1
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Liu Y, Chen Y, Fukui K. α-Tocotrienol Protects Neurons by Preventing Tau Hyperphosphorylation via Inhibiting Microtubule Affinity-Regulating Kinase Activation. Int J Mol Sci 2024; 25:8428. [PMID: 39125998 PMCID: PMC11313320 DOI: 10.3390/ijms25158428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2024] [Revised: 07/28/2024] [Accepted: 07/29/2024] [Indexed: 08/12/2024] Open
Abstract
In the pathological process of Alzheimer's disease, neuronal cell death is closely related to the accumulation of reactive oxygen species. Our previous studies have found that oxidative stress can activate microtubule affinity-regulating kinases, resulting in elevated phosphorylation levels of tau protein specifically at the Ser262 residue in N1E-115 cells that have been subjected to exposure to hydrogen peroxide. This process may be one of the pathogenic mechanisms of Alzheimer's disease. Vitamin E is a fat-soluble, naturally occurring antioxidant that plays a crucial role in biological systems. This study aimed to examine the probable processes that contribute to the inhibiting effect on the abnormal phosphorylation of tau protein and the neuroprotective activity of a particular type of vitamin E, α-tocotrienol. The experimental analysis revealed that α-tocotrienol showed significant neuroprotective effects in the N1E-115 cell line. Our data further suggest that one of the mechanisms underlying the neuroprotective effects of α-tocotrienol may be through the inhibition of microtubule affinity-regulated kinase activation, which significantly reduces the oxidative stress-induced aberrant elevation of p-Tau (Ser262) levels. These results indicate that α-tocotrienol may represent an intriguing strategy for treating or preventing Alzheimer's disease.
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Affiliation(s)
- Yuhong Liu
- Molecular Cell Biology Laboratory, Department of Functional Control Systems, Graduate School of Engineering and Science, Shibaura Institute of Technology, Saitama 337-8570, Japan;
| | - Yunxi Chen
- Molecular Cell Biology Laboratory, Department of Systems Engineering and Science, Graduate School of Engineering and Science, Shibaura Institute of Technology, Saitama 337-8570, Japan;
| | - Koji Fukui
- Molecular Cell Biology Laboratory, Department of Functional Control Systems, Graduate School of Engineering and Science, Shibaura Institute of Technology, Saitama 337-8570, Japan;
- Molecular Cell Biology Laboratory, Department of Systems Engineering and Science, Graduate School of Engineering and Science, Shibaura Institute of Technology, Saitama 337-8570, Japan;
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2
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NGF Modulates Cholesterol Metabolism and Stimulates ApoE Secretion in Glial Cells Conferring Neuroprotection against Oxidative Stress. Int J Mol Sci 2022; 23:ijms23094842. [PMID: 35563230 PMCID: PMC9100774 DOI: 10.3390/ijms23094842] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 04/24/2022] [Accepted: 04/25/2022] [Indexed: 12/18/2022] Open
Abstract
Cholesterol plays a crucial role in the brain, where its metabolism is particularly regulated by astrocytic activity. Indeed, adult neurons suppress their own cholesterol biosynthesis and import this sterol through ApoE-rich particles secreted from astrocytes. Recent evidence suggests that nerve growth factor (NGF) may exert neurotrophic activity by influencing cell metabolism. Nevertheless, the effect of NGF on glial cholesterol homeostasis has still not been elucidated. Thus, the aim of this project is to assess whether NGF could influence cholesterol metabolism in glial cells. To reach this objective, the U373 astrocyte-derived cell line was used as an experimental model. Immunoblot and ELISA analysis showed that proteins and enzymes belonging to the cholesterol metabolism network were increased upon NGF treatment in glial cells. Furthermore, NGF significantly increased ApoE secretion and the amount of extracellular cholesterol in the culture medium. Co-culture and U373-conditioned medium experiments demonstrated that NGF treatment efficiently counteracted rotenone-mediated cytotoxicity in N1E-115 neuronal cells. Conversely, neuroprotection mediated by NGF treatment was suppressed when N1E-115 were co-cultured with ApoE-silenced U373 cells. Taken together, these data suggest that NGF controls cholesterol homeostasis in glial cells. More importantly, NGF exerts neuroprotection against oxidative stress, which is likely associated with the induction of glial ApoE secretion.
