1
|
Inukai R, Mori K, Maki M, Takahara T, Shibata H. Cytoprotective Role of Autophagy in CDIP1 Expression-Induced Apoptosis in MCF-7 Breast Cancer Cells. Int J Mol Sci 2024; 25:6520. [PMID: 38928226 PMCID: PMC11203953 DOI: 10.3390/ijms25126520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Revised: 05/31/2024] [Accepted: 06/08/2024] [Indexed: 06/28/2024] Open
Abstract
Cell death-inducing p53-target protein 1 (CDIP1) is a proapoptotic protein that is normally expressed at low levels and is upregulated by genotoxic and endoplasmic reticulum stresses. CDIP1 has been reported to be localized to endosomes and to interact with several proteins, including B-cell receptor-associated protein 31 (BAP31) and apoptosis-linked gene 2 (ALG-2). However, the cellular and molecular mechanisms underlying CDIP1 expression-induced apoptosis remain unclear. In this study, we first demonstrated that CDIP1 was upregulated after treatment with the anticancer drug adriamycin in human breast cancer MCF-7 cells but was degraded rapidly in the lysosomal pathway. We also demonstrated that treatment with the cyclin-dependent kinase 5 (CDK5) inhibitor roscovitine led to an increase in the electrophoretic mobility of CDIP1. In addition, a phosphomimetic mutation at Ser-32 in CDIP1 resulted in an increase in CDIP1 expression-induced apoptosis. We also found that CDIP1 expression led to the induction of autophagy prior to apoptosis. Treatment of cells expressing CDIP1 with SAR405, an inhibitor of the class III phosphatidylinositol 3-kinase VPS34, caused a reduction in autophagy and promoted apoptosis. Therefore, autophagy is thought to be a defense mechanism against CDIP1 expression-induced apoptosis.
Collapse
Affiliation(s)
| | | | | | | | - Hideki Shibata
- Department of Applied Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; (R.I.); (K.M.); (M.M.); (T.T.)
| |
Collapse
|
2
|
Tang C, Qiao X, Jin Y, Yang W, Yu Z, Wang L, Song L. An LPS-induced TNF-α factor involved in immune response of oyster Crassostrea gigas by regulating haemocytes apoptosis. FISH & SHELLFISH IMMUNOLOGY 2024; 148:109513. [PMID: 38521141 DOI: 10.1016/j.fsi.2024.109513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 03/13/2024] [Accepted: 03/15/2024] [Indexed: 03/25/2024]
Abstract
LPS induced TNF-α Factor (LITAF) is a transcription factor widely involving in activation of Tumor Necrosis Factor (TNF) and other cytokines in the inflammatory response. In the present study, a homologue of LITAF with a conserved LITAF domain was identified from the Pacific oyster Crassostrea gigas. The transcripts of CgLITAF were detected in all examined tissues with highest expression in hepatopancrease. The immunofluorescence assay and Western blot showed that LPS stimulation induced an obvious nucleus translocation of CgLITAF protein in haemocytes. While the mRNA level of CgLITAF changed slightly after LPS stimulation. When the siRNA of CgLITAF was injected to inhibit its expression, the apoptotic level of haemocytes decreased observably after LPS stimulation. Consistently, the transcripts of CgTNF3 and CgTNF4 (LOC105343080, LOC105341146), the apoptotic-related molecules including CgBax, CgCytochrome c, CgCaspase9 and CgCaspase3, were significantly suppressed in the CgLITAF-RNAi oysters. While the mRNA expression level of CgBcl was enhanced significantly in the CgLITAF-RNAi oysters. These results indicated that CgLITAF promoted haemocyte apoptosis by regulating the expression of apoptotic-related factors, suggesting its important role in the immune response of oysters.
Collapse
Affiliation(s)
- Chunyu Tang
- Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian, 116023, China; Laboratory of Marine Fisheries Science and Food Production Process, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266235, China
| | - Xue Qiao
- Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian, 116023, China; Southern Laboratory of Ocean Science and Engineering (Guangdong, Zhuhai), Zhuhai, 519000, China; Laboratory of Marine Fisheries Science and Food Production Process, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266235, China.
| | - Yuhao Jin
- Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian, 116023, China; Laboratory of Marine Fisheries Science and Food Production Process, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266235, China
| | - Wenwen Yang
- Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian, 116023, China; Laboratory of Marine Fisheries Science and Food Production Process, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266235, China
| | - Zhuo Yu
- Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian, 116023, China; Laboratory of Marine Fisheries Science and Food Production Process, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266235, China
| | - Lingling Wang
- Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian, 116023, China; Southern Laboratory of Ocean Science and Engineering (Guangdong, Zhuhai), Zhuhai, 519000, China; Laboratory of Marine Fisheries Science and Food Production Process, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266235, China; Dalian Key Laboratory of Aquatic Animal Disease Prevention and Control, Dalian Ocean University, Dalian, 116023, China.
| | - Linsheng Song
- Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian, 116023, China; Southern Laboratory of Ocean Science and Engineering (Guangdong, Zhuhai), Zhuhai, 519000, China; Laboratory of Marine Fisheries Science and Food Production Process, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266235, China; Dalian Key Laboratory of Aquatic Animal Disease Prevention and Control, Dalian Ocean University, Dalian, 116023, China
| |
Collapse
|
3
|
Stefani C, Bruchez AM, Rosasco MG, Yoshida AE, Fasano KJ, Levan PF, Lorant A, Hubbard NW, Oberst A, Stuart LM, Lacy-Hulbert A. LITAF protects against pore-forming protein-induced cell death by promoting membrane repair. Sci Immunol 2024; 9:eabq6541. [PMID: 38181093 DOI: 10.1126/sciimmunol.abq6541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 11/09/2023] [Indexed: 01/07/2024]
Abstract
Pore-forming toxins (PFTs) are the largest class of bacterial toxins and contribute to virulence by triggering host cell death. Vertebrates also express endogenous pore-forming proteins that induce cell death as part of host defense. To mitigate damage and promote survival, cells mobilize membrane repair mechanisms to neutralize and counteract pores, but how these pathways are activated is poorly understood. Here, we use a transposon-based gene activation screen to discover pathways that counteract the cytotoxicity of the archetypal PFT Staphylococcus aureus α-toxin. We identify the endolysosomal protein LITAF as a mediator of cellular resistance to PFT-induced cell death that is active against both bacterial toxins and the endogenous pore, gasdermin D, a terminal effector of pyroptosis. Activation of the ubiquitin ligase NEDD4 by potassium efflux mobilizes LITAF to recruit the endosomal sorting complexes required for transport (ESCRT) machinery to repair damaged membrane. Cells lacking LITAF, or carrying naturally occurring disease-associated mutations of LITAF, are highly susceptible to pore-induced death. Notably, LITAF-mediated repair occurs at endosomal membranes, resulting in expulsion of damaged membranes as exosomes, rather than through direct excision of pores from the surface plasma membrane. These results identify LITAF as a key effector that links sensing of cellular damage to repair.
Collapse
Affiliation(s)
- Caroline Stefani
- Center for Systems Immunology, Benaroya Research Institute at Virginia Mason, Seattle, WA, USA
| | - Anna M Bruchez
- Center for Systems Immunology, Benaroya Research Institute at Virginia Mason, Seattle, WA, USA
| | - Mario G Rosasco
- Center for Systems Immunology, Benaroya Research Institute at Virginia Mason, Seattle, WA, USA
| | - Anna E Yoshida
- Center for Systems Immunology, Benaroya Research Institute at Virginia Mason, Seattle, WA, USA
| | - Kayla J Fasano
- Center for Systems Immunology, Benaroya Research Institute at Virginia Mason, Seattle, WA, USA
- Department of Immunology, University of Washington, Seattle, WA, USA
| | - Paula F Levan
- Center for Systems Immunology, Benaroya Research Institute at Virginia Mason, Seattle, WA, USA
| | - Alina Lorant
- Center for Systems Immunology, Benaroya Research Institute at Virginia Mason, Seattle, WA, USA
- Department of Immunology, University of Washington, Seattle, WA, USA
| | | | - Andrew Oberst
- Department of Immunology, University of Washington, Seattle, WA, USA
| | - Lynda M Stuart
- Center for Systems Immunology, Benaroya Research Institute at Virginia Mason, Seattle, WA, USA
- Institute for Protein Design, Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Adam Lacy-Hulbert
- Center for Systems Immunology, Benaroya Research Institute at Virginia Mason, Seattle, WA, USA
- Department of Immunology, University of Washington, Seattle, WA, USA
| |
Collapse
|
4
|
Libberecht K, Vangansewinkel T, Van Den Bosch L, Lambrichts I, Wolfs E. Proteostasis plays an important role in demyelinating Charcot Marie Tooth disease. Biochem Pharmacol 2023; 216:115760. [PMID: 37604292 DOI: 10.1016/j.bcp.2023.115760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 08/17/2023] [Accepted: 08/18/2023] [Indexed: 08/23/2023]
Abstract
Type 1 Charcot-Marie-Tooth disease (CMT1) is the most common demyelinating peripheral neuropathy. Patients suffer from progressive muscle weakness and sensory problems. The underlying disease mechanisms of CMT1 are still unclear and no therapy is currently available, hence patients completely rely on supportive care. Balancing protein levels is a complex multistep process fundamental to maintain cells in their healthy state and a disrupted proteostasis is a hallmark of several neurodegenerative diseases. When protein misfolding occurs, protein quality control systems are activated such as chaperones, the lysosomal-autophagy system and proteasomal degradation to ensure proper degradation. However, in pathological circumstances, these mechanisms are overloaded and thereby become inefficient to clear the load of misfolded proteins. Recent evidence strongly indicates that a disbalance in proteostasis plays an important role in several forms of CMT1. In this review, we present an overview of the protein quality control systems, their role in CMT1, and potential treatment strategies to restore proteostasis.
Collapse
Affiliation(s)
- Karen Libberecht
- UHasselt, Biomedical Research Institute (BIOMED), Lab for Functional Imaging & Research on Stem Cells (FIERCELab), Diepenbeek, Belgium; VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium.
| | - Tim Vangansewinkel
- UHasselt, Biomedical Research Institute (BIOMED), Lab for Functional Imaging & Research on Stem Cells (FIERCELab), Diepenbeek, Belgium; VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium; UHasselt, Biomedical Research Institute (BIOMED), Lab for Histology and Regeneration (HISTOREGEN Lab), Diepenbeek, Belgium
| | - Ludo Van Den Bosch
- KU Leuven, Department of Neurosciences, Experimental Neurology, and Leuven Brain Institute (LBI), Leuven, Belgium; VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium
| | - Ivo Lambrichts
- UHasselt, Biomedical Research Institute (BIOMED), Lab for Histology and Regeneration (HISTOREGEN Lab), Diepenbeek, Belgium
| | - Esther Wolfs
- UHasselt, Biomedical Research Institute (BIOMED), Lab for Functional Imaging & Research on Stem Cells (FIERCELab), Diepenbeek, Belgium.
| |
Collapse
|
5
|
Mitrakos A, Kosma K, Makrythanasis P, Tzetis M. Prenatal Chromosomal Microarray Analysis: Does Increased Resolution Equal Increased Yield? Genes (Basel) 2023; 14:1519. [PMID: 37628571 PMCID: PMC10454647 DOI: 10.3390/genes14081519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 07/16/2023] [Accepted: 07/24/2023] [Indexed: 08/27/2023] Open
Abstract
Chromosomal microarray analysis (CMA) is considered a first-tier test for patients with developmental disabilities and congenital anomalies and is also routinely applied in prenatal diagnosis. The current consensus size cut-off for reporting copy number variants (CNVs) in the prenatal setting ranges from 200 Kb to 400 Kb, with the intention of minimizing the impact of variants of uncertain significance (VUS). Very limited data are currently available on the application of higher resolution platforms prenatally. The aim of this study is to investigate the feasibility and impact of applying high-resolution CMA in the prenatal setting. To that end, we report on the outcomes of applying CMA with a size cut-off of 20 Kb in 250 prenatal samples and discuss the findings and diagnostic yield and also provide follow-up for cases with variants of uncertain significance. Overall, 19.6% (49) showed one or more chromosomal abnormalities, with the findings classified as Pathogenic (P) or Likely Pathogenic (LP) in 15.6% and as VUS in 4%. When excluding the cases with known familial aberrations, the diagnostic yield was 12%. The smallest aberration detected was a 32 Kb duplication of the 16p11.2 region. In conclusion, this study demonstrates that prenatal diagnosis with a high-resolution aCGH platform can reliably detect smaller CNVs that are often associated with neurodevelopmental phenotypes while providing an increased diagnostic yield, regardless of the indication for testing, with only a marginal increase in the VUS incidence. Thus, it can be an important tool in the prenatal setting.
