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Werthmann GC, Herz J. Apoer2/Lrp8: the undercover cop of synaptic homeostasis. Neural Regen Res 2024; 19:2563-2564. [PMID: 38808982 PMCID: PMC11168519 DOI: 10.4103/nrr.nrr-d-23-02002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 01/18/2024] [Accepted: 02/03/2024] [Indexed: 05/30/2024] Open
Affiliation(s)
- Gordon C. Werthmann
- Department of Molecular Genetics and Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Joachim Herz
- Department of Molecular Genetics and Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
- Department of Neuroscience; Department of Neurology; University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
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Gallo CM, Kistler SA, Natrakul A, Labadorf AT, Beffert U, Ho A. APOER2 splicing repertoire in Alzheimer's disease: Insights from long-read RNA sequencing. PLoS Genet 2024; 20:e1011348. [PMID: 39038048 PMCID: PMC11293713 DOI: 10.1371/journal.pgen.1011348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 08/01/2024] [Accepted: 06/21/2024] [Indexed: 07/24/2024] Open
Abstract
Disrupted alternative splicing plays a determinative role in neurological diseases, either as a direct cause or as a driver in disease susceptibility. Transcriptomic profiling of aged human postmortem brain samples has uncovered hundreds of aberrant mRNA splicing events in Alzheimer's disease (AD) brains, associating dysregulated RNA splicing with disease. We previously identified a complex array of alternative splicing combinations across apolipoprotein E receptor 2 (APOER2), a transmembrane receptor that interacts with both the neuroprotective ligand Reelin and the AD-associated risk factor, APOE. Many of the human APOER2 isoforms, predominantly featuring cassette splicing events within functionally important domains, are critical for the receptor's function and ligand interaction. However, a comprehensive repertoire and the functional implications of APOER2 isoforms under both physiological and AD conditions are not fully understood. Here, we present an in-depth analysis of the splicing landscape of human APOER2 isoforms in normal and AD states. Using single-molecule, long-read sequencing, we profiled the entire APOER2 transcript from the parietal cortex and hippocampus of Braak stage IV AD brain tissues along with age-matched controls and investigated several functional properties of APOER2 isoforms. Our findings reveal diverse patterns of cassette exon skipping for APOER2 isoforms, with some showing region-specific expression and others unique to AD-affected brains. Notably, exon 15 of APOER2, which encodes the glycosylation domain, showed less inclusion in AD compared to control in the parietal cortex of females with an APOE ɛ3/ɛ3 genotype. Also, some of these APOER2 isoforms demonstrated changes in cell surface expression, APOE-mediated receptor processing, and synaptic number. These variations are likely critical in inducing synaptic alterations and may contribute to the neuronal dysfunction underlying AD pathogenesis.
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Affiliation(s)
- Christina M. Gallo
- Department of Biology, Boston University, Boston, Massachusetts, United States of America
- Department of Pharmacology, Physiology & Biophysics, Boston University Chobanian & Avedisian School of Medicine, Boston, Massachusetts, United States of America
| | - Sabrina A. Kistler
- Department of Biology, Boston University, Boston, Massachusetts, United States of America
- Department of Pharmacology, Physiology & Biophysics, Boston University Chobanian & Avedisian School of Medicine, Boston, Massachusetts, United States of America
| | - Anna Natrakul
- Department of Biology, Boston University, Boston, Massachusetts, United States of America
| | - Adam T. Labadorf
- Bioinformatics Program, Boston University, Boston, Massachusetts, United States of America
- Department of Neurology, Boston University Chobanian & Avedisian School of Medicine, Boston, Massachusetts, United States of America
| | - Uwe Beffert
- Department of Biology, Boston University, Boston, Massachusetts, United States of America
| | - Angela Ho
- Department of Biology, Boston University, Boston, Massachusetts, United States of America
- Department of Pharmacology, Physiology & Biophysics, Boston University Chobanian & Avedisian School of Medicine, Boston, Massachusetts, United States of America
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田 学, 陈 婵, 王 雄. [Tau Protein Induces Aberrant Alternative Splicing Changes in PS19 Transgenic Mice]. SICHUAN DA XUE XUE BAO. YI XUE BAN = JOURNAL OF SICHUAN UNIVERSITY. MEDICAL SCIENCE EDITION 2023; 54:874-883. [PMID: 37866941 PMCID: PMC10579071 DOI: 10.12182/20230960501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Indexed: 10/24/2023]
Abstract
Objective To explore through big data analysis whether aberrant alternative splicing (AS) events precede tau P301S-induced neurodegenerative phenotype in 6-month-old PS19 mice. Methods The original sequencing files of the GSE182170 dataset was downloaded from the European Nucleotide Archive (ENA) database with axel, aligned to the reference genome of the ENSEMBL database by using STAR software, and common AS event analysis and visualization were performed with rMATS and rmats2sashimiplot R packages. RSEM software was utilized for gene transcript quantification, Deseq2, edgeR, and limma R packages were used for differential expression analysis, and clusterProfiler R package was applied for GO enrichment analysis. String and Cytoscape were used for protein-protein interaction (PPI) analysis. Gene expression correlation analysis was performed with ggcorrplot R package. AS events were validated using PCR followed by agarose electrophoresis. Results A total of 8 079 AS events were identified with rMATS and 117 significant AS events (ΔPSI>0.1, sequencing coverage >1) were selected eventually. The most frequent type of AS event was skipped exon (SE) (50.43%), followed by alternative 3' splice site (A3SS) and mutually exclusive exons (MXE). GO enrichment analysis revealed that synapse organization genes were aberrantly spliced in SE events and spliceosome genes were spliced in A3SS events. PPI and correlation analyses showed that the splicing factor Snrpn was significantly associated with the largest number of transcripts. Agarose electrophoresis confirmed the aberrant AS event of the Lrp8 gene in PS19 mice. Conclusion Dysregulated splicing factors may contribute to tau P301S-induced aberrant AS changes. The study also increases the understanding of the cycling of tau protein and splicing factors in tauopathies.
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Affiliation(s)
- 学文 田
- 华中科技大学同济医学院附属同济医院 检验科 (武汉 430030)Department of Clinical Laboratory, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - 婵 陈
- 华中科技大学同济医学院附属同济医院 检验科 (武汉 430030)Department of Clinical Laboratory, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - 雄 王
- 华中科技大学同济医学院附属同济医院 检验科 (武汉 430030)Department of Clinical Laboratory, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
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Mizuno A, Toyama T, Ichikawa A, Sakai N, Yoshioka Y, Nishito Y, Toga R, Amesaka H, Kaneko T, Arisawa K, Tsutsumi R, Mita Y, Tanaka SI, Noguchi N, Saito Y. An efficient selenium transport pathway of selenoprotein P utilizing a high-affinity ApoER2 receptor variant and being independent of selenocysteine lyase. J Biol Chem 2023; 299:105009. [PMID: 37406814 PMCID: PMC10407282 DOI: 10.1016/j.jbc.2023.105009] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 06/22/2023] [Accepted: 06/23/2023] [Indexed: 07/07/2023] Open
Abstract
Selenoprotein P (SeP, encoded by the SELENOP gene) is a plasma protein that contains selenium in the form of selenocysteine residues (Sec, a cysteine analog containing selenium instead of sulfur). SeP functions for the transport of selenium to specific tissues in a receptor-dependent manner. Apolipoprotein E receptor 2 (ApoER2) has been identified as a SeP receptor. However, diverse variants of ApoER2 have been reported, and the details of its tissue specificity and the molecular mechanism of its efficiency remain unclear. In the present study, we found that human T lymphoma Jurkat cells have a high ability to utilize selenium via SeP, while this ability was low in human rhabdomyosarcoma cells. We identified an ApoER2 variant with a high affinity for SeP in Jurkat cells. This variant had a dissociation constant value of 0.67 nM and a highly glycosylated O-linked sugar domain. Moreover, the acidification of intracellular vesicles was necessary for selenium transport via SeP in both cell types. In rhabdomyosarcoma cells, SeP underwent proteolytic degradation in lysosomes and transported selenium in a Sec lyase-dependent manner. However, in Jurkat cells, SeP transported selenium in Sec lyase-independent manner. These findings indicate a preferential selenium transport pathway involving SeP and high-affinity ApoER2 in a Sec lyase-independent manner. Herein, we provide a novel dynamic transport pathway for selenium via SeP.
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Affiliation(s)
- Ayako Mizuno
- Laboratory of Molecular Biology and Metabolism, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Takashi Toyama
- Laboratory of Molecular Biology and Metabolism, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Atsuya Ichikawa
- Laboratory of Molecular Biology and Metabolism, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Naoko Sakai
- The Systems Life Sciences Laboratory, Department of Medical Life Systems, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Japan
| | - Yuya Yoshioka
- The Systems Life Sciences Laboratory, Department of Medical Life Systems, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Japan
| | - Yukina Nishito
- The Systems Life Sciences Laboratory, Department of Medical Life Systems, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Japan
| | - Renya Toga
- Laboratory of Biostructural Chemistry, Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto, Japan
| | - Hiroshi Amesaka
- Laboratory of Biostructural Chemistry, Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto, Japan
| | - Takayuki Kaneko
- Laboratory of Molecular Biology and Metabolism, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Kotoko Arisawa
- Laboratory of Molecular Biology and Metabolism, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Ryouhei Tsutsumi
- Laboratory of Molecular Biology and Metabolism, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Yuichiro Mita
- The Systems Life Sciences Laboratory, Department of Medical Life Systems, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Japan
| | - Shun-Ichi Tanaka
- Laboratory of Biostructural Chemistry, Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto, Japan; Department of Biotechnology, College of Life Sciences, Ritsumeikan University, Shiga, Japan
| | - Noriko Noguchi
- The Systems Life Sciences Laboratory, Department of Medical Life Systems, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Japan
| | - Yoshiro Saito
- Laboratory of Molecular Biology and Metabolism, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan; The Systems Life Sciences Laboratory, Department of Medical Life Systems, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Japan.
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Wasser C, Werthmann GC, Hall EM, Kuhbandner K, Wong CH, Durakoglugil MS, Herz J. Apoer2-ICD-dependent regulation of hippocampal ribosome mRNA loading. RESEARCH SQUARE 2023:rs.3.rs-3040567. [PMID: 37461529 PMCID: PMC10350194 DOI: 10.21203/rs.3.rs-3040567/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/24/2023]
Abstract
Background ApoE4, the most significant genetic risk factor for late-onset Alzheimer's disease (AD), sequesters a pro-synaptogenic Reelin receptor, Apoer2, in the endosomal compartment and prevents its normal recycling. In the adult brain, Reelin potentiates excitatory synapses and thereby protects against amyloid-β toxicity. Recently, a gain-of-function mutation in Reelin that is protective against early-onset AD has been described. Alternative splicing of the Apoer2 intracellular domain (Apoer2-ICD) regulates Apoer2 signaling. Splicing of juxtamembraneous exon 16 alters the g-secretase mediated release of the Apoer2-ICD as well as synapse number and LTP, and inclusion of exon 19 ameliorates behavioral deficits in an AD mouse model. The Apoer2-ICD has also been shown to alter transcription of synaptic genes. However, the role of Apoer2 splicing for transcriptional regulation and its role in AD pathogenesis is unknown. Methods To assess in vivo mRNA-primed ribosomes specifically in hippocampi transduced with Apoer2-ICD splice variants, we crossed wild-type, cKO, and Apoer2 cleavage-resistant mice to a Cre-inducible translating ribosome affinity purification (TRAP) model. This allowed us to perform RNA-Seq on ribosome-loaded mRNA harvested specifically from hippocampal cells transduced with Apoer2-ICDs. Results Across all conditions, we observed ~ 4,700 altered ribosome-associated transcripts, several of which comprise key synaptic components such as extracellular matrix and focal adhesions with concomitant perturbation of critical signaling cascades, energy metabolism, translation, and apoptosis. We further demonstrated the ability of the Apoer2-ICD to rescue many of these altered transcripts, underscoring the importance of Apoer2 splicing in synaptic homeostasis. A variety of these altered genes have been implicated in AD, demonstrating how dysregulated Apoer2 splicing may contribute to neurodegeneration. Conclusions Our findings demonstrate how alternative splicing of the APOE and Reelin receptor Apoer2 and release of the Apoer2-ICD regulates numerous ribosome-associated transcripts in mouse hippocampi in vivo . These transcripts comprise a wide range of functions, and alterations in these transcripts suggest a mechanistic basis for the synaptic deficits seen in Apoer2 mutant mice and AD patients. Our findings, together with the recently reported AD-protective effects of a Reelin gain-of-function mutation in the presence of an early-onset AD mutation in Presenilin-1, implicate the Reelin/Apoer2 pathway as a target for AD therapeutics.
