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Alshehabi Y, Martin DDO. Protective Proteolysis in Huntington's Disease: Unraveling the Role of Post-Translational Myristoylation of Huntingtin in Autophagy. J Huntingtons Dis 2024:JHD240028. [PMID: 38995796 DOI: 10.3233/jhd-240028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/14/2024]
Abstract
Huntington's disease (HD) is a devastating neurodegenerative disorder characterized by impaired motor function and cognitive decline, ultimately leading to death. HD is caused by a polyglutamine expansion in the N-terminal region of the huntingtin (HTT) protein, which is linked to decreased HTT turnover, increased HTT proteolysis, increased HTT aggregation, and subsequent neuronal death. In this review, we explore the mechanism of the protective effect of blocking HTT proteolysis at D586, which has been shown to rescue the HD phenotype in HD mouse models. Until recently, the mechanism remained unclear. Herein, we discuss how blocking HTT proteolysis at D586 promotes HTT turnover by correcting autophagy, and making HTT a better autophagy substrate, through post-translational myristoylation of HTT at G553.
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Affiliation(s)
- Yasmeen Alshehabi
- NeurdyPhagy Lab, Department of Biology, Faculty of Science, University of Waterloo, Waterloo, ON, Canada
| | - Dale D O Martin
- NeurdyPhagy Lab, Department of Biology, Faculty of Science, University of Waterloo, Waterloo, ON, Canada
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2
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Shirguppe S, Gapinske M, Swami D, Gosstola N, Acharya P, Miskalis A, Joulani D, Szkwarek MG, Bhattacharjee A, Elias G, Stilger M, Winter J, Woods WS, Anand D, Lim CKW, Gaj T, Perez-Pinera P. In vivo CRISPR base editing for treatment of Huntington's disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.05.602282. [PMID: 39005280 PMCID: PMC11245100 DOI: 10.1101/2024.07.05.602282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
Huntington's disease (HD) is an inherited and ultimately fatal neurodegenerative disorder caused by an expanded polyglutamine-encoding CAG repeat within exon 1 of the huntingtin (HTT) gene, which produces a mutant protein that destroys striatal and cortical neurons. Importantly, a critical event in the pathogenesis of HD is the proteolytic cleavage of the mutant HTT protein by caspase-6, which generates fragments of the N-terminal domain of the protein that form highly toxic aggregates. Given the role that proteolysis of the mutant HTT protein plays in HD, strategies for preventing this process hold potential for treating the disorder. By screening 141 CRISPR base editor variants targeting splice elements in the HTT gene, we identified platforms capable of producing HTT protein isoforms resistant to caspase-6-mediated proteolysis via editing of the splice acceptor sequence for exon 13. When delivered to the striatum of a rodent HD model, these base editors induced efficient exon skipping and decreased the formation of the N-terminal fragments, which in turn reduced HTT protein aggregation and attenuated striatal and cortical atrophy. Collectively, these results illustrate the potential for CRISPR base editing to decrease the toxicity of the mutant HTT protein for HD.
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3
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Sahoo G, Samal D, Khandayataray P, Murthy MK. A Review on Caspases: Key Regulators of Biological Activities and Apoptosis. Mol Neurobiol 2023; 60:5805-5837. [PMID: 37349620 DOI: 10.1007/s12035-023-03433-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Accepted: 06/06/2023] [Indexed: 06/24/2023]
Abstract
Caspases are proteolytic enzymes that belong to the cysteine protease family and play a crucial role in homeostasis and programmed cell death. Caspases have been broadly classified by their known roles in apoptosis (caspase-3, caspase-6, caspase-7, caspase-8, and caspase-9 in mammals) and in inflammation (caspase-1, caspase-4, caspase-5, and caspase-12 in humans, and caspase-1, caspase-11, and caspase-12 in mice). Caspases involved in apoptosis have been subclassified by their mechanism of action as either initiator caspases (caspase-8 and caspase-9) or executioner caspases (caspase-3, caspase-6, and caspase-7). Caspases that participate in apoptosis are inhibited by proteins known as inhibitors of apoptosis (IAPs). In addition to apoptosis, caspases play a role in necroptosis, pyroptosis, and autophagy, which are non-apoptotic cell death processes. Dysregulation of caspases features prominently in many human diseases, including cancer, autoimmunity, and neurodegenerative disorders, and increasing evidence shows that altering caspase activity can confer therapeutic benefits. This review covers the different types of caspases, their functions, and their physiological and biological activities and roles in different organisms.
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Affiliation(s)
- Gayatri Sahoo
- Department of Zoology, PSSJ College, Banarpal, 759128, Odisha, India
| | - Dibyaranjan Samal
- Department of Biotechnology, Academy of Management and Information Technology (AMIT, affiliated to Utkal University), Khurda, 752057, Odisha, India
| | | | - Meesala Krishna Murthy
- Department of Allied Health Sciences, Chitkara School of Health Sciences, Chitkara University, Rajpura, Punjab, 140401, India.
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4
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Hong JY, Wang JY, Yue HW, Zhang XL, Zhang SX, Jiang LL, Hu HY. Coaggregation of polyglutamine (polyQ) proteins is mediated by polyQ-tract interactions and impairs cellular proteostasis. Acta Biochim Biophys Sin (Shanghai) 2023. [PMID: 37171184 DOI: 10.3724/abbs.2023081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023] Open
Abstract
Nine polyglutamine (polyQ) proteins have already been identified that are considered to be associated with the pathologies of neurodegenerative disorders called polyQ diseases, but whether these polyQ proteins mutually interact and synergize in proteinopathies remains to be elucidated. In this study, 4 polyQ-containing proteins, androgen receptor (AR), ataxin-7 (Atx7), huntingtin (Htt) and ataxin-3 (Atx3), are used as model molecules to investigate their heterologous coaggregation and consequent impact on cellular proteostasis. Our data indicate that the N-terminal fragment of polyQ-expanded (PQE) Atx7 or Htt can coaggregate with and sequester AR and Atx3 into insoluble aggregates or inclusions through their respective polyQ tracts. In vitro coprecipitation and NMR titration experiments suggest that this specific coaggregation depends on polyQ lengths and is probably mediated by polyQ-tract interactions. Luciferase reporter assay shows that these coaggregation and sequestration effects can deplete the cellular availability of AR and consequently impair its transactivation function. This study provides valid evidence supporting the viewpoint that coaggregation of polyQ proteins is mediated by polyQ-tract interactions and benefits our understanding of the molecular mechanism underlying the accumulation of different polyQ proteins in inclusions and their copathological causes of polyQ diseases.
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Affiliation(s)
- Jun-Ye Hong
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jian-Yang Wang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hong-Wei Yue
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiang-Le Zhang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shu-Xian Zhang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lei-Lei Jiang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, China
| | - Hong-Yu Hu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, China
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5
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Qi L, Wang L, Jin M, Jiang M, Li L, Li Y. Caspase-6 is a key regulator of cross-talk signal way in PANoptosis in cancer. Immunology 2023. [PMID: 36814103 DOI: 10.1111/imm.13633] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Accepted: 02/20/2023] [Indexed: 02/24/2023] Open
Abstract
Cysteinyl aspartate specific proteinase (caspase)-6 belongs to the caspase family and plays a vital role in mediating cell death. Under certain conditions, three pathways of programmed cell death (PCD), including apoptosis, necroptosis and pyroptosis (PANoptosis), transform one way into another, with enormous therapeutic potential. Initially, scholars reported that caspase-6 is a caspase executor that mediates apoptosis. With the ceaseless exploration of the PCD types, studies have demonstrated that caspase-6 mediates pyroptosis by regulating gasdermin D and mediates necroptosis by regulating mixed lineage kinase domain-like. By regulating PANoptosis, caspase-6 plays a crucial role in tumorigenesis in humans and mediates anti-tumour immunity. Therefore, a comprehensive understanding of caspase-6 function in cancer via PANoptosis is important for the prevention and therapy of tumours. This article summarized the function of caspase-6 in PANoptosis and its impact on cancer development, providing targets and strategies for tumour treatment.
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Affiliation(s)
- Ling Qi
- Department of Gastrointestinal Oncology, Harbin Medical University Cancer Hospital, Harbin, Heilongjiang, China.,Department of Medical Oncology, the Affiliated Hospital of Hebei North University, Zhangjiakou, Hebei, China
| | - Li Wang
- Department of Gastrointestinal Oncology, Harbin Medical University Cancer Hospital, Harbin, Heilongjiang, China
| | - Mengru Jin
- Department of Gastrointestinal Oncology, Harbin Medical University Cancer Hospital, Harbin, Heilongjiang, China.,Department of Medical Oncology, National Cancer Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Mingxia Jiang
- Department of Gastrointestinal Oncology, Harbin Medical University Cancer Hospital, Harbin, Heilongjiang, China.,Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Lisha Li
- Department of Gastrointestinal Oncology, Harbin Medical University Cancer Hospital, Harbin, Heilongjiang, China.,Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Yanjing Li
- Department of Gastrointestinal Oncology, Harbin Medical University Cancer Hospital, Harbin, Heilongjiang, China
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6
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Song XY, Liu XW, Wang J. Suberoylanilide hydroxamic acid (SAHA) attenuates memory impairment in the offspring of rats exposed to sevoflurane anesthesia. Biochem Biophys Res Commun 2023; 643:139-146. [PMID: 36609154 DOI: 10.1016/j.bbrc.2022.11.073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 09/13/2022] [Accepted: 11/23/2022] [Indexed: 11/27/2022]
Abstract
BACKGROUND SAHA was reported to enhance the expression of miR-129-5p, which was predicted to bind to 3' UTR of CASP-6, a gene playing crucial roles in the pathogenesis of memory impairment. Whether SAHA/miR-129-5p/CASP-6 is involved in the pathogenesis of prenatal exposure to sevoflurane remains to be explored. METHODS Morris water maze test was performed to evaluate the functional parameters of learning and memory. Quantitative real-time qPCR was carried out to analyze the expression of miRNAs and CASP-6 mRNA under different conditions. RESULTS Sevoflurane exposure of pregnant rats and SAHA treatment of the offspring had no effect on the blood gases, litter size, survival rate and weight. SAHA administration remarkably reversed the learning and memory impairment in prenatal rats caused by sevoflurane exposure. Mechanistically, the abnormal expression of miR-129-5p and CASP-6 in the offspring of pregnant rats exposed to sevoflurane was effectively restored by SAHA treatment. The luciferase activity of CASP-6 vector was effectively inhibited by miR-129-5p in primary neuron cells of rats. Moreover, the expression of CASP-6 mRNA and protein was significantly suppressed by miR-129-5p and SAHA treatment in a dose-dependent manner. CONCLUSION Our work demonstrated that the administration of SAHA suppressed the expression of CASP-6 via modulating the expression of miR-129-5p, and SAHA may rescue the apoptosis of neurons caused by exposure to sevoflurane. The underlying mechanism might be the ability of SAHA to relieve learning and memory impairment in the offspring of the pregnant rats exposed to sevoflurane.
