1
|
Mykins M, Bridges B, Jo A, Krishnan K. Multidimensional Analysis of a Social Behavior Identifies Regression and Phenotypic Heterogeneity in a Female Mouse Model for Rett Syndrome. J Neurosci 2024; 44:e1078232023. [PMID: 38199865 PMCID: PMC10957218 DOI: 10.1523/jneurosci.1078-23.2023] [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: 06/09/2023] [Revised: 11/01/2023] [Accepted: 11/17/2023] [Indexed: 01/12/2024] Open
Abstract
Regression is a key feature of neurodevelopmental disorders such as autism spectrum disorder, Fragile X syndrome, and Rett syndrome (RTT). RTT is caused by mutations in the X-linked gene methyl-CpG-binding protein 2 (MECP2). It is characterized by an early period of typical development with subsequent regression of previously acquired motor and speech skills in girls. The syndromic phenotypes are individualistic and dynamic over time. Thus far, it has been difficult to capture these dynamics and syndromic heterogeneity in the preclinical Mecp2-heterozygous female mouse model (Het). The emergence of computational neuroethology tools allows for robust analysis of complex and dynamic behaviors to model endophenotypes in preclinical models. Toward this first step, we utilized DeepLabCut, a marker-less pose estimation software to quantify trajectory kinematics and multidimensional analysis to characterize behavioral heterogeneity in Het in the previously benchmarked, ethologically relevant social cognition task of pup retrieval. We report the identification of two distinct phenotypes of adult Het: Het that display a delay in efficiency in early days and then improve over days like wild-type mice and Het that regress and perform worse in later days. Furthermore, regression is dependent on age and behavioral context and can be detected in the initial days of retrieval. Together, the novel identification of two populations of Het suggests differential effects on neural circuitry, opens new avenues to investigate the underlying molecular and cellular mechanisms of heterogeneity, and designs better studies for stratifying therapeutics.
Collapse
Affiliation(s)
- Michael Mykins
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee
| | - Benjamin Bridges
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee
| | - Angela Jo
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee
| | - Keerthi Krishnan
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee
| |
Collapse
|
2
|
Balicza P, Gezsi A, Fedor M, Sagi JC, Gal A, Varga NA, Molnar MJ. Multilevel evidence of MECP2-associated mitochondrial dysfunction and its therapeutic implications. Front Psychiatry 2024; 14:1301272. [PMID: 38250256 PMCID: PMC10796460 DOI: 10.3389/fpsyt.2023.1301272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Accepted: 11/22/2023] [Indexed: 01/23/2024] Open
Abstract
We present a male patient carrying a pathogenic MECP2 p. Arg179Trp variant with predominant negative psychiatric features and multilevel evidence of mitochondrial dysfunction who responded to the cariprazine treatment. He had delayed speech development and later experienced severe social anxiety, learning disabilities, cognitive slowing, and predominant negative psychiatric symptoms associated with rigidity. Clinical examinations showed multisystemic involvement. Together with elevated ergometric lactate levels, the clinical picture suggested mitochondrial disease, which was also supported by muscle histopathology. Exploratory transcriptome analysis also revealed the involvement of metabolic and oxidative phosphorylation pathways. Whole-exome sequencing identified a pathogenic MECP2 variant, which can explain both the dopamine imbalance and mitochondrial dysfunction in this patient. Mitochondrial dysfunction was previously suggested in classical Rett syndrome, and we detected related phenotype evidence on multiple consistent levels for the first time in a MECP2 variant carrier male. This study further supports the importance of the MECP2 gene in the mitochondrial pathways, which can open the gate for more personalized therapeutic interventions. Good cariprazine response highlights the role of dopamine dysfunction in the complex psychiatric symptoms of Rett syndrome. This can help identify the optimal treatment strategy from a transdiagnostic perspective instead of a classical diagnostic category.
Collapse
Affiliation(s)
- Peter Balicza
- Institute of Genomic Medicine and Rare Disorders, Semmelweis University, Budapest, Hungary
- Eotvos Lorand Research Network, Multiomic Neurodegeneration Research Group, Budapest, Hungary
| | - Andras Gezsi
- Department of Measurement and Information Systems, Budapest University of Technology and Economics, Budapest, Hungary
| | - Mariann Fedor
- Institute of Genomic Medicine and Rare Disorders, Semmelweis University, Budapest, Hungary
| | - Judit C. Sagi
- Institute of Genomic Medicine and Rare Disorders, Semmelweis University, Budapest, Hungary
| | - Aniko Gal
- Institute of Genomic Medicine and Rare Disorders, Semmelweis University, Budapest, Hungary
| | - Noemi Agnes Varga
- Institute of Genomic Medicine and Rare Disorders, Semmelweis University, Budapest, Hungary
| | - Maria Judit Molnar
- Institute of Genomic Medicine and Rare Disorders, Semmelweis University, Budapest, Hungary
- Eotvos Lorand Research Network, Multiomic Neurodegeneration Research Group, Budapest, Hungary
| |
Collapse
|
3
|
Liao W, Lee KZ. CDKL5-mediated developmental tuning of neuronal excitability and concomitant regulation of transcriptome. Hum Mol Genet 2023; 32:3276-3298. [PMID: 37688574 DOI: 10.1093/hmg/ddad149] [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: 04/03/2023] [Revised: 08/31/2023] [Accepted: 09/06/2023] [Indexed: 09/11/2023] Open
Abstract
Cyclin-dependent kinase-like 5 (CDKL5) is a serine-threonine kinase enriched in the forebrain to regulate neuronal development and function. Patients with CDKL5 deficiency disorder (CDD), a severe neurodevelopmental condition caused by mutations of CDKL5 gene, present early-onset epilepsy as the most prominent feature. However, spontaneous seizures have not been reported in mouse models of CDD, raising vital questions on the human-mouse differences and the roles of CDKL5 in early postnatal brains. Here, we firstly measured electroencephalographic (EEG) activities via a wireless telemetry system coupled with video-recording in neonatal mice. We found that mice lacking CDKL5 exhibited spontaneous epileptic EEG discharges, accompanied with increased burst activities and ictal behaviors, specifically at postnatal day 12 (P12). Intriguingly, those epileptic spikes disappeared after P14. We next performed an unbiased transcriptome profiling in the dorsal hippocampus and motor cortex of Cdkl5 null mice at different developmental timepoints, uncovering a set of age-dependent and brain region-specific alterations of gene expression in parallel with the transient display of epileptic activities. Finally, we validated multiple differentially expressed genes, such as glycine receptor alpha 2 and cholecystokinin, at the transcript or protein levels, supporting the relevance of these genes to CDKL5-regulated excitability. Our findings reveal early-onset neuronal hyperexcitability in mouse model of CDD, providing new insights into CDD etiology and potential molecular targets to ameliorate intractable neonatal epilepsy.
