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Khaliulin I, Hamoudi W, Amal H. The multifaceted role of mitochondria in autism spectrum disorder. Mol Psychiatry 2024:10.1038/s41380-024-02725-z. [PMID: 39223276 DOI: 10.1038/s41380-024-02725-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Revised: 08/21/2024] [Accepted: 08/23/2024] [Indexed: 09/04/2024]
Abstract
Normal brain functioning relies on high aerobic energy production provided by mitochondria. Failure to supply a sufficient amount of energy, seen in different brain disorders, including autism spectrum disorder (ASD), may have a significant negative impact on brain development and support of different brain functions. Mitochondrial dysfunction, manifested in the abnormal activities of the electron transport chain and impaired energy metabolism, greatly contributes to ASD. The aberrant functioning of this organelle is of such high importance that ASD has been proposed as a mitochondrial disease. It should be noted that aerobic energy production is not the only function of the mitochondria. In particular, these organelles are involved in the regulation of Ca2+ homeostasis, different mechanisms of programmed cell death, autophagy, and reactive oxygen and nitrogen species (ROS and RNS) production. Several syndromes originated from mitochondria-related mutations display ASD phenotype. Abnormalities in Ca2+ handling and ATP production in the brain mitochondria affect synaptic transmission, plasticity, and synaptic development, contributing to ASD. ROS and Ca2+ regulate the activity of the mitochondrial permeability transition pore (mPTP). The prolonged opening of this pore affects the redox state of the mitochondria, impairs oxidative phosphorylation, and activates apoptosis, ultimately leading to cell death. A dysregulation between the enhanced mitochondria-related processes of apoptosis and the inhibited autophagy leads to the accumulation of toxic products in the brains of individuals with ASD. Although many mitochondria-related mechanisms still have to be investigated, and whether they are the cause or consequence of this disorder is still unknown, the accumulating data show that the breakdown of any of the mitochondrial functions may contribute to abnormal brain development leading to ASD. In this review, we discuss the multifaceted role of mitochondria in ASD from the various aspects of neuroscience.
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Affiliation(s)
- Igor Khaliulin
- Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Wajeha Hamoudi
- Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Haitham Amal
- Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel.
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Calvo-Rodriguez M, Kharitonova EK, Snyder AC, Hou SS, Sanchez-Mico MV, Das S, Fan Z, Shirani H, Nilsson KPR, Serrano-Pozo A, Bacskai BJ. Real-time imaging of mitochondrial redox reveals increased mitochondrial oxidative stress associated with amyloid β aggregates in vivo in a mouse model of Alzheimer's disease. Mol Neurodegener 2024; 19:6. [PMID: 38238819 PMCID: PMC10797952 DOI: 10.1186/s13024-024-00702-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Accepted: 01/05/2024] [Indexed: 01/22/2024] Open
Abstract
BACKGROUND Reactive oxidative stress is a critical player in the amyloid beta (Aβ) toxicity that contributes to neurodegeneration in Alzheimer's disease (AD). Damaged mitochondria are one of the main sources of reactive oxygen species and accumulate in Aβ plaque-associated dystrophic neurites in the AD brain. Although Aβ causes neuronal mitochondria reactive oxidative stress in vitro, this has never been directly observed in vivo in the living mouse brain. Here, we tested for the first time whether Aβ plaques and soluble Aβ oligomers induce mitochondrial oxidative stress in surrounding neurons in vivo, and whether this neurotoxic effect can be abrogated using mitochondrial-targeted antioxidants. METHODS We expressed a genetically encoded fluorescent ratiometric mitochondria-targeted reporter of oxidative stress in mouse models of the disease and performed intravital multiphoton microscopy of neuronal mitochondria and Aβ plaques. RESULTS For the first time, we demonstrated by direct observation in the living mouse brain exacerbated mitochondrial oxidative stress in neurons after both Aβ plaque deposition and direct application of soluble oligomeric Aβ onto the brain, and determined the most likely pathological sequence of events leading to oxidative stress in vivo. Oxidative stress could be inhibited by both blocking calcium influx into mitochondria and treating with the mitochondria-targeted antioxidant SS31. Remarkably, the latter ameliorated plaque-associated dystrophic neurites without impacting Aβ plaque burden. CONCLUSIONS Considering these results, combination of mitochondria-targeted compounds with other anti-amyloid beta or anti-tau therapies hold promise as neuroprotective drugs for the prevention and/or treatment of AD.
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Affiliation(s)
- Maria Calvo-Rodriguez
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 114, 16Th St, Charlestown, MA, 02129, USA
- Present address: Foundational Neuroscience Center, AbbVie Inc, Cambridge, MA, USA
| | - Elizabeth K Kharitonova
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 114, 16Th St, Charlestown, MA, 02129, USA
| | - Austin C Snyder
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 114, 16Th St, Charlestown, MA, 02129, USA
| | - Steven S Hou
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 114, 16Th St, Charlestown, MA, 02129, USA
| | - Maria Virtudes Sanchez-Mico
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 114, 16Th St, Charlestown, MA, 02129, USA
| | - Sudeshna Das
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 114, 16Th St, Charlestown, MA, 02129, USA
| | - Zhanyun Fan
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 114, 16Th St, Charlestown, MA, 02129, USA
| | - Hamid Shirani
- Department of Physics, Chemistry and Biology, Linköping University, 581 83, Linköping, Sweden
| | - K Peter R Nilsson
- Department of Physics, Chemistry and Biology, Linköping University, 581 83, Linköping, Sweden
| | - Alberto Serrano-Pozo
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 114, 16Th St, Charlestown, MA, 02129, USA
| | - Brian J Bacskai
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 114, 16Th St, Charlestown, MA, 02129, USA.
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3
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Kotchetkov P, Blakeley N, Lacoste B. Involvement of brain metabolism in neurodevelopmental disorders. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2023; 173:67-113. [PMID: 37993180 DOI: 10.1016/bs.irn.2023.08.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2023]
Abstract
Neurodevelopmental disorders (NDDs) affect a significant portion of the global population and have a substantial social and economic impact worldwide. Most NDDs manifest in early childhood and are characterized by deficits in cognition, communication, social interaction and motor control. Due to a limited understanding of the etiology of NDDs, current treatment options primarily focus on symptom management rather than on curative solutions. Moreover, research on NDDs is problematic due to its reliance on a neurocentric approach. However, recent studies are broadening the scope of research on NDDs, to include dysregulations within a diverse network of brain cell types, including vascular and glial cells. This review aims to summarize studies from the past few decades on potential new contributions to the etiology of NDDs, with a special focus on metabolic signatures of various brain cells. In particular, we aim to convey how the metabolic functions are intimately linked to the onset and/or progression of common NDDs such as autism spectrum disorders, fragile X syndrome, Rett syndrome and Down syndrome.
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Affiliation(s)
- Pavel Kotchetkov
- Neuroscience Program, The Ottawa Hospital Research Institute, Ottawa, ON, Canada; Department of Cellular & Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Nicole Blakeley
- Neuroscience Program, The Ottawa Hospital Research Institute, Ottawa, ON, Canada; Department of Cellular & Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Baptiste Lacoste
- Neuroscience Program, The Ottawa Hospital Research Institute, Ottawa, ON, Canada; Department of Cellular & Molecular Medicine, University of Ottawa, Ottawa, ON, Canada; University of Ottawa Brain and Mind Research Institute, Ottawa, ON, Canada.
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4
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Golubiani G, van Agen L, Tsverava L, Solomonia R, Müller M. Mitochondrial Proteome Changes in Rett Syndrome. BIOLOGY 2023; 12:956. [PMID: 37508386 PMCID: PMC10376342 DOI: 10.3390/biology12070956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 06/28/2023] [Accepted: 06/29/2023] [Indexed: 07/30/2023]
Abstract
Rett syndrome (RTT) is a genetic neurodevelopmental disorder with mutations in the X-chromosomal MECP2 (methyl-CpG-binding protein 2) gene. Most patients are young girls. For 7-18 months after birth, they hardly present any symptoms; later they develop mental problems, a lack of communication, irregular sleep and breathing, motor dysfunction, hand stereotypies, and seizures. The complex pathology involves mitochondrial structure and function. Mecp2-/y hippocampal astrocytes show increased mitochondrial contents. Neurons and glia suffer from oxidative stress, a lack of ATP, and increased hypoxia vulnerability. This spectrum of changes demands comprehensive molecular studies of mitochondria to further define their pathogenic role in RTT. Therefore, we applied a comparative proteomic approach for the first time to study the entity of mitochondrial proteins in a mouse model of RTT. In the neocortex and hippocampus of symptomatic male mice, two-dimensional gel electrophoresis and subsequent mass-spectrometry identified various differentially expressed mitochondrial proteins, including components of respiratory chain complexes I and III and the ATP-synthase FoF1 complex. The NADH-ubiquinone oxidoreductase 75 kDa subunit, NADH dehydrogenase [ubiquinone] iron-sulfur protein 8, NADH dehydrogenase [ubiquinone] flavoprotein 2, cytochrome b-c1 complex subunit 1, and ATP synthase subunit d are upregulated either in the hippocampus alone or both the hippocampus and neocortex of Mecp2-/y mice. Furthermore, the regulatory mitochondrial proteins mitofusin-1, HSP60, and 14-3-3 protein theta are decreased in the Mecp2-/y neocortex. The expressional changes identified provide further details of the altered mitochondrial function and morphology in RTT. They emphasize brain-region-specific alterations of the mitochondrial proteome and support the notion of a metabolic component of this devastating disorder.
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Affiliation(s)
- Gocha Golubiani
- Institut für Neuro- und Sinnesphysiologie, Georg-August Universität Göttingen, Universitätsmedizin Göttingen, D-37073 Göttingen, Germany
- Institute of Chemical Biology, Ilia State University, Tbilisi 0162, Georgia
| | - Laura van Agen
- Institut für Neuro- und Sinnesphysiologie, Georg-August Universität Göttingen, Universitätsmedizin Göttingen, D-37073 Göttingen, Germany
| | - Lia Tsverava
- Institute of Chemical Biology, Ilia State University, Tbilisi 0162, Georgia
- Ivane Beritashvili Centre of Experimental Biomedicine, Tbilisi 0160, Georgia
| | - Revaz Solomonia
- Institute of Chemical Biology, Ilia State University, Tbilisi 0162, Georgia
- Ivane Beritashvili Centre of Experimental Biomedicine, Tbilisi 0160, Georgia
| | - Michael Müller
- Institut für Neuro- und Sinnesphysiologie, Georg-August Universität Göttingen, Universitätsmedizin Göttingen, D-37073 Göttingen, Germany
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Urbinati C, Lanzillotta C, Cosentino L, Valenti D, Quattrini MC, Di Crescenzo L, Prestia F, Pietraforte D, Perluigi M, Di Domenico F, Vacca RA, De Filippis B. Chronic treatment with the anti-diabetic drug metformin rescues impaired brain mitochondrial activity and selectively ameliorates defective cognitive flexibility in a female mouse model of Rett syndrome. Neuropharmacology 2023; 224:109350. [PMID: 36442649 DOI: 10.1016/j.neuropharm.2022.109350] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 10/26/2022] [Accepted: 11/19/2022] [Indexed: 11/26/2022]
Abstract
Metformin is the most common anti-diabetic drug and a promising therapy for disorders beyond diabetes, including Rett syndrome (RTT), a rare neurologic disease characterized by severe intellectual disability. A 10-day-long treatment rescued aberrant mitochondrial activity and restrained oxidative stress in a female RTT mouse model. However, this treatment regimen did not improve the phenotype of RTT mice. In the present study, we demonstrate that a 4-month-long treatment with metformin (150 mg/Kg/day, delivered in drinking bottles) provides a selective normalization of cognitive flexibility defects in RTT female mice at an advanced stage of disease, but it does not affect their impaired general health status and abnormal motor skills. The 4-month-long treatment also rescues the reduced activity of mitochondrial respiratory chain complex activities, the defective brain ATP production and levels as well as the increased production of reactive oxidizing species in the whole blood of RTT mice. A significant boost of PGC-1α-dependent pathways related to mitochondrial biogenesis and antioxidant defense occurs in the brain of RTT mice that received the metformin treatment. Further studies will have to verify whether these effects may underlie its long-lasting beneficial effects on brain energy metabolism.
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Affiliation(s)
- Chiara Urbinati
- Center for Behavioral Sciences and Mental Health, Istituto Superiore di Sanità, Rome, Italy.
| | - Chiara Lanzillotta
- Department of Biochemical Sciences, Sapienza University of Rome, Rome, Italy.
| | - Livia Cosentino
- Center for Behavioral Sciences and Mental Health, Istituto Superiore di Sanità, Rome, Italy.
| | - Daniela Valenti
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, National Council of Research, Bari, Italy.
| | | | - Livia Di Crescenzo
- Center for Behavioral Sciences and Mental Health, Istituto Superiore di Sanità, Rome, Italy.
| | - Francesca Prestia
- Department of Biochemical Sciences, Sapienza University of Rome, Rome, Italy.
| | | | - Marzia Perluigi
- Department of Biochemical Sciences, Sapienza University of Rome, Rome, Italy.
| | - Fabio Di Domenico
- Department of Biochemical Sciences, Sapienza University of Rome, Rome, Italy.
| | - Rosa Anna Vacca
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, National Council of Research, Bari, Italy.
| | - Bianca De Filippis
- Center for Behavioral Sciences and Mental Health, Istituto Superiore di Sanità, Rome, Italy.
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6
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Zlatic SA, Duong D, Gadalla KK, Murage B, Ping L, Shah R, Fink JJ, Khwaja O, Swanson LC, Sahin M, Rayaprolu S, Kumar P, Rangaraju S, Bird A, Tarquinio D, Carpenter R, Cobb S, Faundez V. Convergent cerebrospinal fluid proteomes and metabolic ontologies in humans and animal models of Rett syndrome. iScience 2022; 25:104966. [PMID: 36060065 PMCID: PMC9437849 DOI: 10.1016/j.isci.2022.104966] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 07/30/2022] [Accepted: 08/12/2022] [Indexed: 11/22/2022] Open
Abstract
MECP2 loss-of-function mutations cause Rett syndrome, a neurodevelopmental disorder resulting from a disrupted brain transcriptome. How these transcriptional defects are decoded into a disease proteome remains unknown. We studied the proteome of Rett cerebrospinal fluid (CSF) to identify consensus Rett proteome and ontologies shared across three species. Rett CSF proteomes enriched proteins annotated to HDL lipoproteins, complement, mitochondria, citrate/pyruvate metabolism, synapse compartments, and the neurosecretory protein VGF. We used shared Rett ontologies to select analytes for orthogonal quantification and functional validation. VGF and ontologically selected CSF proteins had genotypic discriminatory capacity as determined by receiver operating characteristic analysis in Mecp2 -/y and Mecp2 -/+ . Differentially expressed CSF proteins distinguished Rett from a related neurodevelopmental disorder, CDKL5 deficiency disorder. We propose that Mecp2 mutant CSF proteomes and ontologies inform putative mechanisms and biomarkers of disease. We suggest that Rett syndrome results from synapse and metabolism dysfunction.
