1
|
Wang J, Kunze M, Villoria-González A, Weinhofer I, Berger J. Peroxisomal Localization of a Truncated HMG-CoA Reductase under Low Cholesterol Conditions. Biomolecules 2024; 14:244. [PMID: 38397481 PMCID: PMC10886633 DOI: 10.3390/biom14020244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 02/07/2024] [Accepted: 02/16/2024] [Indexed: 02/25/2024] Open
Abstract
3-hydroxy-3-methylglutaryl-CoA reductase (HMG-CoA reductase, HMGCR) is one of the rate-limiting enzymes in the mevalonate pathway required for cholesterol biosynthesis. It is an integral membrane protein of the endoplasmic reticulum (ER) but has occasionally been described in peroxisomes. By co-immunofluorescence microscopy using different HMGCR antibodies, we present evidence for a dual localization of HMGCR in the ER and peroxisomes in differentiated human monocytic THP-1 cells, primary human monocyte-derived macrophages and human primary skin fibroblasts under conditions of low cholesterol and statin treatment. Using density gradient centrifugation and Western blot analysis, we observed a truncated HMGCR variant of 76 kDa in the peroxisomal fractions, while a full-length HMGCR of 96 kDa was contained in fractions of the ER. In contrast to primary human control fibroblasts, peroxisomal HMGCR was not found in fibroblasts from patients suffering from type-1 rhizomelic chondrodysplasia punctata, who lack functional PEX7 and, thus, cannot import peroxisomal matrix proteins harboring a type-2 peroxisomal targeting signal (PTS2). Moreover, in the N-terminal region of the soluble 76 kDa C-terminal catalytic domain, we identified a PTS2-like motif, which was functional in a reporter context. We propose that under sterol-depleted conditions, part of the soluble HMGCR domain, which is released from the ER by proteolytic processing for further turnover, remains sufficiently long in the cytosol for peroxisomal import via a PTS2/PEX7-dependent mechanism. Altogether, our findings describe a dual localization of HMGCR under combined lipid depletion and statin treatment, adding another puzzle piece to the complex regulation of HMGCR.
Collapse
Affiliation(s)
| | | | | | | | - Johannes Berger
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, 1090 Vienna, Austria
| |
Collapse
|
2
|
Wegwerth PJ, White AL, Stoway SD, Loken PR, Oglesbee D, Matern D, Tortorelli S, Raymond KM, Braverman NE, Gavrilov DK. A new test method for biochemical analysis of plasmalogens in dried blood spots and erythrocytes from patients with peroxisomal disorders. J Inherit Metab Dis 2023; 46:1159-1169. [PMID: 37747296 DOI: 10.1002/jimd.12682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 09/20/2023] [Accepted: 09/21/2023] [Indexed: 09/26/2023]
Abstract
Measurement of plasmalogens is useful for the biochemical diagnosis of rhizomelic chondrodysplasia punctata (RCDP) and is also informative for Zellweger spectrum disorders (ZSD). We have developed a test method for the simultaneous quantitation of C16:0, C18:0, and C018:1 plasmalogen (PG) species and their corresponding fatty acids (FAs) in dried blood spots (DBS) and erythrocytes (RBC) by using capillary gas chromatography-mass spectrometry. Normal reference ranges for measured markers and 10 calculated ratios were established by the analysis of 720 and 473 unaffected DBS and RBC samples, respectively. Determination of preliminary disease ranges was made by using 45 samples from 43 unique patients: RCDP type 1 (DBS: 1 mild, 17 severe; RBC: 1 mild, 6 severe), RCDP type 2 (DBS: 2 mild, 1 severe; RBC: 2 severe), RCDP type 3 (DBS: 1 severe), RCDP type 4 (RBC: 2 severe), and ZSD (DBS: 3 severe; RBC: 2 mild, 7 severe). Postanalytical interpretive tools in Collaborative Laboratory Integrated Reports (CLIR) were used to generate an integrated score and a likelihood of disease. In conjunction with a review of clinical phenotype, phytanic acid, and very long-chain FA test results, the CLIR analysis allowed for differentiation between RCDP and ZSD. Data will continue to be gathered to improve CLIR analysis as more samples from affected patients with variable disease severity are analyzed. The addition of DBS analysis of PGs may allow for at-home specimen collection and second-tier testing for newborn screening programs.
Collapse
Affiliation(s)
- Peter J Wegwerth
- Division of Laboratory Genetics and Genomics, Mayo Clinic, Rochester, Minnesota, USA
| | - Amy L White
- Division of Laboratory Genetics and Genomics, Mayo Clinic, Rochester, Minnesota, USA
| | - Stephanie D Stoway
- Department of Information Technology, Mayo Clinic, Rochester, Minnesota, USA
| | - Perry R Loken
- Division of Laboratory Genetics and Genomics, Mayo Clinic, Rochester, Minnesota, USA
| | - Devin Oglesbee
- Division of Laboratory Genetics and Genomics, Mayo Clinic, Rochester, Minnesota, USA
| | - Dietrich Matern
- Division of Laboratory Genetics and Genomics, Mayo Clinic, Rochester, Minnesota, USA
| | - Silvia Tortorelli
- Division of Laboratory Genetics and Genomics, Mayo Clinic, Rochester, Minnesota, USA
| | - Kimiyo M Raymond
- Division of Laboratory Genetics and Genomics, Mayo Clinic, Rochester, Minnesota, USA
| | - Nancy E Braverman
- The Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
| | - Dimitar K Gavrilov
- Division of Laboratory Genetics and Genomics, Mayo Clinic, Rochester, Minnesota, USA
| |
Collapse
|
3
|
Honsho M, Fujiki Y. Asymmetric Distribution of Plasmalogens and Their Roles-A Mini Review. MEMBRANES 2023; 13:764. [PMID: 37755186 PMCID: PMC10534842 DOI: 10.3390/membranes13090764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 08/03/2023] [Accepted: 08/25/2023] [Indexed: 09/28/2023]
Abstract
Plasmalogens are a unique family of cellular glycerophospholipids that contain a vinyl-ether bond. The synthesis of plasmalogens is initiated in peroxisomes and completed in the endoplasmic reticulum. Plasmalogens are transported to the post-Golgi compartment, including endosomes and plasma membranes, in a manner dependent on ATP, but not vesicular transport. Plasmalogens are preferentially localized in the inner leaflet of the plasma membrane in a manner dependent on P4-type ATPase ATP8B2, that associates with the CDC50 subunit. Plasmalogen biosynthesis is spatiotemporally regulated by a feedback mechanism that senses the amount of plasmalogens in the inner leaflet of the plasma membrane and controls the stability of fatty acyl-CoA reductase 1 (FAR1), the rate-limiting enzyme for plasmalogen biosynthesis. The physiological consequences of such asymmetric localization and homeostasis of plasmalogens are discussed in this review.
Collapse
Affiliation(s)
- Masanori Honsho
- Department of Neuroinflammation and Brain Fatigue Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8581, Japan
| | - Yukio Fujiki
- Institute of Rheological Functions of Food-Kyushu University Collaboration Program, Kyushu University, Fukuoka 811-2501, Japan
- Graduate School of Science, University of Hyogo, Himeji 671-2280, Japan
| |
Collapse
|
4
|
De Biase I, Yuzyuk T, Cui W, Zuromski LM, Moser AB, Braverman NE. Quantitative analysis of ethanolamine plasmalogen species in red blood cells using liquid chromatography tandem mass spectrometry for diagnosing peroxisome biogenesis disorders. Clin Chim Acta 2023; 542:117295. [PMID: 36914043 DOI: 10.1016/j.cca.2023.117295] [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: 12/14/2022] [Revised: 03/06/2023] [Accepted: 03/07/2023] [Indexed: 03/13/2023]
Abstract
Plasmalogens are glycerophospholipids characterized by a vinyl-ether bond with a fatty alcohol at the sn-1 position, a polyunsaturated fatty acid at the sn-2 position, and a polar head at the sn-3 position, commonly phosphoethanolamine. Plasmalogens play crucial roles in several cellular processes. Reduced levels have been associated with Alzheimer's and Parkinson's disease progression. Markedly reduced plasmalogens are a classic feature of peroxisome biogenesis disorders (PBD) because plasmalogen synthesis requires functional peroxisomes. Particularly, severe plasmalogen deficiency is the biochemical hallmark of rhizomelic chondrodysplasia punctata (RCDP). Traditionally, plasmalogens are evaluated in red blood cells (RBCs) by gas-chromatography/mass-spectrometry (GC-MS), which cannot distinguish individual species. We developed a liquid-chromatography/tandem mass-spectrometry (LC-MS/MS) method to quantify eighteen phosphoethanolamine plasmalogens in RBCs to diagnose PBD patients, especially RCDP. Validation results showed a specific, robust, and precise method with broad analytical range. Age-specific reference intervals were established; control medians were used to assess plasmalogen deficiency in patients' RBCs. Clinical utility was also confirmed in Pex7 deficient mouse models recapitulating severe and milder RCDP clinical phenotypes. To our knowledge, this is the first attempt to replace the GC-MS method in the clinical laboratory. In addition to diagnosing PBDs, structure-specific plasmalogen quantitation could help understand disease pathogenesis and monitor therapy.
Collapse
Affiliation(s)
- Irene De Biase
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT, USA; ARUP Institute for Clinical and Experimental Pathology, Salt Lake City, UT, USA.
| | - Tatiana Yuzyuk
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT, USA; ARUP Institute for Clinical and Experimental Pathology, Salt Lake City, UT, USA
| | - Wei Cui
- Child Health and Human Development Program, Research Institute of the McGill University, Montreal, Quebec, Canada
| | - Lauren M Zuromski
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Ann B Moser
- Hugo W Moser Research Institute, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Nancy E Braverman
- Child Health and Human Development Program, Research Institute of the McGill University, Montreal, Quebec, Canada; Department of Human Genetics and Pediatrics, McGill University, Montreal, Quebec, Canada
| |
Collapse
|
5
|
Song J, Dong L, Sun H, Luo N, Huang Q, Li K, Shen X, Jiang Z, Lv Z, Peng L, Zhang M, Wang K, Liu K, Hong J, Yi C. CRISPR-free, programmable RNA pseudouridylation to suppress premature termination codons. Mol Cell 2023; 83:139-155.e9. [PMID: 36521489 DOI: 10.1016/j.molcel.2022.11.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 10/03/2022] [Accepted: 11/14/2022] [Indexed: 12/15/2022]
Abstract
Nonsense mutations, accounting for >20% of disease-associated mutations, lead to premature translation termination. Replacing uridine with pseudouridine in stop codons suppresses translation termination, which could be harnessed to mediate readthrough of premature termination codons (PTCs). Here, we present RESTART, a programmable RNA base editor, to revert PTC-induced translation termination in mammalian cells. RESTART utilizes an engineered guide snoRNA (gsnoRNA) and the endogenous H/ACA box snoRNP machinery to achieve precise pseudouridylation. We also identified and optimized gsnoRNA scaffolds to increase the editing efficiency. Unexpectedly, we found that a minor isoform of pseudouridine synthase DKC1, lacking a C-terminal nuclear localization signal, greatly improved the PTC-readthrough efficiency. Although RESTART induced restricted off-target pseudouridylation, they did not change the coding information nor the expression level of off-targets. Finally, RESTART enables robust pseudouridylation in primary cells and achieves functional PTC readthrough in disease-relevant contexts. Collectively, RESTART is a promising RNA-editing tool for research and therapeutics.
