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Kirshenbaum GS, Chang CY, Bompolaki M, Bradford VR, Bell J, Kosmidis S, Shansky RM, Orlandi J, Savage LM, Harris AZ, David Leonardo E, Dranovsky A. Adult-born neurons maintain hippocampal cholinergic inputs and support working memory during aging. Mol Psychiatry 2023; 28:5337-5349. [PMID: 37479778 DOI: 10.1038/s41380-023-02167-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 06/21/2023] [Accepted: 06/26/2023] [Indexed: 07/23/2023]
Abstract
Adult neurogenesis is reduced during aging and impaired in disorders of stress, memory, and cognition though its normal function remains unclear. Moreover, a systems level understanding of how a small number of young hippocampal neurons could dramatically influence brain function is lacking. We examined whether adult neurogenesis sustains hippocampal connections cumulatively across the life span. Long-term suppression of neurogenesis as occurs during stress and aging resulted in an accelerated decline in hippocampal acetylcholine signaling and a slow and progressing emergence of profound working memory deficits. These deficits were accompanied by compensatory reorganization of cholinergic dentate gyrus inputs with increased cholinergic innervation to the ventral hippocampus and recruitment of ventrally projecting neurons by the dorsal projection. While increased cholinergic innervation was dysfunctional and corresponded to overall decreases in cholinergic levels and signaling, it could be recruited to correct the resulting memory dysfunction even in old animals. Our study demonstrates that hippocampal neurogenesis supports memory by maintaining the septohippocampal cholinergic circuit across the lifespan. It also provides a systems level explanation for the progressive nature of memory deterioration during normal and pathological aging and indicates that the brain connectome is malleable by experience.
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Affiliation(s)
- Greer S Kirshenbaum
- Department of Psychiatry, Columbia University, New York, NY, 10032, USA
- New York State Psychiatric Institute, New York, NY, 10032, USA
| | - Chia-Yuan Chang
- Department of Psychiatry, Columbia University, New York, NY, 10032, USA
- New York State Psychiatric Institute, New York, NY, 10032, USA
- Department of Psychology, National Taiwan University, Taipei, Taiwan
| | - Maria Bompolaki
- Department of Psychiatry, Columbia University, New York, NY, 10032, USA
- New York State Psychiatric Institute, New York, NY, 10032, USA
| | - Victoria R Bradford
- Department of Psychiatry, Columbia University, New York, NY, 10032, USA
- New York State Psychiatric Institute, New York, NY, 10032, USA
| | - Joseph Bell
- Department of Psychiatry, Columbia University, New York, NY, 10032, USA
- New York State Psychiatric Institute, New York, NY, 10032, USA
| | - Stylianos Kosmidis
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, 10027, USA
| | - Rebecca M Shansky
- Department of Psychiatry, Columbia University, New York, NY, 10032, USA
- New York State Psychiatric Institute, New York, NY, 10032, USA
- Department of Psychology, Northeastern University, Boston, MA, 02115, USA
| | | | - Lisa M Savage
- Department of Psychology, Binghamton University, Binghamton, NY, 13902, USA
| | - Alexander Z Harris
- Department of Psychiatry, Columbia University, New York, NY, 10032, USA
- New York State Psychiatric Institute, New York, NY, 10032, USA
| | - E David Leonardo
- Department of Psychiatry, Columbia University, New York, NY, 10032, USA.
- New York State Psychiatric Institute, New York, NY, 10032, USA.
| | - Alex Dranovsky
- Department of Psychiatry, Columbia University, New York, NY, 10032, USA.
- New York State Psychiatric Institute, New York, NY, 10032, USA.
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2
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Atsumi Y, Oisi Y, Odagawa M, Matsubara C, Saito Y, Uwamori H, Kobayashi K, Kato S, Kobayashi K, Murayama M. Anatomical identification of a corticocortical top-down recipient inhibitory circuitry by enhancer-restricted transsynaptic tracing. Front Neural Circuits 2023; 17:1245097. [PMID: 37720921 PMCID: PMC10502327 DOI: 10.3389/fncir.2023.1245097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 08/07/2023] [Indexed: 09/19/2023] Open
Abstract
Despite the importance of postsynaptic inhibitory circuitry targeted by mid/long-range projections (e.g., top-down projections) in cognitive functions, its anatomical properties, such as laminar profile and neuron type, are poorly understood owing to the lack of efficient tracing methods. To this end, we developed a method that combines conventional adeno-associated virus (AAV)-mediated transsynaptic tracing with a distal-less homeobox (Dlx) enhancer-restricted expression system to label postsynaptic inhibitory neurons. We called this method "Dlx enhancer-restricted Interneuron-SpECific transsynaptic Tracing" (DISECT). We applied DISECT to a top-down corticocortical circuit from the secondary motor cortex (M2) to the primary somatosensory cortex (S1) in wild-type mice. First, we injected AAV1-Cre into the M2, which enabled Cre recombinase expression in M2-input recipient S1 neurons. Second, we injected AAV1-hDlx-flex-green fluorescent protein (GFP) into the S1 to transduce GFP into the postsynaptic inhibitory neurons in a Cre-dependent manner. We succeeded in exclusively labeling the recipient inhibitory neurons in the S1. Laminar profile analysis of the neurons labeled via DISECT indicated that the M2-input recipient inhibitory neurons were distributed in the superficial and deep layers of the S1. This laminar distribution was aligned with the laminar density of axons projecting from the M2. We further classified the labeled neuron types using immunohistochemistry and in situ hybridization. This post hoc classification revealed that the dominant top-down M2-input recipient neuron types were somatostatin-expressing neurons in the superficial layers and parvalbumin-expressing neurons in the deep layers. These results demonstrate that DISECT enables the investigation of multiple anatomical properties of the postsynaptic inhibitory circuitry.
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Affiliation(s)
- Yusuke Atsumi
- Laboratory for Haptic Perception and Cognitive Physiology, RIKEN Center for Brain Science, Saitama, Japan
- Department of Life Science and Technology, School of Life Sciences and Technology, Tokyo Institute of Technology, Tokyo, Japan
| | - Yasuhiro Oisi
- Laboratory for Haptic Perception and Cognitive Physiology, RIKEN Center for Brain Science, Saitama, Japan
| | - Maya Odagawa
- Laboratory for Haptic Perception and Cognitive Physiology, RIKEN Center for Brain Science, Saitama, Japan
| | - Chie Matsubara
- Laboratory for Haptic Perception and Cognitive Physiology, RIKEN Center for Brain Science, Saitama, Japan
| | - Yoshihito Saito
- Laboratory for Haptic Perception and Cognitive Physiology, RIKEN Center for Brain Science, Saitama, Japan
- Department of Biology, Graduate School of Science, Kobe University, Kobe-shi, Japan
| | - Hiroyuki Uwamori
- Laboratory for Haptic Perception and Cognitive Physiology, RIKEN Center for Brain Science, Saitama, Japan
| | - Kenta Kobayashi
- Section of Viral Vector Development, National Institute for Physiological Sciences, Okazaki-shi, Japan
| | - Shigeki Kato
- Department of Molecular Genetics, Institute of Biomedical Sciences, Fukushima Medical University School of Medicine, Fukushima, Japan
| | - Kazuto Kobayashi
- Department of Molecular Genetics, Institute of Biomedical Sciences, Fukushima Medical University School of Medicine, Fukushima, Japan
| | - Masanori Murayama
- Laboratory for Haptic Perception and Cognitive Physiology, RIKEN Center for Brain Science, Saitama, Japan
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Dranovsky A, Kirshenbaum G, Chang CY, Bompolaki M, Bradford V, Bell J, Kosmidis S, Shansky R, Orlandi J, Savage L, Leonardo E, Harris A. Adult-born neurons maintain hippocampal cholinergic inputs and support working memory during aging. RESEARCH SQUARE 2023:rs.3.rs-1851645. [PMID: 36778445 PMCID: PMC9915786 DOI: 10.21203/rs.3.rs-1851645/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Adult neurogenesis is reduced during aging and impaired in disorders of stress, memory, and cognition though its normal function remains unclear. Moreover, a systems level understanding of how a small number of young hippocampal neurons could dramatically influence brain function is lacking. We examined whether adult neurogenesis sustains hippocampal connections cumulatively across the life span. Long-term suppression of neurogenesis as occurs during stress and aging resulted in an accelerated decline in hippocampal acetylcholine signaling and a slow and progressing emergence of profound working memory deficits. These deficits were accompanied by compensatory reorganization of cholinergic dentate gyrus inputs with increased cholinergic innervation to the ventral hippocampus and recruitment of ventrally projecting neurons by the dorsal projection. While increased cholinergic innervation was dysfunctional and corresponded to overall decreases in cholinergic levels and signaling, it could be recruited to correct the resulting memory dysfunction even in old animals. Our study demonstrates that hippocampal neurogenesis supports memory by maintaining the septohippocampal cholinergic circuit across the lifespan. It also provides a systems level explanation for the progressive nature of memory deterioration during normal and pathological aging and indicates that the brain connectome is malleable by experience.
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Affiliation(s)
- Alex Dranovsky
- Columbia University, New York State Psychiatric Institute
| | | | | | | | | | - Joseph Bell
- Columbia University, New York State Psychiatric Institute
| | | | | | - Javier Orlandi
- Columbia University, New York State Psychiatric Institute
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Tetanus Toxin Fragment C: Structure, Drug Discovery Research and Production. Pharmaceuticals (Basel) 2022; 15:ph15060756. [PMID: 35745675 PMCID: PMC9227095 DOI: 10.3390/ph15060756] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 06/09/2022] [Accepted: 06/13/2022] [Indexed: 12/05/2022] Open
Abstract
Tetanus toxoid (TTd) plays an important role in the pharmaceutical world, especially in vaccines. The toxoid is obtained after formaldehyde treatment of the tetanus toxin. In parallel, current emphasis in the drug discovery field is put on producing well-defined and safer drugs, explaining the interest in finding new alternative proteins. The tetanus toxin fragment C (TTFC) has been extensively studied both as a neuroprotective agent for central nervous system disorders owing to its neuronal properties and as a carrier protein in vaccines. Indeed, it is derived from a part of the tetanus toxin and, as such, retains its immunogenic properties without being toxic. Moreover, this fragment has been well characterized, and its entire structure is known. Here, we propose a systematic review of TTFC by providing information about its structural features, its properties and its methods of production. We also describe the large uses of TTFC in the field of drug discovery. TTFC can therefore be considered as an attractive alternative to TTd and remarkably offers a wide range of uses, including as a carrier, delivery vector, conjugate, booster, inducer, and neuroprotector.
