1
|
Aishworiya R, Chi MH, Zafarullah M, Mendoza G, Ponzini MD, Kim K, Biag HMB, Thurman AJ, Abbeduto L, Hessl D, Randol JL, Bolduc FV, Jacquemont S, Lippé S, Hagerman P, Hagerman R, Schneider A, Tassone F. Intercorrelation of Molecular Biomarkers and Clinical Phenotype Measures in Fragile X Syndrome. Cells 2023; 12:1920. [PMID: 37508583 PMCID: PMC10377864 DOI: 10.3390/cells12141920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 07/05/2023] [Accepted: 07/13/2023] [Indexed: 07/30/2023] Open
Abstract
This study contributes to a greater understanding of the utility of molecular biomarkers to identify clinical phenotypes of fragile X syndrome (FXS). Correlations of baseline clinical trial data (molecular measures-FMR1 mRNA, CYFIP1 mRNA, MMP9 and FMRP protein expression levels, nonverbal IQ, body mass index and weight, language level, NIH Toolbox, adaptive behavior rating, autism, and other mental health correlates) of 59 participants with FXS ages of 6-32 years are reported. FMR1 mRNA expression levels correlated positively with adaptive functioning levels, expressive language, and specific NIH Toolbox measures. The findings of a positive correlation of MMP-9 levels with obesity, CYFIP1 mRNA with mood and autistic symptoms, and FMR1 mRNA expression level with better cognitive, language, and adaptive functions indicate potential biomarkers for specific FXS phenotypes. These may be potential markers for future clinical trials for targeted treatments of FXS.
Collapse
Affiliation(s)
- Ramkumar Aishworiya
- MIND Institute, University of California Davis Medical Center, Sacramento, CA 95817, USA; (R.A.); (M.D.P.); (H.M.B.B.)
- Khoo Teck Puat-National University Children’s Medical Institute, National University Health System, Singapore 119074, Singapore
- Department of Pediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
| | - Mei-Hung Chi
- MIND Institute, University of California Davis Medical Center, Sacramento, CA 95817, USA; (R.A.); (M.D.P.); (H.M.B.B.)
- Department of Psychiatry, National Cheng Kung University Hospital, Tainan 704, Taiwan
| | - Marwa Zafarullah
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California Davis, Sacramento, CA 95817, USA (G.M.)
| | - Guadalupe Mendoza
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California Davis, Sacramento, CA 95817, USA (G.M.)
| | - Matthew Dominic Ponzini
- MIND Institute, University of California Davis Medical Center, Sacramento, CA 95817, USA; (R.A.); (M.D.P.); (H.M.B.B.)
- Department of Public Health Sciences, School of Medicine, University of California Davis, Sacramento, CA 95817, USA
| | - Kyoungmi Kim
- MIND Institute, University of California Davis Medical Center, Sacramento, CA 95817, USA; (R.A.); (M.D.P.); (H.M.B.B.)
- Department of Public Health Sciences, School of Medicine, University of California Davis, Sacramento, CA 95817, USA
| | - Hazel Maridith Barlahan Biag
- MIND Institute, University of California Davis Medical Center, Sacramento, CA 95817, USA; (R.A.); (M.D.P.); (H.M.B.B.)
- Department of Pediatrics, School of Medicine, University of California Davis, Sacramento, CA 95817, USA
| | - Angela John Thurman
- MIND Institute, University of California Davis Medical Center, Sacramento, CA 95817, USA; (R.A.); (M.D.P.); (H.M.B.B.)
- Department of Psychiatry and Behavioral Sciences, School of Medicine, University of California Davis, Sacramento, CA 95817, USA
| | - Leonard Abbeduto
- MIND Institute, University of California Davis Medical Center, Sacramento, CA 95817, USA; (R.A.); (M.D.P.); (H.M.B.B.)
- Department of Psychiatry and Behavioral Sciences, School of Medicine, University of California Davis, Sacramento, CA 95817, USA
| | - David Hessl
- MIND Institute, University of California Davis Medical Center, Sacramento, CA 95817, USA; (R.A.); (M.D.P.); (H.M.B.B.)
- Department of Psychiatry and Behavioral Sciences, School of Medicine, University of California Davis, Sacramento, CA 95817, USA
| | - Jamie Leah Randol
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California Davis, Sacramento, CA 95817, USA (G.M.)
- Integrative Genetics and Genomics Graduate Group, University of California Davis, One Shields Avenue, Davis, CA 95616, USA
- UC Davis Biotechnology Program, University of California Davis, Davis, CA 95616, USA
| | - Francois V. Bolduc
- Department of Pediatrics, Department of Medical Genetics, Women and Children Health Research Institute, University of Alberta, Edmonton, AB T6G 2R3, Canada
| | - Sebastien Jacquemont
- CHU Sainte-Justine Research Center, Université de Montréal, Montreal, QC H3T 1J4, Canada
- Department of Pediatrics, University of Montreal, Montreal, QC H3T 1J4, Canada
| | - Sarah Lippé
- CHU Sainte-Justine Research Center, Université de Montréal, Montreal, QC H3T 1J4, Canada
- Department of Psychology, Université de Montréal, Montreal, QC H3T 1J4, Canada
| | - Paul Hagerman
- MIND Institute, University of California Davis Medical Center, Sacramento, CA 95817, USA; (R.A.); (M.D.P.); (H.M.B.B.)
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California Davis, Sacramento, CA 95817, USA (G.M.)
| | - Randi Hagerman
- MIND Institute, University of California Davis Medical Center, Sacramento, CA 95817, USA; (R.A.); (M.D.P.); (H.M.B.B.)
- Department of Pediatrics, School of Medicine, University of California Davis, Sacramento, CA 95817, USA
| | - Andrea Schneider
- MIND Institute, University of California Davis Medical Center, Sacramento, CA 95817, USA; (R.A.); (M.D.P.); (H.M.B.B.)
- Department of Pediatrics, School of Medicine, University of California Davis, Sacramento, CA 95817, USA
| | - Flora Tassone
- MIND Institute, University of California Davis Medical Center, Sacramento, CA 95817, USA; (R.A.); (M.D.P.); (H.M.B.B.)
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California Davis, Sacramento, CA 95817, USA (G.M.)
| |
Collapse
|
2
|
Di Menna L, Orlando R, D'Errico G, Ginerete RP, Machaczka A, Bonaccorso CM, Arena A, Spatuzza M, Celli R, Alborghetti M, Ciocca E, Zuena AR, Scioli MR, Bruno V, Battaglia G, Nicoletti F, Catania MV. Blunted type-5 metabotropic glutamate receptor-mediated polyphosphoinositide hydrolysis in two mouse models of monogenic autism. Neuropharmacology 2023:109642. [PMID: 37392820 DOI: 10.1016/j.neuropharm.2023.109642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 06/06/2023] [Accepted: 06/20/2023] [Indexed: 07/03/2023]
Abstract
The involvement of the mGlu5 receptors in the pathophysiology of several forms of monogenic autism has been supported by numerous studies following the seminal observation that mGlu5 receptor-dependent long-term depression was enhanced in the hippocampus of mice modeling the fragile-X syndrome (FXS). Surprisingly, there are no studies examining the canonical signal transduction pathway activated by mGlu5 receptors (i.e. polyphosphoinositide - PI - hydrolysis) in mouse models of autism. We have developed a method for in vivo assessment of PI hydrolysis based on systemic injection of lithium chloride followed by treatment with the selective mGlu5 receptor PAM, VU0360172, and measurement of endogenous inositolmonophosphate (InsP) in brain tissue. Here, we report that mGlu5 receptor-mediated PI hydrolysis was blunted in the cerebral cortex, hippocampus, and corpus striatum of Ube3am-/p+ mice modeling Angelman syndrome (AS), and in the cerebral cortex and hippocampus of fmr1 knockout mice modeling FXS. In vivo mGlu5 receptor-mediated stimulation of Akt on threonine 308 was also blunted in the hippocampus of FXS mice. These changes were associated with a significant increase in cortical and striatal Homer1 levels and striatal mGlu5 receptor and Gαq levels in AS mice, and with a reduction in cortical mGlu5 receptor and hippocampal Gαq levels, and an increase in cortical phospholipase-Cβ and hippocampal Homer1 levels in FXS mice. This is the first evidence that the canonical transduction pathway activated by mGlu5 receptors is down-regulated in brain regions of mice modeling monogenic autism.
