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1.
Adv Exp Med Biol ; 1265: 1-20, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32761567

RESUMO

Dietary protein digestion is an efficient process resulting in the absorption of amino acids by epithelial cells, mainly in the jejunum. Some amino acids are extensively metabolized in enterocytes supporting their high energy demand and/or production of bioactive metabolites such as glutathione or nitric oxide. In contrast, other amino acids are mainly used as building blocks for the intense protein synthesis associated with the rapid epithelium renewal and mucin production. Several amino acids have been shown to support the intestinal barrier function and the intestinal endocrine function. In addition, amino acids are metabolized by the gut microbiota that use them for their own protein synthesis and in catabolic pathways releasing in the intestinal lumen numerous metabolites such as ammonia, hydrogen sulfide, branched-chain amino acids, polyamines, phenolic and indolic compounds. Some of them (e.g. hydrogen sulfide) disrupts epithelial energy metabolism and may participate in mucosal inflammation when present in excess, while others (e.g. indole derivatives) prevent gut barrier dysfunction or regulate enteroendocrine functions. Lastly, some recent data suggest that dietary amino acids might regulate the composition of the gut microbiota, but the relevance for the intestinal health remains to be determined. In summary, amino acid utilization by epithelial cells or by intestinal bacteria appears to play a pivotal regulator role for intestinal homeostasis. Thus, adequate dietary supply of amino acids represents a key determinant of gut health and functions.


Assuntos
Aminoácidos/metabolismo , Saúde , Intestinos/fisiologia , Proteínas na Dieta/metabolismo , Microbioma Gastrointestinal , Humanos
2.
Adv Exp Med Biol ; 1262: 39-57, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32613579

RESUMO

Novel scientific concepts must be made understandable to allow their further development, highlighting the need for better communication of abstract ideas that these discoveries are built upon. This project focused on visually communicating the discovery of microbiome-derived molecules that play a major role in microbiome-gut-brain axis communication through multimedia learning.A 4-min animated video that was segmented and used a combination of 2D and 3D models was created. It communicated the important information about the process of discovering the molecules in mouse models, their production by bacteria and their potential implications for human health. The animation was then provided to a scientific audience, alongside a short-answer survey and a Likert scale, to assess how visual aspects accompanied with narration compare to learning and comprehension of the same content if it is read.The findings are based on the total of 15 participants, 9 of which were exposed to the information via animation (Group A) and 6 who were given information in a form of written narrative (Group B). It was found that Group A scored average M = 15 (out of 25) on the post assessment compared to Group B with an average of M = 7. Higher scores correlated with higher rating on questions about perceived understanding through animated media. Additionally, the animation scored higher on helpfulness in learning abstract ideas, especially having to do with structure and spatial navigation. This indicates that scientific abstract concepts that are likely comprehended are needed in order to make definite conclusions.


Assuntos
Encéfalo , Microbioma Gastrointestinal , Intestinos , Fisiologia , Materiais de Ensino , Animais , Encéfalo/fisiologia , Comunicação , Microbioma Gastrointestinal/fisiologia , Humanos , Intestinos/fisiologia , Camundongos , Fisiologia/educação , Materiais de Ensino/normas , Gravação em Vídeo/normas
3.
Life Sci ; 257: 118017, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32603821

RESUMO

AIMS: Mesenchymal stem cell (MSC)-derived exosomes (MSCs-exos) regulate biological functions in different diseases, such as liver fibrosis, diabetes, and ischaemic heart injury. However, the function of MSC-derived exosomes on the intestinal barrier and the underlying mechanisms are poorly characterized. MAIN METHODS: The expression of miR-34a/c-5p, miR-29b-3p and Claudin-3 in human normal intestinal tissues and damaged intestinal tissues was evaluated by RT-qPCR. The effect of MSC-secreted exosomes on Claudins in Caco-2 cells was measured by using confocal microscopy, RT-qPCR and Western blot. Dual luciferase reporter assays and RNA immunoprecipitation (RIP) assays were performed to study the interaction between miR-34a/c-5p, miR-29b-3p and Snail. I/R-induced intestinal damage in rats was used to determine the in vivo effect of MSC-exos on intestinal barrier function. KEY FINDINGS: In this study, we found that miR-34a/c-5p, miR-29b-3p and Claudin-3 were downregulated in damaged human intestinal tissues. MSC-exos increased the expression of Claudin-3, Claudin-2 and ZO-1 in Caco-2 cells. Further studies demonstrated that MSC-exos promoted Claudin-3, Claudin-2 and ZO-1 expression in Caco-2 cells by Snail, which was targeted by miR-34a/c-5p and miR-29b-3p. In vivo experiments showed that MSC-derived exosomes could improve I/R-induced intestinal damage through the Snail/Claudins signaling pathway. SIGNIFICANCE: The findings here suggest a novel molecular basis for the therapy of intestinal barrier dysfunction.


