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1.
Microorganisms ; 12(8)2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-39203412

RESUMO

Inflammatory bowel disease (IBD), which includes Crohn's disease and ulcerative colitis, involves chronic inflammatory disorders of the digestive tract. Oxidative stress, associated with increased reactive oxygen species generation, is a major risk factor for IBD pathogenesis. Industrialized lifestyles expose us to a variety of factors that contribute to deteriorating gut health, especially for IBD patients. Many alternative therapeutic strategies have been developed against oxidative stress along with conventional therapy to alleviate IBD pathogenesis. Polyphenol-rich foods have attracted growing interest from scientists due to their antioxidant properties. Polyphenols are natural compounds found in plants, fruits, vegetables, and nuts that exhibit antioxidant properties and protect the body from oxidative damage. This review presents an overview of polyphenol benefits and describes the different types of polyphenols. It also discusses polyphenols' role in inhibiting oxidative stress and fungal growth prevention. Overall, this review highlights how a healthy and balanced diet and avoiding the industrialized lifestyles of our modern society can minimize oxidative stress damage and protect against pathogen infections. It also highlights how polyphenol-rich foods play an important role in protecting against oxidative stress and fungal growth.

2.
Antibiotics (Basel) ; 12(6)2023 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-37370362

RESUMO

Candida albicans, an opportunistic yeast, is the most common cause of fungal infection. In the past decade, there has been an increase in C. albicans resistance to existing antifungal drugs, which has necessitated the development of new antifungal agents. In the present study, screening 60 compounds from the JUNIA chemical library enabled us to explore an additional 11 hybrid compounds that contain pyrrolidinone rings and hydrazine moieties for their potential antifungal activities. This chemical series was identified with fair to excellent antifungal activities. Among this series, three molecules (Hyd.H, Hyd.OCH3, and Hyd.Cl) significantly reduced C. albicans viability, with rapid fungicidal activity. In addition, these three compounds exhibited significant antifungal activity against clinically isolated fluconazole- or caspofungin-resistant C. albicans strains. Hyd.H, Hyd.OCH3, and Hyd.Cl did not show any cytotoxicity against human cancer cell lines up to a concentration of 50 µg/mL and decreased Candida biofilm formation, with a significant reduction of 60% biofilm formation with Hyd.OCH3. In an infection model of Caenorhabditis elegans with C. albicans, hydrazine-based compounds significantly reduced nematode mortality. Overall, fungicidal activity was observed for Hyd.H, Hyd.OCH3, and Hyd.Cl against C. albicans, and these compounds protected C. elegans from C. albicans infection.

3.
Microorganisms ; 11(6)2023 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-37375058

RESUMO

Western diets are rapidly spreading due to globalization, causing an increase in obesity and diseases of civilization. These Western diets are associated with changes in the gut microbiota related to intestinal inflammation. This review discusses the adverse effects of Western diets, which are high in fat and sugar and low in vegetable fiber, on the gut microbiota. This leads to gut dysbiosis and overgrowth of Candida albicans, which is a major cause of fungal infection worldwide. In addition to an unhealthy Western diet, other factors related to disease development and gut dysbiosis include smoking, excessive alcohol consumption, lack of physical activity, prolonged use of antibiotics, and chronic psychological stress. This review suggests that a diversified diet containing vegetable fiber, omega-3 polyunsaturated fatty acids, vitamins D and E, as well as micronutrients associated with probiotic or prebiotic supplements can improve the biodiversity of the microbiota, lead to short-chain fatty acid production, and reduce the abundance of fungal species in the gut. The review also discusses a variety of foods and plants that are effective against fungal overgrowth and gut dysbiosis in traditional medicine. Overall, healthy diets and lifestyle factors contribute to human well-being and increase the biodiversity of the gut microbiota, which positively modulates the brain and central nervous system.

