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Hensel N, Rademacher S, Claus P. Chatting with the neighbors: crosstalk between Rho-kinase (ROCK) and other signaling pathways for treatment of neurological disorders. Front Neurosci 2015; 9:198. [PMID: 26082680 PMCID: PMC4451340 DOI: 10.3389/fnins.2015.00198] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Accepted: 05/18/2015] [Indexed: 12/11/2022] Open
Abstract
ROCK inhibition has been largely applied as a strategy to treat neurodegenerative diseases (NDDs) and promising results have been obtained in the recent years. However, the underlying molecular and cellular mechanisms are not fully understood and different models have been proposed for neurodegenerative disorders. Here, we aim to review the current knowledge obtained for NDDs identifying common mechanisms as well as disease-specific models. In addition to the role of ROCK in different cell types such as neurons and microglia, we focus on the molecular signaling-pathways which mediate the beneficial effects of ROCK. Besides canonical ROCK signaling, modulation of neighboring pathways by non-canonical ROCK-crosstalk is a recurrent pattern in many NDD-model systems and has been suggested to mediate beneficial effects of ROCK-inhibition.
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Affiliation(s)
- Niko Hensel
- Hannover Medical School, Institute of Neuroanatomy Hannover, Germany ; Niedersachsen Research Network on Neuroinfectiology Hannover, Germany
| | - Sebastian Rademacher
- Hannover Medical School, Institute of Neuroanatomy Hannover, Germany ; Center for Systems Neuroscience Hannover, Germany
| | - Peter Claus
- Hannover Medical School, Institute of Neuroanatomy Hannover, Germany ; Niedersachsen Research Network on Neuroinfectiology Hannover, Germany ; Center for Systems Neuroscience Hannover, Germany
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Sanhueza M, Chai A, Smith C, McCray BA, Simpson TI, Taylor JP, Pennetta G. Network analyses reveal novel aspects of ALS pathogenesis. PLoS Genet 2015; 11:e1005107. [PMID: 25826266 PMCID: PMC4380362 DOI: 10.1371/journal.pgen.1005107] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 02/27/2015] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease characterized by selective loss of motor neurons, muscle atrophy and paralysis. Mutations in the human VAMP-associated protein B (hVAPB) cause a heterogeneous group of motor neuron diseases including ALS8. Despite extensive research, the molecular mechanisms underlying ALS pathogenesis remain largely unknown. Genetic screens for key interactors of hVAPB activity in the intact nervous system, however, represent a fundamental approach towards understanding the in vivo function of hVAPB and its role in ALS pathogenesis. Targeted expression of the disease-causing allele leads to neurodegeneration and progressive decline in motor performance when expressed in the adult Drosophila, eye or in its entire nervous system, respectively. By using these two phenotypic readouts, we carried out a systematic survey of the Drosophila genome to identify modifiers of hVAPB-induced neurotoxicity. Modifiers cluster in a diverse array of biological functions including processes and genes that have been previously linked to hVAPB function, such as proteolysis and vesicular trafficking. In addition to established mechanisms, the screen identified endocytic trafficking and genes controlling proliferation and apoptosis as potent modifiers of ALS8-mediated defects. Surprisingly, the list of modifiers was mostly enriched for proteins linked to lipid droplet biogenesis and dynamics. Computational analysis reveals that most modifiers can be linked into a complex network of interacting genes, and that the human genes homologous to the Drosophila modifiers can be assembled into an interacting network largely overlapping with that in flies. Identity markers of the endocytic process were also found to abnormally accumulate in ALS patients, further supporting the relevance of the fly data for human biology. Collectively, these results not only lead to a better understanding of hVAPB function but also point to potentially relevant targets for therapeutic intervention. Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disease causing loss of motor neurons and consequently a progressive deterioration of motor functions. ALS is uniformly fatal with death occurring 5 years after onset of symptoms. There is currently no effective treatment for ALS. Several mutations in a gene called hVAPB have shown that this gene is causative of a type of ALS known as ALS8. In this study we sought to identify genes and cellular processes that are involved in the toxicity conferred by the defective ALS8 allele. By using the power of Drosophila genetics, we performed a large scale genomic screen and identified a number of genes that can affect hVAPB-mediated toxicity. These modifiers cluster into functional pathways known to be involved in ALS as well as novel ones. The relevance of these modifiers and mechanisms for the human disease was confirmed by showing that the human homologues of the fly modifiers can be organized into a network that closely resembles that of the Drosophila genes. Identifying cellular processes and proteins that modulate hVAPB pathological activity can facilitate the discovery of an effective treatment for ALS.
