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Shahid Karim - One of the best experts on this subject based on the ideXlab platform.
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Repurposing of Glycine-Rich Proteins in Abiotic and Biotic Stresses in the Lone-Star Tick (Amblyomma americanum).
Frontiers in physiology, 2019Co-Authors: Rebekah L. Bullard, Surendra Raj Sharma, Pradipta K. Das, Sarah E. Morgan, Shahid KarimAbstract:Tick feeding requires the secretion of a huge number of pharmacologically dynamic proteins and other molecules which are vital for the formation of the cement cone, the establishment of the blood pool and to counter against the host immune response. Glycine-rich proteins (GRP) are found in many organisms and can function in a variety of cellular processes and structures. The functional characterization of the GRPs in the tick salivary glands has not been elucidated. GRPs have been found to play a role in the formation of the cement cone; however, new evidence suggests repurposing of GRPs in the tick physiology. In this study, an RNA interference approach was utilized to silence two glycine-rich protein genes expressed in early phase of tick feeding to determine their functional role in tick Hematophagy, cement cone structure, and microbial homeostasis within the tick host. Additionally, the transcriptional regulation of GRPs was determined after exposure to biotic and abiotic stresses including cold and hot temperature, injury, and oxidative stress. This caused a significant up-regulation of AamerSigP-34358, Aam-40766, AamerSigP-39259, and Aam-36909. Our results suggest ticks repurpose these proteins and further functional characterization of GRPs may help to design novel molecular strategies to disrupt the homeostasis and the pathogen transmission.
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Assessment of tick antioxidant responses to exogenous oxidative stressors and insight into the role of catalase in the reproductive fitness of the Gulf Coast tick, Amblyomma maculatum.
Insect molecular biology, 2016Co-Authors: Deepak Kumar, Khemraj Budachetri, Virginia C. Meyers, Shahid KarimAbstract:As obligate blood-sucking ectoparasites, to avoid tissue damage, ticks must neutralize the reactive oxygen species (ROS) generated from uptake and digestion of a bloodmeal. Consequently, ticks utilize a battery of antioxidant molecules, including catalase (CAT), an enzyme that converts hydrogen peroxide (H2 O2 ) into water and oxygen. Here, we investigated the tick antioxidant machinery by exogenous injection of sublethal doses of H2 O2 or paraquat. The relative transcript levels of selected Amblyomma maculatum antioxidant targets in tissues were determined by quantitative reverse transcriptase PCR following treatment. The results showed 2-16-fold increases in target antioxidant gene transcripts, signifying the ability of Am. maculatum to regulate its antioxidant machinery when exposed to increased ROS levels. Next, RNA interference was used to determine the functional role of CAT in haematophagy, redox homeostasis and reproductive fitness. CAT gene silencing was confirmed by transcript depletion within tick tissues; however, CAT knockdown alone did not interfere with tick haematophagy or phenotype, as confirmed by the resulting differential expression of antioxidant genes, thereby indicating an alternative mechanism for ROS control. Interestingly, double stranded RNA of CAT gene (dsCAT) and the CAT inhibitor, 3-aminotriazole, together reduced tick reproductive fitness via a marked reduction in egg mass and larval eclosion rates, highlighting a role for CAT in tick redox-homeostasis, making it a potential target for tick control.
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Sialomes and Mialomes: A Systems-Biology View of Tick Tissues and Tick-Host Interactions
Trends in parasitology, 2015Co-Authors: Jindřich Chmelař, Ivo M. B. Francischetti, Petr Kopáček, Jan Kotál, Shahid Karim, Joao H. F. Pedra, Michail KotsyfakisAbstract:Tick saliva facilitates tick feeding and infection of the host. Gene expression analysis of tick salivary glands and other tissues involved in host-pathogen interactions has revealed a wide range of bioactive tick proteins. Transcriptomic analysis has been a milestone in the field and has recently been enhanced by next-generation sequencing (NGS). Furthermore, the application of quantitative proteomics to ticks with unknown genomes has provided deeper insights into the molecular mechanisms underlying tick Hematophagy, pathogen transmission, and tick-host-pathogen interactions. We review current knowledge on the transcriptomics and proteomics of tick tissues from a systems-biology perspective and discuss future challenges in the field.
