1
|
Ryczko D. The Mesencephalic Locomotor Region: Multiple Cell Types, Multiple Behavioral Roles, and Multiple Implications for Disease. Neuroscientist 2024; 30:347-366. [PMID: 36575956 PMCID: PMC11107129 DOI: 10.1177/10738584221139136] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The mesencephalic locomotor region (MLR) controls locomotion in vertebrates. In humans with Parkinson disease, locomotor deficits are increasingly associated with decreased activity in the MLR. This brainstem region, commonly considered to include the cuneiform and pedunculopontine nuclei, has been explored as a target for deep brain stimulation to improve locomotor function, but the results are variable, from modest to promising. However, the MLR is a heterogeneous structure, and identification of the best cell type to target is only beginning. Here, I review the studies that uncovered the role of genetically defined MLR cell types, and I highlight the cells whose activation improves locomotor function in animal models of Parkinson disease. The promising cell types to activate comprise some glutamatergic neurons in the cuneiform and caudal pedunculopontine nuclei, as well as some cholinergic neurons of the pedunculopontine nucleus. Activation of MLR GABAergic neurons should be avoided, since they stop locomotion or evoke bouts flanked with numerous stops. MLR is also considered a potential target in spinal cord injury, supranuclear palsy, primary progressive freezing of gait, or stroke. Better targeting of the MLR cell types should be achieved through optimized deep brain stimulation protocols, pharmacotherapy, or the development of optogenetics for human use.
Collapse
Affiliation(s)
- Dimitri Ryczko
- Département de Pharmacologie-Physiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Canada
- Centre de recherche du Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, Canada
- Neurosciences Sherbrooke, Sherbrooke, Canada
- Institut de Pharmacologie de Sherbrooke, Sherbrooke, Canada
| |
Collapse
|
2
|
Rupert DD, Pagliaro AH, Choe J, Shea SD. Selective Deletion of Methyl CpG Binding Protein 2 from Parvalbumin Interneurons in the Auditory Cortex Delays the Onset of Maternal Retrieval in Mice. J Neurosci 2023; 43:6745-6759. [PMID: 37625856 PMCID: PMC10552946 DOI: 10.1523/jneurosci.0838-23.2023] [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: 05/08/2023] [Revised: 08/05/2023] [Accepted: 08/15/2023] [Indexed: 08/27/2023] Open
Abstract
Mutations in MECP2 cause the neurodevelopmental disorder Rett syndrome. MECP2 codes for methyl CpG binding protein 2 (MECP2), a transcriptional regulator that activates genetic programs for experience-dependent plasticity. Many neural and behavioral symptoms of Rett syndrome may result from dysregulated timing and thresholds for plasticity. As a model of adult plasticity, we examine changes to auditory cortex inhibitory circuits in female mice when they are first exposed to pups; this plasticity facilitates behavioral responses to pups emitting distress calls. Brainwide deletion of Mecp2 alters expression of markers associated with GABAergic parvalbumin interneurons (PVins) and impairs the emergence of pup retrieval. We hypothesized that loss of Mecp2 in PVins disproportionately contributes to the phenotype. Here, we find that deletion of Mecp2 from PVins delayed the onset of maternal retrieval behavior and recapitulated the major molecular and neurophysiological features of brainwide deletion of Mecp2 We observed that when PVin-selective mutants were exposed to pups, auditory cortical expression of PVin markers increased relative to that in wild-type littermates. PVin-specific mutants also failed to show the inhibitory auditory cortex plasticity seen in wild-type mice on exposure to pups and their vocalizations. Finally, using an intersectional viral genetic strategy, we demonstrate that postdevelopmental loss of Mecp2 in PVins of the auditory cortex is sufficient to delay onset of maternal retrieval. Our results support a model in which PVins play a central role in adult cortical plasticity and may be particularly impaired by loss of Mecp2 SIGNIFICANCE STATEMENT Rett syndrome is a neurodevelopmental disorder that includes deficits in both communication and the ability to update brain connections and activity during learning (plasticity). This condition is caused by mutations in the gene MECP2 We use a maternal behavioral test in mice requiring both vocal perception and neural plasticity to probe the role of Mecp2 in social and sensory learning. Mecp2 is normally active in all brain cells, but here we remove it from a specific population (parvalbumin neurons). We find that this is sufficient to delay learned behavioral responses to pups and recreates many deficits seen in whole-brain Mecp2 deletion. Our findings suggest that parvalbumin neurons specifically are central to the consequences of loss of Mecp2 activity and yield clues as to possible mechanisms by which Rett syndrome impairs brain function.
Collapse
Affiliation(s)
- Deborah D Rupert
- Department of Neurobiology and Behavior and Medical Scientist Training Program, School of Medicine, Stony Brook University, Stony Brook, New York 11794-8434
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724
| | - Alexa H Pagliaro
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724
| | - Jane Choe
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724
| | - Stephen D Shea
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724
| |
Collapse
|
3
|
Mykins M, Layo-Carris D, Dunn LR, Skinner DW, McBryar AH, Perez S, Shultz TR, Willems A, Lau BYB, Hong T, Krishnan K. Wild-type MECP2 expression coincides with age-dependent sensory phenotypes in a female mouse model for Rett syndrome. J Neurosci Res 2023; 101:1236-1258. [PMID: 37026482 PMCID: PMC10332853 DOI: 10.1002/jnr.25190] [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: 09/14/2022] [Revised: 02/07/2023] [Accepted: 03/12/2023] [Indexed: 04/08/2023]
Abstract
Rett syndrome is characterized by an early period of typical development and then, regression of learned motor and speech skills in girls. Loss of MECP2 protein is thought to cause Rett syndrome phenotypes. The specific underlying mechanisms from typical developmental trajectory to regression features throughout life are unclear. Lack of established timelines to study the molecular, cellular, and behavioral features of regression in female mouse models is a major contributing factor. Due to random X-chromosome inactivation, female patients with Rett syndrome and female mouse models for Rett syndrome (Mecp2Heterozygous , Het) express a functional copy of wild-type MECP2 protein in approximately half of all cells. As MECP2 expression is regulated during early postnatal development and experience, we characterized the expression of wild-type MECP2 in the primary somatosensory cortex of female Het mice. Here, we report increased MECP2 levels in non-parvalbumin-positive neurons of 6-week-old adolescent Het relative to age-matched wild-type controls, while also displaying typical levels of perineuronal net expression in the barrel field subregion of the primary somatosensory cortex, mild tactile sensory perception deficits, and efficient pup retrieval behavior. In contrast, 12-week-old adult Het express MECP2 at levels similar to age-matched wild-type mice, show increased perineuronal net expression in the cortex, and display significant tactile sensory perception deficits. Thus, we have identified a set of behavioral metrics and the cellular substrates to study regression during a specific time in the female Het mouse model, which coincides with changes in wild-type MECP2 expression. We speculate that the precocious increase in MECP2 expression within specific cell types of adolescent Het may provide compensatory benefits at the behavioral level, while the inability to further increase MECP2 levels leads to regressive behavioral phenotypes over time.
Collapse
Affiliation(s)
- Michael Mykins
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Dana Layo-Carris
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Logan Reid Dunn
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - David Wilson Skinner
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Alexandra Hart McBryar
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Sarah Perez
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Trinity Rose Shultz
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Andrew Willems
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Billy You Bun Lau
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Tian Hong
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Keerthi Krishnan
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| |
Collapse
|
4
|
Hong H, Yoon SB, Park JE, Lee JI, Kim HY, Nam HJ, Cho H. MeCP2 dysfunction prevents proper BMP signaling and neural progenitor expansion in brain organoid. Ann Clin Transl Neurol 2023. [PMID: 37302988 DOI: 10.1002/acn3.51799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 04/26/2023] [Accepted: 05/10/2023] [Indexed: 06/13/2023] Open
Abstract
OBJECTIVES Sporadic mutations in MeCP2 are a hallmark of Rett syndrome (RTT). Many RTT brain organoid models have exhibited pathogenic phenotypes such as decreased spine density and small size of soma with altered electrophysiological signals. However, previous models are mainly focused on the phenotypes observed in the late phase and rarely provide clues for the defect of neural progenitors which generate different types of neurons and glial cells. METHODS We newly established the RTT brain organoid model derived from MeCP2-truncated iPS cells which were genetically engineered by CRISPR/Cas9 technology. By immunofluorescence imaging, we studied the development of NPC pool and its fate specification into glutamatergic neurons or astrocytes in RTT organoids. By total RNA sequencing, we investigated which signaling pathways were altered during the early brain development in RTT organoids. RESULTS Dysfunction of MeCP2 caused the defect of neural rosette formation in the early phase of cortical development. In total transcriptome analysis, BMP pathway-related genes are highly associated with MeCP2 depletion. Moreover, levels of pSMAD1/5 and BMP target genes are excessively increased, and treatment of BMP inhibitors partially rescues the cell cycle progression of neural progenitors. Subsequently, MeCP2 dysfunction reduced the glutamatergic neurogenesis and induced overproduction of astrocytes. Nevertheless, early inhibition of BMP pathway rescued VGLUT1 expression and suppressed astrocyte maturation. INTERPRETATION Our results demonstrate that MeCP2 is required for the expansion of neural progenitor cells by modulating BMP pathway at early stages of development, and this influence persists during neurogenesis and gliogenesis at later stages of brain organoid development.
Collapse
Affiliation(s)
- Hyowon Hong
- Therapeutics & Biotechnology Division, Korea Research Institute of Chemical Technology, 141 Gajeong-ro, Yuseong-gu, Daejeon, Republic of Korea
| | - Sae-Bom Yoon
- Therapeutics & Biotechnology Division, Korea Research Institute of Chemical Technology, 141 Gajeong-ro, Yuseong-gu, Daejeon, Republic of Korea
| | - Jung Eun Park
- Therapeutics & Biotechnology Division, Korea Research Institute of Chemical Technology, 141 Gajeong-ro, Yuseong-gu, Daejeon, Republic of Korea
| | - Jung In Lee
- Therapeutics & Biotechnology Division, Korea Research Institute of Chemical Technology, 141 Gajeong-ro, Yuseong-gu, Daejeon, Republic of Korea
| | - Hyun Young Kim
- Therapeutics & Biotechnology Division, Korea Research Institute of Chemical Technology, 141 Gajeong-ro, Yuseong-gu, Daejeon, Republic of Korea
| | - Hye Jin Nam
- Therapeutics & Biotechnology Division, Korea Research Institute of Chemical Technology, 141 Gajeong-ro, Yuseong-gu, Daejeon, Republic of Korea
| | - Heeyeong Cho
- Therapeutics & Biotechnology Division, Korea Research Institute of Chemical Technology, 141 Gajeong-ro, Yuseong-gu, Daejeon, Republic of Korea
| |
Collapse
|
5
|
Rupert DD, Pagliaro A, Choe J, Shea SD. Selective deletion of Methyl CpG binding protein 2 from parvalbumin interneurons in the auditory cortex delays the onset of maternal retrieval in mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.30.526321. [PMID: 36778467 PMCID: PMC9915474 DOI: 10.1101/2023.01.30.526321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Mutations in MECP2 cause the neurodevelopmental disorder Rett syndrome. MECP2 codes for methyl CpG binding protein 2 (MECP2), a transcriptional regulator that activates genetic programs for experience-dependent plasticity. Many neural and behavioral symptoms of Rett syndrome may result from dysregulated timing and threshold for plasticity. As a model of adult plasticity, we examine changes to auditory cortex inhibitory circuits in female mice when they are first exposed to pups; this plasticity facilitates behavioral responses to pups emitting distress calls. Brain-wide deletion of Mecp2 alters expression of markers associated with GABAergic parvalbumin interneurons (PVin) and impairs the emergence of pup retrieval. We hypothesized that loss of Mecp2 in PVin disproportionately contributes to the phenotype. Here we find that deletion of Mecp2 from PVin delayed the onset of maternal retrieval behavior and recapitulated the major molecular and neurophysiological features of brain-wide deletion of Mecp2 . We observed that when PVin-selective mutants were exposed to pups, auditory cortical expression of PVin markers increased relative to that in wild type littermates. PVin-specific mutants also failed to show the inhibitory auditory cortex plasticity seen in wild type mice upon exposure to pups and their vocalizations. Finally, using an intersectional viral genetic strategy, we demonstrate that post-developmental loss of Mecp2 in PVin of the auditory cortex is sufficient to delay onset of maternal retrieval. Our results support a model in which PVin play a central role in adult cortical plasticity and may be particularly impaired by loss of Mecp2 . SIGNIFICANCE STATEMENT Rett syndrome is a neurodevelopmental disorder that includes deficits in both communication and the ability to update brain connections and activity during learning ('plasticity'). This condition is caused by mutations in the gene MECP2 . We use a maternal behavioral test in mice requiring both vocal perception and neural plasticity to probe Mecp2' s role in social and sensory learning. Mecp2 is normally active in all brain cells, but here we remove it from a specific population ('parvalbumin neurons'). We find that this is sufficient to delay learned behavioral responses to pups and recreates many deficits seen in whole brain Mecp2 deletion. Our findings suggest that parvalbumin neurons specifically are central to the consequences of loss of Mecp2 activity and yield clues as to possible mechanisms by which Rett syndrome impairs brain function.
Collapse
Affiliation(s)
- Deborah D. Rupert
- Dept of Neurobiology and Behavior, Stony Brook University, and Medical Scientist Training Program, School of Medicine, Stony Brook University, Stony Brook, NY
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY
| | | | - Jane Choe
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY
| | | |
Collapse
|
6
|
Jin Y, Su K, Kong HE, Ma W, Wang Z, Li Y, Li R, Allen EG, Wu H, Jin P. Cell type-specific DNA methylome signatures reveal epigenetic mechanisms for neuronal diversity and neurodevelopmental disorder. Hum Mol Genet 2023; 32:218-230. [PMID: 35947991 PMCID: PMC9840206 DOI: 10.1093/hmg/ddac189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 08/04/2022] [Accepted: 08/08/2022] [Indexed: 01/19/2023] Open
Abstract
DNA methylation plays a critical function in establishing and maintaining cell identity in brain. Disruption of DNA methylation-related processes leads to diverse neurological disorders. However, the role of DNA methylation characteristics in neuronal diversity remains underexplored. Here, we report detailed context-specific DNA methylation maps for GABAergic, glutamatergic (Glu) and Purkinje neurons, together with matched transcriptome profiles. Genome-wide mCH levels are distinguishable, while the mCG levels are similar among the three cell types. Substantial CG-differentially methylated regions (DMRs) are also seen, with Glu neurons experiencing substantial hypomethylation events. The relationship between mCG levels and gene expression displays cell type-specific patterns, while genic CH methylation exhibits a negative effect on transcriptional abundance. We found that cell type-specific CG-DMRs are informative in terms of represented neuronal function. Furthermore, we observed that the identified Glu-specific hypo-DMRs have a high level of consistency with the chromatin accessibility of excitatory neurons and the regions enriched for histone modifications (H3K27ac and H3K4me1) of active enhancers, suggesting their regulatory potential. Hypomethylation regions specific to each cell type are predicted to bind neuron type-specific transcription factors. Finally, we show that the DNA methylation changes in a mouse model of Rett syndrome, a neurodevelopmental disorder caused by the de novo mutations in MECP2, are cell type- and brain region-specific. Our results suggest that cell type-specific DNA methylation signatures are associated with the functional characteristics of the neuronal subtypes. The presented results emphasize the importance of DNA methylation-mediated epigenetic regulation in neuronal diversity and disease.
