1
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Lin NH, Jian WS, Snider N, Perng MD. Glial fibrillary acidic protein is pathologically modified in Alexander disease. J Biol Chem 2024; 300:107402. [PMID: 38782207 PMCID: PMC11259701 DOI: 10.1016/j.jbc.2024.107402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 04/29/2024] [Accepted: 05/01/2024] [Indexed: 05/25/2024] Open
Abstract
Here, we describe pathological events potentially involved in the disease pathogenesis of Alexander disease (AxD). This is a primary genetic disorder of astrocyte caused by dominant gain-of-function mutations in the gene coding for an intermediate filament protein glial fibrillary acidic protein (GFAP). Pathologically, this disease is characterized by the upregulation of GFAP and its accumulation as Rosenthal fibers. Although the genetic basis linking GFAP mutations with Alexander disease has been firmly established, the initiating events that promote GFAP accumulation and the role of Rosenthal fibers (RFs) in the disease process remain unknown. Here, we investigate the hypothesis that disease-associated mutations promote GFAP aggregation through aberrant posttranslational modifications. We found high molecular weight GFAP species in the RFs of AxD brains, indicating abnormal GFAP crosslinking as a prominent pathological feature of this disease. In vitro and cell-based studies demonstrate that cystine-generating mutations promote GFAP crosslinking by cysteine-dependent oxidation, resulting in defective GFAP assembly and decreased filament solubility. Moreover, we found GFAP was ubiquitinated in RFs of AxD patients and rodent models, supporting this modification as a critical factor linked to GFAP aggregation. Finally, we found that arginine could increase the solubility of aggregation-prone mutant GFAP by decreasing its ubiquitination and aggregation. Our study suggests a series of pathogenic events leading to AxD, involving interplay between GFAP aggregation and abnormal modifications by GFAP ubiquitination and oxidation. More important, our findings provide a basis for investigating new strategies to treat AxD by targeting abnormal GFAP modifications.
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Affiliation(s)
- Ni-Hsuan Lin
- Institute of Molecular Medicine, National Tsing Hua University, Hsinchu, Taiwan
| | - Wan-Syuan Jian
- Institute of Molecular Medicine, National Tsing Hua University, Hsinchu, Taiwan
| | - Natasha Snider
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Ming-Der Perng
- Institute of Molecular Medicine, National Tsing Hua University, Hsinchu, Taiwan; School of Medicine, College of Life Sciences and Medicine, National Tsing Hua University, Hsinchu, Taiwan.
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2
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Nowak I, Paździor M, Sarna R, Madej M. Molecular Mechanisms in the Design of Novel Targeted Therapies for Neurodegenerative Diseases. Curr Issues Mol Biol 2024; 46:5436-5453. [PMID: 38920997 PMCID: PMC11202845 DOI: 10.3390/cimb46060325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 05/24/2024] [Accepted: 05/28/2024] [Indexed: 06/27/2024] Open
Abstract
Neurodegenerative diseases are a diverse group of diseases characterized by a progressive loss of neurological function due to damage to nerve cells in the central nervous system. In recent years, there has been a worldwide increase in the expanding associated with increasing human life expectancy. Molecular mechanisms control many of the essential life processes of cells, such as replication, transcription, translation, protein synthesis and gene regulation. These are complex interactions that form the basis for understanding numerous processes in the organism and developing new diagnostic and therapeutic approaches. In the context of neurodegenerative diseases, molecular basis refers to changes at the molecular level that cause damage to or degeneration of nerve cells. These may include protein aggregates leading to pathological structures in brain cells, impaired protein transport in nerve cells, mitochondrial dysfunction, inflammatory processes or genetic mutations that impair nerve cell function. New medical therapies are based on these mechanisms and include gene therapies, reduction in inflammation and oxidative stress, and the use of miRNAs and regenerative medicine. The aim of this study was to bring together the current state of knowledge regarding selected neurodegenerative diseases, presenting the underlying molecular mechanisms involved, which could be potential targets for new forms of treatment.
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Affiliation(s)
- Ilona Nowak
- Silesia LabMed, Centre for Research and Implementation, Medical University of Silesia in Katowice, 18 Medykow Str., 40-752 Katowice, Poland; (M.P.); (R.S.); (M.M.)
| | - Marlena Paździor
- Silesia LabMed, Centre for Research and Implementation, Medical University of Silesia in Katowice, 18 Medykow Str., 40-752 Katowice, Poland; (M.P.); (R.S.); (M.M.)
| | - Robert Sarna
- Silesia LabMed, Centre for Research and Implementation, Medical University of Silesia in Katowice, 18 Medykow Str., 40-752 Katowice, Poland; (M.P.); (R.S.); (M.M.)
| | - Marcel Madej
- Silesia LabMed, Centre for Research and Implementation, Medical University of Silesia in Katowice, 18 Medykow Str., 40-752 Katowice, Poland; (M.P.); (R.S.); (M.M.)
- Department of Molecular Biology, Faculty of Pharmaceutical Sciences in Sosnowiec, Medical University of Silesia, 40-055 Katowice, Poland
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3
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Zheng X, Yang J, Hou Y, Shi X, Liu K. Prediction of clinical progression in nervous system diseases: plasma glial fibrillary acidic protein (GFAP). Eur J Med Res 2024; 29:51. [PMID: 38216970 PMCID: PMC10785482 DOI: 10.1186/s40001-023-01631-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Accepted: 12/29/2023] [Indexed: 01/14/2024] Open
Abstract
Glial fibrillary acidic protein (GFAP), an intracellular type III intermediate filament protein, provides structural support and maintains the mechanical integrity of astrocytes. It is predominantly found in the astrocytes which are the most abundant subtypes of glial cells in the brain and spinal cord. As a marker protein of astrocytes, GFAP may exert a variety of physiological effects in neurological diseases. For example, previous published literatures showed that autoimmune GFAP astrocytopathy is an inflammatory disease of the central nervous system (CNS). Moreover, the studies of GFAP in brain tumors mainly focus on the predictive value of tumor volume. Furthermore, using biomarkers in the early setting will lead to a simplified and standardized way to estimate the poor outcome in traumatic brain injury (TBI) and ischemic stroke. Recently, observational studies revealed that cerebrospinal fluid (CSF) GFAP, as a valuable potential diagnostic biomarker for neurosyphilis, had a sensitivity of 76.60% and specificity of 85.56%. The reason plasma GFAP could serve as a promising biomarker for diagnosis and prediction of Alzheimer's disease (AD) is that it effectively distinguished AD dementia from multiple neurodegenerative diseases and predicted the individual risk of AD progression. In addition, GFAP can be helpful in differentiating relapsing-remitting multiple sclerosis (RRMS) versus progressive MS (PMS). This review article aims to provide an overview of GFAP in the prediction of clinical progression in neuroinflammation, brain tumors, TBI, ischemic stroke, genetic disorders, neurodegeneration and other diseases in the CNS and to explore the potential therapeutic methods.
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Affiliation(s)
- Xiaoxiao Zheng
- Department of Neurology, Neuroscience Center, The First Hospital of Jilin University, Xinmin Street 1#, Changchun, China
| | - Jingyao Yang
- Institute of Physiology, School of Basic Medical Sciences, Shanxi Medical University, Taiyuan, China
| | - Yiwei Hou
- Department of Neurology, Neuroscience Center, The First Hospital of Jilin University, Xinmin Street 1#, Changchun, China
| | - Xinye Shi
- Department of Cardiology, Shanxi Yingkang Yisheng General Hospital, Renmin North Road 5188#, Yuncheng, China
| | - Kangding Liu
- Department of Neurology, Neuroscience Center, The First Hospital of Jilin University, Xinmin Street 1#, Changchun, China.
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4
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Anis S, Fay-Karmon T, Lassman S, Shbat F, Lesman-Segev O, Mor N, Barel O, Dominissini D, Chorin O, Pras E, Greenbaum L, Hassin-Baer S. Adult-onset Alexander disease among patients of Jewish Syrian descent. Neurogenetics 2023; 24:303-310. [PMID: 37658208 DOI: 10.1007/s10048-023-00732-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Accepted: 08/11/2023] [Indexed: 09/03/2023]
Abstract
Alexander disease (AxD) is a rare autosomal dominant leukodystrophy caused by heterozygous mutations in the glial fibrillary acid protein (GFAP) gene. The age of symptoms onset ranges from infancy to adulthood, with variable clinical and radiological manifestations. Adult-onset AxD manifests as a chronic and progressive condition, characterized by bulbar, motor, cerebellar, and other clinical signs and symptoms. Neuroradiological findings typically involve the brainstem and cervical spinal cord. Adult-onset AxD has been described in diverse populations but is rare in Israel. We present a series of patients diagnosed with adult-onset AxD from three families, all of Jewish Syrian descent. Five patients (4 females) were diagnosed with adult-onset AxD due to the heterozygous mutation c.219G > A, p.Met73Ile in GFAP. Age at symptoms onset ranged from 48 to 61 years. Clinical characteristics were typical and involved progressive bulbar and gait disturbance, followed by pyramidal and cerebellar impairment, dysautonomia, and cognitive decline. Imaging findings included medullary and cervical spinal atrophy and mostly infratentorial white matter hyperintensities. A newly recognized cluster of adult-onset AxD in Jews of Syrian origin is presented. This disorder should be considered in differential diagnosis in appropriate circumstances. Genetic counselling for family members is required in order to discuss options for future family planning.
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Affiliation(s)
- Saar Anis
- Movement Disorders Institute and Department of Neurology, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Tsvia Fay-Karmon
- Movement Disorders Institute and Department of Neurology, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Simon Lassman
- St George's Hospital, University of London, London, UK
- Arrow Project for Medical Research, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
| | - Fadi Shbat
- Movement Disorders Institute and Department of Neurology, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
| | - Orit Lesman-Segev
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Department of Diagnostic Imaging, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
| | - Nofar Mor
- Cancer Research Center and Wohl Institute for Translational Medicine, Tel Hashomer, Ramat Gan, Israel
| | - Ortal Barel
- Cancer Research Center and Wohl Institute for Translational Medicine, Tel Hashomer, Ramat Gan, Israel
| | - Dan Dominissini
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Cancer Research Center and Wohl Institute for Translational Medicine, Tel Hashomer, Ramat Gan, Israel
| | - Odelia Chorin
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- The Danek Gertner Institute of Human Genetics, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
- The Institute of Rare Diseases, Lily and Edmond Safra Children's Hospital, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
| | - Elon Pras
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- The Danek Gertner Institute of Human Genetics, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
| | - Lior Greenbaum
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- The Danek Gertner Institute of Human Genetics, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
- The Joseph Sagol Neuroscience Center, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
| | - Sharon Hassin-Baer
- Movement Disorders Institute and Department of Neurology, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel.