Collapse
Affiliation(s)
- Jinghui Song
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, PRC
| | - Liting Dong
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, PRC; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, PRC
| | - Hanxiao Sun
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, PRC
| | - Nan Luo
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, PRC
| | - Qiang Huang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, PRC
| | - Kai Li
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, PRC; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, PRC; Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, PRC
| | - Xiaowen Shen
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, PRC
| | - Zhe Jiang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, PRC
| | - Zhicong Lv
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, PRC
| | - Luxin Peng
- College of Chemistry and Molecular Engineering, Peking University, Beijing, PRC
| | | | - Kun Wang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, PRC
| | - Ke Liu
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, PRC
| | - Jiaxu Hong
- Department of Ophthalmology, Eye and Ear, Nose, Throat Hospital of Fudan University, Shanghai, PRC
| | - Chengqi Yi
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, PRC; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, PRC; Department of Chemical Biology and Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular Engineering, Peking University, Beijing, PRC.
| |
Collapse
|
6
|
Wanders RJA, Baes M, Ribeiro D, Ferdinandusse S, Waterham HR. The physiological functions of human peroxisomes. Physiol Rev 2023; 103:957-1024. [PMID: 35951481 DOI: 10.1152/physrev.00051.2021] [Citation(s) in RCA: 51] [Impact Index Per Article: 51.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Peroxisomes are subcellular organelles that play a central role in human physiology by catalyzing a range of unique metabolic functions. The importance of peroxisomes for human health is exemplified by the existence of a group of usually severe diseases caused by an impairment in one or more peroxisomal functions. Among others these include the Zellweger spectrum disorders, X-linked adrenoleukodystrophy, and Refsum disease. To fulfill their role in metabolism, peroxisomes require continued interaction with other subcellular organelles including lipid droplets, lysosomes, the endoplasmic reticulum, and mitochondria. In recent years it has become clear that the metabolic alliance between peroxisomes and other organelles requires the active participation of tethering proteins to bring the organelles physically closer together, thereby achieving efficient transfer of metabolites. This review intends to describe the current state of knowledge about the metabolic role of peroxisomes in humans, with particular emphasis on the metabolic partnership between peroxisomes and other organelles and the consequences of genetic defects in these processes. We also describe the biogenesis of peroxisomes and the consequences of the multiple genetic defects therein. In addition, we discuss the functional role of peroxisomes in different organs and tissues and include relevant information derived from model systems, notably peroxisomal mouse models. Finally, we pay particular attention to a hitherto underrated role of peroxisomes in viral infections.
Collapse
Affiliation(s)
- Ronald J A Wanders
- Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands.,Department of Pediatrics, Emma Children's Hospital, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands.,United for Metabolic Diseases, Amsterdam, The Netherlands
| | - Myriam Baes
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Daniela Ribeiro
- Institute of Biomedicine (iBiMED) and Department of Medical Sciences, University of Aveiro, Aveiro, Portugal
| | - Sacha Ferdinandusse
- Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands.,United for Metabolic Diseases, Amsterdam, The Netherlands
| | - Hans R Waterham
- Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands.,Department of Pediatrics, Emma Children's Hospital, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands.,United for Metabolic Diseases, Amsterdam, The Netherlands
| |
Collapse
|
7
|
Muacevic A, Adler JR, Mostafa R, Shehata N. A Case of Rhizomelic Chondrodysplasia Punctata in a Neonate. Cureus 2022; 14:e31702. [PMID: 36561594 PMCID: PMC9767646 DOI: 10.7759/cureus.31702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/20/2022] [Indexed: 11/21/2022] Open
Abstract
Rhizomelic chondrodysplasia punctata (RCDP) is a rare, multisystem, autosomal recessive, peroxisomal disorder of a family of congenital disorders known as chondrodysplasia calcificans punctate (CCP). RCDP is characterized by disproportionately short extremities (rhizomelia), congenital cataracts, and joint contractures. Dysmorphic facial features include a broad nasal bridge, epicanthus, high-arched palate, dysplastic external ears, and micrognathia. Severe mental retardation with spasticity and seizures may also be present. X-ray of the limbs showed punctate calcifications in cartilage (chondrodysplasia punctata). Genetic testing reveals the severity of phenotype. Treatment is limited to supportive symptomatic relief and prevention of complications. To the best of our knowledge, after searching through PubMed, our case is the first reported case of RCDP in the Middle East.
Collapse
|
8
|
Fallatah W, Cui W, Di Pietro E, Carter GT, Pounder B, Dorninger F, Pifl C, Moser AB, Berger J, Braverman NE. A Pex7 Deficient Mouse Series Correlates Biochemical and Neurobehavioral Markers to Genotype Severity—Implications for the Disease Spectrum of Rhizomelic Chondrodysplasia Punctata Type 1. Front Cell Dev Biol 2022; 10:886316. [PMID: 35898397 PMCID: PMC9310236 DOI: 10.3389/fcell.2022.886316] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 05/19/2022] [Indexed: 12/31/2022] Open
Abstract
Rhizomelic chondrodysplasia punctata type 1 (RCDP1) is a peroxisome biogenesis disorder caused by defects in PEX7 leading to impairment in plasmalogen (Pls) biosynthesis and phytanic acid (PA) oxidation. Pls deficiency is the main pathogenic factor that determines the severity of RCDP. Severe (classic) RCDP patients have negligible Pls levels, congenital cataracts, skeletal dysplasia, growth and neurodevelopmental deficits, and cerebral hypomyelination and cerebellar atrophy on brain MRI. Individuals with milder or nonclassic RCDP have higher Pls levels, better growth and cognitive outcomes. To better understand the pathophysiology of RCDP disorders, we generated an allelic series of Pex7 mice either homozygous for the hypomorphic allele, compound heterozygous for the hypomorphic and null alleles or homozygous for the null allele. Pex7 transcript and protein were almost undetectable in the hypomorphic model, and negligible in the compound heterozygous and null mice. Pex7 deficient mice showed a graded reduction in Pls and increases in C26:0-LPC and PA in plasma and brain according to genotype. Neuropathological evaluation showed significant loss of cerebellar Purkinje cells over time and a decrease in brain myelin basic protein (MBP) content in Pex7 deficient models, with more severe effects correlating with Pex7 genotype. All Pex7 deficient mice exhibited a hyperactive behavior in the open field environment. Brain neurotransmitters analysis of Pex7 deficient mice showed a significant reduction in levels of dopamine, norepinephrine, serotonin and GABA. Also, a significant correlation was found between brain neurotransmitter levels, the hyperactivity phenotype, Pls level and the severity of Pex7 genotype. In conclusion, our study showed evidence of a genotype-phenotype correlation between the severity of Pex7 deficiency and several clinical and neurobiochemical phenotypes in RCDP1 mouse models. We propose that PA accumulation may underlie the cerebellar atrophy seen in older RCDP1 patients, as even relatively low tissue levels were strongly associated with Purkinje cells loss over time in the murine models. Also, our data demonstrate the interrelation between Pls, brain neurotransmitter deficiencies and the neurobehavioral phenotype, which could be further used as a valuable clinical endpoint for therapeutic interventions. Finally, these models show that incremental increases in Pex7 levels result in dramatic improvements in phenotype.
Collapse
Affiliation(s)
- Wedad Fallatah
- Department of Human Genetics, McGill University, Montreal, QC, Canada
- Department of Medical Genetics, King Abdul-Aziz University, Jeddah, Saudi Arabia
- *Correspondence: Wedad Fallatah, ; Nancy E. Braverman,
| | - Wei Cui
- Child Health and Human Development Program, Peroxisome Disease Laboratory, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Erminia Di Pietro
- Child Health and Human Development Program, Peroxisome Disease Laboratory, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Grace T. Carter
- Child Health and Human Development Program, Peroxisome Disease Laboratory, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Brittany Pounder
- Child Health and Human Development Program, Peroxisome Disease Laboratory, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Fabian Dorninger
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Christian Pifl
- Department of Molecular Neurosciences, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Ann B. Moser
- Hugo W Moser Research Institute, Kennedy Krieger Institute, Baltimore, MD, United States
| | - Johannes Berger
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Nancy E. Braverman
- Department of Human Genetics, McGill University, Montreal, QC, Canada
- Child Health and Human Development Program, Peroxisome Disease Laboratory, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
- *Correspondence: Wedad Fallatah, ; Nancy E. Braverman,
| |
Collapse
|
9
|
Bozelli JC, Azher S, Epand RM. Plasmalogens and Chronic Inflammatory Diseases. Front Physiol 2021; 12:730829. [PMID: 34744771 PMCID: PMC8566352 DOI: 10.3389/fphys.2021.730829] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 09/14/2021] [Indexed: 11/30/2022] Open
Abstract
It is becoming widely acknowledged that lipids play key roles in cellular function, regulating a variety of biological processes. Lately, a subclass of glycerophospholipids, namely plasmalogens, has received increased attention due to their association with several degenerative and metabolic disorders as well as aging. All these pathophysiological conditions involve chronic inflammatory processes, which have been linked with decreased levels of plasmalogens. Currently, there is a lack of full understanding of the molecular mechanisms governing the association of plasmalogens with inflammation. However, it has been shown that in inflammatory processes, plasmalogens could trigger either an anti- or pro-inflammation response. While the anti-inflammatory response seems to be linked to the entire plasmalogen molecule, its pro-inflammatory response seems to be associated with plasmalogen hydrolysis, i.e., the release of arachidonic acid, which, in turn, serves as a precursor to produce pro-inflammatory lipid mediators. Moreover, as plasmalogens comprise a large fraction of the total lipids in humans, changes in their levels have been shown to change membrane properties and, therefore, signaling pathways involved in the inflammatory cascade. Restoring plasmalogen levels by use of plasmalogen replacement therapy has been shown to be a successful anti-inflammatory strategy as well as ameliorating several pathological hallmarks of these diseases. The purpose of this review is to highlight the emerging role of plasmalogens in chronic inflammatory disorders as well as the promising role of plasmalogen replacement therapy in the treatment of these pathologies.
Collapse
Affiliation(s)
- José Carlos Bozelli
- Department of Biochemistry and Biomedical Sciences, Health Sciences Centre, McMaster University, Hamilton, ON, Canada
| | - Sayed Azher
- Department of Biochemistry and Biomedical Sciences, Health Sciences Centre, McMaster University, Hamilton, ON, Canada
| | - Richard M Epand
- Department of Biochemistry and Biomedical Sciences, Health Sciences Centre, McMaster University, Hamilton, ON, Canada
| |
Collapse
|
10
|
Ataluren-Promising Therapeutic Premature Termination Codon Readthrough Frontrunner. Pharmaceuticals (Basel) 2021; 14:ph14080785. [PMID: 34451881 PMCID: PMC8398184 DOI: 10.3390/ph14080785] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 07/30/2021] [Accepted: 08/06/2021] [Indexed: 02/08/2023] Open
Abstract
Around 12% of hereditary disease-causing mutations are in-frame nonsense mutations. The expression of genes containing nonsense mutations potentially leads to the production of truncated proteins with residual or virtually no function. However, the translation of transcripts containing premature stop codons resulting in full-length protein expression can be achieved using readthrough agents. Among them, only ataluren was approved in several countries to treat nonsense mutation Duchenne muscular dystrophy (DMD) patients. This review summarizes ataluren’s journey from its identification, via first in vitro activity experiments, to clinical trials in DMD, cystic fibrosis, and aniridia. Additionally, data on its pharmacokinetics and mechanism of action are presented. The range of diseases with underlying nonsense mutations is described for which ataluren therapy seems to be promising. What is more, experiments in which ataluren did not show its readthrough activity are also included, and reasons for their failures are discussed.
Collapse
|
11
|
Plasmalogens regulate the AKT-ULK1 signaling pathway to control the position of the axon initial segment. Prog Neurobiol 2021; 205:102123. [PMID: 34302896 DOI: 10.1016/j.pneurobio.2021.102123] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 06/11/2021] [Accepted: 07/14/2021] [Indexed: 01/04/2023]
Abstract
The axon initial segment (AIS) is a specialized region in neurons that encompasses two essential functions, the generation of action potentials and the regulation of the axodendritic polarity. The mechanism controlling the position of the axon initial segment to allow plasticity and regulation of neuron excitability is unclear. Here we demonstrate that plasmalogens, the most abundant ether-phospholipid, are essential for the homeostatic positioning of the AIS. Plasmalogen deficiency is a hallmark of Rhizomelic Chondrodysplasia Punctata (RCDP) and Zellweger spectrum disorders, but Alzheimer's and Parkinson's disease, are also characterized by plasmalogen defects. Neurons lacking plasmalogens displaced the AIS to more distal positions and were characterized by reduced excitability. Treatment with a short-chain alkyl glycerol was able to rescue AIS positioning. Plasmalogen deficiency impaired AKT activation, and we show that inhibition of AKT phosphorylation at Ser473 and Thr308 is sufficient to induce a distal relocation of the AIS. Pathway analysis revealed that downstream of AKT, overtly active ULK1 mediates AIS repositioning. Rescuing the impaired AKT signaling pathway was able to normalize AIS position independently of the biochemical defect. These results unveil a previously unknown mechanism that couples the phospholipid composition of the neuronal membrane to the positional assembly of the AIS.
