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Millan MJ, Goodwin GM, Meyer-Lindenberg A, Ove Ögren S. Learning from the past and looking to the future: Emerging perspectives for improving the treatment of psychiatric disorders. Eur Neuropsychopharmacol 2015; 25:599-656. [PMID: 25836356 DOI: 10.1016/j.euroneuro.2015.01.016] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 01/28/2015] [Indexed: 02/06/2023]
Abstract
Modern neuropsychopharmacology commenced in the 1950s with the serendipitous discovery of first-generation antipsychotics and antidepressants which were therapeutically effective yet had marked adverse effects. Today, a broader palette of safer and better-tolerated agents is available for helping people that suffer from schizophrenia, depression and other psychiatric disorders, while complementary approaches like psychotherapy also have important roles to play in their treatment, both alone and in association with medication. Nonetheless, despite considerable efforts, current management is still only partially effective, and highly-prevalent psychiatric disorders of the brain continue to represent a huge personal and socio-economic burden. The lack of success in discovering more effective pharmacotherapy has contributed, together with many other factors, to a relative disengagement by pharmaceutical firms from neuropsychiatry. Nonetheless, interest remains high, and partnerships are proliferating with academic centres which are increasingly integrating drug discovery and translational research into their traditional activities. This is, then, a time of transition and an opportune moment to thoroughly survey the field. Accordingly, the present paper, first, chronicles the discovery and development of psychotropic agents, focusing in particular on their mechanisms of action and therapeutic utility, and how problems faced were eventually overcome. Second, it discusses the lessons learned from past successes and failures, and how they are being applied to promote future progress. Third, it comprehensively surveys emerging strategies that are (1), improving our understanding of the diagnosis and classification of psychiatric disorders; (2), deepening knowledge of their underlying risk factors and pathophysiological substrates; (3), refining cellular and animal models for discovery and validation of novel therapeutic agents; (4), improving the design and outcome of clinical trials; (5), moving towards reliable biomarkers of patient subpopulations and medication efficacy and (6), promoting collaborative approaches to innovation by uniting key partners from the regulators, industry and academia to patients. Notwithstanding the challenges ahead, the many changes and ideas articulated herein provide new hope and something of a framework for progress towards the improved prevention and relief of psychiatric and other CNS disorders, an urgent mission for our Century.
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Affiliation(s)
- Mark J Millan
- Pole for Innovation in Neurosciences, IDR Servier, 125 chemin de ronde, 78290 Croissy sur Seine, France.
| | - Guy M Goodwin
- University Department of Psychiatry, Oxford University, Warneford Hospital, Oxford OX3 7JX, England, UK
| | - Andreas Meyer-Lindenberg
- Central Institute of Mental Health, University of Heidelberg/Medical Faculty Mannheim, J5, D-68159 Mannheim, Germany
| | - Sven Ove Ögren
- Department of Neuroscience, Karolinska Institutet, Retzius väg 8, S-17177 Stockholm, Sweden
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Eom T, Muslimov IA, Tsokas P, Berardi V, Zhong J, Sacktor TC, Tiedge H. Neuronal BC RNAs cooperate with eIF4B to mediate activity-dependent translational control. ACTA ACUST UNITED AC 2014; 207:237-52. [PMID: 25332164 PMCID: PMC4210447 DOI: 10.1083/jcb.201401005] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Regulatory brain cytoplasmic RNAs cooperate with eukaryotic initiation factor 4B to couple translation to receptor activation in support of long-term plastic changes in neurons. In neurons, translational regulation of gene expression has been implicated in the activity-dependent management of synapto-dendritic protein repertoires. However, the fundamentals of stimulus-modulated translational control in neurons remain poorly understood. Here we describe a mechanism in which regulatory brain cytoplasmic (BC) RNAs cooperate with eukaryotic initiation factor 4B (eIF4B) to control translation in a manner that is responsive to neuronal activity. eIF4B is required for the translation of mRNAs with structured 5′ untranslated regions (UTRs), exemplified here by neuronal protein kinase Mζ (PKMζ) mRNA. Upon neuronal stimulation, synapto-dendritic eIF4B is dephosphorylated at serine 406 in a rapid process that is mediated by protein phosphatase 2A. Such dephosphorylation causes a significant decrease in the binding affinity between eIF4B and BC RNA translational repressors, enabling the factor to engage the 40S small ribosomal subunit for translation initiation. BC RNA translational control, mediated via eIF4B phosphorylation status, couples neuronal activity to translational output, and thus provides a mechanistic basis for long-term plastic changes in nerve cells.
