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Pereira Sena P, Weber JJ, Bayezit S, Saup R, Incebacak Eltemur RD, Li X, Velic A, Jung J, Macek B, Nguyen HP, Riess O, Schmidt T. Implications of specific lysine residues within ataxin-3 for the molecular pathogenesis of Machado-Joseph disease. Front Mol Neurosci 2023; 16:1133271. [PMID: 37273907 PMCID: PMC10235640 DOI: 10.3389/fnmol.2023.1133271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 05/03/2023] [Indexed: 06/06/2023] Open
Abstract
Lysine residues are one of the main sites for posttranslational modifications of proteins, and lysine ubiquitination of the Machado-Joseph disease protein ataxin-3 is implicated in its cellular function and polyglutamine expansion-dependent toxicity. Despite previously undertaken efforts, the individual roles of specific lysine residues of the ataxin-3 sequence are not entirely understood and demand further analysis. By retaining single lysine residues of otherwise lysine-free wild-type and polyglutamine-expanded ataxin-3, we assessed the effects of a site-limited modifiability on ataxin-3 protein levels, aggregation propensity, localization, and stability. We confirmed earlier findings that levels of lysine-free ataxin-3 are reduced due to its decreased stability, which led to a diminished load of SDS-insoluble species of its polyglutamine-expanded form. The isolated presence of several single lysine residues within the N-terminus of polyglutamine-expanded ataxin-3 significantly restored its aggregate levels, with highest fold changes induced by the presence of lysine 8 or lysine 85, respectively. Ataxin-3 lacking all lysine residues presented a slightly increased nuclear localization, which was counteracted by the reintroduction of lysine 85, whereas presence of either lysine 8 or lysine 85 led to a significantly higher ataxin-3 stability. Moreover, lysine-free ataxin-3 showed increased toxicity and binding to K48-linked polyubiquitin chains, whereas the reintroduction of lysine 85, located between the ubiquitin-binding sites 1 and 2 of ataxin-3, normalized its binding affinity. Overall, our data highlight the relevance of lysine residues 8 and 85 of ataxin-3 and encourage further analyses, to evaluate the potential of modulating posttranslational modifications of these sites for influencing pathophysiological characteristics of the Machado-Joseph disease protein.
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Affiliation(s)
- Priscila Pereira Sena
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Jonasz Jeremiasz Weber
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
- Department of Human Genetics, Ruhr University Bochum, Bochum, Germany
| | - Sercan Bayezit
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Rafael Saup
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Rana Dilara Incebacak Eltemur
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
- Department of Human Genetics, Ruhr University Bochum, Bochum, Germany
| | - Xiaoling Li
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Ana Velic
- Proteome Center Tübingen, University of Tübingen, Tübingen, Germany
| | - Jaqueline Jung
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Boris Macek
- Proteome Center Tübingen, University of Tübingen, Tübingen, Germany
| | - Huu Phuc Nguyen
- Department of Human Genetics, Ruhr University Bochum, Bochum, Germany
| | - Olaf Riess
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Thorsten Schmidt
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
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2
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Incebacak Eltemur RD, Nguyen HP, Weber JJ. Calpain-mediated proteolysis as driver and modulator of polyglutamine toxicity. Front Mol Neurosci 2022; 15:1020104. [PMID: 36385755 PMCID: PMC9648470 DOI: 10.3389/fnmol.2022.1020104] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 09/26/2022] [Indexed: 09/22/2023] Open
Abstract
Among posttranslational modifications, directed proteolytic processes have the strongest impact on protein integrity. They are executed by a variety of cellular machineries and lead to a wide range of molecular consequences. Compared to other forms of proteolytic enzymes, the class of calcium-activated calpains is considered as modulator proteases due to their limited proteolytic activity, which changes the structure and function of their target substrates. In the context of neurodegeneration and - in particular - polyglutamine disorders, proteolytic events have been linked to modulatory effects on the molecular pathogenesis by generating harmful breakdown products of disease proteins. These findings led to the formulation of the toxic fragment hypothesis, and calpains appeared to be one of the key players and auspicious therapeutic targets in Huntington disease and Machado Joseph disease. This review provides a current survey of the role of calpains in proteolytic processes found in polyglutamine disorders. Together with insights into general concepts behind toxic fragments and findings in polyglutamine disorders, this work aims to inspire researchers to broaden and deepen the knowledge in this field, which will help to evaluate calpain-mediated proteolysis as a unifying and therapeutically targetable posttranslational mechanism in neurodegeneration.
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Affiliation(s)
- Rana Dilara Incebacak Eltemur
- Department of Human Genetics, Ruhr University Bochum, Bochum, Germany
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Huu Phuc Nguyen
- Department of Human Genetics, Ruhr University Bochum, Bochum, Germany
| | - Jonasz Jeremiasz Weber
- Department of Human Genetics, Ruhr University Bochum, Bochum, Germany
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
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3
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Abstract
The thick mucus layer covering of the intestinal epithelium has received increasing attention, owing to its protective role in intestinal infection. However, the exact mechanisms by which the mucus increases intestinal resistance against viral infection remain largely unclear. Here, we identify prominent antiviral activity of the small intestinal mucus and extracted total mucus proteins, as evidenced by their inhibitory effects against porcine epidemic diarrhea virus (PEDV) infection. Of all the extracted mucus proteins, mucin 2 and fraction III (~70 kDa) exhibited potent antiviral activity. We further evaluated the antiviral effects of three candidate factors in fraction III and found that calpain-1 contributed substantially to its antiviral activity. In vivo studies demonstrated that oral administration of calpain-1 provided effective protection against intestinal PEDV infection. As a calcium-activated cysteine protease, calpain-1 inhibited viral invasion by binding to and hydrolyzing the S1 domain of the viral spike protein. The region between amino acids 297 and 337 in the b domain of PEDV S1 protein was critical for calpain-1-mediated hydrolysis. Further investigation indicated that calpain-1 could be produced by goblet cells between intestinal epithelia. Taken together, the results of our study revealed calpain-1 to be a novel antiviral protein in porcine small intestinal mucus, suggesting that calpain-1 has potential for defending against intestinal infections.
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4
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KPNB1 modulates the Machado-Joseph disease protein ataxin-3 through activation of the mitochondrial protease CLPP. Cell Mol Life Sci 2022; 79:401. [PMID: 35794401 PMCID: PMC9259533 DOI: 10.1007/s00018-022-04372-5] [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: 12/20/2021] [Revised: 04/25/2022] [Accepted: 05/11/2022] [Indexed: 11/17/2022]
Abstract
Machado–Joseph disease (MJD) is characterized by a pathological expansion of the polyglutamine (polyQ) tract within the ataxin-3 protein. Despite its primarily cytoplasmic localization, polyQ-expanded ataxin-3 accumulates in the nucleus and forms intranuclear aggregates in the affected neurons. Due to these histopathological hallmarks, the nucleocytoplasmic transport machinery has garnered attention as an important disease relevant mechanism. Here, we report on MJD cell model-based analysis of the nuclear transport receptor karyopherin subunit beta-1 (KPNB1) and its implications in the molecular pathogenesis of MJD. Although directly interacting with both wild-type and polyQ-expanded ataxin-3, modulating KPNB1 did not alter the intracellular localization of ataxin-3. Instead, overexpression of KPNB1 reduced ataxin-3 protein levels and the aggregate load, thereby improving cell viability. On the other hand, its knockdown and inhibition resulted in the accumulation of soluble and insoluble ataxin-3. Interestingly, the reduction of ataxin-3 was apparently based on protein fragmentation independent of the classical MJD-associated proteolytic pathways. Label-free quantitative proteomics and knockdown experiments identified mitochondrial protease CLPP as a potential mediator of the ataxin-3-degrading effect induced by KPNB1. We confirmed reduction of KPNB1 protein levels in MJD by analyzing two MJD transgenic mouse models and induced pluripotent stem cells (iPSCs) derived from MJD patients. Our results reveal a yet undescribed regulatory function of KPNB1 in controlling the turnover of ataxin-3, thereby highlighting a new potential target of therapeutic value for MJD.
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Mitochondrial Dysfunction in Spinocerebellar Ataxia Type 3 Is Linked to VDAC1 Deubiquitination. Int J Mol Sci 2022; 23:ijms23115933. [PMID: 35682609 PMCID: PMC9180688 DOI: 10.3390/ijms23115933] [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: 03/30/2022] [Revised: 05/06/2022] [Accepted: 05/23/2022] [Indexed: 01/01/2023] Open
Abstract
Dysfunctional mitochondria are linked to several neurodegenerative diseases. Metabolic defects, a symptom which can result from dysfunctional mitochondria, are also present in spinocerebellar ataxia type 3 (SCA3), also known as Machado–Joseph disease, the most frequent, dominantly inherited neurodegenerative ataxia worldwide. Mitochondrial dysfunction has been reported for several neurodegenerative disorders and ataxin-3 is known to deubiquitinylate parkin, a key protein required for canonical mitophagy. In this study, we analyzed mitochondrial function and mitophagy in a patient-derived SCA3 cell model. Human fibroblast lines isolated from SCA3 patients were immortalized and characterized. SCA3 patient fibroblasts revealed circular, ring-shaped mitochondria and featured reduced OXPHOS complexes, ATP production and cell viability. We show that wildtype ataxin-3 deubiquitinates VDAC1 (voltage-dependent anion channel 1), a member of the mitochondrial permeability transition pore and a parkin substrate. In SCA3 patients, VDAC1 deubiquitination and parkin recruitment to the depolarized mitochondria is inhibited. Increased p62-linked mitophagy, autophagosome formation and autophagy is observed under disease conditions, which is in line with mitochondrial fission. SCA3 fibroblast lines demonstrated a mitochondrial phenotype and dysregulation of parkin-VDAC1-mediated mitophagy, thereby promoting mitochondrial quality control via alternative pathways.