Collapse
|
12
|
Luisman T, Smith T, Ritchie S, Malone KE. Genetic epidemiology approach to estimating birth incidence and current disease prevalence for rhizomelic chondrodysplasia punctata. Orphanet J Rare Dis 2021; 16:300. [PMID: 34229749 PMCID: PMC8258949 DOI: 10.1186/s13023-021-01889-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 05/24/2021] [Indexed: 11/17/2022] Open
Abstract
Background Rhizomelic chondrodysplasia punctata (RCDP) is an inherited ultra-rare disease which results in severely impaired physical and mental development. Mutations in one of five genes involved in plasmalogen biosynthesis have been reported to drive disease pathology. Estimates of disease incidence have been extremely challenging due to the rarity of the disorder, preventing an understanding of the unmet medical need. To address this, we have prepared a disease incidence and prevalence model based on genetic epidemiology approaches to estimate the total number of RCDP patients affected, and their demographic characteristics. Results Extraction of allelic frequencies for known and predicted pathogenic variants in PEX7, GNPAT, AGPS, FAR1, PEX5 (limited to the PTS2 domain encoding region) genes, from large-scale human genetic diversity datasets (TopMed and gnomAD) revealed the mutational landscape contributing to the RCDP patient population in the US and Europe. We computed genetic prevalence to derive birth incidence for RCDP and modeled the impact to life expectancy to obtain high confidence estimates of disease prevalence. Our population genetics-based model indicates PEX7 variants are expected to contribute to the majority of RCDP cases in both the US and Europe; closely aligning with clinical reports. Furthermore, this model provides estimates for RCDP subtypes due to mutations in other genes, including exceedingly rare subtypes. Conclusion In total, the estimated number of RCDP patients in the US and the five largest European countries (UK, Germany, France, Italy and Spain) is between 516 and 847 patients, all under the age of 35 years old. This model provides a quantitative framework for better understanding the unmet medical need in RCDP, to help guide disease awareness and diagnosis efforts for this specific patient group. Supplementary Information The online version contains supplementary material available at 10.1186/s13023-021-01889-z.
Collapse
Affiliation(s)
| | - Tara Smith
- Med-Life Discoveries, Saskatoon, SK, Canada.
| | | | | |
Collapse
|
13
|
Fallatah W, Schouten M, Yergeau C, Di Pietro E, Engelen M, Waterham HR, Poll-The BT, Braverman N. Clinical, biochemical, and molecular characterization of mild (nonclassic) rhizomelic chondrodysplasia punctata. J Inherit Metab Dis 2021; 44:1021-1038. [PMID: 33337545 DOI: 10.1002/jimd.12349] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 11/27/2020] [Accepted: 12/08/2020] [Indexed: 01/12/2023]
Abstract
Rhizomelic chondrodysplasia punctata (RCDP) is a heterogenous group of disorders due to defects in genes encoding peroxisomal proteins required for plasmalogen (PL) biosynthesis, specifically PEX7 and PEX5 receptors, or GNPAT, AGPS and FAR1 enzymes. Most patients have congenital cataract and skeletal dysplasia. In the classic form, there is profound growth restriction and psychomotor delays, with most patients not advancing past infantile developmental milestones. Disease severity correlates to erythrocyte PL levels, which are almost undetectable in severe (classic) RCDP. In milder (nonclassic) forms, residual PL levels are associated with improved growth and development. However, the clinical course of this milder group remains largely unknown as only a few cases were reported. Using as inclusion criteria the ability to communicate and walk, we identified 16 individuals from five countries, ages 5-37 years, and describe their clinical, biochemical and molecular profiles. The average age at diagnosis was 2.6 years and most had cataract, growth deficiency, joint contractures, and developmental delays. Other major symptoms were learning disability (87%), behavioral issues (56%), seizures (43%), and cardiac defects (31%). All patients had decreased C16:0 PL levels that were higher than in classic RCDP, and up to 43% of average controls. Plasma phytanic acid levels were elevated in most patients. There were several common, and four novel, PEX7, and GNPAT hypomorphic alleles in this cohort. These results can be used to support earlier diagnosis and improve management in patients with mild RCDP.
Collapse
Affiliation(s)
- Wedad Fallatah
- Department of Human Genetics, McGill University, Research Institute of the McGill University Health Centre, Montreal, Québec, Canada
- Department of Medical Genetics, King Abdul-Aziz University, Jeddah, Saudi Arabia
| | - Monica Schouten
- Department of Pediatric Neurology, Emma Children's Hospital, Amsterdam UMC - location AMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Christine Yergeau
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, Québec, Canada
| | - Erminia Di Pietro
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, Québec, Canada
| | - Marc Engelen
- Department of Pediatric Neurology, Emma Children's Hospital, Amsterdam UMC - location AMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Hans R Waterham
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC - location AMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Bwee Tien Poll-The
- Department of Pediatric Neurology, Emma Children's Hospital, Amsterdam UMC - location AMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Nancy Braverman
- Department of Human Genetics and Pediatrics, Child Health and Human Development Program, McGill University, Research Institute of the McGill University Health Centre, Montreal, Québec, Canada
| |
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: 13] [Impact Index Per Article: 4.3] [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
|
Masih S, Moirangthem A, Phadke SR. Twins with PEX7 related intellectual disability and cataract: Highlighting phenotypes of peroxisome biogenesis disorder 9B. Am J Med Genet A 2021; 185:1504-1508. [PMID: 33586206 DOI: 10.1002/ajmg.a.62110] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 11/26/2020] [Accepted: 01/15/2021] [Indexed: 01/13/2023]
Abstract
Peroxisome biogenesis disorders (PBDs) are a group of autosomal recessive disorders caused due to impaired peroxisome assembly affecting the formation of functional peroxisomes. PBDs are caused by a mutation in PEX gene family resulting in disease manifestation with extreme variability ranging from the onset of profound neurologic symptoms in newborns to progressive degenerative disease in adults. Disease causing variations in PEX7 is known to cause severe rhizomelic chondrodysplasia punctata type 1 and PBD 9B, an allelic disorder resulting in a milder phenotype, often indistinguishable from that of classic Refsum disease. This case report highlights the variability of PEX7 related phenotypes and suggests that other than RCDP1 and late onset phenotype similar to Refsum disease, some cases present with cataract and neurodevelopmetal abnormalities during childhood without chondrodysplasia or rhizomelia. This report also underlines the importance of considering PBD 9B in children presenting with neurodevelopmental abnormalities especially if they have congenital cataract.
Collapse
Affiliation(s)
- Suzena Masih
- Department of Medical Genetics, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India
| | - Amita Moirangthem
- Department of Medical Genetics, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India
| | - Shubha R Phadke
- Department of Medical Genetics, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India
| |
Collapse
|
16
|
A missense allele of PEX5 is responsible for the defective import of PTS2 cargo proteins into peroxisomes. Hum Genet 2021; 140:649-666. [PMID: 33389129 DOI: 10.1007/s00439-020-02238-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 11/07/2020] [Indexed: 11/27/2022]
Abstract
Peroxisomes, single-membrane intracellular organelles, play an important role in various metabolic pathways. The translocation of proteins from the cytosol to peroxisomes depends on peroxisome import receptor proteins and defects in peroxisome transport result in a wide spectrum of peroxisomal disorders. Here, we report a large consanguineous family with autosomal recessive congenital cataracts and developmental defects. Genome-wide linkage analysis localized the critical interval to chromosome 12p with a maximum two-point LOD score of 4.2 (θ = 0). Next-generation exome sequencing identified a novel homozygous missense variant (c.653 T > C; p.F218S) in peroxisomal biogenesis factor 5 (PEX5), a peroxisome import receptor protein. This missense mutation was confirmed by bidirectional Sanger sequencing. It segregated with the disease phenotype in the family and was absent in ethnically matched control chromosomes. The lens-specific knockout mice of Pex5 recapitulated the cataractous phenotype. In vitro import assays revealed a normal capacity of the mutant PEX5 to enter the peroxisomal Docking/Translocation Module (DTM) in the presence of peroxisome targeting signal 1 (PTS1) cargo protein, be monoubiquitinated and exported back into the cytosol. Importantly, the mutant PEX5 protein was unable to form a stable trimeric complex with peroxisomal biogenesis factor 7 (PEX7) and a peroxisome targeting signal 2 (PTS2) cargo protein and, therefore, failed to promote the import of PTS2 cargo proteins into peroxisomes. In conclusion, we report a novel missense mutation in PEX5 responsible for the defective import of PTS2 cargo proteins into peroxisomes resulting in congenital cataracts and developmental defects.
Collapse
|
17
|
Yardımcı-Lokmanoğlu BN, Mutlu A, Livanelioğlu A. General Movements and Developmental Functioning in an Individual with Rhizomelic Chondrodysplasia Punctata within the First Months of the Life: A Case Report. Phys Occup Ther Pediatr 2021; 41:326-335. [PMID: 33161810 DOI: 10.1080/01942638.2020.1841870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
AIMS Rhizomelic chondrodysplasia punctata (RCDP) is an autosomal recessive inherited disorder. Individuals with RCDP have a wide range of neurodevelopmental outcomes, but there are limited descriptions of their early motor development before 5 months of age. This study aimed to describe in detail the age-specific spontaneous movements and examine the developmental functioning in an individual with RCDP. METHODS A female infant (born at 39 weeks' gestation), diagnosed with RCDP at 3 weeks of age, was assessed at 4 and 16 weeks for general movements (GMs) and concurrent motor repertoire; the Bayley Scales of Infant and Toddler Development-Third Edition (Bayley-III) was also applied at the same ages. RESULTS At 4 weeks, the infant showed poor repertoire GMs, with a detailed General Movement Optimality Score of 16/42. At 16 weeks, age-specific fidgety movements were absent, and the movement character was monotonous and stiff; the detailed Motor Optimality Score was severely reduced (7/28). All Bayley-III scores were <2 SD, that is <70 indicating severe developmental delay. CONCLUSION Functional assessments such as the GM assessment and age-specific detailed assessment could be complementary to neuroimaging assessments to predict the neurodevelopmental outcomes in infants with RCDP.
Collapse
Affiliation(s)
- Bilge Nur Yardımcı-Lokmanoğlu
- Faculty of Physical Therapy and Rehabilitation, Developmental and Early Physiotherapy Unit, Hacettepe University, Ankara, Turkey
| | - Akmer Mutlu
- Faculty of Physical Therapy and Rehabilitation, Developmental and Early Physiotherapy Unit, Hacettepe University, Ankara, Turkey
| | - Ayşe Livanelioğlu
- Faculty of Physical Therapy and Rehabilitation, Developmental and Early Physiotherapy Unit, Hacettepe University, Ankara, Turkey
| |
Collapse
|
18
|
Fallatah W, Smith T, Cui W, Jayasinghe D, Di Pietro E, Ritchie SA, Braverman N. Oral administration of a synthetic vinyl-ether plasmalogen normalizes open field activity in a mouse model of rhizomelic chondrodysplasia punctata. Dis Model Mech 2020; 13:dmm.042499. [PMID: 31862688 PMCID: PMC6994958 DOI: 10.1242/dmm.042499] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 12/13/2019] [Indexed: 01/06/2023] Open
Abstract
Rhizomelic chondrodysplasia punctata (RCDP) is a rare genetic disorder caused by mutations in peroxisomal genes essential for plasmalogen biosynthesis. Plasmalogens are a class of membrane glycerophospholipids containing a vinyl-ether-linked fatty alcohol at the sn-1 position that affect functions including vesicular transport, membrane protein function and free radical scavenging. A logical rationale for the treatment of RCDP is therefore the therapeutic augmentation of plasmalogens. The objective of this work was to provide a preliminary characterization of a novel vinyl-ether synthetic plasmalogen, PPI-1040, in support of its potential utility as an oral therapeutic option for RCDP. First, wild-type mice were treated with 13C6-labeled PPI-1040, which showed that the sn-1 vinyl-ether and the sn-3 phosphoethanolamine groups remained intact during digestion and absorption. Next, a 4-week treatment of adult plasmalogen-deficient Pex7hypo/null mice with PPI-1040 showed normalization of plasmalogen levels in plasma, and variable increases in plasmalogen levels in erythrocytes and peripheral tissues (liver, small intestine, skeletal muscle and heart). Augmentation was not observed in brain, lung and kidney. Functionally, PPI-1040 treatment normalized the hyperactive behavior observed in the Pex7hypo/null mice as determined by open field test, with a significant inverse correlation between activity and plasma plasmalogen levels. Parallel treatment with an equal amount of ether plasmalogen precursor, PPI-1011, did not effectively augment plasmalogen levels or reduce hyperactivity. Our findings show, for the first time, that a synthetic vinyl-ether plasmalogen is orally bioavailable and can improve plasmalogen levels in an RCDP mouse model. Further exploration of its clinical utility is warranted. This article has an associated First Person interview with the joint first authors of the paper. Summary: This article shows, for the first time, that a synthetic vinyl-ether plasmalogen is orally bioavailable and bioactive in vivo following administration in animals.
