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Kaczmarek KT, Protokowicz K, Kaczmarek L. Matrix metalloproteinase-9: A magic drug target in neuropsychiatry? J Neurochem 2023. [PMID: 37791997 DOI: 10.1111/jnc.15976] [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: 06/28/2023] [Revised: 09/12/2023] [Accepted: 09/15/2023] [Indexed: 10/05/2023]
Abstract
Neuropsychiatric conditions represent a major medical and societal challenge. The etiology of these conditions is very complex and combines genetic and environmental factors. The latter, for example, excessive maternal or early postnatal inflammation, as well as various forms of psychotrauma, often act as triggers leading to mental illness after a prolonged latent period (sometimes years). Matrix metalloproteinase-9 (MMP-9) is an extracellularly and extrasynaptic operating protease that is markedly activated in response to the aforementioned environmental insults. MMP-9 has also been shown to play a pivotal role in the plasticity of excitatory synapses, which, in its aberrant form, has repeatedly been implicated in the etiology of mental illness. In this conceptual review, we evaluate the experimental and clinical evidence supporting the claim that MMP-9 is uniquely positioned to be considered a drug target for ameliorating the adverse effects of environmental insults on the development of a variety of neuropsychiatric conditions, such as schizophrenia, bipolar disorder, major depression, autism spectrum disorders, addiction, and epilepsy. We also identify specific challenges and bottlenecks hampering the translation of knowledge on MMP-9 into new clinical treatments for the conditions above and suggest ways to overcome these barriers.
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2
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Abstract
The fragile X-related disorders are an important group of hereditary disorders that are caused by expanded CGG repeats in the 5' untranslated region of the FMR1 gene or by mutations in the coding sequence of this gene. Two categories of pathological CGG repeats are associated with these disorders, full mutation alleles and shorter premutation alleles. Individuals with full mutation alleles develop fragile X syndrome, which causes autism and intellectual disability, whereas those with premutation alleles, which have shorter CGG expansions, can develop fragile X-associated tremor/ataxia syndrome, a progressive neurodegenerative disease. Thus, fragile X-related disorders can manifest as neurodegenerative or neurodevelopmental disorders, depending on the size of the repeat expansion. Here, we review mouse models of fragile X-related disorders and discuss how they have informed our understanding of neurodegenerative and neurodevelopmental disorders. We also assess the translational value of these models for developing rational targeted therapies for intellectual disability and autism disorders.
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Affiliation(s)
- Rob Willemsen
- Department of Clinical Genetics, Erasmus University Medical Center, 3015 CN Rotterdam, the Netherlands. Department of Medical Genetics, University of Antwerp, 2000 Antwerp, Belgium
| | - R Frank Kooy
- Department of Clinical Genetics, Erasmus University Medical Center, 3015 CN Rotterdam, the Netherlands. Department of Medical Genetics, University of Antwerp, 2000 Antwerp, Belgium
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3
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Tempio A, Boulksibat A, Bardoni B, Delhaye S. Fragile X Syndrome as an interneuronopathy: a lesson for future studies and treatments. Front Neurosci 2023; 17:1171895. [PMID: 37188005 PMCID: PMC10176609 DOI: 10.3389/fnins.2023.1171895] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 04/05/2023] [Indexed: 05/17/2023] Open
Abstract
Fragile X Syndrome (FXS) is the most common form of inherited intellectual disability (ID) and a primary genetic cause of autism spectrum disorder (ASD). FXS arises from the silencing of the FMR1 gene causing the lack of translation of its encoded protein, the Fragile X Messenger RibonucleoProtein (FMRP), an RNA-binding protein involved in translational control and in RNA transport along dendrites. Although a large effort during the last 20 years has been made to investigate the cellular roles of FMRP, no effective and specific therapeutic intervention is available to treat FXS. Many studies revealed a role for FMRP in shaping sensory circuits during developmental critical periods to affect proper neurodevelopment. Dendritic spine stability, branching and density abnormalities are part of the developmental delay observed in various FXS brain areas. In particular, cortical neuronal networks in FXS are hyper-responsive and hyperexcitable, making these circuits highly synchronous. Overall, these data suggest that the excitatory/inhibitory (E/I) balance in FXS neuronal circuitry is altered. However, not much is known about how interneuron populations contribute to the unbalanced E/I ratio in FXS even if their abnormal functioning has an impact on the behavioral deficits of patients and animal models affected by neurodevelopmental disorders. We revise here the key literature concerning the role of interneurons in FXS not only with the purpose to better understand the pathophysiology of this disorder, but also to explore new possible therapeutic applications to treat FXS and other forms of ASD or ID. Indeed, for instance, the re-introduction of functional interneurons in the diseased brains has been proposed as a promising therapeutic approach for neurological and psychiatric disorders.
