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Liu B, Liu G, Li C, Liu S, Sun D. Resection of Scar Tissue in Rats With Spinal Cord Injury Can Promote the Expression of βⅢ-tubulin in the Injured Area. World Neurosurg 2023; 170:e115-e126. [PMID: 36280047 DOI: 10.1016/j.wneu.2022.10.069] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Accepted: 10/19/2022] [Indexed: 11/05/2022]
Abstract
BACKGROUND Previous research shows that scar tissue formed in the injured area after spinal cord injury blocks nerve regeneration and functional recovery. However, those researchers tried to prevent the formation of scar after spinal cord injury to promote nerve regeneration, but it ran counter to their desire, indicating that the formation of scar might play a role in functional recovery after spinal cord injury. METHODS To investigate roles of scar formation on functional repair after spinal cord injury, we selected several different key time points to resect the scar tissue formed after spinal cord injury based on the rat models of the T8-T9 transection injury of spinal cord. First, the recovery of motor function was evaluated by Basso Beattie Bresnahan score and electrophysiologic examination; second, the pathologic features of functional recovery were analyzed mainly by immunofluorescence βⅢ-tubulin staining; finally, the genes related to the recovery of motor function were predicted by high-throughput sequencing analysis. RESULTS Immunofluorescence results showed that the resection of scar tissue promoted significantly the recovery of motor function and the expression of βⅢ-tubulin in the injured area in the second week after spinal cord injury. Furthermore, RNA-seq studies showed that Tubb3 and Tubb6 gene expression and other neural regeneration pathways were significantly different in the tissue before and after early resection. CONCLUSIONS Excision of scar tissue in the second week promoted nerve regeneration after spinal cord injury. Tubb3 and Tubb6 genes might be the potential targets for spinal cord injury therapy in our study.
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Affiliation(s)
- Baoguo Liu
- College of Pharmacy, Jilin University, Changchun, China
| | - Guoqing Liu
- Cell Therapy Center, Xintai Hospital of Traditional Chinese Medicine, Taian, China
| | - Changyang Li
- Cell Therapy Center, Xintai Hospital of Traditional Chinese Medicine, Taian, China
| | - Sumei Liu
- College of Pharmacy, Jilin University, Changchun, China; Cell Therapy Center, Xuanwu Hospital Capital Medical University, Beijing, China.
| | - Dejun Sun
- College of Pharmacy, Jilin University, Changchun, China
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Ahangari N, Munoz DG, Coulombe J, Gray DA, Engle EC, Cheng L, Woulfe J. Nuclear IMPDH Filaments in Human Gliomas. J Neuropathol Exp Neurol 2021; 80:944-954. [PMID: 34498062 PMCID: PMC8560559 DOI: 10.1093/jnen/nlab090] [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] [Indexed: 12/20/2022] Open
Abstract
The analysis of nuclear morphology plays an important role in glioma diagnosis and grading. We previously described intranuclear rods (rods) labeled with the SDL.3D10 monoclonal antibody against class III beta-tubulin (TUBB3) in human ependymomas. In a cohort of adult diffuse gliomas, we identified nuclear rods in 71.1% of IDH mutant lower-grade gliomas and 13.7% of IDH wild-type glioblastomas (GBMs). The presence of nuclear rods was associated with significantly longer postoperative survival in younger (≤65) GBM patients. Consistent with this, nuclear rods were mutually exclusive with Ki67 staining and their prevalence in cell nuclei inversely correlated with the Ki67 proliferation index. In addition, rod-containing nuclei showed a relative depletion of lamin B1, suggesting a possible association with senescence. To gain insight into their functional significance, we addressed their antigenic properties. Using a TUBB3-null mouse model, we demonstrate that the SDL.3D10 antibody does not bind TUBB3 in rods but recognizes an unknown antigen. In the present study, we show that rods show immunoreactivity for the nucleotide synthesizing enzymes inosine monophosphate dehydrogenase (IMPDH) and cytidine triphosphate synthetase. By analogy with the IMPDH filaments that have been described previously, we postulate that rods regulate the activity of nucleotide-synthesizing enzymes in the nucleus by sequestration, with important implications for glioma behavior.
