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Morin-Parent F, Champigny C, Côté S, Mohamad T, Hasani SA, Çaku A, Corbin F, Lepage JF. Neurophysiological effects of a combined treatment of lovastatin and minocycline in patients with fragile X syndrome: Ancillary results of the LOVAMIX randomized clinical trial. Autism Res 2024. [PMID: 39248107 DOI: 10.1002/aur.3222] [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: 06/04/2024] [Accepted: 08/09/2024] [Indexed: 09/10/2024]
Abstract
Fragile X syndrome (FXS) is the primary hereditary cause of intellectual disability and autism spectrum disorder. It is characterized by exacerbated neuronal excitability, and its correction is considered an objective measure of treatment response in animal models, a marker albeit rarely used in clinical trials. Here, we used an extensive transcranial magnetic stimulation (TMS) battery to assess the neurophysiological effects of a therapy combining two disease-modifying drugs, lovastatin (40 mg) and minocycline (100 mg), administered alone for 8 weeks and in combination for 12 weeks, in 19 patients (mean age of 23.58 ± 1.51) with FXS taking part in the LOVAmix trial. The TMS battery, which included the resting motor threshold, short-interval intracortical inhibition, long-interval intracortical inhibition, corticospinal silent period, and intracortical facilitation, was completed at baseline after 8 weeks of monotherapy (visit 2 of the clinical trial) and after 12 weeks of dual therapy (visit 4 of the clinical trial). Repeated measure ANOVAs were performed between baseline and visit 2 (monotherapy) and visit 3 (dual therapy) with interactions for which monotherapy the participants received when they began the clinical trial. Results showed that dual therapy was associated with reduced cortical excitability after 20 weeks. This was reflected by a significant increase in the resting-motor threshold after dual therapy compared to baseline. There was a tendency for enhanced short-intracortical inhibition, a marker of GABAa-mediated inhibition after 8 weeks of monotherapy compared to baseline. Together, these results suggest that a combined therapy of minocycline and lovastatin might act on the core neurophysiopathology of FXS. This trial was registered at clinicaltrials.gov (NCT02680379).
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Affiliation(s)
- Florence Morin-Parent
- Department of Pediatrics, Faculty of Medicine and Health Sciences, Sherbrooke University, Sherbrooke, Canada
- Sherbrooke University Hospital Research Center, Sherbrooke, Canada
| | - Camille Champigny
- Sherbrooke University Hospital Research Center, Sherbrooke, Canada
- Department of Biochemistry and Functional Genomics, Faculty of Medicine and Health Sciences Sherbrooke University, Sherbrooke, Canada
| | - Samantha Côté
- Department of Pediatrics, Faculty of Medicine and Health Sciences, Sherbrooke University, Sherbrooke, Canada
| | - Teddy Mohamad
- Department of Pediatrics, Faculty of Medicine and Health Sciences, Sherbrooke University, Sherbrooke, Canada
- Sherbrooke University Hospital Research Center, Sherbrooke, Canada
| | - Seyede Anis Hasani
- Department of Pediatrics, Faculty of Medicine and Health Sciences, Sherbrooke University, Sherbrooke, Canada
- Sherbrooke University Hospital Research Center, Sherbrooke, Canada
| | - Artuela Çaku
- Sherbrooke University Hospital Research Center, Sherbrooke, Canada
- Department of Biochemistry and Functional Genomics, Faculty of Medicine and Health Sciences Sherbrooke University, Sherbrooke, Canada
| | - François Corbin
- Sherbrooke University Hospital Research Center, Sherbrooke, Canada
- Department of Biochemistry and Functional Genomics, Faculty of Medicine and Health Sciences Sherbrooke University, Sherbrooke, Canada
| | - Jean-François Lepage
- Department of Pediatrics, Faculty of Medicine and Health Sciences, Sherbrooke University, Sherbrooke, Canada
- Sherbrooke University Hospital Research Center, Sherbrooke, Canada
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2
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Lingwood C. Is cholesterol both the lock and key to abnormal transmembrane signals in Autism Spectrum Disorder? Lipids Health Dis 2024; 23:114. [PMID: 38643132 PMCID: PMC11032007 DOI: 10.1186/s12944-024-02075-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 03/08/2024] [Indexed: 04/22/2024] Open
Abstract
Disturbances in cholesterol homeostasis have been associated with ASD. Lipid rafts are central in many transmembrane signaling pathways (including mTOR) and changes in raft cholesterol content affect their order function. Cholesterol levels are controlled by several mechanisms, including endoplasmic reticulum associated degradation (ERAD) of the rate limiting HMGCoA reductase. A new approach to increase cholesterol via temporary ERAD blockade using a benign bacterial toxin-derived competitor for the ERAD translocon is suggested.A new lock and key model for cholesterol/lipid raft dependent signaling is proposed in which the rafts provide both the afferent and efferent 'tumblers' across the membrane to allow 'lock and key' receptor transmembrane signals.
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Affiliation(s)
- Clifford Lingwood
- Division of Molecular Medicine, Research Institute, Peter Gilgan Centre for Research and Learning, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada.
- Departments of Biochemistry and Laboratory Medicine & Pathobiology, University of Toronto, Ontario, M5S 1A8, Canada.
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3
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Lee HB, Khan R, Vally M, Orchard A. A scoping review on natural cholesterol lowering supplements sold in South African pharmacies. Health SA 2024; 29:2299. [PMID: 38445038 PMCID: PMC10913186 DOI: 10.4102/hsag.v29i0.2299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 10/30/2023] [Indexed: 03/07/2024] Open
Abstract
Background Dyslipidaemia is defined as elevated total or low-density lipoprotein (LDL) levels or low levels of high-density lipoprotein (HDL). Patients may often make use of natural cholesterol lowering supplements (NCLSs) available at the pharmacy; however, limited information on these supplements is readily available. Pharmacists should be knowledgeable about NCLSs to ensure that the use of these supplements is supported by evidence and to provide appropriate advice to patients for desirable therapeutic outcomes. Aim This study aimed to identify the NCLSs being sold in South African pharmacies and review the scientific evidence for each of the ingredients in these NCLSs. Methods Seventeen NCLS products were identified, and the Joanna Briggs Institute (JBI) scoping review methodology was used to conduct a literature review of NCLSs. Results From the ingredients reviewed it is evident that co-enzyme Q10, probiotics and sterols have sufficient evidence supporting their use. However, there is still limited scientific evidence available to validate the remaining ingredients. Conclusion Further research on NCLSs will provide practising pharmacists and practitioners with a guide of the evidence available on the various ingredients in NCLSs. Contribution This study provides a review of the available literature on the NCLSs being sold in the pharmacies across South Africa to provide pharmacists with a collated document of the evidence behind these popular supplements to assist them in making evidence based informed decision regarding natural products for cholesterol.
