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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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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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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: 0] [Impact Index Per Article: 0] [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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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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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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Jagtap S, Thanos JM, Fu T, Wang J, Lalonde J, Dial TO, Feiglin A, Chen J, Kohane I, Lee JT, Sheridan SD, Perlis RH. Aberrant mitochondrial function in patient-derived neural cells from CDKL5 deficiency disorder and Rett syndrome. Hum Mol Genet 2020; 28:3625-3636. [PMID: 31518399 DOI: 10.1093/hmg/ddz208] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 07/25/2019] [Accepted: 08/16/2019] [Indexed: 01/09/2023] Open
Abstract
The X-linked neurodevelopmental diseases CDKL5 deficiency disorder (CDD) and Rett syndrome (RTT) are associated with intellectual disability, infantile spasms and seizures. Although mitochondrial dysfunction has been suggested in RTT, less is understood about mitochondrial function in CDD. A comparison of bioenergetics and mitochondrial function between isogenic wild-type and mutant neural progenitor cell (NPC) lines revealed increased oxygen consumption in CDD mutant lines, which is associated with altered mitochondrial function and structure. Transcriptomic analysis revealed differential expression of genes related to mitochondrial and REDOX function in NPCs expressing the mutant CDKL5. Furthermore, a similar increase in oxygen consumption specific to RTT patient-derived isogenic mutant NPCs was observed, though the pattern of mitochondrial functional alterations was distinct from CDKL5 mutant-expressing NPCs. We propose that aberrant neural bioenergetics is a common feature between CDD and RTT disorders. The observed changes in oxidative stress and mitochondrial function may facilitate the development of therapeutic agents for CDD and related disorders.
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Affiliation(s)
- Smita Jagtap
- Center for Quantitative Health, Center for Genomic Medicine, and Department of Psychiatry, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Psychiatry, Harvard Medical School, Boston, MA 02115, USA
| | - Jessica M Thanos
- Center for Quantitative Health, Center for Genomic Medicine, and Department of Psychiatry, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Psychiatry, Harvard Medical School, Boston, MA 02115, USA
| | - Ting Fu
- Center for Quantitative Health, Center for Genomic Medicine, and Department of Psychiatry, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Psychiatry, Harvard Medical School, Boston, MA 02115, USA
| | - Jennifer Wang
- Center for Quantitative Health, Center for Genomic Medicine, and Department of Psychiatry, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Psychiatry, Harvard Medical School, Boston, MA 02115, USA
| | - Jasmin Lalonde
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada N1G 2W1
| | - Thomas O Dial
- Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Ariel Feiglin
- Department of Biomedical Informatics, Harvard Medical School, Boston, MA 02115, USA
| | - Jeffrey Chen
- Center for Quantitative Health, Center for Genomic Medicine, and Department of Psychiatry, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Psychiatry, Harvard Medical School, Boston, MA 02115, USA
| | - Isaac Kohane
- Department of Biomedical Informatics, Harvard Medical School, Boston, MA 02115, USA
| | - Jeannie T Lee
- Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Steven D Sheridan
- Center for Quantitative Health, Center for Genomic Medicine, and Department of Psychiatry, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Psychiatry, Harvard Medical School, Boston, MA 02115, USA
| | - Roy H Perlis
- Center for Quantitative Health, Center for Genomic Medicine, and Department of Psychiatry, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Psychiatry, Harvard Medical School, Boston, MA 02115, USA
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Neul JL, Skinner SA, Annese F, Lane J, Heydemann P, Jones M, Kaufmann WE, Glaze DG, Percy AK. Metabolic Signatures Differentiate Rett Syndrome From Unaffected Siblings. Front Integr Neurosci 2020; 14:7. [PMID: 32161522 PMCID: PMC7052375 DOI: 10.3389/fnint.2020.00007] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Accepted: 01/30/2020] [Indexed: 01/07/2023] Open
Abstract
Rett syndrome (RTT, OMIM 312750), a severe neurodevelopmental disorder characterized by regression with loss of spoken language and hand skills, development of characteristic hand stereotypies, and gait dysfunction, is primarily caused by de novo mutations in the X-linked gene Methyl-CpG-binding protein 2 (MECP2). Currently, treatment options are limited to symptomatic management, however, reversal of disease phenotype is possible in mouse models by restoration of normal MECP2 gene expression. A significant challenge is the lack of biomarkers of disease state, disease severity, or treatment response. Using a non-targeted metabolomic approach we evaluated metabolite profiles in plasma from thirty-four people with RTT compared to thirty-seven unaffected age- and gender-matched siblings. We identified sixty-six significantly altered metabolites that cluster broadly into amino acid, nitrogen handling, and exogenous substance pathways. RTT disease metabolite and metabolic pathways abnormalities point to evidence of oxidative stress, mitochondrial dysfunction, and alterations in gut microflora. These observed changes provide insight into underlying pathological mechanisms and the foundation for biomarker discovery of disease severity biomarkers.
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Affiliation(s)
- Jeffrey L Neul
- Vanderbilt University Medical Center, Nashville, TN, United States.,Department of Neurosciences, University of California, San Diego, San Diego, CA, United States.,Baylor College of Medicine, Houston, TX, United States
| | | | - Fran Annese
- Greenwood Genetic Center, Greenwood, SC, United States
| | - Jane Lane
- Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL, United States
| | | | - Mary Jones
- Benioff Children's Hospital Oakland, University of California, San Francisco, San Francisco, CA, United States
| | | | | | - Alan K Percy
- Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL, United States
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Cordone V, Pecorelli A, Amicarelli F, Hayek J, Valacchi G. The complexity of Rett syndrome models: Primary fibroblasts as a disease-in-a-dish reliable approach. ACTA ACUST UNITED AC 2020. [DOI: 10.1016/j.ddmod.2019.11.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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10
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Effects of oral administration of common antioxidant supplements on the energy metabolism of red blood cells. Attenuation of oxidative stress-induced changes in Rett syndrome erythrocytes by CoQ10. Mol Cell Biochem 2019; 463:101-113. [PMID: 31595423 DOI: 10.1007/s11010-019-03633-5] [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: 05/28/2019] [Accepted: 09/25/2019] [Indexed: 01/15/2023]
Abstract
Nutritional supplements are traditionally employed for overall health and for managing some health conditions, although controversies are found concerning the role of antioxidants-mediated benefits in vivo. Consistently with its critical role in systemic redox buffering, red blood cell (RBC) is recognized as a biologically relevant target to investigate the effects of oxidative stress. In RBC, reduction of the ATP levels and adenylate energy charge brings to disturbance in intracellular redox status. In the present work, several popular antioxidant supplements were orally administrated to healthy adults and examined for their ability to induce changes on the energy metabolism and oxidative status in RBC. Fifteen volunteers (3 per group) were treated for 30 days per os with epigallocatechin gallate (EGCG) (1 g green tea extract containing 50% EGCG), resveratrol (325 mg), coenzyme Q10 (CoQ10) (300 mg), vitamin C (1 g), and vitamin E (400 U.I.). Changes in the cellular levels of high-energy compounds (i.e., ATP and its catabolites, NAD and GTP), GSH, GSSG, and malondialdehyde (MDA) were simultaneously analyzed by ion-pairing HPLC. Response to oxidative stress was further investigated through the oxygen radical absorptive capacity (ORAC) assay. According to our experimental approach, (i) CoQ10 appeared to be the most effective antioxidant inducing a high increase in ATP/ADP, ATP/AMP, GSH/GSSG ratio and ORAC value and, in turn, a reduction of NAD concentration, (ii) EGCG modestly modulated the intracellular energy charge potential, while (iii) Vitamin E, vitamin C, and resveratrol exhibited very weak effects. Given that, the antioxidant potential of CoQ10 was additionally assessed in a pilot study which considered individuals suffering from Rett syndrome (RTT), a severe X-linked neuro-developmental disorder in which RBC oxidative damages provide biological markers for redox imbalance and chronic hypoxemia. RTT patients (n = 11), with the typical clinical form, were supplemented for 12 months with CoQ10 (300 mg, once daily). Level of lipid peroxidation (MDA production) and energy state of RBCs were analyzed at 2 and 12 months. Our data suggest that CoQ10 may significantly attenuate the oxidative stress-induced damage in RTT erythrocytes.
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11
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Frasca A, Bedogni F, Landsberger N. Progress in the development of in vivo redox measurements: New tools for longitudinal studies in Rett syndrome. Neurosci Biobehav Rev 2019; 104:28-29. [DOI: 10.1016/j.neubiorev.2019.06.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2019] [Accepted: 06/12/2019] [Indexed: 11/30/2022]
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12
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Peña-Bautista C, Vento M, Baquero M, Cháfer-Pericás C. Lipid peroxidation in neurodegeneration. Clin Chim Acta 2019; 497:178-188. [PMID: 31377127 DOI: 10.1016/j.cca.2019.07.037] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 07/30/2019] [Accepted: 07/31/2019] [Indexed: 01/14/2023]
Abstract
Neurodegenerative diseases have great social and economic impact and cause millions of deaths every year. The potential molecular mechanisms in these pathologies have been widely studied and implicate lipid peroxidation as an important factor in the development of neurodegenerative disorders such as Alzheimer's, Parkinson's and Huntington's diseases. Data indicates that pathologic mechanisms specifically involve ferroptosis and mitochondrial dysfunction. Here we review the molecular mechanisms related to the lipid peroxidation that involve the development of neurodegeneration, as well as the utility of some biomarkers in diagnosis, prognosis and evaluation of new therapies for neurodegenerative diseases.
