1
|
Wei L, He H, Yang S, Shi Q, Wang X, Huang L, Lu J, Shen Y, Zhi K, Xiang J, Chen C, Mo J, Zheng Z, Zou Y, Yang X, Tang S, Li X, Lu C. Synergistic suppression of BDNF via epigenetic mechanism deteriorating learning and memory impairment caused by Mn and Pb co-exposure. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 277:116365. [PMID: 38657452 DOI: 10.1016/j.ecoenv.2024.116365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 04/11/2024] [Accepted: 04/20/2024] [Indexed: 04/26/2024]
Abstract
Microglia, the resident immune cells of the central nervous system (CNS), play a dual role in neurotoxicity by releasing the NLR Family Pyrin Domain Containing 3 (NLRP3) inflammasome and brain-derived neurotrophic factor (BDNF) in response to environmental stress. Suppression of BDNF is implicated in learning and memory impairment induced by exposure to manganese (Mn) or lead (Pb) individually. Methyl CpG Binding Protein 2 (MeCp2) and its phosphorylation status are related to BDNF suppression. Protein phosphatase2A (PP2A), a member of the serine/threonine phosphatases family, dephosphorylates substrates based on the methylation state of its catalytic C subunit (PP2Ac). However, the specific impairment patterns and molecular mechanisms resulting from co-exposure to Mn and Pb remain unclear. Therefore, the purpose of this study was to explore the effects of Mn and Pb exposure, alone and in combination, on inducing neurotoxicity in the hippocampus of mice and BV2 cells, and to determine whether simultaneous exposure to both metals exacerbate their toxicity. Our findings reveal that co-exposure to Mn and Pb leads to severe learning and memory impairment in mice, which correlates with the accumulation of metals in the hippocampus and synergistic suppression of BDNF. This suppression is accompanied by up-regulation of the epigenetic repressor MeCp2 and its phosphorylation status, as well as demethylation of PP2Ac. Furthermore, inhibition of PP2Ac demethylation using ABL127, an inhibitor for its protein phosphatase methylesterase1 (PME1), or knockdown of MeCp2 via siRNA transfection in vitro effectively increases BDNF expression and mitigates BV2 cell damage induced by Mn and Pb co-exposure. We also observe abnormal activation of microglia characterized by enhanced release of the NLRP3 inflammasome, Casepase-1 and pro-inflammatory cytokines IL-1β, in the hippocampus of mice and BV2 cells. In summary, our experiments demonstrate that simultaneous exposure to Mn and Pb results in more severe hippocampus-dependent learning and memory impairment, which is attributed to epigenetic suppression of BDNF mediated by PP2A regulation.
Collapse
Affiliation(s)
- Lancheng Wei
- School of Public Health, Guangxi Medical University, Nanning 530021, China
| | - Hongjian He
- School of Public Health, Guangxi Medical University, Nanning 530021, China
| | - Shuting Yang
- School of Public Health, Guangxi Medical University, Nanning 530021, China
| | - Qianqian Shi
- School of Public Health, Guangxi Medical University, Nanning 530021, China
| | - Xinhang Wang
- School of Basic Medical Sciences, Guangxi Medical University, Nanning 530021, China; Key Laboratory of Basic Research on Regional Diseases (Guangxi Medical University) , Education Department of Guangxi Zhuang Autonomous Region, Nanning 530021, China
| | - Liyuan Huang
- School of Public Health, Guangxi Medical University, Nanning 530021, China
| | - Jianyong Lu
- School of Public Health, Guangxi Medical University, Nanning 530021, China
| | - Yinghui Shen
- School of Public Health, Guangxi Medical University, Nanning 530021, China
| | - Kaikai Zhi
- School of Public Health, Guangxi Medical University, Nanning 530021, China
| | - Junni Xiang
- School of Public Health, Guangxi Medical University, Nanning 530021, China
| | - Chengying Chen
- School of Basic Medical Sciences, Guangxi Medical University, Nanning 530021, China
| | - Jiao Mo
- School of Public Health, Guangxi Medical University, Nanning 530021, China
| | - Zhijian Zheng
- School of Public Health, Guangxi Medical University, Nanning 530021, China
| | - Yunfeng Zou
- School of Public Health, Guangxi Medical University, Nanning 530021, China; Guangxi Key Laboratory of Environment and Health Research, Guangxi Medical University, Nanning 530021, China
| | - Xiaobo Yang
- School of Public Health, Guangxi Medical University, Nanning 530021, China; Guangxi Key Laboratory of Environment and Health Research, Guangxi Medical University, Nanning 530021, China
| | - Shen Tang
- School of Basic Medical Sciences, Guangxi Medical University, Nanning 530021, China; Key Laboratory of Basic Research on Regional Diseases (Guangxi Medical University) , Education Department of Guangxi Zhuang Autonomous Region, Nanning 530021, China.
| | - Xiyi Li
- School of Public Health, Guangxi Medical University, Nanning 530021, China; Guangxi Key Laboratory of Environment and Health Research, Guangxi Medical University, Nanning 530021, China.
| | - Cailing Lu
- School of Public Health, Guangxi Medical University, Nanning 530021, China; Guangxi Key Laboratory of Environment and Health Research, Guangxi Medical University, Nanning 530021, China.
| |
Collapse
|
2
|
Medeiros D, Ayala-Baylon K, Egido-Betancourt H, Miller E, Chapleau C, Robinson H, Phillips ML, Yang T, Longo FM, Li W, Pozzo-Miller L. A small-molecule TrkB ligand improves dendritic spine phenotypes and atypical behaviors in female Rett syndrome mice. Dis Model Mech 2024; 17:dmm050612. [PMID: 38785269 PMCID: PMC11139040 DOI: 10.1242/dmm.050612] [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: 11/17/2023] [Accepted: 03/06/2024] [Indexed: 05/25/2024] Open
Abstract
Rett syndrome (RTT) is a neurodevelopmental disorder caused by mutations in MECP2, which encodes methyl-CpG-binding protein 2, a transcriptional regulator of many genes, including brain-derived neurotrophic factor (BDNF). BDNF levels are lower in multiple brain regions of Mecp2-deficient mice, and experimentally increasing BDNF levels improve atypical phenotypes in Mecp2 mutant mice. Due to the low blood-brain barrier permeability of BDNF itself, we tested the effects of LM22A-4, a brain-penetrant, small-molecule ligand of the BDNF receptor TrkB (encoded by Ntrk2), on dendritic spine density and form in hippocampal pyramidal neurons and on behavioral phenotypes in female Mecp2 heterozygous (HET) mice. A 4-week systemic treatment of Mecp2 HET mice with LM22A-4 restored spine volume in MeCP2-expressing neurons to wild-type (WT) levels, whereas spine volume in MeCP2-lacking neurons remained comparable to that in neurons from female WT mice. Female Mecp2 HET mice engaged in aggressive behaviors more than WT mice, the levels of which were reduced to WT levels by the 4-week LM22A-4 treatment. These data provide additional support to the potential usefulness of novel therapies not only for RTT but also to other BDNF-related disorders.
Collapse
Affiliation(s)
- Destynie Medeiros
- Department of Neurobiology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Karen Ayala-Baylon
- Department of Neurobiology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Hailey Egido-Betancourt
- Department of Neurobiology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Eric Miller
- Department of Neurobiology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Christopher Chapleau
- Department of Neurobiology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Holly Robinson
- Department of Neurobiology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Mary L. Phillips
- Department of Neurobiology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Tao Yang
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Frank M. Longo
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Wei Li
- Department of Neurobiology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Lucas Pozzo-Miller
- Department of Neurobiology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| |
Collapse
|
3
|
Wong LC, Hsu CJ, Wu YT, Chu HF, Lin JH, Wang HP, Hu SC, Tsai YC, Tsai WC, Lee WT. Investigating the impact of probiotic on neurological outcomes in Rett syndrome: A randomized, double-blind, and placebo-controlled pilot study. AUTISM : THE INTERNATIONAL JOURNAL OF RESEARCH AND PRACTICE 2024:13623613231225899. [PMID: 38361371 DOI: 10.1177/13623613231225899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2024]
Abstract
LAY ABSTRACT Rett syndrome often involves gastrointestinal symptoms and gut microbiota imbalances. We conducted a study to explore the feasibility of probiotic Lactobacillus plantarum PS128 and the impact on neurological functions in Rett syndrome. The results of our investigation demonstrated that the supplementation of probiotic L. plantarum PS128 was feasible and well tolerated, with 100% retention rate and 0% withdrawal rate. In addition, there was only one participant who had loose stool after taking L. plantarum PS128. Further, there was a tendency to enhance overall cognitive developmental level, as assessed using Mullen Scales of Early Learning. In addition, it significantly improved dystonia, as assessed using the Burke-Fahn-Marsden Movement Scale, in comparison with the placebo group. This study provides a strong foundation for future research and clinical trials exploring the potential of L. plantarum PS128 probiotics as a complementary therapy for individuals with Rett syndrome.
Collapse
Affiliation(s)
- Lee Chin Wong
- Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine, Taipei, Taiwan
- Department of Pediatrics, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
| | - Chia-Jui Hsu
- Department of Pediatrics, National Taiwan University Hospital Hsin-Chu Branch, Hsin-Chu, Taiwan
| | - Yen-Tzu Wu
- School and Graduate Institute of Physical Therapy, National Taiwan University College of Medicine, Taiwan
- Department of Physical Medicine and Rehabilitation, National Taiwan University, Taipei, Taiwan
| | - Hsu-Feng Chu
- Biomedical Industry Ph.D. Program, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Jui-Hsiang Lin
- Institute of Statistical Science, Academia Sinica, Taipei, Taiwan
| | - Hsin-Pei Wang
- Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine, Taipei, Taiwan
- Department of Pediatrics, National Taiwan University Hospital YunLin Branch, YunLin, Taiwan
| | - Su-Ching Hu
- Department of Pediatrics, Cathay General Hospital, Taipei, Taiwan
| | - Ying-Chieh Tsai
- Institute of Biochemistry and Molecular Biology, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Wen-Che Tsai
- Department of Psychiatry, National Taiwan University Hospital, Taipei, Taiwan
| | - Wang-Tso Lee
- Department of Pediatrics, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
- Graduate Institute of Brain and Mind Sciences, National Taiwan University College of Medicine, Taipei, Taiwan
| |
Collapse
|
4
|
Medeiros D, Ayala-Baylon K, Egido-Betancourt H, Miller E, Chapleau CA, Robinson HA, Phillips ML, Yang T, Longo F, Li W, Pozzo-Miller L. A small-molecule TrkB ligand improves dendritic spine phenotypes and atypical behaviors in female Rett syndrome mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.09.566435. [PMID: 37986936 PMCID: PMC10659425 DOI: 10.1101/2023.11.09.566435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Rett syndrome (RTT) is a neurodevelopmental disorder caused by mutations in methyl-CpG-binding protein-2 (MECP2), encoding a transcriptional regulator of many genes, including brain-derived neurotrophic factor (Bdnf). BDNF mRNA and protein levels are lower in RTT autopsy brains and in multiple brain regions of Mecp2-deficient mice, and experimentally increasing BDNF levels improve atypical phenotypes in Mecp2 mutant mice. Due to the low blood-brain barrier permeability of BDNF itself, we tested the effects of a brain penetrant, small molecule ligand of its TrkB receptors. Applied in vitro, LM22A-4 increased dendritic spine density in pyramidal neurons in cultured hippocampal slices from postnatal day (P) 7 male Mecp2 knockout (KO) mice as much as recombinant BDNF, and both effects were prevented by the TrkB receptor inhibitors K-252a and ANA-12. Consistent with its partial agonist activity, LM22A-4 did not affect spine density in CA1 pyramidal neurons in slice cultures from male wildtype (WT) mice, where typical BDNF levels outcompete its binding to TrkB. To identify neurons of known genotypes in the "mosaic" brain of female Mecp2 heterozygous (HET) mice, we treated 4-6-month-old female MeCP2-GFP WT and HET mice with peripheral injections of LM22A-4 for 4 weeks. Surprisingly, mutant neurons lacking MeCP2-GFP showed dendritic spine volumes comparable to that in WT controls, while MeCP2-GFP-expressing neurons showed larger spines, similar to the phenotype we described in symptomatic male Mecp2 KO mice where all neurons lack MeCP2. Consistent with this non-cell-autonomous mechanism, a 4-week systemic treatment with LM22A-4 had an effect only in MeCP2-GFP-expressing neurons in female Mecp2 HET mice, bringing dendritic spine volumes down to WT control levels, and without affecting spines of MeCP2-GFP-lacking neurons. At the behavioral level, we found that female Mecp2 HET mice engaged in aggressive behaviors significantly more than WT controls, which were reduced to WT levels by a 4-week systemic treatment with LM22A-4. Altogether, these data revealed differences in dendritic spine size and altered behaviors in Mecp2 HET mice, while providing support to the potential usefulness of BDNF-related therapeutic approaches such as the partial TrkB agonist LM22A-4.
Collapse
|
5
|
Miranda-Lourenço C, Rosa J, Rei N, Belo RF, Lopes AL, Silva D, Vieira C, Magalhães-Cardoso T, Viais R, Correia-de-Sá P, Sebastião AM, Diógenes MJ. Adenosinergic System and BDNF Signaling Changes as a Cross-Sectional Feature of RTT: Characterization of Mecp2 Heterozygous Mouse Females. Int J Mol Sci 2023; 24:16249. [PMID: 38003438 PMCID: PMC10671708 DOI: 10.3390/ijms242216249] [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: 09/23/2023] [Revised: 10/25/2023] [Accepted: 11/01/2023] [Indexed: 11/26/2023] Open
Abstract
Rett Syndrome is an X-linked neurodevelopmental disorder (RTT; OMIM#312750) associated to MECP2 mutations. MeCP2 dysfunction is seen as one cause for the deficiencies found in brain-derived neurotrophic factor (BDNF) signaling, since BDNF is one of the genes under MeCP2 jurisdiction. BDNF signaling is also dependent on the proper function of the adenosinergic system. Indeed, both BDNF signaling and the adenosinergic system are altered in Mecp2-null mice (Mecp2-/y), a representative model of severe manifestation of RTT. Considering that symptoms severity largely differs among RTT patients, we set out to investigate the BDNF and ADO signaling modifications in Mecp2 heterozygous female mice (Mecp2+/-) presenting a less severe phenotype. Symptomatic Mecp2+/- mice have lower BDNF levels in the cortex and hippocampus. This is accompanied by a loss of BDNF-induced facilitation of hippocampal long-term potentiation (LTP), which could be restored upon selective activation of adenosine A2A receptors (A2AR). While no differences were observed in the amount of adenosine in the cortex and hippocampus of Mecp2+/- mice compared with healthy littermates, the density of the A1R and A2AR subtype receptors was, respectively, upregulated and downregulated in the hippocampus. Data suggest that significant changes in BDNF and adenosine signaling pathways are present in an RTT model with a milder disease phenotype: Mecp2+/- female animals. These features strengthen the theory that boosting adenosinergic activity may be a valid therapeutic strategy for RTT patients, regardless of their genetic penetrance.
Collapse
Affiliation(s)
- Catarina Miranda-Lourenço
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; (C.M.-L.); (A.M.S.)
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Jéssica Rosa
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; (C.M.-L.); (A.M.S.)
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Nádia Rei
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; (C.M.-L.); (A.M.S.)
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Rita F. Belo
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; (C.M.-L.); (A.M.S.)
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Ana Luísa Lopes
- Laboratório de Farmacologia e Neurobiologia/MedInUP, Instituto de Ciências Biomédicas Abel Salazar—Universidade do Porto (ICBAS-UP), 4050-313 Porto, Portugal (D.S.); (P.C.-d.-S.)
| | - Diogo Silva
- Laboratório de Farmacologia e Neurobiologia/MedInUP, Instituto de Ciências Biomédicas Abel Salazar—Universidade do Porto (ICBAS-UP), 4050-313 Porto, Portugal (D.S.); (P.C.-d.-S.)
| | - Cátia Vieira
- Laboratório de Farmacologia e Neurobiologia/MedInUP, Instituto de Ciências Biomédicas Abel Salazar—Universidade do Porto (ICBAS-UP), 4050-313 Porto, Portugal (D.S.); (P.C.-d.-S.)
| | - Teresa Magalhães-Cardoso
- Laboratório de Farmacologia e Neurobiologia/MedInUP, Instituto de Ciências Biomédicas Abel Salazar—Universidade do Porto (ICBAS-UP), 4050-313 Porto, Portugal (D.S.); (P.C.-d.-S.)
| | - Ricardo Viais
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; (C.M.-L.); (A.M.S.)