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Zhang CM, Imoto Y, Hikima T, Inoue T. Structural flexibility of the tetanus neurotoxin revealed by crystallographic and solution scattering analyses. JOURNAL OF STRUCTURAL BIOLOGY-X 2021; 5:100045. [PMID: 33598655 PMCID: PMC7868712 DOI: 10.1016/j.yjsbx.2021.100045] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Although the tetanus neurotoxin (TeNT) delivers its protease domain (LC) across the synaptic vesicle lumen into the cytosol via its receptor binding domain (HC) and translocation domain (HN), the molecular mechanism coordinating this membrane translocation remains unresolved. Here, we report the high-resolution crystal structures of full-length reduced TeNT (rTeNT, 2.3 Å), TeNT isolated HN (TeNT/iHN, 2.3 Å), TeNT isolated HC (TeNT/iHC, 1.5 Å), together with the solution structures of TeNT/iHN and beltless TeNT/iHN (TeNT/blHN). TeNT undergoes significant domains rotation of the HN and LC were demonstrated by structural comparison of rTeNT and non-reduced-TeNT (nrTeNT). A linker loop connects the HN and HC is essential for the self-domain rotation of TeNT. The TeNT-specific C869-C1093 disulfide bond is sensitive to the redox environment and its disruption provides linker loop flexibility, which enables domain arrangement of rTeNT distinct from that of nrTeNT. Furthermore, the mobility of C869 in the linker loop and the sensitivity to redox condition of C1093 were confirmed by crystal structure analysis of TeNT/iHC. On the other hand, the structural flexibility of HN was investigated by crystallographic and solution scattering analyses. It was found that the region (residues 698-769), which follows the translocation region had remarkable change in TeNT/iHN. Besides, the so-called belt region has a high propensity to swing around the upper half of TeNT/iHN at acidic pH. It provides the first overview of the dynamics of the Belt in solution. These newly obtained structural information that shed light on the transmembrane mechanism of TeNT.
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Affiliation(s)
- Chun-Ming Zhang
- Graduate School of Pharmaceutical Science, Osaka University, Suita, 565-0871 Osaka, Japan
| | - Yoshihiro Imoto
- Graduate School of Pharmaceutical Science, Osaka University, Suita, 565-0871 Osaka, Japan
| | - Takaaki Hikima
- Advanced Photon Technology Division, RIKEN SPring-8 Center, Sayo-gun, 679-6148, Japan
| | - Tsuyoshi Inoue
- Graduate School of Pharmaceutical Science, Osaka University, Suita, 565-0871 Osaka, Japan
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6
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Vazquez-Roque R, Pacheco-Flores M, Penagos-Corzo JC, Flores G, Aguilera J, Treviño S, Guevara J, Diaz A, Venegas B. The C-terminal fragment of the heavy chain of the tetanus toxin (Hc-TeTx) improves motor activity and neuronal morphology in the limbic system of aged mice. Synapse 2020; 75:e22193. [PMID: 33141999 DOI: 10.1002/syn.22193] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 10/24/2020] [Accepted: 10/27/2020] [Indexed: 12/23/2022]
Abstract
In the aging process, the brain presents biochemical and morphological alterations. The neurons of the limbic system show reduced size dendrites, in addition to the loss of dendritic spines. These disturbances trigger a decrease in motor and cognitive function. Likewise, it is reported that during aging, in the brain, there is a significant decrease in neurotrophic factors, which are essential in promoting the survival and plasticity of neurons. The carboxyl-terminal fragment of the heavy chain of the tetanus toxin (Hc-TeTx) acts similarly to neurotrophic factors, inducing neuroprotection in different models of neuronal damage. The aim here, was to evaluate the effect of Hc-TeTx on the motor processes of elderly mice (18 months old), and its impact on the dendritic morphology and density of dendritic spines of neurons in the limbic system. The morphological analysis in the dendrites was evaluated employing Golgi-Cox staining. Hc-TeTx was administered (0.5 mg/kg) intraperitoneally for three days in 18-month-old mice. Locomotor activity was evaluated in a novel environment 30 days after the last administration of Hc-TeTx. Mice treated with Hc-TeTx showed significant changes in their motor behavior, and an increased dendritic spine density of pyramidal neurons in layers 3 and 5 of the prefrontal cortex in the hippocampus, and medium spiny neurons of the nucleus accumbens (NAcc). In conclusion, the Hc-TeTx improves the plasticity of the brain regions of the limbic system of aged mice. Therefore, it is proposed as a pharmacological alternative to prevent or delay brain damage during aging.
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Affiliation(s)
- Ruben Vazquez-Roque
- Neuropsychiatry Laboratory, Institute of Physiology, Benemérita Universidad Autónoma de Puebla, Puebla, México
| | | | | | - Gonzalo Flores
- Neuropsychiatry Laboratory, Institute of Physiology, Benemérita Universidad Autónoma de Puebla, Puebla, México
| | - José Aguilera
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, Institut de Neurociències, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain.,Networked Biomedical Research Center on Neurodegenerative Diseases (CIBERNED), Barcelona, Spain
| | - Samuel Treviño
- Faculty of Chemical Sciences, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| | - Jorge Guevara
- Department of Biochemistry, Faculty of Medicine, National Autonomous University of Mexico, Mexico City, Mexico
| | - Alfonso Diaz
- Faculty of Chemical Sciences, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| | - Berenice Venegas
- Faculty of Biological Sciences, Benemérita Universidad Autónoma de Puebla, Puebla, México
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7
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Kinoshita N, Huang AJY, McHugh TJ, Miyawaki A, Shimogori T. Diffusible GRAPHIC to visualize morphology of cells after specific cell-cell contact. Sci Rep 2020; 10:14437. [PMID: 32879377 PMCID: PMC7468259 DOI: 10.1038/s41598-020-71474-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Accepted: 08/17/2020] [Indexed: 11/09/2022] Open
Abstract
The ability to identify specific cell-cell contact in the highly heterogeneous mammalian body is crucial to revealing precise control of the body plan and correct function. To visualize local connections, we previously developed a genetically encoded fluorescent indicator, GRAPHIC, which labels cell-cell contacts by restricting the reconstituted green fluorescent protein (GFP) signal to the contact site. Here, we modify GRAPHIC to give the reconstituted GFP motility within the membrane, to detect cells that make contact with other specific cells. Removal of leucine zipper domains, located between the split GFP fragment and glycophosphatidylinositol anchor domain, allowed GFP reconstituted at the contact site to diffuse throughout the entire plasma membrane, revealing cell morphology. Further, depending on the structural spacers employed, the reconstituted GFP could be selectively targeted to N terminal (NT)- or C terminal (CT)-probe-expressing cells. Using these novel constructs, we demonstrated that we can specifically label NT-probe-expressing cells that made contact with CT-probe-expressing cells in an epithelial cell culture and in Xenopus 8-cell-stage blastomeres. Moreover, we showed that diffusible GRAPHIC (dGRAPHIC) can be used in neuronal circuits to trace neurons that make contact to reveal a connection map. Finally, application in the developing brain demonstrated that the dGRAPHIC signal remained on neurons that had transient contacts during circuit development to reveal the contact history. Altogether, dGRAPHIC is a unique probe that can visualize cells that made specific cell-cell contact.
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Affiliation(s)
- Nagatoki Kinoshita
- Molecular Mechanisms of Brain Development, Center for Brain Science (CBS), RIKEN, Saitama, Japan.,Exploratory Research for Advanced Technology (ERATO), Japan Science and Technology Agency (JST), Tokyo, Japan
| | | | - Thomas J McHugh
- Circuit and Behavioral Physiology, CBS, RIKEN, Saitama, Japan
| | - Atsushi Miyawaki
- Exploratory Research for Advanced Technology (ERATO), Japan Science and Technology Agency (JST), Tokyo, Japan.,Cell Function Dynamics, CBS, RIKEN, Saitama, Japan
| | - Tomomi Shimogori
- Molecular Mechanisms of Brain Development, Center for Brain Science (CBS), RIKEN, Saitama, Japan.
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Thompson N, Mastitskaya S, Holder D. Avoiding off-target effects in electrical stimulation of the cervical vagus nerve: Neuroanatomical tracing techniques to study fascicular anatomy of the vagus nerve. J Neurosci Methods 2019; 325:108325. [PMID: 31260728 PMCID: PMC6698726 DOI: 10.1016/j.jneumeth.2019.108325] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 06/25/2019] [Accepted: 06/26/2019] [Indexed: 12/11/2022]
Abstract
Vagus nerve stimulation (VNS) is a promising therapy for treatment of various conditions that are resistant to standard medication, such as heart failure, epilepsy, and depression. The vagus nerve is a complex nerve providing afferent and efferent innervation of the pharynx, larynx, heart, tracheobronchial tree and lungs, oesophagus, stomach, liver, pancreas, small intestine and proximal colon. It is therefore a prime target for intervention for VNS. Surprisingly, the fascicular organisation of the vagus nerve at the cervical level is still not well understood. This, along with the current stimulation techniques, results in the entire nerve being stimulated, which leads to unwanted off-target effects. Neuronal tracing is a promising method to delineate the organ-specific innervation by the vagus nerve, thereby providing valuable insight into the fascicular anatomy. In this review we discuss the current knowledge of vagus nerve anatomy and neuronal tracers used for mapping of its organ-specific projections in various species. Efferent vagal projections are a chain of two neurones (pre- and postganglionic), while afferent projections consist of only one pseudounipolar neurone with one branch terminating in the target organ/tissue directly and another in the brainstem. It would be feasible to retrogradely trace the afferent fibres from their respective visceral targets and identify them at the cervical level using non-transsynaptic neuronal tracers. Using this to create a map of the functional anatomical organisation of the vagus nerve will enable selective VNS ultimately allowing for the avoidance of the off-target effects and improving overall efficacy.
