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Mazzi Esquinca ME, Correa CN, Marques de Barros G, Montenegro H, Mantovani de Castro L. Multiomic Approach for Bioprospection: Investigation of Toxins and Peptides of Brazilian Sea Anemone Bunodosoma caissarum. Mar Drugs 2023; 21:md21030197. [PMID: 36976246 PMCID: PMC10058367 DOI: 10.3390/md21030197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 03/16/2023] [Accepted: 03/20/2023] [Indexed: 03/29/2023] Open
Abstract
Sea anemones are sessile invertebrates of the phylum Cnidaria and their survival and evolutive success are highly related to the ability to produce and quickly inoculate venom, with the presence of potent toxins. In this study, a multi-omics approach was applied to characterize the protein composition of the tentacles and mucus of Bunodosoma caissarum, a species of sea anemone from the Brazilian coast. The tentacles transcriptome resulted in 23,444 annotated genes, of which 1% showed similarity with toxins or proteins related to toxin activity. In the proteome analysis, 430 polypeptides were consistently identified: 316 of them were more abundant in the tentacles while 114 were enriched in the mucus. Tentacle proteins were mostly enzymes, followed by DNA- and RNA-associated proteins, while in the mucus most proteins were toxins. In addition, peptidomics allowed the identification of large and small fragments of mature toxins, neuropeptides, and intracellular peptides. In conclusion, integrated omics identified previously unknown or uncharacterized genes in addition to 23 toxin-like proteins of therapeutic potential, improving the understanding of tentacle and mucus composition of sea anemones.
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Affiliation(s)
- Maria Eduarda Mazzi Esquinca
- Department of Biological and Environmental Sciences, Bioscience Institute, Sao Paulo State University (UNESP), Sao Vicente 11330-900, SP, Brazil
| | - Claudia Neves Correa
- Department of Biological and Environmental Sciences, Bioscience Institute, Sao Paulo State University (UNESP), Sao Vicente 11330-900, SP, Brazil
- Biodiversity of Coastal Environments Postgraduate Program, Department of Biological and Environmental Sciences, Bioscience Institute, Sao Paulo State University (UNESP), Sao Vicente 11330-900, SP, Brazil
| | - Gabriel Marques de Barros
- Department of Biological and Environmental Sciences, Bioscience Institute, Sao Paulo State University (UNESP), Sao Vicente 11330-900, SP, Brazil
- Biodiversity of Coastal Environments Postgraduate Program, Department of Biological and Environmental Sciences, Bioscience Institute, Sao Paulo State University (UNESP), Sao Vicente 11330-900, SP, Brazil
| | | | - Leandro Mantovani de Castro
- Department of Biological and Environmental Sciences, Bioscience Institute, Sao Paulo State University (UNESP), Sao Vicente 11330-900, SP, Brazil
- Biodiversity of Coastal Environments Postgraduate Program, Department of Biological and Environmental Sciences, Bioscience Institute, Sao Paulo State University (UNESP), Sao Vicente 11330-900, SP, Brazil
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2
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Zhou K, Luo W, Liu T, Ni Y, Qin Z. Neurotoxins Acting at Synaptic Sites: A Brief Review on Mechanisms and Clinical Applications. Toxins (Basel) 2022; 15:18. [PMID: 36668838 PMCID: PMC9865788 DOI: 10.3390/toxins15010018] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 12/20/2022] [Accepted: 12/21/2022] [Indexed: 12/29/2022] Open
Abstract
Neurotoxins generally inhibit or promote the release of neurotransmitters or bind to receptors that are located in the pre- or post-synaptic membranes, thereby affecting physiological functions of synapses and affecting biological processes. With more and more research on the toxins of various origins, many neurotoxins are now widely used in clinical treatment and have demonstrated good therapeutic outcomes. This review summarizes the structural properties and potential pharmacological effects of neurotoxins acting on different components of the synapse, as well as their important clinical applications, thus could be a useful reference for researchers and clinicians in the study of neurotoxins.
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Affiliation(s)
- Kunming Zhou
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, College of Pharmaceutical Sciences, Suzhou Medical College of Soochow University, Suzhou 215123, China
| | - Weifeng Luo
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou 215004, China
| | - Tong Liu
- Institute of Pain Medicine and Special Environmental Medicine, Nantong University, Nantong 226019, China
| | - Yong Ni
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou 215004, China
| | - Zhenghong Qin
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, College of Pharmaceutical Sciences, Suzhou Medical College of Soochow University, Suzhou 215123, China
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3
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Hogg DW, Casatti CC, Belsham DD, Baršytė-Lovejoy D, Lovejoy DA. Distal extracellular teneurin region (teneurin C-terminal associated peptide; TCAP) possesses independent intracellular calcium regulating actions, in vitro: A potential antagonist of corticotropin-releasing factor (CRF). Biochem Biophys Rep 2022; 32:101397. [DOI: 10.1016/j.bbrep.2022.101397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 11/15/2022] [Accepted: 11/21/2022] [Indexed: 11/27/2022] Open
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4
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Dodsworth TL, Lovejoy DA. Role of Teneurin C-Terminal Associated Peptides (TCAP) on Intercellular Adhesion and Communication. Front Neurosci 2022; 16:868541. [PMID: 35585927 PMCID: PMC9108700 DOI: 10.3389/fnins.2022.868541] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 03/17/2022] [Indexed: 11/25/2022] Open
Abstract
The teneurin C-terminal associated peptides (TCAP) are encoded by the terminal exon of all metazoan teneurin genes. Evidence supports the liberation of a soluble TCAP peptide either by proteolytic cleavage from the mature transmembrane teneurin protein or by a separately transcribed mRNA. Synthetic versions of TCAP, based on its genomic structure, are efficacious at regulating intercellular communication by promoting neurite outgrowth and increasing dendritic spine density in vitro and in vivo in rodent models. This is achieved through cytoskeletal re-arrangement and metabolic upregulation. The putative receptors for TCAPs are the latrophilin (LPHN) family of adhesion G-protein coupled receptors, which facilitate TCAP’s actions through G-proteins associated with cAMP and calcium-regulating signalling pathways. The teneurin/TCAP and latrophilin genes are phylogenetically ancient, likely serving primitive functions in cell adhesion and energy regulation which have been since adapted for a more complex role in synaptogenesis in vertebrate nervous systems.
