1
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Orrico-Sanchez A, Guiard BP, Manta S, Callebert J, Launay JM, Louis F, Paccard A, Gruszczynski C, Betancur C, Vialou V, Gautron S. Organic cation transporter 2 contributes to SSRI antidepressant efficacy by controlling tryptophan availability in the brain. Transl Psychiatry 2023; 13:302. [PMID: 37775532 PMCID: PMC10542329 DOI: 10.1038/s41398-023-02596-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 09/15/2023] [Accepted: 09/15/2023] [Indexed: 10/01/2023] Open
Abstract
Selective serotonin reuptake inhibitors (SSRI) are common first-line treatments for major depression. However, a significant number of depressed patients do not respond adequately to these pharmacological treatments. In the present preclinical study, we demonstrate that organic cation transporter 2 (OCT2), an atypical monoamine transporter, contributes to the effects of SSRI by regulating the routing of the essential amino acid tryptophan to the brain. Contrarily to wild-type mice, OCT2-invalidated mice failed to respond to prolonged fluoxetine treatment in a chronic depression model induced by corticosterone exposure recapitulating core symptoms of depression, i.e., anhedonia, social withdrawal, anxiety, and memory impairment. After corticosterone and fluoxetine treatment, the levels of tryptophan and its metabolites serotonin and kynurenine were decreased in the brain of OCT2 mutant mice compared to wild-type mice and reciprocally tryptophan and kynurenine levels were increased in mutants' plasma. OCT2 was detected by immunofluorescence in several structures at the blood-cerebrospinal fluid (CSF) or brain-CSF interface. Tryptophan supplementation during fluoxetine treatment increased brain concentrations of tryptophan and, more discreetly, of 5-HT in wild-type and OCT2 mutant mice. Importantly, tryptophan supplementation improved the sensitivity to fluoxetine treatment of OCT2 mutant mice, impacting chiefly anhedonia and short-term memory. Western blot analysis showed that glycogen synthase kinase-3β (GSK3β) and mammalian/mechanistic target of rapamycin (mTOR) intracellular signaling was impaired in OCT2 mutant mice brain after corticosterone and fluoxetine treatment and, conversely, tryptophan supplementation recruited selectively the mTOR protein complex 2. This study provides the first evidence of the physiological relevance of OCT2-mediated tryptophan transport, and its biological consequences on serotonin homeostasis in the brain and SSRI efficacy.
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Affiliation(s)
| | - Bruno P Guiard
- Université Paul Sabatier, CNRS, Research Center on Animal Cognition, Toulouse, France
| | - Stella Manta
- Université Paul Sabatier, CNRS, Research Center on Animal Cognition, Toulouse, France
| | - Jacques Callebert
- Sorbonne Paris Cité, Hôpital Lariboisière, Assistance Publique Hôpitaux de Paris, Paris, France
| | - Jean-Marie Launay
- Sorbonne Paris Cité, Hôpital Lariboisière, Assistance Publique Hôpitaux de Paris, Paris, France
| | - Franck Louis
- Sorbonne Université, INSERM, CNRS, Neuroscience Paris Seine, Paris, France
| | - Antoine Paccard
- Sorbonne Université, INSERM, CNRS, Neuroscience Paris Seine, Paris, France
| | | | - Catalina Betancur
- Sorbonne Université, INSERM, CNRS, Neuroscience Paris Seine, Paris, France
| | - Vincent Vialou
- Sorbonne Université, INSERM, CNRS, Neuroscience Paris Seine, Paris, France.
| | - Sophie Gautron
- Sorbonne Université, INSERM, CNRS, Neuroscience Paris Seine, Paris, France.
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2
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Yu Z, Chen J, Takagi E, Wang F, Saha B, Liu X, Joubert LM, Gleason CE, Jin M, Li C, Nowotny C, Agard D, Cheng Y, Pearce D. Interactions between mTORC2 core subunits Rictor and mSin1 dictate selective and context-dependent phosphorylation of substrate kinases SGK1 and Akt. J Biol Chem 2022; 298:102288. [PMID: 35926713 PMCID: PMC9440446 DOI: 10.1016/j.jbc.2022.102288] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 07/04/2022] [Accepted: 07/05/2022] [Indexed: 12/02/2022] Open
Abstract
Mechanistic target of rapamycin complex 2 (mTORC2) is a multi-subunit kinase complex, central to multiple essential signaling pathways. Two core subunits, Rictor and mSin1, distinguish it from the related mTORC1 and support context-dependent phosphorylation of its substrates. mTORC2 structures have been determined previously; however, important questions remain, particularly regarding the structural determinants mediating substrate specificity and context-dependent activity. Here, we used cryo-EM to obtain high-resolution structures of the human mTORC2 apo-complex in the presence of substrates Akt and SGK1. Using functional assays, we then tested predictions suggested by substrate-induced structural changes in mTORC2. For the first time, we visualized in the apo-state the side chain interactions between Rictor and mTOR that sterically occlude recruitment of mTORC1 substrates and confer resistance to the mTORC1 inhibitor rapamycin. Also in the apo-state, we observed that mSin1 formed extensive contacts with Rictor via a pair of short α-helices nestled between two Rictor helical repeat clusters, as well as by an extended strand that makes multiple weak contacts with Rictor helical cluster 1. In co-complex structures, we found that SGK1, but not Akt, markedly altered the conformation of the mSin1 N-terminal extended strand, disrupting multiple weak interactions while inducing a large rotation of mSin1 residue Arg-83, which then interacts with a patch of negatively charged residues within Rictor. Finally, we demonstrate mutation of Arg-83 to Ala selectively disrupts mTORC2-dependent phosphorylation of SGK1, but not of Akt, supporting context-dependent substrate selection. These findings provide new structural and functional insights into mTORC2 specificity and context-dependent activity.
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Affiliation(s)
- Zanlin Yu
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA
| | - Junliang Chen
- Department of Medicine, Division of Nephrology, and Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, California, USA
| | - Enzo Takagi
- Department of Medicine, Division of Nephrology, and Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, California, USA
| | - Feng Wang
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA
| | - Bidisha Saha
- Department of Medicine, Division of Nephrology, and Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, California, USA
| | - Xi Liu
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California, USA
| | - Lydia-Marie Joubert
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California, USA
| | - Catherine E Gleason
- Department of Medicine, Division of Nephrology, and Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, California, USA
| | - Mingliang Jin
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA
| | - Chengmin Li
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA
| | - Carlos Nowotny
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA
| | - David Agard
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA
| | - Yifan Cheng
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA; Howard Hughes Medical Institute, University of California San Francisco, San Francisco, California, USA
| | - David Pearce
- Department of Medicine, Division of Nephrology, and Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, California, USA.
