401
|
Hill SM, Hanzén S, Nyström T. Restricted access: spatial sequestration of damaged proteins during stress and aging. EMBO Rep 2017; 18:377-391. [PMID: 28193623 PMCID: PMC5331209 DOI: 10.15252/embr.201643458] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 12/19/2016] [Accepted: 01/24/2017] [Indexed: 01/08/2023] Open
Abstract
The accumulation of damaged and aggregated proteins is a hallmark of aging and increased proteotoxic stress. To limit the toxicity of damaged and aggregated proteins and to ensure that the damage is not inherited by succeeding cell generations, a system of spatial quality control operates to sequester damaged/aggregated proteins into inclusions at specific protective sites. Such spatial sequestration and asymmetric segregation of damaged proteins have emerged as key processes required for cellular rejuvenation. In this review, we summarize findings on the nature of the different quality control sites identified in yeast, on genetic determinants required for spatial quality control, and on how aggregates are recognized depending on the stress generating them. We also briefly compare the yeast system to spatial quality control in other organisms. The data accumulated demonstrate that spatial quality control involves factors beyond the canonical quality control factors, such as chaperones and proteases, and opens up new venues in approaching how proteotoxicity might be mitigated, or delayed, upon aging.
Collapse
Affiliation(s)
- Sandra Malmgren Hill
- Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden
| | - Sarah Hanzén
- Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden
| | - Thomas Nyström
- Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden
| |
Collapse
|
402
|
LeWitt PA, Li J, Lu M, Guo L, Auinger P. Metabolomic biomarkers as strong correlates of Parkinson disease progression. Neurology 2017; 88:862-869. [PMID: 28179471 DOI: 10.1212/wnl.0000000000003663] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 11/29/2016] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To determine whether a Parkinson disease (PD)-specific biochemical signature might be found in the total body metabolic milieu or in the CSF compartment, especially since this disorder has systemic manifestations beyond the progressive loss of dopaminergic nigrostriatal neurons. METHODS Our goal was to discover biomarkers of PD progression. Using ultra-high-performance liquid chromatography linked to gas chromatography and tandem mass spectrometry, we measured concentrations of small-molecule (≤1.5 kDa) constituents of plasma and CSF from 49 unmedicated, mildly affected patients with PD (mean age 61.4 years; mean duration of PD 11.4 months). Specimens were collected twice (baseline and final) at intervals up to 24 months. During this time, mean Unified Parkinson's Disease Rating Scale (UPDRS) parts 2 + 3 scores increased 47% (from 28.8 to 42.2). Measured compounds underwent unbiased univariate and multivariate analyses, including fitting data into multiple linear regression with variable selection using least absolute shrinkage and selection operator (LASSO). RESULTS Of 575 identified plasma and 383 CSF biochemicals, LASSO led to selection of 15 baseline plasma constituents with high positive correlation (0.87, p = 2.2e-16) to baseline-to-final change in UPDRS parts 2 + 3 scores. Three of the compounds had xanthine structures, and 4 were either medium- or long-chain fatty acids. For the 15 LASSO-selected biomarkers, pathway enrichment software found no overrepresentation among metabolic pathways. CSF concentrations of the dopamine metabolite homovanillate showed little change between baseline and final collections and minimal correlation with worsening UPDRS parts 2 + 3 scores (0.29, p = 0.041). CONCLUSIONS Metabolomic profiling of plasma yielded strong prediction of PD progression and offered biomarkers that may provide new insights into PD pathogenesis.
Collapse
Affiliation(s)
- Peter A LeWitt
- From the Departments of Neurology (P.A.L.) and Public Health Science (J.L., M.L.), Henry Ford Health System; Wayne State University School of Medicine (P.A.L.), Detroit MI; Metabolon, Inc (L.G.), Durham, NC; and Center for Human Experimental Therapeutics (P.A.), University of Rochester, NY.
| | - Jia Li
- From the Departments of Neurology (P.A.L.) and Public Health Science (J.L., M.L.), Henry Ford Health System; Wayne State University School of Medicine (P.A.L.), Detroit MI; Metabolon, Inc (L.G.), Durham, NC; and Center for Human Experimental Therapeutics (P.A.), University of Rochester, NY
| | - Mei Lu
- From the Departments of Neurology (P.A.L.) and Public Health Science (J.L., M.L.), Henry Ford Health System; Wayne State University School of Medicine (P.A.L.), Detroit MI; Metabolon, Inc (L.G.), Durham, NC; and Center for Human Experimental Therapeutics (P.A.), University of Rochester, NY
| | - Lining Guo
- From the Departments of Neurology (P.A.L.) and Public Health Science (J.L., M.L.), Henry Ford Health System; Wayne State University School of Medicine (P.A.L.), Detroit MI; Metabolon, Inc (L.G.), Durham, NC; and Center for Human Experimental Therapeutics (P.A.), University of Rochester, NY
| | - Peggy Auinger
- From the Departments of Neurology (P.A.L.) and Public Health Science (J.L., M.L.), Henry Ford Health System; Wayne State University School of Medicine (P.A.L.), Detroit MI; Metabolon, Inc (L.G.), Durham, NC; and Center for Human Experimental Therapeutics (P.A.), University of Rochester, NY
| | | |
Collapse
|
403
|
Wong YC, Krainc D. α-synuclein toxicity in neurodegeneration: mechanism and therapeutic strategies. Nat Med 2017; 23:1-13. [PMID: 28170377 PMCID: PMC8480197 DOI: 10.1038/nm.4269] [Citation(s) in RCA: 580] [Impact Index Per Article: 82.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 12/14/2016] [Indexed: 12/13/2022]
Abstract
Alterations in α-synuclein dosage lead to familial Parkinson's disease (PD), and its accumulation results in synucleinopathies that include PD, dementia with Lewy bodies (DLB) and multiple system atrophy (MSA). Furthermore, α-synuclein contributes to the fibrilization of amyloid-b and tau, two key proteins in Alzheimer's disease, which suggests a central role for α-synuclein toxicity in neurodegeneration. Recent studies of factors contributing to α-synuclein toxicity and its disruption of downstream cellular pathways have expanded our understanding of disease pathogenesis in synucleinopathies. In this Review, we discuss these emerging themes, including the contributions of aging, selective vulnerability and non-cell-autonomous factors such as α-synuclein cell-to-cell propagation and neuroinflammation. Finally, we summarize recent efforts toward the development of targeted therapies for PD and related synucleinopathies.
Collapse
Affiliation(s)
- Yvette C Wong
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Dimitri Krainc
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| |
Collapse
|
404
|
Klingelhoefer L, Reichmann H. Parkinson’s disease as a multisystem disorder. J Neural Transm (Vienna) 2017; 124:709-713. [DOI: 10.1007/s00702-017-1692-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 01/26/2017] [Indexed: 12/27/2022]
|
405
|
A Homeostatic Shift Facilitates Endoplasmic Reticulum Proteostasis through Transcriptional Integration of Proteostatic Stress Response Pathways. Mol Cell Biol 2017; 37:MCB.00439-16. [PMID: 27920251 DOI: 10.1128/mcb.00439-16] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 11/23/2016] [Indexed: 01/01/2023] Open
Abstract
Eukaryotic cells maintain protein homeostasis through the activity of multiple basal and inducible systems, which function in concert to allow cells to adapt to a wide range of environmental conditions. Although the transcriptional programs regulating individual pathways have been studied in detail, it is not known how the different pathways are transcriptionally integrated such that a deficiency in one pathway can be compensated by a change in an auxiliary response. One such pathway that plays an essential role in many proteostasis responses is the ubiquitin-proteasome system, which functions to degrade damaged, unfolded, or short half-life proteins. Transcriptional regulation of the proteasome is mediated by the transcription factor Nrf1. Using a conditional knockout mouse model, we found that Nrf1 regulates protein homeostasis in the endoplasmic reticulum (ER) through transcriptional regulation of the ER stress sensor ATF6. In Nrf1 conditional-knockout mice, a reduction in proteasome activity is accompanied by an ATF6-dependent downregulation of the endoplasmic reticulum-associated degradation machinery, which reduces the substrate burden on the proteasome. This indicates that Nrf1 regulates a homeostatic shift through which proteostasis in the endoplasmic reticulum and cytoplasm are coregulated based on a cell's ability to degrade proteins.
Collapse
|
406
|
Abstract
Caenorhabditis elegans is an important model organism with many useful features, including rapid development and aging, easy cultivation, and genetic tractability. Survival assays using C. elegans are powerful methods for studying physiological processes. In this review, we describe diverse types of C. elegans survival assays and discuss the aims, uses, and advantages of specific assays. C. elegans survival assays have played key roles in identifying novel genetic factors that regulate many aspects of animal physiology, such as aging and lifespan, stress response, and immunity against pathogens. Because many genetic factors discovered using C. elegans are evolutionarily conserved, survival assays can provide insights into mechanisms underlying physiological processes in mammals, including humans.
Collapse
Affiliation(s)
- Hae-Eun H. Park
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673,
Korea
| | - Yoonji Jung
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673,
Korea
| | - Seung-Jae V. Lee
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673,
Korea
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang 37673,
Korea
| |
Collapse
|
407
|
The Proline/Arginine Dipeptide from Hexanucleotide Repeat Expanded C9ORF72 Inhibits the Proteasome. eNeuro 2017; 4:eN-NWR-0249-16. [PMID: 28197542 PMCID: PMC5282547 DOI: 10.1523/eneuro.0249-16.2017] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 01/05/2017] [Accepted: 01/12/2017] [Indexed: 12/11/2022] Open
Abstract
An intronic hexanucleotide repeat expansion (HRE) mutation in the C9ORF72 gene is the most common cause of familial ALS and frontotemporal dementia (FTD) and is found in ∼7% of individuals with apparently sporadic disease. Several different diamino acid peptides can be generated from the HRE by noncanonical translation (repeat-associated non-ATG translation, or RAN translation), and some of these peptides can be toxic. Here, we studied the effects of two arginine containing RAN translation products [proline/arginine repeated 20 times (PR20) and glycine/arginine repeated 20 times (GR20)] in primary rat spinal cord neuron cultures grown on an astrocyte feeder layer. We find that PR20 kills motor neurons with an LD50 of 2 µM, but in contrast to the effects of other ALS-causing mutant proteins (i.e., SOD or TDP43), PR20 does not evoke the biochemical signature of mitochondrial dysfunction, ER stress, or mTORC down-regulation. PR20 does result in a time-dependent build-up of ubiquitylated substrates, and this is associated with a reduction of flux through both autophagic and proteasomal degradation pathways. GR20, however, does not have these effects. The effects of PR20 on the proteasome are likely to be direct because (1) PR20 physically associates with proteasomes in biochemical assays, and (2) PR20 inhibits the degradation of a ubiquitylated test substrate when presented to purified proteasomes. Application of a proteasomal activator (IU1) blocks the toxic effects of PR20 on motor neuron survival. This work suggests that proteasomal activators have therapeutic potential in individuals with C9ORF72 HRE.