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Affiliation(s)
- Mario Sanhueza
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, United Kingdom
- Euan MacDonald Centre for Motor Neuron Disease Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Andrea Chai
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, United Kingdom
- Euan MacDonald Centre for Motor Neuron Disease Research, University of Edinburgh, Edinburgh, United Kingdom
- Department of Molecular and Human Genetics, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute, Houston, Texas, United States of America
| | - Colin Smith
- Academic Department of Neuropathology, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Brett A. McCray
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Cambridge, Massachusetts, United States of America
| | - T. Ian Simpson
- Biomathematics and Statistics Scotland, University of Edinburgh, United Kingdom
- Institute for Adaptive and Neural Computation, School of Informatics, University of Edinburgh, United Kingdom
| | - J. Paul Taylor
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Giuseppa Pennetta
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, United Kingdom
- Euan MacDonald Centre for Motor Neuron Disease Research, University of Edinburgh, Edinburgh, United Kingdom
- * E-mail:
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Novel mutations support a role for Profilin 1 in the pathogenesis of ALS. Neurobiol Aging 2014; 36:1602.e17-27. [PMID: 25499087 PMCID: PMC4357530 DOI: 10.1016/j.neurobiolaging.2014.10.032] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 10/01/2014] [Accepted: 10/24/2014] [Indexed: 12/11/2022]
Abstract
Mutations in the gene encoding profilin 1 (PFN1) have recently been shown to cause amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disorder. We sequenced the PFN1 gene in a cohort of ALS patients (n = 485) and detected 2 novel variants (A20T and Q139L), as well as 4 cases with the previously identified E117G rare variant (∼ 1.2%). A case-control meta-analysis of all published E117G ALS+/- frontotemporal dementia cases including those identified in this report was significant p = 0.001, odds ratio = 3.26 (95% confidence interval, 1.6-6.7), demonstrating this variant to be a susceptibility allele. Postmortem tissue from available patients displayed classic TAR DNA-binding protein 43 pathology. In both transient transfections and in fibroblasts from a patient with the A20T change, we showed that this novel PFN1 mutation causes protein aggregation and the formation of insoluble high molecular weight species which is a hallmark of ALS pathology. Our findings show that PFN1 is a rare cause of ALS and adds further weight to the underlying genetic heterogeneity of this disease.