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
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5
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Viedma-Poyatos Á, González-Jiménez P, Pajares MA, Pérez-Sala D. Alexander disease GFAP R239C mutant shows increased susceptibility to lipoxidation and elicits mitochondrial dysfunction and oxidative stress. Redox Biol 2022; 55:102415. [PMID: 35933901 PMCID: PMC9364016 DOI: 10.1016/j.redox.2022.102415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Revised: 07/15/2022] [Accepted: 07/16/2022] [Indexed: 01/04/2023] Open
Abstract
Alexander disease is a fatal neurological disorder caused by mutations in the intermediate filament protein Glial Fibrillary Acidic Protein (GFAP), which is key for astrocyte homeostasis. These mutations cause GFAP aggregation, astrocyte dysfunction and neurodegeneration. Remarkably, most of the known GFAP mutations imply a change by more nucleophilic amino acids, mainly cysteine or histidine, which are more susceptible to oxidation and lipoxidation. Therefore, we hypothesized that a higher susceptibility of Alexander disease GFAP mutants to oxidative or electrophilic damage, which frequently occurs during neurodegeneration, could contribute to disease pathogenesis. To address this point, we have expressed GFP-GFAP wild type or the harmful Alexander disease GFP-GFAP R239C mutant in astrocytic cells. Interestingly, GFAP R239C appears more oxidized than the wild type under control conditions, as indicated both by its lower cysteine residue accessibility and increased presence of disulfide-bonded oligomers. Moreover, GFP-GFAP R239C undergoes lipoxidation to a higher extent than GFAP wild type upon treatment with the electrophilic mediator 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2). Importantly, GFAP R239C filament organization is altered in untreated cells and is earlier and more severely disrupted than GFAP wild type upon exposure to oxidants (diamide, H2O2) or electrophiles (4-hydroxynonenal, 15d-PGJ2), which exacerbate GFAP R239C aggregation. Furthermore, H2O2 causes reversible alterations in GFAP wild type, but irreversible damage in GFAP R239C expressing cells. Finally, we show that GFAP R239C expression induces a more oxidized cellular status, with decreased free thiol content and increased mitochondrial superoxide generation. In addition, mitochondria show decreased mass, increased colocalization with GFAP and altered morphology. Notably, a GFP-GFAP R239H mutant recapitulates R239C-elicited alterations whereas an R239G mutant induces a milder phenotype. Together, our results outline a deleterious cycle involving altered GFAP R239C organization, mitochondrial dysfunction, oxidative stress, and further GFAP R239C protein damage and network disruption, which could contribute to astrocyte derangement in Alexander disease.
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Affiliation(s)
- Álvaro Viedma-Poyatos
- Department of Structural and Chemical Biology, Centro de Investigaciones Biológicas Margarita Salas, C.S.I.C., 28040, Madrid, Spain
| | - Patricia González-Jiménez
- Department of Structural and Chemical Biology, Centro de Investigaciones Biológicas Margarita Salas, C.S.I.C., 28040, Madrid, Spain
| | - María A Pajares
- Department of Structural and Chemical Biology, Centro de Investigaciones Biológicas Margarita Salas, C.S.I.C., 28040, Madrid, Spain
| | - Dolores Pérez-Sala
- Department of Structural and Chemical Biology, Centro de Investigaciones Biológicas Margarita Salas, C.S.I.C., 28040, Madrid, Spain.
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6
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Hagemann TL. Alexander disease: models, mechanisms, and medicine. Curr Opin Neurobiol 2022; 72:140-147. [PMID: 34826654 PMCID: PMC8901527 DOI: 10.1016/j.conb.2021.10.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 09/29/2021] [Accepted: 10/19/2021] [Indexed: 02/03/2023]
Abstract
Alexander disease is a primary disorder of astrocytes caused by gain-of-function mutations in the gene for glial fibrillary acidic protein (GFAP), which lead to protein aggregation and a reactive astrocyte response, with devastating effects on the central nervous system. Over the past two decades since the discovery of GFAP as the culprit, several cellular and animal models have been generated, and much has been learned about underlying mechanisms contributing to the disease. Despite these efforts, many aspects of Alexander disease have remained enigmatic, particularly the initiating events in GFAP accumulation and astrocyte pathology, the relation between astrocyte dysfunction and myelin deficits, and the variability in age of onset and disease severity. More recent work in both old and new models has begun to address these complex questions and identify new therapeutics that finally offer the promise of effective treatment.
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Affiliation(s)
- Tracy L. Hagemann
- Waisman Center, University of Wisconsin – Madison, 1500 Highland Ave, Madison, WI 53705
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7
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Bachetti T, Zanni ED, Adamo A, Rosamilia F, Sechi MM, Solla P, Bozzo M, Ceccherini I, Sechi G. Beneficial Effect of Phenytoin and Carbamazepine on GFAP Gene Expression and Mutant GFAP Folding in a Cellular Model of Alexander's Disease. Front Pharmacol 2021; 12:723218. [PMID: 34950024 PMCID: PMC8688807 DOI: 10.3389/fphar.2021.723218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 11/10/2021] [Indexed: 12/02/2022] Open
Abstract
Alexander’s disease (AxD) is a rare, usually relentlessly progressive disorder of astroglial cells in the central nervous system related to mutations in the gene encoding the type III intermediate filament protein, glial fibrillary acidic protein (GFAP). The pathophysiology of AxD is only partially understood. Available data indicate that an excessive GFAP gene expression may play a role. In particular, a “threshold hypothesis” has been reported, suggesting that mutant GFAP representing about 20% of the total cellular GFAP should be sufficient to cause disease. Thus, strategies based on reducing cellular mutant GFAP protein levels and/or activating biological processes involved in the correct protein folding could be effective in counteracting the toxic effect of misfolded GFAP. Considering that clomipramine (CLM), which has been selected by a wide small molecules screening as the greatest inhibitory potential drug against GFAP expression, is contraindicated because of its proconvulsant activity in the infantile form of AxD, which is also characterized by the occurrence of epileptic seizures, two powerful antiepileptic agents, carbamazepine (CBZ) and phenytoin (PHT), which share specific stereochemical features in common with CLM, were taken into consideration in a reliable in vitro model of AxD. In the present work, we document for the first time that CBZ and PHT have a definite inhibitory effect on pathological GFAP cellular expression and folding. Moreover, we confirm previous results of a similar beneficial effect of CLM. In addition, we have demonstrated that CBZ and CLM play a refolding effect on mutant GFAP proteins, likely ascribed at the induction of CRYAB expression, resulting in the decrease of mutant GFAP aggregates formation. As CBZ and PHT are currently approved for use in humans, their documented effects on pathological GFAP cellular expression and folding may indicate a potential therapeutic role as disease-modifying agents of these drugs in the clinical management of AxD, particularly in AxD patients with focal epilepsy with and without secondary generalization.
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Affiliation(s)
- Tiziana Bachetti
- UOSD Laboratorio di Genetica e Genomica delle Malattie Rare, IRCCS Gaslini, Genova, Italy.,Laboratorio di Neurobiologia dello Sviluppo, DISTAV, Università di Genova, Genova, Italy
| | - Eleonora Di Zanni
- UOSD Laboratorio di Genetica e Genomica delle Malattie Rare, IRCCS Gaslini, Genova, Italy
| | - Annalisa Adamo
- UOSD Laboratorio di Genetica e Genomica delle Malattie Rare, IRCCS Gaslini, Genova, Italy
| | - Francesca Rosamilia
- Dipartimento di Scienze della Salute, DISSAL, Università di Genova, Genova, Italy
| | - M Margherita Sechi
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Paolo Solla
- Department of Medical, Surgical and Experimental Sciences (G.P.S.; P.S.), University of Sassari, Sassari, Italy
| | - Matteo Bozzo
- Laboratorio di Neurobiologia dello Sviluppo, DISTAV, Università di Genova, Genova, Italy
| | - Isabella Ceccherini
- UOSD Laboratorio di Genetica e Genomica delle Malattie Rare, IRCCS Gaslini, Genova, Italy
| | - GianPietro Sechi
- Department of Medical, Surgical and Experimental Sciences (G.P.S.; P.S.), University of Sassari, Sassari, Italy
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8
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Hagemann TL, Powers B, Lin NH, Mohamed AF, Dague KL, Hannah SC, Bachmann G, Mazur C, Rigo F, Olsen AL, Feany MB, Perng MD, Berman RF, Messing A. Antisense therapy in a rat model of Alexander disease reverses GFAP pathology, white matter deficits, and motor impairment. Sci Transl Med 2021; 13:eabg4711. [PMID: 34788075 DOI: 10.1126/scitranslmed.abg4711] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Tracy L Hagemann
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | | | - Ni-Hsuan Lin
- Institute of Molecular Medicine, College of Life Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Ahmed F Mohamed
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Katerina L Dague
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Seth C Hannah
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | | | - Curt Mazur
- Ionis Pharmaceuticals, Carlsbad, CA 92010, USA
| | - Frank Rigo
- Ionis Pharmaceuticals, Carlsbad, CA 92010, USA
| | - Abby L Olsen
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Mel B Feany
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Ming-Der Perng
- Institute of Molecular Medicine, College of Life Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Robert F Berman
- Department of Neurological Surgery and M.I.N.D Institute, University of California, Davis, Davis, CA 95616, USA
| | - Albee Messing
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA.,Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI 53705, USA
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9
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Song X, Jiang J, Tian W, Zhan F, Zhu Z, Li B, Tang H, Cao L. A report of two cases of bulbospinal form Alexander disease and preliminary exploration of the disease. Mol Med Rep 2021; 24:572. [PMID: 34109421 PMCID: PMC8201446 DOI: 10.3892/mmr.2021.12211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 05/10/2021] [Indexed: 11/05/2022] Open
Abstract
Alexander disease (AxD) is a cerebral white matter disease affecting a wide range of ages, from infants to adults. In the present study, two cases of bulbospinal form AxD were reported, and a preliminary exploration of AxD was conducted thorough clinical, functional magnetic resonance imaging (fMRI) and functional analyses. In total, two de novo mutations in the glial fibrillary acidic protein (GFAP) gene (c.214G>A and c.1235C>T) were identified in unrelated patients (one in each patient). Both patients showed increased regional neural activity and functional connectivity in the cerebellum and posterior parietal cortex according to fMRI analysis. Notably, grey matter atrophy was discovered in the patient with c.214G>A variant. Functional experiments revealed aberrant accumulation of mutant GFAP and decreased solubility of c.1235C>T variant. Under pathological conditions, autophagic flux was activated for GFAP aggregate degradation. Moreover, transcriptional data of AxD and healthy human brain samples were obtained from the Gene Expression Omnibus database. Gene set enrichment analysis revealed an upregulation of immune‑related responses and downregulation of ion transport, synaptic transmission and neurotransmitter homeostasis. Enrichment analysis of cell‑specific differentially expressed genes also indicated a marked inflammatory environment in AxD. Overall, the clinical features of the two patients with bulbospinal form AxD were thoroughly described. To the best of our knowledge, the brain atrophy pattern and spontaneous brain functional network activity of patients with AxD were explored for the first time. Cytological experiments provided evidence of the pathogenicity of the identified variants. Furthermore, bioinformatics analysis found that inflammatory immune‑related reactions may play a critical role in AxD, which may be conducive to the understanding of this disease.