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Affiliation(s)
| | - Duc Duong
- Departments of Biochemistry, Emory University, Atlanta, GA 30322, USA
| | - Kamal K.E. Gadalla
- Simons Initiative for the Developing Brain, Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Brenda Murage
- Simons Initiative for the Developing Brain, Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Lingyan Ping
- Departments of Biochemistry, Emory University, Atlanta, GA 30322, USA
| | - Ruth Shah
- The Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, King’s Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | | | - Omar Khwaja
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Lindsay C. Swanson
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Mustafa Sahin
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Sruti Rayaprolu
- Departments of Neurology, Emory University, Atlanta, GA 30322, USA
| | - Prateek Kumar
- Departments of Neurology, Emory University, Atlanta, GA 30322, USA
| | | | - Adrian Bird
- The Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, King’s Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | | | | | - Stuart Cobb
- Simons Initiative for the Developing Brain, Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Victor Faundez
- Departments of Cell Biology, Emory University, Atlanta, GA 30322, USA
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7
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Baroncelli L, Auel S, Rinne L, Schuster AK, Brand V, Kempkes B, Dietrich K, Müller M. Oral Feeding of an Antioxidant Cocktail as a Therapeutic Strategy in a Mouse Model of Rett Syndrome: Merits and Limitations of Long-Term Treatment. Antioxidants (Basel) 2022; 11:antiox11071406. [PMID: 35883897 PMCID: PMC9311910 DOI: 10.3390/antiox11071406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 07/14/2022] [Accepted: 07/15/2022] [Indexed: 02/01/2023] Open
Abstract
Rett syndrome (RTT) is a severe neurodevelopmental disorder that typically arises from spontaneous germline mutations in the X-chromosomal methyl-CpG binding protein 2 (MECP2) gene. For the first 6–18 months of life, the development of the mostly female patients appears normal. Subsequently, cognitive impairment, motor disturbances, hand stereotypies, epilepsy, and irregular breathing manifest, with previously learned skills being lost. Early mitochondrial impairment and a systemic oxidative burden are part of the complex pathogenesis, and contribute to disease progression. Accordingly, partial therapeutic merits of redox-stabilizing and antioxidant (AO) treatments were reported in RTT patients and Mecp2-mutant mice. Pursuing these findings, we conducted a full preclinical trial on male and female mice to define the therapeutic value of an orally administered AO cocktail composed of vitamin E, N-acetylcysteine, and α-lipoic acid. AO treatment ameliorated some of the microcephaly-related aspects. Moreover, the reduced growth, lowered blood glucose levels, and the hippocampal synaptic plasticity of Mecp2−/y mice improved. However, the first-time detected intensified oxidative DNA damage in Mecp2-mutant cortex persisted. The behavioral performance, breathing regularity, and life expectancy of Mecp2-mutant mice did not improve upon AO treatment. Long-term-treated Mecp2+/− mice eventually became obese. In conclusion, the AO cocktail ameliorated a subset of symptoms of the complex RTT-related phenotype, thereby further confirming the potential merits of AO-based pharmacotherapies. Yet, it also became evident that long-term AO treatment may lose efficacy and even aggravate the metabolic disturbances in RTT. This emphasizes the importance of a constantly well-balanced redox balance for systemic well-being.
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Affiliation(s)
- Laura Baroncelli
- Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, Humboldtallee 23, D-37073 Göttingen, Germany; (L.B.); (S.A.); (L.R.); (A.-K.S.); (V.B.); (B.K.); (K.D.)
- Institute of Neuroscience, National Research Council (CNR), via Giuseppe Moruzzi 1, I-56124 Pisa, Italy
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Viale del Tirreno 331, I-56128 Pisa, Italy
| | - Stefanie Auel
- Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, Humboldtallee 23, D-37073 Göttingen, Germany; (L.B.); (S.A.); (L.R.); (A.-K.S.); (V.B.); (B.K.); (K.D.)
| | - Lena Rinne
- Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, Humboldtallee 23, D-37073 Göttingen, Germany; (L.B.); (S.A.); (L.R.); (A.-K.S.); (V.B.); (B.K.); (K.D.)
| | - Ann-Kathrin Schuster
- Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, Humboldtallee 23, D-37073 Göttingen, Germany; (L.B.); (S.A.); (L.R.); (A.-K.S.); (V.B.); (B.K.); (K.D.)
| | - Victoria Brand
- Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, Humboldtallee 23, D-37073 Göttingen, Germany; (L.B.); (S.A.); (L.R.); (A.-K.S.); (V.B.); (B.K.); (K.D.)
| | - Belinda Kempkes
- Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, Humboldtallee 23, D-37073 Göttingen, Germany; (L.B.); (S.A.); (L.R.); (A.-K.S.); (V.B.); (B.K.); (K.D.)
| | - Katharina Dietrich
- Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, Humboldtallee 23, D-37073 Göttingen, Germany; (L.B.); (S.A.); (L.R.); (A.-K.S.); (V.B.); (B.K.); (K.D.)
| | - Michael Müller
- Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, Humboldtallee 23, D-37073 Göttingen, Germany; (L.B.); (S.A.); (L.R.); (A.-K.S.); (V.B.); (B.K.); (K.D.)
- Correspondence: ; Tel.: +49-551-39-22933
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8
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Levy KA, Weisz ED, Jongens TA. Loss of neurexin-1 in Drosophila melanogaster results in altered energy metabolism and increased seizure susceptibility. Hum Mol Genet 2022; 31:3422-3438. [PMID: 35617143 PMCID: PMC9558836 DOI: 10.1093/hmg/ddac115] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 04/28/2022] [Accepted: 05/09/2022] [Indexed: 12/04/2022] Open
Abstract
Although autism is typically characterized by differences in language, social interaction and restrictive, repetitive behaviors, it is becoming more well known in the field that alterations in energy metabolism and mitochondrial function are comorbid disorders in autism. The synaptic cell adhesion molecule, neurexin-1 (NRXN1), has previously been implicated in autism, and here we show that in Drosophila melanogaster, the homologue of NRXN1, called Nrx-1, regulates energy metabolism and nutrient homeostasis. First, we show that Nrx-1-null flies exhibit decreased resistance to nutrient deprivation and heat stress compared to controls. Additionally, Nrx-1 mutants exhibit a significantly altered metabolic profile characterized by decreased lipid and carbohydrate stores. Nrx-1-null Drosophila also exhibit diminished levels of nicotinamide adenine dinucleotide (NAD+), an important coenzyme in major energy metabolism pathways. Moreover, loss of Nrx-1 resulted in striking abnormalities in mitochondrial morphology in the flight muscle of Nrx-1-null Drosophila and impaired flight ability in these flies. Further, following a mechanical shock Nrx-1-null flies exhibited seizure-like activity, a phenotype previously linked to defects in mitochondrial metabolism and a common symptom of patients with NRXN1 deletions. The current studies indicate a novel role for NRXN1 in the regulation of energy metabolism and uncover a clinically relevant seizure phenotype in Drosophila lacking Nrx-1.
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Affiliation(s)
- Kyra A Levy
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.,Neuroscience Graduate Group, University of Pennsylvania, Philadelphia, PA 19104, USA.,Autism Spectrum Program of Excellence, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Eliana D Weisz
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.,Autism Spectrum Program of Excellence, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Thomas A Jongens
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.,Autism Spectrum Program of Excellence, University of Pennsylvania, Philadelphia, PA 19104, USA
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9
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Leoncini S, Signorini C, Boasiako L, Scandurra V, Hayek J, Ciccoli L, Rossi M, Canitano R, De Felice C. Breathing Abnormalities During Sleep and Wakefulness in Rett Syndrome: Clinical Relevance and Paradoxical Relationship With Circulating Pro-oxidant Markers. Front Neurol 2022; 13:833239. [PMID: 35422749 PMCID: PMC9001904 DOI: 10.3389/fneur.2022.833239] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 02/02/2022] [Indexed: 11/13/2022] Open
Abstract
BackgroundBreathing abnormalities are common in Rett syndrome (RTT), a pervasive neurodevelopmental disorder almost exclusively affecting females. RTT is linked to mutations in the methyl-CpG-binding protein 2 (MeCP2) gene. Our aim was to assess the clinical relevance of apneas during sleep-wakefulness cycle in a population with RTT and the possible impact of apneas on circulating oxidative stress markers.MethodsFemale patients with a clinical diagnosis of typical RTT (n = 66), MECP2 gene mutation, and apneas were enrolled (mean age: 12.5 years). Baseline clinical severity, arterial blood gas analysis, and red blood cell count were assessed. Breathing was monitored during the wakefulness and sleep states (average recording time: 13 ± 0.5 h) with a portable polygraphic screening device. According to prevalence of breath holdings, the population was categorized into the wakefulness apnea (WA) and sleep apnea (SA) groups, and apnea-hypopnea index (AHI) was calculated. The impact of respiratory events on oxidative stress was assessed by plasma and intra-erythrocyte non-protein-bound iron (P-NPBI and IE-NPBI, respectively), and plasma F2-isoprostane (F2-IsoP) assays.ResultsSignificant prevalence of obstructive apneas with values of AHI > 15 was present in 69.7% of the population with RTT. The group with SA showed significantly increased AHI values > 15 (p = 0.0032), total breath holding episodes (p = 0.007), and average SpO2 (p = 0.0001) as well as lower nadir SpO2 (p = 0.0004) compared with the patients with WAs. The subgroups of patients with WA and SA showed no significant differences in arterial blood gas analysis variables (p > 0.089). Decreased mean cell hemoglobin (MCH) (p = 0.038) was observed in the group with WAs. P-NPBI levels were significantly higher in the group with WA than in that with SAs (p = 0.0001). Stepwise multiple linear regression models showed WA being related to nadir SpO2, average SpO2, and P-NPBI (adjusted R2 = 0.613, multiple correlation coefficient = 0.795 p < 0.0001), and P-NPBI being related to average SpO2, blood PaCO2, red blood cell mean corpuscular volume (MCV), age, and topiramate treatment (adjusted R2 = 0.551, multiple correlation coefficient = 0.765, p < 0.0001).ConclusionOur findings indicate that the impact of apneas in RTT is uneven according to the sleep-wakefulness cycle, and that plasma redox active iron represents a potential novel therapeutic target.
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Affiliation(s)
- Silvia Leoncini
- Rett Syndrome Trial Center, Child Neuropsychiatry Unit, University Hospital Azienda Ospedaliera Universitaria Senese, Siena, Italy
- Neonatal Intensive Care Unit, University Hospital Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Cinzia Signorini
- Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Lidia Boasiako
- Rett Syndrome Trial Center, Child Neuropsychiatry Unit, University Hospital Azienda Ospedaliera Universitaria Senese, Siena, Italy
- Neonatal Intensive Care Unit, University Hospital Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Valeria Scandurra
- Child Neuropsychiatry Unit, University Hospital, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Joussef Hayek
- Child Neuropsychiatry Unit, University Hospital, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Lucia Ciccoli
- Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Marcello Rossi
- Respiratory Pathophysiology and Rehabilitation Unit, University Hospital, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Roberto Canitano
- Child Neuropsychiatry Unit, University Hospital, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Claudio De Felice
- Rett Syndrome Trial Center, Child Neuropsychiatry Unit, University Hospital Azienda Ospedaliera Universitaria Senese, Siena, Italy
- Neonatal Intensive Care Unit, University Hospital Azienda Ospedaliera Universitaria Senese, Siena, Italy
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10
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Liu S, Pei P, Li L, Wu H, Zheng X, Wang S, Xiao Y, Pan H, Bao X, Qi Y, Ma Y. Mitochondrial DNA Copy Number in Rett Syndrome Caused by Methyl-CpG-Binding Protein-2 Variants. J Pediatr 2022; 241:154-161. [PMID: 34619114 DOI: 10.1016/j.jpeds.2021.09.052] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 09/22/2021] [Accepted: 09/28/2021] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine changes in mitochondrial DNA (mtDNA) copy number in peripheral blood in Rett syndrome caused by methyl-CpG-binding protein-2 (MECP2) variants and explore the mechanism of mitochondrial dysfunction in Rett syndrome. STUDY DESIGN Female patients who were diagnosed with Rett syndrome and had an MECP2 variant (n = 142) were recruited in this study, along with the same number of age- and sex-matched healthy controls. MtDNA copy number was quantified by real-time quantitative polymerase chain reaction with TaqMan probes. The differences in mtDNA copy number between the Rett syndrome group and the control group were analyzed using the independent-samples t test. Linear regression, biserial correlation analysis, and one-way ANOVA were applied for the correlations between mtDNA copy number and age, clinical severity, variant types, functional domains, and hot-spot variants. RESULTS MtDNA copy number was found to be significantly increased in the patients with Rett syndrome with MECP2 gene variants compared with the control subjects. Age, clinical severity, variant types, functional domains, and hot-spot variants were not related to mtDNA copy number in patients with Rett syndrome. CONCLUSIONS MtDNA copy number is increased significantly in patients with Rett syndrome, suggesting that changes in mitochondrial function in Rett syndrome trigger a compensatory increase in mtDNA copy number and providing new possibilities for treating Rett syndrome, such as mitochondria-targeted therapies.