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Affiliation(s)
- Taesun Eom
- Department of Physiology and Pharmacology, Department of Anesthesiology, and Department of Neurology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, NY 11203
| | - Ilham A Muslimov
- Department of Physiology and Pharmacology, Department of Anesthesiology, and Department of Neurology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, NY 11203
| | - Panayiotis Tsokas
- Department of Physiology and Pharmacology, Department of Anesthesiology, and Department of Neurology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, NY 11203 Department of Physiology and Pharmacology, Department of Anesthesiology, and Department of Neurology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, NY 11203
| | - Valerio Berardi
- Department of Physiology and Pharmacology, Department of Anesthesiology, and Department of Neurology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, NY 11203
| | - Jun Zhong
- Department of Physiology and Pharmacology, Department of Anesthesiology, and Department of Neurology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, NY 11203
| | - Todd C Sacktor
- Department of Physiology and Pharmacology, Department of Anesthesiology, and Department of Neurology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, NY 11203 Department of Physiology and Pharmacology, Department of Anesthesiology, and Department of Neurology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, NY 11203 Department of Physiology and Pharmacology, Department of Anesthesiology, and Department of Neurology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, NY 11203
| | - Henri Tiedge
- Department of Physiology and Pharmacology, Department of Anesthesiology, and Department of Neurology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, NY 11203 Department of Physiology and Pharmacology, Department of Anesthesiology, and Department of Neurology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, NY 11203
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Muslimov IA, Tuzhilin A, Tang TH, Wong RKS, Bianchi R, Tiedge H. Interactions of noncanonical motifs with hnRNP A2 promote activity-dependent RNA transport in neurons. ACTA ACUST UNITED AC 2014; 205:493-510. [PMID: 24841565 PMCID: PMC4033767 DOI: 10.1083/jcb.201310045] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Ca2+-dependent RNA–protein interactions enable activity-inducible RNA transport in dendrites. A key determinant of neuronal functionality and plasticity is the targeted delivery of select ribonucleic acids (RNAs) to synaptodendritic sites of protein synthesis. In this paper, we ask how dendritic RNA transport can be regulated in a manner that is informed by the cell’s activity status. We describe a molecular mechanism in which inducible interactions of noncanonical RNA motif structures with targeting factor heterogeneous nuclear ribonucleoprotein (hnRNP) A2 form the basis for activity-dependent dendritic RNA targeting. High-affinity interactions between hnRNP A2 and conditional GA-type RNA targeting motifs are critically dependent on elevated Ca2+ levels in a narrow concentration range. Dendritic transport of messenger RNAs that carry such GA motifs is inducible by influx of Ca2+ through voltage-dependent calcium channels upon β-adrenergic receptor activation. The combined data establish a functional correspondence between Ca2+-dependent RNA–protein interactions and activity-inducible RNA transport in dendrites. They also indicate a role of genomic retroposition in the phylogenetic development of RNA targeting competence.
