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SPTBN2 regulated by miR-424-5p promotes endometrial cancer progression via CLDN4/PI3K/AKT axis. Cell Death Dis 2021; 7:382. [PMID: 34887379 PMCID: PMC8660803 DOI: 10.1038/s41420-021-00776-7] [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: 10/27/2021] [Revised: 11/16/2021] [Accepted: 11/29/2021] [Indexed: 12/24/2022]
Abstract
Endometrioid Endometrial Cancer (EEC) is the main subtype of endometrial cancer. In our study, we demonstrated that SPTBN2 was significantly overexpressed in EEC tissues. Upregulated SPTBN2 expression was positively associated with poor prognosis. In addition, we testified that SPTBN2 knockdown significantly inhibited the proliferation, migration, and invasion of EEC cells. Moreover, we found SPTBN2 could interact with CLDN4 to promote endometrial cancer metastasis via PI3K/AKT pathway. Then we further demonstrated that CLDN4 is upregulated in EEC and promotes EEC metastasis. CLDN4 overexpression could partially reversed the decrease in cell migration and invasion caused by SPTBN2 downregulation. In addition, we confirmed that SPTBN2 was a target of miR-424-5p, which plays a tumor suppressor in endometrial cancer. Rescue experiments showed that inhibition of SPTBN2 could partially reverse the effect of miR-424-5p in EEC. In conclusion, we demonstrated that by acting as a significant target of miR-424-5p, SPTBN2 could interact with CLDN4 to promote endometrial cancer metastasis via PI3K/AKT pathway in EEC. Our study revealed the prognostic and metastatic effects of SPTBN2 in EEC, suggesting that SPTBN2 could serve as a prognostic biomarker and a target for metastasis therapy.
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Falzarano MS, Rossi R, Grilli A, Fang M, Osman H, Sabatelli P, Antoniel M, Lu Z, Li W, Selvatici R, Al-Khalili C, Gualandi F, Bicciato S, Torelli S, Ferlini A. Urine-Derived Stem Cells Express 571 Neuromuscular Disorders Causing Genes, Making Them a Potential in vitro Model for Rare Genetic Diseases. Front Physiol 2021; 12:716471. [PMID: 34744760 PMCID: PMC8565768 DOI: 10.3389/fphys.2021.716471] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 09/21/2021] [Indexed: 12/13/2022] Open
Abstract
Background: Neuromuscular disorders (NMDs) are a heterogeneous group of genetic diseases, caused by mutations in genes involved in spinal cord, peripheral nerve, neuromuscular junction, and muscle functions. To advance the knowledge of the pathological mechanisms underlying NMDs and to eventually identify new potential drugs paving the way for personalized medicine, limitations regarding the availability of neuromuscular disease-related biological samples, rarely accessible from patients, are a major challenge. Aim: We characterized urinary stem cells (USCs) by in-depth transcriptome and protein profiling to evaluate whether this easily accessible source of patient-derived cells is suitable to study neuromuscular genetic diseases, focusing especially on those currently involved in clinical trials. Methods: The global transcriptomics of either native or MyoD transformed USCs obtained from control individuals was performed by RNA-seq. The expression of 610 genes belonging to 16 groups of disorders (http://www.musclegenetable.fr/) whose mutations cause neuromuscular diseases, was investigated on the RNA-seq output. In addition, protein expression of 11 genes related to NMDs including COL6A, EMD, LMNA, SMN, UBA1, DYNC1H1, SOD1, C9orf72, DYSF, DAG1, and HTT was analyzed in native USCs by immunofluorescence and/or Western blot (WB). Results: RNA-seq profile of control USCs shows that 571 out of 610 genes known to be involved in NMDs, are expressed in USCs. Interestingly, the expression levels of the majority of NMD genes remain unmodified following USCs MyoD transformation. Most genes involved in the pathogenesis of all 16 groups of NMDs are well represented except for channelopathies and malignant hyperthermia related genes. All tested proteins showed high expression values, suggesting consistency between transcription and protein representation in USCs. Conclusion: Our data suggest that USCs are human cells, obtainable by non-invasive means, which might be used as a patient-specific cell model to study neuromuscular disease-causing genes and that they can be likely adopted for a variety of in vitro functional studies such as mutation characterization, pathway identification, and drug screening.