Collapse
Affiliation(s)
- Anastasios Mitrakos
- Laboratory of Medical Genetics, Medical School, National and Kapodistrian University of Athens, St. Sophia’s Children’s Hospital, 11527 Athens, Greece; (K.K.); (P.M.)
| | | | | | - Maria Tzetis
- Laboratory of Medical Genetics, Medical School, National and Kapodistrian University of Athens, St. Sophia’s Children’s Hospital, 11527 Athens, Greece; (K.K.); (P.M.)
| |
Collapse
|
6
|
McLean JW, Wilson JA, Tian T, Watson JA, VanHart M, Bean AJ, Scherer SS, Crossman DK, Ubogu E, Wilson SM. Disruption of Endosomal Sorting in Schwann Cells Leads to Defective Myelination and Endosomal Abnormalities Observed in Charcot-Marie-Tooth Disease. J Neurosci 2022; 42:5085-5101. [PMID: 35589390 PMCID: PMC9233440 DOI: 10.1523/jneurosci.2481-21.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 04/24/2022] [Accepted: 05/03/2022] [Indexed: 12/24/2022] Open
Abstract
Endosomal sorting plays a fundamental role in directing neural development. By altering the temporal and spatial distribution of membrane receptors, endosomes regulate signaling pathways that control the differentiation and function of neural cells. Several genes linked to inherited demyelinating peripheral neuropathies, known as Charcot-Marie-Tooth (CMT) disease, encode proteins that directly interact with components of the endosomal sorting complex required for transport (ESCRT). Our previous studies demonstrated that a point mutation in the ESCRT component hepatocyte growth-factor-regulated tyrosine kinase substrate (HGS), an endosomal scaffolding protein that identifies internalized cargo to be sorted by the endosome, causes a peripheral neuropathy in the neurodevelopmentally impaired teetering mice. Here, we constructed a Schwann cell-specific deletion of Hgs to determine the role of endosomal sorting during myelination. Inactivation of HGS in Schwann cells resulted in motor and sensory deficits, slowed nerve conduction velocities, delayed myelination and hypomyelinated axons, all of which occur in demyelinating forms of CMT. Consistent with a delay in Schwann cell maturation, HGS-deficient sciatic nerves displayed increased mRNA levels for several promyelinating genes and decreased mRNA levels for genes that serve as markers of myelinating Schwann cells. Loss of HGS also altered the abundance and activation of the ERBB2/3 receptors, which are essential for Schwann cell development. We therefore hypothesize that HGS plays a critical role in endosomal sorting of the ERBB2/3 receptors during Schwann cell maturation, which further implicates endosomal dysfunction in inherited peripheral neuropathies.SIGNIFICANCE STATEMENT Schwann cells myelinate peripheral axons, and defects in Schwann cell function cause inherited demyelinating peripheral neuropathies known as CMT. Although many CMT-linked mutations are in genes that encode putative endosomal proteins, little is known about the requirements of endosomal sorting during myelination. In this study, we demonstrate that loss of HGS disrupts the endosomal sorting pathway in Schwann cells, resulting in hypomyelination, aberrant myelin sheaths, and impairment of the ERBB2/3 receptor pathway. These findings suggest that defective endosomal trafficking of internalized cell surface receptors may be a common mechanism contributing to demyelinating CMT.
Collapse
Affiliation(s)
- John W McLean
- Department of Neurobiology, Evelyn F. McKnight Brain Institute, Civitan International Research Center, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Julie A Wilson
- Department of Neurobiology, Evelyn F. McKnight Brain Institute, Civitan International Research Center, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Tina Tian
- Department of Neurobiology, Evelyn F. McKnight Brain Institute, Civitan International Research Center, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Jennifer A Watson
- Department of Neurobiology, Evelyn F. McKnight Brain Institute, Civitan International Research Center, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Mary VanHart
- Department of Neurobiology, Evelyn F. McKnight Brain Institute, Civitan International Research Center, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Andrew J Bean
- Graduate College, Rush University, Chicago, Illinois 60612
| | - Steven S Scherer
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - David K Crossman
- Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama, 35294
| | - Eroboghene Ubogu
- Department of Neurobiology, Evelyn F. McKnight Brain Institute, Civitan International Research Center, University of Alabama at Birmingham, Birmingham, Alabama 35294
- Division of Neuromuscular Disease, Department of Neurology, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Scott M Wilson
- Department of Neurobiology, Evelyn F. McKnight Brain Institute, Civitan International Research Center, University of Alabama at Birmingham, Birmingham, Alabama 35294
| |
Collapse
|
7
|
Identification and clinical characterization of Charcot-Marie-Tooth disease type 1C patients with LITAF p.G112S mutation. Genes Genomics 2022; 44:1007-1016. [PMID: 35608774 DOI: 10.1007/s13258-022-01253-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Accepted: 03/30/2022] [Indexed: 11/04/2022]
Abstract
BACKGROUND Charcot-Marie-Tooth disease type 1C (CMT1C) is a rare subtype associated with LITAF gene mutations. Until now, only a few studies have reported the clinical features of CMT1C. OBJECTIVE This study was performed to find CMT1C patients with mutation of LITAF in a Korean CMT cohort and to characterize their clinical features. METHODS In total, 1,143 unrelated Korean families with CMT were enrolled in a cohort. We performed whole exome sequencing to identify LITAF mutations, and examined clinical phenotypes including electrophysiological and MRI features for the identified CMT1C patients. RESULTS We identified 10 CMT1C patients from three unrelated families with p.G112S mutation in LITAF. The frequency of CMT1C among CMT1 patients was 0.59%, which is similar to reports from Western populations. CMT1C patients showed milder symptoms than CMT1A patients. The mean CMT neuropathy score version 2 was 7.7, and the mean functional disability scale was 1.0. Electrophysiological findings showed a conduction block in 22% of affected individuals. Lower extremity MRIs showed that the superficial posterior and anterolateral compartments of the calf were predominantly affected. CONCLUSIONS We found a conduction block in Korean CMT1C patients with p.G112S mutation and first described the characteristic MRI findings of the lower extremities in patients with LITAF mutation. These findings will be helpful for genotype-phenotype correlation and will widen understanding about the clinical spectrum of CMT1C.
Collapse
|
8
|
Diaz JR, Martá-Ariza M, Khodadadi-Jamayran A, Heguy A, Tsirigos A, Pankiewicz JE, Sullivan PM, Sadowski MJ. Apolipoprotein E4 Effects a Distinct Transcriptomic Profile and Dendritic Arbor Characteristics in Hippocampal Neurons Cultured in vitro. Front Aging Neurosci 2022; 14:845291. [PMID: 35572125 PMCID: PMC9099260 DOI: 10.3389/fnagi.2022.845291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 04/06/2022] [Indexed: 11/13/2022] Open
Abstract
The APOE gene is diversified by three alleles ε2, ε3, and ε4 encoding corresponding apolipoprotein (apo) E isoforms. Possession of the ε4 allele is signified by increased risks of age-related cognitive decline, Alzheimer's disease (AD), and the rate of AD dementia progression. ApoE is secreted by astrocytes as high-density lipoprotein-like particles and these are internalized by neurons upon binding to neuron-expressed apoE receptors. ApoE isoforms differentially engage neuronal plasticity through poorly understood mechanisms. We examined here the effects of native apoE lipoproteins produced by immortalized astrocytes homozygous for ε2, ε3, and ε4 alleles on the maturation and the transcriptomic profile of primary hippocampal neurons. Control neurons were grown in the presence of conditioned media from Apoe -/- astrocytes. ApoE2 and apoE3 significantly increase the dendritic arbor branching, the combined neurite length, and the total arbor surface of the hippocampal neurons, while apoE4 fails to produce similar effects and even significantly reduces the combined neurite length compared to the control. ApoE lipoproteins show no systemic effect on dendritic spine density, yet apoE2 and apoE3 increase the mature spines fraction, while apoE4 increases the immature spine fraction. This is associated with opposing effects of apoE2 or apoE3 and apoE4 on the expression of NR1 NMDA receptor subunit and PSD95. There are 1,062 genes differentially expressed across neurons cultured in the presence of apoE lipoproteins compared to the control. KEGG enrichment and gene ontology analyses show apoE2 and apoE3 commonly activate expression of genes involved in neurite branching, and synaptic signaling. In contrast, apoE4 cultured neurons show upregulation of genes related to the glycolipid metabolism, which are involved in dendritic spine turnover, and those which are usually silent in neurons and are related to cell cycle and DNA repair. In conclusion, our work reveals that lipoprotein particles comprised of various apoE isoforms differentially regulate various neuronal arbor characteristics through interaction with neuronal transcriptome. ApoE4 produces a functionally distinct transcriptomic profile, which is associated with attenuated neuronal development. Differential regulation of neuronal transcriptome by apoE isoforms is a newly identified biological mechanism, which has both implication in the development and aging of the CNS.
Collapse
Affiliation(s)
- Jenny R. Diaz
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States
| | - Mitchell Martá-Ariza
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States
| | | | - Adriana Heguy
- Department of Pathology, New York University Grossman School of Medicine, New York, NY, United States
| | - Aristotelis Tsirigos
- Department of Pathology, New York University Grossman School of Medicine, New York, NY, United States
| | - Joanna E. Pankiewicz
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States
- Department of Biochemistry and Pharmacology, New York University Grossman School of Medicine, New York, NY, United States
| | - Patrick M. Sullivan
- Department of Medicine (Geriatrics), Duke University School of Medicine, Durham, NC, United States
- Durham VA Medical Center’s, Geriatric Research Education and Clinical Center, Durham, NC, United States
| | - Martin J. Sadowski
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States
- Department of Biochemistry and Pharmacology, New York University Grossman School of Medicine, New York, NY, United States
- Department of Psychiatry, New York University Grossman School of Medicine, New York, NY, United States
| |
Collapse
|
9
|
Song J, Liu Y, Wan J, Zhao GN, Wang JC, Dai Z, Hu S, Yang L, Liu Z, Fu Y, Dong E, Tang YD. SIMPLE Is an Endosomal Regulator That Protects Against NAFLD by Targeting the Lysosomal Degradation of EGFR. Hepatology 2021; 74:3091-3109. [PMID: 34320238 DOI: 10.1002/hep.32075] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 06/25/2021] [Accepted: 06/28/2021] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND AIMS NAFLD has become a tremendous burden for public health; however, there is no drug for NAFLD therapy at present. Impaired endo-lysosome-mediated protein degradation is observed in a variety of metabolic disorders, such as atherosclerosis, type 2 diabetes mellitus, and NAFLD. Small integral membrane protein of lysosome/late endosome (SIMPLE) is a regulator of endosome-to-lysosome trafficking and cell signaling, but the role that SIMPLE plays in NAFLD progression remains unknown. Here we investigated SIMPLE function in NAFLD development and sophisticated mechanism therein. APPROACH AND RESULTS This study found that in vitro knockdown of SIMPLE significantly aggravated lipid accumulation and inflammation in hepatocytes treated with metabolic stimulation. Consistently, in vivo experiments showed that liver-specific Simple-knockout (Simple-HKO) mice exhibited more severe high-fat diet (HFD)-induced, high-fat-high-cholesterol diet (HFHC)-induced, and methionine-choline-deficient diet (MCD)-induced steatosis, glucose intolerance, inflammation, and fibrosis than those fed with normal chow (NC) diet. Meanwhile, RNA-sequencing demonstrated the up-regulated signaling pathways and signature genes involved in lipid metabolism, inflammation, and fibrosis in Simple-HKO mice compared with control mice under metabolic stress. Mechanically, we found SIMPLE directly interact with epidermal growth factor receptor (EGFR). SIMPLE deficiency results in dysregulated degradation of EGFR, subsequently hyperactivated EGFR phosphorylation, thus exaggerating NAFLD development. Moreover, we demonstrated that using EGFR inhibitor or silencing EGFR expression could ameliorate lipid accumulation induced by the knockdown of SIMPLE. CONCLUSIONS SIMPLE ameliorated NASH by prompting EGFR degradation and can be a potential therapeutic candidate for NASH.
Collapse
Affiliation(s)
- Jingjing Song
- Department of Cardiology, State Key Laboratory of Cardiovascular Disease, National Center for Cardiovascular Diseases, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yupeng Liu
- Department of Cardiology, State Key Laboratory of Cardiovascular Disease, National Center for Cardiovascular Diseases, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Juan Wan
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Guang-Nian Zhao
- Medical Science Research Center, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Jian-Cheng Wang
- Beijing Key Laboratory of Molecular Pharmaceutics and New Drug Delivery Systems, State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, China
| | - Zhifei Dai
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, China
| | - Sha Hu
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Ling Yang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Zhen Liu
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Yi Fu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, China
| | - Erdan Dong
- The Institute of Cardiovascular Sciences, Peking University, NHC Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides, Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China.,Department of Cardiology and Institute of Vascular Medicine, Peking University Third Hospital, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, China
| | - Yi-Da Tang
- Department of Cardiology, State Key Laboratory of Cardiovascular Disease, National Center for Cardiovascular Diseases, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Department of Cardiology and Institute of Vascular Medicine, Peking University Third Hospital, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, China
| |
Collapse
|
10
|
Markworth R, Bähr M, Burk K. Held Up in Traffic-Defects in the Trafficking Machinery in Charcot-Marie-Tooth Disease. Front Mol Neurosci 2021; 14:695294. [PMID: 34483837 PMCID: PMC8415527 DOI: 10.3389/fnmol.2021.695294] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 07/23/2021] [Indexed: 12/13/2022] Open
Abstract
Charcot-Marie-Tooth disease (CMT), also known as motor and sensory neuropathy, describes a clinically and genetically heterogenous group of disorders affecting the peripheral nervous system. CMT typically arises in early adulthood and is manifested by progressive loss of motor and sensory functions; however, the mechanisms leading to the pathogenesis are not fully understood. In this review, we discuss disrupted intracellular transport as a common denominator in the pathogenesis of different CMT subtypes. Intracellular transport via the endosomal system is essential for the delivery of lipids, proteins, and organelles bidirectionally to synapses and the soma. As neurons of the peripheral nervous system are amongst the longest neurons in the human body, they are particularly susceptible to damage of the intracellular transport system, leading to a loss in axonal integrity and neuronal death. Interestingly, defects in intracellular transport, both in neurons and Schwann cells, have been found to provoke disease. This review explains the mechanisms of trafficking and subsequently summarizes and discusses the latest findings on how defects in trafficking lead to CMT. A deeper understanding of intracellular trafficking defects in CMT will expand our understanding of CMT pathogenesis and will provide novel approaches for therapeutic treatments.