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3
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Kobayashi Y, Oguro A, Yagi E, Mitani A, Kudoh SN, Imaoka S. Bisphenol A and rotenone induce S-nitrosylation of protein disulfide isomerase (PDI) and inhibit neurite outgrowth of primary cultured cells of the rat hippocampus and PC12 cells. J Toxicol Sci 2021; 45:783-794. [PMID: 33268678 DOI: 10.2131/jts.45.783] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Bisphenol A (BPA) interferes the function and development of the central nervous system (CNS), resulting in behavioral abnormalities and memory loss. S-nitrosylation of protein disulfide isomerase (PDI) is increased in brains with sporadic Alzheimer's disease and Parkinson's disease. The aim of the present study was to clarify the role of nitric oxide (NO) in BPA-induced neurotoxicity. Since rotenone induces NO-mediated neurodegeneration through S-nitrosylation of PDI, it was used as a positive control. First, rats were treated with BPA and rotenone, and S-nitrosylation of PDI was detected in rat brain microsomes. BPA and rotenone decreased RNase oxidation activity of PDI concomitant with S-nitrosylation of PDI. Next, to clarify S-nitrosylation of PDI by BPA and rotenone in rat brains, we treated the rat pheochromocytoma cell line PC12 and primary cultured neuron cells from the rat hippocampus with BPA (5 and 10 μM) and rotenone (100 or 200 nM). BPA induced S-nitrosylation of PDI, while NG-monomethyl-L-arginine (L-NMMA), a NOS inhibitor, exerted the opposite effects. Finally, to evaluate the toxicity of BPA in the CNS, we investigated its effects on neurite outgrowth of PC12 and primary cultured neuron cells. BPA inhibited neurite outgrowth of these cells, while L-NMMA reversed this inhibition. The involvement of PDI activity in neurite outgrowth was also examined, and bacitracin, a PDI inhibitor, is shown to decrease neurite outgrowth. Furthermore, the overexpression of PDI, but not a catalytically inactive PDI mutant, enhanced neurite outgrowth. These results suggested that S-nitrosylation of PDI induced by excessive NO caused BPA-induced neurotoxicity.
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Affiliation(s)
- Yukino Kobayashi
- Department of Biomedical Chemistry, School of Science and Technology, Kwansei Gakuin University
| | - Ami Oguro
- Department of Biomedical Chemistry, School of Science and Technology, Kwansei Gakuin University.,Program of Biomedical Science, Graduate School of Integrated Sciences for Life, Hiroshima University
| | - Erina Yagi
- Department of Biomedical Chemistry, School of Science and Technology, Kwansei Gakuin University
| | - Akira Mitani
- Department of Human-System Interaction, School of Science and Technology, Kwansei Gakuin University
| | - Suguru N Kudoh
- Department of Human-System Interaction, School of Science and Technology, Kwansei Gakuin University
| | - Susumu Imaoka
- Department of Biomedical Chemistry, School of Science and Technology, Kwansei Gakuin University
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4
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Liu J, Wang X, Ma R, Li T, Guo G, Ning B, Moran TH, Smith WW. AMPK signaling mediates synphilin-1-induced hyperphagia and obesity in Drosophila. J Cell Sci 2021; 134:jcs247742. [PMID: 33443093 PMCID: PMC7875497 DOI: 10.1242/jcs.247742] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 12/15/2020] [Indexed: 12/31/2022] Open
Abstract
Expression of synphilin-1 in neurons induces hyperphagia and obesity in a Drosophila model. However, the molecular pathways underlying synphilin-1-linked obesity remain unclear. Here, Drosophila models and genetic tools were used to study the synphilin-1-linked pathways in energy balance by combining molecular biology and pharmacological approaches. We found that expression of human synphilin-1 in flies increased AMP-activated kinase (AMPK) phosphorylation at Thr172 compared with that in non-transgenic flies. Knockdown of AMPK reduced AMPK phosphorylation and food intake in non-transgenic flies, and further suppressed synphilin-1-induced AMPK phosphorylation, hyperphagia, fat storage and body weight gain in transgenic flies. Expression of constitutively activated AMPK significantly increased food intake and body weight gain in non-transgenic flies, but it did not alter food intake in the synphilin-1 transgenic flies. In contrast, expression of dominant-negative AMPK reduced food intake in both non-transgenic and synphilin-1 transgenic flies. Treatment with STO-609 also suppressed synphilin-1-induced AMPK phosphorylation, hyperphagia and body weight gain. These results demonstrate that the AMPK signaling pathway plays a critical role in synphilin-1-induced hyperphagia and obesity. These findings provide new insights into the mechanisms of synphilin-1-controlled energy homeostasis.