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Affiliation(s)
- Xiaoxuan Song
- Department of Neurology, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, P.R. China
| | - Jingwen Jiang
- Department of Neurology, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, P.R. China
| | - Wotu Tian
- Department of Neurology, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, P.R. China
| | - Feixia Zhan
- Department of Neurology, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, P.R. China
| | - Zeyu Zhu
- Department of Neurology, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, P.R. China
| | - Binyin Li
- Department of Neurology, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, P.R. China
| | - Huidong Tang
- Department of Neurology, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, P.R. China
| | - Li Cao
- Department of Neurology, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, P.R. China
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10
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Segawa K, Blumenthal Y, Yamawaki Y, Ohtsuki G. A Destruction Model of the Vascular and Lymphatic Systems in the Emergence of Psychiatric Symptoms. BIOLOGY 2021; 10:34. [PMID: 33419067 PMCID: PMC7825436 DOI: 10.3390/biology10010034] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 12/24/2020] [Accepted: 12/31/2020] [Indexed: 01/02/2023]
Abstract
The lymphatic system is important for antigen presentation and immune surveillance. The lymphatic system in the brain was originally introduced by Giovanni Mascagni in 1787, while the rediscovery of it by Jonathan Kipnis and Kari Kustaa Alitalo now opens the door for a new interpretation of neurological diseases and therapeutic applications. The glymphatic system for the exchanges of cerebrospinal fluid (CSF) and interstitial fluid (ISF) is associated with the blood-brain barrier (BBB), which is involved in the maintenance of immune privilege and homeostasis in the brain. Recent notions from studies of postmortem brains and clinical studies of neurodegenerative diseases, infection, and cerebral hemorrhage, implied that the breakdown of those barrier systems and infiltration of activated immune cells disrupt the function of both neurons and glia in the parenchyma (e.g., modulation of neurophysiological properties and maturation of myelination), which causes the abnormality in the functional connectivity of the entire brain network. Due to the vulnerability, such dysfunction may occur in developing brains as well as in senile or neurodegenerative diseases and may raise the risk of emergence of psychosis symptoms. Here, we introduce this hypothesis with a series of studies and cellular mechanisms.
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Affiliation(s)
- Kohei Segawa
- Department of Drug Discovery Medicine, Kyoto University Graduate School of Medicine, Kyoto 606-8397, Japan; (K.S.); (Y.Y.)
| | - Yukari Blumenthal
- Urology Department at Cambridge University Hospitals, NHS Foundation Trust, Addenbrooke’s Hospital, Hills Road Cambridge, Cambridge CB2 0QQ, UK;
| | - Yuki Yamawaki
- Department of Drug Discovery Medicine, Kyoto University Graduate School of Medicine, Kyoto 606-8397, Japan; (K.S.); (Y.Y.)
| | - Gen Ohtsuki
- Department of Drug Discovery Medicine, Kyoto University Graduate School of Medicine, Kyoto 606-8397, Japan; (K.S.); (Y.Y.)
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11
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Candiani S, Carestiato S, Mack AF, Bani D, Bozzo M, Obino V, Ori M, Rosamilia F, De Sarlo M, Pestarino M, Ceccherini I, Bachetti T. Alexander Disease Modeling in Zebrafish: An In Vivo System Suitable to Perform Drug Screening. Genes (Basel) 2020; 11:E1490. [PMID: 33322348 PMCID: PMC7764705 DOI: 10.3390/genes11121490] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 12/04/2020] [Accepted: 12/07/2020] [Indexed: 12/03/2022] Open
Abstract
Alexander disease (AxD) is a rare astrogliopathy caused by heterozygous mutations, either inherited or arising de novo, on the glial fibrillary acid protein (GFAP) gene (17q21). Mutations in the GFAP gene make the protein prone to forming aggregates which, together with heat-shock protein 27 (HSP27), αB-crystallin, ubiquitin, and proteasome, contribute to form Rosenthal fibers causing a toxic effect on the cell. Unfortunately, no pharmacological treatment is available yet, except for symptom reduction therapies, and patients undergo a progressive worsening of the disease. The aim of this study was the production of a zebrafish model for AxD, to have a system suitable for drug screening more complex than cell cultures. To this aim, embryos expressing the human GFAP gene carrying the most severe p.R239C under the control of the zebrafish gfap gene promoter underwent functional validation to assess several features already observed in in vitro and other in vivo models of AxD, such as the localization of mutant GFAP inclusions, the ultrastructural analysis of cells expressing mutant GFAP, the effects of treatments with ceftriaxone, and the heat shock response. Our results confirm that zebrafish is a suitable model both to study the molecular pathogenesis of GFAP mutations and to perform pharmacological screenings, likely useful for the search of therapies for AxD.
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Affiliation(s)
- Simona Candiani
- Department of Earth, Environment and Life Sciences (DISTAV), University of Genoa, 16132 Genoa, Italy; (S.C.); (S.C.); (M.B.); (V.O.); (F.R.); (M.P.)
| | - Silvia Carestiato
- Department of Earth, Environment and Life Sciences (DISTAV), University of Genoa, 16132 Genoa, Italy; (S.C.); (S.C.); (M.B.); (V.O.); (F.R.); (M.P.)
| | - Andreas F. Mack
- Institut für Klinische Anatomie und Zellanalytik, Universitaet Tuebingen, 72076 Tuebingen, Germany;
| | - Daniele Bani
- Department of Clinical and Experimental Medicine, University of Florence, 50121 Florence, Italy;
| | - Matteo Bozzo
- Department of Earth, Environment and Life Sciences (DISTAV), University of Genoa, 16132 Genoa, Italy; (S.C.); (S.C.); (M.B.); (V.O.); (F.R.); (M.P.)
| | - Valentina Obino
- Department of Earth, Environment and Life Sciences (DISTAV), University of Genoa, 16132 Genoa, Italy; (S.C.); (S.C.); (M.B.); (V.O.); (F.R.); (M.P.)
| | - Michela Ori
- Department of Biology, University of Pisa, 56126 Pisa, Italy; (M.O.); (M.D.S.)
- Inter-University Center for the Promotion of the 3Rs Principles in Teaching & Research (Centro 3R), 56122 Pisa, Italy
| | - Francesca Rosamilia
- Department of Earth, Environment and Life Sciences (DISTAV), University of Genoa, 16132 Genoa, Italy; (S.C.); (S.C.); (M.B.); (V.O.); (F.R.); (M.P.)
| | - Miriam De Sarlo
- Department of Biology, University of Pisa, 56126 Pisa, Italy; (M.O.); (M.D.S.)
| | - Mario Pestarino
- Department of Earth, Environment and Life Sciences (DISTAV), University of Genoa, 16132 Genoa, Italy; (S.C.); (S.C.); (M.B.); (V.O.); (F.R.); (M.P.)
| | - Isabella Ceccherini
- Laboratory of Genetics and Genomics of Rare Diseases, Unità Operativa Semplice Dipartimentale, Istituto Giannina Gaslini, 16147 Genoa, Italy;
| | - Tiziana Bachetti
- Department of Earth, Environment and Life Sciences (DISTAV), University of Genoa, 16132 Genoa, Italy; (S.C.); (S.C.); (M.B.); (V.O.); (F.R.); (M.P.)
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12
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Sjöqvist M, Antfolk D, Suarez-Rodriguez F, Sahlgren C. From structural resilience to cell specification - Intermediate filaments as regulators of cell fate. FASEB J 2020; 35:e21182. [PMID: 33205514 PMCID: PMC7839487 DOI: 10.1096/fj.202001627r] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 10/05/2020] [Accepted: 10/28/2020] [Indexed: 12/18/2022]
Abstract
During the last decades intermediate filaments (IFs) have emerged as important regulators of cellular signaling events, ascribing IFs with functions beyond the structural support they provide. The organ and developmental stage‐specific expression of IFs regulate cell differentiation within developing or remodeling tissues. Lack of IFs causes perturbed stem cell differentiation in vasculature, intestine, nervous system, and mammary gland, in transgenic mouse models. The aberrant cell fate decisions are caused by deregulation of different stem cell signaling pathways, such as Notch, Wnt, YAP/TAZ, and TGFβ. Mutations in genes coding for IFs cause an array of different diseases, many related to stem cell dysfunction, but the molecular mechanisms remain unresolved. Here, we provide a comprehensive overview of how IFs interact with and regulate the activity, localization and function of different signaling proteins in stem cells, and how the assembly state and PTM profile of IFs may affect these processes. Identifying when, where and how IFs and cell signaling congregate, will expand our understanding of IF‐linked stem cell dysfunction during development and disease.