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Affiliation(s)
- Maria Sofia Falzarano
- UOL (Unità Operativa Logistica) of Medical Genetics, University of Ferrara, Ferrara, Italy
| | - Rachele Rossi
- UOL (Unità Operativa Logistica) of Medical Genetics, University of Ferrara, Ferrara, Italy.,The Dubowitz Neuromuscular Centre, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
| | - Andrea Grilli
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Mingyan Fang
- Beijing Genomics Institute (BGI)-Shenzhen, Shenzhen, China
| | - Hana Osman
- UOL (Unità Operativa Logistica) of Medical Genetics, University of Ferrara, Ferrara, Italy.,Department of Medical Microbiology, Faculty of Medical Laboratory Sciences, University of Khartoum, Khartoum, Sudan
| | - Patrizia Sabatelli
- CNR-Institute of Molecular Genetics "Luigi Luca Cavalli-Sforza"- Unit of Bologna, Bologna, Italy.,Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Manuela Antoniel
- CNR-Institute of Molecular Genetics "Luigi Luca Cavalli-Sforza"- Unit of Bologna, Bologna, Italy.,Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Zhiyuan Lu
- Beijing Genomics Institute (BGI)-Shenzhen, Shenzhen, China
| | - Wenyan Li
- Beijing Genomics Institute (BGI)-Shenzhen, Shenzhen, China
| | - Rita Selvatici
- UOL (Unità Operativa Logistica) of Medical Genetics, University of Ferrara, Ferrara, Italy
| | - Cristina Al-Khalili
- Department of Proteomics, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Francesca Gualandi
- UOL (Unità Operativa Logistica) of Medical Genetics, University of Ferrara, Ferrara, Italy
| | - Silvio Bicciato
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Silvia Torelli
- The Dubowitz Neuromuscular Centre, UCL Great Ormond Street Institute of Child Health, London, United Kingdom.,National Institute for Health Research, Great Ormond Street Institute of Child Health Biomedical Research Centre, University College London, London, United Kingdom
| | - Alessandra Ferlini
- UOL (Unità Operativa Logistica) of Medical Genetics, University of Ferrara, Ferrara, Italy.,The Dubowitz Neuromuscular Centre, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
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3
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Bian X, Wang S, Jin S, Xu S, Zhang H, Wang D, Shang W, Wang P. Two novel missense variants in SPTBN2 likely associated with spinocerebellar ataxia type 5. Neurol Sci 2021; 42:5195-5203. [PMID: 33797620 PMCID: PMC8642373 DOI: 10.1007/s10072-021-05204-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Accepted: 03/17/2021] [Indexed: 12/01/2022]
Abstract
INTRODUCTION Spinocerebellar ataxias (SCAs) are a heterozygous group of neurodegenerative disorders. Spinocerebellar ataxia type 5 (SCA5) is a rare autosomal-dominant ataxia with pure cerebellum involvement. The clinical characteristics are limb and gait ataxia, trunk ataxia, sensory deficits, abnormal eye movement, dysarthria, and hyperactive tendon reflexes. Spectrin beta nonerythrocytic 2 gene (SPTBN2), coding β-III spectrin protein, was identified to be associated with SCA5. To date, more than 19 variants of SPTBN2 have been reported. METHODS A family and an apparently sporadic patient with ataxia and cerebellar atrophy were recruited from Shandong Province (China). To discover the disease-causing variants, capillary electrophoresis and targeted next-generation sequencing were performed in the proband of the family and the sporadic patient. The candidate variants were verified by Sanger sequencing and analyzed by bioinformatics software. RESULTS In our study, we verified two novel heterozygous variants in SPTBN2 in a SCA pedigree and a sporadic patient. The proband of the pedigree and her mother presented with walking instability and progressively getting worse. The sporadic patient suffered from slurred speech, walking instability, and drinking water choking cough. MRI examination of the proband and sporadic patient both displayed moderate cerebellar atrophy. The variants identified were traditionally conserved and predicted probably damaging and disease-causing by bioinformatics analysis. CONCLUSION We identified two novel heterozygous variants of SPTBN2 resulting in severe ataxia which further delineated the correlation between the genotype and phenotype of SCA5, and pathogenesis of variants in SPTBN2 should be further researched.