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Torres SL, Landeros A, Penhallegon EJ, Salazar K, Porter LM. Expression of Brown and Southern Black Widow Spider (Araneae: Theridiidae) Latrotoxins Is Tissue- and Life Stage-Specific for α-Latroinsectotoxins and δ-Latroinsectotoxins and Is Ubiquitous for α-Latrotoxins. JOURNAL OF MEDICAL ENTOMOLOGY 2022; 59:184-191. [PMID: 34632517 DOI: 10.1093/jme/tjab168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Indexed: 06/13/2023]
Abstract
Widow spiders are widely known for their potent venom toxins that make them among the few spiders of medical concern. The latrotoxins are the most well-studied widow toxins and include both the vertebrate-specific latrotoxins and the insect-specific latroinsectotoxins (LITs). Previous studies have shown that toxins are not limited to expression in the venom glands of adult spiders; however, gaps exist in latrotoxin screening across all life stages for brown widows, Latrodectus geometricus and southern black widows, Latrodectus mactans. In this study, we screened male and female venom gland, cephalothorax, and abdomen tissues, spiderling cephalothorax and abdomen tissues, and eggs of both L. geometricus and L. mactans, for the presence of three latrotoxins: α-latrotoxin (α-LTX), and α- and δ-latroinsectotoxins (α/δ-LITs). Widows were locally collected. Extracted RNA was used to prepare cDNA that was analyzed by PCR for the presence or absence of latrotoxin expression. Results show that expression profiles between the two species are very similar but not identical. Expression of α-LTX was found in all life stages in all tissues examined for both species. For both species, no LIT expression was detected in eggs and variable patterns of α-LIT expression were detected in spiderlings and adults. Notably, δ-LIT could only be detected in females for both species. Our results show that latrotoxin expression profiles differ within and between widow species. Data on their expression distribution provide further insight into the specific latrotoxins that contribute to toxicity profiles for each life stage in each species and their specific role in widow biology.
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Affiliation(s)
- Sebastian L Torres
- Department of Biology, Stephen F. Austin State University, SFA Station, Nacogdoches, TX, USA
| | - Abraham Landeros
- Department of Biology, Stephen F. Austin State University, SFA Station, Nacogdoches, TX, USA
| | - Eleanor J Penhallegon
- Department of Biology, Stephen F. Austin State University, SFA Station, Nacogdoches, TX, USA
| | - Kaleth Salazar
- Department of Biology, Stephen F. Austin State University, SFA Station, Nacogdoches, TX, USA
| | - Lindsay M Porter
- Department of Biology, Stephen F. Austin State University, SFA Station, Nacogdoches, TX, USA
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6
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Chen M, Blum D, Engelhard L, Raunser S, Wagner R, Gatsogiannis C. Molecular architecture of black widow spider neurotoxins. Nat Commun 2021; 12:6956. [PMID: 34845192 PMCID: PMC8630228 DOI: 10.1038/s41467-021-26562-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 10/11/2021] [Indexed: 12/14/2022] Open
Abstract
Latrotoxins (LaTXs) are presynaptic pore-forming neurotoxins found in the venom of Latrodectus spiders. The venom contains a toxic cocktail of seven LaTXs, with one of them targeting vertebrates (α-latrotoxin (α-LTX)), five specialized on insects (α, β, γ, δ, ε- latroinsectotoxins (LITs), and one on crustaceans (α-latrocrustatoxin (α-LCT)). LaTXs bind to specific receptors on the surface of neuronal cells, inducing the release of neurotransmitters either by directly stimulating exocytosis or by forming Ca2+-conductive tetrameric pores in the membrane. Despite extensive studies in the past decades, a high-resolution structure of a LaTX is not yet available and the precise mechanism of LaTX action remains unclear. Here, we report cryoEM structures of the α-LCT monomer and the δ-LIT dimer. The structures reveal that LaTXs are organized in four domains. A C-terminal domain of ankyrin-like repeats shields a central membrane insertion domain of six parallel α-helices. Both domains are flexibly linked via an N-terminal α-helical domain and a small β-sheet domain. A comparison between the structures suggests that oligomerization involves major conformational changes in LaTXs with longer C-terminal domains. Based on our data we propose a cyclic mechanism of oligomerization, taking place prior membrane insertion. Both recombinant α-LCT and δ-LIT form channels in artificial membrane bilayers, that are stabilized by Ca2+ ions and allow calcium flux at negative membrane potentials. Our comparative analysis between α-LCT and δ-LIT provides first crucial insights towards understanding the molecular mechanism of the LaTX family. The venom of Latrodectus spiders contains seven Latrotoxins (LaTXs), among them α-latrocrustatoxin (LCT) and δ- latroinsectotoxins δ-LIT. LaTXs bind to specific receptors on the surface of neuronal cells and target the molecular exocytosis machinery. Here, the authors present the cryo-EM structure of the α-LCT monomer and the δ-LIT dimer, which reveal that LaTXs are organized in four domains and they discuss the potential oligomerisation mechanism that takes place before LaTXs membrane insertion. Both recombinant α-LCT and δ-LIT form channels in artificial membrane bilayers, that are stabilized by Ca2+ ions.
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Affiliation(s)
- Minghao Chen
- Institute for Medical Physics and Biophysics and Center for Soft Nanoscience, Westfälische Wilhelms Universität Münster, 48149, Münster, Germany.,Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227, Dortmund, Germany
| | - Daniel Blum
- MOLIFE Research Center, Jacobs University Bremen, 28759, Bremen, Germany
| | - Lena Engelhard
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227, Dortmund, Germany
| | - Stefan Raunser
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227, Dortmund, Germany
| | - Richard Wagner
- MOLIFE Research Center, Jacobs University Bremen, 28759, Bremen, Germany
| | - Christos Gatsogiannis
- Institute for Medical Physics and Biophysics and Center for Soft Nanoscience, Westfälische Wilhelms Universität Münster, 48149, Münster, Germany. .,Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227, Dortmund, Germany.
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7
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Michalec OM, Chang BSW, Lovejoy NR, Lovejoy DA. Corticotropin-Releasing Factor: An Ancient Peptide Family Related to the Secretin Peptide Superfamily. Front Endocrinol (Lausanne) 2020; 11:529. [PMID: 32973673 PMCID: PMC7481443 DOI: 10.3389/fendo.2020.00529] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 06/29/2020] [Indexed: 02/05/2023] Open
Abstract
Corticotropin-releasing factor (CRF) is the hypothalamic releasing peptide that regulates the hypothalamic-pituitary-adrenal/inter-renal (HPA/I) axis in vertebrates. Over the last 25 years, there has been considerable discussion on its paralogs genes, urotensin-I/urocortin-1, and urocortins-2 and-3 and their subsequent role in the vertebrate stress response. Phylogenetically, the CRF family of peptides also belong to the diverse assemblage of Secretin- and Calcitonin-based peptides as evidenced by comparative-based studies of both their ligand and G-protein-coupled receptor (GPCR) structures. Despite this, the common origin of this large assemblage of peptides has not been ascertained. An unusual peptide, teneurin-C-terminal associated peptide (TCAP), reported in 2004, comprises the distal extracellular tip of the teneurin transmembrane proteins. Further studies indicated that this teneurin region binds to the latrophilin family of GPCRs. Initially thought to be a member of the Secretin GPCR family, evidence indicates that the latrophilins are a member of the Adhesion family of GPCRs and are related to the common ancestor of both Adhesion and Secretin GPCR families. In this study, we posit that TCAP may be a distantly related ancestor of the CRF-Calcitonin-Secretin peptide family and evolved near the base of metazoan phylogeny.