Assuntos
Mucosa Intestinal/metabolismo , MicroRNAs/genética , Animais , Condrócitos/metabolismo , Claudinas/metabolismo , Exossomos/genética , Exossomos/metabolismo , Humanos , Intestinos/fisiologia , Masculino , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/fisiologia , MicroRNAs/fisiologia , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/metabolismo , Transdução de Sinais , Fatores de Transcrição da Família Snail/metabolismo
4.
Zhonghua Wei Chang Wai Ke Za Zhi ; 23(Z1): 1-4, 2020 Jul 10.
Artigo em Chinês | MEDLINE | ID: mdl-32594718

RESUMO

As an innovative therapy, FMT has made a breakthrough in the treatment of recurrent Clostridium difficile infection (CDI). With the rapid development of biotechnology, the relationship between intestinal microflora and diseases has been gradually eluciated. Great hope has also been given to FMT in other intestinal and extraintestinal diseases with ineffective traditional treatment. However, as a new therapy method, FMT still has many unknown fields, such as the selection of clinical donors, the preparation of standardized bacterial solution and capsule, the selection of indications, the matching of donor and receptor, and the prevention and treatment of complications. Since 2012, our center has carried out treatment research and practice of FMT, so far with more than 60 000 FMTs for more than 3500 cases. Based on large sample data and experience, this special issue reports and discusses the above topics, and focuses on the establishment and clinical application of standardized methodology of FMT, which will undoubtedly play a positive role in promoting the healthy development of FMT treatment in China.


Assuntos
Infecções por Clostridium/terapia , Clostridium difficile/isolamento & purificação , Transplante de Microbiota Fecal/normas , Fezes/microbiologia , Microbioma Gastrointestinal/fisiologia , Intestinos/microbiologia , China , Transplante de Microbiota Fecal/métodos , Humanos , Intestinos/fisiologia , Intestinos/fisiopatologia , Recidiva , Resultado do Tratamento
5.
PLoS One ; 15(5): e0232418, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32421690

RESUMO

Improving the digestive efficiency of broiler chickens (Gallus gallus) could reduce organic waste, increase the use of alternative feed not used for human consumption and reduce the impact of feed in production costs. By selecting chicken lines divergently for their digestive efficiency, we showed previously that digestive efficiency is under genetic control and that the two resulting divergent lines, D+ (high digestive efficiency or "digestibility +") and D- (low digestive efficiency or "digestibility -"), also differ for the abundance of specific bacteria in their caeca. Here we perform a more extensive census of the bacteria present in the digestive microbiota of 60 chickens selected for their low apparent metabolizable energy corrected for nitrogen balance (AMEn-) or high (AMEn+) digestive efficiency in a [D+ x D-] F8 progeny of 200 individuals. We sequenced the 16S rRNA genes of the ileal, jejunal and caecal microbiotas, and compared the compositions and predicted functions of microbiotas from the different intestinal segments for 20 AMEn+ and 19 AMEn- birds. The intestinal segment of origin was the main factor structuring the samples. The caecal microbiota was the most impacted by the differences in digestive efficiency, with 41 bacterial species with abundances differing between highly and poorly efficient birds. Furthermore, we predicted that the caecal microbiota of efficient birds might be enriched in genes contributing to the degradation of short chain fatty acids (SCFA) from non-starch polysaccharides. These results confirm the impact of the genetic selection led on digestibility on the caecal microbiota taxonomic composition. They open the way toward the identification of specific, causal genes of the host controlling variations in the abundances of bacterial taxons.