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Affiliation(s)
- Nicole Thompson
- Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom.
| | - Svetlana Mastitskaya
- Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - David Holder
- Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
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9
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Effectiveness of Fragment C Domain of Tetanus Toxin and Pramipexole in an Animal Model of Parkinson’s Disease. Neurotox Res 2019; 35:699-710. [DOI: 10.1007/s12640-018-9990-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Revised: 12/05/2018] [Accepted: 12/11/2018] [Indexed: 12/13/2022]
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10
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Watanabe Y, Matsuba T, Nakanishi M, Une M, Hanajima R, Nakashima K. Tetanus toxin fragments and Bcl-2 fusion proteins: cytoprotection and retrograde axonal migration. BMC Biotechnol 2018; 18:39. [PMID: 29890980 PMCID: PMC5996528 DOI: 10.1186/s12896-018-0452-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Accepted: 06/06/2018] [Indexed: 12/14/2022] Open
Abstract
Background Tetanus neurotoxin (TeNT) is taken up at nerve terminals and undergoes retrograde migration. The toxic properties of TeNT reside in the toxin light chain (L), but like complete TeNT, the TeNT heavy chain (TTH) and the C-terminal domain (TTC) alone can bind and enter into neurons. Here, we explored whether atoxic fragments of TeNT could act as drug delivery vehicles in neurons. In this study, we used Bcl-2, a protein known to have anti-apoptotic properties in vivo and in vitro, as a parcel to couple to TeNT fragments. Results We expressed Bcl-2 and the TTC fragments alone, and also attempted to express fusion proteins with the Bcl-2 coupled at the N-terminus of TTH (Bcl2-TTH) and the N- and C-terminus of TTC (TTC-Bcl2 and Bcl2-TTC) in mammalian (Cos7 cells) and Escherichia coli systems. TTC and Bcl-2 were efficiently expressed in E. coli and Cos7 cells, respectively, but Bcl-2 and the fusion proteins did not express well in E. coli. The fusion proteins were also not expressed in Cos7 cells. To improve the yield and purity of the fusion protein, we genetically deleted the N-terminal half of TTC from the Bcl2-TTC fusion to yield Bcl2-hTTC. Purified Bcl2-hTTC exhibited neuronal binding and prevented cell death of neuronal PC12 cells induced by serum and NGF deprivation, as evidenced by the inhibition of cytochrome C release from the mitochondria. For in vivo assays, Bcl2-hTTC was injected into the tongues of mice and was seen to selectively migrate to hypoglossal nuclei mouse brain stems via retrograde axonal transport. Conclusions These results indicate that Bcl2-hTTC retains both Bcl-2 and TTC functions and therefore could be a potent therapeutic agent for various neurological conditions.
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Affiliation(s)
- Yasuhiro Watanabe
- Division of Neurology, Department of Brain and Neurosciences, Faculty of Medicine, Tottori University, Nishi-cho 36-1, Yonago, 683-8504, Japan.
| | - Takashi Matsuba
- Division of Bacteriology, Department of Microbiology and immunology, Faculty of Medicine, Tottori University, Nishi-cho 86, Yonago, 683-8503, Japan
| | - Mami Nakanishi
- Division of Neurology, Department of Brain and Neurosciences, Faculty of Medicine, Tottori University, Nishi-cho 36-1, Yonago, 683-8504, Japan
| | - Mio Une
- Division of Neurology, Department of Brain and Neurosciences, Faculty of Medicine, Tottori University, Nishi-cho 36-1, Yonago, 683-8504, Japan
| | - Ritsuko Hanajima
- Division of Neurology, Department of Brain and Neurosciences, Faculty of Medicine, Tottori University, Nishi-cho 36-1, Yonago, 683-8504, Japan
| | - Kenji Nakashima
- Division of Neurology, Department of Brain and Neurosciences, Faculty of Medicine, Tottori University, Nishi-cho 36-1, Yonago, 683-8504, Japan
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11
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Moreno-Galarza N, Mendieta L, Palafox-Sánchez V, Herrando-Grabulosa M, Gil C, Limón DI, Aguilera J. Peripheral Administration of Tetanus Toxin Hc Fragment Prevents MPP+ Toxicity In Vivo. Neurotox Res 2018; 34:47-61. [DOI: 10.1007/s12640-017-9853-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 12/08/2017] [Accepted: 12/11/2017] [Indexed: 01/13/2023]
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12
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Wang F, Bélanger E, Paquet ME, Côté DC, De Koninck Y. Probing pain pathways with light. Neuroscience 2016; 338:248-271. [PMID: 27702648 DOI: 10.1016/j.neuroscience.2016.09.035] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 09/19/2016] [Accepted: 09/20/2016] [Indexed: 02/06/2023]
Abstract
We have witnessed an accelerated growth of photonics technologies in recent years to enable not only monitoring the activity of specific neurons, while animals are performing certain types of behavior, but also testing whether specific cells, circuits, and regions are sufficient or necessary for initiating, maintaining, or altering this or that behavior. Compared to other sensory systems, however, such as the visual or olfactory system, photonics applications in pain research are only beginning to emerge. One reason pain studies have lagged behind is that many of the techniques originally developed cannot be directly implemented to study key relay sites within pain pathways, such as the skin, dorsal root ganglia, spinal cord, and brainstem. This is due, in part, to difficulties in accessing these structures with light. Here we review a number of recent advances in design and delivery of light-sensitive molecular probes (sensors and actuators) into pain relay circuits to help decipher their structural and functional organization. We then discuss several challenges that have hampered hardware access to specific structures including light scattering, tissue movement and geometries. We review a number of strategies to circumvent these challenges, by delivering light into, and collecting it from the different key sites to unravel how nociceptive signals are encoded at each level of the neuraxis. We conclude with an outlook on novel imaging modalities for label-free chemical detection and opportunities for multimodal interrogation in vivo. While many challenges remain, these advances offer unprecedented opportunities to bridge cellular approaches with context-relevant behavioral testing, an essential step toward improving translation of basic research findings into clinical applications.
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Affiliation(s)
- Feng Wang
- Institut universitaire en santé mentale de Québec, Université Laval, Québec, QC, Canada
| | - Erik Bélanger
- Institut universitaire en santé mentale de Québec, Université Laval, Québec, QC, Canada; Centre d'optique, photonique et laser, Université Laval, Québec, QC, Canada
| | - Marie-Eve Paquet
- Institut universitaire en santé mentale de Québec, Université Laval, Québec, QC, Canada; Département de biochimie, microbiologie et bioinformatique, Université Laval, Québec, QC, Canada
| | - Daniel C Côté
- Institut universitaire en santé mentale de Québec, Université Laval, Québec, QC, Canada; Centre d'optique, photonique et laser, Université Laval, Québec, QC, Canada; Département de physique, de génie physique et d'optique, Université Laval, Québec, QC, Canada
| | - Yves De Koninck
- Institut universitaire en santé mentale de Québec, Université Laval, Québec, QC, Canada; Centre d'optique, photonique et laser, Université Laval, Québec, QC, Canada; Département de psychiatrie et neurosciences, Université Laval, Québec, QC, Canada.
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Lerner TN, Ye L, Deisseroth K. Communication in Neural Circuits: Tools, Opportunities, and Challenges. Cell 2016; 164:1136-1150. [PMID: 26967281 PMCID: PMC5725393 DOI: 10.1016/j.cell.2016.02.027] [Citation(s) in RCA: 109] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 01/27/2016] [Accepted: 02/03/2016] [Indexed: 11/27/2022]
Abstract
Communication, the effective delivery of information, is fundamental to life across all scales and species. Nervous systems (by necessity) may be most specifically adapted among biological tissues for high rate and complexity of information transmitted, and thus, the properties of neural tissue and principles of its organization into circuits may illuminate capabilities and limitations of biological communication. Here, we consider recent developments in tools for studying neural circuits with particular attention to defining neuronal cell types by input and output information streams--i.e., by how they communicate. Complementing approaches that define cell types by virtue of genetic promoter/enhancer properties, this communication-based approach to defining cell types operationally by input/output (I/O) relationships links structure and function, resolves difficulties associated with single-genetic-feature definitions, leverages technology for observing and testing significance of precisely these I/O relationships in intact brains, and maps onto processes through which behavior may be adapted during development, experience, and evolution.
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Affiliation(s)
- Talia N Lerner
- Bioengineering Department, 318 Campus Drive, Stanford University, Stanford, CA 94305, USA
| | - Li Ye
- Bioengineering Department, 318 Campus Drive, Stanford University, Stanford, CA 94305, USA
| | - Karl Deisseroth
- Bioengineering Department, 318 Campus Drive, Stanford University, Stanford, CA 94305, USA; Psychiatry Department, 318 Campus Drive, Stanford University, Stanford, CA 94305, USA; Howard Hughes Medical Institute, 318 Campus Drive, Stanford University, Stanford, CA 94305, USA.