Collapse
Affiliation(s)
- Yulin Jin
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Kenong Su
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Atlanta, GA 30322, USA
| | - Ha Eun Kong
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Wenjing Ma
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Atlanta, GA 30322, USA
| | - Zhiqin Wang
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Yujing Li
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Ronghua Li
- 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
| | - Hao Wu
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Atlanta, GA 30322, USA
| | - Peng Jin
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA
| |
Collapse
|
7
|
Yue Y, Ash RT, Boyle N, Kinter A, Li Y, Zeng C, Lu H. MeCP2 deficiency impairs motor cortical circuit flexibility associated with motor learning. Mol Brain 2022; 15:76. [PMID: 36064580 PMCID: PMC9446698 DOI: 10.1186/s13041-022-00965-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 08/29/2022] [Indexed: 11/19/2022] Open
Abstract
Loss of function mutations in the X-linked gene encoding methyl-CpG binding protein 2 (MECP2) cause Rett syndrome (RTT), a postnatal neurological disorder. The loss of motor function is an important clinical feature of RTT that manifests early during the course of the disease. RTT mouse models with mutations in the murine orthologous Mecp2 gene replicate many human phenotypes, including progressive motor impairments. However, relatively little is known about the changes in circuit function during the progression of motor deficit in this model. As the motor cortex is the key node in the motor system for the control of voluntary movement, we measured firing activity in populations of motor cortical neurons during locomotion on a motorized wheel-treadmill. Different populations of neurons intermingled in the motor cortex signal different aspects of the locomotor state of the animal. The proportion of running selective neurons whose activity positively correlates with locomotion speed gradually decreases with weekly training in wild-type mice, but not in Mecp2-null mice. The fraction of rest-selective neurons whose activity negatively correlates with locomotion speed does not change with training in wild-type mice, but is higher and increases with the progression of locomotion deficit in mutant mice. The synchronization of population activity that occurs in WT mice with training did not occur in Mecp2-null mice, a phenotype most clear during locomotion and observable across all functional cell types. Our results could represent circuit-level biomarkers for motor regression in Rett syndrome.
Collapse
Affiliation(s)
- Yuanlei Yue
- grid.253615.60000 0004 1936 9510Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, DC 20037 USA
| | - Ryan T. Ash
- grid.168010.e0000000419368956Department of Psychiatry, Stanford University, Palo Alto, CA 94305 USA
| | - Natalie Boyle
- grid.253615.60000 0004 1936 9510Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, DC 20037 USA
| | - Anna Kinter
- grid.253615.60000 0004 1936 9510Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, DC 20037 USA
| | - Yipeng Li
- grid.253615.60000 0004 1936 9510Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, DC 20037 USA
| | - Chen Zeng
- grid.253615.60000 0004 1936 9510Department of Physics, Columbian College of Arts and Sciences, The George Washington, University, Washington, DC 20037 USA
| | - Hui Lu
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, DC, 20037, USA.
| |
Collapse
|
8
|
Choi M, Ko SY, Seo JY, Kim DG, Lee H, Chung H, Son H. Autistic-like social deficits in hippocampal MeCP2 knockdown rat models are rescued by ketamine. BMB Rep 2022. [PMID: 35410641 PMCID: PMC9152577 DOI: 10.5483/bmbrep.2022.55.5.038] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Autism or autism spectrum disorder (ASD) is a behavioral syndrome characterized by persistent deficits in social interaction, and repetitive patterns of behavior, interests, or activities. The gene encoding Methyl-CpG binding protein 2 (MeCP2) is one of a few exceptional genes of established causal effect in ASD. Although genetically engineered mice studies may shed light on how MeCP2 loss affects synaptic activity patterns across the whole brain, such studies are not considered practical in ASD patients due to the overall level of impairment, and are technically challenging in mice. For the first time, we show that hippo-campal MeCP2 knockdown produces behavioral abnormalities associated with autism-like traits in rats, providing a new strategy to investigate the efficacy of therapeutics in ASD. Ketamine, an N-Methyl-D-aspartate (NMDA) blocker, has been proposed as a possible treatment for autism. Using the MeCP2 knockdown rats in conjunction with a rat model of valproic acid (VPA)-induced ASD, we examined gene expression and ASD behaviors upon ketamine treatment. We report that the core symptoms of autism in MeCP2 knockdown rats with social impairment recovered dramatically following a single treatment with ketamine.
Collapse
Affiliation(s)
- Miyeon Choi
- Hanyang Biomedical Research Institute, Hanyang University, Seoul 04763, Korea
| | - Seung Yeon Ko
- Hanyang Biomedical Research Institute, Hanyang University, Seoul 04763, Korea
| | - Jee Young Seo
- Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul 04763, Korea
| | - Do Gyeong Kim
- Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul 04763, Korea
| | - Huiju Lee
- Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul 04763, Korea
| | - Heekyoung Chung
- Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul 04763, Korea
| | - Hyeon Son
- Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul 04763, Korea
- Department of Biochemistry and Molecular Biology, College of Medicine, Hanyang University, Seoul 04763, Korea
| |
Collapse
|
9
|
Zhang WJ, Shi LL, Zhang L. Dysregulated cortical synaptic plasticity under methyl-CpG binding protein 2 deficiency and its implication in motor impairments. World J Psychiatry 2022; 12:673-682. [PMID: 35663301 PMCID: PMC9150038 DOI: 10.5498/wjp.v12.i5.673] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 07/16/2021] [Accepted: 04/04/2022] [Indexed: 02/06/2023] Open
Abstract
Caused by the mutation of methyl-CpG binding protein 2 (MeCP2), Rett syndrome leads to a battery of severe neural dysfunctions including the regression of motor coordination and motor learning. Current understanding has revealed the motor cortex as the critical region mediating voluntary movement. In this review article, we will summarize major findings from human patients and animal models regarding the cortical synaptic plasticity under the regulation of MeCP2. We will also discuss how mutation of MeCP2 leads to the disruption of cortical circuitry homeostasis to cause motor deficits. Lastly, potential values of physical exercise and neuromodulation approaches to recover neural plasticity and motor function will be evaluated. All of this evidence may help to accelerate timely diagnosis and effective interventions for Rett syndrome patients.
Collapse
Affiliation(s)
- Wei-Jia Zhang
- GHM Institute of CNS Regeneration, Jinan University, Guangzhou 510632, Guangdong Province, China
| | - Ling-Ling Shi
- GHM Institute of CNS Regeneration, Jinan University, Guangzhou 510632, Guangdong Province, China
| | - Li Zhang
- GHM Institute of CNS Regeneration, Jinan University, Guangzhou 510632, Guangdong Province, China
| |
Collapse
|
10
|
Antoine MW. Paradoxical Hyperexcitability in Disorders of Neurodevelopment. Front Mol Neurosci 2022; 15:826679. [PMID: 35571370 PMCID: PMC9102973 DOI: 10.3389/fnmol.2022.826679] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 03/14/2022] [Indexed: 01/29/2023] Open
Abstract
Autism Spectrum Disorder (ASD), Rett syndrome (RTT) and Angelman Syndrome (AS) are neurodevelopmental disorders (NDDs) that share several clinical characteristics, including displays of repetitive movements, developmental delays, language deficits, intellectual disability, and increased susceptibility to epilepsy. While several reviews address the biological basis of non-seizure-related ASD phenotypes, here, I highlight some shared biological mechanisms that may contribute to increased seizure susceptibility. I focus on genetic studies identifying the anatomical origin of the seizure phenotype in loss-of-function, monogenic, mouse models of these NDDs, combined with insights gained from complementary studies quantifying levels of synaptic excitation and inhibition. Epilepsy is characterized by a sudden, abnormal increase in synchronous activity within neuronal networks, that is posited to arise from excess excitation, largely driven by reduced synaptic inhibition. Primarily for this reason, elevated network excitability is proposed to underlie the causal basis for the ASD, RTT, and AS phenotypes. Although, mouse models of these disorders replicate aspects of the human condition, i.e., hyperexcitability discharges or seizures on cortical electroencephalograms, measures at the synaptic level often reveal deficits in excitatory synaptic transmission, rather than too much excitation. Resolving this apparent paradox has direct implications regarding expected outcomes of manipulating GABAergic tone. In particular, in NDDs associated with seizures, cortical circuits can display reduced, rather than normal or increased levels of synaptic excitation, and therefore suggested treatments aimed at increasing inhibition could further promote hypoactivity instead of normality. In this review, I highlight shared mechanisms across animal models for ASD, RTT, and AS with reduced synaptic excitation that nevertheless promote hyperexcitability in cortical circuits.
Collapse
Affiliation(s)
- Michelle W. Antoine
- Section on Neural Circuits, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, United States
| |
Collapse
|
11
|
Siqueira E, Obiols-Guardia A, Jorge-Torres OC, Oliveira-Mateos C, Soler M, Ramesh-Kumar D, Setién F, van Rossum D, Pascual-Alonso A, Xiol C, Ivan C, Shimizu M, Armstrong J, Calin GA, Pasterkamp RJ, Esteller M, Guil S. Analysis of the circRNA and T-UCR populations identifies convergent pathways in mouse and human models of Rett syndrome. MOLECULAR THERAPY. NUCLEIC ACIDS 2022; 27:621-644. [PMID: 35036070 PMCID: PMC8749388 DOI: 10.1016/j.omtn.2021.12.030] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 12/17/2021] [Indexed: 01/07/2023]
Abstract
Noncoding RNAs play regulatory roles in physiopathology, but their involvement in neurodevelopmental diseases is poorly understood. Rett syndrome is a severe, progressive neurodevelopmental disorder linked to loss-of-function mutations of the MeCP2 gene for which no cure is yet available. Analysis of the noncoding RNA profile corresponding to the brain-abundant circular RNA (circRNA) and transcribed-ultraconserved region (T-UCR) populations in a mouse model of the disease reveals widespread dysregulation and enrichment in glutamatergic excitatory signaling and microtubule cytoskeleton pathways of the corresponding host genes. Proteomic analysis of hippocampal samples from affected individuals confirms abnormal levels of several cytoskeleton-related proteins together with key alterations in neurotransmission. Importantly, the glutamate receptor GRIA3 gene displays altered biogenesis in affected individuals and in vitro human cells and is influenced by expression of two ultraconserved RNAs. We also describe post-transcriptional regulation of SIRT2 by circRNAs, which modulates acetylation and total protein levels of GluR-1. As a consequence, both regulatory mechanisms converge on the biogenesis of AMPA receptors, with an effect on neuronal differentiation. In both cases, the noncoding RNAs antagonize MeCP2-directed regulation. Our findings indicate that noncoding transcripts may contribute to key alterations in Rett syndrome and are not only useful tools for revealing dysregulated processes but also molecules of biomarker value.
Collapse
Affiliation(s)
- Edilene Siqueira
- Josep Carreras Leukaemia Research Institute (IJC), Badalona, Barcelona, 08916 Catalonia, Spain
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, 08908 Catalonia, Spain
- National Council for Scientific and Technological Development (CNPq), Brasilia, 71605-001 Federal District, Brazil
| | - Aida Obiols-Guardia
- Josep Carreras Leukaemia Research Institute (IJC), Badalona, Barcelona, 08916 Catalonia, Spain
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, 08908 Catalonia, Spain
| | - Olga C. Jorge-Torres
- Josep Carreras Leukaemia Research Institute (IJC), Badalona, Barcelona, 08916 Catalonia, Spain
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, 08908 Catalonia, Spain
| | | | - Marta Soler
- Josep Carreras Leukaemia Research Institute (IJC), Badalona, Barcelona, 08916 Catalonia, Spain
| | - Deepthi Ramesh-Kumar
- Josep Carreras Leukaemia Research Institute (IJC), Badalona, Barcelona, 08916 Catalonia, Spain
| | - Fernando Setién
- Josep Carreras Leukaemia Research Institute (IJC), Badalona, Barcelona, 08916 Catalonia, Spain
| | - Daniëlle van Rossum
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, 3584 CG Utrecht, the Netherlands
| | - Ainhoa Pascual-Alonso
- Fundación San Juan de Dios, Barcelona, 08950 Catalonia, Spain
- Institut de Recerca Pediàtrica, Hospital Sant Joan de Déu, Barcelona, 08950 Catalonia, Spain
| | - Clara Xiol
- Fundación San Juan de Dios, Barcelona, 08950 Catalonia, Spain
- Institut de Recerca Pediàtrica, Hospital Sant Joan de Déu, Barcelona, 08950 Catalonia, Spain
| | - Cristina Ivan
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Center for RNA Interference and Non-coding RNAs, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Masayoshi Shimizu
- Department of Translational Molecular Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Center for RNA Interference and Non-coding RNAs, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Judith Armstrong
- Institut de Recerca Pediàtrica, Hospital Sant Joan de Déu, Barcelona, 08950 Catalonia, Spain
- Servei de Medicina Genètica i Molecular, Hospital Sant Joan de Déu, Barcelona, 08950 Catalonia, Spain
- CIBER-ER (Biomedical Network Research Center for Rare Diseases), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - George A. Calin
- Department of Translational Molecular Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Center for RNA Interference and Non-coding RNAs, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - R. Jeroen Pasterkamp
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, 3584 CG Utrecht, the Netherlands
| | - Manel Esteller
- Josep Carreras Leukaemia Research Institute (IJC), Badalona, Barcelona, 08916 Catalonia, Spain
- Centro de Investigacion Biomedica en Red Cancer (CIBERONC), Madrid, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, 08010 Catalonia, Spain
- Physiological Sciences Department, School of Medicine and Health Sciences, University of Barcelona (UB), Barcelona, 08907 Catalonia, Spain
| | - Sonia Guil
- Josep Carreras Leukaemia Research Institute (IJC), Badalona, Barcelona, 08916 Catalonia, Spain
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, 08908 Catalonia, Spain
- Germans Trias i Pujol Health Science Research Institute, Badalona, Barcelona, 08916 Catalonia, Spain
| |
Collapse
|
12
|
Collins BE, Neul JL. Rett Syndrome and MECP2 Duplication Syndrome: Disorders of MeCP2 Dosage. Neuropsychiatr Dis Treat 2022; 18:2813-2835. [PMID: 36471747 PMCID: PMC9719276 DOI: 10.2147/ndt.s371483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 11/14/2022] [Indexed: 11/30/2022] Open
Abstract
Rett syndrome (RTT) is a neurodevelopmental disorder caused predominantly by loss-of-function mutations in the gene Methyl-CpG-binding protein 2 (MECP2), which encodes the MeCP2 protein. RTT is a MECP2-related disorder, along with MECP2 duplication syndrome (MDS), caused by gain-of-function duplications of MECP2. Nearly two decades of research have advanced our knowledge of MeCP2 function in health and disease. The following review will discuss MeCP2 protein function and its dysregulation in the MECP2-related disorders RTT and MDS. This will include a discussion of the genetic underpinnings of these disorders, specifically how sporadic X-chromosome mutations arise and manifest in specific populations. We will then review current diagnostic guidelines and clinical manifestations of RTT and MDS. Next, we will delve into MeCP2 biology, describing the dual landscapes of methylated DNA and its reader MeCP2 across the neuronal genome as well as the function of MeCP2 as a transcriptional modulator. Following this, we will outline common MECP2 mutations and genotype-phenotype correlations in both diseases, with particular focus on mutations associated with relatively mild disease in RTT. We will also summarize decades of disease modeling and resulting molecular, synaptic, and behavioral phenotypes associated with RTT and MDS. Finally, we list several therapeutics in the development pipeline for RTT and MDS and available evidence of their safety and efficacy.