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3
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Wong C, Barkai O, Wang F, Thörn Pérez C, Lev S, Cai W, Tansley S, Yousefpour N, Hooshmandi M, Lister KC, Latif M, Cuello AC, Prager-Khoutorsky M, Mogil JS, Séguéla P, De Koninck Y, Ribeiro-da-Silva A, Binshtok AM, Khoutorsky A. mTORC2 mediates structural plasticity in distal nociceptive endings that contributes to pain hypersensitivity following inflammation. J Clin Invest 2022; 132:152635. [PMID: 35579957 PMCID: PMC9337825 DOI: 10.1172/jci152635] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 05/13/2022] [Indexed: 11/29/2022] Open
Abstract
The encoding of noxious stimuli into action potential firing is largely mediated by nociceptive free nerve endings. Tissue inflammation, by changing the intrinsic properties of the nociceptive endings, leads to nociceptive hyperexcitability and thus to the development of inflammatory pain. Here, we showed that tissue inflammation–induced activation of the mammalian target of rapamycin complex 2 (mTORC2) triggers changes in the architecture of nociceptive terminals and leads to inflammatory pain. Pharmacological activation of mTORC2 induced elongation and branching of nociceptor peripheral endings and caused long-lasting pain hypersensitivity. Conversely, nociceptor-specific deletion of the mTORC2 regulatory protein rapamycin-insensitive companion of mTOR (Rictor) prevented inflammation-induced elongation and branching of cutaneous nociceptive fibers and attenuated inflammatory pain hypersensitivity. Computational modeling demonstrated that mTORC2-mediated structural changes in the nociceptive terminal tree are sufficient to increase the excitability of nociceptors. Targeting mTORC2 using a single injection of antisense oligonucleotide against Rictor provided long-lasting alleviation of inflammatory pain hypersensitivity. Collectively, we showed that tissue inflammation–induced activation of mTORC2 causes structural plasticity of nociceptive free nerve endings in the epidermis and inflammatory hyperalgesia, representing a therapeutic target for inflammatory pain.
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Affiliation(s)
- Calvin Wong
- Department of Anesthesia, McGill University, Montreal, Canada
| | - Omer Barkai
- Department of Medical Neurobiology, The Hebrew University, Jerusalem, Israel
| | - Feng Wang
- Department of Psychiatry and Neuroscience, Université Laval, Quebec City, Canada
| | | | - Shaya Lev
- Department of Medical Neurobiology, The Hebrew University, Jerusalem, Israel
| | - Weihua Cai
- Department of Anesthesia, McGill University, Montreal, Canada
| | - Shannon Tansley
- Department of Psychology, McGill University, Montreal, Canada
| | - Noosha Yousefpour
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada
| | | | - Kevin C Lister
- Department of Anesthesia, McGill University, Montreal, Canada
| | - Mariam Latif
- Department of Anesthesia, McGill University, Montreal, Canada
| | - A Claudio Cuello
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada
| | | | - Jeffrey S Mogil
- Department of Psychology, McGill University, Montreal, Canada
| | - Philippe Séguéla
- Department of Neurology and Neurosurgery, McGill University, Montreal, Canada
| | - Yves De Koninck
- Department of Psychiatry and Neuroscience, Université Laval, Quebec City, Canada
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4
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Chen SL, Liu BT, Lee WP, Liao SB, Deng YB, Wu CL, Ho SM, Shen BX, Khoo GH, Shiu WC, Chang CH, Shih HW, Wen JK, Lan TH, Lin CC, Tsai YC, Tzeng HF, Fu TF. WAKE-mediated modulation of cVA perception via a hierarchical neuro-endocrine axis in Drosophila male-male courtship behaviour. Nat Commun 2022; 13:2518. [PMID: 35523813 PMCID: PMC9076693 DOI: 10.1038/s41467-022-30165-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 04/19/2022] [Indexed: 12/18/2022] Open
Abstract
The nervous and endocrine systems coordinate with each other to closely influence physiological and behavioural responses in animals. Here we show that WAKE (encoded by wide awake, also known as wake) modulates membrane levels of GABAA receptor Resistance to Dieldrin (Rdl), in insulin-producing cells of adult male Drosophila melanogaster. This results in changes to secretion of insulin-like peptides which is associated with changes in juvenile hormone biosynthesis in the corpus allatum, which in turn leads to a decrease in 20-hydroxyecdysone levels. A reduction in ecdysone signalling changes neural architecture and lowers the perception of the male-specific sex pheromone 11-cis-vaccenyl acetate by odorant receptor 67d olfactory neurons. These finding explain why WAKE-deficient in Drosophila elicits significant male-male courtship behaviour. The authors show that the Drosophila master regulator WAKE modulates the secretion of insulin-like peptides, triggering a decrease in 20-hydroxyecdysone levels. This lowers the perception of a male-specific sex pheromone and explains why WAKE-deficient Drosophila flies show male-male courtship behaviour.
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Affiliation(s)
- Shiu-Ling Chen
- Department of Applied Chemistry, National Chi Nan University, Nantou, Taiwan
| | - Bo-Ting Liu
- Department of Applied Chemistry, National Chi Nan University, Nantou, Taiwan
| | - Wang-Pao Lee
- Department of Biochemistry and Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Sin-Bo Liao
- Department of Applied Chemistry, National Chi Nan University, Nantou, Taiwan.,Institute of Biotechnology, National Tsing Hua University, Hsinchu, Taiwan
| | - Yao-Bang Deng
- Department of Applied Chemistry, National Chi Nan University, Nantou, Taiwan
| | - Chia-Lin Wu
- Department of Biochemistry and Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Department of Neurology, Chang Gung Memorial Hospital, Linkou, Taiwan.,Brain Research Center, National Tsing Hua University, Hsinchu, Taiwan
| | - Shuk-Man Ho
- Department of Applied Chemistry, National Chi Nan University, Nantou, Taiwan
| | - Bing-Xian Shen
- Department of Applied Chemistry, National Chi Nan University, Nantou, Taiwan
| | - Guan-Hock Khoo
- Department of Life Science and Life Science Center, Tunghai University, Taichung, Taiwan
| | - Wei-Chiang Shiu
- Department of Applied Chemistry, National Chi Nan University, Nantou, Taiwan
| | - Chih-Hsuan Chang
- Department of Life Science and Life Science Center, Tunghai University, Taichung, Taiwan.,Institute of Systems Neuroscience, National Tsing Hua University, Hsinchu, Taiwan.,National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan, Taiwan
| | - Hui-Wen Shih
- Department of Life Science and Life Science Center, Tunghai University, Taichung, Taiwan
| | - Jung-Kun Wen
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Tsuo-Hung Lan
- Department of Psychiatry, School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan.,Tsaotun Psychiatric Center, Ministry of Health and Welfare, Nantou, Taiwan.,Department of Psychiatry, Taichung Veterans General Hospital, Taichung, Taiwan.,Center for Neuropsychiatric Research, National Health Research Institutes, Miaoli, Taiwan
| | - Chih-Chien Lin
- Department of Psychiatry, School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Yu-Chen Tsai
- Department of Life Science and Life Science Center, Tunghai University, Taichung, Taiwan.
| | - Huey-Fen Tzeng
- Department of Applied Chemistry, National Chi Nan University, Nantou, Taiwan.
| | - Tsai-Feng Fu
- Department of Applied Chemistry, National Chi Nan University, Nantou, Taiwan.