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Affiliation(s)
- Xiao-Yuan Song
- Department of Anesthesiology, Shanxi Provincial People's Hospital, Taiyuan, Shanxi, 030012, China
| | - Xiu-Wen Liu
- Department of Anesthesiology, Shanxi Provincial People's Hospital, Taiyuan, Shanxi, 030012, China.
| | - Jia Wang
- Department of Anesthesiology, Shanxi Provincial People's Hospital, Taiyuan, Shanxi, 030012, China
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7
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Bains M, Kaur J, Akhtar A, Kuhad A, Sah SP. Anti-inflammatory effects of ellagic acid and vanillic acid against quinolinic acid-induced rat model of Huntington's disease by targeting IKK-NF-κB pathway. Eur J Pharmacol 2022; 934:175316. [DOI: 10.1016/j.ejphar.2022.175316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 09/19/2022] [Accepted: 09/30/2022] [Indexed: 11/26/2022]
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8
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Kim H, Lenoir S, Helfricht A, Jung T, Karneva ZK, Lee Y, Beumer W, van der Horst GB, Anthonijsz H, Buil LC, van der Ham F, Platenburg GJ, Purhonen P, Hebert H, Humbert S, Saudou F, Klein P, Song JJ. A pathogenic proteolysis-resistant huntingtin isoform induced by an antisense oligonucleotide maintains huntingtin function. JCI Insight 2022; 7:154108. [PMID: 35943803 PMCID: PMC9536263 DOI: 10.1172/jci.insight.154108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 08/03/2022] [Indexed: 11/17/2022] Open
Abstract
Huntington’s disease (HD) is a late-onset neurological disorder for which therapeutics are not available. Its key pathological mechanism involves the proteolysis of polyglutamine-expanded (polyQ-expanded) mutant huntingtin (mHTT), which generates N-terminal fragments containing polyQ, a key contributor to HD pathogenesis. Interestingly, a naturally occurring spliced form of HTT mRNA with truncated exon 12 encodes an HTT (HTTΔ12) with a deletion near the caspase-6 cleavage site. In this study, we used a multidisciplinary approach to characterize the therapeutic potential of targeting HTT exon 12. We show that HTTΔ12 was resistant to caspase-6 cleavage in both cell-free and tissue lysate assays. However, HTTΔ12 retained overall biochemical and structural properties similar to those of wt-HTT. We generated mice in which HTT exon 12 was truncated and found that the canonical exon 12 was dispensable for the main physiological functions of HTT, including embryonic development and intracellular trafficking. Finally, we pharmacologically induced HTTΔ12 using the antisense oligonucleotide (ASO) QRX-704. QRX-704 showed predictable pharmacology and efficient biodistribution. In addition, it was stable for several months and inhibited pathogenic proteolysis. Furthermore, QRX-704 treatments resulted in a reduction of HTT aggregation and an increase in dendritic spine count. Thus, ASO-induced HTT exon 12 splice switching from HTT may provide an alternative therapeutic strategy for HD.
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Affiliation(s)
- Hyeongju Kim
- Department of Biological Sciences, KAIST (Korea Advanced Institute of Science and Technology), Daejeon, Korea, Republic of
| | - Sophie Lenoir
- Grenoble Institute Neurosciences, University Grenoble Alpes, Grenoble, France
| | | | - Taeyang Jung
- Department of Biological Sciences, KAIST (Korea Advanced Institute of Science and Technology), Daejeon, Korea, Republic of
| | | | - Yejin Lee
- Department of Biological Sciences, KAIST (Korea Advanced Institute of Science and Technology), Daejeon, Korea, Republic of
| | | | | | | | | | | | | | - Pasi Purhonen
- Department of Biomedical Engineering and Health Systems, The Royal Institute of Technology, KTH, Huddinge, Sweden
| | - Hans Hebert
- Department of Biomedical Engineering and Health Systems, The Royal Institute of Technology, KTH, Huddinge, Sweden
| | - Sandrine Humbert
- Grenoble Institute Neurosciences, University Grenoble Alpes, Grenoble, France
| | - Frédéric Saudou
- Grenoble Institute Neurosciences, University Grenoble Alpes, Grenoble, France
| | | | - Ji-Joon Song
- Department of Biological Sciences, KAIST (Korea Advanced Institute of Science and Technology), Daejeon, Korea, Republic of
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9
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Dehkordi MH, Munn RGK, Fearnhead HO. Non-Canonical Roles of Apoptotic Caspases in the Nervous System. Front Cell Dev Biol 2022; 10:840023. [PMID: 35281082 PMCID: PMC8904960 DOI: 10.3389/fcell.2022.840023] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 02/04/2022] [Indexed: 11/13/2022] Open
Abstract
Caspases are a family of cysteine proteases that predominantly cleave their substrates after aspartic acid residues. Much of what we know of caspases emerged from investigation a highly conserved form of programmed cell death called apoptosis. This form of cell death is regulated by several caspases, including caspase-2, caspase-3, caspase-7, caspase-8 and caspase-9. However, these “killer” apoptotic caspases have emerged as versatile enzymes that play key roles in a wide range of non-apoptotic processes. Much of what we understand about these non-apoptotic roles is built on work investigating how “killer” caspases control a range of neuronal cell behaviors. This review will attempt to provide an up to date synopsis of these roles.
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Affiliation(s)
- Mahshid H. Dehkordi
- Pharmacology and Therapeutics, National University of Ireland Galway, Galway, Ireland
| | | | - Howard O. Fearnhead
- Pharmacology and Therapeutics, National University of Ireland Galway, Galway, Ireland
- *Correspondence: Howard O. Fearnhead,
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10
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Huang S, Mei H, Lu L, Kuang Z, Heng Y, Xu L, Liang X, Qiu M, Pan X. Conformational transitions of caspase-6 in substrate-induced activation process explored by perturbation-response scanning combined with targeted molecular dynamics. Comput Struct Biotechnol J 2021; 19:4156-4164. [PMID: 34527189 PMCID: PMC8342898 DOI: 10.1016/j.csbj.2021.07.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 07/17/2021] [Accepted: 07/23/2021] [Indexed: 11/23/2022] Open
Abstract
Caspase-6 participates in a series of neurodegenerative pathways, and has aroused widespread attentions as a promising molecular target for the treatment of neurodegeneration. Caspase-6 is a homodimer with 6 central-stranded β-sheets and 5 α-helices in each monomer. Previous crystallographic studies suggested that the 60′s, 90′s and 130′s helices of caspase-6 undergo a distinctive conformational transition upon substrate binding. Although the caspase-6 structures in apo and active states have been determined, the conformational transition process between the two states remains poorly understood. In this work, perturbation-response scanning (PRS) combined with targeted molecular dynamics (TMD) simulations was employed to unravel the atomistic mechanism of the dynamic conformational transitions underlying the substrate-induced activation process of caspase-6. The results showed that the conformational transition of caspase-6 from apo to active states is mainly characterized by structural rearrangements of the substrate-binding site as well as the conformational changes of 60′s and 130′s extended helices. The H-bond interactions between L1, 130′s helix and 90′s helix are proved to be key determinant factors for substrate-induced conformational transition. These findings provide valuable insights into the activation mechanism of caspase-6 as well as the molecular design of caspase-6 inhibitors.
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Affiliation(s)
- Shuheng Huang
- Key Laboratory of Biorheological Science and Technology (Ministry of Education), College of Bioengineering, Chongqing University, Chongqing 400045, China
| | - Hu Mei
- Key Laboratory of Biorheological Science and Technology (Ministry of Education), College of Bioengineering, Chongqing University, Chongqing 400045, China
| | - Laichun Lu
- Key Laboratory of Biorheological Science and Technology (Ministry of Education), College of Bioengineering, Chongqing University, Chongqing 400045, China
| | - Zuyin Kuang
- Key Laboratory of Biorheological Science and Technology (Ministry of Education), College of Bioengineering, Chongqing University, Chongqing 400045, China
| | - Yu Heng
- Key Laboratory of Biorheological Science and Technology (Ministry of Education), College of Bioengineering, Chongqing University, Chongqing 400045, China
| | - Lei Xu
- Key Laboratory of Biorheological Science and Technology (Ministry of Education), College of Bioengineering, Chongqing University, Chongqing 400045, China
| | - Xiaoqi Liang
- Key Laboratory of Biorheological Science and Technology (Ministry of Education), College of Bioengineering, Chongqing University, Chongqing 400045, China
| | - Minyao Qiu
- Key Laboratory of Biorheological Science and Technology (Ministry of Education), College of Bioengineering, Chongqing University, Chongqing 400045, China
| | - Xianchao Pan
- Department of Medicinal Chemistry, College of Pharmacy, Southwest Medical University, Luzhou, Sichuan 646000, China
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11
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PolyQ-expanded proteins impair cellular proteostasis of ataxin-3 through sequestering the co-chaperone HSJ1 into aggregates. Sci Rep 2021; 11:7815. [PMID: 33837238 PMCID: PMC8035147 DOI: 10.1038/s41598-021-87382-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 03/26/2021] [Indexed: 12/13/2022] Open
Abstract
Polyglutamine (polyQ) expansion of proteins can trigger protein misfolding and amyloid-like aggregation, which thus lead to severe cytotoxicities and even the respective neurodegenerative diseases. However, why polyQ aggregation is toxic to cells is not fully elucidated. Here, we took the fragments of polyQ-expanded (PQE) ataxin-7 (Atx7) and huntingtin (Htt) as models to investigate the effect of polyQ aggregates on the cellular proteostasis of endogenous ataxin-3 (Atx3), a protein that frequently appears in diverse inclusion bodies. We found that PQE Atx7 and Htt impair the cellular proteostasis of Atx3 by reducing its soluble as well as total Atx3 level but enhancing formation of the aggregates. Expression of these polyQ proteins promotes proteasomal degradation of endogenous Atx3 and accumulation of its aggregated form. Then we verified that the co-chaperone HSJ1 is an essential factor that orchestrates the balance of cellular proteostasis of Atx3; and further discovered that the polyQ proteins can sequester HSJ1 into aggregates or inclusions in a UIM domain-dependent manner. Thereby, the impairment of Atx3 proteostasis may be attributed to the sequestration and functional loss of cellular HSJ1. This study deciphers a potential mechanism underlying how PQE protein triggers proteinopathies, and also provides additional evidence in supporting the hijacking hypothesis that sequestration of cellular interacting partners by protein aggregates leads to cytotoxicity or neurodegeneration.
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12
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Compromised IGF signaling causes caspase-6 activation in Huntington disease. Exp Neurol 2020; 332:113396. [DOI: 10.1016/j.expneurol.2020.113396] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 06/16/2020] [Accepted: 06/26/2020] [Indexed: 11/19/2022]
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13
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Laroche M, Lessard-Beaudoin M, Garcia-Miralles M, Kreidy C, Peachey E, Leavitt BR, Pouladi MA, Graham RK. Early deficits in olfaction are associated with structural and molecular alterations in the olfactory system of a Huntington disease mouse model. Hum Mol Genet 2020; 29:2134-2147. [PMID: 32436947 DOI: 10.1093/hmg/ddaa099] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 04/25/2020] [Accepted: 05/12/2020] [Indexed: 12/22/2022] Open
Abstract
Olfactory dysfunction and altered neurogenesis are observed in several neurodegenerative disorders including Huntington disease (HD). These deficits occur early and correlate with a decline in global cognitive performance, depression and structural abnormalities of the olfactory system including the olfactory epithelium, bulb and cortices. However, the role of olfactory system dysfunction in the pathogenesis of HD remains poorly understood and the mechanisms underlying this dysfunction are unknown. We show that deficits in odour identification, discrimination and memory occur in HD individuals. Assessment of the olfactory system in an HD murine model demonstrates structural abnormalities in the olfactory bulb (OB) and piriform cortex, the primary cortical recipient of OB projections. Furthermore, a decrease in piriform neuronal counts and altered expression levels of neuronal nuclei and tyrosine hydroxylase in the OB are observed in the YAC128 HD model. Similar to the human HD condition, olfactory dysfunction is an early phenotype in the YAC128 mice and concurrent with caspase activation in the murine HD OB. These data provide a link between the structural olfactory brain region atrophy and olfactory dysfunction in HD and suggest that cell proliferation and cell death pathways are compromised and may contribute to the olfactory deficits in HD.
