1
|
Vinci M, Vitello GA, Greco D, Treccarichi S, Ragalmuto A, Musumeci A, Fallea A, Federico C, Calì F, Saccone S, Elia M. Next Generation Sequencing and Electromyography Reveal the Involvement of the P2RX6 Gene in Myopathy. Curr Issues Mol Biol 2024; 46:1150-1163. [PMID: 38392191 PMCID: PMC10887510 DOI: 10.3390/cimb46020073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 01/18/2024] [Accepted: 01/26/2024] [Indexed: 02/24/2024] Open
Abstract
Ion channelopathies result from impaired ion channel protein function, due to mutations affecting ion transport across cell membranes. Over 40 diseases, including neuropathy, pain, migraine, epilepsy, and ataxia, are associated with ion channelopathies, impacting electrically excitable tissues and significantly affecting skeletal muscle. Gene mutations affecting transmembrane ionic flow are strongly linked to skeletal muscle disorders, particularly myopathies, disrupting muscle excitability and contraction. Electromyography (EMG) analysis performed on a patient who complained of weakness and fatigue revealed the presence of primary muscular damage, suggesting an early-stage myopathy. Whole exome sequencing (WES) did not detect potentially causative variants in known myopathy-associated genes but revealed a novel homozygous deletion of the P2RX6 gene likely disrupting protein function. The P2RX6 gene, predominantly expressed in skeletal muscle, is an ATP-gated ion channel receptor belonging to the purinergic receptors (P2RX) family. In addition, STRING pathways suggested a correlation with more proteins having a plausible role in myopathy. No previous studies have reported the implication of this gene in myopathy. Further studies are needed on patients with a defective ion channel pathway, and the use of in vitro functional assays in suppressing P2RX6 gene expression will be required to validate its functional role.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - Concetta Federico
- Department of Biological, Geological and Environmental Sciences, University of Catania, Via Androne 81, 95124 Catania, Italy
| | | | - Salvatore Saccone
- Department of Biological, Geological and Environmental Sciences, University of Catania, Via Androne 81, 95124 Catania, Italy
| | | |
Collapse
|
2
|
Melnyk A, Lang S, Sicking M, Zimmermann R, Jung M. Co-chaperones of the Human Endoplasmic Reticulum: An Update. Subcell Biochem 2023; 101:247-291. [PMID: 36520310 DOI: 10.1007/978-3-031-14740-1_9] [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] [Indexed: 06/17/2023]
Abstract
In mammalian cells, the rough endoplasmic reticulum (ER) plays central roles in the biogenesis of extracellular plus organellar proteins and in various signal transduction pathways. For these reasons, the ER comprises molecular chaperones, which are involved in import, folding, assembly, export, plus degradation of polypeptides, and signal transduction components, such as calcium channels, calcium pumps, and UPR transducers plus adenine nucleotide carriers/exchangers in the ER membrane. The calcium- and ATP-dependent ER lumenal Hsp70, termed immunoglobulin heavy-chain-binding protein or BiP, is the central player in all these activities and involves up to nine different Hsp40-type co-chaperones, i.e., ER membrane integrated as well as ER lumenal J-domain proteins, termed ERj or ERdj proteins, two nucleotide exchange factors or NEFs (Grp170 and Sil1), and NEF-antagonists, such as MANF. Here we summarize the current knowledge on the ER-resident BiP/ERj chaperone network and focus on the interaction of BiP with the polypeptide-conducting and calcium-permeable Sec61 channel of the ER membrane as an example for BiP action and how its functional cycle is linked to ER protein import and various calcium-dependent signal transduction pathways.
Collapse
Affiliation(s)
- Armin Melnyk
- Medical Biochemistry & Molecular Biology, Saarland University, Homburg, Germany
| | - Sven Lang
- Medical Biochemistry & Molecular Biology, Saarland University, Homburg, Germany
| | - Mark Sicking
- Medical Biochemistry & Molecular Biology, Saarland University, Homburg, Germany
| | - Richard Zimmermann
- Medical Biochemistry & Molecular Biology, Saarland University, Homburg, Germany.
| | - Martin Jung
- Medical Biochemistry & Molecular Biology, Saarland University, Homburg, Germany
| |
Collapse
|
3
|
Sun H, Wu M, Wang M, Zhang X, Zhu J. The regulatory role of endoplasmic reticulum chaperone proteins in neurodevelopment. Front Neurosci 2022; 16:1032607. [DOI: 10.3389/fnins.2022.1032607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 10/25/2022] [Indexed: 11/16/2022] Open
Abstract
The endoplasmic reticulum (ER) is the largest tubular reticular organelle spanning the cell. As the main site of protein synthesis, Ca2+ homeostasis maintenance and lipid metabolism, the ER plays a variety of essential roles in eukaryotic cells, with ER molecular chaperones participate in all these processes. In recent years, it has been reported that the abnormal expression of ER chaperones often leads to a variety of neurodevelopmental disorders (NDDs), including abnormal neuronal migration, neuronal morphogenesis, and synaptic function. Neuronal development is a complex and precisely regulated process. Currently, the mechanism by which neural development is regulated at the ER level remains under investigation. Therefore, in this work, we reviewed the recent advances in the roles of ER chaperones in neural development and developmental disorders caused by the deficiency of these molecular chaperones.
Collapse
|
4
|
Preusse C, Marteau T, Fischer N, Hentschel A, Sickmann A, Lang S, Schneider U, Schara-Schmidt U, Meyer N, Ruck T, Dengler NF, Prudlo J, Dudesek A, Görl N, Allenbach Y, Benveniste O, Goebel HH, Dittmayer C, Stenzel W, Roos A. Endoplasmic reticulum-stress and unfolded protein response-activation in immune-mediated necrotizing myopathy. Brain Pathol 2022; 32:e13084. [PMID: 35703068 DOI: 10.1111/bpa.13084] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 05/12/2022] [Indexed: 12/13/2022] Open
Abstract
Patients suffering from immune-mediated necrotizing myopathies (IMNM) harbor, the pathognomonic myositis-specific auto-antibodies anti-SRP54 or -HMGCR, while about one third of them do not. Activation of chaperone-assisted autophagy was described as being part of the molecular etiology of IMNM. Endoplasmic reticulum (ER)/sarcoplasmic reticulum (SR)-stress accompanied by activation of the unfolded protein response (UPR) often precedes activation of the protein clearance machinery and represents a cellular defense mechanism toward restoration of proteostasis. Here, we show that ER/SR-stress may be part of the molecular etiology of IMNM. To address this assumption, ER/SR-stress related key players covering the three known branches (PERK-mediated, IRE1-mediated, and ATF6-mediated) were investigated on both, the transcript and the protein levels utilizing 39 muscle biopsy specimens derived from IMNM-patients. Our results demonstrate an activation of all three UPR-branches in IMNM, which most likely precedes the activation of the protein clearance machinery. In detail, we identified increased phosphorylation of PERK and eIF2a along with increased expression and protein abundance of ATF4, all well-documented characteristics for the activation of the UPR. Further, we identified increased general XBP1-level, and elevated XBP1 protein levels. Additionally, our transcript studies revealed an increased ATF6-expression, which was confirmed by immunostaining studies indicating a myonuclear translocation of the cleaved ATF6-form toward the forced transcription of UPR-related chaperones. In accordance with that, our data demonstrate an increase of downstream factors including ER/SR co-chaperones and chaperones (e.g., SIL1) indicating an UPR-activation on a broader level with no significant differences between seropositive and seronegative patients. Taken together, one might assume that UPR-activation within muscle fibers might not only serve to restore protein homeostasis, but also enhance sarcolemmal presentation of proteins crucial for attracting immune cells. Since modulation of ER-stress and UPR via application of chemical chaperones became a promising therapeutic treatment approach, our findings might represent the starting point for new interventional concepts.
Collapse
Affiliation(s)
- Corinna Preusse
- Department of Neuropathology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.,Department of Neurology with Institute for Translational Neurology, University Hospital Münster, Münster, Germany
| | - Theodore Marteau
- Pediatric Neurology, University Children's Hospital, Faculty of Medicine, University of Duisburg-Essen, Essen, Germany
| | - Norina Fischer
- Department of Neuropathology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Andreas Hentschel
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V, Dortmund, Germany
| | - Albert Sickmann
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V, Dortmund, Germany
| | - Sven Lang
- Department of Medical Biochemistry and Molecular Biology, Saarland University, Homburg, Germany
| | - Udo Schneider
- Department of Rheumatology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Ulrike Schara-Schmidt
- Pediatric Neurology, University Children's Hospital, Faculty of Medicine, University of Duisburg-Essen, Essen, Germany
| | - Nancy Meyer
- Pediatric Neurology, University Children's Hospital, Faculty of Medicine, University of Duisburg-Essen, Essen, Germany
| | - Tobias Ruck
- Department of Neurology, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
| | - Nora F Dengler
- Department of Neurosurgery, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Johannes Prudlo
- Department of Neurology, Rostock University Medical Center, Rostock, Germany.,German Center for Neurodegenerative Diseases (DZNE) Rostock/Greifswald, Rostock, Germany.,Department of Neurology, University of Rostock, Rostock, Germany
| | - Ales Dudesek
- Department of Neurology, Rostock University Medical Center, Rostock, Germany
| | - Norman Görl
- Department of Internal Medicine, Klinikum Südstadt Rostock, Rostock, Germany
| | - Yves Allenbach
- Department of Internal Medicine and Clinical Immunology, Sorbonne Université, APHP, Pitié-Salpêtrière University Hospital, Paris, France
| | - Olivier Benveniste
- Department of Internal Medicine and Clinical Immunology, Sorbonne Université, APHP, Pitié-Salpêtrière University Hospital, Paris, France
| | - Hans-Hilmar Goebel
- Department of Neuropathology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.,Department of Neuropathology, University Hospital Mainz, Mainz, Germany
| | - Carsten Dittmayer
- Department of Neuropathology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Werner Stenzel
- Department of Neuropathology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Andreas Roos
- Pediatric Neurology, University Children's Hospital, Faculty of Medicine, University of Duisburg-Essen, Essen, Germany.,Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
| |
Collapse
|
5
|
Zhao H, Ji Q, Wu Z, Wang S, Ren J, Yan K, Wang Z, Hu J, Chu Q, Hu H, Cai Y, Wang Q, Huang D, Ji Z, Li J, Belmonte JCI, Song M, Zhang W, Qu J, Liu GH. Destabilizing heterochromatin by APOE mediates senescence. NATURE AGING 2022; 2:303-316. [PMID: 35368774 DOI: 10.1038/s43587-022-00186-z] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 02/01/2022] [Indexed: 04/30/2023]
Abstract
Apolipoprotein E (APOE) is a component of lipoprotein particles that function in the homeostasis of cholesterol and other lipids. Although APOE is genetically associated with human longevity and Alzheimer's disease, its mechanistic role in aging is largely unknown. Here, we used human genetic, stress-induced and physiological cellular aging models to explore APOE-driven processes in stem cell homeostasis and aging. We report that in aged human mesenchymal progenitor cells (MPCs), APOE accumulation is a driver for cellular senescence. By contrast, CRISPR-Cas9-mediated deletion of APOE endows human MPCs with resistance to cellular senescence. Mechanistically, we discovered that APOE functions as a destabilizer for heterochromatin. Specifically, increased APOE leads to the degradation of nuclear lamina proteins and a heterochromatin-associated protein KRAB-associated protein 1 via the autophagy-lysosomal pathway, thereby disrupting heterochromatin and causing senescence. Altogether, our findings uncover a role of APOE as an epigenetic mediator of senescence and provide potential targets to ameliorate aging-related diseases.
Collapse
Affiliation(s)
- Hongkai Zhao
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Science and Technology of China, Hefei, China
| | - Qianzhao Ji
- University of the Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Zeming Wu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, China
| | - Si Wang
- Advanced Innovation Center for Human Brain Protection, National Clinical Research Center for Geriatric Disorders, Xuanwu Hospital, Capital Medical University, Beijing, China
- Chongqing Renji Hospital, University of the Chinese Academy of Sciences, Chongqing, China
| | - Jie Ren
- University of the Chinese Academy of Sciences, Beijing, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
- Chinese Academy of Sciences Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
- China National Center for Bioinformation, Beijing, China
| | - Kaowen Yan
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, China
| | - Zehua Wang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of the Chinese Academy of Sciences, Beijing, China
| | - Jianli Hu
- University of the Chinese Academy of Sciences, Beijing, China
- Chinese Academy of Sciences Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
- China National Center for Bioinformation, Beijing, China
| | - Qun Chu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, China
| | - Huifang Hu
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, China
| | - Yusheng Cai
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, China
| | - Qiaoran Wang
- University of the Chinese Academy of Sciences, Beijing, China
- Chinese Academy of Sciences Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
- China National Center for Bioinformation, Beijing, China
| | - Daoyuan Huang
- Advanced Innovation Center for Human Brain Protection, National Clinical Research Center for Geriatric Disorders, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Zhejun Ji
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, China
| | - Jingyi Li
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, China
| | | | - Moshi Song
- University of the Chinese Academy of Sciences, Beijing, China.
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China.
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, China.
| | - Weiqi Zhang
- University of the Chinese Academy of Sciences, Beijing, China.
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China.
- Chinese Academy of Sciences Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China.
- China National Center for Bioinformation, Beijing, China.
| | - Jing Qu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
- University of Science and Technology of China, Hefei, China.
- University of the Chinese Academy of Sciences, Beijing, China.
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China.
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, China.
| | - Guang-Hui Liu
- University of the Chinese Academy of Sciences, Beijing, China.
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China.
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, China.
- Advanced Innovation Center for Human Brain Protection, National Clinical Research Center for Geriatric Disorders, Xuanwu Hospital, Capital Medical University, Beijing, China.
- Aging Translational Medicine Center, International Center for Aging and Cancer, Xuanwu Hospital, Capital Medical University, Beijing, China.
| |
Collapse
|
6
|
Potenza F, Cufaro MC, Di Biase L, Panella V, Di Campli A, Ruggieri AG, Dufrusine B, Restelli E, Pietrangelo L, Protasi F, Pieragostino D, De Laurenzi V, Federici L, Chiesa R, Sallese M. Proteomic Analysis of Marinesco-Sjogren Syndrome Fibroblasts Indicates Pro-Survival Metabolic Adaptation to SIL1 Loss. Int J Mol Sci 2021; 22:12449. [PMID: 34830330 PMCID: PMC8620507 DOI: 10.3390/ijms222212449] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 11/15/2021] [Accepted: 11/16/2021] [Indexed: 12/23/2022] Open
Abstract
Marinesco-Sjogren syndrome (MSS) is a rare multisystem pediatric disorder, caused by loss-of-function mutations in the gene encoding the endoplasmic reticulum cochaperone SIL1. SIL1 acts as a nucleotide exchange factor for BiP, which plays a central role in secretory protein folding. SIL1 mutant cells have reduced BiP-assisted protein folding, cannot fulfil their protein needs, and experience chronic activation of the unfolded protein response (UPR). Maladaptive UPR may explain the cerebellar and skeletal muscle degeneration responsible for the ataxia and muscle weakness typical of MSS. However, the cause of other more variable, clinical manifestations, such as mild to severe mental retardation, hypogonadism, short stature, and skeletal deformities, is less clear. To gain insights into the pathogenic mechanisms and/or adaptive responses to SIL1 loss, we carried out cell biological and proteomic investigations in skin fibroblasts derived from a young patient carrying the SIL1 R111X mutation. Despite fibroblasts not being overtly affected in MSS, we found morphological and biochemical changes indicative of UPR activation and altered cell metabolism. All the cell machineries involved in RNA splicing and translation were strongly downregulated, while protein degradation via lysosome-based structures was boosted, consistent with an attempt of the cell to reduce the workload of the endoplasmic reticulum and dispose of misfolded proteins. Cell metabolism was extensively affected as we observed a reduction in lipid synthesis, an increase in beta oxidation, and an enhancement of the tricarboxylic acid cycle, with upregulation of eight of its enzymes. Finally, the catabolic pathways of various amino acids, including valine, leucine, isoleucine, tryptophan, lysine, aspartate, and phenylalanine, were enhanced, while the biosynthetic pathways of arginine, serine, glycine, and cysteine were reduced. These results indicate that, in addition to UPR activation and increased protein degradation, MSS fibroblasts have profound metabolic alterations, which may help them cope with the absence of SIL1.