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Affiliation(s)
- Ilham A Muslimov
- The Robert F. Furchgott Center for Neural and Behavioral Science, Department of Physiology and Pharmacology, and Department of Neurology, State University of New York Downstate Medical Center, Brooklyn, NY 11203The Robert F. Furchgott Center for Neural and Behavioral Science, Department of Physiology and Pharmacology, and Department of Neurology, State University of New York Downstate Medical Center, Brooklyn, NY 11203
| | - Aliya Tuzhilin
- The Robert F. Furchgott Center for Neural and Behavioral Science, Department of Physiology and Pharmacology, and Department of Neurology, State University of New York Downstate Medical Center, Brooklyn, NY 11203The Robert F. Furchgott Center for Neural and Behavioral Science, Department of Physiology and Pharmacology, and Department of Neurology, State University of New York Downstate Medical Center, Brooklyn, NY 11203
| | - Thean Hock Tang
- Advanced Medical and Dental Institute, Universiti Sains Malaysi, 13200 Kepala Batas, Penang, Malaysia
| | - Robert K S Wong
- The Robert F. Furchgott Center for Neural and Behavioral Science, Department of Physiology and Pharmacology, and Department of Neurology, State University of New York Downstate Medical Center, Brooklyn, NY 11203The Robert F. Furchgott Center for Neural and Behavioral Science, Department of Physiology and Pharmacology, and Department of Neurology, State University of New York Downstate Medical Center, Brooklyn, NY 11203The Robert F. Furchgott Center for Neural and Behavioral Science, Department of Physiology and Pharmacology, and Department of Neurology, State University of New York Downstate Medical Center, Brooklyn, NY 11203
| | - Riccardo Bianchi
- The Robert F. Furchgott Center for Neural and Behavioral Science, Department of Physiology and Pharmacology, and Department of Neurology, State University of New York Downstate Medical Center, Brooklyn, NY 11203The Robert F. Furchgott Center for Neural and Behavioral Science, Department of Physiology and Pharmacology, and Department of Neurology, State University of New York Downstate Medical Center, Brooklyn, NY 11203
| | - Henri Tiedge
- The Robert F. Furchgott Center for Neural and Behavioral Science, Department of Physiology and Pharmacology, and Department of Neurology, State University of New York Downstate Medical Center, Brooklyn, NY 11203The Robert F. Furchgott Center for Neural and Behavioral Science, Department of Physiology and Pharmacology, and Department of Neurology, State University of New York Downstate Medical Center, Brooklyn, NY 11203The Robert F. Furchgott Center for Neural and Behavioral Science, Department of Physiology and Pharmacology, and Department of Neurology, State University of New York Downstate Medical Center, Brooklyn, NY 11203
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Satori CP, Henderson MM, Krautkramer EA, Kostal V, Distefano MM, Arriaga EA. Bioanalysis of eukaryotic organelles. Chem Rev 2013; 113:2733-811. [PMID: 23570618 PMCID: PMC3676536 DOI: 10.1021/cr300354g] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Chad P. Satori
- Department of Chemistry, University of Minnesota, Twin Cities, Minneapolis, MN, USA, 55455
| | - Michelle M. Henderson
- Department of Chemistry, University of Minnesota, Twin Cities, Minneapolis, MN, USA, 55455
| | - Elyse A. Krautkramer
- Department of Chemistry, University of Minnesota, Twin Cities, Minneapolis, MN, USA, 55455
| | - Vratislav Kostal
- Tescan, Libusina trida 21, Brno, 623 00, Czech Republic
- Institute of Analytical Chemistry ASCR, Veveri 97, Brno, 602 00, Czech Republic
| | - Mark M. Distefano
- Department of Chemistry, University of Minnesota, Twin Cities, Minneapolis, MN, USA, 55455
| | - Edgar A. Arriaga
- Department of Chemistry, University of Minnesota, Twin Cities, Minneapolis, MN, USA, 55455
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5
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Abstract
In higher eukaryotes, increasing evidence suggests, gene expression is to a large degree controlled by RNA. Regulatory RNAs have been implicated in the management of neuronal function and plasticity in mammalian brains. However, much of the molecular-mechanistic framework that enables neuronal regulatory RNAs to control gene expression remains poorly understood. Here, we establish molecular mechanisms that underlie the regulatory capacity of neuronal BC RNAs in the translational control of gene expression. We report that regulatory BC RNAs employ a two-pronged approach in translational control. One of two distinct repression mechanisms is mediated by C-loop motifs in BC RNA 3' stem-loop domains. These C-loops bind to eIF4B and prevent the factor's interaction with 18S rRNA of the small ribosomal subunit. In the second mechanism, the central A-rich domains of BC RNAs target eIF4A, specifically inhibiting its RNA helicase activity. Thus, BC RNAs repress translation initiation in a bimodal mechanistic approach. As BC RNA functionality has evolved independently in rodent and primate lineages, our data suggest that BC RNA translational control was necessitated and implemented during mammalian phylogenetic development of complex neural systems.