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Affiliation(s)
- Siwen Liu
- Department of Central Laboratory, Peking University First Hospital, Beijing, China
| | - Pei Pei
- Department of Central Laboratory, Peking University First Hospital, Beijing, China
| | - Lin Li
- Department of Central Laboratory, Peking University First Hospital, Beijing, China
| | - Hairong Wu
- Department of Central Laboratory, Peking University First Hospital, Beijing, China
| | - Xuefei Zheng
- Department of Central Laboratory, Peking University First Hospital, Beijing, China
| | - Songtao Wang
- Department of Central Laboratory, Peking University First Hospital, Beijing, China
| | - Yang Xiao
- Department of Central Laboratory, Peking University First Hospital, Beijing, China
| | - Hong Pan
- Department of Central Laboratory, Peking University First Hospital, Beijing, China
| | - Xinhua Bao
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Yu Qi
- Department of Central Laboratory, Peking University First Hospital, Beijing, China
| | - Yinan Ma
- Department of Central Laboratory, Peking University First Hospital, Beijing, China.
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11
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Golubiani G, Lagani V, Solomonia R, Müller M. Metabolomic Fingerprint of Mecp2-Deficient Mouse Cortex: Evidence for a Pronounced Multi-Facetted Metabolic Component in Rett Syndrome. Cells 2021; 10:cells10092494. [PMID: 34572143 PMCID: PMC8472238 DOI: 10.3390/cells10092494] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 09/17/2021] [Accepted: 09/18/2021] [Indexed: 01/10/2023] Open
Abstract
Using unsupervised metabolomics, we defined the complex metabolic conditions in the cortex of a mouse model of Rett syndrome (RTT). RTT, which represents a cause of mental and cognitive disabilities in females, results in profound cognitive impairment with autistic features, motor disabilities, seizures, gastrointestinal problems, and cardiorespiratory irregularities. Typical RTT originates from mutations in the X-chromosomal methyl-CpG-binding-protein-2 (Mecp2) gene, which encodes a transcriptional modulator. It then causes a deregulation of several target genes and metabolic alterations in the nervous system and peripheral organs. We identified 101 significantly deregulated metabolites in the Mecp2-deficient cortex of adult male mice; 68 were increased and 33 were decreased compared to wildtypes. Pathway analysis identified 31 mostly upregulated metabolic pathways, in particular carbohydrate and amino acid metabolism, key metabolic mitochondrial/extramitochondrial pathways, and lipid metabolism. In contrast, neurotransmitter-signaling is dampened. This metabolic fingerprint of the Mecp2-deficient cortex of severely symptomatic mice provides further mechanistic insights into the complex RTT pathogenesis. The deregulated pathways that were identified—in particular the markedly affected amino acid and carbohydrate metabolism—confirm a complex and multifaceted metabolic component in RTT, which in turn signifies putative therapeutic targets. Furthermore, the deregulated key metabolites provide a choice of potential biomarkers for a more detailed rating of disease severity and disease progression.
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Affiliation(s)
- Gocha Golubiani
- Institut für Neuro- und Sinnesphysiologie, Zentrum Physiologie und Pathophysiologie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, D-37130 Göttingen, Germany;
- Institute of Chemical Biology, Ilia State University, 0162 Tbilisi, Georgia; (V.L.); (R.S.)
| | - Vincenzo Lagani
- Institute of Chemical Biology, Ilia State University, 0162 Tbilisi, Georgia; (V.L.); (R.S.)
| | - Revaz Solomonia
- Institute of Chemical Biology, Ilia State University, 0162 Tbilisi, Georgia; (V.L.); (R.S.)
| | - Michael Müller
- Institut für Neuro- und Sinnesphysiologie, Zentrum Physiologie und Pathophysiologie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, D-37130 Göttingen, Germany;
- Correspondence: ; Tel.: +49-551-39-22933
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12
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Rett Syndrome: A Timely Review From Recognition to Current Clinical Approaches and Clinical Study Updates. Semin Pediatr Neurol 2021; 37:100881. [PMID: 33892852 DOI: 10.1016/j.spen.2021.100881] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 02/24/2021] [Accepted: 03/03/2021] [Indexed: 12/11/2022]
Abstract
Since the discovery of the genetic basis of Rett syndrome in 1999, our understanding has grown considerably both in the scientific and the clinical realms. In the last two decades, we have learned about the far-reaching effects of the aberrant MeCP2 protein, the growing list of involved genetic factors, and the genotype-phenotype clinical expression of common MECP2 mutations. This knowledge has led to several basic science research and clinical trials, focusing specifically on emerging treatments of Rett syndrome. As the pathophysiology behind the disease is better understood, treatments aimed at specific molecular targets will become available for clinicians to improve the life of individuals with Rett syndrome.
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13
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Frye RE, Cakir J, Rose S, Palmer RF, Austin C, Curtin P, Arora M. Mitochondria May Mediate Prenatal Environmental Influences in Autism Spectrum Disorder. J Pers Med 2021; 11:218. [PMID: 33803789 PMCID: PMC8003154 DOI: 10.3390/jpm11030218] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 03/17/2021] [Accepted: 03/17/2021] [Indexed: 12/13/2022] Open
Abstract
We propose that the mitochondrion, an essential cellular organelle, mediates the long-term prenatal environmental effects of disease in autism spectrum disorder (ASD). Many prenatal environmental factors which increase the risk of developing ASD influence mitochondria physiology, including toxicant exposures, immune activation, and nutritional factors. Unique types of mitochondrial dysfunction have been associated with ASD and recent studies have linked prenatal environmental exposures to long-term changes in mitochondrial physiology in children with ASD. A better understanding of the role of the mitochondria in the etiology of ASD can lead to targeted therapeutics and strategies to potentially prevent the development of ASD.
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Affiliation(s)
- Richard E. Frye
- Barrow Neurological Institute at Phoenix Children’s Hospital, Phoenix, AZ 85016, USA
| | - Janet Cakir
- Department of Applied Ecology, North Carolina State University, Raleigh, NC 27695, USA;
| | - Shannon Rose
- Department of Pediatrics, Arkansas Children’s Research Institute, University of Arkansas for Medical Sciences, Little Rock, AR 72202, USA;
| | - Raymond F. Palmer
- Department of Family and Community Medicine, University of Texas Health Science Center, San Antonio, TX 78229, USA;
| | - Christine Austin
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; (C.A.); (P.C.); (M.A.)
| | - Paul Curtin
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; (C.A.); (P.C.); (M.A.)
| | - Manish Arora
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; (C.A.); (P.C.); (M.A.)
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14
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Bilinovich SM, Uhl KL, Lewis K, Soehnlen X, Williams M, Vogt D, Prokop JW, Campbell DB. Integrated RNA Sequencing Reveals Epigenetic Impacts of Diesel Particulate Matter Exposure in Human Cerebral Organoids. Dev Neurosci 2021; 42:195-207. [PMID: 33657557 DOI: 10.1159/000513536] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 12/02/2020] [Indexed: 12/25/2022] Open
Abstract
Autism spectrum disorder (ASD) manifests early in childhood. While genetic variants increase risk for ASD, a growing body of literature has established that in utero chemical exposures also contribute to ASD risk. These chemicals include air-based pollutants like diesel particulate matter (DPM). A combination of single-cell and direct transcriptomics of DPM-exposed human-induced pluripotent stem cell-derived cerebral organoids revealed toxicogenomic effects of DPM exposure during fetal brain development. Direct transcriptomics, sequencing RNA bases via Nanopore, revealed that cerebral organoids contain extensive RNA modifications, with DPM-altering cytosine methylation in oxidative mitochondrial transcripts expressed in outer radial glia cells. Single-cell transcriptomics further confirmed an oxidative phosphorylation change in cell groups such as outer radial glia upon DPM exposure. This approach highlights how DPM exposure perturbs normal mitochondrial function and cellular respiration during early brain development, which may contribute to developmental disorders like ASD by altering neurodevelopment.
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Affiliation(s)
- Stephanie M Bilinovich
- Department of Pediatrics & Human Development, Michigan State University, Grand Rapids, Michigan, USA
| | - Katie L Uhl
- Department of Pediatrics & Human Development, Michigan State University, Grand Rapids, Michigan, USA
| | - Kristy Lewis
- Department of Pediatrics & Human Development, Michigan State University, Grand Rapids, Michigan, USA
| | - Xavier Soehnlen
- Department of Pediatrics & Human Development, Michigan State University, Grand Rapids, Michigan, USA
| | - Michael Williams
- Department of Pediatrics & Human Development, Michigan State University, Grand Rapids, Michigan, USA.,Center for Research in Autism, Intellectual, and other Neurodevelopmental Disabilities, Michigan State University, East Lansing, Michigan, USA.,Neuroscience Program, Michigan State University, East Lansing, Michigan, USA
| | - Daniel Vogt
- Department of Pediatrics & Human Development, Michigan State University, Grand Rapids, Michigan, USA.,Center for Research in Autism, Intellectual, and other Neurodevelopmental Disabilities, Michigan State University, East Lansing, Michigan, USA.,Neuroscience Program, Michigan State University, East Lansing, Michigan, USA
| | - Jeremy W Prokop
- Department of Pediatrics & Human Development, Michigan State University, Grand Rapids, Michigan, USA.,Center for Research in Autism, Intellectual, and other Neurodevelopmental Disabilities, Michigan State University, East Lansing, Michigan, USA.,Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan, USA
| | - Daniel B Campbell
- Department of Pediatrics & Human Development, Michigan State University, Grand Rapids, Michigan, USA, .,Center for Research in Autism, Intellectual, and other Neurodevelopmental Disabilities, Michigan State University, East Lansing, Michigan, USA, .,Neuroscience Program, Michigan State University, East Lansing, Michigan, USA,
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15
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Abstract
Epilepsy and autism frequently co-occur. Epilepsy confers an increased risk of autism and autism confers an increased risk of epilepsy. Specific epilepsy syndromes, intellectual disability, and female gender present a particular risk of autism in individuals with epilepsy. Epilepsy and autism are likely to share common etiologies, which predispose individuals to either or both conditions. Genetic factors, metabolic disorders, mitochondrial disorders, and immune dysfunction all can be implicated.
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Affiliation(s)
- Frank M C Besag
- East London NHS Foundation Trust, 5-7 Rush Court, Bedford MK40 3JT, UK; University College London, London, UK; King's College London, London, UK.
| | - Michael J Vasey
- East London NHS Foundation Trust, 5-7 Rush Court, Bedford MK40 3JT, UK
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16
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Emerging physiological and pathological roles of MeCP2 in non-neurological systems. Arch Biochem Biophys 2021; 700:108768. [PMID: 33485848 DOI: 10.1016/j.abb.2021.108768] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Revised: 01/08/2021] [Accepted: 01/14/2021] [Indexed: 02/08/2023]
Abstract
Numerous neurological and non-neurological disorders are associated with dysfunction of epigenetic modulators, and methyl CpG binding protein 2 (MeCP2) is one of such proteins. Initially identified as a transcriptional repressor, MeCP2 specifically binds to methylated DNA, and mutations of MeCP2 have been shown to cause Rett syndrome (RTT), a severe neurological disorder. Recently, accumulating evidence suggests that ubiquitously expressed MeCP2 also plays a central role in non-neurological disorders including cardiac dysfunction, liver injury, respiratory disorders, urological dysfunction, adipose tissue metabolism disorders, movement abnormality and inflammatory responses in a DNA methylation dependent or independent manner. Despite significant progresses in our understanding of MeCP2 over the last few decades, there is still a considerable knowledge gap to translate the in vitro and in vivo experimental findings into therapeutic interventions. In this review, we provide a synopsis of the role of MeCP2 in the pathophysiology of non-neurological disorders, MeCP2-based research directions and therapeutic strategies for non-neurological disorders are also discussed.
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17
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Abnormalities of synaptic mitochondria in autism spectrum disorder and related neurodevelopmental disorders. J Mol Med (Berl) 2020; 99:161-178. [PMID: 33340060 PMCID: PMC7819932 DOI: 10.1007/s00109-020-02018-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 11/27/2020] [Accepted: 12/02/2020] [Indexed: 12/18/2022]
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental condition primarily characterized by an impairment of social interaction combined with the occurrence of repetitive behaviors. ASD starts in childhood and prevails across the lifespan. The variability of its clinical presentation renders early diagnosis difficult. Mutations in synaptic genes and alterations of mitochondrial functions are considered important underlying pathogenic factors, but it is obvious that we are far from a comprehensive understanding of ASD pathophysiology. At the synapse, mitochondria perform diverse functions, which are clearly not limited to their classical role as energy providers. Here, we review the current knowledge about mitochondria at the synapse and summarize the mitochondrial disturbances found in mouse models of ASD and other ASD-related neurodevelopmental disorders, like DiGeorge syndrome, Rett syndrome, Tuberous sclerosis complex, and Down syndrome.
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18
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Cristancho AG, Marsh ED. Epigenetics modifiers: potential hub for understanding and treating neurodevelopmental disorders from hypoxic injury. J Neurodev Disord 2020; 12:37. [PMID: 33327934 PMCID: PMC7745506 DOI: 10.1186/s11689-020-09344-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 11/13/2020] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND The fetal brain is adapted to the hypoxic conditions present during normal in utero development. Relatively more hypoxic states, either chronic or acute, are pathologic and can lead to significant long-term neurodevelopmental sequelae. In utero hypoxic injury is associated with neonatal mortality and millions of lives lived with varying degrees of disability. MAIN BODY Genetic studies of children with neurodevelopmental disease indicate that epigenetic modifiers regulating DNA methylation and histone remodeling are critical for normal brain development. Epigenetic modifiers are also regulated by environmental stimuli, such as hypoxia. Indeed, epigenetic modifiers that are mutated in children with genetic neurodevelopmental diseases are regulated by hypoxia in a number of preclinical models and may be part of the mechanism for the long-term neurodevelopmental sequelae seem in children with hypoxic brain injury. Thus, a comprehensive understanding the role of DNA methylation and histone modifications in hypoxic injury is critical for developing novel strategies to treat children with hypoxic injury. CONCLUSIONS This review focuses on our current understanding of the intersection between epigenetics, brain development, and hypoxia. Opportunities for the use of epigenetics as biomarkers of neurodevelopmental disease after hypoxic injury and potential clinical epigenetics targets to improve outcomes after injury are also discussed. While there have been many published studies on the epigenetics of hypoxia, more are needed in the developing brain in order to determine which epigenetic pathways may be most important for mitigating the long-term consequences of hypoxic brain injury.
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Affiliation(s)
- Ana G Cristancho
- Departments of Neurology and Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, USA
- Division of Child Neurology, Children's Hospital of Philadelphia, Philadelphia, USA
| | - Eric D Marsh
- Departments of Neurology and Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, USA.
- Division of Child Neurology, Children's Hospital of Philadelphia, Philadelphia, USA.
