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Kurbatskaya K, Phillips EC, Croft CL, Dentoni G, Hughes MM, Wade MA, Al-Sarraj S, Troakes C, O’Neill MJ, Perez-Nievas BG, Hanger DP, Noble W. Upregulation of calpain activity precedes tau phosphorylation and loss of synaptic proteins in Alzheimer's disease brain. Acta Neuropathol Commun 2016; 4:34. [PMID: 27036949 PMCID: PMC4818436 DOI: 10.1186/s40478-016-0299-2] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 03/15/2016] [Indexed: 12/05/2022] Open
Abstract
Alterations in calcium homeostasis are widely reported to contribute to synaptic degeneration and neuronal loss in Alzheimer’s disease. Elevated cytosolic calcium concentrations lead to activation of the calcium-sensitive cysteine protease, calpain, which has a number of substrates known to be abnormally regulated in disease. Analysis of human brain has shown that calpain activity is elevated in AD compared to controls, and that calpain-mediated proteolysis regulates the activity of important disease-associated proteins including the tau kinases cyclin-dependent kinase 5 and glycogen kinase synthase-3. Here, we sought to investigate the likely temporal association between these changes during the development of sporadic AD using Braak staged post-mortem brain. Quantification of protein amounts in these tissues showed increased activity of calpain-1 from Braak stage III onwards in comparison to controls, extending previous findings that calpain-1 is upregulated at end-stage disease, and suggesting that activation of calcium-sensitive signalling pathways are sustained from early stages of disease development. Increases in calpain-1 activity were associated with elevated activity of the endogenous calpain inhibitor, calpastatin, itself a known calpain substrate. Activation of the tau kinases, glycogen-kinase synthase-3 and cyclin-dependent kinase 5 were also found to occur in Braak stage II-III brain, and these preceded global elevations in tau phosphorylation and the loss of post-synaptic markers. In addition, we identified transient increases in total amyloid precursor protein and pre-synaptic markers in Braak stage II-III brain, that were lost by end stage Alzheimer's disease, that may be indicative of endogenous compensatory responses to the initial stages of neurodegeneration. These findings provide insight into the molecular events that underpin the progression of Alzheimer's disease, and further highlight the rationale for investigating novel treatment strategies that are based on preventing abnormal calcium homeostasis or blocking increases in the activity of calpain or important calpain substrates.
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152
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Lim D, Strucken EM, Choi BH, Chai HH, Cho YM, Jang GW, Kim TH, Gondro C, Lee SH. Genomic Footprints in Selected and Unselected Beef Cattle Breeds in Korea. PLoS One 2016; 11:e0151324. [PMID: 27023061 PMCID: PMC4811422 DOI: 10.1371/journal.pone.0151324] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Accepted: 02/26/2016] [Indexed: 01/01/2023] Open
Abstract
Korean Hanwoo cattle have been subjected to intensive artificial selection over the past four decades to improve meat production traits. Another three cattle varieties very closely related to Hanwoo reside in Korea (Jeju Black and Brindle) and in China (Yanbian). These breeds have not been part of a breeding scheme to improve production traits. Here, we compare the selected Hanwoo against these similar but presumed to be unselected populations to identify genomic regions that have been under recent selection pressure due to the breeding program. Rsb statistics were used to contrast the genomes of Hanwoo versus a pooled sample of the three unselected population (UN). We identified 37 significant SNPs (FDR corrected) in the HW/UN comparison and 21 known protein coding genes were within 1 MB to the identified SNPs. These genes were previously reported to affect traits important for meat production (14 genes), reproduction including mammary gland development (3 genes), coat color (2 genes), and genes affecting behavioral traits in a broader sense (2 genes). We subsequently sequenced (Illumina HiSeq 2000 platform) 10 individuals of the brown Hanwoo and the Chinese Yanbian to identify SNPs within the candidate genomic regions. Based on allele frequency differences, haplotype structures, and literature research, we singled out one non-synonymous SNP in the APP gene (APP: c.569C>T, Ala199Val) and predicted the mutational effect on the protein structure. We found that protein-protein interactions might be impaired due to increased exposed hydrophobic surfaces of the mutated protein. The APP gene has also been reported to affect meat tenderness in pigs and obesity in humans. Meat tenderness has been linked to intramuscular fat content, which is one of the main breeding goals for brown Hanwoo, potentially supporting a causal influence of the herein described nsSNP in the APP gene.
