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Donoghue S, Wright J, Voss AK, Lockhart PJ, Amor DJ. The Mendelian disorders of chromatin machinery: Harnessing metabolic pathways and therapies for treatment. Mol Genet Metab 2024; 142:108360. [PMID: 38428378 DOI: 10.1016/j.ymgme.2024.108360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 02/25/2024] [Accepted: 02/26/2024] [Indexed: 03/03/2024]
Abstract
The Mendelian disorders of chromatin machinery (MDCMs) represent a distinct subgroup of disorders that present with neurodevelopmental disability. The chromatin machinery regulates gene expression by a range of mechanisms, including by post-translational modification of histones, responding to histone marks, and remodelling nucleosomes. Some of the MDCMs that impact on histone modification may have potential therapeutic interventions. Two potential treatment strategies are to enhance the intracellular pool of metabolites that can act as substrates for histone modifiers and the use of medications that may inhibit or promote the modification of histone residues to influence gene expression. In this article we discuss the influence and potential treatments of histone modifications involving histone acetylation and histone methylation. Genomic technologies are facilitating earlier diagnosis of many Mendelian disorders, providing potential opportunities for early treatment from infancy. This has parallels with how inborn errors of metabolism have been afforded early treatment with newborn screening. Before this promise can be fulfilled, we require greater understanding of the biochemical fingerprint of these conditions, which may provide opportunities to supplement metabolites that can act as substrates for chromatin modifying enzymes. Importantly, understanding the metabolomic profile of affected individuals may also provide disorder-specific biomarkers that will be critical for demonstrating efficacy of treatment, as treatment response may not be able to be accurately assessed by clinical measures.
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Affiliation(s)
- Sarah Donoghue
- Murdoch Children's Research Institute, Parkville 3052, Australia; Department of Biochemical Genetics, Victorian Clinical Genetics Services, Parkville 3052, Australia; Department of Paediatrics, The University of Melbourne, Parkville 3052, Australia.
| | - Jordan Wright
- Murdoch Children's Research Institute, Parkville 3052, Australia; Department of Paediatrics, The University of Melbourne, Parkville 3052, Australia
| | - Anne K Voss
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville 3052, Australia
| | - Paul J Lockhart
- Murdoch Children's Research Institute, Parkville 3052, Australia; Department of Paediatrics, The University of Melbourne, Parkville 3052, Australia
| | - David J Amor
- Murdoch Children's Research Institute, Parkville 3052, Australia; Department of Paediatrics, The University of Melbourne, Parkville 3052, Australia
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2
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Iyer SH, Yeh MY, Netzel L, Lindsey MG, Wallace M, Simeone KA, Simeone TA. Dietary and Metabolic Approaches for Treating Autism Spectrum Disorders, Affective Disorders and Cognitive Impairment Comorbid with Epilepsy: A Review of Clinical and Preclinical Evidence. Nutrients 2024; 16:553. [PMID: 38398876 PMCID: PMC10893388 DOI: 10.3390/nu16040553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2023] [Revised: 02/09/2024] [Accepted: 02/14/2024] [Indexed: 02/25/2024] Open
Abstract
Epilepsy often occurs with other neurological disorders, such as autism, affective disorders, and cognitive impairment. Research indicates that many neurological disorders share a common pathophysiology of dysfunctional energy metabolism, neuroinflammation, oxidative stress, and gut dysbiosis. The past decade has witnessed a growing interest in the use of metabolic therapies for these disorders with or without the context of epilepsy. Over one hundred years ago, the high-fat, low-carbohydrate ketogenic diet (KD) was formulated as a treatment for epilepsy. For those who cannot tolerate the KD, other diets have been developed to provide similar seizure control, presumably through similar mechanisms. These include, but are not limited to, the medium-chain triglyceride diet, low glycemic index diet, and calorie restriction. In addition, dietary supplementation with ketone bodies, polyunsaturated fatty acids, or triheptanoin may also be beneficial. The proposed mechanisms through which these diets and supplements work to reduce neuronal hyperexcitability involve normalization of aberrant energy metabolism, dampening of inflammation, promotion of endogenous antioxidants, and reduction of gut dysbiosis. This raises the possibility that these dietary and metabolic therapies may not only exert anti-seizure effects, but also reduce comorbid disorders in people with epilepsy. Here, we explore this possibility and review the clinical and preclinical evidence where available.
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Affiliation(s)
| | | | | | | | | | | | - Timothy A. Simeone
- Department of Pharmacology & Neuroscience, Creighton University School of Medicine, Omaha, NE 68178, USA; (S.H.I.); (K.A.S.)
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3
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Zlatic SA, Werner E, Surapaneni V, Lee CE, Gokhale A, Singleton K, Duong D, Crocker A, Gentile K, Middleton F, Dalloul JM, Liu WLY, Patgiri A, Tarquinio D, Carpenter R, Faundez V. Systemic proteome phenotypes reveal defective metabolic flexibility in Mecp2 mutants. Hum Mol Genet 2023; 33:12-32. [PMID: 37712894 PMCID: PMC10729867 DOI: 10.1093/hmg/ddad154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 09/01/2023] [Accepted: 09/11/2023] [Indexed: 09/16/2023] Open
Abstract
Genes mutated in monogenic neurodevelopmental disorders are broadly expressed. This observation supports the concept that monogenic neurodevelopmental disorders are systemic diseases that profoundly impact neurodevelopment. We tested the systemic disease model focusing on Rett syndrome, which is caused by mutations in MECP2. Transcriptomes and proteomes of organs and brain regions from Mecp2-null mice as well as diverse MECP2-null male and female human cells were assessed. Widespread changes in the steady-state transcriptome and proteome were identified in brain regions and organs of presymptomatic Mecp2-null male mice as well as mutant human cell lines. The extent of these transcriptome and proteome modifications was similar in cortex, liver, kidney, and skeletal muscle and more pronounced than in the hippocampus and striatum. In particular, Mecp2- and MECP2-sensitive proteomes were enriched in synaptic and metabolic annotated gene products, the latter encompassing lipid metabolism and mitochondrial pathways. MECP2 mutations altered pyruvate-dependent mitochondrial respiration while maintaining the capacity to use glutamine as a mitochondrial carbon source. We conclude that mutations in Mecp2/MECP2 perturb lipid and mitochondrial metabolism systemically limiting cellular flexibility to utilize mitochondrial fuels.
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Affiliation(s)
- Stephanie A Zlatic
- Department of Cell Biology, Emory University, 615 Michael Steet, Atlanta, GA 30322, United States
| | - Erica Werner
- Department of Cell Biology, Emory University, 615 Michael Steet, Atlanta, GA 30322, United States
| | - Veda Surapaneni
- Department of Cell Biology, Emory University, 615 Michael Steet, Atlanta, GA 30322, United States
| | - Chelsea E Lee
- Department of Cell Biology, Emory University, 615 Michael Steet, Atlanta, GA 30322, United States
| | - Avanti Gokhale
- Department of Cell Biology, Emory University, 615 Michael Steet, Atlanta, GA 30322, United States
| | - Kaela Singleton
- Department of Cell Biology, Emory University, 615 Michael Steet, Atlanta, GA 30322, United States
| | - Duc Duong
- Department of Biochemistry, Emory University, 1510 Clifton Rd NE, Atlanta, GA 30322, United States
| | - Amanda Crocker
- Program in Neuroscience, Middlebury College, Bicentennial Way, Middlebury, VT 05753, United States
| | - Karen Gentile
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, 505 Irving Avenue, Syracuse, NY 13210, United States
| | - Frank Middleton
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, 505 Irving Avenue, Syracuse, NY 13210, United States
| | - Joseph Martin Dalloul
- Pharmacology and Chemical Biology, Emory University, 1510 Clifton Rd NE, Atlanta, GA 30322, United States
| | - William Li-Yun Liu
- Pharmacology and Chemical Biology, Emory University, 1510 Clifton Rd NE, Atlanta, GA 30322, United States
| | - Anupam Patgiri
- Pharmacology and Chemical Biology, Emory University, 1510 Clifton Rd NE, Atlanta, GA 30322, United States
| | - Daniel Tarquinio
- Center for Rare Neurological Diseases, 5600 Oakbrook Pkwy, Norcross, GA 30093, United States
| | - Randall Carpenter
- Rett Syndrome Research Trust, 67 Under Cliff Rd, Trumbull, CT 06611, United States
| | - Victor Faundez
- Department of Cell Biology, Emory University, 615 Michael Steet, Atlanta, GA 30322, United States
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Musokhranova U, Grau C, Vergara C, Rodríguez-Pascau L, Xiol C, Castells AA, Alcántara S, Rodríguez-Pombo P, Pizcueta P, Martinell M, García-Cazorla A, Oyarzábal A. Mitochondrial modulation with leriglitazone as a potential treatment for Rett syndrome. J Transl Med 2023; 21:756. [PMID: 37884937 PMCID: PMC10601217 DOI: 10.1186/s12967-023-04622-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 10/12/2023] [Indexed: 10/28/2023] Open
Abstract
BACKGROUND Rett syndrome is a neuropediatric disease occurring due to mutations in MECP2 and characterized by a regression in the neuronal development following a normal postnatal growth, which results in the loss of acquired capabilities such as speech or purposeful usage of hands. While altered neurotransmission and brain development are the center of its pathophysiology, alterations in mitochondrial performance have been previously outlined, shaping it as an attractive target for the disease treatment. METHODS We have thoroughly described mitochondrial performance in two Rett models, patients' primary fibroblasts and female Mecp2tm1.1Bird-/+ mice brain, discriminating between different brain areas. The characterization was made according to their bioenergetics function, oxidative stress, network dynamics or ultrastructure. Building on that, we have studied the effect of leriglitazone, a PPARγ agonist, in the modulation of mitochondrial performance. For that, we treated Rett female mice with 75 mg/kg/day leriglitazone from weaning until sacrifice at 7 months, studying both the mitochondrial performance changes and their consequences on the mice phenotype. Finally, we studied its effect on neuroinflammation based on the presence of reactive glia by immunohistochemistry and through a cytokine panel. RESULTS We have described mitochondrial alterations in Rett fibroblasts regarding both shape and bioenergetic functions, as they displayed less interconnected and shorter mitochondria and reduced ATP production along with increased oxidative stress. The bioenergetic alterations were recalled in Rett mice models, being especially significant in cerebellum, already detectable in pre-symptomatic stages. Treatment with leriglitazone recovered the bioenergetic alterations both in Rett fibroblasts and female mice and exerted an anti-inflammatory effect in the latest, resulting in the amelioration of the mice phenotype both in general condition and exploratory activity. CONCLUSIONS Our studies confirm the mitochondrial dysfunction in Rett syndrome, setting the differences through brain areas and disease stages. Its modulation through leriglitazone is a potential treatment for this disorder, along with other diseases with mitochondrial involvement. This work constitutes the preclinical necessary evidence to lead to a clinical trial.