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Affiliation(s)
- Catherine Wasser
- UT Southwestern: The University of Texas Southwestern Medical Center
| | | | - Eric M Hall
- UT Southwestern: The University of Texas Southwestern Medical Center
| | | | - Connie H Wong
- UT Southwestern: The University of Texas Southwestern Medical Center
| | | | - Joachim Herz
- UT Southwestern: The University of Texas Southwestern Medical Center
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Ramsden CE, Zamora D, Horowitz M, Jahanipour J, Keyes G, Li X, Murray HC, Curtis MA, Faull RM, Sedlock A, Maric D. ApoER2-Dab1 disruption as the origin of pTau-related neurodegeneration in sporadic Alzheimer's disease. RESEARCH SQUARE 2023:rs.3.rs-2968020. [PMID: 37461602 PMCID: PMC10350181 DOI: 10.21203/rs.3.rs-2968020/v1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/23/2023]
Abstract
BACKGROUND Sporadic Alzheimer's disease (sAD) is not a global brain disease. Specific regions, layers and neurons degenerate early while others remain untouched even in advanced disease. The prevailing model used to explain this selective neurodegeneration-prion-like Tau spread-has key limitations and is not easily integrated with other defining sAD features. Instead, we propose that in humans Tau hyperphosphorylation occurs locally via disruption in ApoER2-Dab1 signaling and thus the presence of ApoER2 in neuronal membranes confers vulnerability to degeneration. Further, we propose that disruption of the Reelin/ApoE/ApoJ-ApoER2-Dab1-P85α-LIMK1-Tau-PSD95 (RAAAD-P-LTP) pathway induces deficits in memory and cognition by impeding neuronal lipoprotein internalization and destabilizing actin, microtubules, and synapses. This new model is based in part on our recent finding that ApoER2-Dab1 disruption is evident in entorhinal-hippocampal terminal zones in sAD. Here, we hypothesized that neurons that degenerate in the earliest stages of sAD (1) strongly express ApoER2 and (2) show evidence of ApoER2-Dab1 disruption through co-accumulation of multiple RAAAD-P-LTP components. METHODS We applied in situ hybridization and immunohistochemistry to characterize ApoER2 expression and accumulation of RAAAD-P-LTP components in five regions that are prone to early pTau pathology in 64 rapidly autopsied cases spanning the clinicopathological spectrum of sAD. RESULTS We found that: (1) selectively vulnerable neuron populations strongly express ApoER2; (2) numerous RAAAD-P-LTP pathway components accumulate in neuritic plaques and abnormal neurons; and (3) RAAAD-P-LTP components were higher in MCI and sAD cases and correlated with histological progression and cognitive deficits. Multiplex-IHC revealed that Dab1, pP85αTyr607, pLIMK1Thr508, pTau and pPSD95Thr19 accumulated together within dystrophic dendrites and soma of ApoER2-expressing neurons in the vicinity of ApoE/ApoJ-enriched extracellular plaques. These observations provide evidence for molecular derangements that can be traced back to ApoER2-Dab1 disruption, in each of the sampled regions, layers, and neuron populations that are prone to early pTau pathology. CONCLUSION Findings support the RAAAD-P-LTP hypothesis, a unifying model that implicates dendritic ApoER2-Dab1 disruption as the major driver of both pTau accumulation and neurodegeneration in sAD. This model provides a new conceptual framework to explain why specific neurons degenerate and identifies RAAAD-P-LTP pathway components as potential mechanism-based biomarkers and therapeutic targets for sAD.
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Affiliation(s)
| | - Daisy Zamora
- National Institute on Aging Laboratory of Clinical Investigation
| | - Mark Horowitz
- National Institute on Aging Intramural Research Program
| | | | - Gregory Keyes
- National Institute on Aging Laboratory of Clinical Investigation
| | - Xiufeng Li
- National Institute on Aging Laboratory of Clinical Investigation
| | - Helen C Murray
- The University of Auckland Faculty of Medical and Health Sciences
| | - Maurice A Curtis
- The University of Auckland Faculty of Medical and Health Sciences
| | - Richard M Faull
- The University of Auckland Faculty of Medical and Health Sciences
| | - Andrea Sedlock
- NINDS: National Institute of Neurological Disorders and Stroke
| | - Dragan Maric
- NINDS: National Institute of Neurological Disorders and Stroke
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Ramsden CE, Zamora D, Horowitz MS, Jahanipour J, Keyes GS, Li X, Murray HC, Curtis MA, Faull RM, Sedlock A, Maric D. ApoER2-Dab1 disruption as the origin of pTau-related neurodegeneration in sporadic Alzheimer's disease. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.05.19.23290250. [PMID: 37333406 PMCID: PMC10274982 DOI: 10.1101/2023.05.19.23290250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
BACKGROUND Sporadic Alzheimer's disease (sAD) is not a global brain disease. Specific regions, layers and neurons degenerate early while others remain untouched even in advanced disease. The prevailing model used to explain this selective neurodegeneration-prion-like Tau spread-has key limitations and is not easily integrated with other defining sAD features. Instead, we propose that in humans Tau hyperphosphorylation occurs locally via disruption in ApoER2-Dab1 signaling and thus the presence of ApoER2 in neuronal membranes confers vulnerability to degeneration. Further, we propose that disruption of the Reelin/ApoE/ApoJ-ApoER2-Dab1-P85α-LIMK1-Tau-PSD95 (RAAAD-P-LTP) pathway induces deficits in memory and cognition by impeding neuronal lipoprotein internalization and destabilizing actin, microtubules, and synapses. This new model is based in part on our recent finding that ApoER2-Dab1 disruption is evident in entorhinal-hippocampal terminal zones in sAD. Here, we hypothesized that neurons that degenerate in the earliest stages of sAD (1) strongly express ApoER2 and (2) show evidence of ApoER2-Dab1 disruption through co-accumulation of multiple RAAAD-P-LTP components. METHODS We applied in situ hybridization and immunohistochemistry to characterize ApoER2 expression and accumulation of RAAAD-P-LTP components in five regions that are prone to early pTau pathology in 64 rapidly autopsied cases spanning the clinicopathological spectrum of sAD. RESULTS We found that: (1) selectively vulnerable neuron populations strongly express ApoER2; (2) numerous RAAAD-P-LTP pathway components accumulate in neuritic plaques and abnormal neurons; and (3) RAAAD-P-LTP components were higher in MCI and sAD cases and correlated with histological progression and cognitive deficits. Multiplex-IHC revealed that Dab1, pP85αTyr607, pLIMK1Thr508, pTau and pPSD95Thr19 accumulated together within dystrophic dendrites and soma of ApoER2-expressing neurons in the vicinity of ApoE/ApoJ-enriched extracellular plaques. These observations provide evidence for molecular derangements that can be traced back to ApoER2-Dab1 disruption, in each of the sampled regions, layers, and neuron populations that are prone to early pTau pathology. CONCLUSION Findings support the RAAAD-P-LTP hypothesis, a unifying model that implicates dendritic ApoER2-Dab1 disruption as the major driver of both pTau accumulation and neurodegeneration in sAD. This model provides a new conceptual framework to explain why specific neurons degenerate and identifies RAAAD-P-LTP pathway components as potential mechanism-based biomarkers and therapeutic targets for sAD.
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Affiliation(s)
- Christopher E. Ramsden
- Lipid Peroxidation Unit, Laboratory of Clinical Investigation, National Institute on Aging, NIH 251 Bayview Blvd., Baltimore, MD, 21224, USA
- Intramural Program of the National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, 20892, USA
| | - Daisy Zamora
- Lipid Peroxidation Unit, Laboratory of Clinical Investigation, National Institute on Aging, NIH 251 Bayview Blvd., Baltimore, MD, 21224, USA
- Department of Physical Medicine and Rehabilitation, School of Medicine, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Mark S. Horowitz
- Lipid Peroxidation Unit, Laboratory of Clinical Investigation, National Institute on Aging, NIH 251 Bayview Blvd., Baltimore, MD, 21224, USA
| | - Jahandar Jahanipour
- Flow and Imaging Cytometry Core Facility, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, 20892, USA
| | - Gregory S. Keyes
- Lipid Peroxidation Unit, Laboratory of Clinical Investigation, National Institute on Aging, NIH 251 Bayview Blvd., Baltimore, MD, 21224, USA
| | - Xiufeng Li
- Lipid Peroxidation Unit, Laboratory of Clinical Investigation, National Institute on Aging, NIH 251 Bayview Blvd., Baltimore, MD, 21224, USA
| | - Helen C. Murray
- Department of Anatomy and Medical Imaging and Centre for Brain Research, Faculty of Medical and Health Science, University of Auckland, Private Bag, Auckland, 92019, New Zealand
- Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, 20892, USA
| | - Maurice A. Curtis
- Department of Anatomy and Medical Imaging and Centre for Brain Research, Faculty of Medical and Health Science, University of Auckland, Private Bag, Auckland, 92019, New Zealand
| | - Richard M. Faull
- Department of Anatomy and Medical Imaging and Centre for Brain Research, Faculty of Medical and Health Science, University of Auckland, Private Bag, Auckland, 92019, New Zealand
| | - Andrea Sedlock
- Flow and Imaging Cytometry Core Facility, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, 20892, USA
| | - Dragan Maric
- Flow and Imaging Cytometry Core Facility, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, 20892, USA
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Babio L, Damsteegt EL, Lokman PM. Lipoprotein receptors in ovary of eel, Anguilla australis: molecular characterisation of putative vitellogenin receptors. FISH PHYSIOLOGY AND BIOCHEMISTRY 2023; 49:117-137. [PMID: 36648592 PMCID: PMC9935665 DOI: 10.1007/s10695-023-01169-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 01/04/2023] [Indexed: 06/17/2023]
Abstract
Lipoprotein receptors, including low-density lipoprotein receptor (LDLr) relatives (Lrs) and LDLr-related proteins (Lrps), belong to the LDLr supergene family and participate in diverse physiological functions. In this study, novel sequences of lr and lrp genes expressed in the ovary of the short-finned eel, Anguilla australis, during early gonadal development are presented. The genes encoding the LDLr-like, Lrp1-like, Lrp1b-like, Lrp3, Lrp4-like, Lrp5-like, Lrp6, Lrp10, Lrp11, Lrp12-like, and Lr11-like proteins were found and identified by sequence and structure analysis, in addition to phylogenetic analysis. Genes encoding proteins previously implicated in follicle development and vitellogenin (Vtg) uptake in oviparous vertebrates were also identified, i.e. lr8 (including lr8 + and lr8- variants) and lrp13; their identification was reinforced by conserved synteny with orthologues in other teleost fish. Compared to other lr/lrp genes, the genes encoding Lr8 + , Lr8-, and Lrp13 were highly expressed in ovary during early development, decreasing as oocyte development advanced when induced by hypophysation. Furthermore, lr8 + , lr8-, and lrp13 were dominantly expressed in the ovary when compared with 17 other tissues. Finally, this study successfully detected the expression of both lr8 variants, which showed different expression patterns to those reported in other oviparous vertebrates and provided the first characterisation of Lrp13 in Anguilla sp. We propose that lr8 + , lr8-, and lrp13 encode putative Vtg receptors in anguillid eels.
