1
|
Skolka MP, Naddaf E. Exploring challenges in the management and treatment of inclusion body myositis. Curr Opin Rheumatol 2023; 35:404-413. [PMID: 37503813 PMCID: PMC10552844 DOI: 10.1097/bor.0000000000000958] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
PURPOSE OF REVIEW This review provides an overview of the management and treatment landscape of inclusion body myositis (IBM), while highlighting the current challenges and future directions. RECENT FINDINGS IBM is a slowly progressive myopathy that predominantly affects patients over the age of 40, leading to increased morbidity and mortality. Unfortunately, a definitive cure for IBM remains elusive. Various clinical trials targeting inflammatory and some of the noninflammatory pathways have failed. The search for effective disease-modifying treatments faces numerous hurdles including variability in presentation, diagnostic challenges, poor understanding of pathogenesis, scarcity of disease models, a lack of validated outcome measures, and challenges related to clinical trial design. Close monitoring of swallowing and respiratory function, adapting an exercise routine, and addressing mobility issues are the mainstay of management at this time. SUMMARY Addressing the obstacles encountered by patients with IBM and the medical community presents a multitude of challenges. Effectively surmounting these hurdles requires embracing cutting-edge research strategies aimed at enhancing the management and treatment of IBM, while elevating the quality of life for those affected.
Collapse
|
2
|
Romeo M, Stravalaci M, Beeg M, Rossi A, Fiordaliso F, Corbelli A, Salmona M, Gobbi M, Cagnotto A, Diomede L. Humanin Specifically Interacts with Amyloid-β Oligomers and Counteracts Their in vivo Toxicity. J Alzheimers Dis 2017; 57:857-871. [PMID: 28282805 DOI: 10.3233/jad-160951] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The 24-residue peptide humanin (HN) has been proposed as a peptide-based inhibitor able to interact directly with amyloid-β (Aβ) oligomers and interfere with the formation and/or biological properties of toxic Aβ species. When administered exogenously, HN, or its synthetic S14G-derivative (HNG), exerted multiple cytoprotective effects, counteracting the Aβ-induced toxicity. Whether these peptides interact directly with Aβ, particularly with the soluble oligomeric assemblies, remains largely unknown. We here investigated the ability of HN and HNG to interact directly with highly aggregating Aβ42, and interfere with the formation and toxicity of its oligomers. Experiments were run in cell-free conditions and in vivo in a transgenic C. elegans strain in which the Aβ toxicity was specifically due to oligomeric species. Thioflavin-T assay indicated that both HN and HNG delay the formation and reduce the final amount of Aβ42 fibrils. In vitro surface plasmon resonance studies indicated that they interact with Aβ42 oligomers favoring the formation of amorphous larger assemblies, observed with turbidity and electron microscopy. In vivo studies indicated that both HN and HNG decrease the relative abundance of A11-positive prefibrillar oligomers as well as OC-positive fibrillar oligomers and had similar protective effects. However, while HN possibly decreased the oligomers by promoting their assembly into larger aggregates, the reduction of oligomers caused by HNG can be ascribed to a marked decrease of the total Aβ levels, likely the consequence of the HNG-induced overexpression of the Aβ-degrading enzyme neprilysin. These findings provide information on the mechanisms underlying the anti-oligomeric effects of HN and HNG and illustrate the role of S14G substitution in regulating the in vivo mechanism of action.