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Affiliation(s)
- M Laroche
- Research Center on Aging, CIUSSS-IUGS de l'Estrie-CHUS, FMSS, Department of Pharmacology and Physiology, University of Sherbrooke, Quebec J1K 2R1, Canada
| | - M Lessard-Beaudoin
- Research Center on Aging, CIUSSS-IUGS de l'Estrie-CHUS, FMSS, Department of Pharmacology and Physiology, University of Sherbrooke, Quebec J1K 2R1, Canada
| | - M Garcia-Miralles
- Translational Laboratory in Genetic Medicine, Agency for Science, Technology and Research (ASTAR), Singapore 138632
| | - C Kreidy
- Translational Laboratory in Genetic Medicine, Agency for Science, Technology and Research (ASTAR), Singapore 138632
| | - E Peachey
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, University of British Columbia, Vancouver V6T 1Z4, Canada
| | - B R Leavitt
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, University of British Columbia, Vancouver V6T 1Z4, Canada
| | - M A Pouladi
- Translational Laboratory in Genetic Medicine, Agency for Science, Technology and Research (ASTAR), Singapore 138632.,Departments of Medicine and Physiology, National University of Singapore, Singapore 119077
| | - R K Graham
- Research Center on Aging, CIUSSS-IUGS de l'Estrie-CHUS, FMSS, Department of Pharmacology and Physiology, University of Sherbrooke, Quebec J1K 2R1, Canada
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14
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Zheng M, Kanneganti TD. Newly Identified Function of Caspase-6 in ZBP1-mediated Innate Immune Responses, NLRP3 Inflammasome Activation, PANoptosis, and Host Defense. JOURNAL OF CELLULAR IMMUNOLOGY 2020; 2:341-347. [PMID: 33426542 PMCID: PMC7793005 DOI: 10.33696/immunology.2.064] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Caspase-6 was discovered decades ago, but its roles in biological processes remain largely unknown. Recently, we have demonstrated that caspase-6 plays a critical role in influenza A virus (IAV)-induced cell death and innate immune responses. During IAV infection, Z-DNA binding protein 1 (ZBP1) initiates ZBP1-PANoptosome assembly to drive inflammasome activation and cell death, and we showed that caspase-6 interacts with RIPK3 to enhance the interaction between RIPK3 and ZBP1, thus promoting PANoptosome assembly. Moreover, the caspase activity of caspase-6 is not required for tins process, suggesting a caspase-independent function of caspase-6 during IAV infection. Additionally, we found that caspase-6 is required for the alternative activation of alveolar macrophages in response to IAV infection. Our findings provide an opportunity to reconsider the physiological role of caspase-6.
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Affiliation(s)
- Min Zheng
- Department of Immunology, St. Jude Children’s Research Hospital, Memphis, TN, 38105, USA
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15
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Espinosa-Oliva AM, García-Revilla J, Alonso-Bellido IM, Burguillos MA. Brainiac Caspases: Beyond the Wall of Apoptosis. Front Cell Neurosci 2019; 13:500. [PMID: 31749689 PMCID: PMC6848387 DOI: 10.3389/fncel.2019.00500] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 10/22/2019] [Indexed: 01/04/2023] Open
Abstract
For the last two decades, caspases, a family of cysteine-aspartic proteases, have evolved from being considered solely as regulators of apoptosis or inflammation to having a wider range of functions. In this mini review, we focus on the most recent “non-apoptotic” roles of caspases in the CNS, particularly in neurons, astrocytes and oligodendrocytes. Non-apoptotic caspase functions in microglia have already been reviewed extensively elsewhere. Here we discuss the involvement of caspases in the activation of the inflammasome, autophagy, and non-apoptotic forms of cell death such as necroptosis and pyroptosis. Also, we review the involvement of caspases in synapses and the processing of aggregates key to neurodegenerative diseases such as Parkinson’s, Alzheimer’s and Huntington’s diseases. Likewise, we mention the recently described involvement of caspases in mitochondrial biogenesis, which is a function independent of the enzymatic activity. We conclude discussing the relevance that “new” functions of caspases have in the CNS and the future of this field of research.
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Affiliation(s)
- Ana María Espinosa-Oliva
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, and Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC, Seville, Spain
| | - Juan García-Revilla
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, and Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC, Seville, Spain
| | - Isabel María Alonso-Bellido
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, and Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC, Seville, Spain
| | - Miguel Angel Burguillos
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, and Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC, Seville, Spain
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16
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Activation of Caspase-6 Is Promoted by a Mutant Huntingtin Fragment and Blocked by an Allosteric Inhibitor Compound. Cell Chem Biol 2019; 26:1295-1305.e6. [PMID: 31353319 DOI: 10.1016/j.chembiol.2019.07.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 01/08/2019] [Accepted: 06/28/2019] [Indexed: 01/04/2023]
Abstract
Aberrant activation of caspase-6 (C6) in the absence of other hallmarks of apoptosis has been demonstrated in cells and tissues from patients with Huntington disease (HD) and animal models. C6 activity correlates with disease progression in patients with HD and the cleavage of mutant huntingtin (mHTT) protein is thought to strongly contribute to disease pathogenesis. Here we show that the mHTT1-586 fragment generated by C6 cleavage interacts with the zymogen form of the enzyme, stabilizing a conformation that contains an active site and is prone to full activation. This shift toward enhanced activity can be prevented by a small-molecule inhibitor that blocks the interaction between C6 and mHTT1-586. Molecular docking studies suggest that the inhibitor binds an allosteric site in the C6 zymogen. The interaction of mHTT1-586 with C6 may therefore promote a self-reinforcing, feedforward cycle of C6 zymogen activation and mHTT cleavage driving HD pathogenesis.
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Tellone E, Galtieri A, Ficarra S. Reviewing Biochemical Implications of Normal and Mutated Huntingtin in Huntington's Disease. Curr Med Chem 2019; 27:5137-5158. [PMID: 31223078 DOI: 10.2174/0929867326666190621101909] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 05/08/2019] [Accepted: 05/22/2019] [Indexed: 12/17/2022]
Abstract
Huntingtin (Htt) is a multi-function protein of the brain. Normal Htt shows a common alpha-helical structure but conformational changes in the form with beta strands are the principal cause of Huntington's disease. Huntington's disease is a genetic neurological disorder caused by a repeated expansion of the CAG trinucleotide, causing instability in the N-terminal of the gene coding for the Huntingtin protein. The mutation leads to the abnormal expansion of the production of the polyglutamine tract (polyQ) resulting in the form of an unstable Huntingtin protein commonly referred to as mutant Huntingtin. Mutant Huntingtin is the cause of the complex neurological metabolic alteration of Huntington's disease, resulting in both the loss of all the functions of normal Huntingtin and the genesis of abnormal interactions due to the presence of this mutation. One of the problems arising from the misfolded Huntingtin is the increase in oxidative stress, which is common in many neurological diseases such as Alzheimer's, Parkinson's, Amyotrophic Lateral Sclerosis and Creutzfeldt-Jakob disease. In the last few years, the use of antioxidants had a strong incentive to find valid therapies for defence against neurodegenerations. Although further studies are needed, the use of antioxidant mixtures to counteract neuronal damages seems promising.
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Affiliation(s)
- Ester Tellone
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, V.le Ferdinando Stagno d'Alcontres 31, 98166 Messina, Italy
| | - Antonio Galtieri
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, V.le Ferdinando Stagno d'Alcontres 31, 98166 Messina, Italy
| | - Silvana Ficarra
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, V.le Ferdinando Stagno d'Alcontres 31, 98166 Messina, Italy
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18
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The Role of Neuronal NLRP1 Inflammasome in Alzheimer's Disease: Bringing Neurons into the Neuroinflammation Game. Mol Neurobiol 2019; 56:7741-7753. [PMID: 31111399 DOI: 10.1007/s12035-019-1638-7] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 05/06/2019] [Indexed: 02/06/2023]
Abstract
The innate immune system and inflammatory response in the brain have critical impacts on the pathogenesis of many neurodegenerative diseases including Alzheimer's disease (AD). In the central nervous system (CNS), the innate immune response is primarily mediated by microglia. However, non-glial cells such as neurons could also partake in inflammatory response independently through inflammasome signalling. The NLR family pyrin domain-containing 1 (NLRP1) inflammasome in the CNS is primarily expressed by pyramidal neurons and oligodendrocytes. NLRP1 is activated in response to amyloid-β (Aβ) aggregates, and its activation subsequently cleaves caspase-1 into its active subunits. The activated caspase-1 proteolytically processes interleukin-1β (IL-1β) and interleukin-18 (IL-18) into maturation whilst co-ordinately triggers caspase-6 which is responsible for apoptosis and axonal degeneration. In addition, caspase-1 activation induces pyroptosis, an inflammatory form of programmed cell death. Studies in murine AD models indicate that the Nlrp1 inflammasome is indeed upregulated in AD and neuronal death is observed leading to cognitive decline. However, the mechanism of NLRP1 inflammasome activation in AD is particularly elusive, given its structural and functional complexities. In this review, we examine the implications of the human NLRP1 inflammasome and its signalling pathways in driving neuroinflammation in AD.
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19
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Olfactory bulb atrophy and caspase activation observed in the BACHD rat models of Huntington disease. Neurobiol Dis 2019; 125:219-231. [DOI: 10.1016/j.nbd.2019.02.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 12/14/2018] [Accepted: 02/04/2019] [Indexed: 01/08/2023] Open
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20
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Islam MI, Nagakannan P, Ogungbola O, Djordjevic J, Albensi BC, Eftekharpour E. Thioredoxin system as a gatekeeper in caspase-6 activation and nuclear lamina integrity: Implications for Alzheimer's disease. Free Radic Biol Med 2019; 134:567-580. [PMID: 30769159 DOI: 10.1016/j.freeradbiomed.2019.02.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 01/28/2019] [Accepted: 02/10/2019] [Indexed: 02/01/2023]
Abstract
Recent reports in pathophysiology of neurodegenerative diseases (ND) have linked nuclear lamina degradation/deficits to neuronal cell death. Lamin-B1 damage is specifically involved in this process leading to nuclear envelope invagination and heterochromatin rearrangement. The underlying mechanisms involved in these events are not yet defined. In this study, while examining the effect of Thioredoxin-1(Trx1) inhibition on cell death in a model of oxidative stress, we noted robust nuclear invagination in SH-SY5Y cells. Evaluation of nuclear lamina proteins revealed lamin-B1 cleavage that was prevented by caspase-6 (CASP6) inhibitor and exacerbated after pharmacologic/genetic inhibition of Trx1 system, but not after glutathione depletion. Activation of CASP6 was upstream of CASP3/7 activation and its inhibition was sufficient to prevent cell death in our system. The effect of Trx1 redox status on CASP6 activation was assessed by administration of reduced/oxidized forms in cell-free nuclei preparation and purified enzymatic assays. Although reduced Trx1 decreased CASP6 enzymatic activity and lamin-B1 cleavage, the fully oxidized Trx1 showed opposite effects. The enhanced CASP6 activation was also associated with lower levels of DJ-1, a neuroprotective and master regulator of cellular antioxidants. The implication of our findings in ND pathophysiology was strengthened with detection of lower Trx1 levels in the hippocampi tissue of a mouse model of Alzheimer's disease. This coincided with higher CASP6 activation resulting in increased lamin-B1 and DJ-1 depletion. This study provides a first mechanistic explanation for the key regulatory role of Trx1 as a gatekeeper in activation of CASP6 and induction of nuclear invagination, an important player in ND pathophysiology.