Collapse
Affiliation(s)
| | - Rosamaria Orlando
- IRCCS Neuromed, Pozzilli, Italy; Department of Physiology and Pharmacology, Sapienza University, Roma, Italy
| | | | | | - Agata Machaczka
- Department of Neurobiology, Maj Institute of Pharmacology, Polish Academy of Science, Krakow, Poland
| | | | | | | | | | - Marika Alborghetti
- Department of Neuroscience, Mental Health, and Sensory Organs, Sapienza University, Italy
| | - Eleonora Ciocca
- Department of Physiology and Pharmacology, Sapienza University, Roma, Italy
| | - Anna Rita Zuena
- Department of Physiology and Pharmacology, Sapienza University, Roma, Italy
| | | | - Valeria Bruno
- IRCCS Neuromed, Pozzilli, Italy; Department of Physiology and Pharmacology, Sapienza University, Roma, Italy
| | - Giuseppe Battaglia
- IRCCS Neuromed, Pozzilli, Italy; Department of Physiology and Pharmacology, Sapienza University, Roma, Italy
| | - Ferdinando Nicoletti
- IRCCS Neuromed, Pozzilli, Italy; Department of Physiology and Pharmacology, Sapienza University, Roma, Italy
| | - Maria Vincenza Catania
- Institute for Biomedical Research and Innovation, The National Research Council (IRIB-CNR), Catania, Italy.
| |
Collapse
|
3
|
Chen YS, Zhang SM, Tan W, Zhu Q, Yue CX, Xiang P, Li JQ, Wei Z, Zeng Y. Early 7,8-Dihydroxyflavone Administration Ameliorates Synaptic and Behavioral Deficits in the Young FXS Animal Model by Acting on BDNF-TrkB Pathway. Mol Neurobiol 2023; 60:2539-2552. [PMID: 36680734 DOI: 10.1007/s12035-023-03226-w] [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: 09/21/2022] [Accepted: 12/30/2022] [Indexed: 01/22/2023]
Abstract
Fragile X syndrome (FXS) is the leading inherited form of intellectual disability and the most common cause of autism spectrum disorders. FXS patients exhibit severe syndromic features and behavioral alterations, including anxiety, hyperactivity, impulsivity, and aggression, in addition to cognitive impairment and seizures. At present, there are no effective treatments or cures for FXS. Previously, we have found the divergence of BDNF-TrkB signaling trajectories is associated with spine defects in early postnatal developmental stages of Fmr1 KO mice. Here, young fragile X mice were intraperitoneal injection with 7,8-Dihydroxyflavone (7,8-DHF), a high affinity tropomyosin receptor kinase B (TrkB) agonist. 7,8-DHF ameliorated morphological abnormities in dendritic spine and synaptic structure and rescued synaptic and hippocampus-dependent cognitive dysfunction. These observed improvements of 7,8-DHF involved decreased protein levels of BDNF, p-TrkBY816, p-PLCγ, and p-CaMKII in the hippocampus. In addition, 7,8-DHF intervention in primary hippocampal neurons increased p-TrkBY816 and activated the PLCγ1-CaMKII signaling pathway, leading to improvement of neuronal morphology. This study is the first to account for early life synaptic impairments, neuronal morphological, and cognitive delays in FXS in response to the abnormal BDNF-TrkB pathway. Present studies provide novel evidences about the effective early intervention in FXS mice at developmental stages and a strategy to produce powerful impacts on neural development, synaptic plasticity, and behaviors.
Collapse
Affiliation(s)
- Yu-Shan Chen
- Hubei Province Key Laboratory of Occupational Hazard Identification and Control, School of Medicine, Brain Science and Advanced Technology Institute, Wuhan University of Science and Technology, Wuhan, 430065, China
- Geriatric Hospital Affiliated to Wuhan University of Science and Technology, Wuhan, China
| | - Si-Ming Zhang
- Hubei Province Key Laboratory of Occupational Hazard Identification and Control, School of Medicine, Brain Science and Advanced Technology Institute, Wuhan University of Science and Technology, Wuhan, 430065, China
- Geriatric Hospital Affiliated to Wuhan University of Science and Technology, Wuhan, China
| | - Wei Tan
- Geriatric Hospital Affiliated to Wuhan University of Science and Technology, Wuhan, China
| | - Qiong Zhu
- Hubei Province Key Laboratory of Occupational Hazard Identification and Control, School of Medicine, Brain Science and Advanced Technology Institute, Wuhan University of Science and Technology, Wuhan, 430065, China
- Geriatric Hospital Affiliated to Wuhan University of Science and Technology, Wuhan, China
| | - Chao-Xiong Yue
- Hubei Province Key Laboratory of Occupational Hazard Identification and Control, School of Medicine, Brain Science and Advanced Technology Institute, Wuhan University of Science and Technology, Wuhan, 430065, China
- Geriatric Hospital Affiliated to Wuhan University of Science and Technology, Wuhan, China
| | - Peng Xiang
- Hubei Province Key Laboratory of Occupational Hazard Identification and Control, School of Medicine, Brain Science and Advanced Technology Institute, Wuhan University of Science and Technology, Wuhan, 430065, China
- Geriatric Hospital Affiliated to Wuhan University of Science and Technology, Wuhan, China
| | - Jin-Quan Li
- Hubei Province Key Laboratory of Occupational Hazard Identification and Control, School of Medicine, Brain Science and Advanced Technology Institute, Wuhan University of Science and Technology, Wuhan, 430065, China
- Geriatric Hospital Affiliated to Wuhan University of Science and Technology, Wuhan, China
| | - Zhen Wei
- Hubei Province Key Laboratory of Occupational Hazard Identification and Control, School of Medicine, Brain Science and Advanced Technology Institute, Wuhan University of Science and Technology, Wuhan, 430065, China
- Geriatric Hospital Affiliated to Wuhan University of Science and Technology, Wuhan, China
| | - Yan Zeng
- Hubei Province Key Laboratory of Occupational Hazard Identification and Control, School of Medicine, Brain Science and Advanced Technology Institute, Wuhan University of Science and Technology, Wuhan, 430065, China.
