scholarly journals Microbiome-Gut-Brain-Axis Communication Influences Metabolic Switch in the Mosquito Anopheles Culicifacies

Author(s):  
RAJNIKANT DIXIT

Abstract Periodic ingestion of a protein-rich blood meal by adult female mosquitoes causes a drastic metabolic change in their innate physiological status, which is referred to as ‘metabolic switch. Although the down-regulation of olfactory factors is key to restrain host-attraction, how the gut ‘metabolic switch’ modulates brain functions, and resilience physiological homeostasis remains unexplored. Here we demonstrate that the protein-rich diet induces the expression of brain transcripts related to mitochondrial function and energy metabolism, possibly to cause a shift of the brain’s engagement to manage organismal homeostasis. A dynamic expression pattern of neuro-signalling and neuro-modulatory genes in both gut and brain, establishes an active brain-distant organ communication. Disruption of this comunication through decapitation, does not affect the modulation of the neuro-modulator receptor genes in the gut. In parallel, an unusual and paramount shift in the level of the Neurotransmitters (NTs), from the brain to the gut after blood feeding, further supports the idea of the gut’s ability to serve as a ‘second brain’. Finally, a comparative metagenomics evaluation of gut microbiome population dynamics, highlighted that blood-feeding not only suppresses Enterobacteriaceae family member by 50%, but favors rapid proliferation of Pseudomonadales to 46% of the total community. Notable obesrvation of a rapid proliferation of Pseudomonas bacterial sp. in the gut correlates a possible cause for the suppression of appetite after blood-feeding. Additionally, an altered NTs dynamics of naïve and aseptic mosquitoes provide the initial evidence that gut-endosymbionts are key modulators for the synthesis of major neuroactive molecules. Conclusion: Our data establish a new conceptual understanding of microbiome-gut-brain-axis communication in mosquitoes.Data deposition: Mosquito Brain RNAseq data are accessible under Accession IDs: SRR9853884 (Ac-Br-SF); SRR9853885 (Ac-Br-BF-30Min), SRR9853883 (Ac-Br-BF-30hrs) at NCBI repository. Mosquito Gut metagenomics data are accessible under accession IDs: SRR12579422 (Ac-MG-SF); SRR12622557 (Ac-MG-BF) at NCBI repository.

2019 ◽  
Author(s):  
Tanwee Das De ◽  
Punita Sharma ◽  
Sanjay Tevatiya ◽  
Charu Chauhan ◽  
Seena Kumari ◽  
...  

AbstractPeriodic ingestion of a protein-rich blood meal by adult female mosquitoes causes a drastic metabolic change in their innate physiological status, which is referred to as ‘metabolic switch. Although the down-regulation of olfactory factors is key to restrain host-attraction, how the gut ‘metabolic switch’ modulates brain functions, and resilience physiological homeostasis remains unexplored. Here, we demonstrate that the protein-rich diet induces mitochondrial function and energy metabolism, possibly shifting the brain’s engagement to manage organismal homeostasis. A dynamic expression pattern of neuro-signaling and neuro-modulatory genes in both the brain and gut indicates an optimal brain-distant organ communication. Even after decapitation, significant modulation of the neuro-modulator receptor genes as well as quantitative estimation of neurotransmitters (NTs), together confer the gut’s ability to serve as a ‘second brain’. Finally, data on comparative metagenomic analysis and altered NTs dynamics of naïve and aseptic mosquitoes provide the initial evidence that gut-endosymbionts are key modulators for the synthesis of major neuroactive molecules. Conclusively, our data establish a new conceptual understanding of microbiome-gut-brain-axis communication in mosquitoes.Abstract FigureGraphical abstractHighlightsHighly proteinaceous blood meal uptake causes gut ‘metabolic switch’ activity in mosquitoes.Gut’s calling shifts the brain’s administrative function from external communication to inter-organ management.‘Gut’, as a ‘Second brain’ plays a crucial role in the maintenance of physiological homeostasis.Metabolic switch and proliferation of symbiotic bacteria establish microbiome-gut-brain axis communication in mosquitoes.


2021 ◽  
Author(s):  
Tanwee Das De ◽  
Punita Sharma ◽  
Sanjay Tevatiya ◽  
Charu Chauhan ◽  
Seena Kumari ◽  
...  