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Affiliation(s)
- Dajeong Lim
- Division of Animal Genomics & Bioinformatics, National Institute of Animal Science, RDA, Jeonju 565–851, Republic of Korea
| | - Eva M. Strucken
- School of Environmental and Rural Science, University of New England, Armidale, NSW Australia
| | - Bong Hwan Choi
- Division of Animal Genomics & Bioinformatics, National Institute of Animal Science, RDA, Jeonju 565–851, Republic of Korea
| | - Han Ha Chai
- Division of Animal Genomics & Bioinformatics, National Institute of Animal Science, RDA, Jeonju 565–851, Republic of Korea
| | - Yong Min Cho
- Division of Animal Genomics & Bioinformatics, National Institute of Animal Science, RDA, Jeonju 565–851, Republic of Korea
| | - Gul Won Jang
- Division of Animal Genomics & Bioinformatics, National Institute of Animal Science, RDA, Jeonju 565–851, Republic of Korea
| | - Tae-Hun Kim
- Division of Animal Genomics & Bioinformatics, National Institute of Animal Science, RDA, Jeonju 565–851, Republic of Korea
| | - Cedric Gondro
- School of Environmental and Rural Science, University of New England, Armidale, NSW Australia
| | - Seung Hwan Lee
- Division of Animal and Dairy Science, Chung Nam National University, Daejeon 305–764, Republic of Korea
- * E-mail:
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153
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PP2A methylation controls sensitivity and resistance to β-amyloid-induced cognitive and electrophysiological impairments. Proc Natl Acad Sci U S A 2016; 113:3347-52. [PMID: 26951658 DOI: 10.1073/pnas.1521018113] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Elevated levels of the β-amyloid peptide (Aβ) are thought to contribute to cognitive and behavioral impairments observed in Alzheimer's disease (AD). Protein phosphatase 2A (PP2A) participates in multiple molecular pathways implicated in AD, and its expression and activity are reduced in postmortem brains of AD patients. PP2A is regulated by protein methylation, and impaired PP2A methylation is thought to contribute to increased AD risk in hyperhomocysteinemic individuals. To examine further the link between PP2A and AD, we generated transgenic mice that overexpress the PP2A methylesterase, protein phosphatase methylesterase-1 (PME-1), or the PP2A methyltransferase, leucine carboxyl methyltransferase-1 (LCMT-1), and examined the sensitivity of these animals to behavioral and electrophysiological impairments caused by exogenous Aβ exposure. We found that PME-1 overexpression enhanced these impairments, whereas LCMT-1 overexpression protected against Aβ-induced impairments. Neither transgene affected Aβ production or the electrophysiological response to low concentrations of Aβ, suggesting that these manipulations selectively affect the pathological response to elevated Aβ levels. Together these data identify a molecular mechanism linking PP2A to the development of AD-related cognitive impairments that might be therapeutically exploited to target selectively the pathological effects caused by elevated Aβ levels in AD patients.
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154
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Altered Innate Immune and Glial Cell Responses to Inflammatory Stimuli in Amyloid Precursor Protein Knockout Mice. PLoS One 2015; 10:e0140210. [PMID: 26447481 PMCID: PMC4598170 DOI: 10.1371/journal.pone.0140210] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 09/23/2015] [Indexed: 11/30/2022] Open
Abstract
Amyloid precursor protein (APP) and its cleaved products have been reported to have important functions in CNS health, including in memory and synapse formation, cell survival and neuroprotection. Furthermore APP and its cleaved products have been shown to be transiently increased in response to various CNS stressors, suggesting a role in response to acute cellular injury. In an attempt to further understand the function of APP in response to CNS injury, we have used intracranial LPS injection as an inflammatory injury model in APP knock out mice (APPKO). Our data show that innate immune responses to LPS injection is significantly blunted in APPKO mice compared to APP sufficient wild type (BL6) mice. Morphologically, glial cells in APPKO mice appear less reactive, with shorter ramified processes and smaller cell bodies in response to LPS. Additionally, quantitative RT-PCR analysis for several glia markers and innate immune cytokine levels (e.g. TNFα, IL-6, IL-1β and IL-10) showed significantly reduced expression levels in LPS injected APPKO mice. In vitro cell culture assays confirmed this attenuated response to LPS stimulation by primary microglial cells isolated from APPKO mice. Our data suggests that APP full length protein and/or its cleaved products are necessary to mount a complete and effective innate immune cell response to inflammatory injury.
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155
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Herold S, Kumar P, Wichert SP, Kretzschmar B, Bähr M, Rossner MJ, Hein K. Neurodegeneration in Autoimmune Optic Neuritis Is Associated with Altered APP Cleavage in Neurons and Up-Regulation of p53. PLoS One 2015; 10:e0138852. [PMID: 26426258 PMCID: PMC4591258 DOI: 10.1371/journal.pone.0138852] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 09/06/2015] [Indexed: 11/19/2022] Open
Abstract
Multiple Sclerosis (MS) is a chronic autoimmune inflammatory disease of the central nervous system (CNS). Histopathological and radiological analysis revealed that neurodegeneration occurs early in the disease course. However, the pathological mechanisms involved in neurodegeneration are poorly understood. Myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE) in Brown Norway rats (BN-rats) is a well-established animal model, especially of the neurodegenerative aspects of MS. Previous studies in this animal model indicated that loss of retinal ganglion cells (RGCs), the neurons that form the axons of the optic nerve, occurs in the preclinical phase of the disease and is in part independent of overt histopathological changes of the optic nerve. Therefore, the aim of this study was to identify genes which are involved in neuronal cell loss at different disease stages of EAE. Furthermore, genes that are highly specific for autoimmune-driven neurodegeneration were compared to those regulated in RGCs after optic nerve axotomy at corresponding time points. Using laser capture micro dissection we isolated RNA from unfixed RGCs and performed global transcriptome analysis of retinal neurons. In total, we detected 582 genes sequentially expressed in the preclinical phase and 1150 genes in the clinical manifest EAE (P < 0.05, fold-induction >1.5). Furthermore, using ingenuity pathway analysis (IPA), we identified amyloid precursor protein (APP) as a potential upstream regulator of changes in gene expression in the preclinical EAE but neither in clinical EAE, nor at any time point after optic nerve transection. Therefore, the gene pathway analysis lead to the hypothesis that altered cleavage of APP in neurons in the preclinical phase of EAE leads to the enhanced production of APP intracellular domain (AICD), which in turn acts as a transcriptional regulator and thereby initiates an apoptotic signaling cascade via up-regulation of the target gene p53.