Collapse
Affiliation(s)
- Francesca Potenza
- Department of Innovative Technologies in Medicine and Dentistry, “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (F.P.); (L.D.B.); (A.G.R.); (B.D.); (D.P.); (V.D.L.); (L.F.)
- Center for Advanced Studies and Technology (CAST), “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (M.C.C.); (A.D.C.); (L.P.); (F.P.)
| | - Maria Concetta Cufaro
- Center for Advanced Studies and Technology (CAST), “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (M.C.C.); (A.D.C.); (L.P.); (F.P.)
- Department of Pharmacy, “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy
| | - Linda Di Biase
- Department of Innovative Technologies in Medicine and Dentistry, “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (F.P.); (L.D.B.); (A.G.R.); (B.D.); (D.P.); (V.D.L.); (L.F.)
- Center for Advanced Studies and Technology (CAST), “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (M.C.C.); (A.D.C.); (L.P.); (F.P.)
| | - Valeria Panella
- Department of Life, Health and Environmental Sciences, University of L’Aquila, 67100 L’Aquila, Italy;
| | - Antonella Di Campli
- Center for Advanced Studies and Technology (CAST), “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (M.C.C.); (A.D.C.); (L.P.); (F.P.)
- Institute of Protein Biochemistry (IBP), Italian National Research Council (CNR), 80131 Napoli, Italy
| | - Anna Giulia Ruggieri
- Department of Innovative Technologies in Medicine and Dentistry, “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (F.P.); (L.D.B.); (A.G.R.); (B.D.); (D.P.); (V.D.L.); (L.F.)
- Center for Advanced Studies and Technology (CAST), “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (M.C.C.); (A.D.C.); (L.P.); (F.P.)
| | - Beatrice Dufrusine
- Department of Innovative Technologies in Medicine and Dentistry, “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (F.P.); (L.D.B.); (A.G.R.); (B.D.); (D.P.); (V.D.L.); (L.F.)
- Center for Advanced Studies and Technology (CAST), “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (M.C.C.); (A.D.C.); (L.P.); (F.P.)
| | - Elena Restelli
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, 20156 Milano, Italy; (E.R.); (R.C.)
| | - Laura Pietrangelo
- Center for Advanced Studies and Technology (CAST), “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (M.C.C.); (A.D.C.); (L.P.); (F.P.)
- Department of Medicine and Aging Sciences, “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy
| | - Feliciano Protasi
- Center for Advanced Studies and Technology (CAST), “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (M.C.C.); (A.D.C.); (L.P.); (F.P.)
- Department of Medicine and Aging Sciences, “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy
| | - Damiana Pieragostino
- Department of Innovative Technologies in Medicine and Dentistry, “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (F.P.); (L.D.B.); (A.G.R.); (B.D.); (D.P.); (V.D.L.); (L.F.)
- Center for Advanced Studies and Technology (CAST), “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (M.C.C.); (A.D.C.); (L.P.); (F.P.)
| | - Vincenzo De Laurenzi
- Department of Innovative Technologies in Medicine and Dentistry, “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (F.P.); (L.D.B.); (A.G.R.); (B.D.); (D.P.); (V.D.L.); (L.F.)
- Center for Advanced Studies and Technology (CAST), “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (M.C.C.); (A.D.C.); (L.P.); (F.P.)
| | - Luca Federici
- Department of Innovative Technologies in Medicine and Dentistry, “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (F.P.); (L.D.B.); (A.G.R.); (B.D.); (D.P.); (V.D.L.); (L.F.)
- Center for Advanced Studies and Technology (CAST), “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (M.C.C.); (A.D.C.); (L.P.); (F.P.)
| | - Roberto Chiesa
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, 20156 Milano, Italy; (E.R.); (R.C.)
| | - Michele Sallese
- Department of Innovative Technologies in Medicine and Dentistry, “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (F.P.); (L.D.B.); (A.G.R.); (B.D.); (D.P.); (V.D.L.); (L.F.)
- Center for Advanced Studies and Technology (CAST), “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (M.C.C.); (A.D.C.); (L.P.); (F.P.)
| |
Collapse
|
7
|
Jennings MJ, Hathazi D, Nguyen CDL, Munro B, Münchberg U, Ahrends R, Schenck A, Eidhof I, Freier E, Synofzik M, Horvath R, Roos A. Intracellular Lipid Accumulation and Mitochondrial Dysfunction Accompanies Endoplasmic Reticulum Stress Caused by Loss of the Co-chaperone DNAJC3. Front Cell Dev Biol 2021; 9:710247. [PMID: 34692675 PMCID: PMC8526738 DOI: 10.3389/fcell.2021.710247] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Accepted: 09/02/2021] [Indexed: 12/25/2022] Open
Abstract
Recessive mutations in DNAJC3, an endoplasmic reticulum (ER)-resident BiP co-chaperone, have been identified in patients with multisystemic neurodegeneration and diabetes mellitus. To further unravel these pathomechanisms, we employed a non-biased proteomic approach and identified dysregulation of several key cellular pathways, suggesting a pathophysiological interplay of perturbed lipid metabolism, mitochondrial bioenergetics, ER-Golgi function, and amyloid-beta processing. Further functional investigations in fibroblasts of patients with DNAJC3 mutations detected cellular accumulation of lipids and an increased sensitivity to cholesterol stress, which led to activation of the unfolded protein response (UPR), alterations of the ER-Golgi machinery, and a defect of amyloid precursor protein. In line with the results of previous studies, we describe here alterations in mitochondrial morphology and function, as a major contributor to the DNAJC3 pathophysiology. Hence, we propose that the loss of DNAJC3 affects lipid/cholesterol homeostasis, leading to UPR activation, β-amyloid accumulation, and impairment of mitochondrial oxidative phosphorylation.
Collapse
Affiliation(s)
- Matthew J. Jennings
- Department of Clinical Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Denisa Hathazi
- Department of Clinical Neuroscience, University of Cambridge, Cambridge, United Kingdom
- Leibniz-Institut für Analytische Wissenschaften – ISAS – e.V., Dortmund, Germany
| | - Chi D. L. Nguyen
- Leibniz-Institut für Analytische Wissenschaften – ISAS – e.V., Dortmund, Germany
| | - Benjamin Munro
- Department of Clinical Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Ute Münchberg
- Leibniz-Institut für Analytische Wissenschaften – ISAS – e.V., Dortmund, Germany
| | - Robert Ahrends
- Leibniz-Institut für Analytische Wissenschaften – ISAS – e.V., Dortmund, Germany
| | - Annette Schenck
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, Netherlands
| | - Ilse Eidhof
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, Netherlands
| | - Erik Freier
- Leibniz-Institut für Analytische Wissenschaften – ISAS – e.V., Dortmund, Germany
| | - Matthis Synofzik
- Department of Neurodegenerative Diseases, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
- German Centre for Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Rita Horvath
- Department of Clinical Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Andreas Roos
- Leibniz-Institut für Analytische Wissenschaften – ISAS – e.V., Dortmund, Germany
- Department of Pediatric Neurology, Developmental Neurology and Social Pediatrics, Children’s Hospital University of Essen, Essen, Germany
| |
Collapse
|
8
|
Gangfuß A, Czech A, Hentschel A, Münchberg U, Horvath R, Töpf A, O'Heir E, Lochmüller H, Stehling F, Kiewert C, Sickmann A, Kuechler A, Kaiser FJ, Kölbel H, Christiansen J, Schara-Schmidt U, Roos A. Homozygous WASHC4 variant in two sisters causes a syndromic phenotype defined by dysmorphisms, intellectual disability, profound developmental disorder, and skeletal muscle involvement. J Pathol 2021; 256:93-107. [PMID: 34599609 DOI: 10.1002/path.5812] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 09/01/2021] [Accepted: 09/29/2021] [Indexed: 12/29/2022]
Abstract
Recessive variants in WASHC4 are linked to intellectual disability complicated by poor language skills, short stature, and dysmorphic features. The protein encoded by WASHC4 is part of the Wiskott-Aldrich syndrome protein and SCAR homolog family, co-localizes with actin in cells, and promotes Arp2/3-dependent actin polymerization in vitro. Functional studies in a zebrafish model suggested that WASHC4 knockdown may also affect skeletal muscles by perturbing protein clearance. However, skeletal muscle involvement has not been reported so far in patients, and precise biochemical studies allowing a deeper understanding of the molecular etiology of the disease are still lacking. Here, we report two siblings with a homozygous WASHC4 variant expanding the clinical spectrum of the disease and provide a phenotypical comparison with cases reported in the literature. Proteomic profiling of fibroblasts of the WASHC4-deficient patient revealed dysregulation of proteins relevant for the maintenance of the neuromuscular axis. Immunostaining on a muscle biopsy derived from the same patient confirmed dysregulation of proteins relevant for proper muscle function, thus highlighting an affliction of muscle cells upon loss of functional WASHC4. The results of histological and coherent anti-Stokes Raman scattering microscopic studies support the concept of a functional role of the WASHC4 protein in humans by altering protein processing and clearance. The proteomic analysis confirmed key molecular players in vitro and highlighted, for the first time, the involvement of skeletal muscle in patients. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- Andrea Gangfuß
- Department of Pediatric Neurology, Centre for Neuromuscular Disorders, Centre for Translational Neuro- and Behavioral Sciences, University Duisburg-Essen, Essen, Germany
| | - Artur Czech
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Dortmund, Germany
| | - Andreas Hentschel
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Dortmund, Germany
| | - Ute Münchberg
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Dortmund, Germany
| | - Rita Horvath
- Department of Clinical Neurosciences, John Van Geest Centre for Brain Repair, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Ana Töpf
- The John Walton Muscular Dystrophy Research Centre, Translational and Clinical Research Institute, Newcastle University and Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Emily O'Heir
- Center for Mendelian Genomics, Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Hanns Lochmüller
- Department of Neuropediatrics and Muscle Disorders, Medical Center - University of Freiburg, Faculty of Medicine, Freiburg, Germany.,Centro Nacional de Análisis Genómico (CNAG-CRG), Center for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), Barcelona, Spain.,Children's Hospital of Eastern Ontario Research Institute; Division of Neurology, Department of Medicine, The Ottawa Hospital; and Brain and Mind Research Institute, University of Ottawa, Ottawa, Canada
| | - Florian Stehling
- Children's Hospital, Department of Pneumology, University Hospital Essen, Essen, Germany
| | - Cordula Kiewert
- Children's Hospital, Department of Endocrinology, University Hospital Essen, Essen, Germany
| | - Albert Sickmann
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Dortmund, Germany
| | - Alma Kuechler
- Institute of Human Genetics, University Hospital Essen, University Duisburg-Essen, Essen, Germany.,Essener Zentrum für seltene Erkrankungen (EZSE), University Hospital Essen, University Duisburg-Essen, Essen, Germany
| | - Frank J Kaiser
- Institute of Human Genetics, University Hospital Essen, University Duisburg-Essen, Essen, Germany.,Essener Zentrum für seltene Erkrankungen (EZSE), University Hospital Essen, University Duisburg-Essen, Essen, Germany
| | - Heike Kölbel
- Department of Pediatric Neurology, Centre for Neuromuscular Disorders, Centre for Translational Neuro- and Behavioral Sciences, University Duisburg-Essen, Essen, Germany
| | - Jon Christiansen
- Department of Pediatric Neurology, Centre for Neuromuscular Disorders, Centre for Translational Neuro- and Behavioral Sciences, University Duisburg-Essen, Essen, Germany
| | - Ulrike Schara-Schmidt
- Department of Pediatric Neurology, Centre for Neuromuscular Disorders, Centre for Translational Neuro- and Behavioral Sciences, University Duisburg-Essen, Essen, Germany
| | - Andreas Roos
- Department of Pediatric Neurology, Centre for Neuromuscular Disorders, Centre for Translational Neuro- and Behavioral Sciences, University Duisburg-Essen, Essen, Germany.,Children's Hospital of Eastern Ontario Research Institute; Division of Neurology, Department of Medicine, The Ottawa Hospital; and Brain and Mind Research Institute, University of Ottawa, Ottawa, Canada
| |
Collapse
|
9
|
Hathazi D, Cox D, D'Amico A, Tasca G, Charlton R, Carlier RY, Baumann J, Kollipara L, Zahedi RP, Feldmann I, Deleuze JF, Torella A, Cohn R, Robinson E, Ricci F, Jungbluth H, Fattori F, Boland A, O’Connor E, Horvath R, Barresi R, Lochmüller H, Urtizberea A, Jacquemont ML, Nelson I, Swan L, Bonne G, Roos A. INPP5K and SIL1 associated pathologies with overlapping clinical phenotypes converge through dysregulation of PHGDH. Brain 2021; 144:2427-2442. [PMID: 33792664 PMCID: PMC8418339 DOI: 10.1093/brain/awab133] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 01/12/2021] [Accepted: 01/30/2021] [Indexed: 12/22/2022] Open
Abstract
Marinesco-Sjögren syndrome is a rare human disorder caused by biallelic mutations in SIL1 characterized by cataracts in infancy, myopathy and ataxia, symptoms which are also associated with a novel disorder caused by mutations in INPP5K. While these phenotypic similarities may suggest commonalties at a molecular level, an overlapping pathomechanism has not been established yet. In this study, we present six new INPP5K patients and expand the current mutational and phenotypical spectrum of the disease showing the clinical overlap between Marinesco-Sjögren syndrome and the INPP5K phenotype. We applied unbiased proteomic profiling on cells derived from Marinesco-Sjögren syndrome and INPP5K patients and identified alterations in d-3-PHGDH as a common molecular feature. d-3-PHGDH modulates the production of l-serine and mutations in this enzyme were previously associated with a neurological phenotype, which clinically overlaps with Marinesco-Sjögren syndrome and INPP5K disease. As l-serine administration represents a promising therapeutic strategy for d-3-PHGDH patients, we tested the effect of l-serine in generated sil1, phgdh and inpp5k a+b zebrafish models, which showed an improvement in their neuronal phenotype. Thus, our study defines a core phenotypical feature underpinning a key common molecular mechanism in three rare diseases and reveals a common and novel therapeutic target for these patients.