Jose M C Ribeiro - One of the best experts on this subject based on the ideXlab platform.
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plasmodium falciparum infection induces expression of a mosquito salivary protein agaphelin that targets neutrophil function and inhibits thrombosis without impairing hemostasis
PLOS Pathogens, 2014Co-Authors: Michalis Kotsyfakis, Michael Waisberg, Alvaro Molinacruz, Daniella M Mizurini, Nidhi Gera, Beatriz Coutinho De Sousa, Ana C Leal, Taina Gomes, Jose M C RibeiroAbstract:Background Invasion of mosquito salivary glands (SGs) by Plasmodium falciparum sporozoites is an essential step in the malaria life cycle. How infection modulates gene expression, and affects Hematophagy remains unclear. Principal Findings Using Affimetrix chip microarray, we found that at least 43 genes are differentially expressed in the glands of Plasmodium falciparum-infected Anopheles gambiae mosquitoes. Among the upregulated genes, one codes for Agaphelin, a 58-amino acid protein containing a single Kazal domain with a Leu in the P1 position. Agaphelin displays high homology to orthologs present in Aedes sp and Culex sp salivary glands, indicating an evolutionarily expanded family. Kinetics and surface plasmon resonance experiments determined that chemically synthesized Agaphelin behaves as a slow and tight inhibitor of neutrophil elastase (KD∼10 nM), but does not affect other enzymes, nor promotes vasodilation, or exhibit antimicrobial activity. TAXIscan chamber assay revealed that Agaphelin inhibits neutrophil chemotaxis toward fMLP, affecting several parameter associated with cell migration. In addition, Agaphelin reduces paw edema formation and accumulation of tissue myeloperoxidase triggered by injection of carrageenan in mice. Agaphelin also blocks elastase/cathepsin-mediated platelet aggregation, abrogates elastase-mediated cleavage of tissue factor pathway inhibitor, and attenuates neutrophil-induced coagulation. Notably, Agaphelin inhibits neutrophil extracellular traps (NETs) formation and prevents FeCl3-induced arterial thrombosis, without impairing hemostasis. Conclusions Blockade of neutrophil elastase emerges as a novel antihemostatic mechanism in Hematophagy; it also supports the notion that neutrophils and the innate immune response are targets for antithrombotic therapy. In addition, Agaphelin is the first antihemostatic whose expression is induced by Plasmodium sp infection. These results suggest that an important interplay takes place in parasite-vector-host interactions.
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De novo Ixodes ricinus salivary gland transcriptome analysis using two next-generation sequencing methodologies
FASEB journal : official publication of the Federation of American Societies for Experimental Biology, 2013Co-Authors: Alexandra Schwarz, Jose M C Ribeiro, Björn M. Von Reumont, Jan Erhart, Andrezza C. Chagas, Michalis KotsyfakisAbstract:Tick salivary gland (SG) proteins possess powerful pharmacologic properties that facilitate tick feeding and pathogen transmission. For the first time, SG transcriptomes of Ixodes ricinus, an important disease vector for humans and animals, were analyzed using next-generation sequencing. SGs were collected from different tick life stages fed on various animal species, including cofeeding of nymphs and adults on the same host. Four cDNA samples were sequenced, discriminating tick SG transcriptomes of early- and late-feeding nymphs or adults. In total, 441,381,454 pyrosequencing reads and 67,703,183 Illumina reads were assembled into 272,220 contigs, of which 34,560 extensively annotated coding sequences are disclosed; 8686 coding sequences were submitted to GenBank. Overall, 13% of contigs were classified as secreted proteins that showed significant differences in the transcript representation among the 4 SG samples, including high numbers of sample-specific transcripts. Detailed phylogenetic reconstructions of two relatively abundant SG-secreted protein families demonstrated how this study improves our understanding of the molecular evolution of Hematophagy in arthropods. Our data significantly increase the available genomic information for I. ricinus and form a solid basis for future tick genome/transcriptome assemblies and the functional analysis of effectors that mediate the feeding physiology and parasite-vector interaction of I. ricinus.