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Affiliation(s)
- Sabine Herold
- Department of Neurology, University Medicine Göttingen, Göttingen, Germany
| | - Prateek Kumar
- Department of Neurology, University Medicine Göttingen, Göttingen, Germany
| | - Sven P. Wichert
- Molecular and Behavioral Neurobiology, Department of Psychiatry, Ludwig Maximilians University Munich, Munich, Germany
| | | | - Mathias Bähr
- Department of Neurology, University Medicine Göttingen, Göttingen, Germany
| | - Moritz J. Rossner
- Molecular and Behavioral Neurobiology, Department of Psychiatry, Ludwig Maximilians University Munich, Munich, Germany
| | - Katharina Hein
- Department of Neurology, University Medicine Göttingen, Göttingen, Germany
- * E-mail:
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156
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New Insights into Epigenetic and Pharmacological Regulation of Amyloid-Degrading Enzymes. Neurochem Res 2015; 41:620-30. [PMID: 26376806 DOI: 10.1007/s11064-015-1703-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 08/12/2015] [Accepted: 08/18/2015] [Indexed: 10/23/2022]
Abstract
Currently, deficit of amyloid β-peptide (Aβ) clearance from the brain is considered as one of the possible causes of amyloid accumulation and neuronal death in the sporadic form of Alzheimer's disease (AD). Aβ clearance can involve either specific proteases present in the brain or Aβ-binding/transport proteins. Among amyloid-degrading enzymes the most intensively studied are neprilysin (NEP) and insulin-degrading enzyme (IDE). Since ageing and development of brain pathologies is often accompanied by a deficit in the levels of expression and activity of these enzymes in the brain, there is an urgent need to understand the mechanisms involved in their regulation. We have recently reported that NEP and also an Aβ-transport protein, transthyretin are epigenetically co-regulated by the APP intracellular domain (AICD) and this regulation depends on the cell type and APP695 isoform expression in a process that can be regulated by the tyrosine kinase inhibitor, Gleevec. We have now extended our work and shown that, unlike NEP, another amyloid-degrading enzyme, IDE, is not related to over-expression of APP695 in neuroblastoma SH-SY5Y cells but is up-regulated by APP751 and APP770 isoforms independently of AICD but correlating with reduced HDAC1 binding to its promoter. Studying the effect of the nuclear retinoid X receptor agonist, bexarotene, on NEP and IDE expression, we have found that both enzymes can be up-regulated by this compound but this mechanism is not APP-isoform specific and does not involve AICD but, on the contrary, affects HDAC1 occupancy on the NEP gene promoter. These new insights into the mechanisms of NEP and IDE regulation suggest possible pharmacological targets in developing AD therapies.
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157
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Talwar P, Sinha J, Grover S, Rawat C, Kushwaha S, Agarwal R, Taneja V, Kukreti R. Dissecting Complex and Multifactorial Nature of Alzheimer's Disease Pathogenesis: a Clinical, Genomic, and Systems Biology Perspective. Mol Neurobiol 2015; 53:4833-64. [PMID: 26351077 DOI: 10.1007/s12035-015-9390-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 08/11/2015] [Indexed: 01/14/2023]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by loss of memory and other cognitive functions. AD can be classified into familial AD (FAD) and sporadic AD (SAD) based on heritability and into early onset AD (EOAD) and late onset AD (LOAD) based on age of onset. LOAD cases are more prevalent with genetically complex architecture. In spite of significant research focused on understanding the etiological mechanisms, search for diagnostic biomarker(s) and disease-modifying therapy is still on. In this article, we aim to comprehensively review AD literature on established etiological mechanisms including role of beta-amyloid and apolipoprotein E (APOE) along with promising newer etiological factors such as epigenetic modifications that have been associated with AD suggesting its multifactorial nature. As genomic studies have recently played a significant role in elucidating AD pathophysiology, a systematic review of findings from genome-wide linkage (GWL), genome-wide association (GWA), genome-wide expression (GWE), and epigenome-wide association studies (EWAS) was conducted. The availability of multi-dimensional genomic data has further coincided with the advent of computational and network biology approaches in recent years. Our review highlights the importance of integrative approaches involving genomics and systems biology perspective in elucidating AD pathophysiology. The promising newer approaches may provide reliable means of early and more specific diagnosis and help identify therapeutic interventions for LOAD.