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Affiliation(s)
- Narges Ahangari
- From the Department of Pathology, St. Michael's Hospital, Toronto, Ontario, Canada
| | - David G Munoz
- From the Department of Pathology, St. Michael's Hospital, Toronto, Ontario, Canada
| | - Josee Coulombe
- Center for Cancer Therapeutics, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Douglas A Gray
- Center for Cancer Therapeutics, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Elizabeth C Engle
- Departments of Neurology and Ophthalmology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts
| | - Long Cheng
- Departments of Neurology and Ophthalmology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts
| | - John Woulfe
- Center for Cancer Therapeutics and Neurosciences, Ottawa Hospital Research Institute and Department of Pathology and Laboratory Medicine, University of Ottawa, Ottawa, Ontario, Canada
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Chumová J, Kourová H, Trögelová L, Halada P, Binarová P. Microtubular and Nuclear Functions of γ-Tubulin: Are They LINCed? Cells 2019; 8:cells8030259. [PMID: 30893853 PMCID: PMC6468392 DOI: 10.3390/cells8030259] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 03/07/2019] [Accepted: 03/14/2019] [Indexed: 01/02/2023] Open
Abstract
γ-Tubulin is a conserved member of the tubulin superfamily with a function in microtubule nucleation. Proteins of γ-tubulin complexes serve as nucleation templates as well as a majority of other proteins contributing to centrosomal and non-centrosomal nucleation, conserved across eukaryotes. There is a growing amount of evidence of γ-tubulin functions besides microtubule nucleation in transcription, DNA damage response, chromatin remodeling, and on its interactions with tumor suppressors. However, the molecular mechanisms are not well understood. Furthermore, interactions with lamin and SUN proteins of the LINC complex suggest the role of γ-tubulin in the coupling of nuclear organization with cytoskeletons. γ-Tubulin that belongs to the clade of eukaryotic tubulins shows characteristics of both prokaryotic and eukaryotic tubulins. Both human and plant γ-tubulins preserve the ability of prokaryotic tubulins to assemble filaments and higher-order fibrillar networks. γ-Tubulin filaments, with bundling and aggregating capacity, are suggested to perform complex scaffolding and sequestration functions. In this review, we discuss a plethora of γ-tubulin molecular interactions and cellular functions, as well as recent advances in understanding the molecular mechanisms behind them.
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Affiliation(s)
- Jana Chumová
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague, Czech Republic.
| | - Hana Kourová
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague, Czech Republic.
| | - Lucie Trögelová
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague, Czech Republic.
| | - Petr Halada
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague, Czech Republic.
| | - Pavla Binarová
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague, Czech Republic.
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Hinova-Palova D, Iliev A, Landzhov B, Kotov G, Stanchev S, Georgiev GP, Kirkov V, Edelstein L, Paloff A. Ultrastructure of the dorsal claustrum in cat. I. Types of neurons. ACTA ACUST UNITED AC 2019. [DOI: 10.1080/20023294.2019.1578636] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Dimka Hinova-Palova
- Department of Anatomy, Histology and Embryology, Medical University of Sofia, Sofia, Bulgaria
| | - Alexandar Iliev
- Department of Anatomy, Histology and Embryology, Medical University of Sofia, Sofia, Bulgaria
| | - Boycho Landzhov
- Department of Anatomy, Histology and Embryology, Medical University of Sofia, Sofia, Bulgaria
| | - Georgi Kotov
- Department of Anatomy, Histology and Embryology, Medical University of Sofia, Sofia, Bulgaria
| | - Stancho Stanchev
- Department of Anatomy, Histology and Embryology, Medical University of Sofia, Sofia, Bulgaria
| | - Georgi P. Georgiev
- Department of Orthopedics and Traumatology, University Hospital St. Giovanna-ISUL, Medical University of Sofia, Sofia, Bulgaria
| | - Vidin Kirkov
- Department of Anatomy, Histology and Embryology, Medical University of Sofia, Sofia, Bulgaria
| | | | - Adrian Paloff
- Department of Anatomy, Histology and Embryology, Medical University of Sofia, Sofia, Bulgaria
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Schiavon CR, Griffin ME, Pirozzi M, Parashuraman R, Zhou W, Jinnah HA, Reines D, Kahn RA. Compositional complexity of rods and rings. Mol Biol Cell 2018; 29:2303-2316. [PMID: 30024290 PMCID: PMC6249804 DOI: 10.1091/mbc.e18-05-0274] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Rods and rings (RRs) are large linear- or circular-shaped structures typically described as polymers of IMPDH (inosine monophosphate dehydrogenase). They have been observed across a wide variety of cell types and species and can be induced to form by inhibitors of IMPDH. RRs are thought to play a role in the regulation of de novo guanine nucleotide synthesis; however, the function and regulation of RRs is poorly understood. Here we show that the regulatory GTPase, ARL2, a subset of its binding partners, and several resident proteins at the endoplasmic reticulum (ER) also localize to RRs. We also have identified two new inducers of RR formation: AICAR and glucose deprivation. We demonstrate that RRs can be disassembled if guanine nucleotides can be generated by salvage synthesis regardless of the inducer. Finally, we show that there is an ordered addition of components as RRs mature, with IMPDH first forming aggregates, followed by ARL2, and only later calnexin, a marker of the ER. These findings suggest that RRs are considerably more complex than previously thought and that the function(s) of RRs may include involvement of a regulatory GTPase, its effectors, and potentially contacts with intracellular membranes.