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Affiliation(s)
- Lucila Babio
- Department of Zoology, University of Otago, 340 Great King Street, P.O. Box 56, Dunedin, Otago 9054 New Zealand
| | - Erin L. Damsteegt
- Department of Zoology, University of Otago, 340 Great King Street, P.O. Box 56, Dunedin, Otago 9054 New Zealand
| | - P. Mark Lokman
- Department of Zoology, University of Otago, 340 Great King Street, P.O. Box 56, Dunedin, Otago 9054 New Zealand
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Guo B, Xia Y, Wang C, Wang F, Zhang C, Xiao L, Zhang X, Meng Y, Wang Y, Ding J, Wang L, Zhu C, Jiang S, Huo X, Sun Y, Gao P, Wu J, Yu B, Huo J, Sun T. Decreased cognitive function of ALG13KO female mice may be related to the decreased plasticity of hippocampal neurons. Neuropeptides 2022; 96:102290. [PMID: 36152356 DOI: 10.1016/j.npep.2022.102290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 08/15/2022] [Accepted: 09/13/2022] [Indexed: 02/05/2023]
Abstract
Asparagine-linked glycosylation 13 (ALG13) is an X-linked gene that encodes a protein involved in the glycosylation of the N-terminus. ALG13 deficiency leads to ALG13-congenital disorders of glycosylation (ALG13-CDG), usually in females presenting with mental retardation and epilepsy. Cognitive function is an important function of the hippocampus, and forms the basis for learning, memory and social abilities. However, researchers have not yet investigated the effect of ALG13 on hippocampal cognitive function. In this study, the exploration, learning, memory and social abilities of ALG13 knockout (KO) female mice were decreased in behavioral experiments. Golgi staining demonstrated a decrease in the complexity of hippocampal neurons. Western blot and immunofluorescence staining of the synaptic plasticity factors postsynaptic density protein 95 (PSD95) and synaptophysin (SYP) displayed varying degrees of decline. In other words, the KO of ALG13 may have reduced the expression of PSD95 and SYP in the hippocampus of female mice. Moreover, it may have lowered the synaptic plasticity in various areas of the hippocampus, thus resulting in decreased dendrite length, complexity, and dendrite spine density, which affected the hippocampal function and reduced the cognitive function in female mice.
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Affiliation(s)
- Baorui Guo
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, Ningxia 750004, China
| | - Yu Xia
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, Ningxia 750004, China
| | - Chunlin Wang
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, Ningxia 750004, China
| | - Feng Wang
- Department of Neurosurgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310000, China
| | - Chun Zhang
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, Ningxia 750004, China
| | - Lifei Xiao
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, Ningxia 750004, China
| | - Xian Zhang
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, Ningxia 750004, China
| | - Yuan Meng
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, Ningxia 750004, China
| | - Yangyang Wang
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, Ningxia 750004, China
| | - Jiangwei Ding
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, Ningxia 750004, China
| | - Lei Wang
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, Ningxia 750004, China
| | - Changliang Zhu
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, Ningxia 750004, China
| | - Shucai Jiang
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, Ningxia 750004, China
| | - Xianhao Huo
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, Ningxia 750004, China
| | - Yangyang Sun
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, Ningxia 750004, China
| | - Peng Gao
- Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, Ningxia 750004, China
| | - Ji Wu
- Renji Hospital Shanghai Jiaotong University School of Medicine, Key Laboratory for the Genetics of Developmental & Neuropsychiatric Disorders (Ministry of Education), Bio-X Institutes, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Baoli Yu
- Renji Hospital Shanghai Jiaotong University School of Medicine, Key Laboratory for the Genetics of Developmental & Neuropsychiatric Disorders (Ministry of Education), Bio-X Institutes, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Junming Huo
- Department of Neurosurgery, The First Affiliated Hospital of Baotou Medical College, Inner Mongolia 014017, China
| | - Tao Sun
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, Ningxia 750004, China.
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10
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Hawkinson TR, Clarke HA, Young LEA, Conroy LR, Markussen KH, Kerch KM, Johnson LA, Nelson PT, Wang C, Allison DB, Gentry MS, Sun RC. In situ spatial glycomic imaging of mouse and human Alzheimer's disease brains. Alzheimers Dement 2022; 18:1721-1735. [PMID: 34908231 PMCID: PMC9198106 DOI: 10.1002/alz.12523] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 10/06/2021] [Accepted: 10/10/2021] [Indexed: 01/28/2023]
Abstract
N-linked protein glycosylation in the brain is an understudied facet of glucose utilization that impacts a myriad of cellular processes including resting membrane potential, axon firing, and synaptic vesicle trafficking. Currently, a spatial map of N-linked glycans within the normal and Alzheimer's disease (AD) human brain does not exist. A comprehensive analysis of the spatial N-linked glycome would improve our understanding of brain energy metabolism, linking metabolism to signaling events perturbed during AD progression, and could illuminate new therapeutic strategies. Herein we report an optimized in situ workflow for enzyme-assisted, matrix-assisted laser desorption and ionization (MALDI) mass spectrometry imaging (MSI) of brain N-linked glycans. Using this workflow, we spatially interrogated N-linked glycan heterogeneity in both mouse and human AD brains and their respective age-matched controls. We identified robust regional-specific N-linked glycan changes associated with AD in mice and humans. These data suggest that N-linked glycan dysregulation could be an underpinning of AD pathologies.
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Affiliation(s)
- Tara R. Hawkinson
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Harrison A. Clarke
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Lyndsay E. A. Young
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
- Markey Cancer Center, University of Kentucky, Lexington, Kentucky, USA
| | - Lindsey R. Conroy
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Kia H. Markussen
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Kayla M. Kerch
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Lance A. Johnson
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky, USA
| | - Peter T. Nelson
- Department of Pathology and Laboratory Medicine, University of Kentucky, Lexington, Kentucky, USA
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky, USA
| | - Chi Wang
- Markey Cancer Center, University of Kentucky, Lexington, Kentucky, USA
- Department of Biostatistics, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Derek B. Allison
- Markey Cancer Center, University of Kentucky, Lexington, Kentucky, USA
- Department of Pathology and Laboratory Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Matthew S. Gentry
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
- Markey Cancer Center, University of Kentucky, Lexington, Kentucky, USA
| | - Ramon C. Sun
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
- Markey Cancer Center, University of Kentucky, Lexington, Kentucky, USA
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky, USA
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11
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Passarella D, Ciampi S, Di Liberto V, Zuccarini M, Ronci M, Medoro A, Foderà E, Frinchi M, Mignogna D, Russo C, Porcile C. Low-Density Lipoprotein Receptor-Related Protein 8 at the Crossroad between Cancer and Neurodegeneration. Int J Mol Sci 2022; 23:ijms23168921. [PMID: 36012187 PMCID: PMC9408729 DOI: 10.3390/ijms23168921] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/07/2022] [Accepted: 08/09/2022] [Indexed: 11/16/2022] Open
Abstract
The low-density-lipoprotein receptors represent a family of pleiotropic cell surface receptors involved in lipid homeostasis, cell migration, proliferation and differentiation. The family shares common structural features but also has significant differences mainly due to tissue-specific interactors and to peculiar proteolytic processing. Among the receptors in the family, recent studies place low-density lipoprotein receptor-related protein 8 (LRP8) at the center of both neurodegenerative and cancer-related pathways. From one side, its overexpression has been highlighted in many types of cancer including breast, gastric, prostate, lung and melanoma; from the other side, LRP8 has a potential role in neurodegeneration as apolipoprotein E (ApoE) and reelin receptor, which are, respectively, the major risk factor for developing Alzheimer’s disease (AD) and the main driver of neuronal migration, and as a γ-secretase substrate, the main enzyme responsible for amyloid formation in AD. The present review analyzes the contributions of LDL receptors, specifically of LRP8, in both cancer and neurodegeneration, pointing out that depending on various interactions and peculiar processing, the receptor can contribute to both proliferative and neurodegenerative processes.
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Affiliation(s)
- Daniela Passarella
- Department of Medicine and Health Sciences “V. Tiberio”, University of Molise, 86100 Campobasso, Italy
| | - Silvia Ciampi
- Department of Medicine and Health Sciences “V. Tiberio”, University of Molise, 86100 Campobasso, Italy
| | - Valentina Di Liberto
- Department of Experimental Biomedicine and Clinical Neurosciences, University of Palermo, 90133 Palermo, Italy
| | - Mariachiara Zuccarini
- Department of Medical Oral and Biotechnological Sciences, University of Chieti-Pescara, 66100 Chieti, Italy
| | - Maurizio Ronci
- Department of Pharmacy, University of Chieti-Pescara, 66100 Chieti, Italy
| | - Alessandro Medoro
- Department of Medicine and Health Sciences “V. Tiberio”, University of Molise, 86100 Campobasso, Italy
| | - Emanuele Foderà
- Department of Medicine and Health Sciences “V. Tiberio”, University of Molise, 86100 Campobasso, Italy
| | - Monica Frinchi
- Department of Experimental Biomedicine and Clinical Neurosciences, University of Palermo, 90133 Palermo, Italy
| | - Donatella Mignogna
- Department of Medicine and Health Sciences “V. Tiberio”, University of Molise, 86100 Campobasso, Italy
| | - Claudio Russo
- Department of Medicine and Health Sciences “V. Tiberio”, University of Molise, 86100 Campobasso, Italy
- Correspondence: ; Tel.: +39-0874404897
| | - Carola Porcile
- Department of Medicine and Health Sciences “V. Tiberio”, University of Molise, 86100 Campobasso, Italy
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12
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Omuro KC, Gallo CM, Scrandis L, Ho A, Beffert U. Human APOER2 Isoforms Have Differential Cleavage Events and Synaptic Properties. J Neurosci 2022; 42:4054-4068. [PMID: 35414534 PMCID: PMC9121830 DOI: 10.1523/jneurosci.1800-21.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 03/24/2022] [Accepted: 04/06/2022] [Indexed: 11/21/2022] Open
Abstract
Human apolipoprotein E receptor 2 (APOER2) is a type I transmembrane protein with a large extracellular domain (ECD) and a short cytoplasmic tail. APOER2-ECD contains several ligand-binding domains (LBDs) that are organized into exons with aligning phase junctions, which allows for in-frame exon cassette splicing events. We have identified 25 human APOER2 isoforms from cerebral cortex using gene-specific APOER2 primers, where the majority are exon-skipping events within the N-terminal LBD regions compared with six identified in the heart. APOER2 undergoes proteolytic cleavage in response to ligand binding that releases a C-terminal fragment (CTF) and transcriptionally active intracellular domain (ICD). We tested whether the diversity of human brain-specific APOER2 variants affects APOER2 cleavage. We found isoforms with differing numbers of ligand-binding repeats generated different amounts of CTFs compared with full-length APOER2 (APOER2-FL). Specifically, APOER2 isoforms lacking exons 5-8 (Δex5-8) and lacking exons 4-6 (Δex4-6) generated the highest and lowest amounts of CTF generation, respectively, in response to APOE peptide compared with APOER2-FL. The differential CTF generation of Δex5-8 and Δex4-6 coincides with the proteolytic release of the ICD, which mediates transcriptional activation facilitated by the Mint1 adaptor protein. Functionally, we demonstrated loss of mouse Apoer2 decreased miniature event frequency in excitatory synapses, which may be because of a decrease in the total number of synapses and/or VAMP2 positive neurons. Lentiviral infection with human APOER2-FL or Δex4-6 isoform in Apoer2 knockout neurons restored the miniature event frequency but not Δex5-8 isoform. These results suggest that human APOER2 isoforms have differential cleavage events and synaptic properties.SIGNIFICANCE STATEMENT Humans and mice share virtually the same number of protein-coding genes. However, humans have greater complexity of any higher eukaryotic organisms by encoding multiple protein forms through alternative splicing modifications. Alternative splicing allows pre-mRNAs transcribed from genes to be spliced in different arrangements, producing structurally and functionally distinct protein variants that increase proteomic diversity and are particularly prevalent in the human brain. Here, we identified 25 distinct human APOER2 splice variants from the cerebral cortex using gene-specific APOER2 primers, where the majority are exon-skipping events that exclude N-terminal ligand-binding regions of APOER2. We show that some of the APOER2 variants have differential proteolytic properties in response to APOE ligand and exhibit distinct synaptic properties.
