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López-Aranda MF, Bach K, Bui R, Phan M, Lu O, Thadani C, Luchetti A, Mandanas R, Herrera I, López-Ávalos MD, Silva AJ. Early Post-Natal Immune Activation Leads to Object Memory Deficits in Female Tsc2+/- Mice: The Importance of Including Both Sexes in Neuroscience Research. Biomedicines 2024; 12:203. [PMID: 38255309 PMCID: PMC10813674 DOI: 10.3390/biomedicines12010203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Revised: 12/19/2023] [Accepted: 12/22/2023] [Indexed: 01/24/2024] Open
Abstract
There is evidence that viral infections during pre-natal development constitute a risk factor for neuropsychiatric disorders and lead to learning and memory deficits. However, little is known about why viral infections during early post-natal development have a different impact on learning and memory depending on the sex of the subject. We previously showed that early post-natal immune activation induces hippocampal-dependent social memory deficits in a male, but not in a female, mouse model of tuberous sclerosis complex (TSC; Tsc2+/- mice). Here, we explored the impact of a viral-like immune challenge in object memory. We demonstrate that early post-natal immune activation (during the first 2 weeks of life) leads to object memory deficits in female, but not male, mice that are heterozygous for a gene responsible for tuberous sclerosis complex (Tsc2+/- mice), while no effect was observed in wild type (WT) mice. Moreover, we found that the same immune activation in Tsc2+/- adult mice was not able to cause object memory deficits in females, which suggests that the early post-natal development stage constitutes a critical window for the effects of immune challenge on adult memory. Also, our results suggest that mTOR plays a critical role in the observed deficit in object memory in female Tsc2+/- mice. These results, together with previous results published by our laboratory, showing sex-specific memory deficits due to early post-natal immune activation, reinforce the necessity of using both males and females for research studies. This is especially true for studies related to immune activation, since the higher levels of estrogens in females are known to affect inflammation and to provide neuroprotection.
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Affiliation(s)
- Manuel F. López-Aranda
- Departamento de Biología Celular, Genética y Fisiología, Facultad de Ciencias, Universidad de Málaga, 29010 Málaga, Spain
- Departments of Neurobiology, Psychology, Psychiatry, Integrative Center for Learning and Memory and Brain Research Institute, University of California Los Angeles, Los Angeles, CA 90095, USA (A.J.S.)
- Instituto de Investigación Biomédica de Málaga (IBIMA)-Plataforma BIONAND, 29590 Málaga, Spain
| | - Karen Bach
- Departments of Neurobiology, Psychology, Psychiatry, Integrative Center for Learning and Memory and Brain Research Institute, University of California Los Angeles, Los Angeles, CA 90095, USA (A.J.S.)
| | - Raymond Bui
- Departments of Neurobiology, Psychology, Psychiatry, Integrative Center for Learning and Memory and Brain Research Institute, University of California Los Angeles, Los Angeles, CA 90095, USA (A.J.S.)
| | - Miranda Phan
- Departments of Neurobiology, Psychology, Psychiatry, Integrative Center for Learning and Memory and Brain Research Institute, University of California Los Angeles, Los Angeles, CA 90095, USA (A.J.S.)
| | - Odilia Lu
- Departments of Neurobiology, Psychology, Psychiatry, Integrative Center for Learning and Memory and Brain Research Institute, University of California Los Angeles, Los Angeles, CA 90095, USA (A.J.S.)
| | - Chirag Thadani
- Departments of Neurobiology, Psychology, Psychiatry, Integrative Center for Learning and Memory and Brain Research Institute, University of California Los Angeles, Los Angeles, CA 90095, USA (A.J.S.)
| | - Alessandro Luchetti
- Departments of Neurobiology, Psychology, Psychiatry, Integrative Center for Learning and Memory and Brain Research Institute, University of California Los Angeles, Los Angeles, CA 90095, USA (A.J.S.)
| | - Rochelle Mandanas
- Departments of Neurobiology, Psychology, Psychiatry, Integrative Center for Learning and Memory and Brain Research Institute, University of California Los Angeles, Los Angeles, CA 90095, USA (A.J.S.)
| | - Isaiah Herrera
- Departments of Neurobiology, Psychology, Psychiatry, Integrative Center for Learning and Memory and Brain Research Institute, University of California Los Angeles, Los Angeles, CA 90095, USA (A.J.S.)
| | - María Dolores López-Ávalos
- Departamento de Biología Celular, Genética y Fisiología, Facultad de Ciencias, Universidad de Málaga, 29010 Málaga, Spain
- Instituto de Investigación Biomédica de Málaga (IBIMA)-Plataforma BIONAND, 29590 Málaga, Spain
| | - Alcino J. Silva
- Departments of Neurobiology, Psychology, Psychiatry, Integrative Center for Learning and Memory and Brain Research Institute, University of California Los Angeles, Los Angeles, CA 90095, USA (A.J.S.)
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Scheper M, Romagnolo A, Besharat ZM, Iyer AM, Moavero R, Hertzberg C, Weschke B, Riney K, Feucht M, Scholl T, Petrak B, Maulisova A, Nabbout R, Jansen AC, Jansen FE, Lagae L, Urbanska M, Ferretti E, Tempes A, Blazejczyk M, Jaworski J, Kwiatkowski DJ, Jozwiak S, Kotulska K, Sadowski K, Borkowska J, Curatolo P, Mills JD, Aronica E. miRNAs and isomiRs: Serum-Based Biomarkers for the Development of Intellectual Disability and Autism Spectrum Disorder in Tuberous Sclerosis Complex. Biomedicines 2022; 10:biomedicines10081838. [PMID: 36009385 PMCID: PMC9405248 DOI: 10.3390/biomedicines10081838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 07/22/2022] [Accepted: 07/28/2022] [Indexed: 11/16/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is a rare multi-system genetic disorder characterized by a high incidence of epilepsy and neuropsychiatric manifestations known as tuberous-sclerosis-associated neuropsychiatric disorders (TANDs), including autism spectrum disorder (ASD) and intellectual disability (ID). MicroRNAs (miRNAs) are small regulatory non-coding RNAs that regulate the expression of more than 60% of all protein-coding genes in humans and have been reported to be dysregulated in several diseases, including TSC. In the current study, RNA sequencing analysis was performed to define the miRNA and isoform (isomiR) expression patterns in serum. A Receiver Operating Characteristic (ROC) curve analysis was used to identify circulating molecular biomarkers, miRNAs, and isomiRs, able to discriminate the development of neuropsychiatric comorbidity, either ASD, ID, or ASD + ID, in patients with TSC. Part of our bioinformatics predictions was verified with RT-qPCR performed on RNA isolated from patients’ serum. Our results support the notion that circulating miRNAs and isomiRs have the potential to aid standard clinical testing in the early risk assessment of ASD and ID development in TSC patients.
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Affiliation(s)
- Mirte Scheper
- Department of (Neuro)Pathology Amsterdam Neuroscience, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands; (M.S.); (A.R.); (A.M.I.)
| | - Alessia Romagnolo
- Department of (Neuro)Pathology Amsterdam Neuroscience, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands; (M.S.); (A.R.); (A.M.I.)
| | - Zein Mersini Besharat
- Department of Experimental Medicine, Sapienza University of Rome, 00161 Rome, Italy; (Z.M.B.); (E.F.)
| | - Anand M. Iyer
- Department of (Neuro)Pathology Amsterdam Neuroscience, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands; (M.S.); (A.R.); (A.M.I.)
- Internal Medicine, Erasmus MC, 3015 GD Rotterdam, The Netherlands
| | - Romina Moavero
- Child Neurology and Psychiatry Unit, Systems Medicine Department, Tor Vergata University, 00133 Rome, Italy; (R.M.); (P.C.)
- Child Neurology Unit, Neuroscience Department, Bambino Gesù Children’s Hospital, IRCCS, 00165 Rome, Italy
| | - Christoph Hertzberg
- Diagnose-und Behandlungszentrum für Kinder, Vivantes-Klinikum Neukölln, 12351 Berlin, Germany;
| | - Bernhard Weschke
- Department of Neuropediatrics, Charité University Medicine Berlin, 13353 Berlin, Germany;
| | - Kate Riney
- Faculty of Medicine, The University of Queensland, Herston, QLD 4029, Australia;
- Neurosciences Unit, Queensland Children’s Hospital, South Brisbane, QLD 4101, Australia
| | - Martha Feucht
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, “Member of ERN EpiCARE”, 1090 Vienna, Austria; (M.F.); (T.S.)
| | - Theresa Scholl
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, “Member of ERN EpiCARE”, 1090 Vienna, Austria; (M.F.); (T.S.)
| | - Borivoj Petrak
- Motol University Hospital, Charles University, 15000 Prague, Czech Republic; (B.P.); (A.M.)
| | - Alice Maulisova
- Motol University Hospital, Charles University, 15000 Prague, Czech Republic; (B.P.); (A.M.)
| | - Rima Nabbout
- Reference Centre for Rare Epilepsies, Department of Pediatric Neurology, Necker Enfants Malades University Hospital, APHP, Member of ERN EpiCARE, Université de Paris, 149 Rue de Sèvres, 75015 Paris, France;
| | - Anna C. Jansen
- Department of Translational Neurosciences, University of Antwerp, 2000 Antwerp, Belgium;
| | - Floor E. Jansen
- Department of Child Neurology, Brain Center University Medical Center, Member of ERN EpiCare, 3584 BA Utrecht, The Netherlands;
| | - Lieven Lagae
- Department of Development and Regeneration Section Pediatric Neurology, University Hospitals KU Leuven, 3000 Leuven, Belgium;
| | - Malgorzata Urbanska
- Department of Neurology and Epileptology, The Children’s Memorial Health Institute, 04-730 Warsaw, Poland; (M.U.); (S.J.); (K.K.); (K.S.); (J.B.)
| | - Elisabetta Ferretti
- Department of Experimental Medicine, Sapienza University of Rome, 00161 Rome, Italy; (Z.M.B.); (E.F.)
| | - Aleksandra Tempes
- International Institute of Molecular and Cell Biology, 02-109 Warsaw, Poland; (A.T.); (M.B.); (J.J.)
| | - Magdalena Blazejczyk
- International Institute of Molecular and Cell Biology, 02-109 Warsaw, Poland; (A.T.); (M.B.); (J.J.)
| | - Jacek Jaworski
- International Institute of Molecular and Cell Biology, 02-109 Warsaw, Poland; (A.T.); (M.B.); (J.J.)
| | | | - Sergiusz Jozwiak
- Department of Neurology and Epileptology, The Children’s Memorial Health Institute, 04-730 Warsaw, Poland; (M.U.); (S.J.); (K.K.); (K.S.); (J.B.)
- Department of Child Neurology, Medical University of Warsaw, 02-097 Warsaw, Poland
| | - Katarzyna Kotulska
- Department of Neurology and Epileptology, The Children’s Memorial Health Institute, 04-730 Warsaw, Poland; (M.U.); (S.J.); (K.K.); (K.S.); (J.B.)
| | - Krzysztof Sadowski
- Department of Neurology and Epileptology, The Children’s Memorial Health Institute, 04-730 Warsaw, Poland; (M.U.); (S.J.); (K.K.); (K.S.); (J.B.)
| | - Julita Borkowska
- Department of Neurology and Epileptology, The Children’s Memorial Health Institute, 04-730 Warsaw, Poland; (M.U.); (S.J.); (K.K.); (K.S.); (J.B.)
| | - Paolo Curatolo
- Child Neurology and Psychiatry Unit, Systems Medicine Department, Tor Vergata University, 00133 Rome, Italy; (R.M.); (P.C.)
| | - James D. Mills
- Department of (Neuro)Pathology Amsterdam Neuroscience, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands; (M.S.); (A.R.); (A.M.I.)
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London WC1E 6BT, UK
- Chalfont Centre for Epilepsy, Chalfont St Peter SL9 0RJ, UK
- Correspondence: (J.D.M.); (E.A.)
| | - Eleonora Aronica
- Department of (Neuro)Pathology Amsterdam Neuroscience, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands; (M.S.); (A.R.); (A.M.I.)
- Correspondence: (J.D.M.); (E.A.)