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Affiliation(s)
- Cara R Schiavon
- Cancer Biology Graduate Program, Graduate Division of Biomedical and Biological Sciences, Laney Graduate School, Atlanta, GA 30307
| | - Maxwell E Griffin
- Cancer Biology Graduate Program, Graduate Division of Biomedical and Biological Sciences, Laney Graduate School, Atlanta, GA 30307
| | - Marinella Pirozzi
- EuroBioImaging Facility, Institute of Protein Biochemistry, 80131 Naples, Italy
| | - Raman Parashuraman
- EuroBioImaging Facility, Institute of Protein Biochemistry, 80131 Naples, Italy
| | - Wei Zhou
- Department of Hematology and Medical Oncology, Emory University School of Medicine, Atlanta, GA 30322
| | - H A Jinnah
- Department of Neurology and Human Genetics, Emory University School of Medicine, Atlanta, GA 30322
| | - Daniel Reines
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
| | - Richard A Kahn
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
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Hua K, Ferland RJ. Primary cilia proteins: ciliary and extraciliary sites and functions. Cell Mol Life Sci 2018; 75:1521-1540. [PMID: 29305615 PMCID: PMC5899021 DOI: 10.1007/s00018-017-2740-5] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 12/21/2017] [Accepted: 12/27/2017] [Indexed: 02/07/2023]
Abstract
Primary cilia are immotile organelles known for their roles in development and cell signaling. Defects in primary cilia result in a range of disorders named ciliopathies. Because this organelle can be found singularly on almost all cell types, its importance extends to most organ systems. As such, elucidating the importance of the primary cilium has attracted researchers from all biological disciplines. As the primary cilia field expands, caution is warranted in attributing biological defects solely to the function of this organelle, since many of these "ciliary" proteins are found at other sites in cells and likely have non-ciliary functions. Indeed, many, if not all, cilia proteins have locations and functions outside the primary cilium. Extraciliary functions are known to include cell cycle regulation, cytoskeletal regulation, and trafficking. Cilia proteins have been observed in the nucleus, at the Golgi apparatus, and even in immune synapses of T cells (interestingly, a non-ciliated cell). Given the abundance of extraciliary sites and functions, it can be difficult to definitively attribute an observed phenotype solely to defective cilia rather than to some defective extraciliary function or a combination of both. Thus, extraciliary sites and functions of cilia proteins need to be considered, as well as experimentally determined. Through such consideration, we will understand the true role of the primary cilium in disease as compared to other cellular processes' influences in mediating disease (or through a combination of both). Here, we review a compilation of known extraciliary sites and functions of "cilia" proteins as a means to demonstrate the potential non-ciliary roles for these proteins.
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Affiliation(s)
- Kiet Hua
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, 47 New Scotland Avenue, MC-136, Albany, NY, 12208, USA.
| | - Russell J Ferland
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, 47 New Scotland Avenue, MC-136, Albany, NY, 12208, USA.
- Department of Neurology, Albany Medical College, Albany, NY, 12208, USA.
