scholarly journals The ecdysteroid receptor regulates salivary gland degeneration through apoptosis in Rhipicephalus haemaphysaloides

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Xiaojuan Lu ◽  
Zhipeng Zhang ◽  
Dongqi Yuan ◽  
Yongzhi Zhou ◽  
Jie Cao ◽  
...  

Abstract Background It is well established that ecdysteroid hormones play an important role in arthropod development and reproduction, mediated by ecdysteroid receptors. Ticks are obligate hematophagous arthropods and vectors of pathogens. The salivary gland plays an essential role in tick growth and reproduction and in the transmission of pathogens to vertebrate hosts. During tick development, the salivary gland undergoes degeneration triggered by ecdysteroid hormones and activated by apoptosis. However, it is unknown how the ecdysteroid receptor and apoptosis regulate salivary gland degeneration. Here, we report the functional ecdysteroid receptor (a heterodimer of the ecdysone receptor [EcR] and ultraspiracle [USP]) isolated from the salivary gland of the tick Rhipicephalus haemaphysaloides and explore the molecular mechanism of ecdysteroid receptor regulation of salivary gland degeneration. Methods The full length of RhEcR and RhUSP open reading frames (ORFs) was obtained from the transcriptome. The RhEcR and RhUSP proteins were expressed in a bacterial heterologous system, Escherichia coli. Polyclonal antibodies were produced against synthetic peptides and were able to recognize recombinant and native proteins. Quantitative real-time PCR and western blot were used to detect the distribution of RhEcR, RhUSP, and RhCaspases in the R. haemaphysaloides organs. A proteomics approach was used to analyze the expression profiles of the ecdysteroid receptors, RhCaspases, and other proteins. To analyze the function of the ecdysteroid receptor, RNA interference (RNAi) was used to silence the genes in adult female ticks. Finally, the interaction of RhEcR and RhUSP was identified by heterologous co-expression assays in HEK293T cells. Results We identified the functional ecdysone receptor (RhEcR/RhUSP) of 20-hydroxyecdysone from the salivary gland of the tick R. haemaphysaloides. The RhEcR and RhUSP genes have three and two isoforms, respectively, and belong to a nuclear receptor family but with variable N-terminal A/B domains. The RhEcR gene silencing inhibited blood-feeding, blocked engorgement, and restrained salivary gland degeneration, showing the biological role of the RhEcR gene in ticks. In the ecdysteroid signaling pathway, RhEcR silencing inhibited salivary gland degeneration by suppressing caspase-dependent apoptosis. The heterologous expression in mammalian HEK293T cells showed that RhEcR1 interacts with RhUSP1 and induces caspase-dependent apoptosis. Conclusions These data show that RhEcR has an essential role in tick physiology and represents a putative target for the control of ticks and tick-borne diseases. Graphical Abstract

2021 ◽  
Author(s):  
Shanming Hu ◽  
Yanan Wang ◽  
Zhengmao Xu ◽  
Yongzhi Zhou ◽  
Jie Cao ◽  
...  

Abstract BackgroundThe salivary gland of female ticks degenerates rapidly by apoptosis and autophagy after feeding. Bcl-2 family proteins play an important role in the apoptosis pathways but the functions of these proteins in ticks are unclear. We studied Bcl-2 and Bax homologs from the tick Rhipicephalus haemaphysaloides and determined their functions in the degeneration of the salivary glands.MethodsThe full-length cDNA of the RhBcl-2 and RhBax genes were obtained by transcriptome analysis and RhBcl-2 and RhBax were expressed in E. coli. Two molecules containing conserved BH (Bcl-2 family homology) domains were identified and named RhBcl-2 and RhBax. After protein purification and mouse immunizations, specific polyclonal antibodies (PcAb) were created in response to the recombinant protein. Reverse transcription quantitative PCR (RT-qPCR) and western blot were used to detect the existence of RhBcl-2 and RhBax in ticks. TUNEL assays were used to determine the apoptosis level in the salivary glands at different feeding times after gene silencing. The interactions between RhBcl-2 and RhBax were identified by co-transfection and GST pull-down assays. The RT-qPCR assay demonstrated that the transcription of RhBax genes increased significantly during the engorged periods of the tick developmental stages (engorged larval, nymph, and adult female ticks). ResultsTranscriptional levels of RhBcl-2 and RhBax in the salivary glands increased more significantly than other tissues post engorgement. RhBcl-2 treatment significantly restrained tick feeding. In contrast, RhBax interference had no effect on tick feeding. TUNEL staining showed that apoptosis levels were significantly reduced after interfering with RhBcl-2 expression. Co-transfection and GST pull-down assays showed that RhBcl-2 and RhBax could combine with each other, but failed to combine without the BH3 domain. ConclusionsThis study identified the roles of RhBcl-2 and RhBax in tick salivary gland degeneration and clarifies their interactions.