Collapse
Affiliation(s)
- Ronja Markworth
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany.,Center for Biostructural Imaging of Neurodegeneration, Göttingen, Germany
| | - Mathias Bähr
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany
| | - Katja Burk
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany.,Center for Biostructural Imaging of Neurodegeneration, Göttingen, Germany
| |
Collapse
|
11
|
Wrestling and Wrapping: A Perspective on SUMO Proteins in Schwann Cells. Biomolecules 2021; 11:biom11071055. [PMID: 34356679 PMCID: PMC8301837 DOI: 10.3390/biom11071055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 07/12/2021] [Accepted: 07/13/2021] [Indexed: 11/20/2022] Open
Abstract
Schwann cell development and peripheral nerve myelination are finely orchestrated multistep processes; some of the underlying mechanisms are well described and others remain unknown. Many posttranslational modifications (PTMs) like phosphorylation and ubiquitination have been reported to play a role during the normal development of the peripheral nervous system (PNS) and in demyelinating neuropathies. However, a relatively novel PTM, SUMOylation, has not been studied in these contexts. SUMOylation involves the covalent attachment of one or more small ubiquitin-like modifier (SUMO) proteins to a substrate, which affects the function, cellular localization, and further PTMs of the conjugated protein. SUMOylation also regulates other proteins indirectly by facilitating non-covalent protein–protein interaction via SUMO interaction motifs (SIM). This pathway has important consequences on diverse cellular processes, and dysregulation of this pathway has been reported in several diseases including neurological and degenerative conditions. In this article, we revise the scarce literature on SUMOylation in Schwann cells and the PNS, we propose putative substrate proteins, and we speculate on potential mechanisms underlying the possible involvement of this PTM in peripheral myelination and neuropathies.
Collapse
|
12
|
Genetic mechanisms of peripheral nerve disease. Neurosci Lett 2020; 742:135357. [PMID: 33249104 DOI: 10.1016/j.neulet.2020.135357] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 08/24/2020] [Accepted: 09/02/2020] [Indexed: 12/17/2022]
Abstract
Peripheral neuropathies of genetic etiology are a very diverse group of disorders manifesting either as non-syndromic inherited neuropathies without significant manifestations outside the peripheral nervous system, or as part of a systemic or syndromic genetic disorder. The former and most frequent group is collectively known as Charcot-Marie-Tooth disease (CMT), with prevalence as high as 1:2,500 world-wide, and has proven to be genetically highly heterogeneous. More than 100 different genes have been identified so far to cause various CMT forms, following all possible inheritance patterns. CMT causative genes belong to several common functional pathways that are essential for the integrity of the peripheral nerve. Their discovery has provided insights into the normal biology of axons and myelinating cells, and has highlighted the molecular mechanisms including both loss of function and gain of function effects, leading to peripheral nerve degeneration. Demyelinating neuropathies result from dysfunction of genes primarily affecting myelinating Schwann cells, while axonal neuropathies are caused by genes affecting mostly neurons and their long axons. Furthermore, mutation in genes expressed outside the nervous system, as in the case of inherited amyloid neuropathies, may cause peripheral neuropathy resulting from accumulation of β-structured amyloid fibrils in peripheral nerves in addition to various organs. Increasing insights into the molecular-genetic mechanisms have revealed potential therapeutic targets. These will enable the development of novel therapeutics for genetic neuropathies that remain, in their majority, without effective treatment.
Collapse
|
13
|
Edgar JR, Ho AK, Laurá M, Horvath R, Reilly MM, Luzio JP, Roberts RC. A dysfunctional endolysosomal pathway common to two sub-types of demyelinating Charcot-Marie-Tooth disease. Acta Neuropathol Commun 2020; 8:165. [PMID: 33059769 PMCID: PMC7559459 DOI: 10.1186/s40478-020-01043-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 09/24/2020] [Indexed: 12/17/2022] Open
Abstract
Autosomal dominant mutations in LITAF are responsible for the rare demyelinating peripheral neuropathy, Charcot-Marie-Tooth disease type 1C (CMT1C). The LITAF protein is expressed in many human cell types and we have investigated the consequences of two different LITAF mutations in primary fibroblasts from CMT1C patients using confocal and electron microscopy. We observed the appearance of vacuolation/enlargement of late endocytic compartments (late endosomes and lysosomes). This vacuolation was also observed after knocking out LITAF from either control human fibroblasts or from the CMT1C patient-derived cells, consistent with it being the result of loss-of-function mutations in the CMT1C fibroblasts. The vacuolation was similar to that previously observed in fibroblasts from CMT4J patients, which have autosomal recessive mutations in FIG4. The FIG4 protein is a component of a phosphoinositide kinase complex that synthesises phosphatidylinositol 3,5-bisphosphate on the limiting membrane of late endosomes. Phosphatidylinositol 3,5-bisphosphate activates the release of lysosomal Ca2+ through the cation channel TRPML1, which is required to maintain the homeostasis of endosomes and lysosomes in mammalian cells. We observed that a small molecule activator of TRPML1, ML-SA1, was able to rescue the vacuolation phenotype of LITAF knockout, FIG4 knockout and CMT1C patient fibroblasts. Our data describe the first cellular phenotype common to two different subtypes of demyelinating CMT and are consistent with LITAF and FIG4 functioning on a common endolysosomal pathway that is required to maintain the homeostasis of late endosomes and lysosomes. Although our experiments were on human fibroblasts, they have implications for our understanding of the molecular pathogenesis and approaches to therapy in two subtypes of demyelinating Charcot-Marie-Tooth disease.
Collapse
Affiliation(s)
- James R Edgar
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0XY, UK.
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK.
| | - Anita K Ho
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0XY, UK
- Department of Biology, University of York, York, YO10 5DD, UK
| | - Matilde Laurá
- Centre for Neuromuscular Diseases, UCL, Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - Rita Horvath
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 0PY, UK
| | - Mary M Reilly
- Centre for Neuromuscular Diseases, UCL, Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - J Paul Luzio
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0XY, UK
| | - Rhys C Roberts
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0XY, UK.
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 0PY, UK.
| |
Collapse
|
14
|
The Ubiquitin Proteasome System in Neuromuscular Disorders: Moving Beyond Movement. Int J Mol Sci 2020; 21:ijms21176429. [PMID: 32899400 PMCID: PMC7503226 DOI: 10.3390/ijms21176429] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/30/2020] [Accepted: 08/31/2020] [Indexed: 12/12/2022] Open
Abstract
Neuromuscular disorders (NMDs) affect 1 in 3000 people worldwide. There are more than 150 different types of NMDs, where the common feature is the loss of muscle strength. These disorders are classified according to their neuroanatomical location, as motor neuron diseases, peripheral nerve diseases, neuromuscular junction diseases, and muscle diseases. Over the years, numerous studies have pointed to protein homeostasis as a crucial factor in the development of these fatal diseases. The ubiquitin-proteasome system (UPS) plays a fundamental role in maintaining protein homeostasis, being involved in protein degradation, among other cellular functions. Through a cascade of enzymatic reactions, proteins are ubiquitinated, tagged, and translocated to the proteasome to be degraded. Within the ubiquitin system, we can find three main groups of enzymes: E1 (ubiquitin-activating enzymes), E2 (ubiquitin-conjugating enzymes), and E3 (ubiquitin-protein ligases). Only the ubiquitinated proteins with specific chain linkages (such as K48) will be degraded by the UPS. In this review, we describe the relevance of this system in NMDs, summarizing the UPS proteins that have been involved in pathological conditions and neuromuscular disorders, such as Spinal Muscular Atrophy (SMA), Charcot-Marie-Tooth disease (CMT), or Duchenne Muscular Dystrophy (DMD), among others. A better knowledge of the processes involved in the maintenance of proteostasis may pave the way for future progress in neuromuscular disorder studies and treatments.
Collapse
|
15
|
Liu J, Zuo Z, Sastalla I, Liu C, Jang JY, Sekine Y, Li Y, Pirooznia M, Leppla SH, Finkel T, Liu S. Sequential CRISPR-Based Screens Identify LITAF and CDIP1 as the Bacillus cereus Hemolysin BL Toxin Host Receptors. Cell Host Microbe 2020; 28:402-410.e5. [PMID: 32544461 DOI: 10.1016/j.chom.2020.05.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 04/16/2020] [Accepted: 05/15/2020] [Indexed: 12/18/2022]
Abstract
Bacteria and their toxins are associated with significant human morbidity and mortality. While a few bacterial toxins are well characterized, the mechanism of action for most toxins has not been elucidated, thereby limiting therapeutic advances. One such example is the highly potent pore-forming toxin, hemolysin BL (HBL), produced by the gram-positive pathogen Bacillus cereus. However, how HBL exerts its effects and whether it requires any host factors is unknown. Here, we describe an unbiased genome-wide CRISPR-Cas9 knockout screen that identified LPS-induced TNF-α factor (LITAF) as the HBL receptor. Using LITAF-deficient cells, a second, subsequent whole-genome CRISPR-Cas9 screen identified the LITAF-like protein CDIP1 as a second, alternative receptor. We generated LITAF-deficient mice, which exhibit marked resistance to lethal HBL challenges. This work outlines and validates an approach to use iterative genome-wide CRISPR-Cas9 screens to identify the complement of host factors exploited by bacterial toxins to exert their myriad biological effects.
Collapse
Affiliation(s)
- Jie Liu
- Aging Institute of University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA; Division of Cardiology, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Zehua Zuo
- Aging Institute of University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA
| | - Inka Sastalla
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Chengyu Liu
- Transgenic Core Facility, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ji Yong Jang
- Aging Institute of University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA
| | - Yusuke Sekine
- Aging Institute of University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA
| | - Yuesheng Li
- DNA Sequencing and Genomics Core Facility, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Mehdi Pirooznia
- Bioinformatics and Computational Biology Core Facility, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Stephen H Leppla
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Toren Finkel
- Aging Institute of University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA; Division of Cardiology, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Shihui Liu
- Aging Institute of University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA; Division of Infectious Diseases, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA.
| |
Collapse
|
16
|
Blanco-Cantó ME, Patel N, Velasco-Aviles S, Casillas-Bajo A, Salas-Felipe J, García-Escrivá A, Díaz-Marín C, Cabedo H. Novel EGR2 variant that associates with Charcot-Marie-Tooth disease when combined with lipopolysaccharide-induced TNF-α factor T49M polymorphism. NEUROLOGY-GENETICS 2020; 6:e407. [PMID: 32337334 PMCID: PMC7164973 DOI: 10.1212/nxg.0000000000000407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 12/30/2019] [Indexed: 11/15/2022]
Abstract
Objective To identify novel genetic mechanisms causing Charcot-Marie-Tooth (CMT) disease. Methods We performed a next-generation sequencing study of 34 genes associated with CMT in a patient with peripheral neuropathy. Results We found a non-previously described mutation in EGR2 (p.P397H). P397H mutation is located within the loop that connects zinc fingers 2 and 3, a pivotal domain for the activity of this transcription factor. Using promoter activity luciferase assays, we found that this mutation promotes decreased transcriptional activity of EGR2. In this patient, we also found a previously described nonpathogenic polymorphism in lipopolysaccharide-induced TNF-α factor (LITAF) (p.T49M). We show that the p.T49M mutation decreases the steady-state levels of the LITAF protein in Schwann cells. Loss of function of LITAF has been shown to produce deregulation in the NRG1-erbB signaling, a pivotal pathway for EGR2 expression by Schwann cells. Surprisingly, our segregation study demonstrates that p.P397H mutation in EGR2 is not sufficient to produce CMT disease. Most notably, only those patients expressing simultaneously the LITAF T49M polymorphism develop peripheral neuropathy. Conclusions Our data support that the LITAF loss-of-function interferes with the expression of the transcriptional-deficient EGR2 P397H mutant hampering Schwann cell differentiation and suggest that in vivo both genes act in tandem to allow the proper development of myelin.