- Geriatric Hospital Affiliated to Wuhan University of Science and Technology, Wuhan, China.
| |
Collapse
|
4
|
Murari K, Abushaibah A, Rho JM, Turner RW, Cheng N. A clinically relevant selective ERK-pathway inhibitor reverses core deficits in a mouse model of autism. EBioMedicine 2023; 91:104565. [PMID: 37088035 PMCID: PMC10149189 DOI: 10.1016/j.ebiom.2023.104565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 03/07/2023] [Accepted: 03/29/2023] [Indexed: 04/25/2023] Open
Abstract
BACKGROUND Extracellular signal-regulated kinase (ERK/MAPK) pathway in the brain is hypothesized to be a critical convergent node in the development of autism spectrum disorder. We reasoned that selectively targeting this pathway could reverse core autism-like phenotype in animal models. METHODS Here we tested a clinically relevant, selective inhibitor of ERK pathway, PD325901 (Mirdametinib), in a mouse model of idiopathic autism, the BTBR mice. FINDINGS We report that treating juvenile mice with PD325901 reduced ERK pathway activation, dose and duration-dependently reduced core disease-modeling deficits in sociability, vocalization and repetitive behavior, and reversed abnormal EEG signals. Further analysis revealed that subchronic treatment did not affect weight gain, locomotion, or neuronal density in the brain. Parallel treatment in the C57BL/6J mice did not alter their phenotype. INTERPRETATION Our data indicate that selectively inhibiting ERK pathway using PD325901 is beneficial in the BTBR model, thus further support the notion that ERK pathway is critically involved in the pathophysiology of autism. These results suggest that a similar approach could be applied to animal models of syndromic autism with dysregulated ERK signaling, to further test selectively targeting ERK pathway as a new approach for treating autism. FUNDING This has beenwork was supported by Alberta Children's Hospital Research Foundation (JMR & NC), University of Calgary Faculty of Veterinary Medicine (NC), Kids Brain Health Network (NC), and Natural Sciences and Engineering Research Council of Canada (NC).
Collapse
Affiliation(s)
- Kartikeya Murari
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Canada; Department of Biomedical Engineering, Schulich School of Engineering, University of Calgary, Canada; Department of Electrical and Software Engineering, Schulich School of Engineering, University of Calgary, Canada
| | - Abdulrahman Abushaibah
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Canada; Bachelor of Health Sciences, Cumming School of Medicine, University of Calgary, Canada
| | - Jong M Rho
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Canada; Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Canada
| | - Ray W Turner
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Canada; Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Canada; Department of Cell Biology & Anatomy, Cumming School of Medicine, University of Calgary, Canada
| | - Ning Cheng
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Canada; Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Canada; Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Canada.
| |
Collapse
|
5
|
Sánchez-Castillo C, Cuartero MI, Fernández-Rodrigo A, Briz V, López-García S, Jiménez-Sánchez R, López JA, Graupera M, Esteban JA. Functional specialization of different PI3K isoforms for the control of neuronal architecture, synaptic plasticity, and cognition. SCIENCE ADVANCES 2022; 8:eabq8109. [PMID: 36417513 PMCID: PMC9683729 DOI: 10.1126/sciadv.abq8109] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 10/25/2022] [Indexed: 06/16/2023]
Abstract
Neuronal connectivity and activity-dependent synaptic plasticity are fundamental properties that support brain function and cognitive performance. Phosphatidylinositol 3-kinase (PI3K) intracellular signaling controls multiple mechanisms mediating neuronal growth, synaptic structure, and plasticity. However, it is still unclear how these pleiotropic functions are integrated at molecular and cellular levels. To address this issue, we used neuron-specific virally delivered Cre expression to delete either p110α or p110β (the two major catalytic isoforms of type I PI3K) from the hippocampus of adult mice. We found that dendritic and postsynaptic structures are almost exclusively supported by p110α activity, whereas p110β controls neurotransmitter release and metabotropic glutamate receptor-dependent long-term depression at the presynaptic terminal. In addition to these separate functions, p110α and p110β jointly contribute to N-methyl-d-aspartate receptor-dependent postsynaptic long-term potentiation. This molecular and functional specialization is reflected in different proteomes controlled by each isoform and in distinct behavioral alterations for learning/memory and sociability in mice lacking p110α or p110β.
Collapse
Affiliation(s)
- Carla Sánchez-Castillo
- Department of Molecular Neuropathology, Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Madrid, Spain
| | - María I. Cuartero
- Department of Molecular Neuropathology, Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Madrid, Spain
| | - Alba Fernández-Rodrigo
- Department of Molecular Neuropathology, Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Madrid, Spain
| | - Víctor Briz
- Department of Molecular Neuropathology, Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Madrid, Spain
| | - Sergio López-García
- Department of Molecular Neuropathology, Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Madrid, Spain
| | - Raquel Jiménez-Sánchez
- Department of Molecular Neuropathology, Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Madrid, Spain
| | - Juan A. López
- Proteomics Unit, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Instituto de Salud Carlos III, Madrid, Spain
| | - Mariona Graupera
- Endothelial Pathobiology and Microenviroment Group, Josep Carreras Leukaemia Research Institute (IJC), 08916 Badalona, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Instituto de Salud Carlos III, Madrid, Spain
| | - José A. Esteban
- Department of Molecular Neuropathology, Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Madrid, Spain
| |
Collapse
|
6
|
Chen J, Ding Q, An L, Wang H. Ca2+-stimulated adenylyl cyclases as therapeutic targets for psychiatric and neurodevelopmental disorders. Front Pharmacol 2022; 13:949384. [PMID: 36188604 PMCID: PMC9523369 DOI: 10.3389/fphar.2022.949384] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 09/05/2022] [Indexed: 11/13/2022] Open
Abstract
As the main secondary messengers, cyclic AMP (cAMP) and Ca2+ trigger intracellular signal transduction cascade and, in turn, regulate many aspects of cellular function in developing and mature neurons. The group I adenylyl cyclase (ADCY, also known as AC) isoforms, including ADCY1, 3, and 8 (also known as AC1, AC3, and AC8), are stimulated by Ca2+ and thus functionally positioned to integrate cAMP and Ca2+ signaling. Emerging lines of evidence have suggested the association of the Ca2+-stimulated ADCYs with bipolar disorder, schizophrenia, major depressive disorder, post-traumatic stress disorder, and autism. In this review, we discuss the molecular and cellular features as well as the physiological functions of ADCY1, 3, and 8. We further discuss the recent therapeutic development to target the Ca2+-stimulated ADCYs for potential treatments of psychiatric and neurodevelopmental disorders.
Collapse
|
7
|
Chaudry S, Vasudevan N. mTOR-Dependent Spine Dynamics in Autism. Front Mol Neurosci 2022; 15:877609. [PMID: 35782388 PMCID: PMC9241970 DOI: 10.3389/fnmol.2022.877609] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 04/25/2022] [Indexed: 12/12/2022] Open
Abstract
Autism Spectrum Conditions (ASC) are a group of neurodevelopmental disorders characterized by deficits in social communication and interaction as well as repetitive behaviors and restricted range of interests. ASC are complex genetic disorders with moderate to high heritability, and associated with atypical patterns of neural connectivity. Many of the genes implicated in ASC are involved in dendritic spine pruning and spine development, both of which can be mediated by the mammalian target of rapamycin (mTOR) signaling pathway. Consistent with this idea, human postmortem studies have shown increased spine density in ASC compared to controls suggesting that the balance between autophagy and spinogenesis is altered in ASC. However, murine models of ASC have shown inconsistent results for spine morphology, which may underlie functional connectivity. This review seeks to establish the relevance of changes in dendritic spines in ASC using data gathered from rodent models. Using a literature survey, we identify 20 genes that are linked to dendritic spine pruning or development in rodents that are also strongly implicated in ASC in humans. Furthermore, we show that all 20 genes are linked to the mTOR pathway and propose that the mTOR pathway regulating spine dynamics is a potential mechanism underlying the ASC signaling pathway in ASC. We show here that the direction of change in spine density was mostly correlated to the upstream positive or negative regulation of the mTOR pathway and most rodent models of mutant mTOR regulators show increases in immature spines, based on morphological analyses. We further explore the idea that these mutations in these genes result in aberrant social behavior in rodent models that is due to these altered spine dynamics. This review should therefore pave the way for further research on the specific genes outlined, their effect on spine morphology or density with an emphasis on understanding the functional role of these changes in ASC.