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Affiliation(s)
- Xianli Bian
- Department of Neurology, The Second Hospital of Shandong University, Jinan, 250033, Shandong, China
| | - Shang Wang
- Department of Neurology, The Second Hospital of Shandong University, Jinan, 250033, Shandong, China
| | - Suqin Jin
- Department of Neurology, The Second Hospital of Shandong University, Jinan, 250033, Shandong, China
| | - Shunliang Xu
- Department of Neurology, The Second Hospital of Shandong University, Jinan, 250033, Shandong, China
| | - Hong Zhang
- Department of Neurology, The Second Hospital of Shandong University, Jinan, 250033, Shandong, China
| | - Dewei Wang
- Department of Neurology, The Second Hospital of Shandong University, Jinan, 250033, Shandong, China
| | - Wei Shang
- Department of Neurology, The Second Hospital of Shandong University, Jinan, 250033, Shandong, China
| | - Ping Wang
- Department of Neurology, The Second Hospital of Shandong University, Jinan, 250033, Shandong, China.
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Fujishima K, Kurisu J, Yamada M, Kengaku M. βIII spectrin controls the planarity of Purkinje cell dendrites by modulating perpendicular axon-dendrite interactions. Development 2020; 147:226102. [PMID: 33234719 DOI: 10.1242/dev.194530] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 11/04/2020] [Indexed: 01/14/2023]
Abstract
The mechanism underlying the geometrical patterning of axon and dendrite wiring remains elusive, despite its crucial importance in the formation of functional neural circuits. The cerebellar Purkinje cell (PC) arborizes a typical planar dendrite, which forms an orthogonal network with granule cell (GC) axons. By using electrospun nanofiber substrates, we reproduce the perpendicular contacts between PC dendrites and GC axons in culture. In the model system, PC dendrites show a preference to grow perpendicularly to aligned GC axons, which presumably contribute to the planar dendrite arborization in vivo We show that βIII spectrin, a causal protein for spinocerebellar ataxia type 5, is required for the biased growth of dendrites. βIII spectrin deficiency causes actin mislocalization and excessive microtubule invasion in dendritic protrusions, resulting in abnormally oriented branch formation. Furthermore, disease-associated mutations affect the ability of βIII spectrin to control dendrite orientation. These data indicate that βIII spectrin organizes the mouse dendritic cytoskeleton and thereby regulates the oriented growth of dendrites with respect to the afferent axons.
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Affiliation(s)
- Kazuto Fujishima
- Institute for Integrated Cell-Material Sciences (KUIAS-iCeMS), Kyoto University, Kyoto 606-8501, Japan
| | - Junko Kurisu
- Institute for Integrated Cell-Material Sciences (KUIAS-iCeMS), Kyoto University, Kyoto 606-8501, Japan
| | - Midori Yamada
- Institute for Integrated Cell-Material Sciences (KUIAS-iCeMS), Kyoto University, Kyoto 606-8501, Japan.,Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
| | - Mineko Kengaku
- Institute for Integrated Cell-Material Sciences (KUIAS-iCeMS), Kyoto University, Kyoto 606-8501, Japan.,Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
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Cerebellar Astrocytes: Much More Than Passive Bystanders In Ataxia Pathophysiology. J Clin Med 2020; 9:jcm9030757. [PMID: 32168822 PMCID: PMC7141261 DOI: 10.3390/jcm9030757] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 03/06/2020] [Accepted: 03/09/2020] [Indexed: 12/22/2022] Open
Abstract
Ataxia is a neurodegenerative syndrome, which can emerge as a major element of a disease or represent a symptom of more complex multisystemic disorders. It comprises several forms with a highly variegated etiology, mainly united by motor, balance, and speech impairments and, at the tissue level, by cerebellar atrophy and Purkinje cells degeneration. For this reason, the contribution of astrocytes to this disease has been largely overlooked in the past. Nevertheless, in the last few decades, growing evidences are pointing to cerebellar astrocytes as crucial players not only in the progression but also in the onset of distinct forms of ataxia. Although the current knowledge on this topic is very fragmentary and ataxia type-specific, the present review will attempt to provide a comprehensive view of astrocytes’ involvement across the distinct forms of this pathology. Here, it will be highlighted how, through consecutive stage-specific mechanisms, astrocytes can lead to non-cell autonomous neurodegeneration and, consequently, to the behavioral impairments typical of this disease. In light of that, treating astrocytes to heal neurons will be discussed as a potential complementary therapeutic approach for ataxic patients, a crucial point provided the absence of conclusive treatments for this disease.
