RESUMO
Enzymes or enzyme complexes can be concentrated in different cellular loci to modulate distinct functional processes in response to specific signals. How cells condense and compartmentalize enzyme complexes for spatiotemporally distinct cellular events is not well understood. Here we discover that specific and tight association of GIT1 and ß-Pix, a pair of GTPase regulatory enzymes, leads to phase separation of the complex without additional scaffolding molecules. GIT1/ß-Pix condensates are modular in nature and can be positioned at distinct cellular compartments, such as neuronal synapses, focal adhesions, and cell-cell junctions, by upstream adaptors. Guided by the structure of the GIT/PIX complex, we specifically probed the role of phase separation of the enzyme complex in cell migration and synapse formation. Our study suggests that formation of modular enzyme complex condensates via phase separation can dynamically concentrate limited quantities of enzymes to distinct cellular compartments for specific and optimal signaling.
Assuntos
Proteínas de Ciclo Celular/metabolismo , Proteínas Ativadoras de GTPase/metabolismo , Fatores de Troca de Nucleotídeo Guanina Rho/metabolismo , Transdução de Sinais , Animais , Proteínas de Ciclo Celular/química , Proteínas Ativadoras de GTPase/química , Células HEK293 , Células HeLa , Humanos , Camundongos , Modelos Moleculares , Paxilina/metabolismo , Ligação Proteica , Proteínas Recombinantes/metabolismoRESUMO
The tumour suppressor, Lethal (2) giant larvae [Lgl; also known as L(2)gl], is an evolutionarily conserved protein that was discovered in the vinegar fly Drosophila, where its depletion results in tissue overgrowth and loss of cell polarity. Lgl links cell polarity and tissue growth through regulation of the Notch and the Hippo signalling pathways. Lgl regulates the Notch pathway by inhibiting V-ATPase activity via Vap33. How Lgl regulates the Hippo pathway was unclear. In this current study, we show that V-ATPase activity inhibits the Hippo pathway, whereas Vap33 acts to activate Hippo signalling. Vap33 physically and genetically interacts with the actin cytoskeletal regulators RtGEF (Pix) and Git, which also bind to the Hippo protein (Hpo) and are involved in the activation of the Hippo pathway. Additionally, we show that the ADP ribosylation factor Arf79F (Arf1), which is a Hpo interactor, is involved in the inhibition of the Hippo pathway. Altogether, our data suggest that Lgl acts via Vap33 to activate the Hippo pathway by a dual mechanism: (1) through interaction with RtGEF, Git and Arf79F, and (2) through interaction and inhibition of the V-ATPase, thereby controlling epithelial tissue growth.
Assuntos
Proteínas de Drosophila , Neoplasias , Animais , Adenosina Trifosfatases/metabolismo , Polaridade Celular , Drosophila/metabolismo , Drosophila melanogaster , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Via de Sinalização Hippo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Proteínas Supressoras de Tumor/metabolismoRESUMO
Spinal cord injury (SCI) can result in severe motor and sensory deficits, for which currently no effective cure exists. The pathological process underlying this injury is extremely complex and involves many cell types in the central nervous system. In this study, we have uncovered a novel function for macrophage G protein-coupled receptor kinase-interactor 1 (GIT1) in promoting remyelination and functional repair after SCI. Using GIT1flox/flox Lyz2-Cre (GIT1 CKO) mice, we identified that GIT1 deficiency in macrophages led to an increased generation of tumor necrosis factor-alpha (TNFα), reduced proportion of mature oligodendrocytes (mOLs), impaired remyelination, and compromised functional recovery in vivo. These effects in GIT1 CKO mice were reversed with the administration of soluble TNF inhibitor. Moreover, bone marrow transplantation from GIT1 CWT mice reversed adverse outcomes in GIT1 CKO mice, further indicating the role of macrophage GIT1 in modulating spinal cord injury repair. Our in vitro experiments showed that macrophage GIT1 plays a critical role in secreting TNFα and influences the differentiation of oligodendrocyte precursor cells (OPCs) after stimulation with myelin debris. Collectively, our data uncovered a new role of macrophage GIT1 in regulating the transformation of OPCs into mOLs, essential for functional remyelination after SCI, suggesting that macrophage GIT1 could be a promising treatment target of SCI.