Collapse
|
408
|
Shen J, Xu S, Zhou H, Liu H, Jiang W, Hao J, Hu Z. IL-1β induces apoptosis and autophagy via mitochondria pathway in human degenerative nucleus pulposus cells. Sci Rep 2017; 7:41067. [PMID: 28120948 PMCID: PMC5264394 DOI: 10.1038/srep41067] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 12/14/2016] [Indexed: 12/13/2022] Open
Abstract
IL-1β has been reported highly expressed in degenerative intervertebral disc, and our previous study indicated IL-1β facilitates apoptosis of human degenerative nucleus pulposus (NP) cell. However, the underlying molecular mechanism remains unclear. We here demonstrate that IL-1β played a significantly pro-apoptotic effect under serum deprivation. IL-1β decreased Bcl-2/Bax ratio and enhanced cytochrome C released from mitochondria to cytosol, which proved mitochondria-meidated apoptosis was induced. Subsequently, mitochondria damage was detected under IL-1β stimualtion. In addition, IL-1β-mediated injuried mitochondria contributes to activate autophagy. However, pretreatment with the autophagy inhibitor 3-methyladenine showed the potential in further elevating the apoptosis rate induced by IL-1β in NP cells. Our results indicated that the mitochondrial pathway was involved in IL-1β-induced apoptosis of NP cells. Meanwhile, the damaged mitochondria-induced autophagy played a protective role against apoptosis, suggesting a postive feedback mechanism under inflammatory stress.
Collapse
Affiliation(s)
- Jieliang Shen
- Department of Orthopaedic Surgery, the First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Shengxi Xu
- Department of Orthopaedic Surgery, the First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Hao Zhou
- Department of Orthopaedic Surgery, the First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Huzhe Liu
- Department of Orthopaedic Surgery, the First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Wei Jiang
- Department of Orthopaedic Surgery, the First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Jie Hao
- Department of Orthopaedic Surgery, the First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Zhenming Hu
- Department of Orthopaedic Surgery, the First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| |
Collapse
|
409
|
Affiliation(s)
- Jessica M. Mc Donald
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611-4296; ,
| | - Dimitri Krainc
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611-4296; ,
| |
Collapse
|
410
|
Continued 26S proteasome dysfunction in mouse brain cortical neurons impairs autophagy and the Keap1-Nrf2 oxidative defence pathway. Cell Death Dis 2017; 8:e2531. [PMID: 28055010 PMCID: PMC5386360 DOI: 10.1038/cddis.2016.443] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 11/18/2016] [Accepted: 11/29/2016] [Indexed: 12/22/2022]
Abstract
The ubiquitin–proteasome system (UPS) and macroautophagy (autophagy) are central to normal proteostasis and interdependent in that autophagy is known to compensate for the UPS to alleviate ensuing proteotoxic stress that impairs cell function. UPS and autophagy dysfunctions are believed to have a major role in the pathomechanisms of neurodegenerative disease. Here we show that continued 26S proteasome dysfunction in mouse brain cortical neurons causes paranuclear accumulation of fragmented dysfunctional mitochondria, associated with earlier recruitment of Parkin and lysine 48-linked ubiquitination of mitochondrial outer membrane (MOM) proteins, including Mitofusin-2. Early events also include phosphorylation of p62/SQSTM1 (p62) and increased optineurin, as well as autophagosomal LC3B and removal of some mitochondria, supporting the induction of selective autophagy. Inhibition of the degradation of ubiquitinated MOM proteins with continued 26S proteasome dysfunction at later stages may impede efficient mitophagy. However, continued 26S proteasome dysfunction also decreases the levels of essential autophagy proteins ATG9 and LC3B, which is characterised by decreases in their gene expression, ultimately leading to impaired autophagy. Intriguingly, serine 351 phosphorylation of p62 did not enhance its binding to Keap1 or stabilise the nuclear factor erythroid 2-related factor 2 (Nrf2) transcription factor in this neuronal context. Nrf2 protein levels were markedly decreased despite transcriptional activation of the Nrf2 gene. Our study reveals novel insights into the interplay between the UPS and autophagy in neurons and is imperative to understanding neurodegenerative disease where long-term proteasome inhibition has been implicated.
Collapse
|
411
|
Lee NK, Park SE, Kwon SJ, Shim S, Byeon Y, Kim JH, Na DL, Chang JW. Agouti Related Peptide Secreted Via Human Mesenchymal Stem Cells Upregulates Proteasome Activity in an Alzheimer's Disease Model. Sci Rep 2017; 7:39340. [PMID: 28051110 PMCID: PMC5209736 DOI: 10.1038/srep39340] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 11/18/2016] [Indexed: 01/08/2023] Open
Abstract
The activity of the ubiquitin proteasome system (UPS) is downregulated in aggregation diseases such as Alzheimer’s disease (AD). In this study, we investigated the therapeutic potential of the Agouti-related peptide (AgRP), which is secreted by human mesenchymal stem cells (MSCs), in terms of its effect on the regulation of proteasome activity in AD. When SH-SY5Y human neuroblastoma cells were co-cultured with MSCs isolated from human Wharton’s Jelly (WJ-MSC), their proteasome activity was significantly upregulated. Further analysis of the conditioned media after co-culture allowed us to identify significant concentrations of a neuropeptide, called AgRP. The stereotactic delivery of either WJ-MSCs or AgRP into the hippocampi of C57BL6/J and 5XFAD mice induced a significant increase of proteasome activity and suppressed the accumulation of ubiquitin-conjugated proteins. Collectively, these findings suggest strong therapeutic potential for WJ-MSCs and AgRP to enhance proteasome activity, thereby potentially reducing abnormal protein aggregation and delaying the clinical progression of various neurodegenerative diseases.
Collapse
Affiliation(s)
- Na Kyung Lee
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea.,Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.,Neuroscience Center, Samsung Medical Center, Seoul, Republic of Korea.,Stem Cell &Regenerative Medicine Institute, Samsung Medical Center, Seoul, Republic of Korea
| | - Sang Eon Park
- Stem Cell &Regenerative Medicine Institute, Samsung Medical Center, Seoul, Republic of Korea
| | - Soo Jin Kwon
- Stem Cell &Regenerative Medicine Institute, Samsung Medical Center, Seoul, Republic of Korea
| | - Sangmi Shim
- Department of Biomedical Sciences, Seoul National University, Seoul, Republic of Korea
| | - Yeji Byeon
- Stem Cell &Regenerative Medicine Institute, Samsung Medical Center, Seoul, Republic of Korea
| | - Jong-Hwa Kim
- Department of Obstetrics and Gynecology, Samsung Medical Center, Seoul, Republic of Korea
| | - Duk L Na
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea.,Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.,Neuroscience Center, Samsung Medical Center, Seoul, Republic of Korea.,Stem Cell &Regenerative Medicine Institute, Samsung Medical Center, Seoul, Republic of Korea
| | - Jong Wook Chang
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea.,Stem Cell &Regenerative Medicine Institute, Samsung Medical Center, Seoul, Republic of Korea
| |
Collapse
|
412
|
Chu J, Praticò D. The retromer complex system in a transgenic mouse model of AD: influence of age. Neurobiol Aging 2017; 52:32-38. [PMID: 28110103 DOI: 10.1016/j.neurobiolaging.2016.12.025] [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] [Received: 09/06/2016] [Revised: 12/21/2016] [Accepted: 12/27/2016] [Indexed: 10/20/2022]
Abstract
Deficiencies of the retrograde transport mediated by the retromer complex have been described in Alzheimer's disease (AD). Genetic manipulation of retromer modulates brain amyloidosis in Tg2576 mice. However, whether the complex is altered during the development of the AD-like phenotype remains unknown. In this study we assayed the expression levels of the vacuolar sorting protein 35 (VPS35), VPS26, VPS29, and its cargo proteins, cation independent mannose 6-phosphate receptor, sortilin-related receptor in brains of Tg2576 and controls at the ages of 3, 8, and 14 months. While cortex showed an age-dependent decrease in all but VPS29, levels of the same proteins in the cerebellum were unchanged at any age. Neuronal cells expressing human amyloid beta precursor protein Swedish mutant had also reduced retromer complex levels. However, incubation with a pharmacological chaperone dose-dependently restored these levels together with a reduction in amyloid beta. Our study is the first to show that in a transgenic mouse model of AD the changes in the expression levels of the retromer complex are age and region dependent, and that the complex is a viable therapeutic target since its deficiency can be restored pharmacologically by a retromer chaperone.
Collapse
Affiliation(s)
- Jin Chu
- Department of Pharmacology and Center for Translational Medicine, Temple University Lewis Katz School of Medicine, Philadelphia, PA, USA
| | - Domenico Praticò
- Department of Pharmacology and Center for Translational Medicine, Temple University Lewis Katz School of Medicine, Philadelphia, PA, USA.
| |
Collapse
|
413
|
Faus-Garriga J, Novoa I, Ozaita A. mTOR signaling in proteostasis and its relevance to autism spectrum disorders. AIMS BIOPHYSICS 2017. [DOI: 10.3934/biophy.2017.1.63] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
|
414
|
Grasso G, Axelsen PH. Effects of covalent modification by 4-hydroxy-2-nonenal on the noncovalent oligomerization of ubiquitin. JOURNAL OF MASS SPECTROMETRY : JMS 2017; 52:36-42. [PMID: 27862610 PMCID: PMC5360464 DOI: 10.1002/jms.3897] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2016] [Revised: 11/05/2016] [Accepted: 11/08/2016] [Indexed: 06/06/2023]
Abstract
When lipid membranes containing ω-6 polyunsaturated fatty acyl chains are subjected to oxidative stress, one of the reaction products is 4-hydroxy-2-nonenal (HNE)-a chemically reactive short chain alkenal that can covalently modify proteins. The ubiquitin proteasome system is involved in the clearing of proteins modified by oxidation products such as HNE, but the chemical structure, stability and function of ubiquitin may be impaired by HNE modification. To evaluate this possibility, the susceptibility of ubiquitin to modification by HNE has been characterized over a range of concentrations where ubiquitin forms non-covalent oligomers. Results indicate that HNE modifies ubiquitin at only two of the many possible sites, and that HNE modification at these two sites alters the ubiquitin oligomerization equilibrium. These results suggest that any role ubiquitin may have in clearing proteins damaged by oxidative stress may itself be impaired by oxidative lipid degradation products. Copyright © 2016 John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- Giuseppe Grasso
- University of Catania, Viale A. Doria 6, 95125, Catania, Italy
| | - Paul H Axelsen
- Department of Pharmacology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| |
Collapse
|
415
|
|
416
|
Ross CA, Kronenbuerger M, Duan W, Margolis RL. Mechanisms underlying neurodegeneration in Huntington disease: applications to novel disease-modifying therapies. HANDBOOK OF CLINICAL NEUROLOGY 2017; 144:15-28. [PMID: 28947113 DOI: 10.1016/b978-0-12-801893-4.00002-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The CAG repeat expansion mutation that causes Huntington Disease (HD) was discovered more than 20 years ago, yet no treatment has yet been developed to stop the relentless course of the disease. Nonetheless, substantial progress has been made in understanding HD pathogenesis. We review insights that have been gleaned from HD genetics, metabolism, and pathology; HD mouse and cell models; the structure, function and post-translational modification of normal and mutant huntingtin (htt) protein; gene expression profiles in HD cells and tissue; the neurotoxicy of mutant htt RNA; and the expression of an antisense transcript from the HD locus. We conclude that rationale therapeutics for HD is within sight, though many questions remain to be answered.
