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Lebeda D, Fierenz A, Werfel L, Rosin-Arbesfeld R, Hofhuis J, Thoms S. Systematic and quantitative analysis of stop codon readthrough in Rett syndrome nonsense mutations. J Mol Med (Berl) 2024; 102:641-653. [PMID: 38430393 PMCID: PMC11055764 DOI: 10.1007/s00109-024-02436-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 01/16/2024] [Accepted: 02/20/2024] [Indexed: 03/03/2024]
Abstract
Rett syndrome (RTT) is a neurodevelopmental disorder resulting from genetic mutations in the methyl CpG binding protein 2 (MeCP2) gene. Specifically, around 35% of RTT patients harbor premature termination codons (PTCs) within the MeCP2 gene due to nonsense mutations. A promising therapeutic avenue for these individuals involves the use of aminoglycosides, which stimulate translational readthrough (TR) by causing stop codons to be interpreted as sense codons. However, the effectiveness of this treatment depends on several factors, including the type of stop codon and the surrounding nucleotides, collectively referred to as the stop codon context (SCC). Here, we develop a high-content reporter system to precisely measure TR efficiency at different SCCs, assess the recovery of the full-length MeCP2 protein, and evaluate its subcellular localization. We have conducted a comprehensive investigation into the intricate relationship between SCC characteristics and TR induction, examining a total of 14 pathogenic MeCP2 nonsense mutations with the aim to advance the prospects of personalized therapy for individuals with RTT. Our results demonstrate that TR induction can successfully restore full-length MeCP2 protein, albeit to varying degrees, contingent upon the SCC and the specific position of the PTC within the MeCP2 mRNA. TR induction can lead to the re-establishment of nuclear localization of MeCP2, indicating the potential restoration of protein functionality. In summary, our findings underscore the significance of SCC-specific approaches in the development of tailored therapies for RTT. By unraveling the relationship between SCC and TR therapy, we pave the way for personalized, individualized treatment strategies that hold promise for improving the lives of individuals affected by this debilitating neurodevelopmental disorder. KEY MESSAGES: The efficiency of readthrough induction at MeCP2 premature termination codons strongly depends on the stop codon context. The position of the premature termination codon on the transcript influences the readthrough inducibility. A new high-content dual reporter assay facilitates the measurement and prediction of readthrough efficiency of specific nucleotide stop contexts. Readthrough induction results in the recovery of full-length MeCP2 and its re-localization to the nucleus. MeCP2 requires only one of its annotated nuclear localization signals.
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Affiliation(s)
- Dennis Lebeda
- Department for Biochemistry and Molecular Medicine, Medical School EWL, Bielefeld University, Bielefeld, Germany
| | - Adrian Fierenz
- Department of Child and Adolescent Health, University Medical Center Göttingen, Göttingen, Germany
| | - Lina Werfel
- Department of Child and Adolescent Health, University Medical Center Göttingen, Göttingen, Germany
- Present Address: Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany
| | - Rina Rosin-Arbesfeld
- Department of Clinical Microbiology and Immunology, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Julia Hofhuis
- Department for Biochemistry and Molecular Medicine, Medical School EWL, Bielefeld University, Bielefeld, Germany
| | - Sven Thoms
- Department for Biochemistry and Molecular Medicine, Medical School EWL, Bielefeld University, Bielefeld, Germany.
- Department of Child and Adolescent Health, University Medical Center Göttingen, Göttingen, Germany.