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Affiliation(s)
- Jingnan Liu
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201, USA
| | - Xiaobo Wang
- Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Rui Ma
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201, USA
| | - Tianxia Li
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201, USA
| | - Gongbo Guo
- Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Bo Ning
- Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Timothy H Moran
- Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Wanli W Smith
- Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
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5
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Synphilin-1 Interacts with AMPK and Increases AMPK Phosphorylation. Int J Mol Sci 2020; 21:ijms21124352. [PMID: 32570982 PMCID: PMC7352261 DOI: 10.3390/ijms21124352] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 06/08/2020] [Accepted: 06/09/2020] [Indexed: 01/16/2023] Open
Abstract
A role for the cytoplasmic protein synphilin-1 in regulating energy balance has been demonstrated recently. Expression of synphilin-1 increases ATP levels in cultured cells. However, the mechanism by which synphilin-1 alters cellular energy status is unknown. Here, we used cell models and biochemical approaches to investigate the cellular functions of synphilin-1 on the AMP-activated protein kinase (AMPK) signaling pathway, which may affect energy balance. Overexpression of synphilin-1 increased AMPK phosphorylation (activation). Moreover, synphilin-1 interacted with AMPK by co-immunoprecipitation and GST (glutathione S-transferase) pull-down assays. Knockdown of synphilin-1 reduced AMPK phosphorylation. Overexpression of synphilin-1 also altered AMPK downstream signaling, i.e., a decrease in acetyl CoA carboxylase (ACC) phosphorylation, and an increase in p70S6K phosphorylation. Treatment of compound C (an AMPK inhibitor) reduced synphilin-1 binding with AMPK. In addition, compound C diminished synphilin-1-induced AMPK phosphorylation, and the increase in cellular ATP (adenosine triphosphate) levels. Our results demonstrated that synphilin-1 couples with AMPK, and they exert mutual effects on each other to regulate cellular energy status. These findings not only identify novel cellular actions of synphilin-1, but also provide new insights into the roles of synphilin-1 in regulating energy currency, ATP.
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Shishido T, Nagano Y, Araki M, Kurashige T, Obayashi H, Nakamura T, Takahashi T, Matsumoto M, Maruyama H. Synphilin-1 has neuroprotective effects on MPP +-induced Parkinson's disease model cells by inhibiting ROS production and apoptosis. Neurosci Lett 2018; 690:145-150. [PMID: 30316984 DOI: 10.1016/j.neulet.2018.10.020] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 10/09/2018] [Accepted: 10/10/2018] [Indexed: 12/29/2022]
Abstract
Synphilin-1, a cytoplasmic protein, interacts with α-synuclein which is one of the main constituents of Lewy bodies and plays an important role in the pathology of Parkinson's disease (PD), in neurons. This interaction indicates that synphilin-1 may also play a central role in PD. However, the biological functions of synphilin-1 are not fully understood, and whether synphilin-1 is neurotoxic or neuroprotective remains controversial. This study examined the function of synphilin-1 in a PD model in vitro. We used an inhibitor of mitochondrial complex I, 1-methyl-4-phenylpyridinium (MPP+). We established human neuroblastoma SH-SY5Y cell lines that stably expressed human synphilin-1. We found that overexpression of synphilin-1 increased SH-SY5Y cell viability after MPP+ treatment. We further found that synphilin-1 significantly suppressed apoptotic changes in nuclei, including nuclear condensation and fragmentation, after MPP+ treatment. We showed that synphilin-1 significantly decreased MPP+-induced cleaved caspase-3 and cleaved poly-ADP-ribose polymerase levels by using western blotting. Production of reactive oxygen species (ROS) induced by MPP+ was significantly reduced in cells expressing synphilin-1 compared to those expressing empty vector. Synphilin-1 inhibited MPP+-induced cytochrome c release from mitochondria into the cytosol. These data suggested that synphilin-1 may function to protect against dopaminergic cell death by preserving mitochondrial function and inhibiting early steps in the intrinsic apoptotic pathway. Taken together, our results indicated that synphilin-1 may play neuroprotective roles in PD pathogenesis by inhibiting ROS production and apoptosis.