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Affiliation(s)
- Uliana Musokhranova
- Synaptic Metabolism and Personalized Therapies Lab, Department of Neurology and MetabERN, Institut de Recerca Sant Joan de Déu, 39-57 Santa Rosa Street, Esplugues de Llobregat , 08950, Barcelona, Spain
| | - Cristina Grau
- Synaptic Metabolism and Personalized Therapies Lab, Department of Neurology and MetabERN, Institut de Recerca Sant Joan de Déu, 39-57 Santa Rosa Street, Esplugues de Llobregat , 08950, Barcelona, Spain
| | | | | | - Clara Xiol
- Department of Medical Genetics, Institut de Recerca Pediàtrica, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Alba A Castells
- Neural Development Lab, Departament de Patologia i Terapèutica Experimental, Institut de Neurociències, IDIBELL, Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Soledad Alcántara
- Neural Development Lab, Departament de Patologia i Terapèutica Experimental, Institut de Neurociències, IDIBELL, Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Pilar Rodríguez-Pombo
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular Severo Ochoa, CBM-CSIC, Departamento de Biología Molecular, Institute for Molecular Biology-IUBM, Universidad Autónoma Madrid, IDIPAZ, Madrid, Spain
- CIBERER-Spanish Biomedical Research Centre in Rare Diseases, Madrid, Spain
| | | | - Marc Martinell
- Minoryx Therapeutics BE S.A., Gosselies, Charleroi, Belgium
- Minoryx Therapeutics S.L., Barcelona, Spain
| | - Angels García-Cazorla
- Synaptic Metabolism and Personalized Therapies Lab, Department of Neurology and MetabERN, Institut de Recerca Sant Joan de Déu, 39-57 Santa Rosa Street, Esplugues de Llobregat , 08950, Barcelona, Spain
- CIBERER-Spanish Biomedical Research Centre in Rare Diseases, Madrid, Spain
| | - Alfonso Oyarzábal
- Synaptic Metabolism and Personalized Therapies Lab, Department of Neurology and MetabERN, Institut de Recerca Sant Joan de Déu, 39-57 Santa Rosa Street, Esplugues de Llobregat , 08950, Barcelona, Spain.
- CIBERER-Spanish Biomedical Research Centre in Rare Diseases, Madrid, Spain.
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5
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Zlatic SA, Werner E, Surapaneni V, Lee CE, Gokhale A, Singleton K, Duong D, Crocker A, Gentile K, Middleton F, Dalloul JM, Liu WLY, Patgiri A, Tarquinio D, Carpenter R, Faundez V. Systemic Proteome Phenotypes Reveal Defective Metabolic Flexibility in Mecp2 Mutants. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.03.535431. [PMID: 37066332 PMCID: PMC10103972 DOI: 10.1101/2023.04.03.535431] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/24/2023]
Abstract
Genes mutated in monogenic neurodevelopmental disorders are broadly expressed. This observation supports the concept that monogenic neurodevelopmental disorders are systemic diseases that profoundly impact neurodevelopment. We tested the systemic disease model focusing on Rett syndrome, which is caused by mutations in MECP2. Transcriptomes and proteomes of organs and brain regions from Mecp2-null mice as well as diverse MECP2-null male and female human cells were assessed. Widespread changes in the steady-state transcriptome and proteome were identified in brain regions and organs of presymptomatic Mecp2-null male mice as well as mutant human cell lines. The extent of these transcriptome and proteome modifications was similar in cortex, liver, kidney, and skeletal muscle and more pronounced than in the hippocampus and striatum. In particular, Mecp2- and MECP2-sensitive proteomes were enriched in synaptic and metabolic annotated gene products, the latter encompassing lipid metabolism and mitochondrial pathways. MECP2 mutations altered pyruvate-dependent mitochondrial respiration while maintaining the capacity to use glutamine as a mitochondrial carbon source. We conclude that mutations in Mecp2/MECP2 perturb lipid and mitochondrial metabolism systemically limiting cellular flexibility to utilize mitochondrial fuels.
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Affiliation(s)
| | - Erica Werner
- Department of Cell Biology, Emory University, Atlanta, GA, USA, 30322
| | - Veda Surapaneni
- Department of Cell Biology, Emory University, Atlanta, GA, USA, 30322
| | - Chelsea E. Lee
- Department of Cell Biology, Emory University, Atlanta, GA, USA, 30322
| | - Avanti Gokhale
- Department of Cell Biology, Emory University, Atlanta, GA, USA, 30322
| | - Kaela Singleton
- Department of Cell Biology, Emory University, Atlanta, GA, USA, 30322
| | - Duc Duong
- Department of Biochemistry, Emory University, Atlanta, GA, USA, 30322
| | - Amanda Crocker
- Program in Neuroscience, Middlebury College, Middlebury, Vermont 05753
| | - Karen Gentile
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Frank Middleton
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Joseph Martin Dalloul
- Department of Pharmacology & Chemical Biology, Emory University, Atlanta, GA, USA, 30322
| | - William Li-Yun Liu
- Department of Pharmacology & Chemical Biology, Emory University, Atlanta, GA, USA, 30322
| | - Anupam Patgiri
- Department of Pharmacology & Chemical Biology, Emory University, Atlanta, GA, USA, 30322
| | | | | | - Victor Faundez
- Department of Cell Biology, Emory University, Atlanta, GA, USA, 30322
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6
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Belaïdouni Y, Diabira D, Brosset-Heckel M, Valsamides V, Graziano JC, Santos C, Menuet C, Wayman GA, Gaiarsa JL. Leptin antagonism improves Rett syndrome phenotype in symptomatic male Mecp2-null mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.03.526251. [PMID: 36778454 PMCID: PMC9915649 DOI: 10.1101/2023.02.03.526251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Rett syndrome (RTT) is a severe neurodevelopmental disorder that arise from de novo mutations in the X-linked gene MECP2 (methyl-CpG-binding protein 2). Circulating levels of the adipocyte hormone leptin are elevated in RTT patients and rodent models of the disease. Leptin targets a large number of brain structures and regulates a wide range of developmental and physiological functions which are altered in RTT. We hypothesized that elevated leptin levels might contribute to RTT pathogenesis. Accordingly, we show that pharmacological antagonism of leptin or genetic reduction of leptin production prevents the degradation of health status, weight loss and the progression of breathing and locomotor deficits. At the neuronal level, the anti-leptin strategies rescue the hippocampal excitatory/inhibitory imbalance and synaptic plasticity impairment. Targeting leptin might therefore represent a new approach for RTT treatment.
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7
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Akol I, Gather F, Vogel T. Paving Therapeutic Avenues for FOXG1 Syndrome: Untangling Genotypes and Phenotypes from a Molecular Perspective. Int J Mol Sci 2022; 23:ijms23020954. [PMID: 35055139 PMCID: PMC8780739 DOI: 10.3390/ijms23020954] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 12/23/2021] [Accepted: 01/13/2022] [Indexed: 02/01/2023] Open
Abstract
Development of the central nervous system (CNS) depends on accurate spatiotemporal control of signaling pathways and transcriptional programs. Forkhead Box G1 (FOXG1) is one of the master regulators that play fundamental roles in forebrain development; from the timing of neurogenesis, to the patterning of the cerebral cortex. Mutations in the FOXG1 gene cause a rare neurodevelopmental disorder called FOXG1 syndrome, also known as congenital form of Rett syndrome. Patients presenting with FOXG1 syndrome manifest a spectrum of phenotypes, ranging from severe cognitive dysfunction and microcephaly to social withdrawal and communication deficits, with varying severities. To develop and improve therapeutic interventions, there has been considerable progress towards unravelling the multi-faceted functions of FOXG1 in the neurodevelopment and pathogenesis of FOXG1 syndrome. Moreover, recent advances in genome editing and stem cell technologies, as well as the increased yield of information from high throughput omics, have opened promising and important new avenues in FOXG1 research. In this review, we provide a summary of the clinical features and emerging molecular mechanisms underlying FOXG1 syndrome, and explore disease-modelling approaches in animals and human-based systems, to highlight the prospects of research and possible clinical interventions.
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Affiliation(s)
- Ipek Akol
- Department of Molecular Embryology, Institute for Anatomy and Cell Biology, Medical Faculty, University of Freiburg, 79104 Freiburg, Germany; (I.A.); (F.G.)
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
- Center for Basics in NeuroModulation (NeuroModul Basics), Medical Faculty, Albert-Ludwigs-University Freiburg, 79104 Freiburg, Germany
| | - Fabian Gather
- Department of Molecular Embryology, Institute for Anatomy and Cell Biology, Medical Faculty, University of Freiburg, 79104 Freiburg, Germany; (I.A.); (F.G.)
| | - Tanja Vogel
- Department of Molecular Embryology, Institute for Anatomy and Cell Biology, Medical Faculty, University of Freiburg, 79104 Freiburg, Germany; (I.A.); (F.G.)
- Center for Basics in NeuroModulation (NeuroModul Basics), Medical Faculty, Albert-Ludwigs-University Freiburg, 79104 Freiburg, Germany
- Correspondence:
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Shovlin S, Delepine C, Swanson L, Bach S, Sahin M, Sur M, Kaufmann WE, Tropea D. Molecular Signatures of Response to Mecasermin in Children With Rett Syndrome. Front Neurosci 2022; 16:868008. [PMID: 35712450 PMCID: PMC9197456 DOI: 10.3389/fnins.2022.868008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 04/26/2022] [Indexed: 11/21/2022] Open
Abstract
Rett syndrome (RTT) is a devastating neurodevelopmental disorder without effective treatments. Attempts at developing targetted therapies have been relatively unsuccessful, at least in part, because the genotypical and phenotypical variability of the disorder. Therefore, identification of biomarkers of response and patients' stratification are high priorities. Administration of Insulin-like Growth Factor 1 (IGF-1) and related compounds leads to significant reversal of RTT-like symptoms in preclinical mouse models. However, improvements in corresponding clinical trials have not been consistent. A 20-weeks phase I open label trial of mecasermin (recombinant human IGF-1) in children with RTT demonstrated significant improvements in breathing phenotypes. However, a subsequent randomised controlled phase II trial did not show significant improvements in primary outcomes although two secondary clinical endpoints showed positive changes. To identify molecular biomarkers of response and surrogate endpoints, we used RNA sequencing to measure differential gene expression in whole blood samples of participants in the abovementioned phase I mecasermin trial. When all participants (n = 9) were analysed, gene expression was unchanged during the study (baseline vs. end of treatment, T0-T3). However, when participants were subclassified in terms of breathing phenotype improvement, specifically by their plethysmography-based apnoea index, individuals with moderate-severe apnoea and breathing improvement (Responder group) displayed significantly different transcript profiles compared to the other participants in the study (Mecasermin Study Reference group, MSR). Many of the differentially expressed genes are involved in the regulation of cell cycle processes and immune responses, as well as in IGF-1 signalling and breathing regulation. While the Responder group showed limited gene expression changes in response to mecasermin, the MSR group displayed marked differences in the expression of genes associated with inflammatory processes (e.g., neutrophil activation, complement activation) throughout the trial. Our analyses revealed gene expression profiles associated with severe breathing phenotype and its improvement after mecasermin administration in RTT, and suggest that inflammatory/immune pathways and IGF-1 signalling contribute to treatment response. Overall, these data support the notion that transcript profiles have potential as biomarkers of response to IGF-1 and related compounds.