Assuntos
Galinhas/microbiologia , Microbioma Gastrointestinal/genética , Ração Animal , Fenômenos Fisiológicos da Nutrição Animal , Animais , Biodiversidade , Galinhas/genética , Galinhas/crescimento & desenvolvimento , Digestão/genética , Digestão/fisiologia , Feminino , Microbioma Gastrointestinal/fisiologia , Interações entre Hospedeiro e Microrganismos/genética , Interações entre Hospedeiro e Microrganismos/fisiologia , Intestinos/anatomia & histologia , Intestinos/microbiologia , Intestinos/fisiologia , Masculino , Filogenia , RNA Ribossômico 16S/genética , Seleção Genética
6.
Chemosphere ; 256: 127204, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32470746

RESUMO

The digestive tract is an important target organ for microplastics (MPs). However, little is known about the effects of digestive treatment on the intestinal toxicity of MPs. In this study, an in vitro digestive process was applied to transform 100 nm and 5 µm polystyrene microplastics (PS-MPs). Intestinal toxicities of original PS-MPs and transformed PS-MPs (t-PS-MPs) were determined using an in vitro Caco-2 monolayer model. Results showed that the digestive process did not alter the chemical constitution of PS-MPs, but formed a corona on the surface of PS-MPs. The 100 nm PS-MPs showed higher intestinal toxicity than 5 µm PS-MPs. Digestive treatment relieved cytotoxicity and transport function disorder of the Caco-2 monolayer induced by the original PS-MPs. Moreover, the combined toxicities of PS-MPs and arsenic were also decreased by digestive treatment. However, the in vitro digestive process increased the proinflammatory effects of PS-MPs. The formation of a corona on the PS-MP surface, which lead to a change in size, Zeta potential, and adsorbed compounds, might induce the above influence of digestive treatment. Our study suggests that direct cytotoxicity assays of PS-MPs might misestimate their intestinal effects, which provide new lights to the toxicity evaluation of PS-MPs by oral exposure.


Assuntos
Digestão/fisiologia , Intestinos/fisiologia , Microplásticos/toxicidade , Poliestirenos/toxicidade , Poluentes Químicos da Água/toxicidade , Adsorção , Células CACO-2 , Linhagem Celular Tumoral , Humanos
7.
Proc Natl Acad Sci U S A ; 117(20): 11136-11146, 2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32371487

RESUMO

The intestinal epithelium acts as a barrier between the organism and its microenvironment, including the gut microbiota. It is the most rapidly regenerating tissue in the human body thanks to a pool of intestinal stem cells (ISCs) expressing Lgr5 The intestinal epithelium has to cope with continuous stress linked to its digestive and barrier functions. Epithelial repair is crucial to maintain its integrity, and Lgr5-positive intestinal stem cell (Lgr5+ISC) resilience following cytotoxic stresses is central to this repair stage. We show here that autophagy, a pathway allowing the lysosomal degradation of intracellular components, plays a crucial role in the maintenance and genetic integrity of Lgr5+ISC under physiological and stress conditions. Using conditional mice models lacking the autophagy gene Atg7 specifically in all intestinal epithelial cells or in Lgr5+ISC, we show that loss of Atg7 induces the p53-mediated apoptosis of Lgr5+ISC. Mechanistically, this is due to increasing oxidative stress, alterations to interactions with the microbiota, and defective DNA repair. Following irradiation, we show that Lgr5+ISC repair DNA damage more efficiently than their progenitors and that this protection is Atg7 dependent. Accordingly, we found that the stimulation of autophagy on fasting protects Lgr5+ISC against DNA damage and cell death mediated by oxaliplatin and doxorubicin treatments. Finally, p53 deletion prevents the death of Atg7-deficient Lgr5+ISC but promotes genetic instability and tumor formation. Altogether, our findings provide insights into the mechanisms underlying maintenance and integrity of ISC and highlight the key functions of Atg7 and p53.