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19
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Adebayo OL, Dewenter I, Rinne L, Golubiani G, Solomonia R, Müller M. Intensified mitochondrial hydrogen peroxide release occurs in all brain regions, affects male as well as female Rett mice, and constitutes a life-long burden. Arch Biochem Biophys 2020; 696:108666. [PMID: 33160914 DOI: 10.1016/j.abb.2020.108666] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 10/29/2020] [Accepted: 10/31/2020] [Indexed: 12/28/2022]
Abstract
The neurodevelopmental disorder Rett syndrome (RTT) affects mostly females. Upon an apparently normal initial development, cognitive impairment, irregular breathing, motor dysfunction, and epilepsy occur. The complex pathogenesis includes, among others, mitochondrial impairment, redox imbalance, and oxidative damage. As these arise already in neonatal Rett mice, they were proposed contributors of disease progression. Several mitochondrial studies in RTT used either full brains or selected brain regions only. Here, we mapped mitochondria-related ROS generation brain wide. Using sophisticated multi-sample spectrofluorimetry, H2O2 release by isolated mitochondria was quantified in a coupled reaction of Amplex UltraRed and horseradish peroxidase. All brain regions and the entire lifespan were characterized in male and female mice. In WT mice, mitochondrial H2O2 release was usually highest in cortex and lowest in hippocampus. Maximum rates occurred at postnatal day (PD) 10 and they slightly declined with further maturation. Already at PD 10, male and female Rett mice showed exaggerated mitochondrial H2O2 releases in first brain regions and persistent brain-wide increases from PD 50 on. Interestingly, female Rett mice were more intensely affected than male Rett mice, with their brainstem, midbrain and hippocampus being most severely struck. In conclusion, we used a reliable multi-sample cuvette-based assay on mitochondrial ROS release to perform brain-wide analyzes along the entire lifespan. Mitochondrial H2O2 release in Rett mice is intensified in all brain regions, affects hemizygous males and heterozygous females, and involves all maturational stages. Therefore, intensified mitochondrial H2O2 release seriously needs to be considered throughout RTT pathogenesis and may constitute a potential therapeutic target.
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Affiliation(s)
- Olusegun L Adebayo
- Georg-August-Universität Göttingen, Universitätsmedizin Göttingen, Zentrum Physiologie und Pathophysiologie, Institut für Neuro- und Sinnesphysiologie, Germany; Department of Biochemistry, Faculty of Basic Medical Sciences, Redeemer's University, P.M.B. 230, Ede, Osun State, Nigeria
| | - Ina Dewenter
- Georg-August-Universität Göttingen, Universitätsmedizin Göttingen, Zentrum Physiologie und Pathophysiologie, Institut für Neuro- und Sinnesphysiologie, Germany
| | - Lena Rinne
- Georg-August-Universität Göttingen, Universitätsmedizin Göttingen, Zentrum Physiologie und Pathophysiologie, Institut für Neuro- und Sinnesphysiologie, Germany
| | - Gocha Golubiani
- Georg-August-Universität Göttingen, Universitätsmedizin Göttingen, Zentrum Physiologie und Pathophysiologie, Institut für Neuro- und Sinnesphysiologie, Germany; Institute of Chemical Biology, Ilia State University, Tbilisi, Georgia
| | - Revaz Solomonia
- Institute of Chemical Biology, Ilia State University, Tbilisi, Georgia
| | - Michael Müller
- Georg-August-Universität Göttingen, Universitätsmedizin Göttingen, Zentrum Physiologie und Pathophysiologie, Institut für Neuro- und Sinnesphysiologie, Germany.
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20
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Overshooting Subcellular Redox-Responses in Rett-Mouse Hippocampus during Neurotransmitter Stimulation. Cells 2020; 9:cells9122539. [PMID: 33255426 PMCID: PMC7760232 DOI: 10.3390/cells9122539] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/16/2020] [Accepted: 11/22/2020] [Indexed: 12/21/2022] Open
Abstract
Rett syndrome (RTT) is a neurodevelopmental disorder associated with disturbed neuronal responsiveness and impaired neuronal network function. Furthermore, mitochondrial alterations and a weakened cellular redox-homeostasis are considered part of the complex pathogenesis. So far, overshooting redox-responses of MeCP2-deficient neurons were observed during oxidant-mediated stress, hypoxia and mitochondrial inhibition. To further clarify the relevance of the fragile redox-balance for the neuronal (dys)function in RTT, we addressed more physiological stimuli and quantified the subcellular redox responses to neurotransmitter-stimulation. The roGFP redox sensor was expressed in either the cytosol or the mitochondrial matrix of cultured mouse hippocampal neurons, and the responses to transient stimulation by glutamate, serotonin, dopamine and norepinephrine were characterized. Each neurotransmitter evoked more intense oxidizing responses in the cytosol of MeCP2-deficient than in wildtype neurons. In the mitochondrial matrix the neurotransmitter-evoked oxidizing changes were more moderate and more uniform among genotypes. This identifies the cytosol as an important reactive oxygen species (ROS) source and as less stably redox buffered. Fura-2 imaging and extracellular Ca2+ withdrawal confirmed cytosolic Ca2+ transients as a contributing factor of neurotransmitter-induced redox responses and their potentiation in the cytosol of MeCP2-deficient neurons. Chemical uncoupling demonstrated the involvement of mitochondria. Nevertheless, cytosolic NADPH- and xanthine oxidases interact to play the leading role in the neurotransmitter-mediated oxidizing responses. As exaggerated redox-responses were already evident in neonatal MeCP2-deficient neurons, they may contribute remarkably to the altered neuronal network performance and the disturbed neuronal signaling, which are among the hallmarks of RTT.
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21
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Lee HM, Kuijer MB, Ruiz Blanes N, Clark EP, Aita M, Galiano Arjona L, Kokot A, Sciaky N, Simon JM, Bhatnagar S, Philpot BD, Cerase A. A small-molecule screen reveals novel modulators of MeCP2 and X-chromosome inactivation maintenance. J Neurodev Disord 2020; 12:29. [PMID: 33172406 PMCID: PMC7657357 DOI: 10.1186/s11689-020-09332-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 10/22/2020] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Rett syndrome (RTT) is a neurodevelopmental disorder caused by mutations in the X-linked methyl-CpG binding protein 2 (MeCP2) gene. While MeCP2 mutations are lethal in most males, females survive birth but show severe neurological defects. Because X-chromosome inactivation (XCI) is a random process, approximately 50% of the cells silence the wild-type (WT) copy of the MeCP2 gene. Thus, reactivating the silent WT copy of MeCP2 could provide therapeutic intervention for RTT. METHODS Toward this goal, we screened ~ 28,000 small-molecule compounds from several libraries using a MeCP2-luciferase reporter cell line and cortical neurons from a MeCP2-EGFP mouse model. We used gain/increase of luminescence or fluorescence as a readout of MeCP2 reactivation and tested the efficacy of these drugs under different drug regimens, conditions, and cellular contexts. RESULTS We identified inhibitors of the JAK/STAT pathway as XCI-reactivating agents, both by in vitro and ex vivo assays. In particular, we show that AG-490, a Janus Kinase 2 (JAK2) kinase inhibitor, and Jaki, a pan JAK/STAT inhibitor, are capable of reactivating MeCP2 from the inactive X chromosome, in different cellular contexts. CONCLUSIONS Our results suggest that inhibition of the JAK/STAT pathway is a new potential pathway to reinstate MeCP2 gene expression as an efficient RTT treatment.
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Affiliation(s)
- Hyeong-Min Lee
- Department of Cell Biology & Physiology, University of North Carolina School of Medicine, Chapel Hill, NC, USA
- UNC Neuroscience Center, Carolina Institute for Developmental Disabilities, University of North Carolina School of Medicine, Chapel Hill, NC, USA
- Current Address: High-Throughput Bioscience Center, Chemical Biology & Therapeutics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - M Bram Kuijer
- Department of Cell Biology & Physiology, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | | | - Ellen P Clark
- Department of Cell Biology & Physiology, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Megumi Aita
- Department of Cell Biology & Physiology, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | | | - Agnieszka Kokot
- Department of Biochemistry and Molecular Genetics, Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Noah Sciaky
- Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Jeremy M Simon
- UNC Neuroscience Center, Carolina Institute for Developmental Disabilities, University of North Carolina School of Medicine, Chapel Hill, NC, USA
- Department of Genetics, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Sanchita Bhatnagar
- Department of Biochemistry and Molecular Genetics, Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Benjamin D Philpot
- Department of Cell Biology & Physiology, University of North Carolina School of Medicine, Chapel Hill, NC, USA
- UNC Neuroscience Center, Carolina Institute for Developmental Disabilities, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Andrea Cerase
- Blizard Institute, Queen Mary University of London, London, UK.
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22
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Kostyuk AI, Panova AS, Kokova AD, Kotova DA, Maltsev DI, Podgorny OV, Belousov VV, Bilan DS. In Vivo Imaging with Genetically Encoded Redox Biosensors. Int J Mol Sci 2020; 21:E8164. [PMID: 33142884 PMCID: PMC7662651 DOI: 10.3390/ijms21218164] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 10/28/2020] [Accepted: 10/29/2020] [Indexed: 12/13/2022] Open
Abstract
Redox reactions are of high fundamental and practical interest since they are involved in both normal physiology and the pathogenesis of various diseases. However, this area of research has always been a relatively problematic field in the context of analytical approaches, mostly because of the unstable nature of the compounds that are measured. Genetically encoded sensors allow for the registration of highly reactive molecules in real-time mode and, therefore, they began a new era in redox biology. Their strongest points manifest most brightly in in vivo experiments and pave the way for the non-invasive investigation of biochemical pathways that proceed in organisms from different systematic groups. In the first part of the review, we briefly describe the redox sensors that were used in vivo as well as summarize the model systems to which they were applied. Next, we thoroughly discuss the biological results obtained in these studies in regard to animals, plants, as well as unicellular eukaryotes and prokaryotes. We hope that this work reflects the amazing power of this technology and can serve as a useful guide for biologists and chemists who work in the field of redox processes.
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Affiliation(s)
- Alexander I. Kostyuk
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Anastasiya S. Panova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Aleksandra D. Kokova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Daria A. Kotova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Dmitry I. Maltsev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Federal Center for Cerebrovascular Pathology and Stroke, 117997 Moscow, Russia
| | - Oleg V. Podgorny
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Vsevolod V. Belousov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
- Federal Center for Cerebrovascular Pathology and Stroke, 117997 Moscow, Russia
- Institute for Cardiovascular Physiology, Georg August University Göttingen, D-37073 Göttingen, Germany
| | - Dmitry S. Bilan
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
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23
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Miranda-Lourenço C, Duarte ST, Palminha C, Gaspar C, Rodrigues TM, Magalhães-Cardoso T, Rei N, Colino-Oliveira M, Gomes R, Ferreira S, Rosa J, Xapelli S, Armstrong J, García-Cazorla À, Correia-de-Sá P, Sebastião AM, Diógenes MJ. Impairment of adenosinergic system in Rett syndrome: Novel therapeutic target to boost BDNF signalling. Neurobiol Dis 2020; 145:105043. [PMID: 32798727 DOI: 10.1016/j.nbd.2020.105043] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 07/23/2020] [Accepted: 08/08/2020] [Indexed: 01/20/2023] Open
Abstract
Rett syndrome (RTT; OMIM#312750) is mainly caused by mutations in the X-linked MECP2 gene (methyl-CpG-binding protein 2 gene; OMIM*300005), which leads to impairments in the brain-derived neurotrophic factor (BDNF) signalling. The boost of BDNF mediated effects would be a significant breakthrough but it has been hampered by the difficulty to administer BDNF to the central nervous system. Adenosine, an endogenous neuromodulator, may accomplish that role since through A2AR it potentiates BDNF synaptic actions in healthy animals. We thus characterized several hallmarks of the adenosinergic and BDNF signalling in RTT and explored whether A2AR activation could boost BDNF actions. For this study, the RTT animal model, the Mecp2 knockout (Mecp2-/y) (B6.129P2 (C)-Mecp2tm1.1Bird/J) mouse was used. Whenever possible, parallel data was also obtained from post-mortem brain samples from one RTT patient. Ex vivo extracellular recordings of field excitatory post-synaptic potentials in CA1 hippocampal area were performed to evaluate synaptic transmission and long-term potentiation (LTP). RT-PCR was used to assess mRNA levels and Western Blot or radioligand binding assays were performed to evaluate protein levels. Changes in cortical and hippocampal adenosine content were assessed by liquid chromatography with diode array detection (LC/DAD). Hippocampal ex vivo experiments revealed that the facilitatory actions of BDNF upon LTP is absent in Mecp2-/y mice and that TrkB full-length (TrkB-FL) receptor levels are significantly decreased. Extracts of the hippocampus and cortex of Mecp2-/y mice revealed less adenosine amount as well as less A2AR protein levels when compared to WT littermates, which may partially explain the deficits in adenosinergic tonus in these animals. Remarkably, the lack of BDNF effect on hippocampal LTP in Mecp2-/y mice was overcome by selective activation of A2AR with CGS21680. Overall, in Mecp2-/y mice there is an impairment on adenosinergic system and BDNF signalling. These findings set the stage for adenosine-based pharmacological therapeutic strategies for RTT, highlighting A2AR as a therapeutic target in this devastating pathology.