Collapse
Affiliation(s)
- Christopher A Ross
- Division of Neurobiology, Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD, United States; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, United States; Departments of Neuroscience and Pharmacology, Johns Hopkins University School of Medicine, Baltimore, MD, United States.
| | - Martin Kronenbuerger
- Division of Movement Disorders, Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Wenzhen Duan
- Division of Neurobiology, Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD, United States; Translational Neurobiology Laboratory, Johns Hopkins University School of Medicine, Baltimore, MD, United States; Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Russell L Margolis
- Division of Neurobiology, Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD, United States; Translational Neurobiology Laboratory, Johns Hopkins University School of Medicine, Baltimore, MD, United States; Laboratory of Genetic Neurobiology and Johns Hopkins Schizophrenia Center, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| |
Collapse
|
417
|
Theocharopoulou G, Bobori C, Vlamos P. Formal Models of Biological Systems. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 988:325-338. [PMID: 28971411 DOI: 10.1007/978-3-319-56246-9_27] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Recent biomedical research studies are focused in the mechanisms by which misfolded proteins lead to the generation of oxidative stress in the form of reactive oxygen species (ROS), often implicated in neurodegenerative diseases and aging. Moreover, biological experiments are designed to investigate how proteostasis depends on the balance between the folding capacity of chaperone networks and the continuous flux of potentially nonnative proteins. Nevertheless, biological experimental methods can examine the protein folding quality control mechanisms only in individual cells, but not in a multicellular level. Formal models offer a dynamic form of modelling, which allows to explore various parameter values in an integrated time-dependent system. This paper aims to present a formal approach of a mathematical descriptive model using as example a representation of a known molecular chaperone system and its relation to diseases associated to protein misfolding and neurodegeneration.
Collapse
Affiliation(s)
| | | | - Panayiotis Vlamos
- Department of Informatics, Bioinformatics and Human Electrophysiology Laboratory, Ionian University, Corfu, Greece
| |
Collapse
|
418
|
Division modes and physical asymmetry in cerebral cortex progenitors. Curr Opin Neurobiol 2016; 42:75-83. [PMID: 27978481 DOI: 10.1016/j.conb.2016.11.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Revised: 11/21/2016] [Accepted: 11/22/2016] [Indexed: 12/26/2022]
Abstract
Neural stem cells go through a sequence of timely regulated gene expression and pattern of division mode to generate diverse neurons during brain development. During vertebrate cerebral cortex development, neural stem cells begin with proliferative symmetric divisions, subsequently undergo neurogenic asymmetric divisions, and finally gliogenic divisions. In this review, we explore the relationship between stem cell versus neural fate specification and the division mode. Specifically, we discuss recent findings on the mechanisms of asymmetric divisions, division mode, and developmental progression of neural progenitor identity.
Collapse
|
419
|
Bonet-Costa V, Pomatto LCD, Davies KJA. The Proteasome and Oxidative Stress in Alzheimer's Disease. Antioxid Redox Signal 2016; 25:886-901. [PMID: 27392670 PMCID: PMC5124752 DOI: 10.1089/ars.2016.6802] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
SIGNIFICANCE Alzheimer's disease is a neurodegenerative disorder that is projected to exceed more than 100 million cases worldwide by 2050. Aging is considered the primary risk factor for some 90% of Alzheimer's cases but a significant 10% of patients suffer from aggressive, early-onset forms of the disease. There is currently no effective Alzheimer's treatment and this, coupled with a growing aging population, highlights the necessity to understand the mechanism(s) of disease initiation and propagation. A major hallmark of Alzheimer's disease pathology is the accumulation of amyloid-β (Aβ) aggregates (an early marker of Alzheimer's disease), and neurofibrillary tangles, comprising the hyper-phosphorylated microtubule-associated protein Tau. Recent Advances: Protein oxidation is frequently invoked as a potential factor in the progression of Alzheimer's disease; however, whether it is a cause or a consequence of the pathology is still being debated. The Proteasome complex is a major regulator of intracellular protein quality control and an essential proteolytic enzyme for the processing of both Aβ and Tau. Recent studies have indicated that both protein oxidation and excessive phosphorylation may limit Proteasomal processing of Aβ and Tau in Alzheimer's disease. CRITICAL ISSUES Thus, the Proteasome may be a key factor in understanding the development of Alzheimer's disease pathology; however, its significance is still very much under investigation. FUTURE DIRECTIONS Discovering how the proteasome is affected, regulated, or dysregulated in Alzheimer's disease could be a valuable tool in the efforts to understand and, ultimately, eradicate the disease. Antioxid. Redox Signal. 25, 886-901.
Collapse
Affiliation(s)
- Vicent Bonet-Costa
- Leonard Davis School of Gerontology, Ethel Percy Andrus Gerontology Center, The Division of Molecular and Computational Biology, Department of Biological Sciences, Dornsife College of Letters, Arts, and Sciences, The University of Southern California , Los Angeles, California
| | - Laura Corrales-Diaz Pomatto
- Leonard Davis School of Gerontology, Ethel Percy Andrus Gerontology Center, The Division of Molecular and Computational Biology, Department of Biological Sciences, Dornsife College of Letters, Arts, and Sciences, The University of Southern California , Los Angeles, California
| | - Kelvin J A Davies
- Leonard Davis School of Gerontology, Ethel Percy Andrus Gerontology Center, The Division of Molecular and Computational Biology, Department of Biological Sciences, Dornsife College of Letters, Arts, and Sciences, The University of Southern California , Los Angeles, California
| |
Collapse
|
420
|
Combined in-situ imaging of structural organization and elemental composition of substantia nigra neurons in the elderly. Talanta 2016; 161:368-376. [DOI: 10.1016/j.talanta.2016.08.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 08/02/2016] [Accepted: 08/04/2016] [Indexed: 12/24/2022]
|
421
|
Solé-Domènech S, Cruz DL, Capetillo-Zarate E, Maxfield FR. The endocytic pathway in microglia during health, aging and Alzheimer's disease. Ageing Res Rev 2016; 32:89-103. [PMID: 27421577 DOI: 10.1016/j.arr.2016.07.002] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 07/01/2016] [Accepted: 07/05/2016] [Indexed: 12/14/2022]
Abstract
Microglia, the main phagocytes of the central nervous system (CNS), are involved in the surveillance and maintenance of nervous tissue. During normal tissue homeostasis, microglia migrates within the CNS, phagocytose dead cells and tissue debris, and modulate synapse pruning and spine formation via controlled phagocytosis. In the event of an invasion by a foreign body, microglia are able to phagocytose the invading pathogen and process it proteolytically for antigen presentation. Internalized substrates are incorporated and sorted within the endocytic pathway and thereafter transported via complex vesicular routes. When targeted for degradation, substrates are delivered to acidic late endosomes and lysosomes. In these, the enzymatic degradation relies on pH and enzyme content. Endocytosis, sorting, transport, compartment acidification and degradation are regulated by complex signaling mechanisms, and these may be altered during aging and pathology. In this review, we discuss the endocytic pathway in microglia, with insight into the mechanisms controlling lysosomal biogenesis and pH regulation. We also discuss microglial lysosome function associated with Alzheimer's disease (AD) and the mechanisms of amyloid-beta (Aβ) internalization and degradation. Finally, we explore some therapies currently being investigated to treat AD and their effects on microglial response to Aβ, with insight in those involving enhancement of lysosomal function.
Collapse
|
422
|
Schröder B, Saftig P. Intramembrane proteolysis within lysosomes. Ageing Res Rev 2016; 32:51-64. [PMID: 27143694 DOI: 10.1016/j.arr.2016.04.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 04/01/2016] [Accepted: 04/26/2016] [Indexed: 11/26/2022]
Abstract
Regulated intramembrane proteolysis is of pivotal importance in a diverse set of developmental and physiological processes. Altered intramembrane substrate turnover may be associated with neurodegeneration, cancer and impaired immune function. In this review we will focus on the intramembrane proteases which have been localized in the lysosomal membrane. Members of the γ-secretase complex and γ-secretase activity are found in the lysosomal membrane and are discussed to contribute to intracellular amyloid β production. Mutant or deficient γ-secretase may cause disturbed lysosomal function. The signal peptide peptidase-like (SPPL) protease 2a is a lysosomal membrane component and cleaves CD74, the invariant chain of the MHC II complex, as well as FasL, TNF, ITM2B and TMEM106, type II transmembrane proteins involved in the regulation of immunity and neurodegeneration. Therefore, it can be concluded, that not only proteolysis within the lysosomal lumen but also within lysosomal membranes regulates important cellular functions and contributes essentially to proteostasis of membrane proteins what may become increasingly compromised in the aged individual.
Collapse
|
423
|
Xilouri M, Stefanis L. Chaperone mediated autophagy in aging: Starve to prosper. Ageing Res Rev 2016; 32:13-21. [PMID: 27484893 DOI: 10.1016/j.arr.2016.07.001] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 06/07/2016] [Accepted: 07/04/2016] [Indexed: 10/21/2022]
Abstract
The major lysosomal proteolytic pathways essential for maintaining proper cellular homeostasis are macroautophagy, chaperone-mediated autophagy (CMA) and microautophagy. What differentiates CMA from the other types of autophagy is the fact that it does not involve vesicle formation; the unique feature of this pathway is the selective targeting of substrate proteins containing a CMA-targeting motif and the direct translocation into the lysosomal lumen, through the aid of chaperones/co-chaperones localized both at the cytosol and the lysosomes. CMA operates at basal conditions in most mammalian cell models analyzed so far, but it is mostly activated in response to stressors, such as trophic deprivation or oxidative stress. The activity of CMA has been shown to decline with age and such decline, correlating with accumulation of damaged/oxidized/aggregated proteins, may contribute to tissue dysfunction and, possibly, neurodegeneration. Herein, we review the recent knowledge regarding the molecular components, regulation and physiology of the CMA pathway, the contribution of impaired CMA activity to poor cellular homeostasis and inefficient response to stress during aging, and discuss the therapeutic opportunities offered by the restoration of CMA-dependent proteolysis in age-associated degenerative diseases.
