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RBFox2-miR-34a-Jph2 axis contributes to cardiac decompensation during heart failure. Proc Natl Acad Sci U S A 2019; 116:6172-6180. [PMID: 30867288 DOI: 10.1073/pnas.1822176116] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Heart performance relies on highly coordinated excitation-contraction (EC) coupling, and defects in this critical process may be exacerbated by additional genetic defects and/or environmental insults to cause eventual heart failure. Here we report a regulatory pathway consisting of the RNA binding protein RBFox2, a stress-induced microRNA miR-34a, and the essential EC coupler JPH2. In this pathway, initial cardiac defects diminish RBFox2 expression, which induces transcriptional repression of miR-34a, and elevated miR-34a targets Jph2 to impair EC coupling, which further manifests heart dysfunction, leading to progressive heart failure. The key contribution of miR-34a to this process is further established by administrating its mimic, which is sufficient to induce cardiac defects, and by using its antagomir to alleviate RBFox2 depletion-induced heart dysfunction. These findings elucidate a potential feed-forward mechanism to account for a critical transition to cardiac decompensation and suggest a potential therapeutic avenue against heart failure.
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52
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Lee KY, Jewett KA, Chung HJ, Tsai NP. Loss of fragile X protein FMRP impairs homeostatic synaptic downscaling through tumor suppressor p53 and ubiquitin E3 ligase Nedd4-2. Hum Mol Genet 2019; 27:2805-2816. [PMID: 29771335 DOI: 10.1093/hmg/ddy189] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 05/09/2018] [Indexed: 12/23/2022] Open
Abstract
Synaptic scaling allows neurons to homeostatically readjust synaptic strength upon chronic neural activity perturbations. Although altered synaptic scaling has been implicated to underlie imbalanced brain excitability in neurological disorders such as autism spectrum disorders and epilepsy, the molecular dysregulation and restoration of synaptic scaling in those diseases have not been demonstrated. Here, we showed that the homeostatic synaptic downscaling is absent in the hippocampal neurons of Fmr1 KO mice, the mouse model of the most common inherited autism, fragile X syndrome (FXS). We found that the impaired homeostatic synaptic downscaling in Fmr1 KO neurons is caused by loss-of-function dephosphorylation of an epilepsy-associated ubiquitin E3 ligase, neural precursor cell expressed developmentally down-regulated gene 4-2, Nedd4-2. Such dephosphorylation of Nedd4-2 is surprisingly caused by abnormally stable tumor suppressor p53 and subsequently destabilized kinase Akt. Dephosphorylated Nedd4-2 fails to elicit 14-3-3-dependent ubiquitination and down-regulation of the GluA1 subunit of AMPA receptor, and therefore impairs synaptic downscaling. Most importantly, using a pharmacological inhibitor of p53, Nedd4-2 phosphorylation, GluA1 ubiquitination and synaptic downscaling are all restored in Fmr1 KO neurons. Together, our results discover a novel cellular mechanism underlying synaptic downscaling, and demonstrate the dysregulation and successful restoration of this mechanism in the FXS mouse model.
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Affiliation(s)
- Kwan Young Lee
- Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology
| | - Kathryn A Jewett
- Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology
| | - Hee Jung Chung
- Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology.,Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Nien-Pei Tsai
- Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology.,Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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53
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MicroRNA-186-5p controls GluA2 surface expression and synaptic scaling in hippocampal neurons. Proc Natl Acad Sci U S A 2019; 116:5727-5736. [PMID: 30808806 DOI: 10.1073/pnas.1900338116] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Homeostatic synaptic scaling is a negative feedback response to fluctuations in synaptic strength induced by developmental or learning-related processes, which maintains neuronal activity stable. Although several components of the synaptic scaling apparatus have been characterized, the intrinsic regulatory mechanisms promoting scaling remain largely unknown. MicroRNAs may contribute to posttranscriptional control of mRNAs implicated in different stages of synaptic scaling, but their role in these mechanisms is still undervalued. Here, we report that chronic blockade of glutamate receptors of the AMPA and NMDA types in hippocampal neurons in culture induces changes in the neuronal mRNA and miRNA transcriptomes, leading to synaptic upscaling. Specifically, we show that synaptic activity blockade persistently down-regulates miR-186-5p. Moreover, we describe a conserved miR-186-5p-binding site within the 3'UTR of the mRNA encoding the AMPA receptor GluA2 subunit, and demonstrate that GluA2 is a direct target of miR-186-5p. Overexpression of miR-186 decreased GluA2 surface levels, increased synaptic expression of GluA2-lacking AMPA receptors, and blocked synaptic scaling, whereas inhibition of miR-186-5p increased GluA2 surface levels and the amplitude and frequency of AMPA receptor-mediated currents, and mimicked excitatory synaptic scaling induced by synaptic inactivity. Our findings elucidate an activity-dependent miRNA-mediated mechanism for regulation of AMPA receptor expression.
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54
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Zampa F, Hartzell AL, Zolboot N, Lippi G. Non-coding RNAs: the gatekeepers of neural network activity. Curr Opin Neurobiol 2019; 57:54-61. [PMID: 30743177 DOI: 10.1016/j.conb.2019.01.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Revised: 01/08/2019] [Accepted: 01/10/2019] [Indexed: 01/24/2023]
Abstract
Non-coding RNAs have emerged as potent regulators of numerous cellular processes. In neurons and circuits, these molecules serve especially critical functions that ensure neural activity is maintained within appropriate physiological parameters. Their targets include synaptic proteins, ion channels, neurotransmitter receptors, and components of essential signaling cascades. Here, we discuss how several species of non-coding RNAs (ncRNAs) regulate intrinsic excitability and synaptic transmission, both during development and in mature circuits. Furthermore, we present the relationships between aberrant ncRNA expression and psychiatric disorders. The research presented here demonstrates how ncRNAs can be useful tools for elucidating fundamental neurobiology mechanisms and identifying the key molecular players.