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Affiliation(s)
- Stephen Shovlin
- Neuropsychiatric Genetics, Trinity Center for Health Sciences, Trinity Translational Medicine Institute, St James Hospital, Dublin, Ireland
| | - Chloe Delepine
- Department of Brain and Cognitive Sciences, Simons Center for the Social Brain, Picower Institute for Learning and Memory, MIT, Cambridge, MA, United States
| | - Lindsay Swanson
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital and Harvard Medical School, Boston, MA, United States
| | - Snow Bach
- Neuropsychiatric Genetics, Trinity Center for Health Sciences, Trinity Translational Medicine Institute, St James Hospital, Dublin, Ireland
| | - Mustafa Sahin
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital and Harvard Medical School, Boston, MA, United States
| | - Mriganka Sur
- Department of Brain and Cognitive Sciences, Simons Center for the Social Brain, Picower Institute for Learning and Memory, MIT, Cambridge, MA, United States
| | - Walter E Kaufmann
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, United States.,Department of Neurology, Boston Children's Hospital, Boston, MA, United States
| | - Daniela Tropea
- Neuropsychiatric Genetics, Trinity Center for Health Sciences, Trinity Translational Medicine Institute, St James Hospital, Dublin, Ireland.,Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland.,FutureNeuro, The SFI Research Centre for Chronic and Rare Neurological Diseases, Dublin, Ireland
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9
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Lee SK, Gupta M, Shi J, McKeever K. The Pharmacokinetics of Triheptanoin and Its Metabolites in Healthy Subjects and Patients With Long-Chain Fatty Acid Oxidation Disorders. Clin Pharmacol Drug Dev 2021; 10:1325-1334. [PMID: 33789001 PMCID: PMC8597155 DOI: 10.1002/cpdd.944] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 03/07/2021] [Indexed: 12/31/2022]
Abstract
Long-chain fatty acid oxidation disorders (LC-FAODs) are a group of life-threatening autosomal recessive disorders caused by defects in nuclear genes encoding mitochondrial enzymes involved in the conversion of dietary long-chain fatty acids into energy. Triheptanoin is an odd-carbon, medium-chain triglyceride consisting of 3 fatty acids with 7 carbons each on a glycerol backbone developed to treat adult and pediatric patients with LC-FAODs. The pharmacokinetics of triheptanoin and circulating metabolites were explored in healthy subjects and patients with LC-FAODs using noncompartmental analyses. Systemic exposure to triheptanoin following an oral administration was negligible, as triheptanoin is extensively hydrolyzed to glycerol and heptanoate in the gastrointestinal tract. Multiple peaks for triheptanoin metabolites were observed in the plasma following oral administration of triheptanoin, generally coinciding with the time that meals were served. Heptanoate, the pharmacologically active metabolite of triheptanoin supplementing energy sources in patients with LC-FAODs, showed the greatest exposure among the metabolites of triheptanoin in human plasma following oral administration of triheptanoin. The exposure of heptanoate was approximately 10-fold greater than that of beta-hydroxypentoate, a downstream metabolite of heptanoate. Exposure to triheptanoin metabolites appeared to increase following multiple doses as compared with the single dose, and with the increase in triheptanoin dose levels.
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Affiliation(s)
- Sun Ku Lee
- Ultragenyx Pharmaceutical Inc.NovatoCaliforniaUSA
| | - Manju Gupta
- Ultragenyx Pharmaceutical Inc.NovatoCaliforniaUSA
| | - Jack Shi
- Ultragenyx Pharmaceutical Inc.NovatoCaliforniaUSA
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10
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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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11
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Unterman I, Bloch I, Cazacu S, Kazimirsky G, Ben-Zeev B, Berman BP, Brodie C, Tabach Y. Expanding the MECP2 network using comparative genomics reveals potential therapeutic targets for Rett syndrome. eLife 2021; 10:e67085. [PMID: 34355696 PMCID: PMC8346285 DOI: 10.7554/elife.67085] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 07/23/2021] [Indexed: 12/12/2022] Open
Abstract
Inactivating mutations in the Methyl-CpG Binding Protein 2 (MECP2) gene are the main cause of Rett syndrome (RTT). Despite extensive research into MECP2 function, no treatments for RTT are currently available. Here, we used an evolutionary genomics approach to construct an unbiased MECP2 gene network, using 1028 eukaryotic genomes to prioritize proteins with strong co-evolutionary signatures with MECP2. Focusing on proteins targeted by FDA-approved drugs led to three promising targets, two of which were previously linked to MECP2 function (IRAK, KEAP1) and one that was not (EPOR). The drugs targeting these three proteins (Pacritinib, DMF, and EPO) were able to rescue different phenotypes of MECP2 inactivation in cultured human neural cell types, and appeared to converge on Nuclear Factor Kappa B (NF-κB) signaling in inflammation. This study highlights the potential of comparative genomics to accelerate drug discovery, and yields potential new avenues for the treatment of RTT.
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Affiliation(s)
- Irene Unterman
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-CanadaJerusalemIsrael
| | - Idit Bloch
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-CanadaJerusalemIsrael
| | - Simona Cazacu
- Hermelin Brain Tumor Center, Henry Ford HospitalDetroitUnited States
| | - Gila Kazimirsky
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan UniversityRamat-GanIsrael
| | - Bruria Ben-Zeev
- Edmond and Lily Safra Children's Hospital, Chaim Sheba Medical CenterRamat GanIsrael
| | - Benjamin P Berman
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-CanadaJerusalemIsrael
| | - Chaya Brodie
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan UniversityRamat-GanIsrael
| | - Yuval Tabach
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-CanadaJerusalemIsrael
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12
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Abstract
Triheptanoin (Dojolvi™), a synthetic medium-chain triglyceride, is being developed by Ultragenyx Pharmaceutical as a pharmaceutical-grade anaplerotic compound for use in the treatment of inherited metabolic disorders. In June 2020, triheptanoin received its first regulatory approval, in the USA, for use as a source of calories and fatty acids for the treatment of pediatric and adult patients with molecularly confirmed long-chain fatty acid oxidation disorders (LC-FAOD). Triheptanoin has also been investigated for use as a treatment in a range of other metabolic disorders or other diseases where energy deficiency is implicated. This article summarizes the milestones in the development of triheptanoin leading to this first regulatory approval for use in the treatment of pediatric and adult patients with LC-FAOD.
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Affiliation(s)
- Matt Shirley
- Springer Nature, Private Bag 65901, Mairangi Bay, Auckland, 0754, New Zealand.
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13
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Transcriptomic and Epigenomic Landscape in Rett Syndrome. Biomolecules 2021; 11:biom11070967. [PMID: 34209228 PMCID: PMC8301932 DOI: 10.3390/biom11070967] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 06/26/2021] [Accepted: 06/28/2021] [Indexed: 12/13/2022] Open
Abstract
Rett syndrome (RTT) is an extremely invalidating, cureless, developmental disorder, and it is considered one of the leading causes of intellectual disability in female individuals. The vast majority of RTT cases are caused by de novo mutations in the X-linked Methyl-CpG binding protein 2 (MECP2) gene, which encodes a multifunctional reader of methylated DNA. MeCP2 is a master epigenetic modulator of gene expression, with a role in the organization of global chromatin architecture. Based on its interaction with multiple molecular partners and the diverse epigenetic scenario, MeCP2 triggers several downstream mechanisms, also influencing the epigenetic context, and thus leading to transcriptional activation or repression. In this frame, it is conceivable that defects in such a multifaceted factor as MeCP2 lead to large-scale alterations of the epigenome, ranging from an unbalanced deposition of epigenetic modifications to a transcriptional alteration of both protein-coding and non-coding genes, with critical consequences on multiple downstream biological processes. In this review, we provide an overview of the current knowledge concerning the transcriptomic and epigenomic alterations found in RTT patients and animal models.
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14
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Acupuncture alleviates chronic pain and comorbid conditions in a mouse model of neuropathic pain: the involvement of DNA methylation in the prefrontal cortex. Pain 2021; 162:514-530. [PMID: 32796318 PMCID: PMC7808350 DOI: 10.1097/j.pain.0000000000002031] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 07/13/2020] [Indexed: 12/12/2022]
Abstract
ABSTRACT Chronic pain reduces life quality and is an important clinical problem associated with emotional and cognitive dysfunction. Epigenetic regulation of DNA methylation is involved in the induction of abnormal behaviors and pathological gene expression. We examined whether acupuncture can restore epigenetic changes caused by chronic pain, and identified the underlying mechanisms in neuropathic pain mice. Acupuncture treatment for 6 months (3 days/week) improved mechanical/cold allodynia and the emotional/cognitive dysfunction caused by left partial sciatic nerve ligation (PSNL)-induced neuropathic pain. The effects of acupuncture were associated with global DNA methylation recovery in the prefrontal cortex (PFC). Analysis of DNA methylation patterns in PFC indicated that 1364 overlapping genes among 4442 and 4416 methylated genes in the PSNL vs sham and PSNL vs acupuncture points groups, respectively, were highly associated with the DNA methylation process. Acupuncture restored the reduced expression of 5-methylcytosine, methyl-cytosine-phospho-guanine binding protein 2, and DNA methyltransferase family enzymes induced by PSNL in PFC. Methylation levels of Nr4a1 and Chkb associated with mitochondrial dysfunction were decreased in PFC of the PSNL mice, and increased by acupuncture. By contrast, high expression of Nr4a1 and Chkb mRNA in PSNL mice decreased after acupuncture. We also found that acupuncture inhibited the expression of Ras pathway-related genes such as Rasgrp1 and Rassf1. Finally, the expression of Nr4a1, Rasgrp1, Rassf1, and Chkb mRNA increased in the neuronal cells treated with Mecp2 small interfering RNA. These results suggest that acupuncture can relieve chronic pain-induced comorbid conditions by altering DNA methylation of Nr4a1, Rasgrp1, Rassf1, and Chkb in the PFC.
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15
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Dumon C, Belaidouni Y, Diabira D, Appleyard SM, Wayman GA, Gaiarsa JL. Leptin down-regulates KCC2 activity and controls chloride homeostasis in the neonatal rat hippocampus. Mol Brain 2020; 13:151. [PMID: 33183317 PMCID: PMC7661183 DOI: 10.1186/s13041-020-00689-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 10/28/2020] [Indexed: 11/10/2022] Open
Abstract
The canonical physiological role of leptin is to regulate hunger and satiety acting on specific hypothalamic nuclei. Beyond this key metabolic function; leptin also regulates many aspects of development and functioning of neuronal hippocampal networks throughout life. Here we show that leptin controls chloride homeostasis in the developing rat hippocampus in vitro. The effect of leptin relies on the down-regulation of the potassium/chloride extruder KCC2 activity and is present during a restricted period of postnatal development. This study confirms and extends the role of leptin in the ontogenesis of functional GABAergic inhibition and helps understanding how abnormal levels of leptin may contribute to neurological disorders.
