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Babaee M, Nilipour Y, Alijanpour S, Ghasemi A, Taghdiri MM, Sarraf P, Miryounesi M, Ramezani M. Phenotypic and genotyping spectrum of two Iranian cases with RBCK1-associated polyglucosan body myopathy. Neuropathology 2024. [PMID: 38922716 DOI: 10.1111/neup.12993] [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: 03/28/2024] [Revised: 05/30/2024] [Accepted: 06/02/2024] [Indexed: 06/28/2024]
Abstract
Glycogen storage diseases (GSDs) are a group of metabolic disorders affecting glycogen metabolism, with polyglucosan body myopathy type 1 (PGBM1) being a rare variant linked to RBCK1 gene mutations. Understanding the clinical diversity of PGBM1 aids in better characterization of the disease. Two unrelated Iranian families with individuals exhibiting progressive muscle weakness underwent clinical evaluations, genetic analysis using whole exome sequencing (WES), and histopathological examinations of muscle biopsies. In one case, a novel homozygous RBCK1 variant was identified, presenting with isolated myopathy without cardiac or immune involvement. Conversely, the second case harbored a known homozygous RBCK1 variant, displaying a broader phenotype encompassing myopathy, cardiomyopathy, inflammation, and immunodeficiency. Histopathological analyses confirmed characteristic skeletal muscle abnormalities consistent with PGBM1. Our study contributes to the expanding understanding of RBCK1-related diseases, illustrating the spectrum of phenotypic variability associated with distinct RBCK1 variants. These findings underscore the importance of genotype-phenotype correlations in elucidating disease mechanisms and guiding clinical management. Furthermore, the utility of next-generation sequencing techniques in diagnosing complex neurogenetic disorders is emphasized, facilitating precise diagnosis and enabling tailored genetic counseling for affected individuals and their families.
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Affiliation(s)
- Marzieh Babaee
- Physical Medicine, and Rehabilitation, Mofid Children's Hospital, Tehran, Iran
- Physical Medicine and Rehabilitation Research Center, SBMU, Tehran, Iran
| | - Yalda Nilipour
- Pediatric Pathology Research Center, Research Institute for Children's Health, Shahid Beheshti University of Medical sciences, Tehran, Iran
| | - Sahar Alijanpour
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Aida Ghasemi
- Neuromuscular Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Mehdi Taghdiri
- Pediatric Neurology Research Center, Research Institute for Children Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Pediatric Neurology Department, Mofid Children Hospital, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Payam Sarraf
- Department of Neuromuscular Diseases, Iranian Center of Neurological Research, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran
- Department of Neurology, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Miryounesi
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mahtab Ramezani
- Neuromuscular Research Center, Tehran University of Medical Sciences, Tehran, Iran
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MozafaryBazargany M, Esmaeili S, Hesami M, Houshmand G, Mahdavi M, Maleki M, Kalayinia S. A novel likely pathogenic homozygous RBCK1 variant in dilated cardiomyopathy with muscle weakness. ESC Heart Fail 2024; 11:1472-1482. [PMID: 38329383 PMCID: PMC11098654 DOI: 10.1002/ehf2.14702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 11/27/2023] [Accepted: 01/09/2024] [Indexed: 02/09/2024] Open
Abstract
AIMS Polyglucosan body myopathy 1 (PGBM1) is a type of glycogen storage disease where polyglucosan accumulation leads to cardiomyopathy and skeletal muscle myopathy. Variants of RBCK1 is related with PGBM1. We present a newly discovered pathogenic RBCK1 variant resulting in dilated cardiomyopathy (DCM) and a comprehensive literature review. METHODS AND RESULTS Whole-exome sequencing (WES) was utilized to detect genetic variations in a 7-year-old girl considered the proband. Sanger sequencing was performed to validate the variant in the patient and all the available family members, whether affected or unaffected. The variant's pathogenicity was assessed by conducting a cosegregation analysis within the family with in silico predictive software. WES showed that the proband's RBCK1 gene contained a missense likely pathogenic homozygous nucleotide variant, c.598_599insT: p.His200LeufsTer14 (NM_001323956.1), in exon 8. The computational analysis supported the variant's pathogenicity. The variant was identified in a heterozygous form among all the healthy members of the family. Variants with changes in N-terminal part of the protein were more likely to manifest immunodeficiency and auto-inflammation than those with C-terminal protein modifications according to prior variations of RBCK1 reported in the literature. CONCLUSIONS Our study offers novel findings indicating an RBCK1 variant in individuals of Iranian ancestry presenting with DCM leading to heart transplantation and myopathy without immunodeficiency or auto-inflammation.