Collapse
Affiliation(s)
- Wenlin Liao
- Institute of Neuroscience, National Cheng-Chi University, Taipei 116, Taiwan
- Research Center for Mind, Brain and Learning, National Cheng-Chi University, Taipei 116, Taiwan
| | - Kun-Ze Lee
- Department of Biological Sciences, National Sun Yat-Sen University, No. 70, Lienhai Road, Kaohsiung 80424, Taiwan
- Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, 100, Shih-Chuan 1st Road, Kaohsiung 80708, Taiwan
| |
Collapse
|
4
|
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
|
5
|
DiCarlo GE, Wallace MT. Modeling dopamine dysfunction in autism spectrum disorder: From invertebrates to vertebrates. Neurosci Biobehav Rev 2022; 133:104494. [PMID: 34906613 PMCID: PMC8792250 DOI: 10.1016/j.neubiorev.2021.12.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 11/29/2021] [Accepted: 12/09/2021] [Indexed: 02/03/2023]
Abstract
Autism Spectrum Disorder (ASD) is a highly heterogeneous neurodevelopmental disorder characterized by deficits in social communication and by patterns of restricted interests and/or repetitive behaviors. The Simons Foundation Autism Research Initiative's Human Gene and CNV Modules now list over 1000 genes implicated in ASD and over 2000 copy number variant loci reported in individuals with ASD. Given this ever-growing list of genetic changes associated with ASD, it has become evident that there is likely not a single genetic cause of this disorder nor a single neurobiological basis of this disorder. Instead, it is likely that many different neurobiological perturbations (which may represent subtypes of ASD) can result in the set of behavioral symptoms that we called ASD. One such of possible subtype of ASD may be associated with dopamine dysfunction. Precise regulation of synaptic dopamine (DA) is required for reward processing and behavioral learning, behaviors which are disrupted in ASD. Here we review evidence for DA dysfunction in ASD and in animal models of ASD. Further, we propose that these studies provide a scaffold for scientists and clinicians to consider subcategorizing the ASD diagnosis based on the genetic changes, neurobiological difference, and behavioral features identified in individuals with ASD.
Collapse
Affiliation(s)
- Gabriella E DiCarlo
- Massachusetts General Hospital, Department of Medicine, Boston, MA, United States
| | - Mark T Wallace
- Vanderbilt University Brain Institute, Nashville, TN, United States; Department of Psychology, Vanderbilt University, Nashville, TN, United States; Department of Hearing & Speech Sciences, Vanderbilt University Medical Center, Nashville, TN, United States; Department of Pharmacology, Vanderbilt University, Nashville, TN, United States; Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN, United States.
| |
Collapse
|
6
|
Reversal of prenatal heroin-induced alterations in hippocampal gene expression via transplantation of mesenchymal stem cells during adulthood. Neurotoxicol Teratol 2022; 90:107063. [PMID: 34999215 DOI: 10.1016/j.ntt.2022.107063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 01/03/2022] [Accepted: 01/03/2022] [Indexed: 11/22/2022]
Abstract
Neurobehavioral teratology is the study of typically subtle neurobehavioral birth defects. Our previously described mouse model demonstrated septohippocampal cholinergic innervation-related molecular and behavioral deficits after prenatal exposure to heroin. Since the alterations are below malformation level, they are likely to represent consequences of regulatory processes, feasibly gene expression. Consequently, in the present study pregnant mice were injected with heroin on gestation days 9-18 and were transplanted with mesenchymal stem cells (MSC) on postnatal day (PD) 105. The hippocampi of the offspring were analyzed on PD120 for the expression of the pertinent genes. Heroin induced global gender-dependent statistically significant changes in the expression of several genes. Significant Treatment X Sex interaction occurred in D1 and SOX2 genes (p < 0.01). Transplantation of MSC reversed the prenatal heroin-induced alterations in approximately 80% of the genes. The reversal index (RI), shifting the score of the heroin-exposed offspring by transplantation back toward the control level, was 0.61 ± 0.10 for the difference from RI = 0 (p < 0.001), confirming the validity of the effect of the neuroteratogens across variations among different genes. The present study suggests that neurobehavioral defects induced by prenatal heroin exposure are likely to be a consequence of regulatory changes. This study on prenatal exposure to insults with subsequent MSC therapy provides a model for elucidating the mechanisms of both the neuroteratogenicity and the therapy, steps that are critical for progress toward therapeutic applications.
Collapse
|
7
|
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
|
8
|
Jhang CL, Lee HY, Chen JC, Liao W. Dopaminergic loss of cyclin-dependent kinase-like 5 recapitulates methylphenidate-remediable hyperlocomotion in mouse model of CDKL5 deficiency disorder. Hum Mol Genet 2021; 29:2408-2419. [PMID: 32588892 DOI: 10.1093/hmg/ddaa122] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 05/24/2020] [Accepted: 06/11/2020] [Indexed: 12/20/2022] Open
Abstract
Cyclin-dependent kinase-like 5 (CDKL5), a serine-threonine kinase encoded by an X-linked gene, is highly expressed in the mammalian forebrain. Mutations in this gene cause CDKL5 deficiency disorder, a neurodevelopmental encephalopathy characterized by early-onset seizures, motor dysfunction, and intellectual disability. We previously found that mice lacking CDKL5 exhibit hyperlocomotion and increased impulsivity, resembling the core symptoms in attention-deficit hyperactivity disorder (ADHD). Here, we report the potential neural mechanisms and treatment for hyperlocomotion induced by CDKL5 deficiency. Our results showed that loss of CDKL5 decreases the proportion of phosphorylated dopamine transporter (DAT) in the rostral striatum, leading to increased levels of extracellular dopamine and hyperlocomotion. Administration of methylphenidate (MPH), a DAT inhibitor clinically effective to improve symptoms in ADHD, significantly alleviated the hyperlocomotion phenotype in Cdkl5 null mice. In addition, the improved behavioral effects of MPH were accompanied by a region-specific restoration of phosphorylated dopamine- and cAMP-regulated phosphoprotein Mr 32 kDa, a key signaling protein for striatal motor output. Finally, mice carrying a Cdkl5 deletion selectively in DAT-expressing dopaminergic neurons, but not dopamine receptive neurons, recapitulated the hyperlocomotion phenotype found in Cdkl5 null mice. Our findings suggest that CDKL5 is essential to control locomotor behavior by regulating region-specific dopamine content and phosphorylation of dopamine signaling proteins in the striatum. The direct, as well as indirect, target proteins regulated by CDKL5 may play a key role in movement control and the therapeutic development for hyperactivity disorders.
