RESUMO
Intestinal stem cells (ISCs) sustain epithelial renewal by dynamically altering behaviors of proliferation and differentiation in response to various nutrition and stress inputs. However, how ISCs integrate bioactive substance morin cues to protect against heat-stable enterotoxin b (STb) produced by Escherichia coli remains an uncertain question with implications for treating bacterial diarrhea. Our recent work showed that oral mulberry leaf-derived morin improved the growth performance in STb-challenged mice. Furthermore, morin supplementation reinstated the impaired small-intestinal epithelial structure and barrier function by stimulating ISC proliferation and differentiation as well as supporting intestinal organoid expansion ex vivo. Importantly, the Wnt/ß-catenin pathway, an ISC fate commitment signal, was reactivated by morin to restore the jejunal crypt-villus architecture in response to STb stimulation. Mechanically, the extracellular morin-initiated ß-catenin axis is dependent or partially dependent on the Wnt membrane receptor Frizzled7 (FZD7). Our data reveal an unexpected role of leaf-derived morin, which represents molecular signaling targeting the FZD7 platform instrumental for controlling ISC regeneration upon STb injury.
Assuntos
Antioxidantes , Toxinas Bacterianas , Enterotoxinas , Infecções por Escherichia coli , Proteínas de Escherichia coli , Jejuno , Morus , Extratos Vegetais , Camundongos , Morus/química , Folhas de Planta/química , Via de Sinalização Wnt , Células-Tronco/efeitos dos fármacos , Células-Tronco/microbiologia , Células-Tronco/patologia , Proteínas de Escherichia coli/metabolismo , Técnicas In Vitro , Extratos Vegetais/farmacologia , Jejuno/efeitos dos fármacos , Jejuno/metabolismo , Jejuno/microbiologia , Jejuno/patologia , Regeneração , Toxinas Bacterianas/isolamento & purificação , Enterotoxinas/isolamento & purificação , Infecções por Escherichia coli/tratamento farmacológico , Antioxidantes/farmacologiaRESUMO
The immune response to mycobacteria is characterized by granuloma formation, which features multinucleated giant cells as a unique macrophage type. We previously found that multinucleated giant cells result from Toll-like receptor-induced DNA damage and cell autonomous cell cycle modifications. However, the giant cell progenitor identity remained unclear. Here, we show that the giant cell-forming potential is a particular trait of monocyte progenitors. Common monocyte progenitors potently produce cytokines in response to mycobacteria and their immune-active molecules. In addition, common monocyte progenitors accumulate cholesterol and lipids, which are prerequisites for giant cell transformation. Inducible monocyte progenitors are so far undescribed circulating common monocyte progenitor descendants with high giant cell-forming potential. Monocyte progenitors are induced in mycobacterial infections and localize to granulomas. Accordingly, they exhibit important immunological functions in mycobacterial infections. Moreover, their signature trait of high cholesterol metabolism may be piggy-backed by mycobacteria to create a permissive niche.
Assuntos
Citocinas/imunologia , Células Gigantes/imunologia , Macrófagos/imunologia , Monócitos/imunologia , Células-Tronco/imunologia , Animais , Células Cultivadas , Citocinas/metabolismo , Feminino , Células Gigantes/metabolismo , Células Gigantes/microbiologia , Granuloma/imunologia , Granuloma/metabolismo , Humanos , Macrófagos/metabolismo , Macrófagos/microbiologia , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Monócitos/metabolismo , Monócitos/microbiologia , Mycobacterium/imunologia , Mycobacterium/fisiologia , Células-Tronco/metabolismo , Células-Tronco/microbiologiaRESUMO
Stem cells maintain tissues by balancing self-renewal with differentiation. A stem cell's local microenvironment, or niche, informs stem cell behavior and receives inputs at multiple levels. Increasingly, it is becoming clear that the overall metabolic status of an organism or metabolites themselves can function as integral members of the niche to alter stem cell fate. Macroscopic dietary interventions such as caloric restriction, the ketogenic diet, and a high-fat diet systemically alter an organism's metabolic state in different ways. Intriguingly, however, they all converge on a propensity to enhance self-renewal. Here, we highlight our current knowledge on how dietary changes feed into stem cell behavior across a wide variety of tissues and illuminate possible explanations for why diverse interventions can result in similar stem cell phenotypes. In so doing, we hope to inspire new avenues of inquiry into the importance of metabolism in stem cell homeostasis and disease.