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Weber JJ, Anger SC, Pereira Sena P, Incebacak Eltemur RD, Huridou C, Fath F, Gross C, Casadei N, Riess O, Nguyen HP. Calpains as novel players in the molecular pathogenesis of spinocerebellar ataxia type 17. Cell Mol Life Sci 2022; 79:262. [PMID: 35482253 PMCID: PMC9050766 DOI: 10.1007/s00018-022-04274-6] [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: 08/09/2021] [Revised: 03/07/2022] [Accepted: 03/25/2022] [Indexed: 11/23/2022]
Abstract
Spinocerebellar ataxia type 17 (SCA17) is a neurodegenerative disease caused by a polyglutamine-encoding trinucleotide repeat expansion in the gene of transcription factor TATA box-binding protein (TBP). While its underlying pathomechanism is elusive, polyglutamine-expanded TBP fragments of unknown origin mediate the mutant protein’s toxicity. Calcium-dependent calpain proteases are protagonists in neurodegenerative disorders. Here, we demonstrate that calpains cleave TBP, and emerging C-terminal fragments mislocalize to the cytoplasm. SCA17 cell and rat models exhibited calpain overactivation, leading to excessive fragmentation and depletion of neuronal proteins in vivo. Transcriptome analysis of SCA17 cells revealed synaptogenesis and calcium signaling perturbations, indicating the potential cause of elevated calpain activity. Pharmacological or genetic calpain inhibition reduced TBP cleavage and aggregation, consequently improving cell viability. Our work underlines the general significance of calpains and their activating pathways in neurodegenerative disorders and presents these proteases as novel players in the molecular pathogenesis of SCA17.
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Affiliation(s)
- Jonasz Jeremiasz Weber
- Department of Human Genetics, Ruhr University Bochum, Universitätsstraße 150, 44801, Bochum, Germany.,Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany
| | - Stefanie Cari Anger
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany
| | - Priscila Pereira Sena
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany.,Graduate School of Cellular Neuroscience, University of Tübingen, 72074, Tübingen, Germany
| | - Rana Dilara Incebacak Eltemur
- Department of Human Genetics, Ruhr University Bochum, Universitätsstraße 150, 44801, Bochum, Germany.,Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany
| | - Chrisovalantou Huridou
- Department of Human Genetics, Ruhr University Bochum, Universitätsstraße 150, 44801, Bochum, Germany.,Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany
| | - Florian Fath
- Department of Human Genetics, Ruhr University Bochum, Universitätsstraße 150, 44801, Bochum, Germany.,Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany
| | - Caspar Gross
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany.,NGS Competence Center Tübingen, 72076, Tübingen, Germany
| | - Nicolas Casadei
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany.,NGS Competence Center Tübingen, 72076, Tübingen, Germany
| | - Olaf Riess
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany.,NGS Competence Center Tübingen, 72076, Tübingen, Germany
| | - Huu Phuc Nguyen
- Department of Human Genetics, Ruhr University Bochum, Universitätsstraße 150, 44801, Bochum, Germany.
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7
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Ding D, Chen Z, Wang C, Tang X, Zhang L, Fang Q, Qiu R, Jiang H. A Variant in Genes of the NPY System as Modifier Factor of Machado-Joseph Disease in the Chinese Population. Front Aging Neurosci 2022; 14:822657. [PMID: 35185528 PMCID: PMC8851415 DOI: 10.3389/fnagi.2022.822657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 01/11/2022] [Indexed: 11/13/2022] Open
Abstract
Recently, NPY overexpression has been proposed to alleviate motor deficits and neuropathy in Machado-Joseph disease (MJD) mouse models, indicating its neuroprotective role in the pathogenesis of MJD. We aimed to evaluate the association between SNPs in NPY and its receptors and the susceptibility of MJD in the Chinese population. Moreover, we investigated whether these SNPs modulate the age at onset (AO) of MJD. In total, 527 MJD patients and 487 healthy controls were enrolled in the study, and four specific selected SNPs (rs16139, rs3037354, rs2234759, and rs11100494) in NPY and its receptor genes were genotyped. In this study, the genotypic frequency using the dominant model and the allelic distribution of rs11100494 in NPY5R revealed a significant difference between the MJD and control group during the first-stage analysis (P = 0.048 and P = 0.024, respectively). After we expanded the sample size, significant differences were observed between the two groups using the dominant model in genotypic and allelic distribution (P = 0.034, P = 0.046, and P = 0.016, respectively). No significant differences in genotypic and allelic distribution were found between the MJD and control groups for the other three SNPs. All selected SNPs had no significant effect on the AO of MJD. The association of rs11100494 in the NPY5R gene and susceptibility of MJD suggested that the NPY system might be implicated in the pathogenesis of MJD. Our study demonstrated the existence of other genetic modifiers in MJD, along with CAG expansion and known genetic modifier factors, which might lead to a better understanding of MJD pathogenesis.
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Affiliation(s)
- Dongxue Ding
- Department of Neurology, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Zhao Chen
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Chunrong Wang
- Department of Pathology, Xiangya Hospital, Central South University, Changsha, China
| | - Xiang Tang
- Department of Neurology, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Lulu Zhang
- Department of Neurology, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Qi Fang
- Department of Neurology, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Rong Qiu
- School of Information Science and Engineering, Central South University, Changsha, China
| | - Hong Jiang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
- Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Diseases, Central South University, Changsha, China
- Laboratory of Medical Genetics, Central South University, Changsha, China
- School of Basic Medical Science, Central South University, Changsha, China
- Hunan International Scientific and Technological Cooperation Base of Neurodegenerative and Neurogenetic Diseases, Changsha, China
- *Correspondence: Hong Jiang,
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8
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Patient-Specific iPSCs-Based Models of Neurodegenerative Diseases: Focus on Aberrant Calcium Signaling. Int J Mol Sci 2022; 23:ijms23020624. [PMID: 35054808 PMCID: PMC8776084 DOI: 10.3390/ijms23020624] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 12/30/2021] [Accepted: 12/31/2021] [Indexed: 02/04/2023] Open
Abstract
The development of cell reprogramming technologies became a breakthrough in the creation of new models of human diseases, including neurodegenerative pathologies. The iPSCs-based models allow for the studying of both hereditary and sporadic cases of pathologies and produce deep insight into the molecular mechanisms underlying neurodegeneration. The use of the cells most vulnerable to a particular pathology makes it possible to identify specific pathological mechanisms and greatly facilitates the task of selecting the most effective drugs. To date, a large number of studies on patient-specific models of neurodegenerative diseases has been accumulated. In this review, we focused on the alterations of such a ubiquitous and important intracellular regulatory pathway as calcium signaling. Here, we reviewed and analyzed the data obtained from iPSCs-based models of different neurodegenerative disorders that demonstrated aberrant calcium signaling.
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9
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Pathophysiological interplay between O-GlcNAc transferase and the Machado-Joseph disease protein ataxin-3. Proc Natl Acad Sci U S A 2021; 118:2025810118. [PMID: 34785590 DOI: 10.1073/pnas.2025810118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/28/2021] [Indexed: 11/18/2022] Open
Abstract
Aberrant O-GlcNAcylation, a protein posttranslational modification defined by the O-linked attachment of the monosaccharide N-acetylglucosamine (O-GlcNAc), has been implicated in neurodegenerative diseases. However, although many neuronal proteins are substrates for O-GlcNAcylation, this process has not been extensively investigated in polyglutamine disorders. We aimed to evaluate the enzyme O-GlcNAc transferase (OGT), which attaches O-GlcNAc to target proteins, in Machado-Joseph disease (MJD). MJD is a neurodegenerative condition characterized by ataxia and caused by the expansion of a polyglutamine stretch within the deubiquitinase ataxin-3, which then present increased propensity to aggregate. By analyzing MJD cell and animal models, we provide evidence that OGT is dysregulated in MJD, therefore compromising the O-GlcNAc cycle. Moreover, we demonstrate that wild-type ataxin-3 modulates OGT protein levels in a proteasome-dependent manner, and we present OGT as a substrate for ataxin-3. Targeting OGT levels and activity reduced ataxin-3 aggregates, improved protein clearance and cell viability, and alleviated motor impairment reminiscent of ataxia of MJD patients in zebrafish model of the disease. Taken together, our results point to a direct interaction between OGT and ataxin-3 in health and disease and propose the O-GlcNAc cycle as a promising target for the development of therapeutics in the yet incurable MJD.