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Affiliation(s)
| | | | - Lauren Scrandis
- Department of Biology, Boston University, Boston, Massachusetts 02215
| | - Angela Ho
- Department of Biology, Boston University, Boston, Massachusetts 02215
| | - Uwe Beffert
- Department of Biology, Boston University, Boston, Massachusetts 02215
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13
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Ramsden CE, Keyes GS, Calzada E, Horowitz MS, Zamora D, Jahanipour J, Sedlock A, Indig FE, Moaddel R, Kapogiannis D, Maric D. Lipid Peroxidation Induced ApoE Receptor-Ligand Disruption as a Unifying Hypothesis Underlying Sporadic Alzheimer's Disease in Humans. J Alzheimers Dis 2022; 87:1251-1290. [PMID: 35466940 DOI: 10.3233/jad-220071] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Sporadic Alzheimer's disease (sAD) lacks a unifying hypothesis that can account for the lipid peroxidation observed early in the disease, enrichment of ApoE in the core of neuritic plaques, hallmark plaques and tangles, and selective vulnerability of entorhinal-hippocampal structures. OBJECTIVE We hypothesized that 1) high expression of ApoER2 (receptor for ApoE and Reelin) helps explain this anatomical vulnerability; 2) lipid peroxidation of ApoE and ApoER2 contributes to sAD pathogenesis, by disrupting neuronal ApoE delivery and Reelin-ApoER2-Dab1 signaling cascades. METHODS In vitro biochemical experiments; Single-marker and multiplex fluorescence-immunohistochemistry (IHC) in postmortem specimens from 26 individuals who died cognitively normal, with mild cognitive impairment or with sAD. RESULTS ApoE and ApoER2 peptides and proteins were susceptible to attack by reactive lipid aldehydes, generating lipid-protein adducts and crosslinked ApoE-ApoER2 complexes. Using in situ hybridization alongside IHC, we observed that: 1) ApoER2 is strongly expressed in terminal zones of the entorhinal-hippocampal 'perforant path' projections that underlie memory; 2) ApoE, lipid aldehyde-modified ApoE, Reelin, ApoER2, and the downstream Reelin-ApoER2 cascade components Dab1 and Thr19-phosphorylated PSD95 accumulated in the vicinity of neuritic plaques in perforant path terminal zones in sAD cases; 3) several ApoE/Reelin-ApoER2-Dab1 pathway markers were higher in sAD cases and positively correlated with histological progression and cognitive deficits. CONCLUSION Results demonstrate derangements in multiple ApoE/Reelin-ApoER2-Dab1 axis components in perforant path terminal zones in sAD and provide proof-of-concept that ApoE and ApoER2 are vulnerable to aldehyde-induced adduction and crosslinking. Findings provide the foundation for a unifying hypothesis implicating lipid peroxidation of ApoE and ApoE receptors in sAD.
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Affiliation(s)
- Christopher E Ramsden
- Lipid Peroxidation Unit, Laboratory of Clinical Investigation, National Institute on Aging, NIH, Baltimore, MD, USA.,Intramural Program of the National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, USA
| | - Gregory S Keyes
- Lipid Peroxidation Unit, Laboratory of Clinical Investigation, National Institute on Aging, NIH, Baltimore, MD, USA
| | - Elizabeth Calzada
- Lipid Peroxidation Unit, Laboratory of Clinical Investigation, National Institute on Aging, NIH, Baltimore, MD, USA
| | - Mark S Horowitz
- Lipid Peroxidation Unit, Laboratory of Clinical Investigation, National Institute on Aging, NIH, Baltimore, MD, USA
| | - Daisy Zamora
- Lipid Peroxidation Unit, Laboratory of Clinical Investigation, National Institute on Aging, NIH, Baltimore, MD, USA
| | - Jahandar Jahanipour
- Flow and Imaging Cytometry Core Facility, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Andrea Sedlock
- Flow and Imaging Cytometry Core Facility, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Fred E Indig
- Confocal Imaging Facility, National Institute on Aging Intramural Research Program, NIH, Baltimore, MD, USA
| | - Ruin Moaddel
- Laboratory of Clinical Investigation, National Institute on Aging, NIH, Baltimore, MD, USA
| | - Dimitrios Kapogiannis
- Human Neuroscience Unit, Laboratory of Clinical Investigation, National Institute on Aging, NIH, Baltimore, MD, USA
| | - Dragan Maric
- Flow and Imaging Cytometry Core Facility, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
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14
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Gallo CM, Labadorf AT, Ho A, Beffert U. Single molecule, long-read Apoer2 sequencing identifies conserved and species-specific splicing patterns. Genomics 2022; 114:110318. [PMID: 35192893 PMCID: PMC8978334 DOI: 10.1016/j.ygeno.2022.110318] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 02/11/2022] [Accepted: 02/15/2022] [Indexed: 11/04/2022]
Abstract
Apolipoprotein E receptor 2 (Apoer2) is a synaptic receptor in the brain that binds disease-relevant ligand Apolipoprotein E (Apoe) and is highly alternatively spliced. We examined alternative splicing (AS) of conserved Apoer2 exons across vertebrate species and identified gain of exons in mammals encoding functional domains such as the cytoplasmic and furin inserts, and loss of an exon in primates encoding the eighth LDLa repeat, likely altering receptor surface levels and ligand-binding specificity. We utilized single molecule, long-read RNA sequencing to profile full-length Apoer2 isoforms and identified 68 and 48 unique full-length Apoer2 transcripts in the mouse and human cerebral cortex, respectively. Furthermore, we identified two exons encoding protein functional domains, the third EGF-precursor like repeat and glycosylation domain, that are tandemly skipped specifically in mouse. Our study provides new insight into Apoer2 isoform complexity in the vertebrate brain and highlights species-specific differences in splicing decisions that support functional diversity.
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Affiliation(s)
- Christina M Gallo
- Department of Pharmacology & Experimental Therapeutics, Boston University School of Medicine, United States of America; Department of Biology, Boston University, United States of America
| | - Adam T Labadorf
- Bioinformatics Program, Boston University, United States of America; Department of Neurology, Boston University School of Medicine, United States of America
| | - Angela Ho
- Department of Pharmacology & Experimental Therapeutics, Boston University School of Medicine, United States of America; Department of Biology, Boston University, United States of America.
| | - Uwe Beffert
- Department of Biology, Boston University, United States of America
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15
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Calvier L, Herz J, Hansmann G. Interplay of Low-Density Lipoprotein Receptors, LRPs, and Lipoproteins in Pulmonary Hypertension. JACC Basic Transl Sci 2022; 7:164-180. [PMID: 35257044 PMCID: PMC8897182 DOI: 10.1016/j.jacbts.2021.09.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 09/17/2021] [Accepted: 09/18/2021] [Indexed: 12/21/2022]
Abstract
The low-density lipoprotein receptor (LDLR) gene family includes LDLR, very LDLR, and LDL receptor-related proteins (LRPs) such as LRP1, LRP1b (aka LRP-DIT), LRP2 (aka megalin), LRP4, and LRP5/6, and LRP8 (aka ApoER2). LDLR family members constitute a class of closely related multifunctional, transmembrane receptors, with diverse functions, from embryonic development to cancer, lipid metabolism, and cardiovascular homeostasis. While LDLR family members have been studied extensively in the systemic circulation in the context of atherosclerosis, their roles in pulmonary arterial hypertension (PAH) are understudied and largely unknown. Endothelial dysfunction, tissue infiltration of monocytes, and proliferation of pulmonary artery smooth muscle cells are hallmarks of PAH, leading to vascular remodeling, obliteration, increased pulmonary vascular resistance, heart failure, and death. LDLR family members are entangled with the aforementioned detrimental processes by controlling many pathways that are dysregulated in PAH; these include lipid metabolism and oxidation, but also platelet-derived growth factor, transforming growth factor β1, Wnt, apolipoprotein E, bone morpohogenetic proteins, and peroxisome proliferator-activated receptor gamma. In this paper, we discuss the current knowledge on LDLR family members in PAH. We also review mechanisms and drugs discovered in biological contexts and diseases other than PAH that are likely very relevant in the hypertensive pulmonary vasculature and the future care of patients with PAH or other chronic, progressive, debilitating cardiovascular diseases.
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Key Words
- ApoE, apolipoprotein E
- Apoer2
- BMP
- BMPR, bone morphogenetic protein receptor
- BMPR2
- COPD, chronic obstructive pulmonary disease
- CTGF, connective tissue growth factor
- HDL, high-density lipoprotein
- KO, knockout
- LDL receptor related protein
- LDL, low-density lipoprotein
- LDLR
- LDLR, low-density lipoprotein receptor
- LRP
- LRP, low-density lipoprotein receptor–related protein
- LRP1
- LRP1B
- LRP2
- LRP4
- LRP5
- LRP6
- LRP8
- MEgf7
- Mesd, mesoderm development
- PAH
- PAH, pulmonary arterial hypertension
- PASMC, pulmonary artery smooth muscle cell
- PDGF
- PDGFR-β, platelet-derived growth factor receptor-β
- PH, pulmonary hypertension
- PPARγ
- PPARγ, peroxisome proliferator-activated receptor gamma
- PVD
- RV, right ventricle/ventricular
- RVHF
- RVSP, right ventricular systolic pressure
- TGF-β1
- TGF-β1, transforming growth factor β1
- TGFBR, transforming growth factor β1 receptor
- TNF, tumor necrosis factor receptor
- VLDLR
- VLDLR, very low density lipoprotein receptor
- VSMC, vascular smooth muscle cell
- Wnt
- apolipoprotein E receptor 2
- endothelial cell
- gp330
- low-density lipoprotein receptor
- mRNA, messenger RNA
- megalin
- monocyte
- multiple epidermal growth factor-like domains 7
- pulmonary arterial hypertension
- pulmonary vascular disease
- right ventricle heart failure
- smooth muscle cell
- very low density lipoprotein receptor
- β-catenin
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Affiliation(s)
- Laurent Calvier
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Joachim Herz
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Georg Hansmann
- Department of Pediatric Cardiology and Critical Care, Hannover Medical School, Hannover, Germany
- Pulmonary Vascular Research Center, Hannover Medical School, Hannover, Germany
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16
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Yang M, Ke Y, Kim P, Zhou X. ExonSkipAD provides the functional genomic landscape of exon skipping events in Alzheimer's disease. Brief Bioinform 2021; 22:bbaa438. [PMID: 33497435 PMCID: PMC8425305 DOI: 10.1093/bib/bbaa438] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Revised: 12/23/2020] [Accepted: 12/28/2020] [Indexed: 12/18/2022] Open
Abstract
Exon skipping (ES), the most common alternative splicing event, has been reported to contribute to diverse human diseases due to the loss of functional domains/sites or frameshifting of the open reading frame (ORF) and noticed as therapeutic targets. Accumulating transcriptomic studies of aging brains show the splicing disruption is a widespread hallmark of neurodegenerative diseases such as Alzheimer's disease (AD). Here, we built ExonSkipAD, the ES annotation database aiming to provide a resource/reference for functional annotation of ES events in AD and identify therapeutic targets in exon units. We identified 16 414 genes that have ~156 K, ~ 69 K, ~ 231 K ES events from the three representative AD cohorts of ROSMAP, MSBB and Mayo, respectively. For these ES events, we performed multiple functional annotations relating to ES mechanisms or downstream. Specifically, through the functional feature retention studies followed by the open reading frames (ORFs), we identified 275 important cellular regulators that might lose their cellular regulator roles due to exon skipping in AD. ExonSkipAD provides twelve categories of annotations: gene summary, gene structures and expression levels, exon skipping events with PSIs, ORF annotation, exon skipping events in the canonical protein sequence, 3'-UTR located exon skipping events lost miRNA-binding sites, SNversus in the skipped exons with a depth of coverage, AD stage-associated exon skipping events, splicing quantitative trait loci (sQTLs) in the skipped exons, correlation with RNA-binding proteins, and related drugs & diseases. ExonSkipAD will be a unique resource of transcriptomic diversity research for understanding the mechanisms of neurodegenerative disease development and identifying potential therapeutic targets in AD. Significance AS the first comprehensive resource of the functional genomics of the alternative splicing events in AD, ExonSkipAD will be useful for many researchers in the fields of pathology, AD genomics and precision medicine, and pharmaceutical and therapeutic researches.
