Honey bee promoter sequences for targeted gene expression

The honey bee, Apis mellifera, displays a rich behavioural repertoire, social organization and caste differentiation, and has an interesting mode of sex determination, but we still know little about its underlying genetic programs. We lack stable transgenic tools in honey bees that would allow genetic control of gene activity in stable transgenic lines. As an initial step towards a transgenic method, we identified promoter sequences in the honey bee that can drive constitutive, tissue‐specific and cold shock‐induced gene expression. We identified the promoter sequences of Am‐actin5c, elp2l, Am‐hsp83 and Am‐hsp70 and showed that, except for the elp2l sequence, the identified sequences were able to drive reporter gene expression in Sf21 cells. We further demonstrated through electroporation experiments that the putative neuron‐specific elp2l promoter sequence can direct gene expression in the honey bee brain. The identification of these promoter sequences is an important initial step in studying the function of genes with transgenic experiments in the honey bee, an organism with a rich set of interesting phenotypes.     

A honey bee can threat ear: Sudden sensorineural hearing loss

Sudden sensorineural hearing loss is an otologic emergency. Many etiological factors can lead to this pathology. Honey bee (Apis mellifera) sting may lead to local and systemic reactions due to sensitization of the patient. In this paper we described a sudden sensorineural hearing loss occurred after honey bee sting.     

Division of labour in honey bees: age‐ and task‐related changes in the expression of octopamine receptor genes

The honey bee (Apis mellifera L.) has developed into an important ethological model organism for social behaviour and behavioural plasticity. Bees perform a complex age‐dependent division of labour with the most pronounced behavioural differences occurring between in‐hive bees and foragers. Whereas nurse bees, for example, stay inside the hive and provide the larvae with food, foragers leave the hive to collect pollen and nectar for the entire colony. The biogenic amine octopamine appears to play a major role in division of labour but the molecular mechanisms involved are unknown. We here investigated the role of two characterized octopamine receptors in honey bee division of labour. AmOctαR1 codes for a Ca²⁺‐linked octopamine receptor. AmOctβR3/4 codes for a cyclic adenosine monophosphate‐coupled octopamine receptor. Messenger RNA expression of AmOctαR1 in different brain neuropils correlates with social task, whereas expression of AmOctβR3/4 changes with age rather than with social role per se. Our results for the first time link the regulatory role of octopamine in division of labour to specific receptors and brain regions. They are an important step forward in our understanding of complex behavioural organization in social groups.     

A Clinician's Primer on the Role of the Microbiome in Human Health and Disease

The importance of the commensal microbiota that colonizes the skin, gut, and mucosal surfaces of the human body is being increasingly recognized through a rapidly expanding body of science studying the human microbiome. Although, at first glance, these discoveries may seem esoteric, the clinical implications of the microbiome in human health and disease are becoming clear. As such, it will soon be important for practicing clinicians to have an understanding of the basic concepts of the human microbiome and its relation to human health and disease. In this Concise Review, we provide a brief introduction to clinicians of the concepts underlying this burgeoning scientific field and briefly explore specific disease states for which the potential role of the human microbiome is becoming increasingly evident, including Clostridium difficile infection, inflammatory bowel disease, colonization with multidrug-resistant organisms, obesity, allergic diseases, autoimmune diseases, and neuropsychiatric illnesses, and we also discuss current and future roles of microbiome restorative therapies.     

Fecal transplantation for ulcerative colitis: current evidence and future applications

ABSTRACT

Introduction: Established evidence suggests that gut microbiota plays a role in ulcerative colitis (UC). Fecal microbiota transplantation (FMT) is clearly recognized as a highly effective treatment for patients with recurrent Clostridium difficile infection and has been investigated also in patients with UC, with promising results.

Areas covered: Literature review was performed to select publications concerning current evidence on the role of gut microbiota in the pathogenesis of UC, and on the effectiveness of FMT in this disorder.