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Affiliation(s)
- Md Imamul Islam
- Regenerative Medicine Program and Spinal Cord Research Centre, Canada; Dept. Physiology and Pathophysiology, University of Manitoba, Winnipeg, Canada
| | - Pandian Nagakannan
- Regenerative Medicine Program and Spinal Cord Research Centre, Canada; Dept. Physiology and Pathophysiology, University of Manitoba, Winnipeg, Canada
| | - Olamide Ogungbola
- Regenerative Medicine Program and Spinal Cord Research Centre, Canada; Dept. Physiology and Pathophysiology, University of Manitoba, Winnipeg, Canada
| | - Jelena Djordjevic
- Division of Neurodegenerative Disorders, St. Boniface Hospital Research, Winnipeg, Manitoba, Canada; Department of Pharmacology and Therapeutics, Faculty of Health Sciences, College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Benedict C Albensi
- Division of Neurodegenerative Disorders, St. Boniface Hospital Research, Winnipeg, Manitoba, Canada; Department of Pharmacology and Therapeutics, Faculty of Health Sciences, College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Eftekhar Eftekharpour
- Regenerative Medicine Program and Spinal Cord Research Centre, Canada; Dept. Physiology and Pathophysiology, University of Manitoba, Winnipeg, Canada.
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Battaglia RA, Beltran AS, Delic S, Dumitru R, Robinson JA, Kabiraj P, Herring LE, Madden VJ, Ravinder N, Willems E, Newman RA, Quinlan RA, Goldman JE, Perng MD, Inagaki M, Snider NT. Site-specific phosphorylation and caspase cleavage of GFAP are new markers of Alexander disease severity. eLife 2019; 8:47789. [PMID: 31682229 PMCID: PMC6927689 DOI: 10.7554/elife.47789] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 11/04/2019] [Indexed: 12/28/2022] Open
Abstract
Alexander disease (AxD) is a fatal neurodegenerative disorder caused by mutations in glial fibrillary acidic protein (GFAP), which supports the structural integrity of astrocytes. Over 70 GFAP missense mutations cause AxD, but the mechanism linking different mutations to disease-relevant phenotypes remains unknown. We used AxD patient brain tissue and induced pluripotent stem cell (iPSC)-derived astrocytes to investigate the hypothesis that AxD-causing mutations perturb key post-translational modifications (PTMs) on GFAP. Our findings reveal selective phosphorylation of GFAP-Ser13 in patients who died young, independently of the mutation they carried. AxD iPSC-astrocytes accumulated pSer13-GFAP in cytoplasmic aggregates within deep nuclear invaginations, resembling the hallmark Rosenthal fibers observed in vivo. Ser13 phosphorylation facilitated GFAP aggregation and was associated with increased GFAP proteolysis by caspase-6. Furthermore, caspase-6 was selectively expressed in young AxD patients, and correlated with the presence of cleaved GFAP. We reveal a novel PTM signature linking different GFAP mutations in infantile AxD.
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Affiliation(s)
- Rachel A Battaglia
- Department of Cell Biology and PhysiologyUniversity of North CarolinaChapel HillUnited States
| | - Adriana S Beltran
- Department of PharmacologyUniversity of North CarolinaChapel HillUnited States,Human Pluripotent Stem Cell CoreUniversity of North CarolinaChapel HillUnited States
| | - Samed Delic
- Department of Cell Biology and PhysiologyUniversity of North CarolinaChapel HillUnited States,Department of BiosciencesUniversity of DurhamDurhamUnited Kingdom
| | - Raluca Dumitru
- Human Pluripotent Stem Cell CoreUniversity of North CarolinaChapel HillUnited States
| | - Jasmine A Robinson
- Department of Cell Biology and PhysiologyUniversity of North CarolinaChapel HillUnited States
| | - Parijat Kabiraj
- Department of Cell Biology and PhysiologyUniversity of North CarolinaChapel HillUnited States
| | - Laura E Herring
- Department of PharmacologyUniversity of North CarolinaChapel HillUnited States
| | - Victoria J Madden
- Department of PathologyUniversity of North CarolinaChapel HillUnited States
| | | | | | | | - Roy A Quinlan
- Department of BiosciencesUniversity of DurhamDurhamUnited Kingdom
| | - James E Goldman
- Department of PathologyColumbia UniversityNew YorkUnited States
| | - Ming-Der Perng
- Institute of Molecular MedicineNational Tsing Hua UniversityHsinchuTaiwan, Republic of China
| | - Masaki Inagaki
- Department of PhysiologyMie University Graduate School of MedicineMieJapan
| | - Natasha T Snider
- Department of Cell Biology and PhysiologyUniversity of North CarolinaChapel HillUnited States
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22
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Soares TR, Reis SD, Pinho BR, Duchen MR, Oliveira JMA. Targeting the proteostasis network in Huntington's disease. Ageing Res Rev 2019; 49:92-103. [PMID: 30502498 PMCID: PMC6320389 DOI: 10.1016/j.arr.2018.11.006] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 11/19/2018] [Accepted: 11/26/2018] [Indexed: 12/31/2022]
Abstract
Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by a polyglutamine expansion mutation in the huntingtin protein. Expansions above 40 polyglutamine repeats are invariably fatal, following a symptomatic period characterised by choreiform movements, behavioural abnormalities, and cognitive decline. While mutant huntingtin (mHtt) is widely expressed from early life, most patients with HD present in mid-adulthood, highlighting the role of ageing in disease pathogenesis. mHtt undergoes proteolytic cleavage, misfolding, accumulation, and aggregation into inclusion bodies. The emerging model of HD pathogenesis proposes that the chronic production of misfolded mHtt overwhelms the chaperone machinery, diverting other misfolded clients to the proteasome and the autophagy pathways, ultimately leading to a global collapse of the proteostasis network. Multiple converging hypotheses also implicate ageing and its impact in the dysfunction of organelles as additional contributing factors to the collapse of proteostasis in HD. In particular, mitochondrial function is required to sustain the activity of ATP-dependent chaperones and proteolytic machinery. Recent studies elucidating mitochondria-endoplasmic reticulum interactions and uncovering a dedicated proteostasis machinery in mitochondria, suggest that mitochondria play a more active role in the maintenance of cellular proteostasis than previously thought. The enhancement of cytosolic proteostasis pathways shows promise for HD treatment, protecting cells from the detrimental effects of mHtt accumulation. In this review, we consider how mHtt and its post translational modifications interfere with protein quality control pathways, and how the pharmacological and genetic modulation of components of the proteostasis network impact disease phenotypes in cellular and in vivo HD models.
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Affiliation(s)
- Tânia R Soares
- REQUIMTE/LAQV, Department of Drug Sciences, Pharmacology Lab, Faculty of Pharmacy, University of Porto, 4050-313, Porto, Portugal; Department of Cell and Developmental Biology, University College London, London, WC1E 6BT, UK
| | - Sara D Reis
- REQUIMTE/LAQV, Department of Drug Sciences, Pharmacology Lab, Faculty of Pharmacy, University of Porto, 4050-313, Porto, Portugal
| | - Brígida R Pinho
- REQUIMTE/LAQV, Department of Drug Sciences, Pharmacology Lab, Faculty of Pharmacy, University of Porto, 4050-313, Porto, Portugal
| | - Michael R Duchen
- Department of Cell and Developmental Biology, University College London, London, WC1E 6BT, UK; Consortium for Mitochondrial Research (CfMR), University College London, Gower Street, WC1E 6BT, London, UK
| | - Jorge M A Oliveira
- REQUIMTE/LAQV, Department of Drug Sciences, Pharmacology Lab, Faculty of Pharmacy, University of Porto, 4050-313, Porto, Portugal; Consortium for Mitochondrial Research (CfMR), University College London, Gower Street, WC1E 6BT, London, UK.
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23
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MacPherson DJ, Mills CL, Ondrechen MJ, Hardy JA. Tri-arginine exosite patch of caspase-6 recruits substrates for hydrolysis. J Biol Chem 2018; 294:71-88. [PMID: 30420425 DOI: 10.1074/jbc.ra118.005914] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 11/07/2018] [Indexed: 12/15/2022] Open
Abstract
Caspases are cysteine-aspartic proteases involved in the regulation of programmed cell death (apoptosis) and a number of other biological processes. Despite overall similarities in structure and active-site composition, caspases show striking selectivity for particular protein substrates. Exosites are emerging as one of the mechanisms by which caspases can recruit, engage, and orient these substrates for proper hydrolysis. Following computational analyses and database searches for candidate exosites, we utilized site-directed mutagenesis to identify a new exosite in caspase-6 at the hinge between the disordered N-terminal domain (NTD), residues 23-45, and core of the caspase-6 structure. We observed that substitutions of the tri-arginine patch Arg-42-Arg-44 or the R44K cancer-associated mutation in caspase-6 markedly alter its rates of protein substrate hydrolysis. Notably, turnover of protein substrates but not of short peptide substrates was affected by these exosite alterations, underscoring the importance of this region for protein substrate recruitment. Hydrogen-deuterium exchange MS-mediated interrogation of the intrinsic dynamics of these enzymes suggested the presence of a substrate-binding platform encompassed by the NTD and the 240's region (containing residues 236-246), which serves as a general exosite for caspase-6-specific substrate recruitment. In summary, we have identified an exosite on caspase-6 that is critical for protein substrate recognition and turnover and therefore highly relevant for diseases such as cancer in which caspase-6-mediated apoptosis is often disrupted, and in neurodegeneration in which caspase-6 plays a central role.
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Affiliation(s)
- Derek J MacPherson
- Department of Chemistry, University of Massachusetts, Amherst, Amherst, Massachusetts 01003
| | - Caitlyn L Mills
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115
| | - Mary Jo Ondrechen
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115
| | - Jeanne A Hardy
- Department of Chemistry, University of Massachusetts, Amherst, Amherst, Massachusetts 01003.
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Quantification of Total and Mutant Huntingtin Protein Levels in Biospecimens Using a Novel alphaLISA Assay. eNeuro 2018; 5:eN-MNT-0234-18. [PMID: 30310861 PMCID: PMC6179573 DOI: 10.1523/eneuro.0234-18.2018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2018] [Revised: 07/04/2018] [Accepted: 07/06/2018] [Indexed: 12/20/2022] Open
Abstract
The neurodegenerative Huntington's disease (HD) is caused by a polyglutamine (polyQ) amplification in the huntingtin protein (HTT). Currently there is no effective therapy available for HD; however, several efforts are directed to develop and optimize HTT-lowering methods to improve HD phenotypes. To validate these approaches, there is an immediate need for reliable, sensitive, and easily accessible methods to quantify HTT expression. Using the AlphaLISA platform, we developed two novel sensitive and robust assays for quantification of HTT in biological samples using commercially available antibodies. The first, a polyQ-independent assay, measures the total pool of HTT, while the second, a polyQ-dependent assay, preferentially detects the mutant form of HTT. Using purified HTT protein standards and brain homogenates from an HD mouse model, we determine a lower limit of quantification of 1 and 3 pm and optimal reproducibility with CV values lower than 7% for intra- and 20% for interassay. In addition, we used the assays to quantify HTT in neural stem cells generated from patient-derived induced pluripotent stem cells in vitro and in human brain tissue lysates. Finally, we could detect changes in HTT levels in a mouse model where mutant HTT was conditionally deleted in neural tissue, verifying the potential to monitor the outcome of HTT-lowering strategies. This analytical platform is ideal for high-throughput screens and thus has an added value for the HD community as a tool to optimize novel therapeutic approaches aimed at modulating HTT protein levels.