Collapse
Affiliation(s)
- Denisa Hathazi
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V, Dortmund, Germany
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge, CB2 0PY, UK
| | - Dan Cox
- The John Walton Muscular Dystrophy Research Centre, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, International Centre for Life, Newcastle upon Tyne, NE1 3BZ, UK
| | - Adele D'Amico
- Laboratory of Molecular Medicine for Neuromuscular and Neurodegenerative Disorders, Bambino Gesù Children’s Hospital, 00146 Rome, Italy
| | - Giorgio Tasca
- Unità Operativa Complessa di Neurologia, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Richard Charlton
- The John Walton Muscular Dystrophy Research Centre, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, International Centre for Life, Newcastle upon Tyne, NE1 3BZ, UK
| | - Robert-Yves Carlier
- AP-HP, Service d’Imagerie Médicale, Raymond Poincaré Hospital, 92380 Garches, France
- Inserm U 1179, University of Versailles Saint-Quentin-en-Yvelines (UVSQ), 78180 Versailles, France
| | - Jennifer Baumann
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V, Dortmund, Germany
| | | | - René P Zahedi
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V, Dortmund, Germany
- Segal Cancer Proteomics Centre, Lady Davis Institute, Jewish General Hospital, McGill University, Montreal, QC H3T 1E2, Canada
| | - Ingo Feldmann
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V, Dortmund, Germany
| | - Jean-Francois Deleuze
- Centre National de Recherche en Génomique Humaine (CNRGH) (A.B., J.F.D.), Institut de Biologie François Jacob, CEA, Université Paris-Saclay, 91000 Evry, France
| | - Annalaura Torella
- Dipartimento di Medicina di Precisione, Università degli Studi della Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
- Telethon Institute of Genetics and Medicine (TIGEM), 80078 Pozzuoli, Italy
| | - Ronald Cohn
- SickKids Research Institute, Department of Paediatrics and Molecular Genetics, University of Toronto, Toronto, ON M5G 0A4, Canada
| | - Emily Robinson
- Department of molecular Physiology and Cell Signalling, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, L69 7BE, UK
| | - Francesco Ricci
- Department of molecular Physiology and Cell Signalling, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, L69 7BE, UK
| | - Heinz Jungbluth
- Guy’s and St Thomas’ NHS Trust, King’s College London, London, SE1 7EH, UK
| | - Fabiana Fattori
- Laboratory of Molecular Medicine for Neuromuscular and Neurodegenerative Disorders, Bambino Gesù Children’s Hospital, 00146 Rome, Italy
| | - Anne Boland
- Centre National de Recherche en Génomique Humaine (CNRGH) (A.B., J.F.D.), Institut de Biologie François Jacob, CEA, Université Paris-Saclay, 91000 Evry, France
| | - Emily O’Connor
- Children’s Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON K1H 5B2, Canada
| | - Rita Horvath
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge, CB2 0PY, UK
| | - Rita Barresi
- The John Walton Muscular Dystrophy Research Centre, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, International Centre for Life, Newcastle upon Tyne, NE1 3BZ, UK
| | - Hanns Lochmüller
- Children’s Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON K1H 5B2, Canada
- Department of Neuropediatrics and Muscle Disorders, Medical Center—University of Freiburg, Faculty of Medicine, 79095 Freiburg, Germany
| | | | - Marie-Line Jacquemont
- Unité de Génétique Médicale, Pôle Femme-Mère-Enfant, Groupe Hospitalier Sud Réunion, CHU de La Réunion, 97410 La Réunion, France
| | - Isabelle Nelson
- Sorbonne Université, Inserm UMRS974, Centre de Recherche en Myologie, Institut de Myologie, 75013 Paris, France
| | - Laura Swan
- Department of molecular Physiology and Cell Signalling, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, L69 7BE, UK
| | - Gisèle Bonne
- Sorbonne Université, Inserm UMRS974, Centre de Recherche en Myologie, Institut de Myologie, 75013 Paris, France
| | - Andreas Roos
- Children’s Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON K1H 5B2, Canada
- Department of Pediatric Neurology, University Hospital Essen, University of Duisburg-Essen, Faculty of Medicine, 45147 Essen, Germany
| |
Collapse
|
10
|
Pathomechanisms of ALS8: altered autophagy and defective RNA binding protein (RBP) homeostasis due to the VAPB P56S mutation. Cell Death Dis 2021; 12:466. [PMID: 33972508 PMCID: PMC8110809 DOI: 10.1038/s41419-021-03710-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 04/12/2021] [Accepted: 04/13/2021] [Indexed: 02/03/2023]
Abstract
Mutations in RNA binding proteins (RBPs) and in genes regulating autophagy are frequent causes of familial amyotrophic lateral sclerosis (fALS). The P56S mutation in vesicle-associated membrane protein-associated protein B (VAPB) leads to fALS (ALS8) and spinal muscular atrophy (SMA). While VAPB is primarily involved in the unfolded protein response (UPR), vesicular trafficking and in initial steps of the autophagy pathway, the effect of mutant P56S-VAPB on autophagy regulation in connection with RBP homeostasis has not been explored yet. Examining the muscle biopsy of our index ALS8 patient of European origin revealed globular accumulations of VAPB aggregates co-localised with autophagy markers LC3 and p62 in partially atrophic and atrophic muscle fibres. In line with this skin fibroblasts obtained from the same patient showed accumulation of P56S-VAPB aggregates together with LC3 and p62. Detailed investigations of autophagic flux in cell culture models revealed that P56S-VAPB alters both initial and late steps of the autophagy pathway. Accordingly, electron microscopy complemented with live cell imaging highlighted the impaired fusion of accumulated autophagosomes with lysosomes in cells expressing P56S-VAPB. Consistent with these observations, neuropathological studies of brain and spinal cord of P56S-VAPB transgenic mice revealed signs of neurodegeneration associated with altered protein quality control and defective autophagy. Autophagy and RBP homeostasis are interdependent, as demonstrated by the cytoplasmic mis-localisation of several RBPs including pTDP-43, FUS, Matrin 3 which often sequestered with P56S-VAPB aggregates both in cell culture and in the muscle biopsy of the ALS8 patient. Further confirming the notion that aggregation of the RBPs proceeds through the stress granule (SG) pathway, we found persistent G3BP- and TIAR1-positive SGs in P56S-VAPB expressing cells as well as in the ALS8 patient muscle biopsy. We conclude that P56S-VAPB-ALS8 involves a cohesive pathomechanism of aberrant RBP homeostasis together with dysfunctional autophagy.
Collapse
|
11
|
Sicking M, Lang S, Bochen F, Roos A, Drenth JPH, Zakaria M, Zimmermann R, Linxweiler M. Complexity and Specificity of Sec61-Channelopathies: Human Diseases Affecting Gating of the Sec61 Complex. Cells 2021; 10:1036. [PMID: 33925740 PMCID: PMC8147068 DOI: 10.3390/cells10051036] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 04/15/2021] [Accepted: 04/17/2021] [Indexed: 12/14/2022] Open
Abstract
The rough endoplasmic reticulum (ER) of nucleated human cells has crucial functions in protein biogenesis, calcium (Ca2+) homeostasis, and signal transduction. Among the roughly one hundred components, which are involved in protein import and protein folding or assembly, two components stand out: The Sec61 complex and BiP. The Sec61 complex in the ER membrane represents the major entry point for precursor polypeptides into the membrane or lumen of the ER and provides a conduit for Ca2+ ions from the ER lumen to the cytosol. The second component, the Hsp70-type molecular chaperone immunoglobulin heavy chain binding protein, short BiP, plays central roles in protein folding and assembly (hence its name), protein import, cellular Ca2+ homeostasis, and various intracellular signal transduction pathways. For the purpose of this review, we focus on these two components, their relevant allosteric effectors and on the question of how their respective functional cycles are linked in order to reconcile the apparently contradictory features of the ER membrane, selective permeability for precursor polypeptides, and impermeability for Ca2+. The key issues are that the Sec61 complex exists in two conformations: An open and a closed state that are in a dynamic equilibrium with each other, and that BiP contributes to its gating in both directions in cooperation with different co-chaperones. While the open Sec61 complex forms an aqueous polypeptide-conducting- and transiently Ca2+-permeable channel, the closed complex is impermeable even to Ca2+. Therefore, we discuss the human hereditary and tumor diseases that are linked to Sec61 channel gating, termed Sec61-channelopathies, as disturbances of selective polypeptide-impermeability and/or aberrant Ca2+-permeability.
Collapse
Affiliation(s)
- Mark Sicking
- Department of Medical Biochemistry & Molecular Biology, Saarland University, D-66421 Homburg, Germany;
| | - Sven Lang
- Department of Medical Biochemistry & Molecular Biology, Saarland University, D-66421 Homburg, Germany;
| | - Florian Bochen
- Department of Otorhinolaryngology, Head and Neck Surgery, Saarland University Medical Center, D-66421 Homburg, Germany; (F.B.); (M.L.)
| | - Andreas Roos
- Department of Neuropediatrics, Essen University Hospital, D-45147 Essen, Germany;
| | - Joost P. H. Drenth
- Department of Molecular Gastroenterology and Hepatology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands;
| | - Muhammad Zakaria
- Department of Genetics, Hazara University, Mansehra 21300, Pakistan;
| | - Richard Zimmermann
- Department of Medical Biochemistry & Molecular Biology, Saarland University, D-66421 Homburg, Germany;
| | - Maximilian Linxweiler
- Department of Otorhinolaryngology, Head and Neck Surgery, Saarland University Medical Center, D-66421 Homburg, Germany; (F.B.); (M.L.)
| |
Collapse
|
12
|
Grande V, Hathazi D, O'Connor E, Marteau T, Schara-Schmidt U, Hentschel A, Gourdon G, Nikolenko N, Lochmüller H, Roos A. Dysregulation of GSK3β-Target Proteins in Skin Fibroblasts of Myotonic Dystrophy Type 1 (DM1) Patients. J Neuromuscul Dis 2021; 8:603-619. [PMID: 33682722 DOI: 10.3233/jnd-200558] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Myotonic dystrophy type 1 (DM1) is the most common monogenetic muscular disorder of adulthood. This multisystemic disease is caused by CTG repeat expansion in the 3'-untranslated region of the DM1 protein kinase gene called DMPK. DMPK encodes a myosin kinase expressed in skeletal muscle cells and other cellular populations such as smooth muscle cells, neurons and fibroblasts. The resultant expanded (CUG)n RNA transcripts sequester RNA binding factors leading to ubiquitous and persistent splicing deregulation. The accumulation of mutant CUG repeats is linked to increased activity of glycogen synthase kinase 3 beta (GSK3β), a highly conserved and ubiquitous serine/threonine kinase with functions in pathways regulating inflammation, metabolism, oncogenesis, neurogenesis and myogenesis. As GSK3β-inhibition ameliorates defects in myogenesis, muscle strength and myotonia in a DM1 mouse model, this kinase represents a key player of DM1 pathobiochemistry and constitutes a promising therapeutic target. To better characterise DM1 patients, and monitor treatment responses, we aimed to define a set of robust disease and severity markers linked to GSK3βby unbiased proteomic profiling utilizing fibroblasts derived from DM1 patients with low (80- 150) and high (2600- 3600) CTG-repeats. Apart from GSK3β increase, we identified dysregulation of nine proteins (CAPN1, CTNNB1, CTPS1, DNMT1, HDAC2, HNRNPH3, MAP2K2, NR3C1, VDAC2) modulated by GSK3β. In silico-based expression studies confirmed expression in neuronal and skeletal muscle cells and revealed a relatively elevated abundance in fibroblasts. The potential impact of each marker in the myopathology of DM1 is discussed based on respective function to inform potential uses as severity markers or for monitoring GSK3β inhibitor treatment responses.
Collapse
Affiliation(s)
- Valentina Grande
- Department of Neuropediatrics, University Hospital Essen, Duisburg-Essen University, Germany
| | - Denisa Hathazi
- Leibniz-Institut für Analytische Wissenschaften -ISAS- e.V., Dortmund, Germany.,Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Emily O'Connor
- Childrens Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON, Canada
| | - Theo Marteau
- Department of Neuropediatrics, University Hospital Essen, Duisburg-Essen University, Germany
| | - Ulrike Schara-Schmidt
- Department of Neuropediatrics, University Hospital Essen, Duisburg-Essen University, Germany
| | - Andreas Hentschel
- Leibniz-Institut für Analytische Wissenschaften -ISAS- e.V., Dortmund, Germany
| | - Genevieve Gourdon
- Centre de Recherche en Myologie, Association Institut de Myologie, Sorbonne Université, Inserm UMR 974, Paris, France
| | - Nikoletta Nikolenko
- National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, London, UK
| | - Hanns Lochmüller
- Childrens Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON, Canada.,Division of Neurology, Department of Medicine, The Ottawa Hospital, Ottawa, ON, Canada.,Department of Neuropediatrics and Muscle Disorders, Faculty of Medicine, Medical Center - University of Freiburg, Freiburg, Germany.,Centro Nacional de AnálisisGenómico, Center for Genomic Regulation (CNAG-CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Catalonia, Spain
| | - Andreas Roos
- Department of Neuropediatrics, University Hospital Essen, Duisburg-Essen University, Germany.,Childrens Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON, Canada
| |
Collapse
|
13
|
Ichhaporia VP, Hendershot LM. Role of the HSP70 Co-Chaperone SIL1 in Health and Disease. Int J Mol Sci 2021; 22:ijms22041564. [PMID: 33557244 PMCID: PMC7913895 DOI: 10.3390/ijms22041564] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 01/30/2021] [Accepted: 01/30/2021] [Indexed: 12/04/2022] Open
Abstract
Cell surface and secreted proteins provide essential functions for multicellular life. They enter the endoplasmic reticulum (ER) lumen co-translationally, where they mature and fold into their complex three-dimensional structures. The ER is populated with a host of molecular chaperones, associated co-factors, and enzymes that assist and stabilize folded states. Together, they ensure that nascent proteins mature properly or, if this process fails, target them for degradation. BiP, the ER HSP70 chaperone, interacts with unfolded client proteins in a nucleotide-dependent manner, which is tightly regulated by eight DnaJ-type proteins and two nucleotide exchange factors (NEFs), SIL1 and GRP170. Loss of SIL1′s function is the leading cause of Marinesco-Sjögren syndrome (MSS), an autosomal recessive, multisystem disorder. The development of animal models has provided insights into SIL1′s functions and MSS-associated pathologies. This review provides an in-depth update on the current understanding of the molecular mechanisms underlying SIL1′s NEF activity and its role in maintaining ER homeostasis and normal physiology. A precise understanding of the underlying molecular mechanisms associated with the loss of SIL1 may allow for the development of new pharmacological approaches to treat MSS.
Collapse
|
14
|
Kölbel H, Roos A, van der Ven PFM, Evangelista T, Nolte K, Johnson K, Töpf A, Wilson M, Kress W, Sickmann A, Straub V, Kollipara L, Weis J, Fürst DO, Schara U. First clinical and myopathological description of a myofibrillar myopathy with congenital onset and homozygous mutation in FLNC. Hum Mutat 2020; 41:1600-1614. [PMID: 32516863 DOI: 10.1002/humu.24062] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 05/17/2020] [Accepted: 06/07/2020] [Indexed: 02/06/2023]
Abstract
Filamin C (encoded by the FLNC gene) is a large actin-cross-linking protein involved in shaping the actin cytoskeleton in response to signaling events both at the sarcolemma and at myofibrillar Z-discs of cross-striated muscle cells. Multiple mutations in FLNC are associated with myofibrillar myopathies of autosomal-dominant inheritance. Here, we describe for the first time a boy with congenital onset of generalized muscular hypotonia and muscular weakness, delayed motor development but no cardiac involvement associated with a homozygous FLNC mutation c.1325C>G (p.Pro442Arg). We performed ultramorphological, proteomic, and functional investigations as well as immunological studies of known marker proteins for dominant filaminopathies. We show that the mutant protein is expressed in similar quantities as the wild-type variant in control skeletal muscle fibers. The proteomic signature of quadriceps muscle is altered and ultrastructural perturbations are evident. Moreover, filaminopathy marker proteins are comparable both in our homozygous and a dominant control case (c.5161delG). Biochemical investigations demonstrate that the recombinant mutant protein is less stable and more prone to degradation by proteolytic enzymes than the wild-type variant. The unusual congenital presentation of the disease clearly demonstrates that homozygosity for mutations in FLNC severely aggravates the phenotype.