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Affiliation(s)
- Federico Zampa
- Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Andrea L Hartzell
- Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Norjin Zolboot
- Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Giordano Lippi
- Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA, 92037, USA.
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55
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Fu H, Cheng Y, Luo H, Rong Z, Li Y, Lu P, Ye X, Huang W, Qi Z, Li X, Cheng B, Wang X, Yao Y, Zhang YW, Zheng W, Zheng H. Silencing MicroRNA-155 Attenuates Kainic Acid-Induced Seizure by Inhibiting Microglia Activation. Neuroimmunomodulation 2019; 26:67-76. [PMID: 30928987 DOI: 10.1159/000496344] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 12/16/2018] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE(S) Neuroinflammation is an important contributor to the development of seizures and epilepsy. Micro-RNA-155 (miR-155) plays a critical role in immunity and -inflammation. This study aims to explore the function of miR-155 and miR-155-mediated inflammation in epilepsy. METHODS About 8-week-old male C57BL/6 mice were administered an intraperitoneal injection (i.p.) of kainic acid (KA) (15 mg/kg) or saline. The mice in the KA group developing acute seizure were further subjected to intracerebroventricular injection (i.c.v.) of antagomir negative control (NC) or miR-155 antagomir. Animal behavior was observed according to Racine's scale, and electroencephalographs were recorded. Primary microglia were cultured and treated with antagomir NC or antagomir. Whole-cell electrophysiological recording was conducted to detect the spontaneous EPSCs and IPSCs in the neurons treated with different conditioned medium from those microglia. miR-155 were detected by qRT-PCR in those models, as well as in the brain or blood from epileptic patients and healthy controls. RESULTS miR-155 was abundantly expressed in glial cells compared with neurons, and its expression was markedly elevated in the brain of epilepsy patients and KA-induced seizure mice. Silencing miR-155 attenuated KA-induced seizure, abnormal electroencephalography, proinflammatory cytokine expression, and microglia morphology change. Moreover, conditioned media from KA-treated microglia impaired neuron excitability, whereas conditioned media from KA and miR-155 antagomir co-treated microglia had no such effects. Finally, miR-155 levels were significantly higher in the blood of epilepsy patients than those of healthy controls. CONCLUSION(S) These findings demonstrate that aberrant upregulation of miR-155 contributes to epileptogenesis through inducing microglia neuroinflammation.
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Affiliation(s)
- Huajun Fu
- Department of Neurology, Affiliated Zhongshan Hospital, Xiamen University, Xiamen, China
- Fujian Provincial Key Laboratory of Neurodegenerative Diseases and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
- Department of Neurology, The Affiliated Longyan First Hospital of Fujian Medical University, Longyan, China
| | - Yiyun Cheng
- Department of Neurology, Affiliated Zhongshan Hospital, Xiamen University, Xiamen, China
- Fujian Provincial Key Laboratory of Neurodegenerative Diseases and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
- Graduate School of Fujian Medical University, Xiamen, China
| | - Haijuan Luo
- Department of Neurology, Affiliated Zhongshan Hospital, Xiamen University, Xiamen, China
- Fujian Provincial Key Laboratory of Neurodegenerative Diseases and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
| | - Zhouyi Rong
- Fujian Provincial Key Laboratory of Neurodegenerative Diseases and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
| | - Yanfang Li
- Fujian Provincial Key Laboratory of Neurodegenerative Diseases and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
| | - Ping Lu
- Fujian Provincial Key Laboratory of Neurodegenerative Diseases and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
- Institute of Clinical Pharmacology, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Xiaowen Ye
- Department of Neurology, Affiliated Zhongshan Hospital, Xiamen University, Xiamen, China
- Fujian Provincial Key Laboratory of Neurodegenerative Diseases and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
| | - Weiyan Huang
- Fujian Provincial Key Laboratory of Neurodegenerative Diseases and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
- Clinical Medicine of Grade 2014, School of Medicine, Xiamen University, Xiamen, China
| | - Ziguo Qi
- Fujian Provincial Key Laboratory of Neurodegenerative Diseases and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
- Clinical Medicine of Grade 2014, School of Medicine, Xiamen University, Xiamen, China
| | - Xiuying Li
- Fujian Provincial Key Laboratory of Neurodegenerative Diseases and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
- Clinical Medicine of Grade 2014, School of Medicine, Xiamen University, Xiamen, China
| | - Baoying Cheng
- Fujian Provincial Key Laboratory of Neurodegenerative Diseases and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
| | - Xintian Wang
- Department of Neurology, Affiliated Zhongshan Hospital, Xiamen University, Xiamen, China
- Fujian Provincial Key Laboratory of Neurodegenerative Diseases and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
- Graduate School of Fujian Medical University, Xiamen, China
| | - Yi Yao
- Epilepsy Research Center, Department of Neurosurgery, Hongai Hospital, Xiamen, China
| | - Yun-Wu Zhang
- Fujian Provincial Key Laboratory of Neurodegenerative Diseases and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
| | - Weihong Zheng
- Department of Neurology, Affiliated Zhongshan Hospital, Xiamen University, Xiamen, China
- Graduate School of Fujian Medical University, Xiamen, China
| | - Honghua Zheng
- Fujian Provincial Key Laboratory of Neurodegenerative Diseases and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China,
- Shenzhen Research Institute, Xiamen University, Shenzhen, China,
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56
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Lackinger M, Sungur AÖ, Daswani R, Soutschek M, Bicker S, Stemmler L, Wüst T, Fiore R, Dieterich C, Schwarting RK, Wöhr M, Schratt G. A placental mammal-specific microRNA cluster acts as a natural brake for sociability in mice. EMBO Rep 2018; 20:embr.201846429. [PMID: 30552145 DOI: 10.15252/embr.201846429] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 11/16/2018] [Accepted: 11/23/2018] [Indexed: 01/12/2023] Open
Abstract
Aberrant synaptic function is thought to underlie social deficits in neurodevelopmental disorders such as autism and schizophrenia. Although microRNAs have been shown to regulate synapse development and plasticity, their potential involvement in the control of social behaviour in mammals remains unexplored. Here, we show that deletion of the placental mammal-specific miR379-410 cluster in mice leads to hypersocial behaviour, which is accompanied by increased excitatory synaptic transmission, and exaggerated expression of ionotropic glutamate receptor complexes in the hippocampus. Bioinformatic analyses further allowed us to identify five "hub" microRNAs whose deletion accounts largely for the upregulation of excitatory synaptic genes observed, including Cnih2, Dlgap3, Prr7 and Src. Thus, the miR379-410 cluster acts a natural brake for sociability, and interfering with specific members of this cluster could represent a therapeutic strategy for the treatment of social deficits in neurodevelopmental disorders.
