insights into pathogenesis of PBDs are still underway. In this chapter, we overview the phenotypes of Pex-inactivated mice and the current understanding of the pathogenesis underlying PBDs.
Collapse
Affiliation(s)
- Yuichi Abe
- Faculty of Arts and Science, Kyushu University, Fukuoka, Japan
| | | | | | - Yukio Fujiki
- Institute of Rheological Functions of Food, Fukuoka, Japan. .,Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan.
| |
Collapse
|
23
|
Argyriou C, Polosa A, Cecyre B, Hsieh M, Di Pietro E, Cui W, Bouchard JF, Lachapelle P, Braverman N. A longitudinal study of retinopathy in the PEX1-Gly844Asp mouse model for mild Zellweger Spectrum Disorder. Exp Eye Res 2019; 186:107713. [PMID: 31254513 DOI: 10.1016/j.exer.2019.107713] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 05/17/2019] [Accepted: 06/25/2019] [Indexed: 02/03/2023]
Abstract
Zellweger Spectrum Disorder (ZSD) is an autosomal recessive disease caused by mutations in any one of 13 PEX genes whose protein products are required for peroxisome assembly. Retinopathy leading to blindness is one of the major untreatable handicaps faced by patients with ZSD but is not well characterized, and the requirement for peroxisomes in retinal health is unknown. To address this, we examined the progression of retinopathy from 2 to 32 weeks of age in our murine model for the common human PEX1-p.Gly843Asp allele (PEX1-p.Gly844Asp) using electrophysiology, histology, immunohistochemistry, electron microscopy, biochemistry, and visual function tests. We found that retinopathy in male and female PEX1-G844D mice was marked by an attenuated cone function and abnormal cone morphology early in life, with gradually decreasing rod function. Structural defects at the inner retina occurred later in the form of bipolar cell degradation (between 13 and 32 weeks). Inner segment disorganization and enlarged mitochondria were seen at 32 weeks, while other inner retinal cells appeared preserved. Visual acuity was diminished by 11 weeks of age, while signal transmission from the retina to the brain was relatively intact from 7 to 32 weeks of age. Molecular analyses showed that PEX1-G844D is a subfunctional but stable protein, contrary to human PEX1-G843D. Finally, C26:0 lysophosphatidylcholine was elevated in the PEX1-G844D retina, while phopshoethanolamine plasmalogen lipids were present at normal levels. These characterization studies identify therapeutic endpoints for future preclinical trials, including improving or preserving the electroretinogram response, improving visual acuity, and/or preventing loss of bipolar cells.
Collapse
Affiliation(s)
- Catherine Argyriou
- Department of Human Genetics, McGill University, Research Institute of the McGill University Health Centre, 1001 Decarie Boulevard, Montreal, Quebec, H4A 3J1, Canada.
| | - Anna Polosa
- Department of Ophthalmology, McGill University, 1001 Decarie Boulevard, Montreal, Quebec, H4A 3J1, Canada.
| | - Bruno Cecyre
- School of Optometry, Université de Montréal, Pavillon 3744 Jean-Brillant, Bureau 260-39, Montréal, Québec, H3T 1P1, Canada.
| | - Monica Hsieh
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, 1001 Decarie Boulevard, Montreal, Quebec, H4A 3J1, Canada.
| | - Erminia Di Pietro
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, 1001 Decarie Boulevard, Montreal, Quebec, H4A 3J1, Canada.
| | - Wei Cui
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, 1001 Decarie Boulevard, Montreal, Quebec, H4A 3J1, Canada.
| | - Jean-François Bouchard
- School of Optometry, Université de Montréal, Pavillon 3744 Jean-Brillant, Bureau 260-39, Montréal, Québec, H3T 1P1, Canada.
| | - Pierre Lachapelle
- Department of Ophthalmology, McGill University, 1001 Decarie Boulevard, Montreal, Quebec, H4A 3J1, Canada; Child Health and Human Development Program, Research Institute of the McGill University Health Centre, 1001 Decarie Boulevard, Montreal, Quebec, H4A 3J1, Canada.
| | - Nancy Braverman
- Department of Human Genetics, McGill University, Research Institute of the McGill University Health Centre, 1001 Decarie Boulevard, Montreal, Quebec, H4A 3J1, Canada; Child Health and Human Development Program, Research Institute of the McGill University Health Centre, 1001 Decarie Boulevard, Montreal, Quebec, H4A 3J1, Canada; Department of Pediatrics, 1001 Decarie Boulevard, Montreal, Quebec, H4A 3J1, Canada.
| |
Collapse
|
24
|
Berendse K, Boek M, Gijbels M, Van der Wel NN, Klouwer FC, van den Bergh-Weerman MA, Shinde AB, Ofman R, Poll-The BT, Houten SM, Baes M, Wanders RJA, Waterham HR. Liver disease predominates in a mouse model for mild human Zellweger spectrum disorder. Biochim Biophys Acta Mol Basis Dis 2019; 1865:2774-2787. [PMID: 31207289 DOI: 10.1016/j.bbadis.2019.06.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 05/28/2019] [Accepted: 06/12/2019] [Indexed: 11/29/2022]
Abstract
Zellweger spectrum disorders (ZSDs) are autosomal recessive diseases caused by defective peroxisome assembly. They constitute a clinical continuum from severe early lethal to relatively milder presentations in adulthood. Liver disease is a prevalent symptom in ZSD patients. The underlying pathogenesis for the liver disease, however, is not fully understood. We report a hypomorphic ZSD mouse model, which is homozygous for Pex1-c.2531G>A (p.G844D), the equivalent of the most common pathogenic variant found in ZSD, and which predominantly presents with liver disease. After introducing the Pex1-G844D allele by knock-in, we characterized homozygous Pex1-G844D mice for survival, biochemical parameters, including peroxisomal and mitochondrial functions, organ histology, and developmental parameters. The first 20 post-natal days (P20) were critical for survival of homozygous Pex1-G844D mice (~20% survival rate). Lethality was likely due to a combination of cholestatic liver problems, liver dysfunction and caloric deficit, probably as a consequence of defective bile acid biosynthesis. Survival beyond P20 was nearly 100%, but surviving mice showed a marked delay in growth. Surviving mice showed similar hepatic problems as described for mild ZSD patients, including hepatomegaly, bile duct proliferation, liver fibrosis and mitochondrial alterations. Biochemical analyses of various tissues showed the absence of functional peroxisomes accompanied with aberrant levels of peroxisomal metabolites predominantly in the liver, while other tissues were relatively spared. ur findings show that homozygous Pex1-G844D mice have a predominant liver disease phenotype, mimicking the hepatic pathology of ZSD patients, and thus constitute a good model to study pathogenesis and treatment of liver disease in ZSD patients.