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Paulo Correia-de-Sá
- Laboratório de Farmacologia e Neurobiologia/MedInUP, Instituto de Ciências Biomédicas Abel Salazar—Universidade do Porto (ICBAS-UP), 4050-313 Porto, Portugal (D.S.); (P.C.-d.-S.)
| | - Ana M. Sebastião
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; (C.M.-L.); (A.M.S.)
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Maria J. Diógenes
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; (C.M.-L.); (A.M.S.)
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| |
Collapse
|
6
|
Abdolahi S, Zare-Chahoki A, Noorbakhsh F, Gorji A. A Review of Molecular Interplay between Neurotrophins and miRNAs in Neuropsychological Disorders. Mol Neurobiol 2022; 59:6260-6280. [PMID: 35916975 PMCID: PMC9463196 DOI: 10.1007/s12035-022-02966-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 07/17/2022] [Indexed: 01/10/2023]
Abstract
Various neurotrophins (NTs), including nerve growth factor, brain-derived neurotrophic factor, neurotrophin-3, and neurotrophin-4, promote cellular differentiation, survival, and maintenance, as well as synaptic plasticity, in the peripheral and central nervous system. The function of microRNAs (miRNAs) and other small non-coding RNAs, as regulators of gene expression, is pivotal for the appropriate control of cell growth and differentiation. There are positive and negative loops between NTs and miRNAs, which exert modulatory effects on different signaling pathways. The interplay between NTs and miRNAs plays a crucial role in the regulation of several physiological and pathological brain procedures. Emerging evidence suggests the diagnostic and therapeutic roles of the interactions between NTs and miRNAs in several neuropsychological disorders, including epilepsy, multiple sclerosis, Alzheimer's disease, Huntington's disease, amyotrophic lateral sclerosis, schizophrenia, anxiety disorders, depression, post-traumatic stress disorder, bipolar disorder, and drug abuse. Here, we review current data regarding the regulatory interactions between NTs and miRNAs in neuropsychological disorders, for which novel diagnostic and/or therapeutic strategies are emerging. Targeting NTs-miRNAs interactions for diagnostic or therapeutic approaches needs to be validated by future clinical studies.
Collapse
Affiliation(s)
- Sara Abdolahi
- Shefa Neuroscience Research Center, Khatam Alanbia Hospital, Tehran, Iran
| | - Ameneh Zare-Chahoki
- Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran
| | - Farshid Noorbakhsh
- Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Ali Gorji
- Neuroscience Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
- Department of Neurosurgery, Westfälische Wilhelms-Universität, Münster, Germany.
- Department of Neurology and Institute for Translational Neurology, Westfälische Wilhelms-Universität, Münster, Germany.
- Epilepsy Research Center, Westfälische Wilhelms-Universität, 48149, Münster, Germany.
| |
Collapse
|
7
|
Lim HK, Yoon JH, Song M. Autism Spectrum Disorder Genes: Disease-Related Networks and Compensatory Strategies. Front Mol Neurosci 2022; 15:922840. [PMID: 35726297 PMCID: PMC9206533 DOI: 10.3389/fnmol.2022.922840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 05/17/2022] [Indexed: 11/16/2022] Open
Abstract
The mammalian brain comprises structurally and functionally distinct regions. Each of these regions has characteristic molecular mechanisms that mediate higher-order tasks, such as memory, learning, emotion, impulse, and motor control. Many genes are involved in neuronal signaling and contribute to normal brain development. Dysfunction of essential components of neural signals leads to various types of brain disorders. Autism spectrum disorder is a neurodevelopmental disorder characterized by social deficits, communication challenges, and compulsive repetitive behaviors. Long-term genetic studies have uncovered key genes associated with autism spectrum disorder, such as SH3 and multiple ankyrin repeat domains 3, methyl-CpG binding protein 2, neurexin 1, and chromodomain helicase DNA binding protein 8. In addition, disease-associated networks have been identified using animal models, and the understanding of the impact of these genes on disease susceptibility and compensation is deepening. In this review, we examine rescue strategies using key models of autism spectrum disorder.
Collapse
Affiliation(s)
- Hye Kyung Lim
- Department of Life Sciences, Yeungnam University, Gyeongsan, South Korea
| | - Jong Hyuk Yoon
- Neurodegenerative Diseases Research Group, Korea Brain Research Institute, Daegu, South Korea
| | - Minseok Song
- Department of Life Sciences, Yeungnam University, Gyeongsan, South Korea
| |
Collapse
|
8
|
Pleiotropic effects of BDNF on the cerebellum and hippocampus: Implications for neurodevelopmental disorders. Neurobiol Dis 2022; 163:105606. [PMID: 34974125 DOI: 10.1016/j.nbd.2021.105606] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 12/22/2021] [Accepted: 12/29/2021] [Indexed: 12/17/2022] Open
Abstract
Brain-derived neurotrophic factor (BDNF) is one of the most studied neurotrophins in the mammalian brain, essential not only to the development of the central nervous system but also to synaptic plasticity. BDNF is present in various brain areas, but highest levels of expression are seen in the cerebellum and hippocampus. After birth, BDNF acts in the cerebellum as a mitogenic and chemotactic factor, stimulating the cerebellar granule cell precursors to proliferate, migrate and maturate, while in the hippocampus BDNF plays a fundamental role in synaptic transmission and plasticity, representing a key regulator for the long-term potentiation, learning and memory. Furthermore, the expression of BDNF is highly regulated and changes of its expression are associated with both physiological and pathological conditions. The purpose of this review is to provide an overview of the current state of knowledge on the BDNF biology and its neurotrophic role in the proper development and functioning of neurons and synapses in two important brain areas of postnatal neurogenesis, the cerebellum and hippocampus. Dysregulation of BDNF expression and signaling, resulting in alterations in neuronal maturation and plasticity in both systems, is a common hallmark of several neurodevelopmental diseases, such as autism spectrum disorder, suggesting that neuronal malfunction present in these disorders is the result of excessive or reduced of BDNF support. We believe that the more the relevance of the pathophysiological actions of BDNF, and its downstream signals, in early postnatal development will be highlighted, the more likely it is that new neuroprotective therapeutic strategies will be identified in the treatment of various neurodevelopmental disorders.
Collapse
|
9
|
Barros II, Leão V, Santis JO, Rosa RCA, Brotto DB, Storti CB, Siena ÁDD, Molfetta GA, Silva WA. Non-Syndromic Intellectual Disability and Its Pathways: A Long Noncoding RNA Perspective. Noncoding RNA 2021; 7:ncrna7010022. [PMID: 33799572 PMCID: PMC8005948 DOI: 10.3390/ncrna7010022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 12/05/2020] [Accepted: 12/07/2020] [Indexed: 02/06/2023] Open
Abstract
Non-syndromic intellectual disability (NS-ID or idiopathic) is a complex neurodevelopmental disorder that represents a global health issue. Although many efforts have been made to characterize it and distinguish it from syndromic intellectual disability (S-ID), the highly heterogeneous aspect of this disorder makes it difficult to understand its etiology. Long noncoding RNAs (lncRNAs) comprise a large group of transcripts that can act through various mechanisms and be involved in important neurodevelopmental processes. In this sense, comprehending the roles they play in this intricate context is a valuable way of getting new insights about how NS-ID can arise and develop. In this review, we attempt to bring together knowledge available in the literature about lncRNAs involved with molecular and cellular pathways already described in intellectual disability and neural function, to better understand their relevance in NS-ID and the regulatory complexity of this disorder.
Collapse
Affiliation(s)
- Isabela I. Barros
- Department of Genetics at the Ribeirão Preto Medical School, University of São Paulo, Avenida Bandeirantes 3900, Monte Alegre, Ribeirão Preto, São Paulo 14049-900, Brazil; (I.I.B.); (V.L.); (J.O.S.); (R.C.A.R.); (D.B.B.); (C.B.S.); (Á.D.D.S.); (G.A.M.)
| | - Vitor Leão
- Department of Genetics at the Ribeirão Preto Medical School, University of São Paulo, Avenida Bandeirantes 3900, Monte Alegre, Ribeirão Preto, São Paulo 14049-900, Brazil; (I.I.B.); (V.L.); (J.O.S.); (R.C.A.R.); (D.B.B.); (C.B.S.); (Á.D.D.S.); (G.A.M.)
| | - Jessica O. Santis
- Department of Genetics at the Ribeirão Preto Medical School, University of São Paulo, Avenida Bandeirantes 3900, Monte Alegre, Ribeirão Preto, São Paulo 14049-900, Brazil; (I.I.B.); (V.L.); (J.O.S.); (R.C.A.R.); (D.B.B.); (C.B.S.); (Á.D.D.S.); (G.A.M.)
| | - Reginaldo C. A. Rosa
- Department of Genetics at the Ribeirão Preto Medical School, University of São Paulo, Avenida Bandeirantes 3900, Monte Alegre, Ribeirão Preto, São Paulo 14049-900, Brazil; (I.I.B.); (V.L.); (J.O.S.); (R.C.A.R.); (D.B.B.); (C.B.S.); (Á.D.D.S.); (G.A.M.)
| | - Danielle B. Brotto
- Department of Genetics at the Ribeirão Preto Medical School, University of São Paulo, Avenida Bandeirantes 3900, Monte Alegre, Ribeirão Preto, São Paulo 14049-900, Brazil; (I.I.B.); (V.L.); (J.O.S.); (R.C.A.R.); (D.B.B.); (C.B.S.); (Á.D.D.S.); (G.A.M.)
| | - Camila B. Storti
- Department of Genetics at the Ribeirão Preto Medical School, University of São Paulo, Avenida Bandeirantes 3900, Monte Alegre, Ribeirão Preto, São Paulo 14049-900, Brazil; (I.I.B.); (V.L.); (J.O.S.); (R.C.A.R.); (D.B.B.); (C.B.S.); (Á.D.D.S.); (G.A.M.)
| | - Ádamo D. D. Siena
- Department of Genetics at the Ribeirão Preto Medical School, University of São Paulo, Avenida Bandeirantes 3900, Monte Alegre, Ribeirão Preto, São Paulo 14049-900, Brazil; (I.I.B.); (V.L.); (J.O.S.); (R.C.A.R.); (D.B.B.); (C.B.S.); (Á.D.D.S.); (G.A.M.)
| | - Greice A. Molfetta
- Department of Genetics at the Ribeirão Preto Medical School, University of São Paulo, Avenida Bandeirantes 3900, Monte Alegre, Ribeirão Preto, São Paulo 14049-900, Brazil; (I.I.B.); (V.L.); (J.O.S.); (R.C.A.R.); (D.B.B.); (C.B.S.); (Á.D.D.S.); (G.A.M.)
| | - Wilson A. Silva
- Department of Genetics at the Ribeirão Preto Medical School, University of São Paulo, Avenida Bandeirantes 3900, Monte Alegre, Ribeirão Preto, São Paulo 14049-900, Brazil; (I.I.B.); (V.L.); (J.O.S.); (R.C.A.R.); (D.B.B.); (C.B.S.); (Á.D.D.S.); (G.A.M.)
- National Institute of Science and Technology in Stem Cell and Cell Therapy and Center for Cell Based Therapy, Ribeirão Preto Medical School, University of São Paulo, Rua Tenente Catão Roxo, 2501, Monte Alegre, Ribeirão Preto 14051-140, Brazil
- Center for Integrative Systems Biology-CISBi, NAP/USP, Ribeirão Preto Medical School, University of São Paulo, Rua Catão Roxo, 2501, Monte Alegre, Ribeirão Preto 14051-140, Brazil
- Department of Medicine at the Midwest State University of Paraná-UNICENTRO, and Guarapuava Institute for Cancer Research, Rua Fortim Atalaia, 1900, Cidade dos Lagos, Guarapuava 85100-000, Brazil
- Correspondence: ; Tel.: +55-16-3315-3293
| |
Collapse
|
10
|
Langhnoja J, Buch L, Pillai P. Potential role of NGF, BDNF, and their receptors in oligodendrocytes differentiation from neural stem cell: An in vitro study. Cell Biol Int 2020; 45:432-446. [PMID: 33200854 DOI: 10.1002/cbin.11500] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 10/12/2020] [Accepted: 11/11/2020] [Indexed: 12/11/2022]
Abstract
Neural stem cells (NSCs) or neuronal progenitor cells are cells capable of differentiating into oligodendrocytes, myelin-forming cells that have the potential of remyelination. Brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) are two neurotrophic factors that have been studied to stimulate NSC differentiation thus playing a role in multiple sclerosis pathogenesis and several other demyelinating disorders. While several studies have demonstrated the proliferative and protective capabilities of these neurotrophic factors, their cellular and molecular functions are still not well understood. Thus, in the present study, we focus on understanding the role of these neurotrophins (BDNF and NGF) in oligodendrogenesis from NSCs. Both neurotrophic factors have been shown to promote NSC proliferation and NSC differentiation particularly into oligodendroglial lineage in a dose-dependent fashion. Further, to establish the role of these neurotrophins in NSC differentiation, we have employed pharmacological inhibitors for TrkA and TrkB receptors in NSCs. The use of these inhibitors suppressed NSC differentiation into oligodendrocytes along with the downregulation of phosphorylated ERK suggesting active involvement of ERK in the functioning of these neurotrophins. The morphometric analysis also revealed the important role of both neurotrophins in oligodendrocytes development. These findings highlight the importance of neurotrophic factors in stimulating NSC differentiation and may pave a role for future studies to develop neurotrophic factor replacement therapies to achieve remyelination.
Collapse
Affiliation(s)
- Jaldeep Langhnoja
- Department of Zoology, Division of Neurobiology, The Maharaja Sayajirao University of Baroda, Vadodara, Gujarat, India
| | - Lipi Buch
- Department of Zoology, Division of Neurobiology, The Maharaja Sayajirao University of Baroda, Vadodara, Gujarat, India
| | - Prakash Pillai
- Department of Zoology, Division of Neurobiology, The Maharaja Sayajirao University of Baroda, Vadodara, Gujarat, India
| |
Collapse
|
11
|
Miranda-Lourenço C, Ribeiro-Rodrigues L, Fonseca-Gomes J, Tanqueiro SR, Belo RF, Ferreira CB, Rei N, Ferreira-Manso M, de Almeida-Borlido C, Costa-Coelho T, Freitas CF, Zavalko S, Mouro FM, Sebastião AM, Xapelli S, Rodrigues TM, Diógenes MJ. Challenges of BDNF-based therapies: From common to rare diseases. Pharmacol Res 2020; 162:105281. [PMID: 33161136 DOI: 10.1016/j.phrs.2020.105281] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 10/20/2020] [Accepted: 10/22/2020] [Indexed: 12/11/2022]
Abstract
Neurotrophins are a well-known family of neurotrophic factors that play an important role both in the central and peripheral nervous systems, where they modulate neuronal survival, development, function and plasticity. Brain-derived neurotrophic factor (BDNF) possesses diverse biological functions which are mediated by the activation of two main classes of receptors, the tropomyosin-related kinase (Trk) B and the p75 neurotrophin receptor (p75NTR). The therapeutic potential of BDNF has drawn attention since dysregulation of its signalling cascades has been suggested to underlie the pathogenesis of both common and rare diseases. Multiple strategies targeting this neurotrophin have been tested; most have found obstacles that ultimately hampered their effectiveness. This review focuses on the involvement of BDNF and its receptors in the pathophysiology of Alzheimer's disease (AD), Amyotrophic Lateral Sclerosis (ALS) and Rett Syndrome (RTT). We describe the known mechanisms leading to the impairment of BDNF/TrkB signalling in these disorders. Such mechanistic insight highlights how BDNF signalling compromise can take various shapes, nearly disease-specific. Therefore, BDNF-based therapeutic strategies must be specifically tailored and are more likely to succeed if a combination of resources is employed.