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Affiliation(s)
| | - Shiva Esmaeili
- Rajaie Cardiovascular Medical and Research CenterIran University of Medical SciencesTehranIran
| | - Mahshid Hesami
- Rajaie Cardiovascular Medical and Research CenterIran University of Medical SciencesTehranIran
| | - Golnaz Houshmand
- Rajaie Cardiovascular Medical and Research CenterIran University of Medical SciencesTehranIran
| | - Mohamad Mahdavi
- Rajaie Cardiovascular Medical and Research CenterIran University of Medical SciencesTehranIran
| | - Majid Maleki
- Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research CenterIran University of Medical SciencesTehranIran
| | - Samira Kalayinia
- Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research CenterIran University of Medical SciencesTehranIran
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3
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Visuttijai K, Hedberg-Oldfors C, Costello DJ, Bermingham N, Oldfors A. Proteomic profiling of polyglucosan bodies associated with glycogenin-1 deficiency in skeletal muscle. Neuropathol Appl Neurobiol 2024; 50:e12995. [PMID: 38923610 DOI: 10.1111/nan.12995] [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: 01/29/2024] [Revised: 05/29/2024] [Accepted: 05/31/2024] [Indexed: 06/28/2024]
Abstract
AIMS Polyglucosan storage disorders represent an emerging field within neurodegenerative and neuromuscular conditions, including Lafora disease (EPM2A, EPM2B), adult polyglucosan body disease (APBD, GBE1), polyglucosan body myopathies associated with RBCK1 deficiency (PGBM1, RBCK1) or glycogenin-1 deficiency (PGBM2, GYG1). While the storage material primarily comprises glycans, this study aimed to gain deeper insights into the protein components by proteomic profiling of the storage material in glycogenin-1 deficiency. METHODS We employed molecular genetic analyses, quantitative mass spectrometry of laser micro-dissected polyglucosan bodies and muscle homogenate, immunohistochemistry and western blot analyses in muscle tissue from a 45-year-old patient with proximal muscle weakness from late teenage years due to polyglucosan storage myopathy. RESULTS The muscle tissue exhibited a complete absence of glycogenin-1 due to a novel homozygous deep intronic variant in GYG1 (c.7+992T>G), introducing a pseudo-exon causing frameshift and a premature stop codon. Accumulated proteins in the polyglucosan bodies constituted components of glycogen metabolism, protein quality control pathways and desmin. Muscle fibres containing polyglucosan bodies frequently exhibited depletion of normal glycogen. CONCLUSIONS The absence of glycogenin-1, a protein important for glycogen synthesis initiation, causes storage of polyglucosan that displays accumulation of several proteins, including those essential for glycogen synthesis, sequestosome 1/p62 and desmin, mirroring findings in RBCK1 deficiency. These results suggest shared pathogenic pathways across different diseases exhibiting polyglucosan storage. Such insights have implications for therapy in these rare yet devastating and presently untreatable disorders.
