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Courraud J, Engel C, Quartier A, Drouot N, Houessou U, Plassard D, Sorlin A, Brischoux-Boucher E, Gouy E, Van Maldergem L, Rossi M, Lesca G, Edery P, Putoux A, Bilan F, Gilbert-Dussardier B, Atallah I, Kalscheuer VM, Mandel JL, Piton A. Molecular consequences of PQBP1 deficiency, involved in the X-linked Renpenning syndrome. Mol Psychiatry 2024; 29:287-296. [PMID: 38030819 DOI: 10.1038/s41380-023-02323-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 10/18/2023] [Accepted: 11/13/2023] [Indexed: 12/01/2023]
Abstract
Mutations in the PQBP1 gene (polyglutamine-binding protein-1) are responsible for a syndromic X-linked form of neurodevelopmental disorder (XL-NDD) with intellectual disability (ID), named Renpenning syndrome. PQBP1 encodes a protein involved in transcriptional and post-transcriptional regulation of gene expression. To investigate the consequences of PQBP1 loss, we used RNA interference to knock-down (KD) PQBP1 in human neural stem cells (hNSC). We observed a decrease of cell proliferation, as well as the deregulation of the expression of 58 genes, comprising genes encoding proteins associated with neurodegenerative diseases, playing a role in mRNA regulation or involved in innate immunity. We also observed an enrichment of genes involved in other forms of NDD (CELF2, APC2, etc). In particular, we identified an increase of a non-canonical isoform of another XL-NDD gene, UPF3B, an actor of nonsense mRNA mediated decay (NMD). This isoform encodes a shorter protein (UPF3B_S) deprived from the domains binding NMD effectors, however no notable change in NMD was observed after PQBP1-KD in fibroblasts containing a premature termination codon. We showed that short non-canonical and long canonical UPF3B isoforms have different interactomes, suggesting they could play distinct roles. The link between PQBP1 loss and increase of UPF3B_S expression was confirmed in mRNA obtained from patients with pathogenic variants in PQBP1, particularly pronounced for truncating variants and missense variants located in the C-terminal domain. We therefore used it as a molecular marker of Renpenning syndrome, to test the pathogenicity of variants of uncertain clinical significance identified in PQPB1 in individuals with NDD, using patient blood mRNA and HeLa cells expressing wild-type or mutant PQBP1 cDNA. We showed that these different approaches were efficient to prove a functional effect of variants in the C-terminal domain of the protein. In conclusion, our study provided information on the pathological mechanisms involved in Renpenning syndrome, but also allowed the identification of a biomarker of PQBP1 deficiency useful to test variant effect.
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Affiliation(s)
- Jérémie Courraud
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
- Centre National de la Recherche Scientifique, UMR7104, Illkirch, France
- Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France
- Université de Strasbourg, 67 400, Illkirch, France
| | - Camille Engel
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
- Centre National de la Recherche Scientifique, UMR7104, Illkirch, France
- Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France
- Université de Strasbourg, 67 400, Illkirch, France
| | - Angélique Quartier
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
- Centre National de la Recherche Scientifique, UMR7104, Illkirch, France
- Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France
- Université de Strasbourg, 67 400, Illkirch, France
| | - Nathalie Drouot
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
- Centre National de la Recherche Scientifique, UMR7104, Illkirch, France
- Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France
- Université de Strasbourg, 67 400, Illkirch, France
| | - Ursula Houessou
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
- Centre National de la Recherche Scientifique, UMR7104, Illkirch, France
- Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France
- Université de Strasbourg, 67 400, Illkirch, France
| | - Damien Plassard
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
- Centre National de la Recherche Scientifique, UMR7104, Illkirch, France
- Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France
- Université de Strasbourg, 67 400, Illkirch, France
| | - Arthur Sorlin
- National Center of Genetics, Laboratoire national de santé, Dudelange, Luxembourg
| | - Elise Brischoux-Boucher