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Affiliation(s)
| | - Máximo Vento
- Health Research Institute La Fe, Valencia, Spain
| | - Miguel Baquero
- Division of Neurology, University and Polytechnic Hospital La Fe, Valencia, Spain
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13
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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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14
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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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15
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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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16
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Valacchi G, Virgili F, Cervellati C, Pecorelli A. OxInflammation: From Subclinical Condition to Pathological Biomarker. Front Physiol 2018; 9:858. [PMID: 30038581 PMCID: PMC6046448 DOI: 10.3389/fphys.2018.00858] [Citation(s) in RCA: 122] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 06/15/2018] [Indexed: 12/18/2022] Open
Abstract
Inflammation is a complex systemic response evolved to cope with cellular injury, either due to infectious agents or, in general, with sporadic events challenging tissue integrity and function. Researchers involved in different fields have the tendency to look at the inflammatory response with different angles, according to their specific interest. Established its complexity, one of the most evident features of the inflammatory response is the generation of a pro-oxidative environment due to the production of high fluxes of pro-oxidant species. This production begins locally, close to the sites of tissue damage or infection, but eventually becomes a chronic challenge for the organism, if the inflammatory response is not properly controlled. In this review, we focus on this specific aspect of chronic, low-level sub-clinical inflammatory response. We propose the term "OxInflammation" as a novel operative term describing a permanent pro-oxidative feature that interact, in a positive feed-back manner, to a not yet clinically detectable inflammatory process, leading in a long run (chronically) to a systemic/local damage, as a consequence of the cross talk between inflammatory, and oxidative stress mediators. Therefore, it could be useful to analyze inflammatory markers in pathologies where there is an alteration of the redox homeostasis, although an inflammatory status is not clinically evident.
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Affiliation(s)
- Giuseppe Valacchi
- Plants for Human Health Institute, Department of Animal Sciences, North Carolina State University, Kannapolis, NC, United States
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Fabio Virgili
- Council for Agricultural Research and Economics - Food and Nutrition Research Centre (C.R.E.A.-AN), Rome, Italy
| | - Carlo Cervellati
- Department of Biomedical and Specialist Surgical Sciences, University of Ferrara, Ferrara, Italy
| | - Alessandra Pecorelli
- Plants for Human Health Institute, Department of Animal Sciences, North Carolina State University, Kannapolis, NC, United States
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17
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Kyle SM, Vashi N, Justice MJ. Rett syndrome: a neurological disorder with metabolic components. Open Biol 2018; 8:170216. [PMID: 29445033 PMCID: PMC5830535 DOI: 10.1098/rsob.170216] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 01/18/2018] [Indexed: 02/06/2023] Open
Abstract
Rett syndrome (RTT) is a neurological disorder caused by mutations in the X-linked gene methyl-CpG-binding protein 2 (MECP2), a ubiquitously expressed transcriptional regulator. Despite remarkable scientific progress since its discovery, the mechanism by which MECP2 mutations cause RTT symptoms is largely unknown. Consequently, treatment options for patients are currently limited and centred on symptom relief. Thought to be an entirely neurological disorder, RTT research has focused on the role of MECP2 in the central nervous system. However, the variety of phenotypes identified in Mecp2 mutant mouse models and RTT patients implicate important roles for MeCP2 in peripheral systems. Here, we review the history of RTT, highlighting breakthroughs in the field that have led us to present day. We explore the current evidence supporting metabolic dysfunction as a component of RTT, presenting recent studies that have revealed perturbed lipid metabolism in the brain and peripheral tissues of mouse models and patients. Such findings may have an impact on the quality of life of RTT patients as both dietary and drug intervention can alter lipid metabolism. Ultimately, we conclude that a thorough knowledge of MeCP2's varied functional targets in the brain and body will be required to treat this complex syndrome.
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Affiliation(s)
- Stephanie M Kyle
- Genetics and Genome Biology Program, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, Ontario, Canada M5G 0A4
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Neeti Vashi
- Genetics and Genome Biology Program, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, Ontario, Canada M5G 0A4
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A1
| | - Monica J Justice
- Genetics and Genome Biology Program, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, Ontario, Canada M5G 0A4
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A1
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18
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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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19
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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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20
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Demion M, Oger C, Vigor C, Thireau J, Guennec JYL, Durand T, Galano JM, Lee JCY. Two sides of the same coin: NEO-PUFAs in Rett syndrome and post-infarction cardiac arrhythmias. EUR J LIPID SCI TECH 2017. [DOI: 10.1002/ejlt.201600320] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Marie Demion
- Inserm U1046-UMR CNRS 9214 Physiologie et Médecine Expérimentale du cœur et des muscles−PHYMEDEX; Université de Montpellier; Montpellier France
| | - Camille Oger
- Institut des Biomolécules Max Mousseron, (IBMM) UMR 5247; CNRS Université de Montpellier, ENSCM; Montpellier France
| | - Claire Vigor
- Institut des Biomolécules Max Mousseron, (IBMM) UMR 5247; CNRS Université de Montpellier, ENSCM; Montpellier France
| | - Jérôme Thireau
- Inserm U1046-UMR CNRS 9214 Physiologie et Médecine Expérimentale du cœur et des muscles−PHYMEDEX; Université de Montpellier; Montpellier France
| | - Jean-Yves Le Guennec
- Inserm U1046-UMR CNRS 9214 Physiologie et Médecine Expérimentale du cœur et des muscles−PHYMEDEX; Université de Montpellier; Montpellier France
| | - Thierry Durand
- Institut des Biomolécules Max Mousseron, (IBMM) UMR 5247; CNRS Université de Montpellier, ENSCM; Montpellier France
| | - Jean-Marie Galano
- Institut des Biomolécules Max Mousseron, (IBMM) UMR 5247; CNRS Université de Montpellier, ENSCM; Montpellier France
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21
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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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22
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Ciaccio C, Di Pierro D, Sbardella D, Tundo GR, Curatolo P, Galasso C, Santarone ME, Casasco M, Cozza P, Cortelazzo A, Rossi M, De Felice C, Hayek J, Coletta M, Marini S. Oxygen exchange and energy metabolism in erythrocytes of Rett syndrome and their relationships with respiratory alterations. Mol Cell Biochem 2017; 426:205-213. [PMID: 28063007 DOI: 10.1007/s11010-016-2893-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 12/02/2016] [Indexed: 10/20/2022]
Abstract
Rett syndrome (RTT) is a neurodevelopmental disorder, mainly affecting females, which is associated to a mutation on the methyl-CpG-binding protein 2 gene. In the pathogenesis and progression of classic RTT, red blood cell (RBC) morphology has been shown to be an important biosensor for redox imbalance and chronic hypoxemia. Here we have evaluated the impact of oxidation and redox imbalance on several functional properties of RTT erythrocytes. In particular, we report for the first time a stopped-flow measurement of the kinetics of oxygen release by RBCs and the analysis of the intrinsic affinity of the hemoglobin (Hb). According to our experimental approach, RBCs from RTT patients do not show any intrinsic difference with respect to those from healthy controls neither in Hb's oxygen-binding affinity nor in O2 exchange processes at 37 °C. Therefore, these factors do not contribute to the observed alteration of the respiratory function in RTT patients. Moreover, the energy metabolism of RBCs, from both RTT patients and controls, was evaluated by ion-pairing HPLC method and related to the level of malondialdehyde and to the oxidative radical scavenging capacity of red cells. Results have clearly confirmed significant alterations in antioxidant defense capability, adding important informations concerning the high-energy compound levels in RBCs of RTT subjects, underlying possible correlations with inflammatory tissue alterations.