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Affiliation(s)
- Catarina Miranda-Lourenço
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina e Instituto de Medicina Molecular - João Lobo Antunes, Universidade de Lisboa, Lisboa, Portugal.
| | - Sofia T Duarte
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina e Instituto de Medicina Molecular - João Lobo Antunes, Universidade de Lisboa, Lisboa, Portugal; Child Neurology Department, Hospital Dona Estefânia - Centro Hospitalar Universitário de Lisboa Central, Portugal.
| | - Cátia Palminha
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina e Instituto de Medicina Molecular - João Lobo Antunes, Universidade de Lisboa, Lisboa, Portugal.
| | - Cláudia Gaspar
- Instituto de Medicina Molecular - João Lobo Antunes, Universidade de Lisboa, Lisboa, Portugal.
| | - Tiago M Rodrigues
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina e Instituto de Medicina Molecular - João Lobo Antunes, Universidade de Lisboa, Lisboa, Portugal; Institute of Molecular and Clinical Ophtalmology, Mittlere Strasse 91, CH-4031 Basel, Switzerland.
| | - Teresa Magalhães-Cardoso
- Laboratório de Farmacologia e Neurobiologia / MedInUP, Instituto de Ciências Biomédicas Abel Salazar - Universidade do Porto (ICBAS-UP), Porto, Portugal.
| | - Nádia Rei
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina e Instituto de Medicina Molecular - João Lobo Antunes, Universidade de Lisboa, Lisboa, Portugal.
| | - Mariana Colino-Oliveira
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina e Instituto de Medicina Molecular - João Lobo Antunes, Universidade de Lisboa, Lisboa, Portugal.
| | - Rui Gomes
- Instituto de Medicina Molecular - João Lobo Antunes, Universidade de Lisboa, Lisboa, Portugal.
| | - Sara Ferreira
- Instituto de Medicina Molecular - João Lobo Antunes, Universidade de Lisboa, Lisboa, Portugal.
| | - Jéssica Rosa
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina e Instituto de Medicina Molecular - João Lobo Antunes, Universidade de Lisboa, Lisboa, Portugal.
| | - Sara Xapelli
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina e Instituto de Medicina Molecular - João Lobo Antunes, Universidade de Lisboa, Lisboa, Portugal.
| | - Judith Armstrong
- Genetics Department, Hospital Sant Joan de Deu. Institut Pediàtric de Recerca and CIBERER. (ISCIII), Barcelona, Spain.
| | - Àngels García-Cazorla
- Synaptic Metabolism Laboratory, Neurology Department; Institut Pediàtric de Recerca and CIBERER. (ISCIII), Barcelona, Spain.
| | - Paulo Correia-de-Sá
- Laboratório de Farmacologia e Neurobiologia / MedInUP, Instituto de Ciências Biomédicas Abel Salazar - Universidade do Porto (ICBAS-UP), Porto, Portugal.
| | - Ana M Sebastião
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina e Instituto de Medicina Molecular - João Lobo Antunes, Universidade de Lisboa, Lisboa, Portugal.
| | - Maria José Diógenes
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina e Instituto de Medicina Molecular - João Lobo Antunes, Universidade de Lisboa, Lisboa, Portugal.
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24
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Abstract
Epilepsy and autism frequently co-occur. Epilepsy confers an increased risk of autism and autism confers an increased risk of epilepsy. Specific epilepsy syndromes, intellectual disability, and female gender present a particular risk of autism in individuals with epilepsy. Epilepsy and autism are likely to share common etiologies, which predispose individuals to either or both conditions. Genetic factors, metabolic disorders, mitochondrial disorders, and immune dysfunction all can be implicated.
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Affiliation(s)
- Frank M C Besag
- East London NHS Foundation Trust, 5-7 Rush Court, Bedford MK40 3JT, UK; University College London, London, UK; King's College London, London, UK.
| | - Michael J Vasey
- East London NHS Foundation Trust, 5-7 Rush Court, Bedford MK40 3JT, UK
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25
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Zuliani I, Urbinati C, Valenti D, Quattrini MC, Medici V, Cosentino L, Pietraforte D, Di Domenico F, Perluigi M, Vacca RA, De Filippis B. The Anti-Diabetic Drug Metformin Rescues Aberrant Mitochondrial Activity and Restrains Oxidative Stress in a Female Mouse Model of Rett Syndrome. J Clin Med 2020; 9:jcm9061669. [PMID: 32492904 PMCID: PMC7355965 DOI: 10.3390/jcm9061669] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 05/26/2020] [Accepted: 05/28/2020] [Indexed: 12/25/2022] Open
Abstract
Metformin is the first-line therapy for diabetes, even in children, and a promising attractive candidate for drug repurposing. Mitochondria are emerging as crucial targets of metformin action both in the periphery and in the brain. The present study evaluated whether treatment with metformin may rescue brain mitochondrial alterations and contrast the increased oxidative stress in a validated mouse model of Rett syndrome (RTT), a rare neurologic disorder of monogenic origin characterized by severe behavioral and physiological symptoms. No cure for RTT is available. In fully symptomatic RTT mice (12 months old MeCP2-308 heterozygous female mice), systemic treatment with metformin (100 mg/kg ip for 10 days) normalized the reduced mitochondrial ATP production and ATP levels in the whole-brain, reduced brain oxidative damage, and rescued the increased production of reactive oxidizing species in blood. A 10-day long treatment with metformin also boosted pathways related to mitochondrial biogenesis and antioxidant defense in the brain of metformin-treated RTT mice. This treatment regimen did not improve general health status and motor dysfunction in RTT mice at an advanced stage of the disease. Present results provide evidence that systemic treatment with metformin may represent a novel, repurposable therapeutic strategy for RTT.
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Affiliation(s)
- Ilaria Zuliani
- Department of Biochemical Sciences, Sapienza University of Rome, 00185 Rome, Italy; (I.Z.); (F.D.D.); (M.P.)
| | - Chiara Urbinati
- Center for Behavioral Sciences and Mental Health, Istituto Superiore di Sanità, 00161 Rome, Italy; (C.U.); (V.M.); (L.C.)
| | - Daniela Valenti
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, National Council of Research, 70126 Bari, Italy; (D.V.); (R.A.V.)
| | | | - Vanessa Medici
- Center for Behavioral Sciences and Mental Health, Istituto Superiore di Sanità, 00161 Rome, Italy; (C.U.); (V.M.); (L.C.)
| | - Livia Cosentino
- Center for Behavioral Sciences and Mental Health, Istituto Superiore di Sanità, 00161 Rome, Italy; (C.U.); (V.M.); (L.C.)
| | | | - Fabio Di Domenico
- Department of Biochemical Sciences, Sapienza University of Rome, 00185 Rome, Italy; (I.Z.); (F.D.D.); (M.P.)
| | - Marzia Perluigi
- Department of Biochemical Sciences, Sapienza University of Rome, 00185 Rome, Italy; (I.Z.); (F.D.D.); (M.P.)
| | - Rosa Anna Vacca
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, National Council of Research, 70126 Bari, Italy; (D.V.); (R.A.V.)
| | - Bianca De Filippis
- Center for Behavioral Sciences and Mental Health, Istituto Superiore di Sanità, 00161 Rome, Italy; (C.U.); (V.M.); (L.C.)
- Correspondence:
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26
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Fagiolini M, Patrizi A, LeBlanc J, Jin LW, Maezawa I, Sinnett S, Gray SJ, Molholm S, Foxe JJ, Johnston MV, Naidu S, Blue M, Hossain A, Kadam S, Zhao X, Chang Q, Zhou Z, Zoghbi H. Intellectual and Developmental Disabilities Research Centers: A Multidisciplinary Approach to Understand the Pathogenesis of Methyl-CpG Binding Protein 2-related Disorders. Neuroscience 2020; 445:190-206. [PMID: 32360592 DOI: 10.1016/j.neuroscience.2020.04.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/20/2020] [Accepted: 04/21/2020] [Indexed: 12/20/2022]
Abstract
Disruptions in the gene encoding methyl-CpG binding protein 2 (MECP2) underlie complex neurodevelopmental disorders including Rett Syndrome (RTT), MECP2 duplication disorder, intellectual disabilities, and autism. Significant progress has been made on the molecular and cellular basis of MECP2-related disorders providing a new framework for understanding how altered epigenetic landscape can derail the formation and refinement of neuronal circuits in early postnatal life and proper neurological function. This review will summarize selected major findings from the past years and particularly highlight the integrated and multidisciplinary work done at eight NIH-funded Intellectual and Developmental Disabilities Research Centers (IDDRC) across the US. Finally, we will outline a path forward with identification of reliable biomarkers and outcome measures, longitudinal preclinical and clinical studies, reproducibility of results across centers as a synergistic effort to decode and treat the pathogenesis of the complex MeCP2 disorders.
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Affiliation(s)
- Michela Fagiolini
- Children's Hospital Intellectual and Developmental Disabilities Research Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
| | - Annarita Patrizi
- Children's Hospital Intellectual and Developmental Disabilities Research Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jocelyn LeBlanc
- Children's Hospital Intellectual and Developmental Disabilities Research Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Lee-Way Jin
- UC Davis MIND Institute, University of California, Sacramento, CA, USA
| | - Izumi Maezawa
- UC Davis MIND Institute, University of California, Sacramento, CA, USA
| | - Sarah Sinnett
- UNC Intellectual and Developmental Disabilities Research Center, University of North Carolina, Gene Therapy Center and Dept. of Ophthalmology, Chapel Hill, NC, USA; Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX, USA
| | - Steven J Gray
- UNC Intellectual and Developmental Disabilities Research Center, University of North Carolina, Gene Therapy Center and Dept. of Ophthalmology, Chapel Hill, NC, USA; Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX, USA
| | - Sophie Molholm
- The Cognitive Neurophysiology Laboratory, Departments of Pediatrics, Neuroscience, and Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, NY, USA
| | - John J Foxe
- The Cognitive Neurophysiology Laboratory, Ernest J. Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Michael V Johnston
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Sakkubai Naidu
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Mary Blue
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Ahamed Hossain
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Shilpa Kadam
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Xinyu Zhao
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
| | - Quiang Chang
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
| | - Zhaolan Zhou
- Department of Genetic, Epigenetic Institute, University of Pennsylvania Perelman School of Medicine, Intellectual and Developmental Disabilities Research Center, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Huda Zoghbi
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Program in Developmental Biology, Baylor College of Medicine, Houston, TX, USA; Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA; Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA; Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX, USA
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27
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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.
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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.
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28
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Cortelazzo A, De Felice C, Guy J, Timperio AM, Zolla L, Guerranti R, Leoncini S, Signorini C, Durand T, Hayek J. Brain protein changes in Mecp2 mouse mutant models: Effects on disease progression of Mecp2 brain specific gene reactivation. J Proteomics 2019; 210:103537. [PMID: 31629059 DOI: 10.1016/j.jprot.2019.103537] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 09/10/2019] [Accepted: 09/27/2019] [Indexed: 12/29/2022]
Abstract
Rett syndrome (RTT) is a leading cause of severe intellectual disability in females, caused by de novo loss-of function mutations in the X-linked methyl-CpG binding protein 2 (MECP2). To better investigate RTT disease progression/pathogenesis animal models of Mecp2 deficiency have been developed. Here, Mecp2 mouse models are employed to investigate the role of protein patterns in RTT. A proteome analysis was carried out in brain tissue from i) Mecp2 deficient mice at the pre-symptomatic and symptomatic stages and, ii) mice in which the disease phenotype was reversed by Mecp2 reactivation. Several proteins were shown to be differentially expressed in the pre-symptomatic (n = 18) and symptomatic (n = 20) mice. Mecp2 brain reactivated mice showed wild-type comparable levels of expression for twelve proteins, mainly related to proteostasis (n = 4) and energy metabolic pathways (n = 4). The remaining ones were found to be involved in redox homeostasis (n = 2), nitric oxide regulation (n = 1), neurodevelopment (n = 1). Ten out of twelve proteins were newly linked to Mecp2 deficiency. Our study sheds light on the relevance of the protein-regulation of main physiological process in the complex mechanisms leading from Mecp2 mutation to the RTT clinical phenotype. SIGNIFICANCE: We performed a proteomic study of a Mecp2stop/y mouse model for Rett syndrome (RTT) at the pre-symptomatic and symptomatic Mecp2 deficient mice stage and for the brain specific reactivated Mecp2 model. Our results reveal major protein expression changes pointing out to defects in proteostasis or energy metabolic pathways other than, to a lesser extent, in redox homeostasis, nitric oxide regulation or neurodevelopment. The Mecp2 mouse rescued model provides the possibility to select target proteins more susceptible to the Mecp2 gene mutation, potential and promising therapeutical targets.
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Affiliation(s)
- Alessio Cortelazzo
- Child Neuropsychiatry Unit, University Hospital, Azienda Ospedaliera Universitaria Senese (AOUS), Siena, Italy; Department of Medical Biotechnologies, University of Siena, Siena, Italy; Clinical Pathology Laboratory Unit, University Hospital, AOUS, Siena, Italy.
| | - Claudio De Felice
- Neonatal Intensive Care Unit, University Hospital, AOUS, Siena, Italy
| | - Jacky Guy
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Anna Maria Timperio
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
| | - Lello Zolla
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
| | - Roberto Guerranti
- Department of Medical Biotechnologies, University of Siena, Siena, Italy; Clinical Pathology Laboratory Unit, University Hospital, AOUS, Siena, Italy
| | - Silvia Leoncini
- Child Neuropsychiatry Unit, University Hospital, Azienda Ospedaliera Universitaria Senese (AOUS), Siena, Italy; Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Cinzia Signorini
- Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Thierry Durand
- Institut des Biomolécules Max Mousseron, (IBMM), UMR 5247, CNRS, Université de Montpellier, ENSCM, Montpellier, France
| | - Joussef Hayek
- Child Neuropsychiatry Unit, University Hospital, Azienda Ospedaliera Universitaria Senese (AOUS), Siena, Italy
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29
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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] [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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Sanfeliu A, Kaufmann WE, Gill M, Guasoni P, Tropea D. Transcriptomic Studies in Mouse Models of Rett Syndrome: A Review. Neuroscience 2019; 413:183-205. [PMID: 31229631 DOI: 10.1016/j.neuroscience.2019.06.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 05/10/2019] [Accepted: 06/10/2019] [Indexed: 12/17/2022]
Abstract
Rett Syndrome (RTT) is a neurological disorder mainly associated with mutations in the X-linked gene coding for the methyl-CpG binding protein 2 (MECP2). To assist in studying MECP2's function, researchers have generated Mecp2 mouse mutants showing that MECP2's product (MeCP2) mostly functions as a transcriptional regulator. During the last two decades, these models have been used to determine the genes that are regulated by MeCP2, slowly dissecting the etiological mechanisms underlying RTT. In the present review, we describe the findings of these transcriptomic studies, and highlight differences between them, and discuss how studies on these genetic models can sharpen our understanding of the human disorder. We conclude that - while there's large variability regarding the number of differentially expressed genes identified - there are overlapping features that inform on the biology of RTT.