Collapse
|
8
|
Lee A, Xu J, Wen Z, Jin P. Across Dimensions: Developing 2D and 3D Human iPSC-Based Models of Fragile X Syndrome. Cells 2022; 11:1725. [PMID: 35681419 PMCID: PMC9179297 DOI: 10.3390/cells11111725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 05/11/2022] [Accepted: 05/13/2022] [Indexed: 02/01/2023] Open
Abstract
Fragile X syndrome (FXS) is the most common inherited cause of intellectual disability and autism spectrum disorder. FXS is caused by a cytosine-guanine-guanine (CGG) trinucleotide repeat expansion in the untranslated region of the FMR1 gene leading to the functional loss of the gene's protein product FMRP. Various animal models of FXS have provided substantial knowledge about the disorder. However, critical limitations exist in replicating the pathophysiological mechanisms. Human induced pluripotent stem cells (hiPSCs) provide a unique means of studying the features and processes of both normal and abnormal human neurodevelopment in large sample quantities in a controlled setting. Human iPSC-based models of FXS have offered a better understanding of FXS pathophysiology specific to humans. This review summarizes studies that have used hiPSC-based two-dimensional cellular models of FXS to reproduce the pathology, examine altered gene expression and translation, determine the functions and targets of FMRP, characterize the neurodevelopmental phenotypes and electrophysiological features, and, finally, to reactivate FMR1. We also provide an overview of the most recent studies using three-dimensional human brain organoids of FXS and end with a discussion of current limitations and future directions for FXS research using hiPSCs.
Collapse
Affiliation(s)
- Azalea Lee
- Neuroscience Graduate Program, Emory University, Atlanta, GA 30322, USA;
- MD/PhD Program, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Jie Xu
- Genetics and Molecular Biology Graduate Program, Emory University, Atlanta, GA 30322, USA;
| | - Zhexing Wen
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA 30322, USA
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Peng Jin
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA
| |
Collapse
|
9
|
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.
Collapse
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
| |
Collapse
|
10
|
Ding Q, Wu X, Li X, Wang H. Vorinostat Corrects Cognitive and Non-Cognitive Symptoms in a Mouse Model of Fragile X Syndrome. Int J Neuropsychopharmacol 2021; 25:147-159. [PMID: 34791268 PMCID: PMC8832232 DOI: 10.1093/ijnp/pyab081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 11/04/2021] [Accepted: 11/12/2021] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Fragile X syndrome (FXS) is caused by mutations in the FMR1 gene. It is a form of heritable intellectual disability and autism. Despite recent advance in elucidating disease mechanisms, there is no efficacious medication. Because de novo drug development is a lengthy process, repurposing the existing FDA-approved drugs offers an opportunity to advance clinical intervention for FXS. Our previous study with transcriptome analysis predicts potential therapeutic effects of vorinostat on FXS. METHODS We analyzed the vorinostat-induced transcriptome changes and confirmed its similarity to that induced by trifluoperazine, which was previously shown to correct pathological outcomes associated with FXS. To validate the therapeutic efficacy, we examined vorinostat's effect on correcting the key behavioral and cellular symptoms in a mouse model of FXS. RESULTS We found that vorinostat restores object location memory and passive avoidance memory in the Fmr1 knockout mice. For the non-cognitive behavioral symptoms, vorinostat corrected the autism-associated alterations, including repetitive behavior and social interaction deficits. In the open field test, vorinostat dampened hyperactivity in the center area of the arena. Surprisingly, vorinostat did not correct the abnormally elevated protein synthesis in cultured Fmr1 knockout hippocampal neurons, suggesting that different aspects of pathological outcomes may respond differently to a specific therapeutic intervention. CONCLUSIONS We used the drug-induced transcriptome signature to predict new application of existing drugs. Our data reveal the therapeutic effects of the FDA-approved drug vorinostat in a mouse model of FXS.
Collapse
Affiliation(s)
- Qi Ding
- Department of Physiology Michigan State University, East Lansing, Michigan, USA
| | - Xueting Wu
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Xuan Li
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Hongbing Wang
- Department of Physiology Michigan State University, East Lansing, Michigan, USA,Neuroscience Program Michigan State University, East Lansing, Michigan, USA,Correspondence: Hongbing Wang, PhD, 567 Wilson Road, East Lansing, MI 48824, USA ()
| |
Collapse
|
11
|
Kang Y, Zhou Y, Li Y, Han Y, Xu J, Niu W, Li Z, Liu S, Feng H, Huang W, Duan R, Xu T, Raj N, Zhang F, Dou J, Xu C, Wu H, Bassell GJ, Warren ST, Allen EG, Jin P, Wen Z. A human forebrain organoid model of fragile X syndrome exhibits altered neurogenesis and highlights new treatment strategies. Nat Neurosci 2021; 24:1377-1391. [PMID: 34413513 PMCID: PMC8484073 DOI: 10.1038/s41593-021-00913-6] [Citation(s) in RCA: 79] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Accepted: 07/15/2021] [Indexed: 02/07/2023]
Abstract
Fragile X syndrome (FXS) is caused by the loss of fragile X mental retardation protein (FMRP), an RNA-binding protein that can regulate the translation of specific mRNAs. In this study, we developed an FXS human forebrain organoid model and observed that the loss of FMRP led to dysregulated neurogenesis, neuronal maturation and neuronal excitability. Bulk and single-cell gene expression analyses of FXS forebrain organoids revealed that the loss of FMRP altered gene expression in a cell-type-specific manner. The developmental deficits in FXS forebrain organoids could be rescued by inhibiting the phosphoinositide 3-kinase pathway but not the metabotropic glutamate pathway disrupted in the FXS mouse model. We identified a large number of human-specific mRNAs bound by FMRP. One of these human-specific FMRP targets, CHD2, contributed to the altered gene expression in FXS organoids. Collectively, our study revealed molecular, cellular and electrophysiological abnormalities associated with the loss of FMRP during human brain development.