Collapse
Affiliation(s)
- Maria Empar Blanco-Cantó
- ISABIAL (FISABIO) (M.E.B.-C., N.P., S.V.-A., A.C.-B., C.D.-M., H.C.), Hospital General Universitario de Alicante; Instituto de Neurociencias de Alicante UMH-CSIC (N.P., S.V.-A., A.C.-B., H.C.), San Juan de Alicante, Spain; Hospital Marina Salud (J.S.-F.), Denia; and Hospital IMED Levante (A.G.-E.), Benidorm, Spain
| | - Nikiben Patel
- ISABIAL (FISABIO) (M.E.B.-C., N.P., S.V.-A., A.C.-B., C.D.-M., H.C.), Hospital General Universitario de Alicante; Instituto de Neurociencias de Alicante UMH-CSIC (N.P., S.V.-A., A.C.-B., H.C.), San Juan de Alicante, Spain; Hospital Marina Salud (J.S.-F.), Denia; and Hospital IMED Levante (A.G.-E.), Benidorm, Spain
| | - Sergio Velasco-Aviles
- ISABIAL (FISABIO) (M.E.B.-C., N.P., S.V.-A., A.C.-B., C.D.-M., H.C.), Hospital General Universitario de Alicante; Instituto de Neurociencias de Alicante UMH-CSIC (N.P., S.V.-A., A.C.-B., H.C.), San Juan de Alicante, Spain; Hospital Marina Salud (J.S.-F.), Denia; and Hospital IMED Levante (A.G.-E.), Benidorm, Spain
| | - Angeles Casillas-Bajo
- ISABIAL (FISABIO) (M.E.B.-C., N.P., S.V.-A., A.C.-B., C.D.-M., H.C.), Hospital General Universitario de Alicante; Instituto de Neurociencias de Alicante UMH-CSIC (N.P., S.V.-A., A.C.-B., H.C.), San Juan de Alicante, Spain; Hospital Marina Salud (J.S.-F.), Denia; and Hospital IMED Levante (A.G.-E.), Benidorm, Spain
| | - Juan Salas-Felipe
- ISABIAL (FISABIO) (M.E.B.-C., N.P., S.V.-A., A.C.-B., C.D.-M., H.C.), Hospital General Universitario de Alicante; Instituto de Neurociencias de Alicante UMH-CSIC (N.P., S.V.-A., A.C.-B., H.C.), San Juan de Alicante, Spain; Hospital Marina Salud (J.S.-F.), Denia; and Hospital IMED Levante (A.G.-E.), Benidorm, Spain
| | - Alexandre García-Escrivá
- ISABIAL (FISABIO) (M.E.B.-C., N.P., S.V.-A., A.C.-B., C.D.-M., H.C.), Hospital General Universitario de Alicante; Instituto de Neurociencias de Alicante UMH-CSIC (N.P., S.V.-A., A.C.-B., H.C.), San Juan de Alicante, Spain; Hospital Marina Salud (J.S.-F.), Denia; and Hospital IMED Levante (A.G.-E.), Benidorm, Spain
| | - Carmen Díaz-Marín
- ISABIAL (FISABIO) (M.E.B.-C., N.P., S.V.-A., A.C.-B., C.D.-M., H.C.), Hospital General Universitario de Alicante; Instituto de Neurociencias de Alicante UMH-CSIC (N.P., S.V.-A., A.C.-B., H.C.), San Juan de Alicante, Spain; Hospital Marina Salud (J.S.-F.), Denia; and Hospital IMED Levante (A.G.-E.), Benidorm, Spain
| | - Hugo Cabedo
- ISABIAL (FISABIO) (M.E.B.-C., N.P., S.V.-A., A.C.-B., C.D.-M., H.C.), Hospital General Universitario de Alicante; Instituto de Neurociencias de Alicante UMH-CSIC (N.P., S.V.-A., A.C.-B., H.C.), San Juan de Alicante, Spain; Hospital Marina Salud (J.S.-F.), Denia; and Hospital IMED Levante (A.G.-E.), Benidorm, Spain
| |
Collapse
|
17
|
Michaelidou K, Tsiverdis I, Erimaki S, Papadimitriou D, Amoiridis G, Papadimitriou A, Mitsias P, Zaganas I. Whole exome sequencing establishes diagnosis of Charcot-Marie-Tooth 4J, 1C, and X1 subtypes. Mol Genet Genomic Med 2020; 8:e1141. [PMID: 32022442 PMCID: PMC7196464 DOI: 10.1002/mgg3.1141] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 01/01/2020] [Accepted: 01/03/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Charcot-Marie-Tooth (CMT) hereditary polyneuropathies pose a diagnostic challenge. Our aim here is to describe CMT patients diagnosed by whole exome sequencing (WES) following years of fruitless testing. METHODS/RESULTS Three patients with polyneuropathy suspected to be genetic in origin, but not harboring PMP22 gene deletion/duplication, were offered WES. The first patient, a 66-year-old man, had been suffering from progressive weakness and atrophies in the lower and upper extremities for 20 years. Due to ambiguous electrophysiological findings, immune therapies were administered to no avail. Twelve years after PMP22 deletion/duplication testing, WES revealed two pathogenic variants in the FIG4 gene (p.Ile41Thr and p.Phe598fs, respectively), as a cause of CMT 4J. The second patient, a 19-year-old man, had been suffering from hearing and gait impairment since at least his infancy, and recently presented with weakness and dystonia of the lower extremities. In this patient, WES identified the p.Leu122Val LITAF gene variant in heterozygous state, suggesting the diagnosis of CMT 1C, several years after initial genetic analyses. The third patient, a 44-year-old man, presented with progressive weakness and atrophies of the lower and upper extremities since the age of 17 years old. In this patient, WES identified the hemizygous p.Arg164Gln pathogenic variant in the GJB1 gene, establishing the diagnosis of CMT X1, 8 years after testing for PMP22 deletion/duplication. CONCLUSION Novel diagnostic techniques, such as WES, offer the possibility to decipher the cause of CMT subtypes, ending the diagnostic Odyssey of the patients and sparing them from unnecessary and potentially harmful treatments.
Collapse
Affiliation(s)
- Kleita Michaelidou
- Neurogenetics LaboratoryMedical SchoolUniversity of CreteHeraklion, CreteGreece
| | - Ioannis Tsiverdis
- Neurology DepartmentUniversity Hospital of CreteHeraklion, CreteGreece
| | - Sophia Erimaki
- Neurophysiology UnitUniversity Hospital of CreteHeraklion, CreteGreece
| | | | | | | | - Panayiotis Mitsias
- Neurogenetics LaboratoryMedical SchoolUniversity of CreteHeraklion, CreteGreece
- Neurology DepartmentUniversity Hospital of CreteHeraklion, CreteGreece
- Neurophysiology UnitUniversity Hospital of CreteHeraklion, CreteGreece
- Department of NeurologyHenry Ford Hospital/Wayne State UniversityDetroitMIUSA
| | - Ioannis Zaganas
- Neurogenetics LaboratoryMedical SchoolUniversity of CreteHeraklion, CreteGreece
- Neurology DepartmentUniversity Hospital of CreteHeraklion, CreteGreece
| |
Collapse
|
18
|
Lee SM, Asress S, Hales CM, Gearing M, Vizcarra JC, Fournier CN, Gutman DA, Chin LS, Li L, Glass JD. TDP-43 cytoplasmic inclusion formation is disrupted in C9orf72-associated amyotrophic lateral sclerosis/frontotemporal lobar degeneration. Brain Commun 2019; 1:fcz014. [PMID: 31633109 PMCID: PMC6788139 DOI: 10.1093/braincomms/fcz014] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 08/10/2019] [Accepted: 08/19/2019] [Indexed: 12/12/2022] Open
Abstract
The G4C2 hexanucleotide repeat expansion mutation in the C9orf72 gene is the most common genetic cause underlying both amyotrophic lateral sclerosis and frontotemporal dementia. Pathologically, these two neurodegenerative disorders are linked by the common presence of abnormal phosphorylated TDP-43 neuronal cytoplasmic inclusions. We compared the number and size of phosphorylated TDP-43 inclusions and their morphology in hippocampi from patients dying with sporadic versus C9orf72-related amyotrophic lateral sclerosis with pathologically defined frontotemporal lobar degeneration with phosphorylated TDP-43 inclusions, the pathological substrate of clinical frontotemporal dementia in patients with amyotrophic lateral sclerosis. In sporadic cases, there were numerous consolidated phosphorylated TDP-43 inclusions that were variable in size, whereas inclusions in C9orf72 amyotrophic lateral sclerosis/frontotemporal lobar degeneration were quantitatively smaller than those in sporadic cases. Also, C9orf72 amyotrophic lateral sclerosis/frontotemporal lobar degeneration homogenized brain contained soluble cytoplasmic TDP-43 that was largely absent in sporadic cases. To better understand these pathological differences, we modelled TDP-43 inclusion formation in fibroblasts derived from sporadic or C9orf72-related amyotrophic lateral sclerosis/frontotemporal dementia patients. We found that both sporadic and C9orf72 amyotrophic lateral sclerosis/frontotemporal dementia patient fibroblasts showed impairment in TDP-43 degradation by the proteasome, which may explain increased TDP-43 protein levels found in both sporadic and C9orf72 amyotrophic lateral sclerosis/frontotemporal lobar degeneration frontal cortex and hippocampus. Fibroblasts derived from sporadic patients, but not C9orf72 patients, demonstrated the ability to sequester cytoplasmic TDP-43 into aggresomes via microtubule-dependent mechanisms. TDP-43 aggresomes in vitro and TDP-43 neuronal inclusions in vivo were both tightly localized with autophagy markers and, therefore, were likely to function similarly as sites for autophagic degradation. The inability for C9orf72 fibroblasts to form TDP-43 aggresomes, together with the observations that TDP-43 protein was soluble in the cytoplasm and formed smaller inclusions in the C9orf72 brain compared with sporadic disease, suggests a loss of protein quality control response to sequester and degrade TDP-43 in C9orf72-related diseases.
Collapse
Affiliation(s)
- Samuel M Lee
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA.,Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA, USA
| | - Seneshaw Asress
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA.,Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA, USA
| | - Chadwick M Hales
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA.,Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA, USA
| | - Marla Gearing
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA.,Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA, USA.,Department of Pathology & Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, USA
| | - Juan C Vizcarra
- Department of Biomedical Engineering, Emory University School of Medicine, Atlanta, GA, USA.,Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Christina N Fournier
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA.,Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA, USA
| | - David A Gutman
- Department of Biomedical Engineering, Emory University School of Medicine, Atlanta, GA, USA.,Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Lih-Shen Chin
- Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA, USA.,Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
| | - Lian Li
- Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA, USA.,Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
| | - Jonathan D Glass
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA.,Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA, USA.,Department of Pathology & Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, USA
| |
Collapse
|
19
|
Marinko J, Huang H, Penn WD, Capra JA, Schlebach JP, Sanders CR. Folding and Misfolding of Human Membrane Proteins in Health and Disease: From Single Molecules to Cellular Proteostasis. Chem Rev 2019; 119:5537-5606. [PMID: 30608666 PMCID: PMC6506414 DOI: 10.1021/acs.chemrev.8b00532] [Citation(s) in RCA: 153] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Indexed: 12/13/2022]
Abstract
Advances over the past 25 years have revealed much about how the structural properties of membranes and associated proteins are linked to the thermodynamics and kinetics of membrane protein (MP) folding. At the same time biochemical progress has outlined how cellular proteostasis networks mediate MP folding and manage misfolding in the cell. When combined with results from genomic sequencing, these studies have established paradigms for how MP folding and misfolding are linked to the molecular etiologies of a variety of diseases. This emerging framework has paved the way for the development of a new class of small molecule "pharmacological chaperones" that bind to and stabilize misfolded MP variants, some of which are now in clinical use. In this review, we comprehensively outline current perspectives on the folding and misfolding of integral MPs as well as the mechanisms of cellular MP quality control. Based on these perspectives, we highlight new opportunities for innovations that bridge our molecular understanding of the energetics of MP folding with the nuanced complexity of biological systems. Given the many linkages between MP misfolding and human disease, we also examine some of the exciting opportunities to leverage these advances to address emerging challenges in the development of therapeutics and precision medicine.
Collapse
Affiliation(s)
- Justin
T. Marinko
- Department
of Biochemistry, Vanderbilt University, Nashville, Tennessee 37240, United States
- Center
for Structural Biology, Vanderbilt University, Nashville, Tennessee 37240, United States
| | - Hui Huang
- Department
of Biochemistry, Vanderbilt University, Nashville, Tennessee 37240, United States
- Center
for Structural Biology, Vanderbilt University, Nashville, Tennessee 37240, United States
| | - Wesley D. Penn
- Department
of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - John A. Capra
- Center
for Structural Biology, Vanderbilt University, Nashville, Tennessee 37240, United States
- Department
of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37245, United States
| | - Jonathan P. Schlebach
- Department
of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Charles R. Sanders
- Department
of Biochemistry, Vanderbilt University, Nashville, Tennessee 37240, United States
| |
Collapse
|
20
|
Murakami T, Sunada Y. Schwann Cell and the Pathogenesis of Charcot–Marie–Tooth Disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1190:301-321. [DOI: 10.1007/978-981-32-9636-7_19] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
21
|
Lee CA, Chin LS, Li L. Hypertonia-linked protein Trak1 functions with mitofusins to promote mitochondrial tethering and fusion. Protein Cell 2018; 9:693-716. [PMID: 28924745 PMCID: PMC6053349 DOI: 10.1007/s13238-017-0469-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 08/21/2017] [Indexed: 12/23/2022] Open
Abstract
Hypertonia is a neurological dysfunction associated with a number of central nervous system disorders, including cerebral palsy, Parkinson's disease, dystonia, and epilepsy. Genetic studies have identified a homozygous truncation mutation in Trak1 that causes hypertonia in mice. Moreover, elevated Trak1 protein expression is associated with several types of cancers and variants in Trak1 are linked to childhood absence epilepsy in humans. Despite the importance of Trak1 in health and disease, the mechanisms of Trak1 action remain unclear and the pathogenic effects of Trak1 mutation are unknown. Here we report that Trak1 has a crucial function in regulation of mitochondrial fusion. Depletion of Trak1 inhibits mitochondrial fusion, resulting in mitochondrial fragmentation, whereas overexpression of Trak1 elongates and enlarges mitochondria. Our analyses revealed that Trak1 interacts and colocalizes with mitofusins on the outer mitochondrial membrane and functions with mitofusins to promote mitochondrial tethering and fusion. Furthermore, Trak1 is required for stress-induced mitochondrial hyperfusion and pro-survival response. We found that hypertonia-associated mutation impairs Trak1 mitochondrial localization and its ability to facilitate mitochondrial tethering and fusion. Our findings uncover a novel function of Trak1 as a regulator of mitochondrial fusion and provide evidence linking dysregulated mitochondrial dynamics to hypertonia pathogenesis.
Collapse
Affiliation(s)
- Crystal A Lee
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, 30322, USA
- Cell Biology Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Lih-Shen Chin
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Lian Li
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, 30322, USA.
| |
Collapse
|
22
|
Moriwaki Y, Ohno Y, Ishii T, Takamura Y, Kita Y, Watabe K, Sango K, Tsuji S, Misawa H. SIMPLE binds specifically to PI4P through SIMPLE-like domain and participates in protein trafficking in the trans-Golgi network and/or recycling endosomes. PLoS One 2018; 13:e0199829. [PMID: 29953492 PMCID: PMC6023223 DOI: 10.1371/journal.pone.0199829] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 06/14/2018] [Indexed: 01/12/2023] Open
Abstract
Small integral membrane protein of the lysosome/late endosome (SIMPLE) is a 161-amino acid cellular protein that contains a characteristic C-terminal domain known as the SIMPLE-like domain (SLD), which is well conserved among species. Several studies have demonstrated that SIMPLE localizes to the trans-Golgi network (TGN), early endosomes, lysosomes, multivesicular bodies, aggresomes and the plasma membrane. However, the amino acid regions responsible for its subcellular localization have not yet been identified. The SLD resembles the FYVE domain, which binds phosphatidylinositol (3)-phosphate (PI3P) and determines the subcellular localization of FYVE domain-containing proteins. In the present study, we have found that SIMPLE binds specifically to PI4P through its SLD. SIMPLE co-localized with PI4P and Rab11, a marker for recycling endosomes (REs, organelles enriched in PI4P) in both the IMS32 mouse Schwann cell line and Hela cells. Sucrose density-gradient centrifugation revealed that SIMPLE co-fractionated with syntaxin-6 (a TGN marker) and Rab11. We have also found that SIMPLE knockdown impeded recycling of transferrin and of transferrin receptor. Our overall results indicate that SIMPLE may regulate protein trafficking physiologically by localizing to the TGN and/or REs by binding PI4P.