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Affiliation(s)
- Martin Lackinger
- Institute of Physiological Chemistry, Philipps-University Marburg, Marburg, Germany
| | - A Özge Sungur
- Behavioural Neuroscience, Experimental and Biological Psychology, Philipps-University Marburg, Marburg, Germany
| | - Reetu Daswani
- Institute of Physiological Chemistry, Philipps-University Marburg, Marburg, Germany
| | - Michael Soutschek
- Institute of Physiological Chemistry, Philipps-University Marburg, Marburg, Germany
| | - Silvia Bicker
- Institute of Physiological Chemistry, Philipps-University Marburg, Marburg, Germany
| | - Lea Stemmler
- Behavioural Neuroscience, Experimental and Biological Psychology, Philipps-University Marburg, Marburg, Germany
| | - Tatjana Wüst
- Lab of Systems Neuroscience, Department of Health Science and Technology, Institute for Neuroscience Swiss Federal Institute of Technology, Zurich, Switzerland
| | - Roberto Fiore
- Institute of Physiological Chemistry, Philipps-University Marburg, Marburg, Germany
| | - Christoph Dieterich
- Section of Bioinformatics and Systems Cardiology, Department of Internal Medicine III and Klaus Tschira Institute for Integrative Computational Cardiology, University of Heidelberg, Heidelberg, Germany
| | - Rainer Kw Schwarting
- Behavioural Neuroscience, Experimental and Biological Psychology, Philipps-University Marburg, Marburg, Germany
| | - Markus Wöhr
- Behavioural Neuroscience, Experimental and Biological Psychology, Philipps-University Marburg, Marburg, Germany
| | - Gerhard Schratt
- Institute of Physiological Chemistry, Philipps-University Marburg, Marburg, Germany
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57
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Enright N, Simonato M, Henshall DC. Discovery and validation of blood microRNAs as molecular biomarkers of epilepsy: Ways to close current knowledge gaps. Epilepsia Open 2018; 3:427-436. [PMID: 30525113 PMCID: PMC6276772 DOI: 10.1002/epi4.12275] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/25/2018] [Indexed: 12/24/2022] Open
Abstract
There is a major unmet need for biomarkers of epilepsy. Biofluids such as blood offer a potential source of molecular biomarkers. MicroRNAs (miRNAs) fulfill several key requirements for a blood‐based molecular biomarker being enriched in the brain and dysregulated in epileptic brain tissue, and manipulation of miRNAs can have seizure‐suppressive and disease‐modifying effects in preclinical models. Biofluid miRNAs also possess qualities that are favorable for translation, including stability and easy and cheap assay techniques. Herein we review findings from both clinical and animal models. Studies have featured a mix of unbiased profiling and hypothesis‐driven efforts. Blood levels of several brain‐enriched miRNAs are altered in patients with epilepsy and in patients with drug‐resistant compared to drug‐responsive seizures, with encouraging receiver‐operating characteristic (ROC) curve analyses, both in terms of sensitivity and specificity. Both focal and generalized epilepsies are associated with altered blood miRNA profiles, and associations with clinical parameters including seizure burden have been reported. Results remain preliminary, however. There is a need for continued discovery and validation efforts that include multicenter studies and attention to study design, sample collection methodology, and quality control. Studies focused on epileptogenesis as well as associations with covariables such as sex, etiology, and timing of sampling remain limited. We identify 10 knowledge gaps and propose experiments to close these. If adequately addressed, biofluid miRNAs may be an important future source of diagnostic biomarkers that could also support forthcoming trials of antiepileptogenesis or disease‐modifying therapies.