- Centre de Génétique Humaine, CHU Besançon, Université de Franche-Comté, 25056, Besançon, France
| | - Evan Gouy
- Genetics Department, University Hospital of Lyon, Bron, 69500, France
| | - Lionel Van Maldergem
- Centre de Génétique Humaine, CHU Besançon, Université de Franche-Comté, 25056, Besançon, France
| | - Massimiliano Rossi
- Genetics Department, University Hospital of Lyon, Bron, 69500, France
- Equipe GENDEV, CRNL, Inserm U1028, CNRS UMR 5292, UCB Lyon1, Illkirch, France
| | - Gaetan Lesca
- Genetics Department, University Hospital of Lyon, Bron, 69500, France
- Equipe GENDEV, CRNL, Inserm U1028, CNRS UMR 5292, UCB Lyon1, Illkirch, France
| | - Patrick Edery
- Genetics Department, University Hospital of Lyon, Bron, 69500, France
- Equipe GENDEV, CRNL, Inserm U1028, CNRS UMR 5292, UCB Lyon1, Illkirch, France
| | - Audrey Putoux
- Genetics Department, University Hospital of Lyon, Bron, 69500, France
- Equipe GENDEV, CRNL, Inserm U1028, CNRS UMR 5292, UCB Lyon1, Illkirch, France
| | - Frederic Bilan
- Service de génétique médicale, CHU de Poitiers, 86 000, Poitiers, France
| | | | - Isis Atallah
- Department of Medical Genetics, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | | | - Jean-Louis Mandel
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
- Centre National de la Recherche Scientifique, UMR7104, Illkirch, France
- Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France
- Université de Strasbourg, 67 400, Illkirch, France
| | - Amélie Piton
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.
- Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.
- Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France.
- Université de Strasbourg, 67 400, Illkirch, France.
- Genetic diagnosis laboratory, Strasbourg University Hospital, 67 090, Strasbourg, France.
- Institut Universitaire de France, Paris, France.
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The role of PQBP1 in neural development and function. Biochem Soc Trans 2023; 51:363-372. [PMID: 36815699 DOI: 10.1042/bst20220920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 01/27/2023] [Accepted: 02/07/2023] [Indexed: 11/17/2022]
Abstract
Mutations in the polyglutamine tract-binding protein 1 (PQBP1) gene are associated with Renpenning syndrome, which is characterized by microcephaly, intellectual deficiency, short stature, small testes, and distinct facial dysmorphism. Studies using different models have revealed that PQBP1 plays essential roles in neural development and function. In this mini-review, we summarize recent findings relating to the roles of PQBP1 in these processes, including in the regulation of neural progenitor proliferation, neural projection, synaptic growth, neuronal survival, and cognitive function via mRNA transcription and splicing-dependent or -independent processes. The novel findings provide insights into the mechanisms underlying the pathogenesis of Renpenning syndrome and may advance drug discovery and treatment for this condition.
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3
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PQBP1: The Key to Intellectual Disability, Neurodegenerative Diseases, and Innate Immunity. Int J Mol Sci 2022; 23:ijms23116227. [PMID: 35682906 PMCID: PMC9180999 DOI: 10.3390/ijms23116227] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 05/27/2022] [Accepted: 05/30/2022] [Indexed: 11/16/2022] Open
Abstract
The idea that a common pathology underlies various neurodegenerative diseases and dementias has attracted considerable attention in the basic and medical sciences. Polyglutamine binding protein-1 (PQBP1) was identified in 1998 after a molecule was predicted to bind to polyglutamine tract amino acid sequences, which are associated with a family of neurodegenerative disorders called polyglutamine diseases. Hereditary gene mutations of PQBP1 cause intellectual disability, whereas acquired loss of function of PQBP1 contributes to dementia pathology. PQBP1 functions in innate immune cells as an intracellular receptor that recognizes pathogens and neurodegenerative proteins. It is an intrinsically disordered protein that generates intracellular foci, similar to other neurodegenerative disease proteins such as TDP43, FUS, and hnRNPs. The knowledge accumulated over more than 20 years has given rise to a new concept that shifts in the equilibrium between physiological and pathological processes have their basis in the dysregulation of common protein structure-linked molecular mechanisms.