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Ou M, Chen Y, Liu J, Zhang D, Yang Y, Shen J, Miao C, Tang SJ, Liu X, Mulkey DK, Zhu T, Zhou C. Spinal astrocytic MeCP2 regulates Kir4.1 for the maintenance of chronic hyperalgesia in neuropathic pain. Prog Neurobiol 2023; 224:102436. [PMID: 36931588 PMCID: PMC10372923 DOI: 10.1016/j.pneurobio.2023.102436] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 03/06/2023] [Accepted: 03/14/2023] [Indexed: 03/17/2023]
Abstract
Astrocyte activation in the spinal dorsal horn may play an important role in the development of chronic neuropathic pain, but the mechanisms involved in astrocyte activation and their modulatory effects remain unknown. The inward rectifying potassium channel protein 4.1 (Kir4.1) is the most important background K+ channel in astrocytes. However, how Kir4.1 is regulated and contributes to behavioral hyperalgesia in chronic pain is unknown. In this study, single-cell RNA sequencing analysis indicated that the expression levels of both Kir4.1 and Methyl-CpG-binding protein 2 (MeCP2) were decreased in spinal astrocytes after chronic constriction injury (CCI) in a mouse model. Conditional knockout of the Kir4.1 channel in spinal astrocytes led to hyperalgesia, and overexpression of the Kir4.1 channel in spinal cord relieved CCI-induced hyperalgesia. Expression of spinal Kir4.1 after CCI was regulated by MeCP2. Electrophysiological recording in spinal slices showed that knockdown of Kir4.1 significantly up-regulated the excitability of astrocytes and then functionally changed the firing patterns of neurons in dorsal spinal cord. Therefore, targeting spinal Kir4.1 may be a therapeutic approach for hyperalgesia in chronic neuropathic pain.
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Affiliation(s)
- Mengchan Ou
- Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Yali Chen
- Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu 610041, China; Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Jin Liu
- Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu 610041, China; Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Donghang Zhang
- Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu 610041, China; Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Yaoxin Yang
- Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu 610041, China; Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Jiefei Shen
- Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases and Department of Prosthodontics, West China Stomatology Hospital of Sichuan University, Chengdu 610041, China
| | - Changhong Miao
- Department of Anesthesiology, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Shao-Jun Tang
- Department of Anesthesiology and The Stony Brook University Pain and Analgesia Research Center (SPARC), Stony Brook University, Stony Brook, NY 11794, USA
| | - Xin Liu
- Department of Anesthesiology and The Stony Brook University Pain and Analgesia Research Center (SPARC), Stony Brook University, Stony Brook, NY 11794, USA
| | - Daniel K Mulkey
- Departments of Physiology and Neurobiology, University of Connecticut, Storrs, CT 06269, USA
| | - Tao Zhu
- Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu 610041, China.
| | - Cheng Zhou
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu 610041, China.
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Sanz-garcía C, Fernández-iglesias A, Gracia-sancho J, Arráez-aybar LA, Nevzorova YA, Cubero FJ. The Space of Disse: The Liver Hub in Health and Disease. Livers 2021; 1:3-26. [DOI: 10.3390/livers1010002] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Since it was first described by the German anatomist and histologist, Joseph Hugo Vincenz Disse, the structure and functions of the space of Disse, a thin perisinusoidal area between the endothelial cells and hepatocytes filled with blood plasma, have acquired great importance in liver disease. The space of Disse is home for the hepatic stellate cells (HSCs), the major fibrogenic players in the liver. Quiescent HSCs (qHSCs) store vitamin A, and upon activation they lose their retinol reservoir and become activated. Activated HSCs (aHSCs) are responsible for secretion of extracellular matrix (ECM) into the space of Disse. This early event in hepatic injury is accompanied by loss of the pores—known as fenestrations—of the endothelial cells, triggering loss of balance between the blood flow and the hepatocyte, and underlies the link between fibrosis and organ dysfunction. If the imbalance persists, the expansion of the fibrotic scar followed by the vascularized septae leads to cirrhosis and/or end-stage hepatocellular carcinoma (HCC). Thus, researchers have been focused on finding therapeutic targets that reduce fibrosis. The space of Disse provides the perfect microenvironment for the stem cells niche in the liver and the interchange of nutrients between cells. In the present review article, we focused on the space of Disse, its components and its leading role in liver disease development.