Collapse
|
424
|
Cornils A, Maurya AK, Tereshko L, Kennedy J, Brear AG, Prahlad V, Blacque OE, Sengupta P. Structural and Functional Recovery of Sensory Cilia in C. elegans IFT Mutants upon Aging. PLoS Genet 2016; 12:e1006325. [PMID: 27906968 PMCID: PMC5131903 DOI: 10.1371/journal.pgen.1006325] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 08/25/2016] [Indexed: 01/28/2023] Open
Abstract
The majority of cilia are formed and maintained by the highly conserved process of intraflagellar transport (IFT). Mutations in IFT genes lead to ciliary structural defects and systemic disorders termed ciliopathies. Here we show that the severely truncated sensory cilia of hypomorphic IFT mutants in C. elegans transiently elongate during a discrete period of adult aging leading to markedly improved sensory behaviors. Age-dependent restoration of cilia morphology occurs in structurally diverse cilia types and requires IFT. We demonstrate that while DAF-16/FOXO is dispensable, the age-dependent suppression of cilia phenotypes in IFT mutants requires cell-autonomous functions of the HSF1 heat shock factor and the Hsp90 chaperone. Our results describe an unexpected role of early aging and protein quality control mechanisms in suppressing ciliary phenotypes of IFT mutants, and suggest possible strategies for targeting subsets of ciliopathies. Cilia are ‘antenna-like’ structures that are present on nearly all cell types in animals. These structures are important for sensing and signaling external cues to the cell. Most cilia are formed by a protein transport process called ‘intraflagellar transport’ or IFT. Mutations in IFT genes result in severe cilia defects, and are causal to a large number of diverse human disorders called ciliopathies. Since the genes and processes by which cilia are formed are similar across species, studies in experimental models such as the nematode C. elegans can greatly inform our overall understanding of cilia formation and function. Here we report the surprising observation that the structures and functions of severely defective cilia in nematodes with disrupted IFT genes markedly improve upon aging. We find that protein quality control mechanisms that normally decline in aging are required for this age-dependent recovery of cilia structure. Our results raise the possibility that the effects of some mutations in IFT genes can be bypassed under specific conditions, thereby restoring cilia functions.
Collapse
Affiliation(s)
- Astrid Cornils
- Department of Biology and National Center for Behavioral Genomics, Brandeis University, Waltham, Massachusetts
| | - Ashish K. Maurya
- Department of Biology and National Center for Behavioral Genomics, Brandeis University, Waltham, Massachusetts
| | - Lauren Tereshko
- Department of Biology and National Center for Behavioral Genomics, Brandeis University, Waltham, Massachusetts
| | - Julie Kennedy
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin, Ireland
| | - Andrea G. Brear
- Department of Biology and National Center for Behavioral Genomics, Brandeis University, Waltham, Massachusetts
| | - Veena Prahlad
- Department of Biology, Aging Mind and Brain Initiative, University of Iowa, Iowa City, Iowa
| | - Oliver E. Blacque
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin, Ireland
| | - Piali Sengupta
- Department of Biology and National Center for Behavioral Genomics, Brandeis University, Waltham, Massachusetts
- * E-mail:
| |
Collapse
|
425
|
Counts SE, Mufson EJ. Regulator of Cell Cycle (RGCC) Expression During the Progression of Alzheimer's Disease. Cell Transplant 2016; 26:693-702. [PMID: 27938491 DOI: 10.3727/096368916x694184] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Unscheduled cell cycle reentry of postmitotic neurons has been described in cases of mild cognitive impairment (MCI) and Alzheimer's disease (AD) and may form a basis for selective neuronal vulnerability during disease progression. In this regard, the multifunctional protein regulator of cell cycle (RGCC) has been implicated in driving G1/S and G2/M phase transitions through its interactions with cdc/cyclin-dependent kinase 1 (cdk1) and is induced by p53, which mediates apoptosis in neurons. We tested whether RGCC levels were dysregulated in frontal cortex samples obtained postmortem from subjects who died with a clinical diagnosis of no cognitive impairment (NCI), MCI, or AD. RGCC mRNA and protein levels were upregulated by ∼50%-60% in MCI and AD compared to NCI, and RGCC protein levels were associated with poorer antemortem global cognitive performance in the subjects examined. To test whether RGCC might regulate neuronal cell cycle reentry and apoptosis, we differentiated neuronotypic PC12 cultures with nerve growth factor (NGF) followed by NGF withdrawal to induce abortive cell cycle activation and cell death. Experimental reduction of RGCC levels increased cell survival and reduced levels of the cdk1 target cyclin B1. RGCC may be a candidate cell cycle target for neuroprotection during the onset of AD.
Collapse
|
426
|
Noormohammadi A, Khodakarami A, Gutierrez-Garcia R, Lee HJ, Koyuncu S, König T, Schindler C, Saez I, Fatima A, Dieterich C, Vilchez D. Somatic increase of CCT8 mimics proteostasis of human pluripotent stem cells and extends C. elegans lifespan. Nat Commun 2016; 7:13649. [PMID: 27892468 PMCID: PMC5133698 DOI: 10.1038/ncomms13649] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 10/19/2016] [Indexed: 12/14/2022] Open
Abstract
Human embryonic stem cells can replicate indefinitely while maintaining their undifferentiated state and, therefore, are immortal in culture. This capacity may demand avoidance of any imbalance in protein homeostasis (proteostasis) that would otherwise compromise stem cell identity. Here we show that human pluripotent stem cells exhibit enhanced assembly of the TRiC/CCT complex, a chaperonin that facilitates the folding of 10% of the proteome. We find that ectopic expression of a single subunit (CCT8) is sufficient to increase TRiC/CCT assembly. Moreover, increased TRiC/CCT complex is required to avoid aggregation of mutant Huntingtin protein. We further show that increased expression of CCT8 in somatic tissues extends Caenorhabditis elegans lifespan in a TRiC/CCT-dependent manner. Ectopic expression of CCT8 also ameliorates the age-associated demise of proteostasis and corrects proteostatic deficiencies in worm models of Huntington's disease. Our results suggest proteostasis is a common principle that links organismal longevity with hESC immortality.
Collapse
Affiliation(s)
- Alireza Noormohammadi
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Joseph Stelzmann Strasse 26, Cologne 50931, Germany
| | - Amirabbas Khodakarami
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Joseph Stelzmann Strasse 26, Cologne 50931, Germany
| | - Ricardo Gutierrez-Garcia
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Joseph Stelzmann Strasse 26, Cologne 50931, Germany
| | - Hyun Ju Lee
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Joseph Stelzmann Strasse 26, Cologne 50931, Germany
| | - Seda Koyuncu
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Joseph Stelzmann Strasse 26, Cologne 50931, Germany
| | - Tim König
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Joseph Stelzmann Strasse 26, Cologne 50931, Germany
| | - Christina Schindler
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Joseph Stelzmann Strasse 26, Cologne 50931, Germany
| | - Isabel Saez
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Joseph Stelzmann Strasse 26, Cologne 50931, Germany
| | - Azra Fatima
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Joseph Stelzmann Strasse 26, Cologne 50931, Germany
| | - Christoph Dieterich
- Section of Bioinformatics and Systems Cardiology, Department of Internal Medicine III and Klaus Tschira Institute for Computational Cardiology, Neuenheimer Feld 669, University Hospital, Heidelberg 69120, Germany
| | - David Vilchez
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Joseph Stelzmann Strasse 26, Cologne 50931, Germany
| |
Collapse
|
427
|
Pazoki-Toroudi H, Amani H, Ajami M, Nabavi SF, Braidy N, Kasi PD, Nabavi SM. Targeting mTOR signaling by polyphenols: A new therapeutic target for ageing. Ageing Res Rev 2016; 31:55-66. [PMID: 27453478 DOI: 10.1016/j.arr.2016.07.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Revised: 06/19/2016] [Accepted: 07/15/2016] [Indexed: 12/19/2022]
Abstract
Current ageing research is aimed not only at the promotion of longevity, but also at improving health span through the discovery and development of new therapeutic strategies by investigating molecular and cellular pathways involved in cellular senescence. Understanding the mechanism of action of polyphenolic compounds targeting mTOR (mechanistic target of rapamycin) and related pathways opens up new directions to revolutionize ways to slow down the onset and development of age-dependent degeneration. Herein, we will discuss the mechanisms by which polyphenols can delay the molecular pathogenesis of ageing via manipulation or more specifically inhibition of mTOR-signaling pathways. We will also discuss the implications of polyphenols in targeting mTOR and its related pathways on health life span extension and longevity..
Collapse
|
428
|
Labandeira-Garcia JL, Rodriguez-Perez AI, Valenzuela R, Costa-Besada MA, Guerra MJ. Menopause and Parkinson's disease. Interaction between estrogens and brain renin-angiotensin system in dopaminergic degeneration. Front Neuroendocrinol 2016; 43:44-59. [PMID: 27693730 DOI: 10.1016/j.yfrne.2016.09.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Revised: 09/26/2016] [Accepted: 09/27/2016] [Indexed: 02/07/2023]
Abstract
The neuroprotective effects of menopausal hormonal therapy in Parkinson's disease (PD) have not yet been clarified, and it is controversial whether there is a critical period for neuroprotection. Studies in animal models and clinical and epidemiological studies indicate that estrogens induce dopaminergic neuroprotection. Recent studies suggest that inhibition of the brain renin-angiotensin system (RAS) mediates the effects of estrogens in PD models. In the substantia nigra, ovariectomy induces a decrease in levels of estrogen receptor-α (ER-α) and increases angiotensin activity, NADPH-oxidase activity and expression of neuroinflammatory markers, which are regulated by estrogen replacement therapy. There is a critical period for the neuroprotective effect of estrogen replacement therapy, and local ER-α and RAS play a major role. Astrocytes play a major role in ER-α-induced regulation of local RAS, but neurons and microglia are also involved. Interestingly, treatment with angiotensin receptor antagonists after the critical period induced neuroprotection.