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López-Aranda MF, Boxx GM, Phan M, Bach K, Mandanas R, Herrera I, Taloma S, Thadani C, Lu O, Bui R, Liu S, Li N, Zhou Y, Cheng G, Silva AJ. Role of type I interferon signaling and microglia in the abnormal long term potentiation and object place recognition deficits of male mice with a mutation of the Tuberous Sclerosis 2 gene. BIOLOGICAL PSYCHIATRY GLOBAL OPEN SCIENCE 2022. [PMID: 37519458 PMCID: PMC10382699 DOI: 10.1016/j.bpsgos.2022.03.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Background Tuberous sclerosis complex is a genetic disorder associated with high rates of intellectual disability and autism. Mice with a heterozygous null mutation of the Tsc2 gene (Tsc2+/-) show deficits in hippocampal-dependent tasks and abnormal long-term potentiation (LTP) in the hippocampal CA1 region. Although previous studies focused on the role of neuronal deficits in the memory phenotypes of rodent models of tuberous sclerosis complex, the results presented here demonstrate a role for microglia in these deficits. Methods To test the possible role of microglia and type I interferon in abnormal hippocampal-dependent memory and LTP of Tsc2+/- mice, we used field recordings in CA1 and the object place recognition (OPR) task. We used the colony stimulating factor 1 receptor inhibitor PLX5622 to deplete microglia in Tsc2+/- mice and interferon alpha/beta receptor alpha chain null mutation (Ifnar1-/-) to manipulate a signaling pathway known to modulate microglia function. Results Unexpectedly, we demonstrate that male, but not female, Tsc2+/- mice show OPR deficits. These deficits can be rescued by depletion of microglia and by the Ifnar1-/- mutation. In addition to rescuing OPR deficits, depletion of microglia also reversed abnormal LTP of the Tsc2+/- mice. Altogether, our results suggest that altered IFNAR1 signaling in microglia causes the abnormal LTP and OPR deficits of male Tsc2+/- mice. Conclusions Microglia and IFNAR1 signaling have a key role in the hippocampal-dependent memory deficits and abnormal hippocampal LTP of Tsc2+/- male mice.
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N-acetylcysteine aggravates seizures while improving depressive-like and cognitive impairment comorbidities in the WAG/Rij rat model of absence epilepsy. Mol Neurobiol 2022; 59:2702-2714. [PMID: 35167014 DOI: 10.1007/s12035-021-02720-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 12/23/2021] [Indexed: 12/12/2022]
Abstract
N-acetylcysteine (NAC) is an antioxidant with some demonstrated efficacy in a range of neuropsychiatric disorders. NAC has shown anticonvulsant effects in animal models. NAC effects on absence seizures are still not uncovered, and considering its clinical use as a mucolytic in patients with lung diseases, people with epilepsy are also likely to be exposed to the drug. Therefore, we aimed to study the effects of NAC on absence seizures in the WAG/Rij rat model of absence epilepsy with neuropsychiatric comorbidities. The effects of NAC chronic treatment in WAG/Rij rats were evaluated on: absence seizures at 15 and 30 days by EEG recordings and animal behaviour at 30 days on neuropsychiatric comorbidities. Furthermore, the mechanism of action of NAC was evaluated by analysing brain expression levels of some possible key targets: the excitatory amino acid transporter 2, cystine-glutamate antiporter, metabotropic glutamate receptor 2, the mechanistic target of rapamycin and p70S6K as well as levels of total glutathione. Our results demonstrate that in WAG/Rij rats, NAC treatment significantly increased the number and duration of SWDs, aggravating absence epilepsy while ameliorating neuropsychiatric comorbidities. NAC treatment was linked to an increase in brain mGlu2 receptor expression with this being likely responsible for the observed absence seizure-promoting effects. In conclusion, while confirming the positive effects on animal behaviour induced by NAC also in epileptic animals, we report the aggravating effects of NAC on absence seizures which could have some serious consequences for epilepsy patients with the possible wider use of NAC in clinical therapeutics.
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Fidalgo da Silva E, Fong J, Roye-Azar A, Nadi A, Drouillard C, Pillon A, Porter LA. Beyond Protein Synthesis; The Multifaceted Roles of Tuberin in Cell Cycle Regulation. Front Cell Dev Biol 2022; 9:806521. [PMID: 35096832 PMCID: PMC8795880 DOI: 10.3389/fcell.2021.806521] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 12/16/2021] [Indexed: 12/13/2022] Open
Abstract
The ability of cells to sense diverse environmental signals, including nutrient availability and conditions of stress, is critical for both prokaryotes and eukaryotes to mount an appropriate physiological response. While there is a great deal known about the different biochemical pathways that can detect and relay information from the environment, how these signals are integrated to control progression through the cell cycle is still an expanding area of research. Over the past three decades the proteins Tuberin, Hamartin and TBC1D7 have emerged as a large protein complex called the Tuberous Sclerosis Complex. This complex can integrate a wide variety of environmental signals to control a host of cell biology events including protein synthesis, cell cycle, protein transport, cell adhesion, autophagy, and cell growth. Worldwide efforts have revealed many molecular pathways which alter Tuberin post-translationally to convey messages to these important pathways, with most of the focus being on the regulation over protein synthesis. Herein we review the literature supporting that the Tuberous Sclerosis Complex plays a critical role in integrating environmental signals with the core cell cycle machinery.
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Affiliation(s)
| | | | | | | | | | | | - L. A. Porter
- Department of Biomedical Sciences, University of Windsor, Windsor, ON, Canada
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Uddin MS, Rahman MA, Kabir MT, Behl T, Mathew B, Perveen A, Barreto GE, Bin-Jumah MN, Abdel-Daim MM, Ashraf GM. Multifarious roles of mTOR signaling in cognitive aging and cerebrovascular dysfunction of Alzheimer's disease. IUBMB Life 2020; 72:1843-1855. [PMID: 32472959 DOI: 10.1002/iub.2324] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 05/10/2020] [Accepted: 05/13/2020] [Indexed: 12/19/2022]
Abstract
Age-related cognitive failure is a main devastating incident affecting even healthy people. Alzheimer's disease (AD) is the utmost common form of dementia among the geriatric community. In the pathogenesis of AD, cerebrovascular dysfunction is revealed before the beginning of the cognitive decline. Mounting proof shows a precarious impact of cerebrovascular dysregulation in the development of AD pathology. Recent studies document that the mammalian target of rapamycin (mTOR) acts as a crucial effector of cerebrovascular dysregulation in AD. The mTOR contributes to brain vascular dysfunction and subsequence cerebral blood flow deficits as well as cognitive impairment. Furthermore, mTOR causes the blood-brain barrier (BBB) breakdown in AD models. Inhibition of mTOR hyperactivity protects the BBB integrity in AD. Furthermore, mTOR drives cognitive defect and cerebrovascular dysfunction, which are greatly prevalent in AD, but the central molecular mechanisms underlying these alterations are obscure. This review represents the crucial and current research findings regarding the role of mTOR signaling in cognitive aging and cerebrovascular dysfunction in the pathogenesis of AD.
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Affiliation(s)
- Md Sahab Uddin
- Department of Pharmacy, Southeast University, Dhaka, Bangladesh.,Pharmakon Neuroscience Research Network, Dhaka, Bangladesh
| | - Md Ataur Rahman
- Center for Neuroscience, Brain Science Institute, Korea Institute of Science and Technology, Seoul, Republic of Korea
| | | | - Tapan Behl
- Chitkara College of Pharmacy, Chitkara University, Patiala, India
| | - Bijo Mathew
- Division of Drug Design and Medicinal Chemistry Research Lab, Department of Pharmaceutical Chemistry, Ahalia School of Pharmacy, Palakkad, India
| | - Asma Perveen
- Glocal School of Life Sciences, Glocal University, Saharanpur, India
| | - George E Barreto
- Department of Biological Sciences, University of Limerick, Limerick, Ireland.,Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago, Chile
| | - May N Bin-Jumah
- Department of Biology, College of Science, Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia
| | - Mohamed M Abdel-Daim
- Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia.,Pharmacology Department, Faculty of Veterinary Medicine, Suez Canal University, Ismailia, Egypt
| | - Ghulam Md Ashraf
- King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia.,Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
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Lee J, Lunde-Young R, Naik V, Ramirez J, Orzabal M, Ramadoss J. Chronic Binge Alcohol Exposure During Pregnancy Alters mTOR System in Rat Fetal Hippocampus. Alcohol Clin Exp Res 2020; 44:1329-1336. [PMID: 32333810 DOI: 10.1111/acer.14348] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 04/10/2020] [Accepted: 04/19/2020] [Indexed: 01/04/2023]
Abstract
BACKGROUND Gestational alcohol exposure can contribute to fetal alcohol spectrum disorders (FASD), an array of cognitive, behavioral, and physical developmental impairments. Mammalian target of rapamycin (mTOR) plays a key role in regulating protein synthesis in response to neuronal activity, thereby modulating synaptic plasticity and long-term memory formation in the brain. Based on our previous quantitative mass spectrometry proteomic studies, we hypothesized that gestational chronic binge alcohol exposure alters mTOR signaling and downstream pathways in the fetal hippocampus. METHODS Pregnant Sprague-Dawley rats were assigned to either a pair-fed control (PF-Cont) or a binge alcohol (Alcohol) treatment group. Alcohol dams were acclimatized via a once-daily orogastric gavage of 4.5 g/kg alcohol (peak BAC, 216 mg/dl) from GD 5-10 and progressed to 6 g/kg alcohol (peak BAC, 289 mg/dl) from GD 11-21. Pair-fed dams similarly received isocaloric maltose dextrin. RESULTS In the Alcohol group, following this exposure paradigm, fetal body weight and crown-rump length were decreased. The phosphorylation level of mTOR (P-mTOR) in the fetal hippocampus was decreased in the Alcohol group compared with controls. Alcohol exposure resulted in dysregulation of fetal hippocampal mTORC1 signaling, as evidenced by an increase in total 4E-BP1 expression. Phosphorylation levels of 4E-BP1 and p70 S6K were also increased following alcohol exposure. P-mTOR and P-4E-BP1 were exclusively detected in the dentate gyrus and oriens layer of the fetal hippocampus, respectively. DEPTOR and RICTOR expression levels in the fetal hippocampus were increased; however, RAPTOR was not altered by chronic binge alcohol exposure. CONCLUSION We conclude that chronic binge alcohol exposure during pregnancy alters mTORC1 signaling pathway in the fetal hippocampus. We conjecture that this dysregulation of mTOR protein expression, its activity, and downstream proteins may play a critical role in FASD neurobiological phenotypes.
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Affiliation(s)
- Jehoon Lee
- From the, Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Raine Lunde-Young
- From the, Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Vishal Naik
- From the, Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Josue Ramirez
- From the, Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Marcus Orzabal
- From the, Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Jayanth Ramadoss
- From the, Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
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O’Brien AM, Bayet L, Riley K, Nelson CA, Sahin M, Modi ME. Auditory Processing of Speech and Tones in Children With Tuberous Sclerosis Complex. Front Integr Neurosci 2020; 14:14. [PMID: 32327979 PMCID: PMC7161665 DOI: 10.3389/fnint.2020.00014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 03/05/2020] [Indexed: 11/17/2022] Open
Abstract
Individuals with Tuberous Sclerosis Complex (TSC) have atypical white matter integrity and neural connectivity in the brain, including language pathways. To explore functional activity associated with auditory and language processing in individuals with TSC, we used electroencephalography (EEG) to examine basic auditory correlates of detection (P1, N2, N4) and discrimination (mismatch negativity, MMN) of speech and non-speech stimuli for children with TSC and age- and sex-matched typically developing (TD) children. Children with TSC (TSC group) and without TSC (typically developing, TD group) participated in an auditory MMN paradigm containing two blocks of vowels (/a/and/u/) and two blocks of tones (800 Hz and 400 Hz). Continuous EEG data were collected. Multivariate pattern analysis (MVPA) was used to explore functional specificity of neural auditory processing. Speech-specific P1, N2, and N4 waveform components of the auditory evoked potential (AEP) were compared, and the mismatch response was calculated for both speech and tones. MVPA showed that the TD group, but not the TSC group, demonstrated above-chance pairwise decoding between speech and tones. The AEP component analysis suggested that while the TD group had an increased P1 amplitude in response to vowels compared to tones, the TSC group did not show this enhanced response to vowels. Additionally, the TD group had a greater N2 amplitude in response to vowels, but not tones, compared to the TSC group. The TSC group also demonstrated a longer N4 latency to vowels compared to tones, which was not seen in the TD group. No group differences were observed in the MMN response. In this study we identified features of the auditory response to speech sounds, but not acoustically matched tones, which differentiate children with TSC from TD children.