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Affiliation(s)
- Ola M Michalec
- Department of Cell and Systems Biology, University of Toronto - St. George Campus, Toronto, ON, Canada
| | - Belinda S W Chang
- Department of Cell and Systems Biology, University of Toronto - St. George Campus, Toronto, ON, Canada
| | - Nathan R Lovejoy
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, Canada
| | - David A Lovejoy
- Department of Cell and Systems Biology, University of Toronto - St. George Campus, Toronto, ON, Canada
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8
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Hogg DW, Husić M, Wosnick D, Dodsworth T, D'Aquila AL, Lovejoy DA. Activity of the Carboxy-Terminal Peptide Region of the Teneurins and Its Role in Neuronal Function and Behavior in Mammals. Front Neurosci 2019; 13:581. [PMID: 31417336 PMCID: PMC6685443 DOI: 10.3389/fnins.2019.00581] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 05/22/2019] [Indexed: 01/08/2023] Open
Abstract
Teneurin C-terminal associated peptides (TCAPs) are an evolutionarily ancient family of 40- to 41-residue bioactive peptides located on the extracellular end of each of the four teneurin transmembrane proteins. TCAP-1 may exist as a tethered peptide at the teneurin-1 carboxy end or as an independent peptide that is either released via post-transcriptional cleavage from its teneurin-1 pro-protein or independently expressed as its own mRNA. In neurons, soluble TCAP-1 acts as a paracrine factor to regulate cellular activity and neuroplastic interactions. In vitro studies indicate that, by itself, synthetic TCAP-1 promotes neuron growth and protects cells from chemical insult. In vivo, TCAP-1 increases hippocampal neuron spine density, reduces stress-induced behavior and ablates cocaine-seeking behaviors. Together, these studies suggest that the physiological effects of TCAP-1 are a result of an inhibition of corticotropin-releasing factor (CRF) activity leading to increased energy production. This hypothesis is supported by in vivo functional positron emissions tomography studies, which demonstrate that TCAP-1 significantly increases glucose uptake in rat brain. Complimentary in vitro studies show that enhanced glucose uptake is the result of TCAP-1-induced insertion of the glucose transporter into the neuronal plasma membrane, leading to increased glucose uptake and ATP production. Interestingly, TCAP-1-mediated glucose uptake occurs through a novel insulin-independent pathway. This review will focus on examining the role of TCAP on neuronal energy metabolism in the central nervous system.
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Affiliation(s)
- David W Hogg
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Mia Husić
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - David Wosnick
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Thomas Dodsworth
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Andrea L D'Aquila
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - David A Lovejoy
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
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9
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Neurobiology and therapeutic applications of neurotoxins targeting transmitter release. Pharmacol Ther 2019; 193:135-155. [DOI: 10.1016/j.pharmthera.2018.08.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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10
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Husić M, Barsyte-Lovejoy D, Lovejoy DA. Teneurin C-Terminal Associated Peptide (TCAP)-1 and Latrophilin Interaction in HEK293 Cells: Evidence for Modulation of Intercellular Adhesion. Front Endocrinol (Lausanne) 2019; 10:22. [PMID: 30774623 PMCID: PMC6367273 DOI: 10.3389/fendo.2019.00022] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 01/14/2019] [Indexed: 11/24/2022] Open
Abstract
The teneurins are a family of four transmembrane proteins essential to intercellular adhesion processes, and are required for the development and maintenance of tissues. The Adhesion G protein-coupled receptor (GPCR) subclass latrophilins (ADGRL), or simply the latrophilins (LPHN), are putative receptors of the teneurins and act, in part, to mediate intercellular adhesion via binding with the teneurin extracellular region. At the distal tip of the extracellular region of each teneurin lies a peptide sequence termed the teneurin C-terminal associated peptide (TCAP). TCAP-1, associated with teneurin-1, is itself bioactive, suggesting that TCAP is a critical functional region of teneurin. However, the role of TCAP-1 has not been established with respect to its ability to interact with LPHN to induce downstream effects. To establish that TCAP-1 binds to LPHN1, a FLAG-tagged hormone binding domain (HBD) of LPHN1 and a GFP-tagged TCAP-1 peptide were co-expressed in HEK293 cells. Both immunoreactive epitopes were co-localized as a single band after immunoprecipitation, indicating an association between the two proteins. Moreover, fluorescent co-labeling occurred at the plasma membrane of LPHN1 over-expressing cells when treated with a FITC-tagged TCAP-1 variant. Expression of LPHN1 and treatment with TCAP-1 modulated the actin-based cytoskeleton in these cells in a manner consistent with previously reported actions of TCAP-1 and affected the overall morphology and aggregation of the cells. This study indicates that TCAP-1 may associate directly with LPHN1 and could play a role in the modulation of cytoskeletal organization and intercellular adhesion and aggregation via this interaction.
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Affiliation(s)
- Mia Husić
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | | | - David A. Lovejoy
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
- *Correspondence: David A. Lovejoy
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11
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Carrazoni T, Nguyen C, Maciel LF, Delgado-Cañedo A, Stewart BA, Lange AB, Dal Belo CA, Carlini CR, Orchard I. Jack bean urease modulates neurotransmitter release at insect neuromuscular junctions. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2018; 146:63-70. [PMID: 29626993 DOI: 10.1016/j.pestbp.2018.02.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 02/09/2018] [Accepted: 02/21/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND Plants have developed a vast range of mechanisms to compete with phytophagous insects, including entomotoxic proteins such as ureases. The legume Canavalia ensiformis produces several urease isoforms, of which the more abundant is called Jack Bean Urease (JBU). Previews work has demonstrated the potential insecticidal effects of JBU, by mechanisms so far not entirely elucidated. In this work, we investigated the mechanisms involved in the JBU-induced activity upon neurotransmitter release on insect neuromuscular junctions. METHODS Electrophysiological recordings of nerve and muscle action potentials, and calcium imaging bioassays were employed. RESULTS AND CONCLUSION JBU (0.28 mg/animal/day) in Locusta migratoria 2nd instar through feeding and injection did not induce lethality, although it did result in a reduction of 20% in the weight gain at the end of 168 h (n = 9, p ≤ 0.05). JBU (0.014 and 0.14 mg) injected direct into the locust hind leg induced a dose and time-dependent decrease in the amplitude of muscle action potentials, with a maximum decrease of 70% in the amplitude at the highest dose (n = 5, p ≤ 0.05). At the same doses JBU did not alter the amplitude of action potentials evoked from motor neurons. Using Drosophila 3rd instar larvae neuromuscular preparations, JBU (10-7 M) increased the occurrence of miniature Excitatory Junctional Potentials (mEJPs) in the presence of 1 mM CaCl2 (n = 5, p ≤ 0.05). In low calcium (0.4 mM) assays, JBU (10-7 M) was not able to modulate the occurrence of the events. In Ca2+-free conditions, with EGTA or CoCl2, JBU induced a significant decrease in the occurrence of mEPJs (n = 5, p ≤ 0.05). Injected into the 3rd abdominal ganglion of Nauphoeta cinerea cockroaches, JBU (1 μM) induced a significant increase in Ca2+ influx (n = 7, p ≤ 0.01), similar to that seen for high KCl (35 mM) condition. Taken together the results confirm a direct action of JBU upon insect neuromuscular junctions and possibly central synapses, probably by disrupting the calcium machinery in the pre-synaptic region of the neurons.