Collapse
Affiliation(s)
- Catarina Miranda-Lourenço
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Leonor Ribeiro-Rodrigues
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - João Fonseca-Gomes
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Sara R Tanqueiro
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Rita F Belo
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Catarina B Ferreira
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Nádia Rei
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Mafalda Ferreira-Manso
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Carolina de Almeida-Borlido
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Tiago Costa-Coelho
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Céline Felicidade Freitas
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Svitlana Zavalko
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Francisco M Mouro
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Ana M Sebastião
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Sara Xapelli
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Tiago M Rodrigues
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Universidade de Lisboa, 1649-028 Lisboa, Portugal; Institute of Molecular and Clinical Ophthalmology Basel (IOB), Mittlere Strasse 91, 4031 Basel, Switzerland
| | - Maria J Diógenes
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Universidade de Lisboa, 1649-028 Lisboa, Portugal.
| |
Collapse
|
12
|
Miranda-Lourenço C, Duarte ST, Palminha C, Gaspar C, Rodrigues TM, Magalhães-Cardoso T, Rei N, Colino-Oliveira M, Gomes R, Ferreira S, Rosa J, Xapelli S, Armstrong J, García-Cazorla À, Correia-de-Sá P, Sebastião AM, Diógenes MJ. Impairment of adenosinergic system in Rett syndrome: Novel therapeutic target to boost BDNF signalling. Neurobiol Dis 2020; 145:105043. [PMID: 32798727 DOI: 10.1016/j.nbd.2020.105043] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 07/23/2020] [Accepted: 08/08/2020] [Indexed: 01/20/2023] Open
Abstract
Rett syndrome (RTT; OMIM#312750) is mainly caused by mutations in the X-linked MECP2 gene (methyl-CpG-binding protein 2 gene; OMIM*300005), which leads to impairments in the brain-derived neurotrophic factor (BDNF) signalling. The boost of BDNF mediated effects would be a significant breakthrough but it has been hampered by the difficulty to administer BDNF to the central nervous system. Adenosine, an endogenous neuromodulator, may accomplish that role since through A2AR it potentiates BDNF synaptic actions in healthy animals. We thus characterized several hallmarks of the adenosinergic and BDNF signalling in RTT and explored whether A2AR activation could boost BDNF actions. For this study, the RTT animal model, the Mecp2 knockout (Mecp2-/y) (B6.129P2 (C)-Mecp2tm1.1Bird/J) mouse was used. Whenever possible, parallel data was also obtained from post-mortem brain samples from one RTT patient. Ex vivo extracellular recordings of field excitatory post-synaptic potentials in CA1 hippocampal area were performed to evaluate synaptic transmission and long-term potentiation (LTP). RT-PCR was used to assess mRNA levels and Western Blot or radioligand binding assays were performed to evaluate protein levels. Changes in cortical and hippocampal adenosine content were assessed by liquid chromatography with diode array detection (LC/DAD). Hippocampal ex vivo experiments revealed that the facilitatory actions of BDNF upon LTP is absent in Mecp2-/y mice and that TrkB full-length (TrkB-FL) receptor levels are significantly decreased. Extracts of the hippocampus and cortex of Mecp2-/y mice revealed less adenosine amount as well as less A2AR protein levels when compared to WT littermates, which may partially explain the deficits in adenosinergic tonus in these animals. Remarkably, the lack of BDNF effect on hippocampal LTP in Mecp2-/y mice was overcome by selective activation of A2AR with CGS21680. Overall, in Mecp2-/y mice there is an impairment on adenosinergic system and BDNF signalling. These findings set the stage for adenosine-based pharmacological therapeutic strategies for RTT, highlighting A2AR as a therapeutic target in this devastating pathology.
Collapse
Affiliation(s)
- Catarina Miranda-Lourenço
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina e Instituto de Medicina Molecular - João Lobo Antunes, Universidade de Lisboa, Lisboa, Portugal.
| | - Sofia T Duarte
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina e Instituto de Medicina Molecular - João Lobo Antunes, Universidade de Lisboa, Lisboa, Portugal; Child Neurology Department, Hospital Dona Estefânia - Centro Hospitalar Universitário de Lisboa Central, Portugal.
| | - Cátia Palminha
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina e Instituto de Medicina Molecular - João Lobo Antunes, Universidade de Lisboa, Lisboa, Portugal.
| | - Cláudia Gaspar
- Instituto de Medicina Molecular - João Lobo Antunes, Universidade de Lisboa, Lisboa, Portugal.
| | - Tiago M Rodrigues
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina e Instituto de Medicina Molecular - João Lobo Antunes, Universidade de Lisboa, Lisboa, Portugal; Institute of Molecular and Clinical Ophtalmology, Mittlere Strasse 91, CH-4031 Basel, Switzerland.
| | - Teresa Magalhães-Cardoso
- Laboratório de Farmacologia e Neurobiologia / MedInUP, Instituto de Ciências Biomédicas Abel Salazar - Universidade do Porto (ICBAS-UP), Porto, Portugal.
| | - Nádia Rei
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina e Instituto de Medicina Molecular - João Lobo Antunes, Universidade de Lisboa, Lisboa, Portugal.
| | - Mariana Colino-Oliveira
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina e Instituto de Medicina Molecular - João Lobo Antunes, Universidade de Lisboa, Lisboa, Portugal.
| | - Rui Gomes
- Instituto de Medicina Molecular - João Lobo Antunes, Universidade de Lisboa, Lisboa, Portugal.
| | - Sara Ferreira
- Instituto de Medicina Molecular - João Lobo Antunes, Universidade de Lisboa, Lisboa, Portugal.
| | - Jéssica Rosa
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina e Instituto de Medicina Molecular - João Lobo Antunes, Universidade de Lisboa, Lisboa, Portugal.
| | - Sara Xapelli
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina e Instituto de Medicina Molecular - João Lobo Antunes, Universidade de Lisboa, Lisboa, Portugal.
| | - Judith Armstrong
- Genetics Department, Hospital Sant Joan de Deu. Institut Pediàtric de Recerca and CIBERER. (ISCIII), Barcelona, Spain.
| | - Àngels García-Cazorla
- Synaptic Metabolism Laboratory, Neurology Department; Institut Pediàtric de Recerca and CIBERER. (ISCIII), Barcelona, Spain.
| | - Paulo Correia-de-Sá
- Laboratório de Farmacologia e Neurobiologia / MedInUP, Instituto de Ciências Biomédicas Abel Salazar - Universidade do Porto (ICBAS-UP), Porto, Portugal.
| | - Ana M Sebastião
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina e Instituto de Medicina Molecular - João Lobo Antunes, Universidade de Lisboa, Lisboa, Portugal.
| | - Maria José Diógenes
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina e Instituto de Medicina Molecular - João Lobo Antunes, Universidade de Lisboa, Lisboa, Portugal.
| |
Collapse
|
13
|
Quezada S, van de Looij Y, Hale N, Rana S, Sizonenko SV, Gilchrist C, Castillo-Melendez M, Tolcos M, Walker DW. Genetic and microstructural differences in the cortical plate of gyri and sulci during gyrification in fetal sheep. Cereb Cortex 2020; 30:6169-6190. [PMID: 32609332 DOI: 10.1093/cercor/bhaa171] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 05/29/2020] [Accepted: 05/29/2020] [Indexed: 12/28/2022] Open
Abstract
Gyrification of the cerebral cortex is a developmentally important process, but the mechanisms that drive cortical folding are not fully known. Theories propose that changes within the cortical plate (CP) cause gyrification, yet differences between the CP below gyri and sulci have not been investigated. Here we report genetic and microstructural differences in the CP below gyri and sulci assessed before (at 70 days of gestational age [GA] 70), during (GA 90), and after (GA 110) gyrification in fetal sheep. The areal density of BDNF, CDK5, and NeuroD6 immunopositive cells were increased, and HDAC5 and MeCP2 mRNA levels were decreased in the CP below gyri compared with sulci during gyrification, but not before. Only the areal density of BDNF-immunopositive cells remained increased after gyrification. MAP2 immunoreactivity and neurite outgrowth were also increased in the CP below gyri compared with sulci at GA 90, and this was associated with microstructural changes assessed via diffusion tensor imaging and neurite orientation dispersion and density imaging at GA 98. Differential neurite outgrowth may therefore explain the localized changes in CP architecture that result in gyrification.
Collapse
Affiliation(s)
- Sebastian Quezada
- The Ritchie Centre, Hudson Institute of Medical Research, Monash University, Clayton, VIC 3168, Australia.,Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC 3168, Australia.,School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC 3083 Australia
| | - Yohan van de Looij
- Division of Development and Growth, Department of Paediatrics and Gynaecology-Obstetrics, School of Medicine, University of Geneva, 1204 Geneva, Switzerland.,Functional and Metabolic Imaging Lab, Federal Institute of Technology of Lausanne, Lausanne 1015, Switzerland
| | - Nadia Hale
- The Ritchie Centre, Hudson Institute of Medical Research, Monash University, Clayton, VIC 3168, Australia.,Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC 3168, Australia
| | - Shreya Rana
- The Ritchie Centre, Hudson Institute of Medical Research, Monash University, Clayton, VIC 3168, Australia.,Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC 3168, Australia
| | - Stéphane V Sizonenko
- Division of Development and Growth, Department of Paediatrics and Gynaecology-Obstetrics, School of Medicine, University of Geneva, 1204 Geneva, Switzerland
| | - Courtney Gilchrist
- School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC 3083 Australia.,Clinical Sciences, Murdoch Children's Research Institute, Parkville, VIC 3052, Australia
| | - Margie Castillo-Melendez
- The Ritchie Centre, Hudson Institute of Medical Research, Monash University, Clayton, VIC 3168, Australia.,Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC 3168, Australia
| | - Mary Tolcos
- The Ritchie Centre, Hudson Institute of Medical Research, Monash University, Clayton, VIC 3168, Australia.,Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC 3168, Australia.,School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC 3083 Australia
| | - David W Walker
- The Ritchie Centre, Hudson Institute of Medical Research, Monash University, Clayton, VIC 3168, Australia.,Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC 3168, Australia.,School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC 3083 Australia
| |
Collapse
|
14
|
Singh J, Lanzarini E, Santosh P. Autonomic dysfunction and sudden death in patients with Rett syndrome: a systematic review. J Psychiatry Neurosci 2020; 45:150-181. [PMID: 31702122 PMCID: PMC7828978 DOI: 10.1503/jpn.190033] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Rett syndrome (RTT), a debilitating neuropsychiatric disorder that begins in early childhood, is characterized by impairments in the autonomic nervous system that can lead to sudden unexpected death. This study explores the mechanisms of autonomic dysfunction to identify potential risk factors for sudden death in patients with RTT. METHODS Following the Reporting Items for Systematic Review and Meta-Analyses (PRISMA) criteria, we undertook comprehensive systematic reviews using the PubMed, Scopus, Cochrane, PsycINFO, Embase and Web of Science databases. RESULTS We identified and critically appraised 39 articles for autonomic dysfunction and 5 for sudden death that satisfied the eligibility criteria. Following thematic analysis, we identified 7 themes: breathing irregularities, abnormal spontaneous brainstem activations, heart rate variability metrics, QTc changes, vagal imbalance, fluctuation in peptides and serotonergic neurotransmission. We grouped these 7 themes into 3 final themes: (A) brainstem modulation of breathing, (B) electrical instability of the cardiovascular system and (C) neurochemical changes contributing to autonomic decline. We described key evidence relating to each theme and identified important areas that could improve the clinical management of patients with RTT. LIMITATIONS The heterogeneity of the methods used to assess autonomic function increased the difficulty of making inferences from the different studies. CONCLUSION This study identified the important mediators of autonomic dysfunction and sudden death in patients with RTT. We proposed brainstem mechanisms and emphasized risk factors that increase brainstem vulnerability. We discussed clinical management to reduce sudden death and future directions for this vulnerable population.
Collapse
Affiliation(s)
- Jatinder Singh
- From the Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK (Singh, Santosh); the Centre for Interventional Paediatric Psychopharmacology and Rare Diseases, South London, and Maudsley NHS Foundation Trust, London, UK (Singh, Lanzarini, Santosh); and the Child and Adolescent Neuropsychiatry Unit, S. Orsola-Malpighi Hospital, University of Bologna, Via Massarenti 9, 40138, Bologna, Italy (Lanzarini)
| | - Evamaria Lanzarini
- From the Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK (Singh, Santosh); the Centre for Interventional Paediatric Psychopharmacology and Rare Diseases, South London, and Maudsley NHS Foundation Trust, London, UK (Singh, Lanzarini, Santosh); and the Child and Adolescent Neuropsychiatry Unit, S. Orsola-Malpighi Hospital, University of Bologna, Via Massarenti 9, 40138, Bologna, Italy (Lanzarini)
| | - Paramala Santosh
- From the Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK (Singh, Santosh); the Centre for Interventional Paediatric Psychopharmacology and Rare Diseases, South London, and Maudsley NHS Foundation Trust, London, UK (Singh, Lanzarini, Santosh); and the Child and Adolescent Neuropsychiatry Unit, S. Orsola-Malpighi Hospital, University of Bologna, Via Massarenti 9, 40138, Bologna, Italy (Lanzarini)
| |
Collapse
|
15
|
Pejhan S, Siu VM, Ang LC, Del Bigio MR, Rastegar M. Differential brain region-specific expression of MeCP2 and BDNF in Rett Syndrome patients: a distinct grey-white matter variation. Neuropathol Appl Neurobiol 2020; 46:735-750. [PMID: 32246495 DOI: 10.1111/nan.12619] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 01/03/2020] [Accepted: 03/23/2020] [Indexed: 12/18/2022]
Abstract
INTRODUCTION AND OBJECTIVES Rett Syndrome (RTT) is a neurodevelopmental disorder caused by Methyl CpG Binding Protein 2 (MECP2) gene mutations. Previous studies of MeCP2 in the human brain showed variable and inconsistent mosaic-pattern immunolabelling, which has been interpreted as a reflection of activation-state variability. We aimed to study post mortem MeCP2 and BDNF (MeCP2 target) degradation and brain region-specific detection in relation to RTT pathophysiology. METHODS We investigated MeCP2 and BDNF stabilities in non-RTT human brains by immunohistochemical labelling and compared them in three brain regions of RTT and controls. RESULTS In surgically excised samples of human hippocampus and cerebellum, MeCP2 was universally detected. There was no significantly obvious difference between males and females. However, post mortem delay in autopsy samples had substantial influence on MeCP2 detection. Immunohistochemistry studies in RTT patients showed lower MeCP2 detection in glial cells of the white matter. Glial fibrillary acidic protein (GFAP) expression was also reduced in RTT brain samples without obvious change in myelin basic protein (MBP). Neurons did not show any noticeable decrease in MeCP2 detection. BDNF immunohistochemical detection showed an astroglial/endothelial pattern without noticeable difference between RTT and controls. CONCLUSIONS Our findings indicate that MeCP2 protein is widely expressed in mature human brain cells at all ages. However, our data points towards a possible white matter abnormality in RTT and highlights the importance of studying human RTT brain tissues in parallel with research on animal and cell models of RTT.
Collapse
Affiliation(s)
- S Pejhan
- Regenerative Medicine Program, and Department of Biochemistry and Medical Genetics, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - V M Siu
- Division of Medical Genetics, Department of Paediatrics, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - L C Ang
- Department of Pathology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - M R Del Bigio
- Department of Pathology, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - M Rastegar
- Regenerative Medicine Program, and Department of Biochemistry and Medical Genetics, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| |
Collapse
|
16
|
Brindisi M, Saraswati AP, Brogi S, Gemma S, Butini S, Campiani G. Old but Gold: Tracking the New Guise of Histone Deacetylase 6 (HDAC6) Enzyme as a Biomarker and Therapeutic Target in Rare Diseases. J Med Chem 2019; 63:23-39. [PMID: 31415174 DOI: 10.1021/acs.jmedchem.9b00924] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Epigenetic regulation orchestrates many cellular processes and greatly influences key disease mechanisms. Histone deacetylase (HDAC) enzymes play a crucial role either as biomarkers or therapeutic targets owing to their involvement in specific pathophysiological pathways. Beyond their well-characterized role as histone modifiers, HDACs also interact with several nonhistone substrates and their increased expression has been highlighted in specific diseases. The HDAC6 isoform, due to its unique cytoplasmic localization, modulates the acetylation status of tubulin, HSP90, TGF-β, and peroxiredoxins. HDAC6 also exerts noncatalytic activities through its interaction with ubiquitin. Both catalytic and noncatalytic functions of HDACs are being actively studied in the field of specific rare disorders beyond the well-established role in carcinogenesis. This Perspective outlines the application of HDAC(6) inhibitors in rare diseases, such as Rett syndrome, inherited retinal disorders, idiopathic pulmonary fibrosis, and Charcot-Marie-Tooth disease, highlighting their therapeutic potential as innovative and targeted disease-modifying agents.