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6
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Kovermann P, Untiet V, Kolobkova Y, Engels M, Baader S, Schilling K, Fahlke C. Increased glutamate transporter-associated anion currents cause glial apoptosis in episodic ataxia 6. Brain Commun 2020; 2:fcaa022. [PMID: 32954283 PMCID: PMC7425361 DOI: 10.1093/braincomms/fcaa022] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 01/24/2020] [Accepted: 02/02/2020] [Indexed: 01/08/2023] Open
Abstract
Episodic ataxia type 6 is an inherited neurological condition characterized by combined ataxia and epilepsy. A severe form of this disease with episodes combining ataxia, epilepsy and hemiplegia was recently associated with a proline to arginine substitution at position 290 of the excitatory amino acid transporter 1 in a heterozygous patient. The excitatory amino acid transporter 1 is the predominant glial glutamate transporter in the cerebellum. However, this glutamate transporter also functions as an anion channel and earlier work in heterologous expression systems demonstrated that the mutation impairs the glutamate transport rate, while increasing channel activity. To understand how these changes cause ataxia, we developed a constitutive transgenic mouse model. Transgenic mice display epilepsy, ataxia and cerebellar atrophy and, thus, closely resemble the human disease. We observed increased glutamate-activated chloride efflux in Bergmann glia that triggers the apoptosis of these cells during infancy. The loss of Bergmann glia results in reduced glutamate uptake and impaired neural network formation in the cerebellar cortex. This study shows how gain-of-function of glutamate transporter-associated anion channels causes ataxia through modifying cerebellar development.
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Affiliation(s)
- Peter Kovermann
- Institut für Biologische Informationsprozesse, Molekular- und Zellphysiologie (IBI-1), Forschungszentrum Jülich, 52428 Jülich, Germany
| | - Verena Untiet
- Institut für Biologische Informationsprozesse, Molekular- und Zellphysiologie (IBI-1), Forschungszentrum Jülich, 52428 Jülich, Germany
| | - Yulia Kolobkova
- Institut für Biologische Informationsprozesse, Molekular- und Zellphysiologie (IBI-1), Forschungszentrum Jülich, 52428 Jülich, Germany
| | - Miriam Engels
- Institut für Biologische Informationsprozesse, Molekular- und Zellphysiologie (IBI-1), Forschungszentrum Jülich, 52428 Jülich, Germany
| | - Stephan Baader
- Anatomisches Institut, Anatomie und Zellbiologie, Rheinische Friedrich-Wilhelm Universität Bonn, 53115 Bonn, Germany
| | - Karl Schilling
- Anatomisches Institut, Anatomie und Zellbiologie, Rheinische Friedrich-Wilhelm Universität Bonn, 53115 Bonn, Germany
| | - Christoph Fahlke
- Institut für Biologische Informationsprozesse, Molekular- und Zellphysiologie (IBI-1), Forschungszentrum Jülich, 52428 Jülich, Germany
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7
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Malik AR, Willnow TE. Excitatory Amino Acid Transporters in Physiology and Disorders of the Central Nervous System. Int J Mol Sci 2019; 20:ijms20225671. [PMID: 31726793 PMCID: PMC6888459 DOI: 10.3390/ijms20225671] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 11/07/2019] [Accepted: 11/11/2019] [Indexed: 12/12/2022] Open
Abstract
Excitatory amino acid transporters (EAATs) encompass a class of five transporters with distinct expression in neurons and glia of the central nervous system (CNS). EAATs are mainly recognized for their role in uptake of the amino acid glutamate, the major excitatory neurotransmitter. EAATs-mediated clearance of glutamate released by neurons is vital to maintain proper glutamatergic signalling and to prevent toxic accumulation of this amino acid in the extracellular space. In addition, some EAATs also act as chloride channels or mediate the uptake of cysteine, required to produce the reactive oxygen speciesscavenger glutathione. Given their central role in glutamate homeostasis in the brain, as well as their additional activities, it comes as no surprise that EAAT dysfunctions have been implicated in numerous acute or chronic diseases of the CNS, including ischemic stroke and epilepsy, cerebellar ataxias, amyotrophic lateral sclerosis, Alzheimer’s disease and Huntington’s disease. Here we review the studies in cellular and animal models, as well as in humans that highlight the roles of EAATs in the pathogenesis of these devastating disorders. We also discuss the mechanisms regulating EAATs expression and intracellular trafficking and new exciting possibilities to modulate EAATs and to provide neuroprotection in course of pathologies affecting the CNS.