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Abstract
The 25 years since the identification of the gene responsible for Huntington disease (HD) have stood witness to profound discoveries about the nature of the disease and its pathogenesis. Despite this progress, however, the development of disease-modifying therapies has thus far been slow. Preclinical validation of the therapeutic potential of disrupted pathways in HD has led to the advancement of pharmacological agents, both novel and repurposed, for clinical evaluation. The most promising therapeutic approaches include huntingtin (HTT) lowering and modification as well as modulation of neuroinflammation and synaptic transmission. With clinical trials for many of these approaches imminent or currently ongoing, the coming years are promising not only for HD but also for more prevalent neurodegenerative disorders, such as Alzheimer and Parkinson disease, in which many of these pathways have been similarly implicated.
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Noël A, Zhou L, Foveau B, Sjöström PJ, LeBlanc AC. Differential susceptibility of striatal, hippocampal and cortical neurons to Caspase-6. Cell Death Differ 2018; 25:1319-1335. [PMID: 29352267 PMCID: PMC6030053 DOI: 10.1038/s41418-017-0043-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 10/20/2017] [Accepted: 11/17/2017] [Indexed: 12/31/2022] Open
Abstract
Active cysteinyl protease Caspase-6 is associated with early Alzheimer and Huntington diseases. Higher entorhinal cortex and hippocampal Caspase-6 levels correlate with lower cognitive performance in aged humans. Caspase-6 induces axonal degeneration in human primary neuron cultures and causes inflammation and neurodegeneration in mouse hippocampus, and age-dependent memory impairment. To assess whether Caspase-6 causes damage to another neuronal system, a transgenic knock-in mouse overexpressing a self-activated form of Caspase-6 five-fold in the striatum, the area affected in Huntington disease, and 2.5-fold in the hippocampus and cortex, was generated. Detection of Tubulin cleaved by Caspase-6 confirmed Caspase-6 activity. The Caspase-6 expressing mice and control littermates were subjected to behavioral tests to assess Huntington disease-relevant psychiatric, motor, and cognitive deficits. Depression was excluded with the forced swim and sucrose consumption tests. Motor deficits were absent in the nesting, clasping, rotarod, vertical pole, gait, and open field analyzes. However, Caspase-6 mice developed age-dependent episodic and spatial memory deficits identified by novel object recognition, Barnes maze and Morris water maze assays. Neuron numbers were maintained in the striatum, hippocampus, and cortex. Microglia and astrocytes were increased in the hippocampal stratum lacunosum molecular and in the cortex, but not in the striatum. Synaptic mRNA profiling identified two differentially expressed genes in transgenic hippocampus, but none in striatum. Caspase-6 impaired synaptic transmission and induced neurodegeneration in hippocampal CA1 neurons, but not in striatal medium spiny neurons. These data revealed that active Caspase-6 in the striatal medium spiny neurons failed to induce inflammation, neurodegeneration or behavioral abnormalities, whereas active Caspase-6 in the cortex and hippocampus impaired episodic and spatial memories, and induced inflammation, neuronal dysfunction, and neurodegeneration. The results indicate age and neuronal subtype-dependent Caspase-6 toxicity and highlight the importance of targeting the correct neuronal subtype to identify underlying molecular mechanisms of neurodegenerative diseases.
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Affiliation(s)
- Anastasia Noël
- Bloomfield Center for Research in Aging, Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 Chemin Côte Ste Catherine, Montreal, QC, H3A 2B4, Canada
- Department of Neurology and Neurosurgery, McGill University, 3755 University Street, Montreal, QC, H3A 2B4, Canada
| | - Libin Zhou
- Bloomfield Center for Research in Aging, Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 Chemin Côte Ste Catherine, Montreal, QC, H3A 2B4, Canada
- Department of Neurology and Neurosurgery, McGill University, 3755 University Street, Montreal, QC, H3A 2B4, Canada
- Department of Anatomy and Cell Biology, McGill University, 3755 University Street, Montreal, QC, H3A 2B4, Canada
| | - Bénédicte Foveau
- Bloomfield Center for Research in Aging, Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 Chemin Côte Ste Catherine, Montreal, QC, H3A 2B4, Canada
- Department of Neurology and Neurosurgery, McGill University, 3755 University Street, Montreal, QC, H3A 2B4, Canada
| | - P Jesper Sjöström
- Department of Neurology and Neurosurgery, McGill University, 3755 University Street, Montreal, QC, H3A 2B4, Canada
- Centre for Research in Neuroscience, The BRAIN Program, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montréal, QC, H3G 1A4, Canada
| | - Andréa C LeBlanc
- Bloomfield Center for Research in Aging, Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 Chemin Côte Ste Catherine, Montreal, QC, H3A 2B4, Canada.
- Department of Neurology and Neurosurgery, McGill University, 3755 University Street, Montreal, QC, H3A 2B4, Canada.
- Department of Anatomy and Cell Biology, McGill University, 3755 University Street, Montreal, QC, H3A 2B4, Canada.
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27
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Rhodiola rosea Improves Lifespan, Locomotion, and Neurodegeneration in a Drosophila melanogaster Model of Huntington's Disease. BIOMED RESEARCH INTERNATIONAL 2018; 2018:6726874. [PMID: 29984244 PMCID: PMC6015705 DOI: 10.1155/2018/6726874] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 03/27/2018] [Accepted: 04/26/2018] [Indexed: 11/18/2022]
Abstract
Huntington's disease (HD) is a dominant, late-onset disease characterized by choreiform movements, cognitive decline, and personality disturbance. It is caused by a polyglutamine repeat expansion in the Huntington's disease gene encoding for the Huntingtin protein (Htt) which functions as a scaffold for selective macroautophagy. Mutant Htt (mHtt) disrupts vesicle trafficking and prevents autophagosome fusion with lysosomes, thus deregulating autophagy in neuronal cells, leading to cell death. Autophagy has been described as a therapeutic target for HD, owing to the key role Htt plays in the cellular process. Rhodiola rosea, a plant extract used in traditional medicine in Europe and Asia, has been shown to attenuate aging in the fly and other model species. It has also been shown to inhibit the mTOR pathway and induce autophagy in bladder cancer cell lines. We hypothesized that R. rosea, by inducing autophagy, may improve the phenotype of a Huntington's disease model of the fly. Flies expressing HttQ93 which exhibit decreased lifespan, impaired locomotion, and increased neurodegeneration were supplemented with R. rosea extract, and assays testing lifespan, locomotion, and pseudopupil degeneration provided quantitative measures of improvement. Based on our observations, R. rosea may be further evaluated as a potential therapy for Huntington's disease.
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Khoshnan A, Sabbaugh A, Calamini B, Marinero SA, Dunn DE, Yoo JH, Ko J, Lo DC, Patterson PH. IKKβ and mutant huntingtin interactions regulate the expression of IL-34: implications for microglial-mediated neurodegeneration in HD. Hum Mol Genet 2018; 26:4267-4277. [PMID: 28973132 DOI: 10.1093/hmg/ddx315] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 08/07/2017] [Indexed: 01/04/2023] Open
Abstract
Neuronal interleukin-34 (IL-34) promotes the expansion of microglia in the central nervous system-microglial activation and expansion are in turn implicated in the pathogenesis of Huntington's disease (HD). We thus examined whether the accumulation of an amyloidogenic exon-1 fragment of mutant huntingtin (mHTTx1) modulates the expression of IL-34 in dopaminergic neurons derived from a human embryonic stem cell line. We found that mHTTx1 aggregates induce IL-34 production selectively in post-mitotic neurons. Exposure of neurons to DNA damaging agents or the excitotoxin NMDA elicited similar results suggesting that IL-34 induction may be a general response to neuronal stress including the accumulation of misfolded mHTTx1. We further determined that knockdown or blocking the activity of IκB kinase beta (IKKβ) prevented the aggregation of mHTTx1 and subsequent IL-34 production. While elevated IL-34 itself had no effect on the aggregation or the toxicity of mHTTx1 in neuronal culture, IL-34 expression in a rodent brain slice model with intact neuron-microglial networks exacerbated mHTTx1-induced degeneration of striatal medium-sized spiny neurons. Conversely, an inhibitor of the IL-34 receptor reduced microglial numbers and ameliorated mHTTx1-mediated neurodegeneration. Together, these findings uncover a novel function for IKKβ/mHTTx1 interactions in regulating IL-34 production, and implicate a role for IL-34 in non-cell-autonomous, microglial-dependent neurodegeneration in HD.
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Affiliation(s)
- Ali Khoshnan
- Biology and Bioengineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Adam Sabbaugh
- Biology and Bioengineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Barbara Calamini
- Department of Neurobiology and Center for Drug Discovery, Duke University Medical Center, Durham, NC 27710, USA
| | - Steven A Marinero
- Department of Neurobiology and Center for Drug Discovery, Duke University Medical Center, Durham, NC 27710, USA
| | - Denise E Dunn
- Department of Neurobiology and Center for Drug Discovery, Duke University Medical Center, Durham, NC 27710, USA
| | - Jung Hyun Yoo
- Biology and Bioengineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Jan Ko
- Biology and Bioengineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Donald C Lo
- Department of Neurobiology and Center for Drug Discovery, Duke University Medical Center, Durham, NC 27710, USA
| | - Paul H Patterson
- Biology and Bioengineering, California Institute of Technology, Pasadena, CA 91125, USA
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Caterino M, Squillaro T, Montesarchio D, Giordano A, Giancola C, Melone MAB. Huntingtin protein: A new option for fixing the Huntington's disease countdown clock. Neuropharmacology 2018. [PMID: 29526547 DOI: 10.1016/j.neuropharm.2018.03.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Huntington's disease is a dreadful, incurable disorder. It springs from the autosomal dominant mutation in the first exon of the HTT gene, which encodes for the huntingtin protein (HTT) and results in progressive neurodegeneration. Thus far, all the attempted approaches to tackle the mutant HTT-induced toxicity causing this disease have failed. The mutant protein comes with the aberrantly expanded poly-glutamine tract. It is primarily to blame for the build-up of β-amyloid-like HTT aggregates, deleterious once broadened beyond the critical ∼35-37 repeats threshold. Recent experimental findings have provided valuable information on the molecular basis underlying this HTT-driven neurodegeneration. These findings indicate that the poly-glutamine siding regions and many post-translation modifications either abet or counter the poly-glutamine tract. This review provides an overall, up-to-date insight into HTT biophysics and structural biology, particularly discussing novel pharmacological options to specifically target the mutated protein and thus inhibit its functions and toxicity.