Collapse
Affiliation(s)
- Margherita Brindisi
- Department of Pharmacy, Department of Excellence 2018-2022 , University of Naples Federico II , Via D. Montesano 49 , I-80131 Naples , Italy
| | - A Prasanth Saraswati
- Department of Biotechnology, Chemistry and Pharmacy, Department of Excellence 2018-2022 , University of Siena , via Aldo Moro 2 , 53100 , Siena , Italy
| | - Simone Brogi
- Department of Pharmacy , University of Pisa , via Bonanno 6 , 56126 , Pisa , Italy
| | - Sandra Gemma
- Department of Biotechnology, Chemistry and Pharmacy, Department of Excellence 2018-2022 , University of Siena , via Aldo Moro 2 , 53100 , Siena , Italy
| | - Stefania Butini
- Department of Biotechnology, Chemistry and Pharmacy, Department of Excellence 2018-2022 , University of Siena , via Aldo Moro 2 , 53100 , Siena , Italy
| | - Giuseppe Campiani
- Department of Biotechnology, Chemistry and Pharmacy, Department of Excellence 2018-2022 , University of Siena , via Aldo Moro 2 , 53100 , Siena , Italy
| |
Collapse
|
17
|
Faundez V, Wynne M, Crocker A, Tarquinio D. Molecular Systems Biology of Neurodevelopmental Disorders, Rett Syndrome as an Archetype. Front Integr Neurosci 2019; 13:30. [PMID: 31379529 PMCID: PMC6650571 DOI: 10.3389/fnint.2019.00030] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 07/02/2019] [Indexed: 12/17/2022] Open
Abstract
Neurodevelopmental disorders represent a challenging biological and medical problem due to their genetic and phenotypic complexity. In many cases, we lack the comprehensive understanding of disease mechanisms necessary for targeted therapeutic development. One key component that could improve both mechanistic understanding and clinical trial design is reliable molecular biomarkers. Presently, no objective biological markers exist to evaluate most neurodevelopmental disorders. Here, we discuss how systems biology and "omic" approaches can address the mechanistic and biomarker limitations in these afflictions. We present heuristic principles for testing the potential of systems biology to identify mechanisms and biomarkers of disease in the example of Rett syndrome, a neurodevelopmental disorder caused by a well-defined monogenic defect in methyl-CpG-binding protein 2 (MECP2). We propose that such an approach can not only aid in monitoring clinical disease severity but also provide a measure of target engagement in clinical trials. By deepening our understanding of the "big picture" of systems biology, this approach could even help generate hypotheses for drug development programs, hopefully resulting in new treatments for these devastating conditions.
Collapse
Affiliation(s)
- Victor Faundez
- Department of Cell Biology, Emory University, Atlanta, GA, United States
| | - Meghan Wynne
- Department of Cell Biology, Emory University, Atlanta, GA, United States
| | - Amanda Crocker
- Program in Neuroscience, Middlebury College, Middlebury, VT, United States
| | - Daniel Tarquinio
- Rare Neurological Diseases (Private Research Institution), Atlanta, GA, United States
| |
Collapse
|
18
|
Bertoldi ML, Zalosnik MI, Fabio MC, Aja S, Roth GA, Ronnett GV, Degano AL. MeCP2 Deficiency Disrupts Kainate-Induced Presynaptic Plasticity in the Mossy Fiber Projections in the Hippocampus. Front Cell Neurosci 2019; 13:286. [PMID: 31333414 PMCID: PMC6619486 DOI: 10.3389/fncel.2019.00286] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Accepted: 06/13/2019] [Indexed: 01/19/2023] Open
Abstract
Methyl cytosine binding protein 2 (MeCP2) is a structural chromosomal protein involved in the regulation of gene expression. Mutations in the gene encoding MeCP2 result in Rett Syndrome (RTT), a pervasive neurodevelopmental disorder. RTT is one of few autism spectrum disorders whose cause was identified as a single gene mutation. Remarkably, abnormal levels of MeCP2 have been associated to other neurodevelopmental disorders, as well as neuropsychiatric disorders. Therefore, many studies have been oriented to investigate the role of MeCP2 in the nervous system. In the present work, we explore cellular and molecular mechanisms affecting synaptic plasticity events in vivo in the hippocampus of MeCP2 mutant mice. While most studies addressed postsynaptic defects in the absence of MeCP2, we took advantage of an in vivo activity-paradigm (seizures), two models of MeCP2 deficiency, and neurobiological assays to reveal novel defects in presynaptic structural plasticity in the hippocampus in RTT rodent models. These approaches allowed us to determine that MeCP2 mutations alter presynaptic components, i.e., disrupts the plastic response of mossy fibers to synaptic activity and results in reduced axonal growth which is correlated with imbalanced trophic and guidance support, associated with aberrant expression of brain-derived neurotrophic factor and semaphorin 3F. Our results also revealed that adult-born granule cells recapitulate maturational defects that have been only shown at early postnatal ages. As these cells do not mature timely, they may not integrate properly into the adult hippocampal circuitry. Finally, we performed a hippocampal-dependent test that revealed defective spatial memory in these mice. Altogether, our studies establish a model that allows us to evaluate the effect of the manipulation of specific pathways involved in axonal guidance, synaptogenesis, or maturation in specific circuits and correlate it with changes in behavior. Understanding the mechanisms underlying the neuronal compromise caused by mutations in MeCP2 could provide information on the pathogenic mechanism of autistic spectrum disorders and improve our understanding of brain development and molecular basis of behavior.
Collapse
Affiliation(s)
- Maria Laura Bertoldi
- Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Córdoba, Argentina.,Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Maria Ines Zalosnik
- Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Córdoba, Argentina.,Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Maria Carolina Fabio
- Instituto de Investigaciones Médicas Mercedes y Martin Ferreyra (INIMEC), CONICET, Córdoba, Argentina
| | - Susan Aja
- Center for Metabolism and Obesity Research, Johns Hopkins Medicine, Baltimore, MD, United States
| | - German A Roth
- Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Córdoba, Argentina.,Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Gabriele V Ronnett
- Center for Metabolism and Obesity Research, Johns Hopkins Medicine, Baltimore, MD, United States.,Department of Neuroscience, The Johns Hopkins University, School of Medicine, Baltimore, MD, United States
| | - Alicia L Degano
- Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Córdoba, Argentina.,Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina
| |
Collapse
|
19
|
Sanfeliu A, Hokamp K, Gill M, Tropea D. Transcriptomic Analysis of Mecp2 Mutant Mice Reveals Differentially Expressed Genes and Altered Mechanisms in Both Blood and Brain. Front Psychiatry 2019; 10:278. [PMID: 31110484 PMCID: PMC6501143 DOI: 10.3389/fpsyt.2019.00278] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 04/11/2019] [Indexed: 12/11/2022] Open
Abstract
Rett syndrome is a rare neuropsychiatric disorder with a wide symptomatology including impaired communication and movement, cardio-respiratory abnormalities, and seizures. The clinical presentation is typically associated to mutations in the gene coding for the methyl-CpG-binding protein 2 (MECP2), which is a transcription factor. The gene is ubiquitously present in all the cells of the organism with a peak of expression in neurons. For this reason, most of the studies in Rett models have been performed in brain. However, some of the symptoms of Rett are linked to the peripheral expression of MECP2, suggesting that the effects of the mutations affect gene expression levels in tissues other than the brain. We used RNA sequencing in Mecp2 mutant mice and matched controls, to identify common genes and pathways differentially regulated across different tissues. We performed our study in brain and peripheral blood, and we identified differentially expressed genes (DEGs) and pathways in each tissue. Then, we compared the genes and mechanisms identified in each preparation. We found that some genes and molecular pathways that are differentially expressed in brain are also differentially expressed in blood of Mecp2 mutant mice at a symptomatic-but not presymptomatic-stage. This is the case for the gene Ube2v1, linked to ubiquitination system, and Serpin1, involved in complement and coagulation cascades. Analysis of biological functions in the brain shows the enrichment of mechanisms correlated to circadian rhythms, while in the blood are enriched the mechanisms of response to stimulus-including immune response. Some mechanisms are enriched in both preparations, such as lipid metabolism and response to stress. These results suggest that analysis of peripheral blood can reveal ubiquitous altered molecular mechanisms of Rett and have applications in diagnosis and treatments' assessments.
Collapse
Affiliation(s)
- Albert Sanfeliu
- Neuropsychiatric Genetics, Department of Psychiatry, School of Medicine, Trinity Translational Medicine Institute, St James Hospital, Dublin, Ireland
| | - Karsten Hokamp
- Department of Genetics, School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - Michael Gill
- Neuropsychiatric Genetics, Department of Psychiatry, School of Medicine, Trinity Translational Medicine Institute, St James Hospital, Dublin, Ireland
| | - Daniela Tropea
- Neuropsychiatric Genetics, Department of Psychiatry, School of Medicine, Trinity Translational Medicine Institute, St James Hospital, Dublin, Ireland
- Department of Psychiatry, School of Medicine, Trinity College Institute for Neuroscience, Trinity College Dublin, Dublin, Ireland
| |
Collapse
|
20
|
Tarquinio DC, Hou W, Neul JL, Berkmen GK, Drummond J, Aronoff E, Harris J, Lane JB, Kaufmann WE, Motil KJ, Glaze DG, Skinner SA, Percy AK. The course of awake breathing disturbances across the lifespan in Rett syndrome. Brain Dev 2018; 40:515-529. [PMID: 29657083 PMCID: PMC6026556 DOI: 10.1016/j.braindev.2018.03.010] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 02/15/2018] [Accepted: 03/27/2018] [Indexed: 11/16/2022]
Abstract
Rett syndrome (RTT), an X-linked dominant neurodevelopmental disorder caused by mutations in MECP2, is associated with a peculiar breathing disturbance exclusively during wakefulness that is distressing, and can even prompt emergency resuscitation. Through the RTT Natural History Study, we characterized cross sectional and longitudinal characteristics of awake breathing abnormalities in RTT and identified associated clinical features. Participants were recruited from 2006 to 2015, and cumulative lifetime prevalence of breathing dysfunction was determined using the Kaplan-Meier estimator. Risk factors were assessed using logistic regression. Of 1205 participants, 1185 had sufficient data for analysis, including 922 females with classic RTT, 778 of whom were followed longitudinally for up to 9.0 years, for a total of 3944 person-years. Participants with classic or atypical severe RTT were more likely to have breathing dysfunction (nearly 100% over the lifespan) compared to those with atypical mild RTT (60-70%). Remission was common, lasting 1 year on average, with 15% ending the study in terminal remission. Factors associated with higher odds of severe breathing dysfunction included poor gross and fine motor function, frequency of stereotypical hand movements, seizure frequency, prolonged corrected QT interval on EKG, and two quality of life metrics: caregiver concern about physical health and contracting illness. Factors associated with lower prevalence of severe breathing dysfunction included higher body mass index and head circumference Z-scores, advanced age, and severe scoliosis or contractures. Awake breathing dysfunction is common in RTT, more so than seizures, and is associated with function, quality of life and risk for cardiac dysrhythmia.
Collapse
Affiliation(s)
- Daniel C. Tarquinio
- Emory University, Atlanta, GA,Center for Rare Neurological Diseases, Norcross, GA
| | - Wei Hou
- Statistical analysis, Stony Brook University Medical Center, Stony Brook, NY
| | | | - Gamze Kilic Berkmen
- Emory University, Atlanta, GA,Center for Rare Neurological Diseases, Norcross, GA
| | - Jana Drummond
- Emory University, Atlanta, GA,Center for Rare Neurological Diseases, Norcross, GA
| | - Elizabeth Aronoff
- Emory University, Atlanta, GA,Center for Rare Neurological Diseases, Norcross, GA
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Schulte JT, Wierenga CJ, Bruining H. Chloride transporters and GABA polarity in developmental, neurological and psychiatric conditions. Neurosci Biobehav Rev 2018; 90:260-271. [PMID: 29729285 DOI: 10.1016/j.neubiorev.2018.05.001] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 03/20/2018] [Accepted: 05/01/2018] [Indexed: 12/22/2022]
Abstract
Neuronal chloride regulation is a determinant factor for the dynamic tuning of GABAergic inhibition during and beyond brain development. This regulation is mainly dependent on the two co-transporters K+/Cl- co-transporter KCC2 and Na+/K+/Cl- co-transporter NKCC1, whose activity can decrease or increase neuronal chloride concentrations respectively. Altered expression and/or activity of either of these co-transporters has been associated with a wide variety of brain disorders including developmental disorders, epilepsy, schizophrenia and stroke. Here, we review current knowledge on chloride transporter expression and activity regulation and highlight the intriguing potential for existing and future interventions to support chloride homeostasis across a wide range of mental disorders and neurological conditions.
Collapse
Affiliation(s)
- Joran T Schulte
- Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Center, Heidelberglaan 100, 3508 GA Utrecht The Netherlands
| | - Corette J Wierenga
- Division of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Hilgo Bruining
- Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Center, Heidelberglaan 100, 3508 GA Utrecht The Netherlands.
| |
Collapse
|
22
|
Gogliotti RG, Fisher NM, Stansley BJ, Jones CK, Lindsley CW, Conn PJ, Niswender CM. Total RNA Sequencing of Rett Syndrome Autopsy Samples Identifies the M 4 Muscarinic Receptor as a Novel Therapeutic Target. J Pharmacol Exp Ther 2018; 365:291-300. [PMID: 29523700 PMCID: PMC5878667 DOI: 10.1124/jpet.117.246991] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 03/08/2018] [Indexed: 02/04/2023] Open
Abstract
Mutations in the MeCP2 gene are responsible for the neurodevelopmental disorder Rett syndrome (RTT). MeCP2 is a DNA-binding protein whose abundance and ability to complex with histone deacetylase 3 is linked to the regulation of chromatin structure. Consequently, loss-of-function mutations in MeCP2 are predicted to have broad effects on gene expression. However, to date, studies in mouse models of RTT have identified a limited number of gene or pathway-level disruptions, and even fewer genes have been identified that could be considered amenable to classic drug discovery approaches. Here, we performed RNA sequencing (RNA-seq) on nine motor cortex and six cerebellar autopsy samples from RTT patients and controls. This approach identified 1887 significantly affected genes in the motor cortex and 2110 genes in the cerebellum, with a global trend toward increased expression. Pathway-level analysis identified enrichment in genes associated with mitogen-activated protein kinase signaling, long-term potentiation, and axon guidance. A survey of our RNA-seq results also identified a significant decrease in expression of the CHRM4 gene, which encodes a receptor [muscarinic acetylcholine receptor 4 (M4)] that is the subject of multiple large drug discovery efforts for schizophrenia and Alzheimer's disease. We confirmed that CHRM4 expression was decreased in RTT patients, and, excitingly, we demonstrated that M4 potentiation normalizes social and cognitive phenotypes in Mecp2+/- mice. This work provides an experimental paradigm in which translationally relevant targets can be identified using transcriptomics in RTT autopsy samples, back-modeled in Mecp2+/- mice, and assessed for preclinical efficacy using existing pharmacological tool compounds.