2021 ◽  
Author(s):  
Kathryn Bartley ◽  
Wan Chen ◽  
Richard Lloyd Mills ◽  
Francesca Nunn ◽  
Daniel Price ◽  
...  

Abstract Background: The blood feeding poultry red mite (PRM), Dermanyssus gallinae, causes substantial economic damage to the egg laying industry worldwide, and is serious welfare concern for laying hens and poultry house workers. In this study we have investigated the temporal gene expression across the 6 stages/sexes (egg, larvae, protonymph and deutonymph, adult male and adult female) of this neglected parasite in order to understand the temporal expression associated with development, parasitic lifestyle, reproduction and allergen expression. Results: RNA-seq transcript data for the 6 stages was mapped to the PRM genome creating a publicly available gene expression atlas (on the OrcAE platform in conjunction with the PRM genome). Network analysis and clustering of stage-enriched gene expression in PRM resulted in 17 superclusters with stage-specific or multi-stage expression profiles. The 6 stage specific superclusters were clearly demarked from each other and the adult female supercluster contained the most stage specific transcripts (2,725), whilst the protonymph supercluster the fewest (165). Fifteen pairwise comparisons performed between the different stages resulting in a total of 6025 Differentially Expressed Genes (DEGs) (P>0.99). These data were evaluated alongside a Venn/Euler analysis of the top 100 most abundant genes in each stage. An expanded set of cuticle proteins and enzymes (chitinase and metallacarboxypeptidases) were identified in larvae and underpin cuticle formation and ecdysis to the protonymph stage. Two mucin/peritrophic-A salivary proteins (DEGAL6771g00070, DEGAL6824g00220) were highly expressed in the blood-feeding stages, indicating peritrophic membrane formation during feeding. Reproduction-associated vitellogenins were the most abundant transcripts in adult females, whilst in adult males, an expanded set of serine and cysteine proteinases and an epididymal protein (DEGAL6668g00010) were highly abundant. Assessment of the expression patterns of putative homologues of 32 allergen groups described for the house dust mites indicated a bias in expression towards the non-feeding larval stage.Conclusions: This study is the first evaluation of temporal gene expression across all stages of PRM and has provided insight into developmental, feeding, reproduction and survival strategies employed by this mite. The publicly available PRM resource on OrcAE offers an invaluable tool for researchers investigating the biology and novel interventions of this parasite.


Author(s):  
Seena Kumari ◽  
Tanwee Das De ◽  
Charu Chauhan ◽  
Jyoti Rani ◽  
Sanjay Tevatiya ◽  
...  