4.
J Fungi (Basel) ; 7(5)2021 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-33922391

RESUMO

BACKGROUND AND AIMS: This study prompted by growing evidence of the relationship between the yeast Candida albicans and Crohn's disease (CD) was intended to assess the effect of a 6-month course of the antifungal fluconazole (FCZ) on post-operative recurrence of CD. METHODS: Mycological samples (mouth swabs and stools) and serum samples were collected from 28 CD patients randomized to receive either FCZ (n = 14) or placebo (n = 14) before surgical resection. Serological analysis focused on levels of calprotectin, anti-glycan antibodies, and antibody markers of C. albicans pathogenic transition. Levels of galectin-3 and mannose binding lectin (MBL) involved in C. albicans sensing and inflammation were also measured. RESULTS: 1, 2, 3, and 6 months after surgery, endoscopy revealed recurrence in 5/12 (41.7%) patients in the FCZ group and 5/9 (55.6%) in the placebo group, the small cohort preventing any clinical conclusions. In both groups, surgery was followed by a marked decrease in C. albicans colonization and biomarkers of C. albicans pathogenic transition decreased to non-significant levels. Anti-glycan antibodies also decreased but remained significant for CD. Galectin-3 and calprotectin also decreased. Conversely, MBL levels, which inversely correlated with anti-C. albicans antibodies before surgery, remained stable. Building biostatistical multivariate models to analyze he changes in antibody and lectin levels revealed a significant relationship between C. albicans and CD. CONCLUSION: Several combinations of biomarkers of adaptive and innate immunity targeting C. albicans were predictive of CD recurrence after surgery, with area under the curves (AUCs) as high as 0.86. FCZ had a positive effect on biomarkers evolution. ClinicalTrials.gov ID: NCT02997059, 19 December 2016. University Hospital Lille, Ministry of Health, France. Effect of Fluconazole on the Levels of Anti-Saccharomyces cerevisiae Antibodies (ASCA) After Surgical Resection for Crohn's Disease. Multicenter, Randomized, and Controlled in Two Parallel Groups Versus Placebo.

5.
ChemMedChem ; 15(5): 459-467, 2020 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-32022481

RESUMO

A new environmentally friendly approach for the synthesis of idrocilamide (1), a marketed myorelaxant and anti-inflammatory agent, is reported herein. The synthetic strategy involves a solvent-free aminolysis reaction catalyzed by zinc-containing species (ZnCl2 , montmorillonite K10 (MK10) impregnated with ZnCl2 or eco-catalysts). The latter have been prepared from the aerial parts of Lolium perenne L. plants grown on contaminated soils from northern France without and with thermal activation at 120 °C and supported on MK10 (Ecocat1 and Ecocat2, respectively). The best aminolysis catalysts in the current study (ZnCl2 and Ecocat2) were selected for additional aminolyses. Compared to ZnCl2 , Ecocat2 had the advantage of being reusable over five test runs and constituted a sustainable catalyst allowing a green route to idrocilamide. Synthesized derivatives 1-4, 6 and 9 were first evaluated for their effect on reactive oxygen species (ROS) generation from macrophages and displayed antioxidant properties by preventing ROS production. Next, the analysis of the effect of molecules 1-4, 6 and 9 on macrophage migration between epithelial cells to human opportunistic fungus Candida albicans indicated that molecules 2-4, 6 and 9 exert anti-inflammatory properties via reducing macrophage migration while the parent idrocilamide (1) did not show any significant effect. This work opens the way for the discovery of new analogues of idrocilamide with improved properties.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Antioxidantes/farmacologia , Etanolaminas/farmacologia , Compostos Organometálicos/química , Anti-Inflamatórios não Esteroides/síntese química , Anti-Inflamatórios não Esteroides/química , Antioxidantes/síntese química , Antioxidantes/química , Bentonita/química , Catálise , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Cloretos/química , Etanolaminas/síntese química , Etanolaminas/química , Humanos , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Estrutura Molecular , Espécies Reativas de Oxigênio/antagonistas & inibidores , Espécies Reativas de Oxigênio/metabolismo , Compostos de Zinco/química
6.
Int J Mol Sci ; 20(2)2019 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-30646601

RESUMO

Resistance of the opportunistic pathogen Candida albicans to antifungal drugs has increased significantly in recent years. After screening 55 potential antifungal compounds from a chemical library, 2,3-dihydroxy-4-methoxybenzaldehyde (DHMB) was identified as having potential antifungal activity. The properties of DHMB were then assessed in vitro and in vivo against C. albicans overgrowth and intestinal inflammation. Substitution on the aromatic ring of DHMB led to a strong decrease in its biological activity against C. albicans. The MIC of DHMB was highly effective at eliminating C. albicans when compared to that of caspofungin or fluconazole. Additionally, DHMB was also effective against clinically isolated fluconazole- or caspofungin-resistant C. albicans strains. DHMB was administered to animals at high doses. This compound was not cytotoxic and was well-tolerated. In experimental dextran sodium sulphate (DSS)-induced colitis in mice, DHMB reduced the clinical and histological score of inflammation and promoted the elimination of C. albicans from the gut. This finding was supported by a decrease in aerobic bacteria while anaerobic bacteria populations were re-established in mice treated with DHMB. DHMB is a small organic molecule with antifungal properties and anti-inflammatory activity by exerting protective effects on intestinal epithelial cells.