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Affiliation(s)
- Chiara Ciaccio
- Department of Clinical Sciences and Translational Medicine, University of Roma Tor Vergata, Via Montpellier 1, 00133, Rome, Italy.
| | - Donato Di Pierro
- Department of Clinical Sciences and Translational Medicine, University of Roma Tor Vergata, Via Montpellier 1, 00133, Rome, Italy
| | - Diego Sbardella
- Department of Clinical Sciences and Translational Medicine, University of Roma Tor Vergata, Via Montpellier 1, 00133, Rome, Italy
| | - Grazia Raffaella Tundo
- Department of Clinical Sciences and Translational Medicine, University of Roma Tor Vergata, Via Montpellier 1, 00133, Rome, Italy
| | - Paolo Curatolo
- Department of Systems Medicine, University Hospital of Rome Tor Vergata, Rome, Italy
| | - Cinzia Galasso
- Department of Systems Medicine, University Hospital of Rome Tor Vergata, Rome, Italy
| | - Marta Elena Santarone
- Department of Systems Medicine, University Hospital of Rome Tor Vergata, Rome, Italy
| | | | - Paola Cozza
- Department of Clinical Sciences and Translational Medicine, University of Roma Tor Vergata, Via Montpellier 1, 00133, Rome, Italy
| | - Alessio Cortelazzo
- Department of Medical Biotechnologies, University of Siena, Siena, Italy
| | - Marcello Rossi
- Respiratory Pathophysiology and Rehabilitation Unit, University Hospital, AOUS, Siena, Italy
| | - Claudio De Felice
- Neonatal Intensive Care Unit, University Hospital, AOUS, Siena, Italy
| | - Joussef Hayek
- Child Neuropsychiatry Unit, University Hospital, AOUS, Siena, Italy
| | - Massimo Coletta
- Department of Clinical Sciences and Translational Medicine, University of Roma Tor Vergata, Via Montpellier 1, 00133, Rome, Italy
| | - Stefano Marini
- Department of Clinical Sciences and Translational Medicine, University of Roma Tor Vergata, Via Montpellier 1, 00133, Rome, Italy
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Pecorelli A, Cervellati C, Hayek J, Valacchi G. OxInflammation in Rett syndrome. Int J Biochem Cell Biol 2016; 81:246-253. [DOI: 10.1016/j.biocel.2016.07.015] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 07/11/2016] [Accepted: 07/14/2016] [Indexed: 12/24/2022]
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Janc OA, Hüser MA, Dietrich K, Kempkes B, Menzfeld C, Hülsmann S, Müller M. Systemic Radical Scavenger Treatment of a Mouse Model of Rett Syndrome: Merits and Limitations of the Vitamin E Derivative Trolox. Front Cell Neurosci 2016; 10:266. [PMID: 27895554 PMCID: PMC5109403 DOI: 10.3389/fncel.2016.00266] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 11/01/2016] [Indexed: 12/21/2022] Open
Abstract
Rett syndrome (RTT) is a severe neurodevelopmental disorder typically arising from spontaneous mutations in the X-chromosomal methyl-CpG binding protein 2 (MECP2) gene. The almost exclusively female Rett patients show an apparently normal development during their first 6-18 months of life. Subsequently, cognitive- and motor-impairment, hand stereotypies, loss of learned skills, epilepsy and irregular breathing manifest. Early mitochondrial impairment and oxidative challenge are considered to facilitate disease progression. Along this line, we recently confirmed in vitro that acute treatment with the vitamin E-derivative Trolox dampens neuronal hyperexcitability, reinstates synaptic plasticity, ameliorates cellular redox balance and improves hypoxia tolerance in male MeCP2-deficient (Mecp2-/y ) mouse hippocampus. Pursuing these promising findings, we performed a preclinical study to define the merit of systemic Trolox administration. Blinded, placebo-controlled in vivo treatment of male mice started at postnatal day (PD) 10-11 and continued for ~40 days. Compounds (vehicle only, 10 mg/kg or 40 mg/kg Trolox) were injected intraperitoneally every 48 h. Detailed phenotyping revealed that in Mecp2-/y mice, blood glucose levels, lipid peroxidation, synaptic short-term plasticity, hypoxia tolerance and certain forms of environmental exploration were improved by Trolox. Yet, body weight and size, motor function and the rate and regularity of breathing did not improve. In conclusion, in vivo Trolox treatment partially ameliorated a subset of symptoms of the complex Rett phenotype, thereby confirming a partial merit of the vitamin E-derivative based pharmacotherapy. Yet, it also became evident that frequent animal handling and the route of drug administration are critical issues to be optimized in future trials.
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Affiliation(s)
- Oliwia A Janc
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB)Göttingen, Germany; Zentrum Physiologie und Pathophysiologie, Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-UniversitätGöttingen, Germany
| | - Marc A Hüser
- Zentrum Physiologie und Pathophysiologie, Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, Germany
| | - Katharina Dietrich
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB)Göttingen, Germany; Zentrum Physiologie und Pathophysiologie, Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-UniversitätGöttingen, Germany
| | - Belinda Kempkes
- Zentrum Physiologie und Pathophysiologie, Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, Germany
| | - Christiane Menzfeld
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB)Göttingen, Germany; Zentrum Physiologie und Pathophysiologie, Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-UniversitätGöttingen, Germany
| | - Swen Hülsmann
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB)Göttingen, Germany; Klinik für Anästhesiologie, Universitätsmedizin Göttingen, Georg-August-UniversitätGöttingen, Germany
| | - Michael Müller
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB)Göttingen, Germany; Zentrum Physiologie und Pathophysiologie, Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin Göttingen, Georg-August-UniversitätGöttingen, Germany
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Pintaudi M, Veneselli E, Voci A, Vignoli A, Castiglione D, Calevo MG, Grasselli E, Ragazzoni M, Cogliati F, Calzari L, Scornavacca GF, Russo S, Vergani L. Blood oxidative stress and metallothionein expression in Rett syndrome: Probing for markers. World J Biol Psychiatry 2016; 17:198-209. [PMID: 26469135 DOI: 10.3109/15622975.2015.1077990] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVES Oxidative stress seems to be involved in Rett syndrome (RTT). The aim of this study was to assess the antioxidant status in RTT children with MECP2 gene mutations with respect to healthy controls, and to explore novel blood antioxidant markers for RTT severity. METHODS In erythrocytes from RTT females aged 2-14 years (n = 27) and age-matched controls (n = 27), we measured the levels of malonaldehyde and the activity of two antioxidant enzymes, Cu/Zn-superoxide dismutase and catalase, by spectrophotometric assays. In leukocytes, the expression of metallothioneins, the main non-enzymatic antioxidants, was assessed by real-time RT-PCR. In nine selected RTT children, methylome analysis was also performed. RESULTS Blood of RTT patients showed increased lipid peroxidation and a dysregulated pattern of MT expression, while enzymatic activities did not change significantly with respect to controls. Moreover, we observed no epigenetic dysregulation in CpG-enriched promoter regions of the analysed genes but significant hypomethylation in the random loci. CONCLUSIONS As the haematic level of MT-1A directly correlates with the phenotype severity, this metallothionein can represent a marker for RTT severity. Moreover, the attempt to link the level of blood oxidative stress with MECP2 mutation and specific clinical features led us to draw some interesting conclusions.
