1
|
In silico Methods for Identification of Potential Therapeutic Targets. Interdiscip Sci 2022; 14:285-310. [PMID: 34826045 PMCID: PMC8616973 DOI: 10.1007/s12539-021-00491-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 10/19/2021] [Accepted: 11/01/2021] [Indexed: 11/01/2022]
Abstract
AbstractAt the initial stage of drug discovery, identifying novel targets with maximal efficacy and minimal side effects can improve the success rate and portfolio value of drug discovery projects while simultaneously reducing cycle time and cost. However, harnessing the full potential of big data to narrow the range of plausible targets through existing computational methods remains a key issue in this field. This paper reviews two categories of in silico methods—comparative genomics and network-based methods—for finding potential therapeutic targets among cellular functions based on understanding their related biological processes. In addition to describing the principles, databases, software, and applications, we discuss some recent studies and prospects of the methods. While comparative genomics is mostly applied to infectious diseases, network-based methods can be applied to infectious and non-infectious diseases. Nonetheless, the methods often complement each other in their advantages and disadvantages. The information reported here guides toward improving the application of big data-driven computational methods for therapeutic target discovery.
Graphical abstract
Collapse
|
2
|
Li-Leger E, Feichtinger R, Flibotte S, Holzkamp H, Schnabel R, Moerman DG. Identification of essential genes in Caenorhabditis elegans through whole genome sequencing of legacy mutant collections. G3-GENES GENOMES GENETICS 2021; 11:6373896. [PMID: 34550348 PMCID: PMC8664450 DOI: 10.1093/g3journal/jkab328] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 08/27/2021] [Indexed: 01/23/2023]
Abstract
It has been estimated that 15%–30% of the ∼20,000 genes in C. elegans are essential, yet many of these genes remain to be identified or characterized. With the goal of identifying unknown essential genes, we performed whole-genome sequencing on complementation pairs from legacy collections of maternal-effect lethal and sterile mutants. This approach uncovered maternal genes required for embryonic development and genes with apparent sperm-specific functions. In total, 58 putative essential genes were identified on chromosomes III–V, of which 52 genes are represented by novel alleles in this collection. Of these 52 genes, 19 (40 alleles) were selected for further functional characterization. The terminal phenotypes of embryos were examined, revealing defects in cell division, morphogenesis, and osmotic integrity of the eggshell. Mating assays with wild-type males revealed previously unknown male-expressed genes required for fertilization and embryonic development. The result of this study is a catalog of mutant alleles in essential genes that will serve as a resource to guide further study toward a more complete understanding of this important model organism. As many genes and developmental pathways in C. elegans are conserved and essential genes are often linked to human disease, uncovering the function of these genes may also provide insight to further our understanding of human biology.
Collapse
Affiliation(s)
- Erica Li-Leger
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
| | - Richard Feichtinger
- Department of Developmental Genetics, Institute of Genetics, Technische Universität Braunschweig, 38106, Germany
| | - Stephane Flibotte
- UBC/LSI Bioinformatics Facility, University of British Columbia, Vancouver, British Columbia, Canada
| | - Heinke Holzkamp
- Department of Developmental Genetics, Institute of Genetics, Technische Universität Braunschweig, 38106, Germany
| | - Ralf Schnabel
- Department of Developmental Genetics, Institute of Genetics, Technische Universität Braunschweig, 38106, Germany
| | - Donald G Moerman
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
| |
Collapse
|
3
|
Campos TL, Korhonen PK, Hofmann A, Gasser RB, Young ND. Harnessing model organism genomics to underpin the machine learning-based prediction of essential genes in eukaryotes - Biotechnological implications. Biotechnol Adv 2021; 54:107822. [PMID: 34461202 DOI: 10.1016/j.biotechadv.2021.107822] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 08/17/2021] [Accepted: 08/24/2021] [Indexed: 12/17/2022]
Abstract
The availability of high-quality genomes and advances in functional genomics have enabled large-scale studies of essential genes in model eukaryotes, including the 'elegant worm' (Caenorhabditis elegans; Nematoda) and the 'vinegar fly' (Drosophila melanogaster; Arthropoda). However, this is not the case for other, much less-studied organisms, such as socioeconomically important parasites, for which functional genomic platforms usually do not exist. Thus, there is a need to develop innovative techniques or approaches for the prediction, identification and investigation of essential genes. A key approach that could enable the prediction of such genes is machine learning (ML). Here, we undertake an historical review of experimental and computational approaches employed for the characterisation of essential genes in eukaryotes, with a particular focus on model ecdysozoans (C. elegans and D. melanogaster), and discuss the possible applicability of ML-approaches to organisms such as socioeconomically important parasites. We highlight some recent results showing that high-performance ML, combined with feature engineering, allows a reliable prediction of essential genes from extensive, publicly available 'omic data sets, with major potential to prioritise such genes (with statistical confidence) for subsequent functional genomic validation. These findings could 'open the door' to fundamental and applied research areas. Evidence of some commonality in the essential gene-complement between these two organisms indicates that an ML-engineering approach could find broader applicability to ecdysozoans such as parasitic nematodes or arthropods, provided that suitably large and informative data sets become/are available for proper feature engineering, and for the robust training and validation of algorithms. This area warrants detailed exploration to, for example, facilitate the identification and characterisation of essential molecules as novel targets for drugs and vaccines against parasitic diseases. This focus is particularly important, given the substantial impact that such diseases have worldwide, and the current challenges associated with their prevention and control and with drug resistance in parasite populations.
Collapse
Affiliation(s)
- Tulio L Campos
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria 3010, Australia; Bioinformatics Core Facility, Instituto Aggeu Magalhães, Fundação Oswaldo Cruz (IAM-Fiocruz), Recife, Pernambuco, Brazil
| | - Pasi K Korhonen
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Andreas Hofmann
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Robin B Gasser
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria 3010, Australia.
| | - Neil D Young
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria 3010, Australia.
| |
Collapse
|
4
|
Gangwar M, Jha R, Goyal M, Srivastava M. Biochemical characterization of Recombinase A from Wolbachia endosymbiont of filarial nematode Brugia malayi (wBmRecA). Int J Parasitol 2021; 51:841-853. [PMID: 34273392 DOI: 10.1016/j.ijpara.2021.02.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 02/04/2021] [Accepted: 02/07/2021] [Indexed: 11/17/2022]
Abstract
Lymphatic filariasis is a debilitating disease that affects over 890 million people in 49 countries. A lack of vaccines, non-availability of adulticidal drugs, the threat of emerging drug resistance against available chemotherapeutics and an incomplete understanding of the immunobiology of the disease have sustained the problem. Characterization of Wolbachia proteins, the bacterial endosymbiont which helps in the growth and development of filarial worms, regulates fecundity in female worms and mediates immunopathogenesis of Lymphatic Filariasis, is an important approach to gain insights into the immunopathogenesis of the disease. In this study, we carried out extensive biochemical characterization of Recombinase A from Wolbachia of the filarial nematode Brugia malayi (wBmRecA) using an Electrophoretic Mobility Shift Assay, an ATP binding and hydrolysis assay, DNA strand exchange reactions, DAPI displacement assay and confocal microscopy, and evaluated anti-filarial activity of RecA inhibitors. Confocal studies showed that wBmRecA was expressed and localised within B. malayi microfilariae (Mf) and uteri and lateral chord of adult females. Recombinant wBmRecA was biochemically active and showed intrinsic binding capacity towards both single-stranded DNA and double-stranded DNA that were enhanced by ATP, suggesting ATP-induced cooperativity. wBmRecA promoted ATP hydrolysis and DNA strand exchange reactions in a concentration-dependent manner, and its binding to DNA was sensitive to temperature, pH and salt concentration. Importantly, the anti-parasitic drug Suramin, and Phthalocyanine tetrasulfonate (PcTs)-based inhibitors Fe-PcTs and 3,4-Cu-PcTs, inhibited wBmRecA activity and affected the motility and viability of Mf. The addition of Doxycycline further enhanced microfilaricidal activity of wBmRecA, suggesting potential synergism. Taken together, the omnipresence of wBmRecA in B. malayi life stages and the potent microfilaricidal activity of RecA inhibitors suggest an important role of wBmRecA in filarial pathogenesis.
Collapse
Affiliation(s)
- Mamta Gangwar
- Molecular Parasitology and Immunology Division, CSIR-Central Drug Research Institute, Lucknow, India
| | - Ruchi Jha
- Molecular Parasitology and Immunology Division, CSIR-Central Drug Research Institute, Lucknow, India
| | - Manish Goyal
- Molecular Parasitology and Immunology Division, CSIR-Central Drug Research Institute, Lucknow, India.
| | - Mrigank Srivastava
- Molecular Parasitology and Immunology Division, CSIR-Central Drug Research Institute, Lucknow, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India.
| |
Collapse
|
5
|
McAllister TE, Coleman OD, Roper G, Kawamura A. Structural diversity in
de novo
cyclic peptide ligands from genetically encoded library technologies. Pept Sci (Hoboken) 2020. [DOI: 10.1002/pep2.24204] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Tom E. McAllister
- Chemistry – School of Natural and Environmental Sciences Newcastle University Newcastle upon Tyne UK
| | - Oliver D. Coleman
- Chemistry – School of Natural and Environmental Sciences Newcastle University Newcastle upon Tyne UK
| | - Grace Roper
- Chemistry – School of Natural and Environmental Sciences Newcastle University Newcastle upon Tyne UK
- Chemistry Research Laboratory, Department of Chemistry University of Oxford Oxford UK
| | - Akane Kawamura
- Chemistry – School of Natural and Environmental Sciences Newcastle University Newcastle upon Tyne UK
- Chemistry Research Laboratory, Department of Chemistry University of Oxford Oxford UK
| |
Collapse
|
6
|
Okuma R, Kuwahara T, Yoshikane T, Watanabe M, Dranchak P, Inglese J, Shuto S, Goto Y, Suga H. A Macrocyclic Peptide Library with a Structurally Constrained Cyclopropane-containing Building Block Leads to Thiol-independent Inhibitors of Phosphoglycerate Mutase. Chem Asian J 2020; 15:2631-2636. [PMID: 32633882 DOI: 10.1002/asia.202000700] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Revised: 07/04/2020] [Indexed: 01/20/2023]
Abstract
Here we report the construction of an mRNA-encoded library of thioether-closed macrocyclic peptides by using an N-chloroacetyl-cyclopropane-containing exotic initiator whose structure is more constrained than the ordinary N-chloroacetyl-α-amino acid initiators. The use of such an initiator has led to a macrocycle library with significantly suppressed population of lariat-shaped species compared with the conventional libraries. We previously used a conventional library and identified a small lariat thioether-macrocycle with a tail peptide with a C-terminal free Cys whose sidechain plays an essential role in potent inhibitory activity against a parasitic model enzyme, phosphoglycerate mutase. On the other hand, the cyclopropane-containing macrocycle library has yielded a larger thioether-macrocycle lacking a free Cys residue, which exhibits potent inhibitory activity to the same enzyme with a different mode of action. This result indicates that such a cyclopropane-containing macrocycle library would allow us to access mechanistically distinct macrocycles.
Collapse
Affiliation(s)
- Rika Okuma
- Department of Chemistry Graduate School of Science, The University of Tokyo, Bunkyo, Tokyo, 113-0033, Japan
| | - Tomoki Kuwahara
- Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo, 060-0812, Japan
| | - Takafumi Yoshikane
- Department of Chemistry Graduate School of Science, The University of Tokyo, Bunkyo, Tokyo, 113-0033, Japan
| | - Mizuki Watanabe
- Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo, 060-0812, Japan
| | - Patricia Dranchak
- Division of Preclinical Innovation National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland, USA
| | - James Inglese
- Division of Preclinical Innovation National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland, USA
| | - Satoshi Shuto
- Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo, 060-0812, Japan
| | - Yuki Goto
- Department of Chemistry Graduate School of Science, The University of Tokyo, Bunkyo, Tokyo, 113-0033, Japan
| | - Hiroaki Suga
- Department of Chemistry Graduate School of Science, The University of Tokyo, Bunkyo, Tokyo, 113-0033, Japan
| |
Collapse
|
7
|
Drug Repurposing of Bromodomain Inhibitors as Potential Novel Therapeutic Leads for Lymphatic Filariasis Guided by Multispecies Transcriptomics. mSystems 2019; 4:4/6/e00596-19. [PMID: 31796568 PMCID: PMC6890932 DOI: 10.1128/msystems.00596-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The current treatment regimen for lymphatic filariasis is mostly microfilaricidal. In an effort to identify new drug candidates for lymphatic filariasis, we conducted a three-way transcriptomics/systems biology study of one of the causative agents of lymphatic filariasis, Brugia malayi, its Wolbachia endosymbiont wBm, and its vector host Aedes aegypti at 16 distinct B. malayi life stages. B. malayi upregulates the expression of bromodomain-containing proteins in the adult female, embryo, and microfilaria stages. In vitro, we find that the existing cancer therapeutic JQ1(+), which is a bromodomain and extraterminal protein inhibitor, has adulticidal activity in B. malayi. To better understand the transcriptomic interplay of organisms associated with lymphatic filariasis, we conducted multispecies transcriptome sequencing (RNA-Seq) on the filarial nematode Brugia malayi, its Wolbachia endosymbiont wBm, and its laboratory vector Aedes aegypti across the entire B. malayi life cycle. In wBm, transcription of the noncoding 6S RNA suggests that it may be a regulator of bacterial cell growth, as its transcript levels correlate with bacterial replication rates. For A. aegypti, the transcriptional response reflects the stress that B. malayi infection exerts on the mosquito with indicators of increased energy demand. In B. malayi, expression modules associated with adult female samples consistently contained an overrepresentation of genes involved in chromatin remodeling, such as the bromodomain-containing proteins. All bromodomain-containing proteins encoded by B. malayi were observed to be upregulated in the adult female, embryo, and microfilaria life stages, including 2 members of the bromodomain and extraterminal (BET) protein family. The BET inhibitor JQ1(+), originally developed as a cancer therapeutic, caused lethality of adult worms in vitro, suggesting that it may be a potential therapeutic that can be repurposed for treating lymphatic filariasis. IMPORTANCE The current treatment regimen for lymphatic filariasis is mostly microfilaricidal. In an effort to identify new drug candidates for lymphatic filariasis, we conducted a three-way transcriptomics/systems biology study of one of the causative agents of lymphatic filariasis, Brugia malayi, its Wolbachia endosymbiont wBm, and its vector host Aedes aegypti at 16 distinct B. malayi life stages. B. malayi upregulates the expression of bromodomain-containing proteins in the adult female, embryo, and microfilaria stages. In vitro, we find that the existing cancer therapeutic JQ1(+), which is a bromodomain and extraterminal protein inhibitor, has adulticidal activity in B. malayi.