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Affiliation(s)
- Thiago Carrazoni
- Universidade Federal do Rio Grande do Sul, Graduate Program in Cell and Molecular Biology, Center of Biotechnology, Porto Alegre, RS, Brazil; University of Toronto Mississauga, Department of Biology, Mississauga, ON, Canada; Pontifícia Universidade Católica do Rio Grande de Sul, Brain Institute, Porto Alegre, RS, Brazil.
| | - Christine Nguyen
- University of Toronto Mississauga, Department of Biology, Mississauga, ON, Canada
| | - Lucas F Maciel
- Universidade Federal do Pampa, Campus São Gabriel, São Gabriel, RS, Brazil
| | | | - Bryan A Stewart
- University of Toronto Mississauga, Department of Biology, Mississauga, ON, Canada
| | - Angela B Lange
- University of Toronto Mississauga, Department of Biology, Mississauga, ON, Canada
| | | | - Celia R Carlini
- Universidade Federal do Rio Grande do Sul, Graduate Program in Cell and Molecular Biology, Center of Biotechnology, Porto Alegre, RS, Brazil; Pontifícia Universidade Católica do Rio Grande de Sul, Brain Institute, Porto Alegre, RS, Brazil.
| | - Ian Orchard
- University of Toronto Mississauga, Department of Biology, Mississauga, ON, Canada.
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12
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Chepurny OG, Bonaccorso RL, Leech CA, Wöllert T, Langford GM, Schwede F, Roth CL, Doyle RP, Holz GG. Chimeric peptide EP45 as a dual agonist at GLP-1 and NPY2R receptors. Sci Rep 2018; 8:3749. [PMID: 29491394 PMCID: PMC5830615 DOI: 10.1038/s41598-018-22106-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 02/16/2018] [Indexed: 02/07/2023] Open
Abstract
We report the design and target validation of chimeric peptide EP45, a novel 45 amino acid monomeric dual agonist peptide that contains amino acid sequence motifs present within the blood glucose-lowering agent exendin-4 (Ex-4) and the appetite-suppressing agent PYY(3-36). In a new high-throughput FRET assay that provides real-time kinetic information concerning levels of cAMP in living cells, EP45 recapitulates the action of Ex-4 to stimulate cAMP production via the glucagon-like peptide-1 receptor (GLP-1R), while also recapitulating the action of PYY(3-36) to inhibit cAMP production via the neuropeptide Y2 receptor (NPY2R). EP45 fails to activate glucagon or GIP receptors, whereas for cells that co-express NPY2R and adenosine A2B receptors, EP45 acts in an NPY2R-mediated manner to suppress stimulatory effects of adenosine on cAMP production. Collectively, such findings are remarkable in that they suggest a new strategy in which the co-existing metabolic disorders of type 2 diabetes and obesity will be treatable using a single peptide such as EP45 that lowers levels of blood glucose by virtue of its GLP-1R-mediated effect, while simultaneously suppressing appetite by virtue of its NPY2R-mediated effect.
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Affiliation(s)
- Oleg G Chepurny
- Department of Medicine, State University of New York (SUNY) Upstate Medical University, 505 Irving Avenue, Syracuse, NY, 13210, USA
| | - Ron L Bonaccorso
- Department of Chemistry, Syracuse University, 111 College Place, Syracuse, NY, 13244, USA
| | - Colin A Leech
- Department of Medicine, State University of New York (SUNY) Upstate Medical University, 505 Irving Avenue, Syracuse, NY, 13210, USA
| | - Torsten Wöllert
- Department of Biology, Syracuse University, Syracuse, NY, 13244, USA
| | - George M Langford
- Department of Biology, Syracuse University, Syracuse, NY, 13244, USA
| | - Frank Schwede
- BIOLOG Life Science Institute, 28199, Bremen, Germany
| | - Christian L Roth
- Center for Integrative Brain Research, Seattle Children's Research Institute, Washington, 98105, USA
- Department of Pediatrics, University of Washington, Seattle, Washington, 98105, USA
| | - Robert P Doyle
- Department of Medicine, State University of New York (SUNY) Upstate Medical University, 505 Irving Avenue, Syracuse, NY, 13210, USA.
- Department of Chemistry, Syracuse University, 111 College Place, Syracuse, NY, 13244, USA.
| | - George G Holz
- Department of Medicine, State University of New York (SUNY) Upstate Medical University, 505 Irving Avenue, Syracuse, NY, 13210, USA.
- Department of Pharmacology, State University of New York (SUNY) Upstate Medical University, 505 Irving Avenue, Syracuse, NY, 13210, USA.
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13
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Nicolau CA, Prorock A, Bao Y, Neves-Ferreira AGDC, Valente RH, Fox JW. Revisiting the Therapeutic Potential of Bothrops jararaca Venom: Screening for Novel Activities Using Connectivity Mapping. Toxins (Basel) 2018; 10:toxins10020069. [PMID: 29415440 PMCID: PMC5848170 DOI: 10.3390/toxins10020069] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 01/30/2018] [Accepted: 02/02/2018] [Indexed: 12/12/2022] Open
Abstract
Snake venoms are sources of molecules with proven and potential therapeutic applications. However, most activities assayed in venoms (or their components) are of hemorrhagic, hypotensive, edematogenic, neurotoxic or myotoxic natures. Thus, other relevant activities might remain unknown. Using functional genomics coupled to the connectivity map (C-map) approach, we undertook a wide range indirect search for biological activities within the venom of the South American pit viper Bothrops jararaca. For that effect, venom was incubated with human breast adenocarcinoma cell line (MCF7) followed by RNA extraction and gene expression analysis. A list of 90 differentially expressed genes was submitted to biosimilar drug discovery based on pattern recognition. Among the 100 highest-ranked positively correlated drugs, only the antihypertensive, antimicrobial (both antibiotic and antiparasitic), and antitumor classes had been previously reported for B. jararaca venom. The majority of drug classes identified were related to (1) antimicrobial activity; (2) treatment of neuropsychiatric illnesses (Parkinson’s disease, schizophrenia, depression, and epilepsy); (3) treatment of cardiovascular diseases, and (4) anti-inflammatory action. The C-map results also indicated that B. jararaca venom may have components that target G-protein-coupled receptors (muscarinic, serotonergic, histaminergic, dopaminergic, GABA, and adrenergic) and ion channels. Although validation experiments are still necessary, the C-map correlation to drugs with activities previously linked to snake venoms supports the efficacy of this strategy as a broad-spectrum approach for biological activity screening, and rekindles the snake venom-based search for new therapeutic agents.
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Affiliation(s)
- Carolina Alves Nicolau
- Laboratory of Toxinology, Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro, RJ 21040-900, Brazil.