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Affiliation(s)
- Maria Pintaudi
- a DINOGMI, Dipartimento Di Neuroscienze , Riabilitazione, Oftalmologia, Genetica E Scienze Materno-Infantili, Università Di Genova , Genova , Italy .,b Unità Di Neuropsichiatria Infantile, Istituto Giannina Gaslini , Genova , Italy
| | - Edvige Veneselli
- a DINOGMI, Dipartimento Di Neuroscienze , Riabilitazione, Oftalmologia, Genetica E Scienze Materno-Infantili, Università Di Genova , Genova , Italy .,b Unità Di Neuropsichiatria Infantile, Istituto Giannina Gaslini , Genova , Italy
| | - Adriana Voci
- c DISTAV, Dipartimento Di Scienze Della Terra , Dell'ambiente E Della Vita, Università Di Genova , Genova , Italy
| | - Aglaia Vignoli
- d Centro Epilessia, Azienda Ospedaliera San Paolo, Dipartimento Di Scienze Della Salute , Università Degli Studi Di Milano , Milano , Italy
| | | | - Maria Grazia Calevo
- b Unità Di Neuropsichiatria Infantile, Istituto Giannina Gaslini , Genova , Italy .,f Unità Di Epidemiologia E Biostatistica, Istituto Giannina Gaslini , Genova , Italy , and
| | - Elena Grasselli
- c DISTAV, Dipartimento Di Scienze Della Terra , Dell'ambiente E Della Vita, Università Di Genova , Genova , Italy
| | - Milena Ragazzoni
- c DISTAV, Dipartimento Di Scienze Della Terra , Dell'ambiente E Della Vita, Università Di Genova , Genova , Italy
| | - Francesca Cogliati
- g Laboratorio Di Citogenetica E Genetica Molecolare, I.R.C.C.S. Istituto Auxologico Italiano , Milano
| | - Luciano Calzari
- g Laboratorio Di Citogenetica E Genetica Molecolare, I.R.C.C.S. Istituto Auxologico Italiano , Milano
| | - Giulia Federica Scornavacca
- d Centro Epilessia, Azienda Ospedaliera San Paolo, Dipartimento Di Scienze Della Salute , Università Degli Studi Di Milano , Milano , Italy
| | - Silvia Russo
- g Laboratorio Di Citogenetica E Genetica Molecolare, I.R.C.C.S. Istituto Auxologico Italiano , Milano
| | - Laura Vergani
- c DISTAV, Dipartimento Di Scienze Della Terra , Dell'ambiente E Della Vita, Università Di Genova , Genova , Italy
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Filosa S, Pecorelli A, D'Esposito M, Valacchi G, Hajek J. Exploring the possible link between MeCP2 and oxidative stress in Rett syndrome. Free Radic Biol Med 2015; 88:81-90. [PMID: 25960047 DOI: 10.1016/j.freeradbiomed.2015.04.019] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Revised: 04/10/2015] [Accepted: 04/13/2015] [Indexed: 01/27/2023]
Abstract
Rett syndrome (RTT, MIM 312750) is a rare and orphan progressive neurodevelopmental disorder affecting girls almost exclusively, with a frequency of 1/15,000 live births of girls. The disease is characterized by a period of 6 to 18 months of apparently normal neurodevelopment, followed by early neurological regression, with a progressive loss of acquired cognitive, social, and motor skills. RTT is known to be caused in 95% of the cases by sporadic de novo loss-of-function mutations in the X-linked methyl-CpG-binding protein 2 (MECP2) gene encoding methyl-CpG binding protein 2 (MeCP2), a nuclear protein able to regulate gene expression. Despite almost two decades of research into the functions and role of MeCP2, little is known about the mechanisms leading from MECP2 mutation to the disease. Oxidative stress (OS) is involved in the pathogenic mechanisms of several neurodevelopmental and neurodegenerative disorders, although in many cases it is not clear whether OS is a cause or a consequence of the pathology. Fairly recently, the presence of a systemic OS has been demonstrated in RTT patients with a strong correlation with the patients' clinical status. The link between MECP2 mutation and the redox imbalance found in RTT is not clear. Animal studies have suggested a possible direct correlation between Mecp2 mutation and increased OS levels. In addition, the restoration of Mecp2 function in astrocytes significantly improves the developmental outcome of Mecp2-null mice and reexpression of Mecp2 gene in the brain of null mice restored oxidative damage, suggesting that Mecp2 loss of function can be involved in oxidative brain damage. Starting from the evidence that oxidative damage in the brain of Mecp2-null mice precedes the onset of symptoms, we evaluated whether, based on the current literature, the dysfunctions described in RTT could be a consequence or, in contrast, could be caused by OS. We also analyzed whether therapies that at least partially treated some RTT symptoms can play a role in defense against OS. At this stage we can propose that OS could be one of the main causes of the dysfunctions observed in RTT. In addition, the major part of the therapies recommended to alleviate RTT symptoms have been shown to interfere with oxidative homeostasis, suggesting that MeCP2 could somehow be involved in the protection of the brain from OS.
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Affiliation(s)
- Stefania Filosa
- Institute of Biosciences and BioResources-CNR, UOS Naples, Italy; IRCCS Neuromed, Pozzilli, Italy
| | - Alessandra Pecorelli
- Child Neuropsychiatry Unit, University General Hospital, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Maurizio D'Esposito
- Institute of Genetics and Biophysics "A. Buzzati-Traverso"-CNR, Naples, Italy; IRCCS Neuromed, Pozzilli, Italy
| | - Giuseppe Valacchi
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy; Department of Food and Nutrition, Kyung Hee University, Seoul, South Korea.
| | - Joussef Hajek
- Child Neuropsychiatry Unit, University General Hospital, Azienda Ospedaliera Universitaria Senese, Siena, Italy
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De Filippis B, Valenti D, de Bari L, De Rasmo D, Musto M, Fabbri A, Ricceri L, Fiorentini C, Laviola G, Vacca RA. Mitochondrial free radical overproduction due to respiratory chain impairment in the brain of a mouse model of Rett syndrome: protective effect of CNF1. Free Radic Biol Med 2015; 83:167-77. [PMID: 25708779 DOI: 10.1016/j.freeradbiomed.2015.02.014] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 02/09/2015] [Accepted: 02/11/2015] [Indexed: 11/19/2022]
Abstract
Rett syndrome (RTT) is a pervasive neurodevelopmental disorder mainly caused by mutations in the X-linked MECP2 gene associated with severe intellectual disability, movement disorders, and autistic-like behaviors. Its pathogenesis remains mostly not understood and no effective therapy is available. High circulating levels of oxidative stress markers in patients and the occurrence of oxidative brain damage in MeCP2-deficient mouse models suggest the involvement of oxidative stress in RTT pathogenesis. However, the molecular mechanism and the origin of the oxidative stress have not been elucidated. Here we demonstrate that a redox imbalance arises from aberrant mitochondrial functionality in the brain of MeCP2-308 heterozygous female mice, a condition that more closely recapitulates that of RTT patients. The marked increase in the rate of hydrogen peroxide generation in the brain of RTT mice seems mainly produced by the dysfunctional complex II of the mitochondrial respiratory chain. In addition, both membrane potential generation and mitochondrial ATP synthesis are decreased in RTT mouse brains when succinate, the complex II respiratory substrate, is used as an energy source. Respiratory chain impairment is brain area specific, owing to a decrease in either cAMP-dependent phosphorylation or protein levels of specific complex subunits. Further, we investigated whether the treatment of RTT mice with the bacterial protein CNF1, previously reported to ameliorate the neurobehavioral phenotype and brain bioenergetic markers in an RTT mouse model, exerts specific effects on brain mitochondrial function and consequently on hydrogen peroxide production. In RTT brains treated with CNF1, we observed the reactivation of respiratory chain complexes, the rescue of mitochondrial functionality, and the prevention of brain hydrogen peroxide overproduction. These results provide definitive evidence of mitochondrial reactive oxygen species overproduction in RTT mouse brain and highlight CNF1 efficacy in counteracting RTT-related mitochondrial defects.
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Affiliation(s)
- Bianca De Filippis
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, 00161 Roma, Italy.
| | - Daniela Valenti
- Institute of Biomembranes and Bioenergetics, National Council of Research, Bari, Italy
| | - Lidia de Bari
- Institute of Biomembranes and Bioenergetics, National Council of Research, Bari, Italy
| | - Domenico De Rasmo
- Institute of Biomembranes and Bioenergetics, National Council of Research, Bari, Italy
| | - Mattia Musto
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, 00161 Roma, Italy
| | - Alessia Fabbri
- Department of Therapeutic Research and Medicine Evaluation, Istituto Superiore di Sanità, 00161 Roma, Italy
| | - Laura Ricceri
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, 00161 Roma, Italy
| | - Carla Fiorentini
- Department of Therapeutic Research and Medicine Evaluation, Istituto Superiore di Sanità, 00161 Roma, Italy
| | - Giovanni Laviola
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, 00161 Roma, Italy
| | - Rosa Anna Vacca
- Institute of Biomembranes and Bioenergetics, National Council of Research, Bari, Italy.
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Dysregulation of glutamine transporter SNAT1 in Rett syndrome microglia: a mechanism for mitochondrial dysfunction and neurotoxicity. J Neurosci 2015; 35:2516-29. [PMID: 25673846 DOI: 10.1523/jneurosci.2778-14.2015] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Rett syndrome (RTT) is an autism spectrum disorder caused by loss-of-function mutations in the gene encoding MeCP2, an epigenetic modulator that binds the methyl CpG dinucleotide in target genes to regulate transcription. Previously, we and others reported a role of microglia in the pathophysiology of RTT. To understand the mechanism of microglia dysfunction in RTT, we identified a MeCP2 target gene, SLC38A1, which encodes a major glutamine transporter (SNAT1), and characterized its role in microglia. We found that MeCP2 acts as a microglia-specific transcriptional repressor of SNAT1. Because glutamine is mainly metabolized in the mitochondria, where it is used as an energy substrate and a precursor for glutamate production, we hypothesize that SNAT1 overexpression in MeCP2-deficient microglia would impair the glutamine homeostasis, resulting in mitochondrial dysfunction as well as microglial neurotoxicity because of glutamate overproduction. Supporting this hypothesis, we found that MeCP2 downregulation or SNAT1 overexpression in microglia resulted in (1) glutamine-dependent decrease in microglial viability, which was corroborated by reduced microglia counts in the brains of MECP2 knock-out mice; (2) proliferation of mitochondria and enhanced mitochondrial production of reactive oxygen species; (3) increased oxygen consumption but decreased ATP production (an energy-wasting state); and (4) overproduction of glutamate that caused NMDA receptor-dependent neurotoxicity. The abnormalities could be rectified by mitochondria-targeted expression of catalase and a mitochondria-targeted peptide antioxidant, Szeto-Schiller 31. Our results reveal a novel mechanism via which MeCP2 regulates bioenergetic pathways in microglia and suggest a therapeutic potential of mitochondria-targeted antioxidants for RTT.