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Affiliation(s)
- Alessandra Tempio
- Université Côte d’Azur, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne, France
- Alessandra Tempio,
| | - Asma Boulksibat
- Université Côte d’Azur, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne, France
| | - Barbara Bardoni
- Université Côte d’Azur, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne, France
- Inserm, Université Côte d’Azur, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne, France
- *Correspondence: Barbara Bardoni,
| | - Sébastien Delhaye
- Université Côte d’Azur, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne, France
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4
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Perez-Fernandez C, Matamala Montoya M, Morales-Navas M, Guardia-Escote L, Cabré M, Colomina MT, Giménez E, Sánchez-Santed F. Influence of Gestational Chlorpyrifos Exposure on ASD-like Behaviors in an fmr1-KO Rat Model. Mol Neurobiol 2022; 59:5835-5855. [PMID: 35802248 DOI: 10.1007/s12035-022-02933-0] [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: 03/07/2022] [Accepted: 06/17/2022] [Indexed: 11/26/2022]
Abstract
Based on previous reports, exposure to pesticides could be linked to the prevalence increase of autism spectrum disorders (ASD). Gestational exposure to chlorpyrifos (CPF) has been associated with ASD diagnosis in humans and ASD-like behaviors in rodents. However, ASD severity degree results from the complex relationship between genetic background and environmental factors. Thus, animals with a genetic vulnerability and prenatally exposed to CPF could have a more severe ASD-like phenotype. Fragile X syndrome is one of the most common monogenic causes of ASD, characterized by a mutation in the X chromosome which alters the expression of the fragile X mental retardation protein (FMRP). Based on this, some fmr1 knockout (KO) rodent models have been developed to study the physiological and genetic basis of ASD. Both fmr1-KO and wild-type male rats (F2 generation) were used in the present study. F1 pregnant females were randomly exposed to 1 mg/kg/mL/day of CPF (s.c.) from GD12.5-15.5 or vehicle. Different behavioral, developmental, and molecular variables were analyzed in F2 males. KO rats were heavier, emitted altered USVs, were socially inefficient, reacted more to a novel stimulus, were hyperactive when exploring a new context, but hypoactive when exploring anxiety-inducing environments, and had an upregulated hippocampal expression of the grin2c gene. When exposed to low doses of CPF during gestation, these KO rats showed decreased climbing capacity, dysfunctional social interaction, and increased hippocampal expression for kcc1 and 5ht2c genes. Gestational CPF exposure increased the ASD-like phenotype in those animals with a genetic vulnerability, although its effect was less generalized than expected. It is the first time that this additive effect of CPF exposure and the fmr1-KO genetic vulnerability model is explored concerning social traits or any other behavior.
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Affiliation(s)
- Cristian Perez-Fernandez
- Department of Psychology and Health Research Center (CEINSA), Laboratory of Psychobiology, University of Almería CeiA3, Carretera de Sacramento s/n, La Cañada de San Urbano, 04120, Almería, Spain
| | - María Matamala Montoya
- Biomolecular Mass Spectrometry and Proteomics Group, Faculty of Science, Utrecht University, 3584 CS, Utrecht, The Netherlands
| | - Miguel Morales-Navas
- Department of Psychology and Health Research Center (CEINSA), Laboratory of Psychobiology, University of Almería CeiA3, Carretera de Sacramento s/n, La Cañada de San Urbano, 04120, Almería, Spain
| | - Laia Guardia-Escote
- Research in Neurobehavior and Health (NEUROLAB), Universitat Rovira I Virgili, 43007, Tarragona, Spain
- Department of Psychology and Research Center for Behavior Assessment (CRAMC), Universitat Rovira I Virgili, Campus Sescelades, 43007, Tarragona, Spain
| | - María Cabré
- Research in Neurobehavior and Health (NEUROLAB), Universitat Rovira I Virgili, 43007, Tarragona, Spain
- Department of Biochemistry and Biotechnology, Universitat Rovira I Virgili, 43007, Tarragona, Spain
| | - María Teresa Colomina
- Research in Neurobehavior and Health (NEUROLAB), Universitat Rovira I Virgili, 43007, Tarragona, Spain
- Department of Psychology and Research Center for Behavior Assessment (CRAMC), Universitat Rovira I Virgili, Campus Sescelades, 43007, Tarragona, Spain
| | - Estela Giménez
- Department of Biology and Geology, University of Almería, Ctra. Sacramento, s/n, 04120, Almería, Spain
| | - Fernando Sánchez-Santed
- Department of Psychology and Health Research Center (CEINSA), Laboratory of Psychobiology, University of Almería CeiA3, Carretera de Sacramento s/n, La Cañada de San Urbano, 04120, Almería, Spain.
