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Ueda H, Tran QTH, Tran LNT, Higasa K, Ikeda Y, Kondo N, Hashiyada M, Sato C, Sato Y, Ashida A, Nishio S, Iwata Y, Iida H, Matsuoka D, Hidaka Y, Fukui K, Itami S, Kawashita N, Sugimoto K, Nozu K, Hattori M, Tsukaguchi H. Characterization of cytoskeletal and structural effects of INF2 variants causing glomerulopathy and neuropathy. Sci Rep 2023; 13:12003. [PMID: 37491439 PMCID: PMC10368640 DOI: 10.1038/s41598-023-38588-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 07/11/2023] [Indexed: 07/27/2023] Open
Abstract
Focal segmental glomerulosclerosis (FSGS) is a common glomerular injury leading to end-stage renal disease. Monogenic FSGS is primarily ascribed to decreased podocyte integrity. Variants between residues 184 and 245 of INF2, an actin assembly factor, produce the monogenic FSGS phenotype. Meanwhile, variants between residues 57 and 184 cause a dual-faceted disease involving peripheral neurons and podocytes (Charcot-Marie-Tooth CMT/FSGS). To understand the molecular basis for INF2 disorders, we compared structural and cytoskeletal effects of INF2 variants classified into two subgroups: One (G73D, V108D) causes the CMT/FSGS phenotype, and the other (T161N, N202S) produces monogenic FSGS. Molecular dynamics analysis revealed that all INF2 variants show distinct flexibility compared to the wild-type INF2 and could affect stability of an intramolecular interaction between their N- and C-terminal segments. Immunocytochemistry of cells expressing INF2 variants showed fewer actin stress fibers, and disorganization of cytoplasmic microtubule arrays. Notably, CMT/FSGS variants caused more prominent changes in mitochondrial distribution and fragmentation than FSGS variants and these changes correlated with the severity of cytoskeletal disruption. Our results indicate that CMT/FSGS variants are associated with more severe global cellular defects caused by disrupted cytoskeleton-organelle interactions than are FSGS variants. Further study is needed to clarify tissue-specific pathways and/or cellular functions implicated in FSGS and CMT phenotypes.
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Affiliation(s)
- Hiroko Ueda
- Division of Nephrology, Second Department of Internal Medicine, Kansai Medical University, 2-5-1 Shinmachi, Hirakata, Osaka, 573-1191, Japan
| | - Quynh Thuy Huong Tran
- Division of Nephrology, Second Department of Internal Medicine, Kansai Medical University, 2-5-1 Shinmachi, Hirakata, Osaka, 573-1191, Japan
| | - Linh Nguyen Truc Tran
- Division of Nephrology, Second Department of Internal Medicine, Kansai Medical University, 2-5-1 Shinmachi, Hirakata, Osaka, 573-1191, Japan
| | - Koichiro Higasa
- Department of Genome Analysis, Institute of Biomedical Science, Kansai Medical University, Hirakata, Japan
| | - Yoshiki Ikeda
- Department of Molecular Genetics, Kansai Medical University, Hirakata, Japan
| | - Naoyuki Kondo
- Department of Molecular Genetics, Kansai Medical University, Hirakata, Japan
| | - Masaki Hashiyada
- Department of Legal Medicine, Kansai Medical University, Hirakata, Japan
| | - Chika Sato
- Department of Gynecology and Obstetrics, Kansai Medical University, Hirakata, Japan
| | - Yoshinori Sato
- Division of Nephrology, Department of Medicine, Showa University Fujigaoka Hospital, Yokohama, Kanagawa, Japan
| | - Akira Ashida
- Department of Pediatrics, Osaka Medical and Pharmaceutical University, Takatsuki, Japan
| | - Saori Nishio
- Department of Rheumatology, Endocrinology and Nephrology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Yasunori Iwata
- Department of Nephrology and Laboratory Medicine, Kanazawa University, Kanazawa, Japan
| | - Hiroyuki Iida
- Department of Internal Medicine, Toyama Prefectural Central Hospital, Toyama, Japan
- Toyama Transplantation Promotion Foundation, Toyama, Japan
| | - Daisuke Matsuoka
- Department of Pediatrics, Shinshu University School of Medicine, Matsumoto, Japan
| | - Yoshihiko Hidaka
- Department of Pediatrics, Shinshu University School of Medicine, Matsumoto, Japan
| | - Kenji Fukui
- Department of Biochemistry, Faculty of Medicine, Osaka Medical and Pharmaceutical University, Takatsuki, Japan
| | - Suzu Itami
- Major in Science, Graduate School of Science and Engineering, Kindai University, Higashiosaka, Japan
| | - Norihito Kawashita
- Department of Energy and Materials, Faculty of Science and Engineering, Kindai University, Higashiosaka, Japan
| | - Keisuke Sugimoto
- Department of Pediatrics, Kindai University Faculty of Medicine, Osakasayama, Japan
| | - Kandai Nozu
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Motoshi Hattori
- Department of Pediatric Nephrology, Tokyo Women's Medical University, Tokyo, Japan
| | - Hiroyasu Tsukaguchi
- Division of Nephrology, Second Department of Internal Medicine, Kansai Medical University, 2-5-1 Shinmachi, Hirakata, Osaka, 573-1191, Japan.
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Park JH, Kwon HM, Nam DE, Kim HJ, Nam SH, Kim SB, Choi BO, Chung KW. INF2 mutations in patients with a broad phenotypic spectrum of Charcot-Marie-Tooth disease and focal segmental glomerulosclerosis. J Peripher Nerv Syst 2023; 28:108-118. [PMID: 36637069 DOI: 10.1111/jns.12530] [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: 10/31/2022] [Revised: 01/02/2023] [Accepted: 01/09/2023] [Indexed: 01/14/2023]
Abstract
Mutations in INF2 are associated with the complex symptoms of Charcot-Marie-Tooth disease (CMT) and focal segmental glomerulosclerosis (FSGS). To date, more than 100 and 30 genes have been reported to cause these disorders, respectively. This study aimed to identify INF2 mutations in Korean patients with CMT. This study was conducted with 743 Korean families with CMT who were negative for PMP22 duplication. In addition, a family with FSGS was included in this study. INF2 mutations were screened using whole exome sequencing (WES) and filtering processes. As the results, four pathogenic INF2 mutations were identified in families with different clinical phenotypes: p.L78P and p.L132P in families with symptoms of both CMT and FSGS; p.C104Y in a family with CMT; and p.R218Q in a family with FSGS. Moreover, different CMT types were observed in families with CMT symptoms: CMT1 in two families and Int-CMT in another family. Hearing loss was observed in two families with CMT1. Pathogenicity was predicted by in silico analyses, and considerable conformational changes were predicted in the mutant proteins. Two mutations (p.L78P and p.C104Y) were unreported, and three families showed de novo mutations that were putatively occurred from fathers. This study suggests that patients with INF2 mutations show a broad phenotypic spectrum: CMT1, CMT1 + FSGS, CMTDIE + FSGS, and FSGS. Therefore, the genotype-phenotype correlation may be more complex than previously recognized. We believe that this study expands the clinical spectrum of patients with INF2 mutations and will be helpful in the molecular diagnosis of CMT and FSGS.