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Affiliation(s)
- Kittichate Visuttijai
- Department of Laboratory Medicine, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Carola Hedberg-Oldfors
- Department of Laboratory Medicine, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Daniel J Costello
- Department of Neurology, Cork University Hospital and College of Medicine and Health, University College Cork, Cork, Ireland
| | - Niamh Bermingham
- Department of Neuropathology, Cork University Hospital, Cork, Ireland
| | - Anders Oldfors
- Department of Laboratory Medicine, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
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4
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Zhang N, Liu F, Zhao Y, Sun X, Wen B, Lu JQ, Yan C, Li D. Defect in degradation of glycogenin-exposed residual glycogen in lysosomes is the fundamental pathomechanism of Pompe disease. J Pathol 2024; 263:8-21. [PMID: 38332735 DOI: 10.1002/path.6255] [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: 05/13/2023] [Revised: 11/27/2023] [Accepted: 12/18/2023] [Indexed: 02/10/2024]
Abstract
Pompe disease is a lysosomal storage disorder that preferentially affects muscles, and it is caused by GAA mutation coding acid alpha-glucosidase in lysosome and glycophagy deficiency. While the initial pathology of Pompe disease is glycogen accumulation in lysosomes, the special role of the lysosomal pathway in glycogen degradation is not fully understood. Hence, we investigated the characteristics of accumulated glycogen and the mechanism underlying glycophagy disturbance in Pompe disease. Skeletal muscle specimens were obtained from the affected sites of patients and mouse models with Pompe disease. Histological analysis, immunoblot analysis, immunofluorescence assay, and lysosome isolation were utilized to analyze the characteristics of accumulated glycogen. Cell culture, lentiviral infection, and the CRISPR/Cas9 approach were utilized to investigate the regulation of glycophagy accumulation. We demonstrated residual glycogen, which was distinguishable from mature glycogen by exposed glycogenin and more α-amylase resistance, accumulated in the skeletal muscle of Pompe disease. Lysosome isolation revealed glycogen-free glycogenin in wild type mouse lysosomes and variously sized glycogenin in Gaa-/- mouse lysosomes. Our study identified that a defect in the degradation of glycogenin-exposed residual glycogen in lysosomes was the fundamental pathological mechanism of Pompe disease. Meanwhile, glycogenin-exposed residual glycogen was absent in other glycogen storage diseases caused by cytoplasmic glycogenolysis deficiencies. In vitro, the generation of residual glycogen resulted from cytoplasmic glycogenolysis. Notably, the inhibition of glycogen phosphorylase led to a reduction in glycogenin-exposed residual glycogen and glycophagy accumulations in cellular models of Pompe disease. Therefore, the lysosomal hydrolysis pathway played a crucial role in the degradation of residual glycogen into glycogenin, which took place in tandem with cytoplasmic glycogenolysis. These findings may offer a novel substrate reduction therapeutic strategy for Pompe disease. © 2024 The Pathological Society of Great Britain and Ireland.
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Affiliation(s)
- Na Zhang
- Research Institute of Neuromuscular and Neurodegenerative Diseases, Qilu Hospital, Shandong University, Jinan, PR China
| | - Fuchen Liu
- Research Institute of Neuromuscular and Neurodegenerative Diseases, Qilu Hospital, Shandong University, Jinan, PR China
- Department of Neurology, Qilu Hospital of Shandong University, Jinan, PR China
| | - Yuying Zhao
- Research Institute of Neuromuscular and Neurodegenerative Diseases, Qilu Hospital, Shandong University, Jinan, PR China
- Department of Neurology, Qilu Hospital of Shandong University, Jinan, PR China
| | - Xiaohan Sun
- Research Institute of Neuromuscular and Neurodegenerative Diseases, Qilu Hospital, Shandong University, Jinan, PR China
- Department of Neurology, Qilu Hospital of Shandong University, Jinan, PR China
| | - Bing Wen
- Research Institute of Neuromuscular and Neurodegenerative Diseases, Qilu Hospital, Shandong University, Jinan, PR China
- Department of Neurology, Qilu Hospital of Shandong University, Jinan, PR China
| | - Jian-Qiang Lu
- Department of Pathology and Molecular Medicine, Division of Neuropathology, McMaster University, Hamilton, Ontario, Canada
| | - Chuanzhu Yan
- Research Institute of Neuromuscular and Neurodegenerative Diseases, Qilu Hospital, Shandong University, Jinan, PR China
- Department of Neurology, Qilu Hospital of Shandong University, Jinan, PR China
- Qingdao Key Laboratory of Rare Diseases, Qilu Hospital (Qingdao) of Shandong University, Qingdao, PR China
| | - Duoling Li
- Research Institute of Neuromuscular and Neurodegenerative Diseases, Qilu Hospital, Shandong University, Jinan, PR China
- Department of Neurology, Qilu Hospital of Shandong University, Jinan, PR China
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5
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Mitra S, Chen B, Shelton JM, Nitschke S, Wu J, Covington L, Dear M, Lynn T, Verma M, Nitschke F, Fuseya Y, Iwai K, Evers BM, Minassian BA. Myofiber-type-dependent 'boulder' or 'multitudinous pebble' formations across distinct amylopectinoses. Acta Neuropathol 2024; 147:46. [PMID: 38411740 DOI: 10.1007/s00401-024-02698-x] [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: 11/23/2023] [Revised: 01/13/2024] [Accepted: 01/24/2024] [Indexed: 02/28/2024]