Assuntos
Benzaldeídos/administração & dosagem , Candidíase/tratamento farmacológico , Inflamação/tratamento farmacológico , Intestinos/efeitos dos fármacos , Animais , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/química , Antifúngicos/administração & dosagem , Antifúngicos/química , Benzaldeídos/química , Candida albicans/efeitos dos fármacos , Candida albicans/patogenicidade , Candidíase/microbiologia , Modelos Animais de Doenças , Células Epiteliais/efeitos dos fármacos , Humanos , Inflamação/microbiologia , Inflamação/patologia , Intestinos/microbiologia , Intestinos/patologia , Camundongos
7.
Infect Immun ; 85(1)2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27799334

RESUMO

Integrins αMß2 and αXß2 are homologous adhesive receptors that are expressed on many of the same leukocyte populations and bind many of the same ligands. Although αMß2 was extensively characterized and implicated in leukocyte inflammatory and immune functions, the roles of αXß2 remain largely obscure. Here, we tested the ability of mice deficient in integrin αMß2 or αXß2 to deal with opportunistic infections and the capacity of cells derived from these animals to execute inflammatory functions. The absence of αMß2 affected the recruitment of polymorphonuclear neutrophils (PMN) to bacterial and fungal pathogens as well as to model inflammatory stimuli, and αMß2-deficient PMN displayed defective inflammatory functions. In contrast, deficiency of αXß2 abrogated intraperitoneal recruitment and adhesive functions of monocytes and macrophages (Mϕ) and the ability of these cells to kill/phagocytose Candida albicans or Escherichia coli cells both ex vivo and in vivo During systemic candidiasis, the absence of αXß2 resulted in the loss of antifungal activity by tissue Mϕ and inhibited the production of tumor necrosis factor alpha (TNF-α)/interleukin-6 (IL-6) in infected kidneys. Deficiency of αMß2 suppressed Mϕ egress from the peritoneal cavity, decreased the production of anti-inflammatory IL-10, and stimulated the secretion of IL-6. The absence of αXß2, but not of αMß2, increased survival against a septic challenge with lipopolysaccharide (LPS) by 2-fold. Together, these results suggest that αMß2 plays a primary role in PMN inflammatory functions and regulates the anti-inflammatory functions of Mϕ, whereas αXß2 is central in the regulation of inflammatory functions of recruited and tissue-resident Mϕ.


Assuntos
Anti-Infecciosos/metabolismo , Inflamação/metabolismo , Integrina alfaXbeta2/metabolismo , Leucócitos/metabolismo , Antígeno de Macrófago 1/metabolismo , Animais , Candida albicans/metabolismo , Candidíase/metabolismo , Candidíase/microbiologia , Adesão Celular/fisiologia , Escherichia coli/metabolismo , Infecções por Escherichia coli/metabolismo , Infecções por Escherichia coli/microbiologia , Inflamação/microbiologia , Interleucina-10/metabolismo , Interleucina-6/metabolismo , Leucócitos/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Neutrófilos/metabolismo , Neutrófilos/microbiologia , Fagocitose/fisiologia , Fator de Necrose Tumoral alfa/metabolismo
8.
Sci Rep ; 6: 29636, 2016 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-27404661

RESUMO

Mannose-binding lectin, together with mannose-associated serine proteases, activates the lectin pathway of the complement system and subsequent inflammatory mechanisms. An association between mannose-binding lectin deficiency and anti-Saccharomyces cerevisiae antibody levels is observed in Crohn's disease and this deficiency is frequently associated with a severe Crohn's disease phenotype. In the present study, we assessed the relationship between serum concentrations of mannose-binding lectin, mannose-binding lectin functional activity, MBL2 and NOD2 polymorphisms, anti-S. cerevisiae antibody levels and clinical Crohn's disease phenotype in 69 Crohn's disease patients and 30 age- and sex-matched healthy controls. The results show that the MBL2 variant rs5030737 at codon 52 was associated with a low level of mannose-binding lectin and impaired mannose-binding lectin-mannose-associated serine protease (MBL-MASP) functional activity in Crohn's disease patients. This MBL2 variant was also associated with a higher level of anti-S. cerevisiae antibodies. In addition, the NOD2 variant rs2066844, which is associated with susceptibility to Crohn's disease, was significantly correlated with an impairment in MBL-MASP functional activity. These results provide evidence that Crohn's disease patients have an impairment in MBL-MASP functional activity and that this defect is associated with MBL2 and NOD2 variants.