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Affiliation(s)
- Albert Sanfeliu
- Neuropsychiatric Genetics, School of Medicine, Trinity Center for Health Sciences, St James Hospital D8, Dublin, Ireland
| | - Walter E Kaufmann
- Department of Human Genetics, Emory University School of Medicine and Department of Neurology, University of California Davis School of Medicine, Atlanta, GA 30322, USA
| | - Michael Gill
- Neuropsychiatric Genetics, School of Medicine, Trinity Center for Health Sciences, St James Hospital D8, Dublin, Ireland
| | - Paolo Guasoni
- Department of Mathematical Sciences, Dublin City University, Glasnevin, D9, Dublin, Ireland
| | - Daniela Tropea
- Neuropsychiatric Genetics, School of Medicine, Trinity Center for Health Sciences, St James Hospital D8, Dublin, Ireland; Trinity College Institute of Neuroscience, Lloyd Building, D2, Dublin, Ireland.
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Cosentino L, Vigli D, Franchi F, Laviola G, De Filippis B. Rett syndrome before regression: A time window of overlooked opportunities for diagnosis and intervention. Neurosci Biobehav Rev 2019; 107:115-135. [PMID: 31108160 DOI: 10.1016/j.neubiorev.2019.05.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 05/10/2019] [Accepted: 05/15/2019] [Indexed: 11/29/2022]
Abstract
Rett syndrome (RTT) is a rare neurological disorder primarily affecting females, causing severe cognitive, social, motor and physiological impairments for which no cure currently exists. RTT clinical diagnosis is based on the peculiar progression of the disease, since patients show an apparently normal initial development with a subsequent sudden regression at around 2 years of age. Accumulating evidences are rising doubts regarding the absence of early impairments, hence questioning the concept of regression. We reviewed the published literature addressing the pre-symptomatic stage of the disease in both patients and animal models with a particular focus on behavioral, physiological and brain abnormalities. The emerging picture delineates subtle, but reliable impairments that precede the onset of overt symptoms whose bases are likely set up already during embryogenesis. Some of the outlined alterations appear transient, suggesting compensatory mechanisms to occur in the course of development. There is urgent need for more systematic developmental analyses able to detect early pathological markers to be used as diagnostic tools and precocious targets of time-specific interventions.
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Affiliation(s)
- Livia Cosentino
- Center for Behavioral Sciences and Mental Health, Istituto Superiore di Sanità, Viale Regina Elena, 299, 00161 Rome, Italy
| | - Daniele Vigli
- Center for Behavioral Sciences and Mental Health, Istituto Superiore di Sanità, Viale Regina Elena, 299, 00161 Rome, Italy
| | - Francesca Franchi
- Center for Behavioral Sciences and Mental Health, Istituto Superiore di Sanità, Viale Regina Elena, 299, 00161 Rome, Italy
| | - Giovanni Laviola
- Center for Behavioral Sciences and Mental Health, Istituto Superiore di Sanità, Viale Regina Elena, 299, 00161 Rome, Italy
| | - Bianca De Filippis
- Center for Behavioral Sciences and Mental Health, Istituto Superiore di Sanità, Viale Regina Elena, 299, 00161 Rome, Italy.
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Can K, Menzfeld C, Rinne L, Rehling P, Kügler S, Golubiani G, Dudek J, Müller M. Neuronal Redox-Imbalance in Rett Syndrome Affects Mitochondria as Well as Cytosol, and Is Accompanied by Intensified Mitochondrial O 2 Consumption and ROS Release. Front Physiol 2019; 10:479. [PMID: 31114506 PMCID: PMC6503037 DOI: 10.3389/fphys.2019.00479] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 04/05/2019] [Indexed: 12/31/2022] Open
Abstract
Rett syndrome (RTT), an X chromosome-linked neurodevelopmental disorder affecting almost exclusively females, is associated with various mitochondrial alterations. Mitochondria are swollen, show altered respiratory rates, and their inner membrane is leaking protons. To advance the understanding of these disturbances and clarify their link to redox impairment and oxidative stress, we assessed mitochondrial respiration in defined brain regions and cardiac tissue of male wildtype (WT) and MeCP2-deficient (Mecp2-/y ) mice. Also, we quantified for the first time neuronal redox-balance with subcellular resolution in cytosol and mitochondrial matrix. Quantitative roGFP1 redox imaging revealed more oxidized conditions in the cytosol of Mecp2-/y hippocampal neurons than in WT neurons. Furthermore, cytosol and mitochondria of Mecp2-/y neurons showed exaggerated redox-responses to hypoxia and cell-endogenous reactive oxygen species (ROS) formation. Biochemical analyzes exclude disease-related increases in mitochondrial mass in Mecp2-/y hippocampus and cortex. Protein levels of complex I core constituents were slightly lower in Mecp2-/y hippocampus and cortex than in WT; those of complex V were lower in Mecp2-/y cortex. Respiratory supercomplex-formation did not differ among genotypes. Yet, supplied with the complex II substrate succinate, mitochondria of Mecp2-/y cortex and hippocampus consumed more O2 than WT. Furthermore, mitochondria from Mecp2-/y hippocampus and cortex mediated an enhanced oxidative burden. In conclusion, we further advanced the molecular understanding of mitochondrial dysfunction in RTT. Intensified mitochondrial O2 consumption, increased mitochondrial ROS generation and disturbed redox balance in mitochondria and cytosol may represent a causal chain, which provokes dysregulated proteins, oxidative tissue damage, and contributes to neuronal network dysfunction in RTT.
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Affiliation(s)
- Karolina Can
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Georg-August-University Göttingen, Göttingen, Germany
- Zentrum Physiologie und Pathophysiologie, Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Christiane Menzfeld
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Georg-August-University Göttingen, Göttingen, Germany
- Zentrum Physiologie und Pathophysiologie, Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Lena Rinne
- Zentrum Physiologie und Pathophysiologie, Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Peter Rehling
- Zentrum Biochemie und Molekulare Zellbiologie, Institut für Zellbiochemie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Sebastian Kügler
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Georg-August-University Göttingen, Göttingen, Germany
- Klinik für Neurologie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Gocha Golubiani
- Zentrum Physiologie und Pathophysiologie, Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, Göttingen, Germany
- Institute of Chemical Biology, Ilia State University, Tbilisi, Georgia
| | - Jan Dudek
- Zentrum Biochemie und Molekulare Zellbiologie, Institut für Zellbiochemie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Michael Müller
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Georg-August-University Göttingen, Göttingen, Germany
- Zentrum Physiologie und Pathophysiologie, Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, Göttingen, Germany
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Sanfeliu A, Hokamp K, Gill M, Tropea D. Transcriptomic Analysis of Mecp2 Mutant Mice Reveals Differentially Expressed Genes and Altered Mechanisms in Both Blood and Brain. Front Psychiatry 2019; 10:278. [PMID: 31110484 PMCID: PMC6501143 DOI: 10.3389/fpsyt.2019.00278] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 04/11/2019] [Indexed: 12/11/2022] Open
Abstract
Rett syndrome is a rare neuropsychiatric disorder with a wide symptomatology including impaired communication and movement, cardio-respiratory abnormalities, and seizures. The clinical presentation is typically associated to mutations in the gene coding for the methyl-CpG-binding protein 2 (MECP2), which is a transcription factor. The gene is ubiquitously present in all the cells of the organism with a peak of expression in neurons. For this reason, most of the studies in Rett models have been performed in brain. However, some of the symptoms of Rett are linked to the peripheral expression of MECP2, suggesting that the effects of the mutations affect gene expression levels in tissues other than the brain. We used RNA sequencing in Mecp2 mutant mice and matched controls, to identify common genes and pathways differentially regulated across different tissues. We performed our study in brain and peripheral blood, and we identified differentially expressed genes (DEGs) and pathways in each tissue. Then, we compared the genes and mechanisms identified in each preparation. We found that some genes and molecular pathways that are differentially expressed in brain are also differentially expressed in blood of Mecp2 mutant mice at a symptomatic-but not presymptomatic-stage. This is the case for the gene Ube2v1, linked to ubiquitination system, and Serpin1, involved in complement and coagulation cascades. Analysis of biological functions in the brain shows the enrichment of mechanisms correlated to circadian rhythms, while in the blood are enriched the mechanisms of response to stimulus-including immune response. Some mechanisms are enriched in both preparations, such as lipid metabolism and response to stress. These results suggest that analysis of peripheral blood can reveal ubiquitous altered molecular mechanisms of Rett and have applications in diagnosis and treatments' assessments.
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Affiliation(s)
- Albert Sanfeliu
- Neuropsychiatric Genetics, Department of Psychiatry, School of Medicine, Trinity Translational Medicine Institute, St James Hospital, Dublin, Ireland
| | - Karsten Hokamp
- Department of Genetics, School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - Michael Gill
- Neuropsychiatric Genetics, Department of Psychiatry, School of Medicine, Trinity Translational Medicine Institute, St James Hospital, Dublin, Ireland
| | - Daniela Tropea
- Neuropsychiatric Genetics, Department of Psychiatry, School of Medicine, Trinity Translational Medicine Institute, St James Hospital, Dublin, Ireland
- Department of Psychiatry, School of Medicine, Trinity College Institute for Neuroscience, Trinity College Dublin, Dublin, Ireland
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Treating Rett syndrome: from mouse models to human therapies. Mamm Genome 2019; 30:90-110. [PMID: 30820643 PMCID: PMC6606665 DOI: 10.1007/s00335-019-09793-5] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 02/09/2019] [Indexed: 02/06/2023]
Abstract
Rare diseases are very difficult to study mechanistically and to develop therapies for because of the scarcity of patients. Here, the rare neuro-metabolic disorder Rett syndrome (RTT) is discussed as a prototype for precision medicine, demonstrating how mouse models have led to an understanding of the development of symptoms. RTT is caused by mutations in the X-linked gene methyl-CpG-binding protein 2 (MECP2). Mecp2-mutant mice are being used in preclinical studies that target the MECP2 gene directly, or its downstream pathways. Importantly, this work may improve the health of RTT patients. Clinical presentation may vary widely among individuals based on their mutation, but also because of the degree of X chromosome inactivation and the presence of modifier genes. Because it is a complex disorder involving many organ systems, it is likely that recovery of RTT patients will involve a combination of treatments. Precision medicine is warranted to provide the best efficacy to individually treat RTT patients.
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Müller M. Disturbed redox homeostasis and oxidative stress: Potential players in the developmental regression in Rett syndrome. Neurosci Biobehav Rev 2019; 98:154-163. [PMID: 30639673 DOI: 10.1016/j.neubiorev.2018.12.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 11/30/2018] [Accepted: 12/06/2018] [Indexed: 12/16/2022]
Abstract
Rett syndrome (RTT) is a neurodevelopmental disorder affecting mostly girls. A seemingly normal initial development is followed by developmental stagnation and regression, leading to severe mental impairment with autistic features, motor dysfunction, irregular breathing and epilepsy. Currently, a cure does not exist. Due to the close association of RTT with mitochondrial alterations, cellular redox-impairment and oxidative stress, compounds stabilizing mitochondrial function, cellular redox-homeostasis, and oxidant detoxification are increasingly considered as treatment concepts. Indeed, antioxidants and free-radical scavengers ameliorate certain aspects of the complex and severe clinical presentation of RTT. To further evaluate these strategies, reliable biosensors are needed to quantify redox-conditions in brain and peripheral organs of mouse models or in patient-derived cells. Genetically-encoded redox-sensors meet these requirements. Expressed in transgenic mouse-models such as our unique Rett-redox indicator mice, they will report for any cell type desired the severity of oxidant stress throughout the various disease stages of RTT. Furthermore, these sensors will be crucial to evaluate in vitro and in vivo the outcome of mitochondria- and redox-balance targeted treatments.
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Affiliation(s)
- Michael Müller
- Georg-August-Universität Göttingen, Universitätsmedizin Göttingen, Germany; Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Humboldtallee 23, D-37073 Göttingen, Germany; Zentrum Physiologie und Pathophysiologie, Institut für Neuro-und Sinnesphysiologie, Humboldtallee 23, D-37073 Göttingen, Germany.
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36
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Bennuri SC, Rose S, Frye RE. Mitochondrial Dysfunction Is Inducible in Lymphoblastoid Cell Lines From Children With Autism and May Involve the TORC1 Pathway. Front Psychiatry 2019; 10:269. [PMID: 31133888 PMCID: PMC6514096 DOI: 10.3389/fpsyt.2019.00269] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 04/09/2019] [Indexed: 01/25/2023] Open
Abstract
We previously developed a lymphoblastoid cell line (LCL) model of mitochondrial dysfunction in autism spectrum disorder (ASD); some individuals with ASD showed mitochondrial dysfunction (AD-A) while other individuals (AD-N) demonstrated mitochondrial respiration similar to controls (CNT). To test the hypothesis that mitochondrial dysfunction could be a consequence of environmental exposures through chronic elevations in reactive oxygen species (ROS), we exposed LCLs to prolonged ROS. We also examined expression of metabolic regulatory genes and the modulating effect of the mechanistic target of rapamycin (mTOR) pathway. Prolonged ROS exposure induced or worsened mitochondrial dysfunction in all LCL groups. Expression of genes associated with ROS protection was elevated in both AD-N and AD-A LCLs, but mitochondrial fission/fusion and mitoplasticity gene expression was only increased in AD-N LCLs. Partial least squares discriminant analysis showed that mTOR, UCP2 (uncoupling protein 2), SIRT1 (sirtuin 1), and MFN2 (mitofusin-2) gene expression differentiated LCL groups. Low-dose rapamycin (0.1 nM) normalized respiration with the magnitude of this normalization greater for AD-A LCLs, suggesting that the mammalian target of rapamycin complex 1 (mTORC1) pathway may have a different dynamic range for regulating mitochondrial activity in individuals with ASD with and without mitochondrial dysfunction, potentially related to S6K1 (S6 kinase beta-1) regulation. Understanding pathways that underlie mitochondrial dysfunction in ASD may lead to novel treatments.