Abstract
At least five enzymes including three E3 ubiquitin ligases are dedicated to glycogen's spherical structure. Absence of any reverts glycogen to a structure resembling amylopectin of the plant kingdom. This amylopectinosis (polyglucosan body formation) causes fatal neurological diseases including adult polyglucosan body disease (APBD) due to glycogen branching enzyme deficiency, Lafora disease (LD) due to deficiencies of the laforin glycogen phosphatase or the malin E3 ubiquitin ligase and type 1 polyglucosan body myopathy (PGBM1) due to RBCK1 E3 ubiquitin ligase deficiency. Little is known about these enzymes' functions in glycogen structuring. Toward understanding these functions, we undertake a comparative murine study of the amylopectinoses of APBD, LD and PGBM1. We discover that in skeletal muscle, polyglucosan bodies form as two main types, small and multitudinous ('pebbles') or giant and single ('boulders'), and that this is primarily determined by the myofiber types in which they form, 'pebbles' in glycolytic and 'boulders' in oxidative fibers. This pattern recapitulates what is known in the brain in LD, innumerable dust-like in astrocytes and single giant sized in neurons. We also show that oxidative myofibers are relatively protected against amylopectinosis, in part through highly increased glycogen branching enzyme expression. We present evidence of polyglucosan body size-dependent cell necrosis. We show that sex influences amylopectinosis in genotype, brain region and myofiber-type-specific fashion. RBCK1 is a component of the linear ubiquitin chain assembly complex (LUBAC), the only known cellular machinery for head-to-tail linear ubiquitination critical to numerous cellular pathways. We show that the amylopectinosis of RBCK1 deficiency is not due to loss of linear ubiquitination, and that another function of RBCK1 or LUBAC must exist and operate in the shaping of glycogen. This work opens multiple new avenues toward understanding the structural determinants of the mammalian carbohydrate reservoir critical to neurologic and neuromuscular function and disease.
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Affiliation(s)
- Sharmistha Mitra
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9063, USA.
| | - Baozhi Chen
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9063, USA
| | - John M Shelton
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9148, USA
| | - Silvia Nitschke
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9063, USA
| | - Jun Wu
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9063, USA
| | - Lindsay Covington
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9148, USA
| | - Mathew Dear
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9063, USA
| | - Tori Lynn
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9063, USA
| | - Mayank Verma
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9063, USA
| | - Felix Nitschke
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9063, USA
| | - Yasuhiro Fuseya
- Department of Molecular and Cellular Physiology, Kyoto University School of Medicine, Kyoto, 606-8501, Japan
| | - Kazuhiro Iwai
- Department of Molecular and Cellular Physiology, Kyoto University School of Medicine, Kyoto, 606-8501, Japan
| | - Bret M Evers
- Departments of Pathology and Ophthalmology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-9073, USA
| | - Berge A Minassian
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9063, USA.
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6
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Huang J, Chen J, Wang C, Lai L, Mi H, Chen S. Deciphering the molecular classification of pediatric sepsis: integrating WGCNA and machine learning-based classification with immune signatures for the development of an advanced diagnostic model. Front Genet 2024; 15:1294381. [PMID: 38348451 PMCID: PMC10859440 DOI: 10.3389/fgene.2024.1294381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 01/16/2024] [Indexed: 02/15/2024] Open
Abstract
Introduction: Pediatric sepsis (PS) is a life-threatening infection associated with high mortality rates, necessitating a deeper understanding of its underlying pathological mechanisms. Recently discovered programmed cell death induced by copper has been implicated in various medical conditions, but its potential involvement in PS remains largely unexplored. Methods: We first analyzed the expression patterns of cuproptosis-related genes (CRGs) and assessed the immune landscape of PS using the GSE66099 dataset. Subsequently, PS samples were isolated from the same dataset, and consensus clustering was performed based on differentially expressed CRGs. We applied weighted gene co-expression network analysis to identify hub genes associated with PS and cuproptosis. Results: We observed aberrant expression of 27 CRGs and a specific immune landscape in PS samples. Our findings revealed that patients in the GSE66099 dataset could be categorized into two cuproptosis clusters, each characterized by unique immune landscapes and varying functional classifications or enriched pathways. Among the machine learning approaches, Extreme Gradient Boosting demonstrated optimal performance as a diagnostic model for PS. Discussion: Our study provides valuable insights into the molecular mechanisms underlying PS, highlighting the involvement of cuproptosis-related genes and immune cell infiltration.