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Muslimov IA, Patel MV, Rose A, Tiedge H. Spatial code recognition in neuronal RNA targeting: role of RNA-hnRNP A2 interactions. ACTA ACUST UNITED AC 2011; 194:441-57. [PMID: 21807882 PMCID: PMC3153643 DOI: 10.1083/jcb.201010027] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Recognition of non-canonical purine•purine RNA motifs by hnRNP A2 mediates targeted delivery of neuronal RNAs to dendrites. In neurons, regulation of gene expression occurs in part through translational control at the synapse. A fundamental requirement for such local control is the targeted delivery of select neuronal mRNAs and regulatory RNAs to distal dendritic sites. The nature of spatial RNA destination codes, and the mechanism by which they are interpreted for dendritic delivery, remain poorly understood. We find here that in a key dendritic RNA transport pathway (exemplified by BC1 RNA, a dendritic regulatory RNA, and protein kinase M ζ [PKMζ] mRNA, a dendritic mRNA), noncanonical purine•purine nucleotide interactions are functional determinants of RNA targeting motifs. These motifs are specifically recognized by heterogeneous nuclear ribonucleoprotein A2 (hnRNP A2), a trans-acting factor required for dendritic delivery. Binding to hnRNP A2 and ensuing dendritic delivery are effectively competed by RNAs with CGG triplet repeat expansions. CGG repeats, when expanded in the 5′ untranslated region of fragile X mental retardation 1 (FMR1) mRNA, cause fragile X–associated tremor/ataxia syndrome. The data suggest that cellular dysregulation observed in the presence of CGG repeat RNA may result from molecular competition in neuronal RNA transport pathways.
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Affiliation(s)
- Ilham A Muslimov
- The Robert F. Furchgott Center for Neural and Behavioral Science, Department of Physiology and Pharmacology, State University of New York, Health Science Center at Brooklyn, USA
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Buckley PT, Lee MT, Sul JY, Miyashiro KY, Bell TJ, Fisher SA, Kim J, Eberwine J. Cytoplasmic intron sequence-retaining transcripts can be dendritically targeted via ID element retrotransposons. Neuron 2011; 69:877-84. [PMID: 21382548 DOI: 10.1016/j.neuron.2011.02.028] [Citation(s) in RCA: 111] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/20/2011] [Indexed: 01/26/2023]
Abstract
RNA precursors give rise to mRNA after splicing of intronic sequences traditionally thought to occur in the nucleus. Here, we show that intron sequences are retained in a number of dendritically-targeted mRNAs, by using microarray and Illumina sequencing of isolated dendritic mRNA as well as in situ hybridization. Many of the retained introns contain ID elements, a class of SINE retrotransposon. A portion of these SINEs confers dendritic targeting to exogenous and endogenous transcripts showing the necessity of ID-mediated mechanisms for the targeting of different transcripts to dendrites. ID elements are capable of selectively altering the distribution of endogenous proteins, providing a link between intronic SINEs and protein function. As such, the ID element represents a common dendritic targeting element found across multiple RNAs. Retention of intronic sequence is a more general phenomenon than previously thought and plays a functional role in the biology of the neuron, partly mediated by co-opted repetitive sequences.