Collapse
Affiliation(s)
- Heike Kölbel
- Department of Pediatric Neurology, Developmental Neurology and Social Pediatrics, Children's Hospital University of Essen, Essen, Germany
| | - Andreas Roos
- Department of Pediatric Neurology, Developmental Neurology and Social Pediatrics, Children's Hospital University of Essen, Essen, Germany
| | - Peter F M van der Ven
- Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, Bonn, Germany
| | - Teresinha Evangelista
- Neuromuscular Morphology Unit, Myology Institute, GHU Pitié-Salpêtrière, Paris, France
| | - Kay Nolte
- Institute of Neuropathology, RWTH Aachen University Hospital, Aachen, Germany
| | - Katherine Johnson
- The John Walton Muscular Dystrophy Research Centre, Institute of Translational and Clinical Research, Newcastle University, Newcastle upon Tyne, UK
| | - Ana Töpf
- The John Walton Muscular Dystrophy Research Centre, Institute of Translational and Clinical Research, Newcastle University, Newcastle upon Tyne, UK
| | - Michael Wilson
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, Massachusetts.,Program in Medical and Population Genetics, Broad Institute of Harvard and MIT, Cambridge, Massachusetts
| | - Wolfram Kress
- Department of Human Genetics, University of Würzburg, Würzburg, Germany
| | - Albert Sickmann
- Department of Bioanalytics, Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Dortmund, Germany.,Department of Chemistry, College of Physical Sciences, University of Aberdeen, Aberdeen, Scotland, UK.,Medizinische Proteom-Center (MPC), Medizinische Fakultät, Ruhr-Universität Bochum, Bochum, Germany
| | - Volker Straub
- The John Walton Muscular Dystrophy Research Centre, Institute of Translational and Clinical Research, Newcastle University, Newcastle upon Tyne, UK
| | - Laxmikanth Kollipara
- Department of Bioanalytics, Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Dortmund, Germany
| | - Joachim Weis
- Institute of Neuropathology, RWTH Aachen University Hospital, Aachen, Germany
| | - Dieter O Fürst
- Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, Bonn, Germany
| | - Ulrike Schara
- Department of Pediatric Neurology, Developmental Neurology and Social Pediatrics, Children's Hospital University of Essen, Essen, Germany
| |
Collapse
|
15
|
Chiesa R, Sallese M. Review: Protein misfolding diseases – the rare case of Marinesco‐Sjögren syndrome. Neuropathol Appl Neurobiol 2020; 46:323-343. [DOI: 10.1111/nan.12588] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 11/03/2019] [Indexed: 12/15/2022]
Affiliation(s)
- R. Chiesa
- Department of Neuroscience Istituto di Ricerche Farmacologiche Mario Negri IRCCS MilanItaly
| | - M. Sallese
- Department of Medical, Oral and Biotechnological Sciences University "G. d'Annunzio" Chieti Italy
- CeSI‐MeT Center for Research on Ageing and Translational Medicine University "G. d'Annunzio" Chieti Italy
| |
Collapse
|
16
|
Ross JA, Levy Y, Ripolone M, Kolb JS, Turmaine M, Holt M, Lindqvist J, Claeys KG, Weis J, Monforte M, Tasca G, Moggio M, Figeac N, Zammit PS, Jungbluth H, Fiorillo C, Vissing J, Witting N, Granzier H, Zanoteli E, Hardeman EC, Wallgren-Pettersson C, Ochala J. Impairments in contractility and cytoskeletal organisation cause nuclear defects in nemaline myopathy. Acta Neuropathol 2019; 138:477-495. [PMID: 31218456 PMCID: PMC6689292 DOI: 10.1007/s00401-019-02034-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 05/28/2019] [Accepted: 06/05/2019] [Indexed: 02/07/2023]
Abstract
Nemaline myopathy (NM) is a skeletal muscle disorder caused by mutations in genes that are generally involved in muscle contraction, in particular those related to the structure and/or regulation of the thin filament. Many pathogenic aspects of this disease remain largely unclear. Here, we report novel pathological defects in skeletal muscle fibres of mouse models and patients with NM: irregular spacing and morphology of nuclei; disrupted nuclear envelope; altered chromatin arrangement; and disorganisation of the cortical cytoskeleton. Impairments in contractility are the primary cause of these nuclear defects. We also establish the role of microtubule organisation in determining nuclear morphology, a phenomenon which is likely to contribute to nuclear alterations in this disease. Our results overlap with findings in diseases caused directly by mutations in nuclear envelope or cytoskeletal proteins. Given the important role of nuclear shape and envelope in regulating gene expression, and the cytoskeleton in maintaining muscle fibre integrity, our findings are likely to explain some of the hallmarks of NM, including contractile filament disarray, altered mechanical properties and broad transcriptional alterations.
Collapse
|
17
|
Gatz C, Hathazi D, Münchberg U, Buchkremer S, Labisch T, Munro B, Horvath R, Töpf A, Weis J, Roos A. Identification of Cellular Pathogenicity Markers for SIL1 Mutations Linked to Marinesco-Sjögren Syndrome. Front Neurol 2019; 10:562. [PMID: 31258504 PMCID: PMC6587064 DOI: 10.3389/fneur.2019.00562] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 05/10/2019] [Indexed: 12/13/2022] Open
Abstract
Background and objective: Recessive mutations in the SIL1 gene cause Marinesco-Sjögren syndrome (MSS), a rare neuropediatric disorder. MSS-patients typically present with congenital cataracts, intellectual disability, cerebellar ataxia and progressive vacuolar myopathy. However, atypical clinical presentations associated with SIL1 mutations have been described over the last years; compound heterozygosity of SIL1 missense mutations even resulted in a phenotype not fulfilling the clinical diagnostic criteria of MSS. Thus, a read-out system to evaluate reliably the pathogenicity of amino acid changes in SIL1 is needed. Here, we aim to provide suitable cellular biomarkers enabling the robust evaluation of pathogenicity of SIL1 mutations. Methods: Five SIL1 variants including one polymorphism (p.K132Q), three known pathogenic mutations (p.V231_I232del, p.G312R, and p.L457P) and one ambiguous missense variant (p.R92W) were studied along with the wild-type proteins in Hek293 in vitro models by cell biological assays, immunoprecipitation, immunoblotting, and immunofluorescence as well as electron microscopy. Moreover, the SIL1-interactomes were interrogated by tandem-affinity-purification and subsequent mass spectrometry. Results: Our combined studies confirmed the pathogenicity of p.V231_I232del, p.G312R, and p.L457P by showing instability of the proteins as well as tendency to form aggregates. This observation is in line with altered structure of the ER-Golgi system and vacuole formation upon expression of these pathogenic SIL1-mutants as well as the presence of oxidative or ER-stress. Reduced cellular fitness along with abnormal mitochondrial architecture could also be observed. Notably, both the polymorphic p.K132Q and the ambiguous p.R92W variants did not elicit such alterations. Study of the SIL1-interactome identified POC1A as a novel binding partner of wild-type SIL1; the interaction is disrupted upon the presence of pathogenic mutants but not influenced by the presence of benign variants. Disrupted SIL1-POC1A interaction is associated with centrosome disintegration. Conclusions: We developed a combination of cellular outcome measures to evaluate the pathogenicity of SIL1 variants in suitable in vitro models and demonstrated that the p. R92W missense variant is a polymorphism rather than a pathogenic mutation leading to MSS.
Collapse
Affiliation(s)
- Christian Gatz
- Institute of Neuropathology, RWTH Aachen University Hospital, Aachen, Germany
| | - Denisa Hathazi
- Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Dortmund, Germany.,Department of Clinical Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Ute Münchberg
- Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Dortmund, Germany
| | - Stephan Buchkremer
- Institute of Neuropathology, RWTH Aachen University Hospital, Aachen, Germany
| | - Thomas Labisch
- Institute of Neuropathology, RWTH Aachen University Hospital, Aachen, Germany
| | - Ben Munro
- Department of Clinical Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Rita Horvath
- Department of Clinical Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Ana Töpf
- International Centre for Life, Institute of Genetic Medicine, Newcastle upon Tyne, United Kingdom
| | - Joachim Weis
- Institute of Neuropathology, RWTH Aachen University Hospital, Aachen, Germany
| | - Andreas Roos
- Institute of Neuropathology, RWTH Aachen University Hospital, Aachen, Germany.,Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Dortmund, Germany.,Pediatric Neurology, Faculty of Medicine, University Childrens Hospital, University of Duisburg-Essen, Essen, Germany
| |
Collapse
|
18
|
Conway de Macario E, Yohda M, Macario AJL, Robb FT. Bridging human chaperonopathies and microbial chaperonins. Commun Biol 2019; 2:103. [PMID: 30911678 PMCID: PMC6420498 DOI: 10.1038/s42003-019-0318-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 01/15/2019] [Indexed: 12/19/2022] Open
Abstract
Chaperonins are molecular chaperones that play critical physiological roles, but they can be pathogenic. Malfunctional chaperonins cause chaperonopathies of great interest within various medical specialties. Although the clinical-genetic aspects of many chaperonopathies are known, the molecular mechanisms causing chaperonin failure and tissue lesions are poorly understood. Progress is necessary to improve treatment, and experimental models that mimic the human situation provide a promising solution. We present two models: one prokaryotic (the archaeon Pyrococcus furiosus) with eukaryotic-like chaperonins and one eukaryotic (Chaetomium thermophilum), both convenient for isolation-study of chaperonins, and report illustrative results pertaining to a pathogenic mutation of CCT5.
Collapse
Affiliation(s)
- Everly Conway de Macario
- Department of Microbiology and Immunology, School of Medicine, University of Maryland at Baltimore-Institute of Marine and Environmental Technology (IMET), Columbus Center, Baltimore, MD USA
| | - Masafumi Yohda
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Tokyo Japan
- Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Koganei, Tokyo Japan
| | - Alberto J. L. Macario
- Department of Microbiology and Immunology, School of Medicine, University of Maryland at Baltimore-Institute of Marine and Environmental Technology (IMET), Columbus Center, Baltimore, MD USA
- Euro-Mediterranean Institute of Science and Technology (IEMEST), Palermo, Italy
| | - Frank T. Robb
- Department of Microbiology and Immunology, School of Medicine, University of Maryland at Baltimore-Institute of Marine and Environmental Technology (IMET), Columbus Center, Baltimore, MD USA
- Institute for Bioscience and Biotechnology Research (IBBR), Rockville, MD USA
| |
Collapse
|
19
|
Phan V, Cox D, Cipriani S, Spendiff S, Buchkremer S, O'Connor E, Horvath R, Goebel HH, Hathazi D, Lochmüller H, Straka T, Rudolf R, Weis J, Roos A. SIL1 deficiency causes degenerative changes of peripheral nerves and neuromuscular junctions in fish, mice and human. Neurobiol Dis 2018; 124:218-229. [PMID: 30468864 DOI: 10.1016/j.nbd.2018.11.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 10/21/2018] [Accepted: 11/19/2018] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Marinesco-Sjögren Syndrome (MSS) is a rare neuromuscular condition caused by recessive mutations in the SIL1 gene resulting in the absence of functional SIL1 protein, a co-chaperone for the major ER chaperone, BiP. As BiP is decisive for proper protein processing, loss of SIL1 results in the accumulation of misshaped proteins. This accumulation likely damages and destroys cells in vulnerable tissues, leading to congenital cataracts, cerebellar ataxia, vacuolar myopathy and other MSS phenotypes. Whether the peripheral nervous system (PNS) is affected in MSS has not been conclusively shown. METHODS To study PNS vulnerability in MSS, intramuscular nerves fibres from MSS patients and from SIL1-deficient mice (woozy) as well as sciatic nerves and neuromuscular junctions (NMJ) from these mice have been investigated via transmission electron microscopic and immunofluorescence studies accompanied by transcript studies and unbiased proteomic profiling. In addition, PNS and NMJ integrity were analyzed via immunofluorescence studies in an MSS-zebrafish model which has been generated for that purpose. RESULTS Electron microscopy revealed morphological changes indicative of impaired autophagy and mitochondrial maintenance in distal axons and in Schwann cells. Moreover, changes of the morphology of NMJs as well as of transcripts encoding proteins important for NMJ function were detected in woozy mice. These findings were in line with a grossly abnormal structure of NMJs in SIL1-deficient zebrafish embryos. Proteome profiling of sciatic nerve specimens from woozy mice revealed altered levels of proteins implicated in neuronal maintenance suggesting the activation of compensatory mechanisms. CONCLUSION Taken together, our combined data expand the spectrum of tissues affected by SIL1-loss and suggest that impaired neuromuscular transmission might be part of MSS pathophysiology.
Collapse
Affiliation(s)
- Vietxuan Phan
- Leibniz-Institut für Analytische Wissenschaften, ISAS, e.V. Dortmund, 44227, Dortmund, Germany.
| | - Dan Cox
- MRC Centre for Neuromuscular Diseases, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK.
| | - Silvia Cipriani
- MRC Centre for Neuromuscular Diseases, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK; Department of Neuromotor and Biomedical Sciences, Pathology Unit, University of Bologna, Bologna, Italy.
| | - Sally Spendiff
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada; Division of Neurology, Department of Medicine, The Ottawa Hospital, Ottawa, Canada.
| | - Stephan Buchkremer
- Institute of Neuropathology, University Hospital RWTH Aachen, Aachen, 52074, Germany.
| | - Emily O'Connor
- MRC Centre for Neuromuscular Diseases, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK. emily.o'
| | - Rita Horvath
- Department of Clinical Neurosciences, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0QQ, UK.
| | | | - Denisa Hathazi
- Leibniz-Institut für Analytische Wissenschaften, ISAS, e.V. Dortmund, 44227, Dortmund, Germany.
| | - Hanns Lochmüller
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada; Department of Neuropediatrics and Muscle Disorders, Medical Center, University of Freiburg, Faculty of Medicine, Freiburg, Germany; Division of Neurology, Department of Medicine, The Ottawa Hospital, Ottawa, Canada
| | - Tatjana Straka
- Institute of Molecular and Cell Biology, Mannheim University of Applied Sciences, Mannheim, Germany; Interdisciplinary Center for Neurosciences, Heidelberg University, Heidelberg, Germany; Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany.
| | - Rüdiger Rudolf
- Institute of Molecular and Cell Biology, Mannheim University of Applied Sciences, Mannheim, Germany; Interdisciplinary Center for Neurosciences, Heidelberg University, Heidelberg, Germany; Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany.
| | - Joachim Weis
- Institute of Neuropathology, University Hospital RWTH Aachen, Aachen, 52074, Germany.
| | - Andreas Roos
- Leibniz-Institut für Analytische Wissenschaften, ISAS, e.V. Dortmund, 44227, Dortmund, Germany; Institute of Neuropathology, University Hospital RWTH Aachen, Aachen, 52074, Germany; Pediatric Neurology, University Childrens Hospital, University of Duisburg-Essen, Faculty of Medicine, Essen, Germany.