Collapse
|
8
|
Shivakumara TN, Somvanshi VS, Phani V, Chaudhary S, Hada A, Budhwar R, Shukla RN, Rao U. Meloidogyne incognita (Nematoda: Meloidogynidae) sterol-binding protein Mi-SBP-1 as a target for its management. Int J Parasitol 2019; 49:1061-1073. [PMID: 31733196 DOI: 10.1016/j.ijpara.2019.09.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 09/16/2019] [Accepted: 09/19/2019] [Indexed: 12/16/2022]
Abstract
Meloidogyne incognita is a polyphagous plant-parasitic nematode that causes considerable yield loss in agricultural and horticultural crops. The management options available for M. incognita are extremely limited. Here we identified and characterised a M. incognita homolog of Caenorhabditis elegans sterol-binding protein (Mi-SBP-1), a transcriptional regulator of several lipogenesis pathway genes, and used RNA interference-mediated gene silencing to establish its utility as a target for the management of M. incognita. Mi-sbp-1 is predicted to be a helix-loop-helix domain containing DNA binding transcription factor, and is present in the M. incognita genome in three copies. The RNA-Seq analysis of Mi-sbp-1 silenced second stage juveniles confirmed the key role of this gene in lipogenesis regulation in M. incognita. In vitro and host-induced gene silencing of Mi-sbp-1 in M. incognita second stage juveniles resulted in loss of nematodes' ability to utilise the stored fat reserves, slower nematode development, and reduced parasitism on adzuki bean and tobacco plants. The multiplication factor for the Mi-sbp-1 silenced nematodes on adzuki bean plants was reduced by 51% compared with the control nematodes in which Mi-sbp-1 was not silenced. Transgenic expression of the double-stranded RNA construct of the Mi-sbp-1 gene in tobacco plants caused 40-45% reduction in M. incognita multiplication, 30-43.8% reduction in the number of egg masses, and 33-54% reduction in the number of eggs per egg mass compared with the wild type control plants. Our results confirm that Mi-sbp-1 is a key regulator of lipogenesis in M. incognita and suggest that it can be used as an effective target for its management. The findings of this study can be extended to develop methods to manage other economically important parasitic nematodes.
Collapse
Affiliation(s)
| | - Vishal Singh Somvanshi
- Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi 110012, India.
| | - Victor Phani
- Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi 110012, India
| | - Sonam Chaudhary
- Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi 110012, India
| | - Alkesh Hada
- Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi 110012, India
| | - Roli Budhwar
- Bionivid Technology Private Limited, 209, 4th Cross, Kasturi Nagar, Bangalore 560043, India
| | - Rohit Nandan Shukla
- Bionivid Technology Private Limited, 209, 4th Cross, Kasturi Nagar, Bangalore 560043, India
| | - Uma Rao
- Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi 110012, India.
| |
Collapse
|
9
|
Small ST, Labbé F, Coulibaly YI, Nutman TB, King CL, Serre D, Zimmerman PA. Human Migration and the Spread of the Nematode Parasite Wuchereria bancrofti. Mol Biol Evol 2019; 36:1931-1941. [PMID: 31077328 PMCID: PMC6735882 DOI: 10.1093/molbev/msz116] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The human disease lymphatic filariasis causes the debilitating effects of elephantiasis and hydrocele. Lymphatic filariasis currently affects the lives of 90 million people in 52 countries. There are three nematodes that cause lymphatic filariasis, Brugia malayi, Brugia timori, and Wuchereria bancrofti, but 90% of all cases of lymphatic filariasis are caused solely by W. bancrofti (Wb). Here we use population genomics to reconstruct the probable route and timing of migration of Wb strains that currently infect Africa, Haiti, and Papua New Guinea (PNG). We used selective whole genome amplification to sequence 42 whole genomes of single Wb worms from populations in Haiti, Mali, Kenya, and PNG. Our results are consistent with a hypothesis of an Island Southeast Asia or East Asian origin of Wb. Our demographic models support divergence times that correlate with the migration of human populations. We hypothesize that PNG was infected at two separate times, first by the Melanesians and later by the migrating Austronesians. The migrating Austronesians also likely introduced Wb to Madagascar where later migrations spread it to continental Africa. From Africa, Wb spread to the New World during the transatlantic slave trade. Genome scans identified 17 genes that were highly differentiated among Wb populations. Among these are genes associated with human immune suppression, insecticide sensitivity, and proposed drug targets. Identifying the distribution of genetic diversity in Wb populations and selection forces acting on the genome will build a foundation to test future hypotheses and help predict response to current eradication efforts.
Collapse
Affiliation(s)
- Scott T Small
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN
| | - Frédéric Labbé
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN
| | - Yaya I Coulibaly
- Head Filariasis Unit, NIAID-Mali ICER, University of Bamako, Bamako, Mali
| | | | - Christopher L King
- Global Health and Disease, Case Western Reserve University, Cleveland, OH
| | - David Serre
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD
| | - Peter A Zimmerman
- Global Health and Disease, Case Western Reserve University, Cleveland, OH
- Department of Biology, Case Western Reserve University, Cleveland, OH
| |
Collapse
|
10
|
Tyagi R, Verma S, Mishra S, Srivastava M, Alam S, Khan F, Srivastava SK. In Vitro and In Silico Studies of Glycyrrhetinic Acid Derivatives as Anti- Filarial Agents. Curr Top Med Chem 2019; 19:1191-1200. [PMID: 31210109 DOI: 10.2174/1568026619666190618141450] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 06/12/2019] [Accepted: 06/14/2019] [Indexed: 02/02/2023]
Abstract
BACKGROUND Lymphatic filariasis is one of the chronic diseases in many parts of the tropics and sub-tropics of the world despite the use of standard drugs diethylcarbamazine and ivermectin because they kill microfilaries and not the adult parasites. Therefore, new leads with activity on adult parasites are highly desirable. OBJECTIVE Anti-filarial lead optimization by semi-synthetic modification of glycyrrhetinic acid (GA). METHODS The GA was first converted into 3-O-acyl derivative, which was further converted into 12 amide derivatives. All these derivatives were assessed for their antifilarial potential by parasite motility assay. The binding affinity of active GA derivatives on trehalose-6-phosphate phosphatase (Bm-TPP) was assessed by molecular docking studies. RESULTS Among 15 GA derivatives, GAD-2, GAD-3, and GAD-4 were found more potent than the GA and standard drug DEC. These derivatives reduced the motility of Brugia malayi adult worms by up to 74% while the GA and DEC reduced only up to 49%. Further, GA and most of its derivatives exhibited two times more reduction in MTT assay when compared to the standard drug DEC. These derivatives also showed 100% reduction of microfilariae and good interactions with Bm-TPP protein. CONCLUSION The present study suggests that 3-O-acyl and linear chain amide derivatives of glycyrrhetinic acid may be potent leads against B. malayi microfilariae and adult worms. These results might be helpful in developing QSAR model for optimizing a new class of antifilarial lead from a very common, inexpensive, and non toxic natural product.
Collapse
Affiliation(s)
- Rekha Tyagi
- Medicinal Chemistry Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow 226015, India
| | - Surjeet Verma
- Medicinal Chemistry Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow 226015, India
| | - Shikha Mishra
- Parasitology Division, CSIR-Central Drug Research Institute, Lucknow-226031, India
| | - Mrigank Srivastava
- Parasitology Division, CSIR-Central Drug Research Institute, Lucknow-226031, India.,Academy of Scientific and Innovative Research (AcSIR), New Delhi, India
| | - Sarfaraz Alam
- Metabolic & Structural Biology Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow 226015, India
| | - Feroz Khan
- Academy of Scientific and Innovative Research (AcSIR), New Delhi, India.,Metabolic & Structural Biology Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow 226015, India
| | - Santosh Kumar Srivastava
- Medicinal Chemistry Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow 226015, India
| |
Collapse
|
11
|
Bah SY, Morang'a CM, Kengne-Ouafo JA, Amenga-Etego L, Awandare GA. Highlights on the Application of Genomics and Bioinformatics in the Fight Against Infectious Diseases: Challenges and Opportunities in Africa. Front Genet 2018; 9:575. [PMID: 30538723 PMCID: PMC6277583 DOI: 10.3389/fgene.2018.00575] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 11/08/2018] [Indexed: 01/18/2023] Open
Abstract
Genomics and bioinformatics are increasingly contributing to our understanding of infectious diseases caused by bacterial pathogens such as Mycobacterium tuberculosis and parasites such as Plasmodium falciparum. This ranges from investigations of disease outbreaks and pathogenesis, host and pathogen genomic variation, and host immune evasion mechanisms to identification of potential diagnostic markers and vaccine targets. High throughput genomics data generated from pathogens and animal models can be combined with host genomics and patients’ health records to give advice on treatment options as well as potential drug and vaccine interactions. However, despite accounting for the highest burden of infectious diseases, Africa has the lowest research output on infectious disease genomics. Here we review the contributions of genomics and bioinformatics to the management of infectious diseases of serious public health concern in Africa including tuberculosis (TB), dengue fever, malaria and filariasis. Furthermore, we discuss how genomics and bioinformatics can be applied to identify drug and vaccine targets. We conclude by identifying challenges to genomics research in Africa and highlighting how these can be overcome where possible.
Collapse
Affiliation(s)
- Saikou Y Bah
- West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Accra, Ghana.,Vaccine and Immunity Theme, MRC Unit The Gambia at London School of Hygiene & Tropical Medicine, Banjul, Gambia
| | - Collins Misita Morang'a
- West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Accra, Ghana
| | - Jonas A Kengne-Ouafo
- West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Accra, Ghana
| | - Lucas Amenga-Etego
- West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Accra, Ghana
| | - Gordon A Awandare
- West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Accra, Ghana
| |
Collapse
|
12
|
Novel Insight from Computational Virtual Screening Depict the Binding Potential of Selected Phytotherapeutics Against Probable Drug Targets of Clostridium difficile. Interdiscip Sci 2018; 10:583-604. [PMID: 28217823 DOI: 10.1007/s12539-017-0215-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Revised: 12/28/2016] [Accepted: 01/03/2017] [Indexed: 10/20/2022]
Abstract
This study explores computational screening and molecular docking approaches to screen novel herbal therapeutics against probable drug targets of Clostridium difficile. The essential genes were predicted by comparative genome analysis of C. difficile and best homologous organisms using BLAST search at database of essential genes (DEG). The functions of these genes in various metabolic pathways were predicted and some of these genes were considered as potential targets. Three major proteins were selected as putative targets, namely permease IIC component, ABC transporter and histidine kinase. The three-dimensional structures of these targets were predicted by molecular modelling. The herbal bioactive compounds were screened by computer-aided virtual screening and binding potentials against the drug targets were predicted by molecular docking. Quercetin present in Psidium guajava (binding energy of -9.1 kcal/mol), Ellagic acid found in Punica granatum and Psidium guajava (binding energy -9.0 kcal/mol) and Curcumin, present in Curcuma longa (binding energy -7.8 kcal/mol) demonstrated minimum binding energy and more number of interacting residues with the drug targets. Further, comparative study revealed that phytoligands demonstrated better binding affinities to the drug targets in comparison with usual ligands. Thus, this investigation explores the therapeutic probabilities of selected phytoligands against the putative drug targets of C. difficile.