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17
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Brain glycogen serves as a critical glucosamine cache required for protein glycosylation. Cell Metab 2021; 33:1404-1417.e9. [PMID: 34043942 PMCID: PMC8266748 DOI: 10.1016/j.cmet.2021.05.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 03/02/2021] [Accepted: 05/03/2021] [Indexed: 02/08/2023]
Abstract
Glycosylation defects are a hallmark of many nervous system diseases. However, the molecular and metabolic basis for this pathology is not fully understood. In this study, we found that N-linked protein glycosylation in the brain is metabolically channeled to glucosamine metabolism through glycogenolysis. We discovered that glucosamine is an abundant constituent of brain glycogen, which functions as a glucosamine reservoir for multiple glycoconjugates. We demonstrated the enzymatic incorporation of glucosamine into glycogen by glycogen synthase, and the release by glycogen phosphorylase by biochemical and structural methodologies, in primary astrocytes, and in vivo by isotopic tracing and mass spectrometry. Using two mouse models of glycogen storage diseases, we showed that disruption of brain glycogen metabolism causes global decreases in free pools of UDP-N-acetylglucosamine and N-linked protein glycosylation. These findings revealed fundamental biological roles of brain glycogen in protein glycosylation with direct relevance to multiple human diseases of the central nervous system.
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18
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Li D, McIntosh CS, Mastaglia FL, Wilton SD, Aung-Htut MT. Neurodegenerative diseases: a hotbed for splicing defects and the potential therapies. Transl Neurodegener 2021; 10:16. [PMID: 34016162 PMCID: PMC8136212 DOI: 10.1186/s40035-021-00240-7] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 04/23/2021] [Indexed: 12/14/2022] Open
Abstract
Precursor messenger RNA (pre-mRNA) splicing is a fundamental step in eukaryotic gene expression that systematically removes non-coding regions (introns) and ligates coding regions (exons) into a continuous message (mature mRNA). This process is highly regulated and can be highly flexible through a process known as alternative splicing, which allows for several transcripts to arise from a single gene, thereby greatly increasing genetic plasticity and the diversity of proteome. Alternative splicing is particularly prevalent in neuronal cells, where the splicing patterns are continuously changing to maintain cellular homeostasis and promote neurogenesis, migration and synaptic function. The continuous changes in splicing patterns and a high demand on many cis- and trans-splicing factors contribute to the susceptibility of neuronal tissues to splicing defects. The resultant neurodegenerative diseases are a large group of disorders defined by a gradual loss of neurons and a progressive impairment in neuronal function. Several of the most common neurodegenerative diseases involve some form of splicing defect(s), such as Alzheimer's disease, Parkinson's disease and spinal muscular atrophy. Our growing understanding of RNA splicing has led to the explosion of research in the field of splice-switching antisense oligonucleotide therapeutics. Here we review our current understanding of the effects alternative splicing has on neuronal differentiation, neuronal migration, synaptic maturation and regulation, as well as the impact on neurodegenerative diseases. We will also review the current landscape of splice-switching antisense oligonucleotides as a therapeutic strategy for a number of common neurodegenerative disorders.
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Affiliation(s)
- Dunhui Li
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, Western Australia, Australia.,Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Perth, Western Australia, Australia
| | - Craig Stewart McIntosh
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, Western Australia, Australia.,Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Perth, Western Australia, Australia
| | - Frank Louis Mastaglia
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, Western Australia, Australia.,Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Perth, Western Australia, Australia
| | - Steve Donald Wilton
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, Western Australia, Australia.,Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Perth, Western Australia, Australia
| | - May Thandar Aung-Htut
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, Western Australia, Australia. .,Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Perth, Western Australia, Australia.
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19
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Gallo CM, Ho A, Beffert U. ApoER2: Functional Tuning Through Splicing. Front Mol Neurosci 2020; 13:144. [PMID: 32848602 PMCID: PMC7410921 DOI: 10.3389/fnmol.2020.00144] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 07/13/2020] [Indexed: 11/13/2022] Open
Abstract
Alternative splicing occurs in over 95% of protein-coding genes and contributes to the diversity of the human proteome. Apolipoprotein E receptor 2 (apoER2) is a critical modulator of neuronal development and synaptic plasticity in the brain and is enriched in cassette exon splicing events, in which functional exons are excluded from the final transcript. These alternative splicing events affect apoER2 function, as individual apoER2 exons tend to encode distinct protein functional domains. Although several apoER2 splice variants have been characterized, much work remains to understand how apoER2 splicing events modulate distinct apoER2 activities, including ligand binding specificity, synapse formation and plasticity. Additionally, little is known about how apoER2 splicing events are regulated. Often, alternative splicing events are regulated through the combinatorial action of RNA-binding proteins and other epigenetic mechanisms, however, the regulatory pathways corresponding to each specific exon are unknown in most cases. In this mini-review, we describe the structure of apoER2, highlight the unique functions of known isoforms, discuss what is currently known about the regulation of apoER2 splicing by RNA-binding proteins and pose new questions that will further our understanding of apoER2 splicing complexity.
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Affiliation(s)
- Christina M Gallo
- Department of Biology, Boston University, Boston, MA, United States.,Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA, United States
| | - Angela Ho
- Department of Biology, Boston University, Boston, MA, United States.,Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA, United States
| | - Uwe Beffert
- Department of Biology, Boston University, Boston, MA, United States
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20
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Jackson TC, Kochanek PM. RNA Binding Motif 5 (RBM5) in the CNS-Moving Beyond Cancer to Harness RNA Splicing to Mitigate the Consequences of Brain Injury. Front Mol Neurosci 2020; 13:126. [PMID: 32765218 PMCID: PMC7381114 DOI: 10.3389/fnmol.2020.00126] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 06/22/2020] [Indexed: 12/14/2022] Open
Abstract
Gene splicing modulates the potency of cell death effectors, alters neuropathological disease processes, influences neuronal recovery, but may also direct distinct mechanisms of secondary brain injury. Therapeutic targeting of RNA splicing is a promising avenue for next-generation CNS treatments. RNA-binding proteins (RBPs) regulate a variety of RNA species and are prime candidates in the hunt for druggable targets to manipulate and tailor gene-splicing responses in the brain. RBPs preferentially recognize unique consensus sequences in targeted mRNAs. Also, RBPs often contain multiple RNA-binding domains (RBDs)—each having a unique consensus sequence—suggesting the possibility that drugs could be developed to block individual functional domains, increasing the precision of RBP-targeting therapies. Empirical characterization of most RBPs is lacking and represents a major barrier to advance this emerging therapeutic area. There is a paucity of data on the role of RBPs in the brain including, identification of their unique mRNA targets, defining how CNS insults affect their levels and elucidating which RBPs (and individual domains within) to target to improve neurological outcomes. This review focuses on the state-of-the-art of the RBP tumor suppressor RNA binding motif 5 (RBM5) in the CNS. We discuss its potent pro-death roles in cancer, which motivated our interest to study it in the brain. We review recent studies showing that RBM5 levels are increased after CNS trauma and that it promotes neuronal death in vitro. Finally, we conclude with recent reports on the first set of RBM5 regulated genes identified in the intact brain, and discuss how those findings provide new clues germane to its potential function(s) in the CNS, and pose new questions on its therapeutic utility to mitigate CNS injury.
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Affiliation(s)
- Travis C Jackson
- Morsani College of Medicine, USF Health Heart Institute, University of South Florida, Tampa, FL, United States.,Morsani College of Medicine, Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL, United States
| | - Patrick M Kochanek
- Safar Center for Resuscitation Research, Department of Critical Care Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
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21
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Nik S, Bowman TV. Splicing and neurodegeneration: Insights and mechanisms. WILEY INTERDISCIPLINARY REVIEWS-RNA 2019; 10:e1532. [PMID: 30895702 DOI: 10.1002/wrna.1532] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2019] [Revised: 02/17/2019] [Accepted: 02/20/2019] [Indexed: 12/13/2022]
Abstract
Splicing is the global cellular process whereby intervening sequences (introns) in precursor messenger RNA (pre-mRNA) are removed and expressed regions (exons) are ligated together, resulting in a mature mRNA transcript that is exported and translated in the cytoplasm. The tightly regulated splicing cycle is also flexible allowing for the inclusion or exclusion of some sequences depending on the specific cellular context. Alternative splicing allows for the generation of many transcripts from a single gene, thereby expanding the proteome. Although all cells require the function of the spliceosome, neurons are highly sensitive to splicing perturbations with numerous neurological diseases linked to splicing defects. The sensitivity of neurons to splicing alterations is largely due to the complex neuronal cell types and functions in the nervous system that require specific splice isoforms to maintain cellular homeostasis. In the past several years, the relationship between RNA splicing and the nervous system has been the source of significant investigation. Here, we review the current knowledge on RNA splicing in neurobiology and discuss its potential role and impact in neurodegenerative diseases. We will examine the impact of alternative splicing and the role of splicing regulatory proteins on neurodegeneration, highlighting novel animal models including mouse and zebrafish. We will also examine emerging technologies and therapeutic interventions that aim to "drug" the spliceosome. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA Processing > Splicing Regulation/Alternative Splicing RNA in Disease and Development > RNA in Development.