Collapse
Affiliation(s)
- Cian-Ling Jhang
- Institute of Neuroscience, National Cheng-Chi University, Taipei 116, Taiwan
| | - Hom-Yi Lee
- Department of Psychology, Chung Shan Medical University, Taichung 402, Taiwan.,Department of Speech Language Pathology and Audiology, Chung Shan Medical University, Taichung 402, Taiwan
| | - Jin-Chung Chen
- Graduate Institute of Biomedical Sciences, Chang Gung University, Taoyuan 333, Taiwan
| | - Wenlin Liao
- Institute of Neuroscience, National Cheng-Chi University, Taipei 116, Taiwan.,Research Center for Mind, Brain and Learning, National Cheng-Chi University, Taipei 116, Taiwan
| |
Collapse
|
9
|
Kosillo P, Bateup HS. Dopaminergic Dysregulation in Syndromic Autism Spectrum Disorders: Insights From Genetic Mouse Models. Front Neural Circuits 2021; 15:700968. [PMID: 34366796 PMCID: PMC8343025 DOI: 10.3389/fncir.2021.700968] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 06/21/2021] [Indexed: 12/12/2022] Open
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder defined by altered social interaction and communication, and repetitive, restricted, inflexible behaviors. Approximately 1.5-2% of the general population meet the diagnostic criteria for ASD and several brain regions including the cortex, amygdala, cerebellum and basal ganglia have been implicated in ASD pathophysiology. The midbrain dopamine system is an important modulator of cellular and synaptic function in multiple ASD-implicated brain regions via anatomically and functionally distinct dopaminergic projections. The dopamine hypothesis of ASD postulates that dysregulation of dopaminergic projection pathways could contribute to the behavioral manifestations of ASD, including altered reward value of social stimuli, changes in sensorimotor processing, and motor stereotypies. In this review, we examine the support for the idea that cell-autonomous changes in dopaminergic function are a core component of ASD pathophysiology. We discuss the human literature supporting the involvement of altered dopamine signaling in ASD including genetic, brain imaging and pharmacologic studies. We then focus on genetic mouse models of syndromic neurodevelopmental disorders in which single gene mutations lead to increased risk for ASD. We highlight studies that have directly examined dopamine neuron number, morphology, physiology, or output in these models. Overall, we find considerable support for the idea that the dopamine system may be dysregulated in syndromic ASDs; however, there does not appear to be a consistent signature and some models show increased dopaminergic function, while others have deficient dopamine signaling. We conclude that dopamine dysregulation is common in syndromic forms of ASD but that the specific changes may be unique to each genetic disorder and may not account for the full spectrum of ASD-related manifestations.
Collapse
Affiliation(s)
- Polina Kosillo
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, United States
| | - Helen S. Bateup
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, United States
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, United States
- Chan Zuckerberg Biohub, San Francisco, CA, United States
| |
Collapse
|
10
|
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] [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
|
11
|
Collins BE, Merritt JK, Erickson KR, Neul JL. Safety and efficacy of genetic MECP2 supplementation in the R294X mouse model of Rett syndrome. GENES, BRAIN, AND BEHAVIOR 2021; 21:e12739. [PMID: 33942492 PMCID: PMC8563491 DOI: 10.1111/gbb.12739] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 04/29/2021] [Accepted: 05/01/2021] [Indexed: 01/03/2023]
Abstract
Rett syndrome is a neurodevelopmental disorder caused predominantly by loss-of-function mutations in MECP2, encoding transcriptional modulator methyl-CpG-binding protein 2 (MeCP2). Although no disease-modifying therapies exist at this time, some proposed therapeutic strategies aim to supplement the mutant allele with a wild-type allele producing typical levels of functional MeCP2, such as gene therapy. Because MECP2 is a dosage-sensitive gene, with both loss and gain of function causing disease, these approaches must achieve a narrow therapeutic window to be both safe and effective. While MeCP2 supplementation rescues RTT-like phenotypes in mouse models, the tolerable threshold of MeCP2 is not clear, particularly for partial loss-of-function mutations. We assessed the safety of genetically supplementing full-length human MeCP2 in the context of the R294X allele, a common partial loss-of-function mutation retaining DNA-binding capacity. We assessed the potential for adverse effects from MeCP2 supplementation of a partial loss-of-function mutant and the potential for dominant negative interactions between mutant and full-length MeCP2. In male hemizygous R294X mice, MeCP2 supplementation rescued RTT-like behavioral phenotypes and did not elicit behavioral evidence of excess MeCP2. In female heterozygous R294X mice, RTT-specific phenotypes were similarly rescued. However, MeCP2 supplementation led to evidence of excess MeCP2 activity in a motor coordination assay, suggesting that the underlying motor circuitry is particularly sensitive to MeCP2 dosage in females. These results show that genetic supplementation of full-length MeCP2 is safe in males and largely so females. However, careful consideration of risk for adverse motor effects may be warranted for girls and women with RTT.
Collapse
Affiliation(s)
| | - Jonathan K. Merritt
- Department of PediatricsVanderbilt University Medical CenterNashvilleTennesseeUSA
| | - Kirsty R. Erickson
- Department of PediatricsVanderbilt University Medical CenterNashvilleTennesseeUSA
| | - Jeffrey L. Neul
- Vanderbilt Kennedy Center, Departments of Pediatrics, Pharmacology, and Special EducationVanderbilt University Medical Center and Vanderbilt UniversityNashvilleTennesseeUSA
| |
Collapse
|
12
|
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
|
13
|
Correlation of dystonia severity and iron accumulation in Rett syndrome. Sci Rep 2021; 11:838. [PMID: 33436916 PMCID: PMC7804965 DOI: 10.1038/s41598-020-80723-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 12/21/2020] [Indexed: 01/29/2023] Open
Abstract
Individuals with Rett syndrome (RTT) commonly demonstrate Parkinsonian features and dystonia at teen age; however, the pathological reason remains unclear. Abnormal iron accumulation in deep gray matter were reported in some Parkinsonian-related disorders. In this study, we investigated the iron accumulation in deep gray matter of RTT and its correlation with dystonia severity. We recruited 18 RTT-diagnosed participants with MECP2 mutations, from age 4 to 28, and 28 age-gender matched controls and investigated the iron accumulation by susceptibility weighted image (SWI) in substantia nigra (SN), globus pallidus (GP), putamen, caudate nucleus, and thalamus. Pearson's correlation was applied for the relation between iron accumulation and dystonia severity. In RTT, the severity of dystonia scales showed significant increase in subjects older than 10 years, and the contrast ratios of SWI also showed significant differences in putamen, caudate nucleus and the average values of SN, putamen, and GP between RTT and controls. The age demonstrated moderate to high negative correlations with contrast ratios. The dystonia scales were correlated with the average contrast ratio of SN, putamen and GP, indicating iron accumulation in dopaminergic system and related grey matter. As the first SWI study for RTT individuals, we found increased iron deposition in dopaminergic system and related grey matter, which may partly explain the gradually increased dystonia.
Collapse
|
14
|
Beyer DKE, Horn L, Klinker N, Freund N. Risky decision-making following prefrontal D1 receptor manipulation. Transl Neurosci 2021; 12:432-443. [PMID: 34760299 PMCID: PMC8569284 DOI: 10.1515/tnsci-2020-0187] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 09/13/2021] [Accepted: 09/13/2021] [Indexed: 12/15/2022] Open
Abstract
The prefrontal dopamine D1 receptor (D1R) is involved in cognitive processes. Viral overexpression of this receptor in rats further increases the reward-related behaviors and even its termination induces anhedonia and helplessness. In this study, we investigated the risky decision-making during D1R overexpression and its termination. Rats conducted the rodent version of the Iowa gambling task daily. In addition, the methyl CpG–binding protein-2 (MeCP2), one regulator connecting the dopaminergic system, cognitive processes, and mood-related behavior, was investigated after completion of the behavioral tasks. D1R overexpressing subjects exhibited maladaptive risky decision-making and risky decisions returned to control levels following termination of D1R overexpression; however, after termination, animals earned less reward compared to control subjects. In this phase, MeCP2-positive cells were elevated in the right amygdala. Our results extend the previously reported behavioral changes in the D1R-manipulated animal model to increased risk-taking and revealed differential MeCP2 expression adding further evidence for a bipolar disorder-like phenotype of this model.