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5
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Ruan C, Ouyang X, Liu H, Li S, Jin J, Tang W, Xia Y, Su B. Sin1-mediated mTOR signaling in cell growth, metabolism and immune response. Natl Sci Rev 2019; 6:1149-1162. [PMID: 34691993 PMCID: PMC8291397 DOI: 10.1093/nsr/nwz171] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 10/22/2019] [Accepted: 10/22/2019] [Indexed: 12/22/2022] Open
Abstract
Abstract
The mammalian target of rapamycin (mTOR) is an evolutionarily conserved Ser/Thr protein kinase with essential cellular function via processing various extracellular and intracellular inputs. Two distinct multi-protein mTOR complexes (mTORC), mTORC1 and mTORC2, have been identified and well characterized in eukaryotic cells from yeast to human. Sin1, which stands for Sty1/Spc1-interacting protein1, also known as mitogen-activated protein kinase (MAPK) associated protein (MAPKAP)1, is an evolutionarily conserved adaptor protein. Mammalian Sin1 interacts with many cellular proteins, but it has been widely studied as an essential component of mTORC2, and it is crucial not only for the assembly of mTORC2 but also for the regulation of its substrate specificity. In this review, we summarize our current knowledge of the structure and functions of Sin1, focusing specifically on its protein interaction network and its roles in the mTOR pathway that could account for various cellular functions of mTOR in growth, metabolism, immunity and cancer.
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Affiliation(s)
- Chun Ruan
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and the Minister of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Xinxing Ouyang
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and the Minister of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Hongzhi Liu
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and the Minister of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Song Li
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and the Minister of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Jingsi Jin
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and the Minister of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Weiyi Tang
- Zhiyuan College, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yu Xia
- Zhiyuan College, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Bing Su
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and the Minister of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
- Zhiyuan College, Shanghai Jiao Tong University, Shanghai 200240, China
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6
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Chen CJ, Sgritta M, Mays J, Zhou H, Lucero R, Park J, Wang IC, Park JH, Kaipparettu BA, Stoica L, Jafar-Nejad P, Rigo F, Chin J, Noebels JL, Costa-Mattioli M. Therapeutic inhibition of mTORC2 rescues the behavioral and neurophysiological abnormalities associated with Pten-deficiency. Nat Med 2019; 25:1684-1690. [PMID: 31636454 PMCID: PMC7082835 DOI: 10.1038/s41591-019-0608-y] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 09/10/2019] [Indexed: 01/05/2023]
Abstract
Dysregulation of the mammalian target of rapamycin (mTOR) signaling, which is mediated by two structurally and functionally distinct complexes, mTORC1 and mTORC2, has been implicated in several neurological disorders1-3. Individuals carrying loss-of-function mutations in the phosphatase and tensin homolog (PTEN) gene, a negative regulator of mTOR signaling, are prone to developing macrocephaly, autism spectrum disorder (ASD), seizures and intellectual disability2,4,5. It is generally believed that the neurological symptoms associated with loss of PTEN and other mTORopathies (for example, mutations in the tuberous sclerosis genes TSC1 or TSC2) are due to hyperactivation of mTORC1-mediated protein synthesis1,2,4,6,7. Using molecular genetics, we unexpectedly found that genetic deletion of mTORC2 (but not mTORC1) activity prolonged lifespan, suppressed seizures, rescued ASD-like behaviors and long-term memory, and normalized metabolic changes in the brain of mice lacking Pten. In a more therapeutically oriented approach, we found that administration of an antisense oligonucleotide (ASO) targeting mTORC2's defining component Rictor specifically inhibits mTORC2 activity and reverses the behavioral and neurophysiological abnormalities in adolescent Pten-deficient mice. Collectively, our findings indicate that mTORC2 is the major driver underlying the neuropathophysiology associated with Pten-deficiency, and its therapeutic reduction could represent a promising and broadly effective translational therapy for neurological disorders where mTOR signaling is dysregulated.
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Affiliation(s)
- Chien-Ju Chen
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX, USA
| | - Martina Sgritta
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX, USA
| | - Jacqunae Mays
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX, USA
| | - Hongyi Zhou
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX, USA
| | - Rocco Lucero
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA
| | - Jin Park
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX, USA
| | - I-Ching Wang
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX, USA
| | - Jun Hyoung Park
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Benny Abraham Kaipparettu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX, USA
| | - Loredana Stoica
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX, USA
| | | | - Frank Rigo
- Ionis Pharmaceuticals, Carlsbad, CA, USA
| | - Jeannie Chin
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX, USA
| | - Jeffrey L Noebels
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA
| | - Mauro Costa-Mattioli
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA.
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX, USA.
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
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7
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Altered Actin Filament Dynamics in the Drosophila Mushroom Bodies Lead to Fast Acquisition of Alcohol Consumption Preference. J Neurosci 2019; 39:8877-8884. [PMID: 31558618 DOI: 10.1523/jneurosci.0973-19.2019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 08/22/2019] [Accepted: 09/13/2019] [Indexed: 01/12/2023] Open
Abstract
Alcohol use is highly prevalent in the United States and across the world, and every year millions of people suffer from alcohol use disorders (AUDs). Although the genetic contribution to developing AUDs is estimated to be 50-60%, many of the underlying molecular mechanisms remain unclear. Previous studies from our laboratory revealed that Drosophila melanogaster lacking RhoGAP18B and Ras Suppressor 1 (Rsu1) display reduced sensitivity to ethanol-induced sedation. Both Rsu1 and RhoGAP18B are negative regulators of the small Rho-family GTPase, Rac1, a modulator of actin dynamics. Here we investigate the role of Rac1 and its downstream target, the actin-severing protein cofilin, in alcohol consumption preference. We show that these two regulators of actin dynamics can alter male experience-dependent alcohol preference in a bidirectional manner: expressing either activated Rac1 or dominant-negative cofilin in the mushroom bodies (MBs) abolishes experience-dependent alcohol preference. Conversely, dominant-negative Rac1 or activated cofilin MB expression lead to faster acquisition of alcohol preference. Our data show that Rac1 and cofilin activity are key to determining the rate of acquisition of alcohol preference, revealing a critical role of actin dynamics regulation in the development of voluntary self-administration in Drosophila SIGNIFICANCE STATEMENT The risks for developing an alcohol use disorder (AUD) are strongly determined by genetic factors. Understanding the genes and molecular mechanisms that contribute to that risk is therefore a necessary first step for the development of targeted therapeutic intervention. Here we show that regulators of actin cytoskeleton dynamics can bidirectionally determine the acquisition rate of alcohol self-administration, highlighting this process as a key mechanism contributing to the risk of AUD development.