Collapse
Affiliation(s)
- Kevin Berendse
- Amsterdam UMC, University of Amsterdam, Laboratory Genetic Metabolic Diseases, Amsterdam Gastroenterology & Metabolism, the Netherlands; Emma Children's Hospital, Amsterdam UMC, University of Amsterdam, Paediatric Neurology, the Netherlands
| | - Maxim Boek
- Amsterdam UMC, University of Amsterdam, Laboratory Genetic Metabolic Diseases, Amsterdam Gastroenterology & Metabolism, the Netherlands
| | - Marion Gijbels
- Department of Molecular Genetics, Cardiovascular Research Institute Maastricht, University of Maastricht, the Netherlands
| | | | - Femke C Klouwer
- Amsterdam UMC, University of Amsterdam, Laboratory Genetic Metabolic Diseases, Amsterdam Gastroenterology & Metabolism, the Netherlands; Emma Children's Hospital, Amsterdam UMC, University of Amsterdam, Paediatric Neurology, the Netherlands
| | | | - Abhijit Babaji Shinde
- Department of Pharmaceutical and Pharmacological Sciences, Laboratory of Cell Metabolism, University of Leuven, Belgium
| | - Rob Ofman
- Amsterdam UMC, University of Amsterdam, Laboratory Genetic Metabolic Diseases, Amsterdam Gastroenterology & Metabolism, the Netherlands
| | - Bwee Tien Poll-The
- Emma Children's Hospital, Amsterdam UMC, University of Amsterdam, Paediatric Neurology, the Netherlands
| | - Sander M Houten
- Department of Genetics and Genomic Sciences, Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, USA
| | - Myriam Baes
- Department of Pharmaceutical and Pharmacological Sciences, Laboratory of Cell Metabolism, University of Leuven, Belgium
| | - Ronald J A Wanders
- Amsterdam UMC, University of Amsterdam, Laboratory Genetic Metabolic Diseases, Amsterdam Gastroenterology & Metabolism, the Netherlands
| | - Hans R Waterham
- Amsterdam UMC, University of Amsterdam, Laboratory Genetic Metabolic Diseases, Amsterdam Gastroenterology & Metabolism, the Netherlands.
| |
Collapse
|
25
|
MacLean GE, Argyriou C, Di Pietro E, Sun X, Birjandian S, Saberian P, Hacia JG, Braverman NE. Zellweger spectrum disorder patient-derived fibroblasts with the PEX1-Gly843Asp allele recover peroxisome functions in response to flavonoids. J Cell Biochem 2018; 120:3243-3258. [PMID: 30362618 DOI: 10.1002/jcb.27591] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 08/08/2018] [Indexed: 01/03/2023]
Abstract
Zellweger spectrum disorder (ZSD) results from biallelic mutations in PEX genes required for peroxisome biogenesis. PEX1-G843D is a common hypomorphic allele in the patient population that is associated with milder disease. In prior work using a PEX1-G843D/null patient fibroblast line expressing a green fluorescent protein (GFP) reporter with a peroxisome-targeting signal (GFP-PTS1), we demonstrated that treatments with the chemical chaperone betaine and flavonoid acacetin diacetate recovered peroxisome functions. To identify more effective compounds for preclinical investigation, we evaluated 54 flavonoids using this cell-based phenotype assay. Diosmetin showed the most promising combination of potency and efficacy (EC50 2.5 µM). All active 5',7'-dihydroxyflavones showed greater average efficacy than their corresponding flavonols, whereas the corresponding flavanones, isoflavones, and chalcones tested were inactive. Additional treatment with the proteostasis regulator bortezomib increased the percentage of import-rescued cells over treatment with flavonoids alone. Cotreatments of diosmetin and betaine showed the most robust additive effects, as confirmed by three independent functional assays in primary PEX1-G843D patient cells, but neither agent was active alone or in combination in patient cells homozygous for the PEX1 c.2097_2098insT null allele. Moreover, diosmetin treatment increased PEX1, PEX6, and PEX5 protein levels in PEX1-G843D patient cells, but none of these proteins increased in PEX1 null cells. We propose that diosmetin acts as a pharmacological chaperone that improves the stability, conformation, and functions of PEX1/PEX6 exportomer complexes required for peroxisome assembly. We suggest that diosmetin, in clinical use for chronic venous disease, and related flavonoids warrant further preclinical investigation for the treatment of PEX1-G843D-associated ZSD.
Collapse
Affiliation(s)
- Gillian E MacLean
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Catherine Argyriou
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Erminia Di Pietro
- Department of Pediatrics, Research Institute of the McGill University Health Center, Montreal, Quebec, Canada
| | - Xuting Sun
- Department of Biotechnology, McGill University, Montreal, Quebec, Canada
| | - Sara Birjandian
- Department of Biotechnology, McGill University, Montreal, Quebec, Canada
| | - Panteha Saberian
- Department of Biotechnology, McGill University, Montreal, Quebec, Canada
| | - Joseph G Hacia
- Department of Biochemistry and Molecular Medicine, Keck School of Medicine, Los Angeles, California
| | - Nancy E Braverman
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada.,Department of Pediatrics, Research Institute of the McGill University Health Center, Montreal, Quebec, Canada
| |
Collapse
|
26
|
Abstract
Peroxisomes are ubiquitous and highly dynamic organelles that play a central role in the metabolism of lipids and reactive oxygen species. The importance of peroxisomal metabolism is illustrated by severe peroxisome biogenesis disorders in which functional peroxisomes are absent or disorders caused by single peroxisomal enzyme deficiencies. These multisystemic diseases manifest specific clinical and biochemical disturbances that originate from the affected peroxisomal pathways. An emerging role of the peroxisome has been identified in many types of diseases, including cancer, neurodegenerative disorders, aging, obesity, and diabetes. Peroxisome homeostasis is achieved via a tightly regulated interplay between peroxisome biogenesis and degradation via selective autophagy, which is commonly known as "pexophagy". Dysregulation of either peroxisome biogenesis or pexophagy may be detrimental to the health of cells and contribute to the pathophysiology of these diseases. Autophagy is an evolutionary conserved catabolic process for non-selective degradation of macromolecules and organelles in response to various stressors. In selective autophagy, specific cargo-recognizing receptors connect the cargo to the core autophagic machinery, and additional posttranslational modifications such as ubiquitination and phosphorylation regulate this process. Several stress conditions have been shown to stimulate pexophagy and decrease peroxisome abundance. However, our understanding of the mechanisms that particularly regulate mammalian pexophagy has been limited. In recent years considerable progress has been made uncovering signaling pathways, autophagy receptors and adaptors as well as posttranslational modifications involved in pexophagy. In this review, which is published back-to-back with a peroxisome review by Islinger et al. [(Histochem Cell Biol 137:547-574, 2018). The peroxisome: an update on mysteries 2.0], we focus on recent novel findings on the underlying molecular mechanisms of pexophagy in yeast and mammalian cells and highlight concerns and gaps in our knowledge.