Assuntos
Proteína 7 Relacionada à Autofagia/metabolismo , Autofagia/fisiologia , Intestinos/fisiologia , Células-Tronco/metabolismo , Animais , Apoptose , Proteína 7 Relacionada à Autofagia/genética , Dano ao DNA , Reparo do DNA , Modelos Animais de Doenças , Células Epiteliais/metabolismo , Feminino , Genes p53/genética , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Intestinos/patologia , Masculino , Camundongos , Camundongos Knockout , Receptores Acoplados a Proteínas-G/metabolismo , Células-Tronco/citologia
8.
PLoS One ; 15(5): e0233863, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32470053

RESUMO

Adaptive regulation of epithelial transporters to nutrient intake is essential to decrease energy costs of their synthesis and maintenance, however such regulation is understudied. Previously we demonstrated that the transport function of the basolateral amino acid uniporter LAT4 (Slc43a2) is increased by dephosphorylation of serine 274 (S274) and nearly abolished by dephosphorylation of serine 297 (S297) when expressed in Xenopus oocytes. Phosphorylation changes in the jejunum of food-entrained mice suggested an increase in LAT4 transport function during food expectation. Thus, we investigated further how phosphorylation, expression and localization of mouse intestinal LAT4 respond to food-entrained diurnal rhythm and dietary protein content. In mice entrained with 18% protein diet, LAT4 mRNA was not submitted to diurnal regulation, unlike mRNAs of luminal symporters and antiporters. Only in duodenum, LAT4 protein expression increased during food intake. Concurrently, S274 phosphorylation was decreased in all three small intestinal segments, whereas S297 phosphorylation was increased only in jejunum. Interestingly, during food intake, S274 phosphorylation was nearly absent in ileum and accompanied by strong phosphorylation of mTORC1 target S6. Entraining mice with 8% protein diet provoked a shift in jejunal LAT4 localization from the cell surface to intracellular stores and increased S274 phosphorylation in both jejunum and ileum during food anticipation, suggesting decreased transport function. In contrast, 40% dietary protein content led to increased LAT4 expression in jejunum and its internalization in ileum. Ex vivo treatments of isolated intestinal villi fraction demonstrated that S274 phosphorylation was stimulated by protein kinase A. Rapamycin-sensitive insulin treatment and amino acids increased S297 phosphorylation, suggesting that the response to food intake might be regulated via the insulin-mTORC1 pathway. Ghrelin, an oscillating orexigenic hormone, did not affect phosphorylation of intestinal LAT4. Overall, we show that phosphorylation, expression and localization of intestinal mouse LAT4 responds to diurnal and dietary stimuli in location-specific manner.


Assuntos
Sistema y+ de Transporte de Aminoácidos/metabolismo , Ritmo Circadiano , Proteínas na Dieta/farmacologia , Alimentos , Intestinos/fisiologia , Aminoácidos/metabolismo , Animais , Antiporters/metabolismo , Ritmo Circadiano/efeitos dos fármacos , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Grelina/administração & dosagem , Grelina/farmacologia , Insulina/metabolismo , Intestino Delgado/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Camundongos Endogâmicos C57BL , Microvilosidades/efeitos dos fármacos , Microvilosidades/metabolismo , Fosforilação/efeitos dos fármacos , Fosfosserina/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Frações Subcelulares/metabolismo , Simportadores/metabolismo , Serina-Treonina Quinases TOR/metabolismo
9.
PLoS One ; 15(4): e0230970, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32287318

RESUMO

The ability to predict when an individual will die can be extremely useful for many research problems in aging. A technique for predicting death in the model organism, Drosophila melanogaster, has been proposed which relies on an increase in the permeability of the fly intestinal system, allowing dyes from the diet to permeate the body of the fly shortly before death. In this study we sought to verify this claim in a large cohort study using different populations of D. melanogaster and different dyes. We found that only about 50% of the individuals showed a visible distribution of dye before death. This number did not vary substantially with the dye used. Most flies that did turn a blue color before death did so within 24 hours of death. There was also a measurable effect of the dye on the fly mean longevity. These results would tend to limit the utility of this method depending on the application the method was intended for.