Assuntos
Diferenciação Celular , Macrófagos , Células Precursoras de Oligodendrócitos , Remielinização , Traumatismos da Medula Espinal , Animais , Traumatismos da Medula Espinal/metabolismo , Traumatismos da Medula Espinal/patologia , Macrófagos/metabolismo , Remielinização/fisiologia , Diferenciação Celular/fisiologia , Células Precursoras de Oligodendrócitos/metabolismo , Camundongos , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Camundongos Endogâmicos C57BL , Camundongos Knockout , Recuperação de Função Fisiológica/fisiologia , Modelos Animais de Doenças , Fator de Necrose Tumoral alfa/metabolismo , Camundongos Transgênicos , Feminino , Proteínas Ativadoras de GTPase/metabolismo , Proteínas Ativadoras de GTPase/genética , Oligodendroglia/metabolismoRESUMO
Transparency and reproducibility are major prerequisites for conducting meaningful real-world evidence (RWE) studies that are fit for decision-making. Many advances have been made in the documentation and reporting of study protocols and results, but the principles for version control and sharing of analytic code in RWE are not yet as established as in other quantitative disciplines like computational biology and health informatics. In this practical tutorial, we aim to give an introduction to distributed version control systems (VCS) tailored toward the FAIR (Findable, Accessible, Interoperable, and Reproducible) implementation of RWE studies. To ease adoption, we provide detailed step-by-step instructions with practical examples on how the Git VCS and R programming language can be implemented into RWE study workflows to facilitate reproducible analyzes. We further discuss and showcase how these tools can be used to track changes, collaborate, disseminate, and archive RWE studies through dedicated project repositories that maintain a complete audit trail of all relevant study documents.
Assuntos
Fluxo de Trabalho , Humanos , Reprodutibilidade dos TestesRESUMO
The gastrointestinal tract (GIT) is stationed by a dynamic and complex microbial community with functions in digestion, metabolism, immunomodulation, and reproduction. However, there is relatively little research on the composition and function of microorganisms in different GIT segments in dairy goats. Herein, 80 chyme samples were taken from ten GIT sites of eight Xinong Saanen dairy goats and then analyzed and identified the microbial composition via 16S rRNA V1-V9 amplicon sequencing. A total of 6669 different operational taxonomic units (OTUs) were clustered, and 187 OTUs were shared by ten GIT segments. We observed 264 species belonging to 23 different phyla scattered across ten GITs, with Firmicutes (52.42%) and Bacteroidetes (22.88%) predominating. The results revealed obvious location differences in the composition, diversity, and function of the GIT microbiota. In LEfSe analysis, unidentified_Lachnospiraceae and unidentified_Succinniclassicum were significantly enriched in the four chambers of stomach, with functions in carbohydrate fermentation to compose short-chain fatty acids. Aeriscardovia, Candidatus_Saccharimonas, and Romboutsia were significantly higher in the foregut, playing an important role in synthesizing enzymes, amino acids, and vitamins and immunomodulation. Akkermansia, Bacteroides, and Alistipes were significantly abundant in the hindgut to degrade polysaccharides and oligosaccharides, etc. From rumen to rectum, α-diversity decreased first and then increased, while ß-diversity showed the opposite trend. Metabolism was the major function of the GIT microbiome predicted by PICRUSt2, but with variation in target substrates along the regions. In summary, GIT segments play a decisive role in the composition and functions of microorganisms. KEY POINTS: ⢠The jejunum and ileum were harsh for microorganisms to colonize due to the presence of bile acids, enzymes, faster chyme circulation, etc., exhibiting the lowest α-diversity and the highest ß-diversity. ⢠Variability in microbial profiles between the three foregut segments was greater than four chambers of stomach and hindgut, with a higher abundance of Firmicutes dominating than others. ⢠Dairy goats dominated a higher abundance of Kiritimatiellaeota than cows, which was reported to be associated with fatty acid synthesis.