Expert opinion: The randomized controlled trials published investigating the use of FMT suggested a potential role for FMT in the treatment of mild to moderate UC. However, given several unanswered questions regarding donor selection, dose, route of administration and duration of therapy, this is not yet recommended as a viable therapy option. FMT has allowed for more in depth investigation with regards to the role the gut microbiota may be playing in UC. This knowledge is critical to identifying where FMT may appropriately fit in the UC treatment paradigm. As our understanding of the role the microbiome plays in this chronic disease, FMT, and then eventually defined microbes, will hopefully serve in a complementary role to conventional IBD therapies.     

Differential gene expression of two extreme honey bee (Apis mellifera) colonies showing varroa tolerance and susceptibility

Varroa destructor, an ectoparasitic mite of honey bees (Apis mellifera), is the most serious pest threatening the apiculture industry. In our honey bee breeding programme, two honey bee colonies showing extreme phenotypes for varroa tolerance/resistance (S88) and susceptibility (G4) were identified by natural selection from a large gene pool over a 6‐year period. To investigate potential defence mechanisms for honey bee tolerance to varroa infestation, we employed DNA microarray and real time quantitative (PCR) analyses to identify differentially expressed genes in the tolerant and susceptible colonies at pupa and adult stages. Our results showed that more differentially expressed genes were identified in the tolerant bees than in bees from the susceptible colony, indicating that the tolerant colony showed an increased genetic capacity to respond to varroa mite infestation. In both colonies, there were more differentially expressed genes identified at the pupa stage than at the adult stage, indicating that pupa bees are more responsive to varroa infestation than adult bees. Genes showing differential expression in the colony phenotypes were categorized into several groups based on their molecular functions, such as olfactory signalling, detoxification processes, exoskeleton formation, protein degradation and long‐chain fatty acid metabolism, suggesting that these biological processes play roles in conferring varroa tolerance to naturally selected colonies. Identification of differentially expressed genes between the two colony phenotypes provides potential molecular markers for selecting and breeding varroa‐tolerant honey bees.     

Expression of genes related to reproduction and pollen foraging in honey bees (Apis mellifera) narcotized with carbon dioxide

It has been proposed that a honey bee (Apis mellifera) worker's preference for foraging for pollen or nectar is modulated by a gene network that was originally involved in regulating the reproductive cycles of an ancestral solitary species. We used carbon dioxide to induce narcosis in queens and workers. This treatment is known to initiate oogenesis in queens, reduce oogenesis in queenless workers and to change worker foraging preference. We then assessed changes in gene expression of genes suspected to be involved in either foraging behaviour or reproduction. We show that some genes change expression in the opposite direction between castes in response to treatment. Our results therefore support the hypothesis that reproductive and foraging traits are causally related in the honey bee.     

Engineering the gut microbiota to treat hyperammonemia

Increasing evidence indicates that the gut microbiota can be altered to ameliorate or prevent disease states, and engineering the gut microbiota to therapeutically modulate host metabolism is an emerging goal of microbiome research. In the intestine, bacterial urease converts host-derived urea to ammonia and carbon dioxide, contributing to hyperammonemia-associated neurotoxicity and encephalopathy in patients with liver disease. Here, we engineered murine gut microbiota to reduce urease activity. Animals were depleted of their preexisting gut microbiota and then inoculated with altered Schaedler flora (ASF), a defined consortium of 8 bacteria with minimal urease gene content. This protocol resulted in establishment of a persistent new community that promoted a long-term reduction in fecal urease activity and ammonia production. Moreover, in a murine model of hepatic injury, ASF transplantation was associated with decreased morbidity and mortality. These results provide proof of concept that inoculation of a prepared host with a defined gut microbiota can lead to durable metabolic changes with therapeutic utility.     