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14
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Patricio-Martínez A, Mendieta L, Martínez I, Aguilera J, Limón I. The recombinant C-terminal fragment of tetanus toxin protects against cholinotoxicity by intraseptal injection of β-amyloid peptide (25–35) in rats. Neuroscience 2016; 315:18-30. [DOI: 10.1016/j.neuroscience.2015.11.066] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 11/19/2015] [Accepted: 11/30/2015] [Indexed: 11/30/2022]
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15
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Junyent F, Kremer EJ. CAV-2--why a canine virus is a neurobiologist's best friend. Curr Opin Pharmacol 2015; 24:86-93. [PMID: 26298516 DOI: 10.1016/j.coph.2015.08.004] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 06/22/2015] [Accepted: 08/05/2015] [Indexed: 12/29/2022]
Abstract
Canine adenovirus type 2 (CAV-2) vectors are powerful tools for fundamental and applied neurobiology due to their negligible immunogenicity, preferential transduction of neurons, widespread distribution via axonal transport, and duration of expression in the mammalian brain. CAV-2 vectors are internalized in neurons by the selective use of coxsackievirus and adenovirus receptor (CAR), which is located at the presynapse in neurons. Neuronal internalization and axonal transport is mediated by CAR, which potentiates vector biodistribution. The above characteristics, together with the ∼30kb cloning capacity of helper-dependent (HD) CAV-2 vectors, optimized CAV-2 vector creation, production and purification, is expanding the therapeutic and fundamental options for CNS gene transfer.
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Affiliation(s)
- Felix Junyent
- Institut de Génétique Moléculaire de Montpellier, Montpellier, France; Université de Montpellier, Montpellier, France
| | - Eric J Kremer
- Institut de Génétique Moléculaire de Montpellier, Montpellier, France; Université de Montpellier, Montpellier, France.
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16
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Zhan C, Li C, Wei X, Lu W, Lu W. Toxins and derivatives in molecular pharmaceutics: Drug delivery and targeted therapy. Adv Drug Deliv Rev 2015; 90:101-18. [PMID: 25959429 DOI: 10.1016/j.addr.2015.04.025] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 04/20/2015] [Accepted: 04/29/2015] [Indexed: 01/13/2023]
Abstract
Protein and peptide toxins offer an invaluable source for the development of actively targeted drug delivery systems. They avidly bind to a variety of cognate receptors, some of which are expressed or even up-regulated in diseased tissues and biological barriers. Protein and peptide toxins or their derivatives can act as ligands to facilitate tissue- or organ-specific accumulation of therapeutics. Some toxins have evolved from a relatively small number of structural frameworks that are particularly suitable for addressing the crucial issues of potency and stability, making them an instrumental source of leads and templates for targeted therapy. The focus of this review is on protein and peptide toxins for the development of targeted drug delivery systems and molecular therapies. We summarize disease- and biological barrier-related toxin receptors, as well as targeted drug delivery strategies inspired by those receptors. The design of new therapeutics based on protein and peptide toxins is also discussed.
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Affiliation(s)
- Changyou Zhan
- Department of Pharmaceutics, School of Pharmacy, Fudan University & Key Laboratory of Smart Drug Delivery (Fudan University), Ministry of Education, Shanghai 201203, PR China
| | - Chong Li
- College of Pharmaceutical Sciences, Southwest University & Chongqing Engineering Research Center for Pharmaceutical Process and Quality Control, Chongqing 400716, PR China
| | - Xiaoli Wei
- Department of Pharmaceutics, School of Pharmacy, Fudan University & Key Laboratory of Smart Drug Delivery (Fudan University), Ministry of Education, Shanghai 201203, PR China; State Key Laboratory of Medical Neurobiology and the Collaborative Innovation Center for Brain Science, Fudan University, Shanghai 200032, PR China
| | - Wuyuan Lu
- Institute of Human Virology and Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Weiyue Lu
- Department of Pharmaceutics, School of Pharmacy, Fudan University & Key Laboratory of Smart Drug Delivery (Fudan University), Ministry of Education, Shanghai 201203, PR China; State Key Laboratory of Medical Neurobiology and the Collaborative Innovation Center for Brain Science, Fudan University, Shanghai 200032, PR China; State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai 200433, PR China.
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17
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Nassi JJ, Cepko CL, Born RT, Beier KT. Neuroanatomy goes viral! Front Neuroanat 2015; 9:80. [PMID: 26190977 PMCID: PMC4486834 DOI: 10.3389/fnana.2015.00080] [Citation(s) in RCA: 124] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Accepted: 05/25/2015] [Indexed: 02/03/2023] Open
Abstract
The nervous system is complex not simply because of the enormous number of neurons it contains but by virtue of the specificity with which they are connected. Unraveling this specificity is the task of neuroanatomy. In this endeavor, neuroanatomists have traditionally exploited an impressive array of tools ranging from the Golgi method to electron microscopy. An ideal method for studying anatomy would label neurons that are interconnected, and, in addition, allow expression of foreign genes in these neurons. Fortuitously, nature has already partially developed such a method in the form of neurotropic viruses, which have evolved to deliver their genetic material between synaptically connected neurons while largely eluding glia and the immune system. While these characteristics make some of these viruses a threat to human health, simple modifications allow them to be used in controlled experimental settings, thus enabling neuroanatomists to trace multi-synaptic connections within and across brain regions. Wild-type neurotropic viruses, such as rabies and alpha-herpes virus, have already contributed greatly to our understanding of brain connectivity, and modern molecular techniques have enabled the construction of recombinant forms of these and other viruses. These newly engineered reagents are particularly useful, as they can target genetically defined populations of neurons, spread only one synapse to either inputs or outputs, and carry instructions by which the targeted neurons can be made to express exogenous proteins, such as calcium sensors or light-sensitive ion channels, that can be used to study neuronal function. In this review, we address these uniquely powerful features of the viruses already in the neuroanatomist's toolbox, as well as the aspects of their biology that currently limit their utility. Based on the latter, we consider strategies for improving viral tracing methods by reducing toxicity, improving control of transsynaptic spread, and extending the range of species that can be studied.
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Affiliation(s)
- Jonathan J Nassi
- Systems Neurobiology Laboratories, Salk Institute for Biological Studies La Jolla, CA, USA
| | - Constance L Cepko
- Department of Genetics, Harvard Medical School Boston, MA, USA ; Department of Ophthalmology, Howard Hughes Medical Institute, Harvard Medical School Boston, MA, USA
| | - Richard T Born
- Department of Neurobiology, Harvard Medical School Boston, MA, USA ; Center for Brain Science, Harvard University Cambridge, MA, USA
| | - Kevin T Beier
- Department of Psychiatry and Behavioral Sciences and Department of Biology, Stanford University Stanford, CA, USA
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18
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Soden ME, Gore BB, Zweifel LS. Defining functional gene-circuit interfaces in the mouse nervous system. GENES BRAIN AND BEHAVIOR 2013; 13:2-12. [PMID: 24007626 DOI: 10.1111/gbb.12082] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 07/18/2013] [Accepted: 08/30/2013] [Indexed: 12/21/2022]
Abstract
Complexity in the nervous system is established by developmental genetic programs, maintained by differential genetic profiles and sculpted by experiential and environmental influence over gene expression. Determining how specific genes define neuronal phenotypes, shape circuit connectivity and regulate circuit function is essential for understanding how the brain processes information, directs behavior and adapts to changing environments. Mouse genetics has contributed greatly to current percepts of gene-circuit interfaces in behavior, but considerable work remains. Large-scale initiatives to map gene expression and connectivity in the brain, together with advanced techniques in molecular genetics, now allow detailed exploration of the genetic basis of nervous system function at the level of specific circuit connections. In this review, we highlight several key advances for defining the function of specific genes within a neural network.
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Affiliation(s)
- M E Soden
- Department of Pharmacology; Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, USA
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19
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Ibanes S, Kremer EJ. Canine adenovirus type 2 vector generation via I-Sce1-mediated intracellular genome release. PLoS One 2013; 8:e71032. [PMID: 23936483 PMCID: PMC3731271 DOI: 10.1371/journal.pone.0071032] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Accepted: 06/24/2013] [Indexed: 02/06/2023] Open
Abstract
When canine adenovirus type 2 (CAdV-2, or also commonly referred to as CAV-2) vectors are injected into the brain parenchyma they preferentially transduce neurons, are capable of efficient axonal transport to afferent regions, and allow transgene expression for at last >1 yr. Yet, translating these data into a user-friendly vector platform has been limited because CAV-2 vector generation is challenging. Generation of E1-deleted adenovirus vectors often requires transfection of linear DNA fragments of >30 kb containing the vector genome into an E1-transcomplementing cell line. In contrast to human adenovirus type 5 vector generation, CAV-2 vector generation is less efficient due, in part, to a reduced ability to initiate replication and poor transfectibility of canine cells with large, linear DNA fragments. To improve CAV-2 vector generation, we generated an E1-transcomplementing cell line expressing the estrogen receptor (ER) fused to I-SceI, a yeast meganuclease, and plasmids containing the I-SceI recognition sites flanking the CAV-2 vector genome. Using transfection of supercoiled plasmid and intracellular genome release via 4-OH-tamoxifen-induced nuclear translocation of I-SceI, we improved CAV-2 vector titers 1,000 fold, and in turn increased the efficacy of CAV-2 vector generation.