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10
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Haas E, Incebacak RD, Hentrich T, Huridou C, Schmidt T, Casadei N, Maringer Y, Bahl C, Zimmermann F, Mills JD, Aronica E, Riess O, Schulze-Hentrich JM, Hübener-Schmid J. A Novel SCA3 Knock-in Mouse Model Mimics the Human SCA3 Disease Phenotype Including Neuropathological, Behavioral, and Transcriptional Abnormalities Especially in Oligodendrocytes. Mol Neurobiol 2021; 59:495-522. [PMID: 34716557 PMCID: PMC8786755 DOI: 10.1007/s12035-021-02610-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 10/19/2021] [Indexed: 12/28/2022]
Abstract
Spinocerebellar ataxia type 3 is the most common autosomal dominant inherited ataxia worldwide, caused by a CAG repeat expansion in the Ataxin-3 gene resulting in a polyglutamine (polyQ)-expansion in the corresponding protein. The disease is characterized by neuropathological, phenotypical, and specific transcriptional changes in affected brain regions. So far, there is no mouse model available representing all the different aspects of the disease, yet highly needed for a better understanding of the disease pathomechanisms. Here, we characterized a novel Ataxin-3 knock-in mouse model, expressing a heterozygous or homozygous expansion of 304 CAACAGs in the murine Ataxin-3 locus using biochemical, behavioral, and transcriptomic approaches. We compared neuropathological, and behavioral features of the new knock-in model with the in SCA3 research mostly used YAC84Q mouse model. Further, we compared transcriptional changes found in cerebellar samples of the SCA3 knock-in mice and post-mortem human SCA3 patients. The novel knock-in mouse is characterized by the expression of a polyQ-expansion in the murine Ataxin-3 protein, leading to aggregate formation, especially in brain regions known to be vulnerable in SCA3 patients, and impairment of Purkinje cells. Along these neuropathological changes, the mice showed a reduction in body weight accompanied by gait and balance instability. Transcriptomic analysis of cerebellar tissue revealed age-dependent differential expression, enriched for genes attributed to myelinating oligodendrocytes. Comparing these changes with those found in cerebellar tissue of SCA3 patients, we discovered an overlap of differentially expressed genes pointing towards similar gene expression perturbances in several genes linked to myelin sheaths and myelinating oligodendrocytes.
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Affiliation(s)
- Eva Haas
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany.,Centre for Rare Diseases, University of Tübingen, Tübingen, Germany
| | - Rana D Incebacak
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany.,Centre for Rare Diseases, University of Tübingen, Tübingen, Germany
| | - Thomas Hentrich
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany.,Centre for Rare Diseases, University of Tübingen, Tübingen, Germany
| | - Chrisovalantou Huridou
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany.,Centre for Rare Diseases, University of Tübingen, Tübingen, Germany
| | - Thorsten Schmidt
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany.,Centre for Rare Diseases, University of Tübingen, Tübingen, Germany
| | - Nicolas Casadei
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany.,Centre for Rare Diseases, University of Tübingen, Tübingen, Germany.,DFG NGS Competence Center Tübingen, Tübingen, Germany
| | - Yacine Maringer
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany.,Centre for Rare Diseases, University of Tübingen, Tübingen, Germany
| | - Carola Bahl
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany.,Centre for Rare Diseases, University of Tübingen, Tübingen, Germany
| | - Frank Zimmermann
- Interfaculty Biomedical Facility (IBF) Biotechnology lab, University of Heidelberg, Heidelberg, Germany
| | - James D Mills
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Eleonora Aronica
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Olaf Riess
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany.,Centre for Rare Diseases, University of Tübingen, Tübingen, Germany.,DFG NGS Competence Center Tübingen, Tübingen, Germany
| | - Julia M Schulze-Hentrich
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany.,Centre for Rare Diseases, University of Tübingen, Tübingen, Germany
| | - Jeannette Hübener-Schmid
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany. .,Centre for Rare Diseases, University of Tübingen, Tübingen, Germany.
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11
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Robinson KJ, Yuan K, Plenderleith SK, Watchon M, Laird AS. A Novel Calpain Inhibitor Compound Has Protective Effects on a Zebrafish Model of Spinocerebellar Ataxia Type 3. Cells 2021; 10:cells10102592. [PMID: 34685571 PMCID: PMC8533844 DOI: 10.3390/cells10102592] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 09/22/2021] [Accepted: 09/22/2021] [Indexed: 01/18/2023] Open
Abstract
Spinocerebellar ataxia type 3 (SCA3) is a hereditary ataxia caused by inheritance of a mutated form of the human ATXN3 gene containing an expanded CAG repeat region, encoding a human ataxin-3 protein with a long polyglutamine (polyQ) repeat region. Previous studies have demonstrated that ataxin-3 containing a long polyQ length is highly aggregation prone. Cleavage of the ataxin-3 protein by calpain proteases has been demonstrated to be enhanced in SCA3 models, leading to an increase in the aggregation propensity of the protein. Here, we tested the therapeutic potential of a novel calpain inhibitor BLD-2736 for the treatment of SCA3 by testing its efficacy on a transgenic zebrafish model of SCA3. We found that treatment with BLD-2736 from 1 to 6 days post-fertilisation (dpf) improves the swimming of SCA3 zebrafish larvae and decreases the presence of insoluble protein aggregates. Furthermore, delaying the commencement of treatment with BLD-2736, until a timepoint when protein aggregates were already known to be present in the zebrafish larvae, was still successful at removing enhanced green fluorescent protein (EGFP) fused-ataxin-3 aggregates and improving the zebrafish swimming. Finally, we demonstrate that treatment with BLD-2736 increased the synthesis of LC3II, increasing the activity of the autophagy protein quality control pathway. Together, these findings suggest that BLD-2736 warrants further investigation as a treatment for SCA3 and related neurodegenerative diseases.
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12
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Simões AT, Carmona V, Duarte-Neves J, Cunha-Santos J, Pereira de Almeida L. Identification of the calpain-generated toxic fragment of ataxin-3 protein provides new avenues for therapy of Machado-Joseph disease| Spinocerebellar ataxia type 3. Neuropathol Appl Neurobiol 2021; 48:e12748. [PMID: 34273111 DOI: 10.1111/nan.12748] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Revised: 06/26/2021] [Accepted: 07/11/2021] [Indexed: 12/14/2022]
Abstract
AIMS Machado-Joseph disease (MJD) is the most frequent dominantly inherited cerebellar ataxia worldwide. Expansion of a CAG trinucleotide in the MJD1 gene translates into a polyglutamine tract within ataxin-3, which upon proteolysis may lead to MJD. The aim of this work was to understand the in vivo contribution of calpain proteases to the pathogenesis of MJD. Therefore, we investigated (a) the calpain cleavage sites in ataxin-3 protein, (b) the most toxic ataxin-3 fragment generated by calpain cleavage and (c) whether targeting calpain cleavage sites of mutant ataxin-3 could be a therapeutic strategy for MJD. METHODS We generated truncated and calpain-resistant constructs at the predicted cleavage sites of ataxin-3 using inverse PCR mutagenesis. Lentiviral vectors encoding these constructs were transduced in the adult mouse brain prior to western blot and immunohistochemical analysis 5 and 8 weeks later. RESULTS We identified the putative calpain cleavage sites for both wild-type and mutant ataxin-3 proteins. The mutation of these sites eliminated the formation of the toxic fragments, namely, the 26-kDa fragment, the major contributor for striatal degeneration. Nonetheless, reducing the formation of both the 26- and 34-kDa fragments was required to preclude the intranuclear localisation of ataxin-3. A neuroprotective effect was observed upon mutagenesis of calpain cleavage sites within mutant ataxin-3 protein. CONCLUSIONS These findings suggest that the calpain system should be considered a target for MJD therapy. The identified calpain cleavage sites will contribute to the design of targeted drugs and genome editing systems for those specific locations.