Collapse
Affiliation(s)
- Dominik K. E. Beyer
- Division of Experimental and Molecular Psychiatry, Department of Psychiatry, Psychotherapy and Preventive Medicine, LWL University Hospital, Ruhr-University, 44801 Bochum, Germany
| | - Lisa Horn
- Division of Experimental and Molecular Psychiatry, Department of Psychiatry, Psychotherapy and Preventive Medicine, LWL University Hospital, Ruhr-University, 44801 Bochum, Germany
| | - Nadine Klinker
- Division of Experimental and Molecular Psychiatry, Department of Psychiatry, Psychotherapy and Preventive Medicine, LWL University Hospital, Ruhr-University, 44801 Bochum, Germany
| | - Nadja Freund
- Division of Experimental and Molecular Psychiatry, Department of Psychiatry, Psychotherapy and Preventive Medicine, LWL University Hospital, Ruhr-University, 44801 Bochum, Germany
| |
Collapse
|
15
|
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
|
16
|
Li W, Pozzo-Miller L. Dysfunction of the corticostriatal pathway in autism spectrum disorders. J Neurosci Res 2019; 98:2130-2147. [PMID: 31758607 DOI: 10.1002/jnr.24560] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 11/04/2019] [Accepted: 11/05/2019] [Indexed: 12/14/2022]
Abstract
The corticostriatal pathway that carries sensory, motor, and limbic information to the striatum plays a critical role in motor control, action selection, and reward. Dysfunction of this pathway is associated with many neurological and psychiatric disorders. Corticostriatal synapses have unique features in their cortical origins and striatal targets. In this review, we first describe axonal growth and synaptogenesis in the corticostriatal pathway during development, and then summarize the current understanding of the molecular bases of synaptic transmission and plasticity at mature corticostriatal synapses. Genes associated with autism spectrum disorder (ASD) have been implicated in axonal growth abnormalities, imbalance of the synaptic excitation/inhibition ratio, and altered long-term synaptic plasticity in the corticostriatal pathway. Here, we review a number of ASD-associated high-confidence genes, including FMR1, KMT2A, GRIN2B, SCN2A, NLGN1, NLGN3, MET, CNTNAP2, FOXP2, TSHZ3, SHANK3, PTEN, CHD8, MECP2, DYRK1A, RELN, FOXP1, SYNGAP1, and NRXN, and discuss their relevance to proper corticostriatal function.
Collapse
Affiliation(s)
- Wei Li
- Department of Neurobiology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Lucas Pozzo-Miller
- Department of Neurobiology, The University of Alabama at Birmingham, Birmingham, AL, USA
| |
Collapse
|
17
|
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
|
18
|
Yang H, Li K, Han S, Zhou A, Zhou ZJ. Leveraging the genetic basis of Rett syndrome to ascertain pathophysiology. Neurobiol Learn Mem 2019; 165:106961. [PMID: 30447288 PMCID: PMC6635128 DOI: 10.1016/j.nlm.2018.11.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 09/18/2018] [Accepted: 11/14/2018] [Indexed: 10/27/2022]
Abstract
Mutations in the methyl-CpG binding protein 2 (MECP2) gene cause Rett syndrome (RTT), a progressive X-linked neurological disorder characterized by loss of developmental milestones, intellectual disability and breathing abnormality. Despite being a monogenic disorder, the pathogenic mechanisms by which mutations in MeCP2 impair neuronal function and underlie the RTT symptoms have been challenging to elucidate. The seemingly simple genetic root and the availability of genetic data from RTT patients have led to the generation and characterization of a series of mouse models recapitulating RTT-associated genetic mutations. This review focuses on the studies of RTT mouse models and describe newly obtained pathogenic insights from these studies. We also highlight the potential of studying pathophysiology using genetics-based modeling approaches in rodents and suggest a future direction to tackle the pathophysiology of intellectual disability with known or complex genetic causes.
Collapse
Affiliation(s)
- Hua Yang
- Qingdao Jiaozhou Central Hospital, Jiaozhou City, Shandong Province 266300, China
| | - Kequan Li
- Qingdao Jiaozhou Central Hospital, Jiaozhou City, Shandong Province 266300, China
| | - Song Han
- Jiaozhou People's Hospital, Jiaozhou City, Shandong Province 266300, China
| | - Ailing Zhou
- Jiaozhou People's Hospital, Jiaozhou City, Shandong Province 266300, China
| | - Zhaolan Joe Zhou
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.
| |
Collapse
|
19
|
Smith ES, Smith DR, Eyring C, Braileanu M, Smith-Connor KS, Ei Tan Y, Fowler AY, Hoffman GE, Johnston MV, Kannan S, Blue ME. Altered trajectories of neurodevelopment and behavior in mouse models of Rett syndrome. Neurobiol Learn Mem 2019; 165:106962. [PMID: 30502397 PMCID: PMC8040058 DOI: 10.1016/j.nlm.2018.11.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 10/17/2018] [Accepted: 11/16/2018] [Indexed: 12/12/2022]
Abstract
Rett Syndrome (RTT) is a genetic disorder that is caused by mutations in the x-linked gene coding for methyl-CpG-biding-protein 2 (MECP2) and that mainly affects females. Male and female transgenic mouse models of RTT have been studied extensively, and we have learned a great deal regarding RTT neuropathology and how MeCP2 deficiency may be influencing brain function and maturation. In this manuscript we review what is known concerning structural and coinciding functional and behavioral deficits in RTT and in mouse models of MeCP2 deficiency. We also introduce our own corroborating data regarding behavioral phenotype and morphological alterations in volume of the cortex and striatum and the density of neurons, aberrations in experience-dependent plasticity within the barrel cortex and the impact of MeCP2 loss on glial structure. We conclude that regional structural changes in genetic models of RTT show great similarity to the alterations in brain structure of patients with RTT. These region-specific modifications often coincide with phenotype onset and contribute to larger issues of circuit connectivity, progression, and severity. Although the alterations seen in mouse models of RTT appear to be primarily due to cell-autonomous effects, there are also non-cell autonomous mechanisms including those caused by MeCP2-deficient glia that negatively impact healthy neuronal function. Collectively, this body of work has provided a solid foundation on which to continue to build our understanding of the role of MeCP2 on neuronal and glial structure and function, its greater impact on neural development, and potential new therapeutic avenues.