Assuntos
Drosophila melanogaster/fisiologia , Intestinos/fisiologia , Longevidade/fisiologia , Envelhecimento/fisiologia , Animais , Corantes/administração & dosagem , Corantes/farmacocinética , Corantes/toxicidade , Drosophila melanogaster/efeitos dos fármacos , Feminino , Longevidade/efeitos dos fármacos , Masculino , Modelos Biológicos , Permeabilidade
10.
Nature ; 580(7802): 263-268, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32269334

RESUMO

In cells, organs and whole organisms, nutrient sensing is key to maintaining homeostasis and adapting to a fluctuating environment1. In many animals, nutrient sensors are found within the enteroendocrine cells of the digestive system; however, less is known about nutrient sensing in their cellular siblings, the absorptive enterocytes1. Here we use a genetic screen in Drosophila melanogaster to identify Hodor, an ionotropic receptor in enterocytes that sustains larval development, particularly in nutrient-scarce conditions. Experiments in Xenopus oocytes and flies indicate that Hodor is a pH-sensitive, zinc-gated chloride channel that mediates a previously unrecognized dietary preference for zinc. Hodor controls systemic growth from a subset of enterocytes-interstitial cells-by promoting food intake and insulin/IGF signalling. Although Hodor sustains gut luminal acidity and restrains microbial loads, its effect on systemic growth results from the modulation of Tor signalling and lysosomal homeostasis within interstitial cells. Hodor-like genes are insect-specific, and may represent targets for the control of disease vectors. Indeed, CRISPR-Cas9 genome editing revealed that the single hodor orthologue in Anopheles gambiae is an essential gene. Our findings highlight the need to consider the instructive contributions of metals-and, more generally, micronutrients-to energy homeostasis.


Assuntos
Canais de Cloreto/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/crescimento & desenvolvimento , Drosophila melanogaster/metabolismo , Ingestão de Alimentos/fisiologia , Intestinos/fisiologia , Zinco/metabolismo , Animais , Drosophila melanogaster/genética , Enterócitos/metabolismo , Feminino , Preferências Alimentares , Homeostase , Insetos Vetores , Insulina/metabolismo , Ativação do Canal Iônico , Larva/genética , Larva/crescimento & desenvolvimento , Larva/metabolismo , Lisossomos/metabolismo , Masculino , Oócitos/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Transdução de Sinais , Xenopus
11.
J Vis Exp ; (157)2020 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-32281970

RESUMO

Organoids and three-dimensional (3D) cell cultures allow the investigation of complex biological mechanisms and regulations in vitro, which previously was not possible in classical cell culture monolayers. Moreover, monolayer cell cultures are good in vitro model systems but do not represent the complex cellular differentiation processes and functions that rely on 3D structure. This has so far only been possible in animal experiments, which are laborious, time consuming, and hard to assess by optical techniques. Here we describe an assay to quantitatively determine the barrier integrity over time in living small intestinal mouse organoids. To validate our model, we applied interferon gamma (IFN-γ) as a positive control for barrier destruction and organoids derived from IFN-γ receptor 2 knock out mice as a negative control. The assay allowed us to determine the impact of IFN-γ on the intestinal barrier integrity and the IFN-γ induced degradation of the tight junction proteins claudin-2, -7, and -15. This assay could also be used to investigate the impact of chemical compounds, proteins, toxins, bacteria, or patient-derived probes on the intestinal barrier integrity.


Assuntos
Intestinos/fisiologia , Organoides/fisiologia , Animais , Humanos , Processamento de Imagem Assistida por Computador , Camundongos , Modelos Biológicos , Permeabilidade
12.
Nature ; 580(7804): 511-516, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32322067

RESUMO

The taste of sugar is one of the most basic sensory percepts for humans and other animals. Animals can develop a strong preference for sugar even if they lack sweet taste receptors, indicating a mechanism independent of taste1-3. Here we examined the neural basis for sugar preference and demonstrate that a population of neurons in the vagal ganglia and brainstem are activated via the gut-brain axis to create preference for sugar. These neurons are stimulated in response to sugar but not artificial sweeteners, and are activated by direct delivery of sugar to the gut. Using functional imaging we monitored activity of the gut-brain axis, and identified the vagal neurons activated by intestinal delivery of glucose. Next, we engineered mice in which synaptic activity in this gut-to-brain circuit was genetically silenced, and prevented the development of behavioural preference for sugar. Moreover, we show that co-opting this circuit by chemogenetic activation can create preferences to otherwise less-preferred stimuli. Together, these findings reveal a gut-to-brain post-ingestive sugar-sensing pathway critical for the development of sugar preference. In addition, they explain the neural basis for differences in the behavioural effects of sweeteners versus sugar, and uncover an essential circuit underlying the highly appetitive effects of sugar.