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Affiliation(s)
- Hyeon Bok Lee
- Department of Pharmacy and Pharmacology, Division of Clinical Pharmacy, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Razeeya Khan
- Department of Pharmacy and Pharmacology, Division of Clinical Pharmacy, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Muhammed Vally
- Department of Pharmacy and Pharmacology, Division of Clinical Pharmacy, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Ané Orchard
- Department of Pharmacy and Pharmacology, Division of Clinical Pharmacy, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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4
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Talvio K, Castrén ML. Astrocytes in fragile X syndrome. Front Cell Neurosci 2024; 17:1322541. [PMID: 38259499 PMCID: PMC10800791 DOI: 10.3389/fncel.2023.1322541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 12/11/2023] [Indexed: 01/24/2024] Open
Abstract
Astrocytes have an important role in neuronal maturation and synapse function in the brain. The interplay between astrocytes and neurons is found to be altered in many neurodevelopmental disorders, including fragile X syndrome (FXS) that is the most common inherited cause of intellectual disability and autism spectrum disorder. Transcriptional, functional, and metabolic alterations in Fmr1 knockout mouse astrocytes, human FXS stem cell-derived astrocytes as well as in in vivo models suggest autonomous effects of astrocytes in the neurobiology of FXS. Abnormalities associated with FXS astrocytes include differentiation of central nervous system cell populations, maturation and regulation of synapses, and synaptic glutamate balance. Recently, FXS-specific changes were found more widely in astrocyte functioning, such as regulation of inflammatory pathways and maintenance of lipid homeostasis. Changes of FXS astrocytes impact the brain homeostasis and function both during development and in the adult brain and offer opportunities for novel types of approaches for intervention.
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Affiliation(s)
| | - Maija L. Castrén
- Department of Physiology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
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5
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Talvio K, Wagner VA, Minkeviciene R, Kirkwood JS, Kulinich AO, Umemori J, Bhatia A, Hur M, Käkelä R, Ethell IM, Castrén ML. An iPSC-derived astrocyte model of fragile X syndrome exhibits dysregulated cholesterol homeostasis. Commun Biol 2023; 6:789. [PMID: 37516746 PMCID: PMC10387075 DOI: 10.1038/s42003-023-05147-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 07/14/2023] [Indexed: 07/31/2023] Open
Abstract
Cholesterol is an essential membrane structural component and steroid hormone precursor, and is involved in numerous signaling processes. Astrocytes regulate brain cholesterol homeostasis and they supply cholesterol to the needs of neurons. ATP-binding cassette transporter A1 (ABCA1) is the main cholesterol efflux transporter in astrocytes. Here we show dysregulated cholesterol homeostasis in astrocytes generated from human induced pluripotent stem cells (iPSCs) derived from males with fragile X syndrome (FXS), which is the most common cause of inherited intellectual disability. ABCA1 levels are reduced in FXS human and mouse astrocytes when compared with controls. Accumulation of cholesterol associates with increased desmosterol and polyunsaturated phospholipids in the lipidome of FXS mouse astrocytes. Abnormal astrocytic responses to cytokine exposure together with altered anti-inflammatory and cytokine profiles of human FXS astrocyte secretome suggest contribution of inflammatory factors to altered cholesterol homeostasis. Our results demonstrate changes of astrocytic lipid metabolism, which can critically regulate membrane properties and affect cholesterol transport in FXS astrocytes, providing target for therapy in FXS.
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Affiliation(s)
- Karo Talvio
- Department of Physiology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Victoria A Wagner
- Division of Biomedical Sciences, and Neuroscience Graduate Program, School of Medicine, University of California Riverside, Riverside, CA, USA
| | - Rimante Minkeviciene
- Department of Physiology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Jay S Kirkwood
- Metabolomics Core Facility, Institute for Integrative Genome Biology, University of California Riverside, Riverside, CA, USA
| | - Anna O Kulinich
- Division of Biomedical Sciences, and Neuroscience Graduate Program, School of Medicine, University of California Riverside, Riverside, CA, USA
| | - Juzoh Umemori
- Gene and Cell Technology, A.I.Virtanen Institute, University of Eastern Finland, Kuopio, Finland
| | - Anil Bhatia
- Metabolomics Core Facility, Institute for Integrative Genome Biology, University of California Riverside, Riverside, CA, USA
| | - Manhoi Hur
- Metabolomics Core Facility, Institute for Integrative Genome Biology, University of California Riverside, Riverside, CA, USA
| | - Reijo Käkelä
- Helsinki University Lipidomics Unit, HiLIPID, Helsinki Institute of Life Science, HiLIFE, Biocenter Finland (Metabolomics), and Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Iryna M Ethell
- Division of Biomedical Sciences, and Neuroscience Graduate Program, School of Medicine, University of California Riverside, Riverside, CA, USA
| | - Maija L Castrén
- Department of Physiology, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
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6
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Louros SR, Seo SS, Maio B, Martinez-Gonzalez C, Gonzalez-Lozano MA, Muscas M, Verity NC, Wills JC, Li KW, Nolan MF, Osterweil EK. Excessive proteostasis contributes to pathology in fragile X syndrome. Neuron 2023; 111:508-525.e7. [PMID: 36495869 DOI: 10.1016/j.neuron.2022.11.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 09/06/2022] [Accepted: 11/16/2022] [Indexed: 12/13/2022]
Abstract
In fragile X syndrome (FX), the leading monogenic cause of autism, excessive neuronal protein synthesis is a core pathophysiology; however, an overall increase in protein expression is not observed. Here, we tested whether excessive protein synthesis drives a compensatory rise in protein degradation that is protective for FX mouse model (Fmr1-/y) neurons. Surprisingly, although we find a significant increase in protein degradation through ubiquitin proteasome system (UPS), this contributes to pathological changes. Normalizing proteasome activity with bortezomib corrects excessive hippocampal protein synthesis and hyperactivation of neurons in the inferior colliculus (IC) in response to auditory stimulation. Moreover, systemic administration of bortezomib significantly reduces the incidence and severity of audiogenic seizures (AGS) in the Fmr1-/y mouse, as does genetic reduction of proteasome, specifically in the IC. Together, these results identify excessive activation of the UPS pathway in Fmr1-/y neurons as a contributor to multiple phenotypes that can be targeted for therapeutic intervention.