Collapse
Affiliation(s)
- Yasuhiro Moriwaki
- Division of Pharmacology, Faculty of Pharmacy, Keio University, Minato-ku, Tokyo, Japan
- * E-mail: (YM); (HM)
| | - Yuho Ohno
- Division of Pharmacology, Faculty of Pharmacy, Keio University, Minato-ku, Tokyo, Japan
| | - Tomohiro Ishii
- Division of Pharmacology, Faculty of Pharmacy, Keio University, Minato-ku, Tokyo, Japan
- Laboratory for Neurodegenerative Pathology, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo, Japan
| | - Yuki Takamura
- Division of Pharmacology, Faculty of Pharmacy, Keio University, Minato-ku, Tokyo, Japan
| | - Yuko Kita
- Division of Pharmacology, Faculty of Pharmacy, Keio University, Minato-ku, Tokyo, Japan
| | - Kazuhiko Watabe
- Laboratory for Neurodegenerative Pathology, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo, Japan
| | - Kazunori Sango
- Diabetic Neuropathy Project, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo, Japan
| | - Shoutaro Tsuji
- Molecular Diagnostics Project, Kanagawa Cancer Center Research Institute, Yokohama, Kanagawa, Japan
| | - Hidemi Misawa
- Division of Pharmacology, Faculty of Pharmacy, Keio University, Minato-ku, Tokyo, Japan
- * E-mail: (YM); (HM)
| |
Collapse
|
23
|
Schwartz NU, Linzer RW, Truman JP, Gurevich M, Hannun YA, Senkal CE, Obeid LM. Decreased ceramide underlies mitochondrial dysfunction in Charcot-Marie-Tooth 2F. FASEB J 2018; 32:1716-1728. [PMID: 29133339 DOI: 10.1096/fj.201701067r] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Charcot-Marie-Tooth (CMT) disease is the most commonly inherited neurologic disorder, but its molecular mechanisms remain unclear. One variant of CMT, 2F, is characterized by mutations in heat shock protein 27 (Hsp27). As bioactive sphingolipids have been implicated in neurodegenerative diseases, we sought to determine if their dysregulation is involved in CMT. Here, we show that Hsp27 knockout mice demonstrated decreases in ceramide in peripheral nerve tissue and that the disease-associated Hsp27 S135F mutant demonstrated decreases in mitochondrial ceramide. Given that Hsp27 is a chaperone protein, we examined its role in regulating ceramide synthases (CerSs), an enzyme family responsible for catalyzing generation of the sphingolipid ceramide. We determined that CerSs colocalized with Hsp27, and upon the presence of S135F mutants, CerS1 lost its colocalization with mitochondria suggesting that decreased mitochondrial ceramides result from reduced mitochondrial CerS localization rather than decreased CerS activity. Mitochondria in mutant cells appeared larger with increased interconnectivity. Furthermore, mutant cell lines demonstrated decreased mitochondrial respiratory function and increased autophagic flux. Mitochondrial structural and functional changes were recapitulated by blocking ceramide generation pharmacologically. These results suggest that mutant Hsp27 decreases mitochondrial ceramide levels, producing structural and functional changes in mitochondria leading to neuronal degeneration.-Schwartz, N. U., Linzer, R. W., Truman, J.-P., Gurevich, M., Hannun, Y. A., Senkal, C. E., Obeid, L. M. Decreased ceramide underlies mitochondrial dysfunction in Charcot-Marie-Tooth 2F.
Collapse
Affiliation(s)
- Nicholas U Schwartz
- Department of Neurobiology and Behavior, Stony Brook University School of Medicine, Stony Brook, New York, USA
| | - Ryan W Linzer
- Department of Medicine, Stony Brook University School of Medicine, Stony Brook, New York, USA
| | - Jean-Philip Truman
- Department of Medicine, Stony Brook University School of Medicine, Stony Brook, New York, USA
| | - Mikhail Gurevich
- Department of Pharmacology, Stony Brook University School of Medicine, Stony Brook, New York, USA.,Department of Orthopaedics, Stony Brook University School of Medicine, Stony Brook, New York, USA; and
| | - Yusuf A Hannun
- Department of Medicine, Stony Brook University School of Medicine, Stony Brook, New York, USA
| | - Can E Senkal
- Department of Medicine, Stony Brook University School of Medicine, Stony Brook, New York, USA
| | - Lina M Obeid
- Department of Medicine, Stony Brook University School of Medicine, Stony Brook, New York, USA.,Northport Veterans Affairs Medical Center, Northport, New York, USA
| |
Collapse
|
24
|
Guimarães-Costa R, Iancu Ferfoglia R, Leonard-Louis S, Ziegler F, Magy L, Fournier E, Dubourg O, Bouche P, Maisonobe T, Lacour A, Moerman A, Latour P, Stojkovic T. Phenotypic spectrum of Charcot-Marie-Tooth disease due to LITAF/SIMPLE mutations: a study of 18 patients. Eur J Neurol 2017; 24:530-538. [PMID: 28211240 DOI: 10.1111/ene.13239] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 11/30/2016] [Indexed: 01/11/2023]
Abstract
BACKGROUND AND PURPOSE Charcot-Marie-Tooth (CMT) 1C due to mutations in LITAF/SIMPLE is a rare subtype amongst the autosomal dominant demyelinating forms of CMT. Our objective was to report the clinical and electrophysiological characteristics of 18 CMT1C patients and compare them to 20 patients with PMP22 mutations: 10 CMT1A patients and 10 patients with hereditary neuropathy with liability to pressure palsies (HNPP). METHODS Charcot-Marie-Tooth 1C patients were followed-up in referral centres for neuromuscular diseases or were identified by familial survey. All CMT1A and HNPP patients were recruited at the referral centre for neuromuscular diseases of Pitié-Salpêtrière Hospital. RESULTS Two phenotypes were identified amongst 18 CMT1C patients: the classical CMT form ('CMT-like', 11 cases) and a predominantly sensory form ('sensory form', seven cases). The mean CMT neuropathy score was 4.45 in CMT1C patients. Motor nerve conduction velocities in the upper limbs were significantly more reduced in CMT1A than in CMT1C patients. On the other hand, the motor nerve conduction velocity of the median nerve was significantly lower in CMT1C compared to the HNPP group. Distal motor latency was significantly more prolonged in CMT1A patients compared to the CMT1C and HNPP groups, the latter two groups having similar distal motor latency values. Molecular analysis revealed five new LITAF/SIMPLE mutations (Ala111Thr, Gly112Ala, Trp116Arg, Pro135Leu, Arg160Cys). CONCLUSIONS Our study delineates CMT1C as mostly a mild form of neuropathy, and gives clinical and electrophysiological clues differentiating CMT1C from CMT1A and HNPP. Delineating phenotypes in CMT subtypes is important to orient molecular diagnosis and to help to interpret complex molecular findings.
Collapse
Affiliation(s)
- R Guimarães-Costa
- Centre de Référence des Maladies Neuromusculaires Paris Est, Institut de Myologie, Hôpital Pitié-Salpêtrière, Paris, France
| | - R Iancu Ferfoglia
- Centre de Référence des Maladies Neuromusculaires Paris Est, Institut de Myologie, Hôpital Pitié-Salpêtrière, Paris, France
| | - S Leonard-Louis
- Centre de Référence des Maladies Neuromusculaires Paris Est, Institut de Myologie, Hôpital Pitié-Salpêtrière, Paris, France
| | - F Ziegler
- Service de Neurologie, Centre Hospitalier Intercommunale de la Haute Saône, Vesoul, France
| | - L Magy
- Centre de Référence Neuropathies Périphérique Rares, CHU de Limoges - Hôpital Dupuytren, Limoges, France
| | - E Fournier
- Département de Neurophysiologie Clinique, Hôpital Pitié-Salpêtrière, Paris, France
| | - O Dubourg
- Centre de Référence des Maladies Neuromusculaires Paris Est, Institut de Myologie, Hôpital Pitié-Salpêtrière, Paris, France
| | - P Bouche
- Département de Neurophysiologie Clinique, Hôpital Pitié-Salpêtrière, Paris, France
| | - T Maisonobe
- Département de Neurophysiologie Clinique, Hôpital Pitié-Salpêtrière, Paris, France
| | - A Lacour
- Clinique Neurologique, Centre Hospitalier Universitaire de Lille, Lille, France
| | - A Moerman
- Département de Génétique Médicale, Hôpital Jeanne de Flandres, Centre Hospitalier Universitaire de Lille, Lille, France
| | - P Latour
- Service de Neurobiologie, Centre de Biologie et Pathologie Est, Centre Hospitalier Universitaire de Lyon HCL, GH Est, Lyon, France
| | - T Stojkovic
- Centre de Référence des Maladies Neuromusculaires Paris Est, Institut de Myologie, Hôpital Pitié-Salpêtrière, Paris, France
| |
Collapse
|
25
|
Haidar M, Timmerman V. Autophagy as an Emerging Common Pathomechanism in Inherited Peripheral Neuropathies. Front Mol Neurosci 2017; 10:143. [PMID: 28553203 PMCID: PMC5425483 DOI: 10.3389/fnmol.2017.00143] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 04/26/2017] [Indexed: 12/16/2022] Open
Abstract
The inherited peripheral neuropathies (IPNs) comprise a growing list of genetically heterogeneous diseases. With mutations in more than 80 genes being reported to cause IPNs, a wide spectrum of functional consequences is expected to follow this genotypic diversity. Hence, the search for a common pathomechanism among the different phenotypes has become the holy grail of functional research into IPNs. During the last decade, studies on several affected genes have shown a direct and/or indirect correlation with autophagy. Autophagy, a cellular homeostatic process, is required for the removal of cell aggregates, long-lived proteins and dead organelles from the cell in double-membraned vesicles destined for the lysosomes. As an evolutionarily highly conserved process, autophagy is essential for the survival and proper functioning of the cell. Recently, neuronal cells have been shown to be particularly vulnerable to disruption of the autophagic pathway. Furthermore, autophagy has been shown to be affected in various common neurodegenerative diseases of both the central and the peripheral nervous system including Alzheimer's, Parkinson's, and Huntington's diseases. In this review we provide an overview of the genes involved in hereditary neuropathies which are linked to autophagy and we propose the disruption of the autophagic flux as an emerging common pathomechanism. We also shed light on the different steps of the autophagy pathway linked to these genes. Finally, we review the concept of autophagy being a therapeutic target in IPNs, and the possibilities and challenges of this pathway-specific targeting.
Collapse
Affiliation(s)
- Mansour Haidar
- Peripheral Neuropathy Research Group, Institute Born Bunge, University of AntwerpAntwerpen, Belgium
| | - Vincent Timmerman
- Peripheral Neuropathy Research Group, Institute Born Bunge, University of AntwerpAntwerpen, Belgium
| |
Collapse
|
26
|
Jerath NU, Shy ME. Charcot-Marie-Tooth disease type 1C: Clinical and electrophysiological findings for the c.334G>a (p.Gly112Ser) Litaf/Simple mutation. Muscle Nerve 2017; 56:1092-1095. [PMID: 28164329 DOI: 10.1002/mus.25600] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/02/2017] [Indexed: 01/06/2023]
Abstract
INTRODUCTION Charcot-Marie-Tooth disease type 1C (CMT1C) is a rare, dominantly inherited neuropathy caused by mutations in the lipopolysaccharide-induced tumor necrosis factor (LITAF) or small integral membrane protein of the lysosome/late endosome (SIMPLE) gene. METHODS We present a case series comprised of 10 patients in whom CMT1C is caused by a Gly112Ser substitution in the encoded protein. We focus on clinical presentation, electrodiagnostic analyses, and our findings in the context of previously described cases. RESULTS The Gly112Ser mutation causing CMT1C is a mild form of CMT, as patients walked on time, had less weakness than those with Charcot-Marie-Tooth disease type 1A (CMT1A), had a CMT neuropathy score (CMTNS) indicative of mild disease, and had faster ulnar and median motor nerve conduction velocities compared to those with CMT1A. DISCUSSION The G112S mutation in LITAF seems to be clinically indistinguishable from a mild presentation of CMT1A. Muscle Nerve 56: 1092-1095, 2017.
Collapse
Affiliation(s)
- Nivedita U Jerath
- Department of Neurology, University of Iowa Carver College of Medicine, 200 Hawkins Drive, Iowa City, Iowa, 52242, USA
| | - Michael E Shy
- Department of Neurology, University of Iowa Carver College of Medicine, 200 Hawkins Drive, Iowa City, Iowa, 52242, USA
| |
Collapse
|
27
|
Huang D, He X, Zou J, Guo P, Jiang S, Lv N, Alekseyev Y, Luo L, Luo Z. Negative regulation of Bmi-1 by AMPK and implication in cancer progression. Oncotarget 2017; 7:6188-200. [PMID: 26717043 PMCID: PMC4868749 DOI: 10.18632/oncotarget.6748] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 11/15/2015] [Indexed: 12/31/2022] Open
Abstract
Bmi-1 is a transcriptional regulator that promotes tumor cell self-renewal and epithelial to mesenchymal transition and its upregulation is associated with tumor progression, AMPK is an intracellular fuel-sensing enzyme and plays important roles in tumor cell growth and progression. Thus, the present study aims to examine the regulation of Bmi-1 by AMPK. First, our data revealed that, as compared to adjacent normal tissue, Bmi-1 was highly expressed in gastric cancer, whereas phosphorylation of AMPK (p-AMPK) was reduced. Similar findings were observed in lung adenocarcinomas and appeared that the expression of Bmi-1 was correlated with pathological grades of the cancer, where opposite changes were found in p-AMPK. Second, Metformin, a pharmacological AMPK activator and anti-diabetic drug, or ectopic expression of LKB1, diminished expression of Bmi-1 in cancer cells, an event that was reversed by silencing LKB1. Third, knockdown of LITAF, previously identified as a downstream target of AMPK, upregulated Bmi-1, associated with increased cell viability, colony formation, and migration of cancer cells in vitro. Fourth, metformin increased the abundance of miR-15a, miR-128, miR-192, and miR-194, which was prevented by knockdown of LITAF. Accordingly, transfection of these individual miRNAs downregulated Bmi-1. Altogether, our data for the first time suggest a regulatory axis in cancer cells: AMPK upregulates LITAF, which in turn increases miRNAs, leading to attenuation of Bmi-1 expression.