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Affiliation(s)
- Sara Nik
- Department of Developmental and Molecular Biology and Gottesman Institute for Stem Cell Biology and Regenerative Medicine, Albert Einstein College of Medicine, Bronx, New York
| | - Teresa V Bowman
- Department of Developmental and Molecular Biology, Department of Medicine (Oncology), and Gottesman Institute for Stem Cell Biology and Regenerative Medicine, Albert Einstein College of Medicine, Bronx, New York
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22
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Dlugosz P, Tresky R, Nimpf J. Differential Action of Reelin on Oligomerization of ApoER2 and VLDL Receptor in HEK293 Cells Assessed by Time-Resolved Anisotropy and Fluorescence Lifetime Imaging Microscopy. Front Mol Neurosci 2019; 12:53. [PMID: 30873003 PMCID: PMC6403468 DOI: 10.3389/fnmol.2019.00053] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 02/12/2019] [Indexed: 01/12/2023] Open
Abstract
The canonical Reelin signaling cascade regulates correct neuronal layering during embryonic brain development. Details of this pathway are still not fully understood since the participating components are highly variable and create a complex mixture of interacting molecules. Reelin is proteolytically processed resulting in five different fragments some of which carrying the binding site for two different but highly homologous receptors, apolipoprotein E receptor 2 (ApoER2) and very low density lipoprotein receptor (VLDLR). The receptors are expressed in different variants in different areas of the developing brain. Binding of Reelin and its central fragment to the receptors results in phosphorylation of the intracellular adapter disabled-1 (Dab1) in neurons. Here, we studied the changes of the arrangement of the receptors upon Reelin binding and its central fragment at the molecular level in human embryonic kidney 293 (HEK293) cells by time-resolved anisotropy and fluorescence lifetime imaging microscopy (FLIM). In the off-state of the pathway ApoER2 and VLDLR form homo or hetero-di/oligomers. Upon binding of full length Reelin ApoER2 and VLDLR homo-oligomers are rearranged to higher order receptor clusters which leads to Dab1 phosphorylation. When the central fragment of Reelin binds to the receptors the cluster size of homo-oligomers is not affected and Dab1 is not phosphorylated. Hetero-oligomerization, however, can be induced, but does not lead to Dab1 phosphorylation. Cells expressing only ApoER2 or VLDLR change their shape when stimulated with the central fragment. Cells expressing ApoER2 produce filopodia/lamellipodia and cell size increases, whereas VLDLR-expressing cells decrease in size. These findings demonstrate that the primary event in the canonical Reelin pathway is the rearrangement of preformed receptor homo-oligomers to higher order clusters. In addition the possibility of yet another signaling mechanism which is mediated by the central Reelin fragment independent of Dab1 phosphorylation became apparent.
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Affiliation(s)
- Paula Dlugosz
- Department of Medical Biochemistry, Max F. Perutz Laboratories, Medical University Vienna, Vienna, Austria
| | - Roland Tresky
- Department of Medical Biochemistry, Max F. Perutz Laboratories, Medical University Vienna, Vienna, Austria
| | - Johannes Nimpf
- Department of Medical Biochemistry, Max F. Perutz Laboratories, Medical University Vienna, Vienna, Austria
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23
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Xian X, Pohlkamp T, Durakoglugil MS, Wong CH, Beck JK, Lane-Donovan C, Plattner F, Herz J. Reversal of ApoE4-induced recycling block as a novel prevention approach for Alzheimer's disease. eLife 2018; 7:40048. [PMID: 30375977 PMCID: PMC6261251 DOI: 10.7554/elife.40048] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 10/29/2018] [Indexed: 12/13/2022] Open
Abstract
ApoE4 genotype is the most prevalent and also clinically most important risk factor for late-onset Alzheimer’s disease (AD). Available evidence suggests that the root cause for this increased risk is a trafficking defect at the level of the early endosome. ApoE4 differs from the most common ApoE3 isoform by a single amino acid that increases its isoelectric point and promotes unfolding of ApoE4 upon endosomal vesicle acidification. We found that pharmacological and genetic inhibition of NHE6, the primary proton leak channel in the early endosome, in rodents completely reverses the ApoE4-induced recycling block of the ApoE receptor Apoer2/Lrp8 and the AMPA- and NMDA-type glutamate receptors that are regulated by, and co-endocytosed in a complex with, Apoer2. Moreover, NHE6 inhibition restores the Reelin-mediated modulation of excitatory synapses that is impaired by ApoE4. Our findings suggest a novel potential approach for the prevention of late-onset AD. Alzheimer’s disease is a degenerative condition that destroys connections between brain cells leading to memory loss, confusion and difficulties in thinking. Apolipoprotein E is a protein that carries fatty substances called lipids and cholesterol around the brain, and plays an important role in repair mechanisms. There are three major forms of Apolipoprotein E, and individuals who carry a version known as ApoE4 are up to 10 times more likely to develop Alzheimer’s disease than those who carry other variations. In nerve cells, or neurons, Apolipoprotein E binds to a specific family of receptors. One of these receptors, called Apoer2, is found in the synaptic gap between neurons, where it regulates their activities. Both Apolipoprotein E and Apoer2 are taken into the cell within compartments known as endosomal vesicles. Usually, the Apoer2 receptor is quickly recycled back to the surface of the cell, but this recycling process is delayed in individuals with the ApoE4 version of Apolipoprotein E. Apoer2 is just one of many different receptors on the surface of neurons that are taken into vesicles before being recycled back to the cell surface. The fluid inside these vesicles becomes progressively more acidic as they move through the cell. This process helps to control the interaction of these receptors with their binding partners and to regulate their movement and recycling. Here, Xian, Pohlkamp et al. investigated whether changing the acidity of vesicles in rat neurons could overcome the block in recycling Apoer2 – and other receptors that travel with Apoer2 in the same compartments – in the presence of ApoE4. A protein called NHE6 is embedded in the membrane of vesicles called early endosomes and acts to make the vesicles less acidic. Xian, Pohlkamp et al. used drugs to block the activity of NHE6, which led to the vesicles becoming more acidic and allowed Apoer2 to be recycled faster. Using a genetic approach known as siRNA knockdown to decrease the amount of NHE6 produced in neurons also had a similar effect on Apoer2 recycling. Together these findings suggest that drugs that make vesicles in neurons more acidic may have the potential to help prevent individuals that carry the ApoE4 protein from developing Alzheimer’s disease. Current drugs that target NHE6 also affect other molecules, which can often lead to side effects. A next step will be to develop tailor-made, small molecule drugs that can enter the brain efficiently and selectively block NHE6.
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Affiliation(s)
- Xunde Xian
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, United States.,Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, United States
| | - Theresa Pohlkamp
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, United States.,Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, United States
| | - Murat S Durakoglugil
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, United States.,Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, United States
| | - Connie H Wong
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, United States.,Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, United States
| | | | - Courtney Lane-Donovan
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, United States.,Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, United States
| | - Florian Plattner
- Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, United States
| | - Joachim Herz
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, United States.,Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, United States
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24
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The Reelin Receptors Apolipoprotein E receptor 2 (ApoER2) and VLDL Receptor. Int J Mol Sci 2018; 19:ijms19103090. [PMID: 30304853 PMCID: PMC6213145 DOI: 10.3390/ijms19103090] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 10/03/2018] [Accepted: 10/03/2018] [Indexed: 01/28/2023] Open
Abstract
Apolipoprotein E receptor 2 (ApoER2) and VLDL receptor belong to the low density lipoprotein receptor family and bind apolipoprotein E. These receptors interact with the clathrin machinery to mediate endocytosis of macromolecules but also interact with other adapter proteins to perform as signal transduction receptors. The best characterized signaling pathway in which ApoER2 and VLDL receptor (VLDLR) are involved is the Reelin pathway. This pathway plays a pivotal role in the development of laminated structures of the brain and in synaptic plasticity of the adult brain. Since Reelin and apolipoprotein E, are ligands of ApoER2 and VLDLR, these receptors are of interest with respect to Alzheimer’s disease. We will focus this review on the complex structure of ApoER2 and VLDLR and a recently characterized ligand, namely clusterin.
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25
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Blechingberg J, Poulsen ASA, Kjølby M, Monti G, Allen M, Ivarsen AK, Lincoln SJ, Thotakura G, Vægter CB, Ertekin-Taner N, Nykjær A, Andersen OM. An alternative transcript of the Alzheimer's disease risk gene SORL1 encodes a truncated receptor. Neurobiol Aging 2018; 71:266.e11-266.e24. [PMID: 30078640 DOI: 10.1016/j.neurobiolaging.2018.06.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 06/03/2018] [Accepted: 06/18/2018] [Indexed: 10/28/2022]
Abstract
SORL1 encodes a 250-kDa protein named sorLA, a functional sorting receptor for the amyloid precursor protein (APP). Several single nucleotide polymorphisms of the gene SORL1, encoding sorLA, are genetically associated with Alzheimer's disease (AD). In the existing literature, SORL1 is insufficiently described at the transcriptional level, and there is very limited amount of functional data defining different transcripts. We have characterized a SORL1 transcript containing a novel exon 30B. The transcript is expressed in most brain regions with highest expression in the temporal lobe and hippocampus. Exon 30B is spliced to exon 31, leading to a mature transcript that encodes an 829 amino acid sorLA receptor. This receptor variant lacks the binding site for APP and is unlikely to function in APP sorting. This transcript is expressed in equal amounts in the cerebellum from AD and non-AD individuals. Our data describe a transcript that encodes a truncated sorLA receptor, suggesting novel neuronal functions for sorLA and that alternative transcription provides a mechanism for SORL1 activity regulation.
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Affiliation(s)
- Jenny Blechingberg
- Danish Research Institute of Translational Neuroscience (DANDRITE) Nordic-EMBL Partnership, Aarhus, Denmark
| | | | - Mads Kjølby
- Danish Research Institute of Translational Neuroscience (DANDRITE) Nordic-EMBL Partnership, Aarhus, Denmark; Danish Diabetes Academy, Novo Nordisk Foundation, Aarhus University, Aarhus, Denmark
| | - Giulia Monti
- Danish Research Institute of Translational Neuroscience (DANDRITE) Nordic-EMBL Partnership, Aarhus, Denmark
| | - Mariet Allen
- Department of Neuroscience, Mayo Clinic, FL, USA
| | - Anne Kathrine Ivarsen
- Danish Research Institute of Translational Neuroscience (DANDRITE) Nordic-EMBL Partnership, Aarhus, Denmark
| | | | | | - Christian B Vægter
- Danish Research Institute of Translational Neuroscience (DANDRITE) Nordic-EMBL Partnership, Aarhus, Denmark
| | | | - Anders Nykjær
- Danish Research Institute of Translational Neuroscience (DANDRITE) Nordic-EMBL Partnership, Aarhus, Denmark; The Lundbeck Foundation Research Center MIND, Aarhus, Denmark; The Danish Research Foundation Center PROMEMO, Department of Biomedicine, Aarhus, Denmark; Department of Neurosurgery, Aarhus University Hospital, Aarhus, Denmark
| | - Olav M Andersen
- Danish Research Institute of Translational Neuroscience (DANDRITE) Nordic-EMBL Partnership, Aarhus, Denmark.
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26
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Lei N, Mellem JE, Brockie PJ, Madsen DM, Maricq AV. NRAP-1 Is a Presynaptically Released NMDA Receptor Auxiliary Protein that Modifies Synaptic Strength. Neuron 2017; 96:1303-1316.e6. [DOI: 10.1016/j.neuron.2017.11.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 10/20/2017] [Accepted: 11/14/2017] [Indexed: 12/19/2022]
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27
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Hinrich AJ, Jodelka FM, Chang JL, Brutman D, Bruno AM, Briggs CA, James BD, Stutzmann GE, Bennett DA, Miller SA, Rigo F, Marr RA, Hastings ML. Therapeutic correction of ApoER2 splicing in Alzheimer's disease mice using antisense oligonucleotides. EMBO Mol Med 2017; 8:328-45. [PMID: 26902204 PMCID: PMC4818756 DOI: 10.15252/emmm.201505846] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Apolipoprotein E receptor 2 (ApoER2) is an apolipoprotein E receptor involved in long‐term potentiation, learning, and memory. Given its role in cognition and its association with the Alzheimer's disease (AD) risk gene, apoE, ApoER2 has been proposed to be involved in AD, though a role for the receptor in the disease is not clear. ApoER2 signaling requires amino acids encoded by alternatively spliced exon 19. Here, we report that the balance of ApoER2 exon 19 splicing is deregulated in postmortem brain tissue from AD patients and in a transgenic mouse model of AD. To test the role of deregulated ApoER2 splicing in AD, we designed an antisense oligonucleotide (ASO) that increases exon 19 splicing. Treatment of AD mice with a single dose of ASO corrected ApoER2 splicing for up to 6 months and improved synaptic function and learning and memory. These results reveal an association between ApoER2 isoform expression and AD, and provide preclinical evidence for the utility of ASOs as a therapeutic approach to mitigate Alzheimer's disease symptoms by improving ApoER2 exon 19 splicing.