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Affiliation(s)
- Takeo Shishido
- Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, 1-2-3 Minami-ku Kasumi, Hiroshima, 734-8551, Japan
| | - Yoshito Nagano
- Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, 1-2-3 Minami-ku Kasumi, Hiroshima, 734-8551, Japan.
| | - Mutsuko Araki
- Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, 1-2-3 Minami-ku Kasumi, Hiroshima, 734-8551, Japan
| | - Takashi Kurashige
- Department of Neurology, NHO Kure Medical Center, 3-1 Aoyama-cho, Kure, Hiroshima, 737-0023, Japan
| | - Hitomi Obayashi
- Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, 1-2-3 Minami-ku Kasumi, Hiroshima, 734-8551, Japan
| | - Takeshi Nakamura
- Department of Internal Medicine, Oyamada Memorial Spa Hospital, 5538-1 Yamada-cho, Yokkaichi, Mie, 512-1111, Japan
| | - Tetsuya Takahashi
- Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, 1-2-3 Minami-ku Kasumi, Hiroshima, 734-8551, Japan
| | - Masayasu Matsumoto
- Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, 1-2-3 Minami-ku Kasumi, Hiroshima, 734-8551, Japan; Sakai City Medical Center, Sakai City Hospital Organization, 1-1-1 Ebaraji-cho Nishi-ku, Sakai, Osaka, 593-8304, Japan
| | - Hirofumi Maruyama
- Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, 1-2-3 Minami-ku Kasumi, Hiroshima, 734-8551, Japan
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7
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Liu J, Li T, Thomas JM, Pei Z, Jiang H, Engelender S, Ross CA, Smith WW. Synphilin-1 attenuates mutant LRRK2-induced neurodegeneration in Parkinson's disease models. Hum Mol Genet 2016; 25:672-80. [PMID: 26744328 DOI: 10.1093/hmg/ddv504] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 12/07/2015] [Indexed: 11/12/2022] Open
Abstract
Mutations in leucine-rich repeat kinase 2 (LRRK2) cause autosomal-dominant Parkinsonism with pleomorphic pathology including deposits of aggregated protein and neuronal degeneration. The pathogenesis of LRRK2-linked Parkinson's disease (PD) is not fully understood. Here, using co-immunoprecipitation, we found that LRRK2 interacted with synphilin-1 (SP1), a cytoplasmic protein that interacts with α-synuclein and has implications in PD pathogenesis. LRRK2 interacted with the N-terminus of SP1 whereas SP1 predominantly interacted with the C-terminus of LRRK2, including kinase domain. Co-expression of SP1 with LRRK2 increased LRRK2-induced cytoplasmic aggregation in cultured cells. Moreover, SP1 also attenuated mutant LRRK2-induced toxicity and reduced LRRK2 kinase activity in cultured cells. Knockdown of SP1 by siRNA enhanced LRRK2 neuronal toxicity. In vivo Drosophila studies, co-expression of SP1 and mutant G2019S-LRRK2 in double transgenic Drosophila increased survival and improved locomotor activity. Expression of SP1 protects against G2019S-LRRK2-induced dopamine neuron loss and reduced LRRK2 phosphorylation in double transgenic fly brains. Our findings demonstrate that SP1 attenuates mutant LRRK2-induced PD-like phenotypes and plays a neural protective role.