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Affiliation(s)
- Camille Dumon
- Aix-Marseille Univ UMR 1249, INSERM (Institut National de La Santé et de La Recherche Médicale) Unité 1249, INMED (Institut de Neurobiologie de La Méditerranée), Parc Scientifique de Luminy, Marseille, France
- Neurochlore Parc Scientifique et Technologique de Luminy, Bâtiment Beret Delaage, Zone Luminy Entreprises Biotech, Marseille, France
| | - Yasmine Belaidouni
- Aix-Marseille Univ UMR 1249, INSERM (Institut National de La Santé et de La Recherche Médicale) Unité 1249, INMED (Institut de Neurobiologie de La Méditerranée), Parc Scientifique de Luminy, Marseille, France
| | - Diabe Diabira
- Aix-Marseille Univ UMR 1249, INSERM (Institut National de La Santé et de La Recherche Médicale) Unité 1249, INMED (Institut de Neurobiologie de La Méditerranée), Parc Scientifique de Luminy, Marseille, France
| | - Suzanne M Appleyard
- Program in Neuroscience, Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA, USA
| | - Gary A Wayman
- Program in Neuroscience, Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA, USA
| | - Jean-Luc Gaiarsa
- Aix-Marseille Univ UMR 1249, INSERM (Institut National de La Santé et de La Recherche Médicale) Unité 1249, INMED (Institut de Neurobiologie de La Méditerranée), Parc Scientifique de Luminy, Marseille, France.
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16
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Gomathi M, Padmapriya S, Balachandar V. Drug Studies on Rett Syndrome: From Bench to Bedside. J Autism Dev Disord 2020; 50:2740-2764. [PMID: 32016693 DOI: 10.1007/s10803-020-04381-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Drug studies on Rett syndrome (RTT) have drastically increased over the past few decades. This review aims to provide master data on bench-to-bedside drug studies involving RTT. A comprehensive literature review was performed by searching in PUBMED, MEDLINE and Google Scholar, international, national and regional clinical trial registries and pharmaceutical companies using the keywords "Rett syndrome treatment and/or drug or compound or molecule". Seventy drugs were investigated in non-clinical (N = 65 animal/cell line-based studies; N = 5 iPSC-based study) and clinical trials (N = 34) for ameliorating the symptoms of RTT. Though there is good progress in both clinical and non-clinical studies, none of these drugs entered phase III/IV for being launched as a therapeutic agent for RTT.
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Affiliation(s)
- Mohan Gomathi
- Human Molecular Genetics and Stem Cell Laboratory, Department of Human Genetics and Molecular Biology, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India
| | | | - Vellingiri Balachandar
- Human Molecular Genetics and Stem Cell Laboratory, Department of Human Genetics and Molecular Biology, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India.
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17
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Yuan X, Wang L, Tandon N, Sun H, Tian J, Du H, Pascual JM, Guo L. Triheptanoin Mitigates Brain ATP Depletion and Mitochondrial Dysfunction in a Mouse Model of Alzheimer's Disease. J Alzheimers Dis 2020; 78:425-437. [PMID: 33016909 PMCID: PMC8502101 DOI: 10.3233/jad-200594] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Brain energy failure is an early pathological event associated with synaptic dysfunction in Alzheimer's disease (AD). Thus, mitigation or enhancement of brain energy metabolism may offer a therapeutic avenue. However, there is uncertainty as to what metabolic process(es) may be more appropriate to support or augment since metabolism is a multiform process such that each of the various metabolic precursors available is utilized via a specific metabolic pathway. In the brain, these pathways sustain not only a robust rate of energy production but also of carbon replenishment. OBJECTIVE Triheptanoin, an edible odd-chain fatty acid triglyceride, is uncommon in that it replenishes metabolites in the tricarboxylic acid cycle (TCA) cycle via anaplerosis in addition to fueling the cycle via oxidation, thus potentially leading to both carbon replenishment and enhanced mitochondrial ATP production. METHODS To test the hypothesis that triheptanoin is protective in AD, we supplied mice with severe brain amyloidosis (5×FAD mice) with dietary triheptanoin for four and a half months, followed by biological and biochemical experiments to examine mice metabolic as well as synaptic function. RESULTS Triheptanoin treatment had minimal impact on systemic metabolism and brain amyloidosis as well as tauopathy while attenuating brain ATP deficiency and mitochondrial dysfunction including respiration and redox balance in 5×FAD mice. Synaptic density, a disease hallmark, was also preserved in hippocampus and neocortex despite profound amyloid deposition. None of these effects took place in treated control mice. CONCLUSION These findings support the energy failure hypothesis of AD and justify investigating the mechanisms in greater depth with ultimate therapeutic intent.
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Affiliation(s)
- Xiaodong Yuan
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, TX, USA.,Health Management Center, Jinan Central Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Lu Wang
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, TX, USA
| | - Neha Tandon
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, TX, USA
| | - Huili Sun
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, TX, USA
| | - Jing Tian
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, TX, USA
| | - Heng Du
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, TX, USA.,Department of Pharmacology & Toxicology, The University of Kansas, Lawrence, KS, USA.,Higuchi Biosciences Center, The University of Kansas, Lawrence, KS, USA
| | - Juan M Pascual
- Department of Neurology and Neurotherapeutics, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Lan Guo
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, TX, USA.,Department of Pharmacology & Toxicology, The University of Kansas, Lawrence, KS, USA.,Higuchi Biosciences Center, The University of Kansas, Lawrence, KS, USA
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18
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Wehbe Z, Tucci S. Therapeutic potential of triheptanoin in metabolic and neurodegenerative diseases. J Inherit Metab Dis 2020; 43:385-391. [PMID: 31778232 DOI: 10.1002/jimd.12199] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 11/25/2019] [Accepted: 11/27/2019] [Indexed: 12/15/2022]
Abstract
In the past 15 years the potential of triheptanoin for the treatment of several human diseases in the area of clinical nutrition has grown considerably. Use of this triglyceride of the odd-chain fatty acid heptanoate has been proposed and applied for the treatment of several conditions in which the energy supply from citric acid cycle intermediates or fatty acid degradation are impaired. Neurological diseases due to disturbed glucose metabolism or metabolic diseases associated with impaired β-oxidation of long chain fatty acid may especially take advantage of alternative substrate sources offered by the secondary metabolites of triheptanoin. Epilepsy due to deficiency of the GLUT1 transporter, as well as diseases associated with dysregulation of neuronal signalling, have been treated with triheptanoin supplementation, and very recently the advantages of this oil in long-chain fatty acid oxidation disorders have been reported. The present review summarises the published literature on the metabolism of triheptanoin including clinical reports related to the use of triheptanoin.
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Affiliation(s)
- Zeinab Wehbe
- Laboratory of Clinical Biochemistry and Metabolism, Department of General Pediatrics and Adolescent Medicine, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Sara Tucci
- Laboratory of Clinical Biochemistry and Metabolism, Department of General Pediatrics and Adolescent Medicine, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany
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19
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White CJ, Lee J, Choi J, Chu T, Scafidi S, Wolfgang MJ. Determining the Bioenergetic Capacity for Fatty Acid Oxidation in the Mammalian Nervous System. Mol Cell Biol 2020; 40:e00037-20. [PMID: 32123009 PMCID: PMC7189099 DOI: 10.1128/mcb.00037-20] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 02/16/2020] [Indexed: 12/15/2022] Open
Abstract
The metabolic state of the brain can greatly impact neurologic function. Evidence of this includes the therapeutic benefit of a ketogenic diet in neurologic diseases, including epilepsy. However, brain lipid bioenergetics remain largely uncharacterized. The existence, capacity, and relevance of mitochondrial fatty acid β-oxidation (FAO) in the brain are highly controversial, with few genetic tools available to evaluate the question. We have provided evidence for the capacity of brain FAO using a pan-brain-specific conditional knockout (KO) mouse incapable of FAO due to the loss of carnitine palmitoyltransferase 2, the product of an obligate gene for FAO (CPT2B-/-). Loss of central nervous system (CNS) FAO did not result in gross neuroanatomical changes or systemic differences in metabolism. Loss of CPT2 in the brain did not result in robustly impaired behavior. We demonstrate by unbiased and targeted metabolomics that the mammalian brain oxidizes a substantial quantity of long-chain fatty acids in vitro and in vivo Loss of CNS FAO results in robust accumulation of long-chain acylcarnitines in the brain, suggesting that the mammalian brain mobilizes fatty acids for their oxidation, irrespective of diet or metabolic state. Together, these data demonstrate that the mammalian brain oxidizes fatty acids under normal circumstances with little influence from or on peripheral tissues.
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Affiliation(s)
- Cory J White
- Department of Biological Chemistry, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Jieun Lee
- Department of Biological Chemistry, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Joseph Choi
- Department of Biological Chemistry, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Tiffany Chu
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Susanna Scafidi
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Michael J Wolfgang
- Department of Biological Chemistry, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
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20
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Mitochondrial Damage and Necroptosis in Aging Cochlea. Int J Mol Sci 2020; 21:ijms21072505. [PMID: 32260310 PMCID: PMC7177801 DOI: 10.3390/ijms21072505] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 04/02/2020] [Accepted: 04/02/2020] [Indexed: 12/14/2022] Open
Abstract
Age-related hearing loss (ARHL) is an irreversible, progressive neurodegenerative disorder and is presently untreatable. Previous studies using animal models have suggested mitochondrial damage and programmed cell death to be involved with ARHL. Thus, we further investigated the pathophysiologic role of mitochondria and necroptosis in aged C57BL/6J male mice. Aged mice (20 months old) exhibited a significant loss of hearing, number of hair cells, neuronal fibers, and synaptic ribbons compared to young mice. Ultrastructural analysis of aged cochleae revealed damaged mitochondria with absent or disorganized cristae. Aged mice also showed significant decrease in cochlear blood flow, and exhibited increase in gene expression of proinflammatory cytokines (IL-1β, IL-6, and TNF-α), receptor-interacting serine/threonine-protein kinase 1 and 3 (RIPK1 and RIPK3) and the pseudokinase mixed-lineage kinase domain-like (MLKL). Immunofluorescence (IF) assays of cytochrome C oxidase I (COX1) confirmed mitochondrial dysfunction in aged cochleae, which correlated with the degree of mitochondrial morphological damage. IF assays also revealed localization and increased expression of RIPK3 in sensorineural tissues that underwent significant necroptosis (inner and outer hair cells and stria vascularis). Together, our data shows that the aging cochlea exhibits damaged mitochondria, enhanced synthesis of proinflammatory cytokines, and provides new evidence of necroptosis in the aging cochlea in in vivo.