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5
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Targeted therapy of cognitive deficits in fragile X syndrome. Mol Psychiatry 2022; 27:2766-2776. [PMID: 35354925 PMCID: PMC7612812 DOI: 10.1038/s41380-022-01527-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 03/03/2022] [Accepted: 03/14/2022] [Indexed: 11/08/2022]
Abstract
Breaking an impasse in finding mechanism-based therapies of neuropsychiatric disorders requires a strategic shift towards alleviating individual symptoms. Here we present a symptom and circuit-specific approach to rescue deficits of reward learning in Fmr1 knockout mice, a model of Fragile X syndrome (FXS), the most common monogenetic cause of inherited mental disability and autism. We use high-throughput, ecologically-relevant automated tests of cognition and social behavior to assess effectiveness of the circuit-targeted injections of designer nanoparticles, loaded with TIMP metalloproteinase inhibitor 1 protein (TIMP-1). Further, to investigate the impact of our therapeutic strategy on neuronal plasticity we perform long-term potentiation recordings and high-resolution electron microscopy. We show that central amygdala-targeted delivery of TIMP-1 designer nanoparticles reverses impaired cognition in Fmr1 knockouts, while having no impact on deficits of social behavior, hence corroborating symptom-specificity of the proposed approach. Moreover, we elucidate the neural correlates of the highly specific behavioral rescue by showing that the applied therapeutic intervention restores functional synaptic plasticity and ultrastructure of neurons in the central amygdala. Thus, we present a targeted, symptom-specific and mechanism-based strategy to remedy cognitive deficits in Fragile X syndrome.
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Holley A, Shedd A, Boggs A, Lovelace J, Erickson C, Gross C, Jankovic M, Razak K, Huber K, Gibson JR. A sound-driven cortical phase-locking change in the Fmr1 KO mouse requires Fmr1 deletion in a subpopulation of brainstem neurons. Neurobiol Dis 2022; 170:105767. [PMID: 35588990 PMCID: PMC9273231 DOI: 10.1016/j.nbd.2022.105767] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 04/27/2022] [Accepted: 05/11/2022] [Indexed: 11/30/2022] Open
Abstract
Background: Sensory impairments commonly occur in patients with autism or intellectual disability. Fragile X syndrome (FXS) is one form of intellectual disability that is often comorbid with autism. In electroencephalographic (EEG) recordings obtained from humans with FXS, the ability of cortical regions to consistently synchronize, or “phase-lock”, to modulated auditory stimuli is reduced compared to that of typically developing individuals. At the same time, less time-locked, “non-phase-locked” power induced by sounds is higher. The same changes occur in the Fmr1 knockout (KO) mouse – an animal model of FXS. We determined if Fmr1 deletion in a subset of brainstem auditory neurons plays any role in these EEG changes in the mouse. Methods: We reinstated FMRP expression in a subpopulation of brainstem auditory neurons in an otherwise Fmr1 KO control (conditional on; cON Fmr1) mouse and used EEG recordings to determine if reinstatement normalized, or “rescued”, the phase-locking phenotype observed in the cON Fmr1 mouse. In determining rescue, this also meant that Fmr1 deletion in the same neuron population was necessary for the phenotype to occur. Results: We find that Fmr1 reinstatement in a subset of brainstem neurons rescues certain aspects of the phase-locking phenotype but does not rescue the increase in non-phase-locked power. Unexpectedly, not all electrophysiological phenotypes observed in the Fmr1 KO were observed in the cON Fmr1 mouse used for the reinstatement experiments, and this was likely due to residual expression of FMRP in these Fmr1 KO controls. Conclusions: Fmr1 deletion in brainstem neurons is necessary for certain aspects of the decreased phase-locking phenotype in the Fmr1 KO, but not necessary for the increase in non-phase-locked power induced by a sound. The most likely brainstem structure underlying these results is the inferior colliculus. We also demonstrate that low levels of FMRP can rescue some EEG phenotypes but not others. This latter finding provides a foundation for how symptoms in FXS individuals may vary due to FMRP levels and that reinstatement of low FMRP levels may be sufficient to alleviate particular symptoms.