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Affiliation(s)
- Marika Sjöqvist
- Faculty of Science and Engineering, Cell Biology, Åbo Akademi University, Turku, Finland.,Turku Bioscience, Åbo Akademi University and University of Turku, Turku, Finland
| | - Daniel Antfolk
- Faculty of Science and Engineering, Cell Biology, Åbo Akademi University, Turku, Finland.,Turku Bioscience, Åbo Akademi University and University of Turku, Turku, Finland
| | - Freddy Suarez-Rodriguez
- Faculty of Science and Engineering, Cell Biology, Åbo Akademi University, Turku, Finland.,Turku Bioscience, Åbo Akademi University and University of Turku, Turku, Finland
| | - Cecilia Sahlgren
- Faculty of Science and Engineering, Cell Biology, Åbo Akademi University, Turku, Finland.,Turku Bioscience, Åbo Akademi University and University of Turku, Turku, Finland.,Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands
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13
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Fu MH, Chang YY, Lin NH, Yang AW, Chang CC, Liu JS, Peng CH, Wu KLH, Perng MD, Lan MY. Recessively-Inherited Adult-Onset Alexander Disease Caused by a Homozygous Mutation in the GFAP Gene. Mov Disord 2020; 35:1662-1667. [PMID: 32374915 DOI: 10.1002/mds.28099] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 04/01/2020] [Accepted: 04/09/2020] [Indexed: 11/07/2022] Open
Abstract
BACKGROUND Alexander disease (AxD) is an autosomal-dominant leukodystrophy caused by heterozygous mutations in the glial fibrillary acidic protein (GFAP) gene. OBJECTIVES The objective of this report is to characterize the clinical phenotype and identify the genetic mutation associated with adult-onset AxD. METHODS A man presented with progressive unsteadiness since age 16. Magnetic resonance imaging findings revealed characteristic features of AxD. The GFAP gene was screened, and a candidate variant was functionally tested to evaluate causality. RESULTS A homozygous c.197G > A (p.Arg66Gln) mutation was found in the proband, and his asymptomatic parents were heterozygous for the same mutation. This mutation affected GFAP solubility and promoted filament aggregation. The presence of the wild-type protein rescued mutational effects, consistent with the recessive nature of this mutation. CONCLUSIONS This study is the first report of AxD caused by a homozygous mutation in GFAP. The clinical implication is while examining patients with characteristic features on suspicion of AxD, GFAP screening is recommended even without a supportive family history. © 2020 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Mu-Hui Fu
- Department of Neurology, Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Yung-Yee Chang
- Department of Neurology, Chang Gung University College of Medicine, Kaohsiung, Taiwan.,Center for Parkinson's Disease, Kaohsiung Chang Gung Memorial Hospital, and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Ni-Hsuan Lin
- Institute of Molecular Medicine, College of Life Sciences, National Tsing Hua University, Hsinchu, Taiwan
| | - Ai-Wen Yang
- Institute of Molecular Medicine, College of Life Sciences, National Tsing Hua University, Hsinchu, Taiwan.,Department of Medical Science, College of Life Sciences, National Tsing Hua University, Hsinchu, Taiwan
| | - Chiung-Chih Chang
- Department of Neurology, Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Jia-Shou Liu
- Department of Neurology, Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Cheng-Huei Peng
- Department of Neurology, Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Kay L H Wu
- Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan.,Department of Senior Citizen Services, National Tainan Institute of Nursing, Tainan, Taiwan
| | - Ming-Der Perng
- Institute of Molecular Medicine, College of Life Sciences, National Tsing Hua University, Hsinchu, Taiwan.,Department of Medical Science, College of Life Sciences, National Tsing Hua University, Hsinchu, Taiwan
| | - Min-Yu Lan
- Department of Neurology, Chang Gung University College of Medicine, Kaohsiung, Taiwan.,Center for Parkinson's Disease, Kaohsiung Chang Gung Memorial Hospital, and Chang Gung University College of Medicine, Kaohsiung, Taiwan
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14
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New tools for the visualization of glial fibrillary acidic protein in living cells. EXPERIMENTAL RESULTS 2020. [DOI: 10.1017/exp.2020.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
AbstractThe glial fibrillary acidic protein (GFAP) is an intermediate filament widely used to identify and label astroglial cells, a very abundant and relevant glial cell type in the central nervous system. A major hurdle in studying its behavior and function arises from the fact that GFAP does not tolerate well the addition of protein tags to its termini. Here, we tagged human GFAP (hGFAP) with an enhanced green fluorescent protein (EGFP) for the first time, and substituted a previously reported EGFP tag on mouse GFAP (mGFAP) by a more versatile Halo Tag. Both versions of tagged GFAP were able to incorporate into the normal GFAP filamentous network in glioma cells, and Alexander disease-related mutations or pharmacological disruption of microtubules and actin filaments interfered with GFAP dynamics. These new tools could provide new fruitful venues for the study of GFAP oligomerization, aggregation and dynamics in living cells.
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Heaven MR, Wilson L, Barnes S, Brenner M. Relative stabilities of wild-type and mutant glial fibrillary acidic protein in patients with Alexander disease. J Biol Chem 2019; 294:15604-15612. [PMID: 31484723 DOI: 10.1074/jbc.ra119.009777] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 08/24/2019] [Indexed: 01/13/2023] Open
Abstract
Alexander disease (AxD) is an often fatal astrogliopathy caused by dominant gain-of-function missense mutations in the glial fibrillary acidic protein (GFAP) gene. The mechanism by which the mutations produce the AxD phenotype is not known. However, the observation that features of AxD are displayed by mice that express elevated levels of GFAP from a human WT GFAP transgene has contributed to the notion that the mutations produce AxD by increasing accumulation of total GFAP above some toxic threshold rather than the mutant GFAP being inherently toxic. A possible mechanism for accumulation of GFAP in AxD patients is that the mutated GFAP variants are more stable than the WT, an attribution abetted by observations that GFAP complexes containing GFAP variants are more resistant to solvent extraction. Here we tested this hypothesis by determining the relative levels of WT and mutant GFAP in three individuals with AxD, each of whom carried a common but different GFAP mutation (R79C, R239H, or R416W). Mass spectrometry analysis identified a peptide specific to the mutant or WT GFAP in each patient, and we quantified this peptide by comparing its signal to that of an added [15N]GFAP standard. In all three individuals, the level of mutant GFAP was less than that of the WT. This finding suggests that AxD onset is due to an intrinsic toxicity of the mutant GFAP instead of it acting indirectly by being more stable than WT GFAP and thereby increasing the total GFAP level.
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Affiliation(s)
- Michael R Heaven
- Department of Biochemistry and Molecular Genetics, University of Alabama, Birmingham, Alabama 35294
| | - Landon Wilson
- Department of Pharmacology and Toxicology, Targeted Metabolomics and Proteomics Laboratory, University of Alabama, Birmingham, Alabama 35294
| | - Stephen Barnes
- Department of Biochemistry and Molecular Genetics, University of Alabama, Birmingham, Alabama 35294.,Department of Pharmacology and Toxicology, Targeted Metabolomics and Proteomics Laboratory, University of Alabama, Birmingham, Alabama 35294
| | - Michael Brenner
- Department of Neurobiology, University of Alabama, Birmingham, Alabama 35294
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Karp N, Lee D, Shickh S, Jenkins ME. c.1289G>A (p.Arg430His) variant in the epsilon isoform of the GFAP gene in a patient with adult onset Alexander disease. Eur J Med Genet 2018; 62:235-238. [PMID: 30048824 DOI: 10.1016/j.ejmg.2018.07.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 07/07/2018] [Accepted: 07/22/2018] [Indexed: 12/30/2022]
Abstract
Alexander disease (AD) is a rare form of leukodystrophy caused by pathogenic variants in the GFAP gene. In young children the condition is fatal, while adults have variable neurological symptoms and prognosis. On magnetic resonance imaging, a pattern of atrophy of the medulla oblongata and cervical spinal cord with a 'tadpole' appearance is highly suggestive of adult-onset Alexander disease (AOAD). GFAP gene sequencing is used to confirm the diagnosis. Pre-mRNA of this gene undergoes alternative splicing resulting in formation of at least 8 different protein isoforms. Most patients with AD described to date have a pathogenic variant in the coding sequence of the main and the most abundant gene isoform, the GFAPα. Recently, two half-siblings with neurological symptoms and radiological signs of AOAD were reported and were not found to have any pathogenic variants in the GFAPα gene while further genetic testing by next generation sequencing revealed a c.1289G>A (p.Arg430His) variant in the alternative exon 7A of the GFAPε isoform. Here we present a case of another patient with symptoms and brain MRI pattern suggestive of AOAD. Similarly to the previously described patients, this patient did not have any pathogenic variants in the main gene isoform and had the same c.1289G>A (p.Arg430His) variant in the GFAPε. This report contributes to evidence of pathogenicity of the c.1289G>A (p.Arg430His) variant in the GFAPε.
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17
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Perez-Nievas BG, Serrano-Pozo A. Deciphering the Astrocyte Reaction in Alzheimer's Disease. Front Aging Neurosci 2018; 10:114. [PMID: 29922147 PMCID: PMC5996928 DOI: 10.3389/fnagi.2018.00114] [Citation(s) in RCA: 174] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Accepted: 04/03/2018] [Indexed: 12/24/2022] Open
Abstract
Reactive astrocytes were identified as a component of senile amyloid plaques in the cortex of Alzheimer's disease (AD) patients several decades ago. However, their role in AD pathophysiology has remained elusive ever since, in part owing to the extrapolation of the literature from primary astrocyte cultures and acute brain injury models to a chronic neurodegenerative scenario. Recent accumulating evidence supports the idea that reactive astrocytes in AD acquire neurotoxic properties, likely due to both a gain of toxic function and a loss of their neurotrophic effects. However, the diversity and complexity of this glial cell is only beginning to be unveiled, anticipating that astrocyte reaction might be heterogeneous as well. Herein we review the evidence from mouse models of AD and human neuropathological studies and attempt to decipher the main conundrums that astrocytes pose to our understanding of AD development and progression. We discuss the morphological features that characterize astrocyte reaction in the AD brain, the consequences of astrocyte reaction for both astrocyte biology and AD pathological hallmarks, and the molecular pathways that have been implicated in this reaction.
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Affiliation(s)
| | - Alberto Serrano-Pozo
- Alzheimer's Research Unit, MassGeneral Institute for Neurodegenerative Diseases (MIND), Department of Neurology, Massachusetts General Hospital, Boston, MA, United States
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18
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Gómez-Pinedo U, Sirerol-Piquer MS, Durán-Moreno M, García-Verdugo JM, Matias-Guiu J. Alexander Disease Mutations Produce Cells with Coexpression of Glial Fibrillary Acidic Protein and NG2 in Neurosphere Cultures and Inhibit Differentiation into Mature Oligodendrocytes. Front Neurol 2017; 8:255. [PMID: 28634469 PMCID: PMC5459916 DOI: 10.3389/fneur.2017.00255] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 05/22/2017] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Alexander disease (AxD) is a rare disease caused by mutations in the gene encoding glial fibrillary acidic protein (GFAP). The disease is characterized by presence of GFAP aggregates in the cytoplasm of astrocytes and loss of myelin. OBJECTIVES Determine the effect of AxD-related mutations on adult neurogenesis. METHODS We transfected different types of mutant GFAP into neurospheres using the nucleofection technique. RESULTS We find that mutations may cause coexpression of GFAP and NG2 in neurosphere cultures, which would inhibit the differentiation of precursors into oligodendrocytes and thus explain the myelin loss occurring in the disease. Transfection produces cells that differentiate into new cells marked simultaneously by GFAP and NG2 and whose percentage increased over days of differentiation. Increased expression of GFAP is due to a protein with an anomalous structure that forms aggregates throughout the cytoplasm of new cells. These cells display down-expression of vimentin and nestin. Up-expression of cathepsin D and caspase-3 in the first days of differentiation suggest that apoptosis as a lysosomal response may be at work. HSP27, a protein found in Rosenthal bodies, is expressed less at the beginning of the process although its presence increases in later stages. CONCLUSION Our findings seem to suggest that the mechanism of development of AxD may not be due to a function gain due to increase of GFAP, but to failure in the differentiation process may occur at the stage in which precursor cells transform into oligodendrocytes, and that possibility may provide the best explanation for the clinical and radiological images described in AxD.