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Affiliation(s)
- Anthony J Hinrich
- Department of Cell Biology and Anatomy, Chicago Medical School Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA
| | - Francine M Jodelka
- Department of Cell Biology and Anatomy, Chicago Medical School Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA
| | - Jennifer L Chang
- Department of Cell Biology and Anatomy, Chicago Medical School Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA
| | - Daniella Brutman
- Department of Biology, Lake Forest College, Lake Forest, IL, USA
| | - Angela M Bruno
- Department of Neuroscience, Chicago Medical School Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA
| | - Clark A Briggs
- Department of Neuroscience, Chicago Medical School Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA
| | - Bryan D James
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Grace E Stutzmann
- Department of Neuroscience, Chicago Medical School Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA
| | - David A Bennett
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Steven A Miller
- Department of Psychology, College of Health Professions Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA
| | - Frank Rigo
- Ionis Pharmaceuticals, Carlsbad, CA, USA
| | - Robert A Marr
- Department of Neuroscience, Chicago Medical School Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA
| | - Michelle L Hastings
- Department of Cell Biology and Anatomy, Chicago Medical School Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA
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28
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Gao J, Marosi M, Choi J, Achiro JM, Kim S, Li S, Otis K, Martin KC, Portera-Cailliau C, Tontonoz P. The E3 ubiquitin ligase IDOL regulates synaptic ApoER2 levels and is important for plasticity and learning. eLife 2017; 6:29178. [PMID: 28891791 PMCID: PMC5593505 DOI: 10.7554/elife.29178] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 08/30/2017] [Indexed: 12/12/2022] Open
Abstract
Neuronal ApoE receptors are linked to learning and memory, but the pathways governing their abundance, and the mechanisms by which they affect the function of neural circuits are incompletely understood. Here we demonstrate that the E3 ubiquitin ligase IDOL determines synaptic ApoER2 protein levels in response to neuronal activation and regulates dendritic spine morphogenesis and plasticity. IDOL-dependent changes in ApoER2 abundance modulate dendritic filopodia initiation and synapse maturation. Loss of IDOL in neurons results in constitutive overexpression of ApoER2 and is associated with impaired activity-dependent structural remodeling of spines and defective LTP in primary neuron cultures and hippocampal slices. IDOL-deficient mice show profound impairment in experience-dependent reorganization of synaptic circuits in the barrel cortex, as well as diminished spatial and associative learning. These results identify control of lipoprotein receptor abundance by IDOL as a post-transcriptional mechanism underlying the structural and functional plasticity of synapses and neural circuits.
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Affiliation(s)
- Jie Gao
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California, Los Angeles, United States
| | - Mate Marosi
- Departments of Neurology and Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, United States
| | - Jinkuk Choi
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California, Los Angeles, United States
| | - Jennifer M Achiro
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, United States
| | - Sangmok Kim
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, United States
| | - Sandy Li
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California, Los Angeles, United States
| | - Klara Otis
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, United States
| | - Kelsey C Martin
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, United States
| | - Carlos Portera-Cailliau
- Departments of Neurology and Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, United States
| | - Peter Tontonoz
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California, Los Angeles, United States.,Molecular Biology Institute, David Geffen School of Medicine, University of California, Los Angeles, United States.,Howard Hughes Medical Institute, David Geffen School of Medicine, University of California, Los Angeles, United States
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29
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Das B, Yan R. Role of BACE1 in Alzheimer's synaptic function. Transl Neurodegener 2017; 6:23. [PMID: 28855981 PMCID: PMC5575945 DOI: 10.1186/s40035-017-0093-5] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 08/15/2017] [Indexed: 12/25/2022] Open
Abstract
Alzheimer's disease (AD) is the most common age-dependent disease of dementia, and there is currently no cure available. This hallmark pathologies of AD are the presence of amyloid plaques and neurofibrillary tangles. Although the exact etiology of AD remains a mystery, studies over the past 30 have shown that abnormal generation or accumulation of β-amyloid peptides (Aβ) is likely to be a predominant early event in AD pathological development. Aβ is generated from amyloid precursor protein (APP) via proteolytic cleavage by β-site APP cleaving enzyme 1 (BACE1). Chemical inhibition of BACE1 has been shown to reduce Aβ in animal studies and in human trials. While BACE1 inhibitors are currently being tested in clinical trials to treat AD patients, it is highly important to understand whether BACE1 inhibition will significantly impact cognitive functions in AD patients. This review summarizes the recent studies on BACE1 synaptic functions. This knowledge will help to guide the proper use of BACE1 inhibitors in AD therapy.
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Affiliation(s)
- Brati Das
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue/NC30, Cleveland, OH 44195 USA
| | - Riqiang Yan
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue/NC30, Cleveland, OH 44195 USA
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30
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Lane-Donovan C, Herz J. The ApoE receptors Vldlr and Apoer2 in central nervous system function and disease. J Lipid Res 2017; 58:1036-1043. [PMID: 28292942 DOI: 10.1194/jlr.r075507] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Revised: 03/08/2017] [Indexed: 01/17/2023] Open
Abstract
The LDL receptor (LDLR) family has long been studied for its role in cholesterol transport and metabolism; however, the identification of ApoE4, an LDLR ligand, as a genetic risk factor for late-onset Alzheimer's disease has focused attention on the role this receptor family plays in the CNS. Surprisingly, it was discovered that two LDLR family members, ApoE receptor 2 (Apoer2) and VLDL receptor (Vldlr), play key roles in brain development and adult synaptic plasticity, primarily by mediating Reelin signaling. This review focuses on Apoer2 and Vldlr signaling in the CNS and its role in human disease.
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Affiliation(s)
- Courtney Lane-Donovan
- Departments of Molecular Genetics and Neuroscience and Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Joachim Herz
- Departments of Molecular Genetics and Neuroscience and Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX 75390 .,Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX 75390
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Pohlkamp T, Wasser CR, Herz J. Functional Roles of the Interaction of APP and Lipoprotein Receptors. Front Mol Neurosci 2017; 10:54. [PMID: 28298885 PMCID: PMC5331069 DOI: 10.3389/fnmol.2017.00054] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 02/16/2017] [Indexed: 11/24/2022] Open
Abstract
The biological fates of the key initiator of Alzheimer’s disease (AD), the amyloid precursor protein (APP), and a family of lipoprotein receptors, the low-density lipoprotein (LDL) receptor-related proteins (LRPs) and their molecular roles in the neurodegenerative disease process are inseparably interwoven. Not only does APP bind tightly to the extracellular domains (ECDs) of several members of the LRP group, their intracellular portions are also connected through scaffolds like the one established by FE65 proteins and through interactions with adaptor proteins such as X11/Mint and Dab1. Moreover, the ECDs of APP and LRPs share common ligands, most notably Reelin, a regulator of neuronal migration during embryonic development and modulator of synaptic transmission in the adult brain, and Agrin, another signaling protein which is essential for the formation and maintenance of the neuromuscular junction (NMJ) and which likely also has critical, though at this time less well defined, roles for the regulation of central synapses. Furthermore, the major independent risk factors for AD, Apolipoprotein (Apo) E and ApoJ/Clusterin, are lipoprotein ligands for LRPs. Receptors and ligands mutually influence their intracellular trafficking and thereby the functions and abilities of neurons and the blood-brain-barrier to turn over and remove the pathological product of APP, the amyloid-β peptide. This article will review and summarize the molecular mechanisms that are shared by APP and LRPs and discuss their relative contributions to AD.
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Affiliation(s)
- Theresa Pohlkamp
- Department of Molecular Genetics, UT Southwestern Medical CenterDallas, TX, USA; Center for Translational Neurodegeneration Research, UT Southwestern Medical CenterDallas, TX, USA
| | - Catherine R Wasser
- Department of Molecular Genetics, UT Southwestern Medical CenterDallas, TX, USA; Center for Translational Neurodegeneration Research, UT Southwestern Medical CenterDallas, TX, USA
| | - Joachim Herz
- Department of Molecular Genetics, UT Southwestern Medical CenterDallas, TX, USA; Center for Translational Neurodegeneration Research, UT Southwestern Medical CenterDallas, TX, USA; Department of Neuroscience, UT Southwestern Medical CenterDallas, TX, USA; Department of Neurology and Neurotherapeutics, UT Southwestern Medical CenterDallas, TX, USA
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Lind AL, Emami Khoonsari P, Sjödin M, Katila L, Wetterhall M, Gordh T, Kultima K. Spinal Cord Stimulation Alters Protein Levels in the Cerebrospinal Fluid of Neuropathic Pain Patients: A Proteomic Mass Spectrometric Analysis. Neuromodulation 2017; 19:549-62. [PMID: 27513633 DOI: 10.1111/ner.12473] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 06/07/2016] [Accepted: 06/09/2016] [Indexed: 01/03/2023]
Abstract
OBJECTIVES Electrical neuromodulation by spinal cord stimulation (SCS) is a well-established method for treatment of neuropathic pain. However, the mechanism behind the pain relieving effect in patients remains largely unknown. In this study, we target the human cerebrospinal fluid (CSF) proteome, a little investigated aspect of SCS mechanism of action. METHODS Two different proteomic mass spectrometry protocols were used to analyze the CSF of 14 SCS responsive neuropathic pain patients. Each patient acted as his or her own control and protein content was compared when the stimulator was turned off for 48 hours, and after the stimulator had been used as normal for three weeks. RESULTS Eighty-six proteins were statistically significantly altered in the CSF of neuropathic pain patients using SCS, when comparing the stimulator off condition to the stimulator on condition. The top 12 of the altered proteins are involved in neuroprotection (clusterin, gelsolin, mimecan, angiotensinogen, secretogranin-1, amyloid beta A4 protein), synaptic plasticity/learning/memory (gelsolin, apolipoprotein C1, apolipoprotein E, contactin-1, neural cell adhesion molecule L1-like protein), nociceptive signaling (neurosecretory protein VGF), and immune regulation (dickkopf-related protein 3). CONCLUSION Previously unknown effects of SCS on levels of proteins involved in neuroprotection, nociceptive signaling, immune regulation, and synaptic plasticity are demonstrated. These findings, in the CSF of neuropathic pain patients, expand the picture of SCS effects on the neurochemical environment of the human spinal cord. An improved understanding of SCS mechanism may lead to new tracks of investigation and improved treatment strategies for neuropathic pain.
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Affiliation(s)
- Anne-Li Lind
- Department of Surgical Sciences, Anaesthesiology and Intensive Care, Uppsala University, Uppsala, Sweden
| | - Payam Emami Khoonsari
- Department of Medical Sciences, Cancer Pharmacology and Computational Medicine, Uppsala University, Uppsala, Sweden
| | - Marcus Sjödin
- Department of Chemistry-BMC, Analytical Chemistry, Uppsala University, Uppsala//GE Healthcare, Sweden
| | - Lenka Katila
- Department of Surgical Sciences, Anaesthesiology and Intensive Care, Uppsala University, Uppsala, Sweden
| | - Magnus Wetterhall
- Department of Chemistry-BMC, Analytical Chemistry, Uppsala University, Uppsala//GE Healthcare, Sweden
| | - Torsten Gordh
- Department of Surgical Sciences, Anaesthesiology and Intensive Care, Uppsala University, Uppsala, Sweden
| | - Kim Kultima
- Department of Medical Sciences, Cancer Pharmacology and Computational Medicine, Uppsala University, Uppsala, Sweden
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Wasser CR, Herz J. Reelin: Neurodevelopmental Architect and Homeostatic Regulator of Excitatory Synapses. J Biol Chem 2016; 292:1330-1338. [PMID: 27994051 DOI: 10.1074/jbc.r116.766782] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Over half a century ago, D. S. Falconer first reported a mouse with a reeling gate. Four decades later, the Reln gene was isolated and identified as the cause of the reeler phenotype. Initial studies found that loss of Reelin, a large, secreted glycoprotein encoded by the Reln gene, results in abnormal neuronal layering throughout several regions of the brain. In the years since, the known functions of Reelin signaling in the brain have expanded to include multiple postdevelopmental neuromodulatory roles, revealing an ever increasing body of evidence to suggest that Reelin signaling is a critical player in the modulation of synaptic function. In writing this review, we intend to highlight the most fundamental aspects of Reelin signaling and integrate how these various neuromodulatory effects shape and protect synapses.