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Affiliation(s)
- Amanda M. O’Brien
- Program in Speech and Hearing Bioscience and Technology, Division of Medical Sciences, Harvard University, Cambridge, MA, United States
| | - Laurie Bayet
- Department of Psychology, American University, Washington, DC, United States
| | - Katherine Riley
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Boston Children’s Hospital, Boston, MA, United States
| | - Charles A. Nelson
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Boston Children’s Hospital, Boston, MA, United States
- Harvard Graduate School of Education, Harvard University, Cambridge, MA, United States
| | - Mustafa Sahin
- Translational Neuroscience Center, Boston Children’s Hospital, Boston, MA, United States
- Department of Neurology, Harvard Medical School, Boston, MA, United States
| | - Meera E. Modi
- Translational Neuroscience Center, Boston Children’s Hospital, Boston, MA, United States
- Department of Neurology, Harvard Medical School, Boston, MA, United States
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9
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Structural and molecular correlates of cognitive aging in the rat. Sci Rep 2019; 9:2005. [PMID: 30765864 PMCID: PMC6376121 DOI: 10.1038/s41598-019-39645-w] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 06/01/2018] [Indexed: 12/12/2022] Open
Abstract
Aging is associated with cognitive decline. Herein, we studied a large cohort of old age and young adult male rats and confirmed that, as a group, old rats display poorer spatial learning and behavioral flexibility than younger adults. Surprisingly, when animals were clustered as good and bad performers, our data revealed that while in younger animals better cognitive performance was associated with longer dendritic trees and increased levels of synaptic markers in the hippocampus and prefrontal cortex, the opposite was found in the older group, in which better performance was associated with shorter dendrites and lower levels of synaptic markers. Additionally, in old, but not young individuals, worse performance correlated with increased levels of BDNF and the autophagy substrate p62, but decreased levels of the autophagy complex protein LC3. In summary, while for younger individuals “bigger is better”, “smaller is better” is a more appropriate aphorism for older subjects.
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10
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Sugimoto N, Katakura M, Matsuzaki K, Sumiyoshi E, Yachie A, Shido O. Chronic administration of theobromine inhibits mTOR signal in rats. Basic Clin Pharmacol Toxicol 2018; 124:575-581. [PMID: 30451374 DOI: 10.1111/bcpt.13175] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 11/12/2018] [Indexed: 12/23/2022]
Abstract
Theobromine is a caffeine derivative and the primary methylxanthine in Theobroma cacao. We have shown previously that theobromine inhibits the Akt-mammalian target of rapamycin (mTOR) signal in vitro. In this study, we investigated whether orally administered theobromine could inhibit mTOR activity in rats. mTOR is phosphorylated by Akt. Thus, the level of phosphorylated mTOR was used as an index of mTOR activity. Male Wistar rats were divided into two groups. The control group (CN) was fed a normal diet, while the theobromine group (TB) was fed a diet supplemented with 0.05% theobromine for 40 days. We measured body-weights and tissue weights, food and water intake, blood count, concentrations of theobromine in the plasma, liver and brain, and the levels of phosphorylated mTOR in the liver and brain. Orally administered theobromine did not affect the body-weights and tissue weights, food and water intake, and blood count as determined by comparison with levels in rats that were fed standard chow. Theobromine was detected in the plasma, liver and brain obtained from TB rats, but was not detected in tissues obtained from CN rats. The phosphorylated mTOR levels in the liver and brain were significantly lower in TB rats than in CN rats. The results suggest that oral theobromine inhibits mTOR signalling in vivo.
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Affiliation(s)
- Naotoshi Sugimoto
- Department of Physiology, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan.,Department of Environmental Physiology, School of Medicine, Shimane University, Izumo, Japan.,Department of Pediatrics, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan
| | - Masanori Katakura
- Department of Environmental Physiology, School of Medicine, Shimane University, Izumo, Japan.,Department of Nutritional Physiology, Faculty of Pharmaceutical Sciences, Josai University, Sakado, Japan
| | - Kentaro Matsuzaki
- Department of Environmental Physiology, School of Medicine, Shimane University, Izumo, Japan
| | - Eri Sumiyoshi
- Department of Environmental Physiology, School of Medicine, Shimane University, Izumo, Japan
| | - Akihiro Yachie
- Department of Pediatrics, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan
| | - Osamu Shido
- Department of Environmental Physiology, School of Medicine, Shimane University, Izumo, Japan
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11
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de Vries PJ, Belousova E, Benedik MP, Carter T, Cottin V, Curatolo P, Dahlin M, D'Amato L, d'Augères GB, Ferreira JC, Feucht M, Fladrowski C, Hertzberg C, Jozwiak S, Kingswood JC, Lawson JA, Macaya A, Marques R, Nabbout R, O'Callaghan F, Qin J, Sander V, Sauter M, Shah S, Takahashi Y, Touraine R, Youroukos S, Zonnenberg B, Jansen AC. TSC-associated neuropsychiatric disorders (TAND): findings from the TOSCA natural history study. Orphanet J Rare Dis 2018; 13:157. [PMID: 30201051 PMCID: PMC6131901 DOI: 10.1186/s13023-018-0901-8] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 08/29/2018] [Indexed: 12/21/2022] Open
Abstract
Background Most evidence for TSC-associated neuropsychiatric disorders (TAND) to date have come from small studies and case reports, and very little is known about TAND in adults. We explored baseline TAND data from the large-scale international TOSCA natural history study to compare childhood and adult patterns, describe age-based patterns, and explore genotype-TAND correlations. Results The study enrolled 2216 eligible participants with TSC from 170 sites across 31 countries at the data cut-off for the third interim analysis (data cut-off date: September 30, 2015). The most common behavioural problems (reported in > 10% of participants) were overactivity, sleep difficulties, impulsivity, anxiety, mood swings, severe aggression, depressed mood, self-injury, and obsessions. Psychiatric disorders included autism spectrum disorder (ASD, 21.1%), attention deficit hyperactivity disorder (ADHD, 19.1%), anxiety disorder (9.7%), and depressive disorder (6.1%). Intelligence quotient (IQ) scores were available for 885 participants. Of these, 44.4% had normal IQ, while mild, moderate, severe, and profound degrees of intellectual disability (ID) were observed in 28.1, 15.1, 9.3, and 3.1%, respectively. Academic difficulties were identified in 58.6% of participants, and neuropsychological deficits (performance <5th percentile) in 55.7%. Significantly higher rates of overactivity and impulsivity were observed in children and higher rates of anxiety, depressed mood, mood swings, obsessions, psychosis and hallucinations were observed in adults. Genotype-TAND correlations showed a higher frequency of self-injury, ASD, academic difficulties and neuropsychological deficits in TSC2. Those with no mutations identified (NMI) showed a mixed pattern of TAND manifestations. Children and those with TSC2 had significantly higher rates of intellectual disability, suggesting that age and genotype comparisons should be interpreted with caution. Conclusions These results emphasize the magnitude of TAND in TSC and the importance of evaluating for neuropsychiatric comorbidity in all children and adults with TSC, across TSC1 and TSC2 genotypes, as well as in those with no mutations identified. However, the high rates of unreported or missing TAND data in this study underline the fact that, even in expert centres, TAND remains underdiagnosed and potentially undertreated.
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Affiliation(s)
- Petrus J de Vries
- Division of Child and Adolescent Psychiatry, University of Cape Town, 46 Sawkins Road, Rondebosch, Cape Town, 7700, South Africa.
| | - Elena Belousova
- Research and Clinical Institute of Pediatrics, Pirogov Russian National Research Medical University, Moscow, Russian Federation
| | | | - Tom Carter
- TSA Tuberous Sclerosis Association, Nottingham, UK
| | - Vincent Cottin
- Hôpital Louis Pradel, Claude Bernard University Lyon 1, Lyon, France
| | | | - Maria Dahlin
- Karolinska University Hospital, Stockholm, Sweden
| | | | | | | | - Martha Feucht
- Universitätsklinik für Kinder-und Jugendheilkunde, Vienna, Austria
| | - Carla Fladrowski
- Associazione Sclerosi Tuberosa ONLUS, Milan, Italy.,European Tuberous Sclerosis Complex Association, In den Birken, Dattein, Germany
| | | | - Sergiusz Jozwiak
- Department of Child Neurology, Warsaw Medical University, Warsaw, Poland
| | | | - John A Lawson
- The Tuberous Sclerosis Multidisciplinary Management Clinic, Sydney Children's Hospital, Randwick, NSW, Australia
| | - Alfons Macaya
- Hospital Universitari Vall d'Hebron, Barcelona, Spain
| | - Ruben Marques
- Novartis Farma S.p.A, Origgio, Italy.,Institute of Biomedicine, University of Leon, Leon, Spain
| | - Rima Nabbout
- Department of Pediatric Neurology, Necker Enfants Malades Hospital, Paris Descartes University, Paris, France
| | | | - Jiong Qin
- Department of Pediatrics, Peking University People's Hospital (PKUPH), Beijing, China
| | | | | | - Seema Shah
- Novartis Healthcare Pvt. Ltd, Hyderabad, India
| | - Yukitoshi Takahashi
- National Epilepsy Center, Shizuoka Institute of Epilepsy and Neurological Disorders, NHO, 886 Urushiyama, Aoi-ku, Shizuoka, Japan
| | | | | | | | - Anna C Jansen
- UZ Brussel Vrije Universiteit Brussel, Brussels, Belgium
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12
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Emerging Concepts in Brain Glucose Metabolic Functions: From Glucose Sensing to How the Sweet Taste of Glucose Regulates Its Own Metabolism in Astrocytes and Neurons. Neuromolecular Med 2018; 20:281-300. [DOI: 10.1007/s12017-018-8503-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 07/13/2018] [Indexed: 12/16/2022]
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13
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Role of mTOR Complexes in Neurogenesis. Int J Mol Sci 2018; 19:ijms19051544. [PMID: 29789464 PMCID: PMC5983636 DOI: 10.3390/ijms19051544] [Citation(s) in RCA: 100] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 05/13/2018] [Accepted: 05/16/2018] [Indexed: 12/22/2022] Open
Abstract
Dysregulation of neural stem cells (NSCs) is associated with several neurodevelopmental disorders, including epilepsy and autism spectrum disorder. The mammalian target of rapamycin (mTOR) integrates the intracellular signals to control cell growth, nutrient metabolism, and protein translation. mTOR regulates many functions in the development of the brain, such as proliferation, differentiation, migration, and dendrite formation. In addition, mTOR is important in synaptic formation and plasticity. Abnormalities in mTOR activity is linked with severe deficits in nervous system development, including tumors, autism, and seizures. Dissecting the wide-ranging roles of mTOR activity during critical periods in development will greatly expand our understanding of neurogenesis.
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14
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mTOR inhibitor reverses autistic-like social deficit behaviours in adult rats with both Tsc2 haploinsufficiency and developmental status epilepticus. Eur Arch Psychiatry Clin Neurosci 2017; 267:455-463. [PMID: 27263037 DOI: 10.1007/s00406-016-0703-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 05/23/2016] [Indexed: 12/25/2022]
Abstract
Epilepsy is a major risk factor for autism spectrum disorder (ASD) and complicates clinical manifestations and management of ASD significantly. Tuberous sclerosis complex (TSC), caused by TSC1 or TSC2 mutations, is one of the medical conditions most commonly associated with ASD and has become an important model to examine molecular pathways associated with ASD. Previous research showed reversal of autism-like social deficits in Tsc1 +/- and Tsc2 +/- mouse models by mammalian target of rapamycin (mTOR) inhibitors. However, at least 70 % of individuals with TSC also have epilepsy, known to complicate the severity and treatment responsiveness of the behavioural phenotype. No previous study has examined the impact of seizures on neurocognitive reversal by mTOR inhibitors. Adult Tsc2 +/- (Eker)-rats express social deficits similar to Tsc2 +/- mice, with additive social deficits from developmental status epilepticus (DSE). DSE was induced by intraperitoneal injection with kainic acid at post-natal days P7 and P14 (n = 12). The experimental group that modelled TSC pathology carried the Tsc2 +/- (Eker)-mutation and was challenged with DSE. The wild-type controls had not received DSE (n = 10). Four-month-old animals were analysed for social behaviour (T1), then treated three times during 1 week with 1 mg/kg everolimus and finally retested in the post-treatment behavioural analysis (T2). In the experimental group, both social interaction and social cognition were impaired at T1. After treatment at T2, behaviour in the experimental group was indistinguishable from controls. The mTOR inhibitor, everolimus, reversed social deficit behaviours in the Tsc2 haploinsufficiency plus DSE animal model to control levels.