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Affiliation(s)
- Noelle Enright
- Department of Physiology & Medical Physics Royal College of Surgeons in Ireland (RCSI) Dublin Ireland.,FutureNeuro Research Centre RCSI Dublin Ireland.,Temple St. Children's University Hospital Dublin Ireland
| | - Michele Simonato
- Department of Medical Sciences University of Ferrara Ferrara Italy.,School of Medicine University Vita-Salute San Raffaele Milan Italy
| | - David C Henshall
- Department of Physiology & Medical Physics Royal College of Surgeons in Ireland (RCSI) Dublin Ireland.,FutureNeuro Research Centre RCSI Dublin Ireland
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58
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Soula A, Valere M, López-González MJ, Ury-Thiery V, Groppi A, Landry M, Nikolski M, Favereaux A. Small RNA-Seq reveals novel miRNAs shaping the transcriptomic identity of rat brain structures. Life Sci Alliance 2018; 1:e201800018. [PMID: 30456375 PMCID: PMC6238413 DOI: 10.26508/lsa.201800018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 10/10/2018] [Accepted: 10/11/2018] [Indexed: 12/19/2022] Open
Abstract
Small RNA-Seq of the rat central nervous system reveals known and novel miRNAs specifically regulated in brain structures and correlated with the expression of their predicted target genes, suggesting a critical role in the transcriptomic identity of brain structures. In the central nervous system (CNS), miRNAs are involved in key functions, such as neurogenesis and synaptic plasticity. Moreover, they are essential to define specific transcriptomes in tissues and cells. However, few studies were performed to determine the miRNome of the different structures of the rat CNS, although a major model in neuroscience. Here, we determined by small RNA-Seq, the miRNome of the olfactory bulb, the hippocampus, the cortex, the striatum, and the spinal cord and showed the expression of 365 known miRNAs and 90 novel miRNAs. Differential expression analysis showed that several miRNAs were specifically enriched/depleted in these CNS structures. Transcriptome analysis by mRNA-Seq and correlation based on miRNA target predictions suggest that the specifically enriched/depleted miRNAs have a strong impact on the transcriptomic identity of the CNS structures. Altogether, these results suggest the critical role played by these enriched/depleted miRNAs, in particular the novel miRNAs, in the functional identities of CNS structures.
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Affiliation(s)
- Anaïs Soula
- University of Bordeaux, Bordeaux, France.,Centre Nationale de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 5297, Interdisciplinary Institute of Neuroscience, Bordeaux, France
| | - Mélissa Valere
- University of Bordeaux, Bordeaux, France.,Centre Nationale de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 5297, Interdisciplinary Institute of Neuroscience, Bordeaux, France
| | - María-José López-González
- University of Bordeaux, Bordeaux, France.,Centre Nationale de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 5297, Interdisciplinary Institute of Neuroscience, Bordeaux, France
| | - Vicky Ury-Thiery
- University of Bordeaux, Bordeaux, France.,Centre Nationale de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 5297, Interdisciplinary Institute of Neuroscience, Bordeaux, France
| | - Alexis Groppi
- Centre de Bioinformatique de Bordeaux, University of Bordeaux, Bordeaux, France
| | - Marc Landry
- University of Bordeaux, Bordeaux, France.,Centre Nationale de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 5297, Interdisciplinary Institute of Neuroscience, Bordeaux, France
| | - Macha Nikolski
- Centre de Bioinformatique de Bordeaux, University of Bordeaux, Bordeaux, France.,CNRS/Laboratoire Bordelais de Recherche en Informatique, University of Bordeaux, Talence, France
| | - Alexandre Favereaux
- University of Bordeaux, Bordeaux, France.,Centre Nationale de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 5297, Interdisciplinary Institute of Neuroscience, Bordeaux, France
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59
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Abstract
PURPOSE OF REVIEW The goal of this focused review is to describe recent studies supporting a critical role of microRNAs in the regulation of ion channels and discuss the resulting implications for the modulation of neuronal excitability in epilepsy. RECENT FINDINGS MicroRNA-induced silencing of ion channels has been shown in several different studies in recent years, and some of these reports suggest a prominent role in epilepsy. The ion channels regulated by microRNAs include ligand- and voltage-gated channels and are not only limited to the central nervous system but have also been found in the peripheral nervous system. Ion channel-targeting microRNAs can regulate the intrinsic excitability of neurons, and thus influence entire networks in the brain. Their dysregulation in epilepsy may contribute to the disease phenotype. More research is needed to better understand the molecular mechanisms of how microRNAs regulate ion channels to control neuronal excitability, and how these processes are altered in epilepsy.
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60
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Wu DM, Zhang YT, Lu J, Zheng YL. Effects of microRNA-129 and its target gene c-Fos on proliferation and apoptosis of hippocampal neurons in rats with epilepsy via the MAPK signaling pathway. J Cell Physiol 2018; 233:6632-6643. [PMID: 29194604 DOI: 10.1002/jcp.26297] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2017] [Accepted: 11/28/2017] [Indexed: 11/12/2022]
Abstract
This study aims to investigate the effect of microRNA-129 (miR-129) on proliferation and apoptosis of hippocampal neurons in epilepsy rats by targeting c-Fos via the MAPK signaling pathway. Thirty rats were equally classified into a model group (successfully established as chronic epilepsy models) and a normal group. Expression of miR-129, c-Fos, bax, and MAPK was detected by RT-qPCR and Western blotting. Hippocampal neurons were assigned into normal, blank, negative control (NC), miR-129 mimic, miR-129 inhibitor, siRNA-c-Fos, miR-129 inhibitor+siRNA-c-Fos groups. The targeting relationship between miR-129 and c-Fos was predicted and verified by bioinformatics websites and dual-luciferase reporter gene assay. Cell proliferation after transfection was measured by MTT assay, and cell cycle and apoptosis by flow cytometry. c-Fos is a potential target gene of miR-129. Compared with the normal group, the other six groups showed a decreased miR-129 expression; increased expression of expression of c-Fos, Bax, and MAPK; decreased proliferation; accelerated apoptosis; more cells arrested in the G1 phase; and fewer cells arrested in the S phase. Compared with the blank and NC groups, the miR-129 mimic group and the siRNA-c-Fos group showed decreased expression of c-Fos, Bax, and MAPK, increased cells proliferation, and decreased cell apoptosis, fewer cells arrested in the G1 phase and more cells arrested in the S phase. However, the miR-129 inhibitor groups showed reverse consequences. This study suggests that miR-129 could inhibit the occurrence and development of epilepsy by repressing c-Fos expression through inhibiting the MAPK signaling pathway.