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Abstract
Methyl-CpG-binding protein 2 (MeCP2) is a well-known transcription repressor, and mutations in MECP2 cause serious neurological disorders. Many studies have suggested that MeCP2 is involved in neural maturation only, and have not reported its role in neural stem cell differentiation. In the present study, we investigated this possible role of MeCP2 in neural stem cells. We used two different differentiation methods to explore how MeCP2 influences neural stem cell differentiation. When we transfected MeCP2-overexpressing lentivirus into neural stem cells, astrocytic differentiation was impaired. This impaired astrocytic differentiation occurred even in conditions of 20% fetal bovine serum, which favored astrocytic differentiation. In addition, miR-132 had the largest expression change after differentiation among several central nervous system related miRNAs. A luciferase assay confirmed that miR-132 directly targeted MeCP2, and that miR-132 was able to reduce MeCP2 expression at both the RNA and protein levels. The upregulation of miR-132 by miRNA mimics promoted astrocytic differentiation, which was fully recovered by MeCP2 overexpression. These results indicate that miR-132 regulates cell lineage differentiation by reducing MeCP2. The study was approved by the Ethics Committee of Shanghai Tenth People's Hospital of TongJi University, China (approval No. SHDSYY-2018-4748) on March 10, 2018.
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Affiliation(s)
- Dong Chen
- Department of Orthopedics, Shanghai Tenth People's Hospital, Tongji University, Shanghai, China
| | - Jie Liu
- Department of Orthopedics, Shanghai Tenth People's Hospital, Tongji University, Shanghai, China
| | - Zhong Wu
- Department of Orthopedics, Shanghai Tenth People's Hospital, Tongji University, Shanghai, China
| | - Shao-Hua Li
- Department of Orthopedics, Shanghai Tenth People's Hospital, Tongji University, Shanghai, China
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Kahanovitch U, Patterson KC, Hernandez R, Olsen ML. Glial Dysfunction in MeCP2 Deficiency Models: Implications for Rett Syndrome. Int J Mol Sci 2019; 20:ijms20153813. [PMID: 31387202 PMCID: PMC6696322 DOI: 10.3390/ijms20153813] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 08/01/2019] [Accepted: 08/02/2019] [Indexed: 02/07/2023] Open
Abstract
Rett syndrome (RTT) is a rare, X-linked neurodevelopmental disorder typically affecting females, resulting in a range of symptoms including autistic features, intellectual impairment, motor deterioration, and autonomic abnormalities. RTT is primarily caused by the genetic mutation of the Mecp2 gene. Initially considered a neuronal disease, recent research shows that glial dysfunction contributes to the RTT disease phenotype. In the following manuscript, we review the evidence regarding glial dysfunction and its effects on disease etiology.
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Affiliation(s)
- Uri Kahanovitch
- School of Neuroscience, Virginia Polytechnic and State University, Life Sciences I Building Room 212, 970 Washington St. SW, Blacksburg, VA 24061, USA
| | - Kelsey C Patterson
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, 1918 University Blvd., Birmingham, AL 35294, USA
| | - Raymundo Hernandez
- School of Neuroscience, Virginia Polytechnic and State University, Life Sciences I Building Room 212, 970 Washington St. SW, Blacksburg, VA 24061, USA
- Graduate Program in Translational Biology Medicine and Health, Virginia Tech, Roanoke, VL 24014, USA
| | - Michelle L Olsen
- School of Neuroscience, Virginia Polytechnic and State University, Life Sciences I Building Room 212, 970 Washington St. SW, Blacksburg, VA 24061, USA.