Collapse
Affiliation(s)
- Bridget E Collins
- Medical Scientist Training Program, Vanderbilt University, Nashville, TN, USA
| | - Jeffrey L Neul
- Vanderbilt Kennedy Center, Departments of Pediatrics, Pharmacology, and Special Education, Vanderbilt University Medical Center and Vanderbilt University, Nashville, TN, USA
| |
Collapse
|
13
|
Ribeiro MC, MacDonald JL. Vitamin D modulates cortical transcriptome and behavioral phenotypes in an Mecp2 heterozygous Rett syndrome mouse model. Neurobiol Dis 2022; 165:105636. [PMID: 35091041 PMCID: PMC8864637 DOI: 10.1016/j.nbd.2022.105636] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 01/19/2022] [Accepted: 01/21/2022] [Indexed: 12/14/2022] Open
Abstract
Rett syndrome (RTT) is an X-linked neurological disorder caused by mutations in the transcriptional regulator MECP2. Mecp2 loss-of-function leads to the disruption of many cellular pathways, including aberrant activation of the NF-κB pathway. Genetically attenuating the NF-κB pathway in Mecp2-null mice ameliorates hallmark phenotypes of RTT, including reduced dendritic complexity, raising the question of whether NF-κB pathway inhibitors could provide a therapeutic avenue for RTT. Vitamin D is a known inhibitor of NF-κB signaling; further, vitamin D deficiency is prevalent in RTT patients and male Mecp2-null mice. We previously demonstrated that vitamin D rescues the aberrant NF-κB activity and reduced neurite outgrowth of Mecp2-knockdown cortical neurons in vitro, and that dietary vitamin D supplementation rescues decreased dendritic complexity and soma size of neocortical projection neurons in both male hemizygous Mecp2-null and female heterozygous mice in vivo. Here, we have identified over 200 genes whose dysregulated expression in the Mecp2+/- cortex is modulated by dietary vitamin D. Genes normalized with vitamin D supplementation are involved in dendritic complexity, synapses, and neuronal projections, suggesting that the rescue of their expression could underpin the rescue of neuronal morphology. Further, there is a disruption in the homeostasis of the vitamin D synthesis pathway in Mecp2+/- mice, and motor and anxiety-like behavioral phenotypes in Mecp2+/- mice correlate with circulating vitamin D levels. Thus, our data indicate that vitamin D modulates RTT pathology and its supplementation could provide a simple and cost-effective partial therapeutic for RTT.
Collapse
Affiliation(s)
- Mayara C Ribeiro
- Department of Biology, Program in Neuroscience, Syracuse University, Syracuse, NY 13244, United States of America
| | - Jessica L MacDonald
- Department of Biology, Program in Neuroscience, Syracuse University, Syracuse, NY 13244, United States of America.
| |
Collapse
|
14
|
Musi CA, Castaldo AM, Valsecchi AE, Cimini S, Morello N, Pizzo R, Renieri A, Meloni I, Bonati M, Giustetto M, Borsello T. JNK signaling provides a novel therapeutic target for Rett syndrome. BMC Biol 2021; 19:256. [PMID: 34911542 PMCID: PMC8675514 DOI: 10.1186/s12915-021-01190-2] [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] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 11/11/2021] [Indexed: 11/24/2022] Open
Abstract
Background Rett syndrome (RTT) is a monogenic X-linked neurodevelopmental disorder characterized by loss-of-function mutations in the MECP2 gene, which lead to structural and functional changes in synapse communication, and impairments of neural activity at the basis of cognitive deficits that progress from an early age. While the restoration of MECP2 in animal models has been shown to rescue some RTT symptoms, gene therapy intervention presents potential side effects, and with gene- and RNA-editing approaches still far from clinical application, strategies focusing on signaling pathways downstream of MeCP2 may provide alternatives for the development of more effective therapies in vivo. Here, we investigate the role of the c-Jun N-terminal kinase (JNK) stress pathway in the pathogenesis of RTT using different animal and cell models and evaluate JNK inhibition as a potential therapeutic approach. Results We discovered that the c-Jun N-terminal kinase (JNK) stress pathway is activated in Mecp2-knockout, Mecp2-heterozygous mice, and in human MECP2-mutated iPSC neurons. The specific JNK inhibitor, D-JNKI1, promotes recovery of body weight and locomotor impairments in two mouse models of RTT and rescues their dendritic spine alterations. Mecp2-knockout presents intermittent crises of apnea/hypopnea, one of the most invalidating RTT pathological symptoms, and D-JNKI1 powerfully reduces this breathing dysfunction. Importantly, we discovered that also neurons derived from hiPSC-MECP2 mut show JNK activation, high-phosphorylated c-Jun levels, and cell death, which is not observed in the isogenic control wt allele hiPSCs. Treatment with D-JNKI1 inhibits neuronal death induced by MECP2 mutation in hiPSCs mut neurons. Conclusions As a summary, we found altered JNK signaling in models of RTT and suggest that D-JNKI1 treatment prevents clinical symptoms, with coherent results at the cellular, molecular, and functional levels. This is the first proof of concept that JNK plays a key role in RTT and its specific inhibition offers a new and potential therapeutic tool to tackle RTT. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-021-01190-2.
Collapse
Affiliation(s)
- Clara Alice Musi
- Department of Pharmacological and Biomolecular Sciences, Milan University, Via Balzaretti 9, 20133, Milan, Italy.,Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri-IRCCS, Via Mario Negri 2, 20156, Milan, Italy
| | - Anna Maria Castaldo
- Department of Pharmacological and Biomolecular Sciences, Milan University, Via Balzaretti 9, 20133, Milan, Italy
| | | | - Sara Cimini
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri-IRCCS, Via Mario Negri 2, 20156, Milan, Italy
| | - Noemi Morello
- Department of Neuroscience and National Institute of Neuroscience, University of Turin, Turin, Italy
| | - Riccardo Pizzo
- Department of Neuroscience and National Institute of Neuroscience, University of Turin, Turin, Italy
| | | | | | - Maurizio Bonati
- Department of Public Heath, Istituto di Ricerche Farmacologiche Mario Negri-IRCCS, Milan, Italy
| | - Maurizio Giustetto
- Department of Neuroscience and National Institute of Neuroscience, University of Turin, Turin, Italy
| | - Tiziana Borsello
- Department of Pharmacological and Biomolecular Sciences, Milan University, Via Balzaretti 9, 20133, Milan, Italy. .,Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri-IRCCS, Via Mario Negri 2, 20156, Milan, Italy.
| |
Collapse
|
15
|
Yue Y, Xu P, Liu Z, Sun X, Su J, Du H, Chen L, Ash RT, Smirnakis S, Simha R, Kusner L, Zeng C, Lu H. Motor training improves coordination and anxiety in symptomatic Mecp2-null mice despite impaired functional connectivity within the motor circuit. SCIENCE ADVANCES 2021; 7:eabf7467. [PMID: 34678068 PMCID: PMC8535852 DOI: 10.1126/sciadv.abf7467] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 09/01/2021] [Indexed: 05/03/2023]
Abstract
Rett syndrome (RTT) is a severe neurodevelopmental disorder caused by loss of function of the X-linked methyl-CpG–binding protein 2 (MECP2). Several case studies report that gross motor function can be improved in children with RTT through treadmill walking, but whether the MeCP2-deficient motor circuit can support actual motor learning remains unclear. We used two-photon calcium imaging to simultaneously observe layer (L) 2/3 and L5a excitatory neuronal activity in the motor cortex (M1) while mice adapted to changing speeds on a computerized running wheel. Despite circuit hypoactivity and weakened functional connectivity across L2/3 and L5a, the Mecp2-null circuit’s firing pattern evolved with improved performance over 2 weeks. Moreover, trained mice became less anxious and lived 20% longer than untrained mice. Because motor deficits and anxiety are core symptoms of RTT, which is not diagnosed until well after symptom onset, these results underscore the benefit of motor learning.
Collapse
Affiliation(s)
- Yuanlei Yue
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, DC 20037, USA
| | - Pan Xu
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, DC 20037, USA
| | - Zhichao Liu
- Department of Physics, Columbian College of Arts and Sciences, The George Washington University, Washington, DC 20037, USA
| | - Xiaoqian Sun
- Department of Computer Science, School of Engineering and Applied Science, The George Washington University, Washington, DC 20037, USA
| | - Juntao Su
- Department of Statistics, Columbian College of Arts and Sciences, The George Washington University, Washington, DC 20037, USA
| | - Hongfei Du
- Department of Statistics, Columbian College of Arts and Sciences, The George Washington University, Washington, DC 20037, USA
| | - Lingling Chen
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, DC 20037, USA
| | - Ryan T. Ash
- Department of Psychiatry, Stanford University, Palo Alto, CA 94305, USA
| | - Stelios Smirnakis
- Department of Neurology, Brigham and Women’s Hospital, Jamaica Plain VA Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Rahul Simha
- Department of Computer Science, School of Engineering and Applied Science, The George Washington University, Washington, DC 20037, USA
| | - Linda Kusner
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, DC 20037, USA
| | - Chen Zeng
- Department of Physics, Columbian College of Arts and Sciences, The George Washington University, Washington, DC 20037, USA
| | - Hui Lu
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, DC 20037, USA
| |
Collapse
|
16
|
Wu X, Morishita W, Beier KT, Heifets BD, Malenka RC. 5-HT modulation of a medial septal circuit tunes social memory stability. Nature 2021; 599:96-101. [PMID: 34616037 DOI: 10.1038/s41586-021-03956-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 08/25/2021] [Indexed: 12/16/2022]
Abstract
Social memory-the ability to recognize and remember familiar conspecifics-is critical for the survival of an animal in its social group1,2. The dorsal CA2 (dCA2)3-5 and ventral CA1 (vCA1)6 subregions of the hippocampus, and their projection targets6,7, have important roles in social memory. However, the relevant extrahippocampal input regions remain poorly defined. Here we identify the medial septum (MS) as a dCA2 input region that is critical for social memory and reveal that modulation of the MS by serotonin (5-HT) bidirectionally controls social memory formation, thereby affecting memory stability. Novel social interactions increase activity in dCA2-projecting MS neurons and induce plasticity at glutamatergic synapses from MS neurons onto dCA2 pyramidal neurons. The activity of dCA2-projecting MS cells is enhanced by the neuromodulator 5-HT acting on 5-HT1B receptors. Moreover, optogenetic manipulation of median raphe 5-HT terminals in the MS bidirectionally regulates social memory stability. This work expands our understanding of the neural mechanisms by which social interactions lead to social memory and provides evidence that 5-HT has a critical role in promoting not only prosocial behaviours8,9, but also social memory, by influencing distinct target structures.
Collapse
Affiliation(s)
- Xiaoting Wu
- Nancy Pritzker Laboratory, Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA
| | - Wade Morishita
- Nancy Pritzker Laboratory, Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA
| | - Kevin T Beier
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA, USA
| | - Boris D Heifets
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University, Stanford, CA, USA
| | - Robert C Malenka
- Nancy Pritzker Laboratory, Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA.
| |
Collapse
|
17
|
Carstens KE, Lustberg DJ, Shaughnessy EK, McCann KE, Alexander GM, Dudek SM. Perineuronal net degradation rescues CA2 plasticity in a mouse model of Rett syndrome. J Clin Invest 2021; 131:e137221. [PMID: 34228646 DOI: 10.1172/jci137221] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 06/25/2021] [Indexed: 12/14/2022] Open
Abstract
Perineuronal nets (PNNs), a specialized form of extracellular matrix, are abnormal in the brains of people with Rett syndrome (RTT). We previously reported that PNNs function to restrict synaptic plasticity in hippocampal area CA2, which is unusually resistant to long-term potentiation (LTP) and has been linked to social learning in mice. Here we report that PNNs appear elevated in area CA2 of the hippocampus of an individual with RTT and that PNNs develop precociously and remain elevated in area CA2 of a mouse model of RTT (Mecp2-null). Further, we provide evidence that LTP could be induced at CA2 synapses prior to PNN maturation (postnatal day 8-11) in wild-type mice and that this window of plasticity was prematurely restricted at CA2 synapses in Mecp2-null mice. Degrading PNNs in Mecp2-null hippocampus was sufficient to rescue the premature disruption of CA2 plasticity. We identified several molecular targets that were altered in the developing Mecp2-null hippocampus that may explain aberrant PNNs and CA2 plasticity, and we discovered that CA2 PNNs are negatively regulated by neuronal activity. Collectively, our findings demonstrate that CA2 PNN development is regulated by Mecp2 and identify a window of hippocampal plasticity that is disrupted in a mouse model of RTT.
Collapse
|
18
|
Bisgaard AM, Wong K, Højfeldt AK, Larsen JL, Schönewolf-Greulich B, Rønde G, Downs J, Stahlhut M. Decline in gross motor skills in adult Rett syndrome; results from a Danish longitudinal study. Am J Med Genet A 2021; 185:3683-3693. [PMID: 34296518 DOI: 10.1002/ajmg.a.62429] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 05/19/2021] [Accepted: 07/02/2021] [Indexed: 12/22/2022]
Abstract
Longevity of individuals with neurodevelopmental diseases as Rett syndrome (RTT) has increased and many reach adulthood and old age. There is therefore a need to increase knowledge about the course of RTT in adults in order to improve medical care management and quality of life. We did a longitudinal study to address if a possible decline in motor skills in adults with RTT can be explained by the presence of common medical conditions as epilepsy, breathing disturbance, and scoliosis. Data from the Danish RTT database, medical files, and videos from visits at the national Center for Rett syndrome were reviewed. The study included 24 individuals aged 30-66 years at last visit after a follow-up period of 6-12 years. Results showed a clinically observable and significant decline in gross motor skills using the Rett syndrome Gross Motor Scale (RSGMS) with a tendency of less decline in the individuals with the best motor abilities. The frequencies of comorbidities were high. Decline in RSGMS score was associated with the presence of epilepsy and severe scoliosis that had been conservatively managed. The results emphasize that epilepsy plays a significant role in the adult RTT life and management of severe scoliosis in the younger years has impact on the motor abilities in adulthood.
Collapse
Affiliation(s)
- Anne-Marie Bisgaard
- Department of Paediatrics and Adolescent Medicine, Center for Rett syndrome, Rigshospitalet, Copenhagen, Denmark
| | - Kingsley Wong
- Telethon Kids Institute, The University of Western Australia, Perth, Western Australia, Australia
| | - Anne-Katrine Højfeldt
- Department of Paediatrics and Adolescent Medicine, Center for Rett syndrome, Rigshospitalet, Copenhagen, Denmark
| | - Jane Lunding Larsen
- Department of Paediatrics and Adolescent Medicine, Center for Rett syndrome, Rigshospitalet, Copenhagen, Denmark
| | | | - Gitte Rønde
- Department of Paediatrics and Adolescent Medicine, Herlev Hospital, Copenhagen, Denmark
| | - Jenny Downs
- Telethon Kids Institute, The University of Western Australia, Perth, Western Australia, Australia
- Curtin School of Allied Health, Curtin University, Perth, Western Australia, Australia
| | - Michelle Stahlhut
- Department of Paediatrics and Adolescent Medicine, Center for Rett syndrome, Rigshospitalet, Copenhagen, Denmark
| |
Collapse
|
19
|
Villani C, Carli M, Castaldo AM, Sacchetti G, Invernizzi RW. Fluoxetine increases brain MeCP2 immuno-positive cells in a female Mecp2 heterozygous mouse model of Rett syndrome through endogenous serotonin. Sci Rep 2021; 11:14690. [PMID: 34282222 PMCID: PMC8290043 DOI: 10.1038/s41598-021-94156-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 07/07/2021] [Indexed: 12/12/2022] Open
Abstract
Motor skill deficit is a common and invalidating symptom of Rett syndrome (RTT), a rare disease almost exclusively affecting girls during the first/second year of life. Loss-of-function mutations of the methyl-CpG-binding protein2 (MECP2; Mecp2 in rodents) gene is the cause in most patients. We recently found that fluoxetine, a selective serotonin (5-HT) reuptake inhibitor and antidepressant drug, fully rescued motor coordination deficits in Mecp2 heterozygous (Mecp2 HET) mice acting through brain 5-HT. Here, we asked whether fluoxetine could increase MeCP2 expression in the brain of Mecp2 HET mice, under the same schedule of treatment improving motor coordination. Fluoxetine increased the number of MeCP2 immuno-positive (MeCP2+) cells in the prefrontal cortex, M1 and M2 motor cortices, and in dorsal, ventral and lateral striatum. Fluoxetine had no effect in the CA3 region of the hippocampus or in any of the brain regions of WT mice. Inhibition of 5-HT synthesis abolished the fluoxetine-induced rise of MeCP2+ cells. These findings suggest that boosting 5-HT transmission is sufficient to enhance the expression of MeCP2 in several brain regions of Mecp2 HET mice. Fluoxetine-induced rise of MeCP2 could potentially rescue motor coordination and other deficits of RTT.
