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Pharmacological and molecular dynamics analyses of differences in inhibitor binding to human and nematode PDE4: Implications for management of parasitic nematodes. PLoS One 2019; 14:e0214554. [PMID: 30917179 PMCID: PMC6436744 DOI: 10.1371/journal.pone.0214554] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Accepted: 03/14/2019] [Indexed: 11/19/2022] Open
Abstract
Novel chemical controls are needed that selectively target human, animal, and plant parasitic nematodes with reduced adverse effects on the host or the environment. We hypothesize that the phosphodiesterase (PDE) enzyme family represents a potential target for development of novel nematicides and anthelmintics. To test this, we identified six PDE families present in the nematode phylum that are orthologous to six of the eleven human PDE families. We characterized the binding interactions of family-selective PDE inhibitors with human and C. elegans PDE4 in conjunction with molecular dynamics (MD) simulations to evaluate differences in binding interactions of these inhibitors within the PDE4 catalytic domain. We observed that roflumilast (human PDE4-selective inhibitor) and zardaverine (selective for human PDE3 and PDE4) were 159- and 77-fold less potent, respectively, in inhibiting C. elegans PDE4. The pan-specific PDE inhibitor isobutyl methyl xanthine (IBMX) had similar affinity for nematode and human PDE4. Of 32 residues within 5 Å of the ligand binding site, five revealed significant differences in non-bonded interaction energies (van der Waals and electrostatic interaction energies) that could account for the differential binding affinities of roflumilast and zardaverine. One site (Phe506 in the human PDE4D3 amino acid sequence corresponding to Tyr253 in C. elegans PDE4) is predicted to alter the binding conformation of roflumilast and zardaverine (but not IBMX) into a less energetically favorable state for the nematode enzyme. The pharmacological differences in sensitivity to PDE4 inhibitors in conjunction with differences in the amino acids comprising the inhibitor binding sites of human and C. elegans PDE4 catalytic domains together support the feasibility of designing the next generation of anthelmintics/nematicides that could selectively bind to nematode PDEs.
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Dallière N, Bhatla N, Luedtke Z, Ma DK, Woolman J, Walker RJ, Holden-Dye L, O'Connor V. Multiple excitatory and inhibitory neural signals converge to fine-tune Caenorhabditis elegans feeding to food availability. FASEB J 2015; 30:836-48. [PMID: 26514165 DOI: 10.1096/fj.15-279257] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 10/13/2015] [Indexed: 01/02/2023]
Abstract
How an animal matches feeding to food availability is a key question for energy homeostasis. We addressed this in the nematode Caenorhabditis elegans, which couples feeding to the presence of its food (bacteria) by regulating pharyngeal activity (pumping). We scored pumping in the presence of food and over an extended time course of food deprivation in wild-type and mutant worms to determine the neural substrates of adaptive behavior. Removal of food initially suppressed pumping but after 2 h this was accompanied by intermittent periods of high activity. We show pumping is fine-tuned by context-specific neural mechanisms and highlight a key role for inhibitory glutamatergic and excitatory cholinergic/peptidergic drives in the absence of food. Additionally, the synaptic protein UNC-31 [calcium-activated protein for secretion (CAPS)] acts through an inhibitory pathway not explained by previously identified contributions of UNC-31/CAPS to neuropeptide or glutamate transmission. Pumping was unaffected by laser ablation of connectivity between the pharyngeal and central nervous system indicating signals are either humoral or intrinsic to the enteric system. This framework in which control is mediated through finely tuned excitatory and inhibitory drives resonates with mammalian hypothalamic control of feeding and suggests that fundamental regulation of this basic animal behavior may be conserved through evolution from nematode to human.
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Affiliation(s)
- Nicolas Dallière
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Nikhil Bhatla
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Zara Luedtke
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Dengke K Ma
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Jonathan Woolman
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Robert J Walker
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Lindy Holden-Dye
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Vincent O'Connor
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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Sheng M, Hosseinzadeh A, Muralidharan SV, Gaur R, Selstam E, Tuck S. Aberrant fat metabolism in Caenorhabditis elegans mutants with defects in the defecation motor program. PLoS One 2015; 10:e0124515. [PMID: 25849533 PMCID: PMC4388766 DOI: 10.1371/journal.pone.0124515] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Accepted: 03/16/2015] [Indexed: 01/08/2023] Open
Abstract
The molecular mechanisms by which dietary fatty acids are absorbed by the intestine, and the way in which the process is regulated are poorly understood. In a genetic screen for mutations affecting fat accumulation in the intestine of Caenorhabditis elegans, nematode worms, we have isolated mutations in the aex-5 gene, which encodes a Kex2/subtilisin-family, Ca2+-sensitive proprotein convertase known to be required for maturation of certain neuropeptides, and for a discrete step in an ultradian rhythmic phenomenon called the defecation motor program. We demonstrate that aex-5 mutants have markedly lower steady-state levels of fat in the intestine, and that this defect is associated with a significant reduction in the rate at which labeled fatty acid derivatives are taken up from the intestinal lumen. Other mutations affecting the defecation motor program also affect steady-state levels of triglycerides, suggesting that the program is required per se for the proper accumulation of neutral lipids. Our results suggest that an important function of the defecation motor program in C. elegans is to promote the uptake of an important class of dietary nutrients. They also imply that modulation of the program might be one way in which worms adjust nutrient uptake in response to altered metabolic status.