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Affiliation(s)
- Anna R. Malik
- Nencki Institute of Experimental Biology, 02-093 Warsaw, Poland
- Correspondence:
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8
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Al-Muhaizea MA, AlMutairi F, Almass R, AlHarthi S, Aldosary MS, Alsagob M, AlOdaib A, Colak D, Kaya N. A Novel Homozygous Mutation in SPTBN2 Leads to Spinocerebellar Ataxia in a Consanguineous Family: Report of a New Infantile-Onset Case and Brief Review of the Literature. THE CEREBELLUM 2019; 17:276-285. [PMID: 29196973 DOI: 10.1007/s12311-017-0893-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The objective of this study was the identification of likely genes and mutations associated with an autosomal recessive (AR) rare spinocerebellar ataxia (SCA) phenotype in two patients with infantile onset, from a consanguineous family. Using genome-wide SNP screening, autozygosity mapping, targeted Sanger sequencing and nextgen sequencing, family segregation analysis, and comprehensive neuropanel, we discovered a novel mutation in SPTBN2. Next, we utilized multiple sequence alignment of amino acids from various species as well as crystal structures provided by protein data bank (PDB# 1WYQ and 1WJM) to model the mutation site and its effect on β-III-spectrin. Finally, we used various bioinformatic classifiers to determine pathogenicity of the missense variant. A comprehensive clinical and diagnostic workup including radiological exams were performed on the patients as part of routine patient care. The homozygous missense variant (c.1572C>T; p.R414C) detected in exon 2 was fully segregated in the family and absent in a large ethnic cohort as well as publicly available data sets. Our comprehensive targeted sequencing approaches did not reveal any other likely candidate variants or mutations in both patients. The two male siblings presented with delayed motor milestones and cognitive and learning disability. Brain MRI revealed isolated cerebellar atrophy more marked in midline inferior vermis at ages of 3 and 6.5 years. Sequence alignments of the amino acids for β-III-spectrin indicated that the arginine at 414 is highly conserved among various species and located towards the end of first spectrin repeat domain. Inclusive bioinformatic analysis predicted that the variant is to be damaging and disease causing. In addition to the novel mutation, a brief literature review of the previously reported mutations as well as clinical comparison of the cases were also presented. Our study reviews the previously reported SPTBN2 mutations and cases. Moreover, the novel mutation, p.R414C, adds up to the literature for the infantile-onset form of autosomal recessive ataxia associated with SPTBN2. Previously, few SPTBN2 recessive mutations have been reported in humans. Animal models especially the β-III-/- mouse model provided insights into early coordination and gait deficit suggestive of loss-of-function. It is expected to see more recessive SPTBN2 mutations appearing in the literature during the upcoming years.
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Affiliation(s)
- Mohammad A Al-Muhaizea
- Department of Neurosciences, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia.,College of Medicine, Al Faisal University, Riyadh, Saudi Arabia
| | - Faten AlMutairi
- Genetics Department, King Faisal Specialist Hospital and Research Center, MBC: 03, Riyadh, 11211, Saudi Arabia
| | - Rawan Almass
- Genetics Department, King Faisal Specialist Hospital and Research Center, MBC: 03, Riyadh, 11211, Saudi Arabia
| | - Safinaz AlHarthi
- Department of Neurosciences, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia
| | - Mazhor S Aldosary
- Genetics Department, King Faisal Specialist Hospital and Research Center, MBC: 03, Riyadh, 11211, Saudi Arabia
| | - Maysoon Alsagob
- Genetics Department, King Faisal Specialist Hospital and Research Center, MBC: 03, Riyadh, 11211, Saudi Arabia
| | - Ali AlOdaib
- Genetics Department, King Faisal Specialist Hospital and Research Center, MBC: 03, Riyadh, 11211, Saudi Arabia
| | - Dilek Colak
- Department of Biostatistics and Scientific Computing, King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia
| | - Namik Kaya
- Genetics Department, King Faisal Specialist Hospital and Research Center, MBC: 03, Riyadh, 11211, Saudi Arabia.