Assuntos
Doença de Crohn/genética , Lectina de Ligação a Manose/genética , Serina Proteases Associadas a Proteína de Ligação a Manose/genética , Proteína Adaptadora de Sinalização NOD2/genética , Doença de Crohn/sangue , Feminino , Genótipo , Humanos , Masculino , Lectina de Ligação a Manose/sangue , Cordão Nucal , Fenótipo , Polimorfismo de Nucleotídeo Único , Saccharomyces cerevisiae/imunologia
9.
Am J Physiol Heart Circ Physiol ; 311(3): H725-34, 2016 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-27288438

RESUMO

Platelets are capable of binding, aggregating, and internalizing microorganisms, which enhances the elimination of pathogens from the blood. The yeast Candida albicans is a pathobiont causing life-threatening invasive infections. Its cell wall contains ß-1,3 glucans that are known to trigger a wide range of host cell activities and to circulate during infection. We studied the effect of ß-1,3 glucan fractions (BGFs) consisting of diglucosides (Glc2), tetraglucosides (Glc4), and pentaglucosides (Glc5) on human platelets, their mechanisms of action, and their possible impact on host defenses. The effect of BGFs on the coagulation process was determined by measuring thrombin generation. Platelets pretreated with BGFs were analyzed in terms of activation, receptor expression, aggregation, and adhesion to neutrophils and to C. albicans The results show that BGFs affected the endogenous thrombin potential in a concentration-dependent manner. For platelet activation, BGFs at a low concentration (2 µmol/l) reduced ATP release and prevented the phosphorylation of protein kinase C. BGFs diminished the expression of P-selectin and the activation of αIIbß3 BGFs decreased platelet aggregation and the interaction between thrombin-stimulated platelets and neutrophils, fibrinogen, and C. albicans GLc5 decreased ATP release and TGF-ß1 production in response to TLR4 upregulation in thrombin-stimulated platelets, but TLR4 blockage abolished the effect of BGFs on platelets. This study provides evidence that fungal pentaglucosides modulate platelet activity mediated via TLR4 stimulation and reduce platelet-neutrophil interaction.


Assuntos
Plaquetas/efeitos dos fármacos , Glucosídeos/farmacologia , Ativação Plaquetária/efeitos dos fármacos , Adesividade Plaquetária/efeitos dos fármacos , Agregação Plaquetária/efeitos dos fármacos , Receptor 4 Toll-Like/metabolismo , beta-Glucanas/farmacologia , Trifosfato de Adenosina/metabolismo , Plaquetas/metabolismo , Candida albicans , Fibrinogênio/efeitos dos fármacos , Fibrinogênio/metabolismo , Fungos/química , Humanos , Neutrófilos , Selectina-P/efeitos dos fármacos , Selectina-P/metabolismo , Fosforilação , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/efeitos dos fármacos , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/metabolismo , Proteína Quinase C/efeitos dos fármacos , Proteína Quinase C/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Trombina/efeitos dos fármacos , Trombina/metabolismo , Receptor 4 Toll-Like/antagonistas & inibidores , Fator de Crescimento Transformador beta1/efeitos dos fármacos , Fator de Crescimento Transformador beta1/metabolismo , Regulação para Cima
10.
Infect Immun ; 82(1): 306-15, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24166952

RESUMO

Pseudomonas aeruginosa and Candida albicans are two pathogens frequently encountered in the intensive care unit microbial community. We have demonstrated that C. albicans airway exposure protected against P. aeruginosa-induced lung injury. The goal of the present study was to characterize the cellular and molecular mechanisms associated with C. albicans-induced protection. Airway exposure by C. albicans led to the recruitment and activation of natural killer cells, innate lymphoid cells (ILCs), macrophages, and dendritic cells. This recruitment was associated with the secretion of interleukin-22 (IL-22), whose neutralization abolished C. albicans-induced protection. We identified, by flow cytometry, ILCs as the only cellular source of IL-22. Depletion of ILCs by anti-CD90.2 antibodies was associated with a decreased IL-22 secretion and impaired survival after P. aeruginosa challenge. Our results demonstrate that the production of IL-22, mainly by ILCs, is a major and inducible step in protection against P. aeruginosa-induced lung injury. This cytokine may represent a clinical target in Pseudomonas aeruginosa-induced lung injury.