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Affiliation(s)
- Jingnan Liu
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, 20 Penn Street, Baltimore, MD 21201, USA
| | - Tianxia Li
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, 20 Penn Street, Baltimore, MD 21201, USA
| | - Joseph M Thomas
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, 20 Penn Street, Baltimore, MD 21201, USA
| | - Zhong Pei
- Division of Neurobiology, Department of Psychiatry
| | | | - Simone Engelender
- Department of Pharmacology, The B. Rappaport Institute of Medical Research, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - Christopher A Ross
- Division of Neurobiology, Department of Psychiatry, Departments of Neuroscience, Neurology, and Pharmacology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA and
| | - Wanli W Smith
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, 20 Penn Street, Baltimore, MD 21201, USA,
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8
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Larsen K, Madsen LB, Farajzadeh L, Bendixen C. Splicing variants of porcine synphilin-1. Meta Gene 2015; 5:32-42. [PMID: 26101749 PMCID: PMC4468357 DOI: 10.1016/j.mgene.2015.04.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 04/29/2015] [Accepted: 04/30/2015] [Indexed: 11/24/2022] Open
Abstract
Parkinson's disease (PD), idiopathic and familial, is characterized by degradation of dopaminergic neurons and the presence of Lewy bodies (LB) in the substantia nigra. LBs contain aggregated proteins of which α-synuclein is the major component. The protein synphilin-1 interacts and colocalizes with α-synuclein in LBs. The aim of this study was to isolate and characterize porcine synphilin-1 and isoforms hereof with the future perspective to use the pig as a model for Parkinson's disease. The porcine SNCAIP cDNA was cloned by reverse transcriptase PCR. The spatial expression of SNCAIP mRNA was investigated by RNAseq. The presented work reports the molecular cloning and characterization of the porcine (Sus scrofa) synphilin-1 cDNA (SNCAIP) and three splice variants hereof. The porcine SNCAIP cDNA codes for a protein (synphilin-1) of 919 amino acids which shows a high similarity to human (90%) and to mouse (84%) synphilin-1. Three shorter transcript variants of the synphilin-1 gene were identified, all lacking one or more exons. SNCAIP transcripts were detected in most examined organs and tissues and the highest expression was found in brain tissues and lung. Conserved splicing variants and a novel splice form of synhilin-1 were found in this study. All synphilin-1 isoforms encoded by the identified transcript variants lack functional domains important for protein degradation. The full-length porcine SNCAIP cDNA encoding synphilin-1 was cloned and characterized. Three splicing variants of synphilin-1 were identified. Both conserved and novel splicing variant were found. SNCAIP mRNA was differently expressed in analyzed tissues and organs with highest expression in brain tissue and lung.
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Affiliation(s)
- Knud Larsen
- Department of Molecular Biology and Genetics, Aarhus University, Blichers Allé 20, P.O. Box 50, DK-8830 Tjele, Denmark
| | - Lone Bruhn Madsen
- Department of Molecular Biology and Genetics, Aarhus University, Blichers Allé 20, P.O. Box 50, DK-8830 Tjele, Denmark
| | - Leila Farajzadeh
- Department of Molecular Biology and Genetics, Aarhus University, Blichers Allé 20, P.O. Box 50, DK-8830 Tjele, Denmark
| | - Christian Bendixen
- Department of Molecular Biology and Genetics, Aarhus University, Blichers Allé 20, P.O. Box 50, DK-8830 Tjele, Denmark
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9
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Li T, Liu J, Smith WW. Synphilin-1 binds ATP and regulates intracellular energy status. PLoS One 2014; 9:e115233. [PMID: 25545246 PMCID: PMC4278857 DOI: 10.1371/journal.pone.0115233] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Accepted: 11/19/2014] [Indexed: 11/19/2022] Open
Abstract
Recent studies have suggested that synphilin-1, a cytoplasmic protein, is involved in energy homeostasis. Overexpression of synphilin-1 in neurons results in hyperphagia and obesity in animal models. However, the mechanism by which synphilin-1 alters energy homeostasis is unknown. Here, we used cell models and biochemical approaches to investigate the cellular functions of synphilin-1 that may affect energy balance. Synphilin-1 was pulled down by ATP-agarose beads, and the addition of ATP and ADP reduced this binding, indicating that synphilin-1 bound ADP and ATP. Synphilin-1 also bound GMP, GDP, and GTP but with a lower affinity than it bound ATP. In contrast, synphilin-1 did not bind with CTP. Overexpression of synphilin-1 in HEK293T cells significantly increased cellular ATP levels. Genetic alteration to abolish predicted ATP binding motifs of synphilin-1 or knockdown of synphilin-1 by siRNA reduced cellular ATP levels. Together, these data demonstrate that synphilin-1 binds and regulates the cellular energy molecule, ATP. These findings provide a molecular basis for understanding the actions of synphilin-1 in energy homeostasis.