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Affiliation(s)
- Marco Caterino
- Department of Pharmacy, University of Napoli Federico II, Via D. Montesano 49, 80131, Napoli, Italy
| | - Tiziana Squillaro
- Department of Medical, Surgical, Neurological, Metabolic Sciences, and Aging, 2nd Division of Neurology, Center for Rare Diseases, University of Campania "Luigi Vanvitelli", Napoli, Italy; InterUniversity Center for Research in Neurosciences, University of Campania "Luigi Vanvitelli", Napoli, Italy
| | - Daniela Montesarchio
- InterUniversity Center for Research in Neurosciences, University of Campania "Luigi Vanvitelli", Napoli, Italy; Department of Chemical Sciences, University of Napoli Federico II, Via Cintia 21, 80126, Napoli, Italy
| | - Antonio Giordano
- Sbarro Institute for Cancer Research and Molecular Medicine, Department of Biology, Center for Biotechnology, College of Science and Technology, Temple University, Philadelphia, PA, USA; Department of Medicine, Surgery and Neuroscience University of Siena, Siena, Italy
| | - Concetta Giancola
- Department of Pharmacy, University of Napoli Federico II, Via D. Montesano 49, 80131, Napoli, Italy; InterUniversity Center for Research in Neurosciences, University of Campania "Luigi Vanvitelli", Napoli, Italy.
| | - Mariarosa A B Melone
- Department of Medical, Surgical, Neurological, Metabolic Sciences, and Aging, 2nd Division of Neurology, Center for Rare Diseases, University of Campania "Luigi Vanvitelli", Napoli, Italy; InterUniversity Center for Research in Neurosciences, University of Campania "Luigi Vanvitelli", Napoli, Italy; Sbarro Institute for Cancer Research and Molecular Medicine, Department of Biology, Center for Biotechnology, College of Science and Technology, Temple University, Philadelphia, PA, USA.
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Ehrnhoefer DE, Martin DDO, Schmidt ME, Qiu X, Ladha S, Caron NS, Skotte NH, Nguyen YTN, Vaid K, Southwell AL, Engemann S, Franciosi S, Hayden MR. Preventing mutant huntingtin proteolysis and intermittent fasting promote autophagy in models of Huntington disease. Acta Neuropathol Commun 2018; 6:16. [PMID: 29510748 PMCID: PMC5839066 DOI: 10.1186/s40478-018-0518-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 02/12/2018] [Indexed: 12/20/2022] Open
Abstract
Huntington disease (HD) is caused by the expression of mutant huntingtin (mHTT) bearing a polyglutamine expansion. In HD, mHTT accumulation is accompanied by a dysfunction in basal autophagy, which manifests as specific defects in cargo loading during selective autophagy. Here we show that the expression of mHTT resistant to proteolysis at the caspase cleavage site D586 (C6R mHTT) increases autophagy, which may be due to its increased binding to the autophagy adapter p62. This is accompanied by faster degradation of C6R mHTT in vitro and a lack of mHTT accumulation the C6R mouse model with age. These findings may explain the previously observed neuroprotective properties of C6R mHTT. As the C6R mutation cannot be easily translated into a therapeutic approach, we show that a scheduled feeding paradigm is sufficient to lower mHTT levels in YAC128 mice expressing cleavable mHTT. This is consistent with a previous model, where the presence of cleavable mHTT impairs basal autophagy, while fasting-induced autophagy remains functional. In HD, mHTT clearance and autophagy may become increasingly impaired as a function of age and disease stage, because of gradually increased activity of mHTT-processing enzymes. Our findings imply that mHTT clearance could be enhanced by a regulated dietary schedule that promotes autophagy.
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Carmo C, Naia L, Lopes C, Rego AC. Mitochondrial Dysfunction in Huntington’s Disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1049:59-83. [DOI: 10.1007/978-3-319-71779-1_3] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Girling KD, Demers MJ, Laine J, Zhang S, Wang YT, Graham RK. Activation of caspase-6 and cleavage of caspase-6 substrates is an early event in NMDA receptor-mediated excitotoxicity. J Neurosci Res 2017; 96:391-406. [DOI: 10.1002/jnr.24153] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 08/10/2017] [Accepted: 08/18/2017] [Indexed: 12/21/2022]
Affiliation(s)
- Kimberly D. Girling
- University of British Columbia, Brain Research Centre & Department of Medicine; Vancouver British Columbia Canada
| | - Marie-Josee Demers
- Research Centre on Aging, Department Pharmacology and Physiology, Faculty of Medicine and Health Sciences; University of Sherbrooke; Sherbrooke Quebec Canada
| | - Jean Laine
- Research Centre on Aging, Department Pharmacology and Physiology, Faculty of Medicine and Health Sciences; University of Sherbrooke; Sherbrooke Quebec Canada
| | - Shu Zhang
- University of British Columbia, Brain Research Centre & Department of Medicine; Vancouver British Columbia Canada
| | - Yu Tian Wang
- University of British Columbia, Brain Research Centre & Department of Medicine; Vancouver British Columbia Canada
| | - Rona K. Graham
- Research Centre on Aging, Department Pharmacology and Physiology, Faculty of Medicine and Health Sciences; University of Sherbrooke; Sherbrooke Quebec Canada
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Lee H, Shin EA, Lee JH, Ahn D, Kim CG, Kim JH, Kim SH. Caspase inhibitors: a review of recently patented compounds (2013-2015). Expert Opin Ther Pat 2017; 28:47-59. [DOI: 10.1080/13543776.2017.1378426] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Hyemin Lee
- Cancer Molecular Targeted Herbal Research Center, College of Korean Medicine, Kyung Hee University, Seoul, South Korea
| | - Eun Ah Shin
- Cancer Molecular Targeted Herbal Research Center, College of Korean Medicine, Kyung Hee University, Seoul, South Korea
| | - Jae Hee Lee
- Department of East West Medical Science, Graduate School of East West Medical Science Kyung Hee University, Yongin, South Korea
| | - Deoksoo Ahn
- Cancer Molecular Targeted Herbal Research Center, College of Korean Medicine, Kyung Hee University, Seoul, South Korea
| | - Chang Geun Kim
- Cancer Molecular Targeted Herbal Research Center, College of Korean Medicine, Kyung Hee University, Seoul, South Korea
| | - Ju-Ha Kim
- Cancer Molecular Targeted Herbal Research Center, College of Korean Medicine, Kyung Hee University, Seoul, South Korea
| | - Sung-Hoon Kim
- Cancer Molecular Targeted Herbal Research Center, College of Korean Medicine, Kyung Hee University, Seoul, South Korea
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Multiple proteolytic events in caspase-6 self-activation impact conformations of discrete structural regions. Proc Natl Acad Sci U S A 2017; 114:E7977-E7986. [PMID: 28864531 DOI: 10.1073/pnas.1704640114] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Caspase-6 is critical to the neurodegenerative pathways of Alzheimer's, Huntington's, and Parkinson's diseases and has been identified as a potential molecular target for treatment of neurodegeneration. Thus, understanding the global and regional changes in dynamics and conformation provides insights into the unique properties of caspase-6 that may contribute to achieving control of its function. In this work, hydrogen/deuterium exchange MS (H/DX-MS) was used to map the local changes in the conformational flexibility of procaspase-6 at the discrete states that reflect the series of cleavage events that ultimately lead to the fully active, substrate-bound state. Intramolecular self-cleavage at Asp-193 evoked higher solvent exposure in the regions of the substrate-binding loops L1, L3, and L4 and in the 130s region, the intersubunit linker region, the 26-32 region as well as in the stabilized loop 2. Additional removal of the linker allowed caspase-6 to gain more flexibility in the 130s region and in the L2 region converting caspase-6 to a competent substrate-binding state. The prodomain region was found to be intrinsically disordered independent of the activation state of caspase-6; however, its complete removal resulted in the protection of the adjacent 26-32 region, suggesting that this region may play a regulatory role. The molecular details of caspase-6 dynamics in solution provide a comprehensive scaffold for strategic design of therapeutic approaches for neurodegenerative disorders.
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Skotte NH, Sanders SS, Singaraja RR, Ehrnhoefer DE, Vaid K, Qiu X, Kannan S, Verma C, Hayden MR. Palmitoylation of caspase-6 by HIP14 regulates its activation. Cell Death Differ 2017; 24:433-444. [PMID: 27911442 PMCID: PMC5344205 DOI: 10.1038/cdd.2016.139] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 10/03/2016] [Accepted: 10/25/2016] [Indexed: 02/06/2023] Open
Abstract
Caspase-6 (CASP6) has an important role in axonal degeneration during neuronal apoptosis and in the neurodegenerative diseases Alzheimer and Huntington disease. Decreasing CASP6 activity may help to restore neuronal function in these and other diseases such as stroke and ischemia, where increased CASP6 activity has been implicated. The key to finding approaches to decrease CASP6 activity is a deeper understanding of the mechanisms regulating CASP6 activation. We show that CASP6 is posttranslationally palmitoylated by the palmitoyl acyltransferase HIP14 and that the palmitoylation of CASP6 inhibits its activation. Palmitoylation of CASP6 is decreased both in Hip14-/- mice, where HIP14 is absent, and in YAC128 mice, a model of Huntington disease, where HIP14 is dysfunctional and where CASP6 activity is increased. Molecular modeling suggests that palmitoylation of CASP6 may inhibit its activation via steric blockage of the substrate-binding groove and inhibition of CASP6 dimerization, both essential for CASP6 function. Our studies identify palmitoylation as a novel CASP6 modification and as a key regulator of CASP6 activity.
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Affiliation(s)
- Niels H Skotte
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child and Family Research Institute, University of British Columbia, Vancouver, BC, Canada
| | - Shaun S Sanders
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child and Family Research Institute, University of British Columbia, Vancouver, BC, Canada
| | - Roshni R Singaraja
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child and Family Research Institute, University of British Columbia, Vancouver, BC, Canada
- Translational Laboratories in Genetic Medicine, Agency for Science, Technology and Research, Singapore, Singapore
- Department of Medicine at Yong Loo Lin School of Medicine, National University of Singapore, Singapore 138648, Singapore
| | - Dagmar E Ehrnhoefer
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child and Family Research Institute, University of British Columbia, Vancouver, BC, Canada
| | - Kuljeet Vaid
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child and Family Research Institute, University of British Columbia, Vancouver, BC, Canada
| | - Xiaofan Qiu
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child and Family Research Institute, University of British Columbia, Vancouver, BC, Canada
| | - Srinivasaragavan Kannan
- Bioinformatics Institute, Agency for Science, Technology and Research, 30 Biopolis Street, #07-01 Matrix, Singapore 138671, Singapore
| | - Chandra Verma
- Bioinformatics Institute, Agency for Science, Technology and Research, 30 Biopolis Street, #07-01 Matrix, Singapore 138671, Singapore
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore
- School of Biological Sciences, Nanyang Technological University, 50 Nanyang Drive, Singapore 637551, Singapore
| | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child and Family Research Institute, University of British Columbia, Vancouver, BC, Canada
- Translational Laboratories in Genetic Medicine, Agency for Science, Technology and Research, Singapore, Singapore
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Dagbay KB, Bolik-Coulon N, Savinov SN, Hardy JA. Caspase-6 Undergoes a Distinct Helix-Strand Interconversion upon Substrate Binding. J Biol Chem 2017; 292:4885-4897. [PMID: 28154009 DOI: 10.1074/jbc.m116.773499] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 02/01/2017] [Indexed: 12/22/2022] Open
Abstract
Caspases are cysteine aspartate proteases that are major players in key cellular processes, including apoptosis and inflammation. Specifically, caspase-6 has also been implicated in playing a unique and critical role in neurodegeneration; however, structural similarities between caspase-6 and other caspase active sites have hampered precise targeting of caspase-6. All caspases can exist in a canonical conformation, in which the substrate binds atop a β-strand platform in the 130's region. This caspase-6 region can also adopt a helical conformation that has not been seen in any other caspases. Understanding the dynamics and interconversion between the helical and strand conformations in caspase-6 is critical to fully assess its unique function and regulation. Here, hydrogen/deuterium exchange mass spectrometry indicated that caspase-6 is inherently and dramatically more conformationally dynamic than closely related caspase-7. In contrast to caspase-7, which rests constitutively in the strand conformation before and after substrate binding, the hydrogen/deuterium exchange data in the L2' and 130's regions suggested that before substrate binding, caspase-6 exists in a dynamic equilibrium between the helix and strand conformations. Caspase-6 transitions exclusively to the canonical strand conformation only upon substrate binding. Glu-135, which showed noticeably different calculated pK a values in the helix and strand conformations, appears to play a key role in the interconversion between the helix and strand conformations. Because caspase-6 has roles in several neurodegenerative diseases, exploiting the unique structural features and conformational changes identified here may provide new avenues for regulating specific caspase-6 functions for therapeutic purposes.