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Affiliation(s)
- Ulises Gómez-Pinedo
- Neurobiology Laboratory, Neuroscience Institute, IdISSC, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid, Spain
| | - Maria Salomé Sirerol-Piquer
- Laboratory of Comparative Neurobiology, Instituto Cavanilles de Biodiversidad y Biologia Evolutiva, Universidad de Valencia, Valencia, Spain
| | - María Durán-Moreno
- Laboratory of Comparative Neurobiology, Instituto Cavanilles de Biodiversidad y Biologia Evolutiva, Universidad de Valencia, Valencia, Spain
| | - José Manuel García-Verdugo
- Laboratory of Comparative Neurobiology, Instituto Cavanilles de Biodiversidad y Biologia Evolutiva, Universidad de Valencia, Valencia, Spain
| | - Jorge Matias-Guiu
- Neurobiology Laboratory, Neuroscience Institute, IdISSC, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid, Spain
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19
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Moody LR, Barrett-Wilt GA, Sussman MR, Messing A. Glial fibrillary acidic protein exhibits altered turnover kinetics in a mouse model of Alexander disease. J Biol Chem 2017; 292:5814-5824. [PMID: 28223355 DOI: 10.1074/jbc.m116.772020] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 02/15/2017] [Indexed: 12/27/2022] Open
Abstract
Mutations in the astrocyte-specific intermediate filament glial fibrillary acidic protein (GFAP) lead to the rare and fatal disorder, Alexander disease (AxD). A prominent feature of the disease is aberrant accumulation of GFAP. It has been proposed that this accumulation occurs because of an increase in gene transcription coupled with impaired proteasomal degradation, yet this hypothesis remains untested. We therefore sought to directly investigate GFAP turnover in a mouse model of AxD that is heterozygous for a disease-causing point mutation (GfapR236H/+) (and thus expresses both wild-type and mutant protein). Stable isotope labeling by amino acids in cell culture, using primary cortical astrocytes, indicated that the in vitro half-lives of total GFAP in astrocytes from wild-type and mutant mice were similar at ∼3-4 days. Surprisingly, results obtained with stable isotope labeling of mammals revealed that, in vivo, the half-life of GFAP in mutant mice (15.4 ± 0.5 days) was much shorter than that in wild-type mice (27.5 ± 1.6 days). These unexpected in vivo data are most consistent with a model in which synthesis and degradation are both increased. Our work reveals that an AxD-causing mutation alters GFAP turnover kinetics in vivo and provides an essential foundation for future studies aimed at preventing or reducing the accumulation of GFAP. In particular, these data suggest that elimination of GFAP might be possible and occurs more quickly than previously surmised.
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Affiliation(s)
| | | | | | - Albee Messing
- From the Waisman Center, .,Comparative Biosciences, University of Wisconsin-Madison, Madison, Wisconsin 53705
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20
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Lin NH, Huang YS, Opal P, Goldman RD, Messing A, Perng MD. The role of gigaxonin in the degradation of the glial-specific intermediate filament protein GFAP. Mol Biol Cell 2016; 27:3980-3990. [PMID: 27798231 PMCID: PMC5156539 DOI: 10.1091/mbc.e16-06-0362] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 10/03/2016] [Accepted: 10/19/2016] [Indexed: 01/04/2023] Open
Abstract
Alexander disease (AxD) is a primary genetic disorder of astrocytes caused by dominant mutations in the gene encoding the intermediate filament (IF) protein GFAP. This disease is characterized by excessive accumulation of GFAP, known as Rosenthal fibers, within astrocytes. Abnormal GFAP aggregation also occurs in giant axon neuropathy (GAN), which is caused by recessive mutations in the gene encoding gigaxonin. Given that one of the functions of gigaxonin is to facilitate proteasomal degradation of several IF proteins, we sought to determine whether gigaxonin is involved in the degradation of GFAP. Using a lentiviral transduction system, we demonstrated that gigaxonin levels influence the degradation of GFAP in primary astrocytes and in cell lines that express this IF protein. Gigaxonin was similarly involved in the degradation of some but not all AxD-associated GFAP mutants. In addition, gigaxonin directly bound to GFAP, and inhibition of proteasome reversed the clearance of GFAP in cells achieved by overexpressing gigaxonin. These studies identify gigaxonin as an important factor that targets GFAP for degradation through the proteasome pathway. Our findings provide a critical foundation for future studies aimed at reducing or reversing pathological accumulation of GFAP as a potential therapeutic strategy for AxD and related diseases.
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Affiliation(s)
- Ni-Hsuan Lin
- Institute of Molecular Medicine, College of Life Sciences, National Tsing Hua University, Hsinchu 300, Taiwan
| | - Yu-Shan Huang
- Institute of Molecular Medicine, College of Life Sciences, National Tsing Hua University, Hsinchu 300, Taiwan
| | - Puneet Opal
- Davee Department of Neurology, Northwestern University, Chicago, IL 60611.,Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Robert D Goldman
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Albee Messing
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705.,Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI 53705
| | - Ming-Der Perng
- Institute of Molecular Medicine, College of Life Sciences, National Tsing Hua University, Hsinchu 300, Taiwan
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21
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Kondo T, Funayama M, Miyake M, Tsukita K, Era T, Osaka H, Ayaki T, Takahashi R, Inoue H. Modeling Alexander disease with patient iPSCs reveals cellular and molecular pathology of astrocytes. Acta Neuropathol Commun 2016; 4:69. [PMID: 27402089 PMCID: PMC4940830 DOI: 10.1186/s40478-016-0337-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 06/15/2016] [Indexed: 01/28/2023] Open
Abstract
Alexander disease is a fatal neurological illness characterized by white-matter degeneration and formation of Rosenthal fibers, which contain glial fibrillary acidic protein as astrocytic inclusion. Alexander disease is mainly caused by a gene mutation encoding glial fibrillary acidic protein, although the underlying pathomechanism remains unclear. We established induced pluripotent stem cells from Alexander disease patients, and differentiated induced pluripotent stem cells into astrocytes. Alexander disease patient astrocytes exhibited Rosenthal fiber-like structures, a key Alexander disease pathology, and increased inflammatory cytokine release compared to healthy control. These results suggested that Alexander disease astrocytes contribute to leukodystrophy and a variety of symptoms as an inflammatory source in the Alexander disease patient brain. Astrocytes, differentiated from induced pluripotent stem cells of Alexander disease, could be a cellular model for future translational medicine.
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22
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Ikonomov OC, Sbrissa D, Compton LM, Kumar R, Tisdale EJ, Chen X, Shisheva A. The Protein Complex of Neurodegeneration-related Phosphoinositide Phosphatase Sac3 and ArPIKfyve Binds the Lewy Body-associated Synphilin-1, Preventing Its Aggregation. J Biol Chem 2015; 290:28515-28529. [PMID: 26405034 DOI: 10.1074/jbc.m115.669929] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Indexed: 12/14/2022] Open
Abstract
The 5-phosphoinositide phosphatase Sac3, in which loss-of-function mutations are linked to neurodegenerative disorders, forms a stable cytosolic complex with the scaffolding protein ArPIKfyve. The ArPIKfyve-Sac3 heterodimer interacts with the phosphoinositide 5-kinase PIKfyve in a ubiquitous ternary complex that couples PtdIns(3,5)P2 synthesis with turnover at endosomal membranes, thereby regulating the housekeeping endocytic transport in eukaryotes. Neuron-specific associations of the ArPIKfyve-Sac3 heterodimer, which may shed light on the neuropathological mechanisms triggered by Sac3 dysfunction, are unknown. Here we conducted mass spectrometry analysis for brain-derived interactors of ArPIKfyve-Sac3 and unraveled the α-synuclein-interacting protein Synphilin-1 (Sph1) as a new component of the ArPIKfyve-Sac3 complex. Sph1, a predominantly neuronal protein that facilitates aggregation of α-synuclein, is a major component of Lewy body inclusions in neurodegenerative α-synucleinopathies. Modulations in ArPIKfyve/Sac3 protein levels by RNA silencing or overexpression in several mammalian cell lines, including human neuronal SH-SY5Y or primary mouse cortical neurons, revealed that the ArPIKfyve-Sac3 complex specifically altered the aggregation properties of Sph1-GFP. This effect required an active Sac3 phosphatase and proceeded through mechanisms that involved increased Sph1-GFP partitioning into the cytosol and removal of Sph1-GFP aggregates by basal autophagy but not by the proteasomal system. If uncoupled from ArPIKfyve elevation, overexpressed Sac3 readily aggregated, markedly enhancing the aggregation potential of Sph1-GFP. These data identify a novel role of the ArPIKfyve-Sac3 complex in the mechanisms controlling aggregate formation of Sph1 and suggest that Sac3 protein deficiency or overproduction may facilitate aggregation of aggregation-prone proteins, thereby precipitating the onset of multiple neuronal disorders.
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Affiliation(s)
- Ognian C Ikonomov
- Departments of Physiology, Wayne State School of Medicine, Detroit, Michigan 48201
| | - Diego Sbrissa
- Departments of Physiology, Wayne State School of Medicine, Detroit, Michigan 48201
| | - Lauren M Compton
- Departments of Physiology, Wayne State School of Medicine, Detroit, Michigan 48201
| | - Rita Kumar
- Departments of Physiology, Wayne State School of Medicine, Detroit, Michigan 48201; Departments of Emergency Medicine, Wayne State School of Medicine, Detroit, Michigan 48201
| | - Ellen J Tisdale
- Departments of Pharmacology, Wayne State School of Medicine, Detroit, Michigan 48201
| | - Xuequn Chen
- Departments of Physiology, Wayne State School of Medicine, Detroit, Michigan 48201
| | - Assia Shisheva
- Departments of Physiology, Wayne State School of Medicine, Detroit, Michigan 48201.
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Yang E, Prabhu SP. Imaging manifestations of the leukodystrophies, inherited disorders of white matter. Radiol Clin North Am 2014; 52:279-319. [PMID: 24582341 DOI: 10.1016/j.rcl.2013.11.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The leukodystrophies are a diverse set of inherited white matter disorders and are uncommonly encountered by radiologists in everyday practice. As a result, it is challenging to recognize these disorders and to provide a useful differential for the referring physician. In this article, leukodystrophies are reviewed from the perspective of 4 imaging patterns: global myelination delay, periventricular/deep white matter predominant, subcortical white matter predominant, and mixed white/gray matter involvement patterns. Special emphasis is placed on pattern recognition and unusual combinations of findings that may suggest a specific diagnosis.
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Affiliation(s)
- Edward Yang
- Department of Radiology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA.
| | - Sanjay P Prabhu
- Department of Radiology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
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24
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Snider NT, Park H, Omary MB. A conserved rod domain phosphotyrosine that is targeted by the phosphatase PTP1B promotes keratin 8 protein insolubility and filament organization. J Biol Chem 2013; 288:31329-37. [PMID: 24003221 DOI: 10.1074/jbc.m113.502724] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Post-translational modifications are important functional determinants for intermediate filament (IF) proteins. Phosphorylation of IF proteins regulates filament organization, solubility, and cell-protective functions. Most known IF protein phosphorylation sites are serines localized in the variable "head" and "tail" domain regions. By contrast, little is known about site-specific tyrosine phosphorylation or its implications on IF protein function. We used available proteomic data from large scale studies to narrow down potential phospho-tyrosine sites on the simple epithelial IF protein keratin 8 (K8). Validation of the predicted sites using a pan-phosphotyrosine and a site-specific antibody, which we generated, revealed that the highly conserved Tyr-267 in the K8 "rod" domain was basally phosphorylated. The charge at this site was critically important, as demonstrated by altered filament organization of site-directed mutants, Y267F and Y267D, the latter exhibiting significantly diminished solubility. Pharmacological inhibition of the protein-tyrosine phosphatase PTP1B increased K8 Tyr-267 phosphorylation, decreased solubility, and increased K8 filament bundling, whereas PTP1B overexpression had the opposite effects. Furthermore, there was significant co-localization between K8 and a "substrate-trapping" mutant of PTP1B (D181A). Because K8 Tyr-267 is conserved in many IFs (QYE motif), we tested the effect of the paralogous Tyr in glial fibrillary acidic protein (GFAP), which is mutated in Alexander disease (Y242D). Similar to K8, Y242D GFAP exhibited highly irregular filament organization and diminished solubility. Our results implicate the rod domain QYE motif tyrosine as an important determinant of IF assembly and solubility properties that can be dynamically modulated by phosphorylation.