Collapse
Affiliation(s)
- Rocco G Gogliotti
- Departments of Pharmacology (R.G.G., N.M.F., B.J.S., C.K.J., C.W.L., P.J.C., C.M.N.) and Chemistry (C.W.L.), and Vanderbilt Center for Neuroscience Drug Discovery (R.G.G., N.M.F., B.J.S., C.K.J., C.W.L., P.J.C., C.M.N.), Vanderbilt University, Nashville, Tennessee; and Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (P.J.C., C.M.N.)
| | - Nicole M Fisher
- Departments of Pharmacology (R.G.G., N.M.F., B.J.S., C.K.J., C.W.L., P.J.C., C.M.N.) and Chemistry (C.W.L.), and Vanderbilt Center for Neuroscience Drug Discovery (R.G.G., N.M.F., B.J.S., C.K.J., C.W.L., P.J.C., C.M.N.), Vanderbilt University, Nashville, Tennessee; and Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (P.J.C., C.M.N.)
| | - Branden J Stansley
- Departments of Pharmacology (R.G.G., N.M.F., B.J.S., C.K.J., C.W.L., P.J.C., C.M.N.) and Chemistry (C.W.L.), and Vanderbilt Center for Neuroscience Drug Discovery (R.G.G., N.M.F., B.J.S., C.K.J., C.W.L., P.J.C., C.M.N.), Vanderbilt University, Nashville, Tennessee; and Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (P.J.C., C.M.N.)
| | - Carrie K Jones
- Departments of Pharmacology (R.G.G., N.M.F., B.J.S., C.K.J., C.W.L., P.J.C., C.M.N.) and Chemistry (C.W.L.), and Vanderbilt Center for Neuroscience Drug Discovery (R.G.G., N.M.F., B.J.S., C.K.J., C.W.L., P.J.C., C.M.N.), Vanderbilt University, Nashville, Tennessee; and Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (P.J.C., C.M.N.)
| | - Craig W Lindsley
- Departments of Pharmacology (R.G.G., N.M.F., B.J.S., C.K.J., C.W.L., P.J.C., C.M.N.) and Chemistry (C.W.L.), and Vanderbilt Center for Neuroscience Drug Discovery (R.G.G., N.M.F., B.J.S., C.K.J., C.W.L., P.J.C., C.M.N.), Vanderbilt University, Nashville, Tennessee; and Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (P.J.C., C.M.N.)
| | - P Jeffrey Conn
- Departments of Pharmacology (R.G.G., N.M.F., B.J.S., C.K.J., C.W.L., P.J.C., C.M.N.) and Chemistry (C.W.L.), and Vanderbilt Center for Neuroscience Drug Discovery (R.G.G., N.M.F., B.J.S., C.K.J., C.W.L., P.J.C., C.M.N.), Vanderbilt University, Nashville, Tennessee; and Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (P.J.C., C.M.N.)
| | - Colleen M Niswender
- Departments of Pharmacology (R.G.G., N.M.F., B.J.S., C.K.J., C.W.L., P.J.C., C.M.N.) and Chemistry (C.W.L.), and Vanderbilt Center for Neuroscience Drug Discovery (R.G.G., N.M.F., B.J.S., C.K.J., C.W.L., P.J.C., C.M.N.), Vanderbilt University, Nashville, Tennessee; and Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (P.J.C., C.M.N.)
| |
Collapse
|
23
|
Li W, Bellot-Saez A, Phillips ML, Yang T, Longo FM, Pozzo-Miller L. A small-molecule TrkB ligand restores hippocampal synaptic plasticity and object location memory in Rett syndrome mice. Dis Model Mech 2018; 10:837-845. [PMID: 28679669 PMCID: PMC5536912 DOI: 10.1242/dmm.029959] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 05/08/2017] [Indexed: 01/06/2023] Open
Abstract
Rett syndrome (RTT) is a neurodevelopmental disorder caused by mutations in methyl-CpG-binding protein-2 (MECP2), a transcriptional regulator of many genes, including brain-derived neurotrophic factor (BDNF). BDNF levels are reduced in RTT autopsy brains and in multiple brain areas of Mecp2-deficient mice. Furthermore, experimental interventions that increase BDNF levels improve RTT-like phenotypes in Mecp2 mutant mice. Here, we characterized the actions of a small-molecule ligand of the BDNF receptor TrkB in hippocampal function in Mecp2 mutant mice. Systemic treatment of female Mecp2 heterozygous (HET) mice with LM22A-4 for 4 weeks improved hippocampal-dependent object location memory and restored hippocampal long-term potentiation (LTP). Mechanistically, LM22A-4 acts to dampen hyperactive hippocampal network activity, reduce the frequency and amplitude of miniature excitatory postsynaptic currents (mEPSCs), and reduce the frequency of spontaneous tetrodotoxin-resistant Ca2+ signals in Mecp2 mutant hippocampal neurons, making them comparable to those features observed in wild-type neurons. Together, these observations indicate that LM22A-4 is a promising therapeutic candidate for the treatment of hippocampal dysfunction in RTT. Editors' choice: The brain-penetrant BDNF loop domain mimetic LM22A-4 improves synaptic plasticity and spatial discrimination memory in Rett syndrome mice, making it a promising therapeutic candidate for the treatment of hippocampal dysfunction.
Collapse
Affiliation(s)
- Wei Li
- Department of Neurobiology, Civitan International Research Center, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Alba Bellot-Saez
- Department of Neurobiology, Civitan International Research Center, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Mary L Phillips
- Department of Neurobiology, Civitan International Research Center, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Tao Yang
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Frank M Longo
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Lucas Pozzo-Miller
- Department of Neurobiology, Civitan International Research Center, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| |
Collapse
|
24
|
Wang HQ, Zhang M, Zhao JX, Wu HQ, Gao Z, Zhang GL, Zhang R. Puerarin Up-regulates Methyl-CpG Binding Protein 2 Phosphorylation in Hippocampus of Vascular Dementia Rats. Chin J Integr Med 2018; 24:372-377. [PMID: 29327124 DOI: 10.1007/s11655-018-2822-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To observe the effect of puerarin on methyl-CpG binding protein 2 (MeCP2) phosphorylation (pMeCP2) in the hippocampus of a rat model of vascular dementia (VD). METHODS Thirty-six healthy Sprague-Dawley rats were randomly assigned to the sham-operated group, dementia group and puerarintreated group using a random number table (n=12 per group). The modifified permanent bilateral common carotid artery occlusion method was used to establish the VD model. The sham-operated and dementia groups were given 2 mL/d of saline, while the puerarin-treated group was given 100 mg/(kg•d) of puerarin for 17 days. The learning and memory abilities were evaluated by the Morris water maze test. Hematoxylin-eosin staining, immunohistochemical (IHC) staining and Western blot analysis were carried out to observe changes in neuron morphology and in level of pMeCP2 in the hippocampus, respectively. RESULTS The morphologies of rat hippocampal neurons in the puerarintreated group were markedly improved compared with the dementia group. The escape latency of the dementia group was significantly longer than the sham-operated group (P<0.05), while the puerarin-treated group was obviously shorter than the dementia group (P<0.05). Cross-platform times of the dementia group were signifificantly decreased compared with the sham-operated group (P<0.05), while the puerarin-treated group was obviously increased compared with the dementia group (P<0.05). IHC staining showed no significant difference in the number of MeCP2 positive cells among 3 groups (P>0.05). The number of pMeCP2 positive cells in the CA1 region of hippocampus in the dementia group was signifificantly increased compared with the sham-operated group, and the puerarin-treated group was signifificantly increased compared with the dementia group (both P<0.05). Western blot analysis showed no signifificant difference of MeCP2 expression among 3 groups (P>0.05). The expression of pMeCP2 in the dementia group was signifificantly increased compared with the sham-operated group, while it in the puerarin-treated group was signifificantly increased compared with the dementia group (P<0.05). CONCLUSION Puerarin could play a role in the protection of nerve cells through up-regulating pMeCP2 in the hippocampus, improving neuron morphologies, and enhancing learning and memory ablities in a rat model of VD.
Collapse
Affiliation(s)
- Hu-Qing Wang
- Department of Neurology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710004, China
| | - Meng Zhang
- Department of Neurology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710004, China
| | - Jia-Xin Zhao
- Department of Neurology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710004, China
| | - Hai-Qin Wu
- Department of Neurology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710004, China.
| | - Zhen Gao
- Department of Neurology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710004, China
| | - Gui-Lian Zhang
- Department of Neurology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710004, China
| | - Ru Zhang
- Department of Neurology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710004, China
| |
Collapse
|
25
|
Jiang C, Cui N, Zhong W, Johnson CM, Wu Y. Breathing abnormalities in animal models of Rett syndrome a female neurogenetic disorder. Respir Physiol Neurobiol 2017; 245:45-52. [PMID: 27884797 PMCID: PMC5438903 DOI: 10.1016/j.resp.2016.11.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 11/17/2016] [Accepted: 11/20/2016] [Indexed: 02/08/2023]
Abstract
A characteristic feature of Rett syndrome (RTT) is abnormal breathing accompanied by several other neurological and cognitive disorders. Since RTT rodent models became available, studies have begun shedding insight into the breathing abnormalities at behavioral, cellular and molecular levels. Defects are found in several groups of brainstem neurons involved in respiratory control, and potential neural mechanisms have been suggested. The findings in animal models are helpful in therapeutic strategies for people with RTT with respect to lowering sudden and unexpected death, preventing secondary developmental consequences, and improving the quality of lives.
Collapse
Affiliation(s)
- Chun Jiang
- Department of Biology, Georgia State University, Atlanta, USA.
| | - Ningren Cui
- Department of Biology, Georgia State University, Atlanta, USA
| | - Weiwei Zhong
- Department of Biology, Georgia State University, Atlanta, USA
| | | | - Yang Wu
- Department of Biology, Georgia State University, Atlanta, USA
| |
Collapse
|
26
|
Xu X, Garcia J, Ewalt R, Nason S, Pozzo-Miller L. The BDNF val-66-met Polymorphism Affects Neuronal Morphology and Synaptic Transmission in Cultured Hippocampal Neurons from Rett Syndrome Mice. Front Cell Neurosci 2017; 11:203. [PMID: 28751857 PMCID: PMC5508027 DOI: 10.3389/fncel.2017.00203] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 06/27/2017] [Indexed: 12/02/2022] Open
Abstract
Brain-derived neurotrophic factor (Bdnf) has been implicated in several neurological disorders including Rett syndrome (RTT), an X-linked neurodevelopmental disorder caused by loss-of-function mutations in the transcriptional modulator methyl-CpG-binding protein 2 (MECP2). The human BDNF gene has a single nucleotide polymorphism (SNP)—a methionine (met) substitution for valine (val) at codon 66—that affects BDNF’s trafficking and activity-dependent release and results in cognitive dysfunction. Humans that are carriers of the met-BDNF allele have subclinical memory deficits and reduced hippocampal volume and activation. It is still unclear whether this BDNF SNP affects the clinical outcome of RTT individuals. To evaluate whether this BDNF SNP contributes to RTT pathophysiology, we examined the consequences of expression of either val-BDNF or met-BDNF on dendrite and dendritic spine morphology, and synaptic function in cultured hippocampal neurons from wildtype (WT) and Mecp2 knockout (KO) mice. Our findings revealed that met-BDNF does not increase dendritic growth and branching, dendritic spine density and individual spine volume, and the number of excitatory synapses in WT neurons, as val-BDNF does. Furthermore, met-BDNF reduces dendritic complexity, dendritic spine volume and quantal excitatory synaptic transmission in Mecp2 KO neurons. These results suggest that the val-BDNF variant contributes to RTT pathophysiology, and that BDNF-based therapies should take into consideration the BDNF genotype of the RTT individuals.
Collapse
Affiliation(s)
- Xin Xu
- Department of Neurobiology, Civitan International Research Center, University of Alabama at BirminghamBirmingham, AL, United States
| | - Jordi Garcia
- Department of Neurobiology, Civitan International Research Center, University of Alabama at BirminghamBirmingham, AL, United States
| | - Rachel Ewalt
- Department of Neurobiology, Civitan International Research Center, University of Alabama at BirminghamBirmingham, AL, United States
| | - Shelly Nason
- Department of Neurobiology, Civitan International Research Center, University of Alabama at BirminghamBirmingham, AL, United States
| | - Lucas Pozzo-Miller
- Department of Neurobiology, Civitan International Research Center, University of Alabama at BirminghamBirmingham, AL, United States
| |
Collapse
|
27
|
Khorshid Ahmad T, Zhou T, AlTaweel K, Cortes C, Lillico R, Lakowski TM, Gozda K, Namaka MP. Experimental Autoimmune Encephalomyelitis (EAE)-Induced Elevated Expression of the E1 Isoform of Methyl CpG Binding Protein 2 (MeCP2E1): Implications in Multiple Sclerosis (MS)-Induced Neurological Disability and Associated Myelin Damage. Int J Mol Sci 2017; 18:ijms18061254. [PMID: 28604632 PMCID: PMC5486076 DOI: 10.3390/ijms18061254] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 04/15/2017] [Accepted: 05/13/2017] [Indexed: 12/26/2022] Open
Abstract
Multiple sclerosis (MS) is a chronic neurological disease characterized by the destruction of central nervous system (CNS) myelin. At present, there is no cure for MS due to the inability to repair damaged myelin. Although the neurotrophin brain derived neurotrophic factor (BDNF) has a beneficial role in myelin repair, these effects may be hampered by the over-expression of a transcriptional repressor isoform of methyl CpG binding protein 2 (MeCP2) called MeCP2E1. We hypothesize that following experimental autoimmune encephalomyelitis (EAE)-induced myelin damage, the immune system induction of the pathogenic MeCP2E1 isoform hampers the myelin repair process by repressing BDNF expression. Using an EAE model of MS, we identify the temporal gene and protein expression changes of MeCP2E1, MeCP2E2 and BDNF. The expression changes of these key biological targets were then correlated with the temporal changes in neurological disability scores (NDS) over the entire disease course. Our results indicate that MeCP2E1 mRNA levels are elevated in EAE animals relative to naïve control (NC) and active control (AC) animals during all time points of disease progression. Our results suggest that the EAE-induced elevations in MeCP2E1 expression contribute to the repressed BDNF production in the spinal cord (SC). The sub-optimal levels of BDNF result in sustained NDS and associated myelin damage throughout the entire disease course. Conversely, we observed no significant differences in the expression patterns displayed for the MeCP2E2 isoform amongst our experimental groups. However, our results demonstrate that baseline protein expression ratios between the MeCP2E1 versus MeCP2E2 isoforms in the SC are higher than those identified within the dorsal root ganglia (DRG). Thus, the DRG represents a more conducive environment than that of the SC for BDNF production and transport to the CNS to assist in myelin repair. Henceforth, the sub-optimal BDNF levels we report in the SC may arise from the elevated MeCP2E1 vs. MeCP2E2 ratio in the SC that creates a more hostile environment thereby preventing local BDNF production. At the level of transcript, we demonstrate that EAE-induces the pathological enhanced expression of MeCP2E1 that contributes to enhanced NDS during the entire disease course. Thus, the pathological induction of the MeCP2E1 isoform contributes to the disruption of the normal homeostatic signaling equilibrium network that exists between cytokines, neurotrophins and chemokines that regulate the myelin repair process by repressing BDNF. Our research suggests that the elevated ratio of MeCP2E1 relative to MeCP2E2 may be a useful diagnostic marker that clinicians can utilize to determine the degree of neurological disability with associated myelin damage. The elevated MeCP2E1 vs. MeCP2E2 ratios (E1/E2) in the SC prevent BDNF from reaching optimal levels required for myelin repair. Thus, the lower E1/E2 ratios in the DRG, allow the DRG to serve as a weak secondary compensatory mechanism for enhanced production and delivery of BDNF to the SC to try to assist in myelin repair.
Collapse
Affiliation(s)
- Tina Khorshid Ahmad
- College of Pharmacy, Faculty of Health Sciences, University of Manitoba, Manitoba, Winnipeg, MB R3E 0T5, Canada.
| | - Ting Zhou
- College of Pharmacy, Faculty of Health Sciences, University of Manitoba, Manitoba, Winnipeg, MB R3E 0T5, Canada.
| | - Khaled AlTaweel
- College of Pharmacy, Faculty of Health Sciences, University of Manitoba, Manitoba, Winnipeg, MB R3E 0T5, Canada.
| | - Claudia Cortes
- College of Pharmacy, Faculty of Health Sciences, University of Manitoba, Manitoba, Winnipeg, MB R3E 0T5, Canada.
| | - Ryan Lillico
- College of Pharmacy, Faculty of Health Sciences, University of Manitoba, Manitoba, Winnipeg, MB R3E 0T5, Canada.
| | - Ted Martin Lakowski
- College of Pharmacy, Faculty of Health Sciences, University of Manitoba, Manitoba, Winnipeg, MB R3E 0T5, Canada.
| | - Kiana Gozda
- College of Pharmacy, Faculty of Health Sciences, University of Manitoba, Manitoba, Winnipeg, MB R3E 0T5, Canada.
| | - Michael Peter Namaka
- College of Pharmacy, Faculty of Health Sciences, University of Manitoba, Manitoba, Winnipeg, MB R3E 0T5, Canada.