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Affiliation(s)
- Sirish C Bennuri
- Arkansas Children's Research Institute and Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Shannon Rose
- Arkansas Children's Research Institute and Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Richard E Frye
- Barrow Neurologic Institute at Phoenix Children's Hospital, Phoenix, AZ, United States.,Department of Child Health, University of Arizona College of Medicine-Phoenix, Phoenix, AZ, United States
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Mitochondrial Electron Transport Chain Complex Dysfunction in MeCP2 Knock-Down Astrocytes: Protective Effects of Quercetin Hydrate. J Mol Neurosci 2018; 67:16-27. [PMID: 30519865 DOI: 10.1007/s12031-018-1197-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 10/15/2018] [Indexed: 12/30/2022]
Abstract
Astrocytes play the central role in CNS metabolism to support neuronal functions. Mehyl-CpG-binding protein 2 (MeCP2) is the global transcription factor with differential expression in neuronal and non-neuronal cells. MeCP2 mutation and downstream detrimental effects have been reported in astrocytes also in MeCP2-associated neurodevelopmental disorder-Rett syndrome. Several studies have shown mitochondrial impairment linked to ROS production and reduced ATP synthesis in Rett patients and models, but consequences of MeCP2 deficiency on mitochondrial electron transport chain complexes in astrocytes and effect of known antioxidant quercetin aglycone has not yet been reported. The present study aimed to investigate effect of quercetin on mitochondrial functioning in MeCP2-deficient astrocytes. Our data show onefold upregulated Uqcrc1 and Ndufv2 gene expression, subtle change in protein expression, and significantly reduced mitochondrial respiratory chain complex-II and complex-III enzyme activities in MeCP2 knock-down astrocytes. Intracellular calcium robustly increased and mitochondrial membrane potential decreased, while no change in ROS was observed in MeCP2 knock-down astrocytes. Quercetin increased MeCP2 and normalized Uqcrc1 and Ndufv2 gene expression but did not modulate MeCP2 and Ndufv2 proteins expression. Interestingly, quercetin upregulated significantly the mitochondrial respiratory complex-II, complex-III, and complex-IV activities in dose-dependent manner. It also restored intracellular calcium level and mitochondrial membrane potential. In vitro observations suggest the beneficial effect of quercetin in mitochondrial functioning in MeCP2-deficient condition. There are no reports focusing on role of quercetin in mitochondrial function in MeCP2-deficient astrocytes, and these observations serve as preliminary data to evaluate quercetin's effects in vivo.
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Shovlin S, Tropea D. Transcriptome level analysis in Rett syndrome using human samples from different tissues. Orphanet J Rare Dis 2018; 13:113. [PMID: 29996871 PMCID: PMC6042368 DOI: 10.1186/s13023-018-0857-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 06/27/2018] [Indexed: 01/06/2023] Open
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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Abstract
Rett Syndrome is a severe neurological disorder mainly due to
de novo mutations in the methyl-CpG-binding protein 2 gene (
MECP2). Mecp2 is known to play a role in chromatin organization and transcriptional regulation. In this review, we report the latest advances on the molecular function of Mecp2 and the new animal and cellular models developed to better study Rett syndrome. Finally, we present the latest innovative therapeutic approaches, ranging from classical pharmacology to correct symptoms to more innovative approaches intended to cure the pathology.
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Affiliation(s)
- Yann Ehinger
- Aix Marseille Univ, INSERM, MMG, 13385 Marseille, France
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Tolö J, Taschenberger G, Leite K, Stahlberg MA, Spehlbrink G, Kues J, Munari F, Capaldi S, Becker S, Zweckstetter M, Dean C, Bähr M, Kügler S. Pathophysiological Consequences of Neuronal α-Synuclein Overexpression: Impacts on Ion Homeostasis, Stress Signaling, Mitochondrial Integrity, and Electrical Activity. Front Mol Neurosci 2018; 11:49. [PMID: 29563864 PMCID: PMC5845890 DOI: 10.3389/fnmol.2018.00049] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 02/06/2018] [Indexed: 11/13/2022] Open
Abstract
α-Synuclein (α-Syn) is intimately linked to the etiology of Parkinson's Disease, as mutations and even subtle increases in gene dosage result in early onset of the disease. However, how this protein causes neuronal dysfunction and neurodegeneration is incompletely understood. We thus examined a comprehensive range of physiological parameters in cultured rat primary neurons overexpressing α-Syn at levels causing a slowly progressive neurodegeneration. In contradiction to earlier reports from non-neuronal assay systems we demonstrate that α-Syn does not interfere with essential ion handling capacities, mitochondrial capability of ATP production or basic electro-physiological properties like resting membrane potential or the general ability to generate action potentials. α-Syn also does not activate canonical stress kinase Signaling converging on SAPK/Jun, p38 MAPK or Erk kinases. Causative for α-Syn-induced neurodegeneration are mitochondrial thiol oxidation and activation of caspases downstream of mitochondrial outer membrane permeabilization, leading to apoptosis-like cell death execution with some unusual aspects. We also aimed to elucidate neuroprotective strategies counteracting the pathophysiological processes caused by α-Syn. Neurotrophic factors, calpain inhibition and increased lysosomal protease capacity showed no protective effects against α-Syn overexpression. In contrast, the major watchdog of outer mitochondrial membrane integrity, Bcl-Xl, was capable of almost completely preventing neuron death, but did not prevent mitochondrial thiol oxidation. Importantly, independent from the quite mono-causal induction of neurotoxicity, α-Syn causes diminished excitability of neurons by external stimuli and robust impairments in endogenous neuronal network activity by decreasing the frequency of action potentials generated without external stimulation. This latter finding suggests that α-Syn can induce neuronal dysfunction independent from its induction of neurotoxicity and might serve as an explanation for functional deficits that precede neuronal cell loss in synucleopathies like Parkinson's disease or dementia with Lewy bodies.
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Affiliation(s)
- Johan Tolö
- Department of Physiology, The Sahlgrenska Academy at Gothenburg University, Gothenburg, Sweden
| | - Grit Taschenberger
- Department of Neurology, University Medical Center Goettingen, Göttingen, Germany.,Center Nanoscale Microscopy and Physiology of the Brain, Göttingen, Germany
| | - Kristian Leite
- Department of Neurology, University Medical Center Goettingen, Göttingen, Germany
| | - Markus A Stahlberg
- European Neuroscience Institute, Department of Transsynaptic Signaling, Göttingen, Germany
| | - Gesche Spehlbrink
- Department of Neurology, University Medical Center Goettingen, Göttingen, Germany
| | - Janina Kues
- Department of Neurology, University Medical Center Goettingen, Göttingen, Germany
| | - Francesca Munari
- German Center for Neurodegenerative Diseases, Göttingen, Germany.,Department for NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Stefano Capaldi
- Biocrystallography Laboratory, Department of Biotechnology, University of Verona, Verona, Italy
| | - Stefan Becker
- Department for NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Markus Zweckstetter
- Department of Neurology, University Medical Center Goettingen, Göttingen, Germany.,Center Nanoscale Microscopy and Physiology of the Brain, Göttingen, Germany.,German Center for Neurodegenerative Diseases, Göttingen, Germany.,Department for NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Camin Dean
- Center Nanoscale Microscopy and Physiology of the Brain, Göttingen, Germany.,European Neuroscience Institute, Department of Transsynaptic Signaling, Göttingen, Germany
| | - Mathias Bähr
- Department of Neurology, University Medical Center Goettingen, Göttingen, Germany.,Center Nanoscale Microscopy and Physiology of the Brain, Göttingen, Germany
| | - Sebastian Kügler
- Department of Neurology, University Medical Center Goettingen, Göttingen, Germany.,Center Nanoscale Microscopy and Physiology of the Brain, Göttingen, Germany
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Wong S, Giulivi C. Autism, Mitochondria and Polybrominated Diphenyl Ether Exposure. CNS & NEUROLOGICAL DISORDERS-DRUG TARGETS 2017; 15:614-23. [PMID: 27071785 DOI: 10.2174/1871527315666160413122624] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 12/29/2015] [Accepted: 01/09/2016] [Indexed: 12/11/2022]
Abstract
BACKGROUND Autism spectrum disorders (ASD) are a growing concern with more than 1 in every 68 children affected in the United States by age 8. Limited scientific advances have been made regarding the etiology of autism, with general agreement that both genetic and environmental factors contribute to this disorder. OBJECTIVE To explore the link between exposure to PBDE, mitochondrial dysfunction and autism risk. RESULTS Perinatal exposures to PBDEs may contribute to the etiology or morbidity of ASD including mitochondrial dysfunction based on (i) their increased environmental abundance and human exposures, (ii) their activity towards implicated in neuronal development and synaptic plasticity including mitochondria, and (iii) their bioaccumulation in mitochondria. CONCLUSION In this review, we propose that PBDE, and possibly other environmental exposures, during child development can induce or compound mitochondrial dysfunction, which in conjunction with a dysregulated antioxidant response, increase a child's susceptibility of autism.
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Affiliation(s)
| | - Cecilia Giulivi
- University of California, Department of Molecular Biosciences, 1089 Veterinary Medicine Dr., 3009 VetMed3B, Davis, CA 95616, USA.
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Valacchi G, Pecorelli A, Cervellati C, Hayek J. 4-hydroxynonenal protein adducts: Key mediator in Rett syndrome oxinflammation. Free Radic Biol Med 2017; 111:270-280. [PMID: 28063942 DOI: 10.1016/j.freeradbiomed.2016.12.045] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 12/24/2016] [Accepted: 12/30/2016] [Indexed: 12/13/2022]
Abstract
In the last 15 years a strong correlation between oxidative stress (OxS) and Rett syndrome (RTT), a rare neurodevelopmental disorder known to be caused in 95% of the cases, by a mutation in the methyl-CpG-binding protein 2 (MECP2) gene, has been well documented. Here, we revised, summarized and discussed the current knowledge on the role of lipid peroxidation byproducts, with special emphasis on 4-hydroxynonenal (4HNE), in RTT pathophysiology. The posttranslational modifications of proteins via 4HNE, known as 4HNE protein adducts (4NHE-PAs), causing detrimental effects on protein functions, appear to contribute to the clinical severity of the syndrome, since their levels increase significantly during the subsequent 4 clinical stages, reaching the maximum degree at stage 4, represented by a late motor deterioration. In addition, 4HNE-PA are only partially removed due to the compromised functionality of the proteasome activity, contributing therefore to the cellular damage in RTT. All this will lead to a characteristic subclinical inflammation, defined "OxInflammation", derived by a positive feedback loop between OxS byproducts and inflammatory mediators that in a long run further aggravates the clinical features of RTT patients. Therefore, in a pathology completely orphan of any therapy, aiming 4HNE as a therapeutic target could represent a coadjuvant treatment with some beneficial impact in these patients..
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Affiliation(s)
- Giuseppe Valacchi
- Plants for Human Health Institute, Department of Animal Sciences, NC State University, NC Research Campus, 600 Laureate Way, Kannapolis, NC 28081, USA; Department of Life Sciences and Biotechnology, University of Ferrara, Via Luigi Borsari 46, 44121 Ferrara, Italy.
| | - Alessandra Pecorelli
- Plants for Human Health Institute, Department of Animal Sciences, NC State University, NC Research Campus, 600 Laureate Way, Kannapolis, NC 28081, USA; Department of Life Sciences and Biotechnology, University of Ferrara, Via Luigi Borsari 46, 44121 Ferrara, Italy
| | - Carlo Cervellati
- Department of Biomedical and Specialist Surgical Sciences, Section of Medical Biochemistry, Molecular Biology and Genetics, University of Ferrara, Via Luigi Borsari 46, 44121 Ferrara, Italy
| | - Joussef Hayek
- Child Neuropsychiatry Unit, University Hospital, AOUS, Viale Mario Bracci, 53100 Siena, Italy
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Increased Mitochondrial Mass and Cytosolic Redox Imbalance in Hippocampal Astrocytes of a Mouse Model of Rett Syndrome: Subcellular Changes Revealed by Ratiometric Imaging of JC-1 and roGFP1 Fluorescence. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:3064016. [PMID: 28894505 PMCID: PMC5574314 DOI: 10.1155/2017/3064016] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 06/16/2017] [Accepted: 06/27/2017] [Indexed: 12/21/2022]
Abstract
Rett syndrome (RTT) is a neurodevelopmental disorder with mutations in the MECP2 gene. Mostly girls are affected, and an apparently normal development is followed by cognitive impairment, motor dysfunction, epilepsy, and irregular breathing. Various indications suggest mitochondrial dysfunction. In Rett mice, brain ATP levels are reduced, mitochondria are leaking protons, and respiratory complexes are dysregulated. Furthermore, we found in MeCP2-deficient mouse (Mecp2−/y) hippocampus an intensified mitochondrial metabolism and ROS generation. We now used emission ratiometric 2-photon imaging to assess mitochondrial morphology, mass, and membrane potential (ΔΨm) in Mecp2−/y hippocampal astrocytes. Cultured astrocytes were labeled with the ΔΨm marker JC-1, and semiautomated analyses yielded the number of mitochondria per cell, their morphology, and ΔΨm. Mecp2−/y astrocytes contained more mitochondria than wild-type (WT) cells and were more oxidized. Mitochondrial size, ΔΨm, and vulnerability to pharmacological challenge did not differ. The antioxidant Trolox opposed the oxidative burden and decreased the mitochondrial mass, thereby dampening the differences among WT and Mecp2−/y astrocytes; mitochondrial size and ΔΨm were not markedly affected. In conclusion, mitochondrial alterations and redox imbalance in RTT also involve astrocytes. Mitochondria are more numerous in Mecp2−/y than in WT astrocytes. As this genotypic difference is abolished by Trolox, it seems linked to the oxidative stress in RTT.
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Effect of temperature on FAD and NADH-derived signals and neurometabolic coupling in the mouse auditory and motor cortex. Pflugers Arch 2017; 469:1631-1649. [PMID: 28785802 DOI: 10.1007/s00424-017-2037-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 07/03/2017] [Accepted: 07/13/2017] [Indexed: 12/13/2022]
Abstract
Tight coupling of neuronal metabolism to synaptic activity is critical to ensure that the supply of metabolic substrates meets the demands of neuronal signaling. Given the impact of temperature on metabolism, and the wide fluctuations of brain temperature observed during clinical hypothermia, we examined the effect of temperature on neurometabolic coupling. Intrinsic fluorescence signals of the oxidized form of flavin adenine dinucleotide (FAD) and the reduced form of nicotinamide adenine dinucleotide (NADH), and their ratios, were measured to assess neural metabolic state and local field potentials were recorded to measure synaptic activity in the mouse brain. Brain slice preparations were used to remove the potential impacts of blood flow. Tight coupling between metabolic signals and local field potential amplitudes was observed at a range of temperatures below 29 °C. However, above 29 °C, the metabolic and synaptic signatures diverged such that FAD signals were diminished, but local field potentials retained their amplitude. It was also observed that the declines in the FAD signals seen at high temperatures (and hence the decoupling between synaptic and metabolic events) are driven by low FAD availability at high temperatures. These data suggest that neurometabolic coupling, thought to be critical for ensuring the metabolic health of the brain, may show temperature dependence, and is related to temperature-dependent changes in FAD supplies.