Assuntos
Dieta , Células-Tronco/fisiologia , Animais , Dieta Hiperlipídica/efeitos adversos , Jejum/fisiologia , Glucose/metabolismo , Humanos , Metabolismo dos Lipídeos/fisiologia , Células-Tronco/microbiologia , Células-Tronco/parasitologia , Estresse Fisiológico/fisiologiaRESUMO
Microbial factors influence homeostatic and oncogenic growth in the intestinal epithelium. However, we know little about immediate effects of commensal bacteria on stem cell division programs. In this study, we examined the effects of commensal Lactobacillus species on homeostatic and tumorigenic stem cell proliferation in the female Drosophila intestine. We identified Lactobacillus brevis as a potent stimulator of stem cell divisions. In a wild-type midgut, L.brevis activates growth regulatory pathways that drive stem cell divisions. In a Notch-deficient background, L.brevis-mediated proliferation causes rapid expansion of mutant progenitors, leading to accumulation of large, multi-layered tumors throughout the midgut. Mechanistically, we showed that L.brevis disrupts expression and subcellular distribution of progenitor cell integrins, supporting symmetric divisions that expand intestinal stem cell populations. Collectively, our data emphasize the impact of commensal microbes on division and maintenance of the intestinal progenitor compartment.
Assuntos
Adesão Celular , Proliferação de Células , Drosophila/metabolismo , Intestinos/citologia , Levilactobacillus brevis/fisiologia , Células-Tronco/metabolismo , Animais , Animais Geneticamente Modificados/metabolismo , Antibacterianos/farmacologia , Diferenciação Celular , Linhagem da Célula , Transformação Celular Neoplásica/efeitos dos fármacos , Regulação para Baixo , Drosophila/microbiologia , Proteínas de Drosophila/deficiência , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Integrinas/metabolismo , Intestinos/microbiologia , Levilactobacillus brevis/efeitos dos fármacos , Receptores Notch/deficiência , Receptores Notch/genética , Células-Tronco/citologia , Células-Tronco/microbiologiaRESUMO
Constraints related to sample preparation are some of the primary obstacles to widespread deployment of molecular diagnostics for rapid detection of trace quantities (≤103 CFU/mL) of food-borne pathogens. In this research, we report a sample preparation method using a novel handheld electroflotation system to concentrate and recover dilute quantities (102-103 CFU/mL) of Escherichia coli (E. coli) 25922 in artificially contaminated samples for reliable, rapid detection by loop-mediated isothermal amplification (LAMP). To protect suspended cells from shear stresses at bubble surfaces, a non-ionic surfactant (Pluronic-F68) and flocculant (chitosan oligosaccharide) were used to aggregate cells and reduce their surface hydrophobicity. Effective conditions for recovery were determined through multifactorial experiments including various concentrations of Pluronic-F68 (0.001, 0.01, 0.1, 1 g L-1), chitosan oligosaccharide (0.01, 0.1, 1, 10 g L-1), bacteria (102, 103, 104 CFU/mL E. coli 25922), recovery times (10, 15 and 20 minutes), and degrees of turbulent gas flux ("high" and "low"). The automated electroflotation system was capable of concentrating effectively all of the bacteria from a large sample (380 mL 0.1 M potassium phosphate buffer containing 102 CFU/mL E. coli) into a 1 mL recovered fraction in less than 30 minutes. This enabled detection of bacterial contaminants within 2 hours of collecting the sample, without a specialized laboratory facility or traditional enrichment methods, with at least a 2-3 order of magnitude improvement in detection limit compared to direct assay with LAMP.