- College of Pharmacy, Third Military Medical University, Chongqing 400038, China.
- Department of Medical Rehabilitation, College of Medicine, Faculty of Health Sciences, Winnipeg, MB R3E 0T6, Canada.
- Department of Internal Medicine, College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3A 1R9, Canada.
| |
Collapse
|
28
|
A Potential Life-Threatening Reaction to Glatiramer Acetate in Rett Syndrome. Pediatr Neurol 2017; 68:40-43. [PMID: 28254244 DOI: 10.1016/j.pediatrneurol.2016.11.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 11/23/2016] [Indexed: 11/20/2022]
Abstract
BACKGROUND Rett syndrome is an X-linked dominant neurodevelopmental disorder manifesting with severe intellectual disability in females caused by various mutations in the MECP2 gene. Brain-derived neurotrophic factor (BDNF) is one of the main proteins regulated by the MECP2 protein; its overexpression in the MeCP2 mouse model partially corrects the Rett phenotype. Pharmacologic manipulations that lead to increased BDNF in individuals with Rett syndrome are expected to have a positive effect on the disorder. Glatiramer acetate, a well-known and safe multiple sclerosis immune modulator, increases BDNF levels in multiple sclerosis animal models and patients responding to treatment, as well as in Rett mouse models. METHODS Fourteen patients with mutation-proven Rett syndrome were recruited for a clinical trial with glatiramer acetate. Baseline data and follow-up data were collected during the trial, which had to be stopped because of a severe adverse event. Our objective is to describe this unexpected potentially life-threatening event in response to glatiramer in patients with Rett syndrome. RESULTS Four of 14 patients with Rett syndrome who were recruited and treated with daily injections of glatiramer acetate as part of an open-label clinical trial developed an exaggerated immediate postinjection response, which was experienced as life threatening in three of the patients, necessitating arrest of the trial. CONCLUSION Despite the known safety profile of glatiramer acetate in adult and pediatric patients with multiple sclerosis, its use in Rett syndrome should be cautiously reconsidered. The described severe adverse event can be related to these patients' primary autonomic nervous system dysfunction.
Collapse
|
29
|
Neurodevelopmental Effects of Serotonin on the Brainstem Respiratory Network. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1015:193-216. [DOI: 10.1007/978-3-319-62817-2_11] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
|
30
|
Neurotrophic Factors in Mouse Models of Autism Spectrum Disorder: Focus on BDNF and IGF-1. TRANSLATIONAL ANATOMY AND CELL BIOLOGY OF AUTISM SPECTRUM DISORDER 2017; 224:121-134. [DOI: 10.1007/978-3-319-52498-6_7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
|
31
|
Sampathkumar C, Wu YJ, Vadhvani M, Trimbuch T, Eickholt B, Rosenmund C. Loss of MeCP2 disrupts cell autonomous and autocrine BDNF signaling in mouse glutamatergic neurons. eLife 2016; 5. [PMID: 27782879 PMCID: PMC5108590 DOI: 10.7554/elife.19374] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 10/25/2016] [Indexed: 12/16/2022] Open
Abstract
Mutations in the MECP2 gene cause the neurodevelopmental disorder Rett syndrome (RTT). Previous studies have shown that altered MeCP2 levels result in aberrant neurite outgrowth and glutamatergic synapse formation. However, causal molecular mechanisms are not well understood since MeCP2 is known to regulate transcription of a wide range of target genes. Here, we describe a key role for a constitutive BDNF feed forward signaling pathway in regulating synaptic response, general growth and differentiation of glutamatergic neurons. Chronic block of TrkB receptors mimics the MeCP2 deficiency in wildtype glutamatergic neurons, while re-expression of BDNF quantitatively rescues MeCP2 deficiency. We show that BDNF acts cell autonomous and autocrine, as wildtype neurons are not capable of rescuing growth deficits in neighboring MeCP2 deficient neurons in vitro and in vivo. These findings are relevant for understanding RTT pathophysiology, wherein wildtype and mutant neurons are intermixed throughout the nervous system. DOI:http://dx.doi.org/10.7554/eLife.19374.001 Rett syndrome is a progressive brain disorder. Individuals with the condition (who are typically girls) grow normally until they are 6-18 months old and then developmentally regress, with symptoms including anxiety, impaired coordination, seizures and breathing problems. Rett syndrome is caused by mutations in the gene that encodes a protein called MeCP2. Researchers know that MeCP2 is vital for “excitatory” neurons in the brain to communicate with (and activate) their neighbors. Neurons that lack MeCP2 tend to make fewer of the connections across which they communicate – called synapses – with others. Many researchers who study Rett syndrome use male mice that lack the MeCP2 protein. This mouse model mimics the symptoms seen in Rett patients, but at a faster and more severe rate. These studies have shown that restoring normal levels of the protein in neurons prevents the majority of Rett-like symptoms in these mice and reverses the disorder. MeCP2 controls the activity of a number of other genes. These include the gene that produces a protein called Brain-Derived Neurotrophic Factor (BDNF), which helps neurons to grow. Sampathkumar et al. have now studied neurons from mouse models of Rett syndrome to investigate whether BDNF can overcome the defects seen in neurons that lack MeCP2. Viewed under a high-powered microscope, the Rett-like neurons appear smaller than healthy neurons and form fewer synapses. However, increasing the amount of BDNF in the diseased neurons restores normal growth and enables the cells to form more synapses. Girls with Rett syndrome tend to have a mixture of healthy neurons and those that do not produce the right amount of MeCP2. To mimic this, Sampathkumar et al. grew a mixture of normal and Rett-like mouse neurons in a culture dish. The healthy neurons did not help the diseased neurons to form the correct number of synapses. However, increasing the levels of BDNF in the Rett-like neurons enhanced their ability to form synapses, and increased their cell size to match their healthy counterparts. Further work is now required to uncover whether manipulating the gene that encodes BDNF – or other genes that MeCP2 controls the activity of – in the brain can reduce the symptoms and slow the progression of Rett syndrome. DOI:http://dx.doi.org/10.7554/eLife.19374.002
Collapse
Affiliation(s)
- Charanya Sampathkumar
- Department of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany.,NeuroCure Cluster of Excellence, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Yuan-Ju Wu
- Department of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany.,NeuroCure Cluster of Excellence, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Mayur Vadhvani
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin Berlin, Berlin, Germany.,Institute of Biochemistry, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Thorsten Trimbuch
- Department of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany.,NeuroCure Cluster of Excellence, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Britta Eickholt
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin Berlin, Berlin, Germany.,Institute of Biochemistry, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Christian Rosenmund
- Department of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany.,NeuroCure Cluster of Excellence, Charité Universitätsmedizin Berlin, Berlin, Germany
| |
Collapse
|
32
|
Djukic A, Holtzer R, Shinnar S, Muzumdar H, Rose SA, Mowrey W, Galanopoulou AS, Shinnar R, Jankowski JJ, Feldman JF, Pillai S, Moshé SL. Pharmacologic Treatment of Rett Syndrome With Glatiramer Acetate. Pediatr Neurol 2016; 61:51-7. [PMID: 27363291 DOI: 10.1016/j.pediatrneurol.2016.05.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Revised: 05/17/2016] [Accepted: 05/20/2016] [Indexed: 10/21/2022]
Abstract
BACKGROUND Rett syndrome (RTT) is a severe neurological disease that primarily affects females. The level of brain derived neurotropic factor (BDNF) expression directly correlates with the severity of RTT related symptoms. Because Glatiramer acetate (GA) stimulates secretion of BDNF in the brain, we conducted the study with the objective to assess its efficacy in improving gait velocity cognition, respiratory function, electroencephalographic findings, and quality of life in patients with RTT. METHODS Phase two, open label, single center trial. INCLUSION CRITERIA ambulatory girls with genetically confirmed RTT, 10 years or older. Pre- and post-treatment measures were compared using the non-parametric Wilcoxon signed rank sum test and paired t-tests. RESULTS Ten patients were enrolled and completed the trial. Gait velocity improved significantly (improvement range 13%-95%, p=0.03 for both tests) and emerged as an especially valuable outcome measure with excellent test- retest reliability of the 2 trials within sessions (intraclass correlation coefficient=0.94). Memory, and the breath holding index also improved significantly (p≤0.03). Epileptiform discharges decreased in all four patients who had them at baseline. There was a trend towards improved quality of life, which did not reach statistical significance. CONCLUSIONS This prospective open-label trial provides important preliminary information related to the efficacy of GA in improving gait velocity in female patients with RTT who are 10 years or older. The results of this trial justify the need for larger scale controlled trials of GA as well as provide a template for assessing the efficacy of other interventions in RTT.
Collapse
Affiliation(s)
- Aleksandra Djukic
- Saul R. Korey Department of Neurology, Albert Einstein College of Medicine, Bronx, New York; Rett Syndrome Center, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York; Department of Pediatrics, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York.
| | - Roee Holtzer
- Saul R. Korey Department of Neurology, Albert Einstein College of Medicine, Bronx, New York; Ferkauf Graduate School of Psychology of Yeshiva University, Bronx, New York
| | - Shlomo Shinnar
- Saul R. Korey Department of Neurology, Albert Einstein College of Medicine, Bronx, New York; Rett Syndrome Center, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York; Department of Pediatrics, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York; Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, New York
| | - Hiren Muzumdar
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Susan A Rose
- Department of Pediatrics, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York
| | - Wenzhu Mowrey
- Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, New York
| | - Aristea S Galanopoulou
- Saul R. Korey Department of Neurology, Albert Einstein College of Medicine, Bronx, New York; Rett Syndrome Center, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York; Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York
| | - Ruth Shinnar
- Saul R. Korey Department of Neurology, Albert Einstein College of Medicine, Bronx, New York
| | - Jeffrey J Jankowski
- Department of Social Sciences, Queensborough Community College, City University of New York, Bayside, New York
| | - Judith F Feldman
- Department of Pediatrics, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York
| | - Sophia Pillai
- Department of Pediatrics, Weill Cornell Medical College, New York, New York
| | - Solomon L Moshé
- Saul R. Korey Department of Neurology, Albert Einstein College of Medicine, Bronx, New York; Rett Syndrome Center, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York; Department of Pediatrics, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York; Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York
| |
Collapse
|
33
|
Bal-Price A, Lein PJ, Keil KP, Sethi S, Shafer T, Barenys M, Fritsche E, Sachana M, Meek MEB. Developing and applying the adverse outcome pathway concept for understanding and predicting neurotoxicity. Neurotoxicology 2016; 59:240-255. [PMID: 27212452 DOI: 10.1016/j.neuro.2016.05.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 05/13/2016] [Accepted: 05/13/2016] [Indexed: 12/12/2022]
Abstract
The Adverse Outcome Pathway (AOP) concept has recently been proposed to support a paradigm shift in regulatory toxicology testing and risk assessment. This concept is similar to the Mode of Action (MOA), in that it describes a sequence of measurable key events triggered by a molecular initiating event in which a stressor interacts with a biological target. The resulting cascade of key events includes molecular, cellular, structural and functional changes in biological systems, resulting in a measurable adverse outcome. Thereby, an AOP ideally provides information relevant to chemical structure-activity relationships as a basis for predicting effects of structurally similar compounds. AOPs could potentially also form the basis for qualitative and quantitative predictive modeling of the human adverse outcome resulting from molecular initiating or other key events for which higher-throughput testing methods are available or can be developed. A variety of cellular and molecular processes are known to be critical for normal function of the central (CNS) and peripheral nervous systems (PNS). Because of the biological and functional complexity of the CNS and PNS, it has been challenging to establish causative links and quantitative relationships between key events that comprise the pathways leading from chemical exposure to an adverse outcome in the nervous system. Following introduction of the principles of MOA and AOPs, examples of potential or putative adverse outcome pathways specific for developmental or adult neurotoxicity are summarized and aspects of their assessment considered. Their possible application in developing mechanistically informed Integrated Approaches to Testing and Assessment (IATA) is also discussed.
Collapse
Affiliation(s)
- Anna Bal-Price
- European Commission Joint Research Centre, Institute for Health and Consumer Protection, Ispra, Italy.
| | - Pamela J Lein
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California Davis, Davis, CA 95616, USA
| | - Kimberly P Keil
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California Davis, Davis, CA 95616, USA
| | - Sunjay Sethi
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California Davis, Davis, CA 95616, USA
| | - Timothy Shafer
- Integrated Systems Toxicology Division, Office of Research and Development, U.S. Environmental Protection Agency, RTP, USA
| | - Marta Barenys
- IUF-Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany
| | - Ellen Fritsche
- IUF-Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany
| | - Magdalini Sachana
- European Commission Joint Research Centre, Institute for Health and Consumer Protection, Ispra, Italy
| | - M E Bette Meek
- McLaughlin Centre for Risk Science, University of Ottawa, Ottawa, Canada
| |
Collapse
|
34
|
Filosa S, Pecorelli A, D'Esposito M, Valacchi G, Hajek J. Exploring the possible link between MeCP2 and oxidative stress in Rett syndrome. Free Radic Biol Med 2015; 88:81-90. [PMID: 25960047 DOI: 10.1016/j.freeradbiomed.2015.04.019] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Revised: 04/10/2015] [Accepted: 04/13/2015] [Indexed: 01/27/2023]
Abstract
Rett syndrome (RTT, MIM 312750) is a rare and orphan progressive neurodevelopmental disorder affecting girls almost exclusively, with a frequency of 1/15,000 live births of girls. The disease is characterized by a period of 6 to 18 months of apparently normal neurodevelopment, followed by early neurological regression, with a progressive loss of acquired cognitive, social, and motor skills. RTT is known to be caused in 95% of the cases by sporadic de novo loss-of-function mutations in the X-linked methyl-CpG-binding protein 2 (MECP2) gene encoding methyl-CpG binding protein 2 (MeCP2), a nuclear protein able to regulate gene expression. Despite almost two decades of research into the functions and role of MeCP2, little is known about the mechanisms leading from MECP2 mutation to the disease. Oxidative stress (OS) is involved in the pathogenic mechanisms of several neurodevelopmental and neurodegenerative disorders, although in many cases it is not clear whether OS is a cause or a consequence of the pathology. Fairly recently, the presence of a systemic OS has been demonstrated in RTT patients with a strong correlation with the patients' clinical status. The link between MECP2 mutation and the redox imbalance found in RTT is not clear. Animal studies have suggested a possible direct correlation between Mecp2 mutation and increased OS levels. In addition, the restoration of Mecp2 function in astrocytes significantly improves the developmental outcome of Mecp2-null mice and reexpression of Mecp2 gene in the brain of null mice restored oxidative damage, suggesting that Mecp2 loss of function can be involved in oxidative brain damage. Starting from the evidence that oxidative damage in the brain of Mecp2-null mice precedes the onset of symptoms, we evaluated whether, based on the current literature, the dysfunctions described in RTT could be a consequence or, in contrast, could be caused by OS. We also analyzed whether therapies that at least partially treated some RTT symptoms can play a role in defense against OS. At this stage we can propose that OS could be one of the main causes of the dysfunctions observed in RTT. In addition, the major part of the therapies recommended to alleviate RTT symptoms have been shown to interfere with oxidative homeostasis, suggesting that MeCP2 could somehow be involved in the protection of the brain from OS.