Collapse
|
27
|
Tam PKH, Yiu RS, Lendahl U, Andersson ER. Cholangiopathies - Towards a molecular understanding. EBioMedicine 2018; 35:381-393. [PMID: 30236451 PMCID: PMC6161480 DOI: 10.1016/j.ebiom.2018.08.024] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 08/06/2018] [Accepted: 08/09/2018] [Indexed: 12/14/2022] Open
Abstract
Liver diseases constitute an important medical problem, and a number of these diseases, termed cholangiopathies, affect the biliary system of the liver. In this review, we describe the current understanding of the causes of cholangiopathies, which can be genetic, viral or environmental, and the few treatment options that are currently available beyond liver transplantation. We then discuss recent rapid progress in a number of areas relevant for decoding the disease mechanisms for cholangiopathies. This includes novel data from analysis of transgenic mouse models and organoid systems, and we outline how this information can be used for disease modeling and potential development of novel therapy concepts. We also describe recent advances in genomic and transcriptomic analyses and the importance of such studies for improving diagnosis and determining whether certain cholangiopathies should be viewed as distinct or overlapping disease entities.
Collapse
Affiliation(s)
- Paul K H Tam
- Department of Surgery, Li Ka Shing Faculty of Medicine, and Dr. Li Dak-Sum Research Centre, The University of Hong Kong - Karolinska Institutet Collaboration in Regenerative Medicine, and The University of Hong Kong, Hong Kong.
| | - Rachel S Yiu
- Department of Surgery, Li Ka Shing Faculty of Medicine, and Dr. Li Dak-Sum Research Centre, The University of Hong Kong - Karolinska Institutet Collaboration in Regenerative Medicine, and The University of Hong Kong, Hong Kong
| | - Urban Lendahl
- Department of Cell and Molecular Biology, Karolinska Institute, Stockholm, Sweden
| | - Emma R Andersson
- Department of Cell and Molecular Biology, Karolinska Institute, Stockholm, Sweden; Department of Biosciences and Nutrition, Karolinska Institute, Huddinge, Sweden.
| |
Collapse
|
28
|
Law KB, Bronte-Tinkew D, Di Pietro E, Snowden A, Jones RO, Moser A, Brumell JH, Braverman N, Kim PK. The peroxisomal AAA ATPase complex prevents pexophagy and development of peroxisome biogenesis disorders. Autophagy 2018; 13:868-884. [PMID: 28521612 PMCID: PMC5446072 DOI: 10.1080/15548627.2017.1291470] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Peroxisome biogenesis disorders (PBDs) are metabolic disorders caused by the loss of peroxisomes. The majority of PBDs result from mutation in one of 3 genes that encode for the peroxisomal AAA ATPase complex (AAA-complex) required for cycling PEX5 for peroxisomal matrix protein import. Mutations in these genes are thought to result in a defect in peroxisome assembly by preventing the import of matrix proteins. However, we show here that loss of the AAA-complex does not prevent matrix protein import, but instead causes an upregulation of peroxisome degradation by macroautophagy, or pexophagy. The loss of AAA-complex function in cells results in the accumulation of ubiquitinated PEX5 on the peroxisomal membrane that signals pexophagy. Inhibiting autophagy by genetic or pharmacological approaches rescues peroxisome number, protein import and function. Our findings suggest that the peroxisomal AAA-complex is required for peroxisome quality control, whereas its absence results in the selective degradation of the peroxisome. Thus the loss of peroxisomes in PBD patients with mutations in their peroxisomal AAA-complex is a result of increased pexophagy. Our study also provides a framework for the development of novel therapeutic treatments for PBDs.
Collapse
Affiliation(s)
- Kelsey B Law
- a Cell Biology Program , Hospital for Sick Children, Peter Gilgan Centre for Research and Learning , Toronto , ON , Canada.,b Department of Biochemistry , University of Toronto , Toronto , ON , Canada
| | - Dana Bronte-Tinkew
- a Cell Biology Program , Hospital for Sick Children, Peter Gilgan Centre for Research and Learning , Toronto , ON , Canada
| | - Erminia Di Pietro
- c Research Institute of the MUHC and McGill University , Montreal , QC , Canada
| | - Ann Snowden
- d Kennedy Krieger Institute , Baltimore , MD , USA
| | | | - Ann Moser
- d Kennedy Krieger Institute , Baltimore , MD , USA
| | - John H Brumell
- a Cell Biology Program , Hospital for Sick Children, Peter Gilgan Centre for Research and Learning , Toronto , ON , Canada.,e Department of Molecular Genetics , University of Toronto , Toronto , ON , Canada.,f Institute of Medical Science, University of Toronto , Toronto , ON , Canada.,g SickKids IBD Centre , Hospital for Sick Children , Toronto , ON , Canada
| | - Nancy Braverman
- c Research Institute of the MUHC and McGill University , Montreal , QC , Canada
| | - Peter K Kim
- a Cell Biology Program , Hospital for Sick Children, Peter Gilgan Centre for Research and Learning , Toronto , ON , Canada.,b Department of Biochemistry , University of Toronto , Toronto , ON , Canada
| |
Collapse
|
29
|
Jafari N, Golnik K, Shahriari M, Karimzadeh P, Jabbehdari S. Ophthalmologic Findings in Patients with Neuro-metabolic Disorders. J Ophthalmic Vis Res 2018; 13:34-38. [PMID: 29403587 PMCID: PMC5782454 DOI: 10.4103/jovr.jovr_242_16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Purpose: We aimed to present the ophthalmic manifestations of neuro-metabolic disorders. Methods: Patients who were diagnosed with neuro-metabolic disorders in the Neurology Department of Mofid Pediatric Hospital in Tehran, Iran, between 2004 and 2014 were included in this study. Disorders were confirmed using clinical findings, neuroimaging, laboratory data, and genomic analyses. All enrolled patients were assessed for ophthalmological abnormalities. Results: A total of 213 patients with 34 different neuro-metabolic disorders were included. Ophthalmological abnormalities were observed in 33.5% of patients. Abnormal findings in the anterior segment included Kayser–Fleischer rings, congenital or secondary cataracts, and lens dislocation into the anterior chamber. Posterior segment (i.e., retina, vitreous body, and optic nerve) evaluation revealed retinitis pigmentosa, cherry-red spots, and optic atrophy. In addition, strabismus, nystagmus, and lack of fixation were noted during external examination. Conclusion: Ophthalmological examination and assessment is essential in patients that may exhibit neuro-metabolic disorders.