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An Insight into the Sialomes of Bloodsucking Heteroptera
Psyche: A Journal of Entomology, 2012Co-Authors: Jose M C Ribeiro, Teresa C. F. Assumpção, Ivo M. B. FrancischettiAbstract:Saliva of bloodsucking arthropods contains dozens or hundreds of proteins that affect their hosts' mechanisms against blood loss (hemostasis) and inflammation. Because acquisition of the hematophagous habit evolved independently in several arthropod orders and at least twice within the true bugs, there is a convergent evolutionary scenario that creates a different salivary potion for each organism evolving independently to Hematophagy. Additionally, the immune pressure posed by their hosts creates additional evolutionary pressure on the genes coding for salivary proteins, including gene obsolescence, which opens the niche for coopting new genes (exaptation). In the past 10 years, several salivary transcriptomes from bloodsucking Heteroptera and one from a seed-feeding Pentatomorpha were produced, allowing insight into the salivary potion of these organisms and the evolutionary pathway to the blood-feeding mode.
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Insight into the Sialome of the Bed Bug, Cimex lectularius
Journal of proteome research, 2010Co-Authors: Ivo M. B. Francischetti, John F Andersen, Jesus G Valenzuela, Eric Calvo, Van My Pham, Amanda J. Favreau, Kent D. Barbian, Alvaro Romero, Jose M C RibeiroAbstract:The evolution of insects to a blood diet leads to the development of a saliva that antagonizes their hosts' hemostasis and inflammation. Hemostasis and inflammation are redundant processes, and thus a complex salivary potion comprised of dozens or near one hundred different polypeptides is commonly found by transcriptome or proteome analysis of these organisms. Several insect orders or families evolved independently to Hematophagy creating unique salivary potions in the form of novel pharmacological use of endogenous substances, and in the form of unique proteins not matching other known proteins, these probably arriving by fast evolution of salivary proteins as they evade their hosts' immune response. In this work we present a preliminary description of the sialome (from the Greek Sialo = saliva) of the common bed bug Cimex lectularius, the first such work from a member of the Cimicidae family. This manuscript is a guide for the supplemental database files http://exon.niaid.nih.gov/transcriptome/C_lectularius/S1/Cimex-S1.zip and http://exon.niaid.nih.gov/transcriptome/C_lectularius/S2/Cimex-S2.xls
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delayed type hypersensitivity to phlebotomus papatasi sand fly bite an adaptive response induced by the fly
Proceedings of the National Academy of Sciences of the United States of America, 2000Co-Authors: Yasmine Belkaid, Jesus G Valenzuela, Shaden Kamhawi, Edgar Rowton, David L Sacks, Jose M C RibeiroAbstract:The saliva of bloodsucking arthropods contains a large array of pharmacologically active compounds that assist Hematophagy. Arthropod saliva is also responsible for causing uncomfortable allergic responses in its vertebrate hosts. In this article, we investigate whether the sand fly Phlebotomus papatasi, known to produce a strong delayed-type hypersensitivity (DTH) in humans, could benefit from, and possibly adaptively induce, this response in their vertebrate hosts. In this study, we show that flies fed on humans to completion nearly twice as fast in DTH sites as compared with normal skin sites. DTH sites had significantly larger blood flow as measured by the laser Doppler method. Sand flies feeding at sites in mouse ears that had a DTH response also fed faster than at normal sites. We conclude that in the case of P. papatasi, and possibly other arthropods such as fleas and bed bugs, the strong saliva-induced DTH response may reflect an adaptation of the fly to manipulate host immunity for the insect's own advantage.
Marco Oliverio - One of the best experts on this subject based on the ideXlab platform.