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Affiliation(s)
- Ana Teresa Simões
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,CIBB-Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal
| | - Vítor Carmona
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,CIBB-Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal
| | - Joana Duarte-Neves
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,CIBB-Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal
| | - Janete Cunha-Santos
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,CIBB-Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal
| | - Luís Pereira de Almeida
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,CIBB-Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal.,Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
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13
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Weber JJ, Haas E, Maringer Y, Hauser S, Casadei NLP, Chishti AH, Riess O, Hübener-Schmid J. Calpain-1 ablation partially rescues disease-associated hallmarks in models of Machado-Joseph disease. Hum Mol Genet 2021; 29:892-906. [PMID: 31960910 DOI: 10.1093/hmg/ddaa010] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 01/14/2020] [Accepted: 01/16/2020] [Indexed: 12/13/2022] Open
Abstract
Proteolytic fragmentation of polyglutamine-expanded ataxin-3 is a concomitant and modifier of the molecular pathogenesis of Machado-Joseph disease (MJD), the most common autosomal dominant cerebellar ataxia. Calpains, a group of calcium-dependent cysteine proteases, are important mediators of ataxin-3 cleavage and implicated in multiple neurodegenerative conditions. Pharmacologic and genetic approaches lowering calpain activity showed beneficial effects on molecular and behavioural disease characteristics in MJD model organisms. However, specifically targeting one of the calpain isoforms by genetic means has not yet been evaluated as a potential therapeutic strategy. In our study, we tested whether calpains are overactivated in the MJD context and if reduction or ablation of calpain-1 expression ameliorates the disease-associated phenotype in MJD cells and mice. In all analysed MJD models, we detected an elevated calpain activity at baseline. Lowering or removal of calpain-1 in cells or mice counteracted calpain system overactivation and led to reduced cleavage of ataxin-3 without affecting its aggregation. Moreover, calpain-1 knockout in YAC84Q mice alleviated excessive fragmentation of important synaptic proteins. Despite worsening some motor characteristics, YAC84Q mice showed a rescue of body weight loss and extended survival upon calpain-1 knockout. Together, our findings emphasize the general potential of calpains as a therapeutic target in MJD and other neurodegenerative diseases.
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Affiliation(s)
- Jonasz J Weber
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen 72076, Germany.,Centre for Rare Diseases, University of Tübingen, Tübingen 72076, Germany.,Department of Human Genetics, Ruhr-University Bochum, Bochum 44801, Germany
| | - Eva Haas
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen 72076, Germany.,Centre for Rare Diseases, University of Tübingen, Tübingen 72076, Germany
| | - Yacine Maringer
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen 72076, Germany.,Centre for Rare Diseases, University of Tübingen, Tübingen 72076, Germany
| | - Stefan Hauser
- German Center for Neurodegenerative Diseases, Tübingen 72076, Germany
| | - Nicolas L P Casadei
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen 72076, Germany.,Centre for Rare Diseases, University of Tübingen, Tübingen 72076, Germany
| | - Athar H Chishti
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Olaf Riess
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen 72076, Germany.,Centre for Rare Diseases, University of Tübingen, Tübingen 72076, Germany
| | - Jeannette Hübener-Schmid
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen 72076, Germany.,Centre for Rare Diseases, University of Tübingen, Tübingen 72076, Germany
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14
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Gupta R, Sahu M, Srivastava D, Tiwari S, Ambasta RK, Kumar P. Post-translational modifications: Regulators of neurodegenerative proteinopathies. Ageing Res Rev 2021; 68:101336. [PMID: 33775891 DOI: 10.1016/j.arr.2021.101336] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 03/10/2021] [Accepted: 03/22/2021] [Indexed: 12/14/2022]
Abstract
One of the hallmark features in the neurodegenerative disorders (NDDs) is the accumulation of aggregated and/or non-functional protein in the cellular milieu. Post-translational modifications (PTMs) are an essential regulator of non-functional protein aggregation in the pathogenesis of NDDs. Any alteration in the post-translational mechanism and the protein quality control system, for instance, molecular chaperone, ubiquitin-proteasome system, autophagy-lysosomal degradation pathway, enhances the accumulation of misfolded protein, which causes neuronal dysfunction. Post-translational modification plays many roles in protein turnover rate, accumulation of aggregate and can also help in the degradation of disease-causing toxic metabolites. PTMs such as acetylation, glycosylation, phosphorylation, ubiquitination, palmitoylation, SUMOylation, nitration, oxidation, and many others regulate protein homeostasis, which includes protein structure, functions and aggregation propensity. Different studies demonstrated the involvement of PTMs in the regulation of signaling cascades such as PI3K/Akt/GSK3β, MAPK cascade, AMPK pathway, and Wnt signaling pathway in the pathogenesis of NDDs. Further, mounting evidence suggests that targeting different PTMs with small chemical molecules, which acts as an inhibitor or activator, reverse misfolded protein accumulation and thus enhances the neuroprotection. Herein, we briefly discuss the protein aggregation and various domain structures of different proteins involved in the NDDs, indicating critical amino acid residues where PTMs occur. We also describe the implementation and involvement of various PTMs on signaling cascade and cellular processes in NDDs. Lastly, we implement our current understanding of the therapeutic importance of PTMs in neurodegeneration, along with emerging techniques targeting various PTMs.
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15
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Temussi PA, Tartaglia GG, Pastore A. The seesaw between normal function and protein aggregation: How functional interactions may increase protein solubility. Bioessays 2021; 43:e2100031. [PMID: 33783021 DOI: 10.1002/bies.202100031] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 02/26/2021] [Accepted: 03/02/2021] [Indexed: 12/12/2022]
Abstract
Protein aggregation has been studied for at least 3 decades, and many of the principles that regulate this event are relatively well understood. Here, however, we present a different perspective to explain why proteins aggregate: we argue that aggregation may occur as a side-effect of the lack of one or more natural partners that, under physiologic conditions, would act as chaperones. This would explain why the same surfaces that have evolved for functional purposes are also those that favour aggregation. In the course of reviewing this field, we substantiate our hypothesis with three paradigmatic examples that argue for the generality of our proposal. An obvious corollary of this hypothesis is, of course, that targeting the physiological partners of a protein could be the most direct and specific approach to designing anti-aggregation molecules. Our analysis may thus inform a different strategy for combating diseases of protein aggregation and misfolding.
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Affiliation(s)
- Piero Andrea Temussi
- UK Dementia Research Institute at King's College London, The Maurice Wohl Institute, London, UK
| | - Gian Gaetano Tartaglia
- Center for Human Technologies, Central RNA laboratory, Istituto Italiano di Tecnologia, Genova, Italy
- Charles Darwin Department of Biology and Biotechnology, Sapienza University of Rome, Rome, Italy
| | - Annalisa Pastore
- UK Dementia Research Institute at King's College London, The Maurice Wohl Institute, London, UK
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16
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Hommersom MP, Buijsen RAM, van Roon-Mom WMC, van de Warrenburg BPC, van Bokhoven H. Human Induced Pluripotent Stem Cell-Based Modelling of Spinocerebellar Ataxias. Stem Cell Rev Rep 2021; 18:441-456. [PMID: 34031815 PMCID: PMC8930896 DOI: 10.1007/s12015-021-10184-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/11/2021] [Indexed: 12/13/2022]
Abstract
Abstract Dominant spinocerebellar ataxias (SCAs) constitute a large group of phenotypically and genetically heterogeneous disorders that mainly present with dysfunction of the cerebellum as their main hallmark. Although animal and cell models have been highly instrumental for our current insight into the underlying disease mechanisms of these neurodegenerative disorders, they do not offer the full human genetic and physiological context. The advent of human induced pluripotent stem cells (hiPSCs) and protocols to differentiate these into essentially every cell type allows us to closely model SCAs in a human context. In this review, we systematically summarize recent findings from studies using hiPSC-based modelling of SCAs, and discuss what knowledge has been gained from these studies. We conclude that hiPSC-based models are a powerful tool for modelling SCAs as they contributed to new mechanistic insights and have the potential to serve the development of genetic therapies. However, the use of standardized methods and multiple clones of isogenic lines are essential to increase validity and reproducibility of the insights gained. Graphical Abstract ![]()
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Affiliation(s)
- Marina P Hommersom
- Department of Human Genetics, Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical Center, 6500 HB, Nijmegen, The Netherlands
| | - Ronald A M Buijsen
- Department of Human Genetics, Leiden University Medical Center, 2300 RC, Leiden, The Netherlands
| | - Willeke M C van Roon-Mom
- Department of Human Genetics, Leiden University Medical Center, 2300 RC, Leiden, The Netherlands
| | - Bart P C van de Warrenburg
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6500 HB, Nijmegen, The Netherlands.
| | - Hans van Bokhoven
- Department of Human Genetics, Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical Center, 6500 HB, Nijmegen, The Netherlands. .,Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6500 HB, Nijmegen, Netherlands.