Assuntos
Candida albicans/fisiologia , Imunidade Inata/imunologia , Interleucinas/imunologia , Lesão Pulmonar/microbiologia , Linfócitos/imunologia , Infecções por Pseudomonas/imunologia , Pseudomonas aeruginosa/imunologia , Análise de Variância , Animais , Candida albicans/imunologia , Células Dendríticas/imunologia , Modelos Animais de Doenças , Citometria de Fluxo , Imunidade Celular/imunologia , Imunidade Inata/fisiologia , Interleucinas/metabolismo , Células Matadoras Naturais/imunologia , Lesão Pulmonar/imunologia , Linfócitos/metabolismo , Macrófagos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Interleucina 22
11.
PLoS One ; 7(7): e40648, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22848391

RESUMO

Yeasts and their glycan components can have a beneficial or adverse effect on intestinal inflammation. Previous research has shown that the presence of Saccharomyces cerevisiae var. boulardii (Sb) reduces intestinal inflammation and colonization by Candida albicans. The aim of this study was to identify dietary yeasts, which have comparable effects to the anti-C. albicans and anti-inflammatory properties of Sb and to assess the capabilities of yeast cell wall components to modulate intestinal inflammation. Mice received a single oral challenge of C. albicans and were then given 1.5% dextran-sulphate-sodium (DSS) for 2 weeks followed by a 3-day restitution period. S. cerevisiae strains (Sb, Sc1 to Sc4), as well as mannoprotein (MP) and ß-glucan crude fractions prepared from Sc2 and highly purified ß-glucans prepared from C. albicans were used in this curative model, starting 3 days after C. albicans challenge. Mice were assessed for the clinical, histological and inflammatory responses related to DSS administration. Strain Sc1-1 gave the same level of protection against C. albicans as Sb when assessed by mortality, clinical scores, colonization levels, reduction of TNFα and increase in IL-10 transcription. When Sc1-1 was compared with the other S. cerevisiae strains, the preparation process had a strong influence on biological activity. Interestingly, some S. cerevisiae strains dramatically increased mortality and clinical scores. Strain Sc4 and MP fraction favoured C. albicans colonization and inflammation, whereas ß-glucan fraction was protective against both. Surprisingly, purified ß-glucans from C. albicans had the same protective effect. Thus, some yeasts appear to be strong modulators of intestinal inflammation. These effects are dependent on the strain, species, preparation process and cell wall fraction. It was striking that ß-glucan fractions or pure ß-glucans from C. albicans displayed the most potent anti-inflammatory effect in the DSS model.


Assuntos
Candida albicans , Candidíase/tratamento farmacológico , Parede Celular/química , Misturas Complexas/química , Misturas Complexas/farmacologia , Enteropatias/tratamento farmacológico , Saccharomyces cerevisiae , beta-Glucanas/farmacologia , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Candidíase/imunologia , Candidíase/patologia , Feminino , Interleucina-10/imunologia , Enteropatias/imunologia , Enteropatias/microbiologia , Intestinos/imunologia , Intestinos/microbiologia , Intestinos/patologia , Camundongos , Camundongos Endogâmicos BALB C , Fator de Necrose Tumoral alfa/imunologia , beta-Glucanas/química
12.
Crit Care ; 15(3): R150, 2011 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-21689424