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PFN1 mutations are also rare in the Catalan population with amyotrophic lateral sclerosis. J Neurol 2014; 261:2387-92. [DOI: 10.1007/s00415-014-7501-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 09/08/2014] [Accepted: 09/09/2014] [Indexed: 12/11/2022]
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Freischmidt A, Müller K, Zondler L, Weydt P, Volk AE, Božič AL, Walter M, Bonin M, Mayer B, von Arnim CAF, Otto M, Dieterich C, Holzmann K, Andersen PM, Ludolph AC, Danzer KM, Weishaupt JH. Serum microRNAs in patients with genetic amyotrophic lateral sclerosis and pre-manifest mutation carriers. ACTA ACUST UNITED AC 2014; 137:2938-50. [PMID: 25193138 DOI: 10.1093/brain/awu249] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Knowledge about the nature of pathomolecular alterations preceding onset of symptoms in amyotrophic lateral sclerosis is largely lacking. It could not only pave the way for the discovery of valuable therapeutic targets but might also govern future concepts of pre-manifest disease modifying treatments. MicroRNAs are central regulators of transcriptome plasticity and participate in pathogenic cascades and/or mirror cellular adaptation to insults. We obtained comprehensive expression profiles of microRNAs in the serum of patients with familial amyotrophic lateral sclerosis, asymptomatic mutation carriers and healthy control subjects. We observed a strikingly homogenous microRNA profile in patients with familial amyotrophic lateral sclerosis that was largely independent from the underlying disease gene. Moreover, we identified 24 significantly downregulated microRNAs in pre-manifest amyotrophic lateral sclerosis mutation carriers up to two decades or more before the estimated time window of disease onset; 91.7% of the downregulated microRNAs in mutation carriers overlapped with the patients with familial amyotrophic lateral sclerosis. Bioinformatic analysis revealed a consensus sequence motif present in the vast majority of downregulated microRNAs identified in this study. Our data thus suggest specific common denominators regarding molecular pathogenesis of different amyotrophic lateral sclerosis genes. We describe the earliest pathomolecular alterations in amyotrophic lateral sclerosis mutation carriers known to date, which provide a basis for the discovery of novel therapeutic targets and strongly argue for studies evaluating presymptomatic disease-modifying treatment in amyotrophic lateral sclerosis.
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Affiliation(s)
| | | | - Lisa Zondler
- 1 Department of Neurology, Ulm University, Ulm, Germany
| | - Patrick Weydt
- 1 Department of Neurology, Ulm University, Ulm, Germany
| | | | | | - Michael Walter
- 4 Department of Medical Genetics, University of Tübingen, Tübingen, Germany
| | - Michael Bonin
- 4 Department of Medical Genetics, University of Tübingen, Tübingen, Germany
| | - Benjamin Mayer
- 5 Institute for Epidemiology and Medical Biometry, Ulm University, Ulm, Germany
| | | | - Markus Otto
- 1 Department of Neurology, Ulm University, Ulm, Germany
| | | | - Karlheinz Holzmann
- 6 Genomics-Core Facility, University Hospital Ulm, Centre for Biomedical Research, Ulm, Germany
| | - Peter M Andersen
- 1 Department of Neurology, Ulm University, Ulm, Germany 7 The Institute of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden 8 Virtual Helmholtz Institute RNA dysmetabolism in Amyotrophic Lateral Sclerosis and Fronto-temporal Dementia, Germany
| | - Albert C Ludolph
- 1 Department of Neurology, Ulm University, Ulm, Germany 8 Virtual Helmholtz Institute RNA dysmetabolism in Amyotrophic Lateral Sclerosis and Fronto-temporal Dementia, Germany
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Profilin 1 associates with stress granules and ALS-linked mutations alter stress granule dynamics. J Neurosci 2014; 34:8083-97. [PMID: 24920614 DOI: 10.1523/jneurosci.0543-14.2014] [Citation(s) in RCA: 113] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Mutations in the PFN1 gene encoding profilin 1 are a rare cause of familial amyotrophic lateral sclerosis (ALS). Profilin 1 is a well studied actin-binding protein but how PFN1 mutations cause ALS is unknown. The budding yeast, Saccharomyces cerevisiae, has one PFN1 ortholog. We expressed the ALS-linked profilin 1 mutant proteins in yeast, demonstrating a loss of protein stability and failure to restore growth to profilin mutant cells, without exhibiting gain-of-function toxicity. This model provides for simple and rapid screening of novel ALS-linked PFN1 variants. To gain insight into potential novel roles for profilin 1, we performed an unbiased, genome-wide synthetic lethal screen with yeast cells lacking profilin (pfy1Δ). Unexpectedly, deletion of several stress granule and processing body genes, including pbp1Δ, were found to be synthetic lethal with pfy1Δ. Mutations in ATXN2, the human ortholog of PBP1, are a known ALS genetic risk factor and ataxin 2 is a stress granule component in mammalian cells. Given this genetic interaction and recent evidence linking stress granule dynamics to ALS pathogenesis, we hypothesized that profilin 1 might also associate with stress granules. Here we report that profilin 1 and related protein profilin 2 are novel stress granule-associated proteins in mouse primary cortical neurons and in human cell lines and that ALS-linked mutations in profilin 1 alter stress granule dynamics, providing further evidence for the potential role of stress granules in ALS pathogenesis.