Collapse
Affiliation(s)
- Margherita Romeo
- Department of Molecular Biochemistry and Pharmacology, IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy
| | - Matteo Stravalaci
- Department of Molecular Biochemistry and Pharmacology, IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy
| | - Marten Beeg
- Department of Molecular Biochemistry and Pharmacology, IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy
| | - Alessandro Rossi
- Department of Molecular Biochemistry and Pharmacology, IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy
| | - Fabio Fiordaliso
- Department of Cardiovascular Research, Unit of Bio-imaging, IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy
| | - Alessandro Corbelli
- Department of Cardiovascular Research, Unit of Bio-imaging, IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy
| | - Mario Salmona
- Department of Molecular Biochemistry and Pharmacology, IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy
| | - Marco Gobbi
- Department of Molecular Biochemistry and Pharmacology, IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy
| | - Alfredo Cagnotto
- Department of Molecular Biochemistry and Pharmacology, IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy
| | - Luisa Diomede
- Department of Molecular Biochemistry and Pharmacology, IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy
| |
Collapse
|
3
|
Morales-Zavala F, Arriagada H, Hassan N, Velasco C, Riveros A, Álvarez AR, Minniti AN, Rojas-Silva X, Muñoz LL, Vasquez R, Rodriguez K, Sanchez-Navarro M, Giralt E, Araya E, Aldunate R, Kogan MJ. Peptide multifunctionalized gold nanorods decrease toxicity of β-amyloid peptide in a Caenorhabditis elegans model of Alzheimer's disease. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2017; 13:2341-2350. [PMID: 28673851 DOI: 10.1016/j.nano.2017.06.013] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 06/01/2017] [Accepted: 06/26/2017] [Indexed: 12/01/2022]
Abstract
The properties of nanometric materials make nanotechnology a promising platform for tackling problems of contemporary medicine. In this work, gold nanorods were synthetized and stabilized with polyethylene glycols and modified with two kinds of peptides. The D1 peptide that recognizes toxic aggregates of Aβ, a peptide involved in Alzheimer's disease (AD); and the Angiopep 2 that can be used to deliver nanorods to the mammalian central nervous system. The nanoconjugates were characterized using absorption spectrophotometry, dynamic light scattering, and transmission electron microscopy, among other techniques. We determined that the nanoconjugate does not affect neuronal viability; it penetrates the cells, and decreases aggregation of Aβ peptide in vitro. We also showed that when we apply our nanosystem to a Caenorhabditis elegans AD model, the toxicity of aggregated Aβ peptide is decreased. This work may contribute to the development of therapies for AD based on metallic nanoparticles.
Collapse
Affiliation(s)
- Francisco Morales-Zavala
- Departamento de Química Farmacológica y Toxicológica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago; Advanced Center for Chronic Diseases (ACCDiS), Sergio Livingstone 1007, Independencia, Santiago, Chile.
| | - Hector Arriagada
- Escuela de Biotecnología, Facultad de Ciencias, Universidad Santo Tomás, Ejercito 146, Santiago, Chile.
| | - Natalia Hassan
- Departamento de Química Farmacológica y Toxicológica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago; Programa Institucional de Fomento a la I+D+I, Universidad Tecnológica Metropolitana, Edificio de Ciencia y Tecnologia, Ignacio Valdivieso 2409, San Joaquin.
| | - Carolina Velasco
- Departamento de Química Farmacológica y Toxicológica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago; Advanced Center for Chronic Diseases (ACCDiS), Sergio Livingstone 1007, Independencia, Santiago, Chile.
| | - Ana Riveros
- Departamento de Química Farmacológica y Toxicológica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago; Advanced Center for Chronic Diseases (ACCDiS), Sergio Livingstone 1007, Independencia, Santiago, Chile.
| | - Alejandra R Álvarez
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Alameda 340, Santiago 8331010, Chile; Centro de envejecimiento y regeneración (CARE), Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.
| | - Alicia N Minniti
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Alameda 340, Santiago 8331010, Chile.
| | - Ximena Rojas-Silva
- Sección de Metrología Química, Comisión Chilena de Energía Nuclear, Nueva Bilbao 12501, La Reina, Santiago, Chile.
| | - Luis L Muñoz
- Sección de Metrología Química, Comisión Chilena de Energía Nuclear, Nueva Bilbao 12501, La Reina, Santiago, Chile.
| | - Rodrigo Vasquez
- Departamento de Química Farmacológica y Toxicológica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago; Advanced Center for Chronic Diseases (ACCDiS), Sergio Livingstone 1007, Independencia, Santiago, Chile; Departamento de Ciencias Quimicas, Facultad de Ciencias Exactas, Universidad Andres Bello, Av. Republica 275, Santiago, Chile.
| | - Katherine Rodriguez
- Departamento de Ciencias Quimicas, Facultad de Ciencias Exactas, Universidad Andres Bello, Av. Republica 275, Santiago, Chile.
| | - Macarena Sanchez-Navarro
- Institute for Research in Biomedicine-Barcelona Institute of Science and Technology, Baldiri Reixac 10, 08028 Barcelona, Spain.
| | - Ernest Giralt
- Institute for Research in Biomedicine-Barcelona Institute of Science and Technology, Baldiri Reixac 10, 08028 Barcelona, Spain.
| | - Eyleen Araya
- Departamento de Ciencias Quimicas, Facultad de Ciencias Exactas, Universidad Andres Bello, Av. Republica 275, Santiago, Chile.
| | - Rebeca Aldunate
- Escuela de Biotecnología, Facultad de Ciencias, Universidad Santo Tomás, Ejercito 146, Santiago, Chile.