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Chumová J, Trögelová L, Kourová H, Volc J, Sulimenko V, Halada P, Kučera O, Benada O, Kuchařová A, Klebanovych A, Dráber P, Daniel G, Binarová P. γ-Tubulin has a conserved intrinsic property of self-polymerization into double stranded filaments and fibrillar networks. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1865:734-748. [PMID: 29499229 DOI: 10.1016/j.bbamcr.2018.02.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 02/22/2018] [Accepted: 02/23/2018] [Indexed: 12/22/2022]
Abstract
γ-Tubulin is essential for microtubule nucleation and also plays less understood roles in nuclear and cell-cycle-related functions. High abundancy of γ-tubulin in acentrosomal Arabidopsis cells facilitated purification and biochemical characterization of large molecular species of γ-tubulin. TEM, fluorescence, and atomic force microscopy of purified high molecular γ-tubulin forms revealed the presence of linear filaments with a double protofilament substructure, filament bundles and aggregates. Filament formation from highly purified γ-tubulin free of γ-tubulin complex proteins (GCPs) was demonstrated for both plant and human γ-tubulin. Moreover, γ-tubulin associated with porcine brain microtubules formed oligomers. Experimental evidence on the intrinsic ability of γ-tubulin to oligomerize/polymerize was supported by conservation of α- and β-tubulin interfaces for longitudinal and lateral interactions for γ-tubulins. STED (stimulated emission depletion) microscopy of Arabidopsis cells revealed fine, short γ-tubulin fibrillar structures enriched on mitotic microtubular arrays that accumulated at polar regions of acentrosomal spindles and the outer nuclear envelope before mitosis, and were also present in nuclei. Fine fibrillar structures of γ-tubulin representing assemblies of higher order were localized in cell-cycle-dependent manner at sites of dispersed γ-tubulin location in acentrosomal plant cells as well as at sites of local γ-tubulin enrichment after drug treatment. Our findings that γ-tubulin preserves the capability of prokaryotic tubulins to self-organize into filaments assembling by lateral interaction into bundles/clusters help understanding of the relationship between structure and multiple cellular functions of this protein species and suggest that besides microtubule nucleation and organization, γ-tubulin may also have scaffolding or sequestration functions.
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Affiliation(s)
- Jana Chumová
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague 4, Czech Republic
| | - Lucie Trögelová
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague 4, Czech Republic
| | - Hana Kourová
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague 4, Czech Republic
| | - Jindřich Volc
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague 4, Czech Republic
| | - Vadym Sulimenko
- Institute of Molecular Genetics of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague 4, Czech Republic
| | - Petr Halada
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague 4, Czech Republic
| | - Ondřej Kučera
- Institute of Photonics and Electronics of the Czech Academy of Sciences, Chaberská 57, 182 00 Prague 8, Czech Republic
| | - Oldřich Benada
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague 4, Czech Republic
| | - Anna Kuchařová
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague 4, Czech Republic
| | - Anastasiya Klebanovych
- Institute of Molecular Genetics of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague 4, Czech Republic
| | - Pavel Dráber
- Institute of Molecular Genetics of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague 4, Czech Republic
| | - Geoffrey Daniel
- Department of Forest Biomaterials Technology, Swedish University of Agricultural Sciences, Box 7008, Uppsala SE-75007, Sweden
| | - Pavla Binarová
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague 4, Czech Republic.