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Abstract
The mechanisms of neuro-genetic disorders have been mostly investigated in the brain, however, for some pathologies, transcriptomic analysis in multiple tissues represent an opportunity and a challenge to understand the consequences of the genetic mutation. This is the case for Rett Syndrome (RTT): a neurodevelopmental disorder predominantly affecting females that is characterised by a loss of purposeful movements and language accompanied by gait abnormalities and hand stereotypies. Although the genetic aetiology is largely associated to Methyl CpG binding protein 2 (MECP2) mutations, linking the pathophysiology of RTT and its clinical symptoms to direct molecular mechanisms has been difficult.One approach used to study the consequences of MECP2 dysfunction in patients, is to perform transcriptomic analysis in tissues derived from RTT patients or Induced Pluripotent Stem cells. The growing affordability and efficiency of this approach has led to a far greater understanding of the complexities of RTT syndrome but is also raised questions about previously held convictions such as the regulatory role of MECP2, the effects of different molecular mechanisms in different tissues and role of X Chromosome Inactivation in RTT.In this review we consider the results of a number of different transcriptomic analyses in different patients-derived preparations to unveil specific trends in differential gene expression across the studies. Although the analyses present limitations- such as the limited sample size- overlaps exist across these studies, and they report dysregulations in three main categories: dendritic connectivity and synapse maturation, mitochondrial dysfunction, and glial cell activity.These observations have a direct application to the disorder and give insights on the altered mechanisms in RTT, with implications on potential diagnostic criteria and treatments.
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Affiliation(s)
- Stephen Shovlin
- Neuropsychiatric Genetics Research Group, Trinity Translational Medicine Institute- TTMI, St James Hospital, D8, Dublin, Ireland
| | - Daniela Tropea
- Neuropsychiatric Genetics Research Group, Trinity Translational Medicine Institute- TTMI, St James Hospital, D8, Dublin, Ireland
- Trinity College Institute of Neuroscience, TCIN, Loyd Building, Dublin2, Dublin, Ireland
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Kahanovitch U, Cuddapah VA, Pacheco NL, Holt LM, Mulkey DK, Percy AK, Olsen ML. MeCP2 Deficiency Leads to Loss of Glial Kir4.1. eNeuro 2018; 5:ENEURO. [PMID: 29464197 DOI: 10.1523/ENEURO.0194-17.2018] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 02/01/2018] [Accepted: 02/08/2018] [Indexed: 01/05/2023] Open
Abstract
Rett syndrome (RTT) is an X-linked neurodevelopmental disorder usually caused by mutations in methyl-CpG-binding protein 2 (MeCP2). RTT is typified by apparently normal development until 6-18 mo of age, when motor and communicative skills regress and hand stereotypies, autonomic symptoms, and seizures present. Restoration of MeCP2 function selectively to astrocytes reversed several deficits in a murine model of RTT, but the mechanism of this rescue is unknown. Astrocytes carry out many essential functions required for normal brain functioning, including extracellular K+ buffering. Kir4.1, an inwardly rectifying K+ channel, is largely responsible for the channel-mediated K+ regulation by astrocytes. Loss-of-function mutations in Kir4.1 in human patients result in a severe neurodevelopmental disorder termed EAST or SESAME syndrome. Here, we evaluated astrocytic Kir4.1 expression in a murine model of Rett syndrome. We demonstrate by chromatin immunoprecipitation analysis that Kir4.1 is a direct molecular target of MeCP2. Astrocytes from Mecp2-deficient mice express significantly less Kir4.1 mRNA and protein, which translates into a >50% deficiency in Ba2+-sensitive Kir4.1-mediated currents, and impaired extracellular potassium dynamics. By examining astrocytes in isolation, we demonstrate that loss of Kir4.1 is cell autonomous. Assessment through postnatal development revealed that Kir4.1 expression in Mecp2-deficient animals never reaches adult, wild-type levels, consistent with a neurodevelopmental disorder. These are the first data implicating a direct MeCP2 molecular target in astrocytes and provide novel mechanistic insight explaining a potential mechanism by which astrocytic dysfunction may contribute to RTT.