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Abstract
Our understanding of amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disease, is expanding rapidly as its genetic causes are uncovered. The pace of new gene discovery over the last 5 years has accelerated, providing new insights into the pathogenesis of disease and highlighting biological pathways as targets for therapeutic development. This article reviews our current understanding of the heritability of ALS and provides an overview of each of the major ALS genes, highlighting their phenotypic characteristics and frequencies as a guide for clinicians evaluating patients with ALS.
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Affiliation(s)
- Matthew B Harms
- Neuromuscular Division, Department of Neurology, Hope Center for Neurological Disorders, Washington University School of Medicine, 660 South Euclid Avenue, St Louis, MO 63110, USA.
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Fratta P, Charnock J, Collins T, Devoy A, Howard R, Malaspina A, Orrell R, Sidle K, Clarke J, Shoai M, Lu CH, Hardy J, Plagnol V, Fisher EMC. Profilin1 E117G is a moderate risk factor for amyotrophic lateral sclerosis. J Neurol Neurosurg Psychiatry 2014; 85:506-8. [PMID: 24309268 PMCID: PMC3995330 DOI: 10.1136/jnnp-2013-306761] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are progressive neurodegenerative disorders that share significant clinical, pathological and genetic overlap and are considered to represent different ends of a common disease spectrum. Mutations in Profilin1 have recently been described as a rare cause of familial ALS. The PFN1 E117G missense variant has been described in familial and sporadic cases, and also found in controls, casting doubt on its pathogenicity. Interpretation of such variants represents a significant clinical-genetics challenge. OBJECTIVE AND RESULTS Here, we combine a screen of a new cohort of 383 ALS patients with multiple-sequence datasets to refine estimates of the ALS and FTD risk associated with PFN1 E117G. Together, our cohorts add up to 5118 ALS and FTD cases and 13 089 controls. We estimate a frequency of E117G of 0.11% in controls and 0.25% in cases. Estimated odds after population stratification is 2.44 (95% CI 1.048 to ∞, Mantel-Haenszel test p=0.036). CONCLUSIONS Our results show an association between E117G and ALS, with a moderate effect size.
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Affiliation(s)
- Pietro Fratta
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, , London, UK
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Recent progress in the genetics of motor neuron disease. Eur J Med Genet 2014; 57:103-12. [DOI: 10.1016/j.ejmg.2014.01.002] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Accepted: 01/14/2014] [Indexed: 01/07/2023]
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61
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Rosenbohm A, Kassubek J, Weydt P, Marroquin N, Volk AE, Kubisch C, Huppertz HJ, Weber M, Andersen PM, Weishaupt JH, Ludolph AC. Can lesions to the motor cortex induce amyotrophic lateral sclerosis? J Neurol 2013; 261:283-90. [DOI: 10.1007/s00415-013-7185-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 11/05/2013] [Accepted: 11/05/2013] [Indexed: 12/11/2022]
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Fernández-Borges N, Eraña H, Elezgarai SR, Harrathi C, Gayosso M, Castilla J. Infectivity versus Seeding in Neurodegenerative Diseases Sharing a Prion-Like Mechanism. Int J Cell Biol 2013; 2013:583498. [PMID: 24187553 PMCID: PMC3800648 DOI: 10.1155/2013/583498] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Accepted: 08/21/2013] [Indexed: 12/11/2022] Open
Abstract
Prions are considered the best example to prove that the biological information can be transferred protein to protein through a conformational change. The term "prion-like" is used to describe molecular mechanisms that share similarities with the mammalian prion protein self-perpetuating aggregation and spreading characteristics. Since prions are presumably composed only of protein and are infectious, the more similar the mechanisms that occur in the different neurodegenerative diseases, the more these processes will resemble an infection. In vitro and in vivo experiments carried out during the last decade in different neurodegenerative disorders such as Alzheimer's disease (AD), Parkinson's diseases (PD), and amyotrophic lateral sclerosis (ALS) have shown a convergence toward a unique mechanism of misfolded protein propagation. In spite of the term "infection" that could be used to explain the mechanism governing the diversity of the pathological processes, other concepts as "seeding" or "de novo induction" are being used to describe the in vivo propagation and transmissibility of misfolded proteins. The current studies are demanding an extended definition of "disease-causing agents" to include those already accepted as well as other misfolded proteins. In this new scenario, "seeding" would be a type of mechanism by which an infectious agent can be transmitted but should not be used to define a whole "infection" process.