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The venomous cocktail of the vampire snail Colubraria reticulata (Mollusca, Gastropoda)
BMC genomics, 2015Co-Authors: Maria Vittoria Modica, Fabrizio Lombardo, Paolo Franchini, Marco OliverioAbstract:Hematophagy arose independently multiple times during metazoan evolution, with several lineages of vampire animals particularly diversified in invertebrates. However, the biochemistry of Hematophagy has been studied in a few species of direct medical interest and is still underdeveloped in most invertebrates, as in general is the study of venom toxins. In cone snails, leeches, arthropods and snakes, the strong target specificity of venom toxins uniquely aligns them to industrial and academic pursuits (pharmacological applications, pest control etc.) and provides a biochemical tool for studying biological activities including cell signalling and immunological response. Neogastropod snails (cones, oyster drills etc.) are carnivorous and include active predators, scavengers, grazers on sessile invertebrates and hematophagous parasites; most of them use venoms to efficiently feed. It has been hypothesized that trophic innovations were the main drivers of rapid radiation of Neogastropoda in the late Cretaceous. We present here the first molecular characterization of the alimentary secretion of a non-conoidean neogastropod, Colubraria reticulata. Colubrariids successfully feed on the blood of fishes, throughout the secretion into the host of a complex mixture of anaesthetics and anticoagulants. We used a NGS RNA-Seq approach, integrated with differential expression analyses and custom searches for putative secreted feeding-related proteins, to describe in detail the salivary and mid-oesophageal transcriptomes of this Mediterranean vampire snail, with functional and evolutionary insights on major families of bioactive molecules. A remarkably low level of overlap was observed between the gene expression in the two target tissues, which also contained a high percentage of putatively secreted proteins when compared to the whole body. At least 12 families of feeding-related proteins were identified, including: 1) anaesthetics, such as ShK Toxin-containing proteins and turripeptides (ion-channel blockers), Cysteine-rich secretory proteins (CRISPs), Adenosine Deaminase (ADA); 2) inhibitors of primary haemostasis, such as novel vWFA domain-containing proteins, the Ectonucleotide pyrophosphatase/phosphodiesterase family member 5 (ENPP5) and the wasp Antigen-5; 3) anticoagulants, such as TFPI-like multiple Kunitz-type protease inhibitors, Peptidases S1 (PS1), CAP/ShKT domain-containing proteins, Astacin metalloproteases and Astacin/ShKT domain-containing proteins; 4) additional proteins, such the Angiotensin-Converting Enzyme (ACE: vasopressive) and the cytolytic Porins. Colubraria feeding physiology seems to involve inhibitors of both primary and secondary haemostasis, anaesthetics, a vasoconstrictive enzyme to reduce feeding time and tissue-degrading proteins such as Porins and Astacins. The complexity of Colubraria venomous cocktail and the divergence from the arsenal of the few neogastropods studied to date (mostly conoideans) suggest that biochemical diversification of neogastropods might be largely underestimated and worth of extensive investigation.
Anthony A. James - One of the best experts on this subject based on the ideXlab platform.
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RNA-seq analyses of blood-induced changes in gene expression in the mosquito vector species, Aedes aegypti
BMC genomics, 2011Co-Authors: Mariangela Bonizzoni, W. Augustine Dunn, Corey L. Campbell, Ken E. Olson, Michelle Dimon, Osvaldo Marinotti, Anthony A. JamesAbstract:Background Hematophagy is a common trait of insect vectors of disease. Extensive genome-wide transcriptional changes occur in mosquitoes after blood meals, and these are related to digestive and reproductive processes, among others. Studies of these changes are expected to reveal molecular targets for novel vector control and pathogen transmission-blocking strategies. The mosquito Aedes aegypti (Diptera, Culicidae), a vector of Dengue viruses, Yellow Fever Virus (YFV) and Chikungunya virus (CV), is the subject of this study to look at genome-wide changes in gene expression following a blood meal.