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15
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Wesseling H, Elgersma Y, Bahn S. A brain proteomic investigation of rapamycin effects in the Tsc1+/- mouse model. Mol Autism 2017; 8:41. [PMID: 28775826 PMCID: PMC5540199 DOI: 10.1186/s13229-017-0151-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 06/14/2017] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Tuberous sclerosis complex (TSC) is a rare monogenic disorder characterized by benign tumors in multiple organs as well as a high prevalence of epilepsy, intellectual disability and autism. TSC is caused by inactivating mutations in the TSC1 or TSC2 genes. Heterozygocity induces hyperactivation of mTOR which can be inhibited by mTOR inhibitors, such as rapamycin, which have proven efficacy in the treatment of TSC-associated symptoms. The aim of the present study was (1) to identify molecular changes associated with social and cognitive deficits in the brain tissue of Tsc1+/- mice and (2) to investigate the molecular effects of rapamycin treatment, which has been shown to ameliorate genotype-related behavioural deficits. METHODS Molecular alterations in the frontal cortex and hippocampus of Tsc1+/- and control mice, with or without rapamycin treatment, were investigated. A quantitative mass spectrometry-based shotgun proteomic approach (LC-MSE) was employed as an unbiased method to detect changes in protein levels. Changes identified in the initial profiling stage were validated using selected reaction monitoring (SRM). Protein Set Enrichment Analysis was employed to identify dysregulated pathways. RESULTS LC-MSE analysis of Tsc1+/- mice and controls (n = 30) identified 51 proteins changed in frontal cortex and 108 in the hippocampus. Bioinformatic analysis combined with targeted proteomic validation revealed several dysregulated molecular pathways. Using targeted assays, proteomic alterations in the hippocampus validated the pathways "myelination", "dendrite," and "oxidative stress", an upregulation of ribosomal proteins and the mTOR kinase. LC-MSE analysis was also employed on Tsc1+/- and wildtype mice (n = 34) treated with rapamycin or vehicle. Rapamycin treatment exerted a stronger proteomic effect in Tsc1+/- mice with significant changes (mainly decreased expression) in 231 and 106 proteins, respectively. The cellular pathways "oxidative stress" and "apoptosis" were found to be affected in Tsc1+/- mice and the cellular compartments "myelin sheet" and "neurofilaments" were affected by rapamycin treatment. Thirty-three proteins which were altered in Tsc1+/- mice were normalized following rapamycin treatment, amongst them oxidative stress related proteins, myelin-specific and ribosomal proteins. CONCLUSIONS Molecular changes in the Tsc1+/- mouse brain were more prominent in the hippocampus compared to the frontal cortex. Pathways linked to myelination and oxidative stress response were prominently affected and, at least in part, normalized following rapamycin treatment. The results could aid in the identification of novel drug targets for the treatment of cognitive, social and psychiatric symptoms in autism spectrum disorders. Similar pathways have also been implicated in other psychiatric and neurodegenerative disorders and could imply similar disease processes. Thus, the potential efficacy of mTOR inhibitors warrants further investigation not only for autism spectrum disorders but also for other neuropsychiatric and neurodegenerative diseases.
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Affiliation(s)
- Hendrik Wesseling
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QT UK
| | - Ype Elgersma
- Department of Neuroscience, Erasmus Medical Center, Rotterdam, 3000 CA The Netherlands
| | - Sabine Bahn
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QT UK
- Department of Neuroscience, Erasmus Medical Center, Rotterdam, 3000 CA The Netherlands
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16
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Jin M, An Q, Wang L. Importance of tuberin in carcinogenesis. Oncol Lett 2017; 14:2598-2602. [PMID: 28928805 PMCID: PMC5588451 DOI: 10.3892/ol.2017.6490] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 06/26/2017] [Indexed: 01/21/2023] Open
Abstract
The cell cycle is a dynamic process with multiple phases regulating cell growth. The proper regulation is essential for avoiding errors and activation of cell death. Tumour suppressor proteins, including tuberin, are crucial in coordinating adequate cell growth and properly timed cell division. So, the present review article is focused on the latest aspects of the tuberin in the process of carcinogenesis. The PubMed was the main database used for the collection of latest data relating to multiple aspects of tuberin especially in context of cancer. Most of the recent studies revealed that mutation, truncation, and deregulation of the tuberin protein could definitely lead to cancer. Recent studies are also devoted to explore implications towards better understanding the progression of disease involving mis-regulated tuberin.
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Affiliation(s)
- Mingwei Jin
- Department of Pediatric Internal Medicine, Xuzhou Children's Hospital, Xuzhou, Jiangsu 221002, P.R. China
| | - Qi An
- Department of Pediatric Internal Medicine, Xuzhou Children's Hospital, Xuzhou, Jiangsu 221002, P.R. China
| | - Lei Wang
- Department of Pediatric Internal Medicine, Xuzhou Children's Hospital, Xuzhou, Jiangsu 221002, P.R. China
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17
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Yang W, Yang LF, Song ZQ, Shah SZA, Cui YY, Li CS, Zhao HF, Gao HL, Zhou XM, Zhao DM. PRAS40 alleviates neurotoxic prion peptide-induced apoptosis via mTOR-AKT signaling. CNS Neurosci Ther 2017; 23:416-427. [PMID: 28294542 DOI: 10.1111/cns.12685] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 02/06/2017] [Accepted: 02/07/2017] [Indexed: 01/04/2023] Open
Abstract
AIMS The proline-rich Akt substrate of 40-kDa (PRAS40) protein is a direct inhibitor of mTORC1 and an interactive linker between the Akt and mTOR pathways. The mammalian target of rapamycin (mTOR) is considered to be a central regulator of cell growth and metabolism. Several investigations have demonstrated that abnormal mTOR activity may contribute to the pathogenesis of several neurodegenerative disorders and lead to cognitive deficits. METHODS Here, we used the PrP peptide 106-126 (PrP106-126 ) in a cell model of prion diseases (also known as transmissible spongiform encephalopathies, TSEs) to investigate the mechanisms of mTOR-mediated cell death in prion diseases. RESULTS We have shown that, upon stress caused by PrP106-126 , the mTOR pathway activates and contributes to cellular apoptosis. Moreover, we demonstrated that PRAS40 down-regulates mTOR hyperactivity under stress conditions and alleviates neurotoxic prion peptide-induced apoptosis. The effect of PRAS40 on apoptosis is likely due to an mTOR/Akt signaling. CONCLUSION PRAS40 inhibits mTORC1 hyperactivation and plays a key role in protecting cells against neurotoxic prion peptide-induced apoptosis. Thus, PRAS40 is a potential therapeutic target for prion disease.
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Affiliation(s)
- Wei Yang
- National Animal Transmissible Spongiform Encephalopathy Laboratory and Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, China.,Hebei Institute of Animal Science and Veterinary Medicine, Baoding, China
| | - Li-Feng Yang
- National Animal Transmissible Spongiform Encephalopathy Laboratory and Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, China
| | - Zhi-Qi Song
- National Animal Transmissible Spongiform Encephalopathy Laboratory and Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, China
| | - Syed Zahid Ali Shah
- National Animal Transmissible Spongiform Encephalopathy Laboratory and Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, China
| | - Yong-Yong Cui
- National Animal Transmissible Spongiform Encephalopathy Laboratory and Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, China
| | - Chao-Si Li
- National Animal Transmissible Spongiform Encephalopathy Laboratory and Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, China
| | - Hua-Fen Zhao
- National Animal Transmissible Spongiform Encephalopathy Laboratory and Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, China
| | - Hong-Li Gao
- National Animal Transmissible Spongiform Encephalopathy Laboratory and Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, China
| | - Xiang-Mei Zhou
- National Animal Transmissible Spongiform Encephalopathy Laboratory and Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, China
| | - De-Ming Zhao
- National Animal Transmissible Spongiform Encephalopathy Laboratory and Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, China
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18
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Trulioff A, Ermakov A, Malashichev Y. Primary Cilia as a Possible Link between Left-Right Asymmetry and Neurodevelopmental Diseases. Genes (Basel) 2017; 8:genes8020048. [PMID: 28125008 PMCID: PMC5333037 DOI: 10.3390/genes8020048] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 12/21/2016] [Accepted: 01/19/2017] [Indexed: 12/11/2022] Open
Abstract
Cilia have multiple functions in the development of the entire organism, and participate in the development and functioning of the central nervous system. In the last decade, studies have shown that they are implicated in the development of the visceral left-right asymmetry in different vertebrates. At the same time, some neuropsychiatric disorders, such as schizophrenia, autism, bipolar disorder, and dyslexia, are known to be associated with lateralization failure. In this review, we consider possible links in the mechanisms of determination of visceral asymmetry and brain lateralization, through cilia. We review the functions of seven genes associated with both cilia, and with neurodevelopmental diseases, keeping in mind their possible role in the establishment of the left-right brain asymmetry.
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Affiliation(s)
- Andrey Trulioff
- Department of Vertebrate Zoology, Faculty of Biology, Saint Petersburg State University, Universitetskaya nab., 7/9, Saint Petersburg 199034, Russia.
| | - Alexander Ermakov
- Department of Vertebrate Zoology, Faculty of Biology, Saint Petersburg State University, Universitetskaya nab., 7/9, Saint Petersburg 199034, Russia.
- Laboratory of Molecular Neurobiology, Department of Ecological Physiology, Institute of Experimental Medicine, ul. Akad. Pavlov, 12, Saint Petersburg 197376, Russia.
| | - Yegor Malashichev
- Department of Vertebrate Zoology, Faculty of Biology, Saint Petersburg State University, Universitetskaya nab., 7/9, Saint Petersburg 199034, Russia.
- Laboratory of Molecular Neurobiology, Department of Ecological Physiology, Institute of Experimental Medicine, ul. Akad. Pavlov, 12, Saint Petersburg 197376, Russia.
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19
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Mullins C, Fishell G, Tsien RW. Unifying Views of Autism Spectrum Disorders: A Consideration of Autoregulatory Feedback Loops. Neuron 2016; 89:1131-1156. [PMID: 26985722 DOI: 10.1016/j.neuron.2016.02.017] [Citation(s) in RCA: 129] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/08/2016] [Indexed: 12/31/2022]
Abstract
Understanding the mechanisms underlying autism spectrum disorders (ASDs) is a challenging goal. Here we review recent progress on several fronts, including genetics, proteomics, biochemistry, and electrophysiology, that raise motivation for forming a viable pathophysiological hypothesis. In place of a traditionally unidirectional progression, we put forward a framework that extends homeostatic hypotheses by explicitly emphasizing autoregulatory feedback loops and known synaptic biology. The regulated biological feature can be neuronal electrical activity, the collective strength of synapses onto a dendritic branch, the local concentration of a signaling molecule, or the relative strengths of synaptic excitation and inhibition. The sensor of the biological variable (which we have termed the homeostat) engages mechanisms that operate as negative feedback elements to keep the biological variable tightly confined. We categorize known ASD-associated gene products according to their roles in such feedback loops and provide detailed commentary for exemplar genes within each module.
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Affiliation(s)
- Caitlin Mullins
- Department of Neuroscience and Physiology, Neuroscience Institute, New York University Langone Medical Center, New York, NY 10016, USA
| | - Gord Fishell
- Department of Neuroscience and Physiology, Neuroscience Institute, New York University Langone Medical Center, New York, NY 10016, USA
| | - Richard W Tsien
- Department of Neuroscience and Physiology, Neuroscience Institute, New York University Langone Medical Center, New York, NY 10016, USA.