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Yoh SM, Schneider M, Seifried J, Soonthornvacharin S, Akleh RE, Olivieri KC, De Jesus PD, Ruan C, de Castro E, Ruiz PA, Germanaud D, des Portes V, García-Sastre A, König R, Chanda SK. PQBP1 Is a Proximal Sensor of the cGAS-Dependent Innate Response to HIV-1. Cell 2015; 161:1293-1305. [PMID: 26046437 DOI: 10.1016/j.cell.2015.04.050] [Citation(s) in RCA: 148] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 02/06/2015] [Accepted: 03/25/2015] [Indexed: 10/23/2022]
Abstract
Dendritic cells (DCs) play a critical role in the immune response to viral infection through the facilitation of cell-intrinsic antiviral activity and the activation of adaptive immunity. HIV-1 infection of DCs triggers an IRF3-dependent innate immune response, which requires the activity of cyclic GAMP synthase (cGAS). We report the results of a targeted RNAi screen utilizing primary human monocyte-derived DCs (MDDCs) to identify immune regulators that directly interface with HIV-1-encoded features to initiate this innate response. Polyglutamine binding protein 1 (PQBP1) emerged as a strong candidate through this analysis. We found that PQBP1 directly binds to reverse-transcribed HIV-1 DNA and interacts with cGAS to initiate an IRF3-dependent innate response. MDDCs derived from Renpenning syndrome patients, who harbor mutations in the PQBP1 locus, possess a severely attenuated innate immune response to HIV-1 challenge, underscoring the role of PQBP1 as a proximal innate sensor of a HIV-1 infection.
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Affiliation(s)
- Sunnie M Yoh
- Infectious and Inflammatory Disease Center, Sanford-Burnham Medical Research Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92116
| | - Monika Schneider
- Infectious and Inflammatory Disease Center, Sanford-Burnham Medical Research Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92116
| | - Janna Seifried
- Paul-Ehrlich-Institut, Paul-Ehrlich-Str. 51-59, D-63225 Langen, Germany
| | - Stephen Soonthornvacharin
- Infectious and Inflammatory Disease Center, Sanford-Burnham Medical Research Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92116
| | - Rana E Akleh
- Infectious and Inflammatory Disease Center, Sanford-Burnham Medical Research Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92116
| | - Kevin C Olivieri
- Infectious and Inflammatory Disease Center, Sanford-Burnham Medical Research Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92116
| | - Paul D De Jesus
- Infectious and Inflammatory Disease Center, Sanford-Burnham Medical Research Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92116
| | - Chunhai Ruan
- Department of Chemistry, University of Michigan, 930 N. University, Ann Arbor, MI 48109
| | - Elisa de Castro
- Department of Microbiology, and Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, 1468 Madison Ave., New York, NY 10029
| | - Pedro A Ruiz
- Infectious and Inflammatory Disease Center, Sanford-Burnham Medical Research Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92116
| | - David Germanaud
- APHP, Hôpital Robert Debré, DHU PROTECT, Service de Neurologie Pédiatrique et Pathologie Métabolique, F-75019 Paris 2. Sorbonne Paris Cité, Université Paris Diderot, F-75010
| | - Vincent des Portes
- National Reference Center for Fragile X and Other XLID, Biobank NeuroBioTec, Hospices Civils de Lyon, Université de Lyon and CNRS UMR 5304 (L2C2), Bron, France
| | - Adolfo García-Sastre
- Department of Microbiology, and Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, 1468 Madison Ave., New York, NY 10029.,Department of Medicine, Division of Infectious Diseases, Icahn School of Medicine at Mount Sinai, 1468 Madison Ave., New York, NY 10029
| | - Renate König
- Paul-Ehrlich-Institut, Paul-Ehrlich-Str. 51-59, D-63225 Langen, Germany.,Infectious and Inflammatory Disease Center, Sanford-Burnham Medical Research Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92116.,German Center for Infection Research (DZIF), Langen, Germany