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Affiliation(s)
- Catherine R Wasser
- From the Department of Molecular Genetics.,Center for Translational Neurodegeneration Research, and
| | - Joachim Herz
- From the Department of Molecular Genetics, .,Center for Translational Neurodegeneration Research, and.,Department of Neuroscience.,Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas, 75390
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Cuchillo-Ibañez I, Mata-Balaguer T, Balmaceda V, Arranz JJ, Nimpf J, Sáez-Valero J. The β-amyloid peptide compromises Reelin signaling in Alzheimer's disease. Sci Rep 2016; 6:31646. [PMID: 27531658 PMCID: PMC4987719 DOI: 10.1038/srep31646] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 07/21/2016] [Indexed: 12/13/2022] Open
Abstract
Reelin is a signaling protein that plays a crucial role in synaptic function, which expression is influenced by β-amyloid (Aβ). We show that Reelin and Aβ oligomers co-immunoprecipitated in human brain extracts and were present in the same size-exclusion chromatography fractions. Aβ treatment of cells led to increase expression of Reelin, but secreted Reelin results trapped together with Aβ aggregates. In frontal cortex extracts an increase in Reelin mRNA, and in soluble and insoluble (guanidine-extractable) Reelin protein, was associated with late Braak stages of Alzheimer's disease (AD), while expression of its receptor, ApoER2, did not change. However, Reelin-dependent induction of Dab1 phosphorylation appeared reduced in AD. In cells, Aβ reduced the capacity of Reelin to induce internalization of biotinylated ApoER2 and ApoER2 processing. Soluble proteolytic fragments of ApoER2 generated after Reelin binding can be detected in cerebrospinal fluid (CSF). Quantification of these soluble fragments in CSF could be a tool to evaluate the efficiency of Reelin signaling in the brain. These CSF-ApoER2 fragments correlated with Reelin levels only in control subjects, not in AD, where these fragments diminished. We conclude that while Reelin expression is enhanced in the Alzheimer's brain, the interaction of Reelin with Aβ hinders its biological activity.
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Affiliation(s)
- Inmaculada Cuchillo-Ibañez
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d’Alacant, E-03550, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Trinidad Mata-Balaguer
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d’Alacant, E-03550, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Valeria Balmaceda
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d’Alacant, E-03550, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Juan José Arranz
- Departamento Producción Animal, Universidad de León, León, Spain
| | - Johannes Nimpf
- Department of Medical Biochemistry, Max F. Perutz Laboratories, Medical University of Vienna, 1030 Vienna, Austria
| | - Javier Sáez-Valero
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d’Alacant, E-03550, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
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Bock HH, May P. Canonical and Non-canonical Reelin Signaling. Front Cell Neurosci 2016; 10:166. [PMID: 27445693 PMCID: PMC4928174 DOI: 10.3389/fncel.2016.00166] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 06/08/2016] [Indexed: 12/11/2022] Open
Abstract
Reelin is a large secreted glycoprotein that is essential for correct neuronal positioning during neurodevelopment and is important for synaptic plasticity in the mature brain. Moreover, Reelin is expressed in many extraneuronal tissues; yet the roles of peripheral Reelin are largely unknown. In the brain, many of Reelin's functions are mediated by a molecular signaling cascade that involves two lipoprotein receptors, apolipoprotein E receptor-2 (Apoer2) and very low density-lipoprotein receptor (Vldlr), the neuronal phosphoprotein Disabled-1 (Dab1), and members of the Src family of protein tyrosine kinases as crucial elements. This core signaling pathway in turn modulates the activity of adaptor proteins and downstream protein kinase cascades, many of which target the neuronal cytoskeleton. However, additional Reelin-binding receptors have been postulated or described, either as coreceptors that are essential for the activation of the "canonical" Reelin signaling cascade involving Apoer2/Vldlr and Dab1, or as receptors that activate alternative or additional signaling pathways. Here we will give an overview of canonical and alternative Reelin signaling pathways, molecular mechanisms involved, and their potential physiological roles in the context of different biological settings.
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Affiliation(s)
- Hans H Bock
- Clinic of Gastroenterology and Hepatology, Heinrich-Heine-University Düsseldorf Düsseldorf, Germany
| | - Petra May
- Clinic of Gastroenterology and Hepatology, Heinrich-Heine-University Düsseldorf Düsseldorf, Germany
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Cuchillo-Ibañez I, Balmaceda V, Mata-Balaguer T, Lopez-Font I, Sáez-Valero J. Reelin in Alzheimer’s Disease, Increased Levels but Impaired Signaling: When More is Less. J Alzheimers Dis 2016; 52:403-16. [DOI: 10.3233/jad-151193] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Inmaculada Cuchillo-Ibañez
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d’Alacant, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Valeria Balmaceda
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d’Alacant, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Trinidad Mata-Balaguer
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d’Alacant, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Inmaculada Lopez-Font
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d’Alacant, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Javier Sáez-Valero
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d’Alacant, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
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Abstract
The earliest clinical manifestation of Alzheimer's disease (AD) is cognitive impairment caused by synaptic dysfunction. ApoE4, the primary risk factor for late‐onset AD, disrupts synaptic homeostasis by impairing synaptic ApoE receptor trafficking. Alternative splicing of ApoE receptor‐2 (Apoer2) maintains synaptic homeostasis. In this issue, Hinrich et al (2016 ) show that Apoer2 splicing is impaired in human AD brains and murine AD models and that restoring normal splicing in the mouse rescues amyloid‐induced cognitive defects.
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Affiliation(s)
- Catherine R Wasser
- Departments of Molecular Genetics, Neuroscience, Neurology and NeurotherapeuticsCenter for Translational Neurodegeneration ResearchUniversity of Texas Southwestern Medical CenterDallasTXUSA
| | - Joachim Herz
- Departments of Molecular Genetics, Neuroscience, Neurology and NeurotherapeuticsCenter for Translational Neurodegeneration ResearchUniversity of Texas Southwestern Medical CenterDallasTXUSA
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38
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Lane-Donovan C, Philips GT, Wasser CR, Durakoglugil MS, Masiulis I, Upadhaya A, Pohlkamp T, Coskun C, Kotti T, Steller L, Hammer RE, Frotscher M, Bock HH, Herz J. Reelin protects against amyloid β toxicity in vivo. Sci Signal 2015; 8:ra67. [PMID: 26152694 DOI: 10.1126/scisignal.aaa6674] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Alzheimer's disease (AD) is a currently incurable neurodegenerative disorder and is the most common form of dementia in people over the age of 65 years. The predominant genetic risk factor for AD is the ε4 allele encoding apolipoprotein E (ApoE4). The secreted glycoprotein Reelin enhances synaptic plasticity by binding to the multifunctional ApoE receptors apolipoprotein E receptor 2 (Apoer2) and very low density lipoprotein receptor (Vldlr). We have previously shown that the presence of ApoE4 renders neurons unresponsive to Reelin by impairing the recycling of the receptors, thereby decreasing its protective effects against amyloid β (Aβ) oligomer-induced synaptic toxicity in vitro. We showed that when Reelin was knocked out in adult mice, these mice behaved normally without overt learning or memory deficits. However, they were strikingly sensitive to amyloid-induced synaptic suppression and had profound memory and learning disabilities with very low amounts of amyloid deposition. Our findings highlight the physiological importance of Reelin in protecting the brain against Aβ-induced synaptic dysfunction and memory impairment.
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Affiliation(s)
- Courtney Lane-Donovan
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Gary T Philips
- Center for Neural Science, New York University, New York, NY 10003, USA
| | - Catherine R Wasser
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Murat S Durakoglugil
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Irene Masiulis
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Ajeet Upadhaya
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Theresa Pohlkamp
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Center for Neuroscience, Department of Neuroanatomy, Albert-Ludwigs-University, Freiburg 79085, Germany
| | - Cagil Coskun
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Tiina Kotti
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Laura Steller
- Institute for Structural Neurobiology, Center for Molecular Neurobiology, Hamburg 20251, Germany
| | - Robert E Hammer
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Michael Frotscher
- Institute for Structural Neurobiology, Center for Molecular Neurobiology, Hamburg 20251, Germany
| | - Hans H Bock
- Clinic for Gastroenterology, Hepatology and Infectiology, Heinrich-Heine-University, Düsseldorf 40225, Germany
| | - Joachim Herz
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Center for Neuroscience, Department of Neuroanatomy, Albert-Ludwigs-University, Freiburg 79085, Germany. Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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39
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Xin X, Akasaka-Manya K, Manya H, Furukawa JI, Kuwahara N, Okada K, Tsumoto H, Higashi N, Kato R, Shinohara Y, Irimura T, Endo T. POMGNT1 Is Glycosylated by Mucin-Type O-Glycans. Biol Pharm Bull 2015; 38:1389-94. [DOI: 10.1248/bpb.b15-00415] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Xin Xin
- Molecular Glycobiology, Research Team for Mechanism of Aging, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology
- Laboratory of Cancer Biology and Molecular Immunology, Graduate School of Pharmaceutical Sciences, The University of Tokyo
| | - Keiko Akasaka-Manya
- Molecular Glycobiology, Research Team for Mechanism of Aging, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology
| | - Hiroshi Manya
- Molecular Glycobiology, Research Team for Mechanism of Aging, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology
| | - Jun-ichi Furukawa
- Laboratory of Medical and Functional Glycomics, Graduate School of Advanced Life Science, and Frontier Research Center for Post-Genome Science and Technology, Hokkaido University
| | - Naoyuki Kuwahara
- Structural Biology Research Center, Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK)
| | - Kazue Okada
- Laboratory of Medical and Functional Glycomics, Graduate School of Advanced Life Science, and Frontier Research Center for Post-Genome Science and Technology, Hokkaido University
| | - Hiroki Tsumoto
- Proteome Research, Research Team for Mechanism of Aging, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology
| | - Nobuaki Higashi
- Laboratory of Cancer Biology and Molecular Immunology, Graduate School of Pharmaceutical Sciences, The University of Tokyo
| | - Ryuichi Kato
- Structural Biology Research Center, Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK)
| | - Yasuro Shinohara
- Laboratory of Medical and Functional Glycomics, Graduate School of Advanced Life Science, and Frontier Research Center for Post-Genome Science and Technology, Hokkaido University
| | | | - Tamao Endo
- Molecular Glycobiology, Research Team for Mechanism of Aging, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology
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40
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Wasser CR, Herz J, VanHook AM. Science Signaling
Podcast: 25 November 2014. Sci Signal 2014. [DOI: 10.1126/scisignal.aaa1326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Normal synaptic function and fear learning require glycosylation of the apolipoprotein E receptor Apoer2.
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Affiliation(s)
- Catherine R. Wasser
- Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - Joachim Herz
- Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - Annalisa M. VanHook
- Web Editor, Science Signaling, American Association for the Advancement of Science, 1200 New York Avenue, NW, Washington, DC 20005, USA
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