Collapse
Affiliation(s)
- Claudia Villani
- Laboratory Neurochemistry and Behavior, Neuroscience Department, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156, Milan, Italy
| | - Mirjana Carli
- Laboratory Neurochemistry and Behavior, Neuroscience Department, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156, Milan, Italy
| | - Anna Maria Castaldo
- Laboratory Neurochemistry and Behavior, Neuroscience Department, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156, Milan, Italy
| | - Giuseppina Sacchetti
- Laboratory Neurochemistry and Behavior, Neuroscience Department, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156, Milan, Italy
| | - Roberto William Invernizzi
- Laboratory Neurochemistry and Behavior, Neuroscience Department, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156, Milan, Italy.
| |
Collapse
|
20
|
Vermudez SAD, Gogliotti RG, Arthur B, Buch A, Morales C, Moxley Y, Rajpal H, Conn PJ, Niswender CM. Profiling beneficial and potential adverse effects of MeCP2 overexpression in a hypomorphic Rett syndrome mouse model. GENES, BRAIN, AND BEHAVIOR 2021; 21:e12752. [PMID: 34002468 PMCID: PMC8599502 DOI: 10.1111/gbb.12752] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 05/15/2021] [Accepted: 05/16/2021] [Indexed: 01/03/2023]
Abstract
De novo loss-of-function mutations in methyl-CpG-binding protein 2 (MeCP2) lead to the neurodevelopmental disorder Rett syndrome (RTT). Despite promising results from strategies aimed at increasing MeCP2 levels, additional studies exploring how hypomorphic MeCP2 mutations impact the therapeutic window are needed. Here, we investigated the consequences of genetically introducing a wild-type MECP2 transgene in the Mecp2 R133C mouse model of RTT. The MECP2 transgene reversed the majority of RTT-like phenotypes exhibited by male and female Mecp2 R133C mice. However, three core symptom domains were adversely affected in female Mecp2R133C/+ animals; these phenotypes resemble those observed in disease contexts of excess MeCP2. Parallel control experiments in Mecp2Null/+ mice linked these adverse effects to the hypomorphic R133C mutation. Collectively, these data provide evidence regarding the safety and efficacy of genetically overexpressing functional MeCP2 in Mecp2 R133C mice and suggest that personalized approaches may warrant consideration for the clinical assessment of MeCP2-targeted therapies.
Collapse
Affiliation(s)
- Sheryl Anne D. Vermudez
- Department of Pharmacology and Warren Center for Neuroscience Drug DiscoveryVanderbilt UniversityNashvilleTennesseeUSA
| | - Rocco G. Gogliotti
- Department of Molecular Pharmacology and NeuroscienceLoyola University ChicagoChicagoIllinoisUSA
| | - Bright Arthur
- Department of Pharmacology and Warren Center for Neuroscience Drug DiscoveryVanderbilt UniversityNashvilleTennesseeUSA
| | - Aditi Buch
- Department of Pharmacology and Warren Center for Neuroscience Drug DiscoveryVanderbilt UniversityNashvilleTennesseeUSA
| | - Clarissa Morales
- Department of Pharmacology and Warren Center for Neuroscience Drug DiscoveryVanderbilt UniversityNashvilleTennesseeUSA
| | - Yuta Moxley
- Department of Pharmacology and Warren Center for Neuroscience Drug DiscoveryVanderbilt UniversityNashvilleTennesseeUSA
| | - Hemangi Rajpal
- Department of Pharmacology and Warren Center for Neuroscience Drug DiscoveryVanderbilt UniversityNashvilleTennesseeUSA
| | - P. Jeffrey Conn
- Department of Pharmacology and Warren Center for Neuroscience Drug DiscoveryVanderbilt UniversityNashvilleTennesseeUSA,Vanderbilt Kennedy CenterVanderbilt UniversityNashvilleTennesseeUSA,Vanderbilt Institute of Chemical BiologyVanderbilt UniversityNashvilleTennesseeUSA
| | - Colleen M. Niswender
- Department of Pharmacology and Warren Center for Neuroscience Drug DiscoveryVanderbilt UniversityNashvilleTennesseeUSA,Vanderbilt Kennedy CenterVanderbilt UniversityNashvilleTennesseeUSA,Vanderbilt Institute of Chemical BiologyVanderbilt UniversityNashvilleTennesseeUSA
| |
Collapse
|
21
|
Reviewing Evidence for the Relationship of EEG Abnormalities and RTT Phenotype Paralleled by Insights from Animal Studies. Int J Mol Sci 2021; 22:ijms22105308. [PMID: 34069993 PMCID: PMC8157853 DOI: 10.3390/ijms22105308] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/09/2021] [Accepted: 05/12/2021] [Indexed: 12/29/2022] Open
Abstract
Rett syndrome (RTT) is a rare neurodevelopmental disorder that is usually caused by mutations of the MECP2 gene. Patients with RTT suffer from severe deficits in motor, perceptual and cognitive domains. Electroencephalogram (EEG) has provided useful information to clinicians and scientists, from the very first descriptions of RTT, and yet no reliable neurophysiological biomarkers related to the pathophysiology of the disorder or symptom severity have been identified to date. To identify consistently observed and potentially informative EEG characteristics of RTT pathophysiology, and ascertain areas most worthy of further systematic investigation, here we review the literature for EEG abnormalities reported in patients with RTT and in its disease models. While pointing to some promising potential EEG biomarkers of RTT, our review identify areas of need to realize the potential of EEG including (1) quantitative investigation of promising clinical-EEG observations in RTT, e.g., shift of mu rhythm frequency and EEG during sleep; (2) closer alignment of approaches between patients with RTT and its animal models to strengthen the translational significance of the work (e.g., EEG measurements and behavioral states); (3) establishment of large-scale consortium research, to provide adequate Ns to investigate age and genotype effects.
Collapse
|
22
|
Rett Syndrome: A Timely Review From Recognition to Current Clinical Approaches and Clinical Study Updates. Semin Pediatr Neurol 2021; 37:100881. [PMID: 33892852 DOI: 10.1016/j.spen.2021.100881] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 02/24/2021] [Accepted: 03/03/2021] [Indexed: 12/11/2022]
Abstract
Since the discovery of the genetic basis of Rett syndrome in 1999, our understanding has grown considerably both in the scientific and the clinical realms. In the last two decades, we have learned about the far-reaching effects of the aberrant MeCP2 protein, the growing list of involved genetic factors, and the genotype-phenotype clinical expression of common MECP2 mutations. This knowledge has led to several basic science research and clinical trials, focusing specifically on emerging treatments of Rett syndrome. As the pathophysiology behind the disease is better understood, treatments aimed at specific molecular targets will become available for clinicians to improve the life of individuals with Rett syndrome.
Collapse
|
23
|
Fisher NM, AlHashim A, Buch AB, Badivuku H, Samman MM, Weiss KM, Cestero GI, Does MD, Rook JM, Lindsley CW, Conn PJ, Gogliotti RG, Niswender CM. A GRM7 mutation associated with developmental delay reduces mGlu7 expression and produces neurological phenotypes. JCI Insight 2021; 6:143324. [PMID: 33476302 PMCID: PMC7934925 DOI: 10.1172/jci.insight.143324] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 01/13/2021] [Indexed: 12/29/2022] Open
Abstract
The metabotropic glutamate receptor 7 (mGlu7) is a G protein–coupled receptor that has been recently linked to neurodevelopmental disorders. This association is supported by the identification of GRM7 variants in patients with autism spectrum disorder, attention deficit hyperactivity disorder, and severe developmental delay. One GRM7 mutation previously reported in 2 patients results in a single amino acid change, I154T, within the mGlu7 ligand-binding domain. Here, we report 2 new patients with this mutation who present with severe developmental delay and epilepsy. Functional studies of the mGlu7-I154T mutant reveal that this substitution resulted in significant loss of mGlu7 protein expression in HEK293A cells and in mice. We show that this occurred posttranscriptionally at the level of protein expression and trafficking. Similar to mGlu7–global KO mice, mGlu7-I154T animals exhibited reduced motor coordination, deficits in contextual fear learning, and seizures. This provides functional evidence that a disease-associated mutation affecting the mGlu7 receptor was sufficient to cause neurological dysfunction in mice and further validates GRM7 as a disease-causing gene in the human population.
Collapse
Affiliation(s)
- Nicole M Fisher
- Department of Pharmacology and.,Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee, USA
| | | | - Aditi B Buch
- Department of Pharmacology and.,Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee, USA
| | - Hana Badivuku
- Department of Pharmacology and.,Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee, USA
| | | | - Kelly M Weiss
- Department of Pharmacology and.,Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee, USA
| | - Gabriela I Cestero
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA
| | - Mark D Does
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA
| | - Jerri M Rook
- Department of Pharmacology and.,Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee, USA
| | - Craig W Lindsley
- Department of Pharmacology and.,Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee, USA.,Department of Chemistry and.,Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee, USA
| | - P Jeffrey Conn
- Department of Pharmacology and.,Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee, USA.,Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee, USA.,Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee USA
| | - Rocco G Gogliotti
- Department of Pharmacology and.,Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee, USA.,Department of Molecular Pharmacology and Neuroscience, Loyola University Chicago, Maywood, Illinois, USA
| | - Colleen M Niswender
- Department of Pharmacology and.,Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee, USA.,Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee, USA.,Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee USA
| |
Collapse
|
24
|
Achilly NP, He LJ, Kim OA, Ohmae S, Wojaczynski GJ, Lin T, Sillitoe RV, Medina JF, Zoghbi HY. Deleting Mecp2 from the cerebellum rather than its neuronal subtypes causes a delay in motor learning in mice. eLife 2021; 10:64833. [PMID: 33494858 PMCID: PMC7837679 DOI: 10.7554/elife.64833] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 01/13/2021] [Indexed: 12/28/2022] Open
Abstract
Rett syndrome is a devastating childhood neurological disorder caused by mutations in MECP2. Of the many symptoms, motor deterioration is a significant problem for patients. In mice, deleting Mecp2 from the cortex or basal ganglia causes motor dysfunction, hypoactivity, and tremor, which are abnormalities observed in patients. Little is known about the function of Mecp2 in the cerebellum, a brain region critical for motor function. Here we show that deleting Mecp2 from the cerebellum, but not from its neuronal subtypes, causes a delay in motor learning that is overcome by additional training. We observed irregular firing rates of Purkinje cells and altered heterochromatin architecture within the cerebellum of knockout mice. These findings demonstrate that the motor deficits present in Rett syndrome arise, in part, from cerebellar dysfunction. For Rett syndrome and other neurodevelopmental disorders, our results highlight the importance of understanding which brain regions contribute to disease phenotypes.
Collapse
Affiliation(s)
- Nathan P Achilly
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, United States.,Program in Developmental Biology, Baylor College of Medicine, Houston, United States.,Medical Scientist Training Program, Baylor College of Medicine, Houston, United States
| | - Ling-Jie He
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, United States.,Department of Human and Molecular Genetics, Baylor College of Medicine, Houston, United States.,Howard Hughes Medical Institute, Baylor College of Medicine, Houston, United States
| | - Olivia A Kim
- Department of Neuroscience, Baylor College of Medicine, Houston, United States
| | - Shogo Ohmae
- Department of Neuroscience, Baylor College of Medicine, Houston, United States
| | | | - Tao Lin
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, United States.,Department of Pathology and Immunology, Baylor College of Medicine, Houston, United States
| | - Roy V Sillitoe
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, United States.,Program in Developmental Biology, Baylor College of Medicine, Houston, United States.,Department of Neuroscience, Baylor College of Medicine, Houston, United States.,Department of Pathology and Immunology, Baylor College of Medicine, Houston, United States
| | - Javier F Medina
- Department of Neuroscience, Baylor College of Medicine, Houston, United States
| | - Huda Y Zoghbi
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, United States.,Program in Developmental Biology, Baylor College of Medicine, Houston, United States.,Howard Hughes Medical Institute, Baylor College of Medicine, Houston, United States.,Department of Neuroscience, Baylor College of Medicine, Houston, United States.,Department of Pathology and Immunology, Baylor College of Medicine, Houston, United States.,Department of Neurology, Baylor College of Medicine, Houston, United States.,Department of Pediatrics, Baylor College of Medicine, Houston, United States
| |
Collapse
|
25
|
Methyl-CpG-binding protein 2 mediates overlapping mechanisms across brain disorders. Sci Rep 2020; 10:22255. [PMID: 33335218 PMCID: PMC7746753 DOI: 10.1038/s41598-020-79268-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 12/01/2020] [Indexed: 12/16/2022] Open
Abstract
MECP2 and its product, Methyl-CpG binding protein 2 (MeCP2), are mostly known for their association to Rett Syndrome (RTT), a rare neurodevelopmental disorder. Additional evidence suggests that MECP2 may underlie other neuropsychiatric and neurological conditions, and perhaps modulate common presentations and pathophysiology across disorders. To clarify the mechanisms of these interactions, we develop a method that uses the binding properties of MeCP2 to identify its targets, and in particular, the genes recognized by MeCP2 and associated to several neurological and neuropsychiatric disorders. Analysing mechanisms and pathways modulated by these genes, we find that they are involved in three main processes: neuronal transmission, immuno-reactivity, and development. Also, while the nervous system is the most relevant in the pathophysiology of the disorders, additional systems may contribute to MeCP2 action through its target genes. We tested our results with transcriptome analysis on Mecp2-null models and cells derived from a patient with RTT, confirming that the genes identified by our procedure are directly modulated by MeCP2. Thus, MeCP2 may modulate similar mechanisms in different pathologies, suggesting that treatments for one condition may be effective for related disorders.
Collapse
|
26
|
Ward CS, Huang TW, Herrera JA, Samaco RC, McGraw CM, Parra DE, Arvide EM, Ito-Ishida A, Meng X, Ure K, Zoghbi HY, Neul JL. Loss of MeCP2 Function Across Several Neuronal Populations Impairs Breathing Response to Acute Hypoxia. Front Neurol 2020; 11:593554. [PMID: 33193060 PMCID: PMC7662121 DOI: 10.3389/fneur.2020.593554] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 10/06/2020] [Indexed: 11/26/2022] Open
Abstract
Rett Syndrome (RTT) is a neurodevelopmental disorder caused by loss of function of the transcriptional regulator Methyl-CpG-Binding Protein 2 (MeCP2). In addition to the characteristic loss of hand function and spoken language after the first year of life, people with RTT also have a variety of physiological and autonomic abnormalities including disrupted breathing rhythms characterized by bouts of hyperventilation and an increased frequency of apnea. These breathing abnormalities, that likely involve alterations in both the circuitry underlying respiratory pace making and those underlying breathing response to environmental stimuli, may underlie the sudden unexpected death seen in a significant fraction of people with RTT. In fact, mice lacking MeCP2 function exhibit abnormal breathing rate response to acute hypoxia and maintain a persistently elevated breathing rate rather than showing typical hypoxic ventilatory decline that can be observed among their wild-type littermates. Using genetic and pharmacological tools to better understand the course of this abnormal hypoxic breathing rate response and the neurons driving it, we learned that the abnormal hypoxic breathing response is acquired as the animals mature, and that MeCP2 function is required within excitatory, inhibitory, and modulatory populations for a normal hypoxic breathing rate response. Furthermore, mice lacking MeCP2 exhibit decreased hypoxia-induced neuronal activity within the nucleus tractus solitarius of the dorsal medulla. Overall, these data provide insight into the neurons driving the circuit dysfunction that leads to breathing abnormalities upon loss of MeCP2. The discovery that combined dysfunction across multiple neuronal populations contributes to breathing dysfunction may provide insight into sudden unexpected death in RTT.