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Affiliation(s)
- Natasha T Snider
- From the Departments of Molecular and Integrative Physiology and
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25
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Effects of a polymorphism in the GFAP promoter on the age of onset and ambulatory disability in late-onset Alexander disease. J Hum Genet 2013; 58:635-8. [PMID: 23903069 DOI: 10.1038/jhg.2013.83] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 06/18/2013] [Accepted: 07/09/2013] [Indexed: 01/01/2023]
Abstract
Alexander disease (AxD) is a rare neurodegenerative disorder. Most patients with AxD have a de novo dominant missense mutation in the glial fibrillary acidic protein (GFAP) gene. Patients with late-onset AxD exhibit a more variable onset and severity than patients with early-onset AxD, suggesting the existence of factors that modify the clinical phenotype of late-onset AxD. A -250-bp C/A single-nucleotide polymorphism (SNP) of the GFAP promoter (rs2070935) in the activator protein-1 binding site is a candidate factor for modification of the clinical phenotype. We analyzed the SNP in 10 patients with late-onset AxD and evaluated the effects of the SNP on the clinical course of late-onset AxD. Three of four cases with the C/C genotype lost the ability to walk in their 30s or 40s, whereas all six cases with the other genotypes retained the ability to walk throughout their 30s. The age of onset in patients with the C/C genotype was significantly earlier than in patients with the other genotypes (P<0.05). A more severe phenotype was observed in the patient in whom the C allele of rs2070935 was in cis with the GFAP mutation compared with the patient in whom the C allele of rs2070935 was in trans with the GFAP mutation. Our investigation revealed the possibility that the C/C genotype at rs2070935 of the GFAP promoter in late-onset AxD was associated with an earlier onset and a more rapid progression of ambulatory disability compared with the other genotypes.
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Clarke JP, Mearow KM. Cell stress promotes the association of phosphorylated HspB1 with F-actin. PLoS One 2013; 8:e68978. [PMID: 23874834 PMCID: PMC3707891 DOI: 10.1371/journal.pone.0068978] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Accepted: 06/10/2013] [Indexed: 01/18/2023] Open
Abstract
Previous studies have suggested that the small heat shock protein, HspB1, has a direct influence on the dynamics of cytoskeletal elements, in particular, filamentous actin (F-actin) polymerization. In this study we have assessed the influence of HspB1 phosphorylation on its interaction(s) with F-actin. We first determined the distribution of endogenous non-phosphorylated HspB1, phosphorylated HspB1 and F-actin in neuroendocrine PC12 cells by immunocytochemistry and confocal microscopy. We then investigated a potential direct interaction between HspB1 with F-actin by precipitating F-actin directly with biotinylated phalloidin followed by Western analyses; the reverse immunoprecipitation of HspB1 was also carried out. The phosphorylation influence of HspB1 in this interaction was investigated by using pharmacologic inhibition of p38 MAPK. In control cells, HspB1 interacts with F-actin as a predominantly non-phosphorylated protein, but subsequent to stress there is a redistribution of HspB1 to the cytoskeletal fraction and a significantly increased association of pHspB1 with F-actin. Our data demonstrate HspB1 is found in a complex with F-actin both in phosphorylated and non-phosphorylated forms, with an increased association of pHspB1 with F-actin after heat stress. Overall, our study combines both cellular and biochemical approaches to show cellular localization and direct demonstration of an interaction between endogenous HspB1 and F-actin using methodolgy that specifically isolates F-actin.
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Affiliation(s)
- Joseph P Clarke
- Division of Biomedical Sciences, Neurosciences Graduate Program, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
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27
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Ramesh K, Sharma S, Kumar A, Salomons GS, van der Knaap MS, Gulati S. Infantile-onset Alexander disease: a genetically proven case with mild clinical course in a 6-year-old Indian boy. J Child Neurol 2013; 28:396-8. [PMID: 22566711 DOI: 10.1177/0883073812444313] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Alexander disease is an autosomal dominant leukoencephalopathy characterized by developmental delay, macrocephaly, and characteristic neuroimaging abnormalities predominantly involving frontal lobes. We report a 6-year-old Indian boy with infantile-onset Alexander disease, who has an unusually mild clinical course and a de novo p.Leu359Val mutation in the glial fibrillary acidic protein gene.
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Affiliation(s)
- Konanki Ramesh
- Department of Pediatrics, Division of Pediatric Neurology, All India Institute of Medical Sciences, New Delhi, India
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28
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Loureiro SO, Heimfarth L, Scherer EB, da Cunha MJ, de Lima BO, Biasibetti H, Pessoa-Pureur R, Wyse AT. Cytoskeleton of cortical astrocytes as a target to proline through oxidative stress mechanisms. Exp Cell Res 2013; 319:89-104. [DOI: 10.1016/j.yexcr.2012.11.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Revised: 10/09/2012] [Accepted: 11/01/2012] [Indexed: 11/28/2022]
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29
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Alexander's disease: reassessment of a neonatal form. Childs Nerv Syst 2012; 28:2029-31. [PMID: 22890470 DOI: 10.1007/s00381-012-1868-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Accepted: 07/17/2012] [Indexed: 10/28/2022]
Abstract
INTRODUCTION Alexander disease is a disorder caused by a mutation and accumulation of the glial fibrillary acidic protein. Currently, three subtypes are acknowledged: an infantile, a juvenile, and an adult form. However, onset early in infancy or in the prenatal period has been shown to present with a uniform pattern of symptoms-suggesting the presence of a distinct neonatal form of the disease. RESULTS AND DISCUSSION Though the neonatal form of Alexander disease is not well acknowledged, a uniform and distinct presentation of the disease in neonates has been observed, suggesting the need for a different course of identification and treatment. Clinical presentation of the neonatal form is distinguished by leukodystrophy and generalized, frequent, and intractable seizures. While the infantile form presents with ataxia, hyperreflexia, and other upper motor neuron symptoms, none of these has been observed in the neonatal form. In the diagnosis of neonatal Alexander disease, it is essential to rule out other causes of leukodystrophy and the presence of neoplasms.
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Bachetti T, Di Zanni E, Balbi P, Ravazzolo R, Sechi G, Ceccherini I. Beneficial effects of curcumin on GFAP filament organization and down-regulation of GFAP expression in an in vitro model of Alexander disease. Exp Cell Res 2012; 318:1844-54. [PMID: 22705585 DOI: 10.1016/j.yexcr.2012.06.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2011] [Revised: 04/19/2012] [Accepted: 06/06/2012] [Indexed: 12/20/2022]
Abstract
Heterozygous mutations of the GFAP gene are responsible for Alexander disease, a neurodegenerative disorder characterized by intracytoplasmic Rosenthal fibers (RFs) in dystrophic astrocytes. In vivo and in vitro models have shown co-localization of mutant GFAP proteins with the small heat shock proteins (sHSPs) HSP27 and alphaB-crystallin, ubiquitin and proteasome components. Results reported by several recent studies agree on ascribing an altered cytoskeletal pattern to mutant GFAP proteins, an effect which induces mutant proteins accumulation, leading to impaired proteasome function and autophagy induction. On the basis of the protective role shown by both these small heat shock proteins (sHSPs), and on the already well established neuroprotective effects of curcumin in several diseases, we have investigated the effects of this compound in an in vitro model of Alexander disease, consisting in U251-MG astrocytoma cells transiently transfected with a construct encoding for GFAP carrying the p.R239C mutation in frame with the reporter green fluorescent protein (GFP). In particular, depending on the dose used, we have observed that curcumin is able to induce both HSP27 and alphaB-crystallin, to reduce expression of both RNA and protein of endogenous GFAP, to induce autophagy and, finally, to rescue the filamentous organization of the GFAP mutant protein, thus suggesting a role of this spice in counteracting the pathogenic effects of GFAP mutations.
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Affiliation(s)
- Tiziana Bachetti
- Laboratorio di Genetica Molecolare, Istituto Giannina Gaslini, Via Gerolamo Gaslini, 5, 16148 Genova, Italy
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31
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Abstract
Diseases of the human brain are almost universally attributed to malfunction or loss of nerve cells. However, a considerable amount of work has, during the last decade, expanded our view on the role of astrocytes in CNS (central nervous system), and this analysis suggests that astrocytes contribute to both initiation and propagation of many (if not all) neurological diseases. Astrocytes provide metabolic and trophic support to neurons and oligodendrocytes. Here, we shall endeavour a broad overviewing of the progress in the field and forward the idea that loss of homoeostatic astroglial function leads to an acute loss of neurons in the setting of acute insults such as ischaemia, whereas more subtle dysfunction of astrocytes over periods of months to years contributes to epilepsy and to progressive loss of neurons in neurodegenerative diseases. The majority of therapeutic drugs currently in clinical use target neuronal receptors, channels or transporters. Future therapeutic efforts may benefit by a stronger focus on the supportive homoeostatic functions of astrocytes.
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Yoshida T, Nakagawa M. Clinical aspects and pathology of Alexander disease, and morphological and functional alteration of astrocytes induced by GFAP mutation. Neuropathology 2011; 32:440-6. [DOI: 10.1111/j.1440-1789.2011.01268.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Chen YS, Lim SC, Chen MH, Quinlan RA, Perng MD. Alexander disease causing mutations in the C-terminal domain of GFAP are deleterious both to assembly and network formation with the potential to both activate caspase 3 and decrease cell viability. Exp Cell Res 2011; 317:2252-66. [PMID: 21756903 DOI: 10.1016/j.yexcr.2011.06.017] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Revised: 06/23/2011] [Accepted: 06/27/2011] [Indexed: 12/12/2022]
Abstract
Alexander disease is a primary genetic disorder of astrocyte caused by dominant mutations in the astrocyte-specific intermediate filament glial fibrillary acidic protein (GFAP). While most of the disease-causing mutations described to date have been found in the conserved α-helical rod domain, some mutations are found in the C-terminal non-α-helical tail domain. Here, we compare five different mutations (N386I, S393I, S398F, S398Y and D417M14X) located in the C-terminal domain of GFAP on filament assembly properties in vitro and in transiently transfected cultured cells. All the mutations disrupted in vitro filament assembly. The mutations also affected the solubility and promoted filament aggregation of GFAP in transiently transfected MCF7, SW13 and U343MG cells. This correlated with the activation of the p38 stress-activated protein kinase and an increased association with the small heat shock protein (sHSP) chaperone, αB-crystallin. Of the mutants studied, D417M14X GFAP caused the most significant effects both upon filament assembly in vitro and in transiently transfected cells. This mutant also caused extensive filament aggregation coinciding with the sequestration of αB-crystallin and HSP27 as well as inhibition of the proteosome and activation of p38 kinase. Associated with these changes were an activation of caspase 3 and a significant decrease in astrocyte viability. We conclude that some mutations in the C-terminus of GFAP correlate with caspase 3 cleavage and the loss of cell viability, suggesting that these could be contributory factors in the development of Alexander disease.