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Affiliation(s)
- Dong-Mei Wu
- Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Science, Jiangsu Normal University, Xuzhou, P. R. China
| | - Yu-Tong Zhang
- Department of Neurology, The Fourth Affiliated Hospital of China Medical University, Shenyang, P. R. China
| | - Jun Lu
- Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Science, Jiangsu Normal University, Xuzhou, P. R. China
| | - Yuan-Lin Zheng
- Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Science, Jiangsu Normal University, Xuzhou, P. R. China
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61
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Liu Q, Zhang L, Li H. New Insights: MicroRNA Function in CNS Development and Psychiatric Diseases. ACTA ACUST UNITED AC 2018. [DOI: 10.1007/s40495-018-0129-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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62
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Meta-Analysis of MicroRNAs Dysregulated in the Hippocampal Dentate Gyrus of Animal Models of Epilepsy. eNeuro 2017; 4:eN-NWR-0152-17. [PMID: 29291240 PMCID: PMC5745610 DOI: 10.1523/eneuro.0152-17.2017] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 11/21/2017] [Accepted: 11/22/2017] [Indexed: 12/12/2022] Open
Abstract
The identification of mechanisms transforming normal to seizure-generating tissue after brain injury is key to developing new antiepileptogenic treatments. MicroRNAs (miRNAs) may act as regulators and potential treatment targets for epileptogenesis. Here, we undertook a meta-analysis of changes in miRNA expression in the hippocampal dentate gyrus (DG) following an epileptogenic insult in three epilepsy models. We identified 26 miRNAs significantly differentially expressed during epileptogenesis, and five differentially expressed in chronic epilepsy. Of these, 13 were not identified in any of the individual studies. To assess the role of these miRNAs, we predicted their mRNA targets and then filtered the list to include only target genes expressed in DG and negatively correlated with miRNA expression. Functional enrichment analysis of mRNA targets of miRNAs dysregulated during epileptogenesis suggested a role for molecular processes related to inflammation and synaptic function. Our results identify new miRNAs associated with epileptogenesis from existing data, highlighting the utility of meta-analysis in maximizing value from preclinical data.
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63
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Chowdhury D, Turner M, Patriarchi T, Hergarden AC, Anderson D, Zhang Y, Sun J, Chen CY, Ames JB, Hell JW. Ca 2+/calmodulin binding to PSD-95 mediates homeostatic synaptic scaling down. EMBO J 2017; 37:122-138. [PMID: 29118000 DOI: 10.15252/embj.201695829] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 09/07/2017] [Accepted: 10/02/2017] [Indexed: 11/09/2022] Open
Abstract
Postsynaptic density protein-95 (PSD-95) localizes AMPA-type glutamate receptors (AMPARs) to postsynaptic sites of glutamatergic synapses. Its postsynaptic displacement is necessary for loss of AMPARs during homeostatic scaling down of synapses. Here, we demonstrate that upon Ca2+ influx, Ca2+/calmodulin (Ca2+/CaM) binding to the N-terminus of PSD-95 mediates postsynaptic loss of PSD-95 and AMPARs during homeostatic scaling down. Our NMR structural analysis identified E17 within the PSD-95 N-terminus as important for binding to Ca2+/CaM by interacting with R126 on CaM. Mutating E17 to R prevented homeostatic scaling down in primary hippocampal neurons, which is rescued via charge inversion by ectopic expression of CaMR126E, as determined by analysis of miniature excitatory postsynaptic currents. Accordingly, increased binding of Ca2+/CaM to PSD-95 induced by a chronic increase in Ca2+ influx is a critical molecular event in homeostatic downscaling of glutamatergic synaptic transmission.
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Affiliation(s)
| | - Matthew Turner
- Department of Chemistry, University of California, Davis, CA, USA
| | | | - Anne C Hergarden
- Department of Pharmacology, University of California, Davis, CA, USA
| | - David Anderson
- Department of Chemistry, University of California, Davis, CA, USA
| | - Yonghong Zhang
- Department of Chemistry, University of Texas, Edinburgh, TX, USA
| | - Junqing Sun
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Chao-Yin Chen
- Department of Pharmacology, University of California, Davis, CA, USA
| | - James B Ames
- Department of Chemistry, University of California, Davis, CA, USA
| | - Johannes W Hell
- Department of Pharmacology, University of California, Davis, CA, USA
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Bauer S, van Alphen N, Becker A, Chiocchetti A, Deichmann R, Deller T, Freiman T, Freitag CM, Gehrig J, Hermsen AM, Jedlicka P, Kell C, Klein KM, Knake S, Kullmann DM, Liebner S, Norwood BA, Omigie D, Plate K, Reif A, Reif PS, Reiss Y, Roeper J, Ronellenfitsch MW, Schorge S, Schratt G, Schwarzacher SW, Steinbach JP, Strzelczyk A, Triesch J, Wagner M, Walker MC, von Wegner F, Rosenow F. Personalized translational epilepsy research - Novel approaches and future perspectives: Part II: Experimental and translational approaches. Epilepsy Behav 2017; 76:7-12. [PMID: 28917498 DOI: 10.1016/j.yebeh.2017.06.040] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 06/05/2017] [Indexed: 11/30/2022]
Abstract
Despite the availability of more than 15 new "antiepileptic drugs", the proportion of patients with pharmacoresistant epilepsy has remained constant at about 20-30%. Furthermore, no disease-modifying treatments shown to prevent the development of epilepsy following an initial precipitating brain injury or to reverse established epilepsy have been identified to date. This is likely in part due to the polyetiologic nature of epilepsy, which in turn requires personalized medicine approaches. Recent advances in imaging, pathology, genetics, and epigenetics have led to new pathophysiological concepts and the identification of monogenic causes of epilepsy. In the context of these advances, the First International Symposium on Personalized Translational Epilepsy Research (1st ISymPTER) was held in Frankfurt on September 8, 2016, to discuss novel approaches and future perspectives for personalized translational research. These included new developments and ideas in a range of experimental and clinical areas such as deep phenotyping, quantitative brain imaging, EEG/MEG-based analysis of network dysfunction, tissue-based translational studies, innate immunity mechanisms, microRNA as treatment targets, functional characterization of genetic variants in human cell models and rodent organotypic slice cultures, personalized treatment approaches for monogenic epilepsies, blood-brain barrier dysfunction, therapeutic focal tissue modification, computational modeling for target and biomarker identification, and cost analysis in (monogenic) disease and its treatment. This report on the meeting proceedings is aimed at stimulating much needed investments of time and resources in personalized translational epilepsy research. This Part II includes the experimental and translational approaches and a discussion of the future perspectives, while the diagnostic methods, EEG network analysis, biomarkers, and personalized treatment approaches were addressed in Part I [1].