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Affiliation(s)
- Tianxia Li
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland 21201, United States of America
| | - Jingnan Liu
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland 21201, United States of America
| | - Wanli W. Smith
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland 21201, United States of America
- * E-mail:
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10
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Li X, Treesukosol Y, Moghadam A, Smith M, Ofeldt E, Yang D, Li T, Tamashiro K, Choi P, Moran TH, Smith WW. Behavioral characterization of the hyperphagia synphilin-1 overexpressing mice. PLoS One 2014; 9:e91449. [PMID: 24829096 PMCID: PMC4020742 DOI: 10.1371/journal.pone.0091449] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 02/12/2014] [Indexed: 01/06/2023] Open
Abstract
Synphilin-1 is a cytoplasmic protein that has been shown to be involved in the control of energy balance. Previously, we reported on the generation of a human synphilin-1 transgenic mouse model (SP1), in which overexpression of human synphilin-1 resulted in hyperphagia and obesity. Here, behavioral measures in SP1 mice were compared with those of their age-matched controls (NTg) at two time points: when there was not yet a group body weight difference (“pre-obese”) and when SP1 mice were heavier (“obese”). At both time points, meal pattern analyses revealed that SP1 mice displayed higher daily chow intake than non-transgenic control mice. Furthermore, there was an increase in meal size in SP1 mice compared with NTg control mice at the obese stage. In contrast, there was no meal number change between SP1 and NTg control mice. In a brief-access taste procedure, both “pre-obese” and “obese“ SP1 mice displayed concentration-dependent licking across a sucrose concentration range similar to their NTg controls. However, at the pre-obese stage, SP1 mice initiated significantly more trials to sucrose across the testing sessions and licked more vigorously at the highest concentration presented, than the NTg counterparts. These group differences in responsiveness to sucrose were no longer apparent in obese SP1 mice. These results suggest that at the pre-obese stage, the increased trials to sucrose in the SP1 mice reflects increased appetitive behavior to sucrose that may be indicative of the behavioral changes that may contribute to hyperphagia and development of obesity in SP1 mice. These studies provide new insight into synphilin-1 contributions to energy homeostasis.