Collapse
Affiliation(s)
- Jose L Labandeira-Garcia
- Laboratory of Neuroanatomy and Experimental Neurology, Dept. of Morphological Sciences, CIMUS, University of Santiago de Compostela, Santiago de Compostela, Spain; Networking Research Center on Neurodegenerative Diseases (CIBERNED), Spain.
| | - Ana I Rodriguez-Perez
- Laboratory of Neuroanatomy and Experimental Neurology, Dept. of Morphological Sciences, CIMUS, University of Santiago de Compostela, Santiago de Compostela, Spain; Networking Research Center on Neurodegenerative Diseases (CIBERNED), Spain
| | - Rita Valenzuela
- Laboratory of Neuroanatomy and Experimental Neurology, Dept. of Morphological Sciences, CIMUS, University of Santiago de Compostela, Santiago de Compostela, Spain; Networking Research Center on Neurodegenerative Diseases (CIBERNED), Spain
| | - Maria A Costa-Besada
- Laboratory of Neuroanatomy and Experimental Neurology, Dept. of Morphological Sciences, CIMUS, University of Santiago de Compostela, Santiago de Compostela, Spain; Networking Research Center on Neurodegenerative Diseases (CIBERNED), Spain
| | - Maria J Guerra
- Laboratory of Neuroanatomy and Experimental Neurology, Dept. of Morphological Sciences, CIMUS, University of Santiago de Compostela, Santiago de Compostela, Spain; Networking Research Center on Neurodegenerative Diseases (CIBERNED), Spain
| |
Collapse
|
429
|
Delayed glial clearance of degenerating axons in aged Drosophila is due to reduced PI3K/Draper activity. Nat Commun 2016; 7:12871. [PMID: 27647497 PMCID: PMC5034330 DOI: 10.1038/ncomms12871] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 08/10/2016] [Indexed: 01/09/2023] Open
Abstract
Advanced age is the greatest risk factor for neurodegenerative disorders, but the mechanisms that render the senescent brain vulnerable to disease are unclear. Glial immune responses provide neuroprotection in a variety of contexts. Thus, we explored how glial responses to neurodegeneration are altered with age. Here we show that glia–axon phagocytic interactions change dramatically in the aged Drosophila brain. Aged glia clear degenerating axons slowly due to low phosphoinositide-3-kinase (PI3K) signalling and, subsequently, reduced expression of the conserved phagocytic receptor Draper/MEGF10. Importantly, boosting PI3K/Draper activity in aged glia significantly reverses slow phagocytic responses. Moreover, several hours post axotomy, early hallmarks of Wallerian degeneration (WD) are delayed in aged flies. We propose that slow clearance of degenerating axons is mechanistically twofold, resulting from deferred initiation of axonal WD and reduced PI3K/Draper-dependent glial phagocytic function. Interventions that boost glial engulfment activity, however, can substantially reverse delayed clearance of damaged neuronal debris. Glial engulfment declines with age, but the mechanism is unclear. Here authors show that in the Drosophila olfactory system, glial phagocytosis of injury-induced degenerating axons decreases with age due to reduced PI3K/Draper activity, and restoring Draper in aged glia rescues such defects.
Collapse
|
430
|
Corpas R, Revilla S, Ursulet S, Castro-Freire M, Kaliman P, Petegnief V, Giménez-Llort L, Sarkis C, Pallàs M, Sanfeliu C. SIRT1 Overexpression in Mouse Hippocampus Induces Cognitive Enhancement Through Proteostatic and Neurotrophic Mechanisms. Mol Neurobiol 2016; 54:5604-5619. [PMID: 27614878 DOI: 10.1007/s12035-016-0087-9] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 08/26/2016] [Indexed: 01/08/2023]
Abstract
SIRT1 induces cell survival and has shown neuroprotection against amyloid and tau pathologies in Alzheimer's disease (AD). However, protective effects against memory loss or the enhancement of cognitive functions have not yet been proven. We aimed to investigate the benefits induced by SIRT1 overexpression in the hippocampus of the AD mouse model 3xTg-AD and in control non-transgenic mice. A lentiviral vector encoding mouse SIRT1 or GFP, selectively transducing neurons, was injected into the dorsal CA1 hippocampal area of 4-month-old mice. Six-month overexpression of SIRT1 fully preserved learning and memory in 10-month-old 3xTg-AD mice. Remarkably, SIRT1 also induced cognitive enhancement in healthy non-transgenic mice. Neuron cultures of 3xTg-AD mice, which show traits of AD-like pathology, and neuron cultures from non-transgenic mice were also transduced with lentiviral vectors to analyze beneficial SIRT1 mechanisms. We uncovered novel pathways of SIRT1 neuroprotection through enhancement of cell proteostatic mechanisms and activation of neurotrophic factors not previously reported such as GDNF, present in both AD-like and healthy neurons. Therefore, SIRT1 may increase neuron function and resilience against AD.
Collapse
Affiliation(s)
- Rubén Corpas
- Institut d'Investigacions Biomèdiques de Barcelona (IIBB) - CSIC, C/Rosselló 161, 6th floor, 08036, Barcelona, Spain
| | - Susana Revilla
- Institut d'Investigacions Biomèdiques de Barcelona (IIBB) - CSIC, C/Rosselló 161, 6th floor, 08036, Barcelona, Spain
| | | | - Marco Castro-Freire
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036, Barcelona, Spain
| | - Perla Kaliman
- Institut d'Investigacions Biomèdiques de Barcelona (IIBB) - CSIC, C/Rosselló 161, 6th floor, 08036, Barcelona, Spain
| | - Valérie Petegnief
- Institut d'Investigacions Biomèdiques de Barcelona (IIBB) - CSIC, C/Rosselló 161, 6th floor, 08036, Barcelona, Spain
| | - Lydia Giménez-Llort
- Department of Psychiatry and Forensic Medicine, Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain
| | | | - Mercè Pallàs
- Facultat de Farmàcia, Institut de Neurociències, Universitat de Barcelona and CIBERNED, 08028, Barcelona, Spain
| | - Coral Sanfeliu
- Institut d'Investigacions Biomèdiques de Barcelona (IIBB) - CSIC, C/Rosselló 161, 6th floor, 08036, Barcelona, Spain. .,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036, Barcelona, Spain.
| |
Collapse
|
431
|
Chew YL, Schafer WR. Dopamine helps worms deal with stress. EMBO J 2016; 35:1851-2. [PMID: 27440403 DOI: 10.15252/embj.201695010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
|
432
|
Metabolic Control of Longevity. Cell 2016; 166:802-821. [DOI: 10.1016/j.cell.2016.07.031] [Citation(s) in RCA: 489] [Impact Index Per Article: 61.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 05/15/2016] [Accepted: 07/20/2016] [Indexed: 12/19/2022]
|
433
|
Hernandez-Garzón E, Fernandez AM, Perez-Alvarez A, Genis L, Bascuñana P, Fernandez de la Rosa R, Delgado M, Angel Pozo M, Moreno E, McCormick PJ, Santi A, Trueba-Saiz A, Garcia-Caceres C, Tschöp MH, Araque A, Martin ED, Torres Aleman I. The insulin-like growth factor I receptor regulates glucose transport by astrocytes. Glia 2016; 64:1962-71. [PMID: 27462832 DOI: 10.1002/glia.23035] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 07/05/2016] [Accepted: 07/07/2016] [Indexed: 12/20/2022]
Abstract
Previous findings indicate that reducing brain insulin-like growth factor I receptor (IGF-IR) activity promotes ample neuroprotection. We now examined a possible action of IGF-IR on brain glucose transport to explain its wide protective activity, as energy availability is crucial for healthy tissue function. Using (18) FGlucose PET we found that shRNA interference of IGF-IR in mouse somatosensory cortex significantly increased glucose uptake upon sensory stimulation. In vivo microscopy using astrocyte specific staining showed that after IGF-IR shRNA injection in somatosensory cortex, astrocytes displayed greater increases in glucose uptake as compared to astrocytes in the scramble-injected side. Further, mice with the IGF-IR knock down in astrocytes showed increased glucose uptake in somatosensory cortex upon sensory stimulation. Analysis of underlying mechanisms indicated that IGF-IR interacts with glucose transporter 1 (GLUT1), the main facilitative glucose transporter in astrocytes, through a mechanism involving interactions with the scaffolding protein GIPC and the multicargo transporter LRP1 to retain GLUT1 inside the cell. These findings identify IGF-IR as a key modulator of brain glucose metabolism through its inhibitory action on astrocytic GLUT1 activity. GLIA 2016;64:1962-1971.
