1
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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.
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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.
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2
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Stamp J, DenAdel A, Weinreich D, Crawford L. Leveraging the genetic correlation between traits improves the detection of epistasis in genome-wide association studies. G3 (BETHESDA, MD.) 2023; 13:jkad118. [PMID: 37243672 PMCID: PMC10484060 DOI: 10.1093/g3journal/jkad118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 01/11/2023] [Accepted: 05/23/2023] [Indexed: 05/29/2023]
Abstract
Epistasis, commonly defined as the interaction between genetic loci, is known to play an important role in the phenotypic variation of complex traits. As a result, many statistical methods have been developed to identify genetic variants that are involved in epistasis, and nearly all of these approaches carry out this task by focusing on analyzing one trait at a time. Previous studies have shown that jointly modeling multiple phenotypes can often dramatically increase statistical power for association mapping. In this study, we present the "multivariate MArginal ePIstasis Test" (mvMAPIT)-a multioutcome generalization of a recently proposed epistatic detection method which seeks to detect marginal epistasis or the combined pairwise interaction effects between a given variant and all other variants. By searching for marginal epistatic effects, one can identify genetic variants that are involved in epistasis without the need to identify the exact partners with which the variants interact-thus, potentially alleviating much of the statistical and computational burden associated with conventional explicit search-based methods. Our proposed mvMAPIT builds upon this strategy by taking advantage of correlation structure between traits to improve the identification of variants involved in epistasis. We formulate mvMAPIT as a multivariate linear mixed model and develop a multitrait variance component estimation algorithm for efficient parameter inference and P-value computation. Together with reasonable model approximations, our proposed approach is scalable to moderately sized genome-wide association studies. With simulations, we illustrate the benefits of mvMAPIT over univariate (or single-trait) epistatic mapping strategies. We also apply mvMAPIT framework to protein sequence data from two broadly neutralizing anti-influenza antibodies and approximately 2,000 heterogeneous stock of mice from the Wellcome Trust Centre for Human Genetics. The mvMAPIT R package can be downloaded at https://github.com/lcrawlab/mvMAPIT.
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Affiliation(s)
- Julian Stamp
- Center for Computational Molecular Biology, Brown University, Providence, RI 02906, USA
| | - Alan DenAdel
- Center for Computational Molecular Biology, Brown University, Providence, RI 02906, USA
| | - Daniel Weinreich
- Center for Computational Molecular Biology, Brown University, Providence, RI 02906, USA
- Department of Ecology, Evolution, and Organismal Biology, Brown University, Providence, RI 02906, USA
| | - Lorin Crawford
- Center for Computational Molecular Biology, Brown University, Providence, RI 02906, USA
- Department of Biostatistics, Brown University, Providence, RI 02903, USA
- Microsoft Research New England, Cambridge, MA 02142, USA
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3
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Loss of pex5 sensitizes zebrafish to fasting due to deregulated mitochondria, mTOR, and autophagy. Cell Mol Life Sci 2023; 80:69. [PMID: 36821008 PMCID: PMC9950184 DOI: 10.1007/s00018-023-04700-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 12/30/2022] [Accepted: 01/09/2023] [Indexed: 02/24/2023]
Abstract
Animal models have been utilized to understand the pathogenesis of Zellweger spectrum disorders (ZSDs); however, the link between clinical manifestations and molecular pathways has not yet been clearly established. We generated peroxin 5 homozygous mutant zebrafish (pex5-/-) to gain insight into the molecular pathogenesis of peroxisome dysfunction. pex5-/- display hallmarks of ZSD in humans and die within one month after birth. Fasting rapidly depletes lipids and glycogen in pex5-/- livers and expedites their mortality. Mechanistically, deregulated mitochondria and mechanistic target of rapamycin (mTOR) signaling act together to induce metabolic alterations that deplete hepatic nutrients and accumulate damaged mitochondria. Accordingly, chemical interventions blocking either the mitochondrial function or mTOR complex 1 (mTORC1) or a combination of both improve the metabolic imbalance shown in the fasted pex5-/- livers and extend the survival of animals. In addition, the suppression of oxidative stress by N-acetyl L-cysteine (NAC) treatment rescued the apoptotic cell death and early mortality observed in pex5-/-. Furthermore, an autophagy activator effectively ameliorated the early mortality of fasted pex5-/-. These results suggest that fasting may be detrimental to patients with peroxisome dysfunction, and that modulating the mitochondria, mTORC1, autophagy activities, or oxidative stress may provide a therapeutic option to alleviate the symptoms of peroxisomal diseases associated with metabolic dysfunction.