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Affiliation(s)
- Puneet Talwar
- Academy of Scientific and Innovative Research (AcSIR), CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB) Campus, New Delhi, India.,Genomics and Molecular Medicine Unit, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Mall Road, Delhi, 110 007, India
| | - Juhi Sinha
- Genomics and Molecular Medicine Unit, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Mall Road, Delhi, 110 007, India
| | - Sandeep Grover
- Genomics and Molecular Medicine Unit, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Mall Road, Delhi, 110 007, India.,Department of Paediatrics, Division of Pneumonology-Immunology, Charité University Medical Centre, Berlin, Germany
| | - Chitra Rawat
- Academy of Scientific and Innovative Research (AcSIR), CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB) Campus, New Delhi, India.,Genomics and Molecular Medicine Unit, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Mall Road, Delhi, 110 007, India
| | - Suman Kushwaha
- Institute of Human Behaviour and Allied Sciences (IHBAS), Delhi, India
| | - Rachna Agarwal
- Institute of Human Behaviour and Allied Sciences (IHBAS), Delhi, India
| | - Vibha Taneja
- Department of Research, Sir Ganga Ram Hospital, New Delhi, India
| | - Ritushree Kukreti
- Academy of Scientific and Innovative Research (AcSIR), CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB) Campus, New Delhi, India. .,Genomics and Molecular Medicine Unit, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Mall Road, Delhi, 110 007, India.
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158
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Zhao Y, Bhattacharjee S, Jones BM, Hill JM, Clement C, Sambamurti K, Dua P, Lukiw WJ. Beta-Amyloid Precursor Protein (βAPP) Processing in Alzheimer's Disease (AD) and Age-Related Macular Degeneration (AMD). Mol Neurobiol 2015; 52:533-44. [PMID: 25204496 PMCID: PMC4362880 DOI: 10.1007/s12035-014-8886-3] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 08/27/2014] [Indexed: 01/18/2023]
Abstract
Amyloid is a generic term for insoluble, often intensely hydrophobic, fibrous protein aggregates that arise from inappropriately folded versions of naturally-occurring polypeptides. The abnormal generation and accumulation of amyloid, often referred to as amyloidogenesis, has been associated with the immune and pro-inflammatory pathology of several progressive age-related diseases of the human central nervous system (CNS) including Alzheimer's disease (AD) and age-related macular degeneration (AMD). This 'research perspective' paper reviews some of the research history, biophysics, molecular-genetics and environmental factors concerning the contribution of amyloid beta (Aβ) peptides, derived from beta-amyloid precursor protein (βAPP), to AD and AMD that suggests an extensive similarity in immune and inflammatory degenerative mechanisms between these two CNS diseases.
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Affiliation(s)
- Yuhai Zhao
- LSU Neuroscience Center, Louisiana State University Health Sciences Center, 2020 Gravier Street, Suite 904, New Orleans LA 70112 USA
| | - Surjyadipta Bhattacharjee
- LSU Neuroscience Center, Louisiana State University Health Sciences Center, 2020 Gravier Street, Suite 904, New Orleans LA 70112 USA
| | - Brandon M. Jones
- LSU Neuroscience Center, Louisiana State University Health Sciences Center, 2020 Gravier Street, Suite 904, New Orleans LA 70112 USA
| | - James M. Hill
- LSU Neuroscience Center, Louisiana State University Health Sciences Center, 2020 Gravier Street, Suite 904, New Orleans LA 70112 USA
- Department of Ophthalmology, Louisiana State University Health Sciences Center, 2020 Gravier Street, Suite 904, New Orleans LA 70112 USA
- Department of Microbiology, Louisiana State University Health Sciences Center, 2020 Gravier Street, Suite 904, New Orleans LA 70112 USA
- Department of Pharmacology, Louisiana State University Health Sciences Center, 2020 Gravier Street, Suite 904, New Orleans LA 70112 USA
- Department of Neurology, Louisiana State University Health Sciences Center, 2020 Gravier Street, Suite 904, New Orleans LA 70112 USA
| | - Christian Clement
- Department of Natural Sciences, Infectious Diseases, Experimental Therapeutics and Human Toxicology Lab, Southern University at New Orleans, New Orleans, LA 70126 USA
| | | | - Prerna Dua
- Department of Health Information Management, Louisiana State University, Ruston, LA 71272 USA
| | - Walter J. Lukiw
- LSU Neuroscience Center, Louisiana State University Health Sciences Center, 2020 Gravier Street, Suite 904, New Orleans LA 70112 USA
- Department of Ophthalmology, Louisiana State University Health Sciences Center, 2020 Gravier Street, Suite 904, New Orleans LA 70112 USA
- Department of Microbiology, Louisiana State University Health Sciences Center, 2020 Gravier Street, Suite 904, New Orleans LA 70112 USA
- Department of Natural Sciences, Infectious Diseases, Experimental Therapeutics and Human Toxicology Lab, Southern University at New Orleans, New Orleans, LA 70126 USA
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159
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Gautam V, D'Avanzo C, Berezovska O, Tanzi RE, Kovacs DM. Synaptotagmins interact with APP and promote Aβ generation. Mol Neurodegener 2015. [PMID: 26202512 PMCID: PMC4511450 DOI: 10.1186/s13024-015-0028-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Background Accumulation of the β-amyloid peptide (Aβ) is a major pathological hallmark of Alzheimer’s disease (AD). Recent studies have shown that synaptic Aβ toxicity may directly impair synaptic function. However, proteins regulating Aβ generation at the synapse have not been characterized. Here, we sought to identify synaptic proteins that interact with the extracellular domain of APP and regulate Aβ generation. Results Affinity purification-coupled mass spectrometry identified members of the Synaptotagmin (Syt) family as novel interacting proteins with the APP ectodomain in mouse brains. Syt-1, −2 and −9 interacted with APP in cells and in mouse brains in vivo. Using a GST pull-down approach, we have further demonstrated that the Syt interaction site lies in the 108 amino acids linker region between the E1 and KPI domains of APP. Stable overexpression of Syt-1 or Syt-9 with APP in CHO and rat pheochromocytoma cells (PC12) significantly increased APP-CTF and sAPP levels, with a 2 to 3 fold increase in secreted Aβ levels in PC12 cells. Moreover, using a stable knockdown approach to reduce the expression of endogenous Syt-1 in PC12 cells, we have observed a ~ 50 % reduction in secreted Aβ generation. APP processing also decreased in these cells, shown by lower CTF levels. Lentiviral-mediated knock down of endogenous Syt-1 in mouse primary neurons also led to a significant reduction in both Aβ40 and Aβ42 generation. As secreted sAPPβ levels were significantly reduced in PC12 cells lacking Syt-1 expression, our results suggest that Syt-1 regulates Aβ generation by modulating BACE1-mediated cleavage of APP. Conclusion Altogether, our data identify the synaptic vesicle proteins Syt-1 and 9 as novel APP-interacting proteins that promote Aβ generation and thus may play an important role in the pathogenesis of AD. Electronic supplementary material The online version of this article (doi:10.1186/s13024-015-0028-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Vivek Gautam
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA.