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Affiliation(s)
- Jin Hee Park
- Department of Biological Sciences, Kongju National University, Gongju, South Korea
| | - Hye Mi Kwon
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - Da Eun Nam
- Department of Biological Sciences, Kongju National University, Gongju, South Korea
| | - Hye Jin Kim
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - Soo Hyun Nam
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.,Cell & Gene Theraphy Institute, Samsung Medical Center, Seoul, South Korea
| | - Sang Beom Kim
- Department of Neurology, Kyung Hee University Hospital at Gangdong, Kyung Hee University School of Medicine, Seoul, Republic of Korea
| | - Byung-Ok Choi
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.,Cell & Gene Theraphy Institute, Samsung Medical Center, Seoul, South Korea.,Samsung Advanced Institute for Health Sciences & Technology, Sungkyunkwan University, Seoul, South Korea
| | - Ki Wha Chung
- Department of Biological Sciences, Kongju National University, Gongju, South Korea
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3
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Sambharia M, Rastogi P, Thomas CP. Monogenic focal segmental glomerulosclerosis: A conceptual framework for identification and management of a heterogeneous disease. AMERICAN JOURNAL OF MEDICAL GENETICS. PART C, SEMINARS IN MEDICAL GENETICS 2022; 190:377-398. [PMID: 35894442 PMCID: PMC9796580 DOI: 10.1002/ajmg.c.31990] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 05/31/2022] [Accepted: 06/30/2022] [Indexed: 01/29/2023]
Abstract
Focal segmental glomerulosclerosis (FSGS) is not a disease, rather a pattern of histological injury occurring from a variety of causes. The exact pathogenesis has yet to be fully elucidated but is likely varied based on the type of injury and the primary target of that injury. However, the approach to treatment is often based on the degree of podocyte foot process effacement and clinical presentation without sufficient attention paid to etiology. In this regard, there are many monogenic causes of FSGS with variable presentation from nephrotic syndrome with histological features of primary podocytopathy to more modest degrees of proteinuria with limited evidence of podocyte foot process injury. It is likely that genetic causes are largely underdiagnosed, as the role and the timing of genetic testing in FSGS is not established and genetic counseling, testing options, and interpretation of genotype in the context of phenotype may be outside the scope of practice for both nephrologists and geneticists. Yet most clinicians believe that a genetic diagnosis can lead to targeted therapy, limit the use of high-dose corticosteroids as a therapeutic trial, and allow the prediction of the natural history and risk for recurrence in the transplanted kidney. In this manuscript, we emphasize that genetic FSGS is not monolithic in its presentation, opine on the importance of genetic testing and provide an algorithmic approach to deployment of genetic testing in a timely fashion when faced with a patient with FSGS.
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Affiliation(s)
- Meenakshi Sambharia
- Division of Nephrology, Department of Internal MedicineUniversity of IowaIowa CityIowaUSA
| | - Prerna Rastogi
- Department of PathologyUniversity of IowaIowa CityIowaUSA
| | - Christie P. Thomas
- Division of Nephrology, Department of Internal MedicineUniversity of IowaIowa CityIowaUSA,Department of PediatricsUniversity of IowaIowa CityIowaUSA,The Iowa Institute of Human GeneticsUniversity of IowaIowa CityIowaUSA,Medical ServiceVeterans Affairs Medical CenterIowa CityIowaUSA
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Abstract
Almost 25 years have passed since a mutation of a formin gene, DIAPH1, was identified as being responsible for a human inherited disorder: a form of sensorineural hearing loss. Since then, our knowledge of the links between formins and disease has deepened considerably. Mutations of DIAPH1 and six other formin genes (DAAM2, DIAPH2, DIAPH3, FMN2, INF2 and FHOD3) have been identified as the genetic cause of a variety of inherited human disorders, including intellectual disability, renal disease, peripheral neuropathy, thrombocytopenia, primary ovarian insufficiency, hearing loss and cardiomyopathy. In addition, alterations in formin genes have been associated with a variety of pathological conditions, including developmental defects affecting the heart, nervous system and kidney, aging-related diseases, and cancer. This review summarizes the most recent discoveries about the involvement of formin alterations in monogenic disorders and other human pathological conditions, especially cancer, with which they have been associated. In vitro results and experiments in modified animal models are discussed. Finally, we outline the directions for future research in this field.
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Affiliation(s)
| | - Miguel A. Alonso
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, 28049 Madrid, Spain;
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5
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Zhao W, Ma X, Zhang X, Luo D, Zhang J, Li M, Ye Z, Peng H. INF2 p.Arg214Cys mutation in a Chinese family with rapidly progressive renal failure and follow-up of renal transplantation: case report and literature review. BMC Nephrol 2021; 22:51. [PMID: 33541266 PMCID: PMC7863463 DOI: 10.1186/s12882-021-02254-9] [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: 08/16/2020] [Accepted: 01/24/2021] [Indexed: 01/10/2023] Open
Abstract
Background Heterozygous mutations in the inverted formin 2 (INF2) gene are related to secondary focal segmental glomerulosclerosis (FSGS), a rare secondary disease associated with rapidly progressive renal failure. Case presentation We report a patient with familial autosomal INF2 mutation manifesting nephritic syndromes and elevated serum creatinine levels. Mutational analysis revealed an autosomal dominant (AD) inheritance pattern and a mutation in exon 4 (p.Arg214Cys) of INF2 as the likely cause, which has not been previously described in an Asian family. The patient progressed to end-stage renal disease (ESRD) and received hemodialysis. His mother had undergone renal transplant 3 years earlier, and his grandmother had carried the p.Arg214Cys mutation for more than 80 years without any sign of renal dysfunction. Conclusions This is the first report to identify an association between a familial autosomal dominant INF2 p.Arg214Cys mutation and rapidly progressive renal disease in an Asian family. INF2 mutation analysis should not be restricted to individuals without family history of FSGS, rather it should also be performed on individuals for whom drug-based therapies are not effective. In this case, kidney transplant is an effective alternative.
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Affiliation(s)
- Wenbo Zhao
- Division of Nephrology, The Third Affiliated Hospital of Sun Yat-sen University, Tianhe Ave #600, Guangzhou, 510630, China
| | - Xinxin Ma
- Division of Nephrology, The Third Affiliated Hospital of Sun Yat-sen University, Tianhe Ave #600, Guangzhou, 510630, China
| | - Xiaohao Zhang
- Division of Nephrology, The Third Affiliated Hospital of Sun Yat-sen University, Tianhe Ave #600, Guangzhou, 510630, China
| | - Dan Luo
- Department of Nephrology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Jun Zhang
- Division of Nephrology, The Third Affiliated Hospital of Sun Yat-sen University, Tianhe Ave #600, Guangzhou, 510630, China
| | - Ming Li
- Division of Nephrology, The Third Affiliated Hospital of Sun Yat-sen University, Tianhe Ave #600, Guangzhou, 510630, China
| | - Zengchun Ye
- Division of Nephrology, The Third Affiliated Hospital of Sun Yat-sen University, Tianhe Ave #600, Guangzhou, 510630, China
| | - Hui Peng
- Division of Nephrology, The Third Affiliated Hospital of Sun Yat-sen University, Tianhe Ave #600, Guangzhou, 510630, China.