Collapse
Affiliation(s)
| | | | - Alberto Perez-Alvarez
- Cajal Institute, CSIC, Madrid, Spain.,Center for Molecular Neurobiology Hamburg, Hamburg, Germany
| | - Laura Genis
- Cajal Institute, CSIC, Madrid, Spain.,Ciberned, Spain
| | - Pablo Bascuñana
- Pluridisciplinary Institute, Complutense University, Madrid, Spain
| | | | - Mercedes Delgado
- Pluridisciplinary Institute, Complutense University, Madrid, Spain
| | | | - Estefania Moreno
- Ciberned, Spain.,Dept Biochemistry and Molecular Biology, University of Barcelona, Barcelona, Spain
| | - Peter J McCormick
- Ciberned, Spain.,Dept Biochemistry and Molecular Biology, University of Barcelona, Barcelona, Spain.,School of Pharmacy, University of East Anglia, Norwich, Norfolk, United Kingdom
| | - Andrea Santi
- Cajal Institute, CSIC, Madrid, Spain.,Ciberned, Spain
| | | | | | | | | | - Eduardo D Martin
- Science and Technology Park, Institute for Research in Neurological Disabilities, University of Castilla-La Mancha, Albacete, Spain
| | | |
Collapse
|
434
|
Lee HJ, Gutierrez‐Garcia R, Vilchez D. Embryonic stem cells: a novel paradigm to study proteostasis? FEBS J 2016; 284:391-398. [DOI: 10.1111/febs.13810] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 06/22/2016] [Accepted: 07/08/2016] [Indexed: 12/12/2022]
Affiliation(s)
- Hyun Ju Lee
- Cologne Excellence Cluster for Cellular Stress Responses in Aging‐Associated Diseases (CECAD) University of Cologne Germany
| | - Ricardo Gutierrez‐Garcia
- Cologne Excellence Cluster for Cellular Stress Responses in Aging‐Associated Diseases (CECAD) University of Cologne Germany
| | - David Vilchez
- Cologne Excellence Cluster for Cellular Stress Responses in Aging‐Associated Diseases (CECAD) University of Cologne Germany
| |
Collapse
|
435
|
Duran-Aniotz C, Cornejo VH, Hetz C. Targeting endoplasmic reticulum acetylation to restore proteostasis in Alzheimer's disease. Brain 2016; 139:650-2. [PMID: 26917585 DOI: 10.1093/brain/awv401] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Affiliation(s)
- Claudia Duran-Aniotz
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile FONDAP Centre for Geroscience, Brain Health and Metabolism, Santiago, Chile Program of Cellular and Molecular Biology, Centre for Molecular Studies of the Cell, Institute of Biomedical Sciences, University of Chile
| | - Victor Hugo Cornejo
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile FONDAP Centre for Geroscience, Brain Health and Metabolism, Santiago, Chile Program of Cellular and Molecular Biology, Centre for Molecular Studies of the Cell, Institute of Biomedical Sciences, University of Chile
| | - Claudio Hetz
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile FONDAP Centre for Geroscience, Brain Health and Metabolism, Santiago, Chile Program of Cellular and Molecular Biology, Centre for Molecular Studies of the Cell, Institute of Biomedical Sciences, University of Chile Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston MA, USA
| |
Collapse
|
436
|
Velazquez R, Shaw DM, Caccamo A, Oddo S. Pim1 inhibition as a novel therapeutic strategy for Alzheimer's disease. Mol Neurodegener 2016; 11:52. [PMID: 27412291 PMCID: PMC4944476 DOI: 10.1186/s13024-016-0118-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 07/02/2016] [Indexed: 01/07/2023] Open
Abstract
Background Alzheimer’s disease (AD) is the most prevalent neurodegenerative disorder worldwide. Clinically, AD is characterized by impairments of memory and cognitive functions. Accumulation of amyloid-β (Aβ) and neurofibrillary tangles are the prominent neuropathologies in patients with AD. Strong evidence indicates that an imbalance between production and degradation of key proteins contributes to the pathogenesis of AD. The mammalian target of rapamycin (mTOR) plays a key role in maintaining protein homeostasis as it regulates both protein synthesis and degradation. A key regulator of mTOR activity is the proline-rich AKT substrate 40 kDa (PRAS40), which directly binds to mTOR and reduces its activity. Notably, AD patients have elevated levels of phosphorylated PRAS40, which correlate with Aβ and tau pathologies as well as cognitive deficits. Physiologically, PRAS40 phosphorylation is regulated by Pim1, a protein kinase of the protoconcogene family. Here, we tested the effects of a selective Pim1 inhibitor (Pim1i), on spatial reference and working memory and AD-like pathology in 3xTg-AD mice. Results We have identified a Pim1i that crosses the blood brain barrier and reduces PRAS40 phosphorylation. Pim1i-treated 3xTg-AD mice performed significantly better than their vehicle treated counterparts as well as non-transgenic mice. Additionally, 3xTg-AD Pim1i-treated mice showed a reduction in soluble and insoluble Aβ40 and Aβ42 levels, as well as a 45.2 % reduction in Aβ42 plaques within the hippocampus. Furthermore, phosphorylated tau immunoreactivity was reduced in the hippocampus of Pim1i–treated 3xTg-AD mice by 38 %. Mechanistically, these changes were linked to a significant increase in proteasome activity. Conclusion These results suggest that reductions in phosphorylated PRAS40 levels via Pim1 inhibition reduce Aβ and Tau pathology and rescue cognitive deficits by increasing proteasome function. Given that Pim1 inhibitors are already being tested in ongoing human clinical trials for cancer, the results presented here may open a new venue of drug discovery for AD by developing more Pim1 inhibitors.
Collapse
Affiliation(s)
- Ramon Velazquez
- Neurodegenerative Disease Research Center, Biodesign Institute, School of Life Sciences, Arizona State University, 727 E. Tyler Street, Tempe, AZ, 85287-5001, USA
| | - Darren M Shaw
- Neurodegenerative Disease Research Center, Biodesign Institute, School of Life Sciences, Arizona State University, 727 E. Tyler Street, Tempe, AZ, 85287-5001, USA.,School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA
| | - Antonella Caccamo
- Neurodegenerative Disease Research Center, Biodesign Institute, School of Life Sciences, Arizona State University, 727 E. Tyler Street, Tempe, AZ, 85287-5001, USA
| | - Salvatore Oddo
- Neurodegenerative Disease Research Center, Biodesign Institute, School of Life Sciences, Arizona State University, 727 E. Tyler Street, Tempe, AZ, 85287-5001, USA. .,School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA.
| |
Collapse
|
437
|
Ricchetti M. How stem cells manage to escape senescence and ageing - while they can: A recent study reveals that autophagy is responsible for senescence-dependent loss of regenerative potential of muscle stem cells during ageing. Bioessays 2016; 38:857-62. [PMID: 27389857 DOI: 10.1002/bies.201600064] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Skeletal muscle stem cells or satellite cells are responsible for muscle regeneration in the adult. Although satellite cells are highly resistant to stress, and display greater capacity to repair molecular damage than the committed progeny, their regenerative potential declines with age. During ageing, satellite cells switch to a state of permanent cell cycle arrest or senescence which prevents their activation. A recent study reveals that the senescence of satellite cell relies on defective autophagy, the quality control mechanism that degrades damaged proteins and organelles. Molecular damage is generated by oxidative stress that also promotes epigenetic changes that activate the expression of master genes, in a double-hit mechanism that ensures senescence. Importantly, genetic, and pharmacological correction of defective autophagy reverses satellite cell senescence and restores muscle regeneration in geriatric mice, with perspectives of modulating age-related functional decline of muscle. This study provides new clues to understand stem cell and organismal ageing.
Collapse
Affiliation(s)
- Miria Ricchetti
- Department of Developmental and Stem Cell Biology, Institut Pasteur, Stem Cells and Development, Paris, France.,CNRS UMR 3525, Team Stability of Nuclear and Mitochondrial DNA, Paris, France
| |
Collapse
|
438
|
Kawasaki F, Koonce NL, Guo L, Fatima S, Qiu C, Moon MT, Zheng Y, Ordway RW. Small heat shock proteins mediate cell-autonomous and -nonautonomous protection in a Drosophila model for environmental-stress-induced degeneration. Dis Model Mech 2016; 9:953-64. [PMID: 27483356 PMCID: PMC5047692 DOI: 10.1242/dmm.026385] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2016] [Accepted: 07/05/2016] [Indexed: 12/28/2022] Open
Abstract
Cell and tissue degeneration, and the development of degenerative diseases, are influenced by genetic and environmental factors that affect protein misfolding and proteotoxicity. To better understand the role of the environment in degeneration, we developed a genetic model for heat shock (HS)-stress-induced degeneration in Drosophila. This model exhibits a unique combination of features that enhance genetic analysis of degeneration and protection mechanisms involving environmental stress. These include cell-type-specific failure of proteostasis and degeneration in response to global stress, cell-nonautonomous interactions within a simple and accessible network of susceptible cell types, and precise temporal control over the induction of degeneration. In wild-type flies, HS stress causes selective loss of the flight ability and degeneration of three susceptible cell types comprising the flight motor: muscle, motor neurons and associated glia. Other motor behaviors persist and, accordingly, the corresponding cell types controlling leg motor function are resistant to degeneration. Flight motor degeneration was preceded by a failure of muscle proteostasis characterized by diffuse ubiquitinated protein aggregates. Moreover, muscle-specific overexpression of a small heat shock protein (HSP), HSP23, promoted proteostasis and protected muscle from HS stress. Notably, neurons and glia were protected as well, indicating that a small HSP can mediate cell-nonautonomous protection. Cell-autonomous protection of muscle was characterized by a distinct distribution of ubiquitinated proteins, including perinuclear localization and clearance of protein aggregates associated with the perinuclear microtubule network. This network was severely disrupted in wild-type preparations prior to degeneration, suggesting that it serves an important role in muscle proteostasis and protection. Finally, studies of resistant leg muscles revealed that they sustain proteostasis and the microtubule cytoskeleton after HS stress. These findings establish a model for genetic analysis of degeneration and protection mechanisms involving contributions of environmental factors, and advance our understanding of the protective functions and therapeutic potential of small HSPs. Summary: A Drosophila model for environmental-stress-induced degeneration exhibits key features for genetic analysis of degenerative disease mechanisms and reveals new forms of protection mediated by small heat shock proteins.
Collapse
Affiliation(s)
- Fumiko Kawasaki
- Department of Biology and Center for Molecular Investigation of Neurological Disorders, The Pennsylvania State University, University Park, PA 16802, USA
| | - Noelle L Koonce
- Department of Biology and Center for Molecular Investigation of Neurological Disorders, The Pennsylvania State University, University Park, PA 16802, USA
| | - Linda Guo
- Department of Biology and Center for Molecular Investigation of Neurological Disorders, The Pennsylvania State University, University Park, PA 16802, USA
| | - Shahroz Fatima
- Department of Biology and Center for Molecular Investigation of Neurological Disorders, The Pennsylvania State University, University Park, PA 16802, USA
| | - Catherine Qiu
- Department of Biology and Center for Molecular Investigation of Neurological Disorders, The Pennsylvania State University, University Park, PA 16802, USA
| | - Mackenzie T Moon
- Department of Biology and Center for Molecular Investigation of Neurological Disorders, The Pennsylvania State University, University Park, PA 16802, USA
| | - Yunzhen Zheng
- Department of Biology and Center for Molecular Investigation of Neurological Disorders, The Pennsylvania State University, University Park, PA 16802, USA
| | - Richard W Ordway
- Department of Biology and Center for Molecular Investigation of Neurological Disorders, The Pennsylvania State University, University Park, PA 16802, USA
| |
Collapse
|
439
|
|
440
|
Chaperone-Mediated Autophagy and Mitochondrial Homeostasis in Parkinson's Disease. PARKINSONS DISEASE 2016; 2016:2613401. [PMID: 27413575 PMCID: PMC4927950 DOI: 10.1155/2016/2613401] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/27/2015] [Revised: 04/04/2016] [Accepted: 05/29/2016] [Indexed: 12/20/2022]
Abstract
Parkinson's disease (PD), a complex neurodegenerative disorder, is pathologically characterized by the formation of Lewy bodies and loss of dopaminergic neurons in the substantia nigra pars compacta (SNc). Mitochondrial dysfunction is considered to be one of the most important causative mechanisms. In addition, dysfunction of chaperone-mediated autophagy (CMA), one of the lysosomal proteolytic pathways, has been shown to play an important role in the pathogenesis of PD. An exciting and important development is recent finding that CMA and mitochondrial quality control may be linked. This review summarizes the studies revealing the link between autophagy and mitochondrial function. Discussions are focused on the connections between CMA and mitochondrial failure and on the role of MEF2D, a neuronal survival factor, in mediating the regulation of mitochondria in the context of CMA. These new findings highlight the need to further explore the possibility of targeting the MEF2D-mitochondria-CMA network in both understanding the PD pathogenesis and developing novel therapeutic strategies.