Collapse
Affiliation(s)
- Deqiang Huang
- Research Institute of Digestive Diseases, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Xiaoling He
- Graduate Program, Jiangxi Medical College, Nanchang University, Nanchang, Jiangxi, P.R. China.,Institute of Basic Medical Sciences, Nanchang University, Nanchang, Jiangxi, P.R. China
| | - Junrong Zou
- Graduate Program, Jiangxi Medical College, Nanchang University, Nanchang, Jiangxi, P.R. China.,Institute of Basic Medical Sciences, Nanchang University, Nanchang, Jiangxi, P.R. China
| | - Pei Guo
- Graduate Program, Jiangxi Medical College, Nanchang University, Nanchang, Jiangxi, P.R. China.,Institute of Basic Medical Sciences, Nanchang University, Nanchang, Jiangxi, P.R. China
| | - Shanshan Jiang
- Graduate Program, Jiangxi Medical College, Nanchang University, Nanchang, Jiangxi, P.R. China.,Institute of Basic Medical Sciences, Nanchang University, Nanchang, Jiangxi, P.R. China
| | - Nonghua Lv
- Research Institute of Digestive Diseases, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Yuriy Alekseyev
- Departments of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, MA 02118, USA
| | - Lingyu Luo
- Research Institute of Digestive Diseases, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Zhijun Luo
- Institute of Basic Medical Sciences, Nanchang University, Nanchang, Jiangxi, P.R. China.,Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118, USA
| |
Collapse
|
28
|
Ho AK, Wagstaff JL, Manna PT, Wartosch L, Qamar S, Garman EF, Freund SMV, Roberts RC. The topology, structure and PE interaction of LITAF underpin a Charcot-Marie-Tooth disease type 1C. BMC Biol 2016; 14:109. [PMID: 27927196 PMCID: PMC5142333 DOI: 10.1186/s12915-016-0332-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 11/16/2016] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Mutations in Lipopolysaccharide-induced tumour necrosis factor-α factor (LITAF) cause the autosomal dominant inherited peripheral neuropathy, Charcot-Marie-Tooth disease type 1C (CMT1C). LITAF encodes a 17 kDa protein containing an N-terminal proline-rich region followed by an evolutionarily-conserved C-terminal 'LITAF domain', which contains all reported CMT1C-associated pathogenic mutations. RESULTS Here, we report the first structural characterisation of LITAF using biochemical, cell biological, biophysical and NMR spectroscopic approaches. Our structural model demonstrates that LITAF is a monotopic zinc-binding membrane protein that embeds into intracellular membranes via a predicted hydrophobic, in-plane, helical anchor located within the LITAF domain. We show that specific residues within the LITAF domain interact with phosphoethanolamine (PE) head groups, and that the introduction of the V144M CMT1C-associated pathogenic mutation leads to protein aggregation in the presence of PE. CONCLUSIONS In addition to the structural characterisation of LITAF, these data lead us to propose that an aberrant LITAF-PE interaction on the surface of intracellular membranes contributes to the molecular pathogenesis that underlies this currently incurable disease.
Collapse
Affiliation(s)
- Anita K Ho
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0XY, UK
| | - Jane L Wagstaff
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, CB2 0QH, UK
| | - Paul T Manna
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0XY, UK
| | - Lena Wartosch
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0XY, UK
| | - Seema Qamar
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0XY, UK
| | - Elspeth F Garman
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Stefan M V Freund
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, CB2 0QH, UK
| | - Rhys C Roberts
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0XY, UK.
| |
Collapse
|
29
|
PIG7 promotes leukemia cell chemosensitivity via lysosomal membrane permeabilization. Oncotarget 2016; 7:4841-59. [PMID: 26716897 PMCID: PMC4826247 DOI: 10.18632/oncotarget.6739] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 11/30/2015] [Indexed: 02/05/2023] Open
Abstract
PIG7 localizes to lysosomal membrane in leukemia cells. Our previous work has shown that transduction of pig7 into a series of leukemia cell lines did not result in either apoptosis or differentiation of most tested cell lines. Interestingly, it did significantly sensitize these cell lines to chemotherapeutic drugs. Here, we further investigated the mechanism underlying pig7-induced improved sensitivity of acute leukemia cells to chemotherapy. Our results demonstrated that the sensitization effect driven by exogenous pig7 was more effective in drug-resistant leukemia cell lines which had lower endogenous pig7 expression. Overexpression of pig7 did not directly activate the caspase apoptotic pathway, but decreased the lysosomal stability. The expression of pig7 resulted in lysosomal membrane permeabilization (LMP) and lysosomal protease (e.g. cathepsin B, D, L) release. Moreover, we also observed increased reactive oxygen species (ROS) and decreased mitochondrial membrane potential (ΔΨm) induced by pig7. Some autophagy markers such as LC3I/II, ATG5 and Beclin-1, and necroptosis maker MLKL were also stimulated. However, intrinsic antagonism such as serine/cysteine protease inhibitors Spi2A and Cystatin C prevented downstream effectors from triggering leukemia cells, which were only on the "verge of apoptosis". When combined with chemotherapy, LMP increased and more proteases were released. Once this process was beyond the limit of intrinsic antagonism, it induced programmed cell death cooperatively via caspase-independent and caspase-dependent pathways.
Collapse
|
30
|
Wang DW, Peng ZJ, Ren GF, Wang GX. The different roles of selective autophagic protein degradation in mammalian cells. Oncotarget 2016; 6:37098-116. [PMID: 26415220 PMCID: PMC4741918 DOI: 10.18632/oncotarget.5776] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 08/31/2015] [Indexed: 01/01/2023] Open
Abstract
Autophagy is an intracellular pathway for bulk protein degradation and the removal of damaged organelles by lysosomes. Autophagy was previously thought to be unselective; however, studies have increasingly confirmed that autophagy-mediated protein degradation is highly regulated. Abnormal autophagic protein degradation has been associated with multiple human diseases such as cancer, neurological disability and cardiovascular disease; therefore, further elucidation of protein degradation by autophagy may be beneficial for protein-based clinical therapies. Macroautophagy and chaperone-mediated autophagy (CMA) can both participate in selective protein degradation in mammalian cells, but the process is quite different in each case. Here, we summarize the various types of macroautophagy and CMA involved in determining protein degradation. For this summary, we divide the autophagic protein degradation pathways into four categories: the post-translational modification dependent and independent CMA pathways and the ubiquitin dependent and independent macroautophagy pathways, and describe how some non-canonical pathways and modifications such as phosphorylation, acetylation and arginylation can influence protein degradation by the autophagy lysosome system (ALS). Finally, we comment on why autophagy can serve as either diagnostics or therapeutic targets in different human diseases.
Collapse
Affiliation(s)
- Da-wei Wang
- Department of Biochemistry and Molecular Biology, School of Medicine, Shandong University, Jinan, Shandong, China
| | - Zhen-ju Peng
- Medical Institute of Paediatrics, Qilu Children's Hospital of Shandong University, Jinan, Shandong, China
| | - Guang-fang Ren
- Medical Institute of Paediatrics, Qilu Children's Hospital of Shandong University, Jinan, Shandong, China
| | - Guang-xin Wang
- Medical Institute of Paediatrics, Qilu Children's Hospital of Shandong University, Jinan, Shandong, China
| |
Collapse
|
31
|
The Charcot Marie Tooth disease protein LITAF is a zinc-binding monotopic membrane protein. Biochem J 2016; 473:3965-3978. [PMID: 27582497 PMCID: PMC5095921 DOI: 10.1042/bcj20160657] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 08/31/2016] [Indexed: 01/11/2023]
Abstract
LITAF (LPS-induced TNF-activating factor) is an endosome-associated integral membrane protein important for multivesicular body sorting. Several mutations in LITAF cause autosomal-dominant Charcot Marie Tooth disease type 1C. These mutations map to a highly conserved C-terminal region, termed the LITAF domain, which includes a 22 residue hydrophobic sequence and flanking cysteine-rich regions that contain peptide motifs found in zinc fingers. Although the LITAF domain is thought to be responsible for membrane integration, the membrane topology of LITAF has not been established. Here, we have investigated whether LITAF is a tail-anchored (TA) membrane-spanning protein or monotopic membrane protein. When translated in vitro, LITAF integrates poorly into ER-derived microsomes compared with Sec61β, a bona fide TA protein. Furthermore, introduction of N-linked glycosylation reporters shows that neither the N-terminal nor C-terminal domains of LITAF translocate into the ER lumen. Expression in cells of an LITAF construct containing C-terminal glycosylation sites confirms that LITAF is not a TA protein in cells. Finally, an immunofluorescence-based latency assay showed that both the N- and C-termini of LITAF are exposed to the cytoplasm. Recombinant LITAF contains 1 mol/mol zinc, while mutation of predicted zinc-binding residues disrupts LITAF membrane association. Hence, we conclude that LITAF is a monotopic membrane protein whose membrane integration is stabilised by a zinc finger. The related human protein, CDIP1 (cell death involved p53 target 1), displays identical membrane topology, suggesting that this mode of membrane integration is conserved in LITAF family proteins.
Collapse
|
32
|
Lu J, Wang H, Zhang Y, Li Y, Lu L. Grass carp reovirus NS26 interacts with cellular lipopolysaccharide-induced tumor necrosis factor-alpha factor, LITAF. Virus Genes 2016; 52:789-796. [PMID: 27405988 DOI: 10.1007/s11262-016-1370-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2016] [Accepted: 07/01/2016] [Indexed: 11/27/2022]
Abstract
The nonstructural protein NS26 of grass carp reovirus (GCRV) is encoded by the 11th genomic dsRNA segment, homolog of which is not found in orthoreoviruses. The role of NS26 in GCRV pathogenesis is still unclear. Previously, grass carp LITAF/SIMPLE protein was identified as a putative binding partner for NS26 in a yeast two-hybrid screen. Here, we further characterized the association between NS26 and LITAF using in vivo and in vitro protein interaction assays. Soluble GST-NS26 and His6-LITAF were expressed and purified from E. coli; recombinant NS26 tagged with myc and LITAF tagged with GFP were expressed in Ctenopharyngon idellus kidney cells (CIK) by transient transfection experiments. A GST pulldown assay demonstrated that GST-tagged NS26 efficiently bound to His6-LITAF. Co-immunoprecipitation assays demonstrated that GCRV NS26 reciprocally precipitated endogenous LITAF in CIK cells. Double-immunofluorescent analyses revealed myc-NS26 colocalized with GFP-LITAF in CIK cells. Taken together, the current in vitro and in vivo data demonstrated the interaction between cellular LITAF and GCRV NS26.
Collapse
Affiliation(s)
- Jianfei Lu
- Aquatic Pathogen Collection Center, MOA Key Laboratory of Freshwater Fishery Germplasm Resources, Shanghai Ocean University, Shanghai, 201306, China
| | - Hao Wang
- Aquatic Pathogen Collection Center, MOA Key Laboratory of Freshwater Fishery Germplasm Resources, Shanghai Ocean University, Shanghai, 201306, China
| | - Yanan Zhang
- Aquatic Pathogen Collection Center, MOA Key Laboratory of Freshwater Fishery Germplasm Resources, Shanghai Ocean University, Shanghai, 201306, China
| | - Yan Li
- Aquatic Pathogen Collection Center, MOA Key Laboratory of Freshwater Fishery Germplasm Resources, Shanghai Ocean University, Shanghai, 201306, China
| | - Liqun Lu
- Aquatic Pathogen Collection Center, MOA Key Laboratory of Freshwater Fishery Germplasm Resources, Shanghai Ocean University, Shanghai, 201306, China.
| |
Collapse
|
33
|
Yung C, Sha D, Li L, Chin LS. Parkin Protects Against Misfolded SOD1 Toxicity by Promoting Its Aggresome Formation and Autophagic Clearance. Mol Neurobiol 2015; 53:6270-6287. [PMID: 26563499 DOI: 10.1007/s12035-015-9537-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 11/08/2015] [Indexed: 12/11/2022]
Abstract
Mutations in Cu/Zn superoxide dismutase (SOD1) cause autosomal dominant amyotrophic lateral sclerosis (ALS), a devastating neurodegenerative disease with no effective treatment. Despite ample evidence indicating involvement of mutation-induced SOD1 protein misfolding and aggregation in ALS pathogenesis, the molecular mechanisms that control cellular management of misfolded, aggregation-prone SOD1 mutant proteins remain unclear. Here, we report that parkin, an E3 ubiquitin-protein ligase which is linked to Parkinson's disease, is a novel regulator of cellular defense against toxicity induced by ALS-associated SOD1 mutant proteins. We find that parkin mediates K63-linked polyubiquitination of SOD1 mutants in cooperation with the UbcH13/Uev1a E2 enzyme and promotes degradation of these misfolded SOD1 proteins by the autophagy-lysosome system. In response to strong proteotoxic stress associated with proteasome impairment, parkin promotes sequestration of misfolded and aggregated SOD1 proteins to form perinuclear aggresomes, regulates positioning of lysosomes around misfolded SOD1 aggresomes, and facilitates aggresome clearance by autophagy. Our findings reveal parkin-mediated cytoprotective mechanisms against misfolded SOD1 toxicity and suggest that enhancing parkin-mediated cytoprotection may provide a novel therapeutic strategy for treating ALS.