Collapse
Affiliation(s)
- Christopher S. Ward
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, United States
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, United States
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Teng-Wei Huang
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, United States
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX, United States
| | - Jose A. Herrera
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, United States
- Interdepartmental Program in Translational Biology and Molecular Medicine, Baylor College of Medicine, Houston, TX, United States
| | - Rodney C. Samaco
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, United States
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Christopher M. McGraw
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, United States
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX, United States
| | - Diana E. Parra
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - E. Melissa Arvide
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Aya Ito-Ishida
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, United States
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Xiangling Meng
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, United States
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States
| | - Kerstin Ure
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, United States
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Huda Y. Zoghbi
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, United States
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX, United States
- Interdepartmental Program in Translational Biology and Molecular Medicine, Baylor College of Medicine, Houston, TX, United States
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX, United States
| | - Jeffrey L. Neul
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, United States
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX, United States
- Interdepartmental Program in Translational Biology and Molecular Medicine, Baylor College of Medicine, Houston, TX, United States
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States
| |
Collapse
|
27
|
Apulei J, Kim N, Testa D, Ribot J, Morizet D, Bernard C, Jourdren L, Blugeon C, Di Nardo AA, Prochiantz A. Non-cell Autonomous OTX2 Homeoprotein Regulates Visual Cortex Plasticity Through Gadd45b/g. Cereb Cortex 2020; 29:2384-2395. [PMID: 29771284 DOI: 10.1093/cercor/bhy108] [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: 12/26/2017] [Revised: 04/19/2018] [Indexed: 11/14/2022] Open
Abstract
The non-cell autonomous transfer of OTX2 homeoprotein transcription factor into juvenile mouse cerebral cortex regulates parvalbumin interneuron maturation and critical period timing. By analyzing gene expression in primary visual cortex of wild-type and Otx2+/GFP mice at plastic and nonplastic ages, we identified several putative genes implicated in Otx2-dependent visual cortex plasticity for ocular dominance. Cortical OTX2 infusion in juvenile mice induced Gadd45b/g expression through direct regulation of transcription. Intriguingly, a reverse effect was found in the adult, where reducing cortical OTX2 resulted in Gadd45b/g upregulation. Viral expression of Gadd45b in adult visual cortex directly induced ocular dominance plasticity with concomitant changes in MeCP2 foci within parvalbumin interneurons and in methylation states of several plasticity gene promoters, suggesting epigenetic regulation. This interaction provides a molecular mechanism for OTX2 to trigger critical period plasticity yet suppress adult plasticity.
Collapse
Affiliation(s)
- Jessica Apulei
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, PSL University, Labex MemoLife, Paris, France
| | - Namsuk Kim
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, PSL University, Labex MemoLife, Paris, France
| | - Damien Testa
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, PSL University, Labex MemoLife, Paris, France
| | - Jérôme Ribot
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, PSL University, Labex MemoLife, Paris, France
| | - David Morizet
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, PSL University, Labex MemoLife, Paris, France
| | - Clémence Bernard
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, PSL University, Labex MemoLife, Paris, France
| | - Laurent Jourdren
- Genomic Core Facility, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, PSL University, Paris, France
| | - Corinne Blugeon
- Genomic Core Facility, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, PSL University, Paris, France
| | - Ariel A Di Nardo
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, PSL University, Labex MemoLife, Paris, France
| | - Alain Prochiantz
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, PSL University, Labex MemoLife, Paris, France
| |
Collapse
|
28
|
Abstract
Based on the analysis of literature, the authors describe the neuropathophysiological mechanism of the formation of synapses, synaptic transmission and plasticity, which may underlie the pathogenesis of autism. The results of some studies confirm the involvement of aberrant expression of genes and proteins of synaptic contacts, cell adhesion molecules p120ctn, CNTN5, CNTN6, activation of NMDA glutamate, TrkB, p75 receptors, Ca2+-input, BDNF, serotonin and testosterone. This leads to an imbalance in the exciting, inhibitory synaptic transmission and forms of synaptic plasticity, including long-term potentiation (LTP) and long-term depression (LTD) at the level of individual neurons and their chains due to suppression of GABA synthesis, expression of its ionotropic and metabotropic receptors, G proteins, NGF, TrkA receptors, a reduction in the number of GABAergic neurons, their contacts and disruption of differentiation. The pathology of the nuclei of the thalamus, especially the reticular nucleus (RN), is associated with a disturbance of the expression of the subunits of metabotropic GABAβ receptors, Ca2+ channels, GABA excretion and the work of chlorine transmitters. These failures do not ensure the inhibitory effect of OC on the exciting associative and ventral nuclei of the thalamus, nor modify the incoming information to the cerebral cortex (CC) from these thalamus nuclei, the dentate gyrus of the hippocampus and the nuclei of the reticular formation. Information propagating into the somatosensory and associative regions of CC is not modified by mirror neurons (MN) when performing arbitrary actions, which prevents the formation of an adequate image in the neural networks of the associative cortex and promotes the development of hyperexcitability, irritability, increased visual and auditory sensitivity, anxiety, and the ability to form a holistic image based on the actions of other people.
Collapse
Affiliation(s)
- A N Chernov
- Almazov National Medical Research Center of the Ministry of Health of Russia, St. Petersburg, Russia
| |
Collapse
|
29
|
Cell-Type-Specific Gene Inactivation and In Situ Restoration via Recombinase-Based Flipping of Targeted Genomic Region. J Neurosci 2020; 40:7169-7186. [PMID: 32801153 DOI: 10.1523/jneurosci.1044-20.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 06/22/2020] [Accepted: 07/30/2020] [Indexed: 11/21/2022] Open
Abstract
Conditional gene inactivation and restoration are powerful tools for studying gene functions in the nervous system and for modeling neuropsychiatric diseases. The combination of the two is necessary to interrogate specific cell types within defined developmental stages. However, very few methods and animal models have been developed for such purpose. Here we present a versatile method for conditional gene inactivation and in situ restoration through reversibly inverting a critical part of its endogenous genomic sequence by Cre- and Flp-mediated recombinations. Using this method, we generated a mouse model to manipulate Mecp2, an X-linked dosage-sensitive gene whose mutations cause Rett syndrome. Combined with multiple Cre- and Flp-expressing drivers and viral tools, we achieved efficient and reliable Mecp2 inactivation and restoration in the germline and several neuronal cell types, and demonstrated phenotypic reversal and prevention on cellular and behavioral levels in male mice. This study not only provides valuable tools and critical insights for Mecp2 and Rett syndrome, but also offers a generally applicable strategy to decipher other neurologic disorders.SIGNIFICANCE STATEMENT Studying neurodevelopment and modeling neurologic disorders rely on genetic tools, such as conditional gene regulation. We developed a new method to combine conditional gene inactivation and restoration on a single allele without disturbing endogenous expression pattern or dosage. We applied it to manipulate Mecp2, a gene residing on X chromosome whose malfunction leads to neurologic disease, including Rett syndrome. Our results demonstrated the efficiency, specificity, and versatility of this new method, provided valuable tools and critical insights for Mecp2 function and Rett syndrome research, and offered a generally applicable strategy to investigate other genes and genetic disorders.
Collapse
|
30
|
Fluoxetine rescues rotarod motor deficits in Mecp2 heterozygous mouse model of Rett syndrome via brain serotonin. Neuropharmacology 2020; 176:108221. [PMID: 32652084 DOI: 10.1016/j.neuropharm.2020.108221] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Revised: 05/24/2020] [Accepted: 06/20/2020] [Indexed: 01/28/2023]
Abstract
Motor skill is a specific area of disability of Rett syndrome (RTT), a rare disorder occurring almost exclusively in girls, caused by loss-of-function mutations of the X-linked methyl-CpG-binding protein2 (MECP2) gene, encoding the MECP2 protein, a member of the methyl-CpG-binding domain nuclear proteins family. Brain 5-HT, which is defective in RTT patients and Mecp2 mutant mice, regulates motor circuits and SSRIs enhance motor skill learning and plasticity. In the present study, we used heterozygous (Het) Mecp2 female and Mecp2-null male mice to investigate whether fluoxetine, a SSRI with pleiotropic effects on neuronal circuits, rescues motor coordination deficits. Repeated administration of 10 mg/kg fluoxetine fully rescued rotarod deficit in Mecp2 Het mice regardless of age, route of administration or pre-training to rotarod. The motor improvement was confirmed in the beam walking test while no effect was observed in the hanging-wire test, suggesting a preferential action of fluoxetine on motor coordination. Citalopram mimicked the effects of fluoxetine, while the inhibition of 5-HT synthesis abolished the fluoxetine-induced improvement of motor coordination. Mecp2 null mice, which responded poorly to fluoxetine in the rotarod, showed reduced 5-HT synthesis in the prefrontal cortex, hippocampus and striatum, and reduced efficacy of fluoxetine in raising extracellular 5-HT as compared to female mutants. No sex differences were observed in the ability of fluoxetine to desensitize 5-HT1A autoreceptors upon repeated administration. These findings indicate that fluoxetine rescues motor coordination in Mecp2 Het mice through its ability to enhance brain 5-HT and suggest that drugs enhancing 5-HT neurotransmission may have beneficial effects on motor symptoms of RTT.
Collapse
|
31
|
Fagiolini M, Patrizi A, LeBlanc J, Jin LW, Maezawa I, Sinnett S, Gray SJ, Molholm S, Foxe JJ, Johnston MV, Naidu S, Blue M, Hossain A, Kadam S, Zhao X, Chang Q, Zhou Z, Zoghbi H. Intellectual and Developmental Disabilities Research Centers: A Multidisciplinary Approach to Understand the Pathogenesis of Methyl-CpG Binding Protein 2-related Disorders. Neuroscience 2020; 445:190-206. [PMID: 32360592 DOI: 10.1016/j.neuroscience.2020.04.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/20/2020] [Accepted: 04/21/2020] [Indexed: 12/20/2022]
Abstract
Disruptions in the gene encoding methyl-CpG binding protein 2 (MECP2) underlie complex neurodevelopmental disorders including Rett Syndrome (RTT), MECP2 duplication disorder, intellectual disabilities, and autism. Significant progress has been made on the molecular and cellular basis of MECP2-related disorders providing a new framework for understanding how altered epigenetic landscape can derail the formation and refinement of neuronal circuits in early postnatal life and proper neurological function. This review will summarize selected major findings from the past years and particularly highlight the integrated and multidisciplinary work done at eight NIH-funded Intellectual and Developmental Disabilities Research Centers (IDDRC) across the US. Finally, we will outline a path forward with identification of reliable biomarkers and outcome measures, longitudinal preclinical and clinical studies, reproducibility of results across centers as a synergistic effort to decode and treat the pathogenesis of the complex MeCP2 disorders.
Collapse
Affiliation(s)
- Michela Fagiolini
- Children's Hospital Intellectual and Developmental Disabilities Research Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
| | - Annarita Patrizi
- Children's Hospital Intellectual and Developmental Disabilities Research Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jocelyn LeBlanc
- Children's Hospital Intellectual and Developmental Disabilities Research Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Lee-Way Jin
- UC Davis MIND Institute, University of California, Sacramento, CA, USA
| | - Izumi Maezawa
- UC Davis MIND Institute, University of California, Sacramento, CA, USA
| | - Sarah Sinnett
- UNC Intellectual and Developmental Disabilities Research Center, University of North Carolina, Gene Therapy Center and Dept. of Ophthalmology, Chapel Hill, NC, USA; Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX, USA
| | - Steven J Gray
- UNC Intellectual and Developmental Disabilities Research Center, University of North Carolina, Gene Therapy Center and Dept. of Ophthalmology, Chapel Hill, NC, USA; Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX, USA
| | - Sophie Molholm
- The Cognitive Neurophysiology Laboratory, Departments of Pediatrics, Neuroscience, and Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, NY, USA
| | - John J Foxe
- The Cognitive Neurophysiology Laboratory, Ernest J. Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Michael V Johnston
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Sakkubai Naidu
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Mary Blue
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Ahamed Hossain
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Shilpa Kadam
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Xinyu Zhao
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
| | - Quiang Chang
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
| | - Zhaolan Zhou
- Department of Genetic, Epigenetic Institute, University of Pennsylvania Perelman School of Medicine, Intellectual and Developmental Disabilities Research Center, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Huda Zoghbi
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Program in Developmental Biology, Baylor College of Medicine, Houston, TX, USA; Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA; Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA; Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX, USA
| |
Collapse
|
32
|
Mossner JM, Batista-Brito R, Pant R, Cardin JA. Developmental loss of MeCP2 from VIP interneurons impairs cortical function and behavior. eLife 2020; 9:55639. [PMID: 32343226 PMCID: PMC7213975 DOI: 10.7554/elife.55639] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 04/28/2020] [Indexed: 12/24/2022] Open
Abstract
Rett Syndrome is a devastating neurodevelopmental disorder resulting from mutations in the gene MECP2. Mutations of Mecp2 that are restricted to GABAergic cell types largely replicate the behavioral phenotypes associated with mouse models of Rett Syndrome, suggesting a pathophysiological role for inhibitory interneurons. Recent work has suggested that vasoactive intestinal peptide-expressing (VIP) interneurons may play a critical role in the proper development and function of cortical circuits, making them a potential key point of vulnerability in neurodevelopmental disorders. However, little is known about the role of VIP interneurons in Rett Syndrome. Here we find that loss of MeCP2 specifically from VIP interneurons replicates key neural and behavioral phenotypes observed following global Mecp2 loss of function.
Collapse
Affiliation(s)
- James M Mossner
- Department of Neuroscience, Yale University, New Haven, United States
| | - Renata Batista-Brito
- Department of Neuroscience, Yale University, New Haven, United States.,Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, United States
| | - Rima Pant
- Department of Neuroscience, Yale University, New Haven, United States
| | - Jessica A Cardin
- Department of Neuroscience, Yale University, New Haven, United States.,Kavli Institute for Neuroscience, Yale University, New Haven, United States
| |
Collapse
|
33
|
Khoury ES, Sharma A, Ramireddy RR, Thomas AG, Alt J, Fowler A, Rais R, Tsukamoto T, Blue ME, Slusher B, Kannan S, Kannan RM. Dendrimer-conjugated glutaminase inhibitor selectively targets microglial glutaminase in a mouse model of Rett syndrome. Am J Cancer Res 2020; 10:5736-5748. [PMID: 32483415 PMCID: PMC7254984 DOI: 10.7150/thno.41714] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 04/14/2020] [Indexed: 12/14/2022] Open
Abstract
Background: Elevated glutamate production and release from glial cells is a common feature of many CNS disorders. Inhibitors of glutaminase (GLS), the enzyme responsible for converting glutamine to glutamate have been developed to target glutamate overproduction. However, many GLS inhibitors have poor aqueous solubility, are unable to cross the blood brain barrier, or demonstrate significant toxicity when given systemically, precluding translation. Enhanced aqueous solubility and systemic therapy targeted to activated glia may address this challenge. Here we examine the impact of microglial-targeted GLS inhibition in a mouse model of Rett syndrome (RTT), a developmental disorder with no viable therapies, manifesting profound central nervous system effects, in which elevated glutamatergic tone, upregulation of microglial GLS, oxidative stress and neuroimmune dysregulation are key features. Methods: To enable this, we conjugated a potent glutaminase inhibitor, N-(5-{2-[2-(5-amino-[1,3,4]thiadiazol-2-yl)-ethylsulfanyl]-ethyl}-[1,3,4]thiadiazol-2-yl)-2-phenyl-acetamide (JHU29) to a generation 4 hydroxyl PAMAM dendrimer (D-JHU29). We then examined the effect of D-JHU29 in organotypic slice culture on glutamate release. We also examined GLS activity in microglial and non-microglial cells, and neurobehavioral phenotype after systemic administration of D-JHU29 in a mouse model of RTT. Results: We report successful conjugation of JHU29 to dendrimer resulting in enhanced water solubility compared to free JHU29. D-JHU29 reduced the excessive glutamate release observed in tissue culture slices in a clinically relevant Mecp2-knockout (KO) RTT mouse. Microglia isolated from Mecp2-KO mice demonstrated upregulation of GLS activity that normalized to wild-type levels following systemic treatment with D-JHU29. Neurobehavioral assessments in D-JHU29 treated Mecp2-KO mice revealed selective improvements in mobility. Conclusion: These findings demonstrate that glutaminase inhibitors conjugated to dendrimers are a viable mechanism to selectively inhibit microglial GLS to reduce glutamate production and improve mobility in a mouse model of RTT, with broader implications for selectively targeting this pathway in other neurodegenerative disorders.