Assuntos
Bactérias , Microbioma Gastrointestinal , Trato Gastrointestinal , Cabras , RNA Ribossômico 16S , Animais , Cabras/microbiologia , Trato Gastrointestinal/microbiologia , RNA Ribossômico 16S/genética , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Filogenia , DNA Bacteriano/genética , Biodiversidade , FemininoRESUMO
BACKGROUND: The nutritional status and growth of children with Autism spectrum disorders (ASD) is influenced significantly by two factors; food selectivity behaviors due to their consumption of a limited variety of food and the high incidence of gastrointestinal (GIT) disorders. AIM: This study aimed to assess the nutritional adequacy and growth pattern of ASD children aged three to twelve years compared to their healthy developing peers. METHODS: A national comparative, facility-based cross-sectional study was conducted in eight Egyptian governorates on 285 Egyptian children diagnosed with ASD and 224 children who are their relatives as healthy developing peers. Anthropometric measurements were obtained, including weight, height, head circumference, and mid-upper arm circumference. Body Mass Index (BMI) was calculated and all numbers were plotted on WHO growth charts. Assessment of food preferences, and nutrient intake adequacy of children was done using the Food preference questionnaire, and the Dietary Reference Intakes (DRIs) of Egyptian children. RESULTS: Calorie-dense food and sugar intake were higher among ASD children than their healthy developing peers. ASD children omit some important protein sources such as dairy (COR = 5.2, 95% CI:2.7-9.9), meat, and poultry (COR = 2.7, 95% CI: 1.6-4.7), and a lower intake of fruits and vegetables than their healthy developing peers. For children with ASD in all age groups, a deficiency in the range of 50-60% was detected for vitamins (C, D, B6, thiamine, riboflavin, niacin) and minerals (iron). A deficiency in the range of 60-70% was detected for folate and calcium. A deficiency of vitamin C calcium and iron was also detected for both children with ASD and their healthy developing relatives aged 6 to 12 years. GIT disorders were common among ASD children compared to healthy developing peers (COR = 2.8 to 10.3). Children with ASD had four-fold higher odds of stunting (COR = 4.1, CI: 1.7-10.1), threefold higher odds of being overweight (COR = 3.3, CI: 1.48-7.32), and nearly eleven-fold higher odds of obesity (COR = 11.4, CI: 4.05-32.17) compared to their healthy developing peers. CONCLUSION: ASD children are prone to overweight and protein malnutrition. Their intake of fruits and vegetables is inadequate and hence their intake of vitamins and minerals is insufficient, contributing to stunting.
Assuntos
Transtorno do Espectro Autista , Transtornos do Crescimento , Obesidade Infantil , Humanos , Transtorno do Espectro Autista/epidemiologia , Transtorno do Espectro Autista/etiologia , Egito/epidemiologia , Masculino , Feminino , Estudos Transversais , Pré-Escolar , Criança , Obesidade Infantil/epidemiologia , Transtornos do Crescimento/epidemiologia , Transtornos do Crescimento/etiologia , Estado Nutricional , Estudos de Casos e Controles , Preferências Alimentares , Índice de Massa Corporal , DietaRESUMO
As a critical regulator of cell growth, the mechanistic target of rapamycin (mTOR) protein operates as part of two molecularly and functionally distinct complexes. Herein, we demonstrate that mTOR complex molecular composition varies in different somatic tissues. In astrocytes and neural stem cells, we identified G-protein-coupled receptor kinase-interacting protein 1 (GIT1) as a novel mTOR-binding protein, creating a unique mTOR complex lacking Raptor and Rictor. Moreover, GIT1 binding to mTOR is regulated by AKT activation and is essential for mTOR-mediated astrocyte survival. Together, these data reveal that mTOR complex function is partly dictated by its molecuflar composition in different cell types.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Astrócitos/citologia , Astrócitos/fisiologia , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Proteínas Ativadoras de GTPase/genética , Proteínas Ativadoras de GTPase/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Animais , Sobrevivência Celular/genética , Células Cultivadas , Ativação Enzimática , Regulação da Expressão Gênica , Técnicas de Silenciamento de Genes , Células HEK293 , Humanos , Camundongos , Neurofibromina 1/genética , Neurofibromina 1/metabolismo , Ligação Proteica , Proteômica , Proteínas Proto-Oncogênicas c-akt/metabolismo , Serina-Treonina Quinases TOR/genéticaRESUMO
This review summarises studies on distribution, diversity, and prevalence of gastrointestinal helminth infections in wild ruminants in sub-Saharan Africa. The results showed that 109 gastrointestinal tract (GIT) helminth species or species complexes were recorded in 10 sub-Saharan African countries. South Africa reported the highest number of species because most studies were carried out in this country. Eighty-eight nematode species or species complexes were recorded from 30 wild ruminant species across eight countries. The genus Trichostrongylus recorded the highest number of species and utilised the highest number of wild ruminant species, and along with Haemonchus spp., was the most widely distributed geographically. Fifteen trematode species or species complexes were reported from seven countries. The genus Paramphistomum recorded the highest number of species, and Calicophoron calicophoron was the most commonly occurring species in sub-Saharan African countries and infected the highest number of hosts. Six cestode species or species complexes from one family were documented from 14 wild hosts in seven countries. Moniezia spp. were the most commonly distributed in terms of host range and geographically. Impala were infected by the highest number of nematodes, whilst Nyala were infected by the highest number of trematode species. Greater kudu and Impala harbored the largest number of cestodes. The prevalence amongst the three GIT helminths taxa ranged between 1.4% and 100% for nematodes, 0.8% and 100% for trematodes, and 1.4% and 50% for cestodes. There is still limited information on the distribution and diversity of GIT helminths in wild ruminants in most sub-Saharan African countries.