Collapse
Affiliation(s)
- Cheryl Yung
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Di Sha
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Lian Li
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Lih-Shen Chin
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, 30322, USA.
| |
Collapse
|
34
|
ZOU JUNRONG, GUO PEI, LV NONGHUA, HUANG DEQIANG. Lipopolysaccharide-induced tumor necrosis factor-α factor enhances inflammation and is associated with cancer (Review). Mol Med Rep 2015; 12:6399-404. [DOI: 10.3892/mmr.2015.4243] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Accepted: 06/03/2015] [Indexed: 11/06/2022] Open
|
35
|
Watson JA, Bhattacharyya BJ, Vaden JH, Wilson JA, Icyuz M, Howard AD, Phillips E, DeSilva TM, Siegal GP, Bean AJ, King GD, Phillips SE, Miller RJ, Wilson SM. Motor and Sensory Deficits in the teetering Mice Result from Mutation of the ESCRT Component HGS. PLoS Genet 2015; 11:e1005290. [PMID: 26115514 PMCID: PMC4482608 DOI: 10.1371/journal.pgen.1005290] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 05/18/2015] [Indexed: 11/18/2022] Open
Abstract
Neurons are particularly vulnerable to perturbations in endo-lysosomal transport, as several neurological disorders are caused by a primary deficit in this pathway. In this report, we used positional cloning to show that the spontaneously occurring neurological mutation teetering (tn) is a single nucleotide substitution in hepatocyte growth factor-regulated tyrosine kinase substrate (Hgs/Hrs), a component of the endosomal sorting complex required for transport (ESCRT). The tn mice exhibit hypokenesis, muscle weakness, reduced muscle size and early perinatal lethality by 5-weeks of age. Although HGS has been suggested to be essential for the sorting of ubiquitinated membrane proteins to the lysosome, there were no alterations in receptor tyrosine kinase levels in the central nervous system, and only a modest decrease in tropomyosin receptor kinase B (TrkB) in the sciatic nerves of the tn mice. Instead, loss of HGS resulted in structural alterations at the neuromuscular junction (NMJ), including swellings and ultra-terminal sprouting at motor axon terminals and an increase in the number of endosomes and multivesicular bodies. These structural changes were accompanied by a reduction in spontaneous and evoked release of acetylcholine, indicating a deficit in neurotransmitter release at the NMJ. These deficits in synaptic transmission were associated with elevated levels of ubiquitinated proteins in the synaptosome fraction. In addition to the deficits in neuronal function, mutation of Hgs resulted in both hypermyelinated and dysmyelinated axons in the tn mice, which supports a growing body of evidence that ESCRTs are required for proper myelination of peripheral nerves. Our results indicate that HGS has multiple roles in the nervous system and demonstrate a previously unanticipated requirement for ESCRTs in the maintenance of synaptic transmission. Endocytic trafficking involves the internalization, endosomal sorting and lysosomal degradation of cell surface cargo. Many factors involved in endosomal sorting in mammalian cells have been identified, and mutations in these components are associated with a variety of neurological disorders. While the function of endosomal sorting components has been intensely studied in immortalized cell lines, it is not known what role these factors play in endosomal sorting in the nervous system. In this study, we show that the teetering (tn) gene encodes the hepatocytegrowth factor regulated tyrosine kinasesubstrate (Hgs), a core component of the endosomal sorting pathway. The tn mice exhibit several signs of motor neuron disease, including reduced muscle mass, muscle weakness and motor abnormalities. Although HGS is predicted to be required for the lysosomal degradation of receptor tyrosine kinases, there was no change in the levels of receptor tyrosine kinases in the spinal cords of the tn mice. Instead, we found that HGS is required for synaptic transmission at the neuromuscular junction and for the proper myelination of the peripheral nervous system.
Collapse
Affiliation(s)
- Jennifer A. Watson
- Department of Neurobiology, University of Alabama at Birmingham, Evelyn F. McKnight Brain Institute, Civitan International Research Center, Birmingham, Alabama, United States of America
| | - Bula J. Bhattacharyya
- Department of Molecular Pharmacology and Biological Chemistry, Northwestern University, Evanston, Illinois, United States of America
| | - Jada H. Vaden
- Department of Neurobiology, University of Alabama at Birmingham, Evelyn F. McKnight Brain Institute, Civitan International Research Center, Birmingham, Alabama, United States of America
| | - Julie A. Wilson
- Department of Neurobiology, University of Alabama at Birmingham, Evelyn F. McKnight Brain Institute, Civitan International Research Center, Birmingham, Alabama, United States of America
| | - Mert Icyuz
- Department of Neurobiology, University of Alabama at Birmingham, Evelyn F. McKnight Brain Institute, Civitan International Research Center, Birmingham, Alabama, United States of America
- Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Alan D. Howard
- Department of Neurobiology, University of Alabama at Birmingham, Evelyn F. McKnight Brain Institute, Civitan International Research Center, Birmingham, Alabama, United States of America
| | - Edward Phillips
- Department of Neurobiology, University of Alabama at Birmingham, Evelyn F. McKnight Brain Institute, Civitan International Research Center, Birmingham, Alabama, United States of America
| | - Tara M. DeSilva
- Department of Physical Medicine and Rehabilitation, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Gene P. Siegal
- Departments of Pathology, Surgery and Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Andrew J. Bean
- Department of Neurobiology and Anatomy and Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston, Houston, Texas, United States of America
- Division of Pediatrics, The University of Texas M.D. Anderson Cancer Center, Houston, Texas, United States of America
| | - Gwendalyn D. King
- Department of Neurobiology, University of Alabama at Birmingham, Evelyn F. McKnight Brain Institute, Civitan International Research Center, Birmingham, Alabama, United States of America
| | - Scott E. Phillips
- Department of Neurobiology, University of Alabama at Birmingham, Evelyn F. McKnight Brain Institute, Civitan International Research Center, Birmingham, Alabama, United States of America
| | - Richard J. Miller
- Department of Molecular Pharmacology and Biological Chemistry, Northwestern University, Evanston, Illinois, United States of America
| | - Scott M. Wilson
- Department of Neurobiology, University of Alabama at Birmingham, Evelyn F. McKnight Brain Institute, Civitan International Research Center, Birmingham, Alabama, United States of America
- * E-mail:
| |
Collapse
|
36
|
Demyelinating CMT–what’s known, what’s new and what’s in store? Neurosci Lett 2015; 596:14-26. [DOI: 10.1016/j.neulet.2015.01.059] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 01/23/2015] [Indexed: 02/06/2023]
|
37
|
Igarashi M, Wada Y, Kojima Y, Miyado M, Nakamura M, Muroya K, Mizuno K, Hayashi Y, Nonomura K, Kohri K, Ogata T, Fukami M. Novel Splice Site Mutation in MAMLD1 in a Patient with Hypospadias. Sex Dev 2015; 9:130-5. [PMID: 25833151 DOI: 10.1159/000380842] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/30/2014] [Indexed: 11/19/2022] Open
Abstract
MAMLD1 is a causative gene for disorders of sex development. Several MAMLD1 mutations have been shown to cause hypospadias by generating dysfunctional proteins and/or unstable mRNAs. Here, we identified an intronic mutation of MAMLD1 (g.IVS4-2A>G) in 1 of 180 hypospadias patients. RT-PCR of the patient's skin sample showed normal expression of full-length MAMLD1 and markedly reduced expression of a known splice variant lacking exon 4. A hitherto unreported splice variant that lacks exon 5 was similarly identified in samples of the patient and control individuals. The full-length transcript of the patient contained mutant mRNA lacking the first 10 nucleotides of exon 5 (c.1822_1831delACTCATGTAG, p.K609fsX1070). In vitro assays using cells expressing the full-length wild-type and mutant proteins revealed reduced expression of the mutant. The expression of the wild-type and mutant MAMLD1 showed parallel changes upon treatment with a proteasome inhibitor and a translation inhibitor. The mutant-expressing cells exerted low transactivation activity for the Hes3 promoter, which reflected limited expression of the mutant protein. These results imply that the pathogenic events resulting from MAMLD1 mutations include splice errors. Furthermore, this study raises the possibility of translation failure of MAMLD1 mutants, which deserves further investigation.
Collapse
Affiliation(s)
- Maki Igarashi
- Department of Molecular Endocrinology, National Research Institute for Child Health and Development, Tokyo, Japan
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Murakami T, Sango K, Watabe K, Niimi N, Takaku S, Li Z, Yamamura KI, Sunada Y. Schwann cells contribute to neurodegeneration in transthyretin amyloidosis. J Neurochem 2015; 134:66-74. [DOI: 10.1111/jnc.13068] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Revised: 01/30/2015] [Accepted: 02/03/2015] [Indexed: 12/15/2022]
Affiliation(s)
| | - Kazunori Sango
- Department of Sensory and Motor Systems (ALS/Neuropathy Project); Tokyo Metropolitan Institute of Medical Science; Tokyo Japan
| | - Kazuhiko Watabe
- Department of Sensory and Motor Systems (ALS/Neuropathy Project); Tokyo Metropolitan Institute of Medical Science; Tokyo Japan
| | - Naoko Niimi
- Department of Sensory and Motor Systems (ALS/Neuropathy Project); Tokyo Metropolitan Institute of Medical Science; Tokyo Japan
| | - Shizuka Takaku
- Department of Sensory and Motor Systems (ALS/Neuropathy Project); Tokyo Metropolitan Institute of Medical Science; Tokyo Japan
| | - Zhenghua Li
- Division of Developmental Genetics; Institute of Resource Development and Analysis; Kumamoto University; Kumamoto Japan
| | - Ken-ichi Yamamura
- Division of Developmental Genetics; Institute of Resource Development and Analysis; Kumamoto University; Kumamoto Japan
| | - Yoshihide Sunada
- Department of Neurology; Kawasaki Medical School; Kurashiki Japan
| |
Collapse
|
39
|
Modeling protein misfolding in charcot-marie-tooth disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 820:91-102. [PMID: 25417019 DOI: 10.1007/978-3-319-09012-2_7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Charcot-Marie-Tooth (CMT) disease is the most common inherited neuromuscular disorder. Recent advancements in molecular biology have elucidated the molecular bases of this genetically heterogeneous neuropathy. Still, the major challenge lies in determining the individual contributions by malfunctions of proteins to the disease's pathology. This paper reviews the identified molecular mechanisms underlying major forms of CMT disease. A growing body of evidence has highlighted the role of protein misfolding in demyelinating peripheral neuropathies and neurodegenerative diseases. Several hypotheses have been proposed to explain how misfolded aggregates induce neuronal damage. Current research focuses on developing novel therapeutic targets which aim to prevent, or even reverse the formation of protein aggregation. Interestingly, the role of the cellular defence mechanisms against accumulation of misfolded proteins may play a key role leading to novel strategies for treatment accelerating the clearance of their toxic early aggregates. Based on these findings we propose a model for describing in terms of a formal computer language, the biomolecular processes involving proteins associated with CMT disease.
Collapse
|
40
|
McKeon JE, Sha D, Li L, Chin LS. Parkin-mediated K63-polyubiquitination targets ubiquitin C-terminal hydrolase L1 for degradation by the autophagy-lysosome system. Cell Mol Life Sci 2014; 72:1811-24. [PMID: 25403879 DOI: 10.1007/s00018-014-1781-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 11/04/2014] [Accepted: 11/13/2014] [Indexed: 11/24/2022]
Abstract
Ubiquitin C-terminal hydrolase L1 (UCH-L1) is a key neuronal deubiquitinating enzyme which is mutated in Parkinson disease (PD) and in childhood-onset neurodegenerative disorder with optic atrophy. Furthermore, reduced UCH-L1 protein levels are associated with a number of neurodegenerative diseases, whereas up-regulation of UCH-L1 protein expression is found in multiple types of cancer. However, very little is known about how UCH-L1 protein level is regulated in cells. Here, we report that UCH-L1 is a novel interactor and substrate of PD-linked E3 ubiquitin-protein ligase parkin. We find that parkin mediates K63-linked polyubiquitination of UCH-L1 in cooperation with the Ubc13/Uev1a E2 ubiquitin-conjugating enzyme complex and promotes UCH-L1 degradation by the autophagy-lysosome pathway. Targeted disruption of parkin gene expression in mice causes a significant decrease in UCH-L1 ubiquitination with a concomitant increase in UCH-L1 protein level in brain, supporting an in vivo role of parkin in regulating UCH-L1 ubiquitination and degradation. Our findings reveal a direct link between parkin-mediated ubiquitin signaling and UCH-L1 regulation, and they have important implications for understanding the roles of these two proteins in health and disease.
Collapse
Affiliation(s)
- Jeanne E McKeon
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | | | | | | |
Collapse
|
41
|
Potulska-Chromik A, Sinkiewicz-Darol E, Ryniewicz B, Lipowska M, Kabzińska D, Kochański A, Kostera-Pruszczyk A. Clinical, electrophysiological, and molecular findings in early onset hereditary neuropathy with liability to pressure palsy. Muscle Nerve 2014; 50:914-8. [DOI: 10.1002/mus.24250] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/21/2014] [Indexed: 01/11/2023]
Affiliation(s)
- Anna Potulska-Chromik
- Department of Neurology; Medical University of Warsaw; Banacha 1a Street 02-097 Warsaw Poland
| | - Elena Sinkiewicz-Darol
- Neuromuscular Unit, Mossakowski Medical Research Centre, Polish Academy of Sciences; Warsaw Poland
| | - Barbara Ryniewicz
- Department of Neurology; Medical University of Warsaw; Banacha 1a Street 02-097 Warsaw Poland
| | - Marta Lipowska
- Department of Neurology; Medical University of Warsaw; Banacha 1a Street 02-097 Warsaw Poland
| | - Dagmara Kabzińska
- Neuromuscular Unit, Mossakowski Medical Research Centre, Polish Academy of Sciences; Warsaw Poland
| | - Andrzej Kochański
- Neuromuscular Unit, Mossakowski Medical Research Centre, Polish Academy of Sciences; Warsaw Poland
| | - Anna Kostera-Pruszczyk
- Department of Neurology; Medical University of Warsaw; Banacha 1a Street 02-097 Warsaw Poland
| |
Collapse
|
42
|
Kumar CV, Swetha RG, Ramaiah S, Anbarasu A. Tryptophan to Glycine mutation in the position 116 leads to protein aggregation and decreases the stability of the LITAF protein. J Biomol Struct Dyn 2014; 33:1695-709. [DOI: 10.1080/07391102.2014.968211] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
43
|
Vaccari I, Carbone A, Previtali SC, Mironova YA, Alberizzi V, Noseda R, Rivellini C, Bianchi F, Del Carro U, D'Antonio M, Lenk GM, Wrabetz L, Giger RJ, Meisler MH, Bolino A. Loss of Fig4 in both Schwann cells and motor neurons contributes to CMT4J neuropathy. Hum Mol Genet 2014; 24:383-96. [PMID: 25187576 PMCID: PMC4275070 DOI: 10.1093/hmg/ddu451] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Mutations of FIG4 are responsible for Yunis-Varón syndrome, familial epilepsy with polymicrogyria, and Charcot-Marie-Tooth type 4J neuropathy (CMT4J). Although loss of the FIG4 phospholipid phosphatase consistently causes decreased PtdIns(3,5)P2 levels, cell-specific sensitivity to partial loss of FIG4 function may differentiate FIG4-associated disorders. CMT4J is an autosomal recessive neuropathy characterized by severe demyelination and axonal loss in human, with both motor and sensory involvement. However, it is unclear whether FIG4 has cell autonomous roles in both motor neurons and Schwann cells, and how loss of FIG4/PtdIns(3,5)P2-mediated functions contribute to the pathogenesis of CMT4J. Here, we report that mice with conditional inactivation of Fig4 in motor neurons display neuronal and axonal degeneration. In contrast, conditional inactivation of Fig4 in Schwann cells causes demyelination and defects in autophagy-mediated degradation. Moreover, Fig4-regulated endolysosomal trafficking in Schwann cells is essential for myelin biogenesis during development and for proper regeneration/remyelination after injury. Our data suggest that impaired endolysosomal trafficking in both motor neurons and Schwann cells contributes to CMT4J neuropathy.