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Affiliation(s)
- Susana R Louros
- Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK; Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
| | - Sang S Seo
- Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK; Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
| | - Beatriz Maio
- Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK; Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
| | - Cristina Martinez-Gonzalez
- Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK; Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
| | - Miguel A Gonzalez-Lozano
- Department of Molecular and Cellular Neurobiology, Centre for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Melania Muscas
- Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK; Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
| | - Nick C Verity
- Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK; Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
| | - Jimi C Wills
- CRUK Edinburgh Centre, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
| | - Ka Wan Li
- Department of Molecular and Cellular Neurobiology, Centre for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Matthew F Nolan
- Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK; Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
| | - Emily K Osterweil
- Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK; Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK.
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7
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Leahy SN, Song C, Vita DJ, Broadie K. FMRP activity and control of Csw/SHP2 translation regulate MAPK-dependent synaptic transmission. PLoS Biol 2023; 21:e3001969. [PMID: 36701299 PMCID: PMC9879533 DOI: 10.1371/journal.pbio.3001969] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 12/16/2022] [Indexed: 01/27/2023] Open
Abstract
Noonan syndrome (NS) and NS with multiple lentigines (NSML) cognitive dysfunction are linked to SH2 domain-containing protein tyrosine phosphatase-2 (SHP2) gain-of-function (GoF) and loss-of-function (LoF), respectively. In Drosophila disease models, we find both SHP2 mutations from human patients and corkscrew (csw) homolog LoF/GoF elevate glutamatergic transmission. Cell-targeted RNAi and neurotransmitter release analyses reveal a presynaptic requirement. Consistently, all mutants exhibit reduced synaptic depression during high-frequency stimulation. Both LoF and GoF mutants also show impaired synaptic plasticity, including reduced facilitation, augmentation, and post-tetanic potentiation. NS/NSML diseases are characterized by elevated MAPK/ERK signaling, and drugs suppressing this signaling restore normal neurotransmission in mutants. Fragile X syndrome (FXS) is likewise characterized by elevated MAPK/ERK signaling. Fragile X Mental Retardation Protein (FMRP) binds csw mRNA and neuronal Csw protein is elevated in Drosophila fragile X mental retardation 1 (dfmr1) nulls. Moreover, phosphorylated ERK (pERK) is increased in dfmr1 and csw null presynaptic boutons. We find presynaptic pERK activation in response to stimulation is reduced in dfmr1 and csw nulls. Trans-heterozygous csw/+; dfmr1/+ recapitulate elevated presynaptic pERK activation and function, showing FMRP and Csw/SHP2 act within the same signaling pathway. Thus, a FMRP and SHP2 MAPK/ERK regulative mechanism controls basal and activity-dependent neurotransmission strength.
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Affiliation(s)
- Shannon N. Leahy
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, Tennessee, United States of America
| | - Chunzhu Song
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, Tennessee, United States of America
| | - Dominic J. Vita
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, Tennessee, United States of America
| | - Kendal Broadie
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, Tennessee, United States of America
- Department of Cell and Developmental Biology, Vanderbilt University and Medical Center, Nashville, Tennessee, United States of America
- Department of Pharmacology, Vanderbilt University and Medical Center, Nashville, Tennessee, United States of America
- Vanderbilt Brain Institute, Vanderbilt University and Medical Center, Nashville, Tennessee, United States of America
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8
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Lacroix A, Proteau-Lemieux M, Côté S, Near J, Hui SC, Edden RA, Lippé S, Çaku A, Corbin F, Lepage JF. Multimodal assessment of the GABA system in patients with fragile-X syndrome and neurofibromatosis of type 1. Neurobiol Dis 2022; 174:105881. [DOI: 10.1016/j.nbd.2022.105881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 09/12/2022] [Accepted: 10/02/2022] [Indexed: 11/24/2022] Open
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9
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Brain Cholesterol Biosynthetic Pathway Is Altered in a Preclinical Model of Fragile X Syndrome. Int J Mol Sci 2022; 23:ijms23063408. [PMID: 35328827 PMCID: PMC8955806 DOI: 10.3390/ijms23063408] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 03/08/2022] [Accepted: 03/18/2022] [Indexed: 12/02/2022] Open
Abstract
Fragile X Syndrome (FXS) is the most frequent form of inherited X-linked pathology, associated with an intellectual and developmental disability, and currently considered the first monogenic cause of autism spectrum disorder (ASD). Low levels of total cholesterol reported in the serum of FXS patients, and evidence that FMRP targets a subset of mRNAs encoding proteins of lipid synthesis and transport suggests that the cholesterol metabolism impairments could be involved in FXS. Thus, the aim of the presented work was to investigate the modulations of the cholesterol biosynthetic pathway and its end-products in a recently developed Fmr1-Δexon 8 rat model of FXS. Here, we show that this experimental model mimics what is found in FXS patients, exhibiting a lower serum cholesterol content, accompanied by a reduction in food intake and body weight compared to WT animals. Moreover, alterations of proteins committed to cholesterol synthesis and uptake have been observed in the amygdala, prefrontal cortex and nucleus accumbens. Interestingly, the end-products show a brain region-dependent modulation in Fmr1-Δexon 8 rats. Overall, our results demonstrate that the cholesterol biosynthetic pathway is altered in some brain regions of this preclinical model of FXS. This finding has relevance for future studies to delve deeper into the involvement of this metabolic process in FXS, and thus its possible role as a therapeutic target.