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Affiliation(s)
- Junming Huang
- Department of Urology, Guangxi Medical University Cancer Hospital, Nanning, Guangxi, China
- Department of Urology, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Jinji Chen
- Department of Urology, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Chengbang Wang
- Department of Urology, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Lichuan Lai
- Department of Laboratory, The People’s Hospital of Guangxi Zhuang Autonomous Region, Nanning, Guangxi, China
| | - Hua Mi
- Department of Urology, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Shaohua Chen
- Department of Urology, Guangxi Medical University Cancer Hospital, Nanning, Guangxi, China
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7
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Jiang Z, Luo Y, Wei L, Gu R, Zhang X, Zhou Y, Zhang S. Bioinformatic Analysis and Machine Learning Methods in Neonatal Sepsis: Identification of Biomarkers and Immune Infiltration. Biomedicines 2023; 11:1853. [PMID: 37509492 PMCID: PMC10377054 DOI: 10.3390/biomedicines11071853] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Revised: 06/18/2023] [Accepted: 06/26/2023] [Indexed: 07/30/2023] Open
Abstract
The disease neonatal sepsis (NS) poses a serious threat to life, and its pathogenesis remains unclear. Using the Gene Expression Omnibus (GEO) database, differentially expressed genes (DEGs) were identified and functional enrichment analyses were conducted. Three machine learning algorithms containing the least absolute shrinkage and selection operator (LASSO), support vector machine recursive feature elimination (SVM-RFE), and random forest (RF) were applied to identify the optimal feature genes (OFGs). This study conducted CIBERSORT to present the abundance of immune infiltrates between septic and control neonates and assessed the relationship between OFGs and immune cells. In total, 44 DEGs were discovered between the septic and control newborns. Throughout the enrichment analysis, DEGs were primarily related to inflammatory signaling pathways and immune responses. The OFGs derived from machine learning algorithms were intersected to yield four biomarkers, namely Hexokinase 3 (HK3), Cystatin 7 (CST7), Resistin (RETN), and Glycogenin 1 (GYG1). The potential biomarkers were validated in other datasets and LPS-stimulated HEUVCs. Septic infants showed a higher proportion of neutrophils (p < 0.001), M0 macrophages (p < 0.001), and regulatory T cells (p = 0.004). HK3, CST7, RETN, and GYG1 showed significant correlations with immune cells. Overall, the biomarkers offered promising insights into the molecular mechanisms of immune regulation for the prediction and treatment of NS.
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Affiliation(s)
- Zhou Jiang
- Department of NICU, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, No. 368 Xiasha Road, Qiantang District, Hangzhou 310016, China
| | - Yujia Luo
- Department of NICU, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, No. 368 Xiasha Road, Qiantang District, Hangzhou 310016, China
| | - Li Wei
- Department of NICU, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, No. 368 Xiasha Road, Qiantang District, Hangzhou 310016, China
| | - Rui Gu
- Department of NICU, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, No. 368 Xiasha Road, Qiantang District, Hangzhou 310016, China
| | - Xuandong Zhang
- Department of NICU, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, No. 368 Xiasha Road, Qiantang District, Hangzhou 310016, China
| | - Yuanyuan Zhou
- Department of Reproductive Endocrinology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China
| | - Songying Zhang
- Department of Obstetrics and Gynecology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, No. 3 Qingchun East Road, Shangcheng District, Hangzhou 310016, China
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8
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Duran J. Role of Astrocytes in the Pathophysiology of Lafora Disease and Other Glycogen Storage Disorders. Cells 2023; 12:cells12050722. [PMID: 36899857 PMCID: PMC10000527 DOI: 10.3390/cells12050722] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 02/05/2023] [Accepted: 02/22/2023] [Indexed: 03/12/2023] Open
Abstract
Lafora disease is a rare disorder caused by loss of function mutations in either the EPM2A or NHLRC1 gene. The initial symptoms of this condition are most commonly epileptic seizures, but the disease progresses rapidly with dementia, neuropsychiatric symptoms, and cognitive deterioration and has a fatal outcome within 5-10 years after onset. The hallmark of the disease is the accumulation of poorly branched glycogen in the form of aggregates known as Lafora bodies in the brain and other tissues. Several reports have demonstrated that the accumulation of this abnormal glycogen underlies all the pathologic traits of the disease. For decades, Lafora bodies were thought to accumulate exclusively in neurons. However, it was recently identified that most of these glycogen aggregates are present in astrocytes. Importantly, astrocytic Lafora bodies have been shown to contribute to pathology in Lafora disease. These results identify a primary role of astrocytes in the pathophysiology of Lafora disease and have important implications for other conditions in which glycogen abnormally accumulates in astrocytes, such as Adult Polyglucosan Body disease and the buildup of Corpora amylacea in aged brains.