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Affiliation(s)
- AndrewJ Holley
- University of Texas Southwestern Medical Center at Dallas, Department of Neuroscience, Dallas, TX 75390-9111, USA
| | - Aleya Shedd
- University of Texas Southwestern Medical Center at Dallas, Department of Neuroscience, Dallas, TX 75390-9111, USA
| | - Anna Boggs
- Division of Child and Adolescent Psychiatry, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Jonathan Lovelace
- Department of Psychology, University of California, Riverside, CA 92521, USA
| | - Craig Erickson
- Division of Child and Adolescent Psychiatry, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; Department of Psychiatry, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Christina Gross
- Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Miranda Jankovic
- University of Texas Southwestern Medical Center at Dallas, Department of Neuroscience, Dallas, TX 75390-9111, USA
| | - Khaleel Razak
- Department of Psychology, University of California, Riverside, CA 92521, USA
| | - Kimberly Huber
- University of Texas Southwestern Medical Center at Dallas, Department of Neuroscience, Dallas, TX 75390-9111, USA
| | - Jay R Gibson
- University of Texas Southwestern Medical Center at Dallas, Department of Neuroscience, Dallas, TX 75390-9111, USA.
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Castro AC, Monteiro P. Auditory Dysfunction in Animal Models of Autism Spectrum Disorder. Front Mol Neurosci 2022; 15:845155. [PMID: 35493332 PMCID: PMC9043325 DOI: 10.3389/fnmol.2022.845155] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 03/17/2022] [Indexed: 11/16/2022] Open
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder mainly characterized by social-communication impairments, repetitive behaviors and altered sensory perception. Auditory hypersensitivity is the most common sensory-perceptual abnormality in ASD, however, its underlying neurobiological mechanisms remain elusive. Consistently with reports in ASD patients, animal models for ASD present sensory-perception alterations, including auditory processing impairments. Here we review the current knowledge regarding auditory dysfunction in rodent models of ASD, exploring both shared and distinct features among them, mechanistic and molecular underpinnings, and potential therapeutic approaches. Overall, auditory dysfunction in ASD models seems to arise from impaired central processing. Depending on the model, impairments may arise at different steps along the auditory pathway, from auditory brainstem up to the auditory cortex. Common defects found across models encompass atypical tonotopicity in different regions of the auditory pathway, temporal and spectral processing impairments and histological differences. Imbalance between excitation and inhibition (E/I imbalance) is one of the most well-supported mechanisms explaining the auditory phenotype in the ASD models studied so far and seems to be linked to alterations in GABAergic signaling. Such E/I imbalance may have a large impact on the development of the auditory pathway, influencing the establishment of connections responsible for normal sound processing.
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Affiliation(s)
- Ana Carolina Castro
- Life and Health Sciences Research Institute, School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B’s–PT Government Associate Laboratory, Braga, Portugal
| | - Patricia Monteiro
- Life and Health Sciences Research Institute, School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B’s–PT Government Associate Laboratory, Braga, Portugal
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8
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Clipperton-Allen AE, Swick H, Botero V, Aceti M, Ellegood J, Lerch JP, Page DT. Pten haploinsufficiency causes desynchronized growth of brain areas involved in sensory processing. iScience 2022; 25:103796. [PMID: 35198865 PMCID: PMC8844819 DOI: 10.1016/j.isci.2022.103796] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 08/25/2021] [Accepted: 01/18/2022] [Indexed: 01/16/2023] Open
Abstract
How changes in brain scaling relate to altered behavior is an important question in neurodevelopmental disorder research. Mice with germline Pten haploinsufficiency (Pten +/-) closely mirror the abnormal brain scaling and behavioral deficits seen in humans with macrocephaly/autism syndrome, which is caused by PTEN mutations. We explored whether deviation from normal patterns of growth can predict behavioral abnormalities. Brain regions associated with sensory processing (e.g., pons and inferior colliculus) had the biggest deviations from expected volume. While Pten +/- mice showed little or no abnormal behavior on most assays, both sexes showed sensory deficits, including impaired sensorimotor gating and hyporeactivity to high-intensity stimuli. Developmental analysis of this phenotype showed sexual dimorphism for hyporeactivity. Mapping behavioral phenotypes of Pten +/- mice onto relevant brain regions suggested abnormal behavior is likely when associated with relatively enlarged brain regions, while unchanged or relatively decreased brain regions have little predictive value.