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Jin XR, Chen XS, Xiao L. MeCP2 Deficiency in Neuroglia: New Progress in the Pathogenesis of Rett Syndrome. Front Mol Neurosci 2017; 10:316. [PMID: 29046627 PMCID: PMC5632713 DOI: 10.3389/fnmol.2017.00316] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Accepted: 09/19/2017] [Indexed: 01/24/2023] Open
Abstract
Rett syndrome (RTT) is an X-linked neurodevelopmental disease predominantly caused by mutations of the methyl-CpG-binding protein 2 (MeCP2) gene. Generally, RTT has been attributed to neuron-centric dysfunction. However, increasing evidence has shown that glial abnormalities are also involved in the pathogenesis of RTT. Mice that are MeCP2-null specifically in glial cells showed similar behavioral and/or neuronal abnormalities as those found in MeCP2-null mice, a mouse model of RTT. MeCP2 deficiency in astrocytes impacts the expression of glial intermediate filament proteins such as fibrillary acidic protein (GFAP) and S100 and induces neuron toxicity by disturbing glutamate metabolism or enhancing microtubule instability. MeCP2 deficiency in oligodendrocytes (OLs) results in down-regulation of myelin gene expression and impacts myelination. While MeCP2-deficient microglia cells fail in response to environmental stimuli, release excessive glutamate, and aggravate impairment of the neuronal circuit. In this review, we mainly focus on the progress in determining the role of MeCP2 in glial cells involved in RTT, which may provide further insight into a therapeutic intervention for RTT.
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Affiliation(s)
- Xu-Rui Jin
- Department of Histology and Embryology, Faculty of Basic Medicine, Collaborative Program for Brain Research, Third Military Medical University, Chongqing, China.,The Cadet Brigade of Clinic Medicine, Third Military Medical University, Chongqing, China
| | - Xing-Shu Chen
- Department of Histology and Embryology, Faculty of Basic Medicine, Collaborative Program for Brain Research, Third Military Medical University, Chongqing, China
| | - Lan Xiao
- Department of Histology and Embryology, Faculty of Basic Medicine, Collaborative Program for Brain Research, Third Military Medical University, Chongqing, China
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Baker SA, Lombardi LM, Zoghbi HY. Karyopherin α 3 and karyopherin α 4 proteins mediate the nuclear import of methyl-CpG binding protein 2. J Biol Chem 2015; 290:22485-93. [PMID: 26245896 DOI: 10.1074/jbc.m115.658104] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Indexed: 11/06/2022] Open
Abstract
Methyl-CpG binding protein 2 (MeCP2) is a nuclear protein with important roles in regulating chromatin structure and gene expression, and mutations in MECP2 cause Rett syndrome (RTT). Within the MeCP2 protein sequence, the nuclear localization signal (NLS) is reported to reside between amino acids 255-271, and certain RTT-causing mutations overlap with the MeCP2 NLS, suggesting that they may alter nuclear localization. One such mutation, R270X, is predicted to interfere with the localization of MeCP2, but recent in vivo studies have demonstrated that this mutant remains entirely nuclear. To clarify the mechanism of MeCP2 nuclear import, we isolated proteins that interact with the NLS and identified karyopherin α 3 (KPNA3 or Kap-α3) and karyopherin α 4 (KPNA4 or Kap-α4) as key binding partners of MeCP2. MeCP2-R270X did not interact with KPNA4, consistent with a requirement for an intact NLS in this interaction. However, this mutant retains binding to KPNA3, accounting for the normal localization of MeCP2-R270X to the nucleus. These data provide a mechanism for MeCP2 nuclear import and have implications for the design of therapeutics aimed at modulating the function of MeCP2 in RTT patients.