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Affiliation(s)
- Ming Sheng
- Umeå Center for Molecular Medicine, Umeå University, SE-901 87 Umeå, Sweden
| | - Ava Hosseinzadeh
- Umeå Center for Molecular Medicine, Umeå University, SE-901 87 Umeå, Sweden
| | | | - Rahul Gaur
- Umeå Center for Molecular Medicine, Umeå University, SE-901 87 Umeå, Sweden
| | - Eva Selstam
- Department of Plant Physiology, Umeå University, SE-901 87 Umeå, Sweden
| | - Simon Tuck
- Umeå Center for Molecular Medicine, Umeå University, SE-901 87 Umeå, Sweden
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Peymen K, Watteyne J, Frooninckx L, Schoofs L, Beets I. The FMRFamide-Like Peptide Family in Nematodes. Front Endocrinol (Lausanne) 2014; 5:90. [PMID: 24982652 PMCID: PMC4058706 DOI: 10.3389/fendo.2014.00090] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 05/31/2014] [Indexed: 12/31/2022] Open
Abstract
In the three decades since the FMRFamide peptide was isolated from the mollusk Macrocallista nimbosa, structurally similar peptides sharing a C-terminal RFamide motif have been identified across the animal kingdom. FMRFamide-like peptides (FLPs) represent the largest known family of neuropeptides in invertebrates. In the phylum Nematoda, at least 32 flp-genes are classified, making the FLP system of nematodes unusually complex. The diversity of the nematode FLP complement is most extensively mapped in Caenorhabditis elegans, where over 70 FLPs have been predicted. FLPs have shown to be expressed in the majority of the 302 C. elegans neurons including interneurons, sensory neurons, and motor neurons. The vast expression of FLPs is reflected in the broad functional repertoire of nematode FLP signaling, including neuroendocrine and neuromodulatory effects on locomotory activity, reproduction, feeding, and behavior. In contrast to the many identified nematode FLPs, only few peptides have been assigned a receptor and there is the need to clarify the pathway components and working mechanisms of the FLP signaling network. Here, we review the diversity, distribution, and functions of FLPs in nematodes.
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Affiliation(s)
- Katleen Peymen
- Functional Genomics and Proteomics Group, Department of Biology, KU Leuven, Leuven, Belgium
| | - Jan Watteyne
- Functional Genomics and Proteomics Group, Department of Biology, KU Leuven, Leuven, Belgium
| | - Lotte Frooninckx
- Functional Genomics and Proteomics Group, Department of Biology, KU Leuven, Leuven, Belgium
| | - Liliane Schoofs
- Functional Genomics and Proteomics Group, Department of Biology, KU Leuven, Leuven, Belgium
| | - Isabel Beets
- Functional Genomics and Proteomics Group, Department of Biology, KU Leuven, Leuven, Belgium
- *Correspondence: Isabel Beets, Functional Genomics and Proteomics Group, Department of Biology, KU Leuven, Naamsestraat 59, Leuven 3000, Belgium e-mail:
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Larsen MJ, Lancheros ER, Williams T, Lowery DE, Geary TG, Kubiak TM. Functional expression and characterization of the C. elegans G-protein-coupled FLP-2 Receptor (T19F4.1) in mammalian cells and yeast. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2012; 3:1-7. [PMID: 24533288 DOI: 10.1016/j.ijpddr.2012.10.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Revised: 10/25/2012] [Accepted: 10/29/2012] [Indexed: 01/16/2023]
Abstract
Profound neuropeptide diversity characterizes the nematode nervous system, but it has proven challenging to match neuropeptide G protein-coupled receptors (GPCR) with their cognate ligands in heterologous systems. We have expressed the Caenorhabditis elegans GPCR encoded in the locus T19F4.1, previously matched with FMRFamide-like peptides encoded on the flp-2 precursor gene, in mammalian cells and in the yeast Saccharomyces cerevisiae. Pharmacological characterization revealed that the receptor is potently activated by flp-2 peptides in CHO cells (∼10 nM EC50) and in yeast (∼100 nM EC50), signaling through a Gqα pathway in each system. The yeast GPCR expression system provides a robust assay for screening for agonists of the flp-2 receptor and is the target of an ongoing high-throughput screening exercise.