Assuntos
Escherichia coli , Microbiologia de Alimentos , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Quitosana/análise , Limite de Detecção , Oligossacarídeos/análise , Poloxâmero/análise , Células-Tronco/microbiologiaRESUMO
Infectious bone defects remain a significant challenge in orthopedics and dentistry. Calcium phosphate cement (CPC) have attracted significant interest in use as local drug delivery system, which with great potential to control release of antibiotics for the treatment of infectious bone defects. Within the current study, a novel antibacterial scaffold of chitosan-reinforced calcium phosphate cement delivering doxycycline hyclate (CPCC + DOX) was developed. Furthermore, the capacity of CPCC + DOX scaffolds for bone regeneration was enhanced by the human periodontal ligament stem cells (hPDLSCs) encapsulated in alginate beads. CPCC + DOX scaffolds were fabricated to contain different concentrations of DOX. Flexural strength of CPCC + DOX ranged from 5.56 ± 0.70 to 6.2 ± 0.72 MPa, which exceeded the reported strength of cancellous bone. Scaffolds exhibited continual DOX release, reaching 80% at 21 days. Scaffold with 5 mg/ml DOX (CPCC + DOX5mg) had a strong antibacterial effect, with a 4-log colony forming unit reduction against S. aureus and P. gingivalis. The proliferation and osteogenic differentiation of hPDLSCs encapsulated in alginate hydrogel microbeads were investigated in culture with CPCC + DOX scaffolds. CPCC + DOX5mg had no negative effect on proliferation of hPDLSCs. Alkaline phosphatase activity, mineral synthesis, and osteogenic gene expressions for CPCC + DOX5mg group were much higher than control group. DOX did not compromise the osteogenic induction. In summary, the novel CPCC + DOX scaffold exhibited excellent mechanical properties and strong antibacterial activity, while supporting the proliferation and osteogenic differentiation of hPDLSCs. The CPCC + DOX + hPDLSCs construct is promising to enhance bone regeneration and combat bone infections in dental, craniofacial, and orthopedic applications.
Assuntos
Antibacterianos , Infecções por Bacteroidaceae , Cimentos Ósseos , Regeneração Óssea/efeitos dos fármacos , Microesferas , Osteogênese , Ligamento Periodontal , Porphyromonas gingivalis/crescimento & desenvolvimento , Infecções Estafilocócicas , Staphylococcus aureus/crescimento & desenvolvimento , Células-Tronco , Antibacterianos/química , Antibacterianos/farmacologia , Infecções por Bacteroidaceae/tratamento farmacológico , Infecções por Bacteroidaceae/microbiologia , Cimentos Ósseos/química , Cimentos Ósseos/farmacologia , Fosfatos de Cálcio , Humanos , Ligamento Periodontal/metabolismo , Ligamento Periodontal/microbiologia , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/metabolismo , Células-Tronco/metabolismo , Células-Tronco/microbiologiaRESUMO
Gastrointestinal infections often induce epithelial damage that must be repaired for optimal gut function. While intestinal stem cells are critical for this regeneration process [R. C. van der Wath, B. S. Gardiner, A. W. Burgess, D. W. Smith, PLoS One 8, e73204 (2013); S. Kozar et al., Cell Stem Cell 13, 626-633 (2013)], how they are impacted by enteric infections remains poorly defined. Here, we investigate infection-mediated damage to the colonic stem cell compartment and how this affects epithelial repair and recovery from infection. Using the pathogen Clostridioides difficile, we show that infection disrupts murine intestinal cellular organization and integrity deep into the epithelium, to expose the otherwise protected stem cell compartment, in a TcdB-mediated process. Exposure and susceptibility of colonic stem cells to intoxication compromises their function during infection, which diminishes their ability to repair the injured epithelium, shown by altered stem cell signaling and a reduction in the growth of colonic organoids from stem cells isolated from infected mice. We also show, using both mouse and human colonic organoids, that TcdB from epidemic ribotype 027 strains does not require Frizzled 1/2/7 binding to elicit this dysfunctional stem cell state. This stem cell dysfunction induces a significant delay in recovery and repair of the intestinal epithelium of up to 2 wk post the infection peak. Our results uncover a mechanism by which an enteric pathogen subverts repair processes by targeting stem cells during infection and preventing epithelial regeneration, which prolongs epithelial barrier impairment and creates an environment in which disease recurrence is likely.
Assuntos
Proteínas de Bactérias/metabolismo , Toxinas Bacterianas/metabolismo , Clostridioides difficile/patogenicidade , Infecções por Clostridium/patologia , Colo/patologia , Mucosa Intestinal/patologia , Células-Tronco/patologia , Animais , Proteínas de Bactérias/toxicidade , Toxinas Bacterianas/toxicidade , Células Cultivadas , Clostridioides difficile/metabolismo , Infecções por Clostridium/microbiologia , Colo/citologia , Colo/microbiologia , Modelos Animais de Doenças , Feminino , Receptores Frizzled/genética , Receptores Frizzled/metabolismo , Humanos , Mucosa Intestinal/citologia , Mucosa Intestinal/microbiologia , Camundongos , Organoides , Cultura Primária de Células , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Células-Tronco/microbiologiaRESUMO
Tissue homeostasis depends on precise yet plastic regulation of stem cell daughter fates. During growth, Drosophila intestinal stem cells (ISCs) adjust fates by switching from asymmetric to symmetric lineages to scale the size of the ISC population. Using a combination of long-term live imaging, lineage tracing, and genetic perturbations, we demonstrate that this switch is executed through the control of mitotic spindle orientation by Jun-N-terminal kinase (JNK) signaling. JNK interacts with the WD40-repeat protein Wdr62 at the spindle and transcriptionally represses the kinesin Kif1a to promote planar spindle orientation. In stress conditions, this function becomes deleterious, resulting in overabundance of symmetric fates and contributing to the loss of tissue homeostasis in the aging animal. Restoring normal ISC spindle orientation by perturbing the JNK/Wdr62/Kif1a axis is sufficient to improve intestinal physiology and extend lifespan. Our findings reveal a critical role for the dynamic control of SC spindle orientation in epithelial maintenance.