Assuntos
Trato Gastrointestinal , Helmintíase Animal , Helmintos , Ruminantes , Animais , África Subsaariana/epidemiologia , Ruminantes/parasitologia , Helmintíase Animal/epidemiologia , Helmintíase Animal/parasitologia , Helmintos/classificação , Helmintos/isolamento & purificação , Helmintos/genética , Trato Gastrointestinal/parasitologia , Prevalência , Animais Selvagens/parasitologia , Biodiversidade , Nematoides/classificação , Nematoides/isolamento & purificaçãoRESUMO
Autochthonous yeasts of oenological origin are adapted to highly stressful and selective environments, which makes them potential candidates for probiotics. The objective of the present study was to explore the probiotic potential of 96 native yeasts of oenological origin, their biosafety, resistance to gastrointestinal tract conditions and adhesion properties. Regarding biosafety, 66 isolates shown negative hemolytic activity, negative urease activity and susceptibility to 3 or more antifungals. After the gastrointestinal resistance test, 15 isolates were selected that showed growth at different temperatures, tolerance to low pH and the presence of bile salts in in vitro tests. In general, survival after simulated conditions of the gastrointestinal tract was high and more restrictive was the duodenal. The results of the adhesion properties showed highly variable hydrophobicity and a high percentage of autoaggregation at 24 h. The maximum production of biofilm was detected in the Pichia strains. Of a total of 96 yeast strains, 15 non-Saccharomyces yeasts presented suitable properties as probiotic candidates. The native winemaking strains performed better than the reference probiotic strain, Saccharomyces cerevisiae var. boulardii CNCM I-745, which reaffirms that these strains are promising probiotic candidates and further studies are necessary to confirm their probiosis.
Assuntos
Probióticos , Vinho , Bioprospecção , Leveduras/genética , Saccharomyces cerevisiae , Trato GastrointestinalRESUMO
BACKGROUND: Interferon-gamma release assay (IGRA) is the main tool for the diagnosis of latent tuberculosis (TB) infection (LTBI). However, the indeterminate results were more frequent in children, and the underlying reasons were largely speculative. We aimed to compare QuantiFERON-TB Gold In-Tube (QFT-GIT) with X.DOT-TB (XDOT) for diagnosing LTBI, and to identify the risk factors associated with indeterminate results in children. METHODS: A retrospective study for children<18 years old, at risk for LTBI or progression to TB disease, received either QFT-GIT or X.DOT-TB tests was performed at Beijing Children's Hospital from August 2019 to August 2022. RESULTS: A total of 33,662 children were recruited, including 15,129 (44.9%) tested with X.DOT-TB and 18,533 (55.1%) with QFT-GIT. Proportion of positive and indeterminate results in children with respiratory disease was significantly higher than did that with other diseases, respectively (P < 0.001). The indeterminate rate of X.DOT-TB and QFT-GIT results decreased with increasing age (P < 0.001). Proportion of QFT-GIT indeterminate results was higher than that of X.DOT-TB across age groups. Male, age and disease classification all presented a statistically significant association with indeterminate IGRA results. CONCLUSIONS: The positive rates of X.DOT-TB and QFT-GIT in children were 3.1% and 1.8%, respectively. The X.DOT-TB assay performed better than QFT-GIT in children, and male, age and underlying diseases were associated with an increased risk of indeterminate IGRA results.