| |
Collapse
|
20
|
Capone V, Clemente E, Restelli E, Di Campli A, Sperduti S, Ornaghi F, Pietrangelo L, Protasi F, Chiesa R, Sallese M. PERK inhibition attenuates the abnormalities of the secretory pathway and the increased apoptotic rate induced by SIL1 knockdown in HeLa cells. Biochim Biophys Acta Mol Basis Dis 2018; 1864:3164-3180. [DOI: 10.1016/j.bbadis.2018.07.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 06/05/2018] [Accepted: 07/03/2018] [Indexed: 02/06/2023]
|
21
|
González Coraspe JA, Weis J, Anderson ME, Münchberg U, Lorenz K, Buchkremer S, Carr S, Zahedi RP, Brauers E, Michels H, Sunada Y, Lochmüller H, Campbell KP, Freier E, Hathazi D, Roos A. Biochemical and pathological changes result from mutated Caveolin-3 in muscle. Skelet Muscle 2018; 8:28. [PMID: 30153853 PMCID: PMC6114045 DOI: 10.1186/s13395-018-0173-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Accepted: 07/24/2018] [Indexed: 12/16/2022] Open
Abstract
Background Caveolin-3 (CAV3) is a muscle-specific protein localized to the sarcolemma. It was suggested that CAV3 is involved in the connection between the extracellular matrix (ECM) and the cytoskeleton. Caveolinopathies often go along with increased CK levels indicative of sarcolemmal damage. So far, more than 40 dominant pathogenic mutations have been described leading to several phenotypes many of which are associated with a mis-localization of the mutant protein to the Golgi. Golgi retention and endoplasmic reticulum (ER) stress has been demonstrated for the CAV3 p.P104L mutation, but further downstream pathophysiological consequences remained elusive so far. Methods We utilized a transgenic (p.P104L mutant) mouse model and performed proteomic profiling along with immunoprecipitation, immunofluorescence and immunoblot examinations (including examination of α-dystroglycan glycosylation), and morphological studies (electron and coherent anti-Stokes Raman scattering (CARS) microscopy) in a systematic investigation of molecular and subcellular events in p.P104L caveolinopathy. Results Our electron and CARS microscopic as well as immunological studies revealed Golgi and ER proliferations along with a build-up of protein aggregates further characterized by immunoprecipitation and subsequent mass spectrometry. Molecular characterization these aggregates showed affection of mitochondrial and cytoskeletal proteins which accords with our ultra-structural findings. Additional global proteomic profiling revealed vulnerability of 120 proteins in diseased quadriceps muscle supporting our previous findings and providing more general insights into the underlying pathophysiology. Moreover, our data suggested that further DGC components are altered by the perturbed protein processing machinery but are not prone to form aggregates whereas other sarcolemmal proteins are ubiquitinated or bind to p62. Although the architecture of the ER and Golgi as organelles of protein glycosylation are altered, the glycosylation of α-dystroglycan presented unchanged. Conclusions Our combined data classify the p.P104 caveolinopathy as an ER-Golgi disorder impairing proper protein processing and leading to aggregate formation pertaining proteins important for mitochondrial function, cytoskeleton, ECM remodeling and sarcolemmal integrity. Glycosylation of sarcolemmal proteins seems to be normal. The new pathophysiological insights might be of relevance for the development of therapeutic strategies for caveolinopathy patients targeting improved protein folding capacity. Electronic supplementary material The online version of this article (10.1186/s13395-018-0173-y) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
| | - Joachim Weis
- Institute of Neuropathology, RWTH Aachen University Hospital, Pauwelsstr. 30, 52074, Aachen, Germany
| | - Mary E Anderson
- Howard Hughes Medical Institute, Departments of Molecular Physiology and Biophysics, of Neurology, University of Iowa, Iowa City, IA, 52242, USA
| | - Ute Münchberg
- Biomedical Research Department, Tissue Omics group, Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V, Otto-Hahn-Str. 6b, 44227, Dortmund, Germany
| | - Kristina Lorenz
- Biomedical Research Department, Tissue Omics group, Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V, Otto-Hahn-Str. 6b, 44227, Dortmund, Germany
| | - Stephan Buchkremer
- Institute of Neuropathology, RWTH Aachen University Hospital, Pauwelsstr. 30, 52074, Aachen, Germany
| | - Stephanie Carr
- Institute of Genetic Medicine, International Centre for Life, Central Parkway, Newcastle upon Tyne, England, UK
| | - René Peiman Zahedi
- Biomedical Research Department, Tissue Omics group, Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V, Otto-Hahn-Str. 6b, 44227, Dortmund, Germany.,Gerald Bronfman Department of Oncology, Jewish General Hospital, McGill University, Montreal, Quebec, H4A 3T2, Canada.,Segal Cancer Proteomics Centre, Lady Davis Institute, Jewish General Hospital, McGill University, Montreal, Quebec, H3T 1E2, Canada
| | - Eva Brauers
- Institute of Neuropathology, RWTH Aachen University Hospital, Pauwelsstr. 30, 52074, Aachen, Germany
| | - Hannah Michels
- Institute of Genetic Medicine, International Centre for Life, Central Parkway, Newcastle upon Tyne, England, UK
| | - Yoshihide Sunada
- Department of Neurology, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192, Japan
| | - Hanns Lochmüller
- Institute of Genetic Medicine, International Centre for Life, Central Parkway, Newcastle upon Tyne, England, UK.,Department of Neuropediatrics and Muscle Disorders, Medical Center - University of Freiburg, Faculty of Medicine, Freiburg, Germany.,Centro Nacional de Análisis Genómico (CNAG-CRG), Center for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), Barcelona, Catalonia, Spain.,Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada and Division of Neurology, Department of Medicine, The Ottawa Hospital, Ottawa, Canada
| | - Kevin P Campbell
- Howard Hughes Medical Institute, Departments of Molecular Physiology and Biophysics, of Neurology, University of Iowa, Iowa City, IA, 52242, USA
| | - Erik Freier
- Biomedical Research Department, Tissue Omics group, Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V, Otto-Hahn-Str. 6b, 44227, Dortmund, Germany
| | - Denisa Hathazi
- Biomedical Research Department, Tissue Omics group, Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V, Otto-Hahn-Str. 6b, 44227, Dortmund, Germany
| | - Andreas Roos
- Biomedical Research Department, Tissue Omics group, Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V, Otto-Hahn-Str. 6b, 44227, Dortmund, Germany.
| |
Collapse
|
22
|
Ichhaporia VP, Kim J, Kavdia K, Vogel P, Horner L, Frase S, Hendershot LM. SIL1, the endoplasmic-reticulum-localized BiP co-chaperone, plays a crucial role in maintaining skeletal muscle proteostasis and physiology. Dis Model Mech 2018; 11:dmm.033043. [PMID: 29666155 PMCID: PMC5992605 DOI: 10.1242/dmm.033043] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 03/22/2018] [Indexed: 01/02/2023] Open
Abstract
Mutations in SIL1, a cofactor for the endoplasmic reticulum (ER)-localized Hsp70 chaperone, BiP, cause Marinesco-Sjögren syndrome (MSS), an autosomal recessive disorder. Using a mouse model, we characterized molecular aspects of the progressive myopathy associated with MSS. Proteomic profiling of quadriceps at the onset of myopathy revealed that SIL1 deficiency affected multiple pathways critical to muscle physiology. We observed an increase in ER chaperones prior to the onset of muscle weakness, which was complemented by upregulation of multiple components of cellular protein degradation pathways. These responses were inadequate to maintain normal expression of secretory pathway proteins, including insulin and IGF-1 receptors. There was a paradoxical enhancement of downstream PI3K-AKT-mTOR signaling and glucose uptake in SIL1-disrupted skeletal muscles, all of which were insufficient to maintain skeletal muscle mass. Together, these data reveal a disruption in ER homeostasis upon SIL1 loss, which is countered by multiple compensatory responses that are ultimately unsuccessful, leading to trans-organellar proteostasis collapse and myopathy. Editor's choice: This study provides molecular insights into the progressive myopathy and cellular compensatory responses attempted upon loss of SIL1, a component of the endoplasmic-reticulum-resident Hsp70 protein-folding machinery.
Collapse
Affiliation(s)
- Viraj P Ichhaporia
- Dept of Microbiology, Immunology, and Biochemistry, The University of Tennessee Health Science Center, Memphis, TN 38163, USA.,Dept of Tumor Cell Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Jieun Kim
- Small Animal Imaging Center, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Kanisha Kavdia
- Proteomics Facility, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Peter Vogel
- Dept of Pathology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Linda Horner
- Cell and Tissue Imaging Center, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Sharon Frase
- Cell and Tissue Imaging Center, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Linda M Hendershot
- Dept of Microbiology, Immunology, and Biochemistry, The University of Tennessee Health Science Center, Memphis, TN 38163, USA .,Dept of Tumor Cell Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| |
Collapse
|
23
|
Buchkremer S, González Coraspe JA, Weis J, Roos A. Sil1-Mutant Mice Elucidate Chaperone Function in Neurological Disorders. J Neuromuscul Dis 2018; 3:169-181. [PMID: 27854219 PMCID: PMC5271578 DOI: 10.3233/jnd-160152] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Chaperone dysfunction leading to the build-up of misfolded proteins could frequently be linked to clinical manifestations also affecting the nervous system and the skeletal muscle. In addition, increase in chaperone function is beneficial to antagonize protein aggregation and thus represents a promising target for therapeutic concepts for many genetic and acquired chaperonopathies. However, little is known on the precise molecular mechanisms defining the cell and tissue abnormalities in the case of impaired chaperone function as well as on underlying effects in the case of compensatory up-regulation of chaperones. This scarcity of knowledge often arises from a lack of appropriate animal models that mimic closely the human molecular, cellular, and histological characteristics. Here, we introduce the Sil1-mutant woozy mouse as a suitable model to investigate molecular and cellular mechanisms of impaired ER-chaperone function affecting the integrity of nervous system and skeletal muscle. The overlapping clinical findings in man and mouse indicate that woozy is a good copy of a human phenotype called Marinesco-Sjögren syndrome. We confirm the presence of ER-stress and expand the biochemical knowledge of altered nuclear envelope in muscle, a hallmark of SIL1-disease. In addition, our data suggest that impaired excitation-contraction coupling might be part of the SIL1-pathophysiology. Our results moreover indicate that divergent expression of pro- and anti-survival proteins is decisive for Purkinje cell survival. By summarizing the current knowledge of woozy, we focus on the suitability of this animal model to study neuroprotective co-chaperone function and to investigate the involvement of co-chaperones in the predisposition of other disorders such as diabetic neuropathy.
Collapse
Affiliation(s)
- Stephan Buchkremer
- Institute of Neuropathology, University Hospital RWTH Aachen, Aachen, Germany
| | | | - Joachim Weis
- Institute of Neuropathology, University Hospital RWTH Aachen, Aachen, Germany
| | - Andreas Roos
- Institute of Neuropathology, University Hospital RWTH Aachen, Aachen, Germany.,Leibniz-Institut für Analytische Wissenschaften ISAS e.V., Dortmund, Germany.,The John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases, Newcastle University, Central Parkway, Newcastle upon Tyne, UK
| |
Collapse
|
24
|
Castets P, Frank S, Sinnreich M, Rüegg MA. "Get the Balance Right": Pathological Significance of Autophagy Perturbation in Neuromuscular Disorders. J Neuromuscul Dis 2018; 3:127-155. [PMID: 27854220 PMCID: PMC5271579 DOI: 10.3233/jnd-160153] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Recent research has revealed that autophagy, a major catabolic process in cells, is dysregulated in several neuromuscular diseases and contributes to the muscle wasting caused by non-muscle disorders (e.g. cancer cachexia) or during aging (i.e. sarcopenia). From there, the idea arose to interfere with autophagy or manipulate its regulatory signalling to help restore muscle homeostasis and attenuate disease progression. The major difficulty for the development of therapeutic strategies is to restore a balanced autophagic flux, due to the dynamic nature of autophagy. Thus, it is essential to better understand the mechanisms and identify the signalling pathways at play in the control of autophagy in skeletal muscle. A comprehensive analysis of the autophagic flux and of the causes of its dysregulation is required to assess the pathogenic role of autophagy in diseased muscle. Furthermore, it is essential that experiments distinguish between primary dysregulation of autophagy (prior to disease onset) and impairments as a consequence of the pathology. Of note, in most muscle disorders, autophagy perturbation is not caused by genetic modification of an autophagy-related protein, but rather through indirect alteration of regulatory signalling or lysosomal function. In this review, we will present the mechanisms involved in autophagy, and those ensuring its tight regulation in skeletal muscle. We will then discuss as to how autophagy dysregulation contributes to the pathogenesis of neuromuscular disorders and possible ways to interfere with this process to limit disease progression.
Collapse
Affiliation(s)
| | - Stephan Frank
- Institute of Pathology, Division of Neuropathology Basel University Hospital, Basel, Switzerland
| | - Michael Sinnreich
- Neuromuscular Research Center, Departments of Neurology and Biomedicine, Pharmazentrum, Basel, Switzerland
| | | |
Collapse
|
25
|
Abstract
The autosomal-recessive cerebellar ataxias comprise more than half of the known genetic forms of ataxia and represent an extensive group of clinically heterogeneous disorders that can occur at any age but whose onset is typically prior to adulthood. In addition to ataxia, patients often present with polyneuropathy and clinical symptoms outside the nervous system. The most common of these diseases is Friedreich ataxia, caused by mutation of the frataxin gene, but recent advances in genetic analysis have greatly broadened the ever-expanding number of causative genes to over 50. In this review, the clinical neurogenetics of the recessive cerebellar ataxias will be discussed, including updates on recently identified novel ataxia genes, advancements in unraveling disease-specific molecular pathogenesis leading to ataxia, potential treatments under development, technologic improvements in diagnostic testing such as clinical exome sequencing, and what the future holds for clinicians and geneticists.
Collapse
Affiliation(s)
- Brent L Fogel
- Program in Neurogenetics, Departments of Neurology and Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA, United States.
| |
Collapse
|
26
|
Targeting the enhanced ER stress response in Marinesco-Sjögren syndrome. J Neurol Sci 2017; 385:49-56. [PMID: 29406913 DOI: 10.1016/j.jns.2017.12.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 11/11/2017] [Accepted: 12/08/2017] [Indexed: 12/23/2022]
Abstract
BACKGROUND AND OBJECTIVE Marinesco-Sjögren syndrome (MSS) is an autosomal recessive infantile-onset disorder characterized by cataracts, cerebellar ataxia, and progressive myopathy caused by mutation of SIL1. In mice, a defect in SIL1 causes endoplasmic reticulum (ER) chaperone dysfunction, leading to unfolded protein accumulation and increased ER stress. However, ER stress and the unfolded protein response (UPR) have not been investigated in MSS patient-derived cells. METHODS Lymphoblastoid cell lines (LCLs) were established from four MSS patients. Spontaneous and tunicamycin-induced ER stress and the UPR were investigated in MSS-LCLs. Expression of UPR markers was analyzed by western blotting. ER stress-induced apoptosis was analyzed by flow cytometry. The cytoprotective effects of ER stress modulators were also examined. RESULTS MSS-LCLs exhibited increased spontaneous ER stress and were highly susceptible to ER stress-induced apoptosis. The inositol-requiring protein 1α (IRE1α)-X-box-binding protein 1 (XBP1) pathway was mainly upregulated in MSS-LCLs. Tauroursodeoxycholic acid (TUDCA) attenuated ER stress-induced apoptosis. CONCLUSION MSS patient-derived cells exhibit increased ER stress, an activated UPR, and susceptibility to ER stress-induced death. TUDCA reduces ER stress-induced death of MSS patient-derived cells. The potential of TUDCA as a therapeutic agent for MSS could be explored further in preclinical studies.
Collapse
|
27
|
Lang S, Pfeffer S, Lee PH, Cavalié A, Helms V, Förster F, Zimmermann R. An Update on Sec61 Channel Functions, Mechanisms, and Related Diseases. Front Physiol 2017; 8:887. [PMID: 29163222 PMCID: PMC5672155 DOI: 10.3389/fphys.2017.00887] [Citation(s) in RCA: 107] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 10/19/2017] [Indexed: 12/18/2022] Open
Abstract
The membrane of the endoplasmic reticulum (ER) of nucleated human cells harbors the protein translocon, which facilitates membrane integration or translocation of almost every newly synthesized polypeptide targeted to organelles of the endo- and exocytotic pathway. The translocon comprises the polypeptide-conducting Sec61 channel and several additional proteins and complexes that are permanently or transiently associated with the heterotrimeric Sec61 complex. This ensemble of proteins facilitates ER targeting of precursor polypeptides, modification of precursor polypeptides in transit through the Sec61 complex, and Sec61 channel gating, i.e., dynamic regulation of the pore forming subunit to mediate precursor transport and calcium efflux. Recently, cryoelectron tomography of translocons in native ER membrane vesicles, derived from human cell lines or patient fibroblasts, and even intact cells has given unprecedented insights into the architecture and dynamics of the native translocon and the Sec61 channel. These structural data are discussed in light of different Sec61 channel activities including ribosome receptor function, membrane insertion, and translocation of newly synthesized polypeptides as well as the putative physiological roles of the Sec61 channel as a passive ER calcium leak channel. Furthermore, the structural insights into the Sec61 channel are incorporated into an overview and update on Sec61 channel-related diseases—the Sec61 channelopathies—and novel therapeutic concepts for their treatment.