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4
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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.
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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.
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5
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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.
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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
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6
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Anderson JN, Ammous Z, Eroglu Y, Hernandez E, Heubi J, Himes R, Palle S. Cholbam® and Zellweger spectrum disorders: treatment implementation and management. Orphanet J Rare Dis 2021; 16:388. [PMID: 34521419 PMCID: PMC8439061 DOI: 10.1186/s13023-021-01940-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 07/02/2021] [Indexed: 01/12/2023] Open
Abstract
Background Zellweger spectrum disorders (ZSDs) are a rare, heterogenous group of autosomal recessively inherited disorders characterized by reduced peroxisomes numbers, impaired peroxisomal formation, and/or defective peroxisomal functioning. In the absence of functional peroxisomes, bile acid synthesis is disrupted, and multisystem disease ensues with abnormalities in the brain, liver, kidneys, muscle, eyes, ears, and nervous system. Main body Liver disease may play an important role in morbidity and mortality, with hepatic fibrosis that can develop as early as the postnatal period and often progressing to cirrhosis within the first year of life. Because hepatic dysfunction can have numerous secondary effects on other organ systems, thereby impacting the overall disease severity, the treatment of liver disease in patients with ZSD is an important focus of disease management. Cholbam® (cholic acid), approved by the U.S. Food and Drug Administration in March 2015, is currently the only therapy approved as adjunctive treatment for patients with ZSDs and single enzyme bile acid synthesis disorders. This review will focus on the use of CA therapy in the treatment of liver disease associated with ZSDs, including recommendations for initiating and maintaining CA therapy and the limitations of available clinical data supporting its use in this patient population. Conclusions Cholbam is a safe and well-tolerated treatment for patients with ZSDs that has been shown to improve liver chemistries and reduce toxic bile acid intermediates in the majority of patients with ZSD. Due to the systemic impacts of hepatic damage, Cholbam should be initiated in patients without signs of advanced liver disease.
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Affiliation(s)
- Janaina Nogueira Anderson
- Department of Pediatric Gastroenterology, Hepatology, and Nutrition, Medical University of South Carolina, 135 Rutledge Avenue, MSC 561, Charleston, SC, 29465, USA.
| | | | - Yasemen Eroglu
- Division of Pediatric Gastroenterology, Hepatology, Pancreatology and Nutrition, Stead Family Department of Pediatrics, IU Carver College of Medicine, Iowa City, IA, USA
| | - Erick Hernandez
- Department of Pediatric Gastroenterology, Hepatology and Nutrition, Pediatric Gastroenterology Associates, Nicklaus Children's Hospital, Miami, FL, USA
| | - James Heubi
- Divisions of Pediatric Gastroenterology, Hepatology and Nutrition and Pathology and Laboratory Medicine, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, OH, USA
| | - Ryan Himes
- Division of Pediatric Hepatology, Ochsner Health, New Orleans, LA, USA
| | - Sirish Palle
- Department of Pediatric Gastroenterology, Oklahoma University Medicine, Oklahoma City, OK, USA
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7
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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.