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Affiliation(s)
- Sandy Ibanes
- Institut de Génétique Moléculaire de Montpellier, CNRS, Montpellier, France
- Université de Montpellier I, Montpellier, France
- Université Montpellier II, Montpellier, France
| | - Eric J. Kremer
- Institut de Génétique Moléculaire de Montpellier, CNRS, Montpellier, France
- Université de Montpellier I, Montpellier, France
- Université Montpellier II, Montpellier, France
- * E-mail:
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20
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Niedworok C, Schwarz I, Ledderose J, Giese G, Conzelmann KK, Schwarz M. Charting Monosynaptic Connectivity Maps by Two-Color Light-Sheet Fluorescence Microscopy. Cell Rep 2012; 2:1375-86. [DOI: 10.1016/j.celrep.2012.10.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 08/30/2012] [Accepted: 10/11/2012] [Indexed: 01/09/2023] Open
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21
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Lo L, Anderson DJ. A Cre-dependent, anterograde transsynaptic viral tracer for mapping output pathways of genetically marked neurons. Neuron 2011; 72:938-50. [PMID: 22196330 PMCID: PMC3275419 DOI: 10.1016/j.neuron.2011.12.002] [Citation(s) in RCA: 147] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/01/2011] [Indexed: 12/21/2022]
Abstract
Neurotropic viruses that conditionally infect or replicate in molecularly defined neuronal subpopulations, and then spread transsynaptically, are powerful tools for mapping neural pathways. Genetically targetable retrograde transsynaptic tracer viruses are available to map the inputs to specific neuronal subpopulations, but an analogous tool for mapping synaptic outputs is not yet available. Here we describe a Cre recombinase-dependent, anterograde transneuronal tracer, based on the H129 strain of herpes simplex virus (HSV). Application of this virus to transgenic or knockin mice expressing Cre in peripheral neurons of the olfactory epithelium or the retina reveals widespread, polysynaptic labeling of higher-order neurons in the olfactory and visual systems, respectively. Polysynaptic pathways were also labeled from cerebellar Purkinje cells. In each system, the pattern of labeling was consistent with classical circuit-tracing studies, restricted to neurons, and anterograde specific. These data provide proof-of-principle for a conditional, nondiluting anterograde transsynaptic tracer for mapping synaptic outputs from genetically marked neuronal subpopulations.
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Affiliation(s)
- Liching Lo
- Division of Biology 156-29, California Institute of Technology, 1201 E. California Blvd, Pasadena, CA 91125
- Howard Hughes Medical Institute, California Institute of Technology, 1201 E. California Blvd, Pasadena, CA 91125
| | - David J. Anderson
- Division of Biology 156-29, California Institute of Technology, 1201 E. California Blvd, Pasadena, CA 91125
- Howard Hughes Medical Institute, California Institute of Technology, 1201 E. California Blvd, Pasadena, CA 91125
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22
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Montesinos MS, Chen Z, Young SM. pUNISHER: a high-level expression cassette for use with recombinant viral vectors for rapid and long term in vivo neuronal expression in the CNS. J Neurophysiol 2011; 106:3230-44. [PMID: 21957229 DOI: 10.1152/jn.00713.2011] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Fast onset and high-level neurospecific transgene expression in vivo is of importance for many areas in neuroscience, from basic to translational, and can significantly reduce the amount of vector load required to maintain transgene expression in vivo. In this study, we tested various cis elements to optimize transgene expression at transcriptional, posttranscriptional, and posttranslational levels and combined them together to create the high-level neuronal transgene expression cassette pUNISHER. Using a second-generation adenoviral vector system in combination with the pUNISHER cassette, we characterized its rate of onset of detectable expression and levels of expression compared with a neurospecific expression cassette driven by the 470-bp human synapsin promoter in vitro and in vivo. Our results demonstrate in primary neurons that the pUNISHER cassette, in a recombinant adenovirus type 5 background, led to a faster rate of onset of detectable transgene expression and higher level of transgene expression. More importantly, this cassette led to highly correlated neuronal expression in vivo and to stable transgene expression up to 30 days in the auditory brain stem with no toxicity on the characteristics of synaptic transmission and plasticity at the calyx of Held synapse. Thus the pUNISHER cassette is an ideal high-level neuronal expression cassette for use in vivo for neuroscience applications.
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Affiliation(s)
- Monica S Montesinos
- Research Group Molecular Mechanisms of Synaptic Function, Max Planck Florida Institute, 5353 Parkside Drive MC19-RE, Jupiter, FL 33458, USA
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23
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Towards new uses of botulinum toxin as a novel therapeutic tool. Toxins (Basel) 2011; 3:63-81. [PMID: 22069690 PMCID: PMC3210455 DOI: 10.3390/toxins3010063] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Revised: 01/03/2011] [Accepted: 01/04/2011] [Indexed: 12/31/2022] Open
Abstract
The uses of botulinum toxin in the fields of neurology, ophthalmology, urology, rehabilitation medicine and aesthetic applications have been revolutionary for the treatment of patients. This non-invasive therapeutic has continually been developed since first discovered in the 1970s as a new approach to what were previously surgical treatments. As these applications develop, so also the molecules are developing into tools with new therapeutic properties in specific clinical areas. This review examines how the botulinum toxin molecule is being adapted to new therapeutic uses and also how new areas of use for the existing molecules are being identified. Prospects for future developments are also considered.
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24
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Kim ML, Han S, Lee SB, Kim JH, Ahn HK, Huh Y. Evaluation of recombinant adenovirus-mediated gene delivery for expression of tracer genes in catecholaminergic neurons. Anat Cell Biol 2010; 43:157-64. [PMID: 21189997 PMCID: PMC2998783 DOI: 10.5115/acb.2010.43.2.157] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2010] [Revised: 05/31/2010] [Accepted: 06/08/2010] [Indexed: 01/15/2023] Open
Abstract
Selective labeling of small populations of neurons of a given phenotype for conventional neuronal tracing is difficult because tracers can be taken up by all neurons at the injection site, resulting in nonspecific labeling of unrelated pathways. To overcome these problems, genetic approaches have been developed that introduce tracer proteins as transgenes under the control of cell-type-specific promoter elements for visualization of specific neuronal pathways. The aim of this study was to explore the use of tracer gene expression for neuroanatomical tracing to chart the complex interconnections of the central nervous system. Genetic tracing methods allow for expression of tracer molecules using cell-type-specific promoters to facilitate neuronal tracing. In this study, the rat tyrosine hydroxylase (TH) promoter and an adenoviral delivery system were used to express tracers specifically in dopaminergic and noradrenergic neurons. Region-specific expression of the transgenes was then analyzed. Initially, we characterized cell-type-specific expression of GFP or RFP in cultured cell lines. We then injected an adenovirus carrying the tracer transgene into several brain regions using a stereotaxic apparatus. Three days after injection, strong GFP expression was observed in the injected site of the brain. RFP and WGA were expressed in a cell-type-specific manner in the cerebellum, locus coeruleus, and ventral tegmental regions. Our results demonstrate that selective tracing of catecholaminergic neuronal circuits is possible in the rat brain using the TH promoter and adenoviral expression.
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Affiliation(s)
- Mi-La Kim
- Department of Anatomy and Neurobiology, School of Medicine, Kyung Hee University, Seoul, Korea
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25
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Toivonen JM, Oliván S, Osta R. Tetanus toxin C-fragment: the courier and the cure? Toxins (Basel) 2010; 2:2622-44. [PMID: 22069568 PMCID: PMC3153173 DOI: 10.3390/toxins2112622] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Accepted: 10/28/2010] [Indexed: 12/14/2022] Open
Abstract
In many neurological disorders strategies for a specific delivery of a biological activity from the periphery to the central nervous system (CNS) remains a considerable challenge for successful therapy. Reporter assays have established that the non-toxic C-fragment of tetanus toxin (TTC), provided either as protein or encoded by non-viral naked DNA plasmid, binds pre-synaptic motor neuron terminals and can facilitate the retrograde axonal transport of desired therapeutic molecules to the CNS. Alleviated symptoms in animal models of neurological diseases upon delivery of therapeutic molecules offer a hopeful prospect for TTC therapy. This review focuses on what has been learned on TTC-mediated neuronal targeting, and discusses the recent discovery that, instead of being merely a carrier molecule, TTC itself may well harbor neuroprotective properties.
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Affiliation(s)
- Janne M Toivonen
- LAGENBIO-I3A, Veterinary School, Aragón Institute of Health Sciences (IACS), Universidad de Zaragoza, Miguel Servet 177, 50013 Zaragoza, Spain.
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26
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Bru T, Salinas S, Kremer EJ. An update on canine adenovirus type 2 and its vectors. Viruses 2010; 2:2134-2153. [PMID: 21994722 PMCID: PMC3185752 DOI: 10.3390/v2092134] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2010] [Revised: 09/23/2010] [Accepted: 09/24/2010] [Indexed: 12/27/2022] Open
Abstract
Adenovirus vectors have significant potential for long- or short-term gene transfer. Preclinical and clinical studies using human derived adenoviruses (HAd) have demonstrated the feasibility of flexible hybrid vector designs, robust expression and induction of protective immunity. However, clinical use of HAd vectors can, under some conditions, be limited by pre-existing vector immunity. Pre-existing humoral and cellular anti-capsid immunity limits the efficacy and duration of transgene expression and is poorly circumvented by injections of larger doses and immuno-suppressing drugs. This review updates canine adenovirus serotype 2 (CAV-2, also known as CAdV-2) biology and gives an overview of the generation of early region 1 (E1)-deleted to helper-dependent (HD) CAV-2 vectors. We also summarize the essential characteristics concerning their interaction with the anti-HAd memory immune responses in humans, the preferential transduction of neurons, and its high level of retrograde axonal transport in the central and peripheral nervous system. CAV-2 vectors are particularly interesting tools to study the pathophysiology and potential treatment of neurodegenerative diseases, as anti-tumoral and anti-viral vaccines, tracer of synaptic junctions, oncolytic virus and as a platform to generate chimeric vectors.
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Affiliation(s)
- Thierry Bru
- Institut de Génétique Moléculaire de Montpellier, CNRS UMR 5535, 1919 Route de Mende Montpellier, 34293 France; E-Mails: (T.B.); (S.S.)
- Université de Montpellier I, 5 Bd Henri IV, 34000 Montpellier, France
- Université de Montpellier II, place Eugène Bataillon, 34090 Montpellier, France
| | - Sara Salinas
- Institut de Génétique Moléculaire de Montpellier, CNRS UMR 5535, 1919 Route de Mende Montpellier, 34293 France; E-Mails: (T.B.); (S.S.)