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Affiliation(s)
- Yi-Song Chen
- Institute of Molecular Medicine, College of Life Sciences, National Tsing Hua University, Hsinchu 300, Taiwan
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34
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In vitro treatments with ceftriaxone promote elimination of mutant glial fibrillary acidic protein and transcription down-regulation. Exp Cell Res 2010; 316:2152-65. [DOI: 10.1016/j.yexcr.2010.05.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Revised: 05/02/2010] [Accepted: 05/06/2010] [Indexed: 01/08/2023]
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35
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Alexander disease mutant glial fibrillary acidic protein compromises glutamate transport in astrocytes. J Neuropathol Exp Neurol 2010; 69:335-45. [PMID: 20448479 DOI: 10.1097/nen.0b013e3181d3cb52] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Alexander disease (AxD) is a leukodystrophy caused by heterozygous mutations in the gene for glial fibrillary acidic protein, an intermediate filament protein expressed by astrocytes. The mutation causes prominent protein aggregates inside astrocytes; there is also loss of myelin and oligodendrocytes and neuronal degeneration. We show that immunohistochemical staining for glutamate transporter 1, the major brain glutamate transporter expressed primarily in astrocytes suggests decreased levels in the hippocampi of infantile AxD patients. A knock-in mouse model of AxD also shows significant reduction of glutamate transporter 1 in the hippocampus. To explore this phenomenon at the cellular level, wild-type and R239C mutant glial fibrillary acidic proteins (the most common mutation) were overexpressed in astrocytes in culture. Western blotting and whole-cell patch clamp recordings demonstrated that the R239C astrocytes exhibited markedly reduced glutamate transporter 1 protein levels; this resulted in attenuated or abolished glutamate-induced inward transporter current. Neurons cocultured with the R239C astrocytes exhibited increased death after glutamate challenge. These results indicate that aberrant astrocytes have decreased glutamate uptake, which may play an important role in the pathogenesis of neuronal and oligodendrocyte injury and death in AxD.
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36
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Tang G, Perng MD, Wilk S, Quinlan R, Goldman JE. Oligomers of mutant glial fibrillary acidic protein (GFAP) Inhibit the proteasome system in alexander disease astrocytes, and the small heat shock protein alphaB-crystallin reverses the inhibition. J Biol Chem 2010; 285:10527-37. [PMID: 20110364 PMCID: PMC2856260 DOI: 10.1074/jbc.m109.067975] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Revised: 01/19/2010] [Indexed: 11/06/2022] Open
Abstract
The accumulation of the intermediate filament protein, glial fibrillary acidic protein (GFAP), in astrocytes of Alexander disease (AxD) impairs proteasome function in astrocytes. We have explored the molecular mechanism that underlies the proteasome inhibition. We find that both assembled and unassembled wild type (wt) and R239C mutant GFAP protein interacts with the 20 S proteasome complex and that the R239C AxD mutation does not interfere with this interaction. However, the R239C GFAP accumulates to higher levels and forms more protein aggregates than wt protein. These aggregates bind components of the ubiquitin-proteasome system and, thus, may deplete the cytosolic stores of these proteins. We also find that the R239C GFAP has a greater inhibitory effect on proteasome system than wt GFAP. Using a ubiquitin-independent degradation assay in vitro, we observed that the proteasome cannot efficiently degrade unassembled R239C GFAP, and the interaction of R239C GFAP with proteasomes actually inhibits proteasomal protease activity. The small heat shock protein, alphaB-crystallin, which accumulates massively in AxD astrocytes, reverses the inhibitory effects of R239C GFAP on proteasome activity and promotes degradation of the mutant GFAP, apparently by shifting the size of the mutant protein from larger oligomers to smaller oligomers and monomers. These observations suggest that oligomeric forms of GFAP are particularly effective at inhibiting proteasome activity.
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Affiliation(s)
- Guomei Tang
- From the Department of Pathology and Cell Biology, Columbia University, New York, New York 10032
| | - Ming D. Perng
- the School of Biological and Medical Science, University of Durham, Durham DH1 3LE, United Kingdom, and
| | - Sherwin Wilk
- the Department of Pharmacology and Biological Chemistry, Mount Sinai School of Medicine, New York, New York 10029
| | - Roy Quinlan
- the School of Biological and Medical Science, University of Durham, Durham DH1 3LE, United Kingdom, and
| | - James E. Goldman
- From the Department of Pathology and Cell Biology, Columbia University, New York, New York 10032
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37
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Liem RKH, Messing A. Dysfunctions of neuronal and glial intermediate filaments in disease. J Clin Invest 2009; 119:1814-24. [PMID: 19587456 DOI: 10.1172/jci38003] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Intermediate filaments (IFs) are abundant structures found in most eukaryotic cells, including those in the nervous system. In the CNS, the primary components of neuronal IFs are alpha-internexin and the neurofilament triplet proteins. In the peripheral nervous system, a fifth neuronal IF protein known as peripherin is also present. IFs in astrocytes are primarily composed of glial fibrillary acidic protein (GFAP), although vimentin is also expressed in immature astrocytes and some mature astrocytes. In this Review, we focus on the IFs of glial cells (primarily GFAP) and neurons as well as their relationship to different neurodegenerative diseases.
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Affiliation(s)
- Ronald K H Liem
- Department of Pathology and Cell Biology, Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University College of Physicians and Surgeons, New York, NY, USA.
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The process of inducing GFAP aggregates in astrocytoma-derived cells is different between R239C and R416W mutant GFAP. A time-lapse recording study. Neurosci Lett 2009; 458:11-4. [DOI: 10.1016/j.neulet.2009.04.032] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Revised: 02/20/2009] [Accepted: 04/08/2009] [Indexed: 11/20/2022]
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Hagemann TL, Boelens WC, Wawrousek EF, Messing A. Suppression of GFAP toxicity by alphaB-crystallin in mouse models of Alexander disease. Hum Mol Genet 2009; 18:1190-9. [PMID: 19129171 DOI: 10.1093/hmg/ddp013] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Alexander disease (AxD) is a primary disorder of astrocytes caused by dominant mutations in the gene for glial fibrillary acidic protein (GFAP). These mutations lead to protein aggregation and formation of Rosenthal fibers, complex astrocytic inclusions that contain GFAP, vimentin, plectin, ubiquitin, Hsp27 and alphaB-crystallin. The small heat shock protein alphaB-crystallin (Cryab) regulates GFAP assembly, and elevation of Cryab is a consistent feature of AxD; however, its role in Rosenthal fibers and AxD pathology is not known. Here, we show in AxD mouse models that loss of Cryab results in increased mortality, whereas elevation of Cryab rescues animals from terminal seizures. When mice with Rosenthal fibers induced by over-expression of GFAP are crossed into a Cryab-null background, over half die at 1 month of age. Restoration of Cryab expression through the GFAP promoter reverses this outcome, showing the effect is astrocyte-specific. Conversely, in mice engineered to express both AxD-associated mutations and elevated GFAP, which despite natural induction of Cryab also die at 1 month, transgenic over-expression of Cryab results in a markedly reduced CNS stress response, restores expression of the glutamate transporter Glt1 (EAAT2) and protects these animals from death. In its most common form, AxD is a devastating neurodegenerative disease, with early onset, characterized by seizures, spasticity and developmental delays, ultimately leading to death. Cryab plays a critical role in tempering AxD pathology and should be investigated as a therapeutic target for this and other diseases with astropathology.
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Affiliation(s)
- Tracy L Hagemann
- Waisman Center, University of Wisconsin, Madison, WI 53705, USA.
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40
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Cho W, Messing A. Properties of astrocytes cultured from GFAP over-expressing and GFAP mutant mice. Exp Cell Res 2008; 315:1260-72. [PMID: 19146851 DOI: 10.1016/j.yexcr.2008.12.012] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2008] [Revised: 12/12/2008] [Accepted: 12/14/2008] [Indexed: 11/29/2022]
Abstract
Alexander disease is a fatal leukoencephalopathy caused by dominantly-acting coding mutations in GFAP. Previous work has also implicated elevations in absolute levels of GFAP as central to the pathogenesis of the disease. However, identification of the critical astrocyte functions that are compromised by mis-expression of GFAP has not yet been possible. To provide new tools for investigating the nature of astrocyte dysfunction in Alexander disease, we have established primary astrocyte cultures from two mouse models of Alexander disease, a transgenic that over-expresses wild type human GFAP, and a knock-in at the endogenous mouse locus that mimics a common Alexander disease mutation. We find that mutant GFAP, as well as excess wild type GFAP, promotes formation of cytoplasmic inclusions, disrupts the cytoskeleton, decreases cell proliferation, increases cell death, reduces proteasomal function, and compromises astrocyte resistance to stress.
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Affiliation(s)
- Woosung Cho
- Waisman Center, Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI 53705, USA
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Tang G, Yue Z, Talloczy Z, Hagemann T, Cho W, Messing A, Sulzer DL, Goldman JE. Autophagy induced by Alexander disease-mutant GFAP accumulation is regulated by p38/MAPK and mTOR signaling pathways. Hum Mol Genet 2008; 17:1540-55. [PMID: 18276609 DOI: 10.1093/hmg/ddn042] [Citation(s) in RCA: 136] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Glial fibrillary acidic protein (GFAP) is the principle intermediate filament (IF) protein in astrocytes. Mutations in the GFAP gene lead to Alexander disease (AxD), a rare, fatal neurological disorder characterized by the presence of abnormal astrocytes that contain GFAP protein aggregates, termed Rosenthal fibers (RFs), and the loss of myelin. All GFAP mutations cause the same histopathological defect, i.e. RFs, though little is known how the mutations affect protein accumulation as well as astrocyte function. In this study, we found that GFAP accumulation induces macroautophagy, a key clearance mechanism for prevention of aggregated proteins. This autophagic response is negatively regulated by mammalian target of rapamycin (mTOR). The activation of p38 MAPK by GFAP accumulation is in part responsible for the down-regulation of phosphorylated-mTOR and the subsequent activation of autophagy. Our study suggests that AxD mutant GFAP accumulation stimulates autophagy, in a manner regulated by p38 MAPK and mTOR signaling pathways. Autophagy, in turn, serves as a mechanism to reduce GFAP levels.