Collapse
|
34
|
Lavery LA, Ure K, Wan YW, Luo C, Trostle AJ, Wang W, Jin H, Lopez J, Lucero J, Durham MA, Castanon R, Nery JR, Liu Z, Goodell M, Ecker JR, Behrens MM, Zoghbi HY. Losing Dnmt3a dependent methylation in inhibitory neurons impairs neural function by a mechanism impacting Rett syndrome. eLife 2020; 9:e52981. [PMID: 32159514 PMCID: PMC7065908 DOI: 10.7554/elife.52981] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 02/20/2020] [Indexed: 12/11/2022] Open
Abstract
Methylated cytosine is an effector of epigenetic gene regulation. In the brain, Dnmt3a is the sole 'writer' of atypical non-CpG methylation (mCH), and MeCP2 is the only known 'reader' for mCH. We asked if MeCP2 is the sole reader for Dnmt3a dependent methylation by comparing mice lacking either protein in GABAergic inhibitory neurons. Loss of either protein causes overlapping and distinct features from the behavioral to molecular level. Loss of Dnmt3a causes global loss of mCH and a subset of mCG sites resulting in more widespread transcriptional alterations and severe neurological dysfunction than MeCP2 loss. These data suggest that MeCP2 is responsible for reading only part of the Dnmt3a dependent methylation in the brain. Importantly, the impact of MeCP2 on genes differentially expressed in both models shows a strong dependence on mCH, but not Dnmt3a dependent mCG, consistent with mCH playing a central role in the pathogenesis of Rett Syndrome.
Collapse
Affiliation(s)
- Laura A Lavery
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- Department of Molecular and Human Genetics, Baylor College of MedicineHoustonUnited States
| | - Kerstin Ure
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- Department of Molecular and Human Genetics, Baylor College of MedicineHoustonUnited States
| | - Ying-Wooi Wan
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- Department of Molecular and Human Genetics, Baylor College of MedicineHoustonUnited States
| | - Chongyuan Luo
- Genomic Analysis Laboratory, The Salk Institute for Biological StudiesLa JollaUnited States
- Howard Hughes Medical Institute, The Salk Institute for Biological StudiesLa JollaUnited States
| | - Alexander J Trostle
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- Department of Pediatrics, Baylor College of MedicineHoustonUnited States
| | - Wei Wang
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- Department of Molecular and Human Genetics, Baylor College of MedicineHoustonUnited States
| | - Haijing Jin
- Graduate Program in Quantitative and Computational Biosciences, Baylor College of MedicineHoustonUnited States
| | - Joanna Lopez
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- Department of Molecular and Human Genetics, Baylor College of MedicineHoustonUnited States
| | - Jacinta Lucero
- Computational Neurobiology Laboratory, The Salk Institute for Biological StudiesLa JollaUnited States
| | - Mark A Durham
- Program in Developmental Biology, Baylor College of MedicineHoustonUnited States
- Medical Scientist Training Program, Baylor College of MedicineHoustonUnited States
| | - Rosa Castanon
- Genomic Analysis Laboratory, The Salk Institute for Biological StudiesLa JollaUnited States
| | - Joseph R Nery
- Genomic Analysis Laboratory, The Salk Institute for Biological StudiesLa JollaUnited States
| | - Zhandong Liu
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- Department of Molecular and Human Genetics, Baylor College of MedicineHoustonUnited States
- Graduate Program in Quantitative and Computational Biosciences, Baylor College of MedicineHoustonUnited States
| | - Margaret Goodell
- Department of Molecular and Human Genetics, Baylor College of MedicineHoustonUnited States
- Program in Developmental Biology, Baylor College of MedicineHoustonUnited States
- Center for Cell and Gene Therapy, Baylor College of MedicineHoustonUnited States
- Stem Cells and Regenerative Medicine Center, Baylor College of MedicineHoustonUnited States
- Department Molecular and Cellular Biology, Baylor College of MedicineHoustonUnited States
| | - Joseph R Ecker
- Genomic Analysis Laboratory, The Salk Institute for Biological StudiesLa JollaUnited States
- Howard Hughes Medical Institute, The Salk Institute for Biological StudiesLa JollaUnited States
| | - M Margarita Behrens
- Computational Neurobiology Laboratory, The Salk Institute for Biological StudiesLa JollaUnited States
- Department of Psychiatry, University of California San DiegoLa JollaUnited States
| | - Huda Y Zoghbi
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- Department of Molecular and Human Genetics, Baylor College of MedicineHoustonUnited States
- Department of Pediatrics, Baylor College of MedicineHoustonUnited States
- Program in Developmental Biology, Baylor College of MedicineHoustonUnited States
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Howard Hughes Medical Institute, Baylor College of MedicineHoustonUnited States
| |
Collapse
|
35
|
Comprehensive Analysis of GABA A-A1R Developmental Alterations in Rett Syndrome: Setting the Focus for Therapeutic Targets in the Time Frame of the Disease. Int J Mol Sci 2020; 21:ijms21020518. [PMID: 31947619 PMCID: PMC7014188 DOI: 10.3390/ijms21020518] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 01/03/2020] [Accepted: 01/10/2020] [Indexed: 02/08/2023] Open
Abstract
Rett syndrome, a serious neurodevelopmental disorder, has been associated with an altered expression of different synaptic-related proteins and aberrant glutamatergic and γ-aminobutyric acid (GABA)ergic neurotransmission. Despite its severity, it lacks a therapeutic option. Through this work we aimed to define the relationship between MeCP2 and GABAA.-A1 receptor expression, emphasizing the time dependence of such relationship. For this, we analyzed the expression of the ionotropic receptor subunit in different MeCP2 gene-dosage and developmental conditions, in cells lines, and in primary cultured neurons, as well as in different developmental stages of a Rett mouse model. Further, RNAseq and systems biology analysis was performed from post-mortem brain biopsies of Rett patients. We observed that the modulation of the MeCP2 expression in cellular models (both Neuro2a (N2A) cells and primary neuronal cultures) revealed a MeCP2 positive effect on the GABAA.-A1 receptor subunit expression, which did not occur in other proteins such as KCC2 (Potassium-chloride channel, member 5). In the Mecp2+/− mouse brain, both the KCC2 and GABA subunits expression were developmentally regulated, with a decreased expression during the pre-symptomatic stage, while the expression was variable in the adult symptomatic mice. Finally, the expression of the gamma-aminobutyric acid (GABA) receptor-related synaptic proteins from the postmortem brain biopsies of two Rett patients was evaluated, specifically revealing the GABA A1R subunit overexpression. The identification of the molecular changes along with the Rett syndrome prodromic stages strongly endorses the importance of time frame when addressing this disease, supporting the need for a neurotransmission-targeted early therapeutic intervention.
Collapse
|
36
|
Ribeiro MC, MacDonald JL. Sex differences in Mecp2-mutant Rett syndrome model mice and the impact of cellular mosaicism in phenotype development. Brain Res 2020; 1729:146644. [PMID: 31904347 DOI: 10.1016/j.brainres.2019.146644] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 12/08/2019] [Accepted: 12/31/2019] [Indexed: 12/29/2022]
Abstract
There is currently no effective treatment for Rett syndrome (RTT), a severe X-linked progressive neurodevelopmental disorder caused by mutations in the transcriptional regulator MECP2. Because MECP2 is subjected to X-inactivation, most affected individuals are female heterozygotes who display cellular mosaicism for normal and mutant MECP2. Males who are hemizygous for mutant MECP2 are more severely affected than heterozygous females and rarely survive. Mecp2 loss-of-function is less severe in mice, however, and male hemizygous null mice not only survive until adulthood, they have been the most commonly studied model system. Although heterozygous female mice better recapitulate human RTT, they have not been as thoroughly characterized. This is likely because of the added experimental challenges that they present, including delayed and more variable phenotypic progression and cellular mosaicism due to X-inactivation. In this review, we compare phenotypes of Mecp2 heterozygous female mice and male hemizygous null mouse models. Further, we discuss the complexities that arise from the many cell-type and tissue-type specific roles of MeCP2, as well as the combination of cell-autonomous and non-cell-autonomous disruptions that result from Mecp2 loss-of-function. This is of particular importance in the context of the female heterozygous brain, composed of a mixture of MeCP2+ and MeCP2- cells, the ratio of which can alter RTT phenotypes in the case of skewed X-inactivation. The goal of this review is to provide a clearer understanding of the pathophysiological differences between the mouse models, which is an essential consideration in the design of future pre-clinical studies.
Collapse
Affiliation(s)
- Mayara C Ribeiro
- Department of Biology, Program in Neuroscience, Syracuse University, Syracuse, NY, United States
| | - Jessica L MacDonald
- Department of Biology, Program in Neuroscience, Syracuse University, Syracuse, NY, United States.
| |
Collapse
|
37
|
Jorge-Torres OC, Szczesna K, Roa L, Casal C, Gonzalez-Somermeyer L, Soler M, Velasco CD, Martínez-San Segundo P, Petazzi P, Sáez MA, Delgado-Morales R, Fourcade S, Pujol A, Huertas D, Llobet A, Guil S, Esteller M. Inhibition of Gsk3b Reduces Nfkb1 Signaling and Rescues Synaptic Activity to Improve the Rett Syndrome Phenotype in Mecp2-Knockout Mice. Cell Rep 2019; 23:1665-1677. [PMID: 29742424 DOI: 10.1016/j.celrep.2018.04.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2017] [Revised: 02/07/2018] [Accepted: 03/31/2018] [Indexed: 12/01/2022] Open
Abstract
Rett syndrome (RTT) is the second leading cause of mental impairment in girls and is currently untreatable. RTT is caused, in more than 95% of cases, by loss-of-function mutations in the methyl CpG-binding protein 2 gene (MeCP2). We propose here a molecular target involved in RTT: the glycogen synthase kinase-3b (Gsk3b) pathway. Gsk3b activity is deregulated in Mecp2-knockout (KO) mice models, and SB216763, a specific inhibitor, is able to alleviate the clinical symptoms with consequences at the molecular and cellular levels. In vivo, inhibition of Gsk3b prolongs the lifespan of Mecp2-KO mice and reduces motor deficits. At the molecular level, SB216763 rescues dendritic networks and spine density, while inducing changes in the properties of excitatory synapses. Gsk3b inhibition can also decrease the nuclear activity of the Nfkb1 pathway and neuroinflammation. Altogether, our findings indicate that Mecp2 deficiency in the RTT mouse model is partially rescued following treatment with SB216763.
Collapse
Affiliation(s)
- Olga C Jorge-Torres
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet, Barcelona, Catalonia, Spain
| | - Karolina Szczesna
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet, Barcelona, Catalonia, Spain
| | - Laura Roa
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet, Barcelona, Catalonia, Spain
| | - Carme Casal
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet, Barcelona, Catalonia, Spain
| | - Louisa Gonzalez-Somermeyer
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet, Barcelona, Catalonia, Spain
| | - Marta Soler
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet, Barcelona, Catalonia, Spain
| | - Cecilia D Velasco
- Laboratory of Neurobiology, Bellvitge Biomedical Research Institute (IDIBELL), 08907 L'Hospitalet de Llobregat, Barcelona, Catalonia, Spain; Department of Pathology and Experimental Therapeutics, Faculty of Medicine, 08907 L'Hospitalet de Llobregat, Barcelona, Catalonia, Spain; Institute of Neurosciences, University of Barcelona, 08907 L'Hospitalet de Llobregat, Barcelona, Catalonia, Spain
| | - Pablo Martínez-San Segundo
- Laboratory of Neurobiology, Bellvitge Biomedical Research Institute (IDIBELL), 08907 L'Hospitalet de Llobregat, Barcelona, Catalonia, Spain; Department of Pathology and Experimental Therapeutics, Faculty of Medicine, 08907 L'Hospitalet de Llobregat, Barcelona, Catalonia, Spain; Institute of Neurosciences, University of Barcelona, 08907 L'Hospitalet de Llobregat, Barcelona, Catalonia, Spain
| | - Paolo Petazzi
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet, Barcelona, Catalonia, Spain
| | - Mauricio A Sáez
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet, Barcelona, Catalonia, Spain
| | - Raúl Delgado-Morales
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet, Barcelona, Catalonia, Spain; Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNs), Maastricht University, Maastricht, the Netherlands
| | - Stephane Fourcade
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet, Barcelona, Catalonia, Spain; Institute of Neuropathology, University of Barcelona, Barcelona, Catalonia, Spain; Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Aurora Pujol
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet, Barcelona, Catalonia, Spain; Institute of Neuropathology, University of Barcelona, Barcelona, Catalonia, Spain; Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain; Institucio Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Catalonia, Spain
| | - Dori Huertas
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet, Barcelona, Catalonia, Spain
| | - Artur Llobet
- Laboratory of Neurobiology, Bellvitge Biomedical Research Institute (IDIBELL), 08907 L'Hospitalet de Llobregat, Barcelona, Catalonia, Spain; Department of Pathology and Experimental Therapeutics, Faculty of Medicine, 08907 L'Hospitalet de Llobregat, Barcelona, Catalonia, Spain; Institute of Neurosciences, University of Barcelona, 08907 L'Hospitalet de Llobregat, Barcelona, Catalonia, Spain
| | - Sonia Guil
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet, Barcelona, Catalonia, Spain.
| | - Manel Esteller
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet, Barcelona, Catalonia, Spain; Institucio Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Catalonia, Spain; Physiological Sciences Department, School of Medicine and Health Sciences, University of Barcelona (UB), 08907 Catalonia, Spain.
| |
Collapse
|
38
|
Lavery LA, Zoghbi HY. The distinct methylation landscape of maturing neurons and its role in Rett syndrome pathogenesis. Curr Opin Neurobiol 2019; 59:180-188. [PMID: 31542590 PMCID: PMC6892602 DOI: 10.1016/j.conb.2019.08.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 08/21/2019] [Indexed: 02/06/2023]
Abstract
Rett syndrome (RTT) is one of the most common causes of intellectual and developmental disabilities in girls, and is caused by mutations in the gene encoding methyl-CpG binding protein 2 (MECP2). Here we will review our current understanding of RTT, the landscape of pathogenic mutations and function of MeCP2, and culminate with recent advances elucidating the distinct DNA methylation landscape in the brain that may explain why disease symptoms are delayed and selective to the nervous system.
Collapse
Affiliation(s)
- Laura A Lavery
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Huda Y Zoghbi
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA; Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030, USA.
| |
Collapse
|
39
|
Sysoeva OV, Smirnov K, Stroganova TA. Sensory evoked potentials in patients with Rett syndrome through the lens of animal studies: Systematic review. Clin Neurophysiol 2019; 131:213-224. [PMID: 31812082 DOI: 10.1016/j.clinph.2019.11.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 11/07/2019] [Accepted: 11/11/2019] [Indexed: 01/04/2023]
Abstract
OBJECTIVE Systematically review the abnormalities in event related potential (ERP) recorded in Rett Syndrome (RTT) patients and animals in search of translational biomarkers of deficits related to the particular neurophysiological processes of known genetic origin (MECP2 mutations). METHODS Pubmed, ISI Web of Knowledge and BIORXIV were searched for the relevant articles according to PRISMA standards. RESULTS ERP components are generally delayed across all sensory modalities both in RTT patients and its animal model, while findings on ERPs amplitude strongly depend on stimulus properties and presentation rate. Studies on RTT animal models uncovered the abnormalities in the excitatory and inhibitory transmission as critical mechanisms underlying the ERPs changes, but showed that even similar ERP alterations in auditory and visual domains have a diverse neural basis. A range of novel approaches has been developed in animal studies bringing along the meaningful neurophysiological interpretation of ERP measures in RTT patients. CONCLUSIONS While there is a clear evidence for sensory ERPs abnormalities in RTT, to further advance the field there is a need in a large-scale ERP studies with the functionally-relevant experimental paradigms. SIGNIFICANCE The review provides insights into domain-specific neural basis of the ERP abnormalities and promotes clinical application of the ERP measures as the non-invasive functional biomarkers of RTT pathophysiology.