Collapse
|
13
|
Mani T, Bourguinat C, Prichard RK. G-protein-coupled receptor genes of Dirofilaria immitis. Mol Biochem Parasitol 2018; 222:6-13. [PMID: 29625152 DOI: 10.1016/j.molbiopara.2018.04.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 02/28/2018] [Accepted: 04/02/2018] [Indexed: 12/27/2022]
Abstract
The diversity and uniqueness of nematode heterotrimeric G-protein-coupled receptors (GPCRs) provides impetus for identifying ligands that can be used as therapeutics for treating diseases caused by parasitic nematode infections. In human medicine, GPCRs have represented the largest group of 'drugable' targets exploited in the market today. In the filarial nematode Dirofilaria immitis, which causes heartworm disease, the macrocyclic lactones (ML) have been used as the sole preventatives for more than 25 years and now there is confirmed ML resistance in this parasite. A novel anthelmintic emodepside, with antifilarial activity, can act on a GPCR. In view of the ML resistance, there is an urgent need to identify new drug targets and GPCRs of D. immitis may be promising receptors. Knowledge of polymorphism within the GPCR superfamily is of interest. A total of 127 GPCR genes have been identified, so far, in the genome of D. immitis. Whole genome sequencing data from four ML susceptible and four ML loss of efficacy populations was used to identify 393 polymorphic loci in 35 D. immitis GPCR genes. Out of 57 SNPs in exonic regions, 36 of them caused a change in an amino acid, out of which 2 changed the predicted secondary structure of the protein. Knowledge about GPCR genes and their polymorphism is valuable information for drug design processes. Further studies need to be carried out to more fully understand the implications of each of the SNPs identified by this study.
Collapse
Affiliation(s)
- Thangadurai Mani
- Institute of Parasitology, McGill University, 21111 Lakeshore Road, Sainte-Anne-de-Bellevue, QC H9X 3V9, Canada
| | - Catherine Bourguinat
- Institute of Parasitology, McGill University, 21111 Lakeshore Road, Sainte-Anne-de-Bellevue, QC H9X 3V9, Canada
| | - Roger K Prichard
- Institute of Parasitology, McGill University, 21111 Lakeshore Road, Sainte-Anne-de-Bellevue, QC H9X 3V9, Canada.
| |
Collapse
|
14
|
Martín Del Campo JS, Eckshtain-Levi M, Sobrado P. Identification of eukaryotic UDP-galactopyranose mutase inhibitors using the ThermoFAD assay. Biochem Biophys Res Commun 2017; 493:58-63. [PMID: 28919416 DOI: 10.1016/j.bbrc.2017.09.074] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 09/14/2017] [Indexed: 11/26/2022]
Abstract
Aspergillus fumigatus is a human pathogen responsible for deadly infections in immune-compromised patients. A potential strategy for treating A. fumigatus infections is by targeting the biosynthesis of cell wall components, such as galactofuranase, which is absent in humans. Galactofuranose biosynthesis is initiated by the flavoenzyme UDP-galactopyranose mutase (UGM), which converts UDP-galactopyranose (UDP-Galp) to UDP-galactofuranose (UDP-Galf). UGM requires the reduced form of the flavin for activity, which is obtained by reacting with NADPH. We aimed to identify inhibitors of UGM by screening a kinase inhibitor library using ThermoFAD, a flavin fluorescence thermal shift assay. The screening assay identified flavopiridol as a compound that increased the melting temperature of A. fumigatus UGM. Further characterization showed that flavopiridol is a non-competitive inhibitor of UGM and docking studies suggest that it binds in the active site. This compound does not inhibit the prokaryotic UGM from Mycobacteria tuberculosis.
Collapse
Affiliation(s)
| | | | - Pablo Sobrado
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA; Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, VA 24061, USA.
| |
Collapse
|
15
|
Martin Del Campo JS, Eckshtain-Levi M, Vogelaar NJ, Sobrado P. Identification of Aspergillus fumigatus UDP-Galactopyranose Mutase Inhibitors. Sci Rep 2017; 7:10836. [PMID: 28883473 PMCID: PMC5589893 DOI: 10.1038/s41598-017-11022-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 08/17/2017] [Indexed: 01/08/2023] Open
Abstract
Aspergillus fumigatus is an opportunistic human pathogen responsible for deadly, invasive infections in immunocompromised patients. The A. fumigatus cell wall is a complex network of polysaccharides among them galactofuran, which is absent in humans. UDP-galactopyranose mutase (UGM) catalyzes the conversion of UDP-galactofuranose (UDP-Galf) to UDP-galactopyranose (UDP-Galp) and is an important virulence factor. UGM is a flavin-dependent enzyme that requires the reduced flavin for activity; flavin reduction is achieved by reaction with NADPH. The aim of this work was to discover inhibitors of UGM by targeting the NADPH binding site using an ADP-TAMRA probe in a high-throughput screening assay. The flavonoids (2S)-hesperetin and (2S)-naringenin were validated as competitive inhibitors of UGM against NADPH with Ki values of 6 µM and 74 µM, respectively. To gain insight into the active chemical substituents involved in the inhibition of UGM, several derivatives of these inhibitors were studied. The results show that the hydroxyl groups of (2S)-hesperetin are important for inhibition, in particular the phenyl-chroman moiety. Congo red susceptibility assay and growth temperature effects showed that these compounds affected cell wall biosynthesis in A. fumigatus. This work is the first report of inhibition studies on UGM from eukaryotic human pathogens.
Collapse
Affiliation(s)
| | | | - Nancy J Vogelaar
- Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Pablo Sobrado
- Department of Biochemistry, Virginia Tech, Blacksburg, VA, 24061, USA. .,Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, VA, 24061, USA.
| |
Collapse
|
16
|
Lažetić V, Fay DS. Molting in C. elegans. WORM 2017; 6:e1330246. [PMID: 28702275 DOI: 10.1080/21624054.2017.1330246] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 05/01/2017] [Accepted: 05/09/2017] [Indexed: 12/21/2022]
Abstract
Molting is an essential developmental process for the majority of animal species on Earth. During the molting process, which is a specialized form of extracellular matrix (ECM) remodeling, the old apical ECM, or cuticle, is replaced with a new one. Many of the genes and pathways identified as important for molting in nematodes are highly conserved in vertebrates and include regulators and components of vesicular trafficking, steroid-hormone signaling, developmental timers, and hedgehog-like signaling. In this review, we discuss what is known about molting, with a focus on studies in Caenorhabditis elegans. We also describe the key structural elements of the cuticle that must be released, newly synthesized, or remodeled for proper molting to occur.
Collapse
Affiliation(s)
- Vladimir Lažetić
- Department of Molecular Biology, College of Agriculture and Natural Resources, University of Wyoming, Laramie, WY, USA
| | - David S Fay
- Department of Molecular Biology, College of Agriculture and Natural Resources, University of Wyoming, Laramie, WY, USA
| |
Collapse
|
17
|
Polymorphism in ABC transporter genes of Dirofilaria immitis. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2017; 7:227-235. [PMID: 28494332 PMCID: PMC5421822 DOI: 10.1016/j.ijpddr.2017.04.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 04/26/2017] [Accepted: 04/28/2017] [Indexed: 11/22/2022]
Abstract
Dirofilaria immitis, a filarial nematode, causes dirofilariasis in dogs, cats and occasionally in humans. Prevention of the disease has been mainly by monthly use of the macrocyclic lactone (ML) endectocides during the mosquito transmission season. Recently, ML resistance has been confirmed in D. immitis and therefore, there is a need to find new classes of anthelmintics. One of the mechanisms associated with ML resistance in nematodes has been the possible role of ATP binding cassette (ABC) transporters in reducing drug concentrations at receptor sites. ABC transporters, mainly from sub-families B, C and G, may contribute to multidrug resistance (MDR) by active efflux of drugs out of the cell. Gene products of ABC transporters may thus serve as the targets for agents that may modulate susceptibility to drugs, by inhibiting drug transport. ABC transporters are believed to be involved in a variety of physiological functions critical to the parasite, such as sterol transport, and therefore may also serve as the target for drugs that can act as anthelmintics on their own. Knowledge of polymorphism in these ABC transporter genes in nematode parasites could provide useful information for the process of drug design. We have identified 15 ABC transporter genes from sub-families A, B, C and G, in D. immitis, by comparative genomic approaches and analyzed them for polymorphism. Whole genome sequencing data from four ML susceptible (SUS) and four loss of efficacy (LOE) pooled populations were used for single nucleotide polymorphism (SNP) genotyping. Out of 231 SNPs identified in those 15 ABC transporter genes, 89 and 75 of them were specific to the SUS or LOE populations, respectively. A few of the SNPs identified may affect gene expression, protein function, substrate specificity or resistance development and may be useful for transporter inhibitor/anthelmintic drug design, or in order to anticipate resistance development. In the D. immitis genome, all ABC-A, -B, -C and -G transporter genes were identified. Within 15 ABC transporter genes identified in D. immitis, 231 SNP loci were found. Four exonic SNPs caused changes in predicted secondary structure of ABC proteins. D. immitis populations have low genetic variability among ABC transporter genes.
Collapse
|
18
|
Yu H, Dranchak P, Li Z, MacArthur R, Munson MS, Mehzabeen N, Baird NJ, Battalie KP, Ross D, Lovell S, Carlow CKS, Suga H, Inglese J. Macrocycle peptides delineate locked-open inhibition mechanism for microorganism phosphoglycerate mutases. Nat Commun 2017; 8:14932. [PMID: 28368002 PMCID: PMC5382265 DOI: 10.1038/ncomms14932] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 02/13/2017] [Indexed: 11/22/2022] Open
Abstract
Glycolytic interconversion of phosphoglycerate isomers is catalysed in numerous pathogenic microorganisms by a cofactor-independent mutase (iPGM) structurally distinct from the mammalian cofactor-dependent (dPGM) isozyme. The iPGM active site dynamically assembles through substrate-triggered movement of phosphatase and transferase domains creating a solvent inaccessible cavity. Here we identify alternate ligand binding regions using nematode iPGM to select and enrich lariat-like ligands from an mRNA-display macrocyclic peptide library containing >1012 members. Functional analysis of the ligands, named ipglycermides, demonstrates sub-nanomolar inhibition of iPGM with complete selectivity over dPGM. The crystal structure of an iPGM macrocyclic peptide complex illuminated an allosteric, locked-open inhibition mechanism placing the cyclic peptide at the bi-domain interface. This binding mode aligns the pendant lariat cysteine thiolate for coordination with the iPGM transition metal ion cluster. The extended charged, hydrophilic binding surface interaction rationalizes the persistent challenges these enzymes have presented to small-molecule screening efforts highlighting the important roles of macrocyclic peptides in expanding chemical diversity for ligand discovery.
Collapse
Affiliation(s)
- Hao Yu
- Department of Chemistry, Graduate School of Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Patricia Dranchak
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland 20850, USA
| | - Zhiru Li
- Division of Genome Biology, New England Biolabs, Ipswich, Massachusetts 01938, USA
| | - Ryan MacArthur
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland 20850, USA
| | - Matthew S. Munson
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Nurjahan Mehzabeen
- Proton Structure Laboratory, Structural Biology Center, University of Kansas, Lawrence, Kansas 66047, USA
| | - Nathan J. Baird
- National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Kevin P. Battalie
- IMCA-CAT Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - David Ross
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Scott Lovell
- Proton Structure Laboratory, Structural Biology Center, University of Kansas, Lawrence, Kansas 66047, USA
| | | | - Hiroaki Suga
- Department of Chemistry, Graduate School of Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - James Inglese
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland 20850, USA
| |
Collapse
|
19
|
Misra S, Valicherla GR, Mohd Shahab, Gupta J, Gayen JR, Misra-Bhattacharya S. UDP-galactopyranose mutase, a potential drug target against human pathogenic nematodeBrugia malayi. Pathog Dis 2016; 74:ftw072. [DOI: 10.1093/femspd/ftw072] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/13/2016] [Indexed: 01/02/2023] Open
|
20
|
Polymorphism in ion channel genes of Dirofilaria immitis: Relevant knowledge for future anthelmintic drug design. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2016; 6:343-355. [PMID: 27682347 PMCID: PMC5196487 DOI: 10.1016/j.ijpddr.2016.06.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 06/22/2016] [Indexed: 11/24/2022]
Abstract
Dirofilaria immitis, a filarial parasite, causes cardiopulmonary dirofilariasis in dogs, cats and wild canids. The macrocyclic lactone (ML) class of drugs has been used to prevent heartworm infection. There is confirmed ML resistance in D. immitis and thus there is an urgent need to find new anthelmintics that could prevent and/or control the disease. Targeting ion channels of D. immitis for drug design has obvious advantages. These channels, present in the nematode nervous system, control movement, feeding, mating and respond to environmental cues which are necessary for survival of the parasite. Any new drug that targets these ion channels is likely to have a motility phenotype and should act to clear the worms from the host. Many of the successful anthelmintics in the past have targeted these ion channels and receptors. Knowledge about genetic variability of the ion channel and receptor genes should be useful information for drug design as receptor polymorphism may affect responses to a drug. Such information may also be useful for anticipation of possible resistance development. A total of 224 ion channel genes/subunits have been identified in the genome of D. immitis. Whole genome sequencing data of parasites from eight different geographical locations, four from ML-susceptible populations and the other four from ML-loss of efficacy (LOE) populations, were used for polymorphism analysis. We identified 1762 single nucleotide polymorphic (SNP) sites (1508 intronic and 126 exonic) in these 224 ion channel genes/subunits with an overall polymorphic rate of 0.18%. Of the SNPs found in the exon regions, 129 of them caused a non-synonymous type of polymorphism. Fourteen of the exonic SNPs caused a change in predicted secondary structure. A few of the SNPs identified may have an effect on gene expression, function of the protein and resistance selection processes. In the Dirofilaria immitis genome, 126 ion channel genes were identified. Within 126 ion channel genes, 1762 polymorphic loci were identified. Fourteen exonic SNPs caused a change in predicted secondary structure. SNPs may effect gene expression, protein function or resistance selection. D. immitis populations have low genetic variability among ion channel genes.