Collapse
Affiliation(s)
- Wedad Fallatah
- Department of Human Genetics and Pediatrics, Research Institute of the McGill University Health Center and McGill University, Montreal, QC H4A3J1, Canada.,Department of Medical Genetics, King Abdul-Aziz University, Jeddah, 21589 Saudi Arabia
| | - Tara Smith
- Med-Life Discoveries LP, Saskatoon, SK S7N2X8, Canada
| | - Wei Cui
- Department of Human Genetics and Pediatrics, Research Institute of the McGill University Health Center and McGill University, Montreal, QC H4A3J1, Canada
| | | | - Erminia Di Pietro
- Department of Human Genetics and Pediatrics, Research Institute of the McGill University Health Center and McGill University, Montreal, QC H4A3J1, Canada
| | | | - Nancy Braverman
- Department of Human Genetics and Pediatrics, Research Institute of the McGill University Health Center and McGill University, Montreal, QC H4A3J1, Canada
| |
Collapse
|
19
|
Laboratory diagnosis of disorders of peroxisomal biogenesis and function: a technical standard of the American College of Medical Genetics and Genomics (ACMG). Genet Med 2019; 22:686-697. [PMID: 31822849 DOI: 10.1038/s41436-019-0713-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 11/18/2019] [Accepted: 11/18/2019] [Indexed: 01/02/2023] Open
Abstract
Peroxisomal disorders are a clinically and genetically heterogeneous group of diseases caused by defects in peroxisomal biogenesis or function, usually impairing several metabolic pathways. Peroxisomal disorders are rare; however, the incidence may be underestimated due to the broad spectrum of clinical presentations. The inclusion of X-linked adrenoleukodystrophy to the Recommended Uniform Screening Panel for newborn screening programs in the United States may increase detection of this and other peroxisomal disorders. The current diagnostic approach relies heavily on biochemical genetic tests measuring peroxisomal metabolites, including very long-chain and branched-chain fatty acids in plasma and plasmalogens in red blood cells. Molecular testing can confirm biochemical findings and identify the specific genetic defect, usually utilizing a multiple-gene panel or exome/genome approach. When next-generation sequencing is used as a first-tier test, evaluation of peroxisome metabolism is often necessary to assess the significance of unknown variants and establish the extent of peroxisome dysfunction. This document provides a resource for laboratories developing and implementing clinical biochemical genetic testing for peroxisomal disorders, emphasizing technical considerations for sample collection, test performance, and result interpretation. Additionally, considerations on confirmatory molecular testing are discussed.
Collapse
|
20
|
Duker AL, Niiler T, Kinderman D, Schouten M, Poll-The BT, Braverman N, Bober MB. Rhizomelic chondrodysplasia punctata morbidity and mortality, an update. Am J Med Genet A 2019; 182:579-583. [PMID: 31769196 DOI: 10.1002/ajmg.a.61413] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 10/22/2019] [Accepted: 10/25/2019] [Indexed: 01/15/2023]
Affiliation(s)
- Angela L Duker
- Nemours/Alfred I. duPont Hospital for Children, Wilmington, Delaware
| | - Timothy Niiler
- Nemours/Alfred I. duPont Hospital for Children, Wilmington, Delaware
| | - Dagmar Kinderman
- Nemours/Alfred I. duPont Hospital for Children, Wilmington, Delaware
| | - Monica Schouten
- Amsterdam University Medical Center, Amsterdam, The Netherlands
| | | | | | - Michael B Bober
- Nemours/Alfred I. duPont Hospital for Children, Wilmington, Delaware
| |
Collapse
|
21
|
Kunze M. The type-2 peroxisomal targeting signal. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2019; 1867:118609. [PMID: 31751594 DOI: 10.1016/j.bbamcr.2019.118609] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Revised: 11/08/2019] [Accepted: 11/13/2019] [Indexed: 12/13/2022]
Abstract
The type-2 peroxisomal targeting signal (PTS2) is one of two peptide motifs destining soluble proteins for peroxisomes. This signal acts as amphiphilic α-helix exposing the side chains of all conserved residues to the same side. PTS2 motifs are recognized by a bipartite protein complex consisting of the receptor PEX7 and a co-receptor. Cargo-loaded receptor complexes are translocated across the peroxisomal membrane by a transient pore and inside peroxisomes, cargo proteins are released and processed in many, but not all species. The components of the bipartite receptor are re-exported into the cytosol by a ubiquitin-mediated and ATP-driven export mechanism. Structurally, PTS2 motifs resemble other N-terminal targeting signals, whereas the functional relation to the second peroxisomal targeting signal (PTS1) is unclear. Although only a few PTS2-carrying proteins are known in humans, subjects lacking a functional import mechanism for these proteins suffer from the severe inherited disease rhizomelic chondrodysplasia punctata.
Collapse
Affiliation(s)
- Markus Kunze
- Medical University of Vienna, Center for Brain Research, Department of Pathobiology of the Nervous System, Spitalgasse 4, 1090 Vienna, Austria.
| |
Collapse
|
22
|
Reis LM, Semina EV. Genetic landscape of isolated pediatric cataracts: extreme heterogeneity and variable inheritance patterns within genes. Hum Genet 2018; 138:847-863. [PMID: 30187164 DOI: 10.1007/s00439-018-1932-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 08/29/2018] [Indexed: 12/12/2022]
Abstract
Pediatric cataract represents an important cause of pediatric visual impairment. While both genetic and environmental causes for pediatric cataract are known, a large proportion remains idiopathic. The purpose of this review is to discuss genes involved in isolated pediatric cataract, with a focus on variable inheritance patterns within genes. Mutations in over 52 genes are known to cause isolated pediatric cataract, with a major contribution from genes encoding for crystallins, transcription factors, membrane proteins, and cytoskeletal proteins. Interestingly, both dominant and recessive inheritance patterns have been reported for mutations in 13 different cataract genes. For some genes, dominant and recessive alleles represent distinct types of mutations, but for many, especially missense variants, there are no clear patterns to distinguish between dominant and recessive alleles. Further research into the functional effects of these mutations, as well as additional data on the frequency of the identified variants, is needed to clarify variant pathogenicity. Exome sequencing continues to be successful in identifying novel genes associated with congenital cataract but is hindered by the extreme genetic heterogeneity of this condition. The large number of idiopathic cases suggests that more genes and potentially novel mechanisms of gene disruption remain to be identified.
Collapse
Affiliation(s)
- Linda M Reis
- Department of Pediatrics and Children's Research Institute, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Elena V Semina
- Department of Pediatrics and Children's Research Institute, Medical College of Wisconsin, Milwaukee, WI, 53226, USA. .,Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA.
| |
Collapse
|
23
|
Rossi M, Anheim M, Durr A, Klein C, Koenig M, Synofzik M, Marras C, van de Warrenburg BP. The genetic nomenclature of recessive cerebellar ataxias. Mov Disord 2018; 33:1056-1076. [PMID: 29756227 DOI: 10.1002/mds.27415] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 03/15/2018] [Accepted: 03/25/2018] [Indexed: 12/17/2022] Open
Abstract
The recessive cerebellar ataxias are a large group of degenerative and metabolic disorders, the diagnostic management of which is difficult because of the enormous clinical and genetic heterogeneity. Because of several limitations, the current classification systems provide insufficient guidance for clinicians and researchers. Here, we propose a new nomenclature for the genetically confirmed recessive cerebellar ataxias according to the principles and criteria laid down by the International Parkinson and Movement Disorder Society Task Force on Classification and Nomenclature of Genetic Movement Disorders. We apply stringent criteria for considering an association between gene and phenotype to be established. The newly proposed list of recessively inherited cerebellar ataxias includes 62 disorders that were assigned an ATX prefix, followed by the gene name, because these typically present with ataxia as a predominant and/or consistent feature. An additional 30 disorders that often combine ataxia with a predominant or consistent other movement disorder received a double prefix (e.g., ATX/HSP). We also identified a group of 89 entities that usually present with complex nonataxia phenotypes, but may occasionally present with cerebellar ataxia. These are listed separately without the ATX prefix. This new, transparent and adaptable nomenclature of the recessive cerebellar ataxias will facilitate the clinical recognition of recessive ataxias, guide diagnostic testing in ataxia patients, and help in interpreting genetic findings. © 2018 International Parkinson and Movement Disorder Society.
Collapse
Affiliation(s)
- Malco Rossi
- Movement Disorders Section, Neuroscience Department, Raul Carrea Institute for Neurological Research, Buenos Aires, Argentina
| | - Mathieu Anheim
- Département de Neurologie, Hôpitaux Universitaires de Strasbourg, Hôpital de Hautepierre, Strasbourg, France.,Institut de Génétique et de Biologie Moléculaire et Cellulaire, INSERM-U964/CNRS-UMR7104/Université de Strasbourg, Illkirch, France.,Fédération de Médecine Translationnelle de Strasbourg, Université de Strasbourg, Strasbourg, France
| | - Alexandra Durr
- Brain and Spine Institute, Sorbonne Université, Inserm U1127, CNRS UMR 7225, Pitié-Salpêtrière University Hospital, Paris, France.,Department of Genetics, AP-HP, Pitié-Salpêtrière University Hospital, 7501, Paris, France
| | - Christine Klein
- Institute of Neurogenetics, University of Luebeck, Luebeck, Germany.,Department of Neurology, University Hospital Schleswig-Holstein, Campus Lübeck, Germany
| | - Michel Koenig
- Laboratoire de Génétique de Maladies Rares, EA7402, Institut Universitaire de Recherche Clinique, Université de Montpellier, CHU Montpellier, Montpellier, France
| | - Matthis Synofzik
- Department of Neurodegenerative Diseases, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.,German Center for Neurodegenerative Diseases, Tübingen, Germany
| | - Connie Marras
- Toronto Western Hospital Morton, Gloria Shulman Movement Disorders Centre, and the Edmond J. Safra Program in Parkinson's Disease, University of Toronto, Toronto, Canada
| | - Bart P van de Warrenburg
- Department of Neurology, Donders Institute for Brain, Cognition & Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | | |
Collapse
|
24
|
Lopez DH, Bestard-Escalas J, Garate J, Maimó-Barceló A, Fernández R, Reigada R, Khorrami S, Ginard D, Okazaki T, Fernández JA, Barceló-Coblijn G. Tissue-selective alteration of ethanolamine plasmalogen metabolism in dedifferentiated colon mucosa. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1863:928-938. [PMID: 29709709 DOI: 10.1016/j.bbalip.2018.04.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 04/12/2018] [Accepted: 04/21/2018] [Indexed: 01/09/2023]
Abstract
Human colon lipid analysis by imaging mass spectrometry (IMS) demonstrates that the lipid fingerprint is highly sensitive to a cell's pathophysiological state. Along the colon crypt axis, and concomitant to the differentiation process, certain lipid species tightly linked to signaling (phosphatidylinositols and arachidonic acid (AA)-containing diacylglycerophospholipids), change following a rather simple mathematical expression. We extend here our observations to ethanolamine plasmalogens (PlsEtn), a unique type of glycerophospholipid presenting a vinyl ether linkage at sn-1 position. PlsEtn distribution was studied in healthy, adenomatous, and carcinomatous colon mucosa sections by IMS. In epithelium, 75% of PlsEtn changed in a highly regular manner along the crypt axis, in clear contrast with diacyl species (67% of which remained constant). Consistently, AA-containing PlsEtn species were more abundant at the base, where stem cells reside, and decreased while ascending the crypt. In turn, mono-/diunsaturated species experienced the opposite change. These gradients were accompanied by a gradual expression of ether lipid synthesis enzymes. In lamina propria, 90% of stromal PlsEtn remained unchanged despite the high content of AA and the gradient in AA-containing diacylglycerophospholipids. Finally, both lipid and protein gradients were severely affected in polyps and carcinoma. These results link PlsEtn species regulation to cell differentiation for the first time and confirm that diacyl and ether species are differently regulated. Furthermore, they reaffirm the observations on cell lipid fingerprint image sensitivity to predict cell pathophysiological status, reinforcing the translational impact both lipidome and IMS might have in clinical research.