Assuntos
Tuberculose Latente , Tuberculose , Criança , Masculino , Humanos , Adolescente , Testes de Liberação de Interferon-gama/métodos , Tuberculose Latente/diagnóstico , Estudos Retrospectivos , Tuberculose/diagnóstico , Teste Tuberculínico/métodosRESUMO
Much concern was directed towards the relationship between migraine and Helicobacter pylori (H. pylori) infection. Some researchers reported a strong association. Meanwhile, others have indicated totally negative results. The aim of this work was to clarify the association between migraine headaches and both H. pylori infection and Gastrointestinal (GIT) symptoms and to study their impact on the frequency and severity of migraine headache attacks.This is a case control study conducted on 77 migraine patients and 77 healthy controls. History was taken from the included patients regarding the frequency of migraine headache attacks/month and GIT symptoms including dyspepsia, flatulence, weight loss, and epigastric pain. Migraine Disability Assessment Test (MIDAS) and Visual Analogue Scale (VAS) were used for assessment of migraine severity. Helicobacter pylori was detected in the stool of the included patients and controls.There was a significantly higher prevalence of infection with H. pylori in migraine patients [77.9% (n = 60)] than control group [50.6% (n = 39)] (P-valueË 0.001, Odds ratio= 3.439, 95% CI =1.708 - 6.923). The prevalence of dyspepsia, flatulence, and epigastric pain. was significantly higher in migraine patients in comparison to control group (P-value= 0.003, 0.017, 0.006 respectively). There was no effect of infection with H. pylori or presence of GIT symptoms on frequency of migraine attacks, MIDAS or VAS scores.GIT symptoms and H. pylori infection are more prevalent in patients with migraine compared to controls, however, they might not have an impact on the frequency or severity of migraine headache attacks.
Assuntos
Dispepsia , Infecções por Helicobacter , Helicobacter pylori , Transtornos de Enxaqueca , Humanos , Infecções por Helicobacter/complicações , Infecções por Helicobacter/diagnóstico , Infecções por Helicobacter/epidemiologia , Dispepsia/complicações , Dispepsia/diagnóstico , Dispepsia/epidemiologia , Flatulência/complicações , Estudos de Casos e Controles , Transtornos de Enxaqueca/complicações , Transtornos de Enxaqueca/epidemiologia , Transtornos de Enxaqueca/diagnóstico , Dor/complicaçõesRESUMO
BACKGROUND: Tuberculosis infection is a major complication of silicosis, but there is no study on whether silicosis can affect the sensitivity of QuantiFERON-TB Gold In-Tube (QFT-GIT) assays. This study will analyze the relationship between silicosis and QFT-GIT, determine the main factor of the QFT-GIT sensitivity decrease in silicosis and explore the methods to increase the sensitivity. METHODS: Silicosis patients with positive tubercle bacillus cultures were collected. The QFT-GIT, flow cytometry and blocking antibodies were used. RESULTS: The sensitivity of QFT-GIT in silicosis patients (58.46%) was significantly decreased and the expression of PD-1 on T cells and CD56+NK cells in pulmonary tuberculosis combined with silicosis were higher than normal tuberculosis patients and silicosis only patients. Further analysis found that the ratio of PD-1+CD4+T and IFN-γwere negatively correlated and blockaded the PD-1 pathway with antibodies can restore the sensitivity of QFT-GIT in silicosis. CONCLUSIONS: This is the first study to analyze the relationship between immune exhaustion and QFT-GIT in silicosis and found that the sensitivity of QFT-GIT was decreased by the expression of PD-1 on lymphocytes. Antibody blocking experiments increased the expression of IFN-γ and provided a new method to improve the sensitivity of QFT in silicosis. The study also found that silicosis can increase PD-1 expression. As PD-1 functions in infectious diseases, it will promote immune exhaustion in silicosis and lead to tuberculosis from latent to active infection. The study provided theoretical evidence for the diagnosis and immunotherapy of silicosis complications, and it has great value in clinical diagnostics and treatment.