Collapse
Affiliation(s)
- Yunhee Kang
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA;,Department of Biostatistics and Bioinformatics, Emory University School of Public Health, Atlanta, GA 30322, USA
| | - Ying Zhou
- Department of Psychiatry and Behavioral Scieces, Emory University School of Medicine, Atlanta, GA 30322, USA;,Department of Biostatistics and Bioinformatics, Emory University School of Public Health, Atlanta, GA 30322, USA
| | - Yujing Li
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA;,Department of Biostatistics and Bioinformatics, Emory University School of Public Health, Atlanta, GA 30322, USA
| | - Yanfei Han
- Department of Psychiatry and Behavioral Scieces, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Jie Xu
- The Graduate Program in Genetics and Molecular Biology, Emory University, GA 30322, USA
| | - Weibo Niu
- Department of Psychiatry and Behavioral Scieces, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Ziyi Li
- Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - Shiying Liu
- Department of Population and Quantitative Health Sciences, Case Western Reserve University, OH 44106, USA
| | - Hao Feng
- Department of Population and Quantitative Health Sciences, Case Western Reserve University, OH 44106, USA
| | - Wen Huang
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, 410078, China
| | - Ranhui Duan
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, 410078, China
| | - Tianmin Xu
- Department of Gynecology and Obstetrics, The Second Hospital of Jilin University, Changchun, Jilin, China
| | - Nisha Raj
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Feiran Zhang
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Juan Dou
- Department of Psychiatry and Behavioral Scieces, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Chongchong Xu
- Department of Psychiatry and Behavioral Scieces, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Hao Wu
- Department of Biostatistics and Bioinformatics, Emory University School of Public Health, Atlanta, GA 30322, USA
| | - Gary J Bassell
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Stephen T Warren
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Emily G Allen
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Peng Jin
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA;,To whom correspondence should be addressed: (P.J.) and (Z.W.)
| | - Zhexing Wen
- Department of Psychiatry and Behavioral Scieces, Emory University School of Medicine, Atlanta, GA 30322, USA;,Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA;,To whom correspondence should be addressed: (P.J.) and (Z.W.)
| |
Collapse
|
12
|
Boksha IS, Prokhorova TA, Tereshkina EB, Savushkina OK, Burbaeva GS. Protein Phosphorylation Signaling Cascades in Autism: The Role of mTOR Pathway. BIOCHEMISTRY (MOSCOW) 2021; 86:577-596. [PMID: 33993859 DOI: 10.1134/s0006297921050072] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The mammalian target of rapamycin (mTOR) signaling pathway is a central regulator of cell metabolism, growth, and survival in response to hormones, growth factors, nutrients, and stress-induced signals. In this review, we analyzed the studies on the molecular abnormalities of the mTOR-associated signaling cascades in autism spectrum disorders (ASDs) and outlined the prospects for the pathogenicity-targeting pharmacotherapeutic approaches to ASDs, in particular syndromic ASDs. Based on available experimental and clinical data, we suggest that very early detection of molecular abnormalities in the ASD risk groups can be facilitated by using peripheral blood platelets. Also, identification of the time window of critical dysregulations in the described pathways in the ASD risk groups might suggest further research directions leading to more efficacious pharmacotherapeutic interventions in ASDs.
Collapse
Affiliation(s)
- Irina S Boksha
- Mental Health Research Center, Moscow, 115522, Russia. .,Gamaleya Research Center of Epidemiology and Microbiology, Ministry of Health of the Russian Federation, Moscow, 123098, Russia
| | | | | | | | | |
Collapse
|
13
|
Shapiro LP, Pitts EG, Li DC, Barbee BR, Hinton EA, Bassell GJ, Gross C, Gourley SL. The PI3-Kinase p110β Isoform Controls Severity of Cocaine-Induced Sequelae and Alters the Striatal Transcriptome. Biol Psychiatry 2021; 89:959-969. [PMID: 33773752 PMCID: PMC8202243 DOI: 10.1016/j.biopsych.2021.01.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 01/04/2021] [Accepted: 01/13/2021] [Indexed: 12/15/2022]
Abstract
BACKGROUND The PI3-kinase (PI3K) complex is a well-validated target for mitigating cocaine-elicited sequelae, but pan-PI3K inhibitors are not viable long-term treatment options. The PI3K complex is composed of p110 catalytic and regulatory subunits, which can be individually manipulated for therapeutic purposes. However, this possibility has largely not been explored in behavioral contexts. METHODS Here, we inhibited PI3K p110β in the medial prefrontal cortex (mPFC) of cocaine-exposed mice. Behavioral models for studying relapse, sensitization, and decision-making biases were paired with protein quantification, RNA sequencing, and cell type-specific chemogenetic manipulation and RNA quantification to determine whether and how inhibiting PI3K p110β confers resilience to cocaine. RESULTS Viral-mediated PI3K p110β silencing reduced cue-induced reinstatement of cocaine seeking by half, blocked locomotor sensitization, and restored mPFC synaptic marker content after exposure to cocaine. Cocaine blocked the ability of mice to select actions based on their consequences, and p110β inhibition restored this ability. Silencing dopamine D2 receptor-expressing excitatory mPFC neurons mimicked cocaine, impairing goal-seeking behavior, and again, p110β inhibition restored goal-oriented action. We verified the presence of p110β in mPFC neurons projecting to the dorsal striatum and orbitofrontal cortex and found that inhibiting p110β in the mPFC altered the expression of functionally defined gene clusters within the dorsal striatum and not orbitofrontal cortex. CONCLUSIONS Subunit-selective PI3K silencing potently mitigates drug seeking, sensitization, and decision-making biases after exposure to cocaine. We suggest that inhibiting PI3K p110β provides neuroprotection against cocaine by triggering coordinated corticostriatal adaptations.
Collapse
Affiliation(s)
- Lauren P. Shapiro
- Graduate Program in Molecular and Systems Pharmacology, Emory University,Department of Pediatrics, Emory University School of Medicine; Yerkes National Primate Research Center
| | - Elizabeth G. Pitts
- Department of Pediatrics, Emory University School of Medicine; Yerkes National Primate Research Center,Graduate Program in Neuroscience, Emory University
| | - Dan C. Li
- Department of Pediatrics, Emory University School of Medicine; Yerkes National Primate Research Center,Graduate Program in Neuroscience, Emory University
| | - Britton R. Barbee
- Graduate Program in Molecular and Systems Pharmacology, Emory University,Department of Pediatrics, Emory University School of Medicine; Yerkes National Primate Research Center
| | - Elizabeth A. Hinton
- Department of Pediatrics, Emory University School of Medicine; Yerkes National Primate Research Center,Graduate Program in Neuroscience, Emory University
| | - Gary J. Bassell
- Graduate Program in Neuroscience, Emory University,Department of Cell Biology, Emory University
| | - Christina Gross
- Division of Neurology, Cincinnati Children’s Hospital Medical Center and Department of Pediatrics, University of Cincinnati College of Medicine
| | - Shannon L. Gourley
- Department of Pediatrics, Emory University School of Medicine; Yerkes National Primate Research Center,Graduate Program in Neuroscience, Emory University,Children’s Healthcare of Atlanta
| |
Collapse
|
14
|
Ehinger Y. PI3-Kinase p110β in Cortical Circuitries and Cocaine-Dependent Maladaptative Behaviors. Biol Psychiatry 2021; 89:e55-e57. [PMID: 33958037 DOI: 10.1016/j.biopsych.2021.03.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 03/12/2021] [Indexed: 10/21/2022]
Affiliation(s)
- Yann Ehinger
- Department of Neurology, University of California, San Francisco, California.
| |
Collapse
|
15
|
Cell-type-specific profiling of human cellular models of fragile X syndrome reveal PI3K-dependent defects in translation and neurogenesis. Cell Rep 2021; 35:108991. [PMID: 33852833 PMCID: PMC8133829 DOI: 10.1016/j.celrep.2021.108991] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 03/08/2021] [Accepted: 03/23/2021] [Indexed: 02/06/2023] Open
Abstract
Transcriptional silencing of the FMR1 gene in fragile X syndrome (FXS) leads to the loss of the RNA-binding protein FMRP. In addition to regulating mRNA translation and protein synthesis, emerging evidence suggests that FMRP acts to coordinate proliferation and differentiation during early neural development. However, whether loss of FMRP-mediated translational control is related to impaired cell fate specification in the developing human brain remains unknown. Here, we use human patient induced pluripotent stem cell (iPSC)-derived neural progenitor cells and organoids to model neurogenesis in FXS. We developed a high-throughput, in vitro assay that allows for the simultaneous quantification of protein synthesis and proliferation within defined neural subpopulations. We demonstrate that abnormal protein synthesis in FXS is coupled to altered cellular decisions to favor proliferative over neurogenic cell fates during early development. Furthermore, pharmacologic inhibition of elevated phosphoinositide 3-kinase (PI3K) signaling corrects both excess protein synthesis and cell proliferation in a subset of patient neural cells. Raj et al. developed a multiparametric assay to measure cellular and molecular phenotypes during neurogenesis in fragile X syndrome iPSC-derived neural cells. Relative to controls, FXS patient cultures have more proliferative cells with increased protein synthesis. Defects in cell fate acquisition can be normalized by inhibiting overactive PI3K signaling.