Collapse
Affiliation(s)
- Daniel H Lopez
- Institut d'Investigació Sanitària Illes Balears (IdISBa, Health Research Institute of the Balearic Islands), Palma, Balearic Islands, Spain.
| | - Joan Bestard-Escalas
- Institut d'Investigació Sanitària Illes Balears (IdISBa, Health Research Institute of the Balearic Islands), Palma, Balearic Islands, Spain.
| | - Jone Garate
- Dep. of Physical Chemistry, University of the Basque Country (UPV/EHU), Leioa, Biscay, Spain.
| | - Albert Maimó-Barceló
- Institut d'Investigació Sanitària Illes Balears (IdISBa, Health Research Institute of the Balearic Islands), Palma, Balearic Islands, Spain.
| | - Roberto Fernández
- Dep. of Physical Chemistry, University of the Basque Country (UPV/EHU), Leioa, Biscay, Spain.
| | - Rebeca Reigada
- Institut d'Investigació Sanitària Illes Balears (IdISBa, Health Research Institute of the Balearic Islands), Palma, Balearic Islands, Spain.
| | - Sam Khorrami
- Institut d'Investigació Sanitària Illes Balears (IdISBa, Health Research Institute of the Balearic Islands), Palma, Balearic Islands, Spain; Gastroenterology Unit, Hospital Universitari Son Espases, Palma, Balearic Islands, Spain.
| | - Daniel Ginard
- Institut d'Investigació Sanitària Illes Balears (IdISBa, Health Research Institute of the Balearic Islands), Palma, Balearic Islands, Spain; Gastroenterology Unit, Hospital Universitari Son Espases, Palma, Balearic Islands, Spain.
| | - Toshiro Okazaki
- Department of Hematology/Immunity, Kanazawa Medical University, Uchinada-machi, Kahoku-gun, Ishikawa 920-0293, Japan.
| | - José A Fernández
- Dep. of Physical Chemistry, University of the Basque Country (UPV/EHU), Leioa, Biscay, Spain.
| | - Gwendolyn Barceló-Coblijn
- Institut d'Investigació Sanitària Illes Balears (IdISBa, Health Research Institute of the Balearic Islands), Palma, Balearic Islands, Spain.
| |
Collapse
|
25
|
Dorninger F, Forss-Petter S, Berger J. From peroxisomal disorders to common neurodegenerative diseases - the role of ether phospholipids in the nervous system. FEBS Lett 2017; 591:2761-2788. [PMID: 28796901 DOI: 10.1002/1873-3468.12788] [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: 07/05/2017] [Revised: 07/26/2017] [Accepted: 08/07/2017] [Indexed: 01/01/2023]
Abstract
The emerging diverse roles of ether (phospho)lipids in nervous system development and function in health and disease are currently attracting growing interest. Plasmalogens, a subgroup of ether lipids, are important membrane components involved in vesicle fusion and membrane raft composition. They store polyunsaturated fatty acids and may serve as antioxidants. Ether lipid metabolites act as precursors for the formation of glycosyl-phosphatidyl-inositol anchors; others, like platelet-activating factor, are implicated in signaling functions. Consolidating the available information, we attempt to provide molecular explanations for the dramatic neurological phenotype in ether lipid-deficient human patients and mice by linking individual functional properties of ether lipids with pathological features. Furthermore, recent publications have identified altered ether lipid levels in the context of many acquired neurological disorders including Alzheimer's disease (AD) and autism. Finally, current efforts to restore ether lipids in peroxisomal disorders as well as AD are critically reviewed.
Collapse
Affiliation(s)
- Fabian Dorninger
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Austria
| | - Sonja Forss-Petter
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Austria
| | - Johannes Berger
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Austria
| |
Collapse
|
26
|
Honsho M, Fujiki Y. Plasmalogen homeostasis - regulation of plasmalogen biosynthesis and its physiological consequence in mammals. FEBS Lett 2017; 591:2720-2729. [PMID: 28686302 DOI: 10.1002/1873-3468.12743] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2015] [Revised: 06/28/2015] [Accepted: 06/29/2016] [Indexed: 11/06/2022]
Abstract
Plasmalogens, mostly ethanolamine-containing alkenyl ether phospholipids, are a major subclass of glycerophospholipids. Plasmalogen synthesis is initiated in peroxisomes and completed in the endoplasmic reticulum. The absence of plasmalogens in several organs of peroxisome biogenesis-defective patients suggests that the de novo synthesis of plasmalogens plays a pivotal role in its homeostasis in tissues. Plasmalogen synthesis is regulated by modulating the stability of fatty acyl-CoA reductase 1 on peroxisomal membranes, a rate-limiting enzyme in plasmalogen synthesis, by sensing plasmalogens in the inner leaflet of plasma membranes. Dysregulation of plasmalogen homeostasis impairs cholesterol biosynthesis by altering the stability of squalene monooxygenase, a key enzyme in cholesterol biosynthesis, implying physiological consequences of plasmalogen homeostasis with respect to cholesterol metabolism in cells, as well as in organs such as the liver.
Collapse
Affiliation(s)
- Masanori Honsho
- Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Yukio Fujiki
- Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| |
Collapse
|
27
|
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
|
28
|
Duker AL, Niiler T, Eldridge G, Brereton NH, Braverman NE, Bober MB. Growth charts for individuals with rhizomelic chondrodysplasia punctata. Am J Med Genet A 2016; 173:108-113. [PMID: 27616591 DOI: 10.1002/ajmg.a.37961] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 08/22/2016] [Indexed: 02/03/2023]
Abstract
Rhizomelic chondrodysplasia punctata (RCDP) is a class of peroxisomal disorders characterized by defective plasmalogen biosynthesis. There are multiple recognized types of RCDP, all of which have autosomal recessive inheritance, and their associated genes are known: RCDP type 1 with PEX7, RCDP type 2 with GNPAT, RCDP type 3 with AGPS, RCDP type 4 with FAR1, and RCDP type 5 with PEX5. Among other medical/developmental issues, plasmalogen deficiency has a direct effect on bone growth and results in postnatal growth failure, the severity of which corresponds to the degree of plasmalogen deficiency. In order to document growth in patients with RCDP, we present detailed growth curves for length, weight, and head circumference derived from retrospective data from 23 individuals with RCDP types 1 and 2 confirmed by molecular and/or biochemical studies. We stratified growth curves by age as well as by plasmalogen level, with those with higher plasmalogens grouped as "non-classic." The growth charts presented here provide guidance to families and physician caretakers on the natural course of growth in individuals with RCDP during infancy into early childhood, and thus will have particular utility in setting expectations and guiding optimal feeding interventions in this population.© 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Angela L Duker
- Division of Medical Genetics, Nemours/Alfred I. duPont Hospital for Children, Wilmington, Delaware
| | - Tim Niiler
- Gait Laboratory, Nemours/Alfred I. duPont Hospital for Children, Wilmington, Delaware
| | - Grant Eldridge
- Department of Research, Nemours/Alfred I. duPont Hospital for Children, Wilmington, Delaware
| | - Nga H Brereton
- Institute for Clinical and Translational Research, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Nancy E Braverman
- Departments of Human Genetics and Pediatrics, McGill University-Montreal Children's Hospital Research Institute, Montreal, Quebec
| | - Michael B Bober
- Division of Medical Genetics, Nemours/Alfred I. duPont Hospital for Children, Wilmington, Delaware
| |
Collapse
|
29
|
Ferdinandusse S, Ebberink MS, Vaz FM, Waterham HR, Wanders RJA. The important role of biochemical and functional studies in the diagnostics of peroxisomal disorders. J Inherit Metab Dis 2016; 39:531-43. [PMID: 26943801 PMCID: PMC4920857 DOI: 10.1007/s10545-016-9922-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 02/09/2016] [Accepted: 02/11/2016] [Indexed: 01/13/2023]
Abstract
Peroxisomes are dynamic organelles that play an essential role in a variety of metabolic pathways. Peroxisomal dysfunction can lead to various biochemical abnormalities and result in abnormal metabolite levels, such as increased very long-chain fatty acid or reduced plasmalogen levels. The metabolite abnormalities in peroxisomal disorders are used in the diagnostics of these disorders. In this paper we discuss in detail the different diagnostic tests available for peroxisomal disorders and focus specifically on the important role of biochemical and functional studies in cultured skin fibroblasts in reaching the right diagnosis. Several examples are shown to underline the power of such studies.
Collapse
Affiliation(s)
- Sacha Ferdinandusse
- Laboratory Genetic Metabolic Diseases, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
| | - Merel S Ebberink
- Laboratory Genetic Metabolic Diseases, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Frédéric M Vaz
- Laboratory Genetic Metabolic Diseases, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Hans R Waterham
- Laboratory Genetic Metabolic Diseases, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Ronald J A Wanders
- Laboratory Genetic Metabolic Diseases, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| |
Collapse
|
30
|
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
|
31
|
Qian G, Fan W, Ahlemeyer B, Karnati S, Baumgart-Vogt E. Peroxisomes in Different Skeletal Cell Types during Intramembranous and Endochondral Ossification and Their Regulation during Osteoblast Differentiation by Distinct Peroxisome Proliferator-Activated Receptors. PLoS One 2015; 10:e0143439. [PMID: 26630504 PMCID: PMC4668026 DOI: 10.1371/journal.pone.0143439] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 11/04/2015] [Indexed: 01/10/2023] Open
Abstract
Ossification defects leading to craniofacial dysmorphism or rhizomelia are typical phenotypes in patients and corresponding knockout mouse models with distinct peroxisomal disorders. Despite these obvious skeletal pathologies, to date no careful analysis exists on the distribution and function of peroxisomes in skeletal tissues and their alterations during ossification. Therefore, we analyzed the peroxisomal compartment in different cell types of mouse cartilage and bone as well as in primary cultures of calvarial osteoblasts. The peroxisome number and metabolism strongly increased in chondrocytes during endochondral ossification from the reserve to the hypertrophic zone, whereas in bone, metabolically active osteoblasts contained a higher numerical abundance of this organelle than osteocytes. The high abundance of peroxisomes in these skeletal cell types is reflected by high levels of Pex11β gene expression. During culture, calvarial pre-osteoblasts differentiated into secretory osteoblasts accompanied by peroxisome proliferation and increased levels of peroxisomal genes and proteins. Since many peroxisomal genes contain a PPAR-responsive element, we analyzed the gene expression of PPARɑ/ß/ɣ in calvarial osteoblasts and MC3T3-E1 cells, revealing higher levels for PPARß than for PPARɑ and PPARɣ. Treatment with different PPAR agonists and antagonists not only changed the peroxisomal compartment and associated gene expression, but also induced complex alterations of the gene expression patterns of the other PPAR family members. Studies in M3CT3-E1 cells showed that the PPARß agonist GW0742 activated the PPRE-mediated luciferase expression and up-regulated peroxisomal gene transcription (Pex11, Pex13, Pex14, Acox1 and Cat), whereas the PPARß antagonist GSK0660 led to repression of the PPRE and a decrease of the corresponding mRNA levels. In the same way, treatment of calvarial osteoblasts with GW0742 increased in peroxisome number and related gene expression and accelerated osteoblast differentiation. Taken together, our results suggest that PPARß regulates the numerical abundance and metabolic function of peroxisomes via Pex11ß in parallel to osteoblast differentiation.