Assuntos
Tuberculose Latente , Silicose , Tuberculose , Humanos , Receptor de Morte Celular Programada 1 , Tuberculose Latente/diagnóstico , Silicose/diagnóstico , Silicose/complicações , Anticorpos Bloqueadores , Linfócitos , Teste Tuberculínico/métodosRESUMO
BACKGROUND: Ubiquitin ligases (Ub-ligases) are essential intracellular enzymes responsible for the regulation of proteome homeostasis, signaling pathway crosstalk, cell differentiation and stress responses. Individual Ub-ligases exhibit their unique functions based on the nature of their substrates. They create a complex regulatory network with alternative and feedback pathways to maintain cell homeostasis, being thus important players in many physiological and pathological conditions. However, the functional classification of Ub-ligases needs to be revised and extended. METHODS: In the current study, we used a novel semantic biclustering technique for expression profiling of Ub-ligases and ubiquitination-related genes in the murine gastrointestinal tract (GIT). We accommodated a general framework of the algorithm for finding tissue-specific gene expression clusters in GIT. In order to test identified clusters in a biological system, we used a model of epithelial regeneration. For this purpose, a dextran sulfate sodium (DSS) mouse model, following with in situ hybridization, was used to expose genes with possible compensatory features. To determine cell-type specific distribution of Ub-ligases and ubiquitination-related genes, principal component analysis (PCA) and Uniform Manifold Approximation and Projection technique (UMAP) were used to analyze the Tabula Muris scRNA-seq data of murine colon followed by comparison with our clustering results. RESULTS: Our established clustering protocol, that incorporates the semantic biclustering algorithm, demonstrated the potential to reveal interesting expression patterns. In this manner, we statistically defined gene clusters consisting of the same genes involved in distinct regulatory pathways vs distinct genes playing roles in functionally similar signaling pathways. This allowed us to uncover the potentially redundant features of GIT-specific Ub-ligases and ubiquitination-related genes. Testing the statistically obtained results on the mouse model showed that genes clustered to the same ontology group simultaneously alter their expression pattern after induced epithelial damage, illustrating their complementary role during tissue regeneration. CONCLUSIONS: An optimized semantic clustering protocol demonstrates the potential to reveal a readable and unique pattern in the expression profiling of GIT-specific Ub-ligases, exposing ontologically relevant gene clusters with potentially redundant features. This extends our knowledge of ontological relationships among Ub-ligases and ubiquitination-related genes, providing an alternative and more functional gene classification. In a similar way, semantic cluster analysis could be used for studding of other enzyme families, tissues and systems.
Assuntos
Semântica , Ubiquitina-Proteína Ligases , Animais , Análise por Conglomerados , Trato Gastrointestinal/metabolismo , Humanos , Camundongos , Ubiquitina/genética , Ubiquitina/metabolismo , Ubiquitina-Proteína Ligases/genéticaRESUMO
BACKGROUND: Starch is a principal dietary source of digestible carbohydrate and energy. Glycaemic and insulinaemic responses to foods containing starch vary considerably and glucose responses to starchy foods are often described by the glycaemic index (GI) and/or glycaemic load (GL). Low GI/GL foods are beneficial in the management of cardiometabolic disorders (e.g., type 2 diabetes, cardiovascular disease). Differences in rates and extents of digestion of starch-containing foods will affect postprandial glycaemia. SCOPE AND APPROACH: Amylolysis kinetics are influenced by structural properties of the food matrix and of starch itself. Native (raw) semi-crystalline starch is digested slowly but hydrothermal processing (cooking) gelatinises the starch and greatly increases its digestibility. In plants, starch granules are contained within cells and intact cell walls can limit accessibility of water and digestive enzymes hindering gelatinisation and digestibility. In vitro studies of starch digestion by α-amylase model early stages in digestion and can suggest likely rates of digestion in vivo and expected glycaemic responses. Reports that metabolic responses to dietary starch are influenced by α-amylase gene copy number, heightens interest in amylolysis. KEY FINDINGS AND CONCLUSIONS: This review shows how enzyme kinetic strategies can provide explanations for differences in digestion rate of different starchy foods. Michaelis-Menten and Log of Slope analyses provide kinetic parameters (e.g., K m and k cat /K m ) for evaluating catalytic efficiency and ease of digestibility of starch by α-amylase. Suitable kinetic methods maximise the information that can be obtained from in vitro work for predictions of starch digestion and glycaemic responses in vivo.