Collapse
|
441
|
Bondulich MK, Guo T, Meehan C, Manion J, Rodriguez Martin T, Mitchell JC, Hortobagyi T, Yankova N, Stygelbout V, Brion JP, Noble W, Hanger DP. Tauopathy induced by low level expression of a human brain-derived tau fragment in mice is rescued by phenylbutyrate. Brain 2016; 139:2290-306. [PMID: 27297240 PMCID: PMC4958900 DOI: 10.1093/brain/aww137] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Accepted: 05/01/2016] [Indexed: 12/11/2022] Open
Abstract
Human neurodegenerative tauopathies exhibit pathological tau aggregates in the brain along with diverse clinical features including cognitive and motor dysfunction. Post-translational modifications including phosphorylation, ubiquitination and truncation, are characteristic features of tau present in the brain in human tauopathy. We have previously reported an N-terminally truncated form of tau in human brain that is associated with the development of tauopathy and is highly phosphorylated. We have generated a new mouse model of tauopathy in which this human brain-derived, 35 kDa tau fragment (Tau35) is expressed in the absence of any mutation and under the control of the human tau promoter. Most existing mouse models of tauopathy overexpress mutant tau at levels that do not occur in human neurodegenerative disease, whereas Tau35 transgene expression is equivalent to less than 10% of that of endogenous mouse tau. Tau35 mice recapitulate key features of human tauopathies, including aggregated and abnormally phosphorylated tau, progressive cognitive and motor deficits, autophagic/lysosomal dysfunction, loss of synaptic protein, and reduced life-span. Importantly, we found that sodium 4-phenylbutyrate (Buphenyl®), a drug used to treat urea cycle disorders and currently in clinical trials for a range of neurodegenerative diseases, reverses the observed abnormalities in tau and autophagy, behavioural deficits, and loss of synapsin 1 in Tau35 mice. Our results show for the first time that, unlike other tau transgenic mouse models, minimal expression of a human disease-associated tau fragment in Tau35 mice causes a profound and progressive tauopathy and cognitive changes, which are rescued by pharmacological intervention using a clinically approved drug. These novel Tau35 mice therefore represent a highly disease-relevant animal model in which to investigate molecular mechanisms and to develop novel treatments for human tauopathies.
Collapse
Affiliation(s)
- Marie K Bondulich
- 1 King's College London, Institute of Psychiatry, Psychology & Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Department of Basic and Clinical Neuroscience, 125 Coldharbour Lane, London SE5 9NU, UK
| | - Tong Guo
- 1 King's College London, Institute of Psychiatry, Psychology & Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Department of Basic and Clinical Neuroscience, 125 Coldharbour Lane, London SE5 9NU, UK
| | - Christopher Meehan
- 1 King's College London, Institute of Psychiatry, Psychology & Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Department of Basic and Clinical Neuroscience, 125 Coldharbour Lane, London SE5 9NU, UK
| | - John Manion
- 1 King's College London, Institute of Psychiatry, Psychology & Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Department of Basic and Clinical Neuroscience, 125 Coldharbour Lane, London SE5 9NU, UK
| | - Teresa Rodriguez Martin
- 1 King's College London, Institute of Psychiatry, Psychology & Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Department of Basic and Clinical Neuroscience, 125 Coldharbour Lane, London SE5 9NU, UK
| | - Jacqueline C Mitchell
- 1 King's College London, Institute of Psychiatry, Psychology & Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Department of Basic and Clinical Neuroscience, 125 Coldharbour Lane, London SE5 9NU, UK
| | - Tibor Hortobagyi
- 1 King's College London, Institute of Psychiatry, Psychology & Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Department of Basic and Clinical Neuroscience, 125 Coldharbour Lane, London SE5 9NU, UK
| | - Natalia Yankova
- 1 King's College London, Institute of Psychiatry, Psychology & Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Department of Basic and Clinical Neuroscience, 125 Coldharbour Lane, London SE5 9NU, UK
| | - Virginie Stygelbout
- 2 Laboratory of Histology, Neuroanatomy and Neuropathology (CP 620), ULB Neuroscience Institute, Université Libre de Bruxelles, Faculty of Medicine 808, route de Lennik, 1070 Brussels, Belgium
| | - Jean-Pierre Brion
- 2 Laboratory of Histology, Neuroanatomy and Neuropathology (CP 620), ULB Neuroscience Institute, Université Libre de Bruxelles, Faculty of Medicine 808, route de Lennik, 1070 Brussels, Belgium
| | - Wendy Noble
- 1 King's College London, Institute of Psychiatry, Psychology & Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Department of Basic and Clinical Neuroscience, 125 Coldharbour Lane, London SE5 9NU, UK
| | - Diane P Hanger
- 1 King's College London, Institute of Psychiatry, Psychology & Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Department of Basic and Clinical Neuroscience, 125 Coldharbour Lane, London SE5 9NU, UK
| |
Collapse
|
442
|
Sahoo B, Arduini I, Drombosky KW, Kodali R, Sanders LH, Greenamyre JT, Wetzel R. Folding Landscape of Mutant Huntingtin Exon1: Diffusible Multimers, Oligomers and Fibrils, and No Detectable Monomer. PLoS One 2016; 11:e0155747. [PMID: 27271685 PMCID: PMC4894636 DOI: 10.1371/journal.pone.0155747] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 05/03/2016] [Indexed: 12/19/2022] Open
Abstract
Expansion of the polyglutamine (polyQ) track of the Huntingtin (HTT) protein above 36 is associated with a sharply enhanced risk of Huntington’s disease (HD). Although there is general agreement that HTT toxicity resides primarily in N-terminal fragments such as the HTT exon1 protein, there is no consensus on the nature of the physical states of HTT exon1 that are induced by polyQ expansion, nor on which of these states might be responsible for toxicity. One hypothesis is that polyQ expansion induces an alternative, toxic conformation in the HTT exon1 monomer. Alternative hypotheses posit that the toxic species is one of several possible aggregated states. Defining the nature of the toxic species is particularly challenging because of facile interconversion between physical states as well as challenges to identifying these states, especially in vivo. Here we describe the use of fluorescence correlation spectroscopy (FCS) to characterize the detailed time and repeat length dependent self-association of HTT exon1-like fragments both with chemically synthesized peptides in vitro and with cell-produced proteins in extracts and in living cells. We find that, in vitro, mutant HTT exon1 peptides engage in polyQ repeat length dependent dimer and tetramer formation, followed by time dependent formation of diffusible spherical and fibrillar oligomers and finally by larger, sedimentable amyloid fibrils. For expanded polyQ HTT exon1 expressed in PC12 cells, monomers are absent, with tetramers being the smallest molecular form detected, followed in the incubation time course by small, diffusible aggregates at 6–9 hours and larger, sedimentable aggregates that begin to build up at 12 hrs. In these cell cultures, significant nuclear DNA damage appears by 6 hours, followed at later times by caspase 3 induction, mitochondrial dysfunction, and cell death. Our data thus defines limits on the sizes and concentrations of different physical states of HTT exon1 along the reaction profile in the context of emerging cellular distress. The data provide some new candidates for the toxic species and some new reservations about more well-established candidates. Compared to other known markers of HTT toxicity, nuclear DNA damage appears to be a relatively early pathological event.
Collapse
Affiliation(s)
- Bankanidhi Sahoo
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, United States of America
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, United States of America
| | - Irene Arduini
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, United States of America
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, United States of America
| | - Kenneth W. Drombosky
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, United States of America
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, United States of America
| | - Ravindra Kodali
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, United States of America
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, United States of America
| | - Laurie H. Sanders
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, United States of America
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, United States of America
| | - J. Timothy Greenamyre
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, United States of America
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, United States of America
| | - Ronald Wetzel
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, United States of America
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, United States of America
- * E-mail:
| |
Collapse
|
443
|
Joshi KK, Matlack TL, Rongo C. Dopamine signaling promotes the xenobiotic stress response and protein homeostasis. EMBO J 2016; 35:1885-901. [PMID: 27261197 DOI: 10.15252/embj.201592524] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 05/03/2016] [Indexed: 01/11/2023] Open
Abstract
Multicellular organisms encounter environmental conditions that adversely affect protein homeostasis (proteostasis), including extreme temperatures, toxins, and pathogens. It is unclear how they use sensory signaling to detect adverse conditions and then activate stress response pathways so as to offset potential damage. Here, we show that dopaminergic mechanosensory neurons in C. elegans release the neurohormone dopamine to promote proteostasis in epithelia. Signaling through the DA receptor DOP-1 activates the expression of xenobiotic stress response genes involved in pathogenic resistance and toxin removal, and these genes are required for the removal of unstable proteins in epithelia. Exposure to a bacterial pathogen (Pseudomonas aeruginosa) results in elevated removal of unstable proteins in epithelia, and this enhancement requires DA signaling. In the absence of DA signaling, nematodes show increased sensitivity to pathogenic bacteria and heat-shock stress. Our results suggest that dopaminergic sensory neurons, in addition to slowing down locomotion upon sensing a potential bacterial feeding source, also signal to frontline epithelia to activate the xenobiotic stress response so as to maintain proteostasis and prepare for possible infection.
Collapse
Affiliation(s)
- Kishore K Joshi
- Department of Genetics, The Waksman Institute Rutgers The State University of New Jersey, Piscataway, NJ, USA
| | - Tarmie L Matlack
- Department of Genetics, The Waksman Institute Rutgers The State University of New Jersey, Piscataway, NJ, USA
| | - Christopher Rongo
- Department of Genetics, The Waksman Institute Rutgers The State University of New Jersey, Piscataway, NJ, USA
| |
Collapse
|
444
|
Chen X, Petranovic D. Role of frameshift ubiquitin B protein in Alzheimer's disease. WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE 2016; 8:300-13. [DOI: 10.1002/wsbm.1340] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 03/10/2016] [Accepted: 03/19/2016] [Indexed: 12/20/2022]
Affiliation(s)
- Xin Chen
- Systems and Synthetic Biology, Department of Biology and Biological Engineering; Chalmers University of Technology; Göteborg Sweden
| | - Dina Petranovic
- Systems and Synthetic Biology, Department of Biology and Biological Engineering; Chalmers University of Technology; Göteborg Sweden
- Novo Nordisk Foundation Center for Biosustainability; Chalmers University of Technology; Göteborg Sweden
| |
Collapse
|
445
|
Hussain M, Lu Y, Liu YQ, Su K, Zhang J, Liu J, Zhou GB. Skp1: Implications in cancer and SCF-oriented anti-cancer drug discovery. Pharmacol Res 2016; 111:34-42. [PMID: 27238229 DOI: 10.1016/j.phrs.2016.05.027] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 04/28/2016] [Accepted: 05/25/2016] [Indexed: 12/29/2022]
Abstract
In the last decade, the ubiquitin proteasome system (UPS), in general, and E3 ubiquitin ligases, in particular, have emerged as valid drug targets for the development of novel anti-cancer therapeutics. Cullin RING Ligases (CRLs), which can be classified into eight groups (CRL1-8) and comprise approximately 200 members, represent the largest family of E3 ubiquitin ligases which facilitate the ubiquitination-derived proteasomal degradation of a myriad of functionally and structurally diverse substrates. S phase kinase-associated protein 1 (Skp1)-Cullin1-F-Box protein (SCF) complexes are the best characterized among CRLs, which play crucial roles in numerous cellular processes and physiological dysfunctions, such as in cancer biology. Currently, there is growing interest in developing SCF-targeting anti-cancer therapies for clinical application. Indeed, the research in this field has seen some progress in the form of cullin neddylation- and Skp2-inhibitors. However, it still remains an underdeveloped area and needs to design new strategies for developing improved form of therapy. In this review, we venture a novel strategy that rational pharmacological targeting of Skp1, a central regulator of SCF complexes, may provide a novel avenue for SCF-oriented anti-cancer therapy, expected: (i) to simultaneously address the critical roles that multiple SCF oncogenic complexes play in cancer biology, (ii) to selectively target cancer cells with minimal normal cell toxicity, and (iii) to offer multiple chemical series, via therapeutic interventions at the Skp1 binding interfaces in SCF complex, thereby maximizing chances of success for drug discovery. In addition, we also discuss the challenges that might be posed regarding rational pharmacological interventions against Skp1.