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Affiliation(s)
- Xueping Li
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland, United States of America
| | - Yada Treesukosol
- Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Alexander Moghadam
- Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Megan Smith
- Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Erica Ofeldt
- Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Dejun Yang
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland, United States of America
| | - Tianxia Li
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland, United States of America
| | - Kellie Tamashiro
- Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Pique Choi
- Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Timothy H. Moran
- Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- * E-mail: (WWS); (THM)
| | - Wanli W. Smith
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland, United States of America
- * E-mail: (WWS); (THM)
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11
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Northcott PA, Shih DJH, Peacock J, Garzia L, Morrissy AS, Zichner T, Stütz AM, Korshunov A, Reimand J, Schumacher SE, Beroukhim R, Ellison DW, Marshall CR, Lionel AC, Mack S, Dubuc A, Yao Y, Ramaswamy V, Luu B, Rolider A, Cavalli FMG, Wang X, Remke M, Wu X, Chiu RYB, Chu A, Chuah E, Corbett RD, Hoad GR, Jackman SD, Li Y, Lo A, Mungall KL, Nip KM, Qian JQ, Raymond AGJ, Thiessen NT, Varhol RJ, Birol I, Moore RA, Mungall AJ, Holt R, Kawauchi D, Roussel MF, Kool M, Jones DTW, Witt H, Fernandez-L A, Kenney AM, Wechsler-Reya RJ, Dirks P, Aviv T, Grajkowska WA, Perek-Polnik M, Haberler CC, Delattre O, Reynaud SS, Doz FF, Pernet-Fattet SS, Cho BK, Kim SK, Wang KC, Scheurlen W, Eberhart CG, Fèvre-Montange M, Jouvet A, Pollack IF, Fan X, Muraszko KM, Gillespie GY, Di Rocco C, Massimi L, Michiels EMC, Kloosterhof NK, French PJ, Kros JM, Olson JM, Ellenbogen RG, Zitterbart K, Kren L, Thompson RC, Cooper MK, Lach B, McLendon RE, Bigner DD, Fontebasso A, Albrecht S, Jabado N, Lindsey JC, Bailey S, Gupta N, Weiss WA, Bognár L, Klekner A, Van Meter TE, Kumabe T, Tominaga T, Elbabaa SK, Leonard JR, Rubin JB, Liau LM, Van Meir EG, Fouladi M, Nakamura H, Cinalli G, Garami M, Hauser P, Saad AG, Iolascon A, Jung S, Carlotti CG, Vibhakar R, Ra YS, Robinson S, Zollo M, Faria CC, Chan JA, Levy ML, Sorensen PHB, Meyerson M, Pomeroy SL, Cho YJ, Bader GD, Tabori U, Hawkins CE, Bouffet E, Scherer SW, Rutka JT, Malkin D, Clifford SC, Jones SJM, Korbel JO, Pfister SM, Marra MA, Taylor MD. Subgroup-specific structural variation across 1,000 medulloblastoma genomes. Nature 2012; 488:49-56. [PMID: 22832581 DOI: 10.1038/nature11327] [Citation(s) in RCA: 664] [Impact Index Per Article: 55.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Accepted: 06/14/2012] [Indexed: 01/22/2023]
Abstract
Medulloblastoma, the most common malignant paediatric brain tumour, is currently treated with nonspecific cytotoxic therapies including surgery, whole-brain radiation, and aggressive chemotherapy. As medulloblastoma exhibits marked intertumoural heterogeneity, with at least four distinct molecular variants, previous attempts to identify targets for therapy have been underpowered because of small samples sizes. Here we report somatic copy number aberrations (SCNAs) in 1,087 unique medulloblastomas. SCNAs are common in medulloblastoma, and are predominantly subgroup-enriched. The most common region of focal copy number gain is a tandem duplication of SNCAIP, a gene associated with Parkinson's disease, which is exquisitely restricted to Group 4α. Recurrent translocations of PVT1, including PVT1-MYC and PVT1-NDRG1, that arise through chromothripsis are restricted to Group 3. Numerous targetable SCNAs, including recurrent events targeting TGF-β signalling in Group 3, and NF-κB signalling in Group 4, suggest future avenues for rational, targeted therapy.
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Affiliation(s)
- Paul A Northcott
- Developmental & Stem Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario M5G 1L7, Canada
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Abstract
AIMS The pathogenesis of obesity remains incompletely understood. Drosophila have conserved neuroendocrine and digestion systems with human and become an excellent system for studying energy homeostasis. Here, we reported a novel obesity Drosophila model, in which expression of human protein, synphilin-1 (SP1), in neurons fosters positive energy balance. SUBJECTS AND METHODS To further understand the actions of SP1 in energy balance control, the upstream activation sequence UAS/GAL4 system was used to generate human SP1 transgenic Drosophila. We characterized a human SP1 transgenic Drosophila by assessing SP1 expression, fat lipid deposition, food intake and fly locomotor activity to determine the major behavioral changes and their consequences in the development of the obesity-like phenotype. RESULTS Overexpression of SP1 in neurons, but not peripheral cells, increased the body weight of flies compared with that of non-transgenic controls. SP1 increased food intake but did not affect locomotor activity. SP1 increased the levels of triacylglycerol, and the size of fat body cells and lipid droplets, indicating that SP1 increased lipid-fat disposition. Survival studies showed that SP1 transgenic flies were more resistant to food deprivation. SP1 regulated lipin gene expression that may participate in SP1-induced fat deposition and starvation resistance. CONCLUSION These studies demonstrate that SP1 expression affects energy homeostasis in ways that enhance positive energy balance and provide a useful obesity model for future pathogenesis and therapeutic studies.