RESUMO

INTRODUCTION: Pseudomonas aeruginosa is a frequent cause of ventilator-acquired pneumonia (VAP). Candida tracheobronchial colonization is associated with higher rates of VAP related to P. aeruginosa. This study was designed to investigate whether prior short term Candida albicans airway colonization modulates the pathogenicity of P. aeruginosa in a murine model of pneumonia and to evaluate the effect of fungicidal drug caspofungin. METHODS: BALB/c mice received a single or a combined intratracheal administration of C. albicans (1 × 10(5) CFU/mouse) and P. aeruginosa (1 × 10(7) CFU/mouse) at time 0 (T0) upon C. albicans colonization, and Day 2. To evaluate the effect of antifungal therapy, mice received caspofungin intraperitoneally daily, either from T0 or from Day 1 post-colonization. After sacrifice at Day 4, lungs were analyzed for histological scoring, measurement of endothelial injury, and quantification of live P. aeruginosa and C. albicans. Blood samples were cultured for dissemination. RESULTS: A significant decrease in lung endothelial permeability, the amount of P. aeruginosa, and bronchiole inflammation was observed in case of prior C. albicans colonization. Mortality rate and bacterial dissemination were unchanged by prior C. albicans colonization. Caspofungin treatment from T0 (not from Day 1) increased their levels of endothelial permeability and lung P. aeruginosa load similarly to mice receiving P. aeruginosa alone. CONCLUSIONS: P. aeruginosa-induced lung injury is reduced when preceded by short term C. albicans airway colonization. Antifungal drug caspofungin reverses that effect when used from T0 and not from Day 1.


Assuntos
Carga Bacteriana/fisiologia , Candida albicans/crescimento & desenvolvimento , Modelos Animais de Doenças , Lesão Pulmonar/microbiologia , Lesão Pulmonar/prevenção & controle , Infecções por Pseudomonas/prevenção & controle , Pseudomonas aeruginosa/crescimento & desenvolvimento , Animais , Carga Bacteriana/métodos , Contagem de Colônia Microbiana/métodos , Camundongos , Camundongos Endogâmicos BALB C , Infecções por Pseudomonas/fisiopatologia , Pseudomonas aeruginosa/isolamento & purificação , Distribuição Aleatória , Fatores de Tempo
13.
Dig Dis ; 27 Suppl 1: 104-10, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-20203505

RESUMO

BACKGROUND: Current research on Crohn's disease (CD) concerns molecular events related to loss of tolerance to microbes that could trigger or maintain inflammation in genetically susceptible individuals. CD is also associated with antimicrobial antibodies, including the antibodies we described against yeast oligomannosides (ASCA). This prompted us to investigate a role for another yeast, Candida albicans, a very common commensal of the human digestive tract and an important opportunistic pathogen. CLINICAL AND EXPERIMENTAL DATA: It has been revealed that the major oligomannose epitopes supporting ASCA are expressed by C. albicans in human tissues, suggesting that C. albicans is the immunogen for ASCA. This link has been reinforced by the demonstration that novel serological markers of CD (ALCA and ACCA), consisting of antibodies against chitin and glucan (two components of the C. albicans cell wall), are also generated during C. albicans infection. Mycological investigation of families with multiple cases of CD shows that patients with CD and their healthy relatives are colonized with C. albicans more commonly than control families. In healthy relatives, C. albicans colonization correlates with ASCA levels, whereas the onset of CD is associated with ASCA stability and is independent of the C. albicans intestinal load. Experimental studies show that chemically-induced colitis promotes C. albicans colonization in mice. In turn, C. albicans colonization generates ASCA, increases inflammation, histological scores and pro-inflammatory cytokine expression. PERSPECTIVES: Current investigations focus on interactions of TLRs and lectins with yeast epitopes that differently polarize the immune response to C. albicans cell wall glycans, which are the targets of an 'excessive' adaptive response associated with CD.


Assuntos
Candida albicans/imunologia , Doença de Crohn/microbiologia , Animais , Anticorpos Antifúngicos/imunologia , Candidíase/sangue , Candidíase/diagnóstico , Candidíase/microbiologia , Parede Celular/metabolismo , Doença de Crohn/sangue , Doença de Crohn/diagnóstico , Humanos , Camundongos , Saccharomyces cerevisiae/imunologia
14.
J Infect Dis ; 197(7): 972-80, 2008 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-18419533