Collapse
Affiliation(s)
- Narjes Jafari
- Pediatric Neurology Research Center, Mofid Children Hospital, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Karl Golnik
- Department of Ophthalmology, University of Cincinnati, Cincinnati, Ohio, USA
| | - Mansoor Shahriari
- Department of Ophthalmology, Imam Hossein Hospital, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Parvaneh Karimzadeh
- Pediatric Neurology Research Center, Mofid Children Hospital, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Sayena Jabbehdari
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| |
Collapse
|
30
|
Wangler MF, Chao YH, Bayat V, Giagtzoglou N, Shinde AB, Putluri N, Coarfa C, Donti T, Graham BH, Faust JE, McNew JA, Moser A, Sardiello M, Baes M, Bellen HJ. Peroxisomal biogenesis is genetically and biochemically linked to carbohydrate metabolism in Drosophila and mouse. PLoS Genet 2017; 13:e1006825. [PMID: 28640802 PMCID: PMC5480855 DOI: 10.1371/journal.pgen.1006825] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 05/16/2017] [Indexed: 01/07/2023] Open
Abstract
Peroxisome biogenesis disorders (PBD) are a group of multi-system human diseases due to mutations in the PEX genes that are responsible for peroxisome assembly and function. These disorders lead to global defects in peroxisomal function and result in severe brain, liver, bone and kidney disease. In order to study their pathogenesis we undertook a systematic genetic and biochemical study of Drosophila pex16 and pex2 mutants. These mutants are short-lived with defects in locomotion and activity. Moreover these mutants exhibit severe morphologic and functional peroxisomal defects. Using metabolomics we uncovered defects in multiple biochemical pathways including defects outside the canonical specialized lipid pathways performed by peroxisomal enzymes. These included unanticipated changes in metabolites in glycolysis, glycogen metabolism, and the pentose phosphate pathway, carbohydrate metabolic pathways that do not utilize known peroxisomal enzymes. In addition, mutant flies are starvation sensitive and are very sensitive to glucose deprivation exhibiting dramatic shortening of lifespan and hyperactivity on low-sugar food. We use bioinformatic transcriptional profiling to examine gene co-regulation between peroxisomal genes and other metabolic pathways and we observe that the expression of peroxisomal and carbohydrate pathway genes in flies and mouse are tightly correlated. Indeed key steps in carbohydrate metabolism were found to be strongly co-regulated with peroxisomal genes in flies and mice. Moreover mice lacking peroxisomes exhibit defective carbohydrate metabolism at the same key steps in carbohydrate breakdown. Our data indicate an unexpected link between these two metabolic processes and suggest metabolism of carbohydrates could be a new therapeutic target for patients with PBD.
Collapse
Affiliation(s)
- Michael F. Wangler
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX, United States of America
- Texas Children’s Hospital, Houston TX, United States of America
- Program in Developmental Biology, BCM, Houston, TX, United States of America
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital (TCH), Houston, TX, United States of America
| | - Yu-Hsin Chao
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX, United States of America
| | - Vafa Bayat
- Program in Developmental Biology, BCM, Houston, TX, United States of America
| | - Nikolaos Giagtzoglou
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX, United States of America
| | - Abhijit Babaji Shinde
- KU Leuven, Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, Leuven, Belgium
| | - Nagireddy Putluri
- Department of Molecular and Cellular Biology, BCM, Houston, TX, United States of America
| | - Cristian Coarfa
- Department of Molecular and Cellular Biology, BCM, Houston, TX, United States of America
| | - Taraka Donti
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX, United States of America
| | - Brett H. Graham
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX, United States of America
| | - Joseph E. Faust
- Department of BioSciences, Rice University, Houston TX, United States of America
| | - James A. McNew
- Department of BioSciences, Rice University, Houston TX, United States of America
| | - Ann Moser
- Kennedy Krieger Institute, Baltimore MD, United States of America
| | - Marco Sardiello
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX, United States of America
- Program in Developmental Biology, BCM, Houston, TX, United States of America
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital (TCH), Houston, TX, United States of America
| | - Myriam Baes
- KU Leuven, Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, Leuven, Belgium
| | - Hugo J. Bellen
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX, United States of America
- Texas Children’s Hospital, Houston TX, United States of America
- Program in Developmental Biology, BCM, Houston, TX, United States of America
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital (TCH), Houston, TX, United States of America
- Howard Hughes Medical Institute, Houston, TX, United States of America
- Department of Neuroscience, BCM, Houston, TX, United States of America
| |
Collapse
|
31
|
Ge MM, Hu L, Li Z, Cheng G, Yan K, Kong Y, Wang H, Yang L, Zhou W. Novel compound heterozygous mutations in the PEX1 gene in two Chinese newborns with Zellweger syndrome based on whole exome sequencing. Clin Chim Acta 2017; 470:24-28. [PMID: 28432012 DOI: 10.1016/j.cca.2017.04.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 04/16/2017] [Accepted: 04/18/2017] [Indexed: 11/18/2022]
Abstract
Peroxisome biogenesis disorders (PBDs) represent a spectrum of human genetic disorders that are characterized by damaged peroxisome assembly. In the newborn period, the characteristics of affected patients include dysmorphic facial features, neonatal hypotonia, seizures, ocular abnormalities, poor feeding, liver cysts with hepatic dysfunction and skeletal defects. These can be caused by a defect in at least 14 different PEX genes. In this study, whole-exome sequencing (WES) was performed on samples from two Chinese newborns with clinical features of Zellweger syndrome. WES identified two novel mutations (c.2416+1G>T and c.2489delT) in patient 1 and another two novel mutations (c.1483+1G>A and c.1727dupG) in patient 2 in the PEX1 gene. All four mutations have a serious influence on the protein function, which also highlights the power of WES, particularly in clinically challenging cases.