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8
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Maruzs T, Simon-Vecsei Z, Kiss V, Csizmadia T, Juhász G. On the Fly: Recent Progress on Autophagy and Aging in Drosophila. Front Cell Dev Biol 2019; 7:140. [PMID: 31396511 PMCID: PMC6667644 DOI: 10.3389/fcell.2019.00140] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 07/09/2019] [Indexed: 01/03/2023] Open
Abstract
Autophagy ensures the lysosome-mediated breakdown and recycling of self-material, as it not only degrades obsolete or damaged intracellular constituents but also provides building blocks for biosynthetic and energy producing reactions. Studies in animal models including Drosophila revealed that autophagy defects lead to the rapid decline of neuromuscular function, neurodegeneration, sensitivity to stress (such as starvation or oxidative damage), and stem cell loss. Of note, recently identified human Atg gene mutations cause similar symptoms including ataxia and mental retardation. Physiologically, autophagic degradation (flux) is known to decrease during aging, and this defect likely contributes to the development of such age-associated diseases. Many manipulations that extend lifespan (including dietary restriction, reduced TOR kinase signaling, exercise or treatment with various anti-aging substances) require autophagy for their beneficial effect on longevity, pointing to the key role of this housekeeping process. Importantly, genetic (e.g., Atg8a overexpression in either neurons or muscle) or pharmacological (e.g., feeding rapamycin or spermidine to animals) promotion of autophagy has been successfully used to extend lifespan in Drosophila, suggesting that this intracellular degradation pathway can rejuvenate cells and organisms. In this review, we highlight key discoveries and recent progress in understanding the relationship of autophagy and aging in Drosophila.
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Affiliation(s)
- Tamás Maruzs
- Institute of Genetics, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, Hungary
| | - Zsófia Simon-Vecsei
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Viktória Kiss
- Institute of Genetics, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, Hungary
| | - Tamás Csizmadia
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Gábor Juhász
- Institute of Genetics, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, Hungary.,Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
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9
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Zhang YY, Liu MY, Liu Z, Zhao JK, Zhao YG, He L, Li W, Zhang JQ. GPR30-mediated estrogenic regulation of actin polymerization and spatial memory involves SRC-1 and PI3K-mTORC2 in the hippocampus of female mice. CNS Neurosci Ther 2019; 25:714-733. [PMID: 30714337 PMCID: PMC6515707 DOI: 10.1111/cns.13108] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 12/18/2018] [Accepted: 01/03/2019] [Indexed: 12/29/2022] Open
Abstract
AIMS The G-protein-coupled estrogen receptor GPR30 (also referred to as GPER) has been implicated in the estrogenic regulation of hippocampal plasticity and spatial memory; however, the molecular mechanisms are largely unclear. METHODS In this study, we initially examined the levels of GPR30 in the hippocampus of postnatal, ovariectomy (OVX)- and letrozole (LET)-treated female mice. Under G1, G15, and/or OVX treatment, the spatial memory, spine density, levels of ERα, ERβ, and SRC-1, selected synaptic proteins, mTORC2 signals (Rictor and p-AKT Ser473), and actin polymerization dynamics were subsequently evaluated. Furthermore, G1, G15, and/or E2 combined with SRC-1 and/or PI3K inhibitors, actin cytoskeleton polymerization modulator JPK, and CytoD treatments were used to address the mechanisms that underlie GPR30 regulation in vitro. Finally, mTORC2 activator A-443654 (A4) was used to explore the role of mTORC2 in GPR30 regulation of spatial memory. RESULTS The results showed that high levels of GPR30 were detected in the adult hippocampus and the levels were downregulated by OVX and LET. OVX induced an impairment of spatial memory, and changes in other parameters previously described were reversed by G1 and mimicked by G15. Furthermore, the E2 effects on SRC-1 and mTORC2 signals, synaptic proteins, and actin polymerization were inhibited by G15, whereas G1 effects on these parameters were inhibited by the blockade of SRC-1 or PI3K; the levels of synaptic proteins were regulated by JPK and CytoD. Importantly, G15-induced actin depolymerization and spatial memory impairment were rescued by mTORC2 activation with A4. CONCLUSIONS Taking together, these results demonstrated that decreased GPR30 induces actin depolymerization through SRC-1 and PI3K/mTORC2 pathways and ultimately impairs learning and memory, indicating its potential role as a therapeutic target against hippocampus-based, E2-related memory impairments.
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Affiliation(s)
- Yuan-Yuan Zhang
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing, China
| | - Meng-Ying Liu
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing, China
| | - Zhi Liu
- Department of Histology and Embryology, Third Military Medical University, Chongqing, China
| | - Ji-Kai Zhao
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing, China
| | - Yan-Gang Zhao
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing, China
| | - Li He
- School of Nursing, Third Military Medical University, Chongqing, China
| | - Wei Li
- School of Nursing, Third Military Medical University, Chongqing, China
| | - Ji-Qiang Zhang
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing, China
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10
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Pergolizzi B, Panuzzo C, Ali MS, Lo Iacono M, Levron CL, Ponzone L, Prelli M, Cilloni D, Calautti E, Bozzaro S, Bracco E. Mammals and Dictyostelium rictor mutations swapping reveals two essential Gly residues for mTORC2 activity and integrity. J Cell Sci 2019; 132:jcs.236505. [DOI: 10.1242/jcs.236505] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 10/15/2019] [Indexed: 12/27/2022] Open
Abstract
mTORC2 regulates a variety of vital cellular processes, and its aberrant functioning is often associated with various diseases. Rictor is a peculiar and distinguishing mTORC2 component playing a pivotal role in controlling its assembly and activity. Among living organisms Rictor is conserved from unicellular eukaryotes to metazoan. We replaced two distinct, but conserved, glycines in both the Dictyostelium piaA gene and its human ortholog, rictor. The two conserved residues are spaced by approximately 50 aminoacids and both are embedded within a conserved region falling in between the Ras-GEFN2 and Rictor_V domains. The effects of point mutations on the mTORC2 activity and integrity were assessed by biochemical and functional assays.In both cases, the reciprocal exchange between mammals and Dictyostelium rictor and piaA gene point mutations impaired mTORC2 activity and integrity.Our data indicate that the two Gly residues are essential for the maintenance of mTORC2 activity and integrity in organisms that appear to be distantly related, suggesting a primeval role in the assembly and proper TOR complex 2 functioning.