- National Institute of Science and Technology on Toxins (INCTTOX), CNPq, Brasília, DF 71605-170, Brazil.
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, VA 22908, USA.
| | - Alyson Prorock
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, VA 22908, USA.
| | - Yongde Bao
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, VA 22908, USA.
| | - Ana Gisele da Costa Neves-Ferreira
- Laboratory of Toxinology, Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro, RJ 21040-900, Brazil.
- National Institute of Science and Technology on Toxins (INCTTOX), CNPq, Brasília, DF 71605-170, Brazil.
| | - Richard Hemmi Valente
- Laboratory of Toxinology, Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro, RJ 21040-900, Brazil.
- National Institute of Science and Technology on Toxins (INCTTOX), CNPq, Brasília, DF 71605-170, Brazil.
| | - Jay William Fox
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, VA 22908, USA.
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D'Aquila AL, Hsieh AHR, Hsieh AHM, De Almeida R, Lovejoy SR, Lovejoy DA. Expression and actions of corticotropin-releasing factor/diuretic hormone-like peptide (CDLP) and teneurin C-terminal associated peptide (TCAP) in the vase tunicate, Ciona intestinalis: Antagonism of the feeding response. Gen Comp Endocrinol 2017; 246:105-115. [PMID: 27292788 DOI: 10.1016/j.ygcen.2016.06.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 05/24/2016] [Accepted: 06/08/2016] [Indexed: 11/19/2022]
Abstract
Teneurin C-terminal associated peptide (TCAP) is a neuropeptide that bears some structural similarity to the corticotropin-releasing factor (CRF) family of peptides. TCAP and CRF are both implicated in the regulation of stress-related behaviors, as established in rodent models. However, in vertebrates, both TCAP and CRF possess three additional paralogous forms making vertebrate models difficult to assess with respect to TCAP-CRF interaction. As a urochordate, this species possesses single homologs of TCAP and of a CRF/Diuretic-like peptide (CDLP) in the genome, thereby establishing Ciona intestinalis as an excellent model organism to examine the interaction of these peptide systems. However, the lack of C. intestinalis synthetic peptides and specific antisera has complicated experimentation. We, therefore, prepared synthetic versions of CDLP and TCAP to prepare specific antisera and to investigate their bioactivity in this species. To analyze stress-related behaviors, a novel behavioral assay was used to characterize different types of contraction-based behaviors, using buccal opening contractions, cloacal opening contractions, lateral contractions, longitudinal contractions and expulsions. Protein and mRNA expression data indicate that the mature versions of both peptides are present in a number of tissues. With respect to behavioral activity, both TCAP- and CDLP-treated animals had distinct contraction profiles under ambient conditions. Moreover, food stimulation tests revealed that whereas CDLP-treated animals displayed a strong expulsion behavior in response to feeding, TCAP-treated animals did not show this effect. These actions are consistent with previous studies done in vertebrates.
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Affiliation(s)
- Andrea L D'Aquila
- Department of Cell and Systems Biology, University of Toronto, Ontario, Canada
| | - Alan Hwa-Ruey Hsieh
- Department of Cell and Systems Biology, University of Toronto, Ontario, Canada
| | - Adam Hwa-Ming Hsieh
- Department of Cell and Systems Biology, University of Toronto, Ontario, Canada
| | - Reuben De Almeida
- Department of Cell and Systems Biology, University of Toronto, Ontario, Canada
| | - Sabine R Lovejoy
- Department of Cell and Systems Biology, University of Toronto, Ontario, Canada
| | - David A Lovejoy
- Department of Cell and Systems Biology, University of Toronto, Ontario, Canada.
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15
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Tsend-Ayush E, He C, Myers MA, Andrikopoulos S, Wong N, Sexton PM, Wootten D, Forbes BE, Grutzner F. Monotreme glucagon-like peptide-1 in venom and gut: one gene - two very different functions. Sci Rep 2016; 6:37744. [PMID: 27898108 PMCID: PMC5127184 DOI: 10.1038/srep37744] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 11/01/2016] [Indexed: 12/11/2022] Open
Abstract
The importance of Glucagon like peptide 1 (GLP-1) for metabolic control and insulin release sparked the evolution of genes mimicking GLP-1 action in venomous species (e.g. Exendin-4 in Heloderma suspectum (gila monster)). We discovered that platypus and echidna express a single GLP-1 peptide in both intestine and venom. Specific changes in GLP-1 of monotreme mammals result in resistance to DPP-4 cleavage which is also observed in the GLP-1 like Exendin-4 expressed in Heloderma venom. Remarkably we discovered that monotremes evolved an alternative mechanism to degrade GLP-1. We also show that monotreme GLP-1 stimulates insulin release in cultured rodent islets, but surprisingly shows low receptor affinity and bias toward Erk signaling. We propose that these changes in monotreme GLP-1 are the result of conflicting function of this peptide in metabolic control and venom. This evolutionary path is fundamentally different from the generally accepted idea that conflicting functions in a single gene favour duplication and diversification, as is the case for Exendin-4 in gila monster. This provides novel insight into the remarkably different metabolic control mechanism and venom function in monotremes and an unique example of how different selective pressures act upon a single gene in the absence of gene duplication.
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Affiliation(s)
- Enkhjargal Tsend-Ayush
- Robinson Research Institute, School of Biological Sciences, The University of Adelaide, South Australia, 5000, Australia
| | - Chuan He
- Robinson Research Institute, School of Biological Sciences, The University of Adelaide, South Australia, 5000, Australia
| | - Mark A Myers
- School of Applied and Biomedical Sciences, Federation University Australia, Mount Helen, Victoria, 3353, Australia
| | - Sof Andrikopoulos
- Department of Medicine, Austin Health, The University of Melbourne, Heidelberg, Victoria 3084, Australia
| | - Nicole Wong
- Department of Medicine, Austin Health, The University of Melbourne, Heidelberg, Victoria 3084, Australia
| | - Patrick M Sexton
- Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, 3052, Australia
| | - Denise Wootten
- Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, 3052, Australia
| | - Briony E Forbes
- Robinson Research Institute, School of Biological Sciences, The University of Adelaide, South Australia, 5000, Australia.,School of Medicine, Flinders University, Bedford Park, South Australia, 5042, Australia
| | - Frank Grutzner
- Robinson Research Institute, School of Biological Sciences, The University of Adelaide, South Australia, 5000, Australia
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16
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Chepurny OG, Leech CA, Tomanik M, DiPoto MC, Li H, Han X, Meng Q, Cooney RN, Wu J, Holz GG. Synthetic small molecule GLP-1 secretagogues prepared by means of a three-component indole annulation strategy. Sci Rep 2016; 6:28934. [PMID: 27352904 PMCID: PMC4926213 DOI: 10.1038/srep28934] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 06/13/2016] [Indexed: 12/14/2022] Open
Abstract
Rational assembly of small molecule libraries for purposes of drug discovery requires an efficient approach in which the synthesis of bioactive compounds is enabled so that numerous structurally related compounds of a similar basic formulation can be derived. Here, we describe (4 + 3) and (3 + 2) indole annulation strategies that quickly generate complex indole heterocycle libraries that contain novel cyclohepta- and cyclopenta[b]indoles, respectively. Screening of one such library comprised of these indoles identifies JWU-A021 to be an especially potent stimulator of glucagon-like peptide-1 (GLP-1) secretion in vitro. Surprisingly, JWU-A021 is also a potent stimulator of Ca2+ influx through TRPA1 cation channels (EC50ca. 200 nM), thereby explaining its ability to stimulate GLP-1 release. Of additional importance, the available evidence indicates that JWU-A021 is one of the most potent non-electrophilic TRPA-1 channel agonists yet to be reported in the literature.