Collapse
Affiliation(s)
- Meng-Meng Ge
- Department of Neonates, Children's Hospital of Fudan University, Shanghai, China
| | - LiYuan Hu
- Department of Neonates, Children's Hospital of Fudan University, Shanghai, China
| | - ZhiHua Li
- Department of Neonates, Children's Hospital of Fudan University, Shanghai, China
| | - GuoQiang Cheng
- Department of Neonates, Children's Hospital of Fudan University, Shanghai, China
| | - Kai Yan
- Department of Neonates, Children's Hospital of Fudan University, Shanghai, China
| | - YanTing Kong
- Department of Neonates, Children's Hospital of Fudan University, Shanghai, China
| | - HuiJun Wang
- Birth Defect Laboratory, Children's Hospital of Fudan University, Shanghai, China
| | - Lin Yang
- Clinical Genetic Center, Children's Hospital of Fudan University, Shanghai, China
| | - WenHao Zhou
- Department of Neonates, Children's Hospital of Fudan University, Shanghai, China; Birth Defect Laboratory, Children's Hospital of Fudan University, Shanghai, China.
| |
Collapse
|
32
|
Bousfiha A, Bakhchane A, Charoute H, Riahi Z, Snoussi K, Rouba H, Bonnet C, Petit C, Barakat A. A novel PEX1 mutation in a Moroccan family with Zellweger spectrum disorders. Hum Genome Var 2017; 4:17009. [PMID: 28446956 PMCID: PMC5390255 DOI: 10.1038/hgv.2017.9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 02/03/2017] [Accepted: 02/07/2017] [Indexed: 01/18/2023] Open
Abstract
Mutations in the PEX1 gene are usually associated with recessive inherited diseases including Zellweger spectrum disorders. In this work, we identified a new pathogenic missense homozygous PEX1 mutation (p.Leu1026Pro, c.3077T>C) in two Moroccan syndromic deaf siblings from consanguineous parents. This variation is located in the P-loop containing nucleoside triphosphate hydrolase of protein domain and probably causes an alteration in the hydrolysis of ATP.
Collapse
Affiliation(s)
- Amale Bousfiha
- Human Molecular Genetics Laboratory, Institut Pasteur du Maroc, Casablanca, Morocco
| | - Amina Bakhchane
- Human Molecular Genetics Laboratory, Institut Pasteur du Maroc, Casablanca, Morocco
| | - Hicham Charoute
- Human Molecular Genetics Laboratory, Institut Pasteur du Maroc, Casablanca, Morocco
| | - Zied Riahi
- INSERM UMRS1120, Institut de la Vision, Paris, France.,UPMC-Sorbonnes Universités Paris VI, Paris, France
| | - Khalid Snoussi
- Human Molecular Genetics Laboratory, Institut Pasteur du Maroc, Casablanca, Morocco
| | - Hassan Rouba
- Human Molecular Genetics Laboratory, Institut Pasteur du Maroc, Casablanca, Morocco
| | - Crystel Bonnet
- INSERM UMRS1120, Institut de la Vision, Paris, France.,UPMC-Sorbonnes Universités Paris VI, Paris, France
| | - Christine Petit
- INSERM UMRS1120, Institut de la Vision, Paris, France.,UPMC-Sorbonnes Universités Paris VI, Paris, France.,Unité de Génétique et Physiologie de l'Audition, Institut Pasteur, Paris, France.,Collège de France, Paris, France
| | - Abdelhamid Barakat
- Human Molecular Genetics Laboratory, Institut Pasteur du Maroc, Casablanca, Morocco
| |
Collapse
|
33
|
Taking Stock of Retinal Gene Therapy: Looking Back and Moving Forward. Mol Ther 2017; 25:1076-1094. [PMID: 28391961 DOI: 10.1016/j.ymthe.2017.03.008] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 03/04/2017] [Accepted: 03/04/2017] [Indexed: 11/23/2022] Open
Abstract
Over the past 20 years, there has been tremendous progress in retinal gene therapy. The safety and efficacy results in one early-onset severe blinding disease may lead to the first gene therapy drug approval in the United States. Here, we review how far the field has come over the past two decades and speculate on the directions that the field will take in the future.
Collapse
|
34
|
Abstract
Peroxisome biogenesis disorders (PBDs) is a group of diseases caused by mutations in one of the peroxins, proteins responsible for biogenesis of the peroxisomes. In recent years, it became clear that many peroxins (e.g., PEX3 and PEX14) play additional roles in peroxisome homeostasis (such as promoting autophagic degradation of peroxisomes or pexophagy), which are often opposite to their originally established functions in peroxisome formation and maintenance. Even more interesting, the peroxins that make up the peroxisomal AAA ATPase complex (AAA-complex) in yeast (Pex1, Pex6 and Pex15) or mammals (PEX1, PEX6, PEX26) are responsible for the downregulation of pexophagy. Moreover, this might be even their primary role in human: to prevent pexophagy by removing from the peroxisomal membrane the ubiquitinated peroxisomal matrix protein import receptor, Ub-PEX5, which is also a signal for the Ub-binding pexophagy receptor, NBR1. Remarkably, the peroxisomes rescued from pexophagy by autophagic inhibitors in PEX1G843D (the most common PBD mutation) cells are able to import matrix proteins and improve their biochemical function suggesting that the AAA-complex per se is not essential for the protein import function in human. This paradigm-shifting discovery published in the current issue of Autophagy has raised hope for up to 65% of all PBD patients with various deficiencies in the AAA-complex. Recognizing PEX1, PEX6 and PEX26 as pexophagy suppressors will allow treating these patients with a new range of tools designed to target mammalian pexophagy.
Collapse
Affiliation(s)
- Taras Y Nazarko
- a Section of Molecular Biology , Division of Biological Sciences, UC San Diego , La Jolla , CA , USA
| |
Collapse
|
35
|
Affiliation(s)
| | - Maria Daniela D'Agostino
- McGill University Department of Human Genetics and McGill University Health Center, Department of Medical Genetics, Montreal, QC, Canada
| | - Nancy Braverman
- McGill University Department of Human Genetics and Pediatrics, and The Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| |
Collapse
|
36
|
Braverman NE, Raymond GV, Rizzo WB, Moser AB, Wilkinson ME, Stone EM, Steinberg SJ, Wangler MF, Rush ET, Hacia JG, Bose M. Peroxisome biogenesis disorders in the Zellweger spectrum: An overview of current diagnosis, clinical manifestations, and treatment guidelines. Mol Genet Metab 2016; 117:313-21. [PMID: 26750748 PMCID: PMC5214431 DOI: 10.1016/j.ymgme.2015.12.009] [Citation(s) in RCA: 154] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Revised: 12/21/2015] [Accepted: 12/21/2015] [Indexed: 10/22/2022]
Abstract
Peroxisome biogenesis disorders in the Zellweger spectrum (PBD-ZSD) are a heterogeneous group of genetic disorders caused by mutations in PEX genes responsible for normal peroxisome assembly and functions. As a result of impaired peroxisomal activities, individuals with PBD-ZSD can manifest a complex spectrum of clinical phenotypes that typically result in shortened life spans. The extreme variability in disease manifestation ranging from onset of profound neurologic symptoms in newborns to progressive degenerative disease in adults presents practical challenges in disease diagnosis and medical management. Recent advances in biochemical methods for newborn screening and genetic testing have provided unprecedented opportunities for identifying patients at the earliest possible time and defining the molecular bases for their diseases. Here, we provide an overview of current clinical approaches for the diagnosis of PBD-ZSD and provide broad guidelines for the treatment of disease in its wide variety of forms. Although we anticipate future progress in the development of more effective targeted interventions, the current guidelines are meant to provide a starting point for the management of these complex conditions in the context of personalized health care.