Assuntos
Drosophila melanogaster/metabolismo , Intestinos/citologia , Longevidade/genética , MAP Quinase Quinase 4/metabolismo , Fuso Acromático/metabolismo , Células-Tronco/metabolismo , Animais , Divisão Celular/efeitos dos fármacos , Divisão Celular/genética , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/enzimologia , Drosophila melanogaster/genética , Drosophila melanogaster/fisiologia , Homeostase/fisiologia , Mucosa Intestinal/metabolismo , Intestinos/efeitos dos fármacos , Intestinos/crescimento & desenvolvimento , Intestinos/microbiologia , Cinesinas/genética , Cinesinas/metabolismo , Longevidade/fisiologia , MAP Quinase Quinase 4/genética , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Pectobacterium carotovorum , Fosforilação , Interferência de RNA , Transdução de Sinais/genética , Fuso Acromático/efeitos dos fármacos , Fuso Acromático/enzimologia , Células-Tronco/citologia , Células-Tronco/efeitos dos fármacos , Células-Tronco/microbiologia , Regulação para CimaRESUMO
Epithelia are exposed to diverse types of stress and damage from pathogens and the environment, and respond by regenerating. Yet, the proximal mechanisms that sense epithelial damage remain poorly understood. Here we report that p38 signaling is activated in adult Drosophila midgut enterocytes in response to diverse stresses including pathogenic bacterial infection and chemical and mechanical insult. Two upstream kinases, Ask1 and Licorne (MKK3), are required for p38 activation following infection, oxidative stress, detergent exposure and wounding. Ask1-p38 signaling in enterocytes is required upon infection to promote full intestinal stem cell (ISC) activation and regeneration, partly through Upd3/Jak-Stat signaling. Furthermore, reactive oxygen species (ROS) produced by the NADPH oxidase Nox in enterocytes, are required for p38 activation in enterocytes following infection or wounding, and for ISC activation upon infection or detergent exposure. We propose that Nox-ROS-Ask1-MKK3-p38 signaling in enterocytes integrates multiple different stresses to induce regeneration.
Assuntos
Proteínas de Drosophila/metabolismo , Intestinos/fisiopatologia , MAP Quinase Quinase 3/metabolismo , MAP Quinase Quinase Quinases/metabolismo , NADPH Oxidases/metabolismo , Regeneração/fisiologia , Transdução de Sinais , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Animais Geneticamente Modificados , Infecções Bacterianas/microbiologia , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Enterócitos/metabolismo , Enterócitos/microbiologia , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Mucosa Intestinal/fisiopatologia , Intestinos/microbiologia , Intestinos/patologia , MAP Quinase Quinase 3/genética , MAP Quinase Quinase Quinases/genética , NADPH Oxidases/genética , Estresse Oxidativo , Regeneração/genética , Células-Tronco/metabolismo , Células-Tronco/microbiologia , Estresse Mecânico , Proteínas Quinases p38 Ativadas por Mitógeno/genéticaRESUMO
BACKGROUND & AIMS: Inflammation, injury, and infection up-regulate expression of the tryptophan metabolizing enzyme indoleamine 2,3-dioxygenase 1 (IDO1) in the intestinal epithelium. We studied the effects of cell-specific IDO1 expression in the epithelium at baseline and during intestinal inflammation in mice. METHODS: We generated transgenic mice that overexpress fluorescence-tagged IDO1 in the intestinal epithelium under control of the villin promoter (IDO1-TG). We generated intestinal epithelial spheroids from mice with full-length Ido1 (controls), disruption of Ido1 (knockout mice), and IDO1-TG and analyzed them for stem cell and differentiation markers by real-time polymerase chain reaction, immunoblotting, and immunofluorescence. Some mice were gavaged with enteropathogenic Escherichia coli (E2348/69) to induce infectious ileitis, and ileum contents were quantified by polymerase chain reaction. Separate sets of mice were given dextran sodium sulfate or 2,4,6-trinitrobenzenesulfonic acid to induce colitis; intestinal tissues were analyzed by histology. We utilized published data sets GSE75214 and GDS2642 of RNA expression data from ilea of healthy individuals undergoing screening colonoscopies (controls) and