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9
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Mouse models and strain-dependency of Chédiak-Higashi syndrome-associated neurologic dysfunction. Sci Rep 2019; 9:6752. [PMID: 31043676 PMCID: PMC6494809 DOI: 10.1038/s41598-019-42159-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 03/18/2019] [Indexed: 12/20/2022] Open
Abstract
Chédiak-Higashi syndrome (CHS) is a lethal disorder caused by mutations in the LYST gene that involves progressive neurologic dysfunction. Lyst-mutant mice exhibit neurologic phenotypes that are sensitive to genetic background. On the DBA/2J-, but not on the C57BL/6J-background, Lyst-mutant mice exhibit overt tremor phenotypes associated with loss of cerebellar Purkinje cells. Here, we tested whether assays for ataxia could measure this observed strain-dependency, and if so, establish parameters for empowering phenotype- and candidate-driven approaches to identify genetic modifier(s). A composite phenotypic scoring system distinguished phenotypes in Lyst-mutants and uncovered a previously unrecognized background difference between wild-type C57BL/6J and DBA/2J mice. Accelerating rotarod performance also distinguished phenotypes in Lyst-mutants, but at more advanced ages. These results establish that genetic background, Lyst genotype, and age significantly influence the severity of CHS-associated neurologic deficits. Purkinje cell quantifications likewise distinguished phenotypes of Lyst-mutant mice, as well as background differences between wild-type C57BL/6J and DBA/2J mice. To aid identification of potential genetic modifier genes causing these effects, we searched public datasets for cerebellar-expressed genes that are differentially expressed and/or contain potentially detrimental genetic variants. From these approaches, Nos1, Prdx2, Cbln3, Gnb1, Pttg1 were confirmed to be differentially expressed and leading candidates.
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10
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Perkins EM, Clarkson YL, Suminaite D, Lyndon AR, Tanaka K, Rothstein JD, Skehel PA, Wyllie DJA, Jackson M. Loss of cerebellar glutamate transporters EAAT4 and GLAST differentially affects the spontaneous firing pattern and survival of Purkinje cells. Hum Mol Genet 2018; 27:2614-2627. [PMID: 29741614 PMCID: PMC6049029 DOI: 10.1093/hmg/ddy169] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 04/30/2018] [Accepted: 05/01/2018] [Indexed: 12/20/2022] Open
Abstract
Loss of excitatory amino acid transporters (EAATs) has been implicated in a number of human diseases including spinocerebellar ataxias, Alzhiemer's disease and motor neuron disease. EAAT4 and GLAST/EAAT1 are the two predominant EAATs responsible for maintaining low extracellular glutamate levels and preventing neurotoxicity in the cerebellum, the brain region essential for motor control. Here using genetically modified mice we identify new critical roles for EAAT4 and GLAST/EAAT1 as modulators of Purkinje cell (PC) spontaneous firing patterns. We show high EAAT4 levels, by limiting mGluR1 signalling, are essential in constraining inherently heterogeneous firing of zebrin-positive PCs. Moreover mGluR1 antagonists were found to restore regular spontaneous PC activity and motor behaviour in EAAT4 knockout mice. In contrast, GLAST/EAAT1 expression is required to sustain normal spontaneous simple spike activity in low EAAT4 expressing (zebrin-negative) PCs by restricting NMDA receptor activation. Blockade of NMDA receptor activity restores spontaneous activity in zebrin-negative PCs of GLAST knockout mice and furthermore alleviates motor deficits. In addition both transporters have differential effects on PC survival, with zebrin-negative PCs more vulnerable to loss of GLAST/EAAT1 and zebrin-positive PCs more vulnerable to loss of EAAT4. These findings reveal that glutamate transporter dysfunction through elevated extracellular glutamate and the aberrant activation of extrasynaptic receptors can disrupt cerebellar output by altering spontaneous PC firing. This expands our understanding of disease mechanisms in cerebellar ataxias and establishes EAATs as targets for restoring homeostasis in a variety of neurological diseases where altered cerebellar output is now thought to play a key role in pathogenesis.