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10
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Romagnoli A, Di Marino D. The Use of Peptides in the Treatment of Fragile X Syndrome: Challenges and Opportunities. Front Psychiatry 2021; 12:754485. [PMID: 34803767 PMCID: PMC8599826 DOI: 10.3389/fpsyt.2021.754485] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 10/11/2021] [Indexed: 01/17/2023] Open
Abstract
Fragile X Syndrome (FXS) is the most frequent cause of inherited intellectual disabilities and autism spectrum disorders, characterized by cognitive deficits and autistic behaviors. The silencing of the Fmr1 gene and consequent lack of FMRP protein, is the major contribution to FXS pathophysiology. FMRP is an RNA binding protein involved in the maturation and plasticity of synapses and its absence culminates in a range of morphological, synaptic and behavioral phenotypes. Currently, there are no approved medications for the treatment of FXS, with the approaches under study being fairly specific and unsatisfying in human trials. Here we propose peptides/peptidomimetics as candidates in the pharmacotherapy of FXS; in the last years this class of molecules has catalyzed the attention of pharmaceutical research, being highly selective and well-tolerated. Thanks to their ability to target protein-protein interactions (PPIs), they are already being tested for a wide range of diseases, including cancer, diabetes, inflammation, Alzheimer's disease, but this approach has never been applied to FXS. As FXS is at the forefront of efforts to develop new drugs and approaches, we discuss opportunities, challenges and potential issues of peptides/peptidomimetics in FXS drug design and development.
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Affiliation(s)
| | - Daniele Di Marino
- Department of Life and Environmental Sciences, New York-Marche Structural Biology Center (NY-MaSBiC), Polytechnic University of Marche, Ancona, Italy
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11
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Hagerman RJ, Hagerman PJ. Fragile X Syndrome: Lessons Learned and What New Treatment Avenues Are on the Horizon. Annu Rev Pharmacol Toxicol 2021; 62:365-381. [PMID: 34499526 DOI: 10.1146/annurev-pharmtox-052120-090147] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Fragile X syndrome (FXS) is the most common form of inherited intellectual disability and the leading single-gene form of autism spectrum disorder, encompassing cognitive, behavioral, and physical forms of clinical involvement. FXS is caused by large expansions of a noncoding CGG repeat (>200 repeats) in the FMR1 gene, at which point the gene is generally silenced. Absence of FMR1 protein (FMRP), important for synaptic development and maintenance, gives rise to the neurodevelopmental disorder. There is, at present, no therapeutic approach that directly reverses the loss of FMRP; however, there is an increasing number of potential treatments that target the pathways dysregulated in FXS, including those that address the enhanced activity of the mGluR5 pathway and deficits in GABA pathways. Based on studies of targeted therapeutics to date, the prospects are good for one or more effective therapies for FXS in the near future. Expected final online publication date for the Annual Review of Pharmacology and Toxicology, Volume 62 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Randi J Hagerman
- Department of Pediatrics, University of California, Davis, School of Medicine, Sacramento, California 95817, USA; .,MIND Institute, University of California Davis Health, Sacramento, California 95817, USA
| | - Paul J Hagerman
- MIND Institute, University of California Davis Health, Sacramento, California 95817, USA.,Department of Biochemistry and Molecular Medicine, University of California, Davis, School of Medicine, Davis, California 95616, USA;
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12
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Reyes ST, Deacon RMJ, Guo SG, Altimiras FJ, Castillo JB, van der Wildt B, Morales AP, Park JH, Klamer D, Rosenberg J, Oberman LM, Rebowe N, Sprouse J, Missling CU, McCurdy CR, Cogram P, Kaufmann WE, Chin FT. Effects of the sigma-1 receptor agonist blarcamesine in a murine model of fragile X syndrome: neurobehavioral phenotypes and receptor occupancy. Sci Rep 2021; 11:17150. [PMID: 34433831 PMCID: PMC8387417 DOI: 10.1038/s41598-021-94079-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 06/21/2021] [Indexed: 11/08/2022] Open
Abstract
Fragile X syndrome (FXS), a disorder of synaptic development and function, is the most prevalent genetic form of intellectual disability and autism spectrum disorder. FXS mouse models display clinically-relevant phenotypes, such as increased anxiety and hyperactivity. Despite their availability, so far advances in drug development have not yielded new treatments. Therefore, testing novel drugs that can ameliorate FXS' cognitive and behavioral impairments is imperative. ANAVEX2-73 (blarcamesine) is a sigma-1 receptor (S1R) agonist with a strong safety record and preliminary efficacy evidence in patients with Alzheimer's disease and Rett syndrome, other synaptic neurodegenerative and neurodevelopmental disorders. S1R's role in calcium homeostasis and mitochondrial function, cellular functions related to synaptic function, makes blarcamesine a potential drug candidate for FXS. Administration of blarcamesine in 2-month-old FXS and wild type mice for 2 weeks led to normalization in two key neurobehavioral phenotypes: open field test (hyperactivity) and contextual fear conditioning (associative learning). Furthermore, there was improvement in marble-burying (anxiety, perseverative behavior). It also restored levels of BDNF, a converging point of many synaptic regulators, in the hippocampus. Positron emission tomography (PET) and ex vivo autoradiographic studies, using the highly selective S1R PET ligand [18F]FTC-146, demonstrated the drug's dose-dependent receptor occupancy. Subsequent analyses also showed a wide but variable brain regional distribution of S1Rs, which was preserved in FXS mice. Altogether, these neurobehavioral, biochemical, and imaging data demonstrates doses that yield measurable receptor occupancy are effective for improving the synaptic and behavioral phenotype in FXS mice. The present findings support the viability of S1R as a therapeutic target in FXS, and the clinical potential of blarcamesine in FXS and other neurodevelopmental disorders.