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45
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Frye RE, Slattery JC, Quadros EV. Folate metabolism abnormalities in autism: potential biomarkers. Biomark Med 2017; 11:687-699. [PMID: 28770615 DOI: 10.2217/bmm-2017-0109] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Autism spectrum disorder (ASD) has been linked to abnormalities in folate metabolism. Polymorphisms in folate genes may act in complex polygenic ways to increase the risk of developing ASD. Autoantibodies that block folate transport into the brain have been associated with ASD and children with ASD and these autoantibodies respond to high doses of a reduced form of folate known as folinic acid (leucovorin calcium). Some of the same abnormalities are also found in mothers of children with ASD and supplementing folate during preconception and gestational periods reduces the risk to the offspring from developing ASD. These data suggest that folate pathway abnormalities may be a major metabolic disturbance underlying ASD that can be leveraged as biomarkers to improve symptoms and prevent ASD.
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Affiliation(s)
- Richard E Frye
- Autism Research Program, Arkansas Children's Research Institute, Little Rock, AR 72202, USA
| | - John C Slattery
- Autism Research Program, Arkansas Children's Research Institute, Little Rock, AR 72202, USA
| | - Edward V Quadros
- Department of Medicine, State University of New York - Downstate Medical Center, Brooklyn, NY 11203, USA
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46
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Bahey NG, Gadalla KKE, McGonigal R, Bailey MES, Edgar JM, Cobb SR. Reduced axonal diameter of peripheral nerve fibers in a mouse model of Rett syndrome. Neuroscience 2017; 358:261-268. [PMID: 28687309 DOI: 10.1016/j.neuroscience.2017.06.061] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 06/27/2017] [Accepted: 06/28/2017] [Indexed: 12/29/2022]
Abstract
Rett syndrome (RTT) is a neurological disorder characterized by motor and cognitive impairment, autonomic dysfunction and a loss of purposeful hand skills. In the majority of cases, typical RTT is caused by de novo mutations in the X-linked gene, MECP2. Alterations in the structure and function of neurons within the central nervous system of RTT patients and Mecp2-null mouse models are well established. In contrast, few studies have investigated the effects of MeCP2-deficiency on peripheral nerves. In this study, we conducted detailed morphometric as well as functional analysis of the sciatic nerves of symptomatic adult female Mecp2+/- mice. We observed a significant reduction in the mean diameter of myelinated nerve fibers in Mecp2+/- mice. In myelinated fibers, mitochondrial densities per unit area of axoplasm were significantly altered in Mecp2+/- mice. However, conduction properties of the sciatic nerve of Mecp2 knockout mice were not different from control. These subtle changes in myelinated peripheral nerve fibers in heterozygous Mecp2 knockout mice could potentially explain some RTT phenotypes.
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Affiliation(s)
- Noha G Bahey
- Institute of Neuroscience and Psychology, University of Glasgow, United Kingdom; Histology Department, Faculty of Medicine, Tanta University, Egypt
| | - Kamal K E Gadalla
- Institute of Neuroscience and Psychology, University of Glasgow, United Kingdom; Pharmacology Department, Faculty of Medicine, Tanta University, Egypt
| | - Rhona McGonigal
- Institute of Infection, Immunity and Inflammation College of Medical, Veterinary and Life Sciences, University of Glasgow, United Kingdom
| | - Mark E S Bailey
- School of Life Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, United Kingdom
| | - Julia M Edgar
- Institute of Infection, Immunity and Inflammation College of Medical, Veterinary and Life Sciences, University of Glasgow, United Kingdom
| | - Stuart R Cobb
- Institute of Neuroscience and Psychology, University of Glasgow, United Kingdom.
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47
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Kim D, Volk H, Girirajan S, Pendergrass S, Hall MA, Verma SS, Schmidt RJ, Hansen RL, Ghosh D, Ludena-Rodriguez Y, Kim K, Ritchie MD, Hertz-Picciotto I, Selleck SB. The joint effect of air pollution exposure and copy number variation on risk for autism. Autism Res 2017; 10:1470-1480. [PMID: 28448694 DOI: 10.1002/aur.1799] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 03/17/2017] [Accepted: 03/23/2017] [Indexed: 11/07/2022]
Abstract
Autism spectrum disorder is a complex trait with a high degree of heritability as well as documented susceptibility from environmental factors. In this study the contributions of copy number variation, exposure to air pollutants, and the interaction between the two on autism risk, were evaluated in the population-based case-control Childhood Autism Risks from Genetics and Environment (CHARGE) Study. For the current investigation, we included only those CHARGE children (a) who met criteria for autism or typical development and (b) for whom our team had conducted both genetic evaluation of copy number burden and determination of environmental air pollution exposures based on mapping addresses from the pregnancy and early childhood. This sample consisted of 158 cases of children with autism and 147 controls with typical development. Multiple logistic regression models were fit with and without environmental variable-copy number burden interactions. We found no correlation between average air pollution exposure from conception to age 2 years and the child's CNV burden. We found a significant interaction in which a 1SD increase in duplication burden combined with a 1SD increase in ozone exposure was associated with an elevated autism risk (OR 3.4, P < 0.005) much greater than the increased risks associated with either genomic duplication (OR 1.85, 95% CI 1.25-2.73) or ozone (OR 1.20, 95% CI 0.93-1.54) alone. Similar results were obtained when CNV and ozone were dichotomized to compare those in the top quartile relative to those having a smaller CNV burden and lower exposure to ozone, and when exposures were assessed separately for pregnancy, the first year of life, and the second year of life. No interactions were observed for other air pollutants, even those that demonstrated main effects; ozone tends to be negatively correlated with the other pollutants examined. While earlier work has demonstrated interactions between the presence of a pathogenic CNV and an environmental exposure [Webb et al., 2016], these findings appear to be the first indication that global copy number variation may increase susceptibility to certain environmental factors, and underscore the need to consider both genomics and environmental exposures as well as the mechanisms by which each may amplify the risks for autism associated with the other. Autism Res 2017, 10: 1470-1480. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.
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Affiliation(s)
- Dokyoon Kim
- Department of Biochemistry & Molecular Biology, The Pennsylvania State University, University Park, PA, 16802.,Biomedical & Translational Informatics Institute, Geisinger Health System, Danville, PA, 17822
| | - Heather Volk
- Department of Mental Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, 21205
| | - Santhosh Girirajan
- Department of Biochemistry & Molecular Biology, The Pennsylvania State University, University Park, PA, 16802
| | - Sarah Pendergrass
- Biomedical & Translational Informatics Institute, Geisinger Health System, Danville, PA, 17822
| | - Molly A Hall
- Department of Biochemistry & Molecular Biology, The Pennsylvania State University, University Park, PA, 16802
| | - Shefali S Verma
- Biomedical & Translational Informatics Institute, Geisinger Health System, Danville, PA, 17822
| | - Rebecca J Schmidt
- Department of Public Health Sciences, University of California, Davis, Davis, CA.,The MIND (Medical Investigation of Neurodevelopmental Disorders) Institute, University of California, Davis, Davis, CA
| | - Robin L Hansen
- The MIND (Medical Investigation of Neurodevelopmental Disorders) Institute, University of California, Davis, Davis, CA.,Department of Pediatrics, Davis School of Medicine, University of California, Sacramento, CA, 95817
| | - Debashis Ghosh
- Department of Biostatistics and Informatics, Colorado School of Public Health, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045
| | | | | | - Marylyn D Ritchie
- Department of Biochemistry & Molecular Biology, The Pennsylvania State University, University Park, PA, 16802.,Biomedical & Translational Informatics Institute, Geisinger Health System, Danville, PA, 17822
| | - Irva Hertz-Picciotto
- Department of Public Health Sciences, University of California, Davis, Davis, CA.,The MIND (Medical Investigation of Neurodevelopmental Disorders) Institute, University of California, Davis, Davis, CA
| | - Scott B Selleck
- Department of Biochemistry & Molecular Biology, The Pennsylvania State University, University Park, PA, 16802
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Endogenous Two-Photon Excited Fluorescence Imaging Characterizes Neuron and Astrocyte Metabolic Responses to Manganese Toxicity. Sci Rep 2017; 7:1041. [PMID: 28432298 PMCID: PMC5430620 DOI: 10.1038/s41598-017-01015-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 03/24/2017] [Indexed: 01/17/2023] Open
Abstract
As neurodegenerative conditions are increasingly linked to mitochondrial dysfunction, methods for studying brain cell metabolism at high spatial resolution are needed to elucidate neurodegeneration mechanisms. Two-photon excited fluorescence (TPEF) imaging is a non-destructive, high-resolution technique for studying cell metabolism via endogenous fluorescence of reduced nicotinamide adenine dinucleotide (phosphate) (NAD(P)H) and flavin adenine dinucleotide (FAD). We employed TPEF to study the metabolism of primary rat astrocyte and neuronal cultures under normal growth conditions and in response to manganese (Mn) treatment. Histograms of pixel-wise optical redox ratio, defined as FAD/(FAD + NAD(P)H), revealed three distinct redox distributions and significant differences in their relative weights between astrocytes and neurons. When treated with Mn, both cell types exhibited redox ratio shifts consistent with increased oxidative stress. However, the manner in which the redox distributions was affected was distinct for the two cell types. Furthermore, NAD(P)H fluorescence lifetime imaging revealed an increase in bound NAD(P)H fraction upon Mn treatment for neurons, consistent with enhanced apoptosis. Astrocytes showed a decrease in bound fraction, possibly due to a shift towards glycolytic metabolism in response to impaired respiration. These results exhibit TPEF’s utility for characterizing detailed metabolic changes of different brain cell types in response to neurotoxins.
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49
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Shulyakova N, Andreazza AC, Mills LR, Eubanks JH. Mitochondrial Dysfunction in the Pathogenesis of Rett Syndrome: Implications for Mitochondria-Targeted Therapies. Front Cell Neurosci 2017; 11:58. [PMID: 28352216 PMCID: PMC5348512 DOI: 10.3389/fncel.2017.00058] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 02/20/2017] [Indexed: 01/20/2023] Open
Abstract
First described over 50 years ago, Rett syndrome (RTT) is a neurodevelopmental disorder caused primarily by mutations of the X-linked MECP2 gene. RTT affects predominantly females, and has a prevalence of roughly 1 in every 10,000 female births. Prior to the discovery that mutations of MECP2 are the leading cause of RTT, there were suggestions that RTT could be a mitochondrial disease. In fact, several reports documented altered mitochondrial structure, and deficiencies in mitochondrial enzyme activity in different cells or tissues derived from RTT patients. With the identification of MECP2 as the causal gene, interest largely shifted toward defining the normal function of MeCP2 in the brain, and how its absence affects the neurodevelopment and neurophysiology. Recently, though, interest in studying mitochondrial function in RTT has been reignited, at least in part due to observations suggesting systemic oxidative stress does play a contributing role in RTT pathogenesis. Here we review data relating to mitochondrial alterations at the structural and functional levels in RTT patients and model systems, and present a hypothesis for how the absence of MeCP2 could lead to altered mitochondrial function and elevated levels of cellular oxidative stress. Finally, we discuss the prospects for treating RTT using interventions that target specific aspects of mitochondrial dysfunction and/or oxidative stress.
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Affiliation(s)
- Natalya Shulyakova
- Division of Genetics and Development, Krembil Research Institute, University Health NetworkToronto, ON, Canada; Department of Physiology, University of TorontoToronto, ON, Canada
| | - Ana C Andreazza
- Department of Pharmacology, University of Toronto Toronto, ON, Canada
| | - Linda R Mills
- Department of Physiology, University of Toronto Toronto, ON, Canada
| | - James H Eubanks
- Division of Genetics and Development, Krembil Research Institute, University Health NetworkToronto, ON, Canada; Department of Physiology, University of TorontoToronto, ON, Canada; Institute of Medical Sciences, University of TorontoToronto, ON, Canada; Department of Surgery (Neurosurgery), University of TorontoToronto, ON, Canada
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50
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CREB Signaling Is Involved in Rett Syndrome Pathogenesis. J Neurosci 2017; 37:3671-3685. [PMID: 28270572 DOI: 10.1523/jneurosci.3735-16.2017] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 02/17/2017] [Accepted: 02/24/2017] [Indexed: 12/21/2022] Open
Abstract
Rett syndrome (RTT) is a debilitating neurodevelopmental disorder caused by mutations in the MECP2 gene. To facilitate the study of cellular mechanisms in human cells, we established several human stem cell lines: human embryonic stem cell (hESC) line carrying the common T158M mutation (MECP2T158M/T158M ), hESC line expressing no MECP2 (MECP2-KO), congenic pair of wild-type and mutant RTT patient-specific induced pluripotent stem cell (iPSC) line carrying the V247fs mutation (V247fs-WT and V247fs-MT), and iPSC line in which the V247fs mutation was corrected by CRISPR/Cas9-based genome editing (V247fs-MT-correction). Detailed analyses of forebrain neurons differentiated from these human stem cell lines revealed genotype-dependent quantitative phenotypes in neurite growth, dendritic complexity, and mitochondrial function. At the molecular level, we found a significant reduction in the level of CREB and phosphorylated CREB in forebrain neurons differentiated from MECP2T158M/T158M , MECP2-KO, and V247fs-MT stem cell lines. Importantly, overexpression of CREB or pharmacological activation of CREB signaling in those forebrain neurons rescued the phenotypes in neurite growth, dendritic complexity, and mitochondrial function. Finally, pharmacological activation of CREB in the female Mecp2 heterozygous mice rescued several behavioral defects. Together, our study establishes a robust in vitro platform for consistent quantitative evaluation of genotype-dependent RTT phenotypes, reveals a previously unappreciated role of CREB signaling in RTT pathogenesis, and identifies a potential therapeutic target for RTT.SIGNIFICANCE STATEMENT Our study establishes a robust human stem cell-based platform for consistent quantitative evaluation of genotype-dependent Rett syndrome (RTT) phenotypes at the cellular level. By providing the first evidence that enhancing cAMP response element binding protein signaling can alleviate RTT phenotypes both in vitro and in vivo, we reveal a previously unappreciated role of cAMP response element binding protein signaling in RTT pathogenesis, and identify a potential therapeutic target for RTT.
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