| | - Marcelo J Kogan
- Departamento de Química Farmacológica y Toxicológica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago; Advanced Center for Chronic Diseases (ACCDiS), Sergio Livingstone 1007, Independencia, Santiago, Chile.
| |
Collapse
|
4
|
Afzali AM, Ruck T, Wiendl H, Meuth SG. Animal models in idiopathic inflammatory myopathies: How to overcome a translational roadblock? Autoimmun Rev 2017; 16:478-494. [DOI: 10.1016/j.autrev.2017.03.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 02/13/2017] [Indexed: 12/19/2022]
|
5
|
Minniti AN, Arrazola MS, Bravo-Zehnder M, Ramos F, Inestrosa NC, Aldunate R. The protein oxidation repair enzyme methionine sulfoxide reductase a modulates Aβ aggregation and toxicity in vivo. Antioxid Redox Signal 2015; 22:48-62. [PMID: 24988428 PMCID: PMC4270145 DOI: 10.1089/ars.2013.5803] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AIMS To examine the role of the enzyme methionine sulfoxide reductase A-1 (MSRA-1) in amyloid-β peptide (Aβ)-peptide aggregation and toxicity in vivo, using a Caenorhabditis elegans model of the human amyloidogenic disease inclusion body myositis. RESULTS MSRA-1 specifically reduces oxidized methionines in proteins. Therefore, a deletion of the msra-1 gene was introduced into transgenic C. elegans worms that express the Aβ-peptide in muscle cells to prevent the reduction of oxidized methionines in proteins. In a constitutive transgenic Aβ strain that lacks MSRA-1, the number of amyloid aggregates decreases while the number of oligomeric Aβ species increases. These results correlate with enhanced synaptic dysfunction and mislocalization of the nicotinic acetylcholine receptor ACR-16 at the neuromuscular junction (NMJ). INNOVATION This approach aims at modulating the oxidation of Aβ in vivo indirectly by dismantling the methionine sulfoxide repair system. The evidence presented here shows that the absence of MSRA-1 influences Aβ aggregation and aggravates locomotor behavior and NMJ dysfunction. The results suggest that therapies which boost the activity of the Msr system could have a beneficial effect in managing amyloidogenic pathologies. CONCLUSION The absence of MSRA-1 modulates Aβ-peptide aggregation and increments its deleterious effects in vivo.
Collapse
Affiliation(s)
- Alicia N Minniti
- 1 Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile , Santiago, Chile
| | | | | | | | | | | |
Collapse
|
6
|
Mace DL, Weisdepp P, Gevirtzman L, Boyle T, Waterston RH. A high-fidelity cell lineage tracing method for obtaining systematic spatiotemporal gene expression patterns in Caenorhabditis elegans. G3 (BETHESDA, MD.) 2013; 3:851-63. [PMID: 23550142 PMCID: PMC3656732 DOI: 10.1534/g3.113.005918] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 03/16/2013] [Indexed: 12/17/2022]
Abstract
Advances in microscopy and fluorescent reporters have allowed us to detect the onset of gene expression on a cell-by-cell basis in a systemic fashion. This information, however, is often encoded in large repositories of images, and developing ways to extract this spatiotemporal expression data is a difficult problem that often uses complex domain-specific methods for each individual data set. We present a more unified approach that incorporates general previous information into a hierarchical probabilistic model to extract spatiotemporal gene expression from 4D confocal microscopy images of developing Caenorhabditis elegans embryos. This approach reduces the overall error rate of our automated lineage tracing pipeline by 3.8-fold, allowing us to routinely follow the C. elegans lineage to later stages of development, where individual neuronal subspecification becomes apparent. Unlike previous methods that often use custom approaches that are organism specific, our method uses generalized linear models and extensions of standard reversible jump Markov chain Monte Carlo methods that can be readily extended to other organisms for a variety of biological inference problems relating to cell fate specification. This modeling approach is flexible and provides tractable avenues for incorporating additional previous information into the model for similar difficult high-fidelity/low error tolerance image analysis problems for systematically applied genomic experiments.