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Affiliation(s)
- Oleg G Chepurny
- Department of Medicine, State University of New York (SUNY), Upstate Medical University, Syracuse, New York, USA
| | - Colin A Leech
- Department of Medicine, State University of New York (SUNY), Upstate Medical University, Syracuse, New York, USA
| | - Martin Tomanik
- Department of Chemistry, Dartmouth College, Hanover, New Hampshire, USA
| | - Maria C DiPoto
- Department of Chemistry, Dartmouth College, Hanover, New Hampshire, USA
| | - Hui Li
- Department of Chemistry, Dartmouth College, Hanover, New Hampshire, USA
| | - Xinping Han
- Department of Chemistry, Dartmouth College, Hanover, New Hampshire, USA
| | - Qinghe Meng
- Department of Surgery, State University of New York (SUNY), Upstate Medical University, Syracuse, New York, USA
| | - Robert N Cooney
- Department of Surgery, State University of New York (SUNY), Upstate Medical University, Syracuse, New York, USA
| | - Jimmy Wu
- Department of Chemistry, Dartmouth College, Hanover, New Hampshire, USA
| | - George G Holz
- Department of Medicine, State University of New York (SUNY), Upstate Medical University, Syracuse, New York, USA.,Department of Pharmacology, State University of New York (SUNY), Upstate Medical University, Syracuse, New York, USA
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17
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Holz GG, Leech CA, Chepurny OG. New insights concerning the molecular basis for defective glucoregulation in soluble adenylyl cyclase knockout mice. Biochim Biophys Acta Mol Basis Dis 2014; 1842:2593-600. [PMID: 24980705 DOI: 10.1016/j.bbadis.2014.06.023] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 06/17/2014] [Accepted: 06/18/2014] [Indexed: 01/09/2023]
Abstract
Recently published findings indicate that a knockout (KO) of soluble adenylyl cyclase (sAC, also known as AC-10) gene expression in mice leads to defective glucoregulation that is characterized by reduced pancreatic insulin secretion and reduced intraperitoneal glucose tolerance. Summarized here are current concepts regarding the molecular basis for this phenotype, with special emphasis on the potential role of sAC as a determinant of glucose-stimulated insulin secretion. Highlighted is new evidence that in pancreatic beta cells, oxidative glucose metabolism stimulates mitochondrial CO₂production that in turn generates bicarbonate ion (HCO(3)(-)). Since HCO(3)(-) binds to and directly stimulates the activity of sAC, we propose that glucose-stimulated cAMP production in beta cells is mediated not simply by transmembrane adenylyl cyclases (TMACs), but also by sAC. Based on evidence that sAC is expressed in mitochondria, there exists the possibility that beta-cell glucose metabolism is linked to mitochondrial cAMP production with consequent facilitation of oxidative phosphorylation. Since sAC is also expressed in the cytoplasm, sAC catalyzed cAMP production may activate cAMP sensors such as PKA and Epac2 to control ion channel function, intracellular Ca²⁺ handling, and Ca²⁺-dependent exocytosis. Thus, we propose that the existence of sAC in beta cells provides a new and unexpected explanation for previously reported actions of glucose metabolism to stimulate cAMP production. It seems possible that alterations of sAC activity might be of importance when evaluating new strategies for the treatment of type 2 diabetes (T2DM), or when evaluating why glucose metabolism fails to stimulate insulin secretion in patients diagnosed with T2DM. This article is part of a Special Issue entitled: The role of soluble adenylyl cyclase in health and disease.
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Affiliation(s)
- George G Holz
- Department of Medicine, State University of New York (SUNY), Upstate Medical University, Syracuse, NY 13210, USA; Department of Pharmacology, State University of New York (SUNY), Upstate Medical University, Syracuse, NY 13210, USA.
| | - Colin A Leech
- Department of Medicine, State University of New York (SUNY), Upstate Medical University, Syracuse, NY 13210, USA
| | - Oleg G Chepurny
- Department of Medicine, State University of New York (SUNY), Upstate Medical University, Syracuse, NY 13210, USA
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18
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McCowan C, Garb JE. Recruitment and diversification of an ecdysozoan family of neuropeptide hormones for black widow spider venom expression. Gene 2014; 536:366-75. [PMID: 24316130 PMCID: PMC4172349 DOI: 10.1016/j.gene.2013.11.054] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 10/25/2013] [Accepted: 11/21/2013] [Indexed: 11/18/2022]
Abstract
Venoms have attracted enormous attention because of their potent physiological effects and dynamic evolution, including the convergent recruitment of homologous genes for venom expression. Here we provide novel evidence for the recruitment of genes from the Crustacean Hyperglycemic Hormone (CHH) and arthropod Ion Transport Peptide (ITP) superfamily for venom expression in black widow spiders. We characterized latrodectin peptides from venom gland cDNAs from the Western black widow spider (Latrodectus hesperus), the brown widow (Latrodectus geometricus) and cupboard spider (Steatoda grossa). Phylogenetic analyses of these sequences with homologs from other spider, scorpion and wasp venom cDNAs, as well as CHH/ITP neuropeptides, show latrodectins as derived members of the CHH/ITP superfamily. These analyses suggest that CHH/ITP homologs are more widespread in spider venoms, and were recruited for venom expression in two additional arthropod lineages. We also found that the latrodectin 2 gene and nearly all CHH/ITP genes include a phase 2 intron in the same position, supporting latrodectin's placement within the CHH/ITP superfamily. Evolutionary analyses of latrodectins suggest episodes of positive selection along some sequence lineages, and positive and purifying selection on specific codons, supporting its functional importance in widow venom. We consider how this improved understanding of latrodectin evolution informs functional hypotheses regarding its role in black widow venom as well as its potential convergent recruitment for venom expression across arthropods.
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Affiliation(s)
- Caryn McCowan
- Department of Biological Sciences, University of Massachusetts Lowell, Lowell, MA 01854, USA
| | - Jessica E Garb
- Department of Biological Sciences, University of Massachusetts Lowell, Lowell, MA 01854, USA.