Collapse
Affiliation(s)
- Elizabeth S Smith
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Dani R Smith
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Charlotte Eyring
- The Hugo W. Moser Research Institute at Kennedy Krieger, Inc., Baltimore, MD 21205, USA
| | - Maria Braileanu
- Undergraduate Program in Neuroscience, The Krieger School of Arts and Sciences, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Karen S Smith-Connor
- The Hugo W. Moser Research Institute at Kennedy Krieger, Inc., Baltimore, MD 21205, USA
| | - Yew Ei Tan
- Perdana University Graduate School of Medicine, Kuala Lumpur, Malaysia
| | - Amanda Y Fowler
- Department of Biology, Morgan State University, Baltimore, MD 21251, USA
| | - Gloria E Hoffman
- Department of Biology, Morgan State University, Baltimore, MD 21251, USA
| | - Michael V Johnston
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; The Hugo W. Moser Research Institute at Kennedy Krieger, Inc., Baltimore, MD 21205, USA
| | - Sujatha Kannan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; The Hugo W. Moser Research Institute at Kennedy Krieger, Inc., Baltimore, MD 21205, USA
| | - Mary E Blue
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; The Hugo W. Moser Research Institute at Kennedy Krieger, Inc., Baltimore, MD 21205, USA.
| |
Collapse
|
20
|
Liao W. Psychomotor Dysfunction in Rett Syndrome: Insights into the Neurochemical and Circuit Roots. Dev Neurobiol 2018; 79:51-59. [PMID: 30430747 DOI: 10.1002/dneu.22651] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 09/29/2018] [Accepted: 10/25/2018] [Indexed: 12/19/2022]
Abstract
Rett syndrome (RTT) is a monogenic neurodevelopmental disorder caused by mutations in the methyl-CpG binding protein 2 (MECP2) gene. Patients with RTT develop symptoms after 6-18 months of age, exhibiting characteristic movement deficits, such as ambulatory difficulties and loss of hand skills, in addition to breathing abnormalities and intellectual disability. Given the striking psychomotor dysfunction, numerous studies have investigated the underlying neurochemical and circuit mechanisms from different aspects. Here, I review the evidence linking MeCP2 deficiency to alterations in neurotransmission and neural circuits that govern the psychomotor function and discuss a recently identified pathological origin underlying the psychomotor deficits in RTT.
Collapse
Affiliation(s)
- Wenlin Liao
- Institute of Neuroscience, National Cheng-Chi University, Taipei 11605, Taiwan.,Research Center for Mind, Brain and Learning, National Cheng-Chi University, Taipei 11605, Taiwan
| |
Collapse
|
21
|
Mätlik K, Võikar V, Vilenius C, Kulesskaya N, Andressoo JO. Two-fold elevation of endogenous GDNF levels in mice improves motor coordination without causing side-effects. Sci Rep 2018; 8:11861. [PMID: 30089897 PMCID: PMC6082872 DOI: 10.1038/s41598-018-29988-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 07/20/2018] [Indexed: 01/11/2023] Open
Abstract
Glial cell line-derived neurotrophic factor (GDNF) promotes the survival of dopaminergic neurons in vitro and in vivo. For this reason, GDNF is currently in clinical trials for the treatment of Parkinson’s disease (PD). However, how endogenous GDNF influences dopamine system function and animal behavior is not fully understood. We recently generated GDNF hypermorphic mice that express increased levels of endogenous GDNF from the native locus, resulting in augmented function of the nigrostriatal dopamine system. Specifically, Gdnf wt/hyper mice have a mild increase in striatal and midbrain dopamine levels, increased dopamine transporter activity, and 15% increased numbers of midbrain dopamine neurons and striatal dopaminergic varicosities. Since changes in the dopamine system are implicated in several neuropsychiatric diseases, including schizophrenia, attention deficit hyperactivity disorder (ADHD) and depression, and ectopic GDNF delivery associates with side-effects in PD models and clinical trials, we further investigated Gdnf wt/hyper mice using 20 behavioral tests. Despite increased dopamine levels, dopamine release and dopamine transporter activity, there were no differences in psychiatric disease related phenotypes. However, compared to controls, male Gdnf wt/hyper mice performed better in tests measuring motor function. Therefore, a modest elevation of endogenous GDNF levels improves motor function but does not induce adverse behavioral outcomes.
Collapse
Affiliation(s)
- Kärt Mätlik
- Department of Pharmacology, Faculty of Medicine & Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Vootele Võikar
- Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Carolina Vilenius
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Natalia Kulesskaya
- Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Jaan-Olle Andressoo
- Department of Pharmacology, Faculty of Medicine & Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland. .,Division of Neurogeriatrics, Department of Neurobiology, Care Sciences and Society (NVS), Karolinska Institutet, Stockholm, Sweden.
| |
Collapse
|
22
|
Jhang CL, Huang TN, Hsueh YP, Liao W. Mice lacking cyclin-dependent kinase-like 5 manifest autistic and ADHD-like behaviors. Hum Mol Genet 2018; 26:3922-3934. [PMID: 29016850 DOI: 10.1093/hmg/ddx279] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2017] [Accepted: 07/10/2017] [Indexed: 01/02/2023] Open
Abstract
Neurodevelopmental disorders frequently share common clinical features and appear high rate of comorbidity, such as those present in patients with attention-deficit hyperactivity disorder (ADHD) and autism spectrum disorders (ASD). While characterizing behavioral phenotypes in the mouse model of cyclin-dependent kinase-like 5 (CDKL5) disorder, a neurodevelopmental disorder caused by mutations in the X-linked gene encoding CDKL5, we found that these mice manifested behavioral phenotypes mimicking multiple key features of ASD, such as impaired social interaction and communication, as well as increased stereotypic digging behaviors. These mice also displayed hyper-locomotion, increased aggressiveness and impulsivity, plus deficits in motor and associative learning, resembling primary symptoms of ADHD. Through brain region-specific biochemical analysis, we uncovered that loss of CDKL5 disrupts dopamine synthesis and the expression of social communication-related key genes, such as forkhead-box P2 and mu-opioid receptor, in the corticostriatal circuit. Together, our findings support that CDKL5 plays a role in the comorbid features of autism and ADHD, and mice lacking CDKL5 may serve as an animal model to study the molecular and circuit mechanisms underlying autism-ADHD comorbidity.
Collapse
Affiliation(s)
- Cian-Ling Jhang
- Institute of Neuroscience, National Cheng-Chi University, Taipei 116, Taiwan
| | - Tzyy-Nan Huang
- Institute of Molecular Biology, Academia Sinica, Taipei 115, Taiwan
| | - Yi-Ping Hsueh
- Institute of Molecular Biology, Academia Sinica, Taipei 115, Taiwan
| | - Wenlin Liao
- Institute of Neuroscience, National Cheng-Chi University, Taipei 116, Taiwan.,Research Center for Mind, Brain and Learning, National Cheng-Chi University, Taipei 116, Taiwan
| |
Collapse
|
23
|
Robinson JE, Gradinaru V. Dopaminergic dysfunction in neurodevelopmental disorders: recent advances and synergistic technologies to aid basic research. Curr Opin Neurobiol 2018; 48:17-29. [PMID: 28850815 PMCID: PMC5825239 DOI: 10.1016/j.conb.2017.08.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2017] [Accepted: 08/03/2017] [Indexed: 12/19/2022]
Abstract
Neurodevelopmental disorders (NDDs) represent a diverse group of syndromes characterized by abnormal development of the central nervous system and whose symptomatology includes cognitive, emotional, sensory, and motor impairments. The identification of causative genetic defects has allowed for creation of transgenic NDD mouse models that have revealed pathophysiological mechanisms of disease phenotypes in a neural circuit- and cell type-specific manner. Mouse models of several syndromes, including Rett syndrome, Fragile X syndrome, Angelman syndrome, Neurofibromatosis type 1, etc., exhibit abnormalities in the structure and function of dopaminergic circuitry, which regulates motivation, motor behavior, sociability, attention, and executive function. Recent advances in technologies for functional circuit mapping, including tissue clearing, viral vector-based tracing methods, and optical readouts of neural activity, have refined our knowledge of dopaminergic circuits in unperturbed states, yet these tools have not been widely applied to NDD research. Here, we will review recent findings exploring dopaminergic function in NDD models and discuss the promise of new tools to probe NDD pathophysiology in these circuits.