Collapse
Affiliation(s)
- Stefania Filosa
- Institute of Biosciences and BioResources-CNR, UOS Naples, Italy; IRCCS Neuromed, Pozzilli, Italy
| | - Alessandra Pecorelli
- Child Neuropsychiatry Unit, University General Hospital, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Maurizio D'Esposito
- Institute of Genetics and Biophysics "A. Buzzati-Traverso"-CNR, Naples, Italy; IRCCS Neuromed, Pozzilli, Italy
| | - Giuseppe Valacchi
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy; Department of Food and Nutrition, Kyung Hee University, Seoul, South Korea.
| | - Joussef Hajek
- Child Neuropsychiatry Unit, University General Hospital, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| |
Collapse
|
35
|
Manners MT, Tian Y, Zhou Z, Ajit SK. MicroRNAs downregulated in neuropathic pain regulate MeCP2 and BDNF related to pain sensitivity. FEBS Open Bio 2015; 5:733-40. [PMID: 26448907 PMCID: PMC4571540 DOI: 10.1016/j.fob.2015.08.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Revised: 08/11/2015] [Accepted: 08/16/2015] [Indexed: 12/31/2022] Open
Abstract
Nerve injury induces chronic pain and dysregulation of microRNAs in dorsal root ganglia (DRG). Several downregulated microRNAs are predicted to target Mecp2. MECP2 mutations cause Rett syndrome and these patients report decreased pain perception. We confirmed MeCP2 upregulation in DRG following nerve injury and repression of MeCP2 by miRNAs in vitro. MeCP2 regulates brain-derived neurotrophic factor (BDNF) and downregulation of MeCP2 by microRNAs decreased Bdnf in vitro. MeCP2 T158A mice exhibited reduced mechanical sensitivity and Mecp2-null and MeCP2 T158A mice have decreased Bdnf in DRG. MeCP2-mediated regulation of Bdnf in the DRG could contribute to altered pain sensitivity.
Collapse
Key Words
- +/Y, male wild-type littermate control for either MeCP2 T158A knock in mouse or Mecp2-null mouse
- 3′UTR, three prime untranslated region
- ATF3, activating transcription factor 3
- BDNF
- BDNF, brain derived neurotrophic factor
- CFA, complete Freund’s adjuvant
- DRG, dorsal root ganglia
- L4/L5, 4th or 5th lumbar vertebra
- MeCP2
- MeCP2 T158A/Y, male MeCP2 T158A knock in mouse
- MeCP2, methyl-CpG-binding protein 2
- Neuropathic pain
- RTT, Rett syndrome
- SNI, spared nerve injury
- T158A, threonine 158 conversion to alanine
- TrkB, tropomyosin receptor kinase B
- miRNA
- −/Y, male Mecp2-null mouse
Collapse
Affiliation(s)
- Melissa T Manners
- Pharmacology & Physiology, Drexel University College of Medicine, Philadelphia, USA
| | - Yuzhen Tian
- Pharmacology & Physiology, Drexel University College of Medicine, Philadelphia, USA
| | - Zhaolan Zhou
- Department of Genetics, University of Pennsylvania School of Medicine, Philadelphia, USA
| | - Seena K Ajit
- Pharmacology & Physiology, Drexel University College of Medicine, Philadelphia, USA
| |
Collapse
|
36
|
Abstract
Two severe, progressive neurological disorders characterized by intellectual disability, autism, and developmental regression, Rett syndrome and MECP2 duplication syndrome, result from loss and gain of function, respectively, of the same critical gene, methyl-CpG-binding protein 2 (MECP2). Neurons acutely require the appropriate dose of MECP2 to function properly but do not die in its absence or overexpression. Instead, neuronal dysfunction can be reversed in a Rett syndrome mouse model if MeCP2 function is restored. Thus, MECP2 disorders provide a unique window into the delicate balance of neuronal health, the power of mouse models, and the importance of chromatin regulation in mature neurons. In this Review, we will discuss the clinical profiles of MECP2 disorders, the knowledge acquired from mouse models of the syndromes, and how that knowledge is informing current and future clinical studies.
Collapse
|
37
|
Kondo MA, Gray LJ, Pelka GJ, Leang SK, Christodoulou J, Tam PPL, Hannan AJ. Affective dysfunction in a mouse model of Rett syndrome: Therapeutic effects of environmental stimulation and physical activity. Dev Neurobiol 2015; 76:209-24. [DOI: 10.1002/dneu.22308] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 03/24/2015] [Accepted: 05/22/2015] [Indexed: 01/06/2023]
Affiliation(s)
- Mari A. Kondo
- Florey Institute of Neuroscience and Mental Health; University of Melbourne; Parkville Victoria 3010 Australia
- Department of Anatomy and Neuroscience; University of Melbourne; Parkville Victoria 3010 Australia
| | - Laura J. Gray
- Florey Institute of Neuroscience and Mental Health; University of Melbourne; Parkville Victoria 3010 Australia
| | - Gregory J. Pelka
- Embryology Unit; Children's Medical Research Institute; Westmead New South Wales 2145 Australia
| | - Sook-Kwan Leang
- Florey Institute of Neuroscience and Mental Health; University of Melbourne; Parkville Victoria 3010 Australia
| | - John Christodoulou
- Western Sydney Genetics Program; Children's Hospital at Westmead; Westmead, New South Wales 2145 Australia
- Disciplines of Paediatrics and Child Health and Genetic Medicine; University of Sydney; Sydney New South Wales 2006 Australia
| | - Patrick P. L. Tam
- Embryology Unit; Children's Medical Research Institute; Westmead New South Wales 2145 Australia
- Sydney Medical School; University of Sydney; Sydney New South Wales 2006 Australia
| | - Anthony J. Hannan
- Florey Institute of Neuroscience and Mental Health; University of Melbourne; Parkville Victoria 3010 Australia
- Department of Anatomy and Neuroscience; University of Melbourne; Parkville Victoria 3010 Australia
| |
Collapse
|
38
|
Turovsky E, Karagiannis A, Abdala AP, Gourine AV. Impaired CO2 sensitivity of astrocytes in a mouse model of Rett syndrome. J Physiol 2015; 593:3159-68. [PMID: 25981852 PMCID: PMC4532534 DOI: 10.1113/jp270369] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 05/11/2015] [Indexed: 12/13/2022] Open
Abstract
Rett syndrome, a prototypical neurological disorder caused by loss of function of the transcriptional regulator methyl-CpG-binding protein 2 (MeCP2) gene, is associated with a severely disordered breathing pattern and reduced ventilatory CO2 sensitivity. In a mouse model of Rett syndrome (MeCP2 knockout), re-introduction of the MeCP2 gene selectively in astrocytes rescues normal respiratory phenotype. In the present study we determined whether the metabolic and/or signalling functions of astrocytes are affected by testing the hypotheses that in conditions of MeCP2 deficiency, medullary astrocytes are unable to produce/release appropriate amounts of lactate or detect changes in PCO2/[H(+) ], or both. No differences in tonic or hypoxia-induced release of lactate from the ventral surface of the medulla oblongata or cerebral cortex in brain slices of MeCP2-knockout and wild-type mice were found. In brainstem slices of wild-type mice, respiratory acidosis triggered robust elevations in [Ca(2+) ]i in astrocytes residing near the ventral surface of the medulla oblongata. The magnitude of CO2 -induced [Ca(2+) ]i responses in medullary astrocytes was markedly reduced in conditions of MeCP2 deficiency, whereas [Ca(2+) ]i responses to ATP were unaffected. These data suggest that (i) metabolic function of astrocytes in releasing lactate into the extracellular space is not affected by MeCP2 deficiency, and (ii) MeCP2 deficiency impairs the ability of medullary astrocytes to sense changes in PCO2/[H(+) ]. Taken together with the evidence of severely blunted ventilatory sensitivity to CO2 in mice with conditional MeCP2 deletion in astroglia, these data support the hypothesis of an important role played by astrocytes in central respiratory CO2 /pH chemosensitivity.
Collapse
Affiliation(s)
- Egor Turovsky
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK.,Institute of Cell Biophysics, Russian Academy of Sciences, Pushchino, Russia
| | - Anastassios Karagiannis
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK
| | - Ana Paula Abdala
- School of Physiology & Pharmacology, University of Bristol, Bristol, BS8 1TD, UK
| | - Alexander V Gourine
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK
| |
Collapse
|
39
|
Brain-derived neurotrophic factor inhibits calcium channel activation, exocytosis, and endocytosis at a central nerve terminal. J Neurosci 2015; 35:4676-82. [PMID: 25788684 DOI: 10.1523/jneurosci.2695-14.2015] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Brain-derived neurotrophic factor (BDNF) is a neurotrophin that regulates synaptic function and plasticity and plays important roles in neuronal development, survival, and brain disorders. Despite such diverse and important roles, how BDNF, or more generally speaking, neurotrophins affect synapses, particularly nerve terminals, remains unclear. By measuring calcium currents and membrane capacitance during depolarization at a large mammalian central nerve terminal, the rat calyx of Held, we report for the first time that BDNF slows down calcium channel activation, including P/Q-type channels, and inhibits exocytosis induced by brief depolarization or single action potentials, inhibits slow and rapid endocytosis, and inhibits vesicle mobilization to the readily releasable pool. These presynaptic mechanisms may contribute to the important roles of BDNF in regulating synapses and neuronal circuits and suggest that regulation of presynaptic calcium channels, exocytosis, and endocytosis are potential mechanisms by which neurotrophins achieve diverse neuronal functions.
Collapse
|
40
|
Kron M, Lang M, Adams IT, Sceniak M, Longo F, Katz DM. A BDNF loop-domain mimetic acutely reverses spontaneous apneas and respiratory abnormalities during behavioral arousal in a mouse model of Rett syndrome. Dis Model Mech 2015; 7:1047-55. [PMID: 25147297 PMCID: PMC4142725 DOI: 10.1242/dmm.016030] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Reduced levels of brain-derived neurotrophic factor (BDNF) are thought to contribute to the pathophysiology of Rett syndrome (RTT), a severe neurodevelopmental disorder caused by loss-of-function mutations in the gene encoding methyl-CpG-binding protein 2 (MeCP2). In Mecp2 mutant mice, BDNF deficits have been associated with breathing abnormalities, a core feature of RTT, as well as with synaptic hyperexcitability within the brainstem respiratory network. Application of BDNF can reverse hyperexcitability in acute brainstem slices from Mecp2-null mice, suggesting that therapies targeting BDNF or its receptor, TrkB, could be effective at acute reversal of respiratory abnormalities in RTT. Therefore, we examined the ability of LM22A-4, a small-molecule BDNF loop-domain mimetic and TrkB partial agonist, to modulate synaptic excitability within respiratory cell groups in the brainstem nucleus tractus solitarius (nTS) and to acutely reverse abnormalities in breathing at rest and during behavioral arousal in Mecp2 mutants. Patch-clamp recordings in Mecp2-null brainstem slices demonstrated that LM22A-4 decreases excitability at primary afferent synapses in the nTS by reducing the amplitude of evoked excitatory postsynaptic currents and the frequency of spontaneous and miniature excitatory postsynaptic currents. In vivo, acute treatment of Mecp2-null and -heterozygous mutants with LM22A-4 completely eliminated spontaneous apneas in resting animals, without sedation. Moreover, we demonstrate that respiratory dysregulation during behavioral arousal, a feature of human RTT, is also reversed in Mecp2 mutants by acute treatment with LM22A-4. Together, these data support the hypothesis that reduced BDNF signaling and respiratory dysfunction in RTT are linked, and establish the proof-of-concept that treatment with a small-molecule structural mimetic of a BDNF loop domain and a TrkB partial agonist can acutely reverse abnormal breathing at rest and in response to behavioral arousal in symptomatic RTT mice.
Collapse
Affiliation(s)
- Miriam Kron
- Department of Neurosciences, Case Western Reserve University School of Medicine, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Min Lang
- Department of Neurosciences, Case Western Reserve University School of Medicine, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Ian T Adams
- Department of Neurosciences, Case Western Reserve University School of Medicine, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Michael Sceniak
- Department of Neurosciences, Case Western Reserve University School of Medicine, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Frank Longo
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA
| | - David M Katz
- Department of Neurosciences, Case Western Reserve University School of Medicine, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| |
Collapse
|
41
|
KhorshidAhmad T, Acosta C, Cortes C, Lakowski TM, Gangadaran S, Namaka M. Transcriptional Regulation of Brain-Derived Neurotrophic Factor (BDNF) by Methyl CpG Binding Protein 2 (MeCP2): a Novel Mechanism for Re-Myelination and/or Myelin Repair Involved in the Treatment of Multiple Sclerosis (MS). Mol Neurobiol 2015; 53:1092-1107. [PMID: 25579386 DOI: 10.1007/s12035-014-9074-1] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 12/29/2014] [Indexed: 12/13/2022]
Abstract
Multiple sclerosis (MS) is a chronic progressive, neurological disease characterized by the targeted immune system-mediated destruction of central nervous system (CNS) myelin. Autoreactive CD4+ T helper cells have a key role in orchestrating MS-induced myelin damage. Once activated, circulating Th1-cells secrete a variety of inflammatory cytokines that foster the breakdown of blood-brain barrier (BBB) eventually infiltrating into the CNS. Inside the CNS, they become reactivated upon exposure to the myelin structural proteins and continue to produce inflammatory cytokines such as tumor necrosis factor α (TNFα) that leads to direct activation of antibodies and macrophages that are involved in the phagocytosis of myelin. Proliferating oligodendrocyte precursors (OPs) migrating to the lesion sites are capable of acute remyelination but unable to completely repair or restore the immune system-mediated myelin damage. This results in various permanent clinical neurological disabilities such as cognitive dysfunction, fatigue, bowel/bladder abnormalities, and neuropathic pain. At present, there is no cure for MS. Recent remyelination and/or myelin repair strategies have focused on the role of the neurotrophin brain-derived neurotrophic factor (BDNF) and its upstream transcriptional repressor methyl CpG binding protein (MeCP2). Research in the field of epigenetic therapeutics involving histone deacetylase (HDAC) inhibitors and lysine acetyl transferase (KAT) inhibitors is being explored to repress the detrimental effects of MeCP2. This review will address the role of MeCP2 and BDNF in remyelination and/or myelin repair and the potential of HDAC and KAT inhibitors as novel therapeutic interventions for MS.
Collapse
Affiliation(s)
- Tina KhorshidAhmad
- College of Pharmacy, University of Manitoba, 750 McDermot Avenue, Winnipeg, R3E 0T5, Manitoba, Canada.,Manitoba Multiple Sclerosis Research Network Organization (MMSRNO), Winnipeg, Canada
| | - Crystal Acosta
- College of Pharmacy, University of Manitoba, 750 McDermot Avenue, Winnipeg, R3E 0T5, Manitoba, Canada.,Manitoba Multiple Sclerosis Research Network Organization (MMSRNO), Winnipeg, Canada
| | - Claudia Cortes
- College of Pharmacy, University of Manitoba, 750 McDermot Avenue, Winnipeg, R3E 0T5, Manitoba, Canada.,Manitoba Multiple Sclerosis Research Network Organization (MMSRNO), Winnipeg, Canada
| | - Ted M Lakowski
- College of Pharmacy, University of Manitoba, 750 McDermot Avenue, Winnipeg, R3E 0T5, Manitoba, Canada.,Manitoba Multiple Sclerosis Research Network Organization (MMSRNO), Winnipeg, Canada
| | - Surendiran Gangadaran
- College of Pharmacy, University of Manitoba, 750 McDermot Avenue, Winnipeg, R3E 0T5, Manitoba, Canada.,Manitoba Multiple Sclerosis Research Network Organization (MMSRNO), Winnipeg, Canada
| | - Michael Namaka
- College of Pharmacy, University of Manitoba, 750 McDermot Avenue, Winnipeg, R3E 0T5, Manitoba, Canada. .,Manitoba Multiple Sclerosis Research Network Organization (MMSRNO), Winnipeg, Canada. .,College of Medicine, University of Manitoba, Winnipeg, Canada. .,School of Medical Rehabilitation, College of Medicine, University of Manitoba, Winnipeg, Canada.
| |
Collapse
|
42
|
Phillips M, Pozzo-Miller L. Dendritic spine dysgenesis in autism related disorders. Neurosci Lett 2015; 601:30-40. [PMID: 25578949 DOI: 10.1016/j.neulet.2015.01.011] [Citation(s) in RCA: 125] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 12/31/2014] [Accepted: 01/04/2015] [Indexed: 01/22/2023]
Abstract
The activity-dependent structural and functional plasticity of dendritic spines has led to the long-standing belief that these neuronal compartments are the subcellular sites of learning and memory. Of relevance to human health, central neurons in several neuropsychiatric illnesses, including autism related disorders, have atypical numbers and morphologies of dendritic spines. These so-called dendritic spine dysgeneses found in individuals with autism related disorders are consistently replicated in experimental mouse models. Dendritic spine dysgenesis reflects the underlying synaptopathology that drives clinically relevant behavioral deficits in experimental mouse models, providing a platform for testing new therapeutic approaches. By examining molecular signaling pathways, synaptic deficits, and spine dysgenesis in experimental mouse models of autism related disorders we find strong evidence for mTOR to be a critical point of convergence and promising therapeutic target.