Collapse
|
16
|
Gandhi T, Lee CC. Neural Mechanisms Underlying Repetitive Behaviors in Rodent Models of Autism Spectrum Disorders. Front Cell Neurosci 2021; 14:592710. [PMID: 33519379 PMCID: PMC7840495 DOI: 10.3389/fncel.2020.592710] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 12/09/2020] [Indexed: 12/15/2022] Open
Abstract
Autism spectrum disorder (ASD) is comprised of several conditions characterized by alterations in social interaction, communication, and repetitive behaviors. Genetic and environmental factors contribute to the heterogeneous development of ASD behaviors. Several rodent models display ASD-like phenotypes, including repetitive behaviors. In this review article, we discuss the potential neural mechanisms involved in repetitive behaviors in rodent models of ASD and related neuropsychiatric disorders. We review signaling pathways, neural circuits, and anatomical alterations in rodent models that display robust stereotypic behaviors. Understanding the mechanisms and circuit alterations underlying repetitive behaviors in rodent models of ASD will inform translational research and provide useful insight into therapeutic strategies for the treatment of repetitive behaviors in ASD and other neuropsychiatric disorders.
Collapse
Affiliation(s)
- Tanya Gandhi
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, LA, United States
| | | |
Collapse
|
17
|
Tiwari D, Schaefer TL, Schroeder-Carter LM, Krzeski JC, Bunk AT, Parkins EV, Snider A, Danzer R, Williams MT, Vorhees CV, Danzer SC, Gross C. The potassium channel Kv4.2 regulates dendritic spine morphology, electroencephalographic characteristics and seizure susceptibility in mice. Exp Neurol 2020; 334:113437. [PMID: 32822706 PMCID: PMC7642025 DOI: 10.1016/j.expneurol.2020.113437] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 08/13/2020] [Accepted: 08/17/2020] [Indexed: 01/21/2023]
Abstract
The voltage-gated potassium channel Kv4.2 is a critical regulator of dendritic excitability in the hippocampus and is crucial for dendritic signal integration. Kv4.2 mRNA and protein expression as well as function are reduced in several genetic and pharmacologically induced rodent models of epilepsy and autism. It is not known, however, whether reduced Kv4.2 is just an epiphenomenon or a disease-contributing cause of neuronal hyperexcitability and behavioral impairments in these neurological disorders. To address this question, we used male and female mice heterozygous for a Kv.2 deletion and adult-onset manipulation of hippocampal Kv4.2 expression in male mice to assess the role of Kv4.2 in regulating neuronal network excitability, morphology and anxiety-related behaviors. We observed a reduction in dendritic spine density and reduced proportions of thin and stubby spines but no changes in anxiety, overall activity, or retention of conditioned freezing memory in Kv4.2 heterozygous mice compared with wildtype littermates. Using EEG analyses, we showed elevated theta power and increased spike frequency in Kv4.2 heterozygous mice under basal conditions. In addition, the latency to onset of kainic acid-induced seizures was significantly shortened in Kv4.2 heterozygous mice compared with wildtype littermates, which was accompanied by a significant increase in theta power. By contrast, overexpressing Kv4.2 in wildtype mice through intrahippocampal injection of Kv4.2-expressing lentivirus delayed seizure onset and reduced EEG power. These results suggest that Kv4.2 is an important regulator of neuronal network excitability and dendritic spine morphology, but not anxiety-related behaviors. In the future, manipulation of Kv4.2 expression could be used to alter seizure susceptibility in epilepsy.
Collapse
Affiliation(s)
- Durgesh Tiwari
- 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
| | - Tori L Schaefer
- Division of Psychiatry, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | | | - Joseph C Krzeski
- Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Alexander T Bunk
- Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Emma V Parkins
- Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Andrew Snider
- Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Reese Danzer
- Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Michael T Williams
- 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
| | - Charles V Vorhees
- 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
| | - Steve C Danzer
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA; Department of Anesthesia, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; Department of Anesthesiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, 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.
| |
Collapse
|
18
|
Hooshmandi M, Wong C, Khoutorsky A. Dysregulation of translational control signaling in autism spectrum disorders. Cell Signal 2020; 75:109746. [PMID: 32858122 DOI: 10.1016/j.cellsig.2020.109746] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 08/17/2020] [Accepted: 08/18/2020] [Indexed: 11/27/2022]
Abstract
Deviations from the optimal level of mRNA translation are linked to disorders with high rates of autism. Loss of function mutations in genes encoding translational repressors such as PTEN, TSC1, TSC2, and FMRP are associated with autism spectrum disorders (ASDs) in humans and their deletion in animals recapitulates many ASD-like phenotypes. Importantly, the activity of key translational control signaling pathways such as PI3K-mTORC1 and ERK is frequently dysregulated in autistic patients and animal models and their normalization rescues many abnormal phenotypes, suggesting a causal relationship. Mutations in several genes encoding proteins not directly involved in translational control have also been shown to mediate ASD phenotypes via altered signaling upstream of translation. This raises the possibility that the dysregulation of translational control signaling is a converging mechanism not only in familiar but also in sporadic forms of autism. Here, we overview the current knowledge on translational signaling in ASD and highlight how correcting the activity of key pathways upstream of translation reverses distinct ASD-like phenotypes.
Collapse
Affiliation(s)
- Mehdi Hooshmandi
- Department of Anesthesia, Faculty of Dentistry, McGill University, Montreal, QC H3A 0G1, Canada
| | - Calvin Wong
- Department of Anesthesia, Faculty of Dentistry, McGill University, Montreal, QC H3A 0G1, Canada
| | - Arkady Khoutorsky
- Department of Anesthesia, Faculty of Dentistry, McGill University, Montreal, QC H3A 0G1, Canada.