Collapse
Affiliation(s)
- J Elliott Robinson
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Viviana Gradinaru
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA.
| |
Collapse
|
24
|
Yuan XS, Wang L, Dong H, Qu WM, Yang SR, Cherasse Y, Lazarus M, Schiffmann SN, d'Exaerde ADK, Li RX, Huang ZL. Striatal adenosine A 2A receptor neurons control active-period sleep via parvalbumin neurons in external globus pallidus. eLife 2017; 6:29055. [PMID: 29022877 PMCID: PMC5655138 DOI: 10.7554/elife.29055] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Accepted: 10/11/2017] [Indexed: 12/20/2022] Open
Abstract
Dysfunction of the striatum is frequently associated with sleep disturbances. However, its role in sleep-wake regulation has been paid little attention even though the striatum densely expresses adenosine A2A receptors (A2ARs), which are essential for adenosine-induced sleep. Here we showed that chemogenetic activation of A2AR neurons in specific subregions of the striatum induced a remarkable increase in non-rapid eye movement (NREM) sleep. Anatomical mapping and immunoelectron microscopy revealed that striatal A2AR neurons innervated the external globus pallidus (GPe) in a topographically organized manner and preferentially formed inhibitory synapses with GPe parvalbumin (PV) neurons. Moreover, lesions of GPe PV neurons abolished the sleep-promoting effect of striatal A2AR neurons. In addition, chemogenetic inhibition of striatal A2AR neurons led to a significant decrease of NREM sleep at active period, but not inactive period of mice. These findings reveal a prominent contribution of striatal A2AR neuron/GPe PV neuron circuit in sleep control.
Collapse
Affiliation(s)
- Xiang-Shan Yuan
- Department of Pharmacology, School of Basic Medical Science, Fudan University, Shanghai, China.,State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China.,Department of Anatomy, Histology and Embryology, School of Basic Medical Science, Fudan University, Shanghai, China
| | - Lu Wang
- Department of Pharmacology, School of Basic Medical Science, Fudan University, Shanghai, China.,State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China
| | - Hui Dong
- Department of Pharmacology, School of Basic Medical Science, Fudan University, Shanghai, China.,State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China
| | - Wei-Min Qu
- Department of Pharmacology, School of Basic Medical Science, Fudan University, Shanghai, China.,State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China
| | - Su-Rong Yang
- Department of Pharmacology, School of Basic Medical Science, Fudan University, Shanghai, China.,State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China
| | - Yoan Cherasse
- International Institute for Integrative Sleep Medicine, University of Tsukuba, Tsukuba, Japan
| | - Michael Lazarus
- International Institute for Integrative Sleep Medicine, University of Tsukuba, Tsukuba, Japan
| | - Serge N Schiffmann
- Laboratory of Neurophysiology, ULB Neuroscience Institute, Université Libre de Bruxelles, Brussels, Belgium
| | | | - Rui-Xi Li
- Department of Anatomy, Histology and Embryology, School of Basic Medical Science, Fudan University, Shanghai, China
| | - Zhi-Li Huang
- Department of Pharmacology, School of Basic Medical Science, Fudan University, Shanghai, China.,State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China
| |
Collapse
|
25
|
Deciphering MECP2-associated disorders: disrupted circuits and the hope for repair. Curr Opin Neurobiol 2017; 48:30-36. [PMID: 28961504 DOI: 10.1016/j.conb.2017.09.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 08/04/2017] [Accepted: 09/11/2017] [Indexed: 12/28/2022]
Abstract
MECP2 is a critical gene for neural development, mutations or duplication of which led to severe neurodevelopmental disorders, such as Rett syndrome (RTT) and autism spectrum disorders (ASD). Extensive works during the past decade yield ample insights into the molecular and cellular functions of MeCP2 in neural development. Furthermore, genetic manipulations in Mecp2 mouse models strongly suggested that deficiency in synaptic plasticity and various behaviors of Mecp2 null or transgenic mice could be rescued in adulthood. Further studies elucidating neural circuits responsible for symptoms in MECP2-associated disorders in rodent and non-human primate models will shed light on the development of potential therapeutic interventions.
Collapse
|
26
|
Allemang-Grand R, Ellegood J, Spencer Noakes L, Ruston J, Justice M, Nieman BJ, Lerch JP. Neuroanatomy in mouse models of Rett syndrome is related to the severity of Mecp2 mutation and behavioral phenotypes. Mol Autism 2017; 8:32. [PMID: 28670438 PMCID: PMC5485541 DOI: 10.1186/s13229-017-0138-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 04/26/2017] [Indexed: 01/25/2023] Open
Abstract
Background Rett syndrome (RTT) is a neurodevelopmental disorder that predominantly affects girls. The majority of RTT cases are caused by de novo mutations in methyl-CpG-binding protein 2 (MECP2), and several mouse models have been created to further understand the disorder. In the current literature, many studies have focused their analyses on the behavioral abnormalities and cellular and molecular impairments that arise from Mecp2 mutations. However, limited efforts have been placed on understanding how Mecp2 mutations disrupt the neuroanatomy and networks of the brain. Methods In this study, we examined the neuroanatomy of male and female mice from the Mecp2tm1Hzo, Mecp2tm1.1Bird/J, and Mecp2tm2Bird/J mouse lines using high-resolution magnetic resonance imaging (MRI) paired with deformation-based morphometry to determine the brain regions susceptible to Mecp2 disruptions. Results We found that many cortical and subcortical regions were reduced in volume within the brains of mutant mice regardless of mutation type, highlighting regions that are susceptible to Mecp2 disruptions. We also found that the volume within these regions correlated with behavioral metrics. Conversely, regions of the cerebellum were differentially affected by the type of mutation, showing an increase in volume in the mutant Mecp2tm1Hzo brain relative to controls and a decrease in the Mecp2tm1.1Bird/J and Mecp2tm2Bird/J lines. Conclusions Our findings demonstrate that the direction and magnitude of the neuroanatomical differences between control and mutant mice carrying Mecp2 mutations are driven by the severity of the mutation and the stage of behavioral impairments.