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20
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The mTOR signalling cascade: paving new roads to cure neurological disease. Nat Rev Neurol 2016; 12:379-92. [PMID: 27340022 DOI: 10.1038/nrneurol.2016.81] [Citation(s) in RCA: 262] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Defining the multiple roles of the mechanistic (formerly 'mammalian') target of rapamycin (mTOR) signalling pathway in neurological diseases has been an exciting and rapidly evolving story of bench-to-bedside translational research that has spanned gene mutation discovery, functional experimental validation of mutations, pharmacological pathway manipulation, and clinical trials. Alterations in the dual contributions of mTOR - regulation of cell growth and proliferation, as well as autophagy and cell death - have been found in developmental brain malformations, epilepsy, autism and intellectual disability, hypoxic-ischaemic and traumatic brain injuries, brain tumours, and neurodegenerative disorders. mTOR integrates a variety of cues, such as growth factor levels, oxygen levels, and nutrient and energy availability, to regulate protein synthesis and cell growth. In line with the positioning of mTOR as a pivotal cell signalling node, altered mTOR activation has been associated with a group of phenotypically diverse neurological disorders. To understand how altered mTOR signalling leads to such divergent phenotypes, we need insight into the differential effects of enhanced or diminished mTOR activation, the developmental context of these changes, and the cell type affected by altered signalling. A particularly exciting feature of the tale of mTOR discovery is that pharmacological mTOR inhibitors have shown clinical benefits in some neurological disorders, such as tuberous sclerosis complex, and are being considered for clinical trials in epilepsy, autism, dementia, traumatic brain injury, and stroke.
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21
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Citraro R, Leo A, Constanti A, Russo E, De Sarro G. mTOR pathway inhibition as a new therapeutic strategy in epilepsy and epileptogenesis. Pharmacol Res 2016; 107:333-343. [DOI: 10.1016/j.phrs.2016.03.039] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 03/23/2016] [Accepted: 03/31/2016] [Indexed: 12/24/2022]
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22
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Mercer AA, Palarz KJ, Tabatadze N, Woolley CS, Raman IM. Sex differences in cerebellar synaptic transmission and sex-specific responses to autism-linked Gabrb3 mutations in mice. eLife 2016; 5. [PMID: 27077953 PMCID: PMC4878876 DOI: 10.7554/elife.07596] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 04/13/2016] [Indexed: 12/18/2022] Open
Abstract
Neurons of the cerebellar nuclei (CbN) transmit cerebellar signals to premotor areas. The cerebellum expresses several autism-linked genes, including GABRB3, which encodes GABAA receptor β3 subunits and is among the maternal alleles deleted in Angelman syndrome. We tested how this Gabrb3 m-/p+ mutation affects CbN physiology in mice, separating responses of males and females. Wild-type mice showed sex differences in synaptic excitation, inhibition, and intrinsic properties. Relative to females, CbN cells of males had smaller synaptically evoked mGluR1/5-dependent currents, slower Purkinje-mediated IPSCs, and lower spontaneous firing rates, but rotarod performances were indistinguishable. In mutant CbN cells, IPSC kinetics were unchanged, but mutant males, unlike females, showed enlarged mGluR1/5 responses and accelerated spontaneous firing. These changes appear compensatory, since mutant males but not females performed indistinguishably from wild-type siblings on the rotarod task. Thus, sex differences in cerebellar physiology produce similar behavioral output, but provide distinct baselines for responses to mutations.
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Affiliation(s)
- Audrey A Mercer
- Northwestern University Interdepartmental Neuroscience Program, Northwestern University, Evanston, United States.,Department of Neurobiology, Northwestern University, Evanston, United States
| | - Kristin J Palarz
- Department of Neurobiology, Northwestern University, Evanston, United States.,Integrated Science Program, Northwestern University, Evanston, United States
| | - Nino Tabatadze
- Department of Neurobiology, Northwestern University, Evanston, United States
| | - Catherine S Woolley
- Northwestern University Interdepartmental Neuroscience Program, Northwestern University, Evanston, United States.,Department of Neurobiology, Northwestern University, Evanston, United States
| | - Indira M Raman
- Northwestern University Interdepartmental Neuroscience Program, Northwestern University, Evanston, United States.,Department of Neurobiology, Northwestern University, Evanston, United States.,Integrated Science Program, Northwestern University, Evanston, United States
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23
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Uzunova G, Pallanti S, Hollander E. Excitatory/inhibitory imbalance in autism spectrum disorders: Implications for interventions and therapeutics. World J Biol Psychiatry 2016; 17:174-86. [PMID: 26469219 DOI: 10.3109/15622975.2015.1085597] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
OBJECTIVES Imbalance between excitation and inhibition and increased excitatory-inhibitory (E-I) ratio is a common mechanism in autism spectrum disorders (ASD) that is responsible for the learning and memory, cognitive, sensory, motor deficits, and seizures occurring in these disorders. ASD are very heterogeneous and better understanding of E-I imbalance in brain will lead to better diagnosis and treatments. METHODS We perform a critical literature review of the causes and presentations of E-I imbalance in ASD. RESULTS E-I imbalance in ASD is due primarily to abnormal glutamatergic and GABAergic neurotransmission in key brain regions such as neocortex, hippocampus, amygdala, and cerebellum. Other causes are due to dysfunction of neuropeptides (oxytocin), synaptic proteins (neuroligins), and immune system molecules (cytokines). At the neuropathological level E-I imbalance in ASD is presented as a "minicolumnopathy". E-I imbalance alters the manner by which the brain processes information and regulates behaviour. New developments for investigating E-I imbalance such as optogenetics and transcranial magnetic stimulation (TMS) are presented. Non-invasive brain stimulation methods such as TMS for treatment of the core symptoms of ASD are discussed. CONCLUSIONS Understanding E-I imbalance has important implications for developing better pharmacological and behavioural treatments for ASD, including TMS, new drugs, biomarkers and patient stratification.
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Affiliation(s)
- Genoveva Uzunova
- a Albert Einstein College of Medicine and Montefiore Medical Center , Bronx , NY , USA
| | - Stefano Pallanti
- a Albert Einstein College of Medicine and Montefiore Medical Center , Bronx , NY , USA.,b Psychiatry and Behavioural Sciences, UC Davis Health System , CA , USA.,c Department Psychiatry , University of Florence , Florence , Italy.,d Icahn School of Medicine at Mount Sinai , New York , NY , USA
| | - Eric Hollander
- a Albert Einstein College of Medicine and Montefiore Medical Center , Bronx , NY , USA
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Welcome MO, Mastorakis NE, Pereverzev VA. Sweet-Taste Receptor Signaling Network and Low-Calorie Sweeteners. REFERENCE SERIES IN PHYTOCHEMISTRY 2016. [DOI: 10.1007/978-3-319-26478-3_25-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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25
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The mammalian target of rapamycin at the crossroad between cognitive aging and Alzheimer's disease. NPJ Aging Mech Dis 2015; 1:15008. [PMID: 28721257 PMCID: PMC5514987 DOI: 10.1038/npjamd.2015.8] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 08/10/2015] [Accepted: 09/01/2015] [Indexed: 12/12/2022] Open
Abstract
Age-dependent cognitive decline is a major debilitating event affecting even individuals who are otherwise healthy. Understanding the molecular basis underlying these changes may increase the healthspan of the elderly population. It may also reveal insights into the pathogenesis of numerous neurodegenerative disorders characterized by cognitive deficits, as aging is the major risk factor for most of these disorders. Alzheimer’s disease (AD), the most common neurodegenerative disorder, first manifests itself as deficits in encoding new memories. As AD progresses, these deficits spread to other cognitive domains that further debilitate the person before contributing to their demise. Suppression of the mammalian target of rapamycin (mTOR) increases healthspan and lifespan in several organisms. Numerous reports have linked alterations in mTOR signaling to age-dependent cognitive decline and the pathogenesis of AD. This review will discuss recent work highlighting the complex role of mTOR in cognitive aging and in the pathogenesis of AD.
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Liu YW, Zhang L, Li Y, Cheng YQ, Zhu X, Zhang F, Yin XX. Activation of mTOR signaling mediates the increased expression of AChE in high glucose condition: in vitro and in vivo evidences. Mol Neurobiol 2015; 53:4972-80. [PMID: 26374551 DOI: 10.1007/s12035-015-9425-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 09/03/2015] [Indexed: 12/19/2022]
Abstract
Acetylcholinesterase (AChE) is impaired in brain of diabetic animals, which may be one of the reasons for diabetes-associated cognitive decline. However, the mechanism is still unknown. The present study was designed to investigate whether the increased expression of AChE in central neurons under high glucose (HG) condition was due to activation of mammalian target of rapamycin (mTOR) signaling. It was found that more production of reactive oxygen species, and higher levels of phospho-Akt, phospho-mTOR, phospho-p70S6K, and AChE were detected in HT-22 cells in HG group than normal glucose group after culture for 24 h, which were all attenuated by an antioxidant N-acetyl-L-cysteine. A PI3K inhibitor LY294002 significantly decreased the levels of phospho-Akt, phospho-mTOR, phospho-p70S6K, and AChE protein expression in HG-cultured HT-22 cells, and an mTOR inhibitor rapamycin markedly reduced the levels of phospho-mTOR, phospho-p70S6K, and AChE expression. Furthermore, compared with normal rats, diabetic rats showed remarkable increases in levels of AChE activity and expression, malondialdehyde, phospho-mTOR, phospho-p70S6K, and a significant decrease in total superoxide dismutase activity in both hippocampus and cerebral cortex. However, much lower levels of phospho-mTOR, phospho-p70S6K, and AChE expression occurred in both brain regions of diabetic rats treated with rapamycin when compared with untreated ones. These results indicated that mTOR signaling was activated through the activation of PI3K/Akt pathway mediated by oxidative stress in HG-cultured HT-22 cells and diabetic rat brains, which contributed to the elevated protein expression of AChE in central neurons under the condition of HG.
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Affiliation(s)
- Yao-Wu Liu
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical College, No. 209, Tongshan Road, Xuzhou, 221004, Jiangsu, China
| | - Liang Zhang
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical College, No. 209, Tongshan Road, Xuzhou, 221004, Jiangsu, China.,Department of Pharmacy, the People's Hospital of Hebi, Henan, China
| | - Yu Li
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical College, No. 209, Tongshan Road, Xuzhou, 221004, Jiangsu, China
| | - Ya-Qin Cheng
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical College, No. 209, Tongshan Road, Xuzhou, 221004, Jiangsu, China
| | - Xia Zhu
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical College, No. 209, Tongshan Road, Xuzhou, 221004, Jiangsu, China
| | - Fan Zhang
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical College, No. 209, Tongshan Road, Xuzhou, 221004, Jiangsu, China
| | - Xiao-Xing Yin
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical College, No. 209, Tongshan Road, Xuzhou, 221004, Jiangsu, China.
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Curatolo P, Moavero R, de Vries PJ. Neurological and neuropsychiatric aspects of tuberous sclerosis complex. Lancet Neurol 2015; 14:733-45. [PMID: 26067126 DOI: 10.1016/s1474-4422(15)00069-1] [Citation(s) in RCA: 365] [Impact Index Per Article: 40.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 04/21/2015] [Accepted: 04/27/2015] [Indexed: 01/22/2023]
Abstract
Tuberous sclerosis (also known as tuberous sclerosis complex [TSC]) is a multisystem genetic disorder that affects almost every organ in the body. Mutations in the TSC1 or TSC2 genes lead to disruption of the TSC1-TSC2 intracellular protein complex, causing overactivation of the mammalian target of rapamycin (mTOR) protein complex. The surveillance and management guidelines and clinical criteria for tuberous sclerosis were revised in 2012, and mTOR inhibitors are now recommended as treatment options for subependymal giant cell astrocytomas and renal angiomyolipomas-two common features of the disease. However, most morbidity and mortality caused by tuberous sclerosis is associated with neurological and neuropsychiatric manifestations. Treatment of epilepsy associated with tuberous sclerosis remains a major challenge, with more than 60% of patients having ongoing seizures. Tuberous-sclerosis-associated neuropsychiatric disorders (TAND) are multilevel and occur in most individuals with the disorder, but are rarely assessed and treated. Clinical trials of mTOR inhibitors to treat seizures and TAND are underway. Management of the neurological and neuropsychiatric manifestations of the disorder should be coordinated with treatment of other organ systems. In view of the age-related expression of manifestations from infancy to adulthood, continuity of clinical care and ongoing monitoring is paramount, and particular attention is needed to plan transition of patient care from childhood to adult services.