RESUMO
Manufactured nanomaterials (NMs) offer incredible scientific and societal benefits but their potential hazard to human health is not yet fully comprehended. In the last decade, a significant body of evidence indicates that certain NMs are capable of translocating from the primary exposure site (skin, lungs and gastrointestinal tract) to a number of secondary organs which includes the liver. Moreover, recent advances in the field of nanomedicine has resulted in increasing direct intravenous injection of NMs with the liver being a particularly important organ with regards to potential toxic effects and accumulation of said materials. It is generally acknowledged that it is not always possible to make direct or meaningful comparisons between in vitro and in vivo xenobiotic-induced toxicological responses. One of the main reasons for the lack of comparability between the testing strategies is that biological responses are not often alike which can in part be attributed to the numerous limitations of traditional mono-cellular in vitro test systems which are acting as a surrogate for a whole organ. In an attempt to address and highlight this important issue, this chapter will discuss the progress made in the production and validation oof next generation more physiologically relevant multi-cellular in vitro models of skin, GIT and the liver utilised for the assessment of the NM-induced toxicological effects.
Assuntos
Nanoestruturas , Humanos , Técnicas In Vitro , Fígado , Nanoestruturas/toxicidadeRESUMO
Subacute ruminal acidosis (SARA) is assumed to be a common disease in high-yielding dairy cows. Despite this, the epidemiological evidence is limited by the lack of survey data. The prevalence of SARA has mainly been determined by measuring the pH of ruminal fluid collected using rumenocentesis. This may not be sufficiently accurate, because the symptoms of SARA are not solely due to ruminal pH depression, and ruminal pH varies among sites in the rumen, throughout a 24-h period, and among days. The impact of SARA has mainly been studied by conducting SARA challenges in cows, sheep, and goats based on a combination of feed restriction and high-grain feeding. The methodologies of these challenges vary considerably among studies. Variations include differences in the duration and amount of grain feeding, type of grain, amount and duration of feed restriction, number of experimental cows, and sensitivity of cows to SARA challenges. Grain-based SARA challenges affect gut health. These effects include depressing the pH in, and increasing the toxin content of, digesta. They also include altering the taxonomic composition of microbiota, reducing the functionality of the epithelia throughout the gastrointestinal tract (GIT), and a moderate inflammatory response. The effects on the epithelia include a reduction in its barrier function. Effects on microbiota include reductions in their richness and diversity, which may reduce their functionality and reflect dysbiosis. Changes in the taxonomic composition of gut microbiota throughout the GIT are evident at the phylum level, but less evident and more variable at the genus level. Effects at the phylum level include an increase in the Firmicutes to Bacteroidetes ratio. More studies on the effects of a SARA challenge on the functionality of gut microbiota are needed. The inflammatory response resulting from grain-based SARA challenges is innate and moderate and mainly consists of an acute phase response. This response is likely a combination of systemic inflammation and inflammation of the epithelia of the GIT. The systemic inflammation is assumed to be caused by translocation of immunogenic compounds, including bacterial endotoxins and bioamines, through the epithelia into the interior circulation. This translocation is increased by the increase in concentrations of toxins in digesta and a reduction of the barrier function of epithelia. Severe SARA can cause rumenitis, but moderate SARA may activate an immune response in the epithelia of the GIT. Cows grazing highly fermentable pastures with high sugar contents can also have a low ruminal pH indicative of SARA. This is not accompanied by an inflammatory response but may affect milk production and gut microbiota. Grain-based SARA affects several aspects of gut health, but SARA resulting from grazing high-digestible pastures and insufficient coarse fiber less so. We need to determine which method for inducing SARA is the most representative of on-farm conditions.