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19
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Li C, Chen M, Sang M, Liu X, Wu W, Li B. Comparative genomic analysis and evolution of family-B G protein-coupled receptors from six model insect species. Gene 2013; 519:1-12. [PMID: 23428791 DOI: 10.1016/j.gene.2013.01.061] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Revised: 12/21/2012] [Accepted: 01/30/2013] [Indexed: 10/27/2022]
Abstract
Family-B G protein-coupled receptors (GPCR-Bs) play vital roles in many biological processes, including growth, development and reproduction. However, the evolution and function of GPCR-Bs have been poorly understood in insects. We have identified 87 GPCR-Bs from six model insect species, 20 from Tribolium castaneum, 9 from Apis mellifera, 11 from Bombyx mori, 9 from Acyrthosiphon pisum, 14 from Anopheles gambiae and 24 from Drosophila melanogaster. 22 of them were reported in this study for the first time. Phylogenetic analysis revealed that there are three kinds of evolutionary patterns that occurred among GPCR-Bs during insect evolution: one-to-one orthologous relationships, species-specific expansion and episodic duplication or loss in certain insect lineages. A striking finding was the discovery of a parathyroid hormone receptor like gene (pthrl) in invertebrates, which was independently duplicated in vertebrates and invertebrates, whereas this gene was lost at least twice during insect evolution. These results indicate that PTHRL is possibly divergent in the functions between mammals and insects. The information of family-B GPCRs in nondrosophiline insects has been established, and will promote the further study on the function of these GPCRs and deorphanization of them. On the other hand, this study provides us with multiple function of GPCR-Bs in differential organisms, which will be also the potential attacking targets for new pesticides and drugs.
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Affiliation(s)
- Chengjun Li
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China
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20
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Garb JE, Hayashi CY. Molecular evolution of α-latrotoxin, the exceptionally potent vertebrate neurotoxin in black widow spider venom. Mol Biol Evol 2013; 30:999-1014. [PMID: 23339183 PMCID: PMC3670729 DOI: 10.1093/molbev/mst011] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Black widow spiders (members of the genus Latrodectus) are widely feared because of their potent neurotoxic venom. α-Latrotoxin is the vertebrate-specific toxin responsible for the dramatic effects of black widow envenomation. The evolution of this toxin is enigmatic because only two α-latrotoxin sequences are known. In this study, ~4 kb α-latrotoxin sequences and their homologs were characterized from a diversity of Latrodectus species, and representatives of Steatoda and Parasteatoda, establishing the wide distribution of latrotoxins across the mega-diverse spider family Theridiidae. Across black widow species, α-latrotoxin shows ≥ 94% nucleotide identity and variability consistent with purifying selection. Multiple codon and branch-specific estimates of the nonsynonymous/synonymous substitution rate ratio also suggest a long history of purifying selection has acted on α-latrotoxin across Latrodectus and Steatoda. However, α-latrotoxin is highly divergent in amino acid sequence between these genera, with 68.7% of protein differences involving non-conservative substitutions, evidence for positive selection on its physiochemical properties and particular codons, and an elevated rate of nonsynonymous substitutions along α-latrotoxin's Latrodectus branch. Such variation likely explains the efficacy of red-back spider, L. hasselti, antivenom in treating bites from other Latrodectus species, and the weaker neurotoxic symptoms associated with Steatoda and Parasteatoda bites. Long-term purifying selection on α-latrotoxin indicates its functional importance in black widow venom, even though vertebrates are a small fraction of their diet. The greater differences between Latrodectus and Steatoda α-latrotoxin, and their relationships to invertebrate-specific latrotoxins, suggest a shift in α-latrotoxin toward increased vertebrate toxicity coincident with the evolution of widow spiders.
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Affiliation(s)
- Jessica E Garb
- Department of Biological Sciences, University of Massachusetts, Lowell, USA.
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21
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Toxins that Modulate Ionic Channels as Tools for Exploring Insulin Secretion. Cell Mol Neurobiol 2010; 30:1275-81. [DOI: 10.1007/s10571-010-9586-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2010] [Accepted: 09/02/2010] [Indexed: 01/26/2023]
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22
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Popescu IR, Morton LA, Franco A, Di S, Ueta Y, Tasker JG. Synchronized bursts of miniature inhibitory postsynaptic currents. J Physiol 2010; 588:939-51. [PMID: 20123785 DOI: 10.1113/jphysiol.2009.181461] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Spike-independent miniature postsynaptic currents are generally stochastic and are therefore not thought to mediate information relay in neuronal circuits. However, we recorded endogenous bursts of IPSCs in hypothalamic magnocellular neurones in the presence of TTX, which implicated a coordinated mechanism of spike-independent GABA release. IPSC bursts were identical in the absence of TTX, although the burst incidence increased 5-fold, indicating that IPSC bursts were composed of miniature IPSCs (mIPSCs), and that the probability of burst generation increased with action potential activity. IPSC bursts required extracellular calcium, although they were not dependent on calcium influx through voltage-gated calcium channels or on calcium mobilization from intracellular stores. Current injections simulating IPSC bursts were capable of triggering and terminating action potential trains. In 25% of dual recordings, a subset of IPSC bursts were highly synchronized in onset in pairs of magnocellular neurones. Synchronized IPSC bursts displayed properties that were consistent with simultaneous release at GABA synapses shared between pairs of postsynaptic magnocellular neurones. Synchronized bursts of inhibitory synaptic inputs represent a novel mechanism that may contribute to the action potential burst generation, termination and synchronization responsible for pulsatile hormone release from neuroendocrine cells.
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Affiliation(s)
- Ion R Popescu
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA, USA
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23
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Staines DR. Postulated vasoactive neuropeptide autoimmunity in fatigue-related conditions: a brief review and hypothesis. Clin Dev Immunol 2006; 13:25-39. [PMID: 16603442 PMCID: PMC2270748 DOI: 10.1080/17402520600568252] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Disorders such as chronic fatigue syndrome (CFS) and gulf war syndrome (GWS) are characterised by prolonged fatigue and a range of debilitating symptoms of pain, intellectual and emotional impairment, chemical sensitivities and immunological dysfunction. Sudden infant death syndrome (SIDS) surprisingly may have certain features in common with these conditions. Post-infection sequelae may be possible contributing factors although ongoing infection is unproven. Immunological aberration may prove to be associated with certain vasoactive neuropeptides (VN) in the context of molecular mimicry, inappropriate immunological memory and autoimmunity. Adenylate cyclase-activating VNs including pituitary adenylate cyclase-activating polypeptide (PACAP), vasoactive intestinal peptide (VIP) and calcitonin gene-related peptide (CGRP) act as hormones, neurotransmitters, neuroregulators, immune modulators and neurotrophic substances. They and their receptors are potentially immunogenic. VNs are widely distributed in the body particularly in the central and peripheral nervous systems and have been identified in the gut, adrenal gland, blood cells, reproductive system, lung, heart and other tissues. They have a vital role in maintaining cardio-respiratory function, thermoregulation, memory, concentration and executive functions such as emotional responses including social cues and appropriate behaviour. They are co-transmitters for a number of neurotransmitters including acetylcholine and gaseous transmitters, are potent immune regulators with primarily anti-inflammatory activity, and have a significant role in protection of the nervous system against toxic assault as well as being important in the maintenance of homeostasis. This paper describes a biologically plausible mechanism for the development of certain fatigue-related syndromes based on loss of immunological tolerance to these VNs or their receptors following infection, other events or de novo resulting in significant pathophysiology possibly mediated via CpG fragments and heat shock (stress) proteins. These conditions extend the public health context of autoimmunity and VN dysregulation and have implications for military medicine where radiological, biological and chemical agents may have a role in pathogenesis. Possible treatment and prevention options are considered.