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Affiliation(s)
- Guomei Tang
- Department of Pathology, Center for Neurobiology and Behavior, Center for Parkinson's Disease and Other Movement Disorders, Columbia University, New York, NY 10032, USA
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42
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Intermediate filament assembly: dynamics to disease. Trends Cell Biol 2008; 18:28-37. [PMID: 18083519 DOI: 10.1016/j.tcb.2007.11.004] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2007] [Revised: 10/31/2007] [Accepted: 11/01/2007] [Indexed: 11/21/2022]
Abstract
Intermediate filament (IF) proteins belong to a large and diverse gene family with broad representation in vertebrate tissues. Although considered the 'toughest' cytoskeletal fibers, studies in cultured cells have revealed that IF can be surprisingly dynamic and highly regulated. This review examines the diversity of IF assembly behaviors, and considers the ideas that IF proteins are co- or post-translationally assembled into oligomeric precursors, which can be delivered to different subcellular compartments by microtubules or actomyosin and associated motor proteins. Their interaction with other cellular elements via IF associated proteins (IFAPs) affects IF dynamics and also results in cellular networks with properties that transcend those of individual components. We end by discussing how mutations leading to defects in IF assembly, network formation or IF-IFAP association compromise in vivo functions of IF as protectors against environmental stress.
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Kinjo S, Yokoo H, Hirato J, Nakazato Y. Anaplastic astrocytoma with eosinophilic granular cells. Neuropathology 2008; 27:457-62. [PMID: 18018480 DOI: 10.1111/j.1440-1789.2007.00795.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A 68-year-old man, who had no remarkable past medical history, was referred to a hospital because of disorientation and right-sided hemiparesis. On magnetic resonance imaging, a contrast-enhanced tumor in the left frontal lobe with perifocal edema was noted. He underwent left frontal lobectomy. Microscopic examination revealed infiltrative atypical astrocytes showing increased cellularity, distinct nuclear atypia, and many mitotic figures, while microvascular proliferation and necrosis were absent. Thus, the tumor was histologically diagnosed as anaplastic astrocytoma. It was of note that cytoplasmic eosinophilic granules were observed in approximately 25% of neoplastic cells. The granules were positively immunostained with anti-alphaB-crystallin antibody, and the other histochemical and immunohistochemical results also corresponded to Rosenthal fibers. The MIB-1 labeling index of the highest area of the tumor was 22%, while that of granular cells was 2.1%. An ultrastructural study revealed amorphous electron-dense structures attached to intermediate filament bundles, compatible with Rosenthal fibers. Such structures are relatively common in oligodendroglial tumors; however, they are extremely rare in astrocytic tumors. Fluorescence in situ hybridization targeted against chromosome 1 failed to demonstrate allelic loss of the short arm. The present case should also be discriminated from granular cell astrocytoma. We review related literature and discuss the significance of granules in gliomas.
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Affiliation(s)
- Sawako Kinjo
- Department of Human Pathology, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan.
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Bachetti T, Caroli F, Bocca P, Prigione I, Balbi P, Biancheri R, Filocamo M, Mariotti C, Pareyson D, Ravazzolo R, Ceccherini I. Mild functional effects of a novel GFAP mutant allele identified in a familial case of adult-onset Alexander disease. Eur J Hum Genet 2008; 16:462-70. [DOI: 10.1038/sj.ejhg.5201995] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Murakami N, Tsuchiya T, Kanazawa N, Tsujino S, Nagai T. Novel deletion mutation in GFAP gene in an infantile form of Alexander disease. Pediatr Neurol 2008; 38:50-2. [PMID: 18054694 DOI: 10.1016/j.pediatrneurol.2007.08.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2007] [Revised: 06/15/2007] [Accepted: 08/27/2007] [Indexed: 11/19/2022]
Abstract
Alexander disease is a rare, fatal neurologic disorder characterized by white-matter degeneration and cytoplasmic inclusions in astrocytes known as Rosenthal fibers, which are immunohistochemically positive to glial fibrillary acidic protein. Mutations in the glial fibrillary acidic protein gene were reported in patients with Alexander disease who had clinical and pathologic characteristics of the disease. All reported cases manifest heterozygous missense mutations, except for some insertions or deletions with no frame shift. Our patient had a heterozygous deletion of genomic sequence 1247-1249GGG>GG in exon 8 of the glial fibrillary acidic protein gene, which leads to a frame shift changing 16 amino acids and inducing a stop codon at codon 431 of 432 codons. The deletion mutation induces a structural conformation change in glial fibrillary acidic protein and their abnormal aggregation in astrocytes. This is the first report of a novel deletion mutation in the glial fibrillary acidic protein gene with a frame shift associated with Alexander disease.
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Affiliation(s)
- Nobuyuki Murakami
- Department of Pediatrics, Dokkyo Medical University, Koshigaya Hospital, Koshigaya, Saitama, Japan.
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Adult-onset Alexander disease. J Neurol 2007; 255:24-30. [DOI: 10.1007/s00415-007-0654-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2007] [Revised: 04/14/2007] [Accepted: 05/04/2007] [Indexed: 10/22/2022]
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Katz ML, Sanders DN, Mooney BP, Johnson GS. Accumulation of glial fibrillary acidic protein and histone H4 in brain storage bodies of Tibetan terriers with hereditary neuronal ceroid lipofuscinosis. J Inherit Metab Dis 2007; 30:952-63. [PMID: 18004671 DOI: 10.1007/s10545-007-0683-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2007] [Revised: 09/20/2007] [Accepted: 10/04/2007] [Indexed: 11/26/2022]
Abstract
The neuronal ceroid lipofuscinoses (NCLs) are inherited neurodegenerative diseases characterized by massive accumulation of autofluorescent storage bodies in neurons and other cells. A late-onset form of NCL occurs in Tibetan terrier dogs. Gel electrophoretic analyses of isolated storage body proteins from brains of affected dogs indicated that a protein of approximately 50 kDa was consistently prominent and a 16 kDa component was present in some brain storage body preparations. Mass spectral analysis identified the 50 kDa protein as glial fibrillary acidic protein (GFAP), isoform 2. GFAP identification was supported by immunoblot and immunohistochemical analyses. Histone H4 was the major protein in the 16 kDa component. Specific accumulation of GFAP and histone H4 in storage bodies has not been previously reported for any of the NCLs. Tibetan terrier NCL may be the canine correlate of one of the human adult-onset NCLs for which the genetic bases and storage body compositions have not yet been determined.
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Affiliation(s)
- M L Katz
- Mason Eye Institute, University of Missouri School of Medicine, One Hospital Dr., Columbia, MO 65212, USA.
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Zhai J, Lin H, Julien JP, Schlaepfer WW. Disruption of neurofilament network with aggregation of light neurofilament protein: a common pathway leading to motor neuron degeneration due to Charcot-Marie-Tooth disease-linked mutations in NFL and HSPB1. Hum Mol Genet 2007; 16:3103-16. [PMID: 17881652 DOI: 10.1093/hmg/ddm272] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Mutations in neurofilament light (NFL) subunit and small heat-shock protein B1 (HSPB1) cause autosomal-dominant axonal Charcot-Marie-Tooth disease type 2E (CMT2E) and type 2F (CMT2F). Previous studies have shown that CMT mutations in NFL and HSPB1 disrupt NF assembly and cause aggregation of NFL protein. In this study, we investigate the role of aggregation of NFL protein in the neurotoxicity of CMT mutant NFL and CMT mutant HSPB1 in motor neurons. We find that expression of CMT mutant NFL leads to progressive degeneration and loss of neuronal viability of cultured motor neurons. Degenerating motor neurons show fragmentation and loss of neuritic processes associated with disruption of NF network and aggregation of NFL protein. Co-expression of wild-type HSPB1 diminishes aggregation of CMT mutant NFL, induces reversal of CMT mutant NFL aggregates and reduces CMT mutant NFL-induced loss of motor neuron viability. Like CMT mutant NFL, expression of S135F CMT mutant HSPB1 also leads to progressive degeneration of motor neurons with disruption of NF network and aggregation of NFL protein. Further studies show that wild-type and S135F mutant HSPB1 associate with wild-type and CMT mutant NFL and that S135F mutant HSPB1 has dominant effect on disruption of NF assembly and aggregation of NFL protein. Finally, we show that deletion of NFL markedly reduces degeneration and loss of motor neuron viability induced by S135F mutant HSPB1. Together, our data support the view that disruption of NF network with aggregation of NFL is a common triggering event of motor neuron degeneration in CMT2E and CMT2F disease.
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Affiliation(s)
- Jinbin Zhai
- Division of Neuropathology, Department of Pathology and Laboratory Medicine, School of Medicine, University of Pennsylvania, Philadelphia, PA 19104,-6100, USA.
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Sakakibara T, Takahashi Y, Fukuda K, Inoue T, Kurosawa T, Nishikubo T, Shima M, Taoka T, Aida N, Tsujino S, Kanazawa N, Yoshioka A. A case of infantile Alexander disease diagnosed by magnetic resonance imaging and genetic analysis. Brain Dev 2007; 29:525-8. [PMID: 17383133 DOI: 10.1016/j.braindev.2007.02.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2006] [Revised: 01/25/2007] [Accepted: 02/03/2007] [Indexed: 10/23/2022]
Abstract
We encountered a male infant with infantile Alexander disease presenting with megalencephaly and hydrocephalus as a neonate and subtle seizures at 3 months of age. At 6 months of age, bulbar paralysis appeared. Brain magnetic resonance imaging (MRI) showed abnormal findings with white matter involvement and a characteristic periventricular rim, satisfying the diagnostic criteria proposed by van der Knaap, except for MRI contrast. R239H mutation of glial fibrillary acidic protein gene was identified, representing a common cause of infantile-type Alexander disease.
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Carmen J, Magnus T, Cassiani-Ingoni R, Sherman L, Rao MS, Mattson MP. Revisiting the astrocyte–oligodendrocyte relationship in the adult CNS. Prog Neurobiol 2007; 82:151-62. [PMID: 17448587 DOI: 10.1016/j.pneurobio.2007.03.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2006] [Revised: 01/26/2007] [Accepted: 03/02/2007] [Indexed: 01/31/2023]
Abstract
The lineages of both astrocytes and oligodendrocytes have been popular areas of research in the last decade. The source of these cells in the mature CNS is relevant to the study of the cellular response to CNS injury. A significant amount of evidence exists to suggest that resident precursor cells proliferate and differentiate into mature glial cells that facilitate tissue repair and recovery. Additionally, the re-entry of mature astrocytes into the cell cycle can also contribute to the pool of new astrocytes that are observed following CNS injury. In order to better understand the glial response to injury in the adult CNS we must revisit the astrocyte-oligodendrocyte relationship. Specifically, we argue that there is a common glial precursor cell from which astrocytes and oligodendrocytes differentiate and that the microenvironment surrounding the injury determines the fate of the stimulated precursor cell. Ideally, better understanding the origin of new glial cells in the injured CNS will facilitate the development of therapeutics targeted to alter the glial response in a beneficial way.
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Affiliation(s)
- Jessica Carmen
- Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, NIH, Baltimore, MD 21224, USA.
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