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Affiliation(s)
- Samantha T Reyes
- Department of Radiology, Stanford University, Stanford, CA, 94305, USA
| | - Robert M J Deacon
- FRAXA-DVI, FRAXA, Santiago, Chile
- IEB, Faculty of Science, University of Chile, Santiago, Chile
- Fraunhofer Chile Research, Center for Systems Biotechnology, Santiago, Chile
| | - Scarlett G Guo
- Department of Radiology, Stanford University, Stanford, CA, 94305, USA
| | - Francisco J Altimiras
- FRAXA-DVI, FRAXA, Santiago, Chile
- Faculty of Engineering and Business, Universidad de las Américas, Santiago, Chile
| | - Jessa B Castillo
- Department of Radiology, Stanford University, Stanford, CA, 94305, USA
| | | | - Aimara P Morales
- Department of Radiology, Stanford University, Stanford, CA, 94305, USA
| | - Jun Hyung Park
- Department of Radiology, Stanford University, Stanford, CA, 94305, USA
| | - Daniel Klamer
- Anavex Life Sciences Corp., New York, NY, 10019, USA
| | - Jarrett Rosenberg
- Department of Radiology, Stanford University, Stanford, CA, 94305, USA
| | - Lindsay M Oberman
- Center for Neuroscience & Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Nell Rebowe
- Anavex Life Sciences Corp., New York, NY, 10019, USA
| | | | | | - Christopher R McCurdy
- Department of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, FL, 32610, USA
| | - Patricia Cogram
- FRAXA-DVI, FRAXA, Santiago, Chile
- IEB, Faculty of Science, University of Chile, Santiago, Chile
- Fraunhofer Chile Research, Center for Systems Biotechnology, Santiago, Chile
| | - Walter E Kaufmann
- Anavex Life Sciences Corp., New York, NY, 10019, USA.
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, 30322, USA.
| | - Frederick T Chin
- Department of Radiology, Stanford University, Stanford, CA, 94305, USA.
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13
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Copping NA, McTighe SM, Fink KD, Silverman JL. Emerging Gene and Small Molecule Therapies for the Neurodevelopmental Disorder Angelman Syndrome. Neurotherapeutics 2021; 18:1535-1547. [PMID: 34528170 PMCID: PMC8608975 DOI: 10.1007/s13311-021-01082-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/26/2021] [Indexed: 02/07/2023] Open
Abstract
Angelman syndrome (AS) is a rare (~1:15,000) neurodevelopmental disorder characterized by severe developmental delay and intellectual disability, impaired communication skills, and a high prevalence of seizures, sleep disturbances, ataxia, motor deficits, and microcephaly. AS is caused by loss-of-function of the maternally inherited UBE3A gene. UBE3A is located on chromosome 15q11-13 and is biallelically expressed throughout the body but only maternally expressed in the brain due to an RNA antisense transcript that silences the paternal copy. There is currently no cure for AS, but advancements in small molecule drugs and gene therapies offer a promising approach for the treatment of the disorder. Here, we review AS and how loss-of-function of the maternal UBE3A contributes to the disorder. We also discuss the strengths and limitations of current animal models of AS. Furthermore, we examine potential small molecule drug and gene therapies for the treatment of AS and associated challenges faced by the therapeutic design. Finally, gene therapy offers the opportunity for precision medicine in AS and advancements in the treatment of this disorder can serve as a foundation for other single-gene neurodevelopmental disorders.
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Affiliation(s)
- Nycole A Copping
- School of Medicine, Department of Psychiatry and Behavioral Sciences, MIND Institute, University of California, Research II Building 96, 4625 2nd Avenue, Suite 1001B, Davis, Sacramento, CA, 95817, USA
- Stem Cell Program and Gene Therapy Center, Department of Neurology, MIND Institute, University of California, Davis, Sacramento, CA, USA
| | | | - Kyle D Fink
- Stem Cell Program and Gene Therapy Center, Department of Neurology, MIND Institute, University of California, Davis, Sacramento, CA, USA
| | - Jill L Silverman
- School of Medicine, Department of Psychiatry and Behavioral Sciences, MIND Institute, University of California, Research II Building 96, 4625 2nd Avenue, Suite 1001B, Davis, Sacramento, CA, 95817, USA.
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14
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Shukla T, de la Peña JB, Perish JM, Ploski JE, Stumpf CR, Webster KR, Thorn CA, Campbell ZT. A Highly Selective MNK Inhibitor Rescues Deficits Associated with Fragile X Syndrome in Mice. Neurotherapeutics 2021; 18:624-639. [PMID: 33006091 PMCID: PMC8116363 DOI: 10.1007/s13311-020-00932-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/12/2020] [Indexed: 12/22/2022] Open
Abstract
Fragile X syndrome (FXS) is the most common inherited source of intellectual disability in humans. FXS is caused by mutations that trigger epigenetic silencing of the Fmr1 gene. Loss of Fmr1 results in increased activity of the mitogen-activated protein kinase (MAPK) pathway. An important downstream consequence is activation of the mitogen-activated protein kinase interacting protein kinase (MNK). MNK phosphorylates the mRNA cap-binding protein, eukaryotic initiation factor 4E (eIF4E). Excessive phosphorylation of eIF4E has been directly implicated in the cognitive and behavioral deficits associated with FXS. Pharmacological reduction of eIF4E phosphorylation is one potential strategy for FXS treatment. We demonstrate that systemic dosing of a highly specific, orally available MNK inhibitor, eFT508, attenuates numerous deficits associated with loss of Fmr1 in mice. eFT508 resolves a range of phenotypic abnormalities associated with FXS including macroorchidism, aberrant spinogenesis, and alterations in synaptic plasticity. Key behavioral deficits related to anxiety, social interaction, obsessive and repetitive activities, and object recognition are ameliorated by eFT508. Collectively, this work establishes eFT508 as a potential means to reverse deficits associated with FXS.