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Affiliation(s)
- Donald R Staines
- Gold Coast Public Health Unit, 10-12 Young Street, Southport, Qld, 4215, Australia.
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24
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Abstract
Bites, stings and infestations can be fatal. Anaphylaxis to vespids and bees can be prevented with immunotherapy. Patients should be referred to an allergist. The acute care and prevention of arthropod injury is discussed below.
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Affiliation(s)
- Dirk M Elston
- Department of Dermatology, Geisinger Medical Center, Danville, PA 17821, USA.
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25
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Staines DR. Therapeutic and preventive interventions for postulated vasoactive neuropeptide autoimmune fatigue-related disorders. Med Hypotheses 2005; 65:797-803. [PMID: 16042995 DOI: 10.1016/j.mehy.2005.03.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2005] [Accepted: 03/09/2005] [Indexed: 10/25/2022]
Abstract
Major advances have been made in understanding the relatively novel group of vasoactive (vasodilatory) neuropeptides (VNs) in humans. VNs comprise a novel but expanding group of substances having immunoregulation, inflammation modulation, neurotransmitter, neurotrophic, hormonal and metabolic functions. These substances may control gene expression for mRNA for themselves and their receptors. They have complex relationships with gaseous and other neurotransmitters and xenobiotic substances. Theoretical arguments have implicated these substances in autoimmune phenomena resulting in fatigue-related conditions such as chronic fatigue syndrome (CFS), sudden infant death syndrome (SIDS), fibromyalgia (FM) and Gulf War syndrome (GWS) but remain unproven. As well as possibly spontaneous onset, the precipitating causes of VN autoimmune dysfunction are likely to be a combination of genetic predisposition, infection and xenobiotic substances. Therapeutic and preventive possibilities for postulated VN autoimmune conditions will be influenced by the complex patholophysiology underpinning them. Some speculative possibilities are VN substitution/replacement, preservation of biological effect, epigenetic DNA modifications, plasma exchange, anti-cholinesterases, e.g., pyridostigmine, corticosteroids and other drug treatments, thymectomy, intravenous immunoglobulin and anti-idiotype antibodies, and CpG/DNA vaccines. Prevention and treatment of possible VN autoimmune fatigue-related disorders may prove to be important areas for future research and development.
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Affiliation(s)
- Donald R Staines
- Gold Coast Public Health Unit, 10-12 Young Street, Southport 4215, Queensland, Australia.
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26
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Abstract
Venomous animals have evolved a vast array of peptide toxins for prey capture and defence. These peptides are directed against a wide variety of pharmacological targets, making them an invaluable source of ligands for studying the properties of these targets in different experimental paradigms. A number of these peptides have been used in vivo for proof-of-concept studies, with several having undergone preclinical or clinical development for the treatment of pain, diabetes, multiple sclerosis and cardiovascular diseases. Here we survey the pharmacology of venom peptides and assess their therapeutic prospects.
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Affiliation(s)
- Richard J Lewis
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia 4072, Australia.
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27
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Abstract
The authors divide biological toxins into animal, plant, and bacterial classes and discuss each within a context of demographic, clinical and research examples. Advances in our knowledge are highlighted, and the authors relate the implications of this knowledge to target-specific neurologic involvement.
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Affiliation(s)
- C G Goetz
- Department of Neurological Sciences, Rush-Presbyterian-St. Luke's Medical Center, Chicago, Il 60612, USA
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28
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Affiliation(s)
- Thomas Brody
- Neurogenetics Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892
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Black widow spider (Latrodectus mactans) envenomation in a term pregnancy. CURRENT SURGERY 2000; 57:346-348. [PMID: 11024247 DOI: 10.1016/s0149-7944(00)00276-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Description of a black widow spider (Latrodectus mactans) envenomation in a term pregnancy.Case report conducted at an Air Force tertiary care hospital of a 27-year-old primigravida at 38 1/7 weeks pregnancy.Latrodectus mactans antivenin can be given to treat symptoms of black widow envenomation.Black widow envenomations can cause symptoms associated with acute intra-abdominal processes. In pregnancy, envenomations can result in symptoms and signs similar to those seen in preeclampsia (abdominal pain, headache, hypertension, and proteinuria). Latrodectism should be considered in patients complaining of these symptoms in association with a spider bite. If latrodectism is considered to be the underlying origin for these symptoms, appropriate treatment should be administered. In cases of pregnancy, treatment should include L. mactans antivenin if believed to be clinically indicated. There is no current evidence that this antivenin is contraindicated in pregnancy. (Curr Surg 57:346-348)
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Holz GG, Leech CA, Habener JF. Insulinotropic toxins as molecular probes for analysis of glucagon-likepeptide-1 receptor-mediated signal transduction in pancreatic beta-cells. Biochimie 2000; 82:915-26. [PMID: 11086221 PMCID: PMC2928854 DOI: 10.1016/s0300-9084(00)01171-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Cholera toxin, pertussis toxin, mastoparan, maitotoxin, and alpha-latrotoxin are complex protein or polyether-based toxins of bacterial, insect, or phytoplankton origin that act with high potency at the endocrine pancreas to stimulate secretion of insulin from beta-cells located in the islets of Langerhans. The remarkable insulinotropic properties of these toxins have attracted considerable attention by virtue of their use as selective molecular probes for analyses of beta-cell stimulus-secretion coupling. Targets of the toxins include heptahelical cell surface receptors, GTP-binding proteins, ion channels, Ca(2+) stores, and the exocytotic secretory apparatus. Here we review the value of insulinotropic toxins from the perspective of their established use in the study of signal transduction pathways activated by the blood glucose-lowering hormone glucagon-like peptide-1 (GLP-1). Our analysis of one insulinotropic toxin (alpha-latrotoxin) leads us to conclude that there exists a process of molecular mimicry whereby the 'lock and key'analogy inherent to hormone-receptor interactions is reproduced by a toxin related in structure to GLP-1.
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Affiliation(s)
- G G Holz
- Department of Physiology and Neuroscience, Medical Sciences Building Room 442, New York University School of Medicine, 550 First Avenue, NY New York 10016, USA.
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Abstract
When different cone snail peptides are injected into the CNS of vertebrates, they elicit diverse behaviors primarily because of their selectivity for specific receptor or ion channel subtypes. The subcellular context of the highly localized targets (i.e. the presence of other cellular elements that are functionally linked to the targets of conopeptides) is another determinant of the elicited behavior. Recent studies have advanced our understanding of the mechanisms by which four conopeptides produce different behaviors in mice.
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Affiliation(s)
- B M Olivera
- Department of Biology, University of Utah, Salt Lake City 84112-0840, USA.
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