patients with Crohn's disease. RESULTS: Histologic analysis of small intestine tissues from IDO1-TG mice revealed increases in secretory cells. Enteroids derived from IDO1-TG intestine had increased markers of stem, goblet, Paneth, enteroendocrine, and tuft cells, compared with control enteroids, with a concomitant decrease in markers of absorptive cells. IDO1 interacted non-enzymatically with the aryl hydrocarbon receptor to inhibit activation of NOTCH1. Intestinal mucus layers from IDO1-TG mice were 2-fold thicker than mucus layers from control mice, with increased proportions of Akkermansia muciniphila and Mucispirillum schaedleri. Compared to controls, IDO1-TG mice demonstrated an 85% reduction in ileal bacteria (P = .03) when challenged with enteropathogenic E coli, and were protected from immune infiltration, crypt dropout, and ulcers following administration of dextran sodium sulfate or 2,4,6-trinitrobenzenesulfonic acid. In ilea of Crohn's disease patients, increased expression of IDO1 correlated with increased levels of MUC2, LYZ1, and aryl hydrocarbon receptor, but reduced levels of SLC2A5. CONCLUSIONS: In mice, expression of IDO1 in the intestinal epithelial promotes secretory cell differentiation and mucus production; levels of IDO1 are positively correlated with secretory cell markers in ilea of healthy individuals and Crohn's disease patients. We propose that IDO1 contributes to intestinal homeostasis.
Assuntos
Bactérias/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Diferenciação Celular , Microbioma Gastrointestinal , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Doenças Inflamatórias Intestinais/enzimologia , Doenças Inflamatórias Intestinais/microbiologia , Mucosa Intestinal/enzimologia , Mucosa Intestinal/microbiologia , Receptores de Hidrocarboneto Arílico/metabolismo , Receptores Notch/metabolismo , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Estudos de Casos e Controles , Linhagem Celular , Linhagem da Célula , Modelos Animais de Doenças , Células Epiteliais/enzimologia , Células Epiteliais/microbiologia , Células Epiteliais/patologia , Genótipo , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/deficiência , Indolamina-Pirrol 2,3,-Dioxigenase/genética , Doenças Inflamatórias Intestinais/genética , Doenças Inflamatórias Intestinais/patologia , Mucosa Intestinal/patologia , Camundongos Knockout , Fenótipo , Receptores de Hidrocarboneto Arílico/genética , Receptores Notch/genética , Via Secretória , Transdução de Sinais , Células-Tronco/enzimologia , Células-Tronco/microbiologia , Células-Tronco/patologiaAssuntos
Neoplasias Gastrointestinais/etiologia , Neoplasias Gastrointestinais/microbiologia , Infecções por Helicobacter/complicações , Helicobacter pylori/fisiologia , Células da Medula Óssea/microbiologia , Células da Medula Óssea/patologia , Disbiose/complicações , Disbiose/microbiologia , Disbiose/patologia , Microbioma Gastrointestinal , Neoplasias Gastrointestinais/patologia , Infecções por Helicobacter/microbiologia , Infecções por Helicobacter/patologia , Humanos , Células-Tronco/microbiologia , Células-Tronco/patologiaRESUMO
Chronic infections of the fallopian tubes with Chlamydia trachomatis (Ctr) cause scarring and can lead to infertility. Here we use human fallopian tube organoids and genital Ctr serovars D, K and E for long-term in vitro analysis. The epithelial monolayer responds with active expulsion of the bacteria into the lumen and with compensatory cellular proliferation-demonstrating a role of epithelial homeostasis in the defense against this pathogen. In addition, Ctr infection activates LIF signaling, which we find to be an essential regulator of stemness in the organoids. Infected organoids exhibit a less differentiated phenotype with higher stemness potential, as confirmed by increased organoid forming efficiency. Moreover, Ctr increases hypermethylation of DNA, which is an indicator of accelerated molecular aging. Thus, the chronic organoid infection model suggests that Ctr has a long-term impact on the epithelium. These heritable changes might be a contributing factor in the development of tubal pathologies, including the initiation of high grade serous ovarian cancer.