| | - Sumit K Chanda
- Infectious and Inflammatory Disease Center, Sanford-Burnham Medical Research Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92116
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Wan D, Zhang ZC, Zhang X, Li Q, Han J. X chromosome-linked intellectual disability protein PQBP1 associates with and regulates the translation of specific mRNAs. Hum Mol Genet 2015; 24:4599-614. [DOI: 10.1093/hmg/ddv191] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 05/19/2015] [Indexed: 01/08/2023] Open
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Iwasaki Y, Thomsen GH. The splicing factor PQBP1 regulates mesodermal and neural development through FGF signaling. Development 2014; 141:3740-51. [PMID: 25209246 DOI: 10.1242/dev.106658] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Alternative splicing of pre-mRNAs is an important means of regulating developmental processes, yet the molecular mechanisms governing alternative splicing in embryonic contexts are just beginning to emerge. Polyglutamine-binding protein 1 (PQBP1) is an RNA-splicing factor that, when mutated, in humans causes Renpenning syndrome, an X-linked intellectual disability disease characterized by severe cognitive impairment, but also by physical defects that suggest PQBP1 has broader functions in embryonic development. Here, we reveal essential roles for PQBP1 and a binding partner, WBP11, in early development of Xenopus embryos. Both genes are expressed in the nascent mesoderm and neurectoderm, and morpholino knockdown of either causes defects in differentiation and morphogenesis of the mesoderm and neural plate. At the molecular level, knockdown of PQBP1 in Xenopus animal cap explants inhibits target gene induction by FGF but not by BMP, Nodal or Wnt ligands, and knockdown of either PQBP1 or WBP11 in embryos inhibits expression of fgf4 and FGF4-responsive cdx4 genes. Furthermore, PQBP1 knockdown changes the alternative splicing of FGF receptor-2 (FGFR2) transcripts, altering the incorporation of cassette exons that generate receptor variants (FGFR2 IIIb or IIIc) with different ligand specificities. Our findings may inform studies into the mechanisms underlying Renpenning syndrome.
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Affiliation(s)
- Yasuno Iwasaki
- Department of Biochemistry and Cell Biology, Center for Developmental Genetics, Stony Brook University, Stony Brook, NY 11794-5215, USA
| | - Gerald H Thomsen
- Department of Biochemistry and Cell Biology, Center for Developmental Genetics, Stony Brook University, Stony Brook, NY 11794-5215, USA
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Gatta V, Granzotto A, Fincati K, Drago D, Bolognin S, Zatta P, Sensi SL. Microarray analysis of gene expression profiles in human neuroblastoma cells exposed to Aβ–Zn and Aβ–Cu complexes. FUTURE NEUROLOGY 2012. [DOI: 10.2217/fnl.12.35] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Aims: Abnormal metal accumulation is associated with Alzheimer’s disease and plays a relevant role in affecting amyloid-β (Aβ) peptide aggregation and neurotoxicity. Material & Methods: In the present study, employing a microarray analysis of 35,129 genes, we analyzed gene expression profile changes due to exposure to Aβ1-42 –Zn or Aβ1-42 –Cu complexes in neuronal-like cells (SH-SY5Y). Results: Microarray data indicated that Aβ–Zn or Aβ–Cu complexes selectively alter expression of genes mainly related to cell death, inflammatory responses, cytoprotective mechanisms and apoptosis. Conclusions: Taken together, these findings indicate that Aβ1–42 –Zn or Aβ1–42 –Cu show some commonalities in affecting Alzheimer’s disease-related target functions. The overall modulatory activity on these genes supports the idea of a possible net effect resulting in the activation of pathways that counteract toxic effects of Aβ–Zn or Aβ–Cu.