AbstractIn the adult female mosquito, successful blood meal acquisition is accomplished by salivary glands, which releases a cocktail of proteins to counteract vertebrate host’s immune-homeostasis. However, the biological relevance of many salivary proteins remains unknown. Here, we characterize a salivary specific Heme peroxidase family member HPX12, originally identified from Plasmodium vivax infected salivary RNAseq data of the mosquito Anopheles stephensi. We demonstrate that dsRNA silencing mediated mRNA depletion of salivary AsHPX12 (80-90%), causes enhanced host attraction but reduced blood-meal acquisition abilities, by increasing probing propensity (31%), as well as probing time (100–200s, P<0.0001) as compared to control (35-90s) mosquitoes group. Altered expression of the salivary secretory and antennal proteins may account for an unusual fast release of salivary cocktail proteins, but the slowing acquisition of blood meal, possibly due to salivary homeostasis disruption of AsHPX12 silenced mosquitoes. A parallel transcriptional modulation in response to blood feeding and P. vivax infection, further establish a possible functional correlation of AsHPX12 role in salivary immune-physiology and Plasmodium sporozoites survival/transmission. We propose that salivary HPX12 may have a vital role in the management of ‘pre- and post’-blood meal associated physiological-homeostasis and parasite transmission.Graphical abstractFigure 1:Schematic representation of mosquito’s blood meal acquisition and upshot on blood-feeding after silencing of salivary gland HPX-12. (A) After landing over host skin, mosquito mouthparts (proboscis) actively engaged to search, probe, and pierce the skin followed by a rapid release of the pre-synthesized salivary cocktail, which counteracts the host homeostasis, inflammation, and immune responses, during blood meal uptake. (B) Silencing of HPX-12 disrupts salivary gland homeostasis, enhancing mosquito attraction, possibly by up-regulating odorant-binding proteins genes-OBP-7,10 and OBP-20 expression in the Olfactory System. However, HPX-12 disruption may also cause significant effects on pre-blood meal associated probing abilities, which may be due to fast down-regulation of salivary cocktail proteins such as Anopheline, Apyrase, D7L proteins.


2020 ◽  
Vol 58 (2) ◽  
pp. 161-171
Author(s):  
Qi Xiao ◽  
Yuhong Hu ◽  
Xiaohong Yang ◽  
Jianna Tang ◽  
Xiaoshuang Wang ◽  
...  

The ticks feed large amount of blood from their hosts and transmit pathogens to the victims. The salivary gland plays an important role in the blood feeding. When the female ticks are near engorgement, the salivary gland gradually loses its functions and begins to rapidly degenerate. In this study, data-independent acquisition quantitative proteomics was used to study changes in the phosphorylation modification of proteins during salivary gland degeneration in <i>Haemaphysalis longicornis</i>. In this quantitative study, 400 phosphorylated proteins and 850 phosphorylation modification sites were identified. Trough RNA interference experiments, we found that among the proteins with changes in phosphorylation, apoptosis-promoting Hippo protein played a role in salivary gland degeneration.


1992 ◽  
Vol 165 (1) ◽  
pp. 61-71 ◽  
Author(s):  
J. M. Ribeiro

Salivary gland homogenates and oil-induced saliva of the mosquito Aedes aegypti dilate the rabbit aortic ring and contract the guinea pig ileum. The vasodilatory activity is endothelium-dependent, heat-stable, sensitive to both trypsin and chymotrypsin treatments, and both smooth muscle activities cross-desensitize to the tachykinin peptide substance P. Both bioactivities co-elute when salivary gland homogenates are fractionated by reversed-phase HPLC. Molecular sieving chromatography indicates a relative molecular mass of 1400. A monoclonal antibody specific to the carboxy terminal region of tachykinins reacts with material in the posterior part of the central lobe of paraformaldehyde-fixed salivary glands. The presence of a vasodilatory peptide of the tachykinin family in the salivary glands of A. aegypti is proposed and its role in blood feeding is discussed.


2021 ◽  
Author(s):  
Jose Manuel Latorre Estivalis ◽  
Ewald Grosse-Wilde ◽  
Gabriel R Fernandes ◽  
Bill S Hansson ◽  
Marcelo Gustavo Lorenzo

Background Triatomine bugs are the blood feeding insect vectors transmitting Chagas disease to humans, a neglected tropical disease that affects over 8 million people, mainly in Latin America. The behavioral responses to host cues and bug signals in Rhodnius prolixus are state dependent, i.e., they vary as a function of post-ecdysis age. At the molecular level, these changes in behavior are probably due to a modulation of peripheral and central processes. In the present study, we report a significant modulation of the expression of a large set of sensory-related genes. Results were generated by means of antennal transcriptomes of 5th instar larvae along the first week (days 0, 2, 4, 6 and 8) after ecdysis sequenced using the Illumina platform. Results Age induced significant changes in transcript abundance were established in more than 6,120 genes (54,7 % of 11,186 genes expressed) in the R. prolixus antenna. This was especially true between the first two days after ecdysis when more than 2,500 genes had their expression significantly altered. In contrast, expression profiles were almost identical between day 6 and 8, with only a few genes showing significant modulation of their expression. A total of 86 sensory receptors, odorant carriers and odorant degrading enzymes were significantly modulated across age points and clustered into three distinct expression profiles. Conclusions The set of sensory genes whose expression increased with age (profile 3) may include candidates underlying the increased responsiveness to host cues shown by R. prolixus during the first days after molting. For the first time, we describe the maturation process undergone at the molecular level by the peripheral sensory system is described in an hemimetabolous insect.