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Xiong N, Long X, Xiong J, Jia M, Chen C, Huang J, Ghoorah D, Kong X, Lin Z, Wang T. Mitochondrial complex I inhibitor rotenone-induced toxicity and its potential mechanisms in Parkinson's disease models. Crit Rev Toxicol 2012; 42:613-32. [PMID: 22574684 DOI: 10.3109/10408444.2012.680431] [Citation(s) in RCA: 121] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The etiology of Parkinson's disease (PD) is attributed to both environmental and genetic factors. The development of PD reportedly involves mitochondrial impairment, oxidative stress, α-synuclein aggregation, dysfunctional protein degradation, glutamate toxicity, calcium overloading, inflammation and loss of neurotrophic factors. Based on a link between mitochondrial dysfunction and pesticide exposure, many laboratories, including ours, have recently developed parkinsonian models by utilization of rotenone, a well-known mitochondrial complex I inhibitor. Rotenone models for PD appear to mimic most clinical features of idiopathic PD and recapitulate the slow and progressive loss of dopaminergic (DA) neurons and the Lewy body formation in the nigral-striatal system. Notably, potential human parkinsonian pathogenetic and pathophysiological mechanisms have been revealed through these models. In this review, we summarized various rotenone-based models for PD and discussed the implied etiology of and treatment for PD.
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Affiliation(s)
- Nian Xiong
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Hubei 430022, China
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Li X, Tamashiro KLK, Liu Z, Bello NT, Wang X, Aja S, Bi S, Ladenheim EE, Ross CA, Moran TH, Smith WW. A novel obesity model: synphilin-1-induced hyperphagia and obesity in mice. Int J Obes (Lond) 2011; 36:1215-21. [PMID: 22158267 PMCID: PMC3439552 DOI: 10.1038/ijo.2011.235] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Aims The pathogenesis of obesity remains incompletely understood and the exploration of the role of novel proteins in obesity may provide important insights into its causes and treatments. Here we report a previously unidentified role for synphilin-1 in the controls of food intake and body weight. Synphilin-1, a cytoplasmic protein, was initially identified as an interaction partner of alpha-synuclein, and has implications in Parkinson's disease pathogenesis related to protein aggregation. Subjects and methods To study the in vivo role of synphilin-1, we characterized a human synphilin-1 transgenic mouse (SP1) by assessing synphilin-1 expression, plasma parameters, food intake and spontaneous activity to determine the major behavioral changes and their consequences in the development of the obesity phenotype. Results Expression of human synphilin-1 in brain neurons in SP1 mice resulted in increased food intake, body weight and body fat. SP1 mice also displayed hyperinsulinemia, hyperleptinemia and impaired glucose tolerance. Pair-feeding SP1 mice to amounts consumed by non-transgenic mice prevented the increased body weight, adiposity, hyperinsulinemia and hyperleptinemia demonstrating that these were all the consequences of increased food intake. Transgenic expression of synphilin-1 was enriched in hypothalamic nuclei involved in feeding control, and fasting induced elevated endogenous synphilin-1 levels at these sites, suggesting that synphilin-1 is an important player in the hypothalamic energy balance regulatory system. Conclusion These studies identify a novel function of synphilin-1 in controlling food intake and body weight, and may provide a unique obesity model for future studies of obesity pathogenesis and therapeutics.
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Affiliation(s)
- X Li
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201, USA
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