Collapse
|
21
|
Sharma OP, Kumar MS. Essential proteins and possible therapeutic targets of Wolbachia endosymbiont and development of FiloBase--a comprehensive drug target database for Lymphatic filariasis. Sci Rep 2016; 6:19842. [PMID: 26806463 PMCID: PMC4726333 DOI: 10.1038/srep19842] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 10/27/2015] [Indexed: 11/26/2022] Open
Abstract
Lymphatic filariasis (Lf) is one of the oldest and most debilitating tropical diseases. Millions of people are suffering from this prevalent disease. It is estimated to infect over 120 million people in at least 80 nations of the world through the tropical and subtropical regions. More than one billion people are in danger of getting affected with this life-threatening disease. Several studies were suggested its emerging limitations and resistance towards the available drugs and therapeutic targets for Lf. Therefore, better medicine and drug targets are in demand. We took an initiative to identify the essential proteins of Wolbachia endosymbiont of Brugia malayi, which are indispensable for their survival and non-homologous to human host proteins. In this current study, we have used proteome subtractive approach to screen the possible therapeutic targets for wBm. In addition, numerous literatures were mined in the hunt for potential drug targets, drugs, epitopes, crystal structures, and expressed sequence tag (EST) sequences for filarial causing nematodes. Data obtained from our study were presented in a user friendly database named FiloBase. We hope that information stored in this database may be used for further research and drug development process against filariasis. URL: http://filobase.bicpu.edu.in.
Collapse
Affiliation(s)
- Om Prakash Sharma
- Centre for Bioinformatics, School of Life Science, Pondicherry University, Pondicherry-605014, India
| | - Muthuvel Suresh Kumar
- Centre for Bioinformatics, School of Life Science, Pondicherry University, Pondicherry-605014, India
| |
Collapse
|
22
|
Berenstein AJ, Magariños MP, Chernomoretz A, Agüero F. A Multilayer Network Approach for Guiding Drug Repositioning in Neglected Diseases. PLoS Negl Trop Dis 2016; 10:e0004300. [PMID: 26735851 PMCID: PMC4703370 DOI: 10.1371/journal.pntd.0004300] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2015] [Accepted: 11/21/2015] [Indexed: 12/16/2022] Open
Abstract
Drug development for neglected diseases has been historically hampered due to lack of market incentives. The advent of public domain resources containing chemical information from high throughput screenings is changing the landscape of drug discovery for these diseases. In this work we took advantage of data from extensively studied organisms like human, mouse, E. coli and yeast, among others, to develop a novel integrative network model to prioritize and identify candidate drug targets in neglected pathogen proteomes, and bioactive drug-like molecules. We modeled genomic (proteins) and chemical (bioactive compounds) data as a multilayer weighted network graph that takes advantage of bioactivity data across 221 species, chemical similarities between 1.7 105 compounds and several functional relations among 1.67 105 proteins. These relations comprised orthology, sharing of protein domains, and shared participation in defined biochemical pathways. We showcase the application of this network graph to the problem of prioritization of new candidate targets, based on the information available in the graph for known compound-target associations. We validated this strategy by performing a cross validation procedure for known mouse and Trypanosoma cruzi targets and showed that our approach outperforms classic alignment-based approaches. Moreover, our model provides additional flexibility as two different network definitions could be considered, finding in both cases qualitatively different but sensible candidate targets. We also showcase the application of the network to suggest targets for orphan compounds that are active against Plasmodium falciparum in high-throughput screens. In this case our approach provided a reduced prioritization list of target proteins for the query molecules and showed the ability to propose new testable hypotheses for each compound. Moreover, we found that some predictions highlighted by our network model were supported by independent experimental validations as found post-facto in the literature. Neglected tropical diseases are human infectious diseases that are often associated with poverty. Historically, lack of interest from the pharmaceutical industry resulted in the lack of good drugs to combat the majority of the pathogens that cause these diseases. Recently, the availability of open chemical information has increased with the advent of public domain chemical resources and the release of data from high throughput screening assays. Our aim in this work was to make use of data from extensively studied organisms like human, mouse, E. coli and yeast, among others, to prioritize and identify candidate drug targets in neglected pathogen proteomes, and drug-like bioactive molecules to foster drug development against neglected diseases. Our approach to the problem relied on applying bioinformatics and computational biology strategies to model large datasets spanning complete proteomes and extensive chemical information from publicly available sources. As a result, we were able to prioritize drug targets and identify potential targets for orphan bioactive drugs.
Collapse
Affiliation(s)
- Ariel José Berenstein
- Laboratorio de Bioinformática, Fundación Instituto Leloir, Buenos Aires, Argentina
- Departamento de Física, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - María Paula Magariños
- Laboratorio de Genómica y Bioinformática, Instituto de Investigaciones Biotecnológicas–Instituto Tecnológico de Chascomús, Universidad de San Martín–CONICET, Sede San Martín, San Martín, Buenos Aires, Argentina
| | - Ariel Chernomoretz
- Laboratorio de Bioinformática, Fundación Instituto Leloir, Buenos Aires, Argentina
- Departamento de Física, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Fernán Agüero
- Laboratorio de Genómica y Bioinformática, Instituto de Investigaciones Biotecnológicas–Instituto Tecnológico de Chascomús, Universidad de San Martín–CONICET, Sede San Martín, San Martín, Buenos Aires, Argentina
- * E-mail: ,
| |
Collapse
|
23
|
Luck AN, Anderson KG, McClung CM, VerBerkmoes NC, Foster JM, Michalski ML, Slatko BE. Tissue-specific transcriptomics and proteomics of a filarial nematode and its Wolbachia endosymbiont. BMC Genomics 2015; 16:920. [PMID: 26559510 PMCID: PMC4642636 DOI: 10.1186/s12864-015-2083-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 10/15/2015] [Indexed: 11/12/2022] Open
Abstract
Background Filarial nematodes cause debilitating human diseases. While treatable, recent evidence suggests drug resistance is developing, necessitating the development of novel targets and new treatment options. Although transcriptomic and proteomic studies around the nematode life cycle have greatly enhanced our knowledge, whole organism approaches have not provided spatial resolution of gene expression, which can be gained by examining individual tissues. Generally, due to their small size, tissue dissection of human-infecting filarial nematodes remains extremely challenging. However, canine heartworm disease is caused by a closely related and much larger filarial nematode, Dirofilaria immitis. As with many other filarial nematodes, D. immitis contains Wolbachia, an obligate bacterial endosymbiont present in the hypodermis and developing oocytes within the uterus. Here, we describe the first concurrent tissue-specific transcriptomic and proteomic profiling of a filarial nematode (D. immitis) and its Wolbachia (wDi) in order to better understand tissue functions and identify tissue-specific antigens that may be used for the development of new diagnostic and therapeutic tools. Methods Adult D. immitis worms were dissected into female body wall (FBW), female uterus (FU), female intestine (FI), female head (FH), male body wall (MBW), male testis (MT), male intestine (MI), male head (MH) and 10.1186/s12864-015-2083-2 male spicule (MS) and used to prepare transcriptomic and proteomic libraries. Results Transcriptomic and proteomic analysis of several D. immitis tissues identified many biological functions enriched within certain tissues. Hierarchical clustering of the D. immitis tissue transcriptomes, along with the recently published whole-worm adult male and female D. immitis transcriptomes, revealed that the whole-worm transcriptome is typically dominated by transcripts originating from reproductive tissue. The uterus appeared to have the most variable transcriptome, possibly due to age. Although many functions are shared between the reproductive tissues, the most significant differences in gene expression were observed between the uterus and testis. Interestingly, wDi gene expression in the male and female body wall is fairly similar, yet slightly different to that of Wolbachia gene expression in the uterus. Proteomic methods verified 32 % of the predicted D. immitis proteome, including over 700 hypothetical proteins of D. immitis. Of note, hypothetical proteins were among some of the most abundant Wolbachia proteins identified, which may fulfill some important yet still uncharacterized biological function. Conclusions The spatial resolution gained from this parallel transcriptomic and proteomic analysis adds to our understanding of filarial biology and serves as a resource with which to develop future therapeutic strategies against filarial nematodes and their Wolbachia endosymbionts. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-2083-2) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Ashley N Luck
- Genome Biology Division, New England Biolabs, Inc., 240 County Road, Ipswich, MA, 01938, USA
| | - Kathryn G Anderson
- Department of Biology and Microbiology, University of Wisconsin Oshkosh, Oshkosh, WI, 54901, USA
| | - Colleen M McClung
- Chemical Biology Division, New England Biolabs, Inc., 240 County Road, Ipswich, MA, 01938, USA
| | - Nathan C VerBerkmoes
- Chemical Biology Division, New England Biolabs, Inc., 240 County Road, Ipswich, MA, 01938, USA
| | - Jeremy M Foster
- Genome Biology Division, New England Biolabs, Inc., 240 County Road, Ipswich, MA, 01938, USA
| | - Michelle L Michalski
- Department of Biology and Microbiology, University of Wisconsin Oshkosh, Oshkosh, WI, 54901, USA
| | - Barton E Slatko
- Genome Biology Division, New England Biolabs, Inc., 240 County Road, Ipswich, MA, 01938, USA.
| |
Collapse
|
24
|
Liu C, Mariano PS. An improved method for the large scale preparation of α,α′-trehalose-6-phosphate. Tetrahedron Lett 2015. [DOI: 10.1016/j.tetlet.2014.10.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
25
|
Sharma OP, Hari Krishna K, Suresh Kumar M. Probing the Structural and Conformational Stability of the Wb-iPGM Enzyme and Role of Mn2+ Ions in Their Catalytic Site. Int J Pept Res Ther 2015. [DOI: 10.1007/s10989-015-9464-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
26
|
Sarangi AN, Lohani M, Aggarwal R. Proteome mining for drug target identification in Listeria monocytogenes strain EGD-e and structure-based virtual screening of a candidate drug target penicillin binding protein 4. J Microbiol Methods 2015; 111:9-18. [DOI: 10.1016/j.mimet.2015.01.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Revised: 01/16/2015] [Accepted: 01/16/2015] [Indexed: 12/27/2022]
|
27
|
Rosa BA, Townsend R, Jasmer DP, Mitreva M. Functional and phylogenetic characterization of proteins detected in various nematode intestinal compartments. Mol Cell Proteomics 2015; 14:812-27. [PMID: 25609831 DOI: 10.1074/mcp.m114.046227] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Indexed: 12/13/2022] Open
Abstract
The parasitic nematode intestine is responsible for nutrient digestion and absorption, and many other processes essential for reproduction and survival, making it a valuable target for anthelmintic drug treatment. However, nematodes display extreme biological diversity (including occupying distinct trophic habitats), resulting in limited knowledge of intestinal cell/protein functions of fundamental or adaptive significance. We developed a perfusion model for isolating intestinal proteins in Ascaris suum (a parasite of humans and swine), allowing for the identification of over 1000 intestinal A. suum proteins (using mass spectrometry), which were assigned to several different intestinal cell compartments (intestinal tissue, the integral and peripheral intestinal membranes, and the intestinal lumen). A multi-omics analysis approach identified a large diversity of biological functions across intestinal compartments, based on both functional enrichment analysis (identifying terms related to detoxification, proteolysis, and host-parasite interactions) and regulatory binding sequence analysis to identify putatively active compartment-specific transcription factors (identifying many related to intestinal sex differentiation or lifespan regulation). Orthologs of A. suum proteins in 15 other nematodes species, five host species, and two outgroups were identified and analyzed. Different cellular compartments demonstrated markedly different levels of protein conservation; e.g. integral intestinal membrane proteins were the most conserved among nematodes (up to 96% conservation), whereas intestinal lumen proteins were the most diverse (only 6% conservation across all nematodes, and 71% with no host orthologs). Finally, this integrated multi-omics analysis identified conserved nematode-specific intestinal proteins likely performing essential functions (including V-type ATPases and ABC transporters), which may serve as promising anthelmintic drug or vaccine targets in future research. Collectively, the findings provide valuable new insights on conserved and adaptive features of nematode intestinal cells, membranes and the intestinal lumen, and potential targets for parasite treatment and control.