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Affiliation(s)
- Steven Andrew Baker
- From the Program in Developmental Biology, the Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030 Medical Scientist Training Program
| | - Laura Marie Lombardi
- the Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030 Department of Molecular and Human Genetics and Howard Hughes Medical Institute
| | - Huda Yahya Zoghbi
- From the Program in Developmental Biology, the Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030 Department of Molecular and Human Genetics and Howard Hughes Medical Institute, Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030 and
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Tantra M, Hammer C, Kästner A, Dahm L, Begemann M, Bodda C, Hammerschmidt K, Giegling I, Stepniak B, Castillo Venzor A, Konte B, Erbaba B, Hartmann A, Tarami A, Schulz-Schaeffer W, Rujescu D, Mannan AU, Ehrenreich H. Mild expression differences of MECP2 influencing aggressive social behavior. EMBO Mol Med 2014; 6:662-84. [PMID: 24648499 PMCID: PMC4023888 DOI: 10.1002/emmm.201303744] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The X-chromosomal MECP2/Mecp2 gene encodes methyl-CpG-binding protein 2, a transcriptional activator and repressor regulating many other genes. We discovered in male FVB/N mice that mild (∼50%) transgenic overexpression of Mecp2 enhances aggression. Surprisingly, when the same transgene was expressed in C57BL/6N mice, transgenics showed reduced aggression and social interaction. This suggests that Mecp2 modulates aggressive social behavior. To test this hypothesis in humans, we performed a phenotype-based genetic association study (PGAS) in >1000 schizophrenic individuals. We found MECP2 SNPs rs2239464 (G/A) and rs2734647 (C/T; 3′UTR) associated with aggression, with the G and C carriers, respectively, being more aggressive. This finding was replicated in an independent schizophrenia cohort. Allele-specific MECP2mRNA expression differs in peripheral blood mononuclear cells by ∼50% (rs2734647: C > T). Notably, the brain-expressed, species-conserved miR-511 binds to MECP2 3′UTR only in T carriers, thereby suppressing gene expression. To conclude, subtle MECP2/Mecp2 expression alterations impact aggression. While the mouse data provides evidence of an interaction between genetic background and mild Mecp2 overexpression, the human data convey means by which genetic variation affects MECP2 expression and behavior.
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Affiliation(s)
- Martesa Tantra
- Clinical Neuroscience, Max Planck Institute of Experimental Medicine, Göttingen, Germany
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Bodda C, Tantra M, Mollajew R, Arunachalam JP, Laccone FA, Can K, Rosenberger A, Mironov SL, Ehrenreich H, Mannan AU. Mild Overexpression of Mecp2 in Mice Causes a Higher Susceptibility toward Seizures. The American Journal of Pathology 2013; 183:195-210. [DOI: 10.1016/j.ajpath.2013.03.019] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Revised: 01/31/2013] [Accepted: 03/14/2013] [Indexed: 10/26/2022]
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12
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Wake H, Moorhouse AJ, Miyamoto A, Nabekura J. Microglia: actively surveying and shaping neuronal circuit structure and function. Trends Neurosci 2013; 36:209-17. [DOI: 10.1016/j.tins.2012.11.007] [Citation(s) in RCA: 332] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Revised: 11/16/2012] [Accepted: 11/17/2012] [Indexed: 11/17/2022]
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Abstract
The discovery of the genetic causes of syndromic autism spectrum disorders and intellectual disabilities has greatly informed our understanding of the molecular pathways critical for normal synaptic function. The top-down approaches using human phenotypes and genetics helped identify causative genes and uncovered the broad spectrum of neuropsychiatric features that can result from various mutations in the same gene. Importantly, the human studies unveiled the exquisite sensitivity of cognitive function to precise levels of many diverse proteins. Bottom-up approaches applying molecular, biochemical, and neurophysiological studies to genetic models of these disorders revealed unsuspected pathogenic mechanisms and identified potential therapeutic targets. Moreover, studies in model organisms showed that symptoms of these devastating disorders can be reversed, which brings hope that affected individuals might benefit from interventions even after symptoms set in. Scientists predict that insights gained from studying these rare syndromic disorders will have an impact on the more common nonsyndromic autism and mild cognitive deficits.