| |
Collapse
|
19
|
White AR, Tiwari D, MacLeod MC, Danzer SC, Gross C. PI3K isoform-selective inhibition in neuron-specific PTEN-deficient mice rescues molecular defects and reduces epilepsy-associated phenotypes. Neurobiol Dis 2020; 144:105026. [PMID: 32712265 DOI: 10.1016/j.nbd.2020.105026] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 07/13/2020] [Accepted: 07/20/2020] [Indexed: 01/16/2023] Open
Abstract
Epilepsy affects all ages, races, genders, and socioeconomic groups. In about one third of patients, epilepsy is uncontrolled with current medications, leaving a vast need for improved therapies. The causes of epilepsy are diverse and not always known but one gene mutated in a small subpopulation of patients is phosphatase and tensin homolog (PTEN). Moreover, focal cortical dysplasia, which constitutes a large fraction of refractory epilepsies, has been associated with signaling defects downstream of PTEN. So far, most preclinical attempts to reverse PTEN deficiency-associated neurological deficits have focused on mTOR, a signaling hub several steps downstream of PTEN. Phosphoinositide 3-kinases (PI3Ks), by contrast, are the direct enzymatic counteractors of PTEN, and thus may be alternative treatment targets. PI3K activity is mediated by four different PI3K catalytic isoforms. Studies in cancer, where PTEN is commonly mutated, have demonstrated that inhibition of only one isoform, p110β, reduces progression of PTEN-deficient tumors. Importantly, inhibition of a single PI3K isoform leaves critical functions of general PI3K signaling throughout the body intact. Here, we show that this disease mechanism-targeted strategy borrowed from cancer research rescues or ameliorates neuronal phenotypes in male and female mice with neuron-specific PTEN deficiency. These phenotypes include cell signaling defects, protein synthesis aberrations, seizures, and cortical dysplasia. Of note, p110β is also dysregulated and a promising treatment target in the intellectual disability Fragile X syndrome, pointing towards a shared biological mechanism that is therapeutically targetable in neurodevelopmental disorders of different etiologies. Overall, this work advocates for further assessment of p110β inhibition not only in PTEN deficiency-associated neurodevelopmental diseases but also other brain disorders characterized by defects in the PI3K/mTOR pathway.
Collapse
Affiliation(s)
- Angela R White
- Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Durgesh Tiwari
- Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; Department of Pediatrics, University of Cincinnati College of Medicine, OH 45229, USA
| | - Molly C MacLeod
- Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Steve C Danzer
- Department of Anesthesia, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; Department of Anesthesiology, University of Cincinnati College of Medicine, 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, OH 45229, USA.
| |
Collapse
|
20
|
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.
Collapse
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.
| |
Collapse
|
21
|
Woon EP, Sequeira MK, Barbee BR, Gourley SL. Involvement of the rodent prelimbic and medial orbitofrontal cortices in goal-directed action: A brief review. J Neurosci Res 2020; 98:1020-1030. [PMID: 31820488 PMCID: PMC7392403 DOI: 10.1002/jnr.24567] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 10/13/2019] [Accepted: 11/15/2019] [Indexed: 01/15/2023]
Abstract
Goal-directed action refers to selecting behaviors based on the expectation that they will be reinforced with desirable outcomes. It is typically conceptualized as opposing habit-based behaviors, which are instead supported by stimulus-response associations and insensitive to consequences. The prelimbic prefrontal cortex (PL) is positioned along the medial wall of the rodent prefrontal cortex. It is indispensable for action-outcome-driven (goal-directed) behavior, consolidating action-outcome relationships and linking contextual information with instrumental behavior. In this brief review, we will discuss the growing list of molecular factors involved in PL function. Ventral to the PL is the medial orbitofrontal cortex (mOFC). We will also summarize emerging evidence from rodents (complementing existing literature describing humans) that it too is involved in action-outcome conditioning. We describe experiments using procedures that quantify responding based on reward value, the likelihood of reinforcement, or effort requirements, touching also on experiments assessing food consumption more generally. We synthesize these findings with the argument that the mOFC is essential to goal-directed action when outcome value information is not immediately observable and must be recalled and inferred.
Collapse
Affiliation(s)
- Ellen P. Woon
- Graduate Program in Neuroscience
- Yerkes National Primate Research Center, Departments of Pediatrics and Psychiatry and Behavioral Sciences, Center for Translational and Social Neuroscience
| | - Michelle K. Sequeira
- Graduate Program in Neuroscience
- Yerkes National Primate Research Center, Departments of Pediatrics and Psychiatry and Behavioral Sciences, Center for Translational and Social Neuroscience
| | - Britton R. Barbee
- Yerkes National Primate Research Center, Departments of Pediatrics and Psychiatry and Behavioral Sciences, Center for Translational and Social Neuroscience
- Graduate Program in Molecular and Systems Pharmacology Emory University, Atlanta, GA
| | - Shannon L. Gourley
- Graduate Program in Neuroscience
- Yerkes National Primate Research Center, Departments of Pediatrics and Psychiatry and Behavioral Sciences, Center for Translational and Social Neuroscience
- Graduate Program in Molecular and Systems Pharmacology Emory University, Atlanta, GA
| |
Collapse
|
22
|
Ding Q, Sethna F, Wu XT, Miao Z, Chen P, Zhang Y, Xiao H, Feng W, Feng Y, Li X, Wang H. Transcriptome signature analysis repurposes trifluoperazine for the treatment of fragile X syndrome in mouse model. Commun Biol 2020; 3:127. [PMID: 32179850 PMCID: PMC7075969 DOI: 10.1038/s42003-020-0833-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 02/07/2020] [Indexed: 02/06/2023] Open
Abstract
Fragile X syndrome (FXS) is a prevailing genetic disorder of intellectual disability and autism. There is no efficacious medication for FXS. Through in silico screening with a public database, computational analysis of transcriptome profile in FXS mouse neurons predicts therapeutic value of an FDA-approved drug trifluoperazine. Systemic administration of low-dose trifluoperazine at 0.05 mg/kg attenuates multiple FXS- and autism-related behavioral symptoms. Moreover, computational analysis of transcriptome alteration caused by trifluoperazine suggests a new mechanism of action against PI3K (Phosphatidylinositol-4,5-bisphosphate 3-kinase) activity. Consistently, trifluoperazine suppresses PI3K activity and its down-stream targets Akt (protein kinase B) and S6K1 (S6 kinase 1) in neurons. Further, trifluoperazine normalizes the aberrantly elevated activity of Akt and S6K1 and enhanced protein synthesis in FXS mouse. Together, our data demonstrate a promising value of transcriptome-based computation in identification of therapeutic strategy and repurposing drugs for neurological disorders, and suggest trifluoperazine as a potential treatment for FXS. Qi Ding, Ferzin Sethna et al. perform a computational analysis of the transcriptome profile of Fmr1−/− neurons and identify trifluoperazine as potential therapeutic agent against Fragile X Syndrome. Next, they show that low doses of trifluoperazine ameliorate some of the behavioral and molecular phenotypes present in Fmr1−/− mice.
Collapse
Affiliation(s)
- Qi Ding
- Department of Physiology, Michigan State University, East Lansing, USA
| | - Ferzin Sethna
- Genetics Program, Michigan State University, East Lansing, USA
| | - Xue-Ting Wu
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 200032, Shanghai, China
| | - Zhuang Miao
- Genetics Program, Michigan State University, East Lansing, USA
| | - Ping Chen
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 200032, Shanghai, China
| | - Yueqi Zhang
- Department of Physiology, Michigan State University, East Lansing, USA
| | - Hua Xiao
- Department of Physiology, Michigan State University, East Lansing, USA
| | - Wei Feng
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, 30322, Georgia
| | - Yue Feng
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, 30322, Georgia
| | - Xuan Li
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 200032, Shanghai, China
| | - Hongbing Wang
- Department of Physiology, Michigan State University, East Lansing, USA. .,Neuroscience Program, Michigan State University, East Lansing, MI, 48824, USA.
| |
Collapse
|
23
|
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.