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Affiliation(s)
| | | | - Sergey N Savinov
- Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts 01003
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37
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Laquinimod decreases Bax expression and reduces caspase-6 activation in neurons. Exp Neurol 2016; 283:121-8. [DOI: 10.1016/j.expneurol.2016.06.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 05/18/2016] [Accepted: 06/09/2016] [Indexed: 12/20/2022]
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Age-dependent differential expression of death-associated protein 6 (Daxx) in various peripheral tissues and different brain regions of C57BL/6 male mice. Biogerontology 2016; 17:817-828. [PMID: 27465500 DOI: 10.1007/s10522-016-9651-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 05/17/2016] [Indexed: 12/17/2022]
Abstract
Death-associated protein 6 (DAXX) is a ubiquitous protein implicated in various cellular processes such as apoptosis, tumorigenesis, development and transcription. The role of DAXX is however ambiguous and many contradictory results regarding its function in apoptosis upon various cellular stresses are described in the literature. In order to have a better understanding of the role of DAXX throughout the entire organism under physiological stress conditions, we have characterized the mRNA levels, protein expression and the proteolytic processing of DAXX in the normal aging process in peripheral organs and brain regions in C57BL/6 male mice. Overall, Daxx mRNA expression decreases with aging in the liver, kidney, heart, cortex and cerebellum. In contrast, an increase is observed in the striatum. The protein expression of DAXX and of its proteolytic fragments increases with aging in the kidney, heart and cortex. In liver and spleen, no changes are observed while in the striatum and cerebellum, certain forms increase and others decrease with age, suggesting that the functions of DAXX may be cell type dependent. This study provides important details regarding the expression and post-translational modifications of DAXX in aging in the entire organism and provides reference data for the deregulation observed in age-associated diseases.
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Unsain N, Barker PA. New Views on the Misconstrued: Executioner Caspases and Their Diverse Non-apoptotic Roles. Neuron 2016; 88:461-74. [PMID: 26539888 DOI: 10.1016/j.neuron.2015.08.029] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Initially characterized for their roles in apoptosis, executioner caspases have emerged as important regulators of an array of cellular activities. This is especially true in the nervous system, where sublethal caspase activity has been implicated in axonal pathfinding and branching, axonal degeneration, dendrite pruning, regeneration, long-term depression, and metaplasticity. Here we examine the roles of sublethal executioner caspase activity in nervous system development and maintenance, consider the mechanisms that locally activate and restrain these potential killers, and discuss how their activity be subverted in neurodegenerative disease.
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Affiliation(s)
- Nicolas Unsain
- Laboratorio de Neurobiología, Instituto de Investigación Médica Mercedes y Martín Ferreyra, Instituto Nacional de Investigación Médica Córdoba-Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Córdoba, Friuli 2434, Córdoba (5016), Argentina
| | - Philip A Barker
- Irving K. Barber School of Arts and Sciences, University of British Columbia, Kelowna, BC V1V 1V7, Canada.
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Riechers SP, Butland S, Deng Y, Skotte N, Ehrnhoefer DE, Russ J, Laine J, Laroche M, Pouladi MA, Wanker EE, Hayden MR, Graham RK. Interactome network analysis identifies multiple caspase-6 interactors involved in the pathogenesis of HD. Hum Mol Genet 2016; 25:1600-18. [DOI: 10.1093/hmg/ddw036] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 02/05/2016] [Indexed: 11/14/2022] Open
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Post-translational myristoylation at the cross roads of cell death, autophagy and neurodegeneration. Biochem Soc Trans 2016; 43:229-34. [PMID: 25849922 DOI: 10.1042/bst20140281] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
In a little more than a decade, post-translational myristoylation (PTMyr) has become an established post-translational modification during cell death. It involves the addition of the fatty acid myristate to newly exposed N-terminal glycines following caspase cleavage. It promotes membrane binding and relocalization of functional protein domains released by caspase cleavage during apoptosis, or programmed cell death. However, as the requirement of caspase cleavage has expanded beyond just cell death, it has become apparent that PTMyr may play a role in cell survival, differentiation and now autophagy. Herein, we describe how myristoylation may play a role in autophagy with an emphasis on PTMyr.
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Waldron-Roby E, Hoerauf J, Arbez N, Zhu S, Kulcsar K, Ross CA. Sox11 Reduces Caspase-6 Cleavage and Activity. PLoS One 2015; 10:e0141439. [PMID: 26505998 PMCID: PMC4624725 DOI: 10.1371/journal.pone.0141439] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 10/08/2015] [Indexed: 11/18/2022] Open
Abstract
The apoptotic cascade is an orchestrated event, whose final stages are mediated by effector caspases. Regulatory binding proteins have been identified for caspases such as caspase-3, -7, -8, and -9. Many of these proteins belong to the inhibitor of apoptosis (IAP) family. By contrast, caspase-6 is not believed to be influenced by IAPs, and little is known about its regulation. We therefore performed a yeast-two-hybrid screen using a constitutively inactive form of caspase-6 for bait in order to identify novel regulators of caspase-6 activity. Sox11 was identified as a potential caspase-6 interacting protein. Sox11 was capable of dramatically reducing caspase-6 activity, as well as preventing caspase-6 self- cleavage. Several regions, including amino acids 117-214 and 362-395 within sox11 as well as a nuclear localization signal (NLS) all contributed to the reduction in caspase-6 activity. Furthermore, sox11 was also capable of decreasing other effector caspase activity but not initiator caspases -8 and -9. The ability of sox11 to reduce effector caspase activity was also reflected in its capacity to reduce cell death following toxic insult. Interestingly, other sox proteins also had the ability to reduce caspase-6 activity but to a lesser extent than sox11.
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Affiliation(s)
- Elaine Waldron-Roby
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, CMSC 8-121, 600 North Wolfe Street, Baltimore, MD, 21287, United States of America
| | - Janine Hoerauf
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, CMSC 8-121, 600 North Wolfe Street, Baltimore, MD, 21287, United States of America
| | - Nicolas Arbez
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, CMSC 8-121, 600 North Wolfe Street, Baltimore, MD, 21287, United States of America
| | - Shanshan Zhu
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, CMSC 8-121, 600 North Wolfe Street, Baltimore, MD, 21287, United States of America
| | - Kirsten Kulcsar
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, CMSC 8-121, 600 North Wolfe Street, Baltimore, MD, 21287, United States of America
| | - Christopher A. Ross
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, CMSC 8-121, 600 North Wolfe Street, Baltimore, MD, 21287, United States of America
- Department of Neurology, Johns Hopkins University School of Medicine, CMSC 8-121, 600 North Wolfe Street, Baltimore, MD, 21287, United States of America
- Department of Pharmacology, Johns Hopkins University School of Medicine, CMSC 8-121, 600 North Wolfe Street, Baltimore, MD, 21287, United States of America
- Department of Neuroscience, Johns Hopkins University School of Medicine, CMSC 8-121, 600 North Wolfe Street, Baltimore, MD, 21287, United States of America
- Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, CMSC 8-121, 600 North Wolfe Street, Baltimore, MD, 21287, United States of America
- * E-mail:
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Exploring Genetic Factors Involved in Huntington Disease Age of Onset: E2F2 as a New Potential Modifier Gene. PLoS One 2015; 10:e0131573. [PMID: 26148071 PMCID: PMC4493078 DOI: 10.1371/journal.pone.0131573] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 06/03/2015] [Indexed: 01/09/2023] Open
Abstract
Age of onset (AO) of Huntington disease (HD) is mainly determined by the length of the CAG repeat expansion (CAGexp) in exon 1 of the HTT gene. Additional genetic variation has been suggested to contribute to AO, although the mechanism by which it could affect AO is presently unknown. The aim of this study is to explore the contribution of candidate genetic factors to HD AO in order to gain insight into the pathogenic mechanisms underlying this disorder. For that purpose, two AO definitions were used: the earliest age with unequivocal signs of HD (earliest AO or eAO), and the first motor symptoms age (motor AO or mAO). Multiple linear regression analyses were performed between genetic variation within 20 candidate genes and eAO or mAO, using DNA and clinical information of 253 HD patients from REGISTRY project. Gene expression analyses were carried out by RT-qPCR with an independent sample of 35 HD patients from Basque Country Hospitals. We found suggestive association signals between HD eAO and/or mAO and genetic variation within the E2F2, ATF7IP, GRIN2A, GRIN2B, LINC01559, HIP1 and GRIK2 genes. Among them, the most significant was the association between eAO and rs2742976, mapping to the promoter region of E2F2 transcription factor. Furthermore, rs2742976 T allele patient carriers exhibited significantly lower lymphocyte E2F2 gene expression, suggesting a possible implication of E2F2-dependent transcriptional activity in HD pathogenesis. Thus, E2F2 emerges as a new potential HD AO modifier factor.
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O'Brien R, DeGiacomo F, Holcomb J, Bonner A, Ring KL, Zhang N, Zafar K, Weiss A, Lager B, Schilling B, Gibson BW, Chen S, Kwak S, Ellerby LM. Integration-independent Transgenic Huntington Disease Fragment Mouse Models Reveal Distinct Phenotypes and Life Span in Vivo. J Biol Chem 2015; 290:19287-306. [PMID: 26025364 DOI: 10.1074/jbc.m114.623561] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Indexed: 11/06/2022] Open
Abstract
The cascade of events that lead to cognitive decline, motor deficits, and psychiatric symptoms in patients with Huntington disease (HD) is triggered by a polyglutamine expansion in the N-terminal region of the huntingtin (HTT) protein. A significant mechanism in HD is the generation of mutant HTT fragments, which are generally more toxic than the full-length HTT. The protein fragments observed in human HD tissue and mouse models of HD are formed by proteolysis or aberrant splicing of HTT. To systematically investigate the relative contribution of the various HTT protein proteolysis events observed in vivo, we generated transgenic mouse models of HD representing five distinct proteolysis fragments ending at amino acids 171, 463, 536, 552, and 586 with a polyglutamine length of 148. All lines contain a single integration at the ROSA26 locus, with expression of the fragments driven by the chicken β-actin promoter at nearly identical levels. The transgenic mice N171-Q148 and N552-Q148 display significantly accelerated phenotypes and a shortened life span when compared with N463-Q148, N536-Q148, and N586-Q148 transgenic mice. We hypothesized that the accelerated phenotype was due to altered HTT protein interactions/complexes that accumulate with age. We found evidence for altered HTT complexes in caspase-2 fragment transgenic mice (N552-Q148) and a stronger interaction with the endogenous HTT protein. These findings correlate with an altered HTT molecular complex and distinct proteins in the HTT interactome set identified by mass spectrometry. In particular, we identified HSP90AA1 (HSP86) as a potential modulator of the distinct neurotoxicity of the caspase-2 fragment mice (N552-Q148) when compared with the caspase-6 transgenic mice (N586-Q148).