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Affiliation(s)
- Tarjani Shukla
- Department of Biological Sciences, University of Texas at Dallas, 800 W. Campbell Road, Richardson, TX, 75080, USA
- Center for Advanced Pain Studies, University of Texas at Dallas, Richardson, TX, 75080, USA
| | - June Bryan de la Peña
- Department of Biological Sciences, University of Texas at Dallas, 800 W. Campbell Road, Richardson, TX, 75080, USA
- Center for Advanced Pain Studies, University of Texas at Dallas, Richardson, TX, 75080, USA
| | - John M Perish
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, 75080, USA
| | - Jonathan E Ploski
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, 75080, USA
| | | | | | - Catherine A Thorn
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, 75080, USA
| | - Zachary T Campbell
- Department of Biological Sciences, University of Texas at Dallas, 800 W. Campbell Road, Richardson, TX, 75080, USA.
- Center for Advanced Pain Studies, University of Texas at Dallas, Richardson, TX, 75080, USA.
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15
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Champigny C, Morin-Parent F, Bellehumeur-Lefebvre L, Çaku A, Lepage JF, Corbin F. Combining Lovastatin and Minocycline for the Treatment of Fragile X Syndrome: Results From the LovaMiX Clinical Trial. Front Psychiatry 2021; 12:762967. [PMID: 35058813 PMCID: PMC8763805 DOI: 10.3389/fpsyt.2021.762967] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 11/29/2021] [Indexed: 11/13/2022] Open
Abstract
Background: Limited success of previous clinical trials for Fragile X syndrome (FXS) has led researchers to consider combining different drugs to correct the pleiotropic consequences caused by the absence of the Fragile X mental retardation protein (FMRP). Here, we report the results of the LovaMiX clinical trial, the first trial for FXS combining two disease-modifying drugs, lovastatin, and minocycline, which have both shown positive effects when used independently. Aim: The main goals of the study were to assess the safety and efficacy of a treatment combining lovastatin and minocycline for patients with FXS. Design: Pilot Phase II open-label clinical trial. Patients with a molecular diagnostic of FXS were first randomized to receive, in two-step titration either lovastatin or minocycline for 8 weeks, followed by dual treatment with lovastatin 40 mg and minocycline 100 mg for 2 weeks. Clinical assessments were performed at the beginning, after 8 weeks of monotherapy, and at week 20 (12 weeks of combined therapy). Outcome Measures: The primary outcome measure was the Aberrant Behavior Checklist-Community (ABC-C) global score. Secondary outcome measures included subscales of the FXS specific ABC-C (ABC-CFX), the Anxiety, Depression, and Mood Scale (ADAMS), the Social Responsiveness Scale (SRS), the Behavior Rating Inventory of Executive Functions (BRIEF), and the Vineland Adaptive Behavior Scale second edition (VABS-II). Results: Twenty-one individuals out of 22 completed the trial. There were no serious adverse events related to the use of either drugs alone or in combination, suggesting good tolerability and safety profile of the combined therapy. Significant improvement was noted on the primary outcome measure with a 40% decrease on ABC-C global score with the combined therapy. Several outcome measures also showed significance. Conclusion: The combination of lovastatin and minocycline is safe in patients for FXS individuals and appears to improve several elements of the behavior. These results set the stage for a larger, placebo-controlled double-blind clinical trial to confirm the beneficial effects of the combined therapy.
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Affiliation(s)
- Camille Champigny
- Department of Biochemistry and Functional Genomics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada.,Centre de Recherche du CHUS (CRCHUS), Sherbrooke, QC, Canada
| | | | - Laurence Bellehumeur-Lefebvre
- Department of Biochemistry and Functional Genomics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada.,Centre de Recherche du CHUS (CRCHUS), Sherbrooke, QC, Canada
| | - Artuela Çaku
- Department of Biochemistry and Functional Genomics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada.,Centre de Recherche du CHUS (CRCHUS), Sherbrooke, QC, Canada
| | - Jean-François Lepage
- Centre de Recherche du CHUS (CRCHUS), Sherbrooke, QC, Canada.,Faculty of Medicine and Health Sciences, Department of Pediatrics, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - François Corbin
- Department of Biochemistry and Functional Genomics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada.,Centre de Recherche du CHUS (CRCHUS), Sherbrooke, QC, Canada
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16
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Licznerski P, Park HA, Rolyan H, Chen R, Mnatsakanyan N, Miranda P, Graham M, Wu J, Cruz-Reyes N, Mehta N, Sohail S, Salcedo J, Song E, Effman C, Effman S, Brandao L, Xu GN, Braker A, Gribkoff VK, Levy RJ, Jonas EA. ATP Synthase c-Subunit Leak Causes Aberrant Cellular Metabolism in Fragile X Syndrome. Cell 2020; 182:1170-1185.e9. [PMID: 32795412 DOI: 10.1016/j.cell.2020.07.008] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 03/04/2020] [Accepted: 07/10/2020] [Indexed: 12/26/2022]
Abstract
Loss of the gene (Fmr1) encoding Fragile X mental retardation protein (FMRP) causes increased mRNA translation and aberrant synaptic development. We find neurons of the Fmr1-/y mouse have a mitochondrial inner membrane leak contributing to a "leak metabolism." In human Fragile X syndrome (FXS) fibroblasts and in Fmr1-/y mouse neurons, closure of the ATP synthase leak channel by mild depletion of its c-subunit or pharmacological inhibition normalizes stimulus-induced and constitutive mRNA translation rate, decreases lactate and key glycolytic and tricarboxylic acid (TCA) cycle enzyme levels, and triggers synapse maturation. FMRP regulates leak closure in wild-type (WT), but not FX synapses, by stimulus-dependent ATP synthase β subunit translation; this increases the ratio of ATP synthase enzyme to its c-subunit, enhancing ATP production efficiency and synaptic growth. In contrast, in FXS, inability to close developmental c-subunit leak prevents stimulus-dependent synaptic maturation. Therefore, ATP synthase c-subunit leak closure encourages development and attenuates autistic behaviors.