Collapse
Affiliation(s)
- Rylan Allemang-Grand
- Mouse Imaging Centre, 25 Orde Street, Toronto, M5T 3H7 Ontario Canada.,Neurosciences and Mental Health, Hospital for Sick Children, 555 University Ave, Toronto, M5G 1X8 Ontario Canada.,Department of Medical Biophysics, Faculty of Medicine, University of Toronto, 101 College Street, Suite 15-701, Toronto, M5G 1L7 Ontario Canada
| | - Jacob Ellegood
- Mouse Imaging Centre, 25 Orde Street, Toronto, M5T 3H7 Ontario Canada.,Neurosciences and Mental Health, Hospital for Sick Children, 555 University Ave, Toronto, M5G 1X8 Ontario Canada
| | - Leigh Spencer Noakes
- Mouse Imaging Centre, 25 Orde Street, Toronto, M5T 3H7 Ontario Canada.,Physiology and Experimental Medicine, Hospital for Sick Children, 555 University Ave, Toronto, M5G 1X8 Ontario Canada
| | - Julie Ruston
- Genetics and Genome Biology, Hospital for Sick Children, 555 University Ave, Toronto, M5G 1X8 Ontario Canada
| | - Monica Justice
- Genetics and Genome Biology, Hospital for Sick Children, 555 University Ave, Toronto, M5G 1X8 Ontario Canada
| | - Brian J Nieman
- Mouse Imaging Centre, 25 Orde Street, Toronto, M5T 3H7 Ontario Canada.,Department of Medical Biophysics, Faculty of Medicine, University of Toronto, 101 College Street, Suite 15-701, Toronto, M5G 1L7 Ontario Canada.,Ontario Institute of Cancer Research, 661 University Ave, Toronto, Suite 510, M5G 0A3 Ontario Canada
| | - Jason P Lerch
- Mouse Imaging Centre, 25 Orde Street, Toronto, M5T 3H7 Ontario Canada.,Neurosciences and Mental Health, Hospital for Sick Children, 555 University Ave, Toronto, M5G 1X8 Ontario Canada.,Department of Medical Biophysics, Faculty of Medicine, University of Toronto, 101 College Street, Suite 15-701, Toronto, M5G 1L7 Ontario Canada
| |
Collapse
|
27
|
Zhou H, Wu W, Zhang Y, He H, Yuan Z, Zhu Z, Zhao Z. Selective preservation of cholinergic MeCP2 rescues specific Rett-syndrome-like phenotypes in MeCP2 stop mice. Behav Brain Res 2017; 322:51-59. [PMID: 28093257 DOI: 10.1016/j.bbr.2017.01.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2016] [Revised: 01/06/2017] [Accepted: 01/10/2017] [Indexed: 01/27/2023]
Abstract
RTT is a neurodevelopmental disorder characterized by growth regression, motor dysfunction, stereotypic hand movements, and autism features. Typical Rett syndrome (RTT) is predominantly caused by mutations in X-linked MeCP2 gene which encodes methyl-CpG-binding protein 2 (MeCP2). The brain-abundant MeCP2 protein mainly functions as a transcriptional regulator for neurodevelopment-associated genes. Specific functions of MeCP2 in certain neuron types remain to be known. Although cholinergic system is an important modulating system in brain, how MeCP2 in cholinergic neurons contribute to RTT has not been clearly understood. Here we use a mouse model with selectively activated endogenous MeCP2 in cholinergic neurons in otherwise MeCP2stop mice to determine the cholinergic MeCP2 effects on rescuing the RTT-like phenotypes. We found cholinergic MeCP2 preservation could reverse some aspects of the RTT-like phenotypes in mice including hypolocomotion and increased anxiety level, and delay the onset of underweight, instead of improving the hypersocial abnormality and the poor general conditions such as short lifespan, low brain weight, and increasing severity score. Our findings suggest that selective activation of cholinergic MeCP2 is sufficient to reverse the locomotor impairment and increased anxiety-like behaviors at least in early symptomatic stage, supporting future development of RTT therapies associated with cholinergic system.
Collapse
Affiliation(s)
- Huanhuan Zhou
- Department of Children Health Care, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China
| | - Wei Wu
- Department of Children Health Care, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China
| | - Ying Zhang
- Institute of Neuroscience, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Haiyang He
- Institute of Neuroscience, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Zhefeng Yuan
- Department of Neurology, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China
| | - Zhiwei Zhu
- Department of Children Health Care, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China
| | - Zhengyan Zhao
- Department of Children Health Care, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China.
| |
Collapse
|
28
|
Nott A, Cheng J, Gao F, Lin YT, Gjoneska E, Ko T, Minhas P, Zamudio AV, Meng J, Zhang F, Jin P, Tsai LH. Histone deacetylase 3 associates with MeCP2 to regulate FOXO and social behavior. Nat Neurosci 2016; 19:1497-1505. [PMID: 27428650 PMCID: PMC5083138 DOI: 10.1038/nn.4347] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 06/23/2016] [Indexed: 12/12/2022]
Abstract
Mutations in MECP2 cause the neurodevelopmental disorder Rett syndrome (RTT). The RTT missense MECP2R306C mutation prevents MeCP2 interaction with NCoR/Histone deacetylase 3 (HDAC3); however, the neuronal function of HDAC3 is incompletely understood. We report that neuronal deletion of Hdac3 in mice elicits abnormal locomotor coordination, sociability, and cognition. Transcriptional and chromatin profiling revealed HDAC3 positively regulates a subset of genes and is recruited to active gene promoters via MeCP2. HDAC3-associated promoters are enriched for the FOXO transcription factors, and FOXO acetylation is elevated in Hdac3 KO and Mecp2 KO neurons. Human RTT patient-derived MECP2R306C neural progenitor cells have deficits in HDAC3 and FOXO recruitment and gene expression. Gene editing of MECP2R306C cells to generate isogenic controls rescued HDAC3-FOXO-mediated impairments in gene expression. Our data suggests that HDAC3 interaction with MeCP2 positively regulates a subset of neuronal genes through FOXO deacetylation, and disruption of HDAC3 contributes to cognitive and social impairment.
Collapse
Affiliation(s)
- Alexi Nott
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Jemmie Cheng
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Fan Gao
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Yuan-Ta Lin
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Elizabeta Gjoneska
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Broad Institute of Harvard University and Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Tak Ko
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Paras Minhas
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Present addresses: Department of Neurology and Neurological Sciences, Stanford University, Stanford, California, USA (P.M.), and Department of Biological Sciences, Xi'an Jiaotong-Liverpool University, Suzhou, Jiangsu, China (J.M.)
| | - Alicia Viridiana Zamudio
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Jia Meng
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Present addresses: Department of Neurology and Neurological Sciences, Stanford University, Stanford, California, USA (P.M.), and Department of Biological Sciences, Xi'an Jiaotong-Liverpool University, Suzhou, Jiangsu, China (J.M.)