Abstract Background: Periodic ingestion of a protein-rich blood meal by adult female mosquitoes causes a drastic metabolic change in their innate physiological status, which is referred to as ‘metabolic switch. Although the down-regulation of olfactory factors is key to restrain host-attraction, how the gut ‘metabolic switch’ modulates brain functions, and resilience physiological homeostasis remains unexplored. Methods: To uncover a possible correlation of gut metabolic switching and brain function, we carried out a comparative RNAseq analysis of naïve and blood-fed mosquito’s brain. Spatio-temporal expression of neuro-signaling and neuro-modulatory genes was monitored through Real-Time PCR. To establish a proof-of-concept, we followed LC/MS-based absolute quantification of different neurotransmitters (NT) and compared their levels in the brain as well as in the gut of the mosquitoes. To correlate how microbiome influences gut-brain-axis communication, we performed a comparative gut metagenomic analysis. Results: Our findings demonstrate that the protein-rich diet induces the expression of brain transcripts related to mitochondrial function and energy metabolism, possibly to cause a shift of the brain’s engagement to manage organismal homeostasis. A dynamic expression pattern of neuro-signaling and neuro-modulatory genes in both gut and brain, presumably a key to establish an active brain-distant organ communication. Disruption of this comunication through decapitation, does not affect the modulation of the neuro-modulator receptor genes in the gut. In parallel, an unusual and paramount shift in the level of the Neurotransmitters (NTs), from the brain to the gut after blood feeding, further supports the idea of the gut’s ability to serve as a ‘second brain’. Finally, a comparative metagenomics evaluation of gut microbiome population dynamics, highlighted that blood-feeding not only suppresses Enterobacteriaceae family member by 50%, but favors rapid proliferation of Pseudomonadales to 46% of the total community. Notable obesrvation of a rapid proliferation of Pseudomonas bacterial sp. in the gut correlates a possible cause for the suppression of appetite after blood-feeding. Additionally, an altered NTs dynamics of naïve and aseptic mosquitoes provide the initial evidence that gut-endosymbionts are key modulators for the synthesis of major neuroactive molecules. Conclusion: Our data establish a new conceptual understanding of microbiome-gut-brain-axis communication in mosquitoes.


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.


Insects ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 200 ◽  
Author(s):  
Rik Clymans ◽  
Vincent Van Kerckvoorde ◽  
Eva Bangels ◽  
Wannes Akkermans ◽  
Ammar Alhmedi ◽  
...  

Worldwide monitoring programs of the invasive fruit pest Drosophila suzukii Matsumura (Diptera: Drosophilidae), using fermentation baits like apple cider vinegar (ACV), revealed a counterintuitive period of low trap catches during summer, followed by an autumn peak. In this study, we demonstrate that ACV baited traps indeed provide a distorted image of the D. suzukii population dynamics as it is possible to capture higher numbers during this “low capture period” with synthetic lures. It was hypothesised that the preference of D. suzukii populations for fermentation cues like ACV is most pronounced during autumn, winter and spring, while the flies prefer fresh fruit cues during summer and that this seasonal preference is related to the changing physiology of the flies over the season. To test this hypothesis, the preference between fermentation cues (ACV) and host fruits (strawberries) and the effect of physiology (sex, seasonal morphology and feeding, mating and reproductive status) was investigated both in olfactometer laboratory experiments and a year-round field preference experiment. In olfactometer experiments we demonstrated that protein deprived females, virgin females with a full complement of unfertilised eggs and males show a strong preference for fermentation cues while fully fed reproductive summer morph females generally prefer fruit cues. These findings indicate that D. suzukii is attracted to fermentation volatiles in search of (protein-rich) food and to fruit volatiles in search of oviposition substrates. Winter morph and starved females displayed indiscriminating olfactory behaviour. In the field preference experiment, the hypothesised seasonal shift between fermentation and fruit cues was confirmed. This shift appeared to be highly temperature-related and was similarly observed for summer and winter morphs.


2020 ◽  
Vol 21 (13) ◽  
pp. 1371-1384 ◽  
Author(s):  
Vivek K. Sharma ◽  
Thakur G. Singh ◽  
Shareen Singh

Defects in brain functions associated with aging and neurodegenerative diseases benefit insignificantly from existing options, suggesting that there is a lack of understanding of pathological mechanisms. Alzheimer’s disease (AD) is such a nearly untreatable, allied to age neurological deterioration for which only the symptomatic cure is available and the agents able to mould progression of the disease, is still far away. The altered expression of phosphodiesterases (PDE) and deregulated cyclic nucleotide signaling in AD has provoked a new thought of targeting cyclic nucleotide signaling in AD. Targeting cyclic nucleotides as an intracellular messenger seems to be a viable approach for certain biological processes in the brain and controlling substantial. Whereas, the synthesis, execution, and/or degradation of cyclic nucleotides has been closely linked to cognitive deficits. In relation to cognition, the cyclic nucleotides (cAMP and cGMP) have an imperative execution in different phases of memory, including gene transcription, neurogenesis, neuronal circuitry, synaptic plasticity and neuronal survival, etc. AD is witnessed by impairments of these basic processes underlying cognition, suggesting a crucial role of cAMP/cGMP signaling in AD populations. Phosphodiesterase inhibitors are the exclusive set of enzymes to facilitate hydrolysis and degradation of cAMP and cGMP thereby, maintains their optimum levels initiating it as an interesting target to explore. The present work reviews a neuroprotective and substantial influence of PDE inhibition on physiological status, pathological progression and neurobiological markers of AD in consonance with the intensities of cAMP and cGMP.