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Affiliation(s)
- Sebastian Bauer
- Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, Center of Neurology and Neurosurgery, Goethe University Frankfurt, 60528 Frankfurt, Germany; Epilepsy Center Marburg, Department of Neurology, Philipps-University Marburg, 35043 Marburg, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Natascha van Alphen
- Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, Center of Neurology and Neurosurgery, Goethe University Frankfurt, 60528 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Albert Becker
- Institute for Neuropathology, University Bonn, 53105 Bonn, Germany
| | - Andreas Chiocchetti
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Goethe University Frankfurt, 60528 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Ralf Deichmann
- Brain Imaging Center (BIC) Frankfurt, Department of Neurology, Center of Neurology and Neurosurgery, Goethe University Frankfurt, 60528 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Thomas Deller
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe University Frankfurt, 60590 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Thomas Freiman
- Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, Center of Neurology and Neurosurgery, Goethe University Frankfurt, 60528 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Christine M Freitag
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Goethe University Frankfurt, 60528 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Johannes Gehrig
- Emmy-Noether Group Kell, Department of Neurology, Center of Neurology and Neurosurgery, Goethe University Frankfurt, 60528 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Anke M Hermsen
- Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, Center of Neurology and Neurosurgery, Goethe University Frankfurt, 60528 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Peter Jedlicka
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe University Frankfurt, 60590 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Christian Kell
- Emmy-Noether Group Kell, Department of Neurology, Center of Neurology and Neurosurgery, Goethe University Frankfurt, 60528 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Karl Martin Klein
- Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, Center of Neurology and Neurosurgery, Goethe University Frankfurt, 60528 Frankfurt, Germany; Epilepsy Center Marburg, Department of Neurology, Philipps-University Marburg, 35043 Marburg, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Susanne Knake
- Epilepsy Center Marburg, Department of Neurology, Philipps-University Marburg, 35043 Marburg, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Dimitri M Kullmann
- Institute of Neurology, University College London (UCL), London WC1E 6BT, United Kingdom
| | - Stefan Liebner
- Edinger-Institute Frankfurt, Neuroscience Center, Goethe University Frankfurt, 60590 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Braxton A Norwood
- Epilepsy Center Marburg, Department of Neurology, Philipps-University Marburg, 35043 Marburg, Germany
| | - Diana Omigie
- Max-Planck-Institute for Empirical Aesthetics, 60322 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Karlheinz Plate
- Edinger-Institute Frankfurt, Neuroscience Center, Goethe University Frankfurt, 60590 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Andreas Reif
- Department of Psychiatry, Psychosomatics and Psychotherapy, Goethe University Frankfurt, 60528 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Philipp S Reif
- Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, Center of Neurology and Neurosurgery, Goethe University Frankfurt, 60528 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Yvonne Reiss
- Edinger-Institute Frankfurt, Neuroscience Center, Goethe University Frankfurt, 60590 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Jochen Roeper
- Institute of Neurophysiology, Neuroscience Center, Goethe-University Frankfurt, 60590 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Michael W Ronellenfitsch
- Dr. Senckenberg Institute for Neurooncology, Center of Neurology and Neurosurgery, Goethe University Frankfurt, 60528 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Stephanie Schorge
- Institute of Neurology, University College London (UCL), London WC1E 6BT, United Kingdom
| | - Gerhard Schratt
- Institute of Physiological Chemistry, Philipps-University Marburg, 35043 Marburg, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Stephan W Schwarzacher
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe University Frankfurt, 60590 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Joachim P Steinbach
- Dr. Senckenberg Institute for Neurooncology, Center of Neurology and Neurosurgery, Goethe University Frankfurt, 60528 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Adam Strzelczyk
- Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, Center of Neurology and Neurosurgery, Goethe University Frankfurt, 60528 Frankfurt, Germany; Epilepsy Center Marburg, Department of Neurology, Philipps-University Marburg, 35043 Marburg, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Jochen Triesch
- Frankfurt Institute for Advanced Studies (FIAS), 60438 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Marlies Wagner
- Institute of Neuroradiology, Center of Neurology and Neurosurgery, Goethe University Frankfurt, 60528 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Matthew C Walker
- Institute of Neurology, University College London (UCL), London WC1E 6BT, United Kingdom
| | - Frederic von Wegner
- Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, Center of Neurology and Neurosurgery, Goethe University Frankfurt, 60528 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Felix Rosenow
- Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, Center of Neurology and Neurosurgery, Goethe University Frankfurt, 60528 Frankfurt, Germany; Epilepsy Center Marburg, Department of Neurology, Philipps-University Marburg, 35043 Marburg, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1).
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SoxC transcription factors: multifunctional regulators of neurodevelopment. Cell Tissue Res 2017; 371:91-103. [PMID: 29079881 DOI: 10.1007/s00441-017-2708-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 10/05/2017] [Indexed: 12/19/2022]
Abstract
During development, generation of neurons is coordinated by the sequential activation of gene expression programs by stage- and subtype-specific transcription factor networks. The SoxC group transcription factors, Sox4 and Sox11, have recently emerged as critical components of this network. Initially identified as survival and differentiation factors for neural precursors, SoxC factors have now been linked to a broader array of developmental processes including neuronal subtype specification, migration, dendritogenesis and establishment of neuronal projections, and are now being employed in experimental strategies for neuronal replacement and axonal regeneration in the diseased central nervous system. This review summarizes the current knowledge regarding SoxC factor function in CNS development and disease and their promise for regeneration.