Connecting the dots: Targeting the microbiome in drug toxicity

The gut microbiota has a vast influence on human health and its role in initiating, aggravating, or ameliorating diseases is beginning to emerge. Recently, its contribution to heterogeneous toxicological responses is also gaining attention, especially in drug-induced toxicity. Whether they are orally administered or not, drugs may interact with the gut microbiota directly or indirectly, which leads to altered toxicity. Present studies focus more on the unidirectional influence of how xenobiotics disturb intestinal microbial composition and functions, and thus induce altered homeostasis. However, interactions between the gut microbiota and xenobiotics are bidirectional and the impact of the gut microbiota on xenobiotics, especially on drugs, should not be neglected. Thus, in this review, we focus on how the gut microbiota modulates drug toxicity by highlighting the microbiome, microbial enzyme, and microbial metabolites. We connect the dots between drugs, the microbiome, microbial enzymes or metabolites, drug metabolites, and host toxicological responses to facilitate the discovery of microbial targets and mechanisms associated with drug toxicity. Besides this, current mainstream strategies to manipulate drug toxicity by targeting the microbiome are summarized and discussed. The review provides technical reference for the evaluation of medicinal properties in the research and development of innovative drugs, and for the future exploitation of strategies to reduce drug toxicity by targeting the microbiome.     

Update on gut microbiota in gastrointestinal diseases

The human gut is a complex microbial ecosystem comprising approximately 100 trillion microbes collectively known as the “gut microbiota”. At a rough estimate, the human gut microbiome contains almost 3.3 million genes, which are about 150 times more than the total human genes present in the human genome. The vast amount of genetic information produces various enzymes and physiologically active substances. Thus, the gut microbiota contributes to the maintenance of host health; however, when healthy microbial composition is perturbed, a condition termed “dysbiosis”, the altered gut microbiota can trigger the development of various gastrointestinal diseases. The gut microbiota has consequently become an extremely important research area in gastroenterology. It is also expected that the results of research into the gut microbiota will be applied to the prevention and treatment of human gastrointestinal diseases. A randomized controlled trial conducted by a Dutch research group in 2013 showed the positive effect of fecal microbiota transplantation (FMT) on recurrent Clostridioides difficile infection (CDI). These findings have led to the development of treatments targeting the gut microbiota, such as probiotics and FMT for inflammatory bowel diseases (IBD) and other diseases. This review focuses on the association of the gut microbiota with human gastrointestinal diseases, including CDI, IBD, and irritable bowel syndrome. We also summarize the therapeutic options for targeting the altered gut microbiota, such as probiotics and FMT.     

Genome‐wide analysis of genes related to ovary activation in worker honey bees

A defining characteristic of eusocial animals is their division of labour into reproductive and nonreproductive specialists. Here, we used a microarray study to identify genes associated with functional sterility in the worker honey bee Apis mellifera. We contrasted gene expression in workers from a functionally sterile wild‐type strain with that in a mutant (anarchist) strain selected for high rates of ovary activation. We identified a small set of genes from the brain (n = 7) and from the abdomen (n = 5) that are correlated in their expression with early stages of ovary activation. Sterile wild‐type workers up‐regulated two unknown genes and a homologue of Drosophila CG6004. By contrast, reproductive anarchist workers up‐regulated genes for the yolk protein vitellogenin, venom peptides and a member of the AdoHycase superfamily, among others. The differentially expressed genes identified are likely to be involved in early differentiation into sterile and reproductive worker phenotypes and may therefore form part of the gene networks associated with the regulation of honey bee worker sterility. Our study may have lacked sufficient power to detect all but a minority of biologically relevant changes taking place; however, the differential expression of vitellogenin and a putative AdoHycase suggests that our screen has captured core reproductive genes and that ovary activation may involve an epigenetic mechanism.     