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Affiliation(s)
- Paolo Curatolo
- Neuroscience Department, Child Neurology and Psychiatry Division, University Hospital of Tor Vergata, Rome, Italy.
| | - Romina Moavero
- Neuroscience Department, Child Neurology and Psychiatry Division, University Hospital of Tor Vergata, Rome, Italy; Neuroscience Department, Child Neurology Division, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Petrus J de Vries
- Division of Child and Adolescent Psychiatry, University of Cape Town, Cape Town, South Africa
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Ishii R, Wataya-Kaneda M, Canuet L, Nonomura N, Nakai Y, Takeda M. Everolimus improves behavioral deficits in a patient with autism associated with tuberous sclerosis: a case report. ACTA ACUST UNITED AC 2015. [DOI: 10.1186/s40810-015-0004-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Kotajima-Murakami H, Sato A, Ikeda K. [Pathology and treatment of autism spectrum disorders]. Nihon Yakurigaku Zasshi 2015; 145:193-200. [PMID: 25864830 DOI: 10.1254/fpj.145.193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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30
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Wang ZX, Tan L, Liu J, Yu JT. The Essential Role of Soluble Aβ Oligomers in Alzheimer's Disease. Mol Neurobiol 2015; 53:1905-1924. [PMID: 25833098 DOI: 10.1007/s12035-015-9143-0] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 03/18/2015] [Indexed: 01/21/2023]
Abstract
Alzheimer's disease (AD) is a common neurodegenerative disease characterized by amyloid plaque and neurofibrillary tangles (NFT). With the finding that soluble nonfibrillar Aβ levels actually correlate strongly with the severity of the disease, the initial focus on amyloid plaques shifted to the contemporary concept that AD memory failure is caused by soluble Aβ oligomers. The soluble Aβ are known to be more neurotoxicthan fibrillar Aβ species. In this paper, we summarize the essential role of soluble Aβ oligomers in AD and discuss therapeutic strategies that target soluble Aβ oligomers.
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Affiliation(s)
- Zi-Xuan Wang
- Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao, China
| | - Lan Tan
- Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao, China.
| | - Jinyuan Liu
- Columbia College, Columbia University, New York, NY, USA
| | - Jin-Tai Yu
- Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao, China. .,Memory and Aging Center, Department of Neurology, University of California, San Francisco, CA, USA.
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Welcome MO, Mastorakis NE, Pereverzev VA. Sweet taste receptor signaling network: possible implication for cognitive functioning. Neurol Res Int 2015; 2015:606479. [PMID: 25653876 PMCID: PMC4306214 DOI: 10.1155/2015/606479] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 12/20/2014] [Indexed: 01/01/2023] Open
Abstract
Sweet taste receptors are transmembrane protein network specialized in the transmission of information from special "sweet" molecules into the intracellular domain. These receptors can sense the taste of a range of molecules and transmit the information downstream to several acceptors, modulate cell specific functions and metabolism, and mediate cell-to-cell coupling through paracrine mechanism. Recent reports indicate that sweet taste receptors are widely distributed in the body and serves specific function relative to their localization. Due to their pleiotropic signaling properties and multisubstrate ligand affinity, sweet taste receptors are able to cooperatively bind multiple substances and mediate signaling by other receptors. Based on increasing evidence about the role of these receptors in the initiation and control of absorption and metabolism, and the pivotal role of metabolic (glucose) regulation in the central nervous system functioning, we propose a possible implication of sweet taste receptor signaling in modulating cognitive functioning.
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Affiliation(s)
- Menizibeya O. Welcome
- World Scientific and Engineering Academy and Society, Ag. Ioannou Theologou 17-23, Zografou, 15773 Athens, Greece
| | - Nikos E. Mastorakis
- World Scientific and Engineering Academy and Society, Ag. Ioannou Theologou 17-23, Zografou, 15773 Athens, Greece
- Department of Industrial Engineering, Technical University of Sofia, 8 Kl. Ohridski Boulevard, 1000 Sofia, Bulgaria
| | - Vladimir A. Pereverzev
- Department of Normal Physiology, Belarusian State Medical University, Dzerzhinsky Avenue 83, 220116 Minsk, Belarus
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de Vries PJ, Whittemore VH, Leclezio L, Byars AW, Dunn D, Ess KC, Hook D, King BH, Sahin M, Jansen A. Tuberous sclerosis associated neuropsychiatric disorders (TAND) and the TAND Checklist. Pediatr Neurol 2015; 52:25-35. [PMID: 25532776 PMCID: PMC4427347 DOI: 10.1016/j.pediatrneurol.2014.10.004] [Citation(s) in RCA: 176] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 10/04/2014] [Accepted: 10/07/2014] [Indexed: 11/25/2022]
Abstract
BACKGROUND Tuberous sclerosis complex is a multisystem genetic disorder with a range of physical manifestations that require evaluation, surveillance, and management. Individuals with tuberous sclerosis complex also have a range of behavioral, psychiatric, intellectual, academic, neuropsychologic, and psychosocial difficulties. These may represent the greatest burden of the disease. Around 90% of individuals with tuberous sclerosis complex will have some of these difficulties during their lifetime, yet only about 20% ever receive evaluation and treatment. The Neuropsychiatry Panel at the 2012 Tuberous Sclerosis Complex International Consensus Conference expressed concern about the significant "treatment gap" and about confusion regarding terminology relating to the biopsychosocial difficulties associated with tuberous sclerosis complex. METHODS The Tuberous Sclerosis Complex Neuropsychiatry Panel coined the term TAND-tuberous sclerosis complex-associated neuropsychiatric disorders-to bring together these multidimensional manifestations of the disorder, and recommended annual screening for TAND. In addition, the Panel agreed to develop a TAND Checklist as a guide for screening. RESULTS Here, we present an outline of the conceptualization of TAND, rationale for the structure of the TAND Checklist, and include the full US English version of the TAND Checklist. CONCLUSION We hope that the unified term TAND and the TAND Checklist will raise awareness of the importance of tuberous sclerosis complex-associated neuropsychiatric disorders and of the major burden of disease associated with it, provide a shared language and a simple tool to describe and evaluate the different levels of TAND, alert clinical teams and families or individuals of the importance of screening, assessment, and treatment of TAND, and provide a shared framework for future studies of tuberous sclerosis complex-associated neuropsychiatric disorders.
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Affiliation(s)
- Petrus J. de Vries
- Division of Child & Adolescent Psychiatry, Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa,Communications should be addressed to: Prof. de Vries; Division of Child & Adolescent Psychiatry; University of Cape Town; 46 Sawkins Road, Rondebosch; Cape Town, 7700, South Africa.
| | - Vicky H. Whittemore
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Loren Leclezio
- Division of Child & Adolescent Psychiatry, Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa
| | - Anna W. Byars
- Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - David Dunn
- Indiana University School of Medicine, Riley Child & Adolescent Psychiatry Clinic, Indianapolis, Indiana
| | - Kevin C. Ess
- Division of Pediatric Neurology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Dena Hook
- Tuberous Sclerosis Alliance, Silver Spring, Maryland
| | - Bryan H. King
- Department of Psychiatry and Behavioral Sciences, University of Washington & Seattle Children’s Hospital, Seattle, Washington
| | - Mustafa Sahin
- Department of Neurology, F.M. Kirby Center for Neuroscience, Boston Children’s Hospital, Boston, Maryland
| | - Anna Jansen
- Pediatric Neurology Unit, UZ Brussel, Department of Public Health, VUB, Brussels, Belgium
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Santini E, Klann E. Reciprocal signaling between translational control pathways and synaptic proteins in autism spectrum disorders. Sci Signal 2014; 7:re10. [PMID: 25351249 DOI: 10.1126/scisignal.2005832] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Autism spectrum disorder (ASD) is a heterogeneous group of heritable neurodevelopmental disorders. Symptoms of ASD, which include deficits in social interaction skills, impaired communication ability, and ritualistic-like repetitive behaviors, appear in early childhood and continue throughout life. Genetic studies have revealed at least two clusters of genes frequently associated with ASD and intellectual disability: those encoding proteins involved in translational control and those encoding proteins involved in synaptic function. We hypothesize that mutations occurring in these two clusters of genes interfere with interconnected downstream signaling pathways in neuronal cells to cause ASD symptomatology. In this review, we discuss the monogenic forms of ASD caused by mutations in genes encoding for proteins that regulate translation and synaptic function. Specifically, we describe the function of these proteins, the intracellular signaling pathways that they regulate, and the current mouse models used to characterize the synaptic and behavioral features associated with their mutation. Finally, we summarize recent studies that have established a connection between mRNA translation and synaptic function in models of ASD and propose that dysregulation of one has a detrimental impact on the other.
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Affiliation(s)
- Emanuela Santini
- Center for Neural Science, New York University, New York, NY 10003, USA
| | - Eric Klann
- Center for Neural Science, New York University, New York, NY 10003, USA.
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Both maternal and pup genotype influence ultrasonic vocalizations and early developmental milestones in tsc2 (+/-) mice. EPILEPSY RESEARCH AND TREATMENT 2014; 2014:784137. [PMID: 25165580 PMCID: PMC4137560 DOI: 10.1155/2014/784137] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 06/24/2014] [Indexed: 11/18/2022]
Abstract
Tuberous sclerosis complex (TSC) is an autosomal dominant disorder characterized by tumor growth and neuropsychological symptoms such as autistic behavior, developmental delay, and epilepsy. While research has shed light on the biochemical and genetic etiology of TSC, the pathogenesis of the neurologic and behavioral manifestations remains poorly understood. TSC patients have a greatly increased risk of developmental delay and autism spectrum disorder, rendering the relationship between the two sets of symptoms an extremely pertinent issue for clinicians. We have expanded on previous observations of aberrant vocalizations in Tsc2+/− mice by testing vocalization output and developmental milestones systematically during the early postnatal period. In this study, we have demonstrated that Tsc2 haploinsufficiency in either dams or their pups results in a pattern of developmental delay in sensorimotor milestones and ultrasonic vocalizations.
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Ji B, Higa KK, Kim M, Zhou L, Young JW, Geyer MA, Zhou X. Inhibition of protein translation by the DISC1-Boymaw fusion gene from a Scottish family with major psychiatric disorders. Hum Mol Genet 2014; 23:5683-705. [PMID: 24908665 DOI: 10.1093/hmg/ddu285] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The t(1; 11) translocation appears to be the causal genetic lesion with 70% penetrance for schizophrenia, major depression and other psychiatric disorders in a Scottish family. Molecular studies identified the disruption of the disrupted-in-schizophrenia 1 (DISC1) gene by chromosome translocation at chromosome 1q42. Our previous studies, however, revealed that the translocation also disrupted another gene, Boymaw (also termed DISC1FP1), on chromosome 11. After translocation, two fusion genes [the DISC1-Boymaw (DB7) and the Boymaw-DISC1 (BD13)] are generated between the DISC1 and Boymaw genes. In the present study, we report that expression of the DB7 fusion gene inhibits both intracellular NADH oxidoreductase activities and protein translation. We generated humanized DISC1-Boymaw mice with gene targeting to examine the in vivo functions of the fusion genes. Consistent with the in vitro studies on the DB7 fusion gene, protein translation activity is decreased in the hippocampus and in cultured primary neurons from the brains of the humanized mice. Expression of Gad67, Nmdar1 and Psd95 proteins are also reduced. The humanized mice display prolonged and increased responses to the NMDA receptor antagonist, ketamine, on various mouse genetic backgrounds. Abnormal information processing of acoustic startle and depressive-like behaviors are also observed. In addition, the humanized mice display abnormal erythropoiesis, which was reported to associate with depression in humans. Expression of the DB7 fusion gene may reduce protein translation to impair brain functions and thereby contribute to the pathogenesis of major psychiatric disorders.