Collapse
Affiliation(s)
- Daniel L Mace
- Department of Genome Sciences, University of Washington, Seattle, Washington 98103, USA.
| | | | | | | | | |
Collapse
|
7
|
Synaptic defects associated with s-inclusion body myositis are prevented by copper. Biometals 2012; 25:815-24. [DOI: 10.1007/s10534-012-9553-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2011] [Accepted: 04/23/2012] [Indexed: 12/26/2022]
|
8
|
|
9
|
|
10
|
Copper reduces Aβ oligomeric species and ameliorates neuromuscular synaptic defects in a C. elegans model of inclusion body myositis. J Neurosci 2011; 31:10149-58. [PMID: 21752991 DOI: 10.1523/jneurosci.0336-11.2011] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Alzheimer's disease and inclusion body myositis (IBM) are disorders frequently found in the elderly and characterized by the presence of amyloid-β peptide (Aβ) aggregates. We used Caenorhabditis elegans that express Aβ in muscle cells as a model of IBM, with the aim of analyzing Aβ-induced muscle pathology and evaluating the consequences of modulating Aβ aggregation. First, we tested whether the altered motility we observed in the Aβ transgenic strain could be the result of a compromised neuromuscular synapse. Our pharmacological analyses show that synaptic transmission is defective in our model and suggest a specific defect on nicotine-sensitive acetylcholine receptors (AChRs). Through GFP-coupled protein visualization, we found that synaptic dysfunction correlates with mislocalization of ACR-16, the AChR subunit essential for nicotine-triggered currents. Histological and biochemical analysis allowed us to determine that copper treatment increases the amyloid deposits and decreases Aβ oligomers in this model. Furthermore, copper treatment improves motility, ACR-16 localization, and synaptic function and delays Aβ-induced paralysis. Our results indicate that copper modulates Aβ-induced pathology and suggest that Aβ oligomers are triggering neuromuscular dysfunction. Our findings emphasize the importance of neuromuscular synaptic dysfunction and the relevance of modulating the amyloidogenic component as an alternative therapeutic approach for this debilitating disease.
Collapse
|
11
|
Abstract
Inclusion body myositis is a progressive disease of the skeletal muscle. Here, specific theories of its pathogenesis are reviewed and general considerations pertaining to modeling of this disease discussed. Understanding of inclusion body myositis disease mechanism remains extremely poor. Current published animal models do not represent the disease. Future studies need to consider the critical role of biomarkers and methodologic issues in their discovery.
Collapse
Affiliation(s)
- Steven A Greenberg
- Department of Neurology, Division of Neuromuscular Disease, Brigham and Women's Hospital, and Children's Hospital Informatics Program, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA.
| |
Collapse
|
12
|
Diomede L, Cassata G, Fiordaliso F, Salio M, Ami D, Natalello A, Doglia SM, De Luigi A, Salmona M. Tetracycline and its analogues protect Caenorhabditis elegans from β amyloid-induced toxicity by targeting oligomers. Neurobiol Dis 2010; 40:424-31. [PMID: 20637283 DOI: 10.1016/j.nbd.2010.07.002] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2010] [Revised: 07/05/2010] [Accepted: 07/07/2010] [Indexed: 02/01/2023] Open
Abstract
The accumulation and deposition of amyloid beta (Aβ) peptide in extracellular dense plaques in the brain is a key phase in Alzheimer's disease (AD). Small oligomeric forms of Aβ are responsible for the toxicity and the early cognitive impairment observed in patients before the amyloid plaque deposits appear. It is essential for the development of an efficient cure for AD to identify compounds that interfere with Aβ aggregation, counteracting the molecular mechanisms involved in conversion of the monomeric amyloid protein into oligomeric and fibrillar forms. Tetracyclines have been proposed for AD therapy, although their effects on the aggregation of Aβ protein, particularly their ability to interact in vivo with the Aβ oligomers and/or aggregates, remain to be understood. Using transgenic Caenorhabditis elegans as a simplified invertebrate model of AD, we evaluated the ability of tetracyclines to interfere with the sequence of events leading to Aβ proteotoxicity. The drugs directly interact with the Aβ assemblies in vivo and reduce Aβ oligomer deposition, protecting C. elegans from oxidative stress and the onset of the paralysis phenotype. These effects were specific, dose-related and not linked to any antibiotic activity, suggesting that the drugs might offer an effective therapeutic strategy to target soluble Aβ aggregates.
Collapse
Affiliation(s)
- Luisa Diomede
- Department of Molecular Biochemistry and Pharmacology, Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy.
| | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Abstract
AbstractThe nematode Caenorhabditis elegans is a genetic model organism and the only animal with a complete nervous system wiring diagram. With only 302 neurons and 95 striated muscle cells, a rich array of mutants with defective locomotion and the facility for individual targeted gene knockdown by RNA interference, it lends itself to the exploration of gene function at nerve muscle junctions. With approximately 60% of human disease genes having a C. elegans homologue, there is growing interest in the deployment of lowcost, high-throughput, drug screens of nematode transgenic and mutant strains mimicking aspects of the pathology of devastating human neuromuscular disorders. Here we explore the contributions already made by C. elegans to our understanding of muscular dystrophies (Duchenne and Becker), spinal muscular atrophy, amyotrophic lateral sclerosis, Friedreich’s ataxia, inclusion body myositis and the prospects for contributions to other neuromuscular disorders. A bottleneck to low-cost, in vivo, large-scale chemical library screening for new candidate therapies has been rapid, automated, behavioural phenotyping. Recent progress in quantifying simple swimming (thrashing) movements is making such screening possible and is expediting the translation of drug candidates towards the clinic.