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Valenti D, de Bari L, De Filippis B, Henrion-Caude A, Vacca RA. Mitochondrial dysfunction as a central actor in intellectual disability-related diseases: An overview of Down syndrome, autism, Fragile X and Rett syndrome. Neurosci Biobehav Rev 2014; 46 Pt 2:202-17. [DOI: 10.1016/j.neubiorev.2014.01.012] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 11/05/2013] [Accepted: 01/13/2014] [Indexed: 12/26/2022]
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Abstract
RTT (Rett syndrome) is a severe progressive neurodevelopmental disorder with a monogenetic cause, but complex and multifaceted clinical appearance. Compelling evidence suggests that mitochondrial alterations and aberrant redox homoeostasis result in oxidative challenge. Yet, compared with other severe neuropathologies, RTT is not associated with marked neurodegeneration, but rather a chemical imbalance and miscommunication of neuronal elements. Different pharmacotherapies mediate partial improvement of conditions in RTT, and also antioxidants or compounds improving mitochondrial function may be of potential merit. In the present paper, we summarize findings from patients and transgenic mice that point towards the nature of RTT as a mitochondrial disease. Also, open questions are addressed that require clarification to fully understand and successfully target the associated cellular redox imbalance.
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Oxidative brain damage in Mecp2-mutant murine models of Rett syndrome. Neurobiol Dis 2014; 68:66-77. [PMID: 24769161 PMCID: PMC4076513 DOI: 10.1016/j.nbd.2014.04.006] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Revised: 03/10/2014] [Accepted: 04/14/2014] [Indexed: 12/03/2022] Open
Abstract
Rett syndrome (RTT) is a rare neurodevelopmental disorder affecting almost exclusively females, caused in the overwhelming majority of the cases by loss-of-function mutations in the gene encoding methyl-CpG binding protein 2 (MECP2). High circulating levels of oxidative stress (OS) markers in patients suggest the involvement of OS in the RTT pathogenesis. To investigate the occurrence of oxidative brain damage in Mecp2 mutant mouse models, several OS markers were evaluated in whole brains of Mecp2-null (pre-symptomatic, symptomatic, and rescued) and Mecp2-308 mutated (pre-symptomatic and symptomatic) mice, and compared to those of wild type littermates. Selected OS markers included non-protein-bound iron, isoprostanes (F2-isoprostanes, F4-neuroprostanes, F2-dihomo-isoprostanes) and 4-hydroxy-2-nonenal protein adducts. Our findings indicate that oxidative brain damage 1) occurs in both Mecp2-null (both −/y and stop/y) and Mecp2-308 (both 308/y males and 308/+ females) mouse models of RTT; 2) precedes the onset of symptoms in both Mecp2-null and Mecp2-308 models; and 3) is rescued by Mecp2 brain specific gene reactivation. Our data provide direct evidence of the link between Mecp2 deficiency, oxidative stress and RTT pathology, as demonstrated by the rescue of the brain oxidative homeostasis following brain-specifically Mecp2-reactivated mice. The present study indicates that oxidative brain damage is a previously unrecognized hallmark feature of murine RTT, and suggests that Mecp2 is involved in the protection of the brain from oxidative stress. Oxidative damage is demonstrated in the brain, and more specifically in the neurons, of Mecp2 mutant mouse models. A direct evidence between enhanced oxidative stress and Mecp2 deficiency is provided. Oxidative damage precedes the behavioral abnormalities in Mecp2 mutant mice. Mecp2 is likely involved in the protection of the brain from oxidative stress.
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Gold WA, Williamson SL, Kaur S, Hargreaves IP, Land JM, Pelka GJ, Tam PPL, Christodoulou J. Mitochondrial dysfunction in the skeletal muscle of a mouse model of Rett syndrome (RTT): implications for the disease phenotype. Mitochondrion 2014; 15:10-7. [PMID: 24613463 DOI: 10.1016/j.mito.2014.02.012] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 02/20/2014] [Accepted: 02/24/2014] [Indexed: 02/05/2023]
Abstract
Rett syndrome (RTT) is a severe neurodevelopmental disorder, predominantly caused by mutations in the X-linked Methyl-CpG-binding protein 2 (MECP2) gene. Patients present with numerous functional deficits including intellectual disability and abnormalities of movement. Clinical and biochemical features may overlap with those seen in patients with primary mitochondrial respiratory chain disorders. In the late stages of the disorder, patients suffer from motor deterioration and usually require assisted mobility. Using a mouse model of RTT (Mecp2(tm1Tam)), we studied the mitochondrial function in the hind-limb skeletal muscle of these mice. We identified a reduction in cytochrome c oxidase subunit I (MTCO1) at both the transcript and protein level, in accordance with our previous findings in RTT patient brain studies. Mitochondrial respiratory chain (MRC) enzyme activity of complexes II+III (COII+III) and complex IV (COIV), and glutathione (GSH) levels were significantly reduced in symptomatic mice, but not in the pre-symptomatic mice. Our findings suggest that mitochondrial abnormalities in the skeletal muscle may contribute to the progressive deterioration in mobility in RTT through the accumulation of free radicals, as evidenced by the decrease in reduced glutathione (GSH). We hypothesise that a diminution in GSH leads to an accumulation of free radicals and an increase in oxidative stress. This may impact on respiratory chain function and contribute in part to the progressive neurological and motor deterioration seen in the Mecp2-mutant mouse. Treatment strategies aimed at restoring cellular GSH levels may prove to be a novel target area to consider in future approaches to RTT therapies.
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Affiliation(s)
- W A Gold
- NSW Centre for Rett Syndrome Research, Western Sydney Genetics Program, Children's Hospital at Westmead, Sydney, Australia; Discipline of Paediatrics & Child Health, University of Sydney, Australia
| | - S L Williamson
- NSW Centre for Rett Syndrome Research, Western Sydney Genetics Program, Children's Hospital at Westmead, Sydney, Australia
| | - S Kaur
- NSW Centre for Rett Syndrome Research, Western Sydney Genetics Program, Children's Hospital at Westmead, Sydney, Australia
| | - I P Hargreaves
- Neurometabolic Unit, National Hospital and Department of Molecular Neuroscience, Institute of Neurology, London, United Kingdom
| | - J M Land
- Neurometabolic Unit, National Hospital and Department of Molecular Neuroscience, Institute of Neurology, London, United Kingdom
| | - G J Pelka
- Embryology Unit, Children's Medical Research Institute, Sydney, Australia
| | - P P L Tam
- Embryology Unit, Children's Medical Research Institute, Sydney, Australia; Discipline of Medicine, Sydney Medical School, University of Sydney, Australia
| | - J Christodoulou
- NSW Centre for Rett Syndrome Research, Western Sydney Genetics Program, Children's Hospital at Westmead, Sydney, Australia; Discipline of Paediatrics & Child Health, University of Sydney, Australia; Discipline of Genetic Medicine, Sydney Medical School, University of Sydney, Australia
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Janc OA, Müller M. The free radical scavenger Trolox dampens neuronal hyperexcitability, reinstates synaptic plasticity, and improves hypoxia tolerance in a mouse model of Rett syndrome. Front Cell Neurosci 2014; 8:56. [PMID: 24605086 PMCID: PMC3932407 DOI: 10.3389/fncel.2014.00056] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 02/06/2014] [Indexed: 11/13/2022] Open
Abstract
Rett syndrome (RS) causes severe cognitive impairment, loss of speech, epilepsy, and breathing disturbances with intermittent hypoxia. Also mitochondria are affected; a subunit of respiratory complex III is dysregulated, the inner mitochondrial membrane is leaking protons, and brain ATP levels seem reduced. Our recent assessment of mitochondrial function in MeCP2 (methyl-CpG-binding protein 2)-deficient mouse (Mecp2-/y) hippocampus confirmed early metabolic alterations, an increased oxidative burden, and a more vulnerable cellular redox balance. As these changes may contribute to the manifestation of symptoms and disease progression, we now evaluated whether free radical scavengers are capable of improving neuronal and mitochondrial function in RS. Acute hippocampal slices of adult mice were incubated with the vitamin E derivative Trolox for 3–5 h. In Mecp2-/y slices this treatment dampened neuronal hyperexcitability, improved synaptic short-term plasticity, and fully restored synaptic long-term potentiation (LTP). Furthermore, Trolox specifically attenuated the increased hypoxia susceptibility of Mecp2-/y slices. Also, the anticonvulsive effects of Trolox were assessed, but the severity of 4-aminopyridine provoked seizure-like discharges was not significantly affected. Adverse side effects of Trolox on mitochondria can be excluded, but clear indications for an improvement of mitochondrial function were not found. Since several ion-channels and neurotransmitter receptors are redox modulated, the mitochondrial alterations and the associated oxidative burden may contribute to the neuronal dysfunction in RS. We confirmed in Mecp2-/y hippocampus that Trolox dampens neuronal hyperexcitability, reinstates synaptic plasticity, and improves the hypoxia tolerance. Therefore, radical scavengers are promising compounds for the treatment of neuronal dysfunction in RS and deserve further detailed evaluation.