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Affiliation(s)
- Emma M Perkins
- The Centre for Discovery Brain Sciences, The University of Edinburgh, Hugh Robson Building, Edinburgh, UK
| | - Yvonne L Clarkson
- The Centre for Discovery Brain Sciences, The University of Edinburgh, Hugh Robson Building, Edinburgh, UK
| | - Daumante Suminaite
- The Centre for Discovery Brain Sciences, The University of Edinburgh, Hugh Robson Building, Edinburgh, UK
| | - Alastair R Lyndon
- School of Energy, Geoscience, Infrastructure and Society, Heriot-Watt University, John Muir Building, Riccarton, Edinburgh, UK
| | - Kohichi Tanaka
- Laboratory of Molecular Neuroscience, Medical Research Institute, Tokyo Medical and Dental University, Bunkyo-Ku, Tokyo, Japan
| | - Jeffrey D Rothstein
- Department of Neurology and Neuroscience, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - Paul A Skehel
- The Centre for Discovery Brain Sciences, The University of Edinburgh, Hugh Robson Building, Edinburgh, UK
| | - David J A Wyllie
- The Centre for Discovery Brain Sciences, The University of Edinburgh, Hugh Robson Building, Edinburgh, UK
- Centre for Brain Development and Repair, Institute for Stem Cell Biology and Regenerative Medicine, Bangalore, India
| | - Mandy Jackson
- The Centre for Discovery Brain Sciences, The University of Edinburgh, Hugh Robson Building, Edinburgh, UK
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11
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Hoxha E, Gabriele RMC, Balbo I, Ravera F, Masante L, Zambelli V, Albergo C, Mitro N, Caruso D, Di Gregorio E, Brusco A, Borroni B, Tempia F. Motor Deficits and Cerebellar Atrophy in Elovl5 Knock Out Mice. Front Cell Neurosci 2017; 11:343. [PMID: 29163054 PMCID: PMC5670146 DOI: 10.3389/fncel.2017.00343] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 10/16/2017] [Indexed: 01/26/2023] Open
Abstract
Spino-Cerebellar-Ataxia type 38 (SCA38) is caused by missense mutations in the very long chain fatty acid elongase 5 gene, ELOVL5. The main clinical findings in this disease are ataxia, hyposmia and cerebellar atrophy. Mice in which Elovl5 has been knocked out represent a model of the loss of function hypothesis of SCA38. In agreement with this hypothesis, Elovl5 knock out mice reproduced the main symptoms of patients, motor deficits at the beam balance test and hyposmia. The cerebellar cortex of Elovl5 knock out mice showed a reduction of thickness of the molecular layer, already detectable at 6 months of age, confirmed at 12 and 18 months. The total perimeter length of the Purkinje cell (PC) layer was also reduced in Elovl5 knock out mice. Since Elovl5 transcripts are expressed by PCs, whose dendrites are a major component of the molecular layer, we hypothesized that an alteration of their dendrites might be responsible for the reduced thickness of this layer. Reconstruction of the dendritic tree of biocytin-filled PCs, followed by Sholl analysis, showed that the distribution of distal dendrites was significantly reduced in Elovl5 knock out mice. Dendritic spine density was conserved. These results suggest that Elovl5 knock out mice recapitulate SCA38 symptoms and that their cerebellar atrophy is due, at least in part, to a reduced extension of PC dendritic arborization.