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Affiliation(s)
| | - Hannah Swick
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Valentina Botero
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA,Doctoral Program in Chemical and Biological Sciences, The Skaggs Graduate School of Chemical and Biological Sciences at Scripps Research, Jupiter, FL 33458, USA
| | - Massimiliano Aceti
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Jacob Ellegood
- Mouse Imaging Centre, Hospital for Sick Children, Toronto, ON M5T 3H7, Canada
| | - Jason P. Lerch
- Mouse Imaging Centre, Hospital for Sick Children, Toronto, ON M5T 3H7, Canada,Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, Oxfordshire OX3 9DU, UK
| | - Damon T. Page
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA,Doctoral Program in Chemical and Biological Sciences, The Skaggs Graduate School of Chemical and Biological Sciences at Scripps Research, Jupiter, FL 33458, USA,Corresponding author
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9
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Liu X, Kumar V, Tsai NP, Auerbach BD. Hyperexcitability and Homeostasis in Fragile X Syndrome. Front Mol Neurosci 2022; 14:805929. [PMID: 35069112 PMCID: PMC8770333 DOI: 10.3389/fnmol.2021.805929] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 12/14/2021] [Indexed: 01/13/2023] Open
Abstract
Fragile X Syndrome (FXS) is a leading inherited cause of autism and intellectual disability, resulting from a mutation in the FMR1 gene and subsequent loss of its protein product FMRP. Despite this simple genetic origin, FXS is a phenotypically complex disorder with a range of physical and neurocognitive disruptions. While numerous molecular and cellular pathways are affected by FMRP loss, there is growing evidence that circuit hyperexcitability may be a common convergence point that can account for many of the wide-ranging phenotypes seen in FXS. The mechanisms for hyperexcitability in FXS include alterations to excitatory synaptic function and connectivity, reduced inhibitory neuron activity, as well as changes to ion channel expression and conductance. However, understanding the impact of FMR1 mutation on circuit function is complicated by the inherent plasticity in neural circuits, which display an array of homeostatic mechanisms to maintain activity near set levels. FMRP is also an important regulator of activity-dependent plasticity in the brain, meaning that dysregulated plasticity can be both a cause and consequence of hyperexcitable networks in FXS. This makes it difficult to separate the direct effects of FMR1 mutation from the myriad and pleiotropic compensatory changes associated with it, both of which are likely to contribute to FXS pathophysiology. Here we will: (1) review evidence for hyperexcitability and homeostatic plasticity phenotypes in FXS models, focusing on similarities/differences across brain regions, cell-types, and developmental time points; (2) examine how excitability and plasticity disruptions interact with each other to ultimately contribute to circuit dysfunction in FXS; and (3) discuss how these synaptic and circuit deficits contribute to disease-relevant behavioral phenotypes like epilepsy and sensory hypersensitivity. Through this discussion of where the current field stands, we aim to introduce perspectives moving forward in FXS research.
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Affiliation(s)
- Xiaopeng Liu
- Deparment of Molecular & Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
- Beckman Institute for Advanced Science & Technology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Vipendra Kumar
- Deparment of Molecular & Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Nien-Pei Tsai
- Deparment of Molecular & Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Benjamin D. Auerbach
- Deparment of Molecular & Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
- Beckman Institute for Advanced Science & Technology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
- *Correspondence: Benjamin D. Auerbach
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10
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Razak KA, Binder DK, Ethell IM. Neural Correlates of Auditory Hypersensitivity in Fragile X Syndrome. Front Psychiatry 2021; 12:720752. [PMID: 34690832 PMCID: PMC8529206 DOI: 10.3389/fpsyt.2021.720752] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 08/16/2021] [Indexed: 01/20/2023] Open
Abstract
The mechanisms underlying the common association between autism spectrum disorders (ASD) and sensory processing disorders (SPD) are unclear, and treatment options to reduce atypical sensory processing are limited. Fragile X Syndrome (FXS) is a leading genetic cause of intellectual disability and ASD behaviors. As in most children with ASD, atypical sensory processing is a common symptom in FXS, frequently manifesting as sensory hypersensitivity. Auditory hypersensitivity is a highly debilitating condition in FXS that may lead to language delays, social anxiety and ritualized repetitive behaviors. Animal models of FXS, including Fmr1 knock out (KO) mouse, also show auditory hypersensitivity, providing a translation relevant platform to study underlying pathophysiological mechanisms. The focus of this review is to summarize recent studies in the Fmr1 KO mouse that identified neural correlates of auditory hypersensitivity. We review results of electroencephalography (EEG) recordings in the Fmr1 KO mice and highlight EEG phenotypes that are remarkably similar to EEG findings in humans with FXS. The EEG phenotypes associated with the loss of FMRP include enhanced resting EEG gamma band power, reduced cross frequency coupling, reduced sound-evoked synchrony of neural responses at gamma band frequencies, increased event-related potential amplitudes, reduced habituation of neural responses and increased non-phase locked power. In addition, we highlight the postnatal period when the EEG phenotypes develop and show a strong association of the phenotypes with enhanced matrix-metalloproteinase-9 (MMP-9) activity, abnormal development of parvalbumin (PV)-expressing inhibitory interneurons and reduced formation of specialized extracellular matrix structures called perineuronal nets (PNNs). Finally, we discuss how dysfunctions of inhibitory PV interneurons may contribute to cortical hyperexcitability and EEG abnormalities observed in FXS. Taken together, the studies reviewed here indicate that EEG recordings can be utilized in both pre-clinical studies and clinical trials, while at the same time, used to identify cellular and circuit mechanisms of dysfunction in FXS. New therapeutic approaches that reduce MMP-9 activity and restore functions of PV interneurons may succeed in reducing FXS sensory symptoms. Future studies should examine long-lasting benefits of developmental vs. adult interventions on sensory phenotypes.