Assuntos
Infecções por Chlamydia/genética , Chlamydia trachomatis/imunologia , Ilhas de CpG/genética , Metilação de DNA/imunologia , Interações entre Hospedeiro e Microrganismos/genética , Células-Tronco/metabolismo , Fatores Etários , Infecções por Chlamydia/imunologia , Infecções por Chlamydia/microbiologia , Chlamydia trachomatis/genética , Doença Crônica , Ilhas de CpG/imunologia , Cistadenocarcinoma Seroso/genética , Cistadenocarcinoma Seroso/imunologia , Cistadenocarcinoma Seroso/microbiologia , Epigênese Genética/genética , Epigênese Genética/imunologia , Epitélio/imunologia , Epitélio/metabolismo , Epitélio/microbiologia , Tubas Uterinas/imunologia , Tubas Uterinas/metabolismo , Tubas Uterinas/microbiologia , Feminino , Interações entre Hospedeiro e Microrganismos/imunologia , Humanos , Microscopia Intravital , Microscopia Confocal , Organoides/imunologia , Organoides/metabolismo , Organoides/microbiologia , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/imunologia , Neoplasias Ovarianas/microbiologia , Sorogrupo , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Análise de Célula Única , Células-Tronco/imunologia , Células-Tronco/microbiologia , Técnicas de Cultura de TecidosAssuntos
Infecções por Mycobacterium não Tuberculosas/diagnóstico , Mycobacterium abscessus/isolamento & purificação , Próstata/microbiologia , Transplante de Células-Tronco/efeitos adversos , Células-Tronco/microbiologia , Fluordesoxiglucose F18/administração & dosagem , Fluordesoxiglucose F18/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Infecções por Mycobacterium não Tuberculosas/sangue , Infecções por Mycobacterium não Tuberculosas/microbiologia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Próstata/diagnóstico por imagem , Próstata/patologia , Antígeno Prostático Específico/análise , Transplante de Células-Tronco/métodosRESUMO
The enteric bacterium and intracellular human pathogen Shigella causes hundreds of millions of cases of the diarrheal disease shigellosis per year worldwide. Shigella is acquired by ingestion of contaminated food or water; upon reaching the colon, the bacteria invade colonic epithelial cells, replicate intracellularly, spread to adjacent cells, and provoke an intense inflammatory response. There is no animal model that faithfully recapitulates human disease; thus, cultured cells have been used to model Shigella pathogenesis. However, the use of transformed cells in culture does not provide the same environment to the bacteria as the normal human intestinal epithelium. Recent advances in tissue culture now enable the cultivation of human intestinal enteroids (HIEs), which are derived from human intestinal stem cells, grown ex vivo, and then differentiated into "mini-intestines." Here, we demonstrate that HIEs can be used to model Shigella pathogenesis. We show that Shigella flexneri invades polarized HIE monolayers preferentially via the basolateral surface. After S. flexneri invades HIE monolayers, S. flexneri replicates within HIE cells and forms actin tails. S. flexneri also increases the expression of HIE proinflammatory signals and the amino acid transporter SLC7A5. Finally, we demonstrate that disruption of HIE tight junctions enables S. flexneri invasion via the apical surface.
Assuntos
Disenteria Bacilar/microbiologia , Mucosa Intestinal/microbiologia , Modelos Biológicos , Organoides/microbiologia , Shigella flexneri/fisiologia , Técnicas de Cultura de Células , Disenteria Bacilar/genética , Disenteria Bacilar/metabolismo , Humanos , Mucosa Intestinal/citologia , Mucosa Intestinal/metabolismo , Transportador 1 de Aminoácidos Neutros Grandes/genética , Transportador 1 de Aminoácidos Neutros Grandes/metabolismo , Organoides/crescimento & desenvolvimento , Organoides/metabolismo , Shigella flexneri/patogenicidade , Células-Tronco/citologia , Células-Tronco/microbiologia , VirulênciaRESUMO
Adult stem and progenitor cells possess unique qualities of proliferative capacity and phenotypic plasticity making their potential interactions with pathogenic and commensal bacteria a significant factor in health and disease. This interaction may result in the hindrance of regenerative capacity and degenerative disease. In other contexts, bacterial-stem cell cross-talk plays an important role in regulating stem cell renewal and maintaining homeostasis. Some stems cells are involved in combating infections and modulating immune responses. The results of these interactions contribute significantly to the outcome of infectious disease. The unique characteristics of stem and progenitor cells also make them attractive targets for bacterial pathogenicity strategies. Several bacterial species have been shown to utilize stem cells as cellular niches or as a means to manipulate host-pathogen interactions. In some cases, bacteria can reprogram end-differentiated tissue cells towards stem-like cells, taking advantage of their unique properties for dissemination and persistence. The ability of bacteria to interfere in stem cell regulatory pathways can also contribute to hyperplastic growth and the development of cancer. In this review, we present current knowledge on the diverse interactions between bacteria and stem cells highlighting the consequences for health and disease.