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17
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Gonsior K, Kaucher GA, Pelz P, Schumann D, Gansel M, Kuhs S, Klockgether T, Forlani S, Durr A, Hauser S, Rattay TW, Synofzik M, Hengel H, Schöls L, Rieß OH, Hübener-Schmid J. PolyQ-expanded ataxin-3 protein levels in peripheral blood mononuclear cells correlate with clinical parameters in SCA3: a pilot study. J Neurol 2020; 268:1304-1315. [PMID: 33106888 PMCID: PMC7990753 DOI: 10.1007/s00415-020-10274-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 10/09/2020] [Accepted: 10/13/2020] [Indexed: 12/14/2022]
Abstract
In view of upcoming clinical trials, quantitative molecular markers accessible in peripheral blood are of critical importance as prognostic or pharmacodynamic markers in genetic neurodegenerative diseases such as Spinocerebellar Ataxia Type 3 (SCA3), in particular for signaling target engagement. In this pilot study, we focused on the quantification of ataxin-3, the protein altered in SCA3, in human peripheral blood mononuclear cells (PBMCs) acquired from preataxic and ataxic SCA3 mutation carriers as well as healthy controls, as a molecular marker directly related to SCA3 pathophysiology. We established two different highly sensitive TR-FRET-based immunoassays to measure the protein levels of either total full-length, non-expanded and expanded, ataxin-3 or specifically polyQ-expanded ataxin-3. In PBMCs, a clear discrimination between SCA3 mutation carrier and controls were seen measuring polyQ-expanded ataxin-3 protein level. Additionally, polyQ-expanded ataxin-3 protein levels correlated with disease progression and clinical severity as assessed by the Scale for the Assessment and Rating of Ataxia. Total full-length ataxin-3 protein levels were directly influenced by the expression levels of the polyQ-expanded ataxin-3 protein, but were not correlated with clinical parameters. Assessment of ataxin-3 levels in fibroblasts or induced pluripotent stem cells allowed to distinguish mutation carriers from controls, thus providing proof-of-principle validation of our PBMC findings across cell lines. Total full-length or polyQ-expanded ataxin-3 protein was not detectable by TR-FRET assays in other biofluids like plasma or cerebrospinal fluid, indicating the need for ultra-sensitive assays for these biofluids. Standardization studies revealed that tube systems, blood sampling, and PBMC preparation may influence ataxin-3 protein levels indicating a high demand for standardized protocols in biomarker studies. In conclusion, the polyQ-expanded ataxin-3 protein is a promising candidate as a molecular target engagement marker in SCA3 in future clinical trials, determinable even in—easily accessible—peripheral blood biomaterials. These results, however, require validation in a larger cohort and further standardization of modifying conditions.
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Affiliation(s)
- Kathrin Gonsior
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany.,Centre for Rare Diseases, University of Tübingen, Tübingen, Germany
| | - Gabriele Anna Kaucher
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany.,Centre for Rare Diseases, University of Tübingen, Tübingen, Germany
| | - Patrik Pelz
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany.,Centre for Rare Diseases, University of Tübingen, Tübingen, Germany
| | - Dorothea Schumann
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany.,Centre for Rare Diseases, University of Tübingen, Tübingen, Germany
| | - Melanie Gansel
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany.,Centre for Rare Diseases, University of Tübingen, Tübingen, Germany
| | - Sandra Kuhs
- Department of Neurology, University of Bonn, Sigmund-Freud-Straße 25, 53127, Bonn, Germany.,German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Thomas Klockgether
- Department of Neurology, University of Bonn, Sigmund-Freud-Straße 25, 53127, Bonn, Germany.,German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Sylvie Forlani
- Institut du Cerveau-Paris Brain Institute (ICM), Sorbonne Université, AP-HP, INSERM, CNRS, University Hospital Pitié-Salpêtrière, Paris, France
| | - Alexandra Durr
- Institut du Cerveau-Paris Brain Institute (ICM), Sorbonne Université, AP-HP, INSERM, CNRS, University Hospital Pitié-Salpêtrière, Paris, France
| | - Stefan Hauser
- Center for Neurology, and Hertie-Institute for Clinical Brain Research, University of Tübingen, Hoppe-Seyler-Str. 3, 72076, Tübingen, Germany.,German Center of Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Tim W Rattay
- Center for Neurology, and Hertie-Institute for Clinical Brain Research, University of Tübingen, Hoppe-Seyler-Str. 3, 72076, Tübingen, Germany.,German Center of Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Matthis Synofzik
- Center for Neurology, and Hertie-Institute for Clinical Brain Research, University of Tübingen, Hoppe-Seyler-Str. 3, 72076, Tübingen, Germany.,German Center of Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Holger Hengel
- Center for Neurology, and Hertie-Institute for Clinical Brain Research, University of Tübingen, Hoppe-Seyler-Str. 3, 72076, Tübingen, Germany.,German Center of Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Ludger Schöls
- Center for Neurology, and Hertie-Institute for Clinical Brain Research, University of Tübingen, Hoppe-Seyler-Str. 3, 72076, Tübingen, Germany.,German Center of Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Olaf H Rieß
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany.,Centre for Rare Diseases, University of Tübingen, Tübingen, Germany.,DFG NGS Competence Center Tübingen, Tübingen, Germany
| | - Jeannette Hübener-Schmid
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany. .,Centre for Rare Diseases, University of Tübingen, Tübingen, Germany.
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18
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Robinson KJ, Watchon M, Laird AS. Aberrant Cerebellar Circuitry in the Spinocerebellar Ataxias. Front Neurosci 2020; 14:707. [PMID: 32765211 PMCID: PMC7378801 DOI: 10.3389/fnins.2020.00707] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 06/11/2020] [Indexed: 12/11/2022] Open
Abstract
The spinocerebellar ataxias (SCAs) are a heterogeneous group of neurodegenerative diseases that share convergent disease features. A common symptom of these diseases is development of ataxia, involving impaired balance and motor coordination, usually stemming from cerebellar dysfunction and neurodegeneration. For most spinocerebellar ataxias, pathology can be attributed to an underlying gene mutation and the impaired function of the encoded protein through loss or gain-of-function effects. Strikingly, despite vast heterogeneity in the structure and function of disease-causing genes across the SCAs and the cellular processes affected, the downstream effects have considerable overlap, including alterations in cerebellar circuitry. Interestingly, aberrant function and degeneration of Purkinje cells, the major output neuronal population present within the cerebellum, precedes abnormalities in other neuronal populations within many SCAs, suggesting that Purkinje cells have increased vulnerability to cellular perturbations. Factors that are known to contribute to perturbed Purkinje cell function in spinocerebellar ataxias include altered gene expression resulting in altered expression or functionality of proteins and channels that modulate membrane potential, downstream impairments in intracellular calcium homeostasis and changes in glutamatergic input received from synapsing climbing or parallel fibers. This review will explore this enhanced vulnerability and the aberrant cerebellar circuitry linked with it in many forms of SCA. It is critical to understand why Purkinje cells are vulnerable to such insults and what overlapping pathogenic mechanisms are occurring across multiple SCAs, despite different underlying genetic mutations. Enhanced understanding of disease mechanisms will facilitate the development of treatments to prevent or slow progression of the underlying neurodegenerative processes, cerebellar atrophy and ataxic symptoms.
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Affiliation(s)
| | | | - Angela S. Laird
- Centre for Motor Neuron Disease Research, Department of Biomedical Science, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia
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19
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Wilke C, Haas E, Reetz K, Faber J, Garcia‐Moreno H, Santana MM, van de Warrenburg B, Hengel H, Lima M, Filla A, Durr A, Melegh B, Masciullo M, Infante J, Giunti P, Neumann M, de Vries J, Pereira de Almeida L, Rakowicz M, Jacobi H, Schüle R, Kaeser SA, Kuhle J, Klockgether T, Schöls L, Barro C, Hübener‐Schmid J, Synofzik M. Neurofilaments in spinocerebellar ataxia type 3: blood biomarkers at the preataxic and ataxic stage in humans and mice. EMBO Mol Med 2020; 12:e11803. [PMID: 32510847 PMCID: PMC7338806 DOI: 10.15252/emmm.201911803] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 05/05/2020] [Accepted: 05/10/2020] [Indexed: 12/13/2022] Open
Abstract
With molecular treatments coming into reach for spinocerebellar ataxia type 3 (SCA3), easily accessible, cross-species validated biomarkers for human and preclinical trials are warranted, particularly for the preataxic disease stage. We assessed serum levels of neurofilament light (NfL) and phosphorylated neurofilament heavy (pNfH) in ataxic and preataxic subjects of two independent multicentric SCA3 cohorts and in a SCA3 knock-in mouse model. Ataxic SCA3 subjects showed increased levels of both NfL and pNfH. In preataxic subjects, NfL levels increased with proximity to the individual expected onset of ataxia, with significant NfL elevations already 7.5 years before onset. Cross-sectional NfL levels correlated with both disease severity and longitudinal disease progression. Blood NfL and pNfH increases in human SCA3 were each paralleled by similar changes in SCA3 knock-in mice, here also starting already at the presymptomatic stage, closely following ataxin-3 aggregation and preceding Purkinje cell loss in the brain. Blood neurofilaments, particularly NfL, might thus provide easily accessible, cross-species validated biomarkers in both ataxic and preataxic SCA3, associated with earliest neuropathological changes, and serve as progression, proximity-to-onset and, potentially, treatment-response markers in both human and preclinical SCA3 trials.