Collapse
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
| | | | | |
Collapse
|
24
|
Crespi BJ. Comparative psychopharmacology of autism and psychotic-affective disorders suggests new targets for treatment. Evol Med Public Health 2019; 2019:149-168. [PMID: 31548888 PMCID: PMC6748779 DOI: 10.1093/emph/eoz022] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 08/07/2019] [Indexed: 12/13/2022] Open
Abstract
The first treatments showing effectiveness for some psychiatric disorders, such as lithium for bipolar disorder and chlorpromazine for schizophrenia, were discovered by accident. Currently, psychiatric drug design is seen as a scientific enterprise, limited though it remains by the complexity of brain development and function. Relatively few novel and effective drugs have, however, been developed for many years. The purpose of this article is to demonstrate how evolutionary biology can provide a useful framework for psychiatric drug development. The framework is based on a diametrical nature of autism, compared with psychotic-affective disorders (mainly schizophrenia, bipolar disorder and depression). This paradigm follows from two inferences: (i) risks and phenotypes of human psychiatric disorders derive from phenotypes that have evolved along the human lineage and (ii) biological variation is bidirectional (e.g. higher vs lower, faster vs slower, etc.), such that dysregulation of psychological traits varies in two opposite ways. In this context, the author review the evidence salient to the hypothesis that autism and psychotic-affective disorders represent diametrical disorders in terms of current, proposed and potential psychopharmacological treatments. Studies of brain-derived neurotrophic factor, the PI3K pathway, the NMDA receptor, kynurenic acid metabolism, agmatine metabolism, levels of the endocannabinoid anandamide, antidepressants, anticonvulsants, antipsychotics, and other treatments, demonstrate evidence of diametric effects in autism spectrum disorders and phenotypes compared with psychotic-affective disorders and phenotypes. These findings yield insights into treatment mechanisms and the development of new pharmacological therapies, as well as providing an explanation for the longstanding puzzle of antagonism between epilepsy and psychosis. Lay Summary: Consideration of autism and schizophrenia as caused by opposite alterations to brain development and function leads to novel suggestions for pharmacological treatments.
Collapse
Affiliation(s)
- Bernard J Crespi
- Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
| |
Collapse
|
25
|
Whyte AJ, Kietzman HW, Swanson AM, Butkovich LM, Barbee BR, Bassell GJ, Gross C, Gourley SL. Reward-Related Expectations Trigger Dendritic Spine Plasticity in the Mouse Ventrolateral Orbitofrontal Cortex. J Neurosci 2019; 39:4595-4605. [PMID: 30940719 PMCID: PMC6554633 DOI: 10.1523/jneurosci.2031-18.2019] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 03/07/2019] [Accepted: 03/26/2019] [Indexed: 02/06/2023] Open
Abstract
An essential aspect of goal-directed decision-making is selecting actions based on anticipated consequences, a process that involves the orbitofrontal cortex (OFC) and potentially, the plasticity of dendritic spines in this region. To investigate this possibility, we trained male and female mice to nose poke for food reinforcers, or we delivered the same number of food reinforcers non-contingently to separate mice. We then decreased the likelihood of reinforcement for trained mice, requiring them to modify action-outcome expectations. In a separate experiment, we blocked action-outcome updating via chemogenetic inactivation of the OFC. In both cases, successfully selecting actions based on their likely consequences was associated with fewer immature, thin-shaped dendritic spines and a greater proportion of mature, mushroom-shaped spines in the ventrolateral OFC. This pattern was distinct from spine loss associated with aging, and we identified no effects on hippocampal CA1 neurons. Given that the OFC is involved in prospective calculations of likely outcomes, even when they are not observable, constraining spinogenesis while preserving mature spines may be important for solidifying durable expectations. To investigate causal relationships, we inhibited the RNA-binding protein fragile X mental retardation protein (encoded by Fmr1), which constrains dendritic spine turnover. Ventrolateral OFC-selective Fmr1 knockdown recapitulated the behavioral effects of inducible OFC inactivation (and lesions; also shown here), impairing action-outcome conditioning, and caused dendritic spine excess. Our findings suggest that a proper balance of dendritic spine plasticity within the OFC is necessary for one's ability to select actions based on anticipated consequences.SIGNIFICANCE STATEMENT Navigating a changing environment requires associating actions with their likely outcomes and updating these associations when they change. Dendritic spine plasticity is likely involved, yet relationships are unconfirmed. Using behavioral, chemogenetic, and viral-mediated gene silencing strategies and high-resolution microscopy, we find that modifying action-outcome expectations is associated with fewer immature spines and a greater proportion of mature spines in the ventrolateral orbitofrontal cortex (OFC). Given that the OFC is involved in prospectively calculating the likely outcomes of one's behavior, even when they are not observable, constraining spinogenesis while preserving mature spines may be important for maintaining durable expectations.
Collapse
Affiliation(s)
- Alonzo J Whyte
- Departments of Cell Biology
- Pediatrics, Emory School of Medicine
- Yerkes National Primate Research Center
| | - Henry W Kietzman
- Pediatrics, Emory School of Medicine
- Yerkes National Primate Research Center
- Graduate Program in Neuroscience
| | - Andrew M Swanson
- Pediatrics, Emory School of Medicine
- Yerkes National Primate Research Center
- Graduate Program in Neuroscience
| | - Laura M Butkovich
- Pediatrics, Emory School of Medicine
- Yerkes National Primate Research Center
- Graduate Program in Neuroscience
| | - Britton R Barbee
- Pediatrics, Emory School of Medicine
- Yerkes National Primate Research Center
- Graduate Program in Molecular and Systems Pharmacology, Emory University, Atlanta, Georgia 30329
| | - Gary J Bassell
- Departments of Cell Biology
- Graduate Program in Neuroscience
| | - Christina Gross
- Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229, and
- Department of Pediatrics, University of Cincinnati, College of Medicine, Cincinnati, Ohio 45267
| | - Shannon L Gourley
- Pediatrics, Emory School of Medicine,
- Yerkes National Primate Research Center
- Graduate Program in Neuroscience
- Graduate Program in Molecular and Systems Pharmacology, Emory University, Atlanta, Georgia 30329
| |
Collapse
|
26
|
Kinase pathway inhibition restores PSD95 induction in neurons lacking fragile X mental retardation protein. Proc Natl Acad Sci U S A 2019; 116:12007-12012. [PMID: 31118285 DOI: 10.1073/pnas.1812056116] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Fragile X syndrome (FXS) is the leading monogenic cause of autism and intellectual disability. FXS is caused by loss of expression of fragile X mental retardation protein (FMRP), an RNA-binding protein that regulates translation of numerous mRNA targets, some of which are present at synapses. While protein synthesis deficits have long been postulated as an etiology of FXS, how FMRP loss affects distributions of newly synthesized proteins is unknown. Here we investigated the role of FMRP in regulating expression of new copies of the synaptic protein PSD95 in an in vitro model of synaptic plasticity. We find that local BDNF application promotes persistent accumulation of new PSD95 at stimulated synapses and dendrites of cultured neurons, and that this accumulation is absent in FMRP-deficient mouse neurons. New PSD95 accumulation at sites of BDNF stimulation does not require known mechanisms regulating FMRP-mRNA interactions but instead requires the PI3K-mTORC1-S6K1 pathway. Surprisingly, in FMRP-deficient neurons, BDNF induction of new PSD95 accumulation can be restored by mTORC1-S6K1 blockade, suggesting that constitutively high mTORC1-S6K1 activity occludes PSD95 regulation by BDNF and that alternative pathways exist to mediate induction when mTORC1-S6K1 is inhibited. This study provides direct evidence for deficits in local protein synthesis and accumulation of newly synthesized protein in response to local stimulation in FXS, and supports mTORC1-S6K1 pathway inhibition as a potential therapeutic approach for FXS.
Collapse
|