Collapse
Affiliation(s)
- Nancy E Braverman
- McGill University Health Centre, 1001 Décarie Blvd Block E, EM02230, Montreal, QC H4A3J1, Canada.
| | - Gerald V Raymond
- Department of Neurology, University of Minnesota, 516 Delaware Street SE, Minneapolis, MN 55455, USA,.
| | - William B Rizzo
- Department of Pediatrics, University of Nebraska Medical Center, 985456 Nebraska Medical Center - MMI 3062, Omaha, NE 68198-5456, USA.
| | - Ann B Moser
- Hugo W. Moser Research Institute at Kennedy Krieger, 707 N. Broadway, Baltimore, MD 21205, USA.
| | - Mark E Wilkinson
- Carver College of Medicine, Department of Ophthalmology and Visual Sciences, University of Iowa, Stephen A. Wynn Institute for Vision Research, 200 Hawkins Drive, Iowa City, IA 52242, USA.
| | - Edwin M Stone
- Carver College of Medicine, Department of Ophthalmology and Visual Sciences, University of Iowa, Stephen A. Wynn Institute for Vision Research, 200 Hawkins Drive, Iowa City, IA 52242, USA.
| | - Steven J Steinberg
- Institute of Genetic Medicine and Department of Neurology, Johns Hopkins University School of Medicine, CMSC1004B, 600 N Wolfe Street, Baltimore, MD 21287, USA.
| | - Michael F Wangler
- Department of Molecular and Human Genetics, Baylor College of Medicine, Duncan Neurological Research Institute, DNRI-1050, Houston, TX 77030, USA.
| | - Eric T Rush
- Munroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center, 985440 Nebraska Medical Center, Omaha, NE 68198, USA.
| | - Joseph G Hacia
- Department of Biochemistry and Molecular Biology, University of Southern California, 1975 Zonal Ave, Los Angeles, CA 90033, USA.
| | - Mousumi Bose
- Global Foundation for Peroxisomal Disorders, 5147 S. Harvard Avenue, Suite 181, Tulsa, OK 74135, USA.
| |
Collapse
|
37
|
Berendse K, Engelen M, Ferdinandusse S, Majoie CBLM, Waterham HR, Vaz FM, Koelman JHTM, Barth PG, Wanders RJA, Poll-The BT. Zellweger spectrum disorders: clinical manifestations in patients surviving into adulthood. J Inherit Metab Dis 2016; 39:93-106. [PMID: 26287655 PMCID: PMC4710674 DOI: 10.1007/s10545-015-9880-2] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Revised: 06/25/2015] [Accepted: 06/25/2015] [Indexed: 11/28/2022]
Abstract
INTRODUCTION We describe the natural history of patients with a Zellweger spectrum disorder (ZSD) surviving into adulthood. METHODS Retrospective cohort study in patients with a genetically confirmed ZSD. RESULTS All patients (n = 19; aged 16-35 years) had a follow-up period of 1-24.4 years (mean 16 years). Seven patients had a progressive disease course, while 12 remained clinically stable during follow-up. Disease progression usually manifests in adolescence as a gait disorder, caused by central and/or peripheral nervous system involvement. Nine were capable of living a partly independent life with supported employment. Systematic MRI review revealed T2 hyperintense white matter abnormalities in the hilus of the dentate nucleus and/or peridentate region in nine out of 16 patients. Biochemical analyses in blood showed abnormal peroxisomal biomarkers in all patients in infancy and childhood, whereas in adolescence/adulthood we observed normalization of some metabolites. CONCLUSIONS The patients described here represent a distinct subgroup within the ZSDs who survive into adulthood. Most remain stable over many years. Disease progression may occur and is mainly due to cerebral and cerebellar white matter abnormalities, and peripheral neuropathy.
Collapse
Affiliation(s)
- Kevin Berendse
- Department of Paediatric Neurology, Emma Children's Hospital, Academic Medical Centre (AMC), University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
- Laboratory Genetic Metabolic Diseases, Emma Children's Hospital, AMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Marc Engelen
- Department of Paediatric Neurology, Emma Children's Hospital, Academic Medical Centre (AMC), University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Sacha Ferdinandusse
- Laboratory Genetic Metabolic Diseases, Emma Children's Hospital, AMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Charles B L M Majoie
- Department of Radiology, AMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Hans R Waterham
- Laboratory Genetic Metabolic Diseases, Emma Children's Hospital, AMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Frédéric M Vaz
- Laboratory Genetic Metabolic Diseases, Emma Children's Hospital, AMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Johannes H T M Koelman
- Department of Neurology and Clinical Neurophysiology, AMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Peter G Barth
- Department of Paediatric Neurology, Emma Children's Hospital, Academic Medical Centre (AMC), University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Ronald J A Wanders
- Laboratory Genetic Metabolic Diseases, Emma Children's Hospital, AMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Bwee Tien Poll-The
- Department of Paediatric Neurology, Emma Children's Hospital, Academic Medical Centre (AMC), University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
| |
Collapse
|
38
|
Berger J, Dorninger F, Forss-Petter S, Kunze M. Peroxisomes in brain development and function. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1863:934-55. [PMID: 26686055 PMCID: PMC4880039 DOI: 10.1016/j.bbamcr.2015.12.005] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 12/04/2015] [Accepted: 12/09/2015] [Indexed: 12/26/2022]
Abstract
Peroxisomes contain numerous enzymatic activities that are important for mammalian physiology. Patients lacking either all peroxisomal functions or a single enzyme or transporter function typically develop severe neurological deficits, which originate from aberrant development of the brain, demyelination and loss of axonal integrity, neuroinflammation or other neurodegenerative processes. Whilst correlating peroxisomal properties with a compilation of pathologies observed in human patients and mouse models lacking all or individual peroxisomal functions, we discuss the importance of peroxisomal metabolites and tissue- and cell type-specific contributions to the observed brain pathologies. This enables us to deconstruct the local and systemic contribution of individual metabolic pathways to specific brain functions. We also review the recently discovered variability of pathological symptoms in cases with unexpectedly mild presentation of peroxisome biogenesis disorders. Finally, we explore the emerging evidence linking peroxisomes to more common neurological disorders such as Alzheimer’s disease, autism and amyotrophic lateral sclerosis. This article is part of a Special Issue entitled: Peroxisomes edited by Ralf Erdmann.