- Université de Montpellier I, 5 Bd Henri IV, 34000 Montpellier, France
- Université de Montpellier II, place Eugène Bataillon, 34090 Montpellier, France
| | - Eric J. Kremer
- Institut de Génétique Moléculaire de Montpellier, CNRS UMR 5535, 1919 Route de Mende Montpellier, 34293 France; E-Mails: (T.B.); (S.S.)
- Université de Montpellier I, 5 Bd Henri IV, 34000 Montpellier, France
- Université de Montpellier II, place Eugène Bataillon, 34090 Montpellier, France
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +33-467-613-372; Fax: +33-467-040-231
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27
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Huh Y, Oh MS, Leblanc P, Kim KS. Gene transfer in the nervous system and implications for transsynaptic neuronal tracing. Expert Opin Biol Ther 2010; 10:763-72. [PMID: 20367126 DOI: 10.1517/14712591003796538] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
IMPORTANCE OF THE FIELD Neuronal circuitries are determined by specific synaptic connections and they provide the cellular basis of cognitive processes and behavioral functions. To investigate neuronal circuitries, tracers are typically used to identify the original neurons and their projection targets. AREAS COVERED IN THIS REVIEW Traditional tracing methods using chemical tracers have major limitations such as non-specificity. In this review, we highlight novel genetic tracing approaches that enable visualization of specific neuronal pathways by introducing cDNA encoding a transsynaptic tracer. In contrast to conventional tracing methods, these genetic approaches use cell-type-specific promoters to express transsynaptic tracers such as wheat germ agglutinin and C-terminal fragment of tetanus toxin, which allows labeling of either the input or output populations and connections of specific neuronal type. WHAT THE READER WILL GAIN Specific neuronal circuit information by these genetic approaches will allow more precise, comprehensive and novel information about individual neural circuits and their function in normal and diseased brains. TAKE HOME MESSAGE Using tracer gene transfer, neuronal circuit plasticity after traumatic injury or neurodegenerative diseases can be visualized. Also, this can provide a good marker for evaluation of therapeutic effects of neuroprotective or neurotrophic agents.
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Affiliation(s)
- Youngbuhm Huh
- Department of Anatomy and Neurobiology, Kyung Hee University, Seoul, Republic of Korea
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28
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Molecular and cellular approaches for diversifying and extending optogenetics. Cell 2010; 141:154-165. [PMID: 20303157 PMCID: PMC4160532 DOI: 10.1016/j.cell.2010.02.037] [Citation(s) in RCA: 714] [Impact Index Per Article: 51.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2009] [Revised: 01/11/2010] [Accepted: 02/18/2010] [Indexed: 12/17/2022]
Abstract
Optogenetic technologies employ light to control biological processes within targeted cells in vivo with high temporal precision. Here, we show that application of molecular trafficking principles can expand the optogenetic repertoire along several long-sought dimensions. Subcellular and transcellular trafficking strategies now permit (1) optical regulation at the far-red/infrared border and extension of optogenetic control across the entire visible spectrum, (2) increased potency of optical inhibition without increased light power requirement (nanoampere-scale chloride-mediated photocurrents that maintain the light sensitivity and reversible, step-like kinetic stability of earlier tools), and (3) generalizable strategies for targeting cells based not only on genetic identity, but also on morphology and tissue topology, to allow versatile targeting when promoters are not known or in genetically intractable organisms. Together, these results illustrate use of cell-biological principles to enable expansion of the versatile fast optogenetic technologies suitable for intact-systems biology and behavior.
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29
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Cordero-Erausquin M, Allard S, Dolique T, Bachand K, Ribeiro-da-Silva A, De Koninck Y. Dorsal horn neurons presynaptic to lamina I spinoparabrachial neurons revealed by transynaptic labeling. J Comp Neurol 2009; 517:601-15. [DOI: 10.1002/cne.22179] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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30
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Triggering genetically-expressed transneuronal tracers by peripheral axotomy reveals convergent and segregated sensory neuron-spinal cord connectivity. Neuroscience 2009; 163:1220-32. [PMID: 19647044 DOI: 10.1016/j.neuroscience.2009.07.051] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2009] [Accepted: 07/21/2009] [Indexed: 11/20/2022]
Abstract
To better understand the mechanisms through which non-painful and painful stimuli evoke behavior, new resources to dissect the complex circuits engaged by subsets of primary afferent neurons are required. This is especially true to understand the consequences of injury, when reorganization of central nervous system circuits likely contributes to the persistence of pain. Here we describe a transgenic mouse line (ZWX) in which there is Cre-recombinase-dependent expression of a transneuronal tracer, wheat germ agglutinin (WGA), in primary somatic or visceral afferent neurons, but only after transection of their peripheral axons. The latter requirement allows for both regional and temporal control of tracer expression, even in the adult. Using a variety of Cre lines to target WGA transport to subpopulations of sensory neurons, here we demonstrate the extent to which myelinated and unmyelinated "pain" fibers (nociceptors) engage different spinal cord circuits. We found significant convergence (i.e., manifest as WGA-transneuronal labeling) of unmyelinated afferents, including the TRPV1-expressing subset, and myelinated afferents to NK1-receptor-expressing neurons of lamina I. By contrast, PKCgamma interneurons of inner lamina II only receive a myelinated afferent input. This differential distribution of WGA labeling in the spinal cord indicates that myelinated and unmyelinated sensory neurons target different and spatially segregated populations of postsynaptic neurons. On the other hand, we show that neurons of deeper laminae (III-V) receive direct (i.e., monosynaptic) inputs from myelinated afferents and polysynaptic input from unmyelinated afferents. Taken together, our results indicate that peripheral sensory information is transmitted to the central nervous system both through segregated and convergent pathways.
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Salinas S, Bilsland LG, Henaff D, Weston AE, Keriel A, Schiavo G, Kremer EJ. CAR-associated vesicular transport of an adenovirus in motor neuron axons. PLoS Pathog 2009; 5:e1000442. [PMID: 19461877 PMCID: PMC2677547 DOI: 10.1371/journal.ppat.1000442] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2009] [Accepted: 04/24/2009] [Indexed: 12/17/2022] Open
Abstract
Axonal transport is responsible for the movement of signals and cargo between nerve termini and cell bodies. Pathogens also exploit this pathway to enter and exit the central nervous system. In this study, we characterised the binding, endocytosis and axonal transport of an adenovirus (CAV-2) that preferentially infects neurons. Using biochemical, cell biology, genetic, ultrastructural and live-cell imaging approaches, we show that interaction with the neuronal membrane correlates with coxsackievirus and adenovirus receptor (CAR) surface expression, followed by endocytosis involving clathrin. In axons, long-range CAV-2 motility was bidirectional with a bias for retrograde transport in nonacidic Rab7-positive organelles. Unexpectedly, we found that CAR was associated with CAV-2 vesicles that also transported cargo as functionally distinct as tetanus toxin, neurotrophins, and their receptors. These results suggest that a single axonal transport carrier is capable of transporting functionally distinct cargoes that target different membrane compartments in the soma. We propose that CAV-2 transport is dictated by an innate trafficking of CAR, suggesting an unsuspected function for this adhesion protein during neuronal homeostasis. Adenoviruses commonly cause subclinical morbidity in the ocular, respiratory, and gastrointestinal tracts, and less frequently, adenovirus-induced disease can be fatal for newborns and immunocompromised hosts. In addition, adenoviruses can reach the central nervous system (CNS) and cause associated encephalitis and tumours. On the flip side, during the last two decades, adenovirus vectors have become powerful tools to treat and address diseases of the CNS. Despite the fact that axonal transport of adenoviruses was reported more than 15 years ago, nothing was known concerning how adenoviruses access the CNS. The characterization of their interactions with brain cells was therefore long overdue. In this study, we describe the axonal trafficking of an adenovirus that preferentially infects neurons and reaches the CNS through long-range axonal transport. We show that this adenovirus exploits an endogenous vesicular pathway used by the adhesion molecule CAR (coxsackievirus and adenovirus receptor). Our study characterizes this endogenous route of access, which is likely to be crucial to neuronal survival, neurodegenerative diseases, gene transfer vectors, and adenovirus-induced morbidity.