Collapse
Affiliation(s)
- Muzammal Hussain
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, 190 Kaiyuan Avenue, Science Park, Guangzhou, 510530, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Yongzhi Lu
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, 190 Kaiyuan Avenue, Science Park, Guangzhou, 510530, PR China
| | - Yong-Qiang Liu
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, PR China
| | - Kai Su
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, 190 Kaiyuan Avenue, Science Park, Guangzhou, 510530, PR China; School of Life Sciences, University of Science and Technology of China, Hefei, 230000, PR China
| | - Jiancun Zhang
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, 190 Kaiyuan Avenue, Science Park, Guangzhou, 510530, PR China; State Key Laboratory of Respiratory Disease, Guangzhou Medical University, Guangzhou, PR China
| | - Jinsong Liu
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, 190 Kaiyuan Avenue, Science Park, Guangzhou, 510530, PR China.
| | - Guang-Biao Zhou
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, PR China.
| |
Collapse
|
446
|
Kaushik S, Cuervo AM. Proteostasis and aging. Nat Med 2016; 21:1406-15. [PMID: 26646497 DOI: 10.1038/nm.4001] [Citation(s) in RCA: 555] [Impact Index Per Article: 69.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2015] [Accepted: 11/02/2015] [Indexed: 12/12/2022]
Abstract
Accumulation of intracellular damage is an almost universal hallmark of aging. An improved understanding of the systems that contribute to cellular protein quality control has shed light on the reasons for the increased vulnerability of the proteome to stress in aging cells. Maintenance of protein homeostasis, or proteostasis, is attained through precisely coordinated systems that rapidly correct unwanted proteomic changes. Here we focus on recent developments that highlight the multidimensional nature of the proteostasis networks, which allow for coordinated protein homeostasis intracellularly, in between cells and even across organs, as well as on how they affect common age-associated diseases when they malfunction in aging.
Collapse
Affiliation(s)
- Susmita Kaushik
- Department of Developmental and Molecular Biology, Institute for Aging Studies, Albert Einstein College of Medicine, New York, New York, USA
| | - Ana Maria Cuervo
- Department of Developmental and Molecular Biology, Institute for Aging Studies, Albert Einstein College of Medicine, New York, New York, USA
| |
Collapse
|
447
|
Booth LN, Brunet A. Shockingly Early: Chromatin-Mediated Loss of the Heat Shock Response. Mol Cell 2016; 59:515-6. [PMID: 26295957 DOI: 10.1016/j.molcel.2015.08.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In this issue of Molecular Cell, Labbadia and Morimoto (2015) show that there is a precipitous decline in stress resistance at the onset of reproduction in C. elegans and that this transition is regulated by changes in repressive chromatin marks.
Collapse
Affiliation(s)
- Lauren N Booth
- Department of Genetics, Stanford University, 300 Pasteur Drive, Stanford, CA 94305, USA
| | - Anne Brunet
- Department of Genetics, Stanford University, 300 Pasteur Drive, Stanford, CA 94305, USA; Glenn Laboratories for the Biology of Aging, Stanford University, 300 Pasteur Drive, Stanford, CA 94305, USA.
| |
Collapse
|
448
|
Johnston-Carey HK, Pomatto LCD, Davies KJA. The Immunoproteasome in oxidative stress, aging, and disease. Crit Rev Biochem Mol Biol 2016; 51:268-81. [PMID: 27098648 DOI: 10.3109/10409238.2016.1172554] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The Immunoproteasome has traditionally been viewed primarily for its role in peptide production for antigen presentation by the major histocompatibility complex, which is critical for immunity. However, recent research has shown that the Immunoproteasome is also very important for the clearance of oxidatively damaged proteins in homeostasis, and especially during stress and disease. The importance of the Immunoproteasome in protein degradation has become more evident as diseases characterized by protein aggregates have also been linked to deficiencies of the Immunoproteasome. Additionally, there are now diseases defined by mutations or polymorphisms within Immunoproteasome-specific subunit genes, further suggesting its crucial role in cytokine signaling and protein homeostasis (or "proteostasis"). The purpose of this review is to highlight our growing understanding of the importance of the Immunoproteasome in the management of protein quality control, and the detrimental impact of its dysregulation during disease and aging.
Collapse
Affiliation(s)
- Helen K Johnston-Carey
- a Leonard Davis School of Gerontology of the Ethel Percy Andrus Gerontology Center , The University of Southern California , Los Angeles , CA , USA
| | - Laura C D Pomatto
- a Leonard Davis School of Gerontology of the Ethel Percy Andrus Gerontology Center , The University of Southern California , Los Angeles , CA , USA
| | - Kelvin J A Davies
- a Leonard Davis School of Gerontology of the Ethel Percy Andrus Gerontology Center , The University of Southern California , Los Angeles , CA , USA ;,b Division of Molecular & Computational Biology, Department of Biological Sciences, Dornsife College of Letters, Arts, & Sciences , Los Angeles , CA , USA
| |
Collapse
|
449
|
Vayndorf EM, Scerbak C, Hunter S, Neuswanger JR, Toth M, Parker JA, Neri C, Driscoll M, Taylor BE. Morphological remodeling of C. elegans neurons during aging is modified by compromised protein homeostasis. NPJ Aging Mech Dis 2016; 2. [PMID: 27347427 PMCID: PMC4920063 DOI: 10.1038/npjamd.2016.1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Understanding cellular outcomes, such as neuronal remodeling, that are common to both healthy and diseased aging brains is essential to the development of successful brain aging strategies. Here, we used Caenorhabdits elegans to investigate how the expression of proteotoxic triggers, such as polyglutamine (polyQ)-expanded huntingtin and silencing of proteostasis regulators, such as the ubiquitin–proteasome system (UPS) and protein clearance components, may impact the morphological remodeling of individual neurons as animals age. We examined the effects of disrupted proteostasis on the integrity of neuronal cytoarchitecture by imaging a transgenic C. elegans strain in which touch receptor neurons express the first 57 amino acids of the human huntingtin (Htt) gene with expanded polyQs (128Q) and by using neuron-targeted RNA interference in adult wild-type neurons to knockdown genes encoding proteins involved in proteostasis. We found that proteostatic challenges conferred by polyQ-expanded Htt and knockdown of specific genes involved in protein homeostasis can lead to morphological changes that are restricted to specific domains of specific neurons. The age-associated branching of PLM neurons is suppressed by N-ter polyQ-expanded Htt expression, whereas ALM neurons with polyQ-expanded Htt accumulate extended outgrowths and other soma abnormalities. Furthermore, knockdown of genes important for ubiquitin-mediated degradation, lysosomal function, and autophagy modulated these age-related morphological changes in otherwise normal neurons. Our results show that the expression of misfolded proteins in neurodegenerative disease such as Huntington’s disease modifies the morphological remodeling that is normally associated with neuronal aging. Our results also show that morphological remodeling of healthy neurons during aging can be regulated by the UPS and other proteostasis pathways. Collectively, our data highlight a model in which morphological remodeling during neuronal aging is strongly affected by disrupted proteostasis and expression of disease-associated, misfolded proteins such as human polyQ-Htt species.
Collapse
Affiliation(s)
- Elena M Vayndorf
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - Courtney Scerbak
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, USA; Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - Skyler Hunter
- Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - Jason R Neuswanger
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA, USA
| | - Marton Toth
- Department of Molecular Biology and Biochemistry, Nelson Biological Laboratories, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - J Alex Parker
- Department of Neuroscience, CRCHUM, University of Montreal, Montreal, QC, Canada
| | - Christian Neri
- Laboratory of Neuronal Cell Biology and Pathology, Centre National de la Recherche Scientifique, Paris, France; Sorbonnes Universités, UPMC Univ Paris 06, Paris, France
| | - Monica Driscoll
- Department of Molecular Biology and Biochemistry, Nelson Biological Laboratories, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Barbara E Taylor
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, USA; Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, AK, USA
| |
Collapse
|
450
|
Triana-Martínez F, Pedraza-Vázquez G, Maciel-Barón LA, Königsberg M. Reflections on the role of senescence during development and aging. Arch Biochem Biophys 2016; 598:40-9. [PMID: 27059850 DOI: 10.1016/j.abb.2016.04.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 04/02/2016] [Accepted: 04/04/2016] [Indexed: 01/07/2023]
Abstract
New and stimulating results have challenged the concept that cellular senescence might not be synonymous with aging. It is indisputable that during aging, senescent cell accumulation has an impact on organismal health. Nevertheless, senescent cells are now known to display physiological roles during embryonic development, during wound healing repair and as a cellular response to stress. The fact that senescence has been found in cells that did not attain their maximal round of replications, nor have metabolic alterations or DNA damage, also challenges the paradigm that senescence is cellular aging, and it is in favor of the idea that cellular senescence is a phenomenon that has a function by itself. Therefore, in order to understand this phenomenon it is important to analyze the relationship between senescence and other cellular responses that have many features in common, such as apoptosis, cancer and autophagy, particularly highlighting their role during development and adulthood.
Collapse
Affiliation(s)
- F Triana-Martínez
- Dept. Ciencias de la Salud, DCBS, Universidad Autónoma Metropolitana Iztapalapa, México D.F. 09340, Mexico
| | - G Pedraza-Vázquez
- Dept. Ciencias de la Salud, DCBS, Universidad Autónoma Metropolitana Iztapalapa, México D.F. 09340, Mexico
| | - L A Maciel-Barón
- Dept. Ciencias de la Salud, DCBS, Universidad Autónoma Metropolitana Iztapalapa, México D.F. 09340, Mexico
| | - M Königsberg
- Dept. Ciencias de la Salud, DCBS, Universidad Autónoma Metropolitana Iztapalapa, México D.F. 09340, Mexico.
| |
Collapse
|