Collapse
Affiliation(s)
- Sven Lang
- Competence Center for Molecular Medicine, Saarland University Medical School, Homburg, Germany
| | - Stefan Pfeffer
- Department of Molecular Structural Biology, Max-Planck Institute of Biochemistry, Martinsried, Germany
| | - Po-Hsien Lee
- Center for Bioinformatics, Saarland University, Saarbrücken, Germany
| | - Adolfo Cavalié
- Experimental and Clinical Pharmacology and Toxicology, Saarland University, Homburg, Germany
| | - Volkhard Helms
- Center for Bioinformatics, Saarland University, Saarbrücken, Germany
| | - Friedrich Förster
- Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands
| | - Richard Zimmermann
- Competence Center for Molecular Medicine, Saarland University Medical School, Homburg, Germany
| |
Collapse
|
28
|
Dreser A, Vollrath JT, Sechi A, Johann S, Roos A, Yamoah A, Katona I, Bohlega S, Wiemuth D, Tian Y, Schmidt A, Vervoorts J, Dohmen M, Beyer C, Anink J, Aronica E, Troost D, Weis J, Goswami A. The ALS-linked E102Q mutation in Sigma receptor-1 leads to ER stress-mediated defects in protein homeostasis and dysregulation of RNA-binding proteins. Cell Death Differ 2017; 24:1655-1671. [PMID: 28622300 PMCID: PMC5596426 DOI: 10.1038/cdd.2017.88] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 03/14/2017] [Accepted: 03/22/2017] [Indexed: 12/21/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is characterized by the selective degeneration of motor neurons (MNs) and their target muscles. Misfolded proteins which often form intracellular aggregates are a pathological hallmark of ALS. Disruption of the functional interplay between protein degradation (ubiquitin proteasome system and autophagy) and RNA-binding protein homeostasis has recently been suggested as an integrated model that merges several ALS-associated proteins into a common pathophysiological pathway. The E102Q mutation in one such candidate gene, the endoplasmic reticulum (ER) chaperone Sigma receptor-1 (SigR1), has been reported to cause juvenile ALS. Although loss of SigR1 protein contributes to neurodegeneration in several ways, the molecular mechanisms underlying E102Q-SigR1-mediated neurodegeneration are still unclear. In the present study, we showed that the E102Q-SigR1 protein rapidly aggregates and accumulates in the ER and associated compartments in transfected cells, leading to structural alterations of the ER, nuclear envelope and mitochondria and to subsequent defects in proteasomal degradation and calcium homeostasis. ER defects and proteotoxic stress generated by E102Q-SigR1 aggregates further induce autophagy impairment, accumulation of stress granules and cytoplasmic aggregation of the ALS-linked RNA-binding proteins (RBPs) matrin-3, FUS, and TDP-43. Similar ultrastructural abnormalities as well as altered protein degradation and misregulated RBP homeostasis were observed in primary lymphoblastoid cells (PLCs) derived from E102Q-SigR1 fALS patients. Consistent with these findings, lumbar α-MNs of both sALS as well as fALS patients showed cytoplasmic matrin-3 aggregates which were not co-localized with pTDP-43 aggregates. Taken together, our results support the notion that E102Q-SigR1-mediated ALS pathogenesis comprises a synergistic mechanism of both toxic gain and loss of function involving a vicious circle of altered ER function, impaired protein homeostasis and defective RBPs.
Collapse
Affiliation(s)
- Alice Dreser
- Institute of Neuropathology, RWTH Aachen University Medical School, Aachen, Germany
| | - Jan Tilmann Vollrath
- Institute of Neuropathology, RWTH Aachen University Medical School, Aachen, Germany
| | - Antonio Sechi
- Institute of Biomedical Engineering, Deparment of Cell Biology, RWTH Aachen University Medical School, Aachen, Germany
| | - Sonja Johann
- Institute of Neuroanatomy, RWTH Aachen University Medical School, Aachen, Germany
| | - Andreas Roos
- Institute of Neuropathology, RWTH Aachen University Medical School, Aachen, Germany
- Leibniz-Institut für Analytische Wissenschaften – ISAS – e.V., Dortmund, Germany
- Institute of Genetic Medicine, John Walton Muscular Dystrophy Research Centre, International Centre for Life, Central Parkway, Newcastle upon Tyne, England, UK
| | - Alfred Yamoah
- Institute of Neuropathology, RWTH Aachen University Medical School, Aachen, Germany
| | - Istvan Katona
- Institute of Neuropathology, RWTH Aachen University Medical School, Aachen, Germany
| | - Saeed Bohlega
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Dominik Wiemuth
- Institute of Physiology, RWTH Aachen University Medical School, Aachen Germany
| | - Yuemin Tian
- Institute of Physiology, RWTH Aachen University Medical School, Aachen Germany
| | - Axel Schmidt
- Institute of Physiology, RWTH Aachen University Medical School, Aachen Germany
| | - Jörg Vervoorts
- Institute of Biochemistry and Molecular Biology, RWTH Aachen University Medical School, Aachen, Germany
| | - Marc Dohmen
- Institute of Biochemistry and Molecular Biology, RWTH Aachen University Medical School, Aachen, Germany
| | - Cordian Beyer
- Institute of Neuroanatomy, RWTH Aachen University Medical School, Aachen, Germany
| | - Jasper Anink
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Eleonora Aronica
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Dirk Troost
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Joachim Weis
- Institute of Neuropathology, RWTH Aachen University Medical School, Aachen, Germany
| | - Anand Goswami
- Institute of Neuropathology, RWTH Aachen University Medical School, Aachen, Germany
| |
Collapse
|
29
|
Longitudinal analysis of motor symptoms and histopathology in woozy mice, a model of cerebellar ataxia. Neuroreport 2017; 28:779-787. [PMID: 28723727 DOI: 10.1097/wnr.0000000000000816] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Woozy (wz) mice develop ataxia and carry a mutation in the Sil1 gene. Homozygous wz mice have been characterized histopathologically, but no details of their motor function have been reported. In the present study, to comprehensively understand the relationship between symptomatic progression and pathological feature, we evaluated motor function and neurodegeneration with age from presymptomatic to terminal stages. We evaluated the motor function of homozygous and heterozygous wz mice aged from 5 to 71 weeks. Motor function was evaluated using the rotarod test, the footprint test, and the parallel rod floor test. Furthermore, we carried out a histopathological analysis of the mice at several ages. Impairment of motor function in homozygous wz mice began at around 11 weeks of age and became markedly worse until around 14 weeks. Heterozygous wz mice did not show motor dysfunction until 71 weeks of age. Features of cerebellar ataxia were evaluated using the footprint test and the parallel rod floor test. In addition to the observation of ubiquitin-positive aggregates at 6 weeks of age, Purkinje cell loss at 9 weeks of age and cerebellar atrophy were confirmed by histopathology. Apart from the cerebellar changes, we detected no other pathology that could contribute toward ataxia. In heterozygous wz mice, only minimal formation of ubiquitin-positive aggregates was observed. Homozygous wz mice showed adult-onset ataxia with progressive neurodegeneration of the cerebellum. Homozygous wz mice might be useful as an animal model of diseases showing adult-onset ataxia because of cerebellar neurodegeneration.
Collapse
|
30
|
Kollipara L, Buchkremer S, Coraspe JAG, Hathazi D, Senderek J, Weis J, Zahedi RP, Roos A. In-depth phenotyping of lymphoblastoid cells suggests selective cellular vulnerability in Marinesco-Sjögren syndrome. Oncotarget 2017; 8:68493-68516. [PMID: 28978133 PMCID: PMC5620273 DOI: 10.18632/oncotarget.19663] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 05/28/2017] [Indexed: 12/18/2022] Open
Abstract
SIL1 is a ubiquitous protein of the Endoplasmic Reticulum (ER) acting as a co-chaperone for the ER-resident chaperone, BiP. Recessive mutations of the corresponding gene lead to vulnerability of skeletal muscle and central nervous system in man (Marinesco-Sjögren syndrome; MSS) and mouse. However, it is still unclear how loss of ubiquitous SIL1 leads to selective vulnerability of the nervous system and skeletal muscle whereas other cells and organs are protected from clinical manifestations. In this study we aimed to disentangle proteins participating in selective vulnerability of SIL1-deficient cells and tissues: morphological examination of MSS patient-derived lymphoblastoid cells revealed altered organelle structures (ER, nucleus and mitochondria) thus showing subclinical vulnerability. To correlate structural perturbations with biochemical changes and to identify proteins potentially preventing phenotypical manifestation, proteomic studies have been carried out. Results of proteomic profiling are in line with the morphological findings and show affection of nuclear, mitochondrial and cytoskeletal proteins as well as of such responsible for cellular viability. Moreover, expression patterns of proteins known to be involved in neuromuscular disorders or in development and function of the nervous system were altered. Paradigmatic findings were confirmed by immunohistochemistry of splenic lymphocytes and the cerebellum of SIL1-deficient mice. Ataxin-10, identified with increased abundance in our proteome profile, is necessary for the neuronal survival but also controls muscle fiber apoptosis, thus declaring this protein as a plausible candidate for selective tissue vulnerability. Our combined results provide first insights into the molecular causes of selective cell and tissue vulnerability defining the MSS phenotype.
Collapse
Affiliation(s)
- Laxmikanth Kollipara
- Leibniz-Institut für Analytische Wissenschaften-ISAS -e.V., 44227 Dortmund, Germany
| | - Stephan Buchkremer
- Institute of Neuropathology, University Hospital Aachen, RWTH Aachen, 5274 Aachen, Germany
| | | | - Denisa Hathazi
- Leibniz-Institut für Analytische Wissenschaften-ISAS -e.V., 44227 Dortmund, Germany
| | - Jan Senderek
- Friedrich-Baur-Institute, Medical Faculty, Ludwig-Maximilians-University, 80336 Munich, Germany
| | - Joachim Weis
- Institute of Neuropathology, University Hospital Aachen, RWTH Aachen, 5274 Aachen, Germany
| | - René P Zahedi
- Leibniz-Institut für Analytische Wissenschaften-ISAS -e.V., 44227 Dortmund, Germany
| | - Andreas Roos
- Leibniz-Institut für Analytische Wissenschaften-ISAS -e.V., 44227 Dortmund, Germany.,Institute of Neuropathology, University Hospital Aachen, RWTH Aachen, 5274 Aachen, Germany.,The John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases, Newcastle University, Newcastle upon Tyne, NE1 3BZ, UK
| |
Collapse
|
31
|
Carr SJ, Zahedi RP, Lochmüller H, Roos A. Mass spectrometry-based protein analysis to unravel the tissue pathophysiology in Duchenne muscular dystrophy. Proteomics Clin Appl 2017. [DOI: 10.1002/prca.201700071] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Stephanie J. Carr
- John Walton Muscular Dystrophy Research Centre; Institute of Genetic Medicine; Newcastle University; Newcastle upon Tyne UK
| | - René P. Zahedi
- Leibniz-Institut für Analytische Wissenschaften, ISAS e.V.; Dortmund Germany
| | - Hanns Lochmüller
- John Walton Muscular Dystrophy Research Centre; Institute of Genetic Medicine; Newcastle University; Newcastle upon Tyne UK
| | - Andreas Roos
- John Walton Muscular Dystrophy Research Centre; Institute of Genetic Medicine; Newcastle University; Newcastle upon Tyne UK
- Leibniz-Institut für Analytische Wissenschaften, ISAS e.V.; Dortmund Germany
| |
Collapse
|
32
|
Tracking Effects of SIL1 Increase: Taking a Closer Look Beyond the Consequences of Elevated Expression Level. Mol Neurobiol 2017; 55:2524-2546. [PMID: 28401474 DOI: 10.1007/s12035-017-0494-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 03/14/2017] [Indexed: 12/31/2022]
Abstract
SIL1 acts as a co-chaperone for the major ER-resident chaperone BiP and thus plays a role in many BiP-dependent cellular functions such as protein-folding control and unfolded protein response. Whereas the increase of BiP upon cellular stress conditions is a well-known phenomenon, elevation of SIL1 under stress conditions was thus far solely studied in yeast, and different studies indicated an adverse effect of SIL1 increase. This is seemingly in contrast with the beneficial effect of SIL1 increase in surviving neurons in neurodegenerative disorders such as amyotrophic lateral sclerosis and Alzheimer's disease. Here, we addressed these controversial findings. Applying cell biological, morphological and biochemical methods, we demonstrated that SIL1 increases in various mammalian cells and neuronal tissues upon cellular stress. Investigation of heterozygous SIL1 mutant cells and tissues supported this finding. Moreover, SIL1 protein was found to be stabilized during ER stress. Increased SIL1 initiates ER stress in a concentration-dependent manner which agrees with the described adverse SIL1 effect. However, our results also suggest that protective levels are achieved by the secretion of excessive SIL1 and GRP170 and that moderately increased SIL1 also ameliorates cellular fitness under stress conditions. Our immunoprecipitation results indicate that SIL1 might act in a BiP-independent manner. Proteomic studies showed that SIL1 elevation alters the expression of proteins including crucial players in neurodegeneration, especially in Alzheimer's disease. This finding agrees with our observation of increased SIL1 immunoreactivity in surviving neurons of Alzheimer's disease autopsy cases and supports the assumption that SIL1 plays a protective role in neurodegenerative disorders.
Collapse
|
33
|
Wiessner M, Roos A, Munn CJ, Viswanathan R, Whyte T, Cox D, Schoser B, Sewry C, Roper H, Phadke R, Marini Bettolo C, Barresi R, Charlton R, Bönnemann CG, Abath Neto O, Reed UC, Zanoteli E, Araújo Martins Moreno C, Ertl-Wagner B, Stucka R, De Goede C, Borges da Silva T, Hathazi D, Dell’Aica M, Zahedi RP, Thiele S, Müller J, Kingston H, Müller S, Curtis E, Walter MC, Strom TM, Straub V, Bushby K, Muntoni F, Swan LE, Lochmüller H, Senderek J. Mutations in INPP5K, Encoding a Phosphoinositide 5-Phosphatase, Cause Congenital Muscular Dystrophy with Cataracts and Mild Cognitive Impairment. Am J Hum Genet 2017; 100:523-536. [PMID: 28190456 PMCID: PMC5339217 DOI: 10.1016/j.ajhg.2017.01.024] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 01/12/2017] [Indexed: 12/26/2022] Open
Abstract
Phosphoinositides are small phospholipids that control diverse cellular downstream signaling events. Their spatial and temporal availability is tightly regulated by a set of specific lipid kinases and phosphatases. Congenital muscular dystrophies are hereditary disorders characterized by hypotonia and weakness from birth with variable eye and central nervous system involvement. In individuals exhibiting congenital muscular dystrophy, early-onset cataracts, and mild intellectual disability but normal cranial magnetic resonance imaging, we identified bi-allelic mutations in INPP5K, encoding inositol polyphosphate-5-phosphatase K. Mutations impaired phosphatase activity toward the phosphoinositide phosphatidylinositol (4,5)-bisphosphate or altered the subcellular localization of INPP5K. Downregulation of INPP5K orthologs in zebrafish embryos disrupted muscle fiber morphology and resulted in abnormal eye development. These data link congenital muscular dystrophies to defective phosphoinositide 5-phosphatase activity that is becoming increasingly recognized for its role in mediating pivotal cellular mechanisms contributing to disease.
Collapse
|
34
|
Inui T, Anzai M, Takezawa Y, Endo W, Kakisaka Y, Kikuchi A, Onuma A, Kure S, Nishino I, Ohba C, Saitsu H, Matsumoto N, Haginoya K. A novel mutation in the proteolytic domain of LONP1 causes atypical CODAS syndrome. J Hum Genet 2017; 62:653-655. [PMID: 28148925 DOI: 10.1038/jhg.2017.11] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 01/05/2017] [Accepted: 01/07/2017] [Indexed: 12/21/2022]
Abstract
Cerebral, ocular, dental, auricular, skeletal (CODAS) syndrome is a rare autosomal recessive multisystem disorder caused by mutations in LONP1. It is characterized by intellectual disability, cataracts, delayed tooth eruption, malformed auricles and skeletal abnormalities. We performed whole-exome sequencing on a 12-year-old Japanese male with severe intellectual disability, congenital bilateral cataracts, spasticity, hypotonia with motor regression and progressive cerebellar atrophy with hyperintensity of the cerebellar cortex on T2-weighted images. We detected compound heterozygous mutation in LONP1. One allele contained a paternally inherited frameshift mutation (p.Ser100Glnfs*46). The other allele contained a maternally inherited missense mutation (p.Arg786Trp), which was predicted to be pathogenic by web-based prediction tools. The two mutations were not found in Exome Variant Server or our 575 in-house control exomes. Some features were not consistent with CODAS syndrome but overlapped with Marinesco-Sjögren syndrome, a multisystem disorder caused by a mutation in SIL1. An atypical mutation site may result in atypical presentation of the LONP1 mutation.
