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Yokoi S, Ito T, Sahashi K, Nakatochi M, Nakamura R, Tohnai G, Fujioka Y, Ishigaki S, Udagawa T, Izumi Y, Morita M, Kano O, Oda M, Sone T, Okano H, Atsuta N, Katsuno M, Okada Y, Sobue G. The SYNGAP1 3'UTR Variant in ALS Patients Causes Aberrant SYNGAP1 Splicing and Dendritic Spine Loss by Recruiting HNRNPK. J Neurosci 2022; 42:8881-8896. [PMID: 36261283 PMCID: PMC9698725 DOI: 10.1523/jneurosci.0455-22.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 08/28/2022] [Accepted: 10/06/2022] [Indexed: 12/29/2022] Open
Abstract
Fused in sarcoma (FUS) is a pathogenic RNA-binding protein in amyotrophic lateral sclerosis (ALS). We previously reported that FUS stabilizes Synaptic Ras-GTPase activating protein 1 (Syngap1) mRNA at its 3' untranslated region (UTR) and maintains spine maturation. To elucidate the pathologic roles of this mechanism in ALS patients, we identified the SYNGAP1 3'UTR variant rs149438267 in seven (four males and three females) out of 807 ALS patients at the FUS binding site from a multicenter cohort in Japan. Human-induced pluripotent stem cell (hiPSC)-derived motor neurons with the SYNGAP1 variant showed aberrant splicing, increased isoform α1 levels, and decreased isoform γ levels, which caused dendritic spine loss. Moreover, the SYNGAP1 variant excessively recruited FUS and heterogeneous nuclear ribonucleoprotein K (HNRNPK), and antisense oligonucleotides (ASOs) blocking HNRNPK altered aberrant splicing and ameliorated dendritic spine loss. These data suggest that excessive recruitment of RNA-binding proteins, especially HNRNPK, as well as changes in SYNGAP1 isoforms, are crucial for spine formation in motor neurons.SIGNIFICANCE STATEMENT It is not yet known which RNAs cause the pathogenesis of amyotrophic lateral sclerosis (ALS). We previously reported that Fused in sarcoma (FUS), a pathogenic RNA-binding protein in ALS, stabilizes synaptic Ras-GTPase activating protein 1 (Syngap1) mRNA at its 3' untranslated region (UTR) and maintains dendritic spine maturation. To elucidate whether this mechanism is crucial for ALS, we identified the SYNGAP1 3'UTR variant rs149438267 at the FUS binding site. Human-induced pluripotent stem cell (hiPSC)-derived motor neurons with the SYNGAP1 variant showed aberrant splicing, which caused dendritic spine loss along with excessive recruitment of FUS and heterogeneous nuclear ribonucleoprotein K (HNRNPK). Our findings that dendritic spine loss is because of excess recruitment of RNA-binding proteins provide a basis for the future exploration of ALS-related RNA-binding proteins.
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Affiliation(s)
- Satoshi Yokoi
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Takuji Ito
- Department of Neurology, Aichi Medical University School of Medicine, Aichi 480-1195, Japan
- Department of Neural iPSC Research, Institute for Medical Science of Aging, Aichi Medical University, Aichi 480-1195, Japan
| | - Kentaro Sahashi
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Masahiro Nakatochi
- Public Health Informatics Unit, Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, Nagoya 461-8673, Japan
| | - Ryoichi Nakamura
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
- Department of Neurology, Aichi Medical University School of Medicine, Aichi 480-1195, Japan
| | - Genki Tohnai
- Division of ALS Research, Aichi Medical University, Aichi 480-1195, Japan
| | - Yusuke Fujioka
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Shinsuke Ishigaki
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
- Research Division of Dementia and Neurodegenerative Disease, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Tsuyoshi Udagawa
- Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya 467-8603, Japan
| | - Yuishin Izumi
- Department of Neurology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8503, Japan
| | - Mitsuya Morita
- Division of Neurology, Department of Internal Medicine, Jichi Medical University, Shimotsuke 329-0498, Japan
| | - Osamu Kano
- Department of Neurology, Toho University Faculty of Medicine, Tokyo 143-8540, Japan
| | - Masaya Oda
- Department of Neurology, Vihara Hananosato Hospital, Miyoshi 728-0001, Japan
| | - Takefumi Sone
- Department of Physiology, Keio University School of Medicine, Tokyo 160-0016, Japan
| | - Hideyuki Okano
- Department of Physiology, Keio University School of Medicine, Tokyo 160-0016, Japan
| | - Naoki Atsuta
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
- Department of Neurology, Aichi Medical University School of Medicine, Aichi 480-1195, Japan
| | - Masahisa Katsuno
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Yohei Okada
- Department of Neurology, Aichi Medical University School of Medicine, Aichi 480-1195, Japan
- Department of Neural iPSC Research, Institute for Medical Science of Aging, Aichi Medical University, Aichi 480-1195, Japan
| | - Gen Sobue
- Research Division of Dementia and Neurodegenerative Disease, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
- Aichi Medical University, Aichi 480-1195, Japan
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Bennett JP, O'Brien LC, Brohawn DG. Pharmacological properties of microneurotrophin drugs developed for treatment of amyotrophic lateral sclerosis. Biochem Pharmacol 2016; 117:68-77. [PMID: 27498123 DOI: 10.1016/j.bcp.2016.08.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 08/01/2016] [Indexed: 12/13/2022]
Abstract
Microneurotrophins (MNT's) are small molecule derivatives of dehydroepiandrosterone (DHEA) and do not have significant interactions with sex steroid receptors. MNT's retain high-affinity binding to protein tyrosine kinase (Trk) receptors and can mimic many pleiotropic actions of neurotrophin (NT) proteins on neurons. MNT's offer therapeutic potential for diseases such as amyotrophic lateral sclerosis (ALS) where motor neurons (MN) degenerate. MNT's cross artificial membranes mimicking the blood-brain barrier, are not major substrates for ABC (ATP-binding cassette) transporters and are metabolized rapidly by mouse but more slowly by human hepatocytes. A lead MNT (BNN27) and its mono-oxidation metabolites enter mouse brain rapidly. RNA-sequencing measured gene expression profiles of human H9eSC-(embryonic stem cell)-derived or CTL (control) subject iPSC-(induced pluripotential stem cell)-derived MN's exposed to NT proteins or MNT molecules. Expression ratios (relative to DMSO (dimethylsulfoxide) vehicle) were calculated, and the resulting top 500 gene lists were analyzed for Gene Ontology (GO) grouping using DAVID (Database for Annotation, Visualization and Integrated Discovery). The MNT's BNN20, BNN23, and BNN27 showed overlap of GO terms with NGF (nerve growth factor) and BDNF (brain-derived neurotrophic factor) in the H9eSC-derived MN's. In the iPSC-derived MN's two (BNN20, BNN27) showed overlap of GO terms with NGF or BDNF. Each NT protein had GO terms that did not overlap with any MNT in the MN cell lines.
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Affiliation(s)
- James P Bennett
- Parkinson's Disease Research Center, Virginia Commonwealth University, Richmond, VA, United States; Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, VA, United States; Department of Neurology, Virginia Commonwealth University, Richmond, VA, United States; Neurodegeneration Therapeutics, Inc., Charlottesville, VA, United States.
| | - Laura C O'Brien
- Parkinson's Disease Research Center, Virginia Commonwealth University, Richmond, VA, United States; Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, VA, United States
| | - David G Brohawn
- Parkinson's Disease Research Center, Virginia Commonwealth University, Richmond, VA, United States; Department of Human Genetics, Virginia Commonwealth University, Richmond, VA, United States
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