Assuntos
Encéfalo/fisiologia , Comportamento de Escolha/fisiologia , Açúcares da Dieta/metabolismo , Preferências Alimentares/fisiologia , Glucose/metabolismo , Intestinos/fisiologia , Animais , Encéfalo/citologia , Açúcares da Dieta/química , Glucose/análogos & derivados , Glucose/química , Masculino , Metilglucosídeos/química , Metilglucosídeos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/fisiologia , Paladar/fisiologia , Tiazinas/metabolismo , Água/metabolismo
14.
Proc Natl Acad Sci U S A ; 117(12): 6792-6800, 2020 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-32152097

RESUMO

Intestinal bile acids are known to modulate the germination and growth of Clostridioides difficile Here we describe a role for intestinal bile acids in directly binding and neutralizing TcdB toxin, the primary determinant of C. difficile disease. We show that individual primary and secondary bile acids reversibly bind and inhibit TcdB to varying degrees through a mechanism that requires the combined oligopeptide repeats region to which no function has previously been ascribed. We find that bile acids induce TcdB into a compact "balled up" conformation that is no longer able to bind cell surface receptors. Lastly, through a high-throughput screen designed to identify bile acid mimetics we uncovered nonsteroidal small molecule scaffolds that bind and inhibit TcdB through a bile acid-like mechanism. In addition to suggesting a role for bile acids in C. difficile pathogenesis, these findings provide a framework for development of a mechanistic class of C. difficile antitoxins.


Assuntos
Toxinas Bacterianas/química , Toxinas Bacterianas/metabolismo , Ácidos e Sais Biliares/metabolismo , Clostridium difficile/metabolismo , Intestinos/fisiologia , Receptores de Superfície Celular/metabolismo , Células CACO-2 , Infecções por Clostridium/microbiologia , Clostridium difficile/crescimento & desenvolvimento , Células HCT116 , Humanos
15.
Anim Sci J ; 91(1): e13357, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32219956

RESUMO

Tight junctions (TJs) play an important role in intestinal barrier function. TJs in intestinal epithelial cells are composed of different junctional molecules, such as claudin and occludin, and regulate the paracellular permeability of water, ions, and macromolecules in adjacent cells. One of the most important roles of the TJ structure is to provide a physical barrier to luminal inflammatory molecules. Impaired integrity and structure of the TJ barrier result in a forcible activation of immune cells and chronic inflammation in different tissues. According to recent studies, the intestinal TJ barrier could be regulated, as a potential target, by dietary factors to prevent and reduce different inflammatory disorders, although the precise mechanisms underlying the dietary regulation remain unclear. This review summarizes currently available information on the regulation of the intestinal TJ barrier by food components.


Assuntos
Fenômenos Fisiológicos da Nutrição Animal , Alimentos , Intestinos/citologia , Intestinos/fisiologia , Nutrientes , Junções Íntimas/fisiologia , Animais , Água Corporal/metabolismo , Claudinas/metabolismo , Células Epiteliais/metabolismo , Inflamação , Intestinos/imunologia , Permeabilidade , Junções Íntimas/imunologia
16.
Chemosphere ; 249: 126172, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32078855