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Affiliation(s)
- Khaleel A. Razak
- Department of Psychology, University of California, Riverside, Riverside, CA, United States
- Graduate Neuroscience Program, University of California, Riverside, Riverside, CA, United States
| | - Devin K. Binder
- Graduate Neuroscience Program, University of California, Riverside, Riverside, CA, United States
- Division of Biomedical Sciences and Graduate Biomedical Sciences Program, School of Medicine, University of California, Riverside, Riverside, CA, United States
| | - Iryna M. Ethell
- Graduate Neuroscience Program, University of California, Riverside, Riverside, CA, United States
- Division of Biomedical Sciences and Graduate Biomedical Sciences Program, School of Medicine, University of California, Riverside, Riverside, CA, United States
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11
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Nomura T. Interneuron Dysfunction and Inhibitory Deficits in Autism and Fragile X Syndrome. Cells 2021; 10:cells10102610. [PMID: 34685590 PMCID: PMC8534049 DOI: 10.3390/cells10102610] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 09/27/2021] [Accepted: 09/28/2021] [Indexed: 01/18/2023] Open
Abstract
The alteration of excitatory–inhibitory (E–I) balance has been implicated in various neurological and psychiatric diseases, including autism spectrum disorder (ASD). Fragile X syndrome (FXS) is a single-gene disorder that is the most common known cause of ASD. Understanding the molecular and physiological features of FXS is thought to enhance our knowledge of the pathophysiology of ASD. Accumulated evidence implicates deficits in the inhibitory circuits in FXS that tips E–I balance toward excitation. Deficits in interneurons, the main source of an inhibitory neurotransmitter, gamma-aminobutyric acid (GABA), have been reported in FXS, including a reduced number of cells, reduction in intrinsic cellular excitability, or weaker synaptic connectivity. Manipulating the interneuron activity ameliorated the symptoms in the FXS mouse model, which makes it reasonable to conceptualize FXS as an interneuronopathy. While it is still poorly understood how the developmental profiles of the inhibitory circuit go awry in FXS, recent works have uncovered several developmental alterations in the functional properties of interneurons. Correcting disrupted E–I balance by potentiating the inhibitory circuit by targeting interneurons may have a therapeutic potential in FXS. I will review the recent evidence about the inhibitory alterations and interneuron dysfunction in ASD and FXS and will discuss the future directions of this field.
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Affiliation(s)
- Toshihiro Nomura
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
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12
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Bordia T, Zahr NM. The Inferior Colliculus in Alcoholism and Beyond. Front Syst Neurosci 2020; 14:606345. [PMID: 33362482 PMCID: PMC7759542 DOI: 10.3389/fnsys.2020.606345] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 11/02/2020] [Indexed: 12/28/2022] Open
Abstract
Post-mortem neuropathological and in vivo neuroimaging methods have demonstrated the vulnerability of the inferior colliculus to the sequelae of thiamine deficiency as occurs in Wernicke-Korsakoff Syndrome (WKS). A rich literature in animal models ranging from mice to monkeys-including our neuroimaging studies in rats-has shown involvement of the inferior colliculi in the neural response to thiamine depletion, frequently accomplished with pyrithiamine, an inhibitor of thiamine metabolism. In uncomplicated alcoholism (i.e., absent diagnosable neurological concomitants), the literature citing involvement of the inferior colliculus is scarce, has nearly all been accomplished in preclinical models, and is predominately discussed in the context of ethanol withdrawal. Our recent work using novel, voxel-based analysis of structural Magnetic Resonance Imaging (MRI) has demonstrated significant, persistent shrinkage of the inferior colliculus using acute and chronic ethanol exposure paradigms in two strains of rats. We speculate that these consistent findings should be considered from the perspective of the inferior colliculi having a relatively high CNS metabolic rate. As such, they are especially vulnerable to hypoxic injury and may be provide a common anatomical link among a variety of disparate insults. An argument will be made that the inferior colliculi have functions, possibly related to auditory gating, necessary for awareness of the external environment. Multimodal imaging including diffusion methods to provide more accurate in vivo visualization and quantification of the inferior colliculi may clarify the roles of brain stem nuclei such as the inferior colliculi in alcoholism and other neuropathologies marked by altered metabolism.