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Affiliation(s)
- Barbara Pergolizzi
- Department of Clinical and Biological Sciences, University of Torino, AOU S. Luigi, 10043 Orbassano (TO), Italy
| | - Cristina Panuzzo
- Department of Clinical and Biological Sciences, University of Torino, AOU S. Luigi, 10043 Orbassano (TO), Italy
| | - M. Shahzad Ali
- Department of Clinical and Biological Sciences, University of Torino, AOU S. Luigi, 10043 Orbassano (TO), Italy
| | - Marco Lo Iacono
- Department of Clinical and Biological Sciences, University of Torino, AOU S. Luigi, 10043 Orbassano (TO), Italy
| | - Chiara Levra Levron
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Centre, University of Torino, Via Nizza 52, Torino, Italy
| | - Luca Ponzone
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Centre, University of Torino, Via Nizza 52, Torino, Italy
| | - Marta Prelli
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Centre, University of Torino, Via Nizza 52, Torino, Italy
| | - Daniela Cilloni
- Department of Clinical and Biological Sciences, University of Torino, AOU S. Luigi, 10043 Orbassano (TO), Italy
| | - Enzo Calautti
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Centre, University of Torino, Via Nizza 52, Torino, Italy
| | - Salvatore Bozzaro
- Department of Clinical and Biological Sciences, University of Torino, AOU S. Luigi, 10043 Orbassano (TO), Italy
| | - Enrico Bracco
- Department of Oncology, University of Torino, AOU S. Luigi, 10043 Orbassano (TO), Italy
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11
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Laguesse S, Morisot N, Phamluong K, Sakhai SA, Ron D. mTORC2 in the dorsomedial striatum of mice contributes to alcohol-dependent F-Actin polymerization, structural modifications, and consumption. Neuropsychopharmacology 2018; 43:1539-1547. [PMID: 29497165 PMCID: PMC5983552 DOI: 10.1038/s41386-018-0012-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 12/22/2017] [Accepted: 01/05/2018] [Indexed: 01/21/2023]
Abstract
Actin is highly enriched at dendritic spines, and actin remodeling plays an essential role in structural plasticity. The mammalian target of rapamycin complex 2 (mTORC2) is a regulator of actin polymerization. Here, we report that alcohol consumption increases F-actin content in the dorsomedial striatum (DMS) of mice, thereby altering dendritic spine morphology in a mechanism that requires mTORC2. Specifically, we found that excessive alcohol consumption increases mTORC2 activity in the DMS, and that knockdown of Rictor, an essential component of mTORC2 signaling, reduces actin polymerization, and attenuates the alcohol-dependent alterations in spine head size and the number of mushroom spines. Finally, we show that knockdown of Rictor in the DMS reduces alcohol consumption, whereas intra-DMS infusion of the mTORC2 activator, A-443654, increases alcohol intake. Together, these results suggest that mTORC2 in the DMS facilitates the formation of F-actin, which in turn induces changes in spine structure to promote and/or maintain excessive alcohol intake.
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Affiliation(s)
- Sophie Laguesse
- 0000 0001 2297 6811grid.266102.1Department of Neurology, University of California, San Francisco, San Francisco, CA 94143 USA ,Present Address: N.M. Brains On-line LLC, South San Francisco, CA USA
| | - Nadege Morisot
- 0000 0001 2297 6811grid.266102.1Department of Neurology, University of California, San Francisco, San Francisco, CA 94143 USA ,0000 0001 0805 7253grid.4861.bPresent Address: S.L. GIGA-Neurosciences, University of Liège, Liège, Belgium
| | - Khanhky Phamluong
- 0000 0001 2297 6811grid.266102.1Department of Neurology, University of California, San Francisco, San Francisco, CA 94143 USA
| | - Samuel A. Sakhai
- 0000 0001 2297 6811grid.266102.1Department of Neurology, University of California, San Francisco, San Francisco, CA 94143 USA
| | - Dorit Ron
- Department of Neurology, University of California, San Francisco, San Francisco, CA, 94143, USA.
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12
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Talos DM, Jacobs LM, Gourmaud S, Coto CA, Sun H, Lim KC, Lucas TH, Davis KA, Martinez-Lage M, Jensen FE. Mechanistic target of rapamycin complex 1 and 2 in human temporal lobe epilepsy. Ann Neurol 2018; 83:311-327. [PMID: 29331082 DOI: 10.1002/ana.25149] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 01/09/2018] [Accepted: 01/10/2018] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Temporal lobe epilepsy (TLE) is a chronic epilepsy syndrome defined by seizures and progressive neurological disabilities, including cognitive impairments, anxiety, and depression. Here, human TLE specimens were investigated focusing on the mechanistic target of rapamycin (mTOR) complex 1 (mTORC1) and complex 2 (mTORC2) activities in the brain, given that both pathways may represent unique targets for treatment. METHODS Surgically resected hippocampal and temporal lobe samples from therapy-resistant TLE patients were analyzed by western blotting to quantify the expression of established mTORC1 and mTORC2 activity markers and upstream or downstream signaling pathways involving the two complexes. Histological and immunohistochemical techniques were used to assess hippocampal and neocortical structural abnormalities and cell-specific expression of individual biomarkers. Samples from patients with focal cortical dysplasia (FCD) type II served as positive controls. RESULTS We found significantly increased expression of phospho-mTOR (Ser2448), phospho-S6 (Ser235/236), phospho-S6 (Ser240/244), and phospho-Akt (Ser473) in TLE samples compared to controls, consistent with activation of both mTORC1 and mTORC2. Our work identified the phosphoinositide 3-kinase and Ras/extracellular signal-regulated kinase signaling pathways as potential mTORC1 and mTORC2 upstream activators. In addition, we found that overactive mTORC2 signaling was accompanied by induction of two protein kinase B-dependent prosurvival pathways, as evidenced by increased inhibitory phosphorylation of forkhead box class O3a (Ser253) and glycogen synthase kinase 3 beta (Ser9). INTERPRETATION Our data demonstrate that mTOR signaling is significantly dysregulated in human TLE, offering new targets for pharmacological interventions. Specifically, clinically available drugs that suppress mTORC1 without compromising mTOR2 signaling, such as rapamycin and its analogs, may represent a new group of antiepileptogenic agents in TLE patients. Ann Neurol 2018;83:311-327.