| | - Carla D'Avanzo
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA.
| | - Oksana Berezovska
- MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA.
| | - Rudolph E Tanzi
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA.
| | - Dora M Kovacs
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA.
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160
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Abstract
Accumulation of toxic protein aggregates-amyloid-β (Aβ) plaques and hyperphosphorylated tau tangles-is the pathological hallmark of Alzheimer disease (AD). Aβ accumulation has been hypothesized to result from an imbalance between Aβ production and clearance; indeed, Aβ clearance seems to be impaired in both early and late forms of AD. To develop efficient strategies to slow down or halt AD, it is critical to understand how Aβ is cleared from the brain. Extracellular Aβ deposits can be removed from the brain by various clearance systems, most importantly, transport across the blood-brain barrier. Findings from the past few years suggest that astroglial-mediated interstitial fluid (ISF) bulk flow, known as the glymphatic system, might contribute to a larger portion of extracellular Aβ (eAβ) clearance than previously thought. The meningeal lymphatic vessels, discovered in 2015, might provide another clearance route. Because these clearance systems act together to drive eAβ from the brain, any alteration to their function could contribute to AD. An understanding of Aβ clearance might provide strategies to reduce excess Aβ deposits and delay, or even prevent, disease onset. In this Review, we describe the clearance systems of the brain as they relate to proteins implicated in AD pathology, with the main focus on Aβ.
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161
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Frick A, Suzuki OT, Benton C, Parks B, Fedoriw Y, Richards KL, Thomas RS, Wiltshire T. Identifying genes that mediate anthracyline toxicity in immune cells. Front Pharmacol 2015; 6:62. [PMID: 25926793 PMCID: PMC4398020 DOI: 10.3389/fphar.2015.00062] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 03/10/2015] [Indexed: 11/13/2022] Open
Abstract
The role of the immune system in response to chemotherapeutic agents remains elusive. The interpatient variability observed in immune and chemotherapeutic cytotoxic responses is likely, at least in part, due to complex genetic differences. Through the use of a panel of genetically diverse mouse inbred strains, we developed a drug screening platform aimed at identifying genes underlying these chemotherapeutic cytotoxic effects on immune cells. Using genome-wide association studies (GWAS), we identified four genome-wide significant quantitative trait loci (QTL) that contributed to the sensitivity of doxorubicin and idarubicin in immune cells. Of particular interest, a locus on chromosome 16 was significantly associated with cell viability following idarubicin administration (p = 5.01 × 10(-8)). Within this QTL lies App, which encodes amyloid beta precursor protein. Comparison of dose-response curves verified that T-cells in App knockout mice were more sensitive to idarubicin than those of C57BL/6J control mice (p < 0.05). In conclusion, the cellular screening approach coupled with GWAS led to the identification and subsequent validation of a gene involved in T-cell viability after idarubicin treatment. Previous studies have suggested a role for App in in vitro and in vivo cytotoxicity to anticancer agents; the overexpression of App enhances resistance, while the knockdown of this gene is deleterious to cell viability. Further investigations should include performing mechanistic studies, validating additional genes from the GWAS, including Ppfia1 and Ppfibp1, and ultimately translating the findings to in vivo and human studies.