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Affiliation(s)
- Jordi Duran
- Institut Químic de Sarrià (IQS), Universitat Ramon Llull (URL), 08017 Barcelona, Spain;
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
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9
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Mitra S, Chen B, Wang P, Chown EE, Dear M, Guisso DR, Mariam U, Wu J, Gumusgoz E, Minassian BA. Laforin targets malin to glycogen in Lafora progressive myoclonus epilepsy. Dis Model Mech 2023; 16:dmm049802. [PMID: 36511140 PMCID: PMC9844227 DOI: 10.1242/dmm.049802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 12/01/2022] [Indexed: 12/15/2022] Open
Abstract
Glycogen is the largest cytosolic macromolecule and is kept in solution through a regular system of short branches allowing hydration. This structure was thought to solely require balanced glycogen synthase and branching enzyme activities. Deposition of overlong branched glycogen in the fatal epilepsy Lafora disease (LD) indicated involvement of the LD gene products laforin and the E3 ubiquitin ligase malin in regulating glycogen structure. Laforin binds glycogen, and LD-causing mutations disrupt this binding, laforin-malin interactions and malin's ligase activity, all indicating a critical role for malin. Neither malin's endogenous function nor location had previously been studied due to lack of suitable antibodies. Here, we generated a mouse in which the native malin gene is tagged with the FLAG sequence. We show that the tagged gene expresses physiologically, malin localizes to glycogen, laforin and malin indeed interact, at glycogen, and malin's presence at glycogen depends on laforin. These results, and mice, open the way to understanding unknown mechanisms of glycogen synthesis critical to LD and potentially other much more common diseases due to incompletely understood defects in glycogen metabolism.
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Affiliation(s)
- Sharmistha Mitra
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Baozhi Chen
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Peixiang Wang
- Program in Genetics and Genome Biology, The Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
| | - Erin E. Chown
- Program in Genetics and Genome Biology, The Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
| | - Mathew Dear
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Dikran R. Guisso
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Ummay Mariam
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jun Wu
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Emrah Gumusgoz
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Berge A. Minassian
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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10
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Pathomorphogenesis of Glycogen-Ground Glass Hepatocytic Inclusions (Polyglucosan Bodies) in Children after Liver Transplantation. Int J Mol Sci 2022; 23:ijms23179996. [PMID: 36077394 PMCID: PMC9456521 DOI: 10.3390/ijms23179996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 07/27/2022] [Accepted: 08/03/2022] [Indexed: 11/17/2022] Open
Abstract
Seventeen out of 764 liver biopsies from transplanted (Tx) livers in children showed glycogen-ground glass (GGG) hepatocytic inclusions. The inclusions were not present in pre-Tx or in the explanted or donor’s liver. Under the electron microscope (EM), the stored material within the cytosol appeared as non-membrane-bound aggregates of electron-lucent globoid or fibrillar granules, previously described as abnormally structured glycogen and identified as Polyglucosan bodies (PB). The appearance of GGG in our children was analogous to that of PB-GGG occurring in a number of congenital diseases due to gene mutations such as Lafora’s d., Andersen’s d., Adult Polyglucosan Body Disease and glycogenin deficiency. The same type of GGG was previously reported in the liver of patients undergoing transplants, immunosuppressive or antiblastic treatment. To explore the potential mechanism of GGG formation, we examined whether the drugs after whose treatment this phenomenon was observed could have a role. By carrying out molecular docking, we found that such drugs somehow present a high binding affinity for the active region of glycogenin, implicating that they can inactivate the protein, thus preventing its interaction with glycogen synthase (GS), as well as the maturation of the nascent glycogen towards gamma, beta or alfa glycogen granules. We could also demonstrate that PG inclusions consist of a complex of PAS positive material (glycogen) and glycogen-associated proteins, i.e., glicogenin-1 and -2 and ubiquitin. These features appear to be analogous to congenital GGG, suggesting that, in both cases, they result from the simultaneous dysregulation of glycogen synthesis and degradation. Drug-induced GGG appear to be toxic to the cell, despite their reversibility.