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Affiliation(s)
| | - Hasier Eraña
- CIC bioGUNE, Parque Tecnológico de Bizkaia, Derio, 48160 Bizkaia, Spain
| | | | - Chafik Harrathi
- CIC bioGUNE, Parque Tecnológico de Bizkaia, Derio, 48160 Bizkaia, Spain
| | - Mayela Gayosso
- CIC bioGUNE, Parque Tecnológico de Bizkaia, Derio, 48160 Bizkaia, Spain
| | - Joaquín Castilla
- CIC bioGUNE, Parque Tecnológico de Bizkaia, Derio, 48160 Bizkaia, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao, 48011 Bizkaia, Spain
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van Blitterswijk M, Baker MC, Bieniek KF, Knopman DS, Josephs KA, Boeve B, Caselli R, Wszolek ZK, Petersen R, Graff-Radford NR, Boylan KB, Dickson DW, Rademakers R. Profilin-1 mutations are rare in patients with amyotrophic lateral sclerosis and frontotemporal dementia. Amyotroph Lateral Scler Frontotemporal Degener 2013; 14:463-9. [PMID: 23634771 PMCID: PMC3923463 DOI: 10.3109/21678421.2013.787630] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Mutations in profilin-1 (PFN1) have recently been identified in patients with amyotrophic lateral sclerosis (ALS). Because of the considerable overlap between ALS and the common subtype of frontotemporal dementia, which is characterized by transactive response DNA-binding protein 43 pathology (FTLD-TDP), we tested cohorts of ALS and FTLD-TDP patients for PFN1 mutations. DNA was obtained from 342 ALS patients and 141 FTLD-TDP patients at our outpatient clinic and brain bank for neurodegenerative diseases at the Mayo Clinic Florida, Jacksonville, USA. We screened these patients for mutations in coding regions of PFN1 by Sanger sequencing. Subsequently, we used TaqMan genotyping assays to investigate the identified variant in 1167 control subjects. From the results, one variant, p.E117G, was detected in one ALS patient, one FTLD-TDP patient, and two control subjects. The mutation frequency of patients versus control subjects was not significantly different (p-value = 0.36). Moreover, PFN1 and TDP-43 staining of autopsy material did not differ between patients with or without this variant. In conclusion, the p.E117G variant appears to represent a benign polymorphism. PFN1 mutations, in general, are rare in ALS and FTLD-TDP patients.