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Schiavon CR, Shadel GS, Manor U. Impaired Mitochondrial Mobility in Charcot-Marie-Tooth Disease. Front Cell Dev Biol 2021; 9:624823. [PMID: 33598463 PMCID: PMC7882694 DOI: 10.3389/fcell.2021.624823] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Accepted: 01/05/2021] [Indexed: 12/13/2022] Open
Abstract
Charcot-Marie-Tooth (CMT) disease is a progressive, peripheral neuropathy and the most commonly inherited neurological disorder. Clinical manifestations of CMT mutations are typically limited to peripheral neurons, the longest cells in the body. Currently, mutations in at least 80 different genes are associated with CMT and new mutations are regularly being discovered. A large portion of the proteins mutated in axonal CMT have documented roles in mitochondrial mobility, suggesting that organelle trafficking defects may be a common underlying disease mechanism. This review will focus on the potential role of altered mitochondrial mobility in the pathogenesis of axonal CMT, highlighting the conceptional challenges and potential experimental and therapeutic opportunities presented by this "impaired mobility" model of the disease.
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Affiliation(s)
- Cara R. Schiavon
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, La Jolla, CA, United States
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, United States
| | - Gerald S. Shadel
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, United States
| | - Uri Manor
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, La Jolla, CA, United States
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7
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Bayraktar S, Nehrig J, Menis E, Karli K, Janning A, Struk T, Halbritter J, Michgehl U, Krahn MP, Schuberth CE, Pavenstädt H, Wedlich-Söldner R. A Deregulated Stress Response Underlies Distinct INF2-Associated Disease Profiles. J Am Soc Nephrol 2021; 31:1296-1313. [PMID: 32444357 DOI: 10.1681/asn.2019111174] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 03/20/2020] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Monogenic diseases provide favorable opportunities to elucidate the molecular mechanisms of disease progression and improve medical diagnostics. However, the complex interplay between genetic and environmental factors in disease etiologies makes it difficult to discern the mechanistic links between different alleles of a single locus and their associated pathophysiologies. Inverted formin 2 (INF2), an actin regulator, mediates a stress response-calcium mediated actin reset, or CaAR-that reorganizes the actin cytoskeleton of mammalian cells in response to calcium influx. It has been linked to the podocytic kidney disease focal segemental glomerulosclerosis (FSGS), as well as to cases of the neurologic disorder Charcot-Marie-Tooth disease that are accompanied by nephropathy, mostly FSGS. METHODS We used a combination of quantitative live cell imaging and validation in primary patient cells and Drosophila nephrocytes to systematically characterize a large panel of >50 autosomal dominant INF2 mutants that have been reported to cause either FSGS alone or with Charcot-Marie-Tooth disease. RESULTS We found that INF2 mutations lead to deregulated activation of formin and a constitutive stress response in cultured cells, primary patient cells, and Drosophila nephrocytes. We were able to clearly distinguish between INF2 mutations that were linked exclusively to FSGS from those that caused a combination of FSGS and Charcot-Marie-Tooth disease. Furthermore, we were able to identify distinct subsets of INF2 variants that exhibit varying degrees of activation. CONCLUSIONS Our results suggest that CaAR can be used as a sensitive assay for INF2 function and for robust evaluation of diseased-linked variants of formin. More broadly, these findings indicate that cellular profiling of disease-associated mutations has potential to contribute substantially to sequence-based phenotype predictions.
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Affiliation(s)
- Samet Bayraktar
- Institute of Cell Dynamics and Imaging and Cells in Motion Interfaculty Centre, University of Münster, Münster, Germany.,Internal Medicine D, University Hospital Münster, Münster, Germany
| | - Julian Nehrig
- Institute of Cell Dynamics and Imaging and Cells in Motion Interfaculty Centre, University of Münster, Münster, Germany
| | - Ekaterina Menis
- Institute of Cell Dynamics and Imaging and Cells in Motion Interfaculty Centre, University of Münster, Münster, Germany
| | - Kevser Karli
- Medical Cell Biology, Internal Medicine D, University Hospital Münster, Münster, Germany
| | - Annette Janning
- Institute of Cell Dynamics and Imaging and Cells in Motion Interfaculty Centre, University of Münster, Münster, Germany
| | - Thaddäus Struk
- Internal Medicine D, University Hospital Münster, Münster, Germany
| | - Jan Halbritter
- Division of Nephrology, University of Leipzig, Leipzig, Germany
| | - Ulf Michgehl
- Internal Medicine D, University Hospital Münster, Münster, Germany
| | - Michael P Krahn
- Medical Cell Biology, Internal Medicine D, University Hospital Münster, Münster, Germany
| | - Christian E Schuberth
- Institute of Cell Dynamics and Imaging and Cells in Motion Interfaculty Centre, University of Münster, Münster, Germany
| | | | - Roland Wedlich-Söldner
- Institute of Cell Dynamics and Imaging and Cells in Motion Interfaculty Centre, University of Münster, Münster, Germany
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8
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Labat-de-Hoz L, Alonso MA. The formin INF2 in disease: progress from 10 years of research. Cell Mol Life Sci 2020; 77:4581-4600. [PMID: 32451589 PMCID: PMC11104792 DOI: 10.1007/s00018-020-03550-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 05/04/2020] [Accepted: 05/13/2020] [Indexed: 02/07/2023]
Abstract
Formins are a conserved family of proteins that primarily act to form linear polymers of actin. Despite their importance to the normal functioning of the cytoskeleton, for a long time, the only two formin genes known to be a genetic cause of human disorders were DIAPH1 and DIAPH3, whose mutation causes two distinct forms of hereditary deafness. In the last 10 years, however, the formin INF2 has emerged as an important target of mutations responsible for the appearance of focal segmental glomerulosclerosis, which are histological lesions associated with glomerulus degeneration that often leads to end-stage renal disease. In some rare cases, focal segmental glomerulosclerosis concurs with Charcot-Marie-Tooth disease, which is a degenerative neurological disorder affecting peripheral nerves. All known INF2 gene mutations causing disease map to the exons encoding the amino-terminal domain. In this review, we summarize the structure, biochemical features and functions of INF2, conduct a systematic and comprehensive analysis of the pathogenic INF2 mutations, including a detailed study exon-by-exon of patient cases and mutations, address the impact of the pathogenic mutations on the structure, regulation and known functions of INF2, draw a series of conclusions that could be useful for INF2-related disease diagnosis, and suggest lines of research for future work on the molecular mechanisms by which INF2 causes disease.
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Affiliation(s)
- Leticia Labat-de-Hoz
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Madrid, Spain
| | - Miguel A Alonso
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Madrid, Spain.