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Affiliation(s)
- Delia M Talos
- Department of Neurology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA
| | - Leah M Jacobs
- Department of Neurology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA
| | - Sarah Gourmaud
- Department of Neurology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA
| | - Carlos A Coto
- Department of Neurology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA
| | - Hongyu Sun
- Department of Neurology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA.,Department of Neuroscience, Carleton University, Ottawa, ON, Canada
| | - Kuei-Cheng Lim
- Department of Neurology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA
| | - Timothy H Lucas
- Department of Neurosurgery, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA
| | - Kathryn A Davis
- Department of Neurology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA
| | - Maria Martinez-Lage
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA
| | - Frances E Jensen
- Department of Neurology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA
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13
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Xing FZ, Zhao YG, Zhang YY, He L, Zhao JK, Liu MY, Liu Y, Zhang JQ. Nuclear and membrane estrogen receptor antagonists induce similar mTORC2 activation-reversible changes in synaptic protein expression and actin polymerization in the mouse hippocampus. CNS Neurosci Ther 2018; 24:495-507. [PMID: 29352507 DOI: 10.1111/cns.12806] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 12/23/2017] [Accepted: 12/24/2017] [Indexed: 11/28/2022] Open
Abstract
AIMS Estrogens play pivotal roles in hippocampal synaptic plasticity through nuclear receptors (nERs; including ERα and ERβ) and the membrane receptor (mER; also called GPR30), but the underlying mechanism and the contributions of nERs and mER remain unclear. Mammalian target of rapamycin complex 2 (mTORC2) is involved in actin cytoskeleton polymerization and long-term memory, but whether mTORC2 is involved in the regulation of hippocampal synaptic plasticity by ERs is unclear. METHODS We treated animals with nER antagonists (MPP/PHTPP) or the mER antagonist (G15) alone or in combination with A-443654, an activator of mTORC2. Then, we examined the changes in hippocampal SRC-1 expression, mTORC2 signaling (rictor and phospho-AKTSer473), actin polymerization (phospho-cofilin and profilin-1), synaptic protein expression (GluR1, PSD95, spinophilin, and synaptophysin), CA1 spine density, and synapse density. RESULTS All of the examined parameters except synaptophysin expression were significantly decreased by MPP/PHTPP and G15 treatment. MPP/PHTPP and G15 induced a similar decrease in most parameters except p-cofilin, GluR1, and spinophilin expression. The ER antagonist-induced decreases in these parameters were significantly reversed by mTORC2 activation, except for the change in SRC-1, rictor, and synaptophysin expression. CONCLUSIONS nERs and mER contribute similarly to the changes in proteins and structures associated with synaptic plasticity, and mTORC2 may be a novel target of hippocampal-dependent dementia such as Alzheimer's disease as proposed by previous studies.
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Affiliation(s)
- Fang-Zhou Xing
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing, China
| | - Yan-Gang Zhao
- Department of Neurobiology, Third Military Medical University, Chongqing, China
| | - Yuan-Yuan Zhang
- Department of Neurobiology, Third Military Medical University, Chongqing, China
| | - Li He
- School of Nursing, Third Military Medical University, Chongqing, China
| | - Ji-Kai Zhao
- Department of Neurobiology, Third Military Medical University, Chongqing, China
| | - Meng-Ying Liu
- Department of Neurobiology, Third Military Medical University, Chongqing, China
| | - Yan Liu
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing, China
| | - Ji-Qiang Zhang
- Department of Neurobiology, Third Military Medical University, Chongqing, China
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14
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Zhao Y, He L, Zhang Y, Zhao J, Liu Z, Xing F, Liu M, Feng Z, Li W, Zhang J. Estrogen receptor alpha and beta regulate actin polymerization and spatial memory through an SRC-1/mTORC2-dependent pathway in the hippocampus of female mice. J Steroid Biochem Mol Biol 2017; 174:96-113. [PMID: 28789972 DOI: 10.1016/j.jsbmb.2017.08.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Revised: 07/29/2017] [Accepted: 08/03/2017] [Indexed: 12/18/2022]
Abstract
Aging-related decline of estrogens, especially 17β-estradiol (E2), has been shown to play an important role in the impairment of learning and memory in dementias, such as Alzheimer's disease (AD), but the underlying molecular mechanisms are poorly understood. In this study, we first demonstrated decreases in E2 signaling (aromatase, classic estrogen receptor ERα and ERβ and their coactivator SRC-1), mTORC2 signaling (Rictor and phospho-AKTser473) and actin polymerization (phospho-Cofilin, Profilin-1 and the F-actin/G-actin ratio) in the hippocampus of old female mice compared with those levels detected in the adult hippocampus. We then showed that ERα and ERβ antagonists induced a significant decrease in SRC-1, mTORC2 signaling, actin polymerization, and CA1 spine density, as well as impairments of learning and memory; however, ovariectomy-induced changes of these parameters could be significantly reversed by treatment with ER agonists. We further showed that expression of SRC-1, mTORC2 signaling and actin polymerization could be upregulated by E2 treatment, and the effects of E2 were blocked by the ER antagonists but mimicked by the agonists. We also showed that the lentivirus-mediated SRC-1 knockdown significantly inhibited the agonist-activated mTORC2 signaling and actin polymerization, and the lentivirus-mediated Rictor knockdown also significantly inhibited the agonist-activated actin polymerization. Finally, we demonstrated that the ERα and ERβ antagonists induced a disruption in actin polymerization and an impairment of spatial memory, which were rescued by activation of mTORC2. Taken together, the above results clearly demonstrated an mTORC2-dependent regulation of actin polymerization that contributed to the effects of ERα and ERβ on spatial learning, which may provide a novel target for the prevention and treatment of E2-related dementia in the aged population.
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Affiliation(s)
- Yangang Zhao
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing 400038, China
| | - Li He
- School of Nursing, Third Military Medical University, Chongqing 400038, China
| | - Yuanyuan Zhang
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing 400038, China
| | - Jikai Zhao
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing 400038, China
| | - Zhi Liu
- Department of Histology and Embryology, Third Military Medical University, Chongqing 400038, China
| | - Fangzhou Xing
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, Key Laboratory of Eco-Environments in Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Mengying Liu
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing 400038, China
| | - Ziqi Feng
- Cadet Brigade, Third Military Medical University, Chongqing 400038, China
| | - Wei Li
- School of Nursing, Third Military Medical University, Chongqing 400038, China.
| | - Jiqiang Zhang
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing 400038, China.
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15
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Increased GSNOR Expression during Aging Impairs Cognitive Function and Decreases S-Nitrosation of CaMKIIα. J Neurosci 2017; 37:9741-9758. [PMID: 28883020 DOI: 10.1523/jneurosci.0681-17.2017] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 07/27/2017] [Accepted: 08/03/2017] [Indexed: 11/21/2022] Open
Abstract
As the population ages, an increasing number of people suffer from age-related cognitive impairment. However, the mechanisms underlying this process remain unclear. Here, we found that S-nitrosoglutathione reductase (GSNOR), the key enzyme that metabolizes intracellular nitric oxide (NO) and regulates S-nitrosation, was significantly increased in the hippocampus of both aging humans and mice. Transgenic mice overexpressing GSNOR exclusively in neurons showed cognitive impairment in behavioral tests, including the Morris water maze, fear conditioning, and the Y-maze test. We also found that GSNOR transgenic mice have LTP defects and lower dendrite spine density, whereas GSNOR knock-out mice rescued the age-related cognitive impairment. Analysis of S-nitrosation showed significantly decreased hippocampal CaMKIIα S-nitrosation in naturally aged mice and GSNOR transgenic mice. Consistent with the change in CaMKIIα S-nitrosation, the accumulation of CaMKIIα in the hippocampal synaptosomal fraction, as well as its downstream signaling targets p(S831)-GLUR1, was also significantly decreased. All these effects could be rescued in the GSNOR knock-out mice. We further verified that the S-nitrosation of CaMKIIα was responsible for the CaMKIIα synaptosomal accumulation by mutating CaMKIIα S-nitrosated sites (C280/C289). Upregulation of the NO signaling pathway rescued the cognitive impairment in GSNOR transgenic mice. In summary, our research demonstrates that GSNOR impairs cognitive function in aging and it could serve as a new potential target for the treatment of age-related cognitive impairment. In contrast to the free radical theory of aging, NO signaling deficiency may be the main mediator of age-related cognitive impairment.SIGNIFICANCE STATEMENT This study indicated that S-nitrosoglutathione reductase (GSNOR), a key protein S-nitrosation metabolic enzyme, is a new potential target in age-related cognitive impairment; and in contrast to the free radical theory of aging, NO signaling deficiency may be the main cause of this process. In addition, increased GSNOR expression during aging decreases S-nitrosation of CaMKIIα and reduces CaMKIIα synaptosomal accumulation. To our knowledge, it is for the first time to show the cellular function regulation of CaMKIIα by GSNOR-dependent S-nitrosation as a new post-translational modification after its phosphorylation was explored. These findings elucidate a novel mechanism of age-related cognitive impairment and may provide a new potential target and strategy for slowing down this process.