Collapse
Affiliation(s)
- Johannes Berger
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria.
| | - Fabian Dorninger
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria.
| | - Sonja Forss-Petter
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria.
| | - Markus Kunze
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria.
| |
Collapse
|
39
|
Klouwer FCC, Berendse K, Ferdinandusse S, Wanders RJA, Engelen M, Poll-The BT. Zellweger spectrum disorders: clinical overview and management approach. Orphanet J Rare Dis 2015; 10:151. [PMID: 26627182 PMCID: PMC4666198 DOI: 10.1186/s13023-015-0368-9] [Citation(s) in RCA: 128] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Accepted: 11/22/2015] [Indexed: 11/15/2022] Open
Abstract
Zellweger spectrum disorders (ZSDs) represent the major subgroup within the peroxisomal biogenesis disorders caused by defects in PEX genes. The Zellweger spectrum is a clinical and biochemical continuum which can roughly be divided into three clinical phenotypes. Patients can present in the neonatal period with severe symptoms or later in life during adolescence or adulthood with only minor features. A defect of functional peroxisomes results in several metabolic abnormalities, which in most cases can be detected in blood and urine. There is currently no curative therapy, but supportive care is available. This review focuses on the management of patients with a ZSD and provides recommendations for supportive therapeutic options for all those involved in the care for ZSD patients.
Collapse
Affiliation(s)
- Femke C C Klouwer
- Department of Paediatric Neurology, Emma Children's Hospital, Academic Medical Center, University of Amsterdam, Meibergdreef 9, PO BOX 22660, 1105 AZ, Amsterdam, The Netherlands. .,Laboratory Genetic Metabolic Diseases, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
| | - Kevin Berendse
- Department of Paediatric Neurology, Emma Children's Hospital, Academic Medical Center, University of Amsterdam, Meibergdreef 9, PO BOX 22660, 1105 AZ, Amsterdam, The Netherlands. .,Laboratory Genetic Metabolic Diseases, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
| | - Sacha Ferdinandusse
- Laboratory Genetic Metabolic Diseases, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
| | - Ronald J A Wanders
- Laboratory Genetic Metabolic Diseases, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
| | - Marc Engelen
- Department of Paediatric Neurology, Emma Children's Hospital, Academic Medical Center, University of Amsterdam, Meibergdreef 9, PO BOX 22660, 1105 AZ, Amsterdam, The Netherlands.
| | - Bwee Tien Poll-The
- Department of Paediatric Neurology, Emma Children's Hospital, Academic Medical Center, University of Amsterdam, Meibergdreef 9, PO BOX 22660, 1105 AZ, Amsterdam, The Netherlands.
| |
Collapse
|
40
|
Baes M, Van Veldhoven PP. Hepatic dysfunction in peroxisomal disorders. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1863:956-70. [PMID: 26453805 DOI: 10.1016/j.bbamcr.2015.09.035] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 09/25/2015] [Accepted: 09/28/2015] [Indexed: 12/18/2022]
Abstract
The peroxisomal compartment in hepatocytes hosts several essential metabolic conversions. These are defective in peroxisomal disorders that are either caused by failure to import the enzymes in the organelle or by mutations in the enzymes or in transporters needed to transfer the substrates across the peroxisomal membrane. Hepatic pathology is one of the cardinal features in disorders of peroxisome biogenesis and peroxisomal β-oxidation although it only rarely determines the clinical fate. In mouse models of these diseases liver pathologies also occur, although these are not always concordant with the human phenotype which might be due to differences in diet, expression of enzymes and backup mechanisms. Besides the morphological changes, we overview the impact of peroxisome malfunction on other cellular compartments including mitochondria and the ER. We further focus on the metabolic pathways that are affected such as bile acid formation, and dicarboxylic acid and branched chain fatty acid degradation. It appears that the association between deregulated metabolites and pathological events remains unclear.
Collapse
Affiliation(s)
- Myriam Baes
- Laboratory for Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, B-3000 Leuven, Belgium.
| | - Paul P Van Veldhoven
- Laboratory for Lipid Biochemistry and Protein Interactions, Department of Cellular and Molecular Medicine, KU Leuven, B-3000 Leuven, Belgium.
| |
Collapse
|
41
|
Wang XM, Yik WY, Zhang P, Lu W, Huang N, Kim BR, Shibata D, Zitting M, Chow RH, Moser AB, Steinberg SJ, Hacia JG. Induced pluripotent stem cell models of Zellweger spectrum disorder show impaired peroxisome assembly and cell type-specific lipid abnormalities. Stem Cell Res Ther 2015; 6:158. [PMID: 26319495 PMCID: PMC4553005 DOI: 10.1186/s13287-015-0149-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 05/26/2015] [Accepted: 08/07/2015] [Indexed: 01/08/2023] Open
Abstract
Introduction Zellweger spectrum disorder (PBD-ZSD) is a disease continuum caused by mutations in a subset of PEX genes required for normal peroxisome assembly and function. They highlight the importance of peroxisomes in the development and functions of the central nervous system, liver, and other organs. To date, the underlying bases for the cell-type specificity of disease are not fully elucidated. Methods Primary skin fibroblasts from seven PBD-ZSD patients with biallelic PEX1, PEX10, PEX12, or PEX26 mutations and three healthy donors were transduced with retroviral vectors expressing Yamanaka reprogramming factors. Candidate induced pluripotent stem cells (iPSCs) were subject to global gene expression, DNA methylation, copy number variation, genotyping, in vitro differentiation and teratoma formation assays. Confirmed iPSCs were differentiated into neural progenitor cells (NPCs), neurons, oligodendrocyte precursor cells (OPCs), and hepatocyte-like cell cultures with peroxisome assembly evaluated by microscopy. Saturated very long chain fatty acid (sVLCFA) and plasmalogen levels were determined in primary fibroblasts and their derivatives. Results iPSCs were derived from seven PBD-ZSD patient-derived fibroblasts with mild to severe peroxisome assembly defects. Although patient and control skin fibroblasts had similar gene expression profiles, genes related to mitochondrial functions and organelle cross-talk were differentially expressed among corresponding iPSCs. Mitochondrial DNA levels were consistent among patient and control fibroblasts, but varied among all iPSCs. Relative to matching controls, sVLCFA levels were elevated in patient-derived fibroblasts, reduced in patient-derived iPSCs, and not significantly different in patient-derived NPCs. All cell types derived from donors with biallelic null mutations in a PEX gene showed plasmalogen deficiencies. Reporter gene assays compatible with high content screening (HCS) indicated patient-derived OPC and hepatocyte-like cell cultures had impaired peroxisome assembly. Conclusions Normal peroxisome activity levels are not required for cellular reprogramming of skin fibroblasts. Patient iPSC gene expression profiles were consistent with hypotheses highlighting the role of altered mitochondrial activities and organelle cross-talk in PBD-ZSD pathogenesis. sVLCFA abnormalities dramatically differed among patient cell types, similar to observations made in iPSC models of X-linked adrenoleukodystrophy. We propose that iPSCs could assist investigations into the cell type-specificity of peroxisomal activities, toxicology studies, and in HCS for targeted therapies for peroxisome-related disorders. Electronic supplementary material The online version of this article (doi:10.1186/s13287-015-0149-3) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Xiao-Ming Wang
- Department of Biochemistry and Molecular Biology, University of Southern California, Los Angeles, California, USA.