Collapse
Affiliation(s)
- Bruce A Rosa
- From the ‡The Genome Institute, Washington University in St Louis, Missouri 63108
| | - Reid Townsend
- §Department of Cell Biology & Physiology and Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63108
| | - Douglas P Jasmer
- ¶Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington 99164
| | - Makedonka Mitreva
- From the ‡The Genome Institute, Washington University in St Louis, Missouri 63108; ‖Department of Medicine and Department of Genetics, Washington University School of Medicine, St. Louis, Missouri 63108
| |
Collapse
|
28
|
A target repurposing approach identifies N-myristoyltransferase as a new candidate drug target in filarial nematodes. PLoS Negl Trop Dis 2014; 8:e3145. [PMID: 25188325 PMCID: PMC4154664 DOI: 10.1371/journal.pntd.0003145] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 07/25/2014] [Indexed: 11/19/2022] Open
Abstract
Myristoylation is a lipid modification involving the addition of a 14-carbon unsaturated fatty acid, myristic acid, to the N-terminal glycine of a subset of proteins, a modification that promotes their binding to cell membranes for varied biological functions. The process is catalyzed by myristoyl-CoA:protein N-myristoyltransferase (NMT), an enzyme which has been validated as a drug target in human cancers, and for infectious diseases caused by fungi, viruses and protozoan parasites. We purified Caenorhabditis elegans and Brugia malayi NMTs as active recombinant proteins and carried out kinetic analyses with their essential fatty acid donor, myristoyl-CoA and peptide substrates. Biochemical and structural analyses both revealed that the nematode enzymes are canonical NMTs, sharing a high degree of conservation with protozoan NMT enzymes. Inhibitory compounds that target NMT in protozoan species inhibited the nematode NMTs with IC50 values of 2.5–10 nM, and were active against B. malayi microfilariae and adult worms at 12.5 µM and 50 µM respectively, and C. elegans (25 µM) in culture. RNA interference and gene deletion in C. elegans further showed that NMT is essential for nematode viability. The effects observed are likely due to disruption of the function of several downstream target proteins. Potential substrates of NMT in B. malayi are predicted using bioinformatic analysis. Our genetic and chemical studies highlight the importance of myristoylation in the synthesis of functional proteins in nematodes and have shown for the first time that NMT is required for viability in parasitic nematodes. These results suggest that targeting NMT could be a valid approach for the development of chemotherapeutic agents against nematode diseases including filariasis. Lymphatic filariasis and onchocerciasis are neglected tropical diseases caused by filarial nematodes. The limitations of existing drugs to treat these infections highlight the need for new drugs. In the present study, we investigated myristoylation, a lipid modification of a subset of proteins that promotes their binding to cell membranes for varied biological functions. The process is catalyzed by N-myristoyltransferase (NMT), an enzyme which has been validated as a drug target in protozoan parasites. We performed kinetic analyses on Caenorhabditis elegans and Brugia malayi NMTs. NMT inhibitors were active against B. malayi microfilariae and adult worms, and C. elegans in culture. RNA interference and gene deletion in C. elegans further demonstrated that NMT is essential for nematode viability. Our genetic and chemical studies indicate the importance of myristoylation in the synthesis of functional proteins in nematodes and have shown for the first time that NMT is required for viability in parasitic nematodes. These results suggest that targeting NMT could be a valid approach for the development of new therapies against nematode infection including filarial diseases.
Collapse
|
29
|
Farelli JD, Galvin BD, Li Z, Liu C, Aono M, Garland M, Hallett OE, Causey TB, Ali-Reynolds A, Saltzberg DJ, Carlow CKS, Dunaway-Mariano D, Allen KN. Structure of the trehalose-6-phosphate phosphatase from Brugia malayi reveals key design principles for anthelmintic drugs. PLoS Pathog 2014; 10:e1004245. [PMID: 24992307 PMCID: PMC4081830 DOI: 10.1371/journal.ppat.1004245] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 05/28/2014] [Indexed: 11/18/2022] Open
Abstract
Parasitic nematodes are responsible for devastating illnesses that plague many of the world's poorest populations indigenous to the tropical areas of developing nations. Among these diseases is lymphatic filariasis, a major cause of permanent and long-term disability. Proteins essential to nematodes that do not have mammalian counterparts represent targets for therapeutic inhibitor discovery. One promising target is trehalose-6-phosphate phosphatase (T6PP) from Brugia malayi. In the model nematode Caenorhabditis elegans, T6PP is essential for survival due to the toxic effect(s) of the accumulation of trehalose 6-phosphate. T6PP has also been shown to be essential in Mycobacterium tuberculosis. We determined the X-ray crystal structure of T6PP from B. malayi. The protein structure revealed a stabilizing N-terminal MIT-like domain and a catalytic C-terminal C2B-type HAD phosphatase fold. Structure-guided mutagenesis, combined with kinetic analyses using a designed competitive inhibitor, trehalose 6-sulfate, identified five residues important for binding and catalysis. This structure-function analysis along with computational mapping provided the basis for the proposed model of the T6PP-trehalose 6-phosphate complex. The model indicates a substrate-binding mode wherein shape complementarity and van der Waals interactions drive recognition. The mode of binding is in sharp contrast to the homolog sucrose-6-phosphate phosphatase where extensive hydrogen-bond interactions are made to the substrate. Together these results suggest that high-affinity inhibitors will be bi-dentate, taking advantage of substrate-like binding to the phosphoryl-binding pocket while simultaneously utilizing non-native binding to the trehalose pocket. The conservation of the key residues that enforce the shape of the substrate pocket in T6PP enzymes suggest that development of broad-range anthelmintic and antibacterial therapeutics employing this platform may be possible. Here, we describe the structure of trehalose-6-phosphate phosphatase (T6PP) from Brugia malayi. This enzyme is essential to the organism; deletion of the gene encoding T6PP results in toxic accumulation of trehalose 6-phosphate. Structure-guided mutagenesis coupled with kinetic analyses revealed residues important for binding and catalysis. The model for substrate binding suggests a binding mode in which shape complementarity plays a major role. Conservation of binding residues among T6PP orthologs present in pathogenic nematodes and bacteria favors T6PP as a suitable target for broad-range anthelmintic and antibacterial drug design.
Collapse
Affiliation(s)
- Jeremiah D. Farelli
- Department of Chemistry, Boston University, Boston, Massachusetts, United States of America
| | - Brendan D. Galvin
- New England Biolabs, Division of Parasitology, Ipswich, Massachusetts, United States of America
| | - Zhiru Li
- New England Biolabs, Division of Parasitology, Ipswich, Massachusetts, United States of America
| | - Chunliang Liu
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Miyuki Aono
- Department of Chemistry, Boston University, Boston, Massachusetts, United States of America
| | - Megan Garland
- Department of Chemistry, Boston University, Boston, Massachusetts, United States of America
| | - Olivia E. Hallett
- Department of Chemistry, Boston University, Boston, Massachusetts, United States of America
| | - Thomas B. Causey
- New England Biolabs, Division of Parasitology, Ipswich, Massachusetts, United States of America
| | - Alana Ali-Reynolds
- New England Biolabs, Division of Parasitology, Ipswich, Massachusetts, United States of America
| | - Daniel J. Saltzberg
- Department of Chemistry, Boston University, Boston, Massachusetts, United States of America
| | - Clotilde K. S. Carlow
- New England Biolabs, Division of Parasitology, Ipswich, Massachusetts, United States of America
| | - Debra Dunaway-Mariano
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico, United States of America
- * E-mail: (DDM); (KNA)
| | - Karen N. Allen
- Department of Chemistry, Boston University, Boston, Massachusetts, United States of America
- * E-mail: (DDM); (KNA)
| |
Collapse
|
30
|
The Conqueror Worm: recent advances with cholinergic anthelmintics and techniques excite research for better therapeutic drugs. J Helminthol 2014; 89:387-97. [PMID: 24871674 PMCID: PMC4247809 DOI: 10.1017/s0022149x1400039x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The following account is based on a review lecture given recently at the British Society of Parasitology. We point out that nematode parasites cause very widespread infections of humans, particularly in economically underdeveloped areas where sanitation and hygiene are not adequate. In the absence of adequate clean water and effective vaccines, control and prophylaxis relies on anthelmintic drugs. Widespread use of anthelmintics to control nematode parasites of animals has given rise to the development of resistance and so there is a concern that similar problems will occur in humans if mass drug administration is continued. Recent research on the cholinergic anthelmintic drugs has renewed enthusiasm for the further development of cholinergic anthelmintics. Here we illustrate the use of three parasite nematode models, Ascaris suum, Oesophagostomum dentatum and Brugia malayi, microfluidic techniques and the Xenopus oocyte expression system for testing and examining the effects of cholinergic anthelmintics. We also show how the combination of derquantel, the selective nematode cholinergic antagonist and abamectin produce increased inhibition of the nicotinic acetylcholine receptors on the nematode body muscle. We are optimistic that new compounds and combinations of compounds can limit the effects of drug resistance, allowing anthelmintics to be continued to be used for effective treatment of human and animal helminth parasites.
Collapse
|
31
|
Arumugam S, Hoerauf A, Pfarr KM. Localization of a filarial phosphate permease that is up-regulated in response to depletion of essential Wolbachia endobacteria. Exp Parasitol 2014; 138:30-9. [PMID: 24480589 DOI: 10.1016/j.exppara.2014.01.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2013] [Revised: 01/17/2014] [Accepted: 01/20/2014] [Indexed: 11/19/2022]
Abstract
Wolbachia of filarial nematodes are essential, obligate endobacteria. When depleted by doxycycline worm embryogenesis, larval development and worm survival are inhibited. The molecular basis governing the endosymbiosis between Wolbachia and their filarial host is still being deciphered. In rodent filarial nematode Litomosoides sigmodontis, a nematode encoded phosphate permease gene (Ls-ppe-1) was up-regulated at the mRNA level in response to Wolbachia depletion and this gene promises to have an important role in Wolbachia-nematode endosymbiosis. To further characterize this gene, the regulation of phosphate permease during Wolbachia depletion was studied at the protein level in L. sigmodontis and in the human filaria Onchocerca volvulus. And the localization of phosphate permease (PPE) and Wolbachia in L. sigmodontis and O. volvulus was investigated in untreated and antibiotic treated worms. Depletion of Wolbachia by tetracycline (Tet) resulted in up-regulation of Ls-ppe-1 in L. sigmodontis. On day 36 of Tet treatment, compared to controls (Con), >98% of Wolbachia were depleted with a 3-fold increase in mRNA levels of Ls-ppe-1. Anti-Ls-PPE serum used in Western blots showed up-regulation of Ls-PPE at the protein level in Tet worms on day 15 and 36 of treatment. Immunohistology revealed the localization of Wolbachia and Ls-PPE in the embryos, microfilariae and hypodermis of L. sigmodontis female worms and up-regulation of Ls-PPE in response to Wolbachia depletion. Expression of O. volvulus phosphate permease (Ov-PPE) studied using anti-Ov-PPE serum, showed up-regulation of Ov-PPE at the protein level in doxycycline treated Wolbachia depleted O. volvulus worms and immunohistology revealed localization of Ov-PPE and Wolbachia and up-regulation of Ov-PPE in the hypodermis and embryos of doxycycline treated worms. Ls-PPE and Ov-PPE are upregulated upon Wolbachia depletion in same tissues and regions where Wolbachia are located in untreated worms, reinforcing a link between Wolbachia and this nematode encoded protein. The function of nematode phosphate permease in the endosymbiosis is unknown but could involve transportation of phosphate to Wolbachia, which encode all the genes necessary for de novo nucleotide biosynthesis. Electron microscopic localization of PPE and Wolbachia and RNAi mediated knock-down of PPE in filarial nematodes will bring further insights to the functions of PPE in the Wolbachia-nematode symbiosis.
Collapse
Affiliation(s)
- Sridhar Arumugam
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Sigmund-Freud-Str. 25, D-53105 Bonn, Germany.
| | - Achim Hoerauf
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Sigmund-Freud-Str. 25, D-53105 Bonn, Germany
| | - Kenneth M Pfarr
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Sigmund-Freud-Str. 25, D-53105 Bonn, Germany
| |
Collapse
|
32
|
Cheng J, Xu Z, Wu W, Zhao L, Li X, Liu Y, Tao S. Training set selection for the prediction of essential genes. PLoS One 2014; 9:e86805. [PMID: 24466248 PMCID: PMC3899339 DOI: 10.1371/journal.pone.0086805] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Accepted: 12/13/2013] [Indexed: 01/23/2023] Open
Abstract
Various computational models have been developed to transfer annotations of gene essentiality between organisms. However, despite the increasing number of microorganisms with well-characterized sets of essential genes, selection of appropriate training sets for predicting the essential genes of poorly-studied or newly sequenced organisms remains challenging. In this study, a machine learning approach was applied reciprocally to predict the essential genes in 21 microorganisms. Results showed that training set selection greatly influenced predictive accuracy. We determined four criteria for training set selection: (1) essential genes in the selected training set should be reliable; (2) the growth conditions in which essential genes are defined should be consistent in training and prediction sets; (3) species used as training set should be closely related to the target organism; and (4) organisms used as training and prediction sets should exhibit similar phenotypes or lifestyles. We then analyzed the performance of an incomplete training set and an integrated training set with multiple organisms. We found that the size of the training set should be at least 10% of the total genes to yield accurate predictions. Additionally, the integrated training sets exhibited remarkable increase in stability and accuracy compared with single sets. Finally, we compared the performance of the integrated training sets with the four criteria and with random selection. The results revealed that a rational selection of training sets based on our criteria yields better performance than random selection. Thus, our results provide empirical guidance on training set selection for the identification of essential genes on a genome-wide scale.