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Affiliation(s)
- Baohu Ji
- Department of Psychiatry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Kerin K Higa
- Department of Psychiatry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Minjung Kim
- Department of Psychiatry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Lynn Zhou
- La Jolla High School, 750 Nautilus St., San Diego, CA 92037, USA and
| | - Jared W Young
- Department of Psychiatry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA, Research Service, VA San Diego Healthcare System, 3350 La Jolla Village Drive, San Diego, CA 92037, USA
| | - Mark A Geyer
- Department of Psychiatry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA, Research Service, VA San Diego Healthcare System, 3350 La Jolla Village Drive, San Diego, CA 92037, USA
| | - Xianjin Zhou
- Department of Psychiatry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA, Research Service, VA San Diego Healthcare System, 3350 La Jolla Village Drive, San Diego, CA 92037, USA
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Kleijer KTE, Schmeisser MJ, Krueger DD, Boeckers TM, Scheiffele P, Bourgeron T, Brose N, Burbach JPH. Neurobiology of autism gene products: towards pathogenesis and drug targets. Psychopharmacology (Berl) 2014; 231:1037-62. [PMID: 24419271 DOI: 10.1007/s00213-013-3403-3] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Accepted: 12/14/2013] [Indexed: 12/22/2022]
Abstract
RATIONALE The genetic heterogeneity of autism spectrum disorders (ASDs) is enormous, and the neurobiology of proteins encoded by genes associated with ASD is very diverse. Revealing the mechanisms on which different neurobiological pathways in ASD pathogenesis converge may lead to the identification of drug targets. OBJECTIVE The main objective is firstly to outline the main molecular networks and neuronal mechanisms in which ASD gene products participate and secondly to answer the question how these converge. Finally, we aim to pinpoint drug targets within these mechanisms. METHOD Literature review of the neurobiological properties of ASD gene products with a special focus on the developmental consequences of genetic defects and the possibility to reverse these by genetic or pharmacological interventions. RESULTS The regulation of activity-dependent protein synthesis appears central in the pathogenesis of ASD. Through sequential consequences for axodendritic function, neuronal disabilities arise expressed as behavioral abnormalities and autistic symptoms in ASD patients. Several known ASD gene products have their effect on this central process by affecting protein synthesis intrinsically, e.g., through enhancing the mammalian target of rapamycin (mTOR) signal transduction pathway or through impairing synaptic function in general. These are interrelated processes and can be targeted by compounds from various directions: inhibition of protein synthesis through Lovastatin, mTOR inhibition using rapamycin, or mGluR-related modulation of synaptic activity. CONCLUSIONS ASD gene products may all feed into a central process of translational control that is important for adequate glutamatergic regulation of dendritic properties. This process can be modulated by available compounds but may also be targeted by yet unexplored routes.
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Affiliation(s)
- Kristel T E Kleijer
- Department Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, Universiteitsweg 100, 3984 CG, Utrecht, The Netherlands
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Weston MC, Chen H, Swann JW. Loss of mTOR repressors Tsc1 or Pten has divergent effects on excitatory and inhibitory synaptic transmission in single hippocampal neuron cultures. Front Mol Neurosci 2014; 7:1. [PMID: 24574959 DOI: 10.3389/fnmol.2014.00001] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Accepted: 01/09/2014] [Indexed: 01/23/2023] Open
Abstract
The Pten and Tsc1 genes both encode proteins that repress mechanistic target of rapamycin (mTOR) signaling. Disruption of either gene in the brain results in epilepsy and autism-like symptoms in humans and mouse models, therefore it is important to understand the molecular and physiological events that lead from gene disruption to disease phenotypes. Given the similar roles these two molecules play in the regulation of cellular growth and the overlap in the phenotypes that result from their loss, we predicted that the deletion of either the Pten or Tsc1 gene from autaptic hippocampal neurons would have similar effects on neuronal morphology and synaptic transmission. Accordingly, we found that loss of either Pten or Tsc1 caused comparable increases in soma size, dendrite length and action potential properties. However, the effects of Pten and Tsc1 loss on synaptic transmission were different. Loss of Pten lead to an increase in both excitatory and inhibitory neurotransmission, while loss of Tsc1 did not affect excitatory neurotransmission and reduced inhibitory transmission by decreasing mIPSC amplitude. Although the loss of Pten or Tsc1 both increased downstream mTORC1 signaling, phosphorylation of Akt was increased in Pten-ko and decreased in Tsc1-ko neurons, potentially accounting for the different effects on synaptic transmission. Despite the different effects at the synaptic level, our data suggest that loss of Pten or Tsc1 may both lead to an increase in the ratio of excitation to inhibition at the network level, an effect that has been proposed to underlie both epilepsy and autism.
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Affiliation(s)
- Matthew C Weston
- The Cain Foundation Laboratories, The Jan and Dan Duncan Neurological Research Institute Houston, TX, USA ; Departments of Neuroscience and Pediatrics, Baylor College of Medicine Houston, TX, USA
| | - Hongmei Chen
- The Cain Foundation Laboratories, The Jan and Dan Duncan Neurological Research Institute Houston, TX, USA ; Departments of Neuroscience and Pediatrics, Baylor College of Medicine Houston, TX, USA
| | - John W Swann
- The Cain Foundation Laboratories, The Jan and Dan Duncan Neurological Research Institute Houston, TX, USA ; Departments of Neuroscience and Pediatrics, Baylor College of Medicine Houston, TX, USA
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Park CS, Rehrauer H, Mansuy IM. Genome-wide analysis of H4K5 acetylation associated with fear memory in mice. BMC Genomics 2013; 14:539. [PMID: 23927422 PMCID: PMC3751108 DOI: 10.1186/1471-2164-14-539] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Accepted: 08/03/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Histone acetylation has been implicated in learning and memory in the brain, however, its function at the level of the genome and at individual genetic loci remains poorly investigated. This study examines a key acetylation mark, histone H4 lysine 5 acetylation (H4K5ac), genome-wide and its role in activity-dependent gene transcription in the adult mouse hippocampus following contextual fear conditioning. RESULTS Using ChIP-Seq, we identified 23,235 genes in which H4K5ac correlates with absolute gene expression in the hippocampus. However, in the absence of transcription factor binding sites 150 bp upstream of the transcription start site, genes were associated with higher H4K5ac and expression levels. We further establish H4K5ac as a ubiquitous modification across the genome. Approximately one-third of all genes have above average H4K5ac, of which ~15% are specific to memory formation and ~65% are co-acetylated for H4K12. Although H4K5ac is prevalent across the genome, enrichment of H4K5ac at specific regions in the promoter and coding region are associated with different levels of gene expression. Additionally, unbiased peak calling for genes differentially acetylated for H4K5ac identified 114 unique genes specific to fear memory, over half of which have not previously been associated with memory processes. CONCLUSIONS Our data provide novel insights into potential mechanisms of gene priming and bookmarking by histone acetylation following hippocampal memory activation. Specifically, we propose that hyperacetylation of H4K5 may prime genes for rapid expression following activity. More broadly, this study strengthens the importance of histone posttranslational modifications for the differential regulation of transcriptional programs in cognitive processes.
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Affiliation(s)
- C Sehwan Park
- Department of Health Science and Technology, ETH Zürich, Zürich, Switzerland.
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Won H, Mah W, Kim E. Autism spectrum disorder causes, mechanisms, and treatments: focus on neuronal synapses. Front Mol Neurosci 2013; 6:19. [PMID: 23935565 PMCID: PMC3733014 DOI: 10.3389/fnmol.2013.00019] [Citation(s) in RCA: 129] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Accepted: 07/16/2013] [Indexed: 12/24/2022] Open
Abstract
Autism spectrum disorder (ASD) is a group of developmental disabilities characterized by impairments in social interaction and communication and restricted and repetitive interests/behaviors. Advances in human genomics have identified a large number of genetic variations associated with ASD. These associations are being rapidly verified by a growing number of studies using a variety of approaches, including mouse genetics. These studies have also identified key mechanisms underlying the pathogenesis of ASD, many of which involve synaptic dysfunctions, and have investigated novel, mechanism-based therapeutic strategies. This review will try to integrate these three key aspects of ASD research: human genetics, animal models, and potential treatments. Continued efforts in this direction should ultimately reveal core mechanisms that account for a larger fraction of ASD cases and identify neural mechanisms associated with specific ASD symptoms, providing important clues to efficient ASD treatment.
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Affiliation(s)
- Hyejung Won
- Department of Biological Sciences, Korea Advanced Institute of Science and TechnologyDaejeon, South Korea
| | - Won Mah
- Department of Biological Sciences, Korea Advanced Institute of Science and TechnologyDaejeon, South Korea
- Center for Synaptic Brain Dysfunctions, Institute for Basic ScienceDaejeon, South Korea
| | - Eunjoon Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and TechnologyDaejeon, South Korea
- Center for Synaptic Brain Dysfunctions, Institute for Basic ScienceDaejeon, South Korea
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40
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Targeting the mTOR Signaling Network for Alzheimer’s Disease Therapy. Mol Neurobiol 2013; 49:120-35. [DOI: 10.1007/s12035-013-8505-8] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2013] [Accepted: 07/01/2013] [Indexed: 12/29/2022]
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Ehninger D. From genes to cognition in tuberous sclerosis: Implications for mTOR inhibitor-based treatment approaches. Neuropharmacology 2013; 68:97-105. [DOI: 10.1016/j.neuropharm.2012.05.015] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Revised: 05/03/2012] [Accepted: 05/13/2012] [Indexed: 01/27/2023]
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O' Neill C. PI3-kinase/Akt/mTOR signaling: impaired on/off switches in aging, cognitive decline and Alzheimer's disease. Exp Gerontol 2013; 48:647-53. [PMID: 23470275 DOI: 10.1016/j.exger.2013.02.025] [Citation(s) in RCA: 199] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 02/07/2013] [Accepted: 02/15/2013] [Indexed: 11/19/2022]
Abstract
The normal on and off switching of the PI3-K (phosphoinositide 3-kinase)/Akt pathway, particularly by its major activators insulin and IGF-1 (insulin-like growth factor-1), is a powerful integrator of physiological responses rudimentary to successful aging. This is highlighted by extensive studies showing that reducing, but not obliterating, activation of the PI3-K/Akt/mTOR signal, at several levels, can extend healthy lifespan in organisms from yeast to mammals. Moreover, aberrant control of the PI3-K/Akt axis is emerging to be a primary causative node in all major diseases of aging: cancer, type 2 diabetes mellitus (T2DM), heart disease and neurodegeneration. Aging is the major risk factor for AD, the most common dementia disorder. The integrated coordination of neuronal responses through the PI3-K/Akt pathway has significant functional impact on key events that go awry in Alzheimer's disease (AD), including: synaptic plasticity, neuronal polarity, neurotransmission, proteostasis, use-dependent translation, metabolic control and stress responses including DNA repair. Investigation of the status of the PI3-K/Akt system in brains of individuals who have had AD shows aberrant and sustained activation of neuronal PI3-K/Akt/mTOR signaling to be an early feature of the disease. This is mechanistically linked to progressive desensitization of normal brain insulin and IGF-1 responses, aberrant proteostasis of Aβ and tau, synaptic loss and cognitive decline in the disease. Notably, concomitantly with feedback inhibition of insulin and IGF-1 responses, increased activation of the neuronal PI3-K/Akt/mTOR axis is a major candidate effector system for transmission of pathophysiological signals from Aβ to tau in the context of defects in synaptic transmission that lead to cognitive decline. Therapeutic approaches targeted at normalizing signaling through either the neuronal PI3-kinase/Akt/mTOR pathway or its activation by insulin and IGF-1 have been shown to be protective against the development of AD pathology and cognitive decline in animal models of AD and some of these therapies are entering clinical trials in patients with the disease.
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Affiliation(s)
- Cora O' Neill
- Department of Biochemistry, BioSciences Institute, University College Cork, Ireland.