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Comparative genomics allows the discovery of cis-regulatory elements in mosquitoes
Proceedings of the National Academy of Sciences of the United States of America, 2009Co-Authors: Douglas H. Sieglaff, W. Augustine Dunn, Osvaldo Marinotti, Xiaohui Xie, Karyn Megy, Anthony A. JamesAbstract:The discovery and mapping of cis-regulatory elements is important for understanding regulation of gene transcription in mosquito vectors of human diseases. Genome sequence data are available for 3 species, Aedes aegypti, Anopheles gambiae, and Culex quinquefasciatus (Diptera: Culicidae), representing 2 subfamilies (Culicinae and Anophelinae) that are estimated to have diverged 145 to 200 million years ago. Comparative genomics tools were used to screen genomic DNA fragments located in the 5′-end flanking regions of orthologous genes. These analyses resulted in the identification of 137 sequences, designated “mosquito motifs,” 7 to 9 nucleotides in length, representing 18 families of putative cis-regulatory elements conserved significantly among the 3 species when compared to the fruit fly, Drosophila melanogaster. Forty-one of the motifs were implicated previously in experiments as sites for binding transcription factors or functioning in the regulation of mosquito gene expression. Further analyses revealed associations between specific motifs and expression profiles, particularly in those genes that show increased or decreased mRNA abundance in females following a blood meal, and those accumulating transcription products exclusively or preferentially in the midgut, fat bodies, or ovaries. These results validate the methodology and support a relationship between the discovered motifs and the conservation of Hematophagy in mosquitoes.
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Gene expression studies in mosquitoes.
Advances in genetics, 2008Co-Authors: Xiao-guang Chen, Geetika Mathur, Anthony A. JamesAbstract:Research on gene expression in mosquitoes is motivated by both basic and applied interests. Studies of genes involved in Hematophagy, reproduction, olfaction, and immune responses reveal an exquisite confluence of biological adaptations that result in these highly-successful life forms. The requirement of female mosquitoes for a bloodmeal for propagation has been exploited by a wide diversity of viral, protozoan and metazoan pathogens as part of their life cycles. Identifying genes involved in host-seeking, blood feeding and digestion, reproduction, insecticide resistance and susceptibility/refractoriness to pathogen development is expected to provide the bases for the development of novel methods to control mosquito-borne diseases. Advances in mosquito transgenesis technologies, the availability of whole genome sequence information, mass sequencing and analyses of transcriptomes and RNAi techniques will assist development of these tools as well as deepen the understanding of the underlying genetic components for biological phenomena characteristic of these insect species.
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Promoter-directed expression of recombinant fire-fly luciferase in the salivary glands of Hermes-transformed Aedes aegypti
Gene, 1999Co-Authors: Craig J. Coates, Nijole Jasinskiene, Gregory B. Pott, Anthony A. JamesAbstract:Molecular genetic analyses of biological properties characteristic of insect vectors of disease, such as Hematophagy and competence for pathogens, require the ability to isolate and characterize genes involved in these processes. We have been working to develop molecular approaches for studying the promoter function of genes that are expressed specifically in the adult salivary glands of the yellow fever mosquito, Aedes aegypti. Genomic DNA fragments containing cis-acting promoter elements from the Maltase-like I (MalI) and Apyrase (Apy) genes were cloned so as to direct the expression of the reporter gene, luciferase (luc). The function of the promoters was assayed transiently in cultured insect cells and by germ-line transformation of Ae. aegypti. MalI and Apy DNA fragments consisting of at least 650 nucleotides (nt) of DNA immediately adjacent to the 5'-end of the initiation codon of the mosquito genes directed constitutive expression of the luc reporter gene in cultured cells. When introduced into Ae. aegypti chromosomes, approximately 1.5 kilobases (kb) of each promoter were able to direct the predicted developmental-, sex- and tissue-specific expression of the reporter gene in patterns identical to those determined for the respective endogenous genes.
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Anticoagulants in vector arthropods.
Parasitology Today, 1996Co-Authors: Kenneth R. Stark, Anthony A. JamesAbstract:Abstract Arthropod-borne diseases cause significant morbidity and mortality worldwide. Mosquitoes alone may account for as many as three million deaths annually via the transmission of malaria. Because these diseases are transmitted to humans and to other vertebrates as a result of the ability of arthropods to feed on blood, the study of the biochemical mechanisms and adaptations that arthropods have evolved to facilitate Hematophagy may provide insight into how this feeding behavior contributes to the transmission of disease. In this review, Kenneth Stark and Anthony James examine the diversity of arthropod anticoagulants and their role in Hematophagy and potential implications for parasite transmission.