Collapse
Affiliation(s)
- Jian Cheng
- College of Life Sciences and State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, Shaanxi, China
- Bioinformatics Center, Northwest A&F University, Yangling, Shaanxi, China
| | - Zhao Xu
- College of Science, Northwest A&F University, Yangling Shaanxi, China
| | - Wenwu Wu
- Bioinformatics Center, Northwest A&F University, Yangling, Shaanxi, China
- Key Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Li Zhao
- College of Life Sciences and State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, Shaanxi, China
- Bioinformatics Center, Northwest A&F University, Yangling, Shaanxi, China
| | - Xiangchen Li
- College of Life Sciences and State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, Shaanxi, China
- Bioinformatics Center, Northwest A&F University, Yangling, Shaanxi, China
| | - Yanlin Liu
- College of Wine, Northwest A&F University, Yangling Shaanxi, China
- * E-mail: (YL); (ST)
| | - Shiheng Tao
- College of Life Sciences and State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, Shaanxi, China
- Bioinformatics Center, Northwest A&F University, Yangling, Shaanxi, China
- * E-mail: (YL); (ST)
| |
Collapse
|
33
|
Cheng J, Wu W, Zhang Y, Li X, Jiang X, Wei G, Tao S. A new computational strategy for predicting essential genes. BMC Genomics 2013; 14:910. [PMID: 24359534 PMCID: PMC3880044 DOI: 10.1186/1471-2164-14-910] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2013] [Accepted: 11/29/2013] [Indexed: 12/17/2022] Open
Abstract
Background Determination of the minimum gene set for cellular life is one of the central goals in biology. Genome-wide essential gene identification has progressed rapidly in certain bacterial species; however, it remains difficult to achieve in most eukaryotic species. Several computational models have recently been developed to integrate gene features and used as alternatives to transfer gene essentiality annotations between organisms. Results We first collected features that were widely used by previous predictive models and assessed the relationships between gene features and gene essentiality using a stepwise regression model. We found two issues that could significantly reduce model accuracy: (i) the effect of multicollinearity among gene features and (ii) the diverse and even contrasting correlations between gene features and gene essentiality existing within and among different species. To address these issues, we developed a novel model called feature-based weighted Naïve Bayes model (FWM), which is based on Naïve Bayes classifiers, logistic regression, and genetic algorithm. The proposed model assesses features and filters out the effects of multicollinearity and diversity. The performance of FWM was compared with other popular models, such as support vector machine, Naïve Bayes model, and logistic regression model, by applying FWM to reciprocally predict essential genes among and within 21 species. Our results showed that FWM significantly improves the accuracy and robustness of essential gene prediction. Conclusions FWM can remarkably improve the accuracy of essential gene prediction and may be used as an alternative method for other classification work. This method can contribute substantially to the knowledge of the minimum gene sets required for living organisms and the discovery of new drug targets.
Collapse
Affiliation(s)
| | | | | | | | | | - Gehong Wei
- College of Life Science, State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi, China.
| | | |
Collapse
|
34
|
Borloo J, De Graef J, Peelaers I, Nguyen DL, Mitreva M, Devreese B, Hokke CH, Vercruysse J, Claerebout E, Geldhof P. In-depth proteomic and glycomic analysis of the adult-stage Cooperia oncophora excretome/secretome. J Proteome Res 2013; 12:3900-11. [PMID: 23895670 DOI: 10.1021/pr400114y] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Cooperia oncophora is one of the most common intestinal parasitic nematodes in cattle worldwide. To date, C. oncophora infections are treated using broad-spectrum anthelmintics. However, during the past decade, reports of anthelmintic resistance in this parasite species have emerged worldwide, necessitating new avenues for its control, possibly through vaccination. In this frame, we analyzed the adult-stage C. oncophora excretome/secretome (ES), covering both the protein and glycan components, since this fraction constitutes the primary interface between parasite and host and may hold potential vaccine candidates. Two-dimensional gel electrophoretic separation of the ES material enabled the MALDI-TOF mass spectrometry (MS)-directed identification of 12 distinct proteins, grouped in three separate molecular weight fractions: (i) a high molecular weight fraction consisting of a double-domain activation-associated secreted protein (ASP), (ii) a midmolecular weight fraction predominantly containing a single-domain ASP, a thioredoxin peroxidase and innexin, and (iii) a low molecular weight protein pool essentially holding two distinct low molecular weight antigens. Further MS-driven glycan analysis mapped a variety of N-glycans to the midmolecular weight single-domain ASP, with Man6GlcNAc2 oligomannosyl glycans as the major species. The predominance of the nonglycosylated double-domain ASP in the high-molecular weight fraction renders it ideal for advancement toward vaccine trials and development.
Collapse
Affiliation(s)
- Jimmy Borloo
- Laboratory of Parasitology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke B-9820, Belgium.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Geary TG, Mackenzie CD. Progress and challenges in the discovery of macrofilaricidal drugs. Expert Rev Anti Infect Ther 2013; 9:681-95. [PMID: 21819332 DOI: 10.1586/eri.11.76] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Control of human filarial infections currently depends on chemotherapeutic strategies predominantly directed at microfilariae. Doxycycline therapy in an extended daily dose regimen sterilizes and kills adult stages, but the utility of this drug for routine field use remains an issue of concern. No macrofilaricidal drugs with efficacy after one or two doses are available for use, delaying the achievement of the elimination or eradication of onchocerciasis and lymphatic filariasis. Moxidectin, a macrocyclic lactone, is currently in clinical trials for onchocerciasis. A few other drugs that have already been approved for use in veterinary practice or in human medicine for other indications are available for investigation. Early drug discovery pipelines are poorly populated and the process of macrofilaricide discovery and development remains highly challenging. In particular, the lack of convenient, validated animal models in an antifilarial drug discovery pathway is an unresolved issue.
Collapse
Affiliation(s)
- Timothy G Geary
- Institute of Parasitology, McGill University, 21111 Lakeshore Road, Ste-Anne-de-Bellevue QC, H9X 3V9, Canada.
| | | |
Collapse
|
36
|
Putative drug and vaccine target protein identification using comparative genomic analysis of KEGG annotated metabolic pathways of Mycoplasma hyopneumoniae. Genomics 2013; 102:47-56. [DOI: 10.1016/j.ygeno.2013.04.011] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Revised: 04/08/2013] [Accepted: 04/18/2013] [Indexed: 11/23/2022]
|
37
|
Current drug targets for helminthic diseases. Parasitol Res 2013; 112:1819-31. [PMID: 23529336 DOI: 10.1007/s00436-013-3383-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Accepted: 03/05/2013] [Indexed: 01/08/2023]
Abstract
More than 2 billion people are infected with helminth parasites across the globe. The burgeoning drug resistance against current anthelmintics in parasitic worms of humans and livestock requires urgent attention to tackle these recalcitrant worms. This review focuses on the advancements made in the area of helminth drug target discovery especially from the last few couple of decades. It highlights various approaches made in this field and enlists the potential drug targets currently being pursued to target economically important helminth species both from human as well as livestock to combat disease pathology of schistosomiasis, onchocerciasis, lymphatic filariasis, and other important macroparasitic diseases. Research in the helminths study is trending to identify potential and druggable targets through genomic, proteomic, biochemical, biophysical, in vitro experiments, and in vivo experiments in animal models. The availability of major helminths genome sequences and the subsequent availability of genome-scale functional datasets through in silico search and prioritization are expected to guide the experimental work necessary for target-based drug discovery. Organized and documented list of drug targets from various helminths of economic importance have been systematically covered in this review for further exploring their use and applications, which can give physicians and veterinarians effective drugs in hand to enable them control worm infections.
Collapse
|
38
|
Singh PK, Kushwaha S, Mohd S, Pathak M, Misra-Bhattacharya S. In vitro gene silencing of independent phosphoglycerate mutase (iPGM) in the filarial parasite Brugia malayi. Infect Dis Poverty 2013; 2:5. [PMID: 23849829 PMCID: PMC3707094 DOI: 10.1186/2049-9957-2-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2012] [Accepted: 03/21/2013] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND The phosphoglycerate mutase (PGM) enzyme catalyzes the interconversion of 2- and 3-phosphoglycerate in the glycolytic /gluconeogenic pathways that are present in the majority of cellular organisms. They can be classified as cofactor-dependent PGM (dPGM) or cofactor-independent PGM (iPGM). Vertebrates, yeasts, and many bacteria have only dPGM, while higher plants, nematodes, archaea, and many other bacteria have only iPGM. A small number of bacteria, including Escherichia coli and certain archaea and protozoa, contain both forms. The silencing of ipgm in Caenorhabditis elegans (C. elegans) has demonstrated the importance of this enzyme in parasite viability and, therefore, its potential as an anthelmintic drug target. In this study, the role of the Brugia malayi (B. malayi) ipgm in parasite viability, microfilaria release, embryogenesis, and in vivo development of infective larvae post-gene silencing was explored by applying ribonucleic acid (RNA) interference studies. RESULTS The in vitro ipgm gene silencing by small interfering RNA (siRNA) leads to severe phenotypic deformities in the intrauterine developmental stages of female worms with a drastic reduction (~90%) in the motility of adult parasites and a significantly reduced (80%) release of microfilariae (mf) by female worms in vitro. Almost half of the in vitro-treated infective L3 displayed sluggish movement. The in vivo survival and development of siRNA-treated infective larvae (L3) was investigated in the peritoneal cavity of jirds where a ~45% reduction in adult worm establishment was observed. CONCLUSION The findings clearly suggest that iPGM is essential for both larval and adult stages of B. malayi parasite and that it plays a pivotal role in female worm embryogenesis. The results thus validate the Bm-iPGM as a putative anti-filarial drug target.
Collapse
Affiliation(s)
- Prashant Kumar Singh
- Division of Parasitology, CSIR-Central Drug Research Institute, B.S. 10/1, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow, UP, 226021, India
| | - Susheela Kushwaha
- Division of Parasitology, CSIR-Central Drug Research Institute, B.S. 10/1, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow, UP, 226021, India
| | - Shahab Mohd
- Division of Parasitology, CSIR-Central Drug Research Institute, B.S. 10/1, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow, UP, 226021, India
| | - Manisha Pathak
- Division of Parasitology, CSIR-Central Drug Research Institute, B.S. 10/1, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow, UP, 226021, India
| | - Shailja Misra-Bhattacharya
- Division of Parasitology, CSIR-Central Drug Research Institute, B.S. 10/1, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow, UP, 226021, India
| |
Collapse
|
39
|
Using existing drugs as leads for broad spectrum anthelmintics targeting protein kinases. PLoS Pathog 2013; 9:e1003149. [PMID: 23459584 PMCID: PMC3573124 DOI: 10.1371/journal.ppat.1003149] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2012] [Accepted: 11/29/2012] [Indexed: 01/22/2023] Open
Abstract
As one of the largest protein families, protein kinases (PKs) regulate nearly all processes within the cell and are considered important drug targets. Much research has been conducted on inhibitors for PKs, leading to a wealth of compounds that target PKs that have potential to be lead anthelmintic drugs. Identifying compounds that have already been developed to treat neglected tropical diseases is an attractive way to obtain lead compounds inexpensively that can be developed into much needed drugs, especially for use in developing countries. In this study, PKs from nematodes, hosts, and DrugBank were identified and classified into kinase families and subfamilies. Nematode proteins were placed into orthologous groups that span the phylum Nematoda. A minimal kinome for the phylum Nematoda was identified, and properties of the minimal kinome were explored. Orthologous groups from the minimal kinome were prioritized for experimental testing based on RNAi phenotype of the Caenorhabditis elegans ortholog, transcript expression over the life-cycle and anatomic expression patterns. Compounds linked to targets in DrugBank belonging to the same kinase families and subfamilies in the minimal nematode kinome were extracted. Thirty-five compounds were tested in the non-parasitic C. elegans and active compounds progressed to testing against nematode species with different modes of parasitism, the blood-feeding Haemonchus contortus and the filarial Brugia malayi. Eighteen compounds showed efficacy in C. elegans, and six compounds also showed efficacy in at least one of the parasitic species. Hypotheses regarding the pathway the compounds may target and their molecular mechanism for activity are discussed. Parasitic nematode infection is a large global health and economic problem, infecting around 2 billion people and costing $100 billion in crops and livestock. People in developing countries often live on one dollar per day, so treatments cannot be expensive, therefore using pre-existing drugs as lead compounds provides an economical way to begin to develop affordable treatments. Protein kinases were chosen as the focus of this work due to the large number of pre-existing drugs that target them and their important role in regulating almost all activities in the cell. Herein we describe a set of protein kinases conserved in diverse nematode species and experimental screening results of pre-existing drugs that target these kinases. The compounds that show in vitro efficacy in both C. elegans and parasitic nematodes, H. contortus or B. malayi have potential to be optimized further. These compounds have potential to provide accessible treatment to people in developing countries, as well as improving the health of livestock and boosting food production globally.