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Nitschke S, Sullivan MA, Mitra S, Marchioni C, Lee JP Y, Smith BH, Ahonen S, Wu J, Chown E, Wang P, Petković S, Zhao X, DiGiovanni LF, Perri AM, Israelian L, Grossman TR, Kordasiewicz H, Vilaplana F, Iwai K, Nitschke F, Minassian BA. Glycogen synthase downregulation rescues the amylopectinosis of murine RBCK1 deficiency. Brain 2022; 145:2361-2377. [PMID: 35084461 PMCID: PMC9612801 DOI: 10.1093/brain/awac017] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 12/17/2021] [Accepted: 01/09/2022] [Indexed: 12/06/2023] Open
Abstract
Longer glucan chains tend to precipitate. Glycogen, by far the largest mammalian glucan and the largest molecule in the cytosol with up to 55 000 glucoses, does not, due to a highly regularly branched spherical structure that allows it to be perfused with cytosol. Aberrant construction of glycogen leads it to precipitate, accumulate into polyglucosan bodies that resemble plant starch amylopectin and cause disease. This pathology, amylopectinosis, is caused by mutations in a series of single genes whose functions are under active study toward understanding the mechanisms of proper glycogen construction. Concurrently, we are characterizing the physicochemical particularities of glycogen and polyglucosans associated with each gene. These genes include GBE1, EPM2A and EPM2B, which respectively encode the glycogen branching enzyme, the glycogen phosphatase laforin and the laforin-interacting E3 ubiquitin ligase malin, for which an unequivocal function is not yet known. Mutations in GBE1 cause a motor neuron disease (adult polyglucosan body disease), and mutations in EPM2A or EPM2B a fatal progressive myoclonus epilepsy (Lafora disease). RBCK1 deficiency causes an amylopectinosis with fatal skeletal and cardiac myopathy (polyglucosan body myopathy 1, OMIM# 615895). RBCK1 is a component of the linear ubiquitin chain assembly complex, with unique functions including generating linear ubiquitin chains and ubiquitinating hydroxyl (versus canonical amine) residues, including of glycogen. In a mouse model we now show (i) that the amylopectinosis of RBCK1 deficiency, like in adult polyglucosan body disease and Lafora disease, affects the brain; (ii) that RBCK1 deficiency glycogen, like in adult polyglucosan body disease and Lafora disease, has overlong branches; (iii) that unlike adult polyglucosan body disease but like Lafora disease, RBCK1 deficiency glycogen is hyperphosphorylated; and finally (iv) that unlike laforin-deficient Lafora disease but like malin-deficient Lafora disease, RBCK1 deficiency's glycogen hyperphosphorylation is limited to precipitated polyglucosans. In summary, the fundamental glycogen pathology of RBCK1 deficiency recapitulates that of malin-deficient Lafora disease. Additionally, we uncover sex and genetic background effects in RBCK1 deficiency on organ- and brain-region specific amylopectinoses, and in the brain on consequent neuroinflammation and behavioural deficits. Finally, we exploit the portion of the basic glycogen pathology that is common to adult polyglucosan body disease, both forms of Lafora disease and RBCK1 deficiency, namely overlong branches, to show that a unified approach based on downregulating glycogen synthase, the enzyme that elongates glycogen branches, can rescue all four diseases.