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Affiliation(s)
- Oliwia A Janc
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Georg-August-Universität Göttingen Göttingen, Germany ; Zentrum für Physiologie und Pathophysiologie, Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin, Georg-August-Universität Göttingen Göttingen, Germany
| | - Michael Müller
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Georg-August-Universität Göttingen Göttingen, Germany ; Zentrum für Physiologie und Pathophysiologie, Institut für Neuro- und Sinnesphysiologie, Universitätsmedizin, Georg-August-Universität Göttingen Göttingen, Germany
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Maurin T, Zongaro S, Bardoni B. Fragile X Syndrome: from molecular pathology to therapy. Neurosci Biobehav Rev 2014; 46 Pt 2:242-55. [PMID: 24462888 DOI: 10.1016/j.neubiorev.2014.01.006] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 01/12/2014] [Accepted: 01/14/2014] [Indexed: 02/09/2023]
Abstract
Fragile X Syndrome (FXS) is the most common form of inherited intellectual disability due to the silencing of the FMR1 gene encoding FMRP (Fragile X Mental Retardation Protein), an RNA-binding protein involved in different steps of RNA metabolism. Of particular interest is the key role of FMRP in translational regulation. Since the first functional characterizations of FMRP, its role has been underlined by its association with actively translating polyribosomes. Furthermore, a plethora of mRNA targets of FMRP have been identified. In the absence of FMRP the deregulation of translation/transport/stability of these mRNAs has a cascade effect on many pathways, resulting into the final phenotype. We review here a set of targets of FMRP (mRNAs and proteins) that may have an impact on the FXS phenotype by deregulating some key cellular processes, such as translation, cytoskeleton remodeling and oxidative stress. The manipulation of these abnormal pathways by specific drugs may represent new therapeutic opportunities for FXS patients.
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Affiliation(s)
- Thomas Maurin
- Institute of Molecular and Cellular Pharmacology, CNRS UMR7275, University of Nice Sophia Antipolis, Route des Lucioles, 06560 Valbonne, France
| | - Samantha Zongaro
- Institute of Molecular and Cellular Pharmacology, CNRS UMR7275, University of Nice Sophia Antipolis, Route des Lucioles, 06560 Valbonne, France
| | - Barbara Bardoni
- Institute of Molecular and Cellular Pharmacology, CNRS UMR7275, University of Nice Sophia Antipolis, Route des Lucioles, 06560 Valbonne, France.
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Isoprostanes and 4-hydroxy-2-nonenal: markers or mediators of disease? Focus on Rett syndrome as a model of autism spectrum disorder. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2013; 2013:343824. [PMID: 23844273 PMCID: PMC3697420 DOI: 10.1155/2013/343824] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Revised: 05/23/2013] [Accepted: 05/24/2013] [Indexed: 11/17/2022]
Abstract
Lipid peroxidation, a process known to induce oxidative damage to key cellular components, has been implicated in several diseases. Following three decades of explorations mainly on in vitro models reproducible in the laboratories, lipid peroxidation has become increasingly relevant for the interpretation of a wide range of pathophysiological mechanisms in the clinical setting. This cumulative effort has led to the identification of several lipid peroxidation end-products meeting the needs of the in vivo evaluation. Among these different molecules, isoprostanes and 4-hydroxy-2-nonenal protein adducts appear to be particularly interesting. This review shows how specific oxidation products, deriving from polyunsaturated fatty acids precursors, are strictly related to the clinical manifestations and the natural history of Rett syndrome, a genetically determined neurodevelopmental pathology, currently classified among the autism spectrum disorders. In our experience, Rett syndrome offers a unique setting for physicians, biologists, and chemists to explore the borders of the lipid mediators concept.
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Panighini A, Duranti E, Santini F, Maffei M, Pizzorusso T, Funel N, Taddei S, Bernardini N, Ippolito C, Virdis A, Costa M. Vascular dysfunction in a mouse model of Rett syndrome and effects of curcumin treatment. PLoS One 2013; 8:e64863. [PMID: 23705018 PMCID: PMC3660336 DOI: 10.1371/journal.pone.0064863] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Accepted: 04/22/2013] [Indexed: 02/07/2023] Open
Abstract
Mutations in the coding sequence of the X-linked gene MeCP2 (Methyl CpG–binding protein) are present in around 80% of patients with Rett Syndrome, a common cause of intellectual disability in female and to date without any effective pharmacological treatment. A relevant, and so far unexplored feature of RTT patients, is a marked reduction in peripheral circulation. To investigate the relationship between loss of MeCP2 and this clinical aspect, we used the MeCP2 null mouse model B6.129SF1-MeCP2tm1Jae for functional and pharmacological studies. Functional experiments were performed on isolated resistance mesenteric vessels, mounted on a pressurized myograph. Vessels from female MeCP2+/− mice show a reduced endothelium-dependent relaxation, due to a reduced Nitric Oxide (NO) availability secondary to an increased Reactive Oxygen Species (ROS) generation. Such functional aspects are associated with an intravascular increase in superoxide anion production, and a decreased vascular eNOS expression. These alterations are reversed by curcumin administration (5% (w/w) dietary curcumin for 21 days), which restores endothelial NO availability, decreases intravascular ROS production and normalizes vascular eNOS gene expression. In conclusion our findings highlight alterations in the vascular/endothelial system in the absence of a correct function of MeCP2, and uncover related cellular/molecular mechanisms that are rescued by an anti-oxidant treatment.
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MESH Headings
- Animals
- Blood Vessels/drug effects
- Blood Vessels/physiopathology
- Curcumin/administration & dosage
- Curcumin/pharmacology
- Curcumin/therapeutic use
- Disease Models, Animal
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/enzymology
- Endothelium, Vascular/pathology
- Endothelium, Vascular/physiopathology
- Female
- Gene Expression Regulation, Enzymologic/drug effects
- Immunohistochemistry
- Malondialdehyde/metabolism
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Nitric Oxide Synthase Type III/genetics
- Nitric Oxide Synthase Type III/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rett Syndrome/complications
- Rett Syndrome/drug therapy
- Rett Syndrome/physiopathology
- Superoxides/metabolism
- Time Factors
- Vascular Diseases/complications
- Vascular Diseases/drug therapy
- Vascular Diseases/physiopathology
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Affiliation(s)
- Anna Panighini
- Institute of Neuroscience, Italian National Research Council (CNR), Pisa, Italy
| | - Emiliano Duranti
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Ferruccio Santini
- Department of Endocrinology and Kidney; University-Hospital of Pisa, Pisa, Italy
| | - Margherita Maffei
- Department of Endocrinology and Kidney; University-Hospital of Pisa, Pisa, Italy
- Dulbecco Telethon Institute, Rome, Italy
- Institute of Food Science, CNR, Avellino, Italy
| | - Tommaso Pizzorusso
- Institute of Neuroscience, Italian National Research Council (CNR), Pisa, Italy
- Institute of Psychology, University of Florence, Florence, Italy
| | - Niccola Funel
- Department of Surgery, University of Pisa, Pisa, Italy
| | - Stefano Taddei
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Nunzia Bernardini
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Chiara Ippolito
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Agostino Virdis
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
- * E-mail: (AV); (MC)
| | - Mario Costa
- Institute of Neuroscience, Italian National Research Council (CNR), Pisa, Italy
- Scuola Normale Superiore, Pisa, Italy
- * E-mail: (AV); (MC)
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De Felice C, Signorini C, Leoncini S, Pecorelli A, Durand T, Valacchi G, Ciccoli L, Hayek J. The role of oxidative stress in Rett syndrome: an overview. Ann N Y Acad Sci 2012; 1259:121-35. [PMID: 22758644 DOI: 10.1111/j.1749-6632.2012.06611.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The main cause of Rett syndrome (RTT), a pervasive development disorder almost exclusively affecting females, is a mutation in the methyl-CpG binding protein 2 (MeCP2) gene. To date, no cure for RTT exists, although disease reversibility has been demonstrated in animal models. Emerging evidence from our and other laboratories indicates a potential role of oxidative stress (OS) in RTT. This review examines the current state of the knowledge on the role of OS in explaining the natural history, genotype-phenotype correlation, and clinical heterogeneity of the human disease. Biochemical evidence of OS appears to be related to neurological symptom severity, mutation type, and clinical presentation. These findings pave the way for potential new genetic downstream therapeutic strategies aimed at improving patient quality of life. Further efforts in the near future are needed for investigating the yet unexplored "black box" between the MeCP2 gene mutation and subsequent OS derangement.
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Affiliation(s)
- Claudio De Felice
- Neonatal Intensive Care Unit University Hospital, Azienda Ospedaliera Universitaria Senese of Siena, Siena, Italy.