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Affiliation(s)
- Valentina Gatta
- Department of Oral Health & Biotechnological Sciences, “G. D’Annunzio” University, Chieti-Pescara, Italy
- Functional Genetics Unit – Center of Excellence in Aging (Ce.S.I.), Chieti, Italy
| | | | | | - Denise Drago
- CNS Repair Unit – INSPE, Biological Mass Spectrometry Unit, San Raffaele Scientific Institute, Milan, Italy
| | - Silvia Bolognin
- Department of Neurological, Neuropsychological, Morphological & Motor Sciences – Physiology & Psychology Unit, Verona, Italy
| | - Paolo Zatta
- National Research Council, Biomedical Technology Institute (CNR-ITB), Metalloproteins Unit, Department of Biology, University of Padua, Padua, Italy
| | - Stefano L Sensi
- Department of Neuroscience & Imaging, “G. D’Annunzio” University, Chieti, Italy
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Weiss E, Ramljak S, Asif AR, Ciesielczyk B, Schmitz M, Gawinecka J, Schulz-Schaeffer W, Behrens C, Zerr I. Cellular prion protein overexpression disturbs cellular homeostasis in SH-SY5Y neuroblastoma cells but does not alter p53 expression: a proteomic study. Neuroscience 2010; 169:1640-50. [PMID: 20547212 DOI: 10.1016/j.neuroscience.2010.06.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2009] [Revised: 06/06/2010] [Accepted: 06/08/2010] [Indexed: 11/29/2022]
Abstract
The definite physiological role of the cellular prion protein (PrP(c)) remains elusive. There is ample in vitro and in vivo evidence suggesting a neuroprotective role for PrP(c). On the other hand, several in vitro and in vivo studies demonstrated detrimental effects of PrP(c) overexpression through activation of a p53 pathway. Recently, we reported that transient overexpression of PrP(c) in human embryonic kidney 293 cells elicits proteome expression changes which point to deregulation of proteins involved in energy metabolism and cellular homeostasis. Here we report proteome expression changes following stable PrP(c) overexpression in human neuronal SH-SY5Y cells. In total 18 proteins that are involved in diverse biological processes were identified as differentially regulated. The majority of these proteins is involved in cell signaling, cytoskeletal organization and protein folding. Annexin V exhibited a several fold up-regulation following stable PrP(c) overexpression in SH-SY5Y cells. This finding has been reproduced in alternative, mouse N2a and human SK-N-LO neuroblastoma cell lines transiently overexpressing PrP(c). Annexin V plays an important role in maintenance of calcium homeostasis which when disturbed can activate a p53-dependent cell death. Although we did not detect changes in p53 expression between PrP(c) overexpressing SH-SY5Y and control cells, deregulation of several proteins including annexin V, polyglutamine tract-binding protein-1, spermine synthase and transgelin 2 indicates disrupted cellular equilibrium. We conclude that stable PrP(c) overexpression in SH-SY5Y cells is sufficient to perturb cellular balance but insufficient to affect p53 expression.
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Affiliation(s)
- E Weiss
- Department of Neurology, Georg-August University, Robert-Koch-Strasse 40, 37075 Göttingen, Germany
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9
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New insights into mitochondrial structure during cell death. Exp Neurol 2009; 218:183-92. [PMID: 19464290 DOI: 10.1016/j.expneurol.2009.05.021] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2009] [Revised: 04/30/2009] [Accepted: 05/08/2009] [Indexed: 01/06/2023]
Abstract
Mitochondria play a pivotal role in the cascade of events associated with cell death pathways that are involved with several forms of neurodegeneration. Recent findings show that in the Bax/Bak-dependent pathway of apoptosis, the release of cytochrome c from mitochondria is a consequence of two carefully coordinated events: opening of crista junctions triggered by OPA1 oligomer disassembly and formation of outer membrane pores. Both steps are necessary for the complete release of pro-apoptotic proteins. The remodeling of mitochondrial structure accompanies this pathway, including mitochondrial fission, and cristae and crista junction alterations. Yet, there is controversy surrounding the timing of certain remodeling events and whether they are necessary early events required for the release of pro-apoptotic factors or are simply a downstream after-effect. Here, we analyze the current knowledge of mitochondrial remodeling during cell death and discuss what structural alterations occur to this organelle during neurodegeneration, focusing on the higher resolution structural correlates obtained by electron microscopy and electron tomography.