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9
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Chapman J, Ng YS, Nicholls TJ. The Maintenance of Mitochondrial DNA Integrity and Dynamics by Mitochondrial Membranes. Life (Basel) 2020; 10:life10090164. [PMID: 32858900 PMCID: PMC7555930 DOI: 10.3390/life10090164] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 08/20/2020] [Accepted: 08/23/2020] [Indexed: 12/18/2022] Open
Abstract
Mitochondria are complex organelles that harbour their own genome. Mitochondrial DNA (mtDNA) exists in the form of a circular double-stranded DNA molecule that must be replicated, segregated and distributed around the mitochondrial network. Human cells typically possess between a few hundred and several thousand copies of the mitochondrial genome, located within the mitochondrial matrix in close association with the cristae ultrastructure. The organisation of mtDNA around the mitochondrial network requires mitochondria to be dynamic and undergo both fission and fusion events in coordination with the modulation of cristae architecture. The dysregulation of these processes has profound effects upon mtDNA replication, manifesting as a loss of mtDNA integrity and copy number, and upon the subsequent distribution of mtDNA around the mitochondrial network. Mutations within genes involved in mitochondrial dynamics or cristae modulation cause a wide range of neurological disorders frequently associated with defects in mtDNA maintenance. This review aims to provide an understanding of the biological mechanisms that link mitochondrial dynamics and mtDNA integrity, as well as examine the interplay that occurs between mtDNA, mitochondrial dynamics and cristae structure.
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Affiliation(s)
- James Chapman
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK;
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
- Correspondence: (J.C.); (T.J.N.)
| | - Yi Shiau Ng
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK;
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Thomas J. Nicholls
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK;
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
- Correspondence: (J.C.); (T.J.N.)
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10
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Much More Than a Scaffold: Cytoskeletal Proteins in Neurological Disorders. Cells 2020; 9:cells9020358. [PMID: 32033020 PMCID: PMC7072452 DOI: 10.3390/cells9020358] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 01/27/2020] [Accepted: 01/29/2020] [Indexed: 02/08/2023] Open
Abstract
Recent observations related to the structure of the cytoskeleton in neurons and novel cytoskeletal abnormalities involved in the pathophysiology of some neurological diseases are changing our view on the function of the cytoskeletal proteins in the nervous system. These efforts allow a better understanding of the molecular mechanisms underlying neurological diseases and allow us to see beyond our current knowledge for the development of new treatments. The neuronal cytoskeleton can be described as an organelle formed by the three-dimensional lattice of the three main families of filaments: actin filaments, microtubules, and neurofilaments. This organelle organizes well-defined structures within neurons (cell bodies and axons), which allow their proper development and function through life. Here, we will provide an overview of both the basic and novel concepts related to those cytoskeletal proteins, which are emerging as potential targets in the study of the pathophysiological mechanisms underlying neurological disorders.
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11
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Krendel M, Pruyne D. New Paradigm for Cytoskeletal Organization in Podocytes: Proteolytic Fragments of INF2 Formin Function Independently of INF2 Actin Regulatory Activity. J Am Soc Nephrol 2020; 31:235-236. [PMID: 31924669 DOI: 10.1681/asn.2019121292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Affiliation(s)
- Mira Krendel
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, New York
| | - David Pruyne
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, New York
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12
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Subramanian B, Chun J, Perez-Gill C, Yan P, Stillman IE, Higgs HN, Alper SL, Schlöndorff JS, Pollak MR. FSGS-Causing INF2 Mutation Impairs Cleaved INF2 N-Fragment Functions in Podocytes. J Am Soc Nephrol 2020; 31:374-391. [PMID: 31924668 DOI: 10.1681/asn.2019050443] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 11/11/2019] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Mutations in the gene encoding inverted formin-2 (INF2), a member of the formin family of actin regulatory proteins, are among the most common causes of autosomal dominant FSGS. INF2 is regulated by interaction between its N-terminal diaphanous inhibitory domain (DID) and its C-terminal diaphanous autoregulatory domain (DAD). INF2 also modulates activity of other formins, such as the mDIA subfamily, and promotes stable microtubule assembly. Why the disease-causing mutations are restricted to the N terminus and how they cause human disease has been unclear. METHODS We examined INF2 isoforms present in podocytes and evaluated INF2 cleavage as an explanation for immunoblot findings. We evaluated the expression of INF2 N- and C-terminal fragments in human kidney disease conditions. We also investigated the localization and functions of the DID-containing N-terminal fragment in podocytes and assessed whether the FSGS-associated R218Q mutation impairs INF2 cleavage or the function of the N-fragment. RESULTS The INF2-CAAX isoform is the predominant isoform in podocytes. INF2 is proteolytically cleaved, a process mediated by cathepsin proteases, liberating the N-terminal DID to function independently. Although the N-terminal region normally localizes to podocyte foot processes, it does not do so in the presence of FSGS-associated INF2 mutations. The C-terminal fragment localizes to the cell body irrespective of INF2 mutations. In podocytes, the N-fragment localizes to the plasma membrane, binds mDIA1, and promotes cell spreading in a cleavage-dependent way. The disease-associated R218Q mutation impairs these N-fragment functions but not INF2 cleavage. CONCLUSIONS INF2 is cleaved into an N-terminal DID-containing fragment and a C-terminal DAD-containing fragment. Cleavage allows the N-terminal fragment to function independently and helps explain the clustering of FSGS-associated mutations.
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Affiliation(s)
| | - Justin Chun
- Division of Nephrology, Department of Medicine, and
| | | | - Paul Yan
- Division of Nephrology, Department of Medicine, and
| | - Isaac E Stillman
- Department of Pathology, Beth Israel Deaconess Medical center, Harvard Medical School, Boston, Massachusetts
| | - Henry N Higgs
- Department of Biochemistry, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire; and
| | - Seth L Alper
- Division of Nephrology, Department of Medicine, and.,Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Massachusetts
| | | | - Martin R Pollak
- Division of Nephrology, Department of Medicine, and .,Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Massachusetts
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13
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Echaniz-Laguna A, Latour P. A cryptic splicing mutation in the INF2 gene causing Charcot-Marie-Tooth disease with minimal glomerular dysfunction. J Peripher Nerv Syst 2019; 24:120-124. [PMID: 30680856 DOI: 10.1111/jns.12308] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 01/21/2019] [Accepted: 01/22/2019] [Indexed: 12/14/2022]
Abstract
Heterozygous mutations in the inverted formin-2 (INF2) gene provoke focal segmental glomerulosclerosis (FSGS) and intermediate Charcot-Marie-Tooth (CMT) disease with FSGS. Here, we report four patients from a three-generation family with a new cryptic splicing INF2 mutation causing autosomal dominant intermediate CMT with minimal glomerular dysfunction. Three males and one female with a mean age of 51 years (26-87) presented with a slowly progressive sensorimotor polyneuropathy, pes cavus, and kyphoscoliosis. Mean age at CMT disease onset was 11.5 years (3-17), and electrophysiological studies showed demyelinating and axonal features consistent with intermediate CMT. Plasma albumin and creatinine were normal in all four cases, and urine protein was normal in one case and mildly raised in three patients (mean: 0.32 g/L [0.18-0.44], N < 0.14). Genetic analysis found a c.271C > G (p. Arg91Gly) variation in INF2 exon 2, and in vitro splicing assays showed the deletion of the last 120 nucleotides of INF2 exon 2 leading to a 40 amino acids in-frame deletion (p. Arg91_p. Gln130del). This report expands the genetic spectrum of INF2-associated disorders and demonstrates that INF2 mutations may provoke isolated CMT with no clinically relevant kidney involvement. Consequently, INF2 mutation analysis should not be restricted to individuals with coincident neuropathy and renal disease.