Assuntos
Fenômenos Fisiológicos Bacterianos , Interações Hospedeiro-Patógeno , Células-Tronco/imunologia , Células-Tronco/microbiologia , Bactérias/imunologia , Neoplasias/microbiologiaRESUMO
The gut, particularly the colon, is the host of approximately 1000 bacterial species, the so-called gut microbiota. The relationship between the gut microbiota and the host is symbiotic and mutualistic, influencing many aspects of the biology of the host. This homeostatic balance can be disrupted by enteric pathogens, such as Shigella flexneri or Listeria monocytogenes, which are able to invade the epithelial layer and consequently subvert physiological functions. To study the host-microbe interactions in vitro, the crypt culture model, known as intestinal organoids, is a powerful tool. Intestinal organoids provide a model in which to examine the response of the epithelium, particularly the response of intestinal stem cells, to the presence of bacteria. Furthermore, the organoid model enables the study of pathogens during the early steps of enteric pathogen invasion.Here, we describe methods that we have established to study the cellular microbiology of symbiosis between the gut microbiota and host intestinal surface and secondly the disruption of host homeostasis due to an enteric pathogen.
Assuntos
Bactérias/crescimento & desenvolvimento , Técnicas de Cultura de Células/métodos , Microbioma Gastrointestinal , Interações Hospedeiro-Patógeno , Mucosa Intestinal/citologia , Organoides/citologia , Células-Tronco/citologia , Diferenciação Celular , Células Cultivadas , Humanos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Organoides/metabolismo , Organoides/microbiologia , Células-Tronco/metabolismo , Células-Tronco/microbiologiaRESUMO
Periodontitis (PD) is a widespread chronic inflammatory disease in the human population. Porphyromonas gingivalis is associated with PD and can citrullinate host proteins via P. gingivalis peptidyl arginine deiminase (PPAD). Here, we hypothesized that infection of human dental follicle stem cells (hDFSCs) with P. gingivalis and subsequent interaction with neutrophils will alter the neutrophil phenotype. To test this hypothesis, we established and analyzed a triple-culture system of neutrophils and hDFSCs primed with P. gingivalis. Mitogen-activated pathway blocking reagents were applied to gain insight into stem cell signaling after infection. Naïve hDFSCs do not influence the neutrophil phenotype. However, infection of hDFSCs with P. gingivalis prolongs the survival of neutrophils and increases their migration. These phenotypic changes depend on direct cellular contacts and PPAD expression by P. gingivalis. Active JNK and ERK pathways in primed hDFSCs are essential for the phenotypic changes in neutrophils. Collectively, our results confirm that P. gingivalis modifies hDFSCs, thereby causing an immune imbalance.
Assuntos
Proteínas de Bactérias/metabolismo , Infecções por Bacteroidaceae/imunologia , Saco Dentário/patologia , Neutrófilos/fisiologia , Periodontite/imunologia , Porphyromonas gingivalis/fisiologia , Desiminases de Arginina em Proteínas/metabolismo , Células-Tronco/fisiologia , Células Cultivadas , Técnicas de Cocultura , Humanos , Imunomodulação , MAP Quinase Quinase 4/metabolismo , Ativação de Neutrófilo , Transdução de Sinais , Células-Tronco/microbiologiaRESUMO
Although symbiotic interactions are ubiquitous in the living world, examples of developmental symbioses are still scarce. We show here the crucial role of Wolbachia in the oogenesis of filarial nematodes, a class of parasites of biomedical and veterinary relevance. We applied newly developed techniques to demonstrate the earliest requirements of Wolbachia in the parasite germline preceding the production of faulty embryos in Wolbachia-depleted nematodes. We show that Wolbachia stimulate germline proliferation in a cell-autonomous manner, and not through nucleotide supplementation as previously hypothesized. We also found Wolbachia to maintain the quiescence of a pool of germline stem cells to ensure a constant delivery of about 1,400 eggs per day for many years. The loss of quiescence upon Wolbachia depletion as well as the disorganization of the distal germline suggest that Wolbachia are required to execute the proper germline stem cell developmental program in order to produce viable eggs and embryos.