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Noble JW, Hunter DV, Roskelley CD, Chan EKL, Mills J. Loukoumasomes Are Distinct Subcellular Structures from Rods and Rings and Are Structurally Associated with MAP2 and the Nuclear Envelope in Retinal Cells. PLoS One 2016; 11:e0165162. [PMID: 27798680 PMCID: PMC5087950 DOI: 10.1371/journal.pone.0165162] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 10/07/2016] [Indexed: 12/19/2022] Open
Abstract
“Rods and rings” (RR) and loukoumasomes are similarly shaped, subcellular macromolecular structures with as yet unknown function. RR, so named because of their shape, are formed in response to inhibition in the GTP or CTP synthetic pathways and are highly enriched in the two key enzymes of the nucleotide synthetic pathway. Loukoumasomes also occur as linear and toroidal bodies and were initially inferred to be the same as RR, largely due to their shared shape and size and the fact that it was unclear if they shared the same subcomponents. In human retinoblastoma tissue and cells we have observed toroidal, perinuclear, macromolecular structures of similar size and antigenicity to those previously reported in neurons (neuronal-loukoumasomes). To further characterize the subcomponents of the retinal-loukoumasomes, confocal analysis following immunocytochemical staining for alpha-tubulin, beta-III tubulin and detyrosinated tubulin was performed. These studies indicate that retinal-loukoumasomes are enriched for beta-III tubulin and other tubulins associated with microtubules. Immunofluorescence together with the in situ proximity ligation assay (PLA), confirmed that beta-III tubulin colocalized with detyrosinated tubulin within loukoumasomes. Our results indicate that these tissues contain only loukoumasomes because these macromolecular structures are immunoreactive with an anti-tubulin antibody but are not recognized by the prototype anti-RR/inosine monophosphate dehydrogenase (IMPDH) antibody (It2006). To further compare the RR and retinal-loukoumasomes, retinoblastoma cells were exposed to the IMPDH-inhibitor ribavirin, a drug known to induce the formation of RR. In contrast to RR, the production of retinal-loukoumasomes was unaffected. Coimmunostaining of Y79 cells for beta-III tubulin and IMPDH indicate that these cells, when treated with ribavirin, can contain both retinal-loukoumasomes and RR and that these structures are antigenically distinct. Subcellular fractionation studies indicate that ribavirin increased the RR subcomponent, IMPDH, in the nuclear fraction of Y79 cells from 21.3 ± 5.8% (0 mM ribavirin) to 122.8 ± 7.9% (1 mM ribavirin) while the subcellular localization of the retinal-loukoumasome subcomponent tubulin went unaltered. Further characterization of retinal-loukoumasomes in retinoblastoma cells reveals that they are intimately associated with lamin folds within the nuclear envelope. Using immunofluorescence and the in situ PLA in this cell type, we have observed colocalization of beta-III tubulin with MAP2. As MAP2 is a microtubule-associated protein implicated in microtubule crosslinking, this supports a role for microtubule crosslinkers in the formation of retinal-loukoumasomes. Together, these results suggest that loukoumasomes and RR are distinct subcellular macromolecular structures, formed by different cellular processes and that there are other loukoumasome-like structures within retinal tissues and cells.
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Affiliation(s)
- Jake W. Noble
- Department of Biology, Trinity Western University, Langley, British Columbia, Canada
| | - Diana V. Hunter
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada
| | - Calvin D. Roskelley
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Edward K. L. Chan
- Department of Oral Biology, University of Florida, Gainesville, Florida, United States of America
| | - Julia Mills
- Department of Biology, Trinity Western University, Langley, British Columbia, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada
- * E-mail:
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De Munter S, Verheijden S, Vanderstuyft E, Malheiro AR, Brites P, Gall D, Schiffmann SN, Baes M. Early-onset Purkinje cell dysfunction underlies cerebellar ataxia in peroxisomal multifunctional protein-2 deficiency. Neurobiol Dis 2016; 94:157-68. [DOI: 10.1016/j.nbd.2016.06.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 06/08/2016] [Accepted: 06/22/2016] [Indexed: 11/29/2022] Open
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Carcamo WC, Calise SJ, von Mühlen CA, Satoh M, Chan EKL. Molecular cell biology and immunobiology of mammalian rod/ring structures. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2014; 308:35-74. [PMID: 24411169 DOI: 10.1016/b978-0-12-800097-7.00002-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Nucleotide biosynthesis is a highly regulated process necessary for cell growth and replication. Cytoplasmic structures in mammalian cells, provisionally described as rods and rings (RR), were identified by human autoantibodies and recently shown to include two key enzymes of the CTP/GTP biosynthetic pathways, cytidine triphosphate synthetase (CTPS) and inosine monophosphate dehydrogenase (IMPDH). Several studies have described CTPS filaments in mammalian cells, Drosophila, yeast, and bacteria. Other studies have identified IMPDH filaments in mammalian cells. Similarities among these studies point to a common evolutionarily conserved cytoplasmic structure composed of a subset of nucleotide biosynthetic enzymes. These structures appear to be a conserved metabolic response to decreased intracellular GTP and/or CTP pools. Antibodies to RR were found to develop in some hepatitis C patients treated with interferon-α and ribavirin. Additionally, the presence of anti-RR antibodies was correlated with poor treatment outcome.