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Affiliation(s)
- Tanuja Bordia
- Neuroscience Program, SRI International, Menlo Park, CA, United States
| | - Natalie M. Zahr
- Neuroscience Program, SRI International, Menlo Park, CA, United States
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, United States
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13
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Lovelace JW, Ethell IM, Binder DK, Razak KA. Minocycline Treatment Reverses Sound Evoked EEG Abnormalities in a Mouse Model of Fragile X Syndrome. Front Neurosci 2020; 14:771. [PMID: 32848552 PMCID: PMC7417521 DOI: 10.3389/fnins.2020.00771] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 06/30/2020] [Indexed: 01/19/2023] Open
Abstract
Fragile X Syndrome (FXS) is a leading known genetic cause of intellectual disability. Many symptoms of FXS overlap with those in autism including repetitive behaviors, language delays, anxiety, social impairments and sensory processing deficits. Electroencephalogram (EEG) recordings from humans with FXS and an animal model, the Fmr1 knockout (KO) mouse, show remarkably similar phenotypes suggesting that EEG phenotypes can serve as biomarkers for developing treatments. This includes enhanced resting gamma band power and sound evoked total power, and reduced fidelity of temporal processing and habituation of responses to repeated sounds. Given the therapeutic potential of the antibiotic minocycline in humans with FXS and animal models, it is important to determine sensitivity and selectivity of EEG responses to minocycline. Therefore, in this study, we examined if a 10-day treatment of adult Fmr1 KO mice with minocycline (oral gavage, 30 mg/kg per day) would reduce EEG abnormalities. We tested if minocycline treatment has specific effects based on the EEG measurement type (e.g., resting versus sound-evoked) from the frontal and auditory cortex of the Fmr1 KO mice. We show increased resting EEG gamma power and reduced phase locking to time varying stimuli as well as the 40 Hz auditory steady state response in the Fmr1 KO mice in the pre-drug condition. Minocycline treatment increased gamma band phase locking in response to auditory stimuli, and reduced sound-evoked power of auditory event related potentials (ERP) in Fmr1 KO mice compared to vehicle treatment. Minocycline reduced resting EEG gamma power in Fmr1 KO mice, but this effect was similar to vehicle treatment. We also report frequency band-specific effects on EEG responses. Taken together, these data indicate that sound-evoked EEG responses may serve as more sensitive measures, compared to resting EEG measures, to isolate minocycline effects from placebo in humans with FXS. Given the use of minocycline and EEG recordings in a number of neurodegenerative and neurodevelopmental conditions, these findings may be more broadly applicable in translational neuroscience.
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Affiliation(s)
- Jonathan W Lovelace
- Department of Psychology and Neuroscience Graduate Program, University of California, Riverside, Riverside, CA, United States
| | - Iryna M Ethell
- Neuroscience Graduate Program, University of California, Riverside, Riverside, CA, United States.,Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, CA, United States
| | - Devin K Binder
- Neuroscience Graduate Program, University of California, Riverside, Riverside, CA, United States.,Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, CA, United States
| | - Khaleel A Razak
- Department of Psychology and Neuroscience Graduate Program, University of California, Riverside, Riverside, CA, United States.,Neuroscience Graduate Program, University of California, Riverside, Riverside, CA, United States
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14
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Nguyen AO, Binder DK, Ethell IM, Razak KA. Abnormal development of auditory responses in the inferior colliculus of a mouse model of Fragile X Syndrome. J Neurophysiol 2020; 123:2101-2121. [PMID: 32319849 DOI: 10.1152/jn.00706.2019] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Sensory processing abnormalities are frequently associated with autism spectrum disorders, but the underlying mechanisms are unclear. Here we studied auditory processing in a mouse model of Fragile X Syndrome (FXS), a leading known genetic cause of autism and intellectual disability. Both humans with FXS and the Fragile X mental retardation gene (Fmr1) knockout (KO) mouse model show auditory hypersensitivity, with the latter showing a strong propensity for audiogenic seizures (AGS) early in development. Because midbrain abnormalities cause AGS, we investigated whether the inferior colliculus (IC) of the Fmr1 KO mice shows abnormal auditory processing compared with wild-type (WT) controls at specific developmental time points. Using antibodies against neural activity marker c-Fos, we found increased density of c-Fos+ neurons in the IC, but not auditory cortex, of Fmr1 KO mice at P21 and P34 following sound presentation. In vivo single-unit recordings showed that IC neurons of Fmr1 KO mice are hyperresponsive to tone bursts and amplitude-modulated tones during development and show broader frequency tuning curves. There were no differences in rate-level responses or phase locking to amplitude-modulated tones in IC neurons between genotypes. Taken together, these data provide evidence for the development of auditory hyperresponsiveness in the IC of Fmr1 KO mice. Although most human and mouse work in autism and sensory processing has centered on the forebrain, our new findings, along with recent work on the lower brainstem, suggest that abnormal subcortical responses may underlie auditory hypersensitivity in autism spectrum disorders.NEW & NOTEWORTHY Autism spectrum disorders (ASD) are commonly associated with sensory sensitivity issues, but the underlying mechanisms are unclear. This study presents novel evidence for neural correlates of auditory hypersensitivity in the developing inferior colliculus (IC) in Fmr1 knockout (KO) mouse, a mouse model of Fragile X Syndrome (FXS), a leading genetic cause of ASD. Responses begin to show genotype differences between postnatal days 14 and 21, suggesting an early developmental treatment window.