Assuntos
Brugia Malayi/crescimento & desenvolvimento , Filariose/patologia , Células Germinativas/citologia , Proteínas de Helminto/metabolismo , Células-Tronco/fisiologia , Simbiose , Wolbachia/fisiologia , Animais , Brugia Malayi/microbiologia , Proliferação de Células , Feminino , Filariose/metabolismo , Filariose/parasitologia , Células Germinativas/microbiologia , Células Germinativas/fisiologia , Proteínas de Helminto/genética , Masculino , Células-Tronco/citologia , Células-Tronco/microbiologiaRESUMO
BACKGROUND: Infection rate associated with intravenous (IV) catheter placement is emerging as an important issue in small animal veterinary medicine, mostly because of the economic costs associated with these infections. Identification of possible associated factors may provide useful information for the surveillance and prevention of such infections. OBJECTIVES: To determine the incidence of positive bacterial cultures obtained from IV catheters used in dogs hospitalized for at least 48 hours and removed because of clinical complication. To identify the bacteria involved and factors associated with bacterial colonization. ANIMALS: One-hundred eighty-two dogs that underwent IV catheterization from January 2015 to July 2015 at the Veterinary Teaching Hospital of Alfonso X el Sabio University of Madrid were enrolled in the study. RESULTS: The bacterial colonization rate of all IV catheters removed in response to clinical complications was 39.6%, the cumulative proportion of catheters that remained in place at 24, 48, and 72 hours after placement was 89.5, 78, and 59.4%, respectively. Multivariable Cox proportional hazards regression indicated significant associations for staff who performed catheterization (junior, P = .002; student, P = .034) and use of steroidal anti-inflammatory drugs (P = .036). The most frequently isolated bacterium was Acinetobacter spp. (21.7%). CONCLUSIONS AND CLINICAL IMPORTANCE: The bacterial colonization incidence related to IV catheter placement was slightly higher than the incidence described in other veterinary studies. Associated factors not previously described in veterinary medicine were found. The most frequently isolated organism was Acinetobacter spp., indicating its importance as an emerging pathogen in catheter colonization.
Assuntos
Infecções Relacionadas a Cateter/veterinária , Doenças do Cão/etiologia , Animais , Infecções Relacionadas a Cateter/epidemiologia , Infecções Relacionadas a Cateter/etiologia , Infecções Relacionadas a Cateter/microbiologia , Cateterismo Periférico/efeitos adversos , Cateterismo Periférico/veterinária , Doenças do Cão/epidemiologia , Doenças do Cão/microbiologia , Cães , Feminino , Incidência , Estudos Longitudinais , Masculino , Modelos de Riscos Proporcionais , Estudos Prospectivos , Fatores de Risco , Células-Tronco/microbiologiaRESUMO
AIM: The aim of the present study was to compare the efficacy of herbal mouthwash and chlorine dioxide mouthwash in reduction of plaque and gingivitis. SETTINGS AND DESIGN: In a randomized clinical trial, forty patients were randomly selected and divided equally into two groups. MATERIALS AND METHODS: After professional oral prophylaxis, the clinical parameters plaque index, gingival index, and modified sulcular bleeding index were recorded at baseline, 7th day, 14th day, and 21st day. The plaque samples were collected from gingival sulcus with an absorbent sterile paper point and were stored in a thioglycollate broth, then sent for microbiological examination. The microbial colony-forming units were assessed at baseline, 7th day, 14th day, and 21st day for Streptococcus mutans, Tannerella forsythia, and Fusobacterium nucleatum. RESULTS: There was a statistical significant reduction in both clinical and microbiological parameters were observed with use of both the mouthwashes. However, herbal mouthwash was more effective in reducing the plaque and gingivitis than chlorine dioxide mouthwash. CONCLUSION: Herbal mouthwash was statistically efficacious in controlling plaque and gingivitis with potent antimicrobial activity.