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Affiliation(s)
- Amber Frick
- Division of Pharmacotherapy and Experimental Therapeutics, Eshelman School of Pharmacy, University of North Carolina Chapel Hill, NC, USA
| | - Oscar T Suzuki
- Division of Pharmacotherapy and Experimental Therapeutics, Eshelman School of Pharmacy, University of North Carolina Chapel Hill, NC, USA
| | - Cristina Benton
- Division of Pharmacotherapy and Experimental Therapeutics, Eshelman School of Pharmacy, University of North Carolina Chapel Hill, NC, USA
| | - Bethany Parks
- The Hamner Institutes for Health Sciences, Research Triangle Park NC, USA
| | - Yuri Fedoriw
- Department of Pathology and Laboratory Medicine, School of Medicine, University of North Carolina Chapel Hill, NC, USA ; Lineberger Comprehensive Cancer Center, School of Medicine, University of North Carolina Chapel Hill, NC, USA
| | - Kristy L Richards
- Lineberger Comprehensive Cancer Center, School of Medicine, University of North Carolina Chapel Hill, NC, USA ; Department of Genetics, School of Medicine, University of North Carolina Chapel Hill, NC, USA
| | - Russell S Thomas
- The Hamner Institutes for Health Sciences, Research Triangle Park NC, USA ; National Center for Computational Toxicology, U.S. Environmental Protection Agency, Research Triangle Park NC, USA
| | - Tim Wiltshire
- Division of Pharmacotherapy and Experimental Therapeutics, Eshelman School of Pharmacy, University of North Carolina Chapel Hill, NC, USA ; Lineberger Comprehensive Cancer Center, School of Medicine, University of North Carolina Chapel Hill, NC, USA
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162
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Dahms SO, Mayer MC, Roeser D, Multhaup G, Than ME. Interaction of the amyloid precursor protein-like protein 1 (APLP1) E2 domain with heparan sulfate involves two distinct binding modes. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2015; 71:494-504. [PMID: 25760599 PMCID: PMC4356362 DOI: 10.1107/s1399004714027114] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 12/10/2014] [Indexed: 01/09/2023]
Abstract
Beyond the pathology of Alzheimer's disease, the members of the amyloid precursor protein (APP) family are essential for neuronal development and cell homeostasis in mammals. APP and its paralogues APP-like protein 1 (APLP1) and APP-like protein 2 (APLP2) contain the highly conserved heparan sulfate (HS) binding domain E2, which effects various (patho)physiological functions. Here, two crystal structures of the E2 domain of APLP1 are presented in the apo form and in complex with a heparin dodecasaccharide at 2.5 Å resolution. The apo structure of APLP1 E2 revealed an unfolded and hence flexible N-terminal helix αA. The (APLP1 E2)2-(heparin)2 complex structure revealed two distinct binding modes, with APLP1 E2 explicitly recognizing the heparin terminus but also interacting with a continuous heparin chain. The latter only requires a certain register of the sugar moieties that fits to a positively charged surface patch and contributes to the general heparin-binding capability of APP-family proteins. Terminal binding of APLP1 E2 to heparin specifically involves a structure of the nonreducing end that is very similar to heparanase-processed HS chains. These data reveal a conserved mechanism for the binding of APP-family proteins to HS and imply a specific regulatory role of HS modifications in the biology of APP and APP-like proteins.
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Affiliation(s)
- Sven O. Dahms
- Protein Crystallography Group, Leibniz Institute for Age Research (FLI), Beutenbergstrasse 11, 07745 Jena, Germany
| | - Magnus C. Mayer
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Thielallee 63, 14195 Berlin, Germany
- Miltenyi Biotec GmbH, Robert-Koch-Strasse 1, 17166 Teterow, Germany
| | - Dirk Roeser
- Protein Crystallography Group, Leibniz Institute for Age Research (FLI), Beutenbergstrasse 11, 07745 Jena, Germany
| | - Gerd Multhaup
- Department of Pharmacology and Therapeutics, McGill University Montreal, Montreal, Quebec H3G 1Y6, Canada
| | - Manuel E. Than
- Protein Crystallography Group, Leibniz Institute for Age Research (FLI), Beutenbergstrasse 11, 07745 Jena, Germany
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163
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The Ubiquitin-Proteasome System and Molecular Chaperone Deregulation in Alzheimer's Disease. Mol Neurobiol 2015; 53:905-931. [PMID: 25561438 DOI: 10.1007/s12035-014-9063-4] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 12/09/2014] [Indexed: 12/18/2022]
Abstract
One of the shared hallmarks of neurodegenerative diseases is the accumulation of misfolded proteins. Therefore, it is suspected that normal proteostasis is crucial for neuronal survival in the brain and that the malfunction of this mechanism may be the underlying cause of neurodegenerative diseases. The accumulation of amyloid plaques (APs) composed of amyloid-beta peptide (Aβ) aggregates and neurofibrillary tangles (NFTs) composed of misfolded Tau proteins are the defining pathological markers of Alzheimer's disease (AD). The accumulation of these proteins indicates a faulty protein quality control in the AD brain. An impaired ubiquitin-proteasome system (UPS) could lead to negative consequences for protein regulation, including loss of function. Another pivotal mechanism for the prevention of misfolded protein accumulation is the utilization of molecular chaperones. Molecular chaperones, such as heat shock proteins (HSPs) and FK506-binding proteins (FKBPs), are highly involved in protein regulation to ensure proper folding and normal function. In this review, we elaborate on the molecular basis of AD pathophysiology using recent data, with a particular focus on the role of the UPS and molecular chaperones as the defensive mechanism against misfolded proteins that have prion-like properties. In addition, we propose a rational therapy approach based on this mechanism.