Collapse
Affiliation(s)
- Takehiko Inui
- Department of Pediatric Neurology, Miyagi Children's Hospital, Miyagi, Japan
| | - Mai Anzai
- Department of Pediatric Neurology, Miyagi Children's Hospital, Miyagi, Japan
| | - Yusuke Takezawa
- Department of Pediatric Neurology, Miyagi Children's Hospital, Miyagi, Japan.,Department of Pediatrics, Tohoku University School of Medicine, Sendai, Japan
| | - Wakaba Endo
- Department of Pediatric Neurology, Miyagi Children's Hospital, Miyagi, Japan
| | - Yosuke Kakisaka
- Department of Pediatrics, Tohoku University School of Medicine, Sendai, Japan
| | - Atsuo Kikuchi
- Department of Pediatrics, Tohoku University School of Medicine, Sendai, Japan
| | - Akira Onuma
- Department of Pediatrics, Ekoh-Ryoikuen, Sendai, Japan
| | - Shigeo Kure
- Department of Pediatrics, Tohoku University School of Medicine, Sendai, Japan
| | - Ichizo Nishino
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Chihiro Ohba
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Hirotomo Saitsu
- Department of Biochemistry, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Naomichi Matsumoto
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Kazuhiro Haginoya
- Department of Pediatric Neurology, Miyagi Children's Hospital, Miyagi, Japan.,Department of Pediatrics, Tohoku University School of Medicine, Sendai, Japan
| |
Collapse
|
35
|
Kawahara G, Hayashi YK. Characterization of Zebrafish Models of Marinesco-Sjögren Syndrome. PLoS One 2016; 11:e0165563. [PMID: 27792754 PMCID: PMC5085058 DOI: 10.1371/journal.pone.0165563] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 10/13/2016] [Indexed: 11/23/2022] Open
Abstract
SIL1 is a nucleotide exchange factor for the endoplasmic reticulum chaperone, BiP. Mutations in the SIL1 gene cause Marinesco-Sjögren syndrome (MSS), an autosomal recessive disease characterized by cerebellar ataxia, mental retardation, congenital cataracts, and myopathy. To create novel zebrafish models of MSS for therapeutic drug screening, we analyzed phenotypes in sil1 knock down fish by two different antisense oligo morpholinos. Both sil1 morphants had abnormal formation of muscle fibers and irregularity of the myosepta. Moreover, they showed smaller-sized eyes and loss of purkinje cells in cerebellar area compared to controls. Immunoblotting analysis revealed increased protein amounts of BiP, lipidated LC3, and caspase 3. These data supported that the sil1 morphants can represent mimicking phenotypes of human MSS. The sil1 morphants phenocopy the human MSS disease pathology and are a good animal model for therapeutic studies.
Collapse
Affiliation(s)
- Genri Kawahara
- Department of Pathophysiology, Tokyo Medical University, Tokyo, Japan
| | - Yukiko K. Hayashi
- Department of Pathophysiology, Tokyo Medical University, Tokyo, Japan
- * E-mail:
| |
Collapse
|
36
|
Disrupted autophagy undermines skeletal muscle adaptation and integrity. Mamm Genome 2016; 27:525-537. [PMID: 27484057 PMCID: PMC5110612 DOI: 10.1007/s00335-016-9659-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 07/12/2016] [Indexed: 12/18/2022]
Abstract
This review assesses the importance of proteostasis in skeletal muscle maintenance with a specific emphasis on autophagy. Skeletal muscle appears to be particularly vulnerable to genetic defects in basal and induced autophagy, indicating that autophagy is co-substantial to skeletal muscle maintenance and adaptation. We discuss emerging evidence that tension-induced protein unfolding may act as a direct link between mechanical stress and autophagic pathways. Mechanistic links between protein damage, autophagy and muscle hypertrophy, which is also induced by mechanical stress, are still poorly understood. However, some mouse models of muscle disease show ameliorated symptoms upon effective targeting of basal autophagy. These findings highlight the importance of autophagy as therapeutic target and suggest that elucidating connections between protein unfolding and mTOR-dependent or mTOR-independent hypertrophic responses is likely to reveal specific therapeutic windows for the treatment of muscle wasting disorders.
Collapse
|
37
|
Leonardi A, Tarricone E, Corrao S, Alaibac M, Corso AJ, Zavan B, Venier P, Conway de Macario E, Macario AJL, Di Stefano A, Cappello F, Brun P. Chaperone patterns in vernal keratoconjunctivitis are distinctive of cell and Hsp type and are modified by inflammatory stimuli. Allergy 2016; 71:403-11. [PMID: 26613380 DOI: 10.1111/all.12814] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/20/2015] [Indexed: 01/18/2023]
Abstract
BACKGROUND Vernal keratoconjunctivitis (VKC) is a severe ocular allergy with pathogenic mechanism poorly understood and no efficacious treatment. The aims of the study were to determine quantities and distribution of Hsp chaperones in the conjunctiva of VKC patients and assess their levels in conjunctival epithelial and fibroblast cultures exposed to inflammatory stimuli. METHODS Hsp10, Hsp27, Hsp40, Hsp60, Hsp70, Hsp90, Hsp105, and Hsp110 were determined in conjunctiva biopsies from nine patients and nine healthy age-matched normal subjects, using immunomorphology and qPCR. Conjunctival epithelial cells and fibroblasts were cultured and stimulated with IL-1β, histamine, IL-4, TNF-α, or UV-B irradiation, and changes in Hsp levels were determined by Western blotting. RESULTS Hsp27, Hsp40, Hsp70, and Hsp90 levels increased in the patients' conjunctiva, whereas Hsp10, Hsp60, Hsp100, and Hsp105 did not. Double immunofluorescence demonstrated colocalization of Hsp27, Hsp40, Hsp70, and Hsp90 with CD68 and tryptase. Testing of cultured conjunctival cells revealed an increase in the levels of Hsp27 in fibroblasts stimulated with IL-4; Hsp40 in epithelial cells stimulated with IL-4 and TNF-α and in fibroblasts stimulated with IL-4, TNF-α, and IL-1β; Hsp70 in epithelial cells stimulated with histamine and IL-4; and Hsp90 in fibroblasts stimulated with IL-1β, TNF-α, and IL-4. UV-B did not induce changes. CONCLUSIONS VKC conjunctiva displays distinctive quantitative patterns of Hsps as compared with healthy controls. Cultured conjunctival cells respond to cytokines and inflammatory stimuli with changes in the Hsps quantitative patterns. The data suggest that interaction between the chaperoning and the immune systems drives disease progression.
Collapse
Affiliation(s)
- A. Leonardi
- Department of Neuroscience; Ophthalmology Unit; University of Padua; Padua Italy
| | - E. Tarricone
- Department of Neuroscience; Ophthalmology Unit; University of Padua; Padua Italy
| | - S. Corrao
- Department of Molecular Medicine; University of Padua; Padua Italy
| | - M. Alaibac
- Department of Neuroscience; Dermatology Unit; University of Padua; Padua Italy
| | - A. J. Corso
- Italian National Research Council - Institute for Photonics and Nanotechnologies; Padua Italy
| | - B. Zavan
- Department of Biomedical Sciences; University of Padua; Padua Italy
| | - P. Venier
- Department of Biology; University of Padua; Padua Italy
| | - E. Conway de Macario
- Department of Microbiology and Immunology; School of Medicine; University of Maryland at Baltimore and IMET; Baltimore MD USA
| | - A. J. L. Macario
- Department of Microbiology and Immunology; School of Medicine; University of Maryland at Baltimore and IMET; Baltimore MD USA
- Euro-Mediterranean Institute of Science and Technology; Palermo Italy
| | - A. Di Stefano
- Pneumology Unit and Laboratory of Heart and Lung Cytoimmunopathology; Fondazione Salvatore Maugeri, IRCCS; Veruno (NO) Italy
| | - F. Cappello
- Human Anatomy Section; Department of Experimental Biomedicine and Clinical, Neurosciences; University of Palermo; Palermo Italy
| | - P. Brun
- Department of Molecular Medicine; University of Padua; Padua Italy
| |
Collapse
|
38
|
Zimmermann R. Components and Mechanisms of Import, Modification, Folding, and Assembly of Immunoglobulins in the Endoplasmic Reticulum. J Clin Immunol 2016; 36 Suppl 1:5-11. [PMID: 26923573 DOI: 10.1007/s10875-016-0250-0] [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: 02/17/2016] [Accepted: 02/19/2016] [Indexed: 11/27/2022]
Abstract
In mammalian cells, the endoplasmic reticulum (ER) plays a central role in biogenesis of secretory- and plasma membrane proteins as well as in cellular calcium (Ca(2+)) homeostasis. The protein biogenesis function involves an aqueous polypeptide conducting channel in the ER membrane, which is formed by the heterotrimeric Sec61 complex; the store- and receptor-controlled Ca(2+)- release function requires a steep ER to cytosol gradient, with more than 500 μM free Ca(2+) in the ER and 50 nM Ca(2+) in the cytosol. Recent work demonstrated that the Sec61 complex can transiently allow passive ER Ca(2+) efflux. Therefore, gating of the Sec61 channel has to be tightly regulated by substrates as well as allosteric effectors. The ER lumenal Hsp70-type molecular chaperone, immunoglobulin heavy-chain binding protein (BiP), together with its membrane resident co-chaperone Sec63 facilitates channel opening in a precursor specific manner. In addition, BiP, together with its lumenal co-chaperones, ERj3 and ERj6, as well as cytosolic Ca(2+)-calmodulin (CaM) in collaboration with the membrane resident Sec62 protein represent allosteric effectors for channel closure. In the course of the last couple of years several human diseases were linked to the Sec61 complex and its effectors and were termed Sec61-channelopathies.
Collapse
Affiliation(s)
- Richard Zimmermann
- Competence Center for Molecular Medicine, Saarland University Medical School, Building 44, D-66421, Homburg, Germany.
| |
Collapse
|
39
|
Kollipara L, Buchkremer S, Weis J, Brauers E, Hoss M, Rütten S, Caviedes P, Zahedi RP, Roos A. Proteome Profiling and Ultrastructural Characterization of the Human RCMH Cell Line: Myoblastic Properties and Suitability for Myopathological Studies. J Proteome Res 2016; 15:945-55. [PMID: 26781476 DOI: 10.1021/acs.jproteome.5b00972] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Studying (neuro)muscular disorders is a major topic in biomedicine with a demand for suitable model systems. Continuous cell culture (in vitro) systems have several technical advantages over in vivo systems and became widely used tools for discovering physiological/pathophysiological mechanisms in muscle. In particular, myoblast cell lines are suitable model systems to study complex biochemical adaptations occurring in skeletal muscle and cellular responses to altered genetic/environmental conditions. Whereas most in vitro studies use extensively characterized murine C2C12 cells, a comprehensive description of an equivalent human cell line, not genetically manipulated for immortalization, is lacking. Therefore, we characterized human immortal myoblastic RCMH cells using scanning (SEM) and transmission electron microscopy (TEM) and proteomics. Among more than 6200 identified proteins we confirm the known expression of proteins important for muscle function. Comparing the RCMH proteome with two well-defined nonskeletal muscle cells lines (HeLa, U2OS) revealed a considerable enrichment of proteins important for muscle function. SEM/TEM confirmed the presence of agglomerates of cytoskeletal components/intermediate filaments and a prominent rough ER. In conclusion, our results indicate RMCH as a suitable in vitro model for investigating muscle function-related processes such as mechanical stress burden and mechanotransduction, EC coupling, cytoskeleton, muscle cell metabolism and development, and (ER-associated) myopathic disorders.
Collapse
Affiliation(s)
- Laxmikanth Kollipara
- Leibniz-Institut für Analytische Wissenschaften, ISAS e.V. , Otto-Hahn-Str. 6b, 44227 Dortmund, Germany
| | - Stephan Buchkremer
- Institute of Neuropathology, RWTH Aachen University Hospital , Pauwelsstrasse 30, D-52074 Aachen, Germany
| | - Joachim Weis
- Institute of Neuropathology, RWTH Aachen University Hospital , Pauwelsstrasse 30, D-52074 Aachen, Germany
| | - Eva Brauers
- Institute of Neuropathology, RWTH Aachen University Hospital , Pauwelsstrasse 30, D-52074 Aachen, Germany
| | - Mareike Hoss
- Electron Microscopic Facility, Institute of Pathology, RWTH Aachen University Hospital , D-52074 Aachen, Germany
| | - Stephan Rütten
- Electron Microscopic Facility, Institute of Pathology, RWTH Aachen University Hospital , D-52074 Aachen, Germany
| | - Pablo Caviedes
- Programa de Farmacología Molecular y Clínica, ICBM, Facultad de Medicina, Universidad de Chile , Santiago 1058, Chile
| | - René P Zahedi
- Leibniz-Institut für Analytische Wissenschaften, ISAS e.V. , Otto-Hahn-Str. 6b, 44227 Dortmund, Germany
| | - Andreas Roos
- Leibniz-Institut für Analytische Wissenschaften, ISAS e.V. , Otto-Hahn-Str. 6b, 44227 Dortmund, Germany.,Institute of Neuropathology, RWTH Aachen University Hospital , Pauwelsstrasse 30, D-52074 Aachen, Germany
| |
Collapse
|
40
|
Roos A, Kollipara L, Buchkremer S, Labisch T, Brauers E, Gatz C, Lentz C, Gerardo-Nava J, Weis J, Zahedi RP. Cellular Signature of SIL1 Depletion: Disease Pathogenesis due to Alterations in Protein Composition Beyond the ER Machinery. Mol Neurobiol 2015; 53:5527-41. [PMID: 26468156 DOI: 10.1007/s12035-015-9456-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 09/25/2015] [Indexed: 12/14/2022]
Abstract
SIL1 acts as nucleotide exchange factor for the endoplasmic reticulum chaperone BiP. Mutations of SIL1 cause Marinesco-Sjögren syndrome (MSS), a neurodegenerative disorder. Moreover, a particular function of SIL1 for etiopathology of amyotrophic lateral sclerosis (ALS) was highlighted, thus declaring the functional SIL1-BiP complex as a modifier for neurodegenerative disorders. Thereby, depletion of SIL1 was associated with an earlier manifestation and in strengthened disease progression in ALS. Owing to the absence of appropriate in vitro models, the precise cellular pathophysiological mechanisms leading to neurodegeneration in MSS and triggering the same in further disorders like ALS are still elusive. We found that SIL1 depletion in human embryonic kidney 293 (HEK293) cells led to structural changes of the endoplasmic reticulum (ER) including the nuclear envelope and mitochondrial degeneration that closely mimic pathological alterations in MSS and ALS. Functional studies revealed disturbed protein transport, cytotoxicity with reduced proliferation and viability, accompanied by activation of cellular defense mechanisms including the unfolded protein response, ER-associated degradation pathway, proteolysis, and expression of apoptotic and survival factors. Our data moreover indicated that proteins involved in cytoskeletal organization, vesicular transport, mitochondrial function, and neurological processes contribute to SIL1 pathophysiology. Altered protein expression upon SIL1 depletion in vitro could be confirmed in Sil1-deficient motoneurones for paradigmatic proteins belonging to different functional classes. Our results demonstrate that SIL1-depleted HEK293 cells are an appropriate model to identify proteins modulated by SIL1 expression level and contributing to neurodegeneration in MSS and further disorders like ALS. Thereby, our combined results point out that proteins beyond such involved ER-related protein processing are affected by SIL1 depletion.
Collapse
Affiliation(s)
- Andreas Roos
- Institute of Neuropathology, RWTH Aachen University Hospital, Pauwelsstr. 30, 52074, Aachen, Germany.