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Affiliation(s)
- Eriola Hoxha
- Neurophysiology of Neurodegenerative Diseases, Neuroscience Institute Cavalieri Ottolenghi (NICO), Torino, Italy.,Department of Neuroscience, University of Torino, Torino, Italy
| | - Rebecca M C Gabriele
- Neurophysiology of Neurodegenerative Diseases, Neuroscience Institute Cavalieri Ottolenghi (NICO), Torino, Italy
| | - Ilaria Balbo
- Neurophysiology of Neurodegenerative Diseases, Neuroscience Institute Cavalieri Ottolenghi (NICO), Torino, Italy
| | - Francesco Ravera
- Neurophysiology of Neurodegenerative Diseases, Neuroscience Institute Cavalieri Ottolenghi (NICO), Torino, Italy
| | - Linda Masante
- Neurophysiology of Neurodegenerative Diseases, Neuroscience Institute Cavalieri Ottolenghi (NICO), Torino, Italy
| | - Vanessa Zambelli
- Neurophysiology of Neurodegenerative Diseases, Neuroscience Institute Cavalieri Ottolenghi (NICO), Torino, Italy
| | - Cristian Albergo
- Neurophysiology of Neurodegenerative Diseases, Neuroscience Institute Cavalieri Ottolenghi (NICO), Torino, Italy
| | - Nico Mitro
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Donatella Caruso
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Eleonora Di Gregorio
- Medical Genetics Unit, Città della Salute e della Scienza Hospital and Department of Medical Sciences, University of Torino, Torino, Italy
| | - Alfredo Brusco
- Medical Genetics Unit, Città della Salute e della Scienza Hospital and Department of Medical Sciences, University of Torino, Torino, Italy
| | - Barbara Borroni
- Neurology Unit, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Filippo Tempia
- Neurophysiology of Neurodegenerative Diseases, Neuroscience Institute Cavalieri Ottolenghi (NICO), Torino, Italy.,Department of Neuroscience, University of Torino, Torino, Italy.,National Institute of Neuroscience, Torino, Italy
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Miyazaki T, Yamasaki M, Hashimoto K, Kohda K, Yuzaki M, Shimamoto K, Tanaka K, Kano M, Watanabe M. Glutamate transporter GLAST controls synaptic wrapping by Bergmann glia and ensures proper wiring of Purkinje cells. Proc Natl Acad Sci U S A 2017; 114:7438-7443. [PMID: 28655840 PMCID: PMC5514701 DOI: 10.1073/pnas.1617330114] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Astrocytes regulate synaptic transmission through controlling neurotransmitter concentrations around synapses. Little is known, however, about their roles in neural circuit development. Here we report that Bergmann glia (BG), specialized cerebellar astrocytes that thoroughly enwrap Purkinje cells (PCs), are essential for synaptic organization in PCs through the action of the l-glutamate/l-aspartate transporter (GLAST). In GLAST-knockout mice, dendritic innervation by the main ascending climbing fiber (CF) branch was significantly weakened, whereas the transverse branch, which is thin and nonsynaptogenic in control mice, was transformed into thick and synaptogenic branches. Both types of CF branches frequently produced aberrant wiring to proximal and distal dendrites, causing multiple CF-PC innervation. Our electrophysiological analysis revealed that slow and small CF-evoked excitatory postsynaptic currents (EPSCs) were recorded from almost all PCs in GLAST-knockout mice. These atypical CF-EPSCs were far more numerous and had significantly faster 10-90% rise time than those elicited by glutamate spillover under pharmacological blockade of glial glutamate transporters. Innervation by parallel fibers (PFs) was also affected. PF synapses were robustly increased in the entire dendritic trees, leading to impaired segregation of CF and PF territories. Furthermore, lamellate BG processes were retracted from PC dendrites and synapses, leading to the exposure of these neuronal elements to the extracellular milieus. These synaptic and glial phenotypes were reproduced in wild-type mice after functional blockade of glial glutamate transporters. These findings highlight that glutamate transporter function by GLAST on BG plays important roles in development and maintenance of proper synaptic wiring and wrapping in PCs.
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Affiliation(s)
- Taisuke Miyazaki
- Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan
| | - Miwako Yamasaki
- Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan
| | - Kouichi Hashimoto
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Hongo, Tokyo 113-0033, Japan
- Department of Neurophysiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8551, Japan
| | - Kazuhisa Kohda
- Department of Physiology, Keio University School of Medicine, Tokyo 160-8582, Japan
- Department of Physiology, St. Marianna University School of Medicine, Kanagawa 216-8511, Japan
| | - Michisuke Yuzaki
- Department of Physiology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Keiko Shimamoto
- Bioorganic Research Institute, Suntory Foundation for Life Sciences, Kyoto, 619-0284, Japan
| | - Kohichi Tanaka
- Laboratory of Molecular Neuroscience, School of Biomedical Science and Medical Research Institute, Tokyo Medical and Dental University, Tokyo 113-8510, Japan
| | - Masanobu Kano
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Hongo, Tokyo 113-0033, Japan
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan;
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