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Affiliation(s)
- Anna O Nguyen
- Bioengineering Program, University of California, Riverside, California
| | - Devin K Binder
- Graduate Neuroscience Program, University of California, Riverside, California.,Division of Biomedical Sciences, University of California, Riverside, California
| | - Iryna M Ethell
- Graduate Neuroscience Program, University of California, Riverside, California.,Division of Biomedical Sciences, University of California, Riverside, California
| | - Khaleel A Razak
- Graduate Neuroscience Program, University of California, Riverside, California.,Psychology Department, University of California, Riverside, California
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15
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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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16
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Kulinich AO, Reinhard SM, Rais M, Lovelace JW, Scott V, Binder DK, Razak KA, Ethell IM. Beneficial effects of sound exposure on auditory cortex development in a mouse model of Fragile X Syndrome. Neurobiol Dis 2019; 134:104622. [PMID: 31698054 DOI: 10.1016/j.nbd.2019.104622] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 08/22/2019] [Accepted: 09/23/2019] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Fragile X syndrome (FXS) is the most common genetic cause of autism and intellectual disability. Fragile X mental retardation gene (Fmr1) knock-out (KO) mice display core deficits of FXS, including abnormally increased sound-evoked responses, and show a delayed development of parvalbumin (PV) cells. Here, we present the surprising result that sound exposure during early development reduces correlates of auditory hypersensitivity in Fmr1 KO mice. METHODS Fmr1 KO and wild-type (WT) mice were raised in a sound-attenuated environment (AE) or sound-exposed (SE) to 14 kHz tones (5 Hz repetition rate) from P9 until P21. At P21-P23, event-related potentials (ERPs), dendritic spine density, PV expression and phosphorylation of tropomyosin receptor kinase B (TrkB) were analyzed in the auditory cortex of AE and SE mice. RESULTS Enhanced N1 amplitude of ERPs, impaired PV cell development, and increased spine density in layers (L) 2/3 and L5/6 excitatory neurons were observed in AE Fmr1 KO compared to WT mice. In contrast, developmental sound exposure normalized ERP N1 amplitude, density of PV cells and dendritic spines in SE Fmr1 KO mice. Finally, TrkB phosphorylation was reduced in AE Fmr1 KO, but was enhanced in SE Fmr1 KO mice, suggesting that BDNF-TrkB signaling may be regulated by sound exposure to influence PV cell development. CONCLUSIONS Our results demonstrate that sound exposure, but not attenuation, during early developmental window restores molecular, cellular and functional properties in the auditory cortex of Fmr1 KO mice, and suggest this approach as a potential treatment for sensory phenotypes in FXS.
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Affiliation(s)
- Anna O Kulinich
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, USA
| | - Sarah M Reinhard
- Psychology Department, University of California, Riverside, CA, USA
| | - Maham Rais
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, USA; Biomedical Sciences Graduate Program, University of California, Riverside, CA, USA
| | | | - Veronica Scott
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, USA
| | - Devin K Binder
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, USA; Neuroscience Graduate Program, University of California, Riverside, CA, USA; Biomedical Sciences Graduate Program, University of California, Riverside, CA, USA
| | - Khaleel A Razak
- Psychology Department, University of California, Riverside, CA, USA; Neuroscience Graduate Program, University of California, Riverside, CA, USA; Biomedical Sciences Graduate Program, University of California, Riverside, CA, USA.
| | - Iryna M Ethell
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, USA; Neuroscience Graduate Program, University of California, Riverside, CA, USA; Biomedical Sciences Graduate Program, University of California, Riverside, CA, USA.
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