| | - Wing Yan Yik
- Department of Biochemistry and Molecular Biology, University of Southern California, Los Angeles, California, USA.
| | - Peilin Zhang
- Department of Biochemistry and Molecular Biology, University of Southern California, Los Angeles, California, USA.
| | - Wange Lu
- Department of Biochemistry and Molecular Biology, University of Southern California, Los Angeles, California, USA.
| | - Ning Huang
- Department of Biochemistry and Molecular Biology, University of Southern California, Los Angeles, California, USA.
| | - Bo Ram Kim
- Department of Biochemistry and Molecular Biology, University of Southern California, Los Angeles, California, USA.
| | - Darryl Shibata
- Department of Pathology, University of Southern California, Los Angeles, California, USA.
| | - Madison Zitting
- Department of Physiology and Biophysics, University of Southern California, Los Angeles, California, USA.
| | - Robert H Chow
- Department of Physiology and Biophysics, University of Southern California, Los Angeles, California, USA.
| | - Ann B Moser
- Hugo W. Moser Research Institute at Kennedy Krieger, Baltimore, Maryland, USA.
| | - Steven J Steinberg
- Hugo W. Moser Research Institute at Kennedy Krieger, Baltimore, Maryland, USA.
| | - Joseph G Hacia
- Department of Biochemistry and Molecular Biology, University of Southern California, Los Angeles, California, USA.
| |
Collapse
|
42
|
Walter KM, Schönenberger MJ, Trötzmüller M, Horn M, Elsässer HP, Moser AB, Lucas MS, Schwarz T, Gerber PA, Faust PL, Moch H, Köfeler HC, Krek W, Kovacs WJ. Hif-2α promotes degradation of mammalian peroxisomes by selective autophagy. Cell Metab 2014; 20:882-897. [PMID: 25440060 DOI: 10.1016/j.cmet.2014.09.017] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 08/26/2014] [Accepted: 09/24/2014] [Indexed: 12/21/2022]
Abstract
Peroxisomes play a central role in lipid metabolism, and their function depends on molecular oxygen. Low oxygen tension or von Hippel-Lindau (Vhl) tumor suppressor loss is known to stabilize hypoxia-inducible factors alpha (Hif-1α and Hif-2α) to mediate adaptive responses, but it remains unknown if peroxisome homeostasis and metabolism are interconnected with Hif-α signaling. By studying liver-specific Vhl, Vhl/Hif1α, and Vhl/Hif2α knockout mice, we demonstrate a regulatory function of Hif-2α signaling on peroxisomes. Hif-2α activation augments peroxisome turnover by selective autophagy (pexophagy) and thereby changes lipid composition reminiscent of peroxisomal disorders. The autophagy receptor Nbr1 localizes to peroxisomes and is likewise degraded by Hif-2α-mediated pexophagy. Furthermore, we demonstrate that peroxisome abundance is reduced in VHL-deficient human clear cell renal cell carcinomas with high HIF-2α levels. These results establish Hif-2α as a negative regulator of peroxisome abundance and metabolism and suggest a mechanism by which cells attune peroxisomal function with oxygen availability.
Collapse
Affiliation(s)
- Katharina M Walter
- Institute of Molecular Health Sciences, ETH Zurich, CH-8093 Zurich, Switzerland; Competence Center for Systems Physiology and Metabolic Diseases, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Miriam J Schönenberger
- Institute of Molecular Health Sciences, ETH Zurich, CH-8093 Zurich, Switzerland; Competence Center for Systems Physiology and Metabolic Diseases, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Martin Trötzmüller
- Core Facility for Mass Spectrometry, Center for Medical Research, Medical University of Graz, A-8010 Graz, Austria
| | - Michael Horn
- Institute of Molecular Health Sciences, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Hans-Peter Elsässer
- Department of Cytobiology, Philipps-University Marburg, D-35037 Marburg, Germany
| | - Ann B Moser
- Kennedy Krieger Institute, Baltimore, MD 21205, USA
| | - Miriam S Lucas
- ScopeM - Scientific Center for Optical and Electron Microscopy, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Tobias Schwarz
- ScopeM - Scientific Center for Optical and Electron Microscopy, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Philipp A Gerber
- Division of Endocrinology and Diabetes, University Hospital Zurich, CH-8091 Zurich, Switzerland
| | - Phyllis L Faust
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Holger Moch
- Institute of Surgical Pathology, University Hospital Zurich, CH-8091 Zurich, Switzerland
| | - Harald C Köfeler
- Core Facility for Mass Spectrometry, Center for Medical Research, Medical University of Graz, A-8010 Graz, Austria
| | - Wilhelm Krek
- Institute of Molecular Health Sciences, ETH Zurich, CH-8093 Zurich, Switzerland; Competence Center for Systems Physiology and Metabolic Diseases, ETH Zurich, CH-8093 Zurich, Switzerland.
| | - Werner J Kovacs
- Institute of Molecular Health Sciences, ETH Zurich, CH-8093 Zurich, Switzerland; Competence Center for Systems Physiology and Metabolic Diseases, ETH Zurich, CH-8093 Zurich, Switzerland.
| |
Collapse
|