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Affiliation(s)
- Andoni Echaniz-Laguna
- Department of Neurology, APHP, CHU de Bicêtre, Le Kremlin Bicêtre, France.,French National Reference Center for Rare Neuropathies (NNERF), Le Kremlin Bicêtre, France.,INSERM U1195 & Paris-Sud University, Le Kremlin Bicêtre, France
| | - Philippe Latour
- Centre de Biologie et de Pathologie Est, Hospices Civils de Lyon, Bron, France
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14
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Multiple roles of the actin and microtubule-regulating formins in the developing brain. Neurosci Res 2019; 138:59-69. [DOI: 10.1016/j.neures.2018.09.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 08/22/2018] [Accepted: 08/23/2018] [Indexed: 01/08/2023]
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15
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Fernández-Barrera J, Alonso MA. Coordination of microtubule acetylation and the actin cytoskeleton by formins. Cell Mol Life Sci 2018; 75:3181-3191. [PMID: 29947928 PMCID: PMC11105221 DOI: 10.1007/s00018-018-2855-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 05/22/2018] [Accepted: 06/12/2018] [Indexed: 12/12/2022]
Abstract
The acetylation of the lysine 40 residue of α-tubulin was described more than 30 years ago and has been the subject of intense research ever since. Although the exact function of this covalent modification of tubulin in the cell remains unknown, it has been established that tubulin acetylation confers resilience to mechanical stress on the microtubules. Formins have a dual role in the fate of the actin and tubulin cytoskeletons. On the one hand, they catalyze the formation of actin filaments, and on the other, they bind microtubules, act on their stability, and regulate their acetylation and alignment with actin fibers. Recent evidence indicates that formins coordinate the actin cytoskeleton and tubulin acetylation by modulating the levels of free globular actin (G-actin). G-actin, in turn, controls the activity of the myocardin-related transcription factor-serum response factor transcriptional complex that regulates the expression of the α-tubulin acetyltransferase 1 (α-TAT1) gene, which encodes the main enzyme responsible for tubulin acetylation. The effect of formins on tubulin acetylation is the combined result of their ability to activate α-TAT1 gene transcription and of their capacity to regulate microtubule stabilization. The contribution of these two mechanisms in different formins is discussed, particularly with respect to INF2, a formin that is mutated in hereditary human renal and neurodegenerative disorders.
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Affiliation(s)
- Jaime Fernández-Barrera
- Department of Cell Biology and Immunology, Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autónoma, Madrid, Spain
| | - Miguel A Alonso
- Department of Cell Biology and Immunology, Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autónoma, Madrid, Spain.
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16
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Hacker B, Schultheiß C, Döring M, Kurzik-Dumke U. Molecular partners of hNOT/ALG3, the human counterpart of the Drosophila NOT and yeast ALG3 gene, suggest its involvement in distinct cellular processes relevant to congenital disorders of glycosylation, cancer, neurodegeneration and a variety of further pathologies. Hum Mol Genet 2018; 27:1858-1878. [DOI: 10.1093/hmg/ddy087] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 03/06/2018] [Indexed: 01/04/2023] Open
Affiliation(s)
- Benedikt Hacker
- Laboratory for Comparative Tumour Biology, Institute of Medical Microbiology and Hygiene, University Medical Centre, Johannes Gutenberg University, 55131 Mainz, Germany
| | - Christoph Schultheiß
- Laboratory for Comparative Tumour Biology, Institute of Medical Microbiology and Hygiene, University Medical Centre, Johannes Gutenberg University, 55131 Mainz, Germany
| | - Michael Döring
- Laboratory for Comparative Tumour Biology, Institute of Medical Microbiology and Hygiene, University Medical Centre, Johannes Gutenberg University, 55131 Mainz, Germany
| | - Ursula Kurzik-Dumke
- Laboratory for Comparative Tumour Biology, Institute of Medical Microbiology and Hygiene, University Medical Centre, Johannes Gutenberg University, 55131 Mainz, Germany
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17
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Hegsted A, Yingling CV, Pruyne D. Inverted formins: A subfamily of atypical formins. Cytoskeleton (Hoboken) 2017; 74:405-419. [PMID: 28921928 DOI: 10.1002/cm.21409] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 08/22/2017] [Accepted: 08/31/2017] [Indexed: 12/25/2022]
Abstract
Formins are a family of regulators of actin and microtubule dynamics that are present in almost all eukaryotes. These proteins are involved in many cellular processes, including cytokinesis, stress fiber formation, and cell polarization. Here we review one subfamily of formins, the inverted formins. Inverted formins as a group break several formin stereotypes, having atypical biochemical properties and domain organization, and they have been linked to kidney disease and neuropathy in humans. In this review, we will explore recent research on members of the inverted formin sub-family in mammals, zebrafish, fruit flies, and worms.
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Affiliation(s)
- Anna Hegsted
- Department of Cell and Developmental Biology, SUNY Upstate Medical University, Syracuse, New York 13210
| | - Curtis V Yingling
- Department of Cell and Developmental Biology, SUNY Upstate Medical University, Syracuse, New York 13210
| | - David Pruyne
- Department of Cell and Developmental Biology, SUNY Upstate Medical University, Syracuse, New York 13210
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18
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Weis J, Claeys KG, Roos A, Azzedine H, Katona I, Schröder JM, Senderek J. Towards a functional pathology of hereditary neuropathies. Acta Neuropathol 2017; 133:493-515. [PMID: 27896434 DOI: 10.1007/s00401-016-1645-y] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 11/10/2016] [Accepted: 11/13/2016] [Indexed: 12/11/2022]
Abstract
A growing number of hereditary neuropathies have been assigned to causative gene defects in recent years. The study of human nerve biopsy samples has contributed substantially to the discovery of many of these neuropathy genes. Genotype-phenotype correlations based on peripheral nerve pathology have provided a comprehensive picture of the consequences of these mutations. Intriguingly, several gene defects lead to distinguishable lesion patterns that can be studied in nerve biopsies. These characteristic features include the loss of certain nerve fiber populations and a large spectrum of distinct structural changes of axons, Schwann cells and other components of peripheral nerves. In several instances the lesion patterns are directly or indirectly linked to the known functions of the mutated gene. The present review is designed to provide an overview on these characteristic patterns. It also considers other aspects important for the manifestation and pathology of hereditary neuropathies including the role of inflammation, effects of chemotherapeutic agents and alterations detectable in skin biopsies.
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Affiliation(s)
- Joachim Weis
- Institute of Neuropathology, RWTH Aachen University Medical School, Pauwelsstr. 30, 52074, Aachen, Germany.
| | - Kristl G Claeys
- Institute of Neuropathology, RWTH Aachen University Medical School, Pauwelsstr. 30, 52074, Aachen, Germany
- Department of Neurology, RWTH Aachen University Medical School, Pauwelsstr. 30, 52074, Aachen, Germany
- Department of Neurology, University Hospitals Leuven and University of Leuven (KU Leuven), Leuven, Belgium
| | - Andreas Roos
- Institute of Neuropathology, RWTH Aachen University Medical School, Pauwelsstr. 30, 52074, Aachen, Germany
- Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Otto-Hahn-Str. 6b, 44227, Dortmund, Germany
| | - Hamid Azzedine
- Institute of Neuropathology, RWTH Aachen University Medical School, Pauwelsstr. 30, 52074, Aachen, Germany
| | - Istvan Katona
- Institute of Neuropathology, RWTH Aachen University Medical School, Pauwelsstr. 30, 52074, Aachen, Germany
| | - J Michael Schröder
- Institute of Neuropathology, RWTH Aachen University Medical School, Pauwelsstr. 30, 52074, Aachen, Germany
| | - Jan Senderek
- Friedrich-Baur-Institute, Department of Neurology, Ludwig-Maximilians-University, Ziemssenstr. 1a, 80336, Munich, Germany.