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Grosser E, Hirt U, Janc OA, Menzfeld C, Fischer M, Kempkes B, Vogelgesang S, Manzke TU, Opitz L, Salinas-Riester G, Müller M. Oxidative burden and mitochondrial dysfunction in a mouse model of Rett syndrome. Neurobiol Dis 2012; 48:102-14. [PMID: 22750529 DOI: 10.1016/j.nbd.2012.06.007] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Revised: 05/22/2012] [Accepted: 06/22/2012] [Indexed: 10/28/2022] Open
Abstract
Rett syndrome is an X chromosome-linked neurodevelopmental disorder associated with cognitive impairment, motor dysfunction and breathing irregularities causing intermittent hypoxia. Evidence for impaired mitochondrial function is also accumulating. A subunit of complex III is among the potentially dys-regulated genes, the inner mitochondrial membrane is leaking protons, brain ATP levels seem reduced, and Rett patient blood samples confirm increased oxidative damage. We therefore screened for mitochondrial dysfunction and impaired redox balance. In hippocampal slices of a Rett mouse model (Mecp2(-/y)) we detected an increased FAD/NADH baseline-ratio indicating intensified oxidization. Cyanide-induced anoxia caused similar decreases in FAD/NADH ratio and mitochondrial membrane potential in both genotypes, but Mecp2(-/y) mitochondria seemed less polarized. Quantifying cytosolic redox balance with the genetically-encoded optical probe roGFP1 confirmed more oxidized baseline conditions, a more vulnerable redox-balance, and more intense responses of Mecp2(-/y) hippocampus to oxidative challenge and mitochondrial impairment. Trolox treatment improved the redox baseline of Mecp2(-/y) hippocampus and dampened its exaggerated responses to oxidative challenge. Microarray analysis of the hippocampal CA1 subfield did not detect alterations of key mitochondrial enzymes or scavenging systems. Yet, quantitative PCR confirmed a moderate upregulation of superoxide dismutase 1 in Mecp2(-/y) hippocampus, which might be a compensatory response to the increased oxidative burden. Since several receptors and ion-channels are redox-modulated, the mitochondrial and redox changes which already manifest in neonates could contribute to the hyperexcitability and diminished synaptic plasticity in MeCP2 deficiency. Therefore, targeting cellular redox balance might qualify as a potential pharmacotherapeutic approach to improve neuronal network function in Rett syndrome.
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Affiliation(s)
- Emanuel Grosser
- DFG Research Center Molecular Physiology of the Brain (CMPB), Zentrum für Physiologie und Pathophysiologie, Abteilung Neuro- und Sinnesphysiologie, Georg-August-Universität Göttingen, Universitätsmedizin, Humboldtallee 23, D-37073 Göttingen, Germany
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Abstract
Autism spectrum disorders (ASDs) including classic autism is a group of complex developmental disabilities with core deficits of impaired social interactions, communication difficulties and repetitive behaviors. Although the neurobiology of ASDs has attracted much attention in the last two decades, the role of microglia has been ignored. Existing data are focused on their recognized role in neuroinflammation, which only covers a small part of the pathological repertoire of microglia. This review highlights recent findings on the broader roles of microglia, including their active surveillance of brain microenvironments and regulation of synaptic connectivity, maturation of brain circuitry and neurogenesis. Emerging evidence suggests that microglia respond to pre- and postnatal environmental stimuli through epigenetic interface to change gene expression, thus acting as effectors of experience-dependent synaptic plasticity. Impairments of these microglial functions could substantially contribute to several major etiological factors of autism, such as environmental toxins and cortical underconnectivity. Our recent study on Rett syndrome, a syndromic autistic disorder, provides an example that intrinsic microglial dysfunction due to genetic and epigenetic aberrations could detrimentally affect the developmental trajectory without evoking neuroinflammation. We propose that ASDs provide excellent opportunities to study the influence of microglia on neurodevelopment, and this knowledge could lead to novel therapies.
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Hayashi M, Miyata R, Tanuma N. Oxidative Stress in Developmental Brain Disorders. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 724:278-90. [DOI: 10.1007/978-1-4614-0653-2_21] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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41
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Leoncini S, De Felice C, Signorini C, Pecorelli A, Durand T, Valacchi G, Ciccoli L, Hayek J. Oxidative stress in Rett syndrome: natural history, genotype, and variants. Redox Rep 2011; 16:145-53. [PMID: 21888765 DOI: 10.1179/1351000211y.0000000004] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
OBJECTIVES Rett syndrome (RTT) is an X-linked autism spectrum disorder caused by mutations in the MeCP2 gene in the great majority of cases. Evidence suggests a potential role of oxidative stress (OS) in its pathogenesis. Here, we investigated the potential value of OS markers (non-protein-bound iron (NPBI) and F2-isoprostanes (F2-IsoPs)) in explaining natural history, genotype-phenotype correlation, and clinical heterogeneity of RTT, and gauging the response to omega-3 polyunsaturated fatty acids (ω-3 PUFAs). METHODS RTT patients (n=113) and healthy controls were assayed for plasma NPBI and F2-IsoPs, and intraerythrocyte NPBI. Forty-two patients with typical RTT were randomly assigned to ω-3 PUFAs supplementation for 12 months. NPBI was measured by HPLC and F2-IsoPs using a gas chromatography/negative ion chemical ionization tandem mass spectrometry (GC/NICI-MS/MS) technique. RESULTS F2-IsoPs were significantly higher in the early stages as compared with the late natural progression of classic RTT. MeCP2 mutations related to more severe phenotypes exhibited higher OS marker levels than those of milder phenotypes. Higher OS markers were observed in typical RTT and early seizure variant as compared with the preserved speech and congenital variants. Significant reduction in OS markers levels and improvement of severity scores were observed after ω-3 PUFAs supplementation. DISCUSSION OS is a key modulator of disease expression in RTT.
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Affiliation(s)
- Silvia Leoncini
- Department of Pathophysiology, Experimental Medicine & Public Health, University of Siena, and Neonatal Intensive Care Unit, University Hospital, Azienda Ospedaliera Senese, Siena, Italy
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Kunde SA, Musante L, Grimme A, Fischer U, Muller E, Wanker EE, Kalscheuer VM. The X-chromosome-linked intellectual disability protein PQBP1 is a component of neuronal RNA granules and regulates the appearance of stress granules. Hum Mol Genet 2011; 20:4916-31. [DOI: 10.1093/hmg/ddr430] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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43
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Signorini C, De Felice C, Leoncini S, Giardini A, D'Esposito M, Filosa S, Della Ragione F, Rossi M, Pecorelli A, Valacchi G, Ciccoli L, Hayek J. F₄-neuroprostanes mediate neurological severity in Rett syndrome. Clin Chim Acta 2011; 412:1399-406. [PMID: 21530498 DOI: 10.1016/j.cca.2011.04.016] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Revised: 04/11/2011] [Accepted: 04/11/2011] [Indexed: 10/18/2022]
Abstract
BACKGROUND Rett syndrome (RTT) is a pervasive development disorder, mainly caused by mutations in the methyl-CpG binding protein 2 (MeCP2) gene. No reliable biochemical markers of the disease are available. Here we assess F₄-neuroprostanes (F₄-NeuroPs), lipid peroxidation products of the docosahexaenoic acid, as a novel disease marker in RTT and correlate it with clinical presentation, MeCP2 mutation type, and disease progression. In addition, we investigate on the impact of ω-3 polyunsaturated fatty acids (ω-3 PUFAs) supplementation on F₄-NeuroPs levels. METHODS A case-control study design was used. A cohort of RTT patients (n=144) exhibiting different clinical presentations, disease stages, and MeCP2 gene mutations were evaluated. F₄-NeuroPs were measured in free form using a GC/NICI-MS/MS technique. Plasma F₄-NeuroPs levels in patients were compared to healthy controls and related to RTT forms, disease progression, and response to ω-3 PUFAs supplementation. RESULTS Plasma F₄-NeuroPs levels were i) higher in RTT than in controls; ii) increased with the severity of neurological symptoms; iii) significantly elevated during the typical disease progression; iv) higher in MeCP2-nonsense as compared to missense mutation carriers; v) higher in typical RTT as compared to RTT variants; and vi) decreased in response to 12 months ω-3 PUFAs oral supplementation. CONCLUSIONS Quantification of plasma F₄-NeuroPs provides a novel RTT marker, related to neurological symptoms severity, mutation type and clinical presentation.
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Affiliation(s)
- Cinzia Signorini
- Department of Pathophysiology, Experimental Medicine & Public Health, University of Siena, Siena, Italy
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Lintas C, Sacco R, Persico AM. Genome-wide expression studies in autism spectrum disorder, Rett syndrome, and Down syndrome. Neurobiol Dis 2010; 45:57-68. [PMID: 21130877 DOI: 10.1016/j.nbd.2010.11.010] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2010] [Revised: 11/11/2010] [Accepted: 11/16/2010] [Indexed: 12/19/2022] Open
Abstract
Though different in their aetiology, autism spectrum disorder (ASD), Rett syndrome (RTT) and Down syndrome (DS) are three neurodevelopmental disorders sharing significant clinical and neuropathological overlaps. Genome-wide expression studies are reviewed and available datasets from post-mortem brains reanalyzed to identify genes and gene pathways dysregulated in all three disorders. Our results surprisingly converge upon immune, and not neurodevelopmental genes, as the most consistently shared abnormality in genome-wide expression patterns. A dysregulated immune response, accompanied by enhanced oxidative stress and abnormal mitochondrial metabolism seemingly represents the common molecular underpinning of these neurodevelopmental disorders. This conclusion may be important for the definition of pharmacological therapies able to ameliorate clinical symptoms across these disorders.