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Nicolaescu E, Beullens M, Lesage B, Keppens S, Himpens B, Bollen M. Nature of the nuclear inclusions formed by PQBP1, a protein linked to neurodegenerative polyglutamine diseases. Eur J Cell Biol 2008; 87:817-29. [PMID: 18599155 DOI: 10.1016/j.ejcb.2008.05.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2008] [Revised: 05/15/2008] [Accepted: 05/19/2008] [Indexed: 11/29/2022] Open
Abstract
PQBP1, for polyglutamine tract-binding protein-1, has been linked to progressive neurodegenerative diseases, such as spinocerebellar ataxia, that are caused by the expansion of a polyglutamine repeat in a key regulatory protein. The overexpression of PQBP1 results in the formation of nuclear inclusions, reminiscent of the protein aggregates that are detected in polyglutamine diseases. We show here that the occurrence of PQBP1-induced nuclear inclusions is dramatically increased by the co-expression of the pre-mRNA splicing factor SIPP1, a protein ligand of PQBP1. These nuclear inclusions did not co-localise with nuclear structures such as nucleoli, coiled bodies, PML bodies, speckles and stress bodies, and were not associated with (in)active chromatin or with nucleic acids. Site-directed mutagenesis showed that the facilitation in the formation of the nuclear inclusions required multiple independent interaction sites between SIPP1 and PQBP1. Moreover, the nuclear inclusions were highly dynamic and their formation did not require energy. Our data suggest that the SIPP1-PQBP1-induced nuclear inclusions are distinct from the protein aggregates that are associated with polyglutamine diseases and represent dynamic nucleoplasmic heteropolymers of SIPP1 and PQBP1.
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Affiliation(s)
- Emilia Nicolaescu
- Laboratory of Biosignaling and Therapeutics, Department of Molecular Cell Biology, University of Leuven, Campus Gasthuisberg, O&N1/Box901, Herestraat 49, B-3000 Leuven, Belgium
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Okuda J, Arikawa Y, Takeuchi Y, Mahmoud MM, Suzaki E, Kataoka K, Suzuki T, Okinaka Y, Nakai T. Intracellular replication of Edwardsiella tarda in murine macrophage is dependent on the type III secretion system and induces an up-regulation of anti-apoptotic NF-κB target genes protecting the macrophage from staurosporine-induced apoptosis. Microb Pathog 2006; 41:226-40. [DOI: 10.1016/j.micpath.2006.08.002] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2006] [Revised: 08/04/2006] [Accepted: 08/28/2006] [Indexed: 12/28/2022]
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Marubuchi S, Okuda T, Tagawa K, Enokido Y, Horiuchi D, Shimokawa R, Tamura T, Qi ML, Eishi Y, Watabe K, Shibata M, Nakagawa M, Okazawa H. Hepatoma-derived growth factor, a new trophic factor for motor neurons, is up-regulated in the spinal cord of PQBP-1 transgenic mice before onset of degeneration. J Neurochem 2006; 99:70-83. [PMID: 16987236 DOI: 10.1111/j.1471-4159.2006.04021.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Hepatoma-derived growth factor (HDGF) is a nuclear protein homologous to the high-mobility group B1 family of proteins. It is known to be released from cells and to act as a trophic factor for dividing cells. In this study HDGF was increased in spinal motor neurons of a mouse model of motor neuron degeneration, polyglutamine-tract-binding protein-1 (PQBP-1) transgenic mice, before onset of degeneration. HDGF promoted neurite extension and survival of spinal motor neurons in primary culture. HDGF repressed cell death of motor neurons after facial nerve section in newborn rats in vivo. We also found a significant increase in p53 in spinal motor neurons of the transgenic mice. p53 bound to a sequence in the upstream of the HDGF gene in a gel mobility shift assay, and promoted gene expression through the cis-element in chloramphenicol acetyl transfer (CAT) assay. Finally, we found that HDGF was increased in CSF of PQBP-1 transgenic mice. Collectively, our results show that HDGF is a novel trophic factor for motor neurons and suggest that it might play a protective role against motor neuron degeneration in PQBP-1 transgenic mice.
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Affiliation(s)
- Shigeki Marubuchi
- Department of Neuropathology, Medical Research Institute and 21st Century Center of Excellence Program for Brain Integration and Its Disorders, Tokyo Medical and Dental University, Tokyo, Japan
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