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Affiliation(s)
| | | | | | | | | | - Bradley Boeve
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | | | | | | | | | | | | | - Rosa Rademakers
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
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Freischmidt A, Müller K, Ludolph AC, Weishaupt JH. Systemic dysregulation of TDP-43 binding microRNAs in amyotrophic lateral sclerosis. Acta Neuropathol Commun 2013; 1:42. [PMID: 24252274 PMCID: PMC3893596 DOI: 10.1186/2051-5960-1-42] [Citation(s) in RCA: 117] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Accepted: 07/25/2013] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND A pathological hallmark of most amyotrophic lateral sclerosis (ALS) cases are intracellular aggregates of the protein TDP-43. The pathophysiological relevance of TDP-43 is underlined by familial ALS cases caused by TDP-43 mutations. TDP-43 is involved in processing of both coding RNAs and microRNAs, which are key epigenetic regulators of transcriptome plasticity and suspected to contribute to neurological diseases. We therefore asked whether the TDP-43 binding microRNAs recently identified in cell lines are also dysregulated in ALS patients. We compared their abundance in cerebrospinal fluid (CSF), serum and immortalized lymphoblast cell lines (LCLs) derived from ALS patients and healthy controls. RESULTS We found that expression levels of 5 out of 9 TDP-43 binding microRNAs were altered in the CSF and serum of sporadic ALS cases. The differentially regulated serum microRNAs together with a poor correlation between CSF and serum levels indicate a systemic dysregulation of microRNA abundance independent from the CSF compartment, in line with the ubiquitous expression of TDP-43. The most strongly regulated microRNAs could be confirmed in LCLs from genetically defined ALS patients. While dysregulation of miR-143-5p/3p seems to be a common feature of ALS pathology, downregulation of miR-132-5p/3p and miR-574-5p/3p was evident in sporadic, TARDBP, FUS and C9ORF72, but not SOD1 mutant patients. This parallels the TDP-43 pathology found in most ALS cases, but usually not in patients with SOD1 mutation. CONCLUSIONS We thus report a systemic and genotype-dependent dysregulation of TDP-43 binding microRNAs in human biomaterial that might reflect an easily accessible biological measure of TDP-43 dysfunction. Furthermore we suggest an independent regulation of TDP-43 binding microRNAs in the serum and CSF compartment as well as a generally low transition of microRNAs across the blood-cerebrospinal fluid barrier.
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Affiliation(s)
- Axel Freischmidt
- Department of Neurology, Ulm University, Albert-Einstein-Allee 11, Ulm 89081, Germany
| | - Kathrin Müller
- Department of Neurology, Ulm University, Albert-Einstein-Allee 11, Ulm 89081, Germany
| | - Albert C Ludolph
- Department of Neurology, Ulm University, Albert-Einstein-Allee 11, Ulm 89081, Germany
| | - Jochen H Weishaupt
- Department of Neurology, Ulm University, Albert-Einstein-Allee 11, Ulm 89081, Germany
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Mutation analysis and immunopathological studies of PFN1 in familial and sporadic amyotrophic lateral sclerosis. Neurobiol Aging 2013; 34:2235.e7-10. [PMID: 23635659 DOI: 10.1016/j.neurobiolaging.2013.04.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Revised: 03/15/2013] [Accepted: 04/01/2013] [Indexed: 11/22/2022]
Abstract
Mutations in PFN1, a gene encoding the actin monomer-binding protein profilin 1, were recently reported in 1% to 2% of familial amyotrophic lateral sclerosis (ALS) patients. In vitro functional studies suggested that PFN1 mutations lead to ubiquitin-positive inclusions and impairment of cytoskeletal pathways. In the present study, mutation analysis of PFN1 was performed in an Australian cohort of 110 ALS families and 715 sporadic ALS patients. No PFN1 mutations were identified in familial ALS patients. Two rare non-synonymous variants (E117D and E117G) were found in sporadic ALS patients at similar incidences to that reported in public SNP databases. Immunostaining of PFN1 in sporadic ALS and familial ALS patients, including those with mutations in SOD1, FUS, UBQLN2 and C9ORF72, found no PFN1-positive inclusions in spinal motor neurons. Our data suggest that PFN1 mutations and pathology are not common in an Australian ALS cohort of predominantly European ancestry.
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