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19
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Challis RC, Ring T, Xu Y, Wong EKS, Flossmann O, Roberts ISD, Ahmed S, Wetherall M, Salkus G, Brocklebank V, Fester J, Strain L, Wilson V, Wood KM, Marchbank KJ, Santibanez-Koref M, Goodship THJ, Kavanagh D. Thrombotic Microangiopathy in Inverted Formin 2 -Mediated Renal Disease. J Am Soc Nephrol 2017; 28:1084-1091. [PMID: 27974406 PMCID: PMC5373440 DOI: 10.1681/asn.2015101189] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 10/19/2016] [Indexed: 12/26/2022] Open
Abstract
The demonstration of impaired C regulation in the thrombotic microangiopathy (TMA) atypical hemolytic uremic syndrome (aHUS) resulted in the successful introduction of the C inhibitor eculizumab into clinical practice. C abnormalities account for approximately 50% of aHUS cases; however, mutations in the non-C gene diacylglycerol kinase-ε have been described recently in individuals not responsive to eculizumab. We report here a family in which the proposita presented with aHUS but did not respond to eculizumab. Her mother had previously presented with a post-renal transplant TMA. Both the proposita and her mother also had Charcot-Marie-Tooth disease. Using whole-exome sequencing, we identified a mutation in the inverted formin 2 gene (INF2) in the mutational hotspot for FSGS. Subsequent analysis of the Newcastle aHUS cohort identified another family with a functionally-significant mutation in INF2 In this family, renal transplantation was associated with post-transplant TMA. All individuals with INF2 mutations presenting with a TMA also had aHUS risk haplotypes, potentially accounting for the genetic pleiotropy. Identifying individuals with TMAs who may not respond to eculizumab will avoid prolonged exposure of such individuals to the infectious complications of terminal pathway C blockade.
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Affiliation(s)
- Rachel C Challis
- National Renal Complement Therapeutics Centre, Institutes of *Genetic Medicine and
| | - Troels Ring
- Department of Nephrology, Aalborg University Hospital and
| | - Yaobo Xu
- National Renal Complement Therapeutics Centre, Institutes of *Genetic Medicine and
| | - Edwin K S Wong
- National Renal Complement Therapeutics Centre, Institutes of *Genetic Medicine and
| | | | - Ian S D Roberts
- Department of Cellular Pathology, Oxford University Hospitals National Health Service Trust, Oxford, United Kingdom
| | - Saeed Ahmed
- Department of Nephrology, City Hospitals Sunderland National Health Service Foundation Trust, Sunderland, United Kingdom
| | - Michael Wetherall
- Department of Pathology, Gateshead Health National Health Service Foundation Trust, Gateshead, United Kingdom
| | - Giedrius Salkus
- Department of Pathology, Aalborg University Hospital, Aalborg, Denmark
| | - Vicky Brocklebank
- National Renal Complement Therapeutics Centre, Institutes of *Genetic Medicine and
| | | | - Lisa Strain
- National Renal Complement Therapeutics Centre, Northern Molecular Genetics Service and
| | - Valerie Wilson
- National Renal Complement Therapeutics Centre, Northern Molecular Genetics Service and
| | - Katrina M Wood
- Department of Cellular Pathology, Newcastle upon Tyne Hospitals National Health Service Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - Kevin J Marchbank
- Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | | | - Timothy H J Goodship
- National Renal Complement Therapeutics Centre, Institutes of *Genetic Medicine and
| | - David Kavanagh
- National Renal Complement Therapeutics Centre, Institutes of *Genetic Medicine and
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20
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Intermediate Charcot–Marie–Tooth disease: an electrophysiological reappraisal and systematic review. J Neurol 2017; 264:1655-1677. [DOI: 10.1007/s00415-017-8474-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 03/23/2017] [Accepted: 03/24/2017] [Indexed: 01/13/2023]
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21
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Tamura H, Nakazato H, Kuraoka S, Yoneda K, Takahashi W, Endo F. Reduced INF2 expression in nephrotic syndrome is possibly related to clinical severity of steroid resistance in children. Nephrology (Carlton) 2017; 21:467-75. [PMID: 26383224 DOI: 10.1111/nep.12627] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 09/14/2015] [Accepted: 09/15/2015] [Indexed: 12/21/2022]
Abstract
AIM Mutations of the inverted formin 2 gene (INF2), which encodes a member of the formin family, cause autosomal dominant focal segmental glomerulosclerosis (FSGS) and Charcot-Marie-Tooth (CMT) disease-associated FSGS. However, their role in idiopathic FSGS remains unclear. This study investigated INF2 localization in the normal adult kidney and its expression in children with idiopathic nephrotic syndrome. METHODS We generated a rabbit polyclonal antibody against the conjugated peptide from human INF2 and studied the glomerular expression of INF2 and synaptopodin using normal human adult kidney tissues and tissues from children with glomerular diseases such as minimal change disease (MCD), FSGS, IgA nephropathy (IgAN), non-IgA mesangial proliferative glomerulonephritis (non-IgAN), and Henoch-Schönlein purpura nephritis (HSPN). RESULTS The anti-INF2 antibody detected an approximately 140-kD fragment isolated from adult mature glomeruli by western blotting. Immunohistochemically, INF2 was detected in podocytes and renal arteries. Among 56 patients, INF2 in glomeruli was expressed at a similar level in patients with MCD, IgAN, non-IgAN, or HSPN and controls. In FSGS patients, INF2 expression in glomeruli was either decreased or absent. There was a relationship between decreased INF2 expression and the clinical severity of steroid resistant nephrotic syndrome (SRNS). CONCLUSION We propose that examination of INF2 expression may help to differentiate MCD from FSGS and evaluate the clinical severity of SRNS in children.