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Affiliation(s)
- Silvia Nitschke
- Program in Genetics and Genome Biology, The Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Mitchell A Sullivan
- Program in Genetics and Genome Biology, The Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
- Glycation and Diabetes Complications, Mater Research Institute–The University of Queensland, Translational Research Institute, Brisbane, QLD, 4102, Australia
| | - Sharmistha Mitra
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Charlotte R Marchioni
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jennifer P Y Lee
- Program in Genetics and Genome Biology, The Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
| | - Brandon H Smith
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Saija Ahonen
- Program in Genetics and Genome Biology, The Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
| | - Jun Wu
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Erin E Chown
- Program in Genetics and Genome Biology, The Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
| | - Peixiang Wang
- Program in Genetics and Genome Biology, The Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
| | - Sara Petković
- Program in Genetics and Genome Biology, The Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
| | - Xiaochu Zhao
- Program in Genetics and Genome Biology, The Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
| | - Laura F DiGiovanni
- Program in Genetics and Genome Biology, The Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
| | - Ami M Perri
- Program in Genetics and Genome Biology, The Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
| | - Lori Israelian
- Program in Genetics and Genome Biology, The Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
| | - Tamar R Grossman
- Department of Antisense Drug Discovery, Ionis Pharmaceuticals, Carlsbad, California, USA
| | - Holly Kordasiewicz
- Department of Antisense Drug Discovery, Ionis Pharmaceuticals, Carlsbad, California, USA
| | - Francisco Vilaplana
- Division of Glycoscience, Department of Chemistry, KTH Royal Institute of Technology, AlbaNova University Centre, Stockholm 10691, Sweden
| | - Kazuhiro Iwai
- Department of Molecular and Cellular Physiology, Kyoto University School of Medicine, Kyoto 606-8501, Japan
| | - Felix Nitschke
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Berge A Minassian
- Program in Genetics and Genome Biology, The Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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Linear ubiquitination in immune and neurodegenerative diseases, and beyond. Biochem Soc Trans 2022; 50:799-811. [PMID: 35343567 DOI: 10.1042/bst20211078] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 03/08/2022] [Accepted: 03/09/2022] [Indexed: 12/28/2022]
Abstract
Ubiquitin regulates numerous aspects of biology via a complex ubiquitin code. The linear ubiquitin chain is an atypical code that forms a unique structure, with the C-terminal tail of the distal ubiquitin linked to the N-terminal Met1 of the proximal ubiquitin. Thus far, LUBAC is the only known ubiquitin ligase complex that specifically generates linear ubiquitin chains. LUBAC-induced linear ubiquitin chains regulate inflammatory responses, cell death and immunity. Genetically modified mouse models and cellular assays have revealed that LUBAC is also involved in embryonic development in mice. LUBAC dysfunction is associated with autoimmune diseases, myopathy, and neurodegenerative diseases in humans, but the underlying mechanisms are poorly understood. In this review, we focus on the roles of linear ubiquitin chains and LUBAC in immune and neurodegenerative diseases. We further discuss LUBAC inhibitors and their potential as therapeutics for these diseases.
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LUBAC: a new player in polyglucosan body disease. Biochem Soc Trans 2021; 49:2443-2454. [PMID: 34709403 PMCID: PMC8589444 DOI: 10.1042/bst20210838] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 10/01/2021] [Accepted: 10/04/2021] [Indexed: 12/13/2022]
Abstract
Altered protein ubiquitination is associated with the pathobiology of numerous diseases; however, its involvement in glycogen metabolism and associated polyglucosan body (PB) disease has not been investigated in depth. In PB disease, excessively long and less branched glycogen chains (polyglucosan bodies, PBs) are formed, which precipitate in different tissues causing myopathy, cardiomyopathy and/or neurodegeneration. Linear ubiquitin chain assembly complex (LUBAC) is a multi-protein complex composed of two E3 ubiquitin ligases HOIL-1L and HOIP and an adaptor protein SHARPIN. Together they are responsible for M1-linked ubiquitination of substrates primarily related to immune signaling and cell death pathways. Consequently, severe immunodeficiency is a hallmark of many LUBAC deficient patients. Remarkably, all HOIL-1L deficient patients exhibit accumulation of PBs in different organs especially skeletal and cardiac muscle resulting in myopathy and cardiomyopathy with heart failure. This emphasizes LUBAC's important role in glycogen metabolism. To date, neither a glycogen metabolism-related LUBAC substrate nor the molecular mechanism are known. Hence, current reviews on LUBAC's involvement in glycogen metabolism are lacking. Here, we aim to fill this gap by describing LUBAC's involvement in PB disease. We present a comprehensive review of LUBAC structure, its role in M1-linked and other types of atypical ubiquitination, PB pathology in human patients and findings in new mouse models to study the disease. We conclude the review with recent drug developments and near-future gene-based therapeutic approaches to treat LUBAC related PB disease.
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