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Affiliation(s)
- Robert O'Brien
- From the Buck Institute for Research on Aging, Novato, California 94945
| | | | - Jennifer Holcomb
- From the Buck Institute for Research on Aging, Novato, California 94945
| | - Akilah Bonner
- From the Buck Institute for Research on Aging, Novato, California 94945
| | - Karen L Ring
- From the Buck Institute for Research on Aging, Novato, California 94945
| | - Ningzhe Zhang
- From the Buck Institute for Research on Aging, Novato, California 94945
| | - Khan Zafar
- From the Buck Institute for Research on Aging, Novato, California 94945
| | - Andreas Weiss
- Evotec AG, Manfred Eigen Campus, Essener Bogen 7, 22419 Hamburg, Germany, and
| | - Brenda Lager
- CHDI Management/CHDI Foundation, Inc., Princeton, New Jersey 08540
| | - Birgit Schilling
- From the Buck Institute for Research on Aging, Novato, California 94945
| | - Bradford W Gibson
- From the Buck Institute for Research on Aging, Novato, California 94945
| | - Sylvia Chen
- From the Buck Institute for Research on Aging, Novato, California 94945
| | - Seung Kwak
- CHDI Management/CHDI Foundation, Inc., Princeton, New Jersey 08540
| | - Lisa M Ellerby
- From the Buck Institute for Research on Aging, Novato, California 94945,
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46
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Aharony I, Ehrnhoefer DE, Shruster A, Qiu X, Franciosi S, Hayden MR, Offen D. A Huntingtin-based peptide inhibitor of caspase-6 provides protection from mutant Huntingtin-induced motor and behavioral deficits. Hum Mol Genet 2015; 24:2604-14. [PMID: 25616965 DOI: 10.1093/hmg/ddv023] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2014] [Accepted: 01/21/2015] [Indexed: 11/14/2022] Open
Abstract
Over the past decade, increasing evidence has implied a significant connection between caspase-6 activity and the pathogenesis of Huntington's disease (HD). Consequently, inhibiting caspase-6 activity was suggested as a promising therapeutic strategy to reduce mutant Huntingtin toxicity, and to provide protection from mutant Huntingtin-induced motor and behavioral deficits. Here, we describe a novel caspase-6 inhibitor peptide based on the huntingtin caspase-6 cleavage site, fused with a cell-penetrating sequence. The peptide reduces mutant Huntingtin proteolysis by caspase-6, and protects cells from mutant Huntingtin toxicity. Continuous subcutaneous administration of the peptide protected pre-symptomatic BACHD mice from motor deficits and behavioral abnormalities. Moreover, administration of the peptide in an advanced disease state resulted in the partial recovery of motor performance, and an alleviation of depression-related behavior and cognitive deficits. Our findings reveal the potential of substrate-based caspase inhibition as a therapeutic strategy, and present a promising agent for the treatment of HD.
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Affiliation(s)
- Israel Aharony
- Neuroscience Laboratory, Felsenstein Medical Research Center, Sackler Faculty of Medicine, Tel-Aviv University, Israel and
| | - Dagmar E Ehrnhoefer
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Adi Shruster
- Neuroscience Laboratory, Felsenstein Medical Research Center, Sackler Faculty of Medicine, Tel-Aviv University, Israel and
| | - Xiaofan Qiu
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Sonia Franciosi
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Daniel Offen
- Neuroscience Laboratory, Felsenstein Medical Research Center, Sackler Faculty of Medicine, Tel-Aviv University, Israel and
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Wong BKY, Ehrnhoefer DE, Graham RK, Martin DDO, Ladha S, Uribe V, Stanek LM, Franciosi S, Qiu X, Deng Y, Kovalik V, Zhang W, Pouladi MA, Shihabuddin LS, Hayden MR. Partial rescue of some features of Huntington Disease in the genetic absence of caspase-6 in YAC128 mice. Neurobiol Dis 2015; 76:24-36. [PMID: 25583186 DOI: 10.1016/j.nbd.2014.12.030] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 12/22/2014] [Accepted: 12/31/2014] [Indexed: 12/13/2022] Open
Abstract
Huntington Disease (HD) is a progressive neurodegenerative disease caused by an elongated CAG repeat in the huntingtin (HTT) gene that encodes a polyglutamine tract in the HTT protein. Proteolysis of the mutant HTT protein (mHTT) has been detected in human and murine HD brains and is implicated in the pathogenesis of HD. Of particular importance is the site at amino acid (aa) 586 that contains a caspase-6 (Casp6) recognition motif. Activation of Casp6 occurs presymptomatically in human HD patients and the inhibition of mHTT proteolysis at aa586 in the YAC128 mouse model results in the full rescue of HD-like phenotypes. Surprisingly, Casp6 ablation in two different HD mouse models did not completely prevent the generation of this fragment, and therapeutic benefits were limited, questioning the role of Casp6 in the disease. We have evaluated the impact of the loss of Casp6 in the YAC128 mouse model of HD. Levels of the mHTT-586 fragment are reduced but not absent in the absence of Casp6 and we identify caspase 8 as an alternate enzyme that can generate this fragment. In vivo, the ablation of Casp6 results in a partial rescue of body weight gain, normalized IGF-1 levels, a reversal of the depression-like phenotype and decreased HTT levels. In the YAC128/Casp6-/- striatum there is a concomitant reduction in p62 levels, a marker of autophagic activity, suggesting increased autophagic clearance. These results implicate the HTT-586 fragment as a key contributor to certain features of HD, irrespective of the enzyme involved in its generation.
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Affiliation(s)
- Bibiana K Y Wong
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada; Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Dagmar E Ehrnhoefer
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Rona K Graham
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada; Research Center on Aging, Department of Physiology and Biophysics, University of Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Dale D O Martin
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Safia Ladha
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Valeria Uribe
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Lisa M Stanek
- Genzyme, a Sanofi Company, Framingham, MA 01701, USA
| | - Sonia Franciosi
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Xiaofan Qiu
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Yu Deng
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Vlad Kovalik
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Weining Zhang
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Mahmoud A Pouladi
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada; Translational Laboratory in Genetic Medicine, Agency for Science, Technology and Research, 138648, Singapore; Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, 138648, Singapore
| | | | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada.
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48
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Wang XJ, Cao Q, Zhang Y, Su XD. Activation and regulation of caspase-6 and its role in neurodegenerative diseases. Annu Rev Pharmacol Toxicol 2014; 55:553-72. [PMID: 25340928 DOI: 10.1146/annurev-pharmtox-010814-124414] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Caspases, a family of cysteine proteases, are major mediators of apoptosis and inflammation. Caspase-6 is classified as an apoptotic effector, and it mediates nuclear shrinkage during apoptosis, but it possesses unique activation and regulation mechanisms that differ from those of other effector caspases. Furthermore, increasing evidence has shown that caspase-6 is highly involved in axon degeneration and neurodegenerative diseases, such as Huntington's disease and Alzheimer's disease. Cleavage at the caspase-6 site in mutated huntingtin protein is a prerequisite for the development of the characteristic behavioral and neuropathological features of Huntington's disease. Active caspase-6 is present in early stages of Alzheimer's disease, and caspase-6 activity is associated with the disease's pathological lesions. In this review, we discuss the evidence relevant to the role of caspase-6 in neurodegenerative diseases and summarize its activation and regulation mechanisms. In doing so, we provide new insight about potential therapeutic approaches that incorporate the modulation of caspase-6 function for the treatment of neurodegenerative diseases.
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Affiliation(s)
- Xiao-Jun Wang
- State Key Laboratory of Protein and Plant Gene Research and
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49
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Picco R, Tomasella A, Fogolari F, Brancolini C. Transcriptomic analysis unveils correlations between regulative apoptotic caspases and genes of cholesterol homeostasis in human brain. PLoS One 2014; 9:e110610. [PMID: 25330190 PMCID: PMC4199739 DOI: 10.1371/journal.pone.0110610] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Accepted: 09/23/2014] [Indexed: 01/09/2023] Open
Abstract
Regulative circuits controlling expression of genes involved in the same biological processes are frequently interconnected. These circuits operate to coordinate the expression of multiple genes and also to compensate dysfunctions in specific elements of the network. Caspases are cysteine-proteases with key roles in the execution phase of apoptosis. Silencing of caspase-2 expression in cultured glioblastoma cells allows the up-regulation of a limited number of genes, among which some are related to cholesterol homeostasis. Lysosomal Acid Lipase A (LIPA) was up-regulated in two different cell lines in response to caspase-2 down-regulation and cells silenced for caspase-2 exhibit reduced cholesterol staining in the lipid droplets. We expanded this observation by large-scale analysis of mRNA expression. All caspases were analyzed in terms of co-expression in comparison with 166 genes involved in cholesterol homeostasis. In the brain, hierarchical clustering has revealed that the expression of regulative apoptotic caspases (CASP2, CASP8 CASP9, CASP10) and of the inflammatory CASP1 is linked to several genes involved in cholesterol homeostasis. These correlations resulted in altered GBM (Glioblastoma Multiforme), in particular for CASP1. We have also demonstrated that these correlations are tissue specific being reduced (CASP9 and CASP10) or different (CASP2) in the liver. For some caspases (CASP1, CASP6 and CASP7) these correlations could be related to brain aging.
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Affiliation(s)
- Raffaella Picco
- Department of Medical and Biological Sciences, Università degli Studi di Udine, Udine, Italy
| | - Andrea Tomasella
- Department of Medical and Biological Sciences, Università degli Studi di Udine, Udine, Italy
| | - Federico Fogolari
- Department of Medical and Biological Sciences, Università degli Studi di Udine, Udine, Italy
| | - Claudio Brancolini
- Department of Medical and Biological Sciences, Università degli Studi di Udine, Udine, Italy
- * E-mail:
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50
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Martin DDO, Ladha S, Ehrnhoefer DE, Hayden MR. Autophagy in Huntington disease and huntingtin in autophagy. Trends Neurosci 2014; 38:26-35. [PMID: 25282404 DOI: 10.1016/j.tins.2014.09.003] [Citation(s) in RCA: 219] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 09/08/2014] [Accepted: 09/09/2014] [Indexed: 01/20/2023]
Abstract
Autophagy is an important biological process that is essential for the removal of damaged organelles and toxic or aggregated proteins by delivering them to the lysosome for degradation. Consequently, autophagy has become a primary target for the treatment of neurodegenerative diseases that involve aggregating proteins. In Huntington disease (HD), an expansion of the polyglutamine (polyQ) tract in the N-terminus of the huntingtin (HTT) protein leads to protein aggregation. However, HD is unique among the neurodegenerative proteinopathies in that autophagy is not only dysfunctional but wild type (wt) HTT also appears to play several roles in regulating the dynamics of autophagy. Herein, we attempt to integrate the recently described novel roles of wtHTT and altered autophagy in HD.
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Affiliation(s)
- Dale D O Martin
- Centre for Molecular Medicine and Therapeutics (CMMT), Department of Medical Genetics, Child and Family Research Institute, University of British Columbia, Vancouver, BC, Canada.
| | - Safia Ladha
- Centre for Molecular Medicine and Therapeutics (CMMT), Department of Medical Genetics, Child and Family Research Institute, University of British Columbia, Vancouver, BC, Canada
| | - Dagmar E Ehrnhoefer
- Centre for Molecular Medicine and Therapeutics (CMMT), Department of Medical Genetics, Child and Family Research Institute, University of British Columbia, Vancouver, BC, Canada
| | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics (CMMT), Department of Medical Genetics, Child and Family Research Institute, University of British Columbia, Vancouver, BC, Canada.
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