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Affiliation(s)
- Wendy C Carcamo
- Department of Oral Biology, University of Florida, Gainesville, Florida, USA
| | - S John Calise
- Department of Oral Biology, University of Florida, Gainesville, Florida, USA
| | | | - Minoru Satoh
- Division of Rheumatology and Clinical Immunology, Department of Medicine, University of Florida, Gainesville, Florida, USA; Department of Clinical Nursing, School of Health Sciences, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Edward K L Chan
- Department of Oral Biology, University of Florida, Gainesville, Florida, USA.
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SHAIKH Y, KRANTZ A, EL-FARRA Y. Anti-rods and rings autoantibodies can occur in the hepatitis c-naïve population. JOURNAL OF PREVENTIVE MEDICINE AND HYGIENE 2013; 54:175-80. [PMID: 24783898 PMCID: PMC4718377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
INTRODUCTION The anti-Rods and Rings autoantibody recently described in clinical populations is thought to occur in the setting of hepatitis C treatment, specifically in the context of cytidine triphosphate (CTP) and guanosine triphosphate (GTP) synthetic pathway inhibitors, and is important in its potential impact on response to therapy. This study asks the question: what is the epidemiology of anti-RR autoantibody in the general, non-clinical population? MATERIALS AND METHODS This is a cross-sectional study using the National Health and Nutrition Examination Survey (NHANES). Immunofluorescence assay for anti-Rods and Rings autoantibody were performed by NHANES labs and the results made publically available. Sample weights were used to calculate the prevalence and distribution of the autoantibody across demographics. A medication profile of the autoantibody positive population was also constructed RESULTS The study sample consisted of 4738 persons over the age of 12 years. Anti-Rods and Rings autoantibodies were found in 39 persons representing 1.3 million persons in the United States population. 38 of 39 persons with anti-Rods and Rings autoantibody had no prior history of hepatitis C virus infection. A majority of these persons were found to have poly-pharmacy. DISCUSSION This is the first study to show that anti-RR can occur in the general population without evidence of hepatits C virus infection, and that the majority of persons with anti-RR in the population have no evidence of prior hepatitis C infection. This indicates that there may be another undetermined etiology for anti-rods and rings autoantibodies besides the currently accepted exposure etiology of hepatitis C virus infection and treatment found in clinical studies.
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Affiliation(s)
- Y. SHAIKH
- Correspondence: Yahya Shaikh, UCLA David Geffen School of Medicine (310) 754-6367, 1735-213 Sawtelle blvd, Los Angeles, CA, 90025 - E-mail:
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Verheijden S, Bottelbergs A, Krysko O, Krysko DV, Beckers L, De Munter S, Van Veldhoven PP, Wyns S, Kulik W, Nave KA, Ramer MS, Carmeliet P, Kassmann CM, Baes M. Peroxisomal multifunctional protein-2 deficiency causes neuroinflammation and degeneration of Purkinje cells independent of very long chain fatty acid accumulation. Neurobiol Dis 2013; 58:258-69. [PMID: 23777740 DOI: 10.1016/j.nbd.2013.06.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 05/27/2013] [Accepted: 06/07/2013] [Indexed: 01/03/2023] Open
Abstract
Although peroxisome biogenesis and β-oxidation disorders are well known for their neurodevelopmental defects, patients with these disorders are increasingly diagnosed with neurodegenerative pathologies. In order to investigate the cellular mechanisms of neurodegeneration in these patients, we developed a mouse model lacking multifunctional protein 2 (MFP2, also called D-bifunctional protein), a central enzyme of peroxisomal β-oxidation, in all neural cells (Nestin-Mfp2(-/-)) or in oligodendrocytes (Cnp-Mfp2(-/-)) and compared these models with an already established general Mfp2 knockout. Nestin-Mfp2 but not Cnp-Mfp2 knockout mice develop motor disabilities and ataxia, similar to the general mutant. Deterioration of motor performance correlates with the demise of Purkinje cell axons in the cerebellum, which precedes loss of Purkinje cells and cerebellar atrophy. This closely mimics spinocerebellar ataxias of patients affected with mild peroxisome β-oxidation disorders. However, general knockouts have a much shorter life span than Nestin-Mfp2 knockouts which is paralleled by a disparity in activation of the innate immune system. Whereas in general mutants a strong and chronic proinflammatory reaction proceeds throughout the brain, elimination of MFP2 from neural cells results in minor neuroinflammation. Neither the extent of the inflammatory reaction nor the cerebellar degeneration could be correlated with levels of very long chain fatty acids, substrates of peroxisomal β-oxidation. In conclusion, MFP2 has multiple tasks in the adult brain, including the maintenance of Purkinje cells and the prevention of neuroinflammation but this is not mediated by its activity in oligodendrocytes nor by its role in very long chain fatty acid degradation.