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Affiliation(s)
- Sara Salinas
- Molecular NeuroPathobiology Laboratory, Cancer Research UK London Research Institute, London, United Kingdom
| | - Lynsey G. Bilsland
- Molecular NeuroPathobiology Laboratory, Cancer Research UK London Research Institute, London, United Kingdom
| | - Daniel Henaff
- Institut de Génétique Moléculaire de Montpellier, CNRS UMR 5535, Montpellier, France
- Universités de Montpellier I & II, Montpellier, France
| | - Anne E. Weston
- Electron Microscopy Laboratory, Cancer Research UK London Research Institute, London, United Kingdom
| | - Anne Keriel
- Institut de Génétique Moléculaire de Montpellier, CNRS UMR 5535, Montpellier, France
- Universités de Montpellier I & II, Montpellier, France
| | - Giampietro Schiavo
- Molecular NeuroPathobiology Laboratory, Cancer Research UK London Research Institute, London, United Kingdom
- * E-mail: (GS); (EJK)
| | - Eric J. Kremer
- Institut de Génétique Moléculaire de Montpellier, CNRS UMR 5535, Montpellier, France
- Universités de Montpellier I & II, Montpellier, France
- * E-mail: (GS); (EJK)
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Carlton E, Teng Q, Federici T, Yang J, Riley J, Boulis NM. FUSION OF THE TETANUS TOXIN C FRAGMENT BINDING DOMAIN AND BCL-XL FOR PROTECTION OF PERIPHERAL NERVE NEURONS. Neurosurgery 2008; 63:1175-82; discussion 1182-4. [DOI: 10.1227/01.neu.0000334415.45003.ea] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Erin Carlton
- Department of Cell Biology, Cleveland Clinic, Cleveland, Ohio
| | - Qingshan Teng
- Department of Neurosurgery, Emory University, Atlanta, Georgia
| | - Thais Federici
- Department of Neurosurgery, Emory University, Atlanta, Georgia
| | - Jun Yang
- Department of Neurosurgery, Cleveland Clinic, Cleveland, Ohio
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Andreu A, Fairweather N, Miller AD. Clostridium neurotoxin fragments as potential targeting moieties for liposomal gene delivery to the CNS. Chembiochem 2008; 9:219-31. [PMID: 18076008 DOI: 10.1002/cbic.200700277] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Targeted transfection of the CNS with synthetic, nonviral vectors represents a huge technical challenge. The approach explored here attempts to combine self-assembly ABCD nanoparticles (Kostarelos and Miller, Chem. Soc. Rev. 2005, 34, 970), with the potential of Clostridium neurotoxin fragments to effect receptor-mediated transfection of neuronal cells. Cationic liposome-plasmid DNA complexes were first modified with a PEG stealth layer, before the addition of C-terminal fragments of tetanus toxin (TH(C)), botulinum toxin (BH(C)) or the truncated C-terminal domain of TH(C) as biological "targeting" ligands. First-generation nanoparticles were identified for the transfection of two neuronal cell lines (human SH-5YSY and rat/mouse hybrid N18-RE105); control studies were also performed with HeLa cells. ABCD nanoparticle transfections of the neuronal cell lines were up to 30-fold higher than corresponding control transfections with nanoparticles that lacked the protein ligand. We also demonstrate apparent receptor-mediated uptake by means of competition-binding and real-time confocal experiments. By contrast, nanoparticle transfection of HeLa cells appeared to involve alternative nonspecific enhanced cellular uptake mechanism(s). Receptor-mediated and nonspecific mechanisms appear to be in competition, potentially harming the capacity of receptor-mediated delivery to effect proper targeted delivery of nucleic acids to cells ex vivo and in vivo.
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Affiliation(s)
- Alice Andreu
- Imperial College Genetic Therapies Centre, Department of Chemistry, Flowers Building, Armstrong Road, Imperial College London, London SW7 2AZ, UK
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Affiliation(s)
- Susan M Dymecki
- Department of Genetics, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA.
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Federici T, Liu JK, Teng Q, Yang J, Boulis NM. A Means for Targeting Therapeutics to Peripheral Nervous System Neurons with Axonal Damage. Neurosurgery 2007; 60:911-8; discussion 911-8. [PMID: 17460527 DOI: 10.1227/01.neu.0000255444.44365.b9] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE Delivery of biological therapeutics to motor and dorsal root ganglion neurons remains a major hurdle in the development of treatments for a variety of neurological processes, including peripheral nerve injury, pain, and motor neuron diseases. Because nerve cell bodies are important in initiating and controlling axonal regeneration, targeted delivery is an appealing strategy to deliver therapeutic proteins after peripheral nerve injury. METHODS Tet1 is a 12-aa peptide, isolated through phage display that is selected for tetanus toxin C fragment-like binding properties. In this study, we surveyed its uptake and retrograde transport using compartmented cultures and sciatic nerve injections. We then characterized the time course of this delivery. Finally, to confirm the retrograde transport involvement, a colchicine pretreatment was performed. We also performed competitive binding studies between Tet1 and a recombinant tetanus toxin C fragment using recombinant tetanus toxin C fragment enzyme-linked immunosorbent assay. RESULTS We were able to demonstrate efficient uptake and retrograde axonal transport of the Tet1 peptide in vitro and in vivo. Intraneural colchicine pretreatment partially blocked fluorescence detection in the spinal cord, revealing a retrograde axonal transport mechanism. Finally, a competitive enzyme-linked immunosorbent assay experiment revealed Tet1-specific binding to the recombinant tetanus toxin C fragment axon terminal trisialogangliosides receptor. CONCLUSION These properties of Tet1 can be applied to the development of therapeutic viral vectors and fusion proteins for neuronal targeting and enhanced spinal cord delivery in the treatment of nerve regeneration, neuroprotection, analgesia, and spasticity. Small peptides can be easily fused to larger proteins without significantly modifying their function and can be used to alter the binding and uptake properties of these proteins.
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Roux S, Saint Cloment C, Curie T, Girard E, Miana Mena FJ, Barbier J, Osta R, Molgó J, Brûlet P. Brain-derived neurotrophic factor facilitates in vivo internalization of tetanus neurotoxin C-terminal fragment fusion proteins in mature mouse motor nerve terminals. Eur J Neurosci 2007; 24:1546-54. [PMID: 17004918 DOI: 10.1111/j.1460-9568.2006.05030.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In a previous study it was reported that fusion proteins composed of the atoxic C-terminal fragment of tetanus toxin (TTC) and green fluorescent protein or beta-galactosidase (GFP-TTC and beta-gal-TTC, respectively) rapidly cluster at motor nerve terminals of the mouse neuromuscular junction (NMJ). Because this traffic involves presynaptic activity, probably via the secretion of active molecules, we examined whether it is affected by brain-derived neurotrophic factor (BDNF). Quantitative confocal microscopy and a fluorimetric assay for beta-gal activity revealed that co-injecting BDNF and the fusion proteins significantly increased the kinetics and amount of the proteins' localization at the NMJ and their internalization by motor nerve terminals. The observed increases were independent of synaptic vesicle recycling because BDNF did not affect spontaneous quantal acetylcholine release. In addition, injecting anti-BDNF antibody shortly before injecting GFP-TTC, and before co-injecting GFP-TTC and BDNF, significantly reduced the fusion protein's localization at the NMJ. Co-injecting GFP-TTC with neurotrophin-4 (NT-4) or glial-derived neurotrophic factor (GDNF), but not with nerve growth factor, neurotrophin-3 or ciliary neurotrophic factor, also significantly increased the fusion protein's localization at the NMJ. Thus, TTC probes may use for their neuronal internalization endocytic pathways normally stimulated by BDNF, NT-4 and GDNF binding. Different tyrosine kinase receptors with similar signalling pathways are activated by BDNF/NT-4 and GDNF binding. Thus, activated components of these signalling pathways may be involved in the TTC probes' internalization, perhaps by facilitating localization of receptors of TTC in specific membrane microdomains or by recruiting various factors needed for internalization of TTC.
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Affiliation(s)
- Sylvie Roux
- CNRS, Institut de Neurobiologie Alfred Fessard, FRC2118, Laboratoire de Neurobiologie Cellulaire et Moléculaire, UPR9040, 1 Avenue de la Terrasse, 91198 Gif sur Yvette, France
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Miyoshi G, Fishell G. Directing neuron-specific transgene expression in the mouse CNS. Curr Opin Neurobiol 2006; 16:577-84. [PMID: 16971113 DOI: 10.1016/j.conb.2006.08.013] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2006] [Accepted: 08/30/2006] [Indexed: 02/04/2023]
Abstract
Recent advances in molecular genetics have produced many novel strategies for directing the expression of both functional and regulatory elements in transgenic mice. With the application of such approaches, the specific populations that comprise CNS networks can be both visualized and manipulated. Transgenic methods now range from the use of specific enhancer elements and large genomic regions assembled using BACs and PACs, to the use of gene targeting to a specific locus. In addition, the advent of transactivators and site-specific recombinases has provided unprecedented spatial and temporal control for directing expression in the CNS using a combination of appropriate alleles. As a result, the promise of being able to use transgenics to target specific neuronal populations is now being realized.
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Affiliation(s)
- Goichi Miyoshi
- Smilow Neuroscience Program and the Department of Cell Biology, New York University School of Medicine, 522 First Avenue, New York, NY 10016, USA
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Perreault MC, Pastor-Bernier A, Renaud JS, Roux S, Glover JC. C fragment of tetanus toxin hybrid proteins evaluated for muscle-specific transsynaptic mapping of spinal motor circuitry in the newborn mouse. Neuroscience 2006; 141:803-816. [PMID: 16713105 DOI: 10.1016/j.neuroscience.2006.04.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2005] [Revised: 03/08/2006] [Accepted: 04/02/2006] [Indexed: 11/17/2022]
Abstract
We investigated whether the non-toxic C fragment of tetanus toxin (TTC) fused to either beta-galactosidase or green fluorescent protein could be utilized to transsynaptically trace muscle-specific spinal circuitry in the neonatal mouse after i.m. injection into a single hindlimb muscle. We found that even with careful low volume injection (0.2-1.0 microl) into a single muscle (medial gastrocnemius), the TTC hybrid proteins spread rapidly to many other hindlimb muscles and to trunk musculature such that retrograde labeling of motoneurons could not be constrained to a single motoneuron pool. Retrogradely labeled motoneurons in the lower lumbar segments harboring the medial gastrocnemius motoneuron pool were first observed two hours after the medial gastrocnemius injection. Within the next 10 h, additional lumbar and lower thoracic motoneurons became labeled, and punctate labeling in the neuropil surrounding the motoneurons appeared. Many of the TTC hybrid protein-labeled puncta in the neuropil co-localized synaptotagmin, indicating that they represent presynaptic axon terminals onto motoneurons. Although this is consistent with retrograde transsynaptic passage, we found no evidence that the TTC hybrid proteins were transported further along premotor axons to label interneuron somata. The i.m. TTC injection procedure described here therefore provides an important tool for the study of presynaptic terminals onto motoneurons. However, additional technical modifications will be required to utilize TTC tracers for transsynaptic mapping of muscle-specific spinal motor circuitry in the neonatal mouse. We provide here a set of criteria for assessing the i.m. delivery of TTC tracers as a basis for future improvements in this technique.