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Rani A, O'Shea A, Ianov L, Cohen RA, Woods AJ, Foster TC. miRNA in Circulating Microvesicles as Biomarkers for Age-Related Cognitive Decline. Front Aging Neurosci 2017; 9:323. [PMID: 29046635 PMCID: PMC5632661 DOI: 10.3389/fnagi.2017.00323] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 09/20/2017] [Indexed: 11/13/2022] Open
Abstract
Community dwelling older individuals from the North Florida region were examined for health status and a comprehensive neuropsychological battery, including the Montreal Cognitive Assessment (MoCA), was performed on each participant. A subpopulation (58 females and 39 males) met the criteria for age (60–89) and no evidence of mild cognitive impairment, with a MoCA score ≥23. Despite the stringent criteria for participation, MoCA scores were negatively correlated within the limited age range. Extracellular microvesicles were isolated from the plasma and samples were found to be positive for the exosome marker CD63, with an enrichment of particles within the size range for exosomes. miRNA was extracted and examined using next generation sequencing with a stringent criterion (average of ≥10 counts per million reads) resulting in 117 miRNA for subsequent analysis. Characterization of expression confirmed pervious work concerning the relative abundance and overall pattern of expression of miRNA in plasma. Correlation analysis indicated that most of the miRNAs (74 miRNAs) were positively correlated with age (p <0.01). Multiple regression was employed to identify the relationship of miRNA expression and MoCA score, accounting for age. MoCA scores were negatively correlated with 13 miRNAs. The pattern of expression for cognition-related miRNA did not match that previously described for Alzheimer’s disease. Enrichment analysis was employed to identify miRNA–gene interactions to reveal possible links to brain function.
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Affiliation(s)
- Asha Rani
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Andrew O'Shea
- Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, United States.,Center for Cognitive Aging and Memory, McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Lara Ianov
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, United States.,Genetics and Genomics Program, Genetics Institute, University of Florida, Gainesville, FL, United States
| | - Ronald A Cohen
- Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, United States.,Center for Cognitive Aging and Memory, McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Adam J Woods
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, United States.,Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, United States.,Center for Cognitive Aging and Memory, McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Thomas C Foster
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, United States.,Genetics and Genomics Program, Genetics Institute, University of Florida, Gainesville, FL, United States
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Santin JM, Vallejo M, Hartzler LK. Synaptic up-scaling preserves motor circuit output after chronic, natural inactivity. eLife 2017; 6:30005. [PMID: 28914603 PMCID: PMC5636609 DOI: 10.7554/elife.30005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 09/11/2017] [Indexed: 12/25/2022] Open
Abstract
Neural systems use homeostatic plasticity to maintain normal brain functions and to prevent abnormal activity. Surprisingly, homeostatic mechanisms that regulate circuit output have mainly been demonstrated during artificial and/or pathological perturbations. Natural, physiological scenarios that activate these stabilizing mechanisms in neural networks of mature animals remain elusive. To establish the extent to which a naturally inactive circuit engages mechanisms of homeostatic plasticity, we utilized the respiratory motor circuit in bullfrogs that normally remains inactive for several months during the winter. We found that inactive respiratory motoneurons exhibit a classic form of homeostatic plasticity, up-scaling of AMPA-glutamate receptors. Up-scaling increased the synaptic strength of respiratory motoneurons and acted to boost motor amplitude from the respiratory network following months of inactivity. Our results show that synaptic scaling sustains strength of the respiratory motor output following months of inactivity, thereby supporting a major neuroscience hypothesis in a normal context for an adult animal. Neurons in the brain communicate using chemical signals that they send and receive across junctions called synapses. To maintain normal behavior over time, circuits of neurons must reliably process these signals. A variety of nervous system disorders may result if they are unable to do so, as may occur when neural activity changes as a result of disease or injury. The processes underlying the stability of a neuron’s synapses is referred to as “homeostatic” synaptic plasticity because the changes made by the neuron directly oppose the altered level of activity. In one form of homeostatic plasticity, known as synaptic scaling, neurons modify the strength of all of their synapses in response to changes in neural activity. There is substantial experimental evidence to show that in young animals, neurons that communicate using a chemical called glutamate undergo synaptic scaling in response to artificial changes in activity. It had not been directly shown that synaptic scaling protects the neural activity of adult animals in their natural environments, in part, because neural activity in most healthy animals generally only goes through small changes. However, the neurons in the brain that cause the breathing muscles of bullfrogs to contract are ideal for studying homeostatic plasticity because they are naturally inactive for several months when frogs hibernate in ponds during the winter. During this time, the bullfrogs do not need to use their lungs to breathe because enough oxygen passes through their skin to keep them alive. Santin et al. have now observed synaptic scaling of glutamate synapses in individual bullfrog neurons that had been inactive for two months. Further experiments that examined the activity of the breathing control circuit in the brainstem provided evidence that synaptic scaling leads to sufficient amounts of neural activity that would activate the breathing muscles when frogs emerge from hibernation. Therefore neural activity after prolonged, natural inactivity relies on synaptic scaling to preserve life-sustaining behavior in frogs. These results open up new questions: mainly, how do synaptic scaling and other forms of homeostatic plasticity operate in animals as they experience normal variations in neural activity? Determining how homeostatic plasticity works normally in an animal will help us to understand what happens when plasticity mechanisms go wrong, as is thought to occur in several human nervous system diseases including nervous system injury, Alzheimer’s disease, and epilepsy.