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164
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Morales R, Callegari K, Soto C. Prion-like features of misfolded Aβ and tau aggregates. Virus Res 2015; 207:106-12. [PMID: 25575736 DOI: 10.1016/j.virusres.2014.12.031] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 12/11/2014] [Accepted: 12/29/2014] [Indexed: 02/07/2023]
Abstract
Recent findings have shown that several misfolded proteins can transmit disease pathogenesis in a prion-like manner by transferring their conformational properties to normally folded units. However, the extent by which these molecule-to-molecule or cell-to-cell spreading processes reflect the entire prion behavior is now subject of controversy, especially due to the lack of epidemiological data supporting inter-individual transmission of non-prion protein misfolding diseases. Nevertheless, extensive research has shown that several of the typical characteristics of prions can be observed for Aβ and tau aggregates when administered in animal models. In this article we review recent studies describing the prion-like features of both proteins, highlighting the similarities with bona fide prions in terms of inter-individual transmission, their strain-like conformational diversity, and the transmission of misfolded aggregates by different routes of administration.
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Affiliation(s)
- Rodrigo Morales
- Mitchell Center for Alzheimer's Disease and Related Brain Disorders, Department of Neurology, University of Texas Houston Medical School, 6431 Fannin Street, Houston, TX 77030, United States.
| | - Keri Callegari
- Mitchell Center for Alzheimer's Disease and Related Brain Disorders, Department of Neurology, University of Texas Houston Medical School, 6431 Fannin Street, Houston, TX 77030, United States.
| | - Claudio Soto
- Mitchell Center for Alzheimer's Disease and Related Brain Disorders, Department of Neurology, University of Texas Houston Medical School, 6431 Fannin Street, Houston, TX 77030, United States.
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165
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Kukharsky MS, Ovchinnikov RK, Bachurin SO. Molecular aspects of the pathogenesis and current approaches to pharmacological correction of Alzheimer’s disease. Zh Nevrol Psikhiatr Im S S Korsakova 2015; 115:103-114. [DOI: 10.17116/jnevro20151156103-114] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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166
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Verwilst P, Sunwoo K, Kim JS. The role of copper ions in pathophysiology and fluorescent sensors for the detection thereof. Chem Commun (Camb) 2015; 51:5556-71. [DOI: 10.1039/c4cc10366a] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Copper ions are crucial to life, and some fundamental roles of copper in pathophysiology have been elucidated using fluorescent sensors.
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Affiliation(s)
- Peter Verwilst
- Department of Chemistry
- Korea Univesity
- Seoul 136-701
- Korea
| | - Kyoung Sunwoo
- Department of Chemistry
- Korea Univesity
- Seoul 136-701
- Korea
| | - Jong Seung Kim
- Department of Chemistry
- Korea Univesity
- Seoul 136-701
- Korea
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167
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Abstract
Many lines of evidence support that β-amyloid (Aβ) peptides play an important role in Alzheimer's disease (AD), the most common cause of dementia. But despite much effort the molecular mechanisms of how Aβ contributes to AD remain unclear. While Aβ is generated from its precursor protein throughout life, the peptide is best known as the main component of amyloid plaques, the neuropathological hallmark of AD. Reduction in Aβ has been the major target of recent experimental therapies against AD. Unfortunately, human clinical trials targeting Aβ have not shown the hoped-for benefits. Thus, doubts have been growing about the role of Aβ as a therapeutic target. Here we review evidence supporting the involvement of Aβ in AD, highlight the importance of differentiating between various forms of Aβ, and suggest that a better understanding of Aβ's precise pathophysiological role in the disease is important for correctly targeting it for potential future therapy.
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Affiliation(s)
- Gunnar K. Gouras
- />Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Tomas T. Olsson
- />Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Oskar Hansson
- />Clinical Memory Research Unit, Clinical Sciences Malmö, Lund University, Lund, Sweden
- />Memory Clinic, Skåne University Hospital, Skåne, Sweden
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168
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169
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Bolós M, Hu Y, Young KM, Foa L, Small DH. Neurogenin 2 mediates amyloid-β precursor protein-stimulated neurogenesis. J Biol Chem 2014; 289:31253-61. [PMID: 25217641 DOI: 10.1074/jbc.m114.581918] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Amyloid-β precursor protein (APP) is well studied for its role in Alzheimer disease, although its normal function remains uncertain. It has been reported that APP stimulates the proliferation and neuronal differentiation of neural stem/progenitor cells (NSPCs). In this study we examined the role of APP in NSPC differentiation. To identify proteins that may mediate the effect of APP on NSPC differentiation, we used a gene array approach to find genes whose expression correlated with APP-induced neurogenesis. We found that the expression of neurogenin 2 (Ngn2), a basic helix-loop-helix transcription factor, was significantly down-regulated in NSPCs from APP knock-out mice (APPKO) and increased in APP transgenic (Tg2576) mice. Ngn2 overexpression in APPKO NSPCs promoted neuronal differentiation, whereas siRNA knockdown of Ngn2 expression in wild-type NSPCs decreased neuronal differentiation. The results demonstrate that APP-stimulated neuronal differentiation of NSPCs is mediated by Ngn2.