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Affiliation(s)
- Peter T Buckley
- Department of Pharmacology, University of Pennsylvania, Philadelphia, PA 19104, USA
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Zhong J, Chuang SC, Bianchi R, Zhao W, Paul G, Thakkar P, Liu D, Fenton AA, Wong RKS, Tiedge H. Regulatory BC1 RNA and the fragile X mental retardation protein: convergent functionality in brain. PLoS One 2010; 5:e15509. [PMID: 21124905 PMCID: PMC2990754 DOI: 10.1371/journal.pone.0015509] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2010] [Accepted: 10/06/2010] [Indexed: 12/22/2022] Open
Abstract
Background BC RNAs and the fragile X mental retardation protein (FMRP) are translational repressors that have been implicated in the control of local protein synthesis at the synapse. Work with BC1 and Fmr1 animal models has revealed that phenotypical consequences resulting from the absence of either BC1 RNA or FMRP are remarkably similar. To establish functional interactions between BC1 RNA and FMRP is important for our understanding of how local protein synthesis regulates neuronal excitability. Methodology/Principal Findings We generated BC1−/− Fmr1−/− double knockout (dKO) mice. We examined such animals, lacking both BC1 RNA and FMRP, in comparison with single knockout (sKO) animals lacking either one repressor. Analysis of neural phenotypical output revealed that at least three attributes of brain functionality are subject to control by both BC1 RNA and FMRP: neuronal network excitability, epileptogenesis, and place learning. The severity of CA3 pyramidal cell hyperexcitability was significantly higher in BC1−/− Fmr1−/− dKO preparations than in the respective sKO preparations, as was seizure susceptibility of BC1−/− Fmr1−/− dKO animals in response to auditory stimulation. In place learning, BC1−/− Fmr1−/− dKO animals were severely impaired, in contrast to BC1−/− or Fmr1−/− sKO animals which exhibited only mild deficits. Conclusions/Significance Our data indicate that BC1 RNA and FMRP operate in sequential-independent fashion. They suggest that the molecular interplay between two translational repressors directly impacts brain functionality.
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Affiliation(s)
- Jun Zhong
- Department of Physiology and Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, State University of New York Health Science Center at Brooklyn, Brooklyn, New York, United States of America
- * E-mail: (HT); (JZ)
| | - Shih-Chieh Chuang
- Department of Physiology and Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, State University of New York Health Science Center at Brooklyn, Brooklyn, New York, United States of America
- Program in Neural and Behavioral Science, State University of New York Health Science Center at Brooklyn, Brooklyn, New York, United States of America
| | - Riccardo Bianchi
- Department of Physiology and Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, State University of New York Health Science Center at Brooklyn, Brooklyn, New York, United States of America
- Program in Neural and Behavioral Science, State University of New York Health Science Center at Brooklyn, Brooklyn, New York, United States of America
| | - Wangfa Zhao
- Department of Physiology and Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, State University of New York Health Science Center at Brooklyn, Brooklyn, New York, United States of America
- Program in Neural and Behavioral Science, State University of New York Health Science Center at Brooklyn, Brooklyn, New York, United States of America
| | - Geet Paul
- Department of Physiology and Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, State University of New York Health Science Center at Brooklyn, Brooklyn, New York, United States of America
| | - Punam Thakkar
- Department of Physiology and Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, State University of New York Health Science Center at Brooklyn, Brooklyn, New York, United States of America
| | - David Liu
- Department of Physiology and Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, State University of New York Health Science Center at Brooklyn, Brooklyn, New York, United States of America
| | - André A. Fenton
- Department of Physiology and Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, State University of New York Health Science Center at Brooklyn, Brooklyn, New York, United States of America
- Program in Neural and Behavioral Science, State University of New York Health Science Center at Brooklyn, Brooklyn, New York, United States of America
| | - Robert K. S. Wong
- Department of Physiology and Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, State University of New York Health Science Center at Brooklyn, Brooklyn, New York, United States of America
- Program in Neural and Behavioral Science, State University of New York Health Science Center at Brooklyn, Brooklyn, New York, United States of America