Assuntos
Acidose , Doenças dos Ovinos , Acidose/veterinária , Animais , Dieta/veterinária , Grão Comestível , Feminino , Inflamação/veterinária , Rúmen/microbiologia , OvinosRESUMO
Lately, the software development industry is going through a slow but real transformation. Software is increasingly a part of everything, and, software developers, are trying to cope with this exploding demand through more automation. The pipelining technique of continuous integration (CI) and continuous delivery (CD) has developed considerably due to the overwhelming demand for the deployment and deliverability of new features and applications. As a result, DevOps approaches and Agile principles have been developed, in which developers collaborate closely with infrastructure engineers to guarantee that their applications are deployed quickly and reliably. Thanks to pipeline approach thinking, the efficiency of projects has greatly improved. Agile practices represent the introduction to the system of new features in each sprint delivery. Those practices may contain well-developed features or can contain bugs or failures which impact the delivery. The pipeline approach, depicted in this paper, overcomes the problems of delivery, improving the delivery timeline, the test load steps, and the benchmarking tasks. It decreases system interruption by integrating multiple test steps and adds stability and deliverability to the entire process. It provides standardization which means having an established, time-tested process to use, and can also decrease ambiguity and guesswork, guarantee quality and boost productivity. This tool is developed with an interpreted language, namely Bash, which offers an easier method to integrate it into any platform. Based on the experimental results, we demonstrate the value that this solution currently creates. This solution provides an effective and efficient way to generate, manage, customize, and automate Agile-based CI and CD projects through automated pipelines. The suggested system acts as a starting point for standard CI/CD processes, caches Docker layers for subsequent usage, and implements highly available deliverables in a Kubernetes cluster using Helm. Changing the principles of this solution and expanding it into multiple platforms (windows) will be addressed in a future discussion.
Assuntos
Software , AutomaçãoRESUMO
During the aging process our body becomes less well equipped to deal with cellular stress, resulting in an increase in unrepaired damage. This causes varying degrees of impaired functionality and an increased risk of mortality. One of the most effective anti-aging strategies involves interventions that combine simultaneous glucometabolic support with augmented DNA damage protection/repair. Thus, it seems prudent to develop therapeutic strategies that target this combinatorial approach. Studies have shown that the ADP-ribosylation factor (ARF) GTPase activating protein GIT2 (GIT2) acts as a keystone protein in the aging process. GIT2 can control both DNA repair and glucose metabolism. Through in vivo co-regulation analyses it was found that GIT2 forms a close coexpression-based relationship with the relaxin-3 receptor (RXFP3). Cellular RXFP3 expression is directly affected by DNA damage and oxidative stress. Overexpression or stimulation of this receptor, by its endogenous ligand relaxin 3 (RLN3), can regulate the DNA damage response and repair processes. Interestingly, RLN3 is an insulin-like peptide and has been shown to control multiple disease processes linked to aging mechanisms, e.g., anxiety, depression, memory dysfunction, appetite, and anti-apoptotic mechanisms. Here we discuss the molecular mechanisms underlying the various roles of RXFP3/RLN3 signaling in aging and age-related disorders.
Assuntos
Relaxina , Ansiedade , Apetite , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Relaxina/genética , Relaxina/metabolismo , Transdução de Sinais/fisiologiaRESUMO
Most vaccines approved by regulatory bodies are administered via intramuscular or subcutaneous injections and have shortcomings, such as the risk of needle-associated blood infections, pain and swelling at the injection site. Orally administered vaccines are of interest, as they elicit both systemic and mucosal immunities, in which mucosal immunity would neutralize the mucosa invading pathogen before the onset of an infection. Hence, oral vaccination can eliminate the injection associated adverse effects and enhance the person's compliance. Conventional approaches to manufacturing oral vaccines, such as coacervation, spray drying, and membrane emulsification, tend to alter the structural proteins in vaccines that result from high temperature, organic and toxic solvents during production. Electrohydrodynamic processes, specifically electrospraying, could solve these challenges, as it also modulates antigen release and has a high loading efficiency. This review will highlight the mucosal immunity and biological basis of the gastrointestinal immune system, different oral vaccine delivery approaches, and the application of electrospraying in vaccines development.
RESUMO
Gastrointestinal (GIT) diseases represent an important part of pediatric health disorders. The recent years have brought not only significant improvement of digestive endoscopy technologies and a new equipment suitable for pediatric age but also progress in management of diagnostic approach and treatment of the pediatric GIT diseases. In contrast to adult patients, endoscopic examination in pediatrics is in most cases performed for diagnostic, not therapeutical purposes. The histological assessment of biopsy specimens taken during endoscopy therefore forms an integral part of the endoscopic examination and in most cases the diagnosis cannot be concluded without their evaluation. In particular, the clinical gastroenterologist expects from the pathologist a description that will help confirm or contradict the diagnosis considered after the macroscopic examination. In this review, we would like to highlight the most common endoscopic findings of the gastrointestinal tract in pediatric population and the role of histology in determining the correct diagnosis.