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16
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Saul D, Ninkovic M, Komrakova M, Wolff L, Simka P, Gasimov T, Menger B, Hoffmann DB, Rohde V, Sehmisch S. Effect of zileuton on osteoporotic bone and its healing, expression of bone, and brain genes in rats. J Appl Physiol (1985) 2017; 124:118-130. [PMID: 28860177 DOI: 10.1152/japplphysiol.01126.2016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Estrogen deficiency and aging are associated with osteoporosis, impaired bone healing, and lower cognitive performance. Close functional and physical connections occur between bone and the central nervous system. An anti-inflammatory drug, zileuton (which is an inhibitor of arachidonate 5-lipoxygenase), is known to have a positive effect on bone tissue repair and brain ischemia. We studied the effect of zileuton on osteopenic bone and its healing and on the genes considered to be crucial for the cross talks between bone and brain. Three-month-old Sprague-Dawley rats were ovariectomized or left untreated. After 8 wk, bilateral metaphyseal tibia osteotomy with plate osteosynthesis was performed in all rats. Ovariectomized rats were fed with food containing zileuton (1, 10, or 100 mg/kg body wt) for 5 wk. In tibiae, bone volume, callus and cortical volume, and gene expression of osteocalcin and alkaline phosphatase were enhanced by zileuton (10 or 100 mg); biomechanical properties and bone density were not changed. In femur, zileuton enlarged cortical volume distal and trabecular volume proximal, decreasing their density. The expression level of brain Sema3a, known to regulate bone mass positively, was downregulated after ovariectomy. In contrast, bone Sema4d, a negative regulator of bone mass, was upregulated in the tibia callus after ovariectomy, whereas zileuton treatment (10 or 100 mg) resulted in reverse effects. Here, we describe for the first time the expression of Rbbp4 mRNA and its increase in tibia after ovariectomy. Zileuton caused downregulation of Rbbp4 in the hippocampus and had an effect on bone healing, changed the expression of genes involved in cross talk between bones and brain, and may be a potent drug for further examination in estrogen deficiency-related dysfunction(s). NEW & NOTEWORTHY Zileuton, a 5-lipoxygenase inhibitor, increased bone volume, callus and cortical volume in osteotomized tibia, and trabecular and cortical volume in femur. Although the expression of Sema3a (positively regulating bone mass) in brain was downregulated and Sema4d (negatively regulating bone mass) was upregulated in tibia callus after ovariectomy, zileuton could counteract these effects. Rbbp4 (involved in age-related memory loss) was increased in tibia callus after ovariectomy.
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Affiliation(s)
- D Saul
- Department of Trauma Surgery, Orthopaedics and Plastic Surgery, University Medical Center Göttingen , Göttingen , Germany
| | - M Ninkovic
- Department of Neurosurgery, University Medical Center Göttingen , Göttingen , Germany
| | - M Komrakova
- Department of Trauma Surgery, Orthopaedics and Plastic Surgery, University Medical Center Göttingen , Göttingen , Germany
| | - L Wolff
- Department of Trauma Surgery, Orthopaedics and Plastic Surgery, University Medical Center Göttingen , Göttingen , Germany
| | - P Simka
- Department of Trauma Surgery, Orthopaedics and Plastic Surgery, University Medical Center Göttingen , Göttingen , Germany
| | - T Gasimov
- Department of Neurosurgery, University Medical Center Göttingen , Göttingen , Germany
| | - B Menger
- Department of Trauma Surgery, Orthopaedics and Plastic Surgery, University Medical Center Göttingen , Göttingen , Germany
| | - D B Hoffmann
- Department of Trauma Surgery, Orthopaedics and Plastic Surgery, University Medical Center Göttingen , Göttingen , Germany
| | - V Rohde
- Department of Neurosurgery, University Medical Center Göttingen , Göttingen , Germany
| | - S Sehmisch
- Department of Trauma Surgery, Orthopaedics and Plastic Surgery, University Medical Center Göttingen , Göttingen , Germany
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Torday JS, Miller WB. The resolution of ambiguity as the basis for life: A cellular bridge between Western reductionism and Eastern holism. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2017; 131:288-297. [PMID: 28743585 DOI: 10.1016/j.pbiomolbio.2017.07.013] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 07/12/2017] [Accepted: 07/21/2017] [Indexed: 01/08/2023]
Abstract
Boundary conditions enable cellular life through negentropy, chemiosmosis, and homeostasis as identifiable First Principles of Physiology. Self-referential awareness of status arises from this organized state to sustain homeostatic imperatives. Preferred homeostatic status is dependent upon the appraisal of information and its communication. However, among living entities, sources of information and their dissemination are always imprecise. Consequently, living systems exist within an innate state of ambiguity. It is presented that cellular life and evolutionary development are a self-organizing cellular response to uncertainty in iterative conformity with its basal initiating parameters. Viewing the life circumstance in this manner permits a reasoned unification between Western rational reductionism and Eastern holism.
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Affiliation(s)
- John S Torday
- Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, CA 90502, USA.