Collapse
Affiliation(s)
- Olga V Sysoeva
- The Cognitive Neurophysiology Laboratory, Department of Pediatrics, Albert Einstein College of Medicine & Montefiore Medical Center, Bronx, New York, USA; The Cognitive Neurophysiology Laboratory, Ernest J. Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA; The Laboratory of Human Higher Nervous Activity, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia.
| | - Kirill Smirnov
- Department of Neuroontogenesis, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Science, Moscow, Russia.
| | - Tatiana A Stroganova
- Center for Neurocognitive Research (MEG-Center), Moscow State University of Psychology and Education (MSUPE), Moscow, Russia; Autism Research Laboratory, Moscow State University of Psychology and Education (MSUPE), Moscow, Russia.
| |
Collapse
|
40
|
Heimer G, van Woerden GM, Barel O, Marek-Yagel D, Kol N, Munting JB, Borghei M, Atawneh OM, Nissenkorn A, Rechavi G, Anikster Y, Elgersma Y, Kushner SA, Ben Zeev B. Netrin-G2 dysfunction causes a Rett-like phenotype with areflexia. Hum Mutat 2019; 41:476-486. [PMID: 31692205 DOI: 10.1002/humu.23945] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 10/17/2019] [Accepted: 10/31/2019] [Indexed: 12/31/2022]
Abstract
We describe the underlying genetic cause of a novel Rett-like phenotype accompanied by areflexia in three methyl-CpG-binding protein 2-negative individuals from two unrelated families. Discovery analysis was performed using whole-exome sequencing followed by Sanger sequencing for validation and segregation. Functional studies using short-hairpin RNA for targeted gene knockdown were implemented by the transfection of mouse cultured primary hippocampal neurons and in vivo by in utero electroporation. All patients shared a common homozygous frameshift mutation (chr9:135073515, c.376dupT, p.(Ser126PhefsTer241)) in netrin-G2 (NTNG2, NM_032536.3) with predicted nonsense-mediated decay. The mutation fully segregated with the disease in both families. The knockdown of either NTNG2 or the related netrin-G family member NTNG1 resulted in severe neurodevelopmental defects of neuronal morphology and migration. While NTNG1 has previously been linked to a Rett syndrome (RTT)-like phenotype, this is the first description of a RTT-like phenotype caused by NTNG2 mutation. Netrin-G proteins have been shown to be required for proper axonal guidance during early brain development and involved in N-methyl- d-aspartate-mediated synaptic transmission. Our results demonstrating that knockdown of murine NTNG2 causes severe impairments of neuronal morphology and cortical migration are consistent with those of RTT animal models and the shared neurodevelopmental phenotypes between the individuals described here and typical RTT patients.
Collapse
Affiliation(s)
- Gali Heimer
- Pediatric Neurology Unit, Edmond and Lily Safra Children's Hospital, Chaim Sheba Medical Center, Ramat Gan, Israel.,The Pinchas Borenstein Talpiot Medical Leadership Program, The Chaim Sheba Medical Center, Ramat Gan, Israel.,The Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Geeske M van Woerden
- Department of Neuroscience, Erasmus University Medical Center, Rotterdam, The Netherlands.,ENCORE Expertise Center for Neurodevelopmental Disorders, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Ortal Barel
- The Genomic Unit, Sheba Cancer Research Center, Sheba Medical Center, Tel-Hashomer, Israel.,Wohl Institute for Translational Medicine, Sheba Medical Center, Ramat Gan, Israel
| | - Dina Marek-Yagel
- Metabolic Disease Unit, Edmond and Lily Safra Children's Hospital, The Chaim Sheba Medical Center, Ramat Gan, Israel
| | - Nitzan Kol
- The Genomic Unit, Sheba Cancer Research Center, Sheba Medical Center, Tel-Hashomer, Israel.,Wohl Institute for Translational Medicine, Sheba Medical Center, Ramat Gan, Israel
| | - Johannes B Munting
- Department of Neuroscience, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Minoeshka Borghei
- Department of Neuroscience, Erasmus University Medical Center, Rotterdam, The Netherlands
| | | | - Andreea Nissenkorn
- Pediatric Neurology Unit, Edmond and Lily Safra Children's Hospital, Chaim Sheba Medical Center, Ramat Gan, Israel.,The Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Gideon Rechavi
- The Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.,The Genomic Unit, Sheba Cancer Research Center, Sheba Medical Center, Tel-Hashomer, Israel.,Wohl Institute for Translational Medicine, Sheba Medical Center, Ramat Gan, Israel
| | - Yair Anikster
- The Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.,Metabolic Disease Unit, Edmond and Lily Safra Children's Hospital, The Chaim Sheba Medical Center, Ramat Gan, Israel
| | - Ype Elgersma
- Department of Neuroscience, Erasmus University Medical Center, Rotterdam, The Netherlands.,ENCORE Expertise Center for Neurodevelopmental Disorders, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Steven A Kushner
- ENCORE Expertise Center for Neurodevelopmental Disorders, Erasmus University Medical Center, Rotterdam, The Netherlands.,Department of Psychiatry, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Bruria Ben Zeev
- Pediatric Neurology Unit, Edmond and Lily Safra Children's Hospital, Chaim Sheba Medical Center, Ramat Gan, Israel.,The Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| |
Collapse
|
41
|
Ballinger EC, Schaaf CP, Patel AJ, de Maio A, Tao H, Talmage DA, Zoghbi HY, Role LW. Mecp2 Deletion from Cholinergic Neurons Selectively Impairs Recognition Memory and Disrupts Cholinergic Modulation of the Perirhinal Cortex. eNeuro 2019; 6:ENEURO.0134-19.2019. [PMID: 31562178 PMCID: PMC6825959 DOI: 10.1523/eneuro.0134-19.2019] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 08/21/2019] [Accepted: 09/17/2019] [Indexed: 12/12/2022] Open
Abstract
Rett Syndrome is a neurological disorder caused by mutations in the gene encoding methyl CpG binding protein 2 (MeCP2) and characterized by severe intellectual disability. The cholinergic system is a critical modulator of cognitive ability and is affected in patients with Rett Syndrome. To better understand the importance of MeCP2 function in cholinergic neurons, we studied the effect of selective Mecp2 deletion from cholinergic neurons in mice. Mice with Mecp2 deletion from cholinergic neurons were selectively impaired in assays of recognition memory, a cognitive task largely mediated by the perirhinal cortex (PRH). Deletion of Mecp2 from cholinergic neurons resulted in profound alterations in baseline firing of L5/6 neurons and eliminated the responses of these neurons to optogenetic stimulation of cholinergic input to PRH. Both the behavioral and the electrophysiological deficits of cholinergic Mecp2 deletion were rescued by inhibiting ACh breakdown with donepezil treatment.
Collapse
Affiliation(s)
- Elizabeth C Ballinger
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, New York 11794
- Program in Neuroscience, Stony Brook University, Stony Brook, New York 11794
- Medical Scientist Training Program, Stony Brook University, Stony Brook, New York 11794
| | - Christian P Schaaf
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Baylor College of Medicine, Houston, Texas 77030
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030
- Institute of Human Genetics, Heidelberg University, 69120 Heidelberg, Germany
| | - Akash J Patel
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Baylor College of Medicine, Houston, Texas 77030
- Department of Neurosurgery, Baylor College of Medicine, Houston, Texas 77030
| | - Antonia de Maio
- Program in Developmental Biology, Baylor College of Medicine, Houston, Texas 77030
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Baylor College of Medicine, Houston, Texas 77030
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030
| | - Huifang Tao
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Baylor College of Medicine, Houston, Texas 77030
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030
| | - David A Talmage
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, New York 11794
- Center for Nervous System Disorders, Stony Brook University, Stony Brook, New York 11794
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York 11794
| | - Huda Y Zoghbi
- Program in Developmental Biology, Baylor College of Medicine, Houston, Texas 77030
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Baylor College of Medicine, Houston, Texas 77030
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, Texas 77030
| | - Lorna W Role
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, New York 11794
- Center for Nervous System Disorders, Stony Brook University, Stony Brook, New York 11794
| |
Collapse
|
42
|
Banerjee A, Miller MT, Li K, Sur M, Kaufmann WE. Towards a better diagnosis and treatment of Rett syndrome: a model synaptic disorder. Brain 2019; 142:239-248. [PMID: 30649225 DOI: 10.1093/brain/awy323] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 10/31/2018] [Indexed: 12/21/2022] Open
Abstract
With the recent 50th anniversary of the first publication on Rett syndrome, and the almost 20 years since the first report on the link between Rett syndrome and MECP2 mutations, it is important to reflect on the tremendous advances in our understanding and their implications for the diagnosis and treatment of this neurodevelopmental disorder. Rett syndrome features an interesting challenge for biologists and clinicians, as the disorder lies at the intersection of molecular mechanisms of epigenetic regulation and neurophysiological alterations in synapses and circuits that together contribute to severe pathophysiological endophenotypes. Genetic, clinical, and neurobiological evidences support the notion that Rett syndrome is primarily a synaptic disorder, and a disease model for both intellectual disability and autism spectrum disorder. This review examines major developments in both recent neurobiological and preclinical findings of Rett syndrome, and to what extent they are beginning to impact our understanding and management of the disorder. It also discusses potential applications of knowledge on synaptic plasticity abnormalities in Rett syndrome to its diagnosis and treatment.
Collapse
Affiliation(s)
- Abhishek Banerjee
- Laboratory of Neural Circuit Dynamics, Brain Research Institute, University of Zürich, Zürich, Switzerland
| | - Meghan T Miller
- Roche Pharma Research and Early Development, Roche Innovation Center, F. Hoffman-La Roche, Basel, Switzerland
| | - Keji Li
- Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge MA, USA
| | - Mriganka Sur
- Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge MA, USA
| | - Walter E Kaufmann
- Department of Human Genetics, Emory University School of Medicine, Atlanta GA, USA
| |
Collapse
|
43
|
Meng X, McGraw CM, Wang W, Jing J, Yeh SY, Wang L, Lopez J, Brown AM, Lin T, Chen W, Xue M, Sillitoe RV, Jiang X, Zoghbi HY. Neurexophilin4 is a selectively expressed α-neurexin ligand that modulates specific cerebellar synapses and motor functions. eLife 2019; 8:e46773. [PMID: 31524598 PMCID: PMC6763262 DOI: 10.7554/elife.46773] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 09/13/2019] [Indexed: 01/03/2023] Open
Abstract
Neurexophilins are secreted neuropeptide-like glycoproteins, and neurexophilin1 and neurexophilin3 are ligands for the presynaptic cell adhesion molecule α-neurexin. Neurexophilins are more selectively expressed in the brain than α-neurexins, however, which led us to ask whether neurexophilins modulate the function of α-neurexin in a context-specific manner. We characterized the expression and function of neurexophilin4 in mice and found it to be expressed in subsets of neurons responsible for feeding, emotion, balance, and movement. Deletion of Neurexophilin4 caused corresponding impairments, most notably in motor learning and coordination. We demonstrated that neurexophilin4 interacts with α-neurexin and GABAARs in the cerebellum. Loss of Neurexophilin4 impaired cerebellar Golgi-granule inhibitory neurotransmission and synapse number, providing a partial explanation for the motor learning and coordination deficits observed in the Neurexophilin4 null mice. Our data illustrate how selectively expressed Neurexophilin4, an α-neurexin ligand, regulates specific synapse function and modulates cerebellar motor control.
Collapse
Affiliation(s)
- Xiangling Meng
- Department of NeuroscienceBaylor College of MedicineHoustonUnited States
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
| | - Christopher M McGraw
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- Program in Developmental BiologyBaylor College of MedicineHoustonUnited States
| | - Wei Wang
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- Department of Molecular and Human GeneticsBaylor College of MedicineHoustonUnited States
| | - Junzhan Jing
- Department of NeuroscienceBaylor College of MedicineHoustonUnited States
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
| | - Szu-Ying Yeh
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- Program in Developmental BiologyBaylor College of MedicineHoustonUnited States
| | - Li Wang
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- Department of Molecular and Human GeneticsBaylor College of MedicineHoustonUnited States
| | - Joanna Lopez
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- Department of Molecular and Human GeneticsBaylor College of MedicineHoustonUnited States
| | - Amanda M Brown
- Department of NeuroscienceBaylor College of MedicineHoustonUnited States
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- Department of Pathology and ImmunologyBaylor College of MedicineHoustonUnited States
| | - Tao Lin
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- Department of Pathology and ImmunologyBaylor College of MedicineHoustonUnited States
| | - Wu Chen
- Department of NeuroscienceBaylor College of MedicineHoustonUnited States
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- The Cain Foundation LaboratoriesJan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
| | - Mingshan Xue
- Department of NeuroscienceBaylor College of MedicineHoustonUnited States
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- Program in Developmental BiologyBaylor College of MedicineHoustonUnited States
- Department of Molecular and Human GeneticsBaylor College of MedicineHoustonUnited States
- The Cain Foundation LaboratoriesJan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
| | - Roy V Sillitoe
- Department of NeuroscienceBaylor College of MedicineHoustonUnited States
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- Program in Developmental BiologyBaylor College of MedicineHoustonUnited States
- Department of Pathology and ImmunologyBaylor College of MedicineHoustonUnited States
| | - Xiaolong Jiang
- Department of NeuroscienceBaylor College of MedicineHoustonUnited States
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
| | - Huda Y Zoghbi
- Department of NeuroscienceBaylor College of MedicineHoustonUnited States
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- Program in Developmental BiologyBaylor College of MedicineHoustonUnited States
- Department of Molecular and Human GeneticsBaylor College of MedicineHoustonUnited States
- Howard Hughes Medical Institute, Baylor College of MedicineHoustonUnited States
| |
Collapse
|
44
|
Walkley SU, Abbeduto L, Batshaw ML, Bhattacharyya A, Bookheimer SY, Christian BT, Constantino JN, de Vellis J, Doherty DA, Nelson DL, Piven J, Poduri A, Pomeroy SL, Samaco RC, Zoghbi HY, Guralnick MJ. Intellectual and developmental disabilities research centers: Fifty years of scientific accomplishments. Ann Neurol 2019; 86:332-343. [PMID: 31206741 PMCID: PMC8320680 DOI: 10.1002/ana.25531] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 06/12/2019] [Accepted: 06/13/2019] [Indexed: 12/17/2022]
Abstract
Progress in addressing the origins of intellectual and developmental disabilities accelerated with the establishment 50 years ago of the Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health and associated Intellectual and Developmental Disabilities Research Centers. Investigators at these Centers have made seminal contributions to understanding human brain and behavioral development and defining mechanisms and treatments of disorders of the developing brain. ANN NEUROL 2019;86:332-343.