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Affiliation(s)
- Simon Verheijden
- Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Belgium.
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Carcamo WC, Satoh M, Kasahara H, Terada N, Hamazaki T, Chan JYF, Yao B, Tamayo S, Covini G, von Mühlen CA, Chan EKL. Induction of cytoplasmic rods and rings structures by inhibition of the CTP and GTP synthetic pathway in mammalian cells. PLoS One 2011; 6:e29690. [PMID: 22220215 PMCID: PMC3248424 DOI: 10.1371/journal.pone.0029690] [Citation(s) in RCA: 150] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Accepted: 12/02/2011] [Indexed: 12/25/2022] Open
Abstract
Background Cytoplasmic filamentous rods and rings (RR) structures were identified using human autoantibodies as probes. In the present study, the formation of these conserved structures in mammalian cells and functions linked to these structures were examined. Methodology/Principal Findings Distinct cytoplasmic rods (∼3–10 µm in length) and rings (∼2–5 µm in diameter) in HEp-2 cells were initially observed in immunofluorescence using human autoantibodies. Co-localization studies revealed that, although RR had filament-like features, they were not enriched in actin, tubulin, or vimentin, and not associated with centrosomes or other known cytoplasmic structures. Further independent studies revealed that two key enzymes in the nucleotide synthetic pathway cytidine triphosphate synthase 1 (CTPS1) and inosine monophosphate dehydrogenase 2 (IMPDH2) were highly enriched in RR. CTPS1 enzyme inhibitors 6-diazo-5-oxo-L-norleucine and Acivicin as well as the IMPDH2 inhibitor Ribavirin exhibited dose-dependent induction of RR in >95% of cells in all cancer cell lines tested as well as mouse primary cells. RR formation by lower concentration of Ribavirin was enhanced in IMPDH2-knockdown HeLa cells whereas it was inhibited in GFP-IMPDH2 overexpressed HeLa cells. Interestingly, RR were detected readily in untreated mouse embryonic stem cells (>95%); upon retinoic acid differentiation, RR disassembled in these cells but reformed when treated with Acivicin. Conclusions/Significance RR formation represented response to disturbances in the CTP or GTP synthetic pathways in cancer cell lines and mouse primary cells and RR are the convergence physical structures in these pathways. The availability of specific markers for these conserved structures and the ability to induce formation in vitro will allow further investigations in structure and function of RR in many biological systems in health and diseases.
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Affiliation(s)
- Wendy C. Carcamo
- Department of Oral Biology, University of Florida, Gainesville, Florida, United States of America
| | - Minoru Satoh
- Department of Medicine, University of Florida, Gainesville, Florida, United States of America
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Hideko Kasahara
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida, United States of America
| | - Naohiro Terada
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Takashi Hamazaki
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Jason Y. F. Chan
- Department of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Bing Yao
- Department of Oral Biology, University of Florida, Gainesville, Florida, United States of America
| | - Stephanie Tamayo
- Department of Oral Biology, University of Florida, Gainesville, Florida, United States of America
| | - Giovanni Covini
- Department of Gastroenterology, Istituto Clinico Humanitas, Rozzano, Milan, Italy
| | | | - Edward K. L. Chan
- Department of Oral Biology, University of Florida, Gainesville, Florida, United States of America
- * E-mail:
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