Collapse
Affiliation(s)
- Ilaria Vaccari
- Division of Neuroscience, INSPE-Institute of Experimental Neurology
| | | | - Stefano Carlo Previtali
- Division of Neuroscience, INSPE-Institute of Experimental Neurology Department of Neurology and
| | | | | | - Roberta Noseda
- Division of Neuroscience, INSPE-Institute of Experimental Neurology
| | | | - Francesca Bianchi
- Division of Neuroscience, INSPE-Institute of Experimental Neurology Department of Neurology and
| | - Ubaldo Del Carro
- Division of Neuroscience, INSPE-Institute of Experimental Neurology Department of Neurology and
| | - Maurizio D'Antonio
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milan, Italy
| | - Guy M Lenk
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109, USA and
| | - Lawrence Wrabetz
- Hunter James Kelly Research Institute, State University of New York, Buffalo, NY 14203, USA
| | | | - Miriam H Meisler
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109, USA and
| | | |
Collapse
|
44
|
Ferreira Lacerda A, Hartjes E, Brunetti CR. LITAF mutations associated with Charcot-Marie-Tooth disease 1C show mislocalization from the late endosome/lysosome to the mitochondria. PLoS One 2014; 9:e103454. [PMID: 25058650 PMCID: PMC4110028 DOI: 10.1371/journal.pone.0103454] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Accepted: 07/02/2014] [Indexed: 01/01/2023] Open
Abstract
Charcot-Marie-Tooth (CMT) disease is one of the most common heritable neuromuscular disorders, affecting 1 in every 2500 people. Mutations in LITAF have been shown to be causative for CMT type 1C disease. In this paper we explore the subcellular localization of wild type LITAF and mutant forms of LITAF known to cause CMT1C (T49M, A111G, G112S, T115N, W116G, L122V and P135T). The results show that LITAF mutants A111G, G112S, W116G, and T115N mislocalize from the late endosome/lysosome to the mitochondria while the mutants T49M, L122V, and P135T show partial mislocalization with a portion of the total protein present in the late endosome/lysosome and the remainder of the protein localized to the mitochondria. This suggests that different mutants of LITAF will produce differing severity of disease. We also explored the effect of the presence of mutant LITAF on wild-type LITAF localization. We showed that in cells heterozygous for LITAF, CMT1C mutants T49M and G112S are dominant since wild-type LITAF localized to the mitochondria when co-transfected with a LITAF mutant. Finally, we demonstrated how LITAF transits to the endosome and mitochondria compartments of the cell. Using Brefeldin A to block ER to Golgi transport we demonstrated that wild type LITAF traffics through the secretory pathway to the late endosome/lysosome while the LITAF mutants transit to the mitochondria independent of the secretory pathway. In addition, we demonstrated that the C-terminus of LITAF is necessary and sufficient for targeting of wild-type LITAF to the late endosome/lysosome and the mutants to the mitochondria. Together these data provide insight into how mutations in LITAF cause CMT1C disease.
Collapse
Affiliation(s)
| | - Emily Hartjes
- Biology Department, Trent University, Peterborough, Ontario, Canada
| | - Craig R. Brunetti
- Biology Department, Trent University, Peterborough, Ontario, Canada
- * E-mail:
| |
Collapse
|
45
|
Rebhandl S, Huemer M, Zaborsky N, Gassner FJ, Catakovic K, Felder TK, Greil R, Geisberger R. Alternative splice variants of AID are not stoichiometrically present at the protein level in chronic lymphocytic leukemia. Eur J Immunol 2014; 44:2175-87. [PMID: 24668151 PMCID: PMC4209801 DOI: 10.1002/eji.201343853] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 02/03/2014] [Accepted: 03/11/2014] [Indexed: 11/11/2022]
Abstract
Activation-induced deaminase (AID) is a DNA-mutating enzyme that mediates class-switch recombination as well as somatic hypermutation of antibody genes in B cells. Due to off-target activity, AID is implicated in lymphoma development by introducing genome-wide DNA damage and initiating chromosomal translocations such as c-myc/IgH. Several alternative splice transcripts of AID have been reported in activated B cells as well as malignant B cells such as chronic lymphocytic leukemia (CLL). As most commercially available antibodies fail to recognize alternative splice variants, their abundance in vivo, and hence their biological significance, has not been determined. In this study, we assessed the protein levels of AID splice isoforms by introducing an AID splice reporter construct into cell lines and primary CLL cells from patients as well as from WT and TCL1tg C57BL/6 mice (where TCL1 is T-cell leukemia/lymphoma 1). The splice construct is 5′-fused to a GFP-tag, which is preserved in all splice isoforms and allows detection of translated protein. Summarizing, we show a thorough quantification of alternatively spliced AID transcripts and demonstrate that the corresponding protein abundances, especially those of splice variants AID-ivs3 and AID-ΔE4, are not stoichiometrically equivalent. Our data suggest that enhanced proteasomal degradation of low-abundance proteins might be causative for this discrepancy.
Collapse
Affiliation(s)
- Stefan Rebhandl
- Laboratory for Immunological and Molecular Cancer Research, Department of Internal Medicine III with Hematology, Medical Oncology, Hemostaseology, Infectious Diseases, Rheumatology, Oncologic Center, Paracelsus Medical University, Salzburg, Austria
| | | | | | | | | | | | | | | |
Collapse
|
46
|
Neefjes J, van der Kant R. Stuck in traffic: an emerging theme in diseases of the nervous system. Trends Neurosci 2014; 37:66-76. [PMID: 24411104 DOI: 10.1016/j.tins.2013.11.006] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 11/25/2013] [Accepted: 11/27/2013] [Indexed: 12/11/2022]
Abstract
The past decade has seen an explosion of DNA sequencing activities and many mutations and genetic variances underlying neurological and neurodegenerative diseases have been determined. This wealth of genetic data is now placed in molecular pathways revealing the nodes that underlie the disrupted processes. Many mutations in neurological diseases affect proteins controlling endosomal/lysosomal transport. Although the age of onset of these diseases range from juvenile [i.e., Niemann-Pick type C (NPC) and Charcot-Marie-Tooth (CMT) disease] to late onset (Parkinson's and Alzheimer's disease), deregulation of endosomal transport is a common theme. This review summarizes how elucidating the genetic basis for the various neurological diseases has advanced our understanding of the endo-lysosomal system and why the various mutations all translate into similar disease phenotypes.
Collapse
Affiliation(s)
- Jacques Neefjes
- Division of Cell Biology, Netherlands Cancer Institute, 1066CX Amsterdam, The Netherlands.
| | - Rik van der Kant
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California 92093, USA.
| |
Collapse
|
47
|
Marinelli S, Nazio F, Tinari A, Ciarlo L, D'Amelio M, Pieroni L, Vacca V, Urbani A, Cecconi F, Malorni W, Pavone F. Schwann cell autophagy counteracts the onset and chronification of neuropathic pain. Pain 2014; 155:93-107. [DOI: 10.1016/j.pain.2013.09.013] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 09/10/2013] [Accepted: 09/10/2013] [Indexed: 11/24/2022]
|
48
|
Bouhy D, Timmerman V. Animal models and therapeutic prospects for Charcot-Marie-Tooth disease. Ann Neurol 2013; 74:391-6. [PMID: 23913540 DOI: 10.1002/ana.23987] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 07/04/2013] [Accepted: 07/29/2013] [Indexed: 12/14/2022]
Abstract
Charcot-Marie-Tooth (CMT) neuropathies are inherited neuromuscular disorders caused by a length-dependent neurodegeneration of peripheral nerves. More than 900 mutations in 60 different genes are causative of the neuropathy. Despite significant progress in therapeutic strategies, the disease remains incurable. The increasing number of genes linked to the disease, and their considerable clinical and genetic heterogeneity render the development of these strategies particularly challenging. In this context, cellular and animals models provide powerful tools. Efficient motor and sensory tests have been developed to assess the behavioral phenotype in transgenic animal models (rodent and fly). When these models reproduce a phenotype comparable to CMT, they allow therapeutic approaches and the discovery of modifiers and biomarkers. In this review, we describe the most convincing transgenic rodent and fly models of CMT and how they can lead to clinical trial. We also discuss the challenges that the research, the clinic, and the pharmaceutical industry will face in developing efficient and accessible treatment for CMT patients.
Collapse
Affiliation(s)
- Delphine Bouhy
- Peripheral Neuropathy Group, Department of Molecular Genetics, Flanders Interuniversity Institute for Biotechnology, Institute Born Bunge, University of Antwerp, Antwerp, Belgium
| | | |
Collapse
|
49
|
Sharma M, Burré J, Südhof TC. Proteasome inhibition alleviates SNARE-dependent neurodegeneration. Sci Transl Med 2013; 4:147ra113. [PMID: 22896677 DOI: 10.1126/scitranslmed.3004028] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Activation of the proteasomal degradation of misfolded proteins has been proposed as a therapeutic strategy for treating neurodegenerative diseases, but it is unclear whether proteasome dysfunction contributes to neurodegeneration. We tested the role of proteasome activity in neurodegeneration developed by mice lacking cysteine string protein-α (CSPα). Unexpectedly, we found that proteasome inhibitors alleviated neurodegeneration in CSPα-deficient mice, reversing impairment of SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor)-complex assembly and extending life span. We tested whether dysfunctional SNARE-complex assembly could contribute to neurodegeneration in Alzheimer's and Parkinson's disease by analyzing postmortem brain tissue from these patients; we found reduced SNARE-complex assembly in the brain tissue samples. Our results suggest that proteasomal activation may not always be beneficial for alleviating neurodegeneration and that blocking the proteasome may represent a potential therapeutic avenue for treating some forms of neurodegenerative disease.
Collapse
Affiliation(s)
- Manu Sharma
- Department of Molecular and Cellular Physiology, and Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305-5453, USA.
| | | | | |
Collapse
|
50
|
Bogdanik LP, Sleigh JN, Tian C, Samuels ME, Bedard K, Seburn KL, Burgess RW. Loss of the E3 ubiquitin ligase LRSAM1 sensitizes peripheral axons to degeneration in a mouse model of Charcot-Marie-Tooth disease. Dis Model Mech 2013; 6:780-92. [PMID: 23519028 PMCID: PMC3634660 DOI: 10.1242/dmm.010942] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Accepted: 03/06/2013] [Indexed: 01/08/2023] Open
Abstract
Charcot-Marie-Tooth disease (CMT) is a clinically and genetically heterogeneous condition characterized by peripheral axon degeneration with subsequent motor and sensory deficits. Several CMT gene products function in endosomal sorting and trafficking to the lysosome, suggesting that defects in this cellular pathway might present a common pathogenic mechanism for these conditions. LRSAM1 is an E3 ubiquitin ligase that is implicated in this process, and mutations in LRSAM1 have recently been shown to cause CMT. We have generated mouse mutations in Lrsam1 to create an animal model of this form of CMT (CMT2P). Mouse Lrsam1 is abundantly expressed in the motor and sensory neurons of the peripheral nervous system. Both homozygous and heterozygous mice have largely normal neuromuscular performance and only a very mild neuropathy phenotype with age. However, Lrsam1 mutant mice are more sensitive to challenge with acrylamide, a neurotoxic agent that causes axon degeneration, indicating that the axons in the mutant mice are indeed compromised. In transfected cells, LRSAM1 primarily localizes in a perinuclear compartment immediately beyond the Golgi and shows little colocalization with components of the endosome to lysosome trafficking pathway, suggesting that other cellular mechanisms also merit consideration.
Collapse
Affiliation(s)
| | - James N. Sleigh
- The Jackson Laboratory, Bar Harbor, ME, 04609, USA
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, OX1 3QX, UK
| | - Cong Tian
- The Jackson Laboratory, Bar Harbor, ME, 04609, USA
- Graduate School of Biomedical Sciences, The University of Maine, Orono, ME 04469, USA
| | - Mark E. Samuels
- Department of Medicine, Montreal University, Montreal, Quebec, H3T 1C5, Canada
| | - Karen Bedard
- Department of Pathology, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada
| | | | - Robert W. Burgess
- The Jackson Laboratory, Bar Harbor, ME, 04609, USA
- Graduate School of Biomedical Sciences, The University of Maine, Orono, ME 04469, USA
| |
Collapse
|