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21
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Luoni M, Giannelli S, Indrigo MT, Niro A, Massimino L, Iannielli A, Passeri L, Russo F, Morabito G, Calamita P, Gregori S, Deverman B, Broccoli V. Whole brain delivery of an instability-prone Mecp2 transgene improves behavioral and molecular pathological defects in mouse models of Rett syndrome. eLife 2020; 9:52629. [PMID: 32207685 PMCID: PMC7117907 DOI: 10.7554/elife.52629] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 03/23/2020] [Indexed: 12/29/2022] Open
Abstract
Rett syndrome is an incurable neurodevelopmental disorder caused by mutations in the gene encoding for methyl-CpG binding-protein 2 (MeCP2). Gene therapy for this disease presents inherent hurdles since MECP2 is expressed throughout the brain and its duplication leads to severe neurological conditions as well. Herein, we use the AAV-PHP.eB to deliver an instability-prone Mecp2 (iMecp2) transgene cassette which, increasing RNA destabilization and inefficient protein translation of the viral Mecp2 transgene, limits supraphysiological Mecp2 protein levels. Intravenous injections of the PHP.eB-iMecp2 virus in symptomatic Mecp2 mutant mice significantly improved locomotor activity, lifespan and gene expression normalization. Remarkably, PHP.eB-iMecp2 administration was well tolerated in female Mecp2 mutant or in wild-type animals. In contrast, we observed a strong immune response to the transgene in treated male Mecp2 mutant mice that was overcome by immunosuppression. Overall, PHP.eB-mediated delivery of iMecp2 provided widespread and efficient gene transfer maintaining physiological Mecp2 protein levels in the brain.
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Affiliation(s)
- Mirko Luoni
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy.,CNR Institute of Neuroscience, Milan, Italy
| | - Serena Giannelli
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Marzia Tina Indrigo
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Antonio Niro
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy.,CNR Institute of Neuroscience, Milan, Italy
| | - Luca Massimino
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Angelo Iannielli
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy.,CNR Institute of Neuroscience, Milan, Italy
| | - Laura Passeri
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), San Raffaele Scientific Institute IRCCS, Via Olgettina, Milan, Italy
| | - Fabio Russo
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), San Raffaele Scientific Institute IRCCS, Via Olgettina, Milan, Italy
| | - Giuseppe Morabito
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Piera Calamita
- National Institute of Molecular Genetics (INGM), Milan, Italy
| | - Silvia Gregori
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), San Raffaele Scientific Institute IRCCS, Via Olgettina, Milan, Italy
| | - Benjamin Deverman
- Stanley Center for Psychiatric Research at Broad Institute, Cambridge, United States
| | - Vania Broccoli
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy.,CNR Institute of Neuroscience, Milan, Italy
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22
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McDonald T, Hodson MP, Bederman I, Puchowicz M, Borges K. Triheptanoin alters [U- 13C 6]-glucose incorporation into glycolytic intermediates and increases TCA cycling by normalizing the activities of pyruvate dehydrogenase and oxoglutarate dehydrogenase in a chronic epilepsy mouse model. J Cereb Blood Flow Metab 2020; 40:678-691. [PMID: 30890077 PMCID: PMC7026856 DOI: 10.1177/0271678x19837380] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Triheptanoin is anticonvulsant in several seizure models. Here, we investigated changes in glucose metabolism by triheptanoin interictally in the chronic stage of the pilocarpine mouse epilepsy model. After injection of [U-13C6]-glucose (i.p.), enrichments of 13C in intermediates of glycolysis and the tricarboxylic acid (TCA) cycle were quantified in hippocampal extracts and maximal activities of enzymes in each pathway were measured. The enrichment of 13C glucose in plasma was similar across all groups. Despite this, we observed reductions in incorporation of 13C in several glycolytic intermediates compared to control mice suggesting glucose utilization may be impaired and/or glycogenolysis increased in the untreated interictal hippocampus. Triheptanoin prevented the interictal reductions of 13C incorporation in most glycolytic intermediates, suggesting it increased glucose utilization or - as an additional astrocytic fuel - it decreased glycogen breakdown. In the TCA cycle metabolites, the incorporation of 13C was reduced in the interictal state. Triheptanoin restored the correlation between 13C enrichments of pyruvate relative to most of the TCA cycle intermediates in "epileptic" mice. Triheptanoin also prevented the reductions of hippocampal pyruvate dehydrogenase and 2-oxoglutarate dehydrogenase activities. Decreased glycogen breakdown and increased glucose utilization and metabolism via the TCA cycle in epileptogenic brain areas may contribute to triheptanoin's anticonvulsant effects.
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Affiliation(s)
- Tanya McDonald
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, St. Lucia, QLD, Australia
| | - Mark P Hodson
- Metabolomics Australia, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St. Lucia, QLD, Australia.,School of Pharmacy, The University of Queensland, Woolloongabba, QLD, Australia.,Victor Chang Cardiac Research Institute, Sydney, NSW, Australia
| | - Ilya Bederman
- Department of Pediatrics, Case Western Reserve University, Cleveland, OH, USA
| | - Michelle Puchowicz
- Department of Nutrition, School of Medicine, Case Western Reserve University, Cleveland, OH USA.,Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Karin Borges
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, St. Lucia, QLD, Australia
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23
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Kadam SD, Sullivan BJ, Goyal A, Blue ME, Smith-Hicks C. Rett Syndrome and CDKL5 Deficiency Disorder: From Bench to Clinic. Int J Mol Sci 2019; 20:ijms20205098. [PMID: 31618813 PMCID: PMC6834180 DOI: 10.3390/ijms20205098] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 10/08/2019] [Accepted: 10/11/2019] [Indexed: 12/18/2022] Open
Abstract
Rett syndrome (RTT) and CDKL5 deficiency disorder (CDD) are two rare X-linked developmental brain disorders with overlapping but distinct phenotypic features. This review examines the impact of loss of methyl-CpG-binding protein 2 (MeCP2) and cyclin-dependent kinase-like 5 (CDKL5) on clinical phenotype, deficits in synaptic- and circuit-homeostatic mechanisms, seizures, and sleep. In particular, we compare the overlapping and contrasting features between RTT and CDD in clinic and in preclinical studies. Finally, we discuss lessons learned from recent clinical trials while reviewing the findings from pre-clinical studies.
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Affiliation(s)
- Shilpa D Kadam
- The Hugo Moser Research Institute at Kennedy Krieger, Baltimore, MD 21205, USA.
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| | - Brennan J Sullivan
- The Hugo Moser Research Institute at Kennedy Krieger, Baltimore, MD 21205, USA.
| | - Archita Goyal
- The Hugo Moser Research Institute at Kennedy Krieger, Baltimore, MD 21205, USA.
| | - Mary E Blue
- The Hugo Moser Research Institute at Kennedy Krieger, Baltimore, MD 21205, USA.
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| | - Constance Smith-Hicks
- The Hugo Moser Research Institute at Kennedy Krieger, Baltimore, MD 21205, USA.
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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Martins VF, Dent JR, Svensson K, Tahvilian S, Begur M, Lakkaraju S, Buckner EH, LaBarge SA, Hetrick B, McCurdy CE, Schenk S. Germline or inducible knockout of p300 or CBP in skeletal muscle does not alter insulin sensitivity. Am J Physiol Endocrinol Metab 2019; 316:E1024-E1035. [PMID: 30888860 PMCID: PMC6620570 DOI: 10.1152/ajpendo.00497.2018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Akt is a critical mediator of insulin-stimulated glucose uptake in skeletal muscle. The acetyltransferases, E1A binding protein p300 (p300) and cAMP response element-binding protein binding protein (CBP) are phosphorylated and activated by Akt, and p300/CBP can acetylate and inactivate Akt, thus giving rise to a possible Akt-p300/CBP axis. Our objective was to determine the importance of p300 and CBP to skeletal muscle insulin sensitivity. We used Cre-LoxP methodology to generate mice with germline [muscle creatine kinase promoter (P-MCK and C-MCK)] or inducible [tamoxifen-activated, human skeletal actin promoter (P-iHSA and C-iHSA)] knockout of p300 or CBP. A subset of P-MCK and C-MCK mice were switched to a calorie-restriction diet (60% of ad libitum intake) or high-fat diet at 10 wk of age. For P-iHSA and C-iHSA mice, knockout was induced at 10 wk of age. At 13-15 wk of age, we measured whole-body energy expenditure, oral glucose tolerance, and/or ex vivo skeletal muscle insulin sensitivity. Although p300 and CBP protein abundance and mRNA expression were reduced 55%-90% in p300 and CBP knockout mice, there were no genotype differences in energy expenditure or fasting glucose and insulin concentrations. Moreover, neither loss of p300 or CBP impacted oral glucose tolerance or skeletal muscle insulin sensitivity, nor did their loss impact alterations in these parameters in response to a calorie restriction or high-fat diet. Muscle-specific loss of either p300 or CBP, be it germline or in adulthood, does not impact energy expenditure, glucose tolerance, or skeletal muscle insulin action.
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Affiliation(s)
- Vitor F Martins
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
- Biomedical Sciences Graduate Program, University of California, San Diego, La Jolla, California
| | - Jessica R Dent
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
| | - Kristoffer Svensson
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
| | - Shahriar Tahvilian
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
| | - Maedha Begur
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
| | - Shivani Lakkaraju
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
| | - Elisa H Buckner
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
| | - Samuel A LaBarge
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
| | - Byron Hetrick
- Department of Human Physiology, University of Oregon , Eugene, Oregon
| | - Carrie E McCurdy
- Department of Human Physiology, University of Oregon , Eugene, Oregon
| | - Simon Schenk
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
- Biomedical Sciences Graduate Program, University of California, San Diego, La Jolla, California
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25
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Squillaro T, Alessio N, Capasso S, Di Bernardo G, Melone MAB, Peluso G, Galderisi U. Senescence Phenomena and Metabolic Alteration in Mesenchymal Stromal Cells from a Mouse Model of Rett Syndrome. Int J Mol Sci 2019; 20:ijms20102508. [PMID: 31117273 PMCID: PMC6567034 DOI: 10.3390/ijms20102508] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Revised: 05/17/2019] [Accepted: 05/19/2019] [Indexed: 12/17/2022] Open
Abstract
Chromatin modifiers play a crucial role in maintaining cell identity through modulation of gene expression patterns. Their deregulation can have profound effects on cell fate and functions. Among epigenetic regulators, the MECP2 protein is particularly attractive. Mutations in the Mecp2 gene are responsible for more than 90% of cases of Rett syndrome (RTT), a progressive neurodevelopmental disorder. As a chromatin modulator, MECP2 can have a key role in the government of stem cell biology. Previously, we showed that deregulated MECP2 expression triggers senescence in mesenchymal stromal cells (MSCs) from (RTT) patients. Over the last few decades, it has emerged that senescent cells show alterations in the metabolic state. Metabolic changes related to stem cell senescence are particularly detrimental, since they contribute to the exhaustion of stem cell compartments, which in turn determine the falling in tissue renewal and functionality. Herein, we dissect the role of impaired MECP2 function in triggering senescence along with other senescence-related aspects, such as metabolism, in MSCs from a mouse model of RTT. We found that MECP2 deficiencies lead to senescence and impaired mitochondrial energy production. Our results support the idea that an alteration in mitochondria metabolic functions could play an important role in the pathogenesis of RTT.