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Affiliation(s)
- M-C Perreault
- Department of Physiology, University of Oslo, Domus Medica, Sognsvannsveien 9, POB 1103 Blindern, N-0317 Oslo, Norway.
| | - A Pastor-Bernier
- Department of Physiology, University of Oslo, Domus Medica, Sognsvannsveien 9, POB 1103 Blindern, N-0317 Oslo, Norway
| | - J-S Renaud
- Department of Physiology, University of Oslo, Domus Medica, Sognsvannsveien 9, POB 1103 Blindern, N-0317 Oslo, Norway
| | - S Roux
- Unité d'Embryologie Moléculaire, Institut Pasteur, Unités de Recherche Associées 2578, Centre National de la Recherche Scientifique, 25 rue du Dr roux, 75724 Paris, France
| | - J C Glover
- Department of Physiology, University of Oslo, Domus Medica, Sognsvannsveien 9, POB 1103 Blindern, N-0317 Oslo, Norway
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Roux S, Colasante C, Saint Cloment C, Barbier J, Curie T, Girard E, Molgó J, Brûlet P. Internalization of a GFP-tetanus toxin C-terminal fragment fusion protein at mature mouse neuromuscular junctions. Mol Cell Neurosci 2005; 30:79-89. [PMID: 16023367 DOI: 10.1016/j.mcn.2005.05.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2005] [Revised: 05/13/2005] [Accepted: 05/27/2005] [Indexed: 01/27/2023] Open
Abstract
The distribution, dynamics, internalization, and retrograde axonal traffic of a fusion protein composed of green fluorescent protein (GFP) and the atoxic C-terminal fragment of tetanus toxin (TTC) were studied after its in vivo injection. Confocal microscopy and immunogold electron microscopy revealed that the fusion protein (GFP-TTC) rapidly clustered in motor nerve terminals of the neuromuscular junction. Clathrin-coated pits, and axolemma infoldings located between active zones appeared to be involved in the internalization of the fusion protein. Biochemical analysis of detergent-extracted neuromuscular preparations showed that the GFP-TTC fusion protein was associated with lipid microdomains. We suggest that GFP-TTC clustering in these lipid microdomains favors the recruitment of other proteins involved in its endocytosis and internalization in motor nerve terminals. During its retrograde trafficking, GFP-TTC accumulated in different axonal compartments than those used by cholera toxin B-subunit suggesting that these two proteins are transported by different pathways and cargos.
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Affiliation(s)
- Sylvie Roux
- Unité d'Embryologie Moléculaire, Institut Pasteur, Unités de Recherche Associées 2578, Centre National de la Recherche Scientifique, 25 rue du Dr Roux, 75724 Paris, France. sroux@nbcm..cnrs-gif.fr
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40
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Abstract
Neural circuits are composed of a meshwork of numerous neuron types, each with their own distinctive morphological and intrinsic physiological properties, connectivity and biochemistry. How do distinct neural subcircuits, composed of different classes of neuron, contribute to brain function? Approaching this question requires methods that can target specific neurons types. This can be achieved by harnessing the same machinery that builds sophistication into the brain and using it to make novel tools for investigating and manipulating the brain: molecular and genetic technology. These tools can be used to target gene expression to specific neuron types within complicated neuronal circuits, and the transgenes that are expressed can be used to elucidate and manipulate these circuits with unprecedented precision and control. These methods are likely to become the archetype for future studies linking perception, cognition and behavior to specific components of the brain.
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Affiliation(s)
- Edward M Callaway
- Systems Neurobiology Laboratories, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
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Jiang K, Watson DJ, Wolfe JH. Α genetic fusion construct between the tetanus toxin C fragment and the lysosomal acid hydrolase β-glucuronidase expresses a bifunctional protein with enhanced secretion and neuronal uptake. J Neurochem 2005; 93:1334-44. [PMID: 15934952 DOI: 10.1111/j.1471-4159.2005.03133.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The neurotropic atoxic fragment of tetanus toxin has been used as a carrier for transporting macromolecules into neurons but all studies to date have tested cytosolic proteins. In this study we investigated the effect of a genetic addition of the tetanus toxin C fragment sequence to a lysosomal enzyme which contains a signal sequence for insertion into the membrane-bound compartment and must be extensively modified in the endoplasmic reticulum (ER) and Golgi to attain functionality. In-frame fusion constructs between the atoxic C fragment and beta-glucuronidase were compared with the wild-type enzyme for: (i) enzymatic activity; (ii) heat stability; (iii) pH dependence; (iv) specific activity; (v) apparent molecular mass and (vi) receptor-mediated uptake by fibroblasts and neurons. The modified proteins had biochemical properties similar to wild-type enzyme but exhibited different enzyme secretion profiles. Addition of the secreted fusion enzyme to cultures of primary neurons showed significantly increased neuronal uptake of the modified protein compared with the wild-type, demonstrating the bifunctionality of the chimeric molecule.
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Affiliation(s)
- Kanli Jiang
- Center for Comparative Medical Genetics, School of Veterinary Medicine, University of Pennsylvania and Division of Neurology, Stokes Research Institute, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA
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Boldogköi Z, Sík A, Dénes A, Reichart A, Toldi J, Gerendai I, Kovács KJ, Palkovits M. Novel tracing paradigms--genetically engineered herpesviruses as tools for mapping functional circuits within the CNS: present status and future prospects. Prog Neurobiol 2004; 72:417-45. [PMID: 15177785 DOI: 10.1016/j.pneurobio.2004.03.010] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2003] [Accepted: 03/29/2004] [Indexed: 11/17/2022]
Abstract
The mammalian CNS is composed of an extremely complex meshwork of highly ordered interconnections among billions of neurons. To understand the diverse functions of this neuronal network we need to differentiate between functionally related and nonrelated elements. A powerful labeling method for defining intricate neural circuits is based on the utilization of neurotropic herpesviruses, including pseudorabies virus and herpes simplex virus type 1. The recent development of genetically engineered tracing viruses can open the way toward the conception of novel tract-tracing paradigms. These new-generation tracing viruses may facilitate the clarification of problems, which were inaccessible to earlier approaches. This article first presents a concise review of the general aspects of neuroanatomical tracing protocols. Subsequently, it discusses the molecular biology of alpha-herpesviruses, and the genetic manipulation and gene expression techniques that are utilized for the construction of virus-based tracers. Finally, it describes the current utilization of genetically modified herpesviruses for circuit analysis, and the future directions in their potential applications.
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Affiliation(s)
- Zsolt Boldogköi
- Laboratory of Neuromorphology, Department of Anatomy, Faculty of Medicine, Semmelweis University and Hungarian Academy of Sciences, Budapest, Hungary.
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Kiehn O, Butt SJB. Physiological, anatomical and genetic identification of CPG neurons in the developing mammalian spinal cord. Prog Neurobiol 2003; 70:347-61. [PMID: 12963092 DOI: 10.1016/s0301-0082(03)00091-1] [Citation(s) in RCA: 156] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The basic motor patterns underlying rhythmic limb movements during locomotion are generated by neuronal networks located within the spinal cord. These networks are called Central Pattern Generators (CPGs). Isolated spinal cord preparations from newborn rats and mice have become increasingly important for understanding the organization of the CPG in the mammalian spinal cord. Early studies using these preparations have focused on the overall network structure and the localization of the CPG. In this review we concentrate on recent experiments aimed at identifying and characterizing CPG-interneurons in the rodent. These experiments include the organization and function of descending commissural interneurons (dCINs) in the hindlimb CPG of the neonatal rat, as well as the role of Ephrin receptor A4 (EphA4) and its Ephrin ligand B3 (EphrinB3), in the construction of the mammalian locomotor network. These latter experiments have defined EphA4 as a molecular marker for mammalian excitatory hindlimb CPG neurons. We also review genetic approaches that can be applied to the mouse spinal cord. These include methods for identifying sub-populations of neurons by genetically encoded reporters, techniques to trace network connectivity with cell-specific genetically encoded tracers, and ways to selectively ablate or eliminate neuron populations from the CPG. We propose that by applying a multidisciplinary approach it will be possible to understand the network structure of the mammalian locomotor CPG. Such an understanding will be instrumental in devising new therapeutic strategies for patients with spinal cord injury.
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Affiliation(s)
- Ole Kiehn
- Department of Neuroscience, Karolinska Institutet, Retzius väg 8, 171 77 Stockholm, Sweden.
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von Bartheld CS. Axonal transport and neuronal transcytosis of trophic factors, tracers, and pathogens. ACTA ACUST UNITED AC 2003; 58:295-314. [PMID: 14704960 DOI: 10.1002/neu.10315] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Neurons can specifically internalize macromolecules, such as trophic factors, lectins, toxins, and other pathogens. Upon internalization in terminals, proteins can move retrogradely along axons, or, upon internalization at somatodendritic domains, they can move into an anterograde axonal transport pathway. Release of internalized proteins from neurons after either retrograde or anterograde axonal transport results in transcytosis and trafficking of proteins across multiple synapses. Recent studies of binding properties of several such proteins suggest that pathogens and lectins may utilize existing transport machineries designed for trafficking of trophic factors. Specific pathways may protect trophic factors, pathogens, and toxins from degradation after internalization and may target the trophic or pathogenic cargo for transcytosis after either retrograde or anterograde transport along axons. Elucidating the molecular mechanisms of sorting steps and transport pathways will further our understanding of trophic signaling and could be relevant for an understanding and possible treatment of neurological diseases such as rabies, Alzheimer's disease, and prion encephalopathies. At present, our knowledge is remarkably sparse about the types of receptors used by pathogens for trafficking, the signals that sort trophins or pathogens into recycling or degradation pathways, and the mechanisms that regulate their release from somatodendritic domains or axon terminals. This review intends to draw attention to potential convergences and parallels in trafficking of trophic and pathogenic proteins. It discusses axonal transport/trafficking mechanisms that may help to understand and eventually treat neurological diseases by targeted drug delivery.
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Affiliation(s)
- Christopher S von Bartheld
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada 89557, USA.
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