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8
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Demaret T, Evraerts J, Ravau J, Roumain M, Muccioli GG, Najimi M, Sokal EM. High Dose Versus Low Dose Syngeneic Hepatocyte Transplantation in Pex1-G844D NMRI Mouse Model is Safe but Does Not Achieve Long Term Engraftment. Cells 2020; 10:cells10010040. [PMID: 33396635 PMCID: PMC7823729 DOI: 10.3390/cells10010040] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 12/21/2020] [Accepted: 12/23/2020] [Indexed: 12/17/2022] Open
Abstract
Genetic alterations in PEX genes lead to peroxisome biogenesis disorder. In humans, they are associated with Zellweger spectrum disorders (ZSD). No validated treatment has been shown to modify the dismal natural history of ZSD. Liver transplantation (LT) improved clinical and biochemical outcomes in mild ZSD patients. Hepatocyte transplantation (HT), developed to overcome LT limitations, was performed in a mild ZSD 4-year-old child with encouraging short-term results. Here, we evaluated low dose (12.5 million hepatocytes/kg) and high dose (50 million hepatocytes/kg) syngeneic male HT via intrasplenic infusion in the Pex1-G844D NMRI mouse model which recapitulates a mild ZSD phenotype. HT was feasible and safe in growth retarded ZSD mice. Clinical (weight and food intake) and biochemical parameters (very long-chain fatty acids, abnormal bile acids, etc.) were in accordance with ZSD phenotype but they were not robustly modified by HT. As expected, one third of the infused cells were detected in the liver 24 h post-HT. No liver nor spleen microchimerism was detected after 7, 14 and 30 days. Future optimizations are required to improve hepatocyte engraftment in Pex1-G844D NMRI mouse liver. The mouse model exhibited the robustness required for ZSD liver-targeted therapies evaluation.
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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; (J.E.); (J.R.); (M.N.); (E.M.S.)
- Correspondence:
| | - 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; (J.E.); (J.R.); (M.N.); (E.M.S.)
| | - 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; (J.E.); (J.R.); (M.N.); (E.M.S.)
| | - Martin Roumain
- Bioanalysis and Pharmacology of Bioactive Lipids Research Group (BPBL), Louvain Drug Research Institute (LDRI), Université Catholique de Louvain (UCLouvain), 1200 Brussels, Belgium; (M.R.); (G.G.M.)
| | - 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; (M.R.); (G.G.M.)
| | - 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; (J.E.); (J.R.); (M.N.); (E.M.S.)
| | - 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; (J.E.); (J.R.); (M.N.); (E.M.S.)
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9
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Hoytema van Konijnenburg EMM, Luirink IK, Schagen SEE, Engelen M, Berendse K, Poll-The BT, Chegary M. Hyperinsulinism in a patient with a Zellweger Spectrum Disorder and a 16p11.2 deletion syndrome. Mol Genet Metab Rep 2020; 23:100590. [PMID: 32373468 PMCID: PMC7191845 DOI: 10.1016/j.ymgmr.2020.100590] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 04/18/2020] [Indexed: 10/28/2022] Open
Affiliation(s)
| | - Ilse K Luirink
- Department of Pediatrics, Emma Children's Hospital, Amsterdam UMC, Meibergdreef 9 1105, AZ, Amsterdam, the Netherlands
| | - Sebastian E E Schagen
- Department of Pediatrics, OLVG Hospital, Jan Tooropstraat 164 1061 AE, Amsterdam, the Netherlands
| | - Marc Engelen
- Department of Pediatric Neurology, Emma Children's Hospital, Amsterdam UMC, Meibergdreef 9 1105, AZ, Amsterdam, the Netherlands
| | - Kevin Berendse
- Department of Pediatrics, Emma Children's Hospital, Amsterdam UMC, Meibergdreef 9 1105, AZ, Amsterdam, the Netherlands
| | - Bwee Tien Poll-The
- Department of Pediatrics, OLVG Hospital, Jan Tooropstraat 164 1061 AE, Amsterdam, the Netherlands.,Department of Pediatric Neurology, Emma Children's Hospital, Amsterdam UMC, Meibergdreef 9 1105, AZ, Amsterdam, the Netherlands
| | - Malika Chegary
- Department of Pediatrics, OLVG Hospital, Jan Tooropstraat 164 1061 AE, Amsterdam, the Netherlands
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10
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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.
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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.
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11
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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.
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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.
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