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Affiliation(s)
- Pawel Licznerski
- Department of Internal Medicine, Section of Endocrinology, Yale University School of Medicine, New Haven, CT 06511, USA.
| | - Han-A Park
- Department of Internal Medicine, Section of Endocrinology, Yale University School of Medicine, New Haven, CT 06511, USA; Department of Human Nutrition and Hospitality Management, College of Human Environmental Sciences, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Harshvardhan Rolyan
- Department of Internal Medicine, Section of Endocrinology, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Rongmin Chen
- Department of Internal Medicine, Section of Endocrinology, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Nelli Mnatsakanyan
- Department of Internal Medicine, Section of Endocrinology, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Paige Miranda
- Department of Internal Medicine, Section of Endocrinology, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Morven Graham
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Jing Wu
- Department of Internal Medicine, Section of Endocrinology, Yale University School of Medicine, New Haven, CT 06511, USA
| | | | - Nikita Mehta
- Marine Biological Laboratory, Woods Hole, MA 02543, USA
| | - Sana Sohail
- Marine Biological Laboratory, Woods Hole, MA 02543, USA
| | - Jorge Salcedo
- Marine Biological Laboratory, Woods Hole, MA 02543, USA
| | - Erin Song
- Marine Biological Laboratory, Woods Hole, MA 02543, USA
| | | | - Samuel Effman
- Marine Biological Laboratory, Woods Hole, MA 02543, USA
| | - Lucas Brandao
- Department of Biology, Clark University, Worcester, MA 01610, USA
| | - Gulan N Xu
- Department of Internal Medicine, Section of Endocrinology, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Amber Braker
- Department of Internal Medicine, Section of Endocrinology, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Valentin K Gribkoff
- Department of Internal Medicine, Section of Endocrinology, Yale University School of Medicine, New Haven, CT 06511, USA; Marine Biological Laboratory, Woods Hole, MA 02543, USA
| | - Richard J Levy
- Department of Anesthesiology, Columbia University Medical Center, New York, NY 10032, USA
| | - Elizabeth A Jonas
- Department of Internal Medicine, Section of Endocrinology, Yale University School of Medicine, New Haven, CT 06511, USA; Marine Biological Laboratory, Woods Hole, MA 02543, USA.
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17
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A Differential Effect of Lovastatin versus Simvastatin in Neurodevelopmental Disorders. eNeuro 2020; 7:ENEURO.0162-20.2020. [PMID: 32651266 PMCID: PMC7433894 DOI: 10.1523/eneuro.0162-20.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 06/08/2020] [Accepted: 06/16/2020] [Indexed: 12/30/2022] Open
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18
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Telias M. Pharmacological Treatments for Fragile X Syndrome Based on Synaptic Dysfunction. Curr Pharm Des 2020; 25:4394-4404. [PMID: 31682210 DOI: 10.2174/1381612825666191102165206] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Accepted: 10/31/2019] [Indexed: 12/29/2022]
Abstract
BACKGROUND Fragile X syndrome (FXS) is the most common form of monogenic hereditary cognitive impairment, including intellectual disability, autism, hyperactivity, and epilepsy. METHODS This article reviews the literature pertaining to the role of synaptic dysfunction in FXS. RESULTS In FXS, synaptic dysfunction alters the excitation-inhibition ratio, dysregulating molecular and cellular processes underlying cognition, learning, memory, and social behavior. Decades of research have yielded important hypotheses that could explain, at least in part, the development of these neurological disorders in FXS patients. However, the main goal of translating lab research in animal models to pharmacological treatments in the clinic has been so far largely unsuccessful, leaving FXS a still incurable disease. CONCLUSION In this concise review, we summarize and analyze the main hypotheses proposed to explain synaptic dysregulation in FXS, by reviewing the scientific evidence that led to pharmaceutical clinical trials and their outcome.
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Affiliation(s)
- Michael Telias
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA, United States
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19
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Wiebe S, Nagpal A, Sonenberg N. Dysregulated translational control in brain disorders: from genes to behavior. Curr Opin Genet Dev 2020; 65:34-41. [PMID: 32535350 DOI: 10.1016/j.gde.2020.05.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 04/20/2020] [Accepted: 05/03/2020] [Indexed: 12/24/2022]
Abstract
Control of protein synthesis (mRNA translation) is essential for proper brain development and function. Perturbations to the mechanisms governing mRNA translation have repeatedly been shown to constitute a neurodegenerative, neuropsychiatric, and neurodevelopmental disorder risk factor. Developing effective therapeutics for brain disorders will require a better understanding of the molecular mechanisms underlying the control of protein synthesis in brain function. Studies using transgenic animal models have been invaluable towards this end, providing exciting new insights into the genetic basis of brain disorders with hopeful prospects for new and effective treatment options.
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Affiliation(s)
- Shane Wiebe
- Department of Biochemistry, McGill University, McIntyre Medical Building, 3655 Promenade Sir William Osler, Montreal, QC H3G 1Y6, Canada; Goodman Cancer Research Centre, 1160 Pine Avenue West, Montreal, QC H3A 1A3, Canada
| | - Anmol Nagpal
- Department of Biochemistry, McGill University, McIntyre Medical Building, 3655 Promenade Sir William Osler, Montreal, QC H3G 1Y6, Canada; Goodman Cancer Research Centre, 1160 Pine Avenue West, Montreal, QC H3A 1A3, Canada; Integrated Program in Neuroscience, McGill University, Montreal Neurological Institute, 3801 University Street, Montreal, QC H3A 2B4, Canada
| | - Nahum Sonenberg
- Department of Biochemistry, McGill University, McIntyre Medical Building, 3655 Promenade Sir William Osler, Montreal, QC H3G 1Y6, Canada; Goodman Cancer Research Centre, 1160 Pine Avenue West, Montreal, QC H3A 1A3, Canada.