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Affiliation(s)
- Huda Y Zoghbi
- Howard Hughes Medical Institute, The Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, ;
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14
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Pantakani DVK, Czyzewska MM, Sikorska A, Bodda C, Mannan AU. Oligomerization of ZFYVE27 (Protrudin) is necessary to promote neurite extension. PLoS One 2011; 6:e29584. [PMID: 22216323 PMCID: PMC3247280 DOI: 10.1371/journal.pone.0029584] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Accepted: 12/01/2011] [Indexed: 11/20/2022] Open
Abstract
ZFYVE27 (Protrudin) was originally identified as an interacting partner of spastin, which is most frequently mutated in hereditary spastic paraplegia. ZFYVE27 is a novel member of FYVE family, which is implicated in the formation of neurite extensions by promoting directional membrane trafficking in neurons. Now, through a yeast two-hybrid screen, we have identified that ZFYVE27 interacts with itself and the core interaction region resides within the third hydrophobic region (HR3) of the protein. We confirmed the ZFYVE27's self-interaction in the mammalian cells by co-immunoprecipitation and co-localization studies. To decipher the oligomeric nature of ZFYVE27, we performed sucrose gradient centrifugation and showed that ZFYVE27 oligomerizes into dimer/tetramer forms. Sub-cellular fractionation and Triton X-114 membrane phase separation analysis indicated that ZFYVE27 is a peripheral membrane protein. Furthermore, ZFYVE27 also binds to phosphatidylinositol 3-phosphate lipid moiety. Interestingly, cells expressing ZFYVE27ΔHR3 failed to produce protrusions instead caused swelling of cell soma. When ZFYVE27ΔHR3 was co-expressed with wild-type ZFYVE27 (ZFYVE27WT), it exerted a dominant negative effect on ZFYVE27WT as the cells co-expressing both proteins were also unable to induce protrusions and showed cytoplasmic swelling. Altogether, it is evident that a functionally active form of oligomer is crucial for ZFYVE27 ability to promote neurite extensions.
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Affiliation(s)
| | - Marta M. Czyzewska
- Institute of Human Genetics, University of Goettingen, Goettingen, Germany
| | - Anna Sikorska
- Institute of Human Genetics, University of Goettingen, Goettingen, Germany
| | - Chiranjeevi Bodda
- Institute of Human Genetics, University of Goettingen, Goettingen, Germany
| | - Ashraf U. Mannan
- Institute of Human Genetics, University of Goettingen, Goettingen, Germany
- * E-mail:
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Leoncini S, De Felice C, Signorini C, Pecorelli A, Durand T, Valacchi G, Ciccoli L, Hayek J. Oxidative stress in Rett syndrome: natural history, genotype, and variants. Redox Rep 2011; 16:145-53. [PMID: 21888765 DOI: 10.1179/1351000211y.0000000004] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
OBJECTIVES Rett syndrome (RTT) is an X-linked autism spectrum disorder caused by mutations in the MeCP2 gene in the great majority of cases. Evidence suggests a potential role of oxidative stress (OS) in its pathogenesis. Here, we investigated the potential value of OS markers (non-protein-bound iron (NPBI) and F2-isoprostanes (F2-IsoPs)) in explaining natural history, genotype-phenotype correlation, and clinical heterogeneity of RTT, and gauging the response to omega-3 polyunsaturated fatty acids (ω-3 PUFAs). METHODS RTT patients (n=113) and healthy controls were assayed for plasma NPBI and F2-IsoPs, and intraerythrocyte NPBI. Forty-two patients with typical RTT were randomly assigned to ω-3 PUFAs supplementation for 12 months. NPBI was measured by HPLC and F2-IsoPs using a gas chromatography/negative ion chemical ionization tandem mass spectrometry (GC/NICI-MS/MS) technique. RESULTS F2-IsoPs were significantly higher in the early stages as compared with the late natural progression of classic RTT. MeCP2 mutations related to more severe phenotypes exhibited higher OS marker levels than those of milder phenotypes. Higher OS markers were observed in typical RTT and early seizure variant as compared with the preserved speech and congenital variants. Significant reduction in OS markers levels and improvement of severity scores were observed after ω-3 PUFAs supplementation. DISCUSSION OS is a key modulator of disease expression in RTT.
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Affiliation(s)
- Silvia Leoncini
- Department of Pathophysiology, Experimental Medicine & Public Health, University of Siena, and Neonatal Intensive Care Unit, University Hospital, Azienda Ospedaliera Senese, Siena, Italy
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