Metagenomics and probiotics

The development of extensive sequencing methods has allowed metagenomic studies on the human gut microbiome to be carried out. This has tremendously increased our knowledge on gut microbiota composition and activity, allowing microbiota aberrations related to different diseases to be identified. These aberrations constitute targets for the development of probiotics directed to correct them. Probiotics are extensively used to modulate gut microbiota. Nevertheless, metagenomic studies on the effects of probiotics are still very scarce. In the near future, the use of metagenomics promises to expand our understanding of probiotic action.     

人体肠道微生物组与疾病研究:现状、机遇与挑战

微生物组是人体的第二基因组,能够决定人的健康状态。微生物组研究促进了人类对微生物群体与人体、生态环境关系的新认识。对人体肠道微生物组的组成和功能进行系统研究,解析相关核心菌群的互作关系和调控机制,将为解决人类面临的健康问题带来革命性的理论创新,由此产生颠覆性的技术革新,有望为微生物组研究提供更好的解决方案。     

Peptidoglycan recognition protein SC (PGRP-SC) shapes gut microbiota richness,diversity and composition by modulating immunity in the house fly Musca domestica

The gastrointestinal tract of all animals, including insects, is colonized by a remarkable array of microorganisms which are referred to collectively as the gut microbiota. The hosts establish mutually beneficial interactions with the gut microbiota. However, the mechanisms shaping these interactions remain to be better understood. Here, we investigated the roles of Musca domestica peptidoglycan recognition protein SC (MdPGRP-SC), a secreted pattern recognition receptor, in shaping the gut microbial community structure by using biochemical and high-throughput sequencing approaches. The recombinant MdPGRP-SC (rMdPGRP-SC) could strongly bind various pathogen-associated molecular patterns (PAMPs) including peptidoglycan, lipopolysaccharide and D-galactose, and exhibited mild affinity to β-1, 3-glucan and D-mannose. Meanwhile, rMdPGRP-SC could also bind different kinds of microorganisms, including gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus), gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and yeast (Pichia pastoris). rMdPGRP-SC also exhibited weak antibacterial activity against Bacillus subtilis. Knockdown of MdPGRP-SC by RNAi reduced the persistence of ingested E. coli and a load of indigenous microbiota in the larval gut significantly. In addition, depleted MdPGRP-SC also altered the gut microbiota composition and led to increased ratios of Gram-negative bacteria. We hypothesize that MdPGRP-SC is involved in maintaining gut homeostasis by modulating the immune intensity of the gut through multiple mechanisms, including degrading or neutralizing various PAMPs and selectively suppressing the growth of some bacteria. Considering the functional conservation of the peptidoglycan recognition protein (PGRP) family in insects, the catalytic PGRPs might be promising candidate targets not only for pest and vector control but also for the treatment of bacterial infection in insect farming.     

Association between metabolic profile and microbiomic changes in rats with functional dyspepsia

Functional dyspepsia (FD) is one of the most prevalent functional gastrointestinal disorders (FGIDs). Accumulated evidence has shown that FD is a metabolic disease that might relate to gut microbiota, but the relationship between microbiome and the host metabolic changes is still uncertain. To clarify the host–microbiota co-metabolism disorders related to FD, an integrated approach combining ¹H NMR-based metabolomics profiles, polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and 16S rRNA gene sequencing was used to investigate the relationship among FD, metabolism of gut microbiota and the host. 34 differential urinary metabolites and 19 differential fecal metabolites, which affected the metabolism of energy, amino acids, nucleotides and short chain fatty acids (SCFAs), were found to have associated with FD. Based on the receiver operating characteristic (ROC) analysis, 10 biomarkers were screened out as diagnostic markers of FD. Meanwhile, the concentrations of Flintibacter, Parasutterella, Eubacterium and Bacteroides significantly increased in the FD group, whereas Eisenbergiella, Butyrivibrio, Intestinimonas, Saccharofermentans, Acetivibrio, Lachnoanaerobaculum and Herbinix significantly decreased. Furthermore, the above altered microbiota revealed a strong correlation with the intermediate products of the tricarboxylic acid (TCA) cycle, amino acids and SCFAs. In our study, it suggested that the energy metabolism was mainly disturbed in FD rats. Our findings also demonstrated that FD might be the result of gut microbiota and metabolism disorders, which was potentially valuable to enrich our understanding of the pathogenesis of FD.