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Affiliation(s)
- Tiziana Squillaro
- Department of Advanced Medical and Surgical Sciences, Center for Rare Diseases and Inter University Center for Research in Neurosciences, University of Campania "Luigi Vanvitelli", via Sergio Pansini, 5, 80131 Naples, Italy.
| | - Nicola Alessio
- Department of Experimental Medicine, Campania University "Luigi Vanvitelli", via Santa Maria di Costantinopoli, 16, 80138 Naples, Italy.
| | - Stefania Capasso
- Department of Experimental Medicine, Campania University "Luigi Vanvitelli", via Santa Maria di Costantinopoli, 16, 80138 Naples, Italy.
| | - Giovanni Di Bernardo
- Department of Experimental Medicine, Campania University "Luigi Vanvitelli", via Santa Maria di Costantinopoli, 16, 80138 Naples, Italy.
| | - Mariarosa Anna Beatrice Melone
- Department of Advanced Medical and Surgical Sciences, Center for Rare Diseases and Inter University Center for Research in Neurosciences, University of Campania "Luigi Vanvitelli", via Sergio Pansini, 5, 80131 Naples, Italy.
- Sbarro Institute for Cancer Research and Molecular Medicine, Department of Biology, BioLife Building (015-00)1900 North 12th Street, Temple University, Philadelphia, PA 19122-6078, USA.
| | - Gianfranco Peluso
- USA Research Institute on Terrestrial Ecosystems, National Research Council, via Pietro Castellino, 111, 80131 Naples, Italy.
| | - Umberto Galderisi
- Department of Experimental Medicine, Campania University "Luigi Vanvitelli", via Santa Maria di Costantinopoli, 16, 80138 Naples, Italy.
- Sbarro Institute for Cancer Research and Molecular Medicine, Department of Biology, BioLife Building (015-00)1900 North 12th Street, Temple University, Philadelphia, PA 19122-6078, USA.
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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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Treating Rett syndrome: from mouse models to human therapies. Mamm Genome 2019; 30:90-110. [PMID: 30820643 PMCID: PMC6606665 DOI: 10.1007/s00335-019-09793-5] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 02/09/2019] [Indexed: 02/06/2023]
Abstract
Rare diseases are very difficult to study mechanistically and to develop therapies for because of the scarcity of patients. Here, the rare neuro-metabolic disorder Rett syndrome (RTT) is discussed as a prototype for precision medicine, demonstrating how mouse models have led to an understanding of the development of symptoms. RTT is caused by mutations in the X-linked gene methyl-CpG-binding protein 2 (MECP2). Mecp2-mutant mice are being used in preclinical studies that target the MECP2 gene directly, or its downstream pathways. Importantly, this work may improve the health of RTT patients. Clinical presentation may vary widely among individuals based on their mutation, but also because of the degree of X chromosome inactivation and the presence of modifier genes. Because it is a complex disorder involving many organ systems, it is likely that recovery of RTT patients will involve a combination of treatments. Precision medicine is warranted to provide the best efficacy to individually treat RTT patients.
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Abstract
Glucose is the long-established, obligatory fuel for brain that fulfills many critical functions, including ATP production, oxidative stress management, and synthesis of neurotransmitters, neuromodulators, and structural components. Neuronal glucose oxidation exceeds that in astrocytes, but both rates increase in direct proportion to excitatory neurotransmission; signaling and metabolism are closely coupled at the local level. Exact details of neuron-astrocyte glutamate-glutamine cycling remain to be established, and the specific roles of glucose and lactate in the cellular energetics of these processes are debated. Glycolysis is preferentially upregulated during brain activation even though oxygen availability is sufficient (aerobic glycolysis). Three major pathways, glycolysis, pentose phosphate shunt, and glycogen turnover, contribute to utilization of glucose in excess of oxygen, and adrenergic regulation of aerobic glycolysis draws attention to astrocytic metabolism, particularly glycogen turnover, which has a high impact on the oxygen-carbohydrate mismatch. Aerobic glycolysis is proposed to be predominant in young children and specific brain regions, but re-evaluation of data is necessary. Shuttling of glucose- and glycogen-derived lactate from astrocytes to neurons during activation, neurotransmission, and memory consolidation are controversial topics for which alternative mechanisms are proposed. Nutritional therapy and vagus nerve stimulation are translational bridges from metabolism to clinical treatment of diverse brain disorders.
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Affiliation(s)
- Gerald A Dienel
- Department of Neurology, University of Arkansas for Medical Sciences , Little Rock, Arkansas ; and Department of Cell Biology and Physiology, University of New Mexico , Albuquerque, New Mexico
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29
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Fukuhara S, Nakajima H, Sugimoto S, Kodo K, Shigehara K, Morimoto H, Tsuma Y, Moroto M, Mori J, Kosaka K, Morimoto M, Hosoi H. High-fat diet accelerates extreme obesity with hyperphagia in female heterozygous Mecp2-null mice. PLoS One 2019; 14:e0210184. [PMID: 30608967 PMCID: PMC6319720 DOI: 10.1371/journal.pone.0210184] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 12/18/2018] [Indexed: 11/18/2022] Open
Abstract
Rett syndrome (RTT) is an X-linked neurodevelopmental disorder caused by mutation of the methyl-CpG-binding protein 2 (MECP2) gene. Although RTT has been associated with obesity, the underlying mechanism has not yet been elucidated. In this study, female heterozygous Mecp2-null mice (Mecp2+/- mice), a model of RTT, were fed a normal chow diet or high-fat diet (HFD), and the changes in molecular signaling pathways were investigated. Specifically, we examined the expression of genes related to the hypothalamus and dopamine reward circuitry, which represent a central network of feeding behavior control. In particular, dopamine reward circuitry has been shown to regulate hedonic feeding behavior, and its disruption is associated with HFD-related changes in palatability. The Mecp2+/- mice that were fed the normal chow showed normal body weight and food consumption, whereas those fed the HFD showed extreme obesity with hyperphagia, an increase of body fat mass, glucose intolerance, and insulin resistance compared with wild-type mice fed the HFD (WT-HFD mice). The main cause of obesity in Mecp2+/--HFD mice was a remarkable increase in calorie intake, with no difference in oxygen consumption or locomotor activity. Agouti-related peptide mRNA and protein levels were increased, whereas proopiomelanocortin mRNA and protein levels were reduced in Mecp2+/--HFD mice with hyperleptinemia, which play an essential role in appetite and satiety in the hypothalamus. The conditioned place preference test revealed that Mecp2+/- mice preferred the HFD. Tyrosine hydroxylase and dopamine transporter mRNA levels in the ventral tegmental area, and dopamine receptor and dopamine- and cAMP-regulated phosphoprotein mRNA levels in the nucleus accumbens were significantly lower in Mecp2+/--HFD mice than those of WT-HFD mice. Thus, HFD feeding induced dysregulation of food intake in the hypothalamus and dopamine reward circuitry, and accelerated the development of extreme obesity associated with addiction-like eating behavior in Mecp2+/- mice.
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Affiliation(s)
- Shota Fukuhara
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto City, Japan
| | - Hisakazu Nakajima
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto City, Japan
- Department of Pediatrics, North Medical Center, Kyoto, Prefectural University of Medicine, Yosa-gun, Japan
- * E-mail:
| | - Satoru Sugimoto
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto City, Japan
| | - Kazuki Kodo
- Department of Pediatrics, North Medical Center, Kyoto, Prefectural University of Medicine, Yosa-gun, Japan
| | - Keiichi Shigehara
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto City, Japan
| | - Hidechika Morimoto
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto City, Japan
| | - Yusuke Tsuma
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto City, Japan
| | - Masaharu Moroto
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto City, Japan
| | - Jun Mori
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto City, Japan
| | - Kitaro Kosaka
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto City, Japan
| | - Masafumi Morimoto
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto City, Japan
| | - Hajime Hosoi
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto City, Japan
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Veyrat-Durebex C, Reynier P, Procaccio V, Hergesheimer R, Corcia P, Andres CR, Blasco H. How Can a Ketogenic Diet Improve Motor Function? Front Mol Neurosci 2018; 11:15. [PMID: 29434537 PMCID: PMC5790787 DOI: 10.3389/fnmol.2018.00015] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 01/10/2018] [Indexed: 12/12/2022] Open
Abstract
A ketogenic diet (KD) is a normocaloric diet composed by high fat (80-90%), low carbohydrate, and low protein consumption that induces fasting-like effects. KD increases ketone body (KBs) production and its concentration in the blood, providing the brain an alternative energy supply that enhances oxidative mitochondrial metabolism. In addition to its profound impact on neuro-metabolism and bioenergetics, the neuroprotective effect of specific polyunsaturated fatty acids and KBs involves pleiotropic mechanisms, such as the modulation of neuronal membrane excitability, inflammation, or reactive oxygen species production. KD is a therapy that has been used for almost a century to treat medically intractable epilepsy and has been increasingly explored in a number of neurological diseases. Motor function has also been shown to be improved by KD and/or medium-chain triglyceride diets in rodent models of Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and spinal cord injury. These studies have proposed that KD may induce a modification in synaptic morphology and function, involving ionic channels, glutamatergic transmission, or synaptic vesicular cycling machinery. However, little is understood about the molecular mechanisms underlying the impact of KD on motor function and the perspectives of its use to acquire the neuromuscular effects. The aim of this review is to explore the conditions through which KD might improve motor function. First, we will describe the main consequences of KD exposure in tissues involved in motor function. Second, we will report and discuss the relevance of KD in pre-clinical and clinical trials in the major diseases presenting motor dysfunction.
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Affiliation(s)
- Charlotte Veyrat-Durebex
- Département de Biochimie et Génétique, Centre Hospitalier Universitaire, Angers, France
- INSERM 1083, CNRS, Equipe Mitolab, Institut MITOVASC, UMR 6015, Université d’Angers, Angers, France
| | - Pascal Reynier
- Département de Biochimie et Génétique, Centre Hospitalier Universitaire, Angers, France
- INSERM 1083, CNRS, Equipe Mitolab, Institut MITOVASC, UMR 6015, Université d’Angers, Angers, France
| | - Vincent Procaccio
- Département de Biochimie et Génétique, Centre Hospitalier Universitaire, Angers, France
- INSERM 1083, CNRS, Equipe Mitolab, Institut MITOVASC, UMR 6015, Université d’Angers, Angers, France
| | | | - Philippe Corcia
- INSERM U930, Université François Rabelais de Tours, Tours, France
- Service de Neurologie, Centre Hospitalier Universitaire de Tours, Tours, France
| | - Christian R. Andres
- INSERM U930, Université François Rabelais de Tours, Tours, France
- Laboratoire de Biochimie et Biologie Moléculaire, Centre Hospitalier Universitaire de Tours, Tours, France
| | - Hélène Blasco
- INSERM 1083, CNRS, Equipe Mitolab, Institut MITOVASC, UMR 6015, Université d’Angers, Angers, France
- INSERM U930, Université François Rabelais de Tours, Tours, France
- Laboratoire de Biochimie et Biologie Moléculaire, Centre Hospitalier Universitaire de Tours, Tours, France
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Tucci S, Mingirulli N, Wehbe Z, Dumit VI, Kirschner J, Spiekerkoetter U. Mitochondrial fatty acid biosynthesis and muscle fiber plasticity in very long-chain acyl-CoA dehydrogenase-deficient mice. FEBS Lett 2018; 592:219-232. [PMID: 29237229 DOI: 10.1002/1873-3468.12940] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 11/27/2017] [Accepted: 12/04/2017] [Indexed: 12/31/2022]
Abstract
The white skeletal muscle of very long-chain acyl-CoA-dehydrogenase-deficient (VLCAD-/- ) mice undergoes metabolic modification to compensate for defective β-oxidation in a progressive and time-dependent manner by upregulating glucose oxidation. This metabolic regulation seems to be accompanied by morphologic adaptation of muscle fibers toward the glycolytic fiber type II with the concomitant upregulation of mitochondrial fatty acid biosynthesis (mFASII) and lipoic acid biosynthesis. Dietary supplementation of VLCAD-/- mice with different medium-chain triglycerides over 1 year revealed that odd-chain species has no effect on muscle fiber switch, whereas even-chain species inhibit progressive metabolic adaptation. Our study shows that muscle may undergo adaptive mechanisms that are modulated by dietary supplementation. We describe for the first time a concomitant change of mFASII in this muscular adaptation process.