| | - Feiran Zhang
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Peng Jin
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Li-Huei Tsai
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Broad Institute of Harvard University and Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| |
Collapse
|
29
|
Patterson KC, Hawkins VE, Arps KM, Mulkey DK, Olsen ML. MeCP2 deficiency results in robust Rett-like behavioural and motor deficits in male and female rats. Hum Mol Genet 2016; 25:3303-3320. [PMID: 27329765 PMCID: PMC5179928 DOI: 10.1093/hmg/ddw179] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 05/18/2016] [Accepted: 06/08/2016] [Indexed: 11/12/2022] Open
Abstract
Since the identification of MECP2 as the causative gene in the majority of Rett Syndrome (RTT) cases, transgenic mouse models have played a critical role in our understanding of this disease. The use of additional mammalian RTT models offers the promise of further elucidating critical early mechanisms of disease as well as providing new avenues for translational studies. We have identified significant abnormalities in growth as well as motor and behavioural function in a novel zinc-finger nuclease model of RTT utilizing both male and female rats throughout development. Male rats lacking MeCP2 (Mecp2ZFN/y) were noticeably symptomatic as early as postnatal day 21, with most dying by postnatal day 55, while females lacking one copy of Mecp2 (Mecp2ZFN/+) displayed a more protracted disease course. Brain weights of Mecp2ZFN/y and Mecp2ZFN/+ rats were significantly reduced by postnatal day 14 and 21, respectively. Early motor and breathing abnormalities were apparent in Mecp2ZFN/y rats, whereas Mecp2ZFN/+ rats displayed functional irregularities later in development. The large size of this species will provide profound advantages in the identification of early disease mechanisms and the development of appropriately timed therapeutics. The current study establishes a foundational basis for the continued utilization of this rat model in future RTT research.
Collapse
Affiliation(s)
- Kelsey C Patterson
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Virginia E Hawkins
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, USA
| | - Kara M Arps
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Daniel K Mulkey
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, USA
| | - Michelle L Olsen
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| |
Collapse
|
30
|
Rothwell PE. Autism Spectrum Disorders and Drug Addiction: Common Pathways, Common Molecules, Distinct Disorders? Front Neurosci 2016; 10:20. [PMID: 26903789 PMCID: PMC4742554 DOI: 10.3389/fnins.2016.00020] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 01/15/2016] [Indexed: 11/17/2022] Open
Abstract
Autism spectrum disorders (ASDs) and drug addiction do not share substantial comorbidity or obvious similarities in etiology or symptomatology. It is thus surprising that a number of recent studies implicate overlapping neural circuits and molecular signaling pathways in both disorders. The purpose of this review is to highlight this emerging intersection and consider implications for understanding the pathophysiology of these seemingly distinct disorders. One area of overlap involves neural circuits and neuromodulatory systems in the striatum and basal ganglia, which play an established role in addiction and reward but are increasingly implicated in clinical and preclinical studies of ASDs. A second area of overlap relates to molecules like Fragile X mental retardation protein (FMRP) and methyl CpG-binding protein-2 (MECP2), which are best known for their contribution to the pathogenesis of syndromic ASDs, but have recently been shown to regulate behavioral and neurobiological responses to addictive drug exposure. These shared pathways and molecules point to common dimensions of behavioral dysfunction, including the repetition of behavioral patterns and aberrant reward processing. The synthesis of knowledge gained through parallel investigations of ASDs and addiction may inspire the design of new therapeutic interventions to correct common elements of striatal dysfunction.
Collapse
Affiliation(s)
- Patrick E Rothwell
- Department of Neuroscience, University of Minnesota Minneapolis, MN, USA
| |
Collapse
|
31
|
Wu J, Zhu D, Zhang J, Li G, Liu Z, Sun J. Melatonin treatment during the incubation of sensitization attenuates methamphetamine-induced locomotor sensitization and MeCP2 expression. Prog Neuropsychopharmacol Biol Psychiatry 2016; 65:145-52. [PMID: 26416230 DOI: 10.1016/j.pnpbp.2015.09.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 09/13/2015] [Accepted: 09/25/2015] [Indexed: 01/11/2023]
Abstract
Behavior sensitization is a long-lasting enhancement of locomotor activity after exposure to psychostimulants. Incubation of sensitization is a phenomenon of remarkable augmentation of locomotor response after withdrawal and reflects certain aspects of compulsive drug craving. However, the mechanisms underlying these phenomena remain elusive. Here we pay special attention to the incubation of sensitization and suppose that the intervention of this procedure will finally decrease the expression of sensitization. Melatonin is an endogenous hormone secreted mainly by the pineal gland. It is effective in treating sleep disorder, which turns out to be one of the major withdrawal symptoms of methamphetamine (MA) addiction. Furthermore, melatonin can also protect neuronal cells against MA-induced neurotoxicity. In the present experiment, we treated mice with low dose (10mg/kg) of melatonin for 14 consecutive days during the incubation of sensitization. We found that melatonin significantly attenuated the expression of sensitization. In contrast, the vehicle treated mice showed prominent enhancement of locomotor activity after incubation. MeCP2 expression was also elevated in the vehicle treated mice and melatonin attenuated its expression. Surprisingly, correlation analysis suggested significant correlation between MeCP2 expression in the nucleus accumbens (NAc) and locomotion in both saline control and vehicle treated mice, but not in melatonin treated ones. MA also induced MeCP2 over-expression in PC12 cells. However, melatonin failed to reduce MeCP2 expression in vitro. Our results suggest that melatonin treatment during the incubation of sensitization attenuates MA-induced expression of sensitization and decreases MeCP2 expression in vivo.
Collapse
Affiliation(s)
- Jintao Wu
- Department of Anatomy, School of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Dexiao Zhu
- Department of Anatomy, School of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Jing Zhang
- Department of Anatomy, School of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Guibao Li
- Department of Anatomy, School of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Zengxun Liu
- Department of Psychiatry, School of Medicine, Shandong University, Jinan, Shandong 250012 China
| | - Jinhao Sun
- Department of Anatomy, School of Medicine, Shandong University, Jinan, Shandong 250012, China.
| |
Collapse
|
32
|
Deficient Purposeful Use of Forepaws in Female Mice Modelling Rett Syndrome. Neural Plast 2015; 2015:326184. [PMID: 26185689 PMCID: PMC4491574 DOI: 10.1155/2015/326184] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 05/21/2015] [Accepted: 05/24/2015] [Indexed: 12/31/2022] Open
Abstract
Rett syndrome (RTT) is a rare neurodevelopmental disorder, characterized by severe behavioural and physiological symptoms. Mutations in the methyl CpG binding protein 2 gene (MECP2) cause more than 95% of classic cases. Motor abnormalities represent a significant part of the spectrum of RTT symptoms. In the present study we investigated motor coordination and fine motor skill domains in MeCP2-308 female mice, a validated RTT model. This was complemented by the in vivo magnetic resonance spectroscopy (MRS) analysis of metabolic profile in behaviourally relevant brain areas. MeCP2-308 heterozygous female mice (Het, 10-12 months of age) were impaired in tasks validated for the assessment of purposeful and coordinated forepaw use (Morag test and Capellini handling task). A fine-grain analysis of spontaneous behaviour in the home-cage also revealed an abnormal handling pattern when interacting with the nesting material, reduced motivation to explore the environment, and increased time devoted to feeding in Het mice. The brain MRS evaluation highlighted decreased levels of bioenergetic metabolites in the striatal area in Het mice compared to controls. Present results confirm behavioural and brain alterations previously reported in MeCP2-308 males and identify novel endpoints on which the efficacy of innovative therapeutic strategies for RTT may be tested.
Collapse
|