Collapse
Affiliation(s)
- Guofeng Qian
- Institute for Anatomy and Cell Biology, Medical Cell Biology, Justus-Liebig-University, Aulweg 123, 35385 Giessen, Germany
| | - Wei Fan
- Institute for Anatomy and Cell Biology, Medical Cell Biology, Justus-Liebig-University, Aulweg 123, 35385 Giessen, Germany
| | - Barbara Ahlemeyer
- Institute for Anatomy and Cell Biology, Medical Cell Biology, Justus-Liebig-University, Aulweg 123, 35385 Giessen, Germany
| | - Srikanth Karnati
- Institute for Anatomy and Cell Biology, Medical Cell Biology, Justus-Liebig-University, Aulweg 123, 35385 Giessen, Germany
| | - Eveline Baumgart-Vogt
- Institute for Anatomy and Cell Biology, Medical Cell Biology, Justus-Liebig-University, Aulweg 123, 35385 Giessen, Germany
- * E-mail:
| |
Collapse
|
32
|
Duker AL, Eldridge G, Braverman NE, Bober MB. Congenital heart defects common in rhizomelic chondrodysplasia punctata. Am J Med Genet A 2015; 170A:270-2. [DOI: 10.1002/ajmg.a.37404] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Accepted: 09/07/2015] [Indexed: 11/08/2022]
Affiliation(s)
- Angela L. Duker
- Division of Medical Genetics; Nemours/Alfred I. duPont Hospital for Children; Wilmington Delaware
| | - Grant Eldridge
- Department of Research; Nemours/Alfred I. duPont Hospital for Children; Wilmington Delaware
| | - Nancy E. Braverman
- Departments of Human Genetics and Pediatrics; McGill University-Montreal Children's Hospital Research Institute; Montreal Quebec Canada
| | - Michael B. Bober
- Division of Medical Genetics; Nemours/Alfred I. duPont Hospital for Children; Wilmington Delaware
| |
Collapse
|
33
|
Kunze M, Berger J. The similarity between N-terminal targeting signals for protein import into different organelles and its evolutionary relevance. Front Physiol 2015; 6:259. [PMID: 26441678 PMCID: PMC4585086 DOI: 10.3389/fphys.2015.00259] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 09/04/2015] [Indexed: 12/04/2022] Open
Abstract
The proper distribution of proteins between the cytosol and various membrane-bound compartments is crucial for the functionality of eukaryotic cells. This requires the cooperation between protein transport machineries that translocate diverse proteins from the cytosol into these compartments and targeting signal(s) encoded within the primary sequence of these proteins that define their cellular destination. The mechanisms exerting protein translocation differ remarkably between the compartments, but the predominant targeting signals for mitochondria, chloroplasts and the ER share the N-terminal position, an α-helical structural element and the removal from the core protein by intraorganellar cleavage. Interestingly, similar properties have been described for the peroxisomal targeting signal type 2 mediating the import of a fraction of soluble peroxisomal proteins, whereas other peroxisomal matrix proteins encode the type 1 targeting signal residing at the extreme C-terminus. The structural similarity of N-terminal targeting signals poses a challenge to the specificity of protein transport, but allows the generation of ambiguous targeting signals that mediate dual targeting of proteins into different compartments. Dual targeting might represent an advantage for adaptation processes that involve a redistribution of proteins, because it circumvents the hierarchy of targeting signals. Thus, the co-existence of two equally functional import pathways into peroxisomes might reflect a balance between evolutionary constant and flexible transport routes.
Collapse
Affiliation(s)
- Markus Kunze
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna Vienna, Austria
| | - Johannes Berger
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna Vienna, Austria
| |
Collapse
|
34
|
Barøy T, Koster J, Strømme P, Ebberink MS, Misceo D, Ferdinandusse S, Holmgren A, Hughes T, Merckoll E, Westvik J, Woldseth B, Walter J, Wood N, Tvedt B, Stadskleiv K, Wanders RJ, Waterham HR, Frengen E. A novel type of rhizomelic chondrodysplasia punctata, RCDP5, is caused by loss of the PEX5 long isoform. Hum Mol Genet 2015. [DOI: 10.1093/hmg/ddv305] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
|
35
|
Nanetti L, Pensato V, Leoni V, Rizzetto M, Caccia C, Taroni F, Mariotti C, Gellera C. PEX7 Mutations Cause Congenital Cataract Retinopathy and Late-Onset Ataxia and Cognitive Impairment: Report of Two Siblings and Review of the Literature. J Clin Neurol 2015; 11:197-9. [PMID: 25851898 PMCID: PMC4387488 DOI: 10.3988/jcn.2015.11.2.197] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Revised: 11/05/2014] [Accepted: 11/06/2014] [Indexed: 12/02/2022] Open
Affiliation(s)
- Lorenzo Nanetti
- Unit of Genetics of Neurodegenerative and Metabolic Diseases, IRCCS Fondazione Istituto Neurologico Carlo Besta, Milano, Italy
| | - Viviana Pensato
- Unit of Genetics of Neurodegenerative and Metabolic Diseases, IRCCS Fondazione Istituto Neurologico Carlo Besta, Milano, Italy
| | - Valerio Leoni
- Unit of Genetics of Neurodegenerative and Metabolic Diseases, IRCCS Fondazione Istituto Neurologico Carlo Besta, Milano, Italy
| | - Manuela Rizzetto
- Unit of Genetics of Neurodegenerative and Metabolic Diseases, IRCCS Fondazione Istituto Neurologico Carlo Besta, Milano, Italy
| | - Claudio Caccia
- Unit of Genetics of Neurodegenerative and Metabolic Diseases, IRCCS Fondazione Istituto Neurologico Carlo Besta, Milano, Italy
| | - Franco Taroni
- Unit of Genetics of Neurodegenerative and Metabolic Diseases, IRCCS Fondazione Istituto Neurologico Carlo Besta, Milano, Italy
| | - Caterina Mariotti
- Unit of Genetics of Neurodegenerative and Metabolic Diseases, IRCCS Fondazione Istituto Neurologico Carlo Besta, Milano, Italy.
| | - Cinzia Gellera
- Unit of Genetics of Neurodegenerative and Metabolic Diseases, IRCCS Fondazione Istituto Neurologico Carlo Besta, Milano, Italy
| |
Collapse
|
36
|
Çim A, Coşkun S, Görükmez O, Yüksel H, Uluca Ü, Di Pietro E, Plourde F, Elise Braverman N. Rhizomelic Chondrodysplasia Punctata Type 1 Caused by a Novel Mutation in the PEX7 Gene. J Clin Res Pediatr Endocrinol 2015; 7:69-72. [PMID: 25800479 PMCID: PMC4439895 DOI: 10.4274/jcrpe.1835] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Peroxisomes are involved in various metabolic reactions. Rhizomelic chondrodysplasia punctata (RCDP) type 1 is one of the peroxisomal biogenesis disorders caused by mutations in the PEX7 gene and is inherited in an autosomal recessive manner. We present a nine-year-old boy with skeletal abnormalities and dysmorphic facial appearance. The patient was born to parents who were first cousins. Very-long-chain fatty acids and pristanic acid levels were in the normal range, but an elevated phytanic acid level was detected by gas chromatography/mass spectrometry. The PEX7 gene was sequenced in the patient and his parents. A novel homozygous mutation, c.192delT (p.F64Lfs*10), was identified in the patient and was present in heterozygosity in both parents. In conclusion, the clinical presentation and peroxisome profile of the patient suggest that this novel mutation leads to RCDP type 1.
Collapse
Affiliation(s)
- Abdullah Çim
- Dicle University Faculty of Medicine, Department of Medical Genetics, Diyarbakır, Turkey. E-mail:
| | - Salih Coşkun
- Dicle University Faculty of Medicine, Department of Medical Genetics, Diyarbakır, Turkey
| | - Orhan Görükmez
- Şevket Yılmaz Training and Research Hospital, Clinic of Medical Genetics, Bursa, Turkey
| | - Hatice Yüksel
- Dicle University Faculty of Medicine, Department of Biochemistry, Diyarbakır, Turkey
| | - Ünal Uluca
- Dicle University Faculty of Medicine, Department of Pediatrics, Diyarbakır, Turkey
| | - Erminia Di Pietro
- McGill University and the Research Institute of the MUHC, Department of Pediatrics and Human Genetics, Quebec, Canada
| | - François Plourde
- McGill University and the Research Institute of the MUHC, Department of Pediatrics and Human Genetics, Quebec, Canada
| | - Nancy Elise Braverman
- McGill University and the Research Institute of the MUHC, Department of Pediatrics and Human Genetics, Quebec, Canada
| |
Collapse
|
37
|
Malheiro AR, da Silva TF, Brites P. Plasmalogens and fatty alcohols in rhizomelic chondrodysplasia punctata and Sjögren-Larsson syndrome. J Inherit Metab Dis 2015; 38:111-21. [PMID: 25432520 DOI: 10.1007/s10545-014-9795-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 11/10/2014] [Accepted: 11/11/2014] [Indexed: 12/29/2022]
Abstract
Plasmalogens are a special class of ether-phospholipids, best recognized by their vinyl-ether bond at the sn-1 position of the glycerobackbone and by the observation that their deficiency causes rhizomelic chondrodysplasia punctata (RCDP). The complex plasmalogen biosynthetic pathway involves multiple enzymatic steps carried-out in peroxisomes and in the endoplasmic reticulum. The rate limiting step in the biosynthesis of plasmalogens resides in the formation of the fatty alcohol responsible for the formation of an intermediate with an alkyl-linked moiety. The regulation in the biosynthesis of plasmalogens also takes place at this step using a feedback mechanism to stimulate or inhibit the biosynthesis. As such, fatty alcohols play a relevant role in the formation of ether-phospholipids. These advances in our understanding of complex lipid biosynthesis brought two seemingly distinct disorders into the spotlight. Sjögren-Larsson syndrome (SLS) is caused by defects in the microsomal fatty aldehyde dehydrogenase (FALDH) leading to the accumulation of fatty alcohols and fatty aldehydes. In RCDP cells, the defect in plasmalogens is thought to generate a feedback signal to increase their biosynthesis, through the activity of fatty acid reductases to produce fatty alcohols. However, the enzymatic defects in either glyceronephosphate O-acyltransferase (GNPAT) or alkylglycerone phosphate synthase (AGPS) disrupt the biosynthesis and result in the accumulation of the fatty alcohols. A detailed characterization on the processes and enzymes that govern these intricate biosynthetic pathways, as well as, the metabolic characterization of defects along the pathway should increase our understanding of the causes and mechanisms behind these disorders.
Collapse
Affiliation(s)
- Ana R Malheiro
- Lab Nerve Regeneration, Instituto de Biologia Molecular e Celular - IBMC, Porto, Portugal
| | | | | |
Collapse
|
38
|
Kunze M, Malkani N, Maurer-Stroh S, Wiesinger C, Schmid JA, Berger J. Mechanistic insights into PTS2-mediated peroxisomal protein import: the co-receptor PEX5L drastically increases the interaction strength between the cargo protein and the receptor PEX7. J Biol Chem 2014; 290:4928-4940. [PMID: 25538232 DOI: 10.1074/jbc.m114.601575] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The destination of peroxisomal matrix proteins is encoded by short peptide sequences, which have been characterized as peroxisomal targeting signals (PTS) residing either at the C terminus (PTS1) or close to the N terminus (PTS2). PTS2-carrying proteins interact with their cognate receptor protein PEX7 that mediates their transport to peroxisomes by a concerted action with a co-receptor protein, which in mammals is the PTS1 receptor PEX5L. Using a modified version of the mammalian two-hybrid assay, we demonstrate that the interaction strength between cargo and PEX7 is drastically increased in the presence of the co-receptor PEX5L. In addition, cargo binding is a prerequisite for the interaction between PEX7 and PEX5L and ectopic overexpression of PTS2-carrying cargo protein drastically increases the formation of PEX7-PEX5L complexes in this assay. Consistently, we find that the peroxisomal transfer of PEX7 depends on cargo binding and that ectopic overexpression of cargo protein stimulates this process. Thus, the sequential formation of a highly stable trimeric complex involving cargo protein, PEX7 and PEX5L stabilizes cargo binding and is a prerequisite for PTS2-mediated peroxisomal import.