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18
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Roesler R. Molecular mechanisms controlling protein synthesis in memory reconsolidation. Neurobiol Learn Mem 2017; 142:30-40. [DOI: 10.1016/j.nlm.2017.04.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 04/27/2017] [Accepted: 04/28/2017] [Indexed: 10/19/2022]
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Shivarama Shetty M, Sajikumar S. 'Tagging' along memories in aging: Synaptic tagging and capture mechanisms in the aged hippocampus. Ageing Res Rev 2017; 35:22-35. [PMID: 28065806 DOI: 10.1016/j.arr.2016.12.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 12/12/2016] [Accepted: 12/30/2016] [Indexed: 02/06/2023]
Abstract
Aging is accompanied by a general decline in the physiological functions of the body with the deteriorating organ systems. Brain is no exception to this and deficits in cognitive functions are quite common in advanced aging. Though a variety of age-related alterations are observed in the structure and function throughout the brain, certain regions show selective vulnerability. Medial temporal lobe, especially the hippocampus, is one such preferentially vulnerable region and is a crucial structure involved in the learning and long-term memory functions. Hippocampal synaptic plasticity, such as long-term potentiation (LTP) and depression (LTD), are candidate cellular correlates of learning and memory and alterations in these properties have been well documented in aging. A related phenomenon called synaptic tagging and capture (STC) has been proposed as a mechanism for cellular memory consolidation and to account for temporal association of memories. Mounting evidences from behavioral settings suggest that STC could be a physiological phenomenon. In this article, we review the recent data concerning STC and provide a framework for how alterations in STC-related mechanisms could contribute to the age-associated memory impairments. The enormity of impairment in learning and memory functions demands an understanding of age-associated memory deficits at the fundamental level given its impact in the everyday tasks, thereby in the quality of life. Such an understanding is also crucial for designing interventions and preventive measures for successful brain aging.
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Switon K, Kotulska K, Janusz-Kaminska A, Zmorzynska J, Jaworski J. Molecular neurobiology of mTOR. Neuroscience 2017; 341:112-153. [PMID: 27889578 DOI: 10.1016/j.neuroscience.2016.11.017] [Citation(s) in RCA: 277] [Impact Index Per Article: 39.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 11/09/2016] [Accepted: 11/13/2016] [Indexed: 01/17/2023]
Abstract
Mammalian/mechanistic target of rapamycin (mTOR) is a serine-threonine kinase that controls several important aspects of mammalian cell function. mTOR activity is modulated by various intra- and extracellular factors; in turn, mTOR changes rates of translation, transcription, protein degradation, cell signaling, metabolism, and cytoskeleton dynamics. mTOR has been repeatedly shown to participate in neuronal development and the proper functioning of mature neurons. Changes in mTOR activity are often observed in nervous system diseases, including genetic diseases (e.g., tuberous sclerosis complex, Pten-related syndromes, neurofibromatosis, and Fragile X syndrome), epilepsy, brain tumors, and neurodegenerative disorders (Alzheimer's disease, Parkinson's disease, and Huntington's disease). Neuroscientists only recently began deciphering the molecular processes that are downstream of mTOR that participate in proper function of the nervous system. As a result, we are gaining knowledge about the ways in which aberrant changes in mTOR activity lead to various nervous system diseases. In this review, we provide a comprehensive view of mTOR in the nervous system, with a special focus on the neuronal functions of mTOR (e.g., control of translation, transcription, and autophagy) that likely underlie the contribution of mTOR to nervous system diseases.
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Affiliation(s)
- Katarzyna Switon
- International Institute of Molecular and Cell Biology, 4 Ks. Trojdena Street, Warsaw 02-109, Poland
| | - Katarzyna Kotulska
- Department of Neurology and Epileptology, Children's Memorial Health Institute, Aleja Dzieci Polskich 20, Warsaw 04-730, Poland
| | | | - Justyna Zmorzynska
- International Institute of Molecular and Cell Biology, 4 Ks. Trojdena Street, Warsaw 02-109, Poland
| | - Jacek Jaworski
- International Institute of Molecular and Cell Biology, 4 Ks. Trojdena Street, Warsaw 02-109, Poland.
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Faus-Garriga J, Novoa I, Ozaita A. mTOR signaling in proteostasis and its relevance to autism spectrum disorders. AIMS BIOPHYSICS 2017. [DOI: 10.3934/biophy.2017.1.63] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Sun J, Liu Y, Tran J, O'Neal P, Baudry M, Bi X. mTORC1-S6K1 inhibition or mTORC2 activation improves hippocampal synaptic plasticity and learning in Angelman syndrome mice. Cell Mol Life Sci 2016; 73:4303-4314. [PMID: 27173058 PMCID: PMC5056144 DOI: 10.1007/s00018-016-2269-z] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 04/27/2016] [Accepted: 05/06/2016] [Indexed: 02/07/2023]
Abstract
Emerging evidence is implicating abnormal activation of the mechanistic target of rapamycin (mTOR) pathway in several monogenetic neuropsychiatric disorders, including Angelman syndrome (AS), which is caused by deficiency in maternally inherited UBE3A. Using an AS mouse model, we show that semi-chronic rapamycin treatment improves long-term potentiation (LTP) and actin polymerization in hippocampal slices, spine morphology, and fear-conditioning learning. Activity of mTORC1 and of its downstream substrate, S6K1, was increased in hippocampus of AS mice. However, mTORC2 activity, as reflected by PKCα levels, was decreased. Both increased mTORC1 and decreased mTORC2 activities were reversed by semi-chronic rapamycin treatment. Acute treatment of hippocampal slices from AS mice with rapamycin or an S6K1 inhibitor, PF4708671, improved LTP, restored actin polymerization, and normalized mTORC1 and mTORC2 activity. These treatments also reduced Arc levels in AS mice. Treatment with Torin 1, an inhibitor of both mTORC1 and mTORC2, partially rescued LTP and actin polymerization in hippocampal slices from AS mice, while partially impairing them in wild-type (WT) mice. Torin 1 decreased mTORC1 and increased mTORC2 activity in slices from AS mice but inhibited both mTORC1 and mTORC2 in WT mice. Finally, an mTORC2 activator, A-443654, increased hippocampal LTP in AS mice and actin polymerization in both WT and AS mice. Collectively, these results indicate that events set in motion by increased mTORC1 and decreased mTORC2 activities, including increased Arc translation and impaired actin remodeling, are crucial in AS pathogenesis. Therefore, selectively targeting these two master kinase complexes may provide new therapeutic approaches for AS treatment.
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Affiliation(s)
- Jiandong Sun
- Department of Basic Medical Sciences, COMP, Western University of Health Sciences, 701 E. Second Street, Pomona, CA, 91766-1854, USA
| | - Yan Liu
- Graduate College of Biomedical Sciences, Western University of Health Sciences, 701 E. Second Street, Pomona, CA, 91766, USA
| | - Jennifer Tran
- Department of Basic Medical Sciences, COMP, Western University of Health Sciences, 701 E. Second Street, Pomona, CA, 91766-1854, USA
| | - Patrick O'Neal
- Department of Basic Medical Sciences, COMP, Western University of Health Sciences, 701 E. Second Street, Pomona, CA, 91766-1854, USA
| | - Michel Baudry
- Graduate College of Biomedical Sciences, Western University of Health Sciences, 701 E. Second Street, Pomona, CA, 91766, USA
| | - Xiaoning Bi
- Department of Basic Medical Sciences, COMP, Western University of Health Sciences, 701 E. Second Street, Pomona, CA, 91766-1854, USA.
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