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Fortress AM, Fan L, Orr PT, Zhao Z, Frick KM. Estradiol-induced object recognition memory consolidation is dependent on activation of mTOR signaling in the dorsal hippocampus. Learn Mem 2013; 20:147-55. [PMID: 23422279 DOI: 10.1101/lm.026732.112] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The mammalian target of rapamycin (mTOR) signaling pathway is an important regulator of protein synthesis and is essential for various forms of hippocampal memory. Here, we asked whether the enhancement of object recognition memory consolidation produced by dorsal hippocampal infusion of 17β-estradiol (E(2)) is dependent on mTOR signaling in the dorsal hippocampus, and whether E(2)-induced mTOR signaling is dependent on dorsal hippocampal phosphatidylinositol 3-kinase (PI3K) and extracellular signal-regulated kinase (ERK) activation. We first demonstrated that the enhancement of object recognition induced by E(2) was blocked by dorsal hippocampal inhibition of ERK, PI3K, or mTOR activation. We then showed that an increase in dorsal hippocampal ERK phosphorylation 5 min after intracerebroventricular (ICV) E(2) infusion was also blocked by dorsal hippocampal infusion of the three cell signaling inhibitors. Next, we found that ICV infusion of E(2) increased phosphorylation of the downstream mTOR targets S6K (Thr-421) and 4E-BP1 in the dorsal hippocampus 5 min after infusion, and that this phosphorylation was blocked by dorsal hippocampal infusion of inhibitors of ERK, PI3K, and mTOR. Collectively, these data demonstrate for the first time that activation of the dorsal hippocampal mTOR signaling pathway is necessary for E(2) to enhance object recognition memory consolidation and that E(2)-induced mTOR activation is dependent on upstream activation of ERK and PI3K signaling.
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Affiliation(s)
- Ashley M Fortress
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, USA
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Feliciano DM, Zhang S, Quon JL, Bordey A. Hypoxia-inducible factor 1a is a Tsc1-regulated survival factor in newborn neurons in tuberous sclerosis complex. Hum Mol Genet 2013; 22:1725-34. [PMID: 23349360 DOI: 10.1093/hmg/ddt018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is a genetic disorder caused by mutations in TSC1 or TSC2 resulting in hyperactivity of the mammalian target of rapamycin and disabling brain lesions. These lesions contain misplaced neurons enriched in hypoxia-inducible factor 1a (HIF1a). However, the relationship between TSC1/2 and HIF1a and the function of HIF1a in TSC neurons remain unexplored. Here, we examine the degree of HIF1a activity and its function in newborn Tsc1(null) neurons in a mouse model of TSC. Using single cell electroporation in the neurogenic subventricular zone (SVZ) of neonatal mice, we deleted Tsc1 and generated olfactory lesions containing misplaced Tsc1(null) neurons as previously reported. These newborn neurons displayed elevated HIF1a-mediated transcriptional activity when compared with Tsc1 heterozygote neurons and a marked resistance to cell death induced by a HIF1a antagonist. Electroporation of Hif1a targeting short hairpin RNA (shRNA) or dominant negative HIF1a constructs resulted in 80-90% loss of Tsc1(null) newborn neurons although sparing SVZ stem cells. Consistent with this later finding, induction of Hif1a shRNA expression during synaptic integration thus bypassing neuron production also resulted in newborn neuron death. Collectively, these results suggest that HIF1a acts as a molecular determinant of newborn neuron survival and that its TSC1-dependent up-regulation gave Tsc1(null) neurons a survival advantage, despite their misplacement in a novel microenvironment.
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Affiliation(s)
- David M Feliciano
- Department of Neurosurgery, Yale University School of Medicine, New Haven, CT, USA
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A comprehensive small interfering RNA screen identifies signaling pathways required for gephyrin clustering. J Neurosci 2013; 32:14821-34. [PMID: 23077067 DOI: 10.1523/jneurosci.1261-12.2012] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The postsynaptic scaffold protein gephyrin is clustered at inhibitory synapses and serves for the stabilization of GABA(A) receptors. Here, a comprehensive kinome-wide siRNA screen in a human HeLa cell-based model for gephyrin clustering was used to identify candidate protein kinases implicated in the stabilization of gephyrin clusters. As a result, 12 hits were identified including FGFR1 (FGF receptor 1), TrkB, and TrkC as well as components of the MAPK and mammalian target of rapamycin (mTOR) pathways. For confirmation, the impact of these hits on gephyrin clustering was analyzed in rat primary hippocampal neurons. We found that brain-derived neurotrophic factor (BDNF) acts on gephyrin clustering through MAPK signaling, and this process may be controlled by the MAPK signaling antagonist sprouty2. BDNF signaling through phosphatidylinositol 3-kinase (PI3K)-Akt also activates mTOR and represses GSK3β, which was previously shown to reduce gephyrin clustering. Gephyrin is associated with inactive mTOR and becomes released upon BDNF-dependent mTOR activation. In primary neurons, a reduction in the number of gephyrin clusters due to manipulation of the BDNF-mTOR signaling is associated with reduced GABA(A) receptor clustering, suggesting functional impairment of GABA signaling. Accordingly, application of the mTOR antagonist rapamycin leads to disinhibition of neuronal networks as measured on microelectrode arrays. In conclusion, we provide evidence that BDNF regulates gephyrin clustering via MAPK as well as PI3K-Akt-mTOR signaling.
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Leung HTT, Ring H. Epilepsy in four genetically determined syndromes of intellectual disability. JOURNAL OF INTELLECTUAL DISABILITY RESEARCH : JIDR 2013; 57:3-20. [PMID: 22142420 DOI: 10.1111/j.1365-2788.2011.01505.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
BACKGROUND Epilepsy occurs with increased frequency in people with an intellectual disability (ID) compared to the rest of the population. A variety of research has in recent years shed light on genetic and biochemical aetiologies of epilepsy and, often in a different literature, on syndromes of ID. The aims of this annotation are to review developments in understanding of the pathophysiology of several ID syndromes in which epilepsy is a frequent co-occurrence and to relate these observations to recent advances in understanding of how these pathophysiological disturbances may lead to epilepsy. METHOD The ID syndromes selected for review were fragile X (FXS), Rett (RTT) and Angelman syndromes (AS) and tuberous sclerosis complex (TSC). Epilepsy is a significant aspect of these syndromes and relevant research into the genetic and biochemical pathophysiology of these four ID syndromes may be informative in establishing the association between epilepsy and ID. Employing a structured approach the authors initially searched the PubMed database for large case series describing the characteristics of epilepsy as manifested in these ID syndromes. The criteria for inclusion of the case series in the review were a sample size of greater than 50 and the description of several of the characteristic features of epilepsy, namely prevalence of seizures, age of seizure onset, seizure frequency, seizure semiology, severity and treatment. Following this, studies of the genetic and biochemical pathophysiology of these four ID syndromes were reviewed and the potential relevance of this research in understanding the association with epilepsy highlighted. Findings were considered in a focused manner in terms of effects on excitatory and inhibitory neurotransmitter systems and on glial function. RESULTS Diverse genetic pathologies underlying several ID syndromes can lead to alterations in the functioning of the glutamatergic and GABAergic neurotransmitter systems. The mechanisms involved include transcriptional regulation in RTT, translational regulation in FXS and TSC, and UBE3A-mediated proteolysis in AS. Expression or functioning of receptor subunits, uptake sites and enzymes involved in neurotransmitter metabolism are often affected by these changes, and may lead to modifications in network excitability and neuronal plasticity that may contribute to epileptogenesis and ID. Dysfunction in astrocytes may also contribute to epileptogenesis and ID in FXS, RTT and TSC with potential mechanisms including failure of astrocytic support functions, glial inflammation and homeostatic disturbances that affect the excitability and architecture of neuronal networks. CONCLUSIONS The annotation highlights research describing disturbances in excitatory and inhibitory neurotransmitter systems, neuronal ion channel and glial functions that provide possible explanations for the co-occurrence of seizures within several ID syndromes, in some cases suggesting possible avenues for research into novel therapeutic targets. Phenotypic overlaps between syndromes may also relate to roles for the implicated genes in different disturbances in linked biochemical pathways.
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Affiliation(s)
- H T T Leung
- Christ's College, University of Cambridge, UK
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Millan MJ. An epigenetic framework for neurodevelopmental disorders: from pathogenesis to potential therapy. Neuropharmacology 2012; 68:2-82. [PMID: 23246909 DOI: 10.1016/j.neuropharm.2012.11.015] [Citation(s) in RCA: 151] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2012] [Revised: 11/11/2012] [Accepted: 11/22/2012] [Indexed: 12/12/2022]
Abstract
Neurodevelopmental disorders (NDDs) are characterized by aberrant and delayed early-life development of the brain, leading to deficits in language, cognition, motor behaviour and other functional domains, often accompanied by somatic symptoms. Environmental factors like perinatal infection, malnutrition and trauma can increase the risk of the heterogeneous, multifactorial and polygenic disorders, autism and schizophrenia. Conversely, discrete genetic anomalies are involved in Down, Rett and Fragile X syndromes, tuberous sclerosis and neurofibromatosis, the less familiar Phelan-McDermid, Sotos, Kleefstra, Coffin-Lowry and "ATRX" syndromes, and the disorders of imprinting, Angelman and Prader-Willi syndromes. NDDs have been termed "synaptopathies" in reference to structural and functional disturbance of synaptic plasticity, several involve abnormal Ras-Kinase signalling ("rasopathies"), and many are characterized by disrupted cerebral connectivity and an imbalance between excitatory and inhibitory transmission. However, at a different level of integration, NDDs are accompanied by aberrant "epigenetic" regulation of processes critical for normal and orderly development of the brain. Epigenetics refers to potentially-heritable (by mitosis and/or meiosis) mechanisms controlling gene expression without changes in DNA sequence. In certain NDDs, prototypical epigenetic processes of DNA methylation and covalent histone marking are impacted. Conversely, others involve anomalies in chromatin-modelling, mRNA splicing/editing, mRNA translation, ribosome biogenesis and/or the regulatory actions of small nucleolar RNAs and micro-RNAs. Since epigenetic mechanisms are modifiable, this raises the hope of novel therapy, though questions remain concerning efficacy and safety. The above issues are critically surveyed in this review, which advocates a broad-based epigenetic framework for understanding and ultimately treating a diverse assemblage of NDDs ("epigenopathies") lying at the interface of genetic, developmental and environmental processes. This article is part of the Special Issue entitled 'Neurodevelopmental Disorders'.
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Affiliation(s)
- Mark J Millan
- Unit for Research and Discovery in Neuroscience, IDR Servier, 125 chemin de ronde, 78290 Croissy sur Seine, Paris, France.
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Insulin and IGF-1 signalling: longevity, protein homoeostasis and Alzheimer's disease. Biochem Soc Trans 2012; 40:721-7. [PMID: 22817723 DOI: 10.1042/bst20120080] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The quality control of protein homoeostasis deteriorates with aging, causing the accumulation of misfolded proteins and neurodegeneration. Thus, in AD (Alzheimer's disease), soluble oligomers, protofibrils and fibrils of the Aβ (amyloid β-peptide) and tau protein accumulate in specific brain regions. This is associated with the progressive destruction of synaptic circuits controlling memory and higher mental function. The primary signalling mechanisms that (i) become defective in AD to alter the normal proteostasis of Aβ and tau, and (ii) initiate a pathophysiological response to cause cognitive decline, are unclear. The IIS [insulin/IGF-1 (insulin-like growth factor 1)-like signalling] pathway is mechanistically linked to longevity, protein homoeostasis, learning and memory, and is emerging to be central to both (i) and (ii). This pathway is aberrantly overactivated in AD brain at the level of increased activation of the serine/threonine kinase Akt and the phosphorylation of its downstream targets, including mTOR (mammalian target of rapamycin). Feedback inhibition of normal insulin/IGF activation of the pathway also occurs in AD due to inactivation of IRS-1 (insulin receptor substrate 1) and decreased IRS-1/2 levels. Pathogenic forms of Aβ may induce aberrant sustained activation of the PI3K (phosphoinositide 3-kinase)/Akt signal in AD, also causing non-responsive insulin and IGF-1 receptor, and altered tau phosphorylation, conformation and function. Reducing IIS activity in animal models by decreasing IGF-1R levels or inhibiting mTOR activity alters Aβ and tau protein homoeostasis towards less toxic protein conformations, improves cognitive function and extends healthy lifespan. Thus normalizing IIS dysfunction may be therapeutically relevant in abrogating Aβ and tau proteotoxicity, synaptic dysfunction and cognitive decline in AD.
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Davies DM. Tuberous sclerosis: from gene to targeted therapy. Clin Med (Lond) 2012. [DOI: 10.7861/clinmedicine.12-6-s7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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