Collapse
|
40
|
Cools HJ, Hammond-Kosack KE. Exploitation of genomics in fungicide research: current status and future perspectives. MOLECULAR PLANT PATHOLOGY 2013; 14:197-210. [PMID: 23157348 PMCID: PMC6638899 DOI: 10.1111/mpp.12001] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Every year, fungicide use to control plant disease caused by pathogenic fungi increases. The global fungicide market is now worth more than £5.3 billion, second only to the herbicide market in importance. In the UK, over 5500 tonnes of fungicide were applied to crops in 2010 (The Food and Environment Research Agency, Pesticide Usage Statistics), with 95.5% of the wheat-growing area receiving three fungicide sprays. Although dependence on fungicides to produce food securely, reliably and cheaply may be moderated in the future by further developments in crop biotechnology, modern crop protection will continue to require a diversity of solutions, including effective and safe chemical control. Therefore, investment in exploiting the increasingly available genome sequences of the most devastating fungal and oomycete phytopathogenic species should bring an array of new opportunities for chemical intervention. To date, the impact of whole genome research on the development, introduction and stewardship of fungicides has been limited, but ongoing improvements in computational analysis, molecular biology, chemical genetics, genome sequencing and transcriptomics will facilitate the development and registration of the future suite of crop protection chemicals.
Collapse
Affiliation(s)
- Hans J Cools
- Department of Biological Chemistry and Crop Protection, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK.
| | | |
Collapse
|
41
|
Menon R, Gasser RB, Mitreva M, Ranganathan S. An analysis of the transcriptome of Teladorsagia circumcincta: its biological and biotechnological implications. BMC Genomics 2012; 13 Suppl 7:S10. [PMID: 23282110 PMCID: PMC3521389 DOI: 10.1186/1471-2164-13-s7-s10] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND Teladorsagia circumcincta (order Strongylida) is an economically important parasitic nematode of small ruminants (including sheep and goats) in temperate climatic regions of the world. Improved insights into the molecular biology of this parasite could underpin alternative methods required to control this and related parasites, in order to circumvent major problems associated with anthelmintic resistance. The aims of the present study were to define the transcriptome of the adult stage of T. circumcincta and to infer the main pathways linked to molecules known to be expressed in this nematode. Since sheep develop acquired immunity against T. circumcincta, there is some potential for the development of a vaccine against this parasite. Hence, we infer excretory/secretory molecules for T. circumcincta as possible immunogens and vaccine candidates. RESULTS A total of 407,357 ESTs were assembled yielding 39,852 putative gene sequences. Conceptual translation predicted 24,013 proteins, which were then subjected to detailed annotation which included pathway mapping of predicted proteins (including 112 excreted/secreted [ES] and 226 transmembrane peptides), domain analysis and GO annotation was carried out using InterProScan along with BLAST2GO. Further analysis was carried out for secretory signal peptides using SignalP and non-classical sec pathway using SecretomeP tools. For ES proteins, key pathways, including Fc epsilon RI, T cell receptor, and chemokine signalling as well as leukocyte transendothelial migration were inferred to be linked to immune responses, along with other pathways related to neurodegenerative diseases and infectious diseases, which warrant detailed future studies. KAAS could identify new and updated pathways like phagosome and protein processing in endoplasmic reticulum. Domain analysis for the assembled dataset revealed families of serine, cysteine and proteinase inhibitors which might represent targets for parasite intervention. InterProScan could identify GO terms pertaining to the extracellular region. Some of the important domain families identified included the SCP-like extracellular proteins which belong to the pathogenesis-related proteins (PRPs) superfamily along with C-type lectin, saposin-like proteins. The 'extracellular region' that corresponds to allergen V5/Tpx-1 related, considered important in parasite-host interactions, was also identified. Six cysteine motif (SXC1) proteins, transthyretin proteins, C-type lectins, activation-associated secreted proteins (ASPs), which could represent potential candidates for developing novel anthelmintics or vaccines were few other important findings. Of these, SXC1, protein kinase domain-containing protein, trypsin family protein, trypsin-like protease family member (TRY-1), putative major allergen and putative lipid binding protein were identified which have not been reported in the published T. circumcincta proteomics analysis. Detailed analysis of 6,058 raw EST sequences from dbEST revealed 315 putatively secreted proteins. Amongst them, C-type single domain activation associated secreted protein ASP3 precursor, activation-associated secreted proteins (ASP-like protein), cathepsin B-like cysteine protease, cathepsin L cysteine protease, cysteine protease, TransThyretin-Related and Venom-Allergen-like proteins were the key findings. CONCLUSIONS We have annotated a large dataset ESTs of T. circumcincta and undertaken detailed comparative bioinformatics analyses. The results provide a comprehensive insight into the molecular biology of this parasite and disease manifestation which provides potential focal point for future research. We identified a number of pathways responsible for immune response. This type of large-scale computational scanning could be coupled with proteomic and metabolomic studies of this parasite leading to novel therapeutic intervention and disease control strategies. We have also successfully affirmed the use of bioinformatics tools, for the study of ESTs, which could now serve as a benchmark for the development of new computational EST analysis pipelines.
Collapse
Affiliation(s)
- Ranjeeta Menon
- Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | | | | | | |
Collapse
|
42
|
RNAi-mediated silencing of paramyosin expression in Trichinella spiralis results in impaired viability of the parasite. PLoS One 2012. [PMID: 23185483 PMCID: PMC3503832 DOI: 10.1371/journal.pone.0049913] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Trichinella spiralis expresses paramyosin (Ts-PMY) not only as a structural protein but also as an immunomodulatory protein to protect the worm from being attacked by host complement components. In this study, the functions of PMY in the viability and the growth development of T. spiralis were confirmed at the first time by silencing the gene function with RNA interference technique. METHODS AND FINDINGS To understand its functions in the viability of the worm, we used RNA interference to silence the expression of Ts-pmy mRNA and protein in the parasite. Significant silencing of Ts-pmy mRNA expression in larval and adult T. spiralis was achieved by siRNA and dsRNA through soaking and electroporation. Electroporation of T. spiralis larvae with 8 µM siRNA1743 or 100 ng/µl dsRNA-PF3 resulted in 66.3% and 60.4% decrease in Ts-pmy transcript and 52.0% and 64.7% decrease in Ts-PMY protein expression, respectively, compared with larvae treated with irrelevant control siRNA or dsRNA. Larvae treated with siRNA1743 displayed significant reduction in molting (40.8%) and serious surface damage as detected with SYTOX fluorescent staining. Infection of mice with larvae electroporated with Ts-pmy siRNA1743 resulted in 37.6% decrease in adult worm burden and 23.2% decrease in muscle larvae burden compared with mice infected with control siRNA-treated larvae. In addition, adult worms recovered from mice infected with siRNA-treated larvae released 24.8% less newborn larvae. CONCLUSION It is the first time RNAi was used on T. spiralis to demonstrate that silencing PMY expression in T. spiralis significantly reduces the parasite's viability and infectivity, further confirming that Ts-PMY plays an important role in the survival of T. spiralis and therefore is a promising target for vaccine development.
Collapse
|
43
|
In vitro silencing of Brugia malayi trehalose-6-phosphate phosphatase impairs embryogenesis and in vivo development of infective larvae in jirds. PLoS Negl Trop Dis 2012; 6:e1770. [PMID: 22905273 PMCID: PMC3419221 DOI: 10.1371/journal.pntd.0001770] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 06/22/2012] [Indexed: 01/19/2023] Open
Abstract
Background The trehalose metabolic enzymes have been considered as potential targets for drug or vaccine in several organisms such as Mycobacterium, plant nematodes, insects and fungi due to crucial role of sugar trehalose in embryogenesis, glucose uptake and protection from stress. Trehalose-6-phosphate phosphatase (TPP) is one of the enzymes of trehalose biosynthesis that has not been reported in mammals. Silencing of tpp gene in Caenorhabditis elegans revealed an indispensable functional role of TPP in nematodes. Methodology and Principal Findings In the present study, functional role of B. malayi tpp gene was investigated by siRNA mediated silencing which further validated this enzyme to be a putative antifilarial drug target. The silencing of tpp gene in adult female B. malayi brought about severe phenotypic deformities in the intrauterine stages such as distortion and embryonic development arrest. The motility of the parasites was significantly reduced and the microfilarial production as well as their in vitro release from the female worms was also drastically abridged. A majority of the microfilariae released in to the culture medium were found dead. B. malayi infective larvae which underwent tpp gene silencing showed 84.9% reduced adult worm establishment after inoculation into the peritoneal cavity of naïve jirds. Conclusions/Significance The present findings suggest that B. malayi TPP plays an important role in the female worm embryogenesis, infectivity of the larvae and parasite viability. TPP enzyme of B. malayi therefore has the potential to be exploited as an antifilarial drug target. Lymphatic filariasis, one of the neglected tropical diseases, is the second leading cause of permanent and long term disability. Control of the disease relies on the mass administration of drugs which mainly act on the microfilariae without substantial effect on adult worms. Drugs need to be continued for several years to block the transmission of infection which may result in to development of resistant parasites. The sugar trehalose has been shown to play several important functions in the nematodes, and trehalose biosynthetic enzymes have been considered as potential targets for drug or vaccine candidate. In the present study we silenced trehalose-6-phosphate phosphatase and studied the biological function of TPP enzyme in the filarial nematode B. malayi viability, female worm embryogenesis and establishment of infection in the host. In vitro gene silencing was done in adult parasites using 5 mM concentration of siRNA while 2 mM of siRNA was used to treat L3 which were further inoculated into the peritoneal cavity of jirds to study the effect of siRNA treatment on in vivo larval development. The present findings validate trehalose-6-phosphate phosphatase as a vital antifilarial drug target.
Collapse
|
44
|
Murfin KE, Dillman AR, Foster JM, Bulgheresi S, Slatko BE, Sternberg PW, Goodrich-Blair H. Nematode-bacterium symbioses--cooperation and conflict revealed in the "omics" age. THE BIOLOGICAL BULLETIN 2012; 223:85-102. [PMID: 22983035 PMCID: PMC3508788 DOI: 10.1086/bblv223n1p85] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Nematodes are ubiquitous organisms that have a significant global impact on ecosystems, economies, agriculture, and human health. The applied importance of nematodes and the experimental tractability of many species have promoted their use as models in various research areas, including developmental biology, evolutionary biology, ecology, and animal-bacterium interactions. Nematodes are particularly well suited for the investigation of host associations with bacteria because all nematodes have interacted with bacteria during their evolutionary history and engage in a variety of association types. Interactions between nematodes and bacteria can be positive (mutualistic) or negative (pathogenic/parasitic) and may be transient or stably maintained (symbiotic). Furthermore, since many mechanistic aspects of nematode-bacterium interactions are conserved, their study can provide broader insights into other types of associations, including those relevant to human diseases. Recently, genome-scale studies have been applied to diverse nematode-bacterial interactions and have helped reveal mechanisms of communication and exchange between the associated partners. In addition to providing specific information about the system under investigation, these studies also have helped inform our understanding of genome evolution, mutualism, and innate immunity. In this review we discuss the importance and diversity of nematodes, "omics"' studies in nematode-bacterial systems, and the wider implications of the findings.