RESUMO

Silver nanoparticles (AgNPs) have been increasingly manufactured and thus are increasingly detected in aquatic systems. However, there are still some overlooked factors (e.g., organism sex) in the field of nano-toxicological assessment. In this study, to explore the role of sex in nanotoxicity, adult male and female zebrafish were exposed to 100 µg/L of two uncoated commercial AgNPs with primary sizes 20 nm and 80 nm for 2 weeks, after which the impacts of AgNPs on intestines and livers of both male and female zebrafish were assessed using a suite of biomarkers. Results demonstrated that the intestinal Na/K-ATPase activity as well as the superoxide dismutase activity in male zebrafish differed significantly between 20-nm AgNPs and 80-nm AgNPs treatments (p < 0.05), indicating 20-nm AgNPs showing higher toxicity to zebrafish than the 80-nm AgNPs. Also, we noted that the used AgNPs induced sex-dependent effects on growth indices, oxidative/anti-oxidative status, neural signaling and hepatic lipid metabolism, with the male zebrafish being more sensitive to AgNPs than the females. Further, the tested AgNPs impaired the intestine much more seriously than the liver, as evidenced by the disruptions of Na/K-ATPase and antioxidant system in intestine but not in liver. These findings imply that prolonged exposure to AgNPs might induce size-related, sex-dependent, and organ-specific toxicity to adult zebrafish, thereby may significantly extend our understanding of the toxic effects of AgNPs in aquatic environment.


Assuntos
Nanopartículas Metálicas/toxicidade , Prata/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/fisiologia , Animais , Feminino , Intestinos/efeitos dos fármacos , Intestinos/fisiologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Sistema Nervoso , Fatores Sexuais , ATPase Trocadora de Sódio-Potássio/metabolismo , Peixe-Zebra/metabolismo
17.
Gene ; 735: 144407, 2020 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-32007582

RESUMO

Krüppel-like factor13 (klf13), a member of the Krüppel-like factor family, plays a vital role in cell proliferation and differentiation. When sea cucumber Apostichopus japonicus is attacted by predators, it can spit viscera in order to escape attack, and then complete the intestine regeneration process within 15 days. However, the potential role of klf13 from A. japonicus (Aj-klf13) in the intestine regeneration of sea cucumber A. japonicus still remains unknown. In present paper, the full-length cDNA of klf13 gene from A. japonicus was cloned by RACE techniques, and it was composed of 2496 bp, including a 245 bp 5' UTR, a 1396 bp 3' UTR and a 855 bp open reading frame, which encoded a polypeptide of 284 amino acids and C2H2 zinc finger domains. The expression level of Aj-klf13 showed an increasing trend in intestine regeneration process of sea cucumber, and it reached the highest at 6 days, returning to the normal at 15 days. By western blot, the expression level of Aj-KLF13 protein was basically consistent with that of Aj-klf13 gene. The expression locations of protein by immunofluorescence indicated that Aj-KLF13 was widely expressed in the normal physiological state and intestine regeneration process of sea cucumbers, which was in the nucleus. There was tissue specificity of the protein, which was mainly distributed in luminal epithelium and coelomic epithelium. These results indicate that Aj-klf13 plays a crucial role in the intestine regeneration process of sea cucumber A. japonicus.


Assuntos
Intestinos/fisiologia , Fatores de Transcrição Kruppel-Like/genética , Regeneração , Stichopus/genética , Animais , Clonagem Molecular , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Quinase 2 Dependente de Ciclina/metabolismo , Mucosa Intestinal/metabolismo , Fatores de Transcrição Kruppel-Like/química , Fatores de Transcrição Kruppel-Like/metabolismo , Stichopus/metabolismo
18.
Nature ; 578(7794): 284-289, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32025031

RESUMO

Neural control of the function of visceral organs is essential for homeostasis and health. Intestinal peristalsis is critical for digestive physiology and host defence, and is often dysregulated in gastrointestinal disorders1. Luminal factors, such as diet and microbiota, regulate neurogenic programs of gut motility2-5, but the underlying molecular mechanisms remain unclear. Here we show that the transcription factor aryl hydrocarbon receptor (AHR) functions as a biosensor in intestinal neural circuits, linking their functional output to the microbial environment of the gut lumen. Using nuclear RNA sequencing of mouse enteric neurons that represent distinct intestinal segments and microbiota states, we demonstrate that the intrinsic neural networks of the colon exhibit unique transcriptional profiles that are controlled by the combined effects of host genetic programs and microbial colonization. Microbiota-induced expression of AHR in neurons of the distal gastrointestinal tract enables these neurons to respond to the luminal environment and to induce expression of neuron-specific effector mechanisms. Neuron-specific deletion of Ahr, or constitutive overexpression of its negative feedback regulator CYP1A1, results in reduced peristaltic activity of the colon, similar to that observed in microbiota-depleted mice. Finally, expression of Ahr in the enteric neurons of mice treated with antibiotics partially restores intestinal motility. Together, our experiments identify AHR signalling in enteric neurons as a regulatory node that integrates the luminal environment with the physiological output of intestinal neural circuits to maintain gut homeostasis and health.