Collapse
|
14
|
Buckingham SD, Jones AK, Brown LA, Sattelle DB. Nicotinic acetylcholine receptor signalling: roles in Alzheimer's disease and amyloid neuroprotection. Pharmacol Rev 2009; 61:39-61. [PMID: 19293145 DOI: 10.1124/pr.108.000562] [Citation(s) in RCA: 208] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Alzheimer's disease (AD), the major contributor to dementia in the elderly, involves accumulation in the brain of extracellular plaques containing the beta-amyloid protein (Abeta) and intracellular neurofibrillary tangles of hyperphosphorylated tau protein. AD is also characterized by a loss of neurons, particularly those expressing nicotinic acetylcholine receptors (nAChRs), thereby leading to a reduction in nAChR numbers. The Abeta(1-42) protein, which is toxic to neurons, is critical to the onset and progression of AD. The discovery of new drug therapies for AD is likely to be accelerated by an improved understanding of the mechanisms whereby Abeta causes neuronal death. We examine the evidence for a role in Abeta(1-42) toxicity of nAChRs; paradoxically, nAChRs can also protect neurons when activated by nicotinic ligands. Abeta peptides and nicotine differentially activate several intracellular signaling pathways, including the phosphatidylinositol 3-kinase/v-akt murine thymoma viral oncogene homolog pathway, the extracellular signal-regulated kinase/mitogen-activated protein kinase, and JAK-2/STAT-3 pathways. These pathways control cell death or survival and the secretion of Abeta peptides. We propose that understanding the differential activation of these pathways by nicotine and/or Abeta(1-42) may offer the prospect of new routes to therapy for AD.
Collapse
Affiliation(s)
- Steven D Buckingham
- Medical Research Council Functional Genomics Unit, Department of Physiology Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, UK, OX1 3QX
| | | | | | | |
Collapse
|
15
|
Minniti AN, Rebolledo DL, Grez PM, Fadic R, Aldunate R, Volitakis I, Cherny RA, Opazo C, Masters C, Bush AI, Inestrosa NC. Intracellular amyloid formation in muscle cells of Abeta-transgenic Caenorhabditis elegans: determinants and physiological role in copper detoxification. Mol Neurodegener 2009; 4:2. [PMID: 19126228 PMCID: PMC2632641 DOI: 10.1186/1750-1326-4-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2008] [Accepted: 01/06/2009] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND The amyloid beta-peptide is a ubiquitous peptide, which is prone to aggregate forming soluble toxic oligomers and insoluble less-toxic aggregates. The intrinsic and external/environmental factors that determine Abeta aggregation in vivo are poorly understood, as well as the cellular meaning of this process itself. Genetic data as well as cell biological and biochemical evidence strongly support the hypothesis that Abeta is a major player in the onset and development of Alzheimer's disease. In addition, it is also known that Abeta is involved in Inclusion Body Myositis, a common myopathy of the elderly in which the peptide accumulates intracellularly. RESULTS In the present work, we found that intracellular Abeta aggregation in muscle cells of Caenorhabditis elegans overexpressing Abeta peptide is affected by two single amino acid substitutions, E22G (Arctic) and V18A (NIC). Both variations show decrease intracellular amyloidogenesis compared to wild type Abeta. We show that intracellular amyloid aggregation of wild type Abeta is accelerated by Cu2+ and diminished by copper chelators. Moreover, we demonstrate through toxicity and behavioral assays that Abeta-transgenic worms display a higher tolerance to Cu2+ toxic effects and that this resistance may be linked to the formation of amyloid aggregates. CONCLUSION Our data show that intracellular Abeta amyloid aggregates may trap excess of free Cu2+ buffering its cytotoxic effects and that accelerated intracellular Abeta aggregation may be part of a cell protective mechanism.
Collapse
Affiliation(s)
- Alicia N Minniti
- Centro de Regulación Celular y Patología "Joaquín V, Luco" (CRCP), MIFAB, Centro de Envejecimiento y Regeneración (CARE), Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Alameda 340, 8331010 Santiago, Chile.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|