Geoffrey M. Attardo - One of the best experts on this subject based on the ideXlab platform.
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interpreting morphological adaptations associated with viviparity in the tsetse fly glossina morsitans westwood by three dimensional analysis
Insects, 2020Co-Authors: Geoffrey M. Attardo, Nicole Tam, Dula Parkinson, Lindsey K Mack, Xavier J Zahnle, Joceline Arguellez, Peter Takac, Anna R MalacridaAbstract:Tsetse flies (genus Glossina), the sole vectors of African trypanosomiasis, are distinct from most other insects, due to dramatic morphological and physiological adaptations required to support their unique biology. These adaptations are driven by demands associated with obligate Hematophagy and viviparous reproduction. Obligate viviparity entails intrauterine larval development and the provision of maternal nutrients for the developing larvae. The reduced reproductive capacity/rate associated with this biology results in increased inter- and intra-sexual competition. Here, we use phase contrast microcomputed tomography (pcMicroCT) to analyze morphological adaptations associated with viviparous biology. These include (1) modifications facilitating abdominal distention required during blood feeding and pregnancy, (2) abdominal and uterine musculature adaptations for gestation and parturition of developed larvae, (3) reduced ovarian structure and capacity, (4) structural features of the male-derived spermatophore optimizing semen/sperm delivery and inhibition of insemination by competing males and (5) structural features of the milk gland facilitating nutrient incorporation and transfer into the uterus. Three-dimensional analysis of these features provides unprecedented opportunities for examination and discovery of internal morphological features not possible with traditional microscopy techniques and provides new opportunities for comparative morphological analyses over time and between species.
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Grandeur Alliances: Symbiont Metabolic Integration and Obligate Arthropod Hematophagy.
Trends in Parasitology, 2016Co-Authors: Geoffrey M. Attardo, Brian L. WeissAbstract:Several arthropod taxa live exclusively on vertebrate blood. This food source lacks essential metabolites required for the maintenance of metabolic homeostasis, and as such, these arthropods have formed symbioses with nutrient-supplementing microbes that facilitate their host's ‘hematophagous' feeding ecology. Herein we highlight metabolic contributions of bacterial symbionts that reside within tsetse flies, bed bugs, lice, reduviid bugs, and ticks, with specific emphasis on B vitamin and cofactor biosynthesis. Importantly, these arthropods can transmit pathogens of medical and veterinary relevance and/or cause infestations that induce psychological and dermatological distress. Microbial metabolites, and the biochemical pathways that generate them, can serve as specific targets of novel control mechanisms aimed at disrupting the metabolism of hematophagous arthropods, thus combatting pest invasion and vector-borne pathogen transmission.
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Emerging roles of aquaporins in relation to the physiology of blood-feeding arthropods
Journal of Comparative Physiology B, 2014Co-Authors: Joshua B. Benoit, Elise M. Szuter, Immo A. Hansen, Lisa L. Drake, Denielle L. Burnett, Geoffrey M. AttardoAbstract:Aquaporins (AQPs) are proteins that span plasma membranes allowing the movement of water and small solutes into or out of cells. The type, expression levels and activity of AQPs play a major role in the relative permeability of each cell to water or other solutes. Research on arthropod AQPs has expanded in the last 10 years due to the completion of several arthropod genome projects and the increased availability of genetic information accessible through other resources such as de novo transcriptome assemblies. In particular, there has been significant advancement in elucidating the roles that AQPs serve in relation to the physiology of blood-feeding arthropods of medical importance. The focus of this review is upon the significance of AQPs in relation to Hematophagy in arthropods. This will be accomplished via a narrative describing AQP functions during the life history of hematophagic arthropods that includes the following critical phases: (1) Saliva production necessary to blood feeding, (2) Intake and excretion of water during blood digestion, (3) Reproduction and egg development and (4) Off-host environmental stress tolerance. The concentration on these phases will highlight known vulnerabilities in the biology of hematophagic arthropods that could be used to develop novel control strategies as well as research topics that have yet to be examined.