Collapse
Affiliation(s)
- Steven U. Walkley
- Department of Neuroscience, Albert Einstein College of Medicine, Rose F. Kennedy Intellectual and Developmental Disabilities Research Center, Bronx, NY
| | - Leonard Abbeduto
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, University of California, Davis Memory Impairments and Neurological Disorders Institute, Sacramento, CA
| | - Mark L. Batshaw
- Children’s Research Institute, Children’s National Medical Center, Washington, DC
| | - Anita Bhattacharyya
- Department of Cell and Regenerative Biology, Waisman Center, University of Wisconsin-Madison, Madison, WI
| | - Susan Y. Bookheimer
- Department of Psychiatry and Biobehavioral Sciences, Intellectual and Developmental Research Center, University of California, Los Angeles School of Medicine, Los Angeles, CA
| | - Bradley T. Christian
- Departments of Medical Physics and Psychiatry, Waisman Center, University of Wisconsin–Madison, Madison, WI
| | - John N. Constantino
- Departments of Psychiatry and Pediatrics, Washington University School of Medicine, Washington University in St Louis Intellectual and Developmental Disabilities Research Center, St Louis, MO
| | - Jean de Vellis
- Department of Psychiatry and Biobehavioral Sciences, Intellectual and Developmental Research Center, University of California, Los Angeles School of Medicine, Los Angeles, CA
| | - Daniel A. Doherty
- Department of Pediatrics, Center on Human Development and Disability, University of Washington, Seattle, WA
| | - David L. Nelson
- Department of Molecular and Human Genetics, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Baylor College of Medicine Intellectual and Developmental Disabilities Research Center, Houston, TX
| | - Joseph Piven
- Carolina Institute for Developmental Disabilities, University of North Carolina, University of North Carolina Intellectual and Developmental Disabilities Research Center, Chapel Hill, NC
| | - Annapurna Poduri
- Department of Neurology, Harvard Medical School, Boston Children’s Hospital and Harvard Medical School Intellectual and Developmental Disabilities Research Center, Boston, MA
| | - Scott L. Pomeroy
- Department of Neurology, Harvard Medical School, Boston Children’s Hospital and Harvard Medical School Intellectual and Developmental Disabilities Research Center, Boston, MA
| | - Rodney C. Samaco
- Department of Molecular and Human Genetics, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Baylor College of Medicine Intellectual and Developmental Disabilities Research Center, Houston, TX
| | - Huda Y. Zoghbi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Baylor College of Medicine Intellectual and Developmental Disabilities Research Center, Houston, TX
| | - Michael J. Guralnick
- Departments of Psychology and Pediatrics, Center on Human Development and Disability, University of Washington, Seattle, WA
| | | |
Collapse
|
45
|
Abstract
Rett syndrome (RTT) is a severe neurological disorder caused by mutations in the gene encoding methyl-CpG-binding protein 2 (MeCP2). Almost two decades of research into RTT have greatly advanced our understanding of the function and regulation of the multifunctional protein MeCP2. Here, we review recent advances in understanding how loss of MeCP2 impacts different stages of brain development, discuss recent findings demonstrating the molecular role of MeCP2 as a transcriptional repressor, assess primary and secondary effects of MeCP2 loss and examine how loss of MeCP2 can result in an imbalance of neuronal excitation and inhibition at the circuit level along with dysregulation of activity-dependent mechanisms. These factors present challenges to the search for mechanism-based therapeutics for RTT and suggest specific approaches that may be more effective than others.
Collapse
|
46
|
Picard N, Fagiolini M. MeCP2: an epigenetic regulator of critical periods. Curr Opin Neurobiol 2019; 59:95-101. [PMID: 31163286 DOI: 10.1016/j.conb.2019.04.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 04/10/2019] [Indexed: 01/30/2023]
Abstract
Complex adult behaviors arise from the integration of sequential and often overlapping critical periods (CPs) early in life and adolescence. These processes rely on a subtle interplay between the set of genes inherited from the parents, the surrounding environment and epigenetic regulation. Methyl-CpG-binding protein 2 (MeCP2) has been shown to recognize epigenetic states and regulate gene expression by reading methylated DNA. Here, we will review the recent findings revealing the role of MeCP2 during postnatal CPs of development using mouse models of Rett (RTT) syndrome.
Collapse
Affiliation(s)
- Nathalie Picard
- FM Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States.
| | - Michela Fagiolini
- FM Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States; International Research Center for Neurointelligence, University of Tokyo Institutes for Advanced Study, Tokyo, 113-0033, Japan.
| |
Collapse
|
47
|
Chin EWM, Lim WM, Ma D, Rosales FJ, Goh ELK. Choline Rescues Behavioural Deficits in a Mouse Model of Rett Syndrome by Modulating Neuronal Plasticity. Mol Neurobiol 2019; 56:3882-3896. [PMID: 30220058 PMCID: PMC6505515 DOI: 10.1007/s12035-018-1345-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 09/05/2018] [Indexed: 12/16/2022]
Abstract
Rett syndrome (RTT) is a postnatal neurodevelopmental disorder that primarily affects girls, with 95% of RTT cases resulting from mutations in the methyl-CpG-binding protein 2 (MECP2) gene. Choline, a dietary micronutrient found in most foods, has been shown to be important for brain development and function. However, the exact effects and mechanisms are still unknown. We found that 13 mg/day (1.7 × required daily intake) of postnatal choline treatment to Mecp2-conditional knockout mice rescued not only deficits in motor coordination, but also their anxiety-like behaviour and reduced social preference. Cortical neurons in the brains of Mecp2-conditional knockout mice supplemented with choline showed enhanced neuronal morphology and increased density of dendritic spines. Modelling RTT in vitro by knocking down the expression of the MeCP2 protein with shRNA, we found that choline supplementation to MeCP2-knockdown neurons increased their soma sizes and the complexity of their dendritic arbors. Rescue of the morphological defects could lead to enhanced neurotransmission, as suggested by an observed trend of increased expression of synaptic proteins and restored miniature excitatory postsynaptic current frequency in choline-supplemented MeCP2-knockdown neurons. Through the use of specific inhibitors targeting each of the known physiological pathways of choline, synthesis of phosphatidylcholine from choline was found to be essential in bringing about the changes seen in the choline-supplemented MeCP2-knockdown neurons. Taken together, these data reveal a role of choline in modulating neuronal plasticity, possibly leading to behavioural changes, and hence, a potential for using choline to treat RTT.
Collapse
Affiliation(s)
- Eunice W M Chin
- Neuroscience Academic Clinical Programme, Duke-NUS Medical School, 20 College Road, Singapore, 169856, Singapore
- Department of Research, National Neuroscience Institute, Singapore, 308433, Singapore
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore, 117456, Singapore
| | - Wee Meng Lim
- Neuroscience Academic Clinical Programme, Duke-NUS Medical School, 20 College Road, Singapore, 169856, Singapore
- Department of Research, National Neuroscience Institute, Singapore, 308433, Singapore
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore, 117456, Singapore
| | - Dongliang Ma
- Neuroscience Academic Clinical Programme, Duke-NUS Medical School, 20 College Road, Singapore, 169856, Singapore
- Department of Research, National Neuroscience Institute, Singapore, 308433, Singapore
| | | | - Eyleen L K Goh
- Neuroscience Academic Clinical Programme, Duke-NUS Medical School, 20 College Road, Singapore, 169856, Singapore.
- Department of Research, National Neuroscience Institute, Singapore, 308433, Singapore.
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore.
- KK Research Center, KK Women's and Children's Hospital, Singapore, 229899, Singapore.
| |
Collapse
|
48
|
Vogel Ciernia A, Yasui DH, Pride MC, Durbin-Johnson B, Noronha AB, Chang A, Knotts TA, Rutkowsky JR, Ramsey JJ, Crawley JN, LaSalle JM. MeCP2 isoform e1 mutant mice recapitulate motor and metabolic phenotypes of Rett syndrome. Hum Mol Genet 2018; 27:4077-4093. [PMID: 30137367 PMCID: PMC6240741 DOI: 10.1093/hmg/ddy301] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 08/10/2018] [Accepted: 08/14/2018] [Indexed: 01/27/2023] Open
Abstract
Mutations in the X-linked gene MECP2 cause the majority of Rett syndrome (RTT) cases. Two differentially spliced isoforms of exons 1 and 2 (MeCP2-e1 and MeCP2-e2) contribute to the diverse functions of MeCP2, but only mutations in exon 1, not exon 2, are observed in RTT. We previously described an isoform-specific MeCP2-e1-deficient male mouse model of a human RTT mutation that lacks MeCP2-e1 while preserving expression of MeCP2-e2. However, RTT patients are heterozygous females that exhibit delayed and progressive symptom onset beginning in late infancy, including neurologic as well as metabolic, immune, respiratory and gastrointestinal phenotypes. Consequently, we conducted a longitudinal assessment of symptom development in MeCP2-e1 mutant females and males. A delayed and progressive onset of motor impairments was observed in both female and male MeCP2-e1 mutant mice, including hind limb clasping and motor deficits in gait and balance. Because these motor impairments were significantly impacted by age-dependent increases in body weight, we also investigated metabolic phenotypes at an early stage of disease progression. Both male and female MeCP2-e1 mutants exhibited significantly increased body fat compared to sex-matched wild-type littermates prior to weight differences. Mecp2e1-/y males exhibited significant metabolic phenotypes of hypoactivity, decreased energy expenditure, increased respiratory exchange ratio, but decreased food intake compared to wild-type. Untargeted analysis of lipid metabolites demonstrated a distinguishable profile in MeCP2-e1 female mutant liver characterized by increased triglycerides. Together, these results demonstrate that MeCP2-e1 mutation in mice of both sexes recapitulates early and progressive metabolic and motor phenotypes of human RTT.
Collapse
Affiliation(s)
- Annie Vogel Ciernia
- Department of Medical Microbiology and Immunology, UC Davis School of Medicine, University of California, Davis, CA, USA
- UC Davis Genome Center, University of California, Davis, CA, USA
- UC Davis MIND Institute, University of California, Davis, CA, USA
| | - Dag H Yasui
- Department of Medical Microbiology and Immunology, UC Davis School of Medicine, University of California, Davis, CA, USA
| | - Michael C Pride
- UC Davis MIND Institute, University of California, Davis, CA, USA
- Department of Psychiatry and Behavioral Sciences, UC Davis School of Medicine, University of California, Davis, CA, USA
| | - Blythe Durbin-Johnson
- Department of Public Health Sciences, UC Davis School of Medicine, University of California, Davis, CA, USA
| | - Adriana B Noronha
- Department of Medical Microbiology and Immunology, UC Davis School of Medicine, University of California, Davis, CA, USA
| | - Alene Chang
- Department of Medical Microbiology and Immunology, UC Davis School of Medicine, University of California, Davis, CA, USA
| | - Trina A Knotts
- Department of Molecular Biosciences, UC Davis School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Jennifer R Rutkowsky
- Department of Molecular Biosciences, UC Davis School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Jon J Ramsey
- Department of Molecular Biosciences, UC Davis School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Jacqueline N Crawley
- UC Davis MIND Institute, University of California, Davis, CA, USA
- Department of Psychiatry and Behavioral Sciences, UC Davis School of Medicine, University of California, Davis, CA, USA
| | - Janine M LaSalle
- Department of Medical Microbiology and Immunology, UC Davis School of Medicine, University of California, Davis, CA, USA
- UC Davis Genome Center, University of California, Davis, CA, USA
- UC Davis MIND Institute, University of California, Davis, CA, USA
| |
Collapse
|
49
|
Jeon SJ, Gonzales EL, Mabunga DFN, Valencia ST, Kim DG, Kim Y, Adil KJL, Shin D, Park D, Shin CY. Sex-specific Behavioral Features of Rodent Models of Autism Spectrum Disorder. Exp Neurobiol 2018; 27:321-343. [PMID: 30429643 PMCID: PMC6221834 DOI: 10.5607/en.2018.27.5.321] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 10/08/2018] [Accepted: 10/10/2018] [Indexed: 12/13/2022] Open
Abstract
Sex is an important factor in understanding the clinical presentation, management, and developmental trajectory of children with neuropsychiatric disorders. While much is known about the clinical and neurobehavioral profiles of males with neuropsychiatric disorders, surprisingly little is known about females in this respect. Animal models may provide detailed mechanistic information about sex differences in autism spectrum disorder (ASD) in terms of manifestation, disease progression, and development of therapeutic options. This review aims to widen our understanding of the role of sex in autism spectrum disorder, by summarizing and comparing behavioral characteristics of animal models. Our current understanding of how differences emerge in boys and girls with neuropsychiatric disorders is limited: Information derived from animal studies will stimulate future research on the role of biological maturation rates, sex hormones, sex-selective protective (or aggravating) factors and psychosocial factors, which are essential to devise sex precision medicine and to improve diagnostic accuracy. Moreover, there is a strong need of novel strategies to elucidate the major mechanisms leading to sex-specific autism features, as well as novel models or methods to examine these sex differences.
Collapse
Affiliation(s)
- Se Jin Jeon
- Center for Neuroscience, Korea Institute of Science & Technology, Seoul 02792, Korea.,Department of Pharmacology and Advanced Translational Medicine, School of Medicine, Konkuk University, Seoul 05029, Korea
| | - Edson Luck Gonzales
- Department of Pharmacology and Advanced Translational Medicine, School of Medicine, Konkuk University, Seoul 05029, Korea.,Department of Neuroscience, School of Medicine and Center for Neuroscience Research, Konkuk University, Seoul 05029, Korea
| | - Darine Froy N Mabunga
- Department of Pharmacology and Advanced Translational Medicine, School of Medicine, Konkuk University, Seoul 05029, Korea.,Department of Neuroscience, School of Medicine and Center for Neuroscience Research, Konkuk University, Seoul 05029, Korea
| | - Schley T Valencia
- Department of Pharmacology and Advanced Translational Medicine, School of Medicine, Konkuk University, Seoul 05029, Korea.,Department of Neuroscience, School of Medicine and Center for Neuroscience Research, Konkuk University, Seoul 05029, Korea
| | - Do Gyeong Kim
- Department of Pharmacology and Advanced Translational Medicine, School of Medicine, Konkuk University, Seoul 05029, Korea.,Department of Neuroscience, School of Medicine and Center for Neuroscience Research, Konkuk University, Seoul 05029, Korea
| | - Yujeong Kim
- Department of Pharmacology and Advanced Translational Medicine, School of Medicine, Konkuk University, Seoul 05029, Korea.,Department of Neuroscience, School of Medicine and Center for Neuroscience Research, Konkuk University, Seoul 05029, Korea
| | - Keremkleroo Jym L Adil
- Department of Pharmacology and Advanced Translational Medicine, School of Medicine, Konkuk University, Seoul 05029, Korea.,Department of Neuroscience, School of Medicine and Center for Neuroscience Research, Konkuk University, Seoul 05029, Korea
| | - Dongpil Shin
- Department of Pharmacology and Advanced Translational Medicine, School of Medicine, Konkuk University, Seoul 05029, Korea.,Department of Neuroscience, School of Medicine and Center for Neuroscience Research, Konkuk University, Seoul 05029, Korea
| | - Donghyun Park
- Department of Pharmacology and Advanced Translational Medicine, School of Medicine, Konkuk University, Seoul 05029, Korea.,Department of Neuroscience, School of Medicine and Center for Neuroscience Research, Konkuk University, Seoul 05029, Korea
| | - Chan Young Shin
- Department of Pharmacology and Advanced Translational Medicine, School of Medicine, Konkuk University, Seoul 05029, Korea.,Department of Neuroscience, School of Medicine and Center for Neuroscience Research, Konkuk University, Seoul 05029, Korea.,KU Open Innovation Center, Konkuk University, Seoul 05029, Korea
| |
Collapse
|
50
|
Maternal high fat diet alters offspring epigenetic regulators, amygdala glutamatergic profile and anxiety. Psychoneuroendocrinology 2018; 96:132-141. [PMID: 29940426 DOI: 10.1016/j.psyneuen.2018.06.015] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 05/12/2018] [Accepted: 06/18/2018] [Indexed: 12/31/2022]
Abstract
Maternal obesity during pregnancy can impact long-term health, predisposition to disease, and risk of neurological disorders in offspring. This may arise from disruption to epigenetic processes during offspring brain development. Using a maternal high fat diet (mHFD) mouse model, we investigated the expression of genes encoding epigenetic regulators in the brains of gestational day (GD) 17.5 mHFD offspring. We found significant, regionally unique changes in expression of epigenetic regulators in the developing brain of mHFD offspring compared to controls, with Gadd45b downregulated in medial prefrontal cortex, Mecp2 downregulated in amygdala, and sex-specific downregulation of Crebbp, Dnmt3b, and Mecp2 in male mHFD hippocampus. Decreased Mecp2 in the amygdala was associated with significant upregulation of the Mecp2-repressed gene, Tbr1, and an increased number of TBR1+ glutamatergic neurons in the basomedial nucleus of the amygdala. Tbr1 upregulation in amygdala was also observed in postnatal day 8 (P8) mHFD offspring, and levels of glutamate receptor gene Grin2b, and Fos, a marker for neuronal activity, were increased. Indications of heightened excitatory drive in mHFD offspring amygdala were associated with an anxiety-like phenotype, with mHFD offspring displaying altered ultrasonic vocalization characteristics at P8, and adult female mHFD offspring spending decreased time on the open arm of the Elevated Plus Maze. Together, this data provides insight into sex-specific offspring vulnerability to perinatal mHFD programming of anxiety-like behaviors.
Collapse
|