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20
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Considerations for Clinical Therapeutic Development of Statins for Neurodevelopmental Disorders. eNeuro 2020; 7:ENEURO.0392-19.2020. [PMID: 32071072 PMCID: PMC7070444 DOI: 10.1523/eneuro.0392-19.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Revised: 01/10/2020] [Accepted: 01/15/2020] [Indexed: 12/18/2022] Open
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21
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McCullagh EA, Rotschafer SE, Auerbach BD, Klug A, Kaczmarek LK, Cramer KS, Kulesza RJ, Razak KA, Lovelace JW, Lu Y, Koch U, Wang Y. Mechanisms underlying auditory processing deficits in Fragile X syndrome. FASEB J 2020; 34:3501-3518. [PMID: 32039504 DOI: 10.1096/fj.201902435r] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 12/31/2019] [Accepted: 01/18/2020] [Indexed: 01/14/2023]
Abstract
Autism spectrum disorders (ASD) are strongly associated with auditory hypersensitivity or hyperacusis (difficulty tolerating sounds). Fragile X syndrome (FXS), the most common monogenetic cause of ASD, has emerged as a powerful gateway for exploring underlying mechanisms of hyperacusis and auditory dysfunction in ASD. This review discusses examples of disruption of the auditory pathways in FXS at molecular, synaptic, and circuit levels in animal models as well as in FXS individuals. These examples highlight the involvement of multiple mechanisms, from aberrant synaptic development and ion channel deregulation of auditory brainstem circuits, to impaired neuronal plasticity and network hyperexcitability in the auditory cortex. Though a relatively new area of research, recent discoveries have increased interest in auditory dysfunction and mechanisms underlying hyperacusis in this disorder. This rapidly growing body of data has yielded novel research directions addressing critical questions regarding the timing and possible outcomes of human therapies for auditory dysfunction in ASD.
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Affiliation(s)
- Elizabeth A McCullagh
- Department of Physiology and Biophysics, University of Colorado Anschutz, Aurora, CO, USA.,Department of Integrative Biology, Oklahoma State University, Stillwater, OK, USA
| | - Sarah E Rotschafer
- Department of Neurobiology and Behavior, University of California, Irvine, CA, USA.,Department of Biomedical Sciences, Mercer University School of Medicine, Savannah, GA, USA
| | - Benjamin D Auerbach
- Center for Hearing and Deafness, Department of Communicative Disorders & Sciences, SUNY at Buffalo, Buffalo, NY, USA
| | - Achim Klug
- Department of Physiology and Biophysics, University of Colorado Anschutz, Aurora, CO, USA
| | - Leonard K Kaczmarek
- Departments of Pharmacology and Cellular and Molecular Physiology, Yale University, New Haven, CT, USA
| | - Karina S Cramer
- Department of Neurobiology and Behavior, University of California, Irvine, CA, USA
| | - Randy J Kulesza
- Department of Anatomy, Lake Erie College of Osteopathic Medicine, Erie, PA, USA
| | - Khaleel A Razak
- Department of Psychology, University of California, Riverside, CA, USA
| | | | - Yong Lu
- Department of Anatomy and Neurobiology, College of Medicine, Northeast Ohio Medical University, Rootstown, OH, USA
| | - Ursula Koch
- Institute of Biology, Neurophysiology, Freie Universität Berlin, Berlin, Germany
| | - Yuan Wang
- Department of Biomedical Sciences, Program in Neuroscience, Florida State University, Tallahassee, FL, USA
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22
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Gonzalez D, Tomasek M, Hays S, Sridhar V, Ammanuel S, Chang CW, Pawlowski K, Huber KM, Gibson JR. Audiogenic Seizures in the Fmr1 Knock-Out Mouse Are Induced by Fmr1 Deletion in Subcortical, VGlut2-Expressing Excitatory Neurons and Require Deletion in the Inferior Colliculus. J Neurosci 2019; 39:9852-9863. [PMID: 31666356 PMCID: PMC6891051 DOI: 10.1523/jneurosci.0886-19.2019] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 09/06/2019] [Accepted: 10/16/2019] [Indexed: 02/07/2023] Open
Abstract
Fragile X syndrome (FXS) is the most common form of inherited intellectual disability and the leading monogenetic cause of autism. One symptom of FXS and autism is sensory hypersensitivity (also called sensory over-responsivity). Perhaps related to this, the audiogenic seizure (AGS) is arguably the most robust behavioral phenotype in the FXS mouse model-the Fmr1 knock-out (KO) mouse. Therefore, the AGS may be considered a mouse model of sensory hypersensitivity. Hyperactive circuits are hypothesized to underlie dysfunction in a number of brain regions in patients with FXS and Fmr1 KO mice, and the AGS may be a result of this. But the specific cell types and brain regions underlying AGSs in the Fmr1 KO are unknown. We used conditional deletion or expression of Fmr1 in different cell populations to determine whether Fmr1 deletion in those cells was sufficient or necessary, respectively, for the AGS phenotype in males. Our data indicate that Fmr1 deletion in glutamatergic neurons that express vesicular glutamate transporter 2 (VGlut2) and are located in subcortical brain regions is sufficient and necessary to cause AGSs. Furthermore, the deletion of Fmr1 in glutamatergic neurons of the inferior colliculus is necessary for AGSs. When we demonstrate necessity, we show that Fmr1 expression in either the larger population of VGlut2-expressing glutamatergic neurons or the smaller population of inferior collicular glutamatergic neurons-in an otherwise Fmr1 KO mouse-eliminates AGSs. Therefore, targeting these neuronal populations in FXS and autism may be part of a therapeutic strategy to alleviate sensory hypersensitivity.SIGNIFICANCE STATEMENT Sensory hypersensitivity in fragile X syndrome (FXS) and autism patients significantly interferes with quality of life. Audiogenic seizures (AGSs) are arguably the most robust behavioral phenotype in the FXS mouse model-the Fmr1 knockout-and may be considered a model of sensory hypersensitivity in FXS. We provide the clearest and most precise genetic evidence to date for the cell types and brain regions involved in causing AGSs in the Fmr1 knockout and, more broadly, for any mouse mutant. The expression of Fmr1 in these same cell types in an otherwise Fmr1 knockout eliminates AGSs indicating possible cellular targets for alleviating sensory hypersensitivity in FXS and other forms of autism.
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Affiliation(s)
| | | | - Seth Hays
- Department of Neuroscience, Dallas, and
| | | | | | | | - Karen Pawlowski
- Department of Otolaryngology and Biomedical Engineering Program, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9035
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