Assuntos
Microbioma Gastrointestinal/fisiologia , Intestinos/fisiologia , Neurônios/fisiologia , Peristaltismo , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Citocromo P-450 CYP1A1/metabolismo , Feminino , Vida Livre de Germes , Intestinos/inervação , Ligantes , Masculino , Camundongos , Vias Neurais , Receptores de Hidrocarboneto Arílico/metabolismo , Transdução de Sinais , Transcriptoma/genética
19.
Am J Physiol Renal Physiol ; 318(3): F835-F842, 2020 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-32068460

RESUMO

Alterations in gut homeostasis may contribute to the progression of diabetic nephropathy. There has been recent attention on the renoprotective effects of metabolite-sensing receptors in chronic renal injury, including the G protein-coupled receptor (GPR)109a, which ligates the short-chain fatty acid butyrate. However, the role of GPR109a in the development of diabetic nephropathy, a milieu of diminished microbiome-derived metabolites, has not yet been determined. The present study aimed to assess the effects of insufficient GPR109a signaling, via genetic deletion of GPR109a, on the development of renal injury in diabetic nephropathy. Gpr109a-/- mice or their wild-type littermates (Gpr109a+/+) were rendered diabetic with streptozotocin. Mice received a control diet or an isocaloric high-fiber diet (12.5% resistant starch) for 24 wk, and gastrointestinal permeability and renal injury were determined. Diabetes was associated with increased albuminuria, glomerulosclerosis, and inflammation. In comparison, Gpr109a-/- mice with diabetes did not show an altered renal phenotype. Resistant starch supplementation did not afford protection from renal injury in diabetic nephropathy. While diabetes was associated with alterations in intestinal morphology, intestinal permeability assessed in vivo using the FITC-dextran test was unaltered. GPR109a deletion did not worsen gastrointestinal permeability. Furthermore, 12.5% resistant starch supplementation, at physiological concentrations, had no effect on intestinal permeability or morphology. The results of this study indicate that GPR109a does not play a critical role in intestinal homeostasis in a model of type 1 diabetes or in the development of diabetic nephropathy.


Assuntos
Nefropatias Diabéticas/metabolismo , Receptores Acoplados a Proteínas-G/metabolismo , Animais , Peso Corporal , Diabetes Mellitus Experimental , Hemoglobina A Glicada , Intestinos/anatomia & histologia , Intestinos/fisiologia , Masculino , Camundongos , Camundongos Knockout , Permeabilidade , Receptores Acoplados a Proteínas-G/genética
20.
J Vis Exp ; (155)2020 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-32065129

RESUMO

Primary cultured cells are used in a variety of scientific disciplines as exceptionally important tools for the functional evaluation of biological substances or characterization of specific biological activities. However, due to the lack of universally applicable cell culture media and protocols, well described cell culture methods for marine organisms are still limited. Meanwhile, the commonly occurring microbial contamination and polytropic properties of marine invertebrate cells further impede the establishment of an effective cell culture strategy for marine invertebrates. Here, we describe an easy-to-handle method for culturing intestinal cells from sea cucumber Apostichopus japonicus; additionally, we provide an example of in vitro apoptosis induction and detection in primary cultured intestinal cells. Moreover, this experiment provides details about the appropriate culture medium and cell collection method. The described protocol is compatible with a variety of widely available tissue samples from marine organisms including Echinodermata, Mollusca, and Crustacea, and it can provide sufficient cells for multiple in vitro experimental applications. This technique would enable researchers to efficiently manipulate primary cell cultures from marine invertebrates and to facilitate the functional evaluation of targeted biological materials on cells.


Assuntos
Intestinos/fisiologia , Animais , Apoptose , Pepinos-do-Mar
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