Collapse
Affiliation(s)
- Mary Phillips
- Department of Neurobiology, Civitan International Research Center, The University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Lucas Pozzo-Miller
- Department of Neurobiology, Civitan International Research Center, The University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| |
Collapse
|
43
|
De-repressing LncRNA-Targeted Genes to Upregulate Gene Expression: Focus on Small Molecule Therapeutics. MOLECULAR THERAPY. NUCLEIC ACIDS 2014; 3:e196. [PMID: 25405465 PMCID: PMC4461991 DOI: 10.1038/mtna.2014.45] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 08/08/2014] [Indexed: 02/07/2023]
Abstract
Non-protein coding RNAs (ncRNAs) make up the overwhelming majority of transcripts in the genome and have recently gained attention for their complex regulatory role in cells, including the regulation of protein-coding genes. Furthermore, ncRNAs play an important role in normal development and their expression levels are dysregulated in several diseases. Recently, several long noncoding RNAs (lncRNAs) have been shown to alter the epigenetic status of genomic loci and suppress the expression of target genes. This review will present examples of such a mechanism and focus on the potential to target lncRNAs for achieving therapeutic gene upregulation by de-repressing genes that are epigenetically silenced in various diseases. Finally, the potential to target lncRNAs, through their interactions with epigenetic enzymes, using various tools, such as small molecules, viral vectors and antisense oligonucleotides, will be discussed. We suggest that small molecule modulators of a novel class of drug targets, lncRNA-protein interactions, have great potential to treat some cancers, cardiovascular disease, and neurological disorders.
Collapse
|
44
|
Xu X, Miller EC, Pozzo-Miller L. Dendritic spine dysgenesis in Rett syndrome. Front Neuroanat 2014; 8:97. [PMID: 25309341 PMCID: PMC4159975 DOI: 10.3389/fnana.2014.00097] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2014] [Accepted: 08/25/2014] [Indexed: 11/13/2022] Open
Abstract
Spines are small cytoplasmic extensions of dendrites that form the postsynaptic compartment of the majority of excitatory synapses in the mammalian brain. Alterations in the numerical density, size, and shape of dendritic spines have been correlated with neuronal dysfunction in several neurological and neurodevelopmental disorders associated with intellectual disability, including Rett syndrome (RTT). RTT is a progressive neurodevelopmental disorder associated with intellectual disability that is caused by loss of function mutations in the transcriptional regulator methyl CpG-binding protein 2 (MECP2). Here, we review the evidence demonstrating that principal neurons in RTT individuals and Mecp2-based experimental models exhibit alterations in the number and morphology of dendritic spines. We also discuss the exciting possibility that signaling pathways downstream of brain-derived neurotrophic factor (BDNF), which is transcriptionally regulated by MeCP2, offer promising therapeutic options for modulating dendritic spine development and plasticity in RTT and other MECP2-associated neurodevelopmental disorders.
Collapse
Affiliation(s)
- Xin Xu
- Department of Neurobiology, Civitan International Research Center, The University of Alabama at Birmingham, Birmingham, AL USA
| | - Eric C Miller
- Department of Neurobiology, Civitan International Research Center, The University of Alabama at Birmingham, Birmingham, AL USA
| | - Lucas Pozzo-Miller
- Department of Neurobiology, Civitan International Research Center, The University of Alabama at Birmingham, Birmingham, AL USA
| |
Collapse
|
45
|
Xie T, Zhang J, Yuan X, Yang J, Ding W, Huang X, Wu Y. Is X-linked methyl-CpG binding protein 2 a new target for the treatment of Parkinson's disease. Neural Regen Res 2014; 8:1948-57. [PMID: 25206503 PMCID: PMC4145902 DOI: 10.3969/j.issn.1673-5374.2013.21.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Accepted: 05/15/2013] [Indexed: 01/20/2023] Open
Abstract
X-linked methyl-CpG binding protein 2 mutations can induce symptoms similar to those of Parkinson's disease and dopamine metabolism disorders, but the specific role of X-linked methyl-CpG binding protein 2 in the pathogenesis of Parkinson's disease remains unknown. In the present study, we used 6-hydroxydopamine-induced human neuroblastoma cell (SH-SY5Y cells) injury as a cell model of Parkinson's disease. The 6-hydroxydopamine (50 μmol/L) treatment decreased protein levels for both X-linked methyl-CpG binding protein 2 and tyrosine hydroxylase in these cells, and led to cell death. However, overexpression of X-linked methyl-CpG binding protein 2 was able to ameliorate the effects of 6-hydroxydopamine, it reduced 6-hydroxydopamine-induced apoptosis, and increased the levels of tyrosine hydroxylase in SH-SY5Y cells. These findings suggesting that X-linked methyl-CpG binding protein 2 may be a potential therapeutic target for the treatment of Parkinson's disease.
Collapse
Affiliation(s)
- Teng Xie
- Department of Neurosurgery, Zhongnan Hospital of Wuhan University, Wuhan 430071, Hubei Province, China
| | - Jie Zhang
- Department of Neurosurgery, Zhongnan Hospital of Wuhan University, Wuhan 430071, Hubei Province, China
| | - Xianhou Yuan
- Department of Neurosurgery, Zhongnan Hospital of Wuhan University, Wuhan 430071, Hubei Province, China
| | - Jing Yang
- Department of Pharmacology, Wuhan University School of Medicine, Wuhan 430071, Hubei Province, China
| | - Wei Ding
- Department of Neurosurgery, Zhongnan Hospital of Wuhan University, Wuhan 430071, Hubei Province, China
| | - Xin Huang
- Department of Neurosurgery, Zhongnan Hospital of Wuhan University, Wuhan 430071, Hubei Province, China
| | - Yong Wu
- Department of Neurosurgery, Zhongnan Hospital of Wuhan University, Wuhan 430071, Hubei Province, China
| |
Collapse
|
46
|
Chapleau CA, Lane J, Pozzo-Miller L, Percy AK. Evaluation of current pharmacological treatment options in the management of Rett syndrome: from the present to future therapeutic alternatives. ACTA ACUST UNITED AC 2014; 8:358-69. [PMID: 24050745 DOI: 10.2174/15748847113086660069] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 02/14/2013] [Accepted: 02/21/2013] [Indexed: 11/22/2022]
Abstract
Neurodevelopmental disorders are a large family of conditions of genetic or environmental origin that are characterized by deficiencies in cognitive and behavioral functions. The therapeutic management of individuals with these disorders is typically complex and is limited to the treatment of specific symptoms that characterize each disorder. The neurodevelopmental disorder Rett syndrome (RTT) is the leading cause of severe intellectual disability in females. Mutations in the gene encoding the transcriptional regulator methyl-CpG-binding protein 2 (MECP2), located on the X chromosome, have been confirmed in more than 95% of individuals meeting diagnostic criteria for classical RTT. RTT is characterized by an uneventful early infancy followed by stagnation and regression of growth, motor, language, and social skills later in development. This review will discuss the genetics, pathology, and symptoms that distinguish RTT from other neurodevelopmental disorders associated with intellectual disability. Because great progress has been made in the basic and clinical science of RTT, the goal of this review is to provide a thorough assessment of current pharmacotherapeutic options to treat the symptoms associated with this disorder. Furthermore, we will highlight recent discoveries made with novel pharmacological interventions in experimental preclinical phases, and which have reversed pathological phenotypes in mouse and cell culture models of RTT and may result in clinical trials.
Collapse
Affiliation(s)
- Christopher A Chapleau
- Department of Pediatrics, CIRC-320, The University of Alabama at Birmingham, 1530 3rd Avenue South, Birmingham, AL 35294-0021, USA.
| | | | | | | |
Collapse
|
47
|
Lavezzi AM, Corna MF, Matturri L. Disruption of the brain-derived neurotrophic factor (BDNF) immunoreactivity in the human Kölliker-Fuse nucleus in victims of unexplained fetal and infant death. Front Hum Neurosci 2014; 8:648. [PMID: 25237300 PMCID: PMC4154391 DOI: 10.3389/fnhum.2014.00648] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Accepted: 08/04/2014] [Indexed: 12/11/2022] Open
Abstract
Experimental studies have demonstrated that the neurotrophin brain-derived neutrophic factor (BDNF) is required for the appropriate development of the central respiratory network, a neuronal complex in the brainstem of vital importance to sustaining life. The pontine Kölliker-Fuse nucleus (KFN) is a fundamental component of this circuitry with strong implications in the pre- and postnatal breathing control. This study provides detailed account for the cytoarchitecture, the physiology and the BDNF behavior of the human KFN in perinatal age. We applied immunohistochemistry in formalin-fixed and paraffin-embedded brainstem samples (from 45 fetuses and newborns died of both known and unknown causes), to analyze BDNF, gliosis and apoptosis patterns of manifestation. The KFN showed clear signs of developmental immaturity, prevalently associated to BDNF altered expression, in high percentages of sudden intrauterine unexplained death syndrome (SIUDS) and sudden infant death syndrome (SIDS) victims. Our results indicate that BDNF pathway dysfunctions can derange the normal KFN development so preventing the breathing control in the sudden perinatal death. The data presented here are also relevant to a better understanding of how the BDNF expression in the KFN can be involved in several human respiratory pathologies such as the Rett's and the congenital central hypoventilation syndromes.
Collapse
Affiliation(s)
- Anna M Lavezzi
- "Lino Rossi" Research Center for the Study and Prevention of Unexpected Perinatal Death and SIDS Department of Biomedical, Surgical and Dental Sciences, University of Milan Milan, Italy
| | - Melissa F Corna
- "Lino Rossi" Research Center for the Study and Prevention of Unexpected Perinatal Death and SIDS Department of Biomedical, Surgical and Dental Sciences, University of Milan Milan, Italy
| | - Luigi Matturri
- "Lino Rossi" Research Center for the Study and Prevention of Unexpected Perinatal Death and SIDS Department of Biomedical, Surgical and Dental Sciences, University of Milan Milan, Italy
| |
Collapse
|
48
|
Is there a relationship between brain-derived neurotrophic factor for driving neuronal auditory circuits with onset of auditory function and the changes following cochlear injury or during aging? Neuroscience 2014; 283:26-43. [PMID: 25064058 DOI: 10.1016/j.neuroscience.2014.07.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 07/15/2014] [Accepted: 07/17/2014] [Indexed: 01/06/2023]
Abstract
Brain-derived neurotrophic factor, BDNF, is one of the most important neurotrophic factors acting in the peripheral and central nervous system. In the auditory system its function was initially defined by using constitutive knockout mouse mutants and shown to be essential for survival of neurons and afferent innervation of hair cells in the peripheral auditory system. Further examination of BDNF null mutants also revealed a more complex requirement during re-innervation processes involving the efferent system of the cochlea. Using adult mouse mutants defective in BDNF signaling, it could be shown that a tonotopical gradient of BDNF expression within cochlear neurons is required for maintenance of a specific spatial innervation pattern of outer hair cells and inner hair cells. Additionally, BDNF is required for maintenance of voltage-gated potassium channels (KV) in cochlear neurons, which may form part of a maturation step within the ascending auditory pathway with onset of hearing and might be essential for cortical acuity of sound-processing and experience-dependent plasticity. A presumptive harmful role of BDNF during acoustic trauma and consequences of a loss of cochlear BDNF during aging are discussed in the context of a partial reversion of this maturation step. We compare the potentially beneficial and harmful roles of BDNF for the mature auditory system with those BDNF functions known in other sensory circuits, such as the vestibular, visual, olfactory, or somatosensory system.
Collapse
|
49
|
Kim SW, Cho KJ. Activity-dependent alterations in the sensitivity to BDNF-TrkB signaling may promote excessive dendritic arborization and spinogenesis in fragile X syndrome in order to compensate for compromised postsynaptic activity. Med Hypotheses 2014; 83:429-35. [PMID: 25113167 DOI: 10.1016/j.mehy.2014.07.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2014] [Accepted: 07/11/2014] [Indexed: 12/20/2022]
Abstract
Fragile X syndrome (FXS), the most common cause of inherited human mental retardation, results from the loss of function of fragile X mental retardation protein (FMRP). To date, most researchers have thought that FXS neural pathologies are primarily caused by extreme dendritic branching and spine formation. With this rationale, several researchers attempted to prune dendritic branches and reduce the number of spines in FXS animal models. We propose that increased dendritic arborization and spinogenesis in FXS are developed rather as secondary compensatory responses to counteract the compromised postsynaptic activity during uncontrollable metabotropic glutamate receptor (mGluR)-dependent long-term depression (LTD). When postsynaptic and electrical activities become dampened in FXS, dendritic trees can increase their sensitivity to brain-derived neurotrophic factor (BDNF) by using the molecular sensor called eukaryotic elongation factor 2 (eEF2) and taking advantage of the tight coupling of mGluR and BDNF-TrkB signaling pathways. Then, this activity-dependent elevation of the BDNF signaling can strategically alter dendritic morphologies to foster branching and develop spine structures in order to improve the postsynaptic response in FXS. Our model suggests a new therapeutic rationale for FXS: correcting the postsynaptic and electrical activity first, and then repairing structural abnormalities of dendrites. Then, it may be possible to successfully fix the dendritic morphologies without affecting the survival of neurons. Our theory may also be generalized to explain aberrant dendritic structures observed in other neurobehavioral diseases, such as tuberous sclerosis, Rett syndrome, schizophrenia, and channelopathies, which accompany high postsynaptic and electrical activity.
Collapse
Affiliation(s)
- Sang Woo Kim
- Department of Neuroscience, Brown University, Providence, RI 02912, United States.
| | - Kyoung Joo Cho
- Department of Anatomy, BK 21 PLUS for Medical Science, College of Medicine, Yonsei University, Seoul, South Korea.
| |
Collapse
|
50
|
Abdala AP, Lioy DT, Garg SK, Knopp SJ, Paton JFR, Bissonnette JM. Effect of Sarizotan, a 5-HT1a and D2-like receptor agonist, on respiration in three mouse models of Rett syndrome. Am J Respir Cell Mol Biol 2014; 50:1031-9. [PMID: 24351104 PMCID: PMC4068914 DOI: 10.1165/rcmb.2013-0372oc] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 12/10/2013] [Indexed: 01/06/2023] Open
Abstract
Disturbances in respiration are common and debilitating features of Rett syndrome (RTT). A previous study showed that the 5-HT1a receptor agonist (R)-(+)-8-hydroxy-dipropyl-2-aminotetralin hydrobromide (8-OH-DPAT) significantly reduced the incidence of apnea and the irregular breathing pattern in a mouse model of the disorder. 8-OH-DPAT, however, is not available for clinical practice. Sarizotan, a full 5-HT1a agonist and a dopamine D2-like agonist/partial agonist, has been used in clinical trials for the treatment of l-dopa-induced dyskinesia. The purpose of this study was to evaluate the effects of sarizotan on respiration and locomotion in mouse models of RTT. Studies were performed in Bird and Jaenisch strains of methyl-CpG-binding protein 2--deficient heterozygous female and Jaenisch strain Mecp2 null male mice and in knock-in heterozygous female mice of a common nonsense mutation (R168X). Respiratory pattern was determined with body plethysmography, and locomotion was determined with open-field recording. Sarizotan or vehicle was administered 20 minutes before a 30-minute recording of respiratory pattern or motor behavior. In separate studies, a crossover design was used to administer the drug for 7 and for 14 days. Sarizotan reduced the incidence of apnea in all three RTT mouse models to approximately 15% of their pretreatment levels. The irregular breathing pattern was corrected to that of wild-type littermates. When administered for 7 or 14 days, apnea decreased to 25 to 33% of the incidence seen with vehicle. This study indicates that the clinically approved drug sarizotan is an effective treatment for respiratory disorders in mouse models of RTT.
Collapse
Affiliation(s)
- Ana P. Abdala
- Department of Physiology and Pharmacology, Medical Sciences Building, University of Bristol, Bristol, United Kingdom; and
| | | | | | | | - Julian F. R. Paton
- Department of Physiology and Pharmacology, Medical Sciences Building, University of Bristol, Bristol, United Kingdom; and
| | - John M. Bissonnette
- Departments of Obstetrics & Gynecology, and
- Cell & Developmental Biology, Oregon Health and Science University, Portland, Oregon
| |
Collapse
|