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Affiliation(s)
- Carla Lintas
- Laboratory of Molecular Psychiatry and Neurogenetics, University Campus Bio-Medico, Rome, Italy
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Gibson JH, Slobedman B, K N H, Williamson SL, Minchenko D, El-Osta A, Stern JL, Christodoulou J. Downstream targets of methyl CpG binding protein 2 and their abnormal expression in the frontal cortex of the human Rett syndrome brain. BMC Neurosci 2010; 11:53. [PMID: 20420693 PMCID: PMC2881102 DOI: 10.1186/1471-2202-11-53] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2009] [Accepted: 04/26/2010] [Indexed: 11/30/2022] Open
Abstract
Background The Rett Syndrome (RTT) brain displays regional histopathology and volumetric reduction, with frontal cortex showing such abnormalities, whereas the occipital cortex is relatively less affected. Results Using microarrays and quantitative PCR, the mRNA expression profiles of these two neuroanatomical regions were compared in postmortem brain tissue from RTT patients and normal controls. A subset of genes was differentially expressed in the frontal cortex of RTT brains, some of which are known to be associated with neurological disorders (clusterin and cytochrome c oxidase subunit 1) or are involved in synaptic vesicle cycling (dynamin 1). RNAi-mediated knockdown of MeCP2 in vitro, followed by further expression analysis demonstrated that the same direction of abnormal expression was recapitulated with MeCP2 knockdown, which for cytochrome c oxidase subunit 1 was associated with a functional respiratory chain defect. Chromatin immunoprecipitation (ChIP) analysis showed that MeCP2 associated with the promoter regions of some of these genes suggesting that loss of MeCP2 function may be responsible for their overexpression. Conclusions This study has shed more light on the subset of aberrantly expressed genes that result from MECP2 mutations. The mitochondrion has long been implicated in the pathogenesis of RTT, however it has not been at the forefront of RTT research interest since the discovery of MECP2 mutations. The functional consequence of the underexpression of cytochrome c oxidase subunit 1 indicates that this is an area that should be revisited.
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Affiliation(s)
- Joanne H Gibson
- Western Sydney Genetics Program, The Children's Hospital at Westmead, Sydney, Australia.
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Experimental Evidence that Phenylalanine Provokes Oxidative Stress in Hippocampus and Cerebral Cortex of Developing Rats. Cell Mol Neurobiol 2009; 30:317-26. [DOI: 10.1007/s10571-009-9455-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2009] [Accepted: 09/03/2009] [Indexed: 12/12/2022]
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De Felice C, Ciccoli L, Leoncini S, Signorini C, Rossi M, Vannuccini L, Guazzi G, Latini G, Comporti M, Valacchi G, Hayek J. Systemic oxidative stress in classic Rett syndrome. Free Radic Biol Med 2009; 47:440-8. [PMID: 19464363 DOI: 10.1016/j.freeradbiomed.2009.05.016] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2009] [Revised: 03/03/2009] [Accepted: 05/13/2009] [Indexed: 11/22/2022]
Abstract
Rett syndrome (RS), a progressive severe neurodevelopmental disorder mainly caused by de novo mutations in the X-chromosomal MeCP2 gene encoding the transcriptional regulator methyl-CpG-binding protein 2, is a leading cause of mental retardation with autistic features in females. However, its pathogenesis remains incompletely understood, and no effective therapy is available to date. We hypothesized that a systemic oxidative stress may play a key role in the pathogenesis of classic RS. Patients with classic RS (n=59) and control subjects (n=43) were evaluated. Oxidative stress markers included intraerythrocyte non-protein-bound iron (NPBI; i.e., free iron), plasma NPBI, F2-isoprostanes (F2-IsoPs, as free, esterified, and total forms), and protein carbonyls. Lung ventilation/perfusion (V/Q) ratio was assessed using a portable gas analyzer, and RS clinical severity was evaluated using standard scales. Significantly increased intraerythrocyte NPBI (2.73-fold), plasma NPBI (x 6.0), free F(2)-IsoP (x1.85), esterified F2-IsoP (x 1.69), total F2-IsoP (x 1.66), and protein carbonyl (x 4.76) concentrations were evident in RS subjects and associated with reduced (-10.53%) arterial oxygen levels compared to controls. Biochemical evidence of oxidative stress was related to clinical phenotype severity and lower peripheral and arterial oxygen levels. Pulmonary V/Q mismatch was found in the majority of the RS population. These data identify hypoxia-induced oxidative stress as a key factor in the pathogenesis of classic RS and suggest new therapeutic approaches based on oxidative stress modulation.
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Affiliation(s)
- Claudio De Felice
- Neonatal Intensive Care Unit, University Hospital AOUS of Siena, I-53100 Siena, Italy.
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Garg SK, Banerjee R, Kipnis J. Neuroprotective immunity: T cell-derived glutamate endows astrocytes with a neuroprotective phenotype. THE JOURNAL OF IMMUNOLOGY 2008; 180:3866-73. [PMID: 18322194 DOI: 10.4049/jimmunol.180.6.3866] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A well-controlled T cell response to CNS injury may result in increased neuronal survival. However, the precise mechanism of T cell-induced neuroprotection is unknown. In this study, we report the unexpected finding that during culture of T cells, high levels of glutamate accumulate, which are efficiently cleared if T cells are cocultured with astrocytes. The T cell-derived glutamate elicits in turn, the release of neuroprotective thiols (cysteine, glutathione, and cysteinyl-glycine) and lactate from astrocytes. Media obtained from astrocytes conditioned in the presence of T cells reduce neuronal apoptosis induced by oxidative stress in primary neuronal cultures from 48 +/- 14 to 9 +/- 4% (p < 0.001). Inhibition of glutamate-dependent signaling during astrocyte-T cell cocultivation by a glutamate uptake inhibitor, l-aspartic acid beta-hydroxamate, abolishes this neuroprotective effect. The ability of astrocytes to clear extracellular glutamate is impaired under conditions of oxidative stress. We demonstrate that T cells, via secreted cytokines, restore glutamate clearance capacity of astrocytes under oxidative conditions. Furthermore, under normoxic conditions, glutamate-buffering capacity of astrocytes is increased upon cocultivation with T cells. It is known that, following CNS injury, astrocytes can respond with beneficial or destructive effects on neurons. However, the context and signaling mechanisms for this dual astrocytic response are unknown. Our results implicate T cells as potential determinants of the context that elicits a protective role for astrocytes in the damaged CNS.
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Affiliation(s)
- Sanjay K Garg
- Redox Biology Center, University of Nebraska, Lincoln, NE 68588, USA
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Oxidative Stress and the Metabolic Pathology of Autism. AUTISM : THE INTERNATIONAL JOURNAL OF RESEARCH AND PRACTICE 2008. [DOI: 10.1007/978-1-60327-489-0_11] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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50
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el Bekay R, Romero-Zerbo Y, Decara J, Sanchez-Salido L, Del Arco-Herrera I, Rodríguez-de Fonseca F, de Diego-Otero Y. Enhanced markers of oxidative stress, altered antioxidants and NADPH-oxidase activation in brains from Fragile X mental retardation 1-deficient mice, a pathological model for Fragile X syndrome. Eur J Neurosci 2007; 26:3169-80. [PMID: 18005058 DOI: 10.1111/j.1460-9568.2007.05939.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Fragile X syndrome is the most common form of inherited mental retardation in humans. It originates from the loss of expression of the Fragile X mental retardation 1 (FMR1) gene, which results in the absence of the Fragile X mental retardation protein. However, the biochemical mechanisms involved in the pathological phenotype are mostly unknown. The availability of the FMR1-knockout mouse model offers an excellent model system in which to study the biochemical alterations related to brain abnormalities in the syndrome. We show for the first time that brains from Fmr1-knockout mice, a validated model for the syndrome, display higher levels of reactive oxygen species, nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase activation, lipid peroxidation and protein oxidation than brains from wild-type mice. Furthermore, the antioxidant system is deficient in Fmr1-knockout mice, as shown by altered levels of components of the glutathione system. FMR1-knockout mice lacking Fragile X mental retardation protein were compared with congenic FVB129 wild-type controls. Our results support the hypothesis that the lack of Fragile X mental retardation protein function leads to a moderate increase of the oxidative stress status in the brain that may contribute to the pathophysiology of the Fragile X syndrome.
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Affiliation(s)
- Rajaa el Bekay
- Research Laboratory, Fundación IMABIS-Hospital Carlos Haya, Hospital Civil, Pabellón 5 Sótano, E-29009 Málaga, Spain
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