Collapse
Affiliation(s)
- Markus Kunze
- Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria,.
| | - Naila Malkani
- Department of Vascular Biology and Thrombosis Research, Medical University of Vienna, Schwarzspanierstrasse 17, 1090 Vienna, Austria
| | - Sebastian Maurer-Stroh
- Bioinformatics Institute (BII), Agency for Science, Technology and Research (A*STAR), 30 Biopolis Street, Singapore 138671; School of Biological Sciences (SBS), Nanyang Technological University (NTU), 8 Medical Drive, Singapore 117597
| | - Christoph Wiesinger
- Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria
| | - Johannes A Schmid
- Department of Vascular Biology and Thrombosis Research, Medical University of Vienna, Schwarzspanierstrasse 17, 1090 Vienna, Austria
| | - Johannes Berger
- Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria
| |
Collapse
|
39
|
Dorninger F, Brodde A, Braverman NE, Moser AB, Just WW, Forss-Petter S, Brügger B, Berger J. Homeostasis of phospholipids - The level of phosphatidylethanolamine tightly adapts to changes in ethanolamine plasmalogens. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1851:117-28. [PMID: 25463479 PMCID: PMC4331674 DOI: 10.1016/j.bbalip.2014.11.005] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 11/04/2014] [Accepted: 11/10/2014] [Indexed: 01/19/2023]
Abstract
Ethanolamine plasmalogens constitute a group of ether glycerophospholipids that, due to their unique biophysical and biochemical properties, are essential components of mammalian cellular membranes. Their importance is emphasized by the consequences of defects in plasmalogen biosynthesis, which in humans cause the fatal disease rhizomelic chondrodysplasia punctata (RCDP). In the present lipidomic study, we used fibroblasts derived from RCDP patients, as well as brain tissue from plasmalogen-deficient mice, to examine the compensatory mechanisms of lipid homeostasis in response to plasmalogen deficiency. Our results show that phosphatidylethanolamine (PE), a diacyl glycerophospholipid, which like ethanolamine plasmalogens carries the head group ethanolamine, is the main player in the adaptation to plasmalogen insufficiency. PE levels were tightly adjusted to the amount of ethanolamine plasmalogens so that their combined levels were kept constant. Similarly, the total amount of polyunsaturated fatty acids (PUFAs) in ethanolamine phospholipids was maintained upon plasmalogen deficiency. However, we found an increased incorporation of arachidonic acid at the expense of docosahexaenoic acid in the PE fraction of plasmalogen-deficient tissues. These data show that under conditions of reduced plasmalogen levels, the amount of total ethanolamine phospholipids is precisely maintained by a rise in PE. At the same time, a shift in the ratio between ω-6 and ω-3 PUFAs occurs, which might have unfavorable, long-term biological consequences. Therefore, our findings are not only of interest for RCDP but may have more widespread implications also for other disease conditions, as for example Alzheimer's disease, that have been associated with a decline in plasmalogens. PE accurately compensates for the lack of plasmalogens in vitro and in vivo. PE levels decrease to adapt to excess of ethanolamine plasmalogens (PlsEtn). Plasmalogen deficiency favors incorporation of arachidonic acid into PE. Docosahexaenoic acid in ethanolamine phospholipids decreases upon PlsEtn depletion.
Collapse
Affiliation(s)
- Fabian Dorninger
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria.
| | - Alexander Brodde
- Heidelberg University Biochemistry Center, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.
| | - Nancy E Braverman
- Department of Human Genetics and Pediatrics, McGill University-Montreal Children's Hospital, 4060 Ste-Catherine West, PT-406.2, Montreal, QC H3Z 2Z3, Canada.
| | - Ann B Moser
- Peroxisomal Diseases Laboratory, The Hugo W Moser Research Institute, The Kennedy Krieger Institute, 707 N. Broadway, Baltimore, MD 21205, USA.
| | - Wilhelm W Just
- Heidelberg University Biochemistry Center, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.
| | - Sonja Forss-Petter
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria.
| | - Britta Brügger
- Heidelberg University Biochemistry Center, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.
| | - Johannes Berger
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria.
| |
Collapse
|
40
|
Buchert R, Tawamie H, Smith C, Uebe S, Innes AM, Al Hallak B, Ekici AB, Sticht H, Schwarze B, Lamont RE, Parboosingh JS, Bernier FP, Abou Jamra R. A peroxisomal disorder of severe intellectual disability, epilepsy, and cataracts due to fatty acyl-CoA reductase 1 deficiency. Am J Hum Genet 2014; 95:602-10. [PMID: 25439727 DOI: 10.1016/j.ajhg.2014.10.003] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 10/02/2014] [Indexed: 11/18/2022] Open
Abstract
Rhizomelic chondrodysplasia punctata (RCDP) is a group of disorders with overlapping clinical features including rhizomelia, chondrodysplasia punctata, coronal clefts, cervical dysplasia, congenital cataracts, profound postnatal growth retardation, severe intellectual disability, and seizures. Mutations in PEX7, GNPAT, and AGPS, all involved in the plasmalogen-biosynthesis pathway, have been described in individuals with RCDP. Here, we report the identification of mutations in another gene in plasmalogen biosynthesis, fatty acyl-CoA reductase 1 (FAR1), in two families affected by severe intellectual disability, early-onset epilepsy, microcephaly, congenital cataracts, growth retardation, and spasticity. Exome analyses revealed a homozygous in-frame indel mutation (c.495_507delinsT [p.Glu165_Pro169delinsAsp]) in two siblings from a consanguineous family and compound-heterozygous mutations (c.[787C>T];[1094A>G], p.[Arg263(∗)];[Asp365Gly]) in a third unrelated individual. FAR1 reduces fatty acids to their respective fatty alcohols for the plasmalogen-biosynthesis pathway. To assess the pathogenicity of the identified mutations, we transfected human embryonic kidney 293 cells with plasmids encoding FAR1 with either wild-type or mutated constructs and extracted the lipids from the cells. We screened the lipids with gas chromatography and mass spectrometry and found that all three mutations abolished the reductase activity of FAR1, given that no fatty alcohols could be detected. We also observed reduced plasmalogens in red blood cells in one individual to a range similar to that seen in individuals with RCDP, further supporting abolished FAR1 activity. We thus expand the spectrum of clinical features associated with defects in plasmalogen biosynthesis to include FAR1 deficiency as a cause of syndromic severe intellectual disability with cataracts, epilepsy, and growth retardation but without rhizomelia.
Collapse
Affiliation(s)
- Rebecca Buchert
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Hasan Tawamie
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Christopher Smith
- Department of Medical Genetics, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Steffen Uebe
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - A Micheil Innes
- Department of Medical Genetics, University of Calgary, Calgary, AB T2N 4N1, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
| | | | - Arif B Ekici
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Heinrich Sticht
- Institute of Biochemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Bernd Schwarze
- Department of Forensic Medicine, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Ryan E Lamont
- Department of Medical Genetics, University of Calgary, Calgary, AB T2N 4N1, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Jillian S Parboosingh
- Department of Medical Genetics, University of Calgary, Calgary, AB T2N 4N1, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Francois P Bernier
- Department of Medical Genetics, University of Calgary, Calgary, AB T2N 4N1, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Rami Abou Jamra
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany.
| |
Collapse
|
41
|
Wanders RJ. Metabolic functions of peroxisomes in health and disease. Biochimie 2014; 98:36-44. [DOI: 10.1016/j.biochi.2013.08.022] [Citation(s) in RCA: 133] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 08/23/2013] [Indexed: 10/26/2022]
|
42
|
Hoover-Fong J, Sobreira N, Jurgens J, Modaff P, Blout C, Moser A, Kim OH, Cho TJ, Cho SY, Kim SJ, Jin DK, Kitoh H, Park WY, Ling H, Hetrick KN, Doheny KF, Valle D, Pauli RM. Mutations in PCYT1A, encoding a key regulator of phosphatidylcholine metabolism, cause spondylometaphyseal dysplasia with cone-rod dystrophy. Am J Hum Genet 2014; 94:105-12. [PMID: 24387990 DOI: 10.1016/j.ajhg.2013.11.018] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 11/22/2013] [Indexed: 12/30/2022] Open
Affiliation(s)
- Julie Hoover-Fong
- McKusick-Nathans Institute of Genetic Medicine, Greenberg Center for Skeletal Dysplasias, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| | - Nara Sobreira
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Julie Jurgens
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Predoctoral Training Program in Human Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Peggy Modaff
- Department of Pediatrics, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Carrie Blout
- McKusick-Nathans Institute of Genetic Medicine, Greenberg Center for Skeletal Dysplasias, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Ann Moser
- Department of Neurogenetics, Kennedy Krieger Institute, Baltimore, MD 21205, USA
| | - Ok-Hwa Kim
- Department of Radiology, Ajou University Hospital, Suwon, Kyunggi 443-721, Korea
| | - Tae-Joon Cho
- Division of Pediatric Orthopaedics, Seoul National University Children's Hospital, Seoul 110-744, Korea
| | - Sung Yoon Cho
- Department of Pediatrics, Hanyang University Guri Hospital, Hanyang University College of Medicine, Guri, Gyeonggi-Do 471-701, Korea
| | - Sang Jin Kim
- Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710, Korea
| | - Dong-Kyu Jin
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710, Korea
| | - Hiroshi Kitoh
- Department of Orthopaedic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan
| | - Woong-Yang Park
- Samsung Genome Institute, Samsung Medical Center, Seoul 135-710, Korea; Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon 440-746, Korea
| | - Hua Ling
- Center for Inherited Disease Research, McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA
| | - Kurt N Hetrick
- Center for Inherited Disease Research, McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA
| | - Kimberly F Doheny
- Center for Inherited Disease Research, McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA
| | - David Valle
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Richard M Pauli
- Department of Pediatrics, University of Wisconsin-Madison, Madison, WI 53705, USA
| |
Collapse
|
43
|
Abstract
Advances in genetic tools and sequencing technology in the past few years have vastly expanded our understanding of the genetics of neurodevelopmental disorders. Recent high-throughput sequencing analyses of structural brain malformations, cognitive and neuropsychiatric disorders, and localized cortical dysplasias have uncovered a diverse genetic landscape beyond classic Mendelian patterns of inheritance. The underlying genetic causes of neurodevelopmental disorders implicate numerous cell biological pathways critical for normal brain development.
Collapse
Affiliation(s)
- Wen F Hu
- Division of Genetics and Genomics, Department of Medicine; Manton Center for Orphan Disease Research; and Howard Hughes Medical Institute, Boston Children's Hospital, Boston, Massachusetts 02115; , ,
| | | | | |
Collapse
|
44
|
Liegel RP, Ronchetti A, Sidjanin DJ. Alkylglycerone phosphate synthase (AGPS) deficient mice: models for rhizomelic chondrodysplasia punctate type 3 (RCDP3) malformation syndrome. Mol Genet Metab Rep 2014; 1:299-311. [PMID: 25197626 PMCID: PMC4151185 DOI: 10.1016/j.ymgmr.2014.06.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Rhizomelic chondrodysplasia punctata (RCDP) is a genetically heterogeneous autosomal recessive syndrome characterized by congenital cataracts, shortening of the proximal limbs, neurological abnormalities, seizures, growth delays, and severe intellectual disability. Most RCDP children die in the first decade of life due to respiratory complications. Mutations in alkylglycerone phosphate synthase (AGPS) cause RCDP type 3 (RCDP3). We've previously established that cataracts and male infertility in blind sterile 2 (bs2) mice are caused by a spontaneous hypomorphic mutation in Agps. As a part of this study, we set out to further explore the bs2 phenotypes and how they correlate to the clinical presentations of RCDP3 patients. Our results show that ∼50% bs2 mice die embryonically and surviving bs2 mice exhibit growth delays that they overcome by adulthood. The X-ray analysis of adult bs2 mice revealed significant humeral, but not femoral shortening. Clinical and histological eye evaluations revealed that bs2 lenses undergo normal development with first opacities developing at P21 that by P28 rapidly progress to mature cataracts. Evaluation of testes determined that infertility in bs2 mice is due to the aberrant formation of multicellular cellular clusters that undergo apoptosis. Given that the bs2 locus is a hypomorphic Agps mutation, we set out to generate Agps knockout mice utilizing Knockout Mouse Project (KOMP) resource. Our results showed that ∼85% of Agps knock-out mice die embryonically whereas surviving adult Agps knock-out mice phenotypically exhibit cataracts and testicular abnormalities similar to those observed in bs2 mice. Given that the majority of Agps knock-out mice die embryonically presented a challenge for further analyses of Agps deficiency in mouse models. Although not done as a part of this study, Agps-KOMP mice or ES cells can be further modified with FLP recombinase to generate mice suitable for subsequent matings with a transgenic Cre strain of choice, thereby providing an opportunity to study conditional Agps deficiency in a specific tissue or desired developmental time points without Agps deficiency-mediated embryonic lethality.