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20
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Thiruvalluvan A, de Mattos EP, Brunsting JF, Bakels R, Serlidaki D, Barazzuol L, Conforti P, Fatima A, Koyuncu S, Cattaneo E, Vilchez D, Bergink S, Boddeke EHWG, Copray S, Kampinga HH. DNAJB6, a Key Factor in Neuronal Sensitivity to Amyloidogenesis. Mol Cell 2020; 78:346-358.e9. [PMID: 32268123 DOI: 10.1016/j.molcel.2020.02.022] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 12/31/2019] [Accepted: 02/25/2020] [Indexed: 01/09/2023]
Abstract
CAG-repeat expansions in at least eight different genes cause neurodegeneration. The length of the extended polyglutamine stretches in the corresponding proteins is proportionally related to their aggregation propensity. Although these proteins are ubiquitously expressed, they predominantly cause toxicity to neurons. To understand this neuronal hypersensitivity, we generated induced pluripotent stem cell (iPSC) lines of spinocerebellar ataxia type 3 and Huntington's disease patients. iPSC generation and neuronal differentiation are unaffected by polyglutamine proteins and show no spontaneous aggregate formation. However, upon glutamate treatment, aggregates form in neurons but not in patient-derived neural progenitors. During differentiation, the chaperone network is drastically rewired, including loss of expression of the anti-amyloidogenic chaperone DNAJB6. Upregulation of DNAJB6 in neurons antagonizes glutamate-induced aggregation, while knockdown of DNAJB6 in progenitors results in spontaneous polyglutamine aggregation. Loss of DNAJB6 expression upon differentiation is confirmed in vivo, explaining why stem cells are intrinsically protected against amyloidogenesis and protein aggregates are dominantly present in neurons.
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Affiliation(s)
- Arun Thiruvalluvan
- Department of Biomedical Sciences of Cells & Systems, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Eduardo P de Mattos
- Department of Biomedical Sciences of Cells & Systems, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Jeanette F Brunsting
- Department of Biomedical Sciences of Cells & Systems, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Rob Bakels
- Department of Biomedical Sciences of Cells & Systems, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Despina Serlidaki
- Department of Biomedical Sciences of Cells & Systems, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Lara Barazzuol
- Department of Biomedical Sciences of Cells & Systems, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Paola Conforti
- Department of Biosciences, University of Milan, Milan, Italy; Istituto Nazionale di Genetica Molecolare, Romeo ed Enrica Invernizzi, Milan, Italy
| | - Azra Fatima
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Seda Koyuncu
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Elena Cattaneo
- Department of Biosciences, University of Milan, Milan, Italy; Istituto Nazionale di Genetica Molecolare, Romeo ed Enrica Invernizzi, Milan, Italy
| | - David Vilchez
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Steven Bergink
- Department of Biomedical Sciences of Cells & Systems, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Erik H W G Boddeke
- Department of Biomedical Sciences of Cells & Systems, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Sjef Copray
- Department of Biomedical Sciences of Cells & Systems, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Harm H Kampinga
- Department of Biomedical Sciences of Cells & Systems, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
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21
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Wang Z. Disulfiram facilitates ataxin-3 nuclear translocation and potentiates the cytotoxicity in a cell model of SCA3. J Toxicol Sci 2019; 44:535-542. [PMID: 31378764 DOI: 10.2131/jts.44.535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Spinocerebellar ataxia type 3 (SCA3) is caused by the expansion of a glutamine-encoding CAG repeat in the ATXN3 gene encoding the protein ataxin-3. The nuclear presence of polyglutamine-expanded ataxin-3 is of critical importance for the pathogenesis of SCA3. Disulfiram, an FDA-approved drug for alcoholism, has also garnered attention in cancer treatment. However, it has shown toxicity in the nervous system. Bearing this in mind, we treated cells expressing ataxin-3 with disulfiram to measure several pathogenic cascades of SCA3, including aggregate formation, soluble ataxin-3 expression and nuclear localization of ataxin-3 and the cytotoxicity, which assess the direct effect of disulfiram on SCA3 cell models. To our knowledge, this is direct evidence that disulfiram elevated the nuclear localization of polyglutamine-expanded ataxin-3 and enhanced the cytotoxicity in a cell model of SCA3. Furthermore, disulfiram did not affect the aggregate formation of polyglutamine-expanded ataxin-3 at least at a single dose. Our findings repurpose disulfiram as a modulator of ataxin-3 nuclear transport that aggravates the pathology of SCA3, which is a new target for disulfiram. This study also represents an important example of determining novel side effects in pre-existing drugs. This study suggests that caution may be warranted when this compound is used to treat alcohol abuse or cancer in patients carrying a SCA3-causing mutation.
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Affiliation(s)
- Zijian Wang
- Genetic Engineering Laboratory, College of Biological and Environmental Engineering, Xi'an University, China
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22
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Killing Two Angry Birds with One Stone: Autophagy Activation by Inhibiting Calpains in Neurodegenerative Diseases and Beyond. BIOMED RESEARCH INTERNATIONAL 2019; 2019:4741252. [PMID: 30895192 PMCID: PMC6393885 DOI: 10.1155/2019/4741252] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 01/27/2019] [Indexed: 12/21/2022]
Abstract
Proteolytic machineries execute vital cellular functions and their disturbances are implicated in diverse medical conditions, including neurodegenerative diseases. Interestingly, calpains, a class of Ca2+-dependent regulatory proteases, can modulate the degradational system of autophagy by cleaving proteins involved in this pathway. Moreover, both machineries are common players in many molecular pathomechanisms and have been targeted individually or together, as a therapeutic strategy in experimental setups. In this review, we briefly introduce calpains and autophagy, with their roles in health and disease, and focus on their direct pathologically relevant interplay in neurodegeneration and beyond. The modulation of calpain activity may comprise a promising treatment approach to attenuate the deregulation of these two essential mechanisms.
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23
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Weishäupl D, Schneider J, Peixoto Pinheiro B, Ruess C, Dold SM, von Zweydorf F, Gloeckner CJ, Schmidt J, Riess O, Schmidt T. Physiological and pathophysiological characteristics of ataxin-3 isoforms. J Biol Chem 2018; 294:644-661. [PMID: 30455355 DOI: 10.1074/jbc.ra118.005801] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 11/08/2018] [Indexed: 12/18/2022] Open
Abstract
Ataxin-3 is a deubiquitinating enzyme and the affected protein in the neurodegenerative disorder Machado-Joseph disease (MJD). The ATXN3 gene is alternatively spliced, resulting in protein isoforms that differ in the number of ubiquitin-interacting motifs. Additionally, nonsynonymous SNPs in ATXN3 cause amino acid changes in ataxin-3, and one of these polymorphisms introduces a premature stop codon in one isoform. Here, we examined the effects of different ataxin-3 isoforms and of the premature stop codon on ataxin-3's physiological function and on main disease mechanisms. At the physiological level, we show that alternative splicing and the premature stop codon alter ataxin-3 stability and that ataxin-3 isoforms differ in their enzymatic deubiquitination activity, subcellular distribution, and interaction with other proteins. At the pathological level, we found that the expansion of the polyglutamine repeat leads to a stabilization of ataxin-3 and that ataxin-3 isoforms differ in their aggregation properties. Interestingly, we observed a functional interaction between normal and polyglutamine-expanded ATXN3 allelic variants. We found that interactions between different ATXN3 allelic variants modify the physiological and pathophysiological properties of ataxin-3. Our findings indicate that alternative splicing and interactions between different ataxin-3 isoforms affect not only major aspects of ataxin-3 function but also MJD pathogenesis. Our results stress the importance of considering isoforms of disease-causing proteins and their interplay with the normal allelic variant as disease modifiers in MJD and autosomal-dominantly inherited diseases in general.
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Affiliation(s)
- Daniel Weishäupl
- From the Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tübingen, Germany.,the Center for Rare Diseases, 72076 Tübingen, Germany.,the NGS Competence Center, 72076 Tübingen, Germany.,the Graduate Training Center of Neuroscience, 72074 Tübingen, Germany
| | - Juliane Schneider
- From the Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tübingen, Germany.,the Center for Rare Diseases, 72076 Tübingen, Germany.,the NGS Competence Center, 72076 Tübingen, Germany
| | - Barbara Peixoto Pinheiro
- From the Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tübingen, Germany.,the Center for Rare Diseases, 72076 Tübingen, Germany.,the NGS Competence Center, 72076 Tübingen, Germany
| | - Corinna Ruess
- From the Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tübingen, Germany.,the Center for Rare Diseases, 72076 Tübingen, Germany.,the NGS Competence Center, 72076 Tübingen, Germany
| | - Sandra Maria Dold
- From the Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tübingen, Germany.,the Center for Rare Diseases, 72076 Tübingen, Germany.,the NGS Competence Center, 72076 Tübingen, Germany
| | - Felix von Zweydorf
- the German Center for Neurodegenerative Diseases (DZNE), 72076 Tübingen, Germany, and
| | - Christian Johannes Gloeckner
- the German Center for Neurodegenerative Diseases (DZNE), 72076 Tübingen, Germany, and.,the Institute for Ophthalmic Research, Center for Ophthalmology, University of Tübingen, 72076 Tübingen, Germany
| | - Jana Schmidt
- From the Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tübingen, Germany.,the Center for Rare Diseases, 72076 Tübingen, Germany.,the NGS Competence Center, 72076 Tübingen, Germany
| | - Olaf Riess
- From the Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tübingen, Germany.,the Center for Rare Diseases, 72076 Tübingen, Germany.,the NGS Competence Center, 72076 Tübingen, Germany
| | - Thorsten Schmidt
- From the Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tübingen, Germany, .,the Center for Rare Diseases, 72076 Tübingen, Germany.,the NGS Competence Center, 72076 Tübingen, Germany
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24
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Weber JJ, Kloock SJ, Nagel M, Ortiz-Rios MM, Hofmann J, Riess O, Nguyen HP. Calpastatin ablation aggravates the molecular phenotype in cell and animal models of Huntington disease. Neuropharmacology 2018; 133:94-106. [PMID: 29355642 DOI: 10.1016/j.neuropharm.2018.01.022] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 12/21/2017] [Accepted: 01/16/2018] [Indexed: 12/15/2022]
Abstract
Deciphering the molecular pathology of Huntington disease is of particular importance, not only for a better understanding of this neurodegenerative disease, but also to identify potential therapeutic targets. The polyglutamine-expanded disease protein huntingtin was shown to undergo proteolysis, which results in the accumulation of toxic and aggregation-prone fragments. Amongst several classes of proteolytic enzymes responsible for huntingtin processing, the group of calcium-activated calpains has been found to be a significant mediator of the disease protein toxicity. To confirm the impact of calpain-mediated huntingtin cleavage in Huntington disease, we analysed the effect of depleting or overexpressing the endogenous calpain inhibitor calpastatin in HEK293T cells transfected with wild-type or polyglutamine-expanded huntingtin. Moreover, we crossbred huntingtin knock-in mice with calpastatin knockout animals to assess its effect not only on huntingtin cleavage and aggregation but also additional molecular markers. We demonstrated that a reduced or ablated expression of calpastatin triggers calpain overactivation and a consequently increased mutant huntingtin cleavage in cells and in vivo. These alterations were accompanied by an elevated formation of predominantly cytoplasmic huntingtin aggregates. On the other hand, overexpression of calpastatin in cells attenuated huntingtin fragmentation and aggregation. In addition, we observed an enhanced cleavage of DARPP-32, p35 and synapsin-1 in neuronal tissue upon calpain overactivation. Our results corroborate the important role of calpains in the molecular pathogenesis of Huntington disease and endorse targeting these proteolytic enzymes as a therapeutic approach.