2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Shih-Yen Chen ◽  
Chi-Neu Tsai ◽  
Yun-Shien Lee ◽  
Chun-Yuan Lin ◽  
Kuan-Yeh Huang ◽  
...  

Abstract The aim of the present study was to evaluate the microbiota of children with severe or complicated acute viral gastroenteritis (AGE). To that end, next-generation sequencing (NGS) technology was used to sequence the 16S ribosomal RNA (16S rRNA) gene in 20 hospitalized pediatric patients with severe or complicated AGE and a further 20 otherwise healthy children; the fecal microbiome was then assessed. Comparative metagenomics data were analyzed by a Wilcoxon rank–sum test and hierarchical clustering analysis of bacterial reads. The statistical analyses showed a significantly decreased Shannon diversity index (entropy score) of the intestinal microbiota in patients with severe AGE compared with normal controls (P = 0.017) and patients with mild-to-moderate AGE (P = 0.011). The intestinal microbiota score of the 5 patients with rotavirus AGE was significantly lower than that of those with norovirus infection (P = 0.048). Greater richness in Campylobacteraceae (P = 0.0003), Neisseriaceae (P = 0.0115), Methylobacteriaceae (P = 0.0004), Sphingomonadaceae (P = 0.0221), and Enterobacteriaceae (P = 0.0451) was found in patients with complicated AGE compared with normal controls. The data suggest a significant reduction in intestinal microbial diversity in patients with severe AGE, particularly those with rotavirus infection.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fabiola Claudio-Piedras ◽  
Benito Recio-Tótoro ◽  
Jorge Cime-Castillo ◽  
Renaud Condé ◽  
Massimo Maffei ◽  
...  

AbstractThe cuticular hydrocarbon (CHC) profile reflects the insects’ physiological states. These include age, sex, reproductive stage, and gravidity. Environmental factors such as diet, relative humidity or exposure to insecticides also affect the CHC composition in mosquitoes. In this work, the CHC profile was analyzed in two Anopheles albimanus phenotypes with different degrees of susceptibility to Plasmodium, the susceptible-White and resistant-Brown phenotypes, in response to the two dietary regimes of mosquitoes: a carbon-rich diet (sugar) and a protein-rich diet (blood) alone or containing Plasmodium ookinetes. The CHCs were analyzed by gas chromatography coupled to mass spectrometry or flame ionization detection, identifying 19 CHCs with chain lengths ranging from 20 to 37 carbons. Qualitative and quantitative changes in CHCs composition were dependent on diet, a parasite challenge, and, to a lesser extent, the phenotype. Blood-feeding caused up to a 40% reduction in the total CHC content compared to sugar-feeding. If blood contained ookinetes, further changes in the CHC profile were observed depending on the Plasmodium susceptibility of the phenotypes. Higher infection prevalence caused greater changes in the CHC profile. These dietary and infection-associated modifications in the CHCs could have multiple effects on mosquito fitness, impacts on disease transmission, and tolerance to insecticides.


Parasitology ◽  
2000 ◽  
Vol 120 (2) ◽  
pp. 195-202 ◽  
Author(s):  
C. E. KELLY ◽  
C. R. KENNEDY ◽  
J. A. BROWN

The effect of the parasitic swimbladder nematode, Anguillicola crassus, on the physiological status of wild European eels (Anguilla anguilla) was investigated during an 18 month survey (February 1995 until September 1996), and compared with that of wild uninfected eels collected over the same time-period. Despite the occurrence of up to 15 blood-feeding adults in the swimbladder lumen of the infected eels and as many as 25 additional larvae in the swimbladder wall, there were no major differences in hormonal, metabolic or osmoregulatory status of the 2 groups of eels. Wild European eels appear to adapt to chronic parasitism with Anguillicola crassus. The possible adverse effects of additional simultaneous stressors are discussed.


Author(s):  
H. J. Kirch ◽  
G. Spates ◽  
R. Droleskey ◽  
W.J. Kloft ◽  
J.R. DeLoach

Blood feeding insects have to rely on the protein content of mammalian blood to insure reproduction. A substantial quantity of protein is provided by hemoglobin present in erythrocytes. Access to hemoglobin is accomplished only via erythrocyte lysis. It has been shown that midgut homogenates from the blood feeding stable fly, Stomoxys calcitrans, contain free fatty acids and it was proposed that these detergent-like compounds play a major role as hemolysins in the digestive physiology of this species. More recently sphingomyelinase activity was detected in midgut preparations of this fly, which would provide a potential tool for the enzymatic cleavage of the erythrocyte's membrane sphingomyelin. The action of specific hemolytic factors should affect the erythrocyte's morphology. The shape of bovine erythrocytes undergoing in vitro hemolysis by crude midgut homogenates from the stable fly was examined by scanning and transmission electron microscopy.


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