Functional dyspepsia (FD) is one of the most prevalent functional gastrointestinal disorders (FGIDs). The aim of our study was to evaluate the effects of FD on the microbiota and its metabolic profiles in feces and urine.     

Proteome profile and lentiviral transduction of cultured honey bee (Apis mellifera L.) cells

Honey bees (Apis mellifera L.) play a vital role in agriculture as pollinators, and serve as model organisms of social behaviour and immunity. The lack of both immortalized cell lines and methods to introduce recombinant DNA reliably into primary cells hinders cellular and molecular studies in this organism. We hereby demonstrate the expression of a GFP gene delivered by lentivirus transduction to cultured embryonic cells. The success of this approach indicates that viral transduction could be used to deliver constitutively active oncogenes in order to immortalize honey bee cells. We were able to revive cells successfully after several months of cryogenic storage and we show how the proteome varies between freshly collected and cultured embryonic cells.     

Obesity,Diabetes, and Gut Microbiota: The hygiene hypothesis expanded?

The connection between gut microbiota and energy homeostasis and inflammation and its role in the pathogenesis of obesity-related disorders are increasingly recognized. Animals models of obesity connect an altered microbiota composition to the development of obesity, insulin resistance, and diabetes in the host through several mechanisms: increased energy harvest from the diet, altered fatty acid metabolism and composition in adipose tissue and liver, modulation of gut peptide YY and glucagon-like peptide (GLP)-1 secretion, activation of the lipopolysaccharide toll-like receptor-4 axis, and modulation of intestinal barrier integrity by GLP-2. Instrumental for gut microbiota manipulation is the understanding of mechanisms regulating gut microbiota composition. Several factors shape the gut microflora during infancy: mode of delivery, type of infant feeding, hospitalization, and prematurity. Furthermore, the key importance of antibiotic use and dietary nutrient composition are increasingly recognized. The role of the Western diet in promoting an obesogenic gut microbiota is being confirmation in subjects. Following encouraging results in animals, several short-term randomized controlled trials showed the benefit of prebiotics and probiotics on insulin sensitivity, inflammatory markers, postprandial incretins, and glucose tolerance. Future research is needed to unravel the hormonal, immunomodulatory, and metabolic mechanisms underlying microbe-microbe and microbiota-host interactions and the specific genes that determine the health benefit derived from probiotics. While awaiting further randomized trials assessing long-term safety and benefits on clinical end points, a healthy lifestyle—including breast lactation, appropriate antibiotic use, and the avoidance of excessive dietary fat intake—may ensure a friendly gut microbiota and positively affect prevention and treatment of metabolic disorders.Along with the increasing worldwide incidence of obesity-associated disorders, research has recently unraveled important pathways reciprocally connecting metabolism with the immune system. The development of obesity is a complex process involving genetic susceptibility and environmental factors, which both remain only partially understood. In such instances, gut microbiota is being increasingly recognized as an important factor connecting genes, environment, and immune system. The human gut hosts an enormous number and variety of microorganisms, including at least 10¹⁴ bacteria belonging to ∼1,000 species (1). The genome size of this microbial organ, collectively named microbiome, exceeds the size of the human nuclear genome by two orders of magnitude and provides important biological and metabolic functions that cannot be performed by researchers. Genomic and environmental factors at the basis of mutual host-microbiota interactions have been intensely investigated with metagenomic and metabolomic approaches in the last 5 years. This article will discuss recent advances in understanding the role of gut microbiota in the pathogenesis of obesity, insulin resistance (IR), and diabetes and their potential therapeutic applications.