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Affiliation(s)
- Marta Bolós
- From the Menzies Research Institute Tasmania and
| | - Yanling Hu
- From the Menzies Research Institute Tasmania and
| | | | - Lisa Foa
- From the Menzies Research Institute Tasmania and School of Medicine, University of Tasmania, Hobart, Tasmania 7000, Australia
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170
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Dawkins E, Gasperini R, Hu Y, Cui H, Vincent AJ, Bolós M, Young KM, Foa L, Small DH. The N-terminal fragment of the β-amyloid precursor protein of Alzheimer's disease (N-APP) binds to phosphoinositide-rich domains on the surface of hippocampal neurons. J Neurosci Res 2014; 92:1478-89. [PMID: 24916405 DOI: 10.1002/jnr.23422] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 04/22/2014] [Accepted: 05/09/2014] [Indexed: 11/11/2022]
Abstract
The function of the β-amyloid precursor protein (APP) of Alzheimer's disease is poorly understood. The secreted ectodomain fragment of APP (sAPPα) can be readily cleaved to produce a small N-terminal fragment (N-APP) that contains heparin-binding and metal-binding domains and that has been found to have biological activity. In the present study, we examined whether N-APP can bind to lipids. We found that N-APP binds selectively to phosphoinositides (PIPs) but poorly to most other lipids. Phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2 )-rich microdomains were identified on the extracellular surface of neurons and glia in primary hippocampal cultures. N-APP bound to neurons and colocalized with PIPs on the cell surface. Furthermore, the binding of N-APP to neurons increased the level of cell-surface PI(4,5)P2 and phosphatidylinositol 3,4,5-trisphosphate. However, PIPs were not the principal cell-surface binding site for N-APP, because N-APP binding to neurons was not inhibited by a short-acyl-chain PIP analogue, and N-APP did not bind to glial cells which also possessed PI(4,5)P2 on the cell surface. The data are explained by a model in which N-APP binds to two distinct components on neurons, one of which is an unidentified receptor and the second of which is a PIP lipid, which binds more weakly to a distinct site within N-APP. Our data provide further support for the idea that N-APP may be an important mediator of APP's biological activity.
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Affiliation(s)
- Edgar Dawkins
- Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia
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171
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Cornelius C, Koverech G, Crupi R, Di Paola R, Koverech A, Lodato F, Scuto M, Salinaro AT, Cuzzocrea S, Calabrese EJ, Calabrese V. Osteoporosis and alzheimer pathology: Role of cellular stress response and hormetic redox signaling in aging and bone remodeling. Front Pharmacol 2014; 5:120. [PMID: 24959146 PMCID: PMC4050335 DOI: 10.3389/fphar.2014.00120] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 05/06/2014] [Indexed: 12/24/2022] Open
Abstract
Alzheimer’s disease (AD) and osteoporosis are multifactorial progressive degenerative disorders. Increasing evidence shows that osteoporosis and hip fracture are common complication observed in AD patients, although the mechanisms underlying this association remain poorly understood. Reactive oxygen species (ROS) are emerging as intracellular redox signaling molecules involved in the regulation of bone metabolism, including receptor activator of nuclear factor-κB ligand-dependent osteoclast differentiation, but they also have cytotoxic effects that include lipoperoxidation and oxidative damage to proteins and DNA. ROS generation, which is implicated in the regulation of cellular stress response mechanisms, is an integrated, highly regulated, process under control of redox sensitive genes coding for redox proteins called vitagenes. Vitagenes, encoding for proteins such as heat shock proteins (Hsps) Hsp32, Hsp70, the thioredoxin, and the sirtuin protein, represent a systems controlling a complex network of intracellular signaling pathways relevant to life span and involved in the preservation of cellular homeostasis under stress conditions. Consistently, nutritional anti-oxidants have demonstrated their neuroprotective potential through a hormetic-dependent activation of vitagenes. The biological relevance of dose–response affects those strategies pointing to the optimal dosing to patients in the treatment of numerous diseases. Thus, the heat shock response has become an important hormetic target for novel cytoprotective strategies focusing on the pharmacological development of compounds capable of modulating stress response mechanisms. Here we discuss possible signaling mechanisms involved in the activation of vitagenes which, relevant to bone remodeling and through enhancement of cellular stress resistance provide a rationale to limit the deleterious consequences associated to homeostasis disruption with consequent impact on the aging process.
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Affiliation(s)
- Carolin Cornelius
- Department of Chemistry, University of Catania Catania, Italy ; Department of Clinical and Experimental Medicine and Pharmacology, School of Medicine Messina, Italy
| | - Guido Koverech
- Department of Biomedical Sciences, University of Catania Catania, Italy
| | - Rosalia Crupi
- Department of Clinical and Experimental Medicine and Pharmacology, School of Medicine Messina, Italy
| | - Rosanna Di Paola
- Department of Clinical and Experimental Medicine and Pharmacology, School of Medicine Messina, Italy
| | - Angela Koverech
- Department of Biomedical Sciences, University of Catania Catania, Italy
| | - Francesca Lodato
- Department of Biomedical Sciences, University of Catania Catania, Italy
| | - Maria Scuto
- Department of Biomedical Sciences, University of Catania Catania, Italy
| | - Angela T Salinaro
- Department of Biomedical Sciences, University of Catania Catania, Italy
| | - Salvatore Cuzzocrea
- Department of Clinical and Experimental Medicine and Pharmacology, School of Medicine Messina, Italy ; University of Manchester Manchester, UK
| | - Edward J Calabrese
- Environmental Health Sciences Division, School of Public Health, University of Massachusetts Amherst, MA, USA
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