Collapse
Affiliation(s)
- Kristen E. Murfin
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706
| | - Adler R. Dillman
- HHMI and Division of Biology, California Institute of Technology, 156-29, Pasadena, CA 91125, USA
| | - Jeremy M. Foster
- Parasitology Division, New England Biolabs, Inc., 240 County Rd, Ipswich, MA 01938, USA
| | - Silvia Bulgheresi
- Department of Genetics in Ecology, University of Vienna, Vienna, Austria
| | - Barton E. Slatko
- Parasitology Division, New England Biolabs, Inc., 240 County Rd, Ipswich, MA 01938, USA
| | - Paul W. Sternberg
- HHMI and Division of Biology, California Institute of Technology, 156-29, Pasadena, CA 91125, USA
| | - Heidi Goodrich-Blair
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706
- Corresponding author Department of Bacteriology, University of Wisconsin-Madison, 1550 Linden Dr., Madison, WI 53706, , phone: 608-265-4537, fax: 608-262-9865
| |
Collapse
|
45
|
Jiang D, Malone J, Townsend R, Weil GJ, Li B. Multiplex proteomics analysis of gender-associated proteins in Brugia malayi. Int J Parasitol 2012; 42:841-50. [PMID: 22819962 DOI: 10.1016/j.ijpara.2012.06.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 06/06/2012] [Accepted: 06/07/2012] [Indexed: 11/17/2022]
Abstract
Gender-associated (GA) genes are important for the development and reproduction of filarial nematodes. Identification and characterization of GA genes may provide insight into major pathways and processes involved in development and reproduction. The recent completion of the Brugia malayi genome has provided a good foundation for proteomics studies. Multiplex protein labelling and two-dimensional difference in-gel electrophoresis (2D-DIGE) combined with MALDI-TOF/TOF tandem MS were used to identify GA proteins. Thirty male and 32 female associated proteins were identified in this study. Many of these GA genes have homologues in Caenorhabditis elegans (83% male and 69% female), and most of the homologues have severe RNA interference (RNAi) phenotypes (72% male and 55% female) in C. elegans. Functional analysis showed that the male-associated genes are enriched for energy production, metabolic processes and cytoskeleton, while the female-associated genes are enriched for RNA modification and transcription. GA genes encode many excreted/secreted proteins. In situ localization studies showed that GA genes are mainly expressed in reproductive organs, and this is further evidence for their involvement in reproduction. Improved understanding of the basic biology of filarial nematodes may lead to improved tools for prevention and treatment of filarial infections. This study combined proteomics, in situ hybridization (ISH) and bioinformatics in a systems biology approach to improve understanding of gender differences and key proteins involved in reproduction in filarial worms. Advanced proteomics methods and bioinformatics led to the identification of 62 GA proteins for B. malayi. ISH revealed that most of those GA genes are expressed during embryogenesis or spermatogenesis. ISH results were consistent with RNAi data for C. elegans that linked the homologues of the B. malayi proteins to gamete production and embryogenesis.
Collapse
Affiliation(s)
- Daojun Jiang
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA.
| | | | | | | | | |
Collapse
|
46
|
Li BW, Wang Z, Rush AC, Mitreva M, Weil GJ. Transcription profiling reveals stage- and function-dependent expression patterns in the filarial nematode Brugia malayi. BMC Genomics 2012; 13:184. [PMID: 22583769 PMCID: PMC3414817 DOI: 10.1186/1471-2164-13-184] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Accepted: 05/14/2012] [Indexed: 11/24/2022] Open
Abstract
Background Brugia malayi is a nematode parasite that causes lymphatic filariasis, a disfiguring and disabiling tropical disease. Although a first draft genome sequence was released in 2007, very little is understood about transcription programs that govern developmental changes required for the parasite’s development and survival in its mammalian and insect hosts. Results We used a microarray with probes that represent some 85% of predicted genes to generate gene expression profiles for seven parasite life cycle stages/sexes. Approximately 41% of transcripts with detectable expression signals were differentially expressed across lifecycle stages. Twenty-six percent of transcripts were exclusively expressed in a single parasite stage, and 27% were expressed in all stages studied. K-means clustering of differentially expressed transcripts revealed five major transcription patterns that were associated with parasite lifecycle stages or gender. Examination of known stage-associated transcripts validated these data sets and suggested that newly identified stage or gender-associated transcripts may exercise biological functions in development and reproduction. The results also indicate that genes with similar transcription patterns were often involved in similar functions or cellular processes. For example, nuclear receptor family gene transcripts were upregulated in gene expression pattern four (female-enriched) while protein kinase gene family transcripts were upregulated in expression pattern five (male-enriched). We also used pair-wise comparisons to identify transcriptional changes between life cycle stages and sexes. Conclusions Analysis of gene expression patterns of lifecycle in B. malayi has provided novel insights into the biology of filarial parasites. Proteins encoded by stage-associated and/or stage-specific transcripts are likely to be critically important for key parasite functions such as establishment and maintenance of infection, development, reproduction, and survival in the host. Some of these may be useful targets for vaccines or new drug treatments for filariasis.
Collapse
Affiliation(s)
- Ben-Wen Li
- Infectious Diseases Division, Department of Internal Medicine, Washington University School of Medicine, St, Louis, MO 63110, USA.
| | | | | | | | | |
Collapse
|
47
|
Dhamodharan R, Hoti SL, Sankari T. Characterization of cofactor-independent phosphoglycerate mutase isoform-1 (Wb-iPGM) gene: a drug and diagnostic target from human lymphatic filarial parasite, Wuchereria bancrofti. INFECTION GENETICS AND EVOLUTION 2012; 12:957-65. [PMID: 22386851 DOI: 10.1016/j.meegid.2012.02.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Revised: 01/25/2012] [Accepted: 02/13/2012] [Indexed: 11/18/2022]
Abstract
The inter-conversion of 3-phosphoglycerate and 2-phosphoglycerate during glycolysis and gluconeogenesis in filarial nematodes, is catalyzed by a co-factor-independent phosphoglycerate mutase (iPGM). The gene encoding iPGM isoform-1 was amplified from Wuchereria bancrofti, the major causative agent of human lymphatic filariasis. Partial genomic DNA (gDNA) fragment of the gene was also amplified from periodic and sub-periodic forms of W. bancrofti and Brugia malayi and sequenced. The Wb-iPGM isoform-1 gene encodes an ORF of 515 amino acids and is found to share 99.4%, 96.0%, and 64.0% amino acid sequence identity with iPGM of B. malayi, Onchocerca volvulus, and Caenorhabditis elegans, respectively. Serine and all the other 13 amino acid residues involved in the catalytic function of iPGM are highly conserved. Further comparison of iPGM nucleotide and amino acid sequences of Wolbachia of B. malayi with Wb-iPGM showed 41% and 54.4% similarity, respectively. The analysis of partial genomic and amino acid sequences and phylogenetic tree of Wb-iPGM indicated that this gene, apart from being a potential drug target, could provide diagnostic, taxonomical, and evolutionary markers. This is the first report of the characterization of iPGM gene from W. bancrofti.
Collapse
Affiliation(s)
- R Dhamodharan
- Vector Control Research Centre (ICMR), Indira Nagar, Puducherry 605 006, India
| | | | | |
Collapse
|
48
|
Abstract
SUMMARYIn this study we assessed three technologies for silencing gene expression by RNA interference (RNAi) in the sheep parasitic nematode Haemonchus contortus. We chose as targets five genes that are essential in Caenorhabditis elegans (mitr-1, pat-12, vha-19, glf-1 and noah-1), orthologues of which are present and expressed in H. contortus, plus four genes previously tested by RNAi in H. contortus (ubiquitin, tubulin, paramyosin, tropomyosin). To introduce double-stranded RNA (dsRNA) into the nematodes we tested (1) feeding free-living stages of H. contortus with Escherichia coli that express dsRNA targetting the test genes; (2) electroporation of dsRNA into H. contortus eggs or larvae; and (3) soaking adult H. contortus in dsRNA. For each gene tested we observed reduced levels of mRNA in the treated nematodes, except for some electroporation conditions. We did not observe any phenotypic changes in the worms in the electroporation or dsRNA soaking experiments. The feeding method, however, elicited observable changes in the development and viability of larvae for five of the eight genes tested, including the ‘essential’ genes, Hc-pat-12, Hc-vha-19 and Hc-glf-1. We recommend the E. coli feeding method for RNAi in H. contortus and provide recommendations for future research directions for RNAi in this species.
Collapse
|
49
|
Rao RU, Huang Y, Abubucker S, Heinz M, Crosby SD, Mitreva M, Weil GJ. Effects of doxycycline on gene expression in Wolbachia and Brugia malayi adult female worms in vivo. J Biomed Sci 2012; 19:21. [PMID: 22321609 PMCID: PMC3352068 DOI: 10.1186/1423-0127-19-21] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Accepted: 02/09/2012] [Indexed: 12/28/2022] Open
Abstract
Background Most filarial nematodes contain Wolbachia symbionts. The purpose of this study was to examine the effects of doxycycline on gene expression in Wolbachia and adult female Brugia malayi. Methods Brugia malayi infected gerbils were treated with doxycycline for 6-weeks. This treatment largely cleared Wolbachia and arrested worm reproduction. RNA recovered from treated and control female worms was labeled by random priming and hybridized to the Version 2- filarial microarray to obtain expression profiles. Results and discussion Results showed significant changes in expression for 200 Wolbachia (29% of Wolbachia genes with expression signals in untreated worms) and 546 B. malayi array elements after treatment. These elements correspond to known genes and also to novel genes with unknown biological functions. Most differentially expressed Wolbachia genes were down-regulated after treatment (98.5%). In contrast, doxycycline had a mixed effect on B. malayi gene expression with many more genes being significantly up-regulated after treatment (85% of differentially expressed genes). Genes and processes involved in reproduction (gender-regulated genes, collagen, amino acid metabolism, ribosomal processes, and cytoskeleton) were down-regulated after doxycycline while up-regulated genes and pathways suggest adaptations for survival in response to stress (energy metabolism, electron transport, anti-oxidants, nutrient transport, bacterial signaling pathways, and immune evasion). Conclusions Doxycycline reduced Wolbachia and significantly decreased bacterial gene expression. Wolbachia ribosomes are believed to be the primary biological target for doxycycline in filarial worms. B. malayi genes essential for reproduction, growth and development were also down-regulated; these changes are consistent with doxycycline effects on embryo development and reproduction. On the other hand, many B. malayi genes involved in energy production, electron-transport, metabolism, anti-oxidants, and others with unknown functions had increased expression signals after doxycycline treatment. These results suggest that female worms are able to compensate in part for the loss of Wolbachia so that they can survive, albeit without reproductive capacity. This study of doxycycline induced changes in gene expression has provided new clues regarding the symbiotic relationship between Wolbachia and B. malayi.
Collapse
Affiliation(s)
- Ramakrishna U Rao
- Infectious Diseases Division, Department of Internal Medicine, St, Louis, Missouri, USA.
| | | | | | | | | | | | | |
Collapse
|
50
|
Choi YJ, Ghedin E, Berriman M, McQuillan J, Holroyd N, Mayhew GF, Christensen BM, Michalski ML. A deep sequencing approach to comparatively analyze the transcriptome of lifecycle stages of the filarial worm, Brugia malayi. PLoS Negl Trop Dis 2011; 5:e1409. [PMID: 22180794 PMCID: PMC3236722 DOI: 10.1371/journal.pntd.0001409] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Accepted: 10/19/2011] [Indexed: 11/19/2022] Open
Abstract
Background Developing intervention strategies for the control of parasitic nematodes continues to be a significant challenge. Genomic and post-genomic approaches play an increasingly important role for providing fundamental molecular information about these parasites, thus enhancing basic as well as translational research. Here we report a comprehensive genome-wide survey of the developmental transcriptome of the human filarial parasite Brugia malayi. Methodology/Principal Findings Using deep sequencing, we profiled the transcriptome of eggs and embryos, immature (≤3 days of age) and mature microfilariae (MF), third- and fourth-stage larvae (L3 and L4), and adult male and female worms. Comparative analysis across these stages provided a detailed overview of the molecular repertoires that define and differentiate distinct lifecycle stages of the parasite. Genome-wide assessment of the overall transcriptional variability indicated that the cuticle collagen family and those implicated in molting exhibit noticeably dynamic stage-dependent patterns. Of particular interest was the identification of genes displaying sex-biased or germline-enriched profiles due to their potential involvement in reproductive processes. The study also revealed discrete transcriptional changes during larval development, namely those accompanying the maturation of MF and the L3 to L4 transition that are vital in establishing successful infection in mosquito vectors and vertebrate hosts, respectively. Conclusions/Significance Characterization of the transcriptional program of the parasite's lifecycle is an important step toward understanding the developmental processes required for the infectious cycle. We find that the transcriptional program has a number of stage-specific pathways activated during worm development. In addition to advancing our understanding of transcriptome dynamics, these data will aid in the study of genome structure and organization by facilitating the identification of novel transcribed elements and splice variants. Lymphatic filariasis, also known as elephantiasis, is a tropical disease affecting over 120 million people worldwide. More than 40 million people live with painful, disfiguring symptoms that can cause severe debilitation and social stigma. The disease is caused by infection with thread-like filarial nematodes (roundworms) that have a complex parasitic lifecycle involving both human and mosquito hosts. In the study, the authors profiled the transcriptome (the set of genes transcribed into messenger RNA rather than all of those in the genome) of the human filarial worm Brugia malayi in different lifecyle stages using deep sequencing technology. The analysis revealed major transitions in RNA expression from eggs through larval stages to adults. Using statistical approaches, the authors identified groups of genes with distinct life stage dependent transcriptional patterns, with particular emphasis on genes displaying sex-biased or germline-enriched patterns and those displaying significant changes during larval development. This study presents a first comprehensive analysis of the lifecycle transcriptome of B. malayi, providing fundamental molecular information that should help researchers better understand parasite biology and could provide clues for the development of more effective interventions.
Collapse
Affiliation(s)
- Young-Jun Choi
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Elodie Ghedin
- Department of Computational and Systems Biology, Center for Vaccine Research, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Matthew Berriman
- The Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Jacqueline McQuillan
- The Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Nancy Holroyd
- The Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - George F. Mayhew
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Bruce M. Christensen
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Michelle L. Michalski
- Department of Biology and Microbiology, University of Wisconsin Oshkosh, Oshkosh, Wisconsin, United States of America
- * E-mail:
| |
Collapse
|