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Affiliation(s)
- Jonasz Jeremiasz Weber
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany; Centre for Rare Diseases, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany.
| | - Simon Johannes Kloock
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany; Centre for Rare Diseases, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany.
| | - Maike Nagel
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany; Centre for Rare Diseases, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany.
| | - Midea Malena Ortiz-Rios
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany; Centre for Rare Diseases, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany.
| | - Julian Hofmann
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany; Centre for Rare Diseases, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany.
| | - Olaf Riess
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany; Centre for Rare Diseases, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany.
| | - Huu Phuc Nguyen
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany; Centre for Rare Diseases, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany.
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25
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Osinalde N, Duarri A, Ramirez J, Barrio R, Perez de Nanclares G, Mayor U. Impaired proteostasis in rare neurological diseases. Semin Cell Dev Biol 2018; 93:164-177. [PMID: 30355526 DOI: 10.1016/j.semcdb.2018.10.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Revised: 10/09/2018] [Accepted: 10/16/2018] [Indexed: 12/19/2022]
Abstract
Rare diseases are classified as such when their prevalence is 1:2000 or lower, but even if each of them is so infrequent, altogether more than 300 million people in the world suffer one of the ∼7000 diseases considered as rare. Over 1200 of these disorders are known to affect the brain or other parts of our nervous system, and their symptoms can affect cognition, motor function and/or social interaction of the patients; we refer collectively to them as rare neurological disorders or RNDs. We have focused this review on RNDs known to have compromised protein homeostasis pathways. Proteostasis can be regulated and/or altered by a chain of cellular mechanisms, from protein synthesis and folding, to aggregation and degradation. Overall, we provide a list comprised of above 215 genes responsible for causing more than 170 distinct RNDs, deepening on some representative diseases, including as well a clinical view of how those diseases are diagnosed and dealt with. Additionally, we review existing methodologies for diagnosis and treatment, discussing the potential of specific deubiquitinating enzyme inhibition as a future therapeutic avenue for RNDs.
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Affiliation(s)
- Nerea Osinalde
- Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, University of the Basque Country (UPV/EHU), 01006 Vitoria-Gasteiz, Spain
| | - Anna Duarri
- Barcelona Stem Cell Bank, Center of Regenerative Medicine in Barcelona, 08908 Hospitalet de Llobregat, Barcelona, Spain
| | - Juanma Ramirez
- Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain
| | - Rosa Barrio
- Functional Genomics Unit, CIC bioGUNE, 48160 Derio, Spain
| | - Guiomar Perez de Nanclares
- Molecular (Epi)Genetics Laboratory, BioAraba National Health Institute, Hospital Universitario Araba-Txagorritxu, Vitoria-Gasteiz, Alava, Spain
| | - Ugo Mayor
- Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain; Ikerbasque, Basque Foundation for Science, 48013 Bilbao, Spain.
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26
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Harmuth T, Prell-Schicker C, Weber JJ, Gellerich F, Funke C, Drießen S, Magg JCD, Krebiehl G, Wolburg H, Hayer SN, Hauser S, Krüger R, Schöls L, Riess O, Hübener-Schmid J. Mitochondrial Morphology, Function and Homeostasis Are Impaired by Expression of an N-terminal Calpain Cleavage Fragment of Ataxin-3. Front Mol Neurosci 2018; 11:368. [PMID: 30364204 PMCID: PMC6192284 DOI: 10.3389/fnmol.2018.00368] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 09/18/2018] [Indexed: 12/14/2022] Open
Abstract
Alterations in mitochondrial morphology and function have been linked to neurodegenerative diseases, including Parkinson disease, Alzheimer disease and Huntington disease. Metabolic defects, resulting from dysfunctional mitochondria, have been reported in patients and respective animal models of all those diseases. Spinocerebellar Ataxia Type 3 (SCA3), another neurodegenerative disorder, also presents with metabolic defects and loss of body weight in early disease stages although the possible role of mitochondrial dysfunction in SCA3 pathology is still to be determined. Interestingly, the SCA3 disease protein ataxin-3, which is predominantly localized in cytoplasm and nucleus, has also been associated with mitochondria in both its mutant and wildtype form. This observation provides an interesting link to a potential mitochondrial involvement of mutant ataxin-3 in SCA3 pathogenesis. Furthermore, proteolytic cleavage of ataxin-3 has been shown to produce toxic fragments and even overexpression of artificially truncated forms of ataxin-3 resulted in mitochondria deficits. Therefore, we analyzed the repercussions of expressing a naturally occurring N-terminal cleavage fragment of ataxin-3 and the influence of an endogenous expression of the S256 cleavage fragment in vitro and in vivo. In our study, expression of a fragment derived from calpain cleavage induced mitochondrial fragmentation and cristae alterations leading to a significantly decreased capacity of mitochondrial respiration and contributing to an increased susceptibility to apoptosis. Furthermore, analyzing mitophagy revealed activation of autophagy in the early pathogenesis with reduced lysosomal activity. In conclusion, our findings indicate that cleavage of ataxin-3 by calpains results in fragments which interfere with mitochondrial function and mitochondrial degradation processes.
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Affiliation(s)
- Tina Harmuth
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany.,Centre for Rare Diseases, Tübingen, Germany.,Graduate School of Cellular Neuroscience, University of Tübingen, Tübingen, Germany
| | - Caroline Prell-Schicker
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Jonasz J Weber
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany.,Centre for Rare Diseases, Tübingen, Germany
| | - Frank Gellerich
- Department of Neurology, University Hospital Magdeburg, Magdeburg, Germany
| | - Claudia Funke
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Stefan Drießen
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Janine C D Magg
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany.,Centre for Rare Diseases, Tübingen, Germany
| | - Guido Krebiehl
- Center of Neurology and Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Hartwig Wolburg
- Institute of Pathology and Neuropathology, University of Tübingen, Tübingen, Germany
| | - Stefanie N Hayer
- German Center for Neurodegenerative Diseases, Tübingen, Germany.,Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research and Center of Neurology, University of Tübingen, Tübingen, Germany
| | - Stefan Hauser
- German Center for Neurodegenerative Diseases, Tübingen, Germany
| | - Rejko Krüger
- Center of Neurology and Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.,Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Centre Hospitalier de Luxembourg, Luxembourg, Luxembourg
| | - Ludger Schöls
- German Center for Neurodegenerative Diseases, Tübingen, Germany.,Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research and Center of Neurology, University of Tübingen, Tübingen, Germany
| | - Olaf Riess
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany.,Centre for Rare Diseases, Tübingen, Germany
| | - Jeannette Hübener-Schmid
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany.,Centre for Rare Diseases, Tübingen, Germany
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27
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Matos CA, de Almeida LP, Nóbrega C. Machado-Joseph disease/spinocerebellar ataxia type 3: lessons from disease pathogenesis and clues into therapy. J Neurochem 2018; 148:8-28. [PMID: 29959858 DOI: 10.1111/jnc.14541] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 06/05/2018] [Accepted: 06/27/2018] [Indexed: 12/25/2022]
Abstract
Machado-Joseph disease (MJD), also known as spinocerebellar ataxia type 3 (SCA3), is an incurable disorder, widely regarded as the most common form of spinocerebellar ataxia in the world. MJD/SCA3 arises from mutation of the ATXN3 gene, but this simple monogenic cause contrasts with the complexity of the pathogenic mechanisms that are currently admitted to underlie neuronal dysfunction and death. The aberrantly expanded protein product - ataxin-3 - is known to aggregate and generate toxic species that disrupt several cell systems, including autophagy, proteostasis, transcription, mitochondrial function and signalling. Over the years, research into putative therapeutic approaches has often been devoted to the development of strategies that counteract disease at different stages of cellular pathogenesis. Silencing the pathogenic protein, blocking aggregation, inhibiting toxic proteolytic processing and counteracting dysfunctions of the cellular systems affected have yielded promising ameliorating results in studies with cellular and animal models. The current review analyses the available studies dedicated to the investigation of MJD/SCA3 pathogenesis and the exploration of possible therapeutic strategies, focusing primarily on gene therapy and pharmacological approaches rooted on the molecular and cellular mechanisms of disease.