- Department of Neurology, State University of New York Health Science Center at Brooklyn, Brooklyn, New York, United States of America
| | - Henri Tiedge
- Department of Physiology and Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, State University of New York Health Science Center at Brooklyn, Brooklyn, New York, United States of America
- Program in Neural and Behavioral Science, State University of New York Health Science Center at Brooklyn, Brooklyn, New York, United States of America
- Department of Neurology, State University of New York Health Science Center at Brooklyn, Brooklyn, New York, United States of America
- * E-mail: (HT); (JZ)
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Eberwine J, Bartfai T. Single cell transcriptomics of hypothalamic warm sensitive neurons that control core body temperature and fever response Signaling asymmetry and an extension of chemical neuroanatomy. Pharmacol Ther 2010; 129:241-59. [PMID: 20970451 DOI: 10.1016/j.pharmthera.2010.09.010] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2010] [Accepted: 09/30/2010] [Indexed: 12/11/2022]
Abstract
We report on an 'unbiased' molecular characterization of individual, adult neurons, active in a central, anterior hypothalamic neuronal circuit, by establishing cDNA libraries from each individual, electrophysiologically identified warm sensitive neuron (WSN). The cDNA libraries were analyzed by Affymetrix microarray. The presence and frequency of cDNAs were confirmed and enhanced with Illumina sequencing of each single cell cDNA library. cDNAs encoding the GABA biosynthetic enzyme Gad1 and of adrenomedullin, galanin, prodynorphin, somatostatin, and tachykinin were found in the WSNs. The functional cellular and in vivo studies on dozens of the more than 500 neurotransmitters, hormone receptors and ion channels, whose cDNA was identified and sequence confirmed, suggest little or no discrepancy between the transcriptional and functional data in WSNs; whenever agonists were available for a receptor whose cDNA was identified, a functional response was found. Sequencing single neuron libraries permitted identification of rarely expressed receptors like the insulin receptor, adiponectin receptor 2 and of receptor heterodimers; information that is lost when pooling cells leads to dilution of signals and mixing signals. Despite the common electrophysiological phenotype and uniform Gad1 expression, WSN transcriptomes show heterogeneity, suggesting strong epigenetic influence on the transcriptome. Our study suggests that it is well-worth interrogating the cDNA libraries of single neurons by sequencing and chipping.
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Affiliation(s)
- James Eberwine
- Department of Pharmacology, School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States
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Stevenson DJ, Gunn-Moore FJ, Campbell P, Dholakia K. Single cell optical transfection. J R Soc Interface 2010; 7:863-71. [PMID: 20064901 DOI: 10.1098/rsif.2009.0463] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The plasma membrane of a eukaryotic cell is impermeable to most hydrophilic substances, yet the insertion of these materials into cells is an extremely important and universal requirement for the cell biologist. To address this need, many transfection techniques have been developed including viral, lipoplex, polyplex, capillary microinjection, gene gun and electroporation. The current discussion explores a procedure called optical injection, where a laser field transiently increases the membrane permeability to allow species to be internalized. If the internalized substance is a nucleic acid, such as DNA, RNA or small interfering RNA (siRNA), then the process is called optical transfection. This contactless, aseptic, single cell transfection method provides a key nanosurgical tool to the microscopist-the intracellular delivery of reagents and single nanoscopic objects. The experimental possibilities enabled by this technology are only beginning to be realized. A review of optical transfection is presented, along with a forecast of future applications of this rapidly developing and exciting technology.
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Affiliation(s)
- David J Stevenson
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, UK.
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12
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Abstract
Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels regulate neuronal excitability, pacemaking, dendritic integration, and homeostatic plasticity and are culprits in aberrant neuronal activity in certain epilepsies. In this issue of Neuron two manuscripts (Santoro et al. and Zolles et al.) report that HCN channel gating and expression are controlled by Trip8b (Pex5R) but with a bidirectional spin.
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Affiliation(s)
- Diane Lipscombe
- Department of Neuroscience, Brown University, Providence, RI 02912, USA.
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