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Affiliation(s)
- Hiroshi Tamura
- Department of Pediatrics, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Hitoshi Nakazato
- Department of Pediatrics, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Shohei Kuraoka
- Department of Pediatrics, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Kaori Yoneda
- Department of Pediatrics, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Wataru Takahashi
- Department of Urology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Fumio Endo
- Department of Pediatrics, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
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22
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Werheid F, Azzedine H, Zwerenz E, Bozkurt A, Moeller MJ, Lin L, Mull M, Häusler M, Schulz JB, Weis J, Claeys KG. Underestimated associated features in CMT neuropathies: clinical indicators for the causative gene? Brain Behav 2016; 6:e00451. [PMID: 27088055 PMCID: PMC4782242 DOI: 10.1002/brb3.451] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 01/25/2016] [Accepted: 02/02/2016] [Indexed: 12/15/2022] Open
Abstract
INTRODUCTION Charcot-Marie-Tooth neuropathy (CMT) is a genetically heterogeneous group of peripheral neuropathies. In addition to the classical clinical phenotype, additional features can occur. METHODS We studied a wide range of additional features in a cohort of 49 genetically confirmed CMT patients and performed a systematic literature revision. RESULTS Patients harbored a PMP22 gene alteration (n = 28) or a mutation in MPZ (n = 11), GJB1 (n = 4), LITAF (n = 2), MFN2 (n = 2), INF2 (n = 1), NEFL (n = 1). We identified four novel mutations (3 MPZ, 1 GJB1). A total of 88% presented at least one additional feature. In MPZ patients, we detected hypertrophic nerve roots in 3/4 cases that underwent spinal MRI, and pupillary abnormalities in 27%. In our cohort, restless legs syndrome (RLS) was present in 18%. We describe for the first time RLS associated with LITAF or MFN2 and predominant upper limb involvement with LITAF. Cold-induced hand cramps occurred in 10% (PMP22,MPZ,MFN2), and autonomous nervous system involvement in 18% (PMP22,MPZ, LITAF,MFN2). RLS and respiratory insufficiency were mostly associated with severe neuropathy, and pupillary abnormalities with mild to moderate neuropathy. CONCLUSIONS In CMT patients, additional features occur frequently. Some of them might be helpful in orienting genetic diagnosis. Our data broaden the clinical spectrum and genotype-phenotype associations with CMT.
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Affiliation(s)
- Friederike Werheid
- Department of Neurology University Hospital RWTH Aachen Aachen Germany; Institute of Neuropathology University Hospital RWTH Aachen Aachen Germany
| | - Hamid Azzedine
- Institute of Neuropathology University Hospital RWTH Aachen Aachen Germany
| | - Eva Zwerenz
- Department of Neurology University Hospital RWTH Aachen Aachen Germany; Institute of Neuropathology University Hospital RWTH Aachen Aachen Germany
| | - Ahmet Bozkurt
- Department of Plastic and Reconstructive Surgery Hand Surgery-Burn Center University Hospital RWTH Aachen Aachen Germany; Department of Plastic & Aesthetic, Reconstructive & Hand Surgery Center for Reconstructive Microsurgery and Peripheral Nerve Surgery (ZEMPEN) Agaplesion Markus Hospital Frankfurt am Main Germany
| | - Marcus J Moeller
- Section Immunology and Nephrology Department of Internal Medicine University Hospital RWTH Aachen Aachen Germany
| | - Lilian Lin
- Department of Neurology University Hospital RWTH Aachen Aachen Germany; Institute of Neuropathology University Hospital RWTH Aachen Aachen Germany
| | - Michael Mull
- Department of Neuroradiology University Hospital RWTH Aachen Aachen Germany
| | - Martin Häusler
- Division of Neuropediatrics and Social Pediatrics Department of Pediatrics University Hospital RWTH Aachen Aachen Germany
| | - Jörg B Schulz
- Department of Neurology University Hospital RWTH Aachen Aachen Germany; JARA - Translational Brain Medicine Aachen Germany
| | - Joachim Weis
- Institute of Neuropathology University Hospital RWTH Aachen Aachen Germany
| | - Kristl G Claeys
- Department of Neurology University Hospital RWTH Aachen Aachen Germany; Institute of Neuropathology University Hospital RWTH Aachen Aachen Germany; Department of Neurology University Hospitals Leuven and University of Leuven (KU Leuven) Leuven Belgium
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23
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Formins at the Junction. Trends Biochem Sci 2015; 41:148-159. [PMID: 26732401 DOI: 10.1016/j.tibs.2015.12.002] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 12/01/2015] [Accepted: 12/04/2015] [Indexed: 12/21/2022]
Abstract
The actin cytoskeleton and adhesion junctions are physically and functionally coupled at the cell-cell interface between epithelial cells. The actin regulatory complex Arp2/3 has an established role in the turnover of junctional actin; however, the role of formins, the largest group of actin regulators, is less clear. Formins dynamically shape the actin cytoskeleton and have various functions within cells. In this review we describe recent progress on how formins regulate actin dynamics at cell-cell contacts and highlight formin functions during polarized protein traffic necessary for epithelialization.
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24
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Roos A, Weis J, Korinthenberg R, Fehrenbach H, Häusler M, Züchner S, Mache C, Hubmann H, Auer-Grumbach M, Senderek J. Inverted formin 2-related Charcot-Marie-Tooth disease: extension of the mutational spectrum and pathological findings in Schwann cells and axons. J Peripher Nerv Syst 2015; 20:52-9. [DOI: 10.1111/jns.12106] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Revised: 01/22/2015] [Accepted: 02/07/2015] [Indexed: 12/21/2022]
Affiliation(s)
- Andreas Roos
- Institute of Neuropathology; RWTH Aachen University Hospital; Aachen Germany
- Department of Bioanalytics; Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V. Dortmund; Dortmund Germany
| | - Joachim Weis
- Institute of Neuropathology; RWTH Aachen University Hospital; Aachen Germany
| | | | | | - Martin Häusler
- Department of Pediatrics; RWTH Aachen University Hospital; Aachen Germany
| | - Stephan Züchner
- Dr. John T. Macdonald Foundation, Department of Human Genetics and John P. Hussman Institute for Human Genomics; University of Miami Miller School of Medicine; Miami FL USA
| | - Christoph Mache
- Department of Pediatrics; Medical University Graz; Graz Austria
| | - Holger Hubmann
- Department of Pediatrics; Medical University Graz; Graz Austria
| | | | - Jan Senderek
- Friedrich-Baur Institute, Department of Neurology; Ludwig-Maximilians University Munich; Munich Germany
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25
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Abstract
PURPOSE OF REVIEW This article focuses on recent advances in Charcot-Marie-Tooth disease, in particular additions to the genetic spectrum, novel paradigms in molecular techniques and an update on therapeutic strategies. RECENT FINDINGS Several new Charcot-Marie-Tooth disease-causing genes have been recently identified, further enlarging the genetic diversity and phenotypic variability, including: SBF1, DHTKD1, TFG, MARS, HARS, HINT1, TRIM1, AIFM1, PDK3 and GNB4. The increasing availability and affordability of next-generation sequencing technologies has ramped up gene discovery and drastically changed genetic screening strategies. All large-scale trials studying the effect of ascorbic acid in Charcot-Marie-Tooth 1A have now been completed and were negative. Efforts have been made to design more robust outcome-measures for clinical trials. Promising results with lonaprisan, curcumin and histone deacetylase 6 inhibitors have been obtained in animal models. SUMMARY Charcot-Marie-Tooth is the most common form of inherited peripheral neuropathy and represents the most prevalent hereditary neuromuscular disorder. The genetic spectrum spans more than 70 genes. Gene discovery has been revolutionized recently by new high-throughput molecular technologies. In addition, the phenotypic diversity has grown tremendously. This is a major challenge for geneticists and neurologists. No effective therapy is available for Charcot-Marie-Tooth. Several large trials with ascorbic acid were negative but research into novel compounds continues.