Collapse
Affiliation(s)
- Ryan P Liegel
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI
| | - Adam Ronchetti
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI
| | - D J Sidjanin
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI ; Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, WI
| |
Collapse
|
45
|
Bams-Mengerink AM, Koelman JH, Waterham H, Barth PG, Poll-The BT. The neurology of rhizomelic chondrodysplasia punctata. Orphanet J Rare Dis 2013; 8:174. [PMID: 24172221 PMCID: PMC4228450 DOI: 10.1186/1750-1172-8-174] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Accepted: 10/05/2013] [Indexed: 11/21/2022] Open
Abstract
Background To describe the neurologic profiles of Rhizomelic chondrodysplasia punctata (RCDP); a peroxisomal disorder clinically characterized by skeletal abnormalities, congenital cataracts, severe growth and developmental impairments and immobility of joints. Defective plasmalogen biosynthesis is the main biochemical feature. Methods Observational study including review of clinical and biochemical abnormalities, genotype, presence of seizures and neurophysiological studies of a cohort of 16 patients with RCDP. Results Patients with the severe phenotype nearly failed to achieve any motor or cognitive skills, whereas patients with the milder phenotype had profound intellectual disability but were able to walk and had verbal communication skills. Eighty-eight percent of patients developed epileptic seizures. The age of onset paralleled the severity of the clinical and biochemical phenotype. Myoclonic jerks, followed by atypical absences were most frequently observed. All patients with clinical seizures had interictal encephalographic evidence of epilepsy. Visual evoked (VEP) and brain auditory potential (BAEP) studies showed initial normal latency times in 93% of patients. Deterioration of VEP occurred in a minority in both the severe and the milder phenotype. BAEP and somatosensory evoked potentials (SSEP) were more likely to become abnormal in the severe phenotype. Plasmalogens were deficient in all patients. In the milder phenotype levels of plasmalogens were significantly higher in erythrocytes than in the severe phenotype. Phytanic acid levels ranged from normal to severely increased, but had no relation with the neurological phenotype. Conclusion Neurodevelopmental deficits and age-related occurrence of seizures are characteristic of RCDP and are related to the rest-activity in plasmalogen biosynthesis. Evoked potential studies are more likely to become abnormal in the severe phenotype, but are of no predictive value in single cases of RCDP.
Collapse
Affiliation(s)
- Annemieke M Bams-Mengerink
- Department of Pediatric Neurology/Emma Children's Hospital, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
| | | | | | | | | |
Collapse
|
46
|
Abstract
Upstream open reading frames (uORFs) are major gene expression regulatory elements. In many eukaryotic mRNAs, one or more uORFs precede the initiation codon of the main coding region. Indeed, several studies have revealed that almost half of human transcripts present uORFs. Very interesting examples have shown that these uORFs can impact gene expression of the downstream main ORF by triggering mRNA decay or by regulating translation. Also, evidence from recent genetic and bioinformatic studies implicates disturbed uORF-mediated translational control in the etiology of many human diseases, including malignancies, metabolic or neurologic disorders, and inherited syndromes. In this review, we will briefly present the mechanisms through which uORFs regulate gene expression and how they can impact on the organism's response to different cell stress conditions. Then, we will emphasize the importance of these structures by illustrating, with specific examples, how disturbed uORF-mediated translational control can be involved in the etiology of human diseases, giving special importance to genotype-phenotype correlations. Identifying and studying more cases of uORF-altering mutations will help us to understand and establish genotype-phenotype associations, leading to advancements in diagnosis, prognosis, and treatment of many human disorders.
Collapse
Affiliation(s)
- Cristina Barbosa
- Departamento de Genética Humana, Instituto Nacional de Saúde Dr. Ricardo Jorge, Lisboa, Portugal
- Center for Biodiversity, Functional and Integrative Genomics, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | - Isabel Peixeiro
- Departamento de Genética Humana, Instituto Nacional de Saúde Dr. Ricardo Jorge, Lisboa, Portugal
- Center for Biodiversity, Functional and Integrative Genomics, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | - Luísa Romão
- Departamento de Genética Humana, Instituto Nacional de Saúde Dr. Ricardo Jorge, Lisboa, Portugal
- Center for Biodiversity, Functional and Integrative Genomics, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
- * E-mail:
| |
Collapse
|
47
|
Crystal structure of peroxisomal targeting signal-2 bound to its receptor complex Pex7p–Pex21p. Nat Struct Mol Biol 2013; 20:987-93. [DOI: 10.1038/nsmb.2618] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Accepted: 05/13/2013] [Indexed: 12/26/2022]
|
48
|
Braverman NE, D'Agostino MD, MacLean GE. Peroxisome biogenesis disorders: Biological, clinical and pathophysiological perspectives. ACTA ACUST UNITED AC 2013; 17:187-96. [DOI: 10.1002/ddrr.1113] [Citation(s) in RCA: 101] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Accepted: 05/17/2012] [Indexed: 01/08/2023]
|
49
|
Mohamadynejad P, Ghaedi K, Shafeghati Y, Salamian A, Tanhaie S, Karamali F, Rabiee F, Parivar K, Baharvand H, Nasr-Esfahani MH. Identification of a novel missense mutation of PEX7 gene in an Iranian patient with rhizomelic chondrodysplasia punctata type 1. Gene 2013; 518:461-6. [DOI: 10.1016/j.gene.2013.01.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Revised: 12/24/2012] [Accepted: 01/10/2013] [Indexed: 11/30/2022]
|
50
|
Mizuno Y, Ninomiya Y, Nakachi Y, Iseki M, Iwasa H, Akita M, Tsukui T, Shimozawa N, Ito C, Toshimori K, Nishimukai M, Hara H, Maeba R, Okazaki T, Alodaib ANA, Amoudi MA, Jacob M, Alkuraya FS, Horai Y, Watanabe M, Motegi H, Wakana S, Noda T, Kurochkin IV, Mizuno Y, Schönbach C, Okazaki Y. Tysnd1 deficiency in mice interferes with the peroxisomal localization of PTS2 enzymes, causing lipid metabolic abnormalities and male infertility. PLoS Genet 2013; 9:e1003286. [PMID: 23459139 PMCID: PMC3573110 DOI: 10.1371/journal.pgen.1003286] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Accepted: 12/12/2012] [Indexed: 12/03/2022] Open
Abstract
Peroxisomes are subcellular organelles involved in lipid metabolic processes, including those of very-long-chain fatty acids and branched-chain fatty acids, among others. Peroxisome matrix proteins are synthesized in the cytoplasm. Targeting signals (PTS or peroxisomal targeting signal) at the C-terminus (PTS1) or N-terminus (PTS2) of peroxisomal matrix proteins mediate their import into the organelle. In the case of PTS2-containing proteins, the PTS2 signal is cleaved from the protein when transported into peroxisomes. The functional mechanism of PTS2 processing, however, is poorly understood. Previously we identified Tysnd1 (Trypsin domain containing 1) and biochemically characterized it as a peroxisomal cysteine endopeptidase that directly processes PTS2-containing prethiolase Acaa1 and PTS1-containing Acox1, Hsd17b4, and ScpX. The latter three enzymes are crucial components of the very-long-chain fatty acids β-oxidation pathway. To clarify the in vivo functions and physiological role of Tysnd1, we analyzed the phenotype of Tysnd1(-/-) mice. Male Tysnd1(-/-) mice are infertile, and the epididymal sperms lack the acrosomal cap. These phenotypic features are most likely the result of changes in the molecular species composition of choline and ethanolamine plasmalogens. Tysnd1(-/-) mice also developed liver dysfunctions when the phytanic acid precursor phytol was orally administered. Phyh and Agps are known PTS2-containing proteins, but were identified as novel Tysnd1 substrates. Loss of Tysnd1 interferes with the peroxisomal localization of Acaa1, Phyh, and Agps, which might cause the mild Zellweger syndrome spectrum-resembling phenotypes. Our data established that peroxisomal processing protease Tysnd1 is necessary to mediate the physiological functions of PTS2-containing substrates.
Collapse
Affiliation(s)
- Yumi Mizuno
- Division of Functional Genomics and Systems Medicine, Research Center for Genomic Medicine, Saitama Medical University, Hidaka-shi, Saitama, Japan
- Division of Translational Research, Research Center for Genomic Medicine, Saitama Medical University, Hidaka-shi, Saitama, Japan
| | - Yuichi Ninomiya
- Division of Functional Genomics and Systems Medicine, Research Center for Genomic Medicine, Saitama Medical University, Hidaka-shi, Saitama, Japan
| | - Yutaka Nakachi
- Division of Functional Genomics and Systems Medicine, Research Center for Genomic Medicine, Saitama Medical University, Hidaka-shi, Saitama, Japan
- Division of Translational Research, Research Center for Genomic Medicine, Saitama Medical University, Hidaka-shi, Saitama, Japan
| | - Mioko Iseki
- Division of Translational Research, Research Center for Genomic Medicine, Saitama Medical University, Hidaka-shi, Saitama, Japan
| | - Hiroyasu Iwasa
- Division of Translational Research, Research Center for Genomic Medicine, Saitama Medical University, Hidaka-shi, Saitama, Japan
| | - Masumi Akita
- Division of Morphological Science, Biomedical Research Center, Saitama Medical University, Iruma-gun, Saitama, Japan
| | - Tohru Tsukui
- Experimental Animal Laboratory, Research Center for Genomic Medicine, Saitama Medical University, Hidaka-shi, Saitama, Japan
| | - Nobuyuki Shimozawa
- Division of Genomics Research, Life Science Research Center, Gifu University, Gifu, Japan
| | - Chizuru Ito
- Department of Anatomy and Developmental Biology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Kiyotaka Toshimori
- Department of Anatomy and Developmental Biology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Megumi Nishimukai
- Laboratory of Nutritional Biochemistry, Research Group of Food Science, Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Hiroshi Hara
- Laboratory of Nutritional Biochemistry, Research Group of Food Science, Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Ryouta Maeba
- Department of Biochemistry, Teikyo University School of Medicine, Itabashi-ku, Tokyo, Japan
| | - Tomoki Okazaki
- Department of Biochemistry, Teikyo University School of Medicine, Itabashi-ku, Tokyo, Japan
| | - Ali Nasser Ali Alodaib
- Developmental Genetics Department, Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Kingdom of Saudi Arabia
- The National Newborn Screening Laboratory, Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Kingdom of Saudi Arabia
| | - Mohammed Al Amoudi
- Developmental Genetics Department, Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Kingdom of Saudi Arabia
- The National Newborn Screening Laboratory, Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Kingdom of Saudi Arabia
| | - Minnie Jacob
- Developmental Genetics Department, Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Kingdom of Saudi Arabia
- The National Newborn Screening Laboratory, Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Kingdom of Saudi Arabia
| | - Fowzan S. Alkuraya
- Developmental Genetics Department, Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Kingdom of Saudi Arabia
- Department of Pediatrics, King Khalid University Hospital and College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia
- Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Kingdom of Saudi Arabia
| | - Yasushi Horai
- Department of Internal Medicine, School of Medicine, Keio University, Shinjuku-ku, Tokyo, Japan
| | - Mitsuhiro Watanabe
- Department of Internal Medicine, School of Medicine, Keio University, Shinjuku-ku, Tokyo, Japan
- Graduate School of Media and Governance, Keio University, Tokyo, Japan
- Faculty of Environment and Information Studies, Keio University, Tokyo, Japan
| | - Hiromi Motegi
- Team for Advanced Development and Evaluation of Human Disease Models, Japan Mouse Clinic, BioResource Center (BRC), Tsukuba, Ibaraki, Japan
| | - Shigeharu Wakana
- The Japan Mouse Clinic, RIKEN BioResource Center (BRC), Tsukuba, Ibaraki, Japan
| | - Tetsuo Noda
- Team for Advanced Development and Evaluation of Human Disease Models, Japan Mouse Clinic, BioResource Center (BRC), Tsukuba, Ibaraki, Japan
- The Cancer Institute of the Japanese Foundation for Cancer Research, Koto-ku, Tokyo, Japan
| | - Igor V. Kurochkin
- Genome and Gene Expression Data Analysis Division, Bioinformatics Institute, A*STAR, Singapore, Republic of Singapore
| | - Yosuke Mizuno
- Division of Functional Genomics and Systems Medicine, Research Center for Genomic Medicine, Saitama Medical University, Hidaka-shi, Saitama, Japan
| | - Christian Schönbach
- Division of Genomics and Genetics, School of Biological Sciences, Nanyang Technological University, Singapore, Republic of Singapore
| | - Yasushi Okazaki
- Division of Functional Genomics and Systems Medicine, Research Center for Genomic Medicine, Saitama Medical University, Hidaka-shi, Saitama, Japan
- Division of Translational Research, Research Center for Genomic Medicine, Saitama Medical University, Hidaka-shi, Saitama, Japan
| |
Collapse
|