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Affiliation(s)
- Martha J Larsen
- Pfizer Animal Health Discovery Research, Veterinary Medicine Discovery Research, Kalamazoo, MI 49001, USA
| | - Elizabeth Ruiz Lancheros
- Institute of Parasitology, McGill University, 21,111 Lakeshore Road, Ste-Anne de Bellevue, Quebec, Canada H9X 3V9
| | - Tracey Williams
- Pfizer Animal Health Discovery Research, Veterinary Medicine Discovery Research, Kalamazoo, MI 49001, USA
| | - David E Lowery
- Pfizer Animal Health Discovery Research, Veterinary Medicine Discovery Research, Kalamazoo, MI 49001, USA
| | - Timothy G Geary
- Pfizer Animal Health Discovery Research, Veterinary Medicine Discovery Research, Kalamazoo, MI 49001, USA
| | - Teresa M Kubiak
- Pfizer Animal Health Discovery Research, Veterinary Medicine Discovery Research, Kalamazoo, MI 49001, USA
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Neurobiology of plant parasitic nematodes. INVERTEBRATE NEUROSCIENCE 2011; 11:9-19. [PMID: 21538093 DOI: 10.1007/s10158-011-0117-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Accepted: 04/19/2011] [Indexed: 12/31/2022]
Abstract
The regulatory constraints imposed on use of chemical control agents in agriculture are rendering crops increasingly vulnerable to plant parasitic nematodes. Thus, it is important that new control strategies which meet requirements for low toxicity to non-target species, vertebrates and the environment are pursued. This would be greatly facilitated by an improved understanding of the physiology and pharmacology of these nematodes, but to date, these microscopic species of the Phylum Nematoda have attracted little attention in this regard. In this review, the current information available for neurotransmitters and neuromodulator in the plant parasitic nematodes is discussed in the context of the more extensive literature for other species in the phylum, most notably Caenorhabditis elegans and Ascaris suum. Areas of commonality and distinctiveness in terms of neurotransmitter profile and function between these species are highlighted with a view to improving understanding of to what extent, and with what level of confidence, this information may be extrapolated to the plant parasitic nematodes.
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Dillon J, Andrianakis I, Bull K, Glautier S, O'Connor V, Holden-Dye L, James C. AutoEPG: software for the analysis of electrical activity in the microcircuit underpinning feeding behaviour of Caenorhabditis elegans. PLoS One 2009; 4:e8482. [PMID: 20041123 PMCID: PMC2795780 DOI: 10.1371/journal.pone.0008482] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2009] [Accepted: 11/09/2009] [Indexed: 11/19/2022] Open
Abstract
Background The pharyngeal microcircuit of the nematode Caenorhabditis elegans serves as a model for analysing neural network activity and is amenable to electrophysiological recording techniques. One such technique is the electropharyngeogram (EPG) which has provided insight into the genetic basis of feeding behaviour, neurotransmission and muscle excitability. However, the detailed manual analysis of the digital recordings necessary to identify subtle differences in activity that reflect modulatory changes within the underlying network is time consuming and low throughput. To address this we have developed an automated system for the high-throughput and discrete analysis of EPG recordings (AutoEPG). Methodology/Principal Findings AutoEPG employs a tailor made signal processing algorithm that automatically detects different features of the EPG signal including those that report on the relaxation and contraction of the muscle and neuronal activity. Manual verification of the detection algorithm has demonstrated AutoEPG is capable of very high levels of accuracy. We have further validated the software by analysing existing mutant strains with known pharyngeal phenotypes detectable by the EPG. In doing so, we have more precisely defined an evolutionarily conserved role for the calcium-dependent potassium channel, SLO-1, in modulating the rhythmic activity of neural networks. Conclusions/Significance AutoEPG enables the consistent analysis of EPG recordings, significantly increases analysis throughput and allows the robust identification of subtle changes in the electrical activity of the pharyngeal nervous system. It is anticipated that AutoEPG will further add to the experimental tractability of the C. elegans pharynx as a model neural circuit.
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Affiliation(s)
- James Dillon
- School of Biological Sciences, Bassett Crescent East, University of Southampton, Southampton, United Kingdom.
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