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Affiliation(s)
- Jonathan Baets
- aNeurogenetics Group bPeripheral Neuropathy Group, VIB-Department of Molecular Genetics cLaboratory of Neurogenetics, Institute Born-Bunge dDepartment of Neurology, Antwerp University Hospital, University of Antwerp, Antwerp, Belgium
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Charcot-Marie-Tooth: are you testing for proteinuria? Eur J Paediatr Neurol 2015; 19:1-5. [PMID: 25439738 DOI: 10.1016/j.ejpn.2014.08.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 08/12/2014] [Accepted: 08/16/2014] [Indexed: 11/24/2022]
Abstract
Charcot-Marie-Tooth disease (CMT) is a clinically and genetically heterogeneous group of inherited disorders affecting motor and sensory nerves of the peripheral nervous system. CMT has been reported to be associated with renal diseases, mostly focal segmental glomerulosclerosis (FSGS). However, it was unknown whether these two clinical manifestations represent one common underlying disorder or separate disease entities. Several reports have shown a high prevalence of mutations (75%) in the inverted formin gene (INF2) in patients with CMT-associated glomerulopathy, suggesting that these mutations are a common cause of the dual phenotype. For this reason, we strongly suggest to screen for proteinuria in CMT patients, in order to identify patients with this renal-neurologic phenotype in an early stage, and to perform genetic testing for INF2 mutations.
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27
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Hereditary motor and sensory neuropathies or Charcot–Marie–Tooth diseases: An update. J Neurol Sci 2014; 347:14-22. [DOI: 10.1016/j.jns.2014.10.013] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 10/06/2014] [Accepted: 10/08/2014] [Indexed: 11/15/2022]
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28
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Caridi G, Lugani F, Dagnino M, Gigante M, Iolascon A, Falco M, Graziano C, Benetti E, Dugo M, Del Prete D, Granata A, Borracelli D, Moggia E, Quaglia M, Rinaldi R, Gesualdo L, Ghiggeri GM. Novel INF2 mutations in an Italian cohort of patients with focal segmental glomerulosclerosis, renal failure and Charcot-Marie-Tooth neuropathy. Nephrol Dial Transplant 2014; 29 Suppl 4:iv80-6. [PMID: 25165188 DOI: 10.1093/ndt/gfu071] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Mutations of INF2 represent the major cause of familial autosomal dominant (AD) focal segmental glomerulosclerosis (FSGS). A few patients present neurological symptoms of Charcot-Marie-Tooth (CMT) disease but the prevalence of the association has not been assessed yet. METHODS We screened 28 families with AD FSGS and identified 8 INF2 mutations in 9 families (32 patients overall), 3 of which were new. Mutations were in all cases localized in the diaphanous-inhibitory domain (DID) of the protein. RESULTS Clinical features associated with INF2 mutations in our patient cohort included mild proteinuria (1.55 g/L; range 1-2.5) and haematuria as a unique symptom that was recognized at a median age of 21.75 years (range 8-30). Eighteen patients developed end-stage renal disease during their third decade of life; 12 patients presented a creatinine range between 1.2 and 1.5 mg/dL and 2 were healthy at 45 and 54 years of age. CMT was diagnosed in four cases (12.5%); one of these patients presented an already known mutation on exon 2 of INF2, whereas the other patients presented the same mutation on exon 4, a region that was not previously associated with CMT. CONCLUSIONS We confirmed the high incidence of INF2 mutations in families with AD FSGS. The clinical phenotype was mild at the onset of the disease, but evolution to ESRD was frequent. The incidence of CMT has, for the first time, been calculated here to be 12.5% of mutation carriers. Our findings support INF2 gene analysis in families in which renal failure and/or neuro-sensorial defects are inherited following an AD model.
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Affiliation(s)
- Gianluca Caridi
- Laboratory on Pathophysiology of Uremia and Division of Nephrology, Dialysis, Transplantation, Istituto Giannina Gaslini, Genova, Italy
| | - Francesca Lugani
- Laboratory on Pathophysiology of Uremia and Division of Nephrology, Dialysis, Transplantation, Istituto Giannina Gaslini, Genova, Italy
| | - Monica Dagnino
- Laboratory on Pathophysiology of Uremia and Division of Nephrology, Dialysis, Transplantation, Istituto Giannina Gaslini, Genova, Italy
| | - Maddalena Gigante
- Department of Medical and Surgical Sciences, University of Foggia, Foggia, Italy
| | - Achille Iolascon
- Department of Molecular Medicine and Medical Biotechnologies, University Federico II of Naples - CEINGE - Advanced Biotechnologies, Napoli, Italy
| | - Mariateresa Falco
- Department of Molecular Medicine and Medical Biotechnologies, University Federico II of Naples - CEINGE - Advanced Biotechnologies, Napoli, Italy
| | - Claudio Graziano
- Medical Genetics Unit, Policlinico S. Orsola-Malpighi, University of Bologna, Bologna, Italy
| | - Elisa Benetti
- Nephrology, Dialysis, Transplantation Unit, Azienda Ospedaliera-University of Padova, Padova, Italy
| | - Mauro Dugo
- Nefrologia, Dialisi, Trapianti Renali, O.C. Ca' Foncello, ULSS 9, Treviso, Italy
| | - Dorella Del Prete
- Department of Medicine, Nephrology Unit, University of Padoa, Padova, Italy
| | - Antonio Granata
- Nephrology and Dialysis Unit, 'San Giovanni di Dio' Hospital, Agrigento, Italy
| | - Donella Borracelli
- Nephrology and Dialysis Unit, Ospedale Alta Val D'Elsa, Poggibonsi, Siena, Italy
| | - Elisabetta Moggia
- Nephrology and Dialysis Unit, Ospedale S. Croce e Carle, Cuneo, Italy
| | - Marco Quaglia
- Nephrology and Transplantation Unit, Department of Translational Medicine, Azienda Ospedaliero-Universitaria 'Maggiore della Carità', 'Amedeo Avogadro' University, Novara, Italy
| | - Rita Rinaldi
- Neurology Unit, Policlinico S. Orsola-Malpighi, Bologna, Italy
| | - Loreto Gesualdo
- Renal, Dialysis and Transplantation Unit, Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy
| | - Gian Marco Ghiggeri
- Laboratory on Pathophysiology of Uremia and Division of Nephrology, Dialysis, Transplantation, Istituto Giannina Gaslini, Genova, Italy
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29
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Park HJ, Kim HJ, Hong YB, Nam SH, Chung KW, Choi BO. A novel INF2
mutation in a Korean family with autosomal dominant intermediate Charcot-Marie-Tooth disease and focal segmental glomerulosclerosis. J Peripher Nerv Syst 2014; 19:175-9. [DOI: 10.1111/jns5.12062] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 02/05/2014] [Accepted: 03/19/2014] [Indexed: 12/16/2022]
Affiliation(s)
- Hyung J. Park
- Department of Neurology, Samsung Medical Center; Sungkyunkwan University School of Medicine; Seoul South Korea
| | - Hye J. Kim
- Department of Biological Science; Kongju National University; Gongju South Korea
| | - Young B. Hong
- Department of Neurology, Samsung Medical Center; Sungkyunkwan University School of Medicine; Seoul South Korea
| | - Soo H. Nam
- Department of Biological Science; Kongju National University; Gongju South Korea
| | - Ki W. Chung
- Department of Biological Science; Kongju National University; Gongju South Korea
| | - Byung-Ok Choi
- Department of Neurology, Samsung Medical Center; Sungkyunkwan University School of Medicine; Seoul South Korea
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