2020 ◽  
Vol 8 (6) ◽  
pp. 888
Author(s):  
Justas Vaitekūnas ◽  
Renata Gasparavičiūtė ◽  
Jonita Stankevičiūtė ◽  
Gintaras Urbelis ◽  
Rolandas Meškys

N-Heterocyclic compounds are widely spread in the biosphere, being constituents of alkaloids, cofactors, allelochemicals, and artificial substances. However, the fate of such compounds including a catabolism of hydroxylated pyridines is not yet fully understood. Arthrobacter sp. IN13 is capable of using 4-hydroxypyridine as a sole source of carbon and energy. Three substrate-inducible proteins were detected by comparing protein expression profiles, and peptide mass fingerprinting was performed using MS/MS. After partial sequencing of the genome, we were able to locate genes encoding 4-hydroxypyridine-inducible proteins and identify the kpi gene cluster consisting of 16 open reading frames. The recombinant expression of genes from this locus in Escherichia coli and Rhodococcus erytropolis SQ1 allowed an elucidation of the biochemical functions of the proteins. We report that in Arthrobacter sp. IN13, the initial hydroxylation of 4-hydroxypyridine is catalyzed by a flavin-dependent monooxygenase (KpiA). A product of the monooxygenase reaction is identified as 3,4-dihydroxypyridine, and a subsequent oxidative opening of the ring is performed by a hypothetical amidohydrolase (KpiC). The 3-(N-formyl)-formiminopyruvate formed in this reaction is further converted by KpiB hydrolase to 3-formylpyruvate. Thus, the degradation of 4-hydroxypyridine in Arthrobacter sp. IN13 was analyzed at genetic and biochemical levels, elucidating this catabolic pathway.


2009 ◽  
Vol 16 (7) ◽  
pp. 639-646 ◽  
Author(s):  
Tomohiro Ueda ◽  
Hiroyuki Manabe ◽  
Keizo Tokuhiro ◽  
Mika Hirose ◽  
Yasuhiro Matsuoka ◽  
...  

2010 ◽  
Vol 25 (1) ◽  
pp. 32-37 ◽  
Author(s):  
Nelly N. Hashem ◽  
Thomas W. Mara ◽  
Mohamed Mohamed ◽  
Irene Zhang ◽  
Kevin Fung ◽  
...  

Objective To analyze the expression of human kallikrein 14 (KLK14) in salivary gland tumors. Methods A standard immunoperoxidase staining technique was used to assess the expression profile of KLK14 in normal salivary glands and tumors including pleomorphic adenoma (PA; n=17), adenoid cystic carcinoma (ACC; n=13) and mucoepidermoid carcinoma (MEC; n=9). Tumor stage, grade, patient age and gender, and site of occurrence were recorded. These clinical parameters were correlated with KLK14 levels in malignant tumors. The expression profiles for KLK3, 5, 6, 8 and 13 were also retrieved. Results Normal salivary glands, PA, ACC and MEC showed strong expression of KLK14 in ductal and non-ductal cells. Both PA and ACC showed higher KLK14 levels than normal glands and MEC tissues. There were no statistically significant associations between levels of KLK14 and clinical parameters. Conclusions The differences in the levels of KLK14 suggest that KLKs may aid in the differential diagnosis of salivary gland tumors. The coexpression of KLKs suggests their possible involvement in an enzymatic pathway activated in salivary gland. KLK14 may be a promising new biomarker in salivary gland tumors.


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