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Affiliation(s)
- Sara Tucci
- Department of General Pediatrics, Center for Paediatrics and Adolescent Medicine, Faculty of Medicine and Medical Centre, University of Freiburg, Germany
| | - Nadja Mingirulli
- Department of General Pediatrics, Center for Paediatrics and Adolescent Medicine, Faculty of Medicine and Medical Centre, University of Freiburg, Germany
| | - Zeinab Wehbe
- Department of General Pediatrics, Center for Paediatrics and Adolescent Medicine, Faculty of Medicine and Medical Centre, University of Freiburg, Germany
| | - Verónica I Dumit
- Core Facility Proteomics, Center for Biological Systems Analysis (ZBSA), University of Freiburg, Germany
| | - Janbernd Kirschner
- Department of Neuropaediatrics, Center for Paediatrics and Adolescent Medicine, Faculty of Medicine and Medical Centre, University of Freiburg, Germany
| | - Ute Spiekerkoetter
- Department of General Pediatrics, Center for Paediatrics and Adolescent Medicine, Faculty of Medicine and Medical Centre, University of Freiburg, Germany
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Pacheco NL, Heaven MR, Holt LM, Crossman DK, Boggio KJ, Shaffer SA, Flint DL, Olsen ML. RNA sequencing and proteomics approaches reveal novel deficits in the cortex of Mecp2-deficient mice, a model for Rett syndrome. Mol Autism 2017; 8:56. [PMID: 29090078 PMCID: PMC5655833 DOI: 10.1186/s13229-017-0174-4] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 10/02/2017] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Rett syndrome (RTT) is an X-linked neurodevelopmental disorder caused by mutations in the transcriptional regulator MeCP2. Much of our understanding of MeCP2 function is derived from transcriptomic studies with the general assumption that alterations in the transcriptome correlate with proteomic changes. Advances in mass spectrometry-based proteomics have facilitated recent interest in the examination of global protein expression to better understand the biology between transcriptional and translational regulation. METHODS We therefore performed the first comprehensive transcriptome-proteome comparison in a RTT mouse model to elucidate RTT pathophysiology, identify potential therapeutic targets, and further our understanding of MeCP2 function. The whole cortex of wild-type and symptomatic RTT male littermates (n = 4 per genotype) were analyzed using RNA-sequencing and data-independent acquisition liquid chromatography tandem mass spectrometry. Ingenuity® Pathway Analysis was used to identify significantly affected pathways in the transcriptomic and proteomic data sets. RESULTS Our results indicate these two "omics" data sets supplement one another. In addition to confirming previous works regarding mRNA expression in Mecp2-deficient animals, the current study identified hundreds of novel protein targets. Several selected protein targets were validated by Western blot analysis. These data indicate RNA metabolism, proteostasis, monoamine metabolism, and cholesterol synthesis are disrupted in the RTT proteome. Hits common to both data sets indicate disrupted cellular metabolism, calcium signaling, protein stability, DNA binding, and cytoskeletal cell structure. Finally, in addition to confirming disrupted pathways and identifying novel hits in neuronal structure and synaptic transmission, our data indicate aberrant myelination, inflammation, and vascular disruption. Intriguingly, there is no evidence of reactive gliosis, but instead, gene, protein, and pathway analysis suggest astrocytic maturation and morphological deficits. CONCLUSIONS This comparative omics analysis supports previous works indicating widespread CNS dysfunction and may serve as a valuable resource for those interested in cellular dysfunction in RTT.
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Affiliation(s)
- Natasha L. Pacheco
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, 1918 University Blvd, Birmingham, AL 35294 USA
| | - Michael R. Heaven
- Vulcan Analytical, LLC, 1500 1st Ave. North, Birmingham, AL 35203 USA
| | - Leanne M. Holt
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, 1918 University Blvd, Birmingham, AL 35294 USA
- School of Neuroscience, Virginia Polytechnic and State University, Life Sciences Building Room 213, 970 Washington St. SW, Blacksburg, VA 24061 USA
| | - David K. Crossman
- UAB Heflin Center for Genomic Science, Department of Genetics, University of Alabama at Birmingham, Kaul 424A, 1720 2nd Ave. South, Birmingham, AL 35294 USA
| | - Kristin J. Boggio
- Proteomics and Mass Spectrometry Facility, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, 222 Maple Ave., Fuller Building, Shrewsbury, MA 01545 USA
| | - Scott A. Shaffer
- Proteomics and Mass Spectrometry Facility, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, 222 Maple Ave., Fuller Building, Shrewsbury, MA 01545 USA
| | - Daniel L. Flint
- Luxumbra Strategic Research, LLC, 1331 South Eads St, Arlington, VA 22202 USA
| | - Michelle L. Olsen
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, 1918 University Blvd, Birmingham, AL 35294 USA
- School of Neuroscience, Virginia Polytechnic and State University, Life Sciences Building Room 213, 970 Washington St. SW, Blacksburg, VA 24061 USA
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33
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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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Mochel F. Triheptanoin for the treatment of brain energy deficit: A 14-year experience. J Neurosci Res 2017; 95:2236-2243. [PMID: 28688166 DOI: 10.1002/jnr.24111] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2017] [Revised: 06/10/2017] [Accepted: 06/15/2017] [Indexed: 12/11/2022]
Abstract
Triheptanoin is an odd-chain triglyceride with anaplerotic properties-that is, replenishing the pool of metabolic intermediates in the Krebs cycle. Unlike even-chain fatty acids metabolized to acetyl-CoA only, triheptanoin can indeed provide both acetyl-CoA and propionyl-CoA, two key carbon sources for the Krebs cycle. Triheptanoin was initially used in patients with long-chain fatty acid oxidation disorders. The first demonstration of the possible benefit of triheptanoin for brain energy deficit came from a patient with pyruvate carboxylase deficiency, a severe metabolic disease that affects anaplerosis in the brain. In an open-label study, triheptanoin was then shown to decrease nonepileptic paroxysmal manifestations by 90% in patients with glucose transporter 1 deficiency syndrome, a disease that affects glucose transport into the brain. 31 P magnetic resonance spectroscopy studies also indicated that triheptanoin was able to correct bioenergetics in the brain of patients with Huntington disease, a neurodegenerative disease associated with brain energy deficit. Altogether, these studies indicate that triheptanoin can be a treatment for brain energy deficit related to altered anaplerosis and/or glucose metabolism. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Fanny Mochel
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, Paris, France.,AP-HP, Pitié-Salpêtrière University Hospital, Department of Genetics, Paris, France.,University Pierre and Marie Curie, Neurometabolic Research Group, Paris, France
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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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36
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Cheng N, Rho JM, Masino SA. Metabolic Dysfunction Underlying Autism Spectrum Disorder and Potential Treatment Approaches. Front Mol Neurosci 2017; 10:34. [PMID: 28270747 PMCID: PMC5318388 DOI: 10.3389/fnmol.2017.00034] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 01/30/2017] [Indexed: 12/14/2022] Open
Abstract
Autism spectrum disorder (ASD) is characterized by deficits in sociability and communication, and increased repetitive and/or restrictive behaviors. While the etio-pathogenesis of ASD is unknown, clinical manifestations are diverse and many possible genetic and environmental factors have been implicated. As such, it has been a great challenge to identify key neurobiological mechanisms and to develop effective treatments. Current therapies focus on co-morbid conditions (such as epileptic seizures and sleep disturbances) and there is no cure for the core symptoms. Recent studies have increasingly implicated mitochondrial dysfunction in ASD. The fact that mitochondria are an integral part of diverse cellular functions and are susceptible to many insults could explain how a wide range of factors can contribute to a consistent behavioral phenotype in ASD. Meanwhile, the high-fat, low-carbohydrate ketogenic diet (KD), used for nearly a century to treat medically intractable epilepsy, has been shown to enhance mitochondrial function through a multiplicity of mechanisms and affect additional molecular targets that may address symptoms and comorbidities of ASD. Here, we review the evidence for the use of metabolism-based therapies such as the KD in the treatment of ASD as well as emerging co-morbid models of epilepsy and autism. Future research directions aimed at validating such therapeutic approaches and identifying additional and novel mechanistic targets are also discussed.
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Affiliation(s)
- Ning Cheng
- Departments of Pediatrics, University of CalgaryCalgary, AB, Canada
| | - Jong M. Rho
- Departments of Pediatrics, University of CalgaryCalgary, AB, Canada
- Clinical Neurosciences, University of CalgaryCalgary, AB, Canada
- Physiology and Pharmacology, Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of CalgaryCalgary, AB, Canada
| | - Susan A. Masino
- Neuroscience Program, Department of Psychology, Trinity CollegeHartford, CT, USA
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Rett Syndrome: A Focus on Gut Microbiota. Int J Mol Sci 2017; 18:ijms18020344. [PMID: 28178201 PMCID: PMC5343879 DOI: 10.3390/ijms18020344] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 01/25/2017] [Accepted: 01/27/2017] [Indexed: 12/12/2022] Open
Abstract
Rett syndrome (RTT) is an X-linked neurodevelopmental disorder affecting 1 in 10,000 live female births. Changes in microbiota composition, as observed in other neurological disorders such as autism spectrum disorders, may account for several symptoms typically associated with RTT. We studied the relationship between disease phenotypes and microbiome by analyzing diet, gut microbiota, and short-chain fatty acid (SCFA) production. We enrolled eight RTT patients and 10 age- and sex-matched healthy women, all without dietary restrictions. The microbiota was characterized by 16S rRNA gene sequencing, and SCFAs concentration was determined by gas chromatographic analysis. The RTT microbiota showed a lower α diversity, an enrichment in Bacteroidaceae, Clostridium spp., and Sutterella spp., and a slight depletion in Ruminococcaceae. Fecal SCFA concentrations were similar, but RTT samples showed slightly higher concentrations of butyrate and propionate, and significant higher levels in branched-chain fatty acids. Daily caloric intake was similar in the two groups, but macronutrient analysis showed a higher protein content in RTT diets. Microbial function prediction suggested in RTT subjects an increased number of microbial genes encoding for propionate and butyrate, and amino acid metabolism. A full understanding of these critical features could offer new, specific strategies for managing RTT-associated symptoms, such as dietary intervention or pre/probiotic supplementation.