- Leibniz-Institut für Analytische Wissenschaften-ISAS e.V, Otto-Hahn-Str. 6b, 44227, Dortmund, Germany.
| | - Laxmikanth Kollipara
- Leibniz-Institut für Analytische Wissenschaften-ISAS e.V, Otto-Hahn-Str. 6b, 44227, Dortmund, Germany
| | - Stephan Buchkremer
- Institute of Neuropathology, RWTH Aachen University Hospital, Pauwelsstr. 30, 52074, Aachen, Germany
| | - Thomas Labisch
- Institute of Neuropathology, RWTH Aachen University Hospital, Pauwelsstr. 30, 52074, Aachen, Germany
| | - Eva Brauers
- Institute of Neuropathology, RWTH Aachen University Hospital, Pauwelsstr. 30, 52074, Aachen, Germany
| | - Christian Gatz
- Institute of Neuropathology, RWTH Aachen University Hospital, Pauwelsstr. 30, 52074, Aachen, Germany
| | - Chris Lentz
- Institute of Neuropathology, RWTH Aachen University Hospital, Pauwelsstr. 30, 52074, Aachen, Germany
| | - José Gerardo-Nava
- Institute of Neuropathology, RWTH Aachen University Hospital, Pauwelsstr. 30, 52074, Aachen, Germany
| | - Joachim Weis
- Institute of Neuropathology, RWTH Aachen University Hospital, Pauwelsstr. 30, 52074, Aachen, Germany
| | - René P Zahedi
- Leibniz-Institut für Analytische Wissenschaften-ISAS e.V, Otto-Hahn-Str. 6b, 44227, Dortmund, Germany
| |
Collapse
|
41
|
Schorr S, Klein MC, Gamayun I, Melnyk A, Jung M, Schäuble N, Wang Q, Hemmis B, Bochen F, Greiner M, Lampel P, Urban SK, Hassdenteufel S, Dudek J, Chen XZ, Wagner R, Cavalié A, Zimmermann R. Co-chaperone Specificity in Gating of the Polypeptide Conducting Channel in the Membrane of the Human Endoplasmic Reticulum. J Biol Chem 2015; 290:18621-35. [PMID: 26085089 DOI: 10.1074/jbc.m115.636639] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Indexed: 11/06/2022] Open
Abstract
In mammalian cells, signal peptide-dependent protein transport into the endoplasmic reticulum (ER) is mediated by a dynamic polypeptide-conducting channel, the heterotrimeric Sec61 complex. Previous work has characterized the Sec61 complex as a potential ER Ca(2+) leak channel in HeLa cells and identified ER lumenal molecular chaperone immunoglobulin heavy-chain-binding protein (BiP) as limiting Ca(2+) leakage via the open Sec61 channel by facilitating channel closing. This BiP activity involves binding of BiP to the ER lumenal loop 7 of Sec61α in the vicinity of tyrosine 344. Of note, the Y344H mutation destroys the BiP binding site and causes pancreatic β-cell apoptosis and diabetes in mice. Here, we systematically depleted HeLa cells of the BiP co-chaperones by siRNA-mediated gene silencing and used live cell Ca(2+) imaging to monitor the effects on ER Ca(2+) leakage. Depletion of either one of the ER lumenal BiP co-chaperones, ERj3 and ERj6, but not the ER membrane-resident co-chaperones (such as Sec63 protein, which assists BiP in Sec61 channel opening) led to increased Ca(2+) leakage via Sec6 complex, thereby phenocopying the effect of BiP depletion. Thus, BiP facilitates Sec61 channel closure (i.e. limits ER Ca(2+) leakage) via the Sec61 channel with the help of ERj3 and ERj6. Interestingly, deletion of ERj6 causes pancreatic β-cell failure and diabetes in mice and humans. We suggest that co-chaperone-controlled gating of the Sec61 channel by BiP is particularly important for cells, which are highly active in protein secretion, and that breakdown of this regulatory mechanism can cause apoptosis and disease.
Collapse
Affiliation(s)
- Stefan Schorr
- From the Departments of Medical Biochemistry and Molecular Biology and
| | | | - Igor Gamayun
- Experimental and Clinical Pharmacology and Toxicology, Saarland University, 66421 Homburg, Germany
| | - Armin Melnyk
- From the Departments of Medical Biochemistry and Molecular Biology and
| | - Martin Jung
- From the Departments of Medical Biochemistry and Molecular Biology and
| | - Nico Schäuble
- From the Departments of Medical Biochemistry and Molecular Biology and
| | - Qian Wang
- the Department of Physiology, University of Alberta, Edmonton T6G 2H7, Canada, and
| | - Birgit Hemmis
- the Division of Biophysics, Universität Osnabrück, FB Biologie/Chemie, 49076 Osnabrück, Germany
| | - Florian Bochen
- From the Departments of Medical Biochemistry and Molecular Biology and
| | - Markus Greiner
- From the Departments of Medical Biochemistry and Molecular Biology and
| | - Pavel Lampel
- From the Departments of Medical Biochemistry and Molecular Biology and
| | | | | | - Johanna Dudek
- From the Departments of Medical Biochemistry and Molecular Biology and
| | - Xing-Zhen Chen
- the Department of Physiology, University of Alberta, Edmonton T6G 2H7, Canada, and
| | - Richard Wagner
- the Division of Biophysics, Universität Osnabrück, FB Biologie/Chemie, 49076 Osnabrück, Germany
| | - Adolfo Cavalié
- Experimental and Clinical Pharmacology and Toxicology, Saarland University, 66421 Homburg, Germany
| | | |
Collapse
|
42
|
Byrne S, Dlamini N, Lumsden D, Pitt M, Zaharieva I, Muntoni F, King A, Robert L, Jungbluth H. SIL1-related Marinesco-Sjoegren syndrome (MSS) with associated motor neuronopathy and bradykinetic movement disorder. Neuromuscul Disord 2015; 25:585-8. [PMID: 25958341 DOI: 10.1016/j.nmd.2015.04.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 03/28/2015] [Accepted: 04/08/2015] [Indexed: 11/18/2022]
Abstract
Marinesco-Sjoegren syndrome (MSS) is a recessively inherited multisystem disorder caused by mutations in SIL1 and characterized by cerebellar atrophy with ataxia, cataracts, a skeletal muscle myopathy, and variable degrees of developmental delay. Pathogenic mechanisms implicated to date include mitochondrial, nuclear envelope and lysosomal-autophagic pathway abnormalities. Here we present a 5-year-old girl with SIL1-related MSS and additional unusual features of an associated motor neuronopathy and a bradykinetic movement disorder preceding the onset of ataxia. These findings suggest that an associated motor neuronopathy may be part of the phenotypical spectrum of SIL1-related MSS and should be actively investigated in genetically confirmed cases. The additional observation of a bradykinetic movement disorder suggests an intriguing continuum between neurodevelopmental and neurodegenerative multisystem disorders intricately linked in the same cellular pathways.
Collapse
Affiliation(s)
- Susan Byrne
- Department of Paediatric Neurology, Evelina's Children Hospital, Guy's & St. Thomas' Hospital NHS Foundation Trust, London, UK
| | - Nomazulu Dlamini
- Department of Paediatric Neurology, Evelina's Children Hospital, Guy's & St. Thomas' Hospital NHS Foundation Trust, London, UK
| | - Daniel Lumsden
- Department of Paediatric Neurology, Evelina's Children Hospital, Guy's & St. Thomas' Hospital NHS Foundation Trust, London, UK
| | - Matthew Pitt
- Department of Neurophysiology, Great Ormond Street Hospital for Children, London, UK
| | - Irina Zaharieva
- Dubowitz Neuromuscular Centre, Institute of Child Health, University College London, London, UK
| | - Francesco Muntoni
- Dubowitz Neuromuscular Centre, Institute of Child Health, University College London, London, UK
| | - Andrew King
- Department of Neuropathology, King's College Hospital, London, UK
| | - Leema Robert
- Department of Clinical Genetics, Guy's Hospital, London, UK
| | - Heinz Jungbluth
- Department of Paediatric Neurology, Evelina's Children Hospital, Guy's & St. Thomas' Hospital NHS Foundation Trust, London, UK; Randall Division for Cell and Molecular Biophysics, Muscle Signalling Section, King's College, London, UK; Department of Basic and Clinical Neuroscience Division, IoPPN, King's College, London, UK.
| |
Collapse
|
43
|
Behnke J, Feige MJ, Hendershot LM. BiP and its nucleotide exchange factors Grp170 and Sil1: mechanisms of action and biological functions. J Mol Biol 2015; 427:1589-608. [PMID: 25698114 DOI: 10.1016/j.jmb.2015.02.011] [Citation(s) in RCA: 135] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 02/10/2015] [Accepted: 02/10/2015] [Indexed: 12/26/2022]
Abstract
BiP (immunoglobulin heavy-chain binding protein) is the endoplasmic reticulum (ER) orthologue of the Hsp70 family of molecular chaperones and is intricately involved in most functions of this organelle through its interactions with a variety of substrates and regulatory proteins. Like all Hsp70 family members, the ability of BiP to bind and release unfolded proteins is tightly regulated by a cycle of ATP binding, hydrolysis, and nucleotide exchange. As a characteristic of the Hsp70 family, multiple DnaJ-like co-factors can target substrates to BiP and stimulate its ATPase activity to stabilize the binding of BiP to substrates. However, only in the past decade have nucleotide exchange factors for BiP been identified, which has shed light not only on the mechanism of BiP-assisted folding in the ER but also on Hsp70 family members that reside throughout the cell. We will review the current understanding of the ATPase cycle of BiP in the unique environment of the ER and how it is regulated by the nucleotide exchange factors, Grp170 (glucose-regulated protein of 170kDa) and Sil1, both of which perform unanticipated roles in various biological functions and disease states.
Collapse
Affiliation(s)
- Julia Behnke
- Department of Tumor Cell Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Matthias J Feige
- Department of Tumor Cell Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Linda M Hendershot
- Department of Tumor Cell Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
| |
Collapse
|
44
|
Filézac de L'Etang A, Maharjan N, Cordeiro Braña M, Ruegsegger C, Rehmann R, Goswami A, Roos A, Troost D, Schneider BL, Weis J, Saxena S. Marinesco-Sjögren syndrome protein SIL1 regulates motor neuron subtype-selective ER stress in ALS. Nat Neurosci 2015; 18:227-38. [PMID: 25559081 DOI: 10.1038/nn.3903] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 11/18/2014] [Indexed: 12/13/2022]
Abstract
Mechanisms underlying motor neuron subtype-selective endoplasmic reticulum (ER) stress and associated axonal pathology in amyotrophic lateral sclerosis (ALS) remain unclear. Here we show that the molecular environment of the ER between motor neuron subtypes is distinct, with characteristic signatures. We identify cochaperone SIL1, mutated in Marinesco-Sjögren syndrome (MSS), as being robustly expressed in disease-resistant slow motor neurons but not in ER stress-prone fast-fatigable motor neurons. In a mouse model of MSS, we demonstrate impaired ER homeostasis in motor neurons in response to loss of SIL1 function. Loss of a single functional Sil1 allele in an ALS mouse model (SOD1-G93A) enhanced ER stress and exacerbated ALS pathology. In SOD1-G93A mice, SIL1 levels were progressively and selectively reduced in vulnerable fast-fatigable motor neurons. Mechanistically, reduction in SIL1 levels was associated with lowered excitability of fast-fatigable motor neurons, further influencing expression of specific ER chaperones. Adeno-associated virus-mediated delivery of SIL1 to familial ALS motor neurons restored ER homeostasis, delayed muscle denervation and prolonged survival.
Collapse
Affiliation(s)
- Audrey Filézac de L'Etang
- 1] Institute of Cell Biology, University of Bern, Bern, Switzerland. [2] Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Niran Maharjan
- 1] Institute of Cell Biology, University of Bern, Bern, Switzerland. [2] Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | | | - Céline Ruegsegger
- 1] Institute of Cell Biology, University of Bern, Bern, Switzerland. [2] Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Ruth Rehmann
- Institute of Cell Biology, University of Bern, Bern, Switzerland
| | - Anand Goswami
- Institute of Neuropathology, Rheinisch-Westfälische Technische Hochschule, Aachen University Hospital, Aachen, Germany
| | - Andreas Roos
- Institute of Neuropathology, Rheinisch-Westfälische Technische Hochschule, Aachen University Hospital, Aachen, Germany
| | - Dirk Troost
- Division of Neuropathology, Department of Pathology, Academic Medical Centre, Amsterdam, the Netherlands
| | - Bernard L Schneider
- Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Joachim Weis
- Institute of Neuropathology, Rheinisch-Westfälische Technische Hochschule, Aachen University Hospital, Aachen, Germany
| | - Smita Saxena
- Institute of Cell Biology, University of Bern, Bern, Switzerland
| |
Collapse
|
45
|
Abstract
In mammalian cells, the rough endoplasmic reticulum or ER plays a central role in the biogenesis of most extracellular plus many organellar proteins and in cellular calcium homeostasis. Therefore, this organelle comprises molecular chaperones that are involved in import, folding/assembly, export, and degradation of polypeptides in millimolar concentrations. In addition, there are calcium channels/pumps and signal transduction components present in the ER membrane that affect and are affected by these processes. The ER lumenal Hsp70, termed immunoglobulin-heavy chain binding protein or BiP, is the central player in all these activities and involves up to seven different co-chaperones, i.e. ER-membrane integrated as well as ER-lumenal Hsp40s, which are termed ERj or ERdj, and two nucleotide exchange factors.
Collapse
|
46
|
Ichhaporia VP, Sanford T, Howes J, Marion TN, Hendershot LM. Sil1, a nucleotide exchange factor for BiP, is not required for antibody assembly or secretion. Mol Biol Cell 2014; 26:420-9. [PMID: 25473114 PMCID: PMC4310734 DOI: 10.1091/mbc.e14-09-1392] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Sil1 is a nucleotide exchange factor for the ER chaperone BiP, and mutations in this gene lead to Marinesco–Sjögren syndrome, a multisystem disorder. Effects of loss of Sil1 on biosynthesis and secretion of antibodies, a well-characterized BiP client, are determined in a mouse model for this disease and patient-derived lymphoblastoid cell lines. Sil1 is a nucleotide exchange factor for the endoplasmic reticulum chaperone BiP, and mutations in this gene lead to Marinesco–Sjögren syndrome (MSS), a debilitating autosomal recessive disease characterized by multisystem defects. A mouse model for MSS was previously produced by disrupting Sil1 using gene-trap methodology. The resulting Sil1Gt mouse phenocopies several pathologies associated with MSS, although its ability to assemble and secrete antibodies, the best-characterized substrate of BiP, has not been investigated. In vivo antigen-specific immunizations and ex vivo LPS stimulation of splenic B cells revealed that the Sil1Gt mouse was indistinguishable from wild-type age-matched controls in terms of both the kinetics and magnitude of antigen-specific antibody responses. There was no significant accumulation of BiP-associated Ig assembly intermediates or evidence that another molecular chaperone system was used for antibody production in the LPS-stimulated splenic B cells from Sil1Gt mice. ER chaperones were expressed at the same level in Sil1WT and Sil1Gt mice, indicating that there was no evident compensation for the disruption of Sil1. Finally, these results were confirmed and extended in three human EBV-transformed lymphoblastoid cell lines from individuals with MSS, leading us to conclude that the BiP cofactor Sil1 is dispensable for antibody production.
Collapse
Affiliation(s)
- Viraj P Ichhaporia
- Department of Tumor Cell Biology, St. Jude Children's Research Hospital, Memphis, TN 38105; Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Sciences Center, Memphis, TN 38163
| | - Tyler Sanford
- Department of Tumor Cell Biology, St. Jude Children's Research Hospital, Memphis, TN 38105; Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Sciences Center, Memphis, TN 38163
| | - Jenny Howes
- Department of Tumor Cell Biology, St. Jude Children's Research Hospital, Memphis, TN 38105
| | - Tony N Marion
- Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Sciences Center, Memphis, TN 38163
| | - Linda M Hendershot
- Department of Tumor Cell Biology, St. Jude Children's Research Hospital, Memphis, TN 38105;
| |
Collapse
|
47
|
Haßdenteufel S, Klein MC, Melnyk A, Zimmermann R. Protein transport into the human ER and related diseases, Sec61-channelopathies. Biochem Cell Biol 2014; 92:499-509. [PMID: 24934166 DOI: 10.1139/bcb-2014-0043] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Protein transport into the human endoplasmic reticulum (ER) is relevant to the biogenesis of most soluble and membrane proteins of organelles, which are involved in endo- or exo-cytsosis. It involves amino-terminal signal peptides in the precursor polypeptides and various transport components in the cytosol plus the ER, and can occur co- or post-translationally. The two mechanisms merge at the level of the ER membrane, specifically at the level of the heterotrimeric Sec61 complex, which forms a dynamic polypeptide-conducting channel in the ER membrane. Since the mammalian ER is also the main intracellular calcium storage organelle, and the Sec61 complex is calcium permeable, the Sec61 complex is tightly regulated in its equilibrium between the closed and open conformations, or "gated", by ligands, such as signal peptides of the transport substrates and the ER lumenal Hsp70-type molecular chaperone BiP. Furthermore, BiP binding to the incoming polypeptide contributes to the efficiency and unidirectionality of transport. Recent insights into the structure and dynamic equilibrium of the Sec61 complex have various mechanistic as well as medical implications.
Collapse
Affiliation(s)
- Sarah Haßdenteufel
- Medical Biochemistry & Molecular Biology, Saarland University, Building 44, Kirrbergerstr, D-66421 Homburg, Germany
| | | | | | | |
Collapse
|