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Affiliation(s)
- Joseph M Santin
- Division of Biological Sciences, University of Missouri-Columbia, Columbia, United States.,Department of Biological Sciences, Wright State University, Dayton, United States
| | - Mauricio Vallejo
- Department of Biological Sciences, Wright State University, Dayton, United States
| | - Lynn K Hartzler
- Department of Biological Sciences, Wright State University, Dayton, United States
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Rajman M, Metge F, Fiore R, Khudayberdiev S, Aksoy-Aksel A, Bicker S, Ruedell Reschke C, Raoof R, Brennan GP, Delanty N, Farrell MA, O'Brien DF, Bauer S, Norwood B, Veno MT, Krüger M, Braun T, Kjems J, Rosenow F, Henshall DC, Dieterich C, Schratt G. A microRNA-129-5p/Rbfox crosstalk coordinates homeostatic downscaling of excitatory synapses. EMBO J 2017; 36:1770-1787. [PMID: 28487411 DOI: 10.15252/embj.201695748] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 04/05/2017] [Accepted: 04/07/2017] [Indexed: 12/31/2022] Open
Abstract
Synaptic downscaling is a homeostatic mechanism that allows neurons to reduce firing rates during chronically elevated network activity. Although synaptic downscaling is important in neural circuit development and epilepsy, the underlying mechanisms are poorly described. We performed small RNA profiling in picrotoxin (PTX)-treated hippocampal neurons, a model of synaptic downscaling. Thereby, we identified eight microRNAs (miRNAs) that were increased in response to PTX, including miR-129-5p, whose inhibition blocked synaptic downscaling in vitro and reduced epileptic seizure severity in vivo Using transcriptome, proteome, and bioinformatic analysis, we identified the calcium pump Atp2b4 and doublecortin (Dcx) as miR-129-5p targets. Restoring Atp2b4 and Dcx expression was sufficient to prevent synaptic downscaling in PTX-treated neurons. Furthermore, we characterized a functional crosstalk between miR-129-5p and the RNA-binding protein (RBP) Rbfox1. In the absence of PTX, Rbfox1 promoted the expression of Atp2b4 and Dcx. Upon PTX treatment, Rbfox1 expression was downregulated by miR-129-5p, thereby allowing the repression of Atp2b4 and Dcx. We therefore identified a novel activity-dependent miRNA/RBP crosstalk during synaptic scaling, with potential implications for neural network homeostasis and epileptogenesis.
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Affiliation(s)
- Marek Rajman
- Biochemisch-Pharmakologisches Centrum, Institut für Physiologische Chemie, Philipps-Universität Marburg, Marburg, Germany
| | - Franziska Metge
- Section of Bioinformatics and Systems Cardiology, Klaus Tschira Institute for Integrative Computational Cardiology, Department of Internal Medicine III, German Center for Cardiovascular Research (DZHK), University Hospital Heidelberg, Heidelberg, Germany
| | - Roberto Fiore
- Biochemisch-Pharmakologisches Centrum, Institut für Physiologische Chemie, Philipps-Universität Marburg, Marburg, Germany
| | - Sharof Khudayberdiev
- Biochemisch-Pharmakologisches Centrum, Institut für Physiologische Chemie, Philipps-Universität Marburg, Marburg, Germany
| | - Ayla Aksoy-Aksel
- Biochemisch-Pharmakologisches Centrum, Institut für Physiologische Chemie, Philipps-Universität Marburg, Marburg, Germany
| | - Silvia Bicker
- Biochemisch-Pharmakologisches Centrum, Institut für Physiologische Chemie, Philipps-Universität Marburg, Marburg, Germany
| | | | - Rana Raoof
- Physiology & Medical Physics Department, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Gary P Brennan
- Physiology & Medical Physics Department, Royal College of Surgeons in Ireland, Dublin, Ireland
| | | | | | | | - Sebastian Bauer
- Epilepsiezentrum Frankfurt Rhein-Main, Neurozentrum, Goethe-Universität Frankfurt, Frankfurt, Germany.,Epilepsiezentrum Hessen - Marburg, Philipps-Universität Marburg, Marburg, Germany
| | - Braxton Norwood
- Epilepsiezentrum Frankfurt Rhein-Main, Neurozentrum, Goethe-Universität Frankfurt, Frankfurt, Germany.,Epilepsiezentrum Hessen - Marburg, Philipps-Universität Marburg, Marburg, Germany
| | - Morten T Veno
- Department of Molecular Biology and Genetics and Interdisciplinary Nanoscience Center, Aarhus University, Aarhus, Denmark
| | - Marcus Krüger
- Institute for Genetics, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.,Center for Molecular Medicine (CMMC), University of Cologne, Cologne, Germany
| | - Thomas Braun
- Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Jørgen Kjems
- Department of Molecular Biology and Genetics and Interdisciplinary Nanoscience Center, Aarhus University, Aarhus, Denmark
| | - Felix Rosenow
- Epilepsiezentrum Frankfurt Rhein-Main, Neurozentrum, Goethe-Universität Frankfurt, Frankfurt, Germany.,Epilepsiezentrum Hessen - Marburg, Philipps-Universität Marburg, Marburg, Germany
| | - David C Henshall
- Physiology & Medical Physics Department, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Christoph Dieterich
- Section of Bioinformatics and Systems Cardiology, Klaus Tschira Institute for Integrative Computational Cardiology, Department of Internal Medicine III, German Center for Cardiovascular Research (DZHK), University Hospital Heidelberg, Heidelberg, Germany
| | - Gerhard Schratt
- Biochemisch-Pharmakologisches Centrum, Institut für Physiologische Chemie, Philipps-Universität Marburg, Marburg, Germany
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