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Tefera TW, Borges K. Metabolic Dysfunctions in Amyotrophic Lateral Sclerosis Pathogenesis and Potential Metabolic Treatments. Front Neurosci 2017; 10:611. [PMID: 28119559 PMCID: PMC5222822 DOI: 10.3389/fnins.2016.00611] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 12/26/2016] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease primarily characterized by loss of motor neurons in brain and spinal cord. The death of motor neurons leads to denervation of muscle which in turn causes muscle weakness and paralysis, decreased respiratory function and eventually death. Growing evidence indicates disturbances in energy metabolism in patients with ALS and animal models of ALS, which are likely to contribute to disease progression. Particularly, defects in glucose metabolism and mitochondrial dysfunction limit the availability of ATP to CNS tissues and muscle. Several metabolic approaches improving mitochondrial function have been investigated in vitro and in vivo and showed varying effects in ALS. The effects of metabolic approaches in ALS models encompass delays in onset of motor symptoms, protection of motor neurons and extension of survival, which signifies an important role of metabolism in the pathogenesis of the disease. There is now an urgent need to test metabolic approaches in controlled clinical trials. In addition, more detailed studies to better characterize the abnormalities in energy metabolism in patients with ALS and ALS models are necessary to develop metabolically targeted effective therapies that can slow the progression of the disease and prolong life for patients with ALS.
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Affiliation(s)
| | - Karin Borges
- Laboratory for Neurological Disorders and Metabolism, School of Biomedical Sciences, Department of Pharmacology, The University of QueenslandBrisbane, QLD, Australia
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The life, times and work of Charles R. Roe, M.D. Neurosci Lett 2017; 637:1-3. [DOI: 10.1016/j.neulet.2016.08.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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40
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Ruskin DN, Fortin JA, Bisnauth SN, Masino SA. Ketogenic diets improve behaviors associated with autism spectrum disorder in a sex-specific manner in the EL mouse. Physiol Behav 2016; 168:138-145. [PMID: 27836684 PMCID: PMC5135580 DOI: 10.1016/j.physbeh.2016.10.023] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 09/08/2016] [Accepted: 10/14/2016] [Indexed: 12/17/2022]
Abstract
The core symptoms of autism spectrum disorder are poorly treated with current medications. Symptoms of autism spectrum disorder are frequently comorbid with a diagnosis of epilepsy and vice versa. Medically-supervised ketogenic diets are remarkably effective nonpharmacological treatments for epilepsy, even in drug-refractory cases. There is accumulating evidence that supports the efficacy of ketogenic diets in treating the core symptoms of autism spectrum disorders in animal models as well as limited reports of benefits in patients. This study tests the behavioral effects of ketogenic diet feeding in the EL mouse, a model with behavioral characteristics of autism spectrum disorder and comorbid epilepsy. Male and female EL mice were fed control diet or one of two ketogenic diet formulas ad libitum starting at 5 weeks of age. Beginning at 8 weeks of age, diet protocols continued and performance of each group on tests of sociability and repetitive behavior was assessed. A ketogenic diet improved behavioral characteristics of autism spectrum disorder in a sex- and test-specific manner; ketogenic diet never worsened relevant behaviors. Ketogenic diet feeding improved multiple measures of sociability and reduced repetitive behavior in female mice, with limited effects in males. Additional experiments in female mice showed that a less strict, more clinically-relevant diet formula was equally effective in improving sociability and reducing repetitive behavior. Taken together these results add to the growing number of studies suggesting that ketogenic and related diets may provide significant relief from the core symptoms of autism spectrum disorder, and suggest that in some cases there may be increased efficacy in females.
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Affiliation(s)
- David N Ruskin
- Department of Psychology, Neuroscience Program, Trinity College, Hartford, CT, United States.
| | - Jessica A Fortin
- Department of Psychology, Neuroscience Program, Trinity College, Hartford, CT, United States.
| | - Subrina N Bisnauth
- Department of Psychology, Neuroscience Program, Trinity College, Hartford, CT, United States.
| | - Susan A Masino
- Department of Psychology, Neuroscience Program, Trinity College, Hartford, CT, United States.
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41
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Lopez AM, Chuang JC, Posey KS, Turley SD. Suppression of brain cholesterol synthesis in male Mecp2-deficient mice is age dependent and not accompanied by a concurrent change in the rate of fatty acid synthesis. Brain Res 2016; 1654:77-84. [PMID: 27789278 DOI: 10.1016/j.brainres.2016.10.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 10/13/2016] [Accepted: 10/21/2016] [Indexed: 12/29/2022]
Abstract
Mutations in the X-linked gene methyl-CpG-binding protein 2 (MECP2) are the principal cause of Rett syndrome, a progressive neurodevelopmental disorder afflicting 1 in 10,000 to 15,000 females. Studies using hemizygous Mecp2 mouse models have revealed disruptions to some aspects of their lipid metabolism including a partial suppression of cholesterol synthesis in the brains of mature Mecp2 mutants. The present studies investigated whether this suppression is evident from early neonatal life, or becomes manifest at a later stage of development. We measured the rate of cholesterol synthesis, in vivo, in the brains of male Mecp2-/y and their Mecp2+/y littermates at 7, 14, 21, 28, 42 and 56 days of age. Brain weight was consistently lower in the Mecp2-/y mice than in their Mecp2+/y controls except at 7 days of age. In the 7- and 14-day-old mice there was no genotypic difference in the rate of brain cholesterol synthesis but, from 21 days and later, it was always marginally lower in the Mecp2-/y mice than in age-matched Mecp2+/y littermates. At no age was a genotypic difference detected in either the rate of fatty acid synthesis or cholesterol concentration in the brain. Cholesterol synthesis rates in the liver and lungs of 56-day-old Mecp2-/y mice were normal. The onset of lower rates of brain cholesterol synthesis at about the time closure of the blood brain barrier purportedly occurs might signify a disruption to mechanism(s) that dictate intracellular levels of cholesterol metabolites including oxysterols known to exert a regulatory influence on the cholesterol biosynthetic pathway.
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Affiliation(s)
- Adam M Lopez
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Jen-Chieh Chuang
- Children's Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Kenneth S Posey
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Stephen D Turley
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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42
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Pfeuffer M, Jaudszus A. Pentadecanoic and Heptadecanoic Acids: Multifaceted Odd-Chain Fatty Acids. Adv Nutr 2016; 7:730-4. [PMID: 27422507 PMCID: PMC4942867 DOI: 10.3945/an.115.011387] [Citation(s) in RCA: 116] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The odd-chain fatty acids (OCFAs) pentadecanoic acid (15:0) and heptadecanoic acid (17:0), which account for only a small proportion of total saturated fatty acids in milk fat and ruminant meat, are accepted biomarkers of dairy fat intake. However, they can also be synthesized endogenously, for example, from gut-derived propionic acid (3:0). A number of studies have shown an inverse association between OCFA concentrations in human plasma phospholipids or RBCs and risk of type 2 diabetes and cardiovascular disease. We propose a possible involvement in metabolic regulation from the assumption that there is a link between 15:0 and 17:0 and the metabolism of other short-chain, medium-chain, and longer-chain OCFAs. The OCFAs 15:0 and 17:0 can be elongated to very-long-chain FAs (VLCFAs) such as tricosanoic acid (23:0) and pentacosanoic acid (25:0) in glycosphingolipids, particularly found in brain tissue, or can be derived from these VLCFAs. Their chains can be shortened, yielding propionyl-coenzyme A (CoA). Propionyl-CoA, by succinyl-CoA, can replenish the citric acid cycle (CAC) with anaplerotic intermediates and, thus, improve mitochondrial energy metabolism. Mitochondrial function is compromised in a number of disorders and may be impaired with increasing age. Optimizing anaplerotic intermediate availability for the CAC may help to cope with demands in times of increased metabolic stress and with aging. OCFAs may serve as substrates for synthesis of both odd-numbered VLCFAs and propionyl-CoA or store away excess propionic acid.
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Affiliation(s)
- Maria Pfeuffer
- Department of Physiology and Biochemistry of Nutrition, Max Rubner-Institut, Karlsruhe, Germany
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Cobolli Gigli C, Scaramuzza L, Gandaglia A, Bellini E, Gabaglio M, Parolaro D, Kilstrup-Nielsen C, Landsberger N, Bedogni F. MeCP2 Related Studies Benefit from the Use of CD1 as Genetic Background. PLoS One 2016; 11:e0153473. [PMID: 27097329 PMCID: PMC4838291 DOI: 10.1371/journal.pone.0153473] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 03/29/2016] [Indexed: 12/20/2022] Open
Abstract
MECP2 mutations cause a number of neurological disorders of which Rett syndrome (RTT) represents the most thoroughly analysed condition. Many Mecp2 mouse models have been generated through the years; their validity is demonstrated by the presence of a broad spectrum of phenotypes largely mimicking those manifested by RTT patients. These mouse models, between which the C57BL/6 Mecp2tm1.1Bird strain probably represents the most used, enabled to disclose much of the roles of Mecp2. However, small litters with little viability and poor maternal care hamper the maintenance of the colony, thus limiting research on such animals. For this reason, past studies often used Mecp2 mouse models on mixed genetic backgrounds, thus opening questions on whether modifier genes could be responsible for at least part of the described effects. To verify this possibility, and facilitate the maintenance of the Mecp2 colony, we transferred the Mecp2tm1.1Bird allele on the stronger CD1 background. The CD1 strain is easier to maintain and largely recapitulates the phenotypes already described in Mecp2-null mice. We believe that this mouse model will foster the research on RTT.
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Affiliation(s)
- Clementina Cobolli Gigli
- San Raffaele Rett Research Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Linda Scaramuzza
- San Raffaele Rett Research Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Anna Gandaglia
- San Raffaele Rett Research Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Elisa Bellini
- San Raffaele Rett Research Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
- Institute of Surgical Pathology, University Hospital Zurich, Zurich, Switzerland
| | - Marina Gabaglio
- Department of Biotechnology and Life Sciences, University of Insubria, Busto Arsizio, Italy
| | - Daniela Parolaro
- Department of Biotechnology and Life Sciences, University of Insubria, Busto Arsizio, Italy
- ZardiGori Foundation, Milan, Italy
| | | | - Nicoletta Landsberger
- San Raffaele Rett Research Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
- Department of Medical Biotechnology and Translational Medicine, University of Milan, L.I.T.A., Segrate, Italy
- * E-mail: (NL); (FB)
| | - Francesco Bedogni
- San Raffaele Rett Research Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
- * E-mail: (NL); (FB)
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Essential role of docosahexaenoic acid towards development of a smarter brain. Neurochem Int 2015; 89:51-62. [DOI: 10.1016/j.neuint.2015.08.014] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 08/18/2015] [Accepted: 08/26/2015] [Indexed: 01/25/2023]
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