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Affiliation(s)
- Carlos A Matos
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal.,Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
| | - Luís Pereira de Almeida
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal.,Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
| | - Clévio Nóbrega
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal.,Department of Biomedical Sciences and Medicine, University of Algarve, Coimbra, Portugal.,Centre for Biomedical Research (CBMR), University of Algarve, Coimbra, Portugal.,Algarve Biomedical Center (ABC), University of Algarve, Faro, Portugal
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28
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Wan L, Xu K, Chen Z, Tang B, Jiang H. Roles of Post-translational Modifications in Spinocerebellar Ataxias. Front Cell Neurosci 2018; 12:290. [PMID: 30283301 PMCID: PMC6156280 DOI: 10.3389/fncel.2018.00290] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Accepted: 08/13/2018] [Indexed: 12/17/2022] Open
Abstract
Post-translational modifications (PTMs), including phosphorylation, acetylation, ubiquitination, SUMOylation, etc., of proteins can modulate protein properties such as intracellular distribution, activity, stability, aggregation, and interactions. Therefore, PTMs are vital regulatory mechanisms for multiple cellular processes. Spinocerebellar ataxias (SCAs) are hereditary, heterogeneous, neurodegenerative diseases for which the primary manifestation involves ataxia. Because the pathogenesis of most SCAs is correlated with mutant proteins directly or indirectly, the PTMs of disease-related proteins might functionally affect SCA development and represent potential therapeutic interventions. Here, we review multiple PTMs related to disease-causing proteins in SCAs pathogenesis and their effects. Furthermore, we discuss these PTMs as potential targets for treating SCAs and describe translational therapies targeting PTMs that have been published.
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Affiliation(s)
- Linlin Wan
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Keqin Xu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Zhao Chen
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Beisha Tang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Diseases, Central South University, Changsha, China
- Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, China
- Laboratory of Medical Genetics, Central South University, Changsha, China
- Parkinson’s Disease Center of Beijing Institute for Brain Disorders, Beijing, China
- Collaborative Innovation Center for Brain Science, Shanghai, China
- Collaborative Innovation Center for Genetics and Development, Shanghai, China
| | - Hong Jiang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Diseases, Central South University, Changsha, China
- Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, China
- Laboratory of Medical Genetics, Central South University, Changsha, China
- Department of Neurology, Xinjiang Medical University, Ürümqi, China
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29
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Cheng SY, Wang SC, Lei M, Wang Z, Xiong K. Regulatory role of calpain in neuronal death. Neural Regen Res 2018; 13:556-562. [PMID: 29623944 PMCID: PMC5900522 DOI: 10.4103/1673-5374.228762] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/26/2017] [Indexed: 12/19/2022] Open
Abstract
Calpains are a group of calcium-dependent proteases that are over activated by increased intracellular calcium levels under pathological conditions. A wide range of substrates that regulate necrotic, apoptotic and autophagic pathways are affected by calpain. Calpain plays a very important role in neuronal death and various neurological disorders. This review introduces recent research progress related to the regulatory mechanisms of calpain in neuronal death. Various neuronal programmed death pathways including apoptosis, autophagy and regulated necrosis can be divided into receptor interacting protein-dependent necroptosis, mitochondrial permeability transition-dependent necrosis, pyroptosis and poly (ADP-ribose) polymerase 1-mediated parthanatos. Calpains cleave series of key substrates that may lead to cell death or participate in cell death. Regarding the investigation of calpain-mediated programed cell death, it is necessary to identify specific inhibitors that inhibit calpain mediated neuronal death and nervous system diseases.
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Affiliation(s)
- Si-ying Cheng
- Xiangya Medical School, Central South University, Changsha, Hunan Province, China
| | - Shu-chao Wang
- Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Central South University, Changsha, Hunan Province, China
| | - Ming Lei
- Xiangya Medical School, Central South University, Changsha, Hunan Province, China
| | - Zhen Wang
- Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Central South University, Changsha, Hunan Province, China
| | - Kun Xiong
- Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Central South University, Changsha, Hunan Province, China
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30
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Wang Z. Experimental and Clinical Strategies for Treating Spinocerebellar Ataxia Type 3. Neuroscience 2017; 371:138-154. [PMID: 29229556 DOI: 10.1016/j.neuroscience.2017.11.051] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 11/28/2017] [Accepted: 11/30/2017] [Indexed: 01/02/2023]
Abstract
Spinocerebellar ataxia type 3 (SCA3), or Machado-Joseph disease (MJD), is an autosomal dominant neurodegenerative disorder caused by the expansion of a polyglutamine (polyQ) tract in the ataxin-3 protein. To date, there is no effective therapy available to prevent progression of this disease. However, clinical strategies for alleviating various symptoms are imperative to promote a better quality of life for SCA3/MJD patients. Furthermore, experimental therapeutic strategies, including gene silencing or mutant protein clearance, mutant polyQ protein modification, stabilizing the native protein conformation, rescue of cellular dysfunction and neuromodulation to slow the progression of SCA3/MJD, have been developed. In this study, based on the current knowledge, I detail the clinical and experimental therapeutic strategies for treating SCA3/MJD, paying particular attention to drug discovery.
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Affiliation(s)
- Zijian Wang
- Genetic Engineering Laboratory, College of Biological and Environmental Engineering, Xi'an University, Xi'an, Shaanxi 710065, China.
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31
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Calpain Inhibition Is Protective in Machado-Joseph Disease Zebrafish Due to Induction of Autophagy. J Neurosci 2017; 37:7782-7794. [PMID: 28687604 DOI: 10.1523/jneurosci.1142-17.2017] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 06/19/2017] [Accepted: 06/20/2017] [Indexed: 02/02/2023] Open
Abstract
The neurodegenerative disease Machado-Joseph disease (MJD), also known as spinocerebellar ataxin-3, affects neurons of the brain and spinal cord, disrupting control of the movement of muscles. We have successfully established the first transgenic zebrafish (Danio rerio) model of MJD by expressing human ataxin-3 protein containing either 23 glutamines (23Q, wild-type) or 84Q (MJD-causing) within neurons. Phenotypic characterization of the zebrafish (male and female) revealed that the ataxin-3-84Q zebrafish have decreased survival compared with ataxin-3-23Q and develop ataxin-3 neuropathology, ataxin-3 cleavage fragments and motor impairment. Ataxin-3-84Q zebrafish swim shorter distances than ataxin-3-23Q zebrafish as early as 6 days old, even if expression of the human ataxin-3 protein is limited to motor neurons. This swimming phenotype provides a valuable readout for drug treatment studies. Treating the EGFP-ataxin-3-84Q zebrafish with the calpain inhibitor compound calpeptin decreased levels of ataxin-3 cleavage fragments, but also removed all human ataxin-3 protein (confirmed by ELISA) and prevented the early MJD zebrafish motor phenotype. We identified that this clearance of ataxin-3 protein by calpeptin treatment resulted from an increase in autophagic flux (indicated by decreased p62 levels and increased LC3II). Cotreatment with the autophagy inhibitor chloroquine blocked the decrease in human ataxin-3 levels and the improved movement produced by calpeptin treatment. This study demonstrates that this first transgenic zebrafish model of MJD is a valuable tool for testing potential treatments for MJD. Calpeptin treatment is protective in this model of MJD and removal of human ataxin-3 through macro-autophagy plays an important role in this beneficial effect.SIGNIFICANCE STATEMENT We have established the first transgenic zebrafish model of the neurodegenerative disease MJD, and identified relevant disease phenotypes, including impaired movement from an early age, which can be used in rapid drug testing studies. We have found that treating the MJD zebrafish with the calpain inhibitor compound calpeptin produces complete removal of human ataxin-3 protein, due to induction of the autophagy quality control pathway. This improves the movement of the MJD zebrafish. Artificially blocking the autophagy pathway prevents the removal of human ataxin-3 and improved movement produced by calpeptin treatment. These findings indicate that induction of autophagy, and removal of ataxin-3 protein, plays an important role in the protective effects of calpain inhibition for the treatment of MJD.
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