RESUMO

BACKGROUND: Little is known about the relationship between colonic inflammation and Candida albicans colonization. Galectin-3 (Gal-3) is an intestinal lectin that binds to specific C. albicans glycans and is involved in inflammation. METHODS: Colitis was experimentally induced in wild-type and Gal3(-/-) mice using dextran sulfate sodium (DSS) before oral administration of C. albicans. Yeast recovered from stools was quantified. The presence of yeast and inflammation were evaluated in sections of colon by histologic examination, quantification of myeloperoxidase (MPO) activity, and by gene expression for cytokines and innate immune receptors. Serum from mice was collected for determination of anti-yeast mannan antibodies, including anti-Saccharomyces cerevisiae antibodies (ASCA), which are biomarkers of an inflammatory bowel disease. RESULTS: Inflammation strongly promoted C. albicans colonization. Conversely, C. albicans augmented inflammation induced by DSS, as assessed by histologic scores, MPO activity, and tumor necrosis factor (TNF)-alpha and Toll-like receptor (TLR)-2 expression. C. albicans colonization generated ASCA. The absence of Gal-3 reduced DSS inflammation and abolished the response of TLR-2 and TNF-alpha to C. albicans colonization. CONCLUSIONS: DSS-induced colitis provides a model for establishing C. albicans colonization in mice. This model reveals that C. albicans augments inflammation and confirms the role of Gal-3 in both inflammation and the control of host responses to C. albicans.


Assuntos
Candida albicans/crescimento & desenvolvimento , Candidíase/microbiologia , Colite/complicações , Galectina 3/metabolismo , Inflamação/induzido quimicamente , Animais , Anticorpos Antifúngicos/sangue , Antígenos de Fungos/imunologia , Colo/microbiologia , Colo/patologia , Contagem de Colônia Microbiana , Citocinas/genética , Sulfato de Dextrana/toxicidade , Fezes/microbiologia , Feminino , Galectina 3/deficiência , Perfilação da Expressão Gênica , Mananas/imunologia , Camundongos , Peroxidase/metabolismo , Receptores Imunológicos/genética , Saccharomyces cerevisiae/imunologia , Índice de Gravidade de Doença
15.
Med Mycol ; 45(8): 691-700, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17885943

RESUMO

The present study was designed to investigate the effects of Saccharomyces boulardii on inflammation and intestinal colonization by Candida albicans in a BALB/c mouse model of colitis that had been induced by dextran-sulfate-sodium (DSS). Colonization with C. albicans was established by oral gavage with a 200 microL suspension of 10(7) yeast cells. A 1.5% solution of DSS was administered in drinking water 1 h after C. albicans oral challenge, while 10(7) cells of S. boulardii was inoculated daily by oral gavage for 1 week. Faeces were collected daily for 2 weeks. Seven groups of mice consisting of those that were administered either C. albicans or S. boulardii or both were sacrificed after 14 days and samples of the colon were taken for histological scoring and real-time PCR (RT-PCR) analysis of inflammatory cytokines and toll-like receptors (TLRs). Compared to control animals that did not receive DSS, the number of C. albicans colonies recovered from faeces was significantly greater in mice receiving DSS. In contrast, the colony forming units (CFUs) of C. albicans were greatly reduced in mice receiving S. boulardii. The administration of this yeast decreased the severity of DSS-induced clinical scores and histological inflammation. At the mRNA expression level, an increase in TLR2 and TLR4 resulting from the presence of S. boulardii was associated with a reduction in the inflammatory cytokines TNFalpha and INFgamma. In mice receiving DSS and C. albicans, TLR4 was over-expressed by stimulation with both yeasts, but TLR2 and TNFalpha, which were increased by the administration of C. albicans alone, were decreased in the presence of S. boulardii. These results indicate that S. boulardii decreased inflammation and C. albicans colonization in this BALB/c mouse model of colitis.


Assuntos
Candida albicans/crescimento & desenvolvimento , Candidíase/microbiologia , Colite/microbiologia , Saccharomyces/crescimento & desenvolvimento , Animais , Candidíase/metabolismo , Candidíase/prevenção & controle , Colite/induzido quimicamente , Colite/metabolismo , Contagem de Colônia Microbiana , Modelos Animais de Doenças , Fezes/microbiologia , Interferon gama/biossíntese , Interferon gama/genética , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Microscopia de Fluorescência , Reação em Cadeia da Polimerase , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Estatísticas não Paramétricas , Receptores Toll-Like/biossíntese , Receptores Toll-Like/genética , Fator de Necrose Tumoral alfa/biossíntese , Fator de Necrose Tumoral alfa/genética
16.
Lasers Med Sci ; 21(3): 153-9, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16897111

RESUMO

The worldwide rise in antibiotic resistance necessitates the development of novel antimicrobial strategies. This study aimed to evaluate the bactericidal action of an 810-nm diode laser in a cutaneous wound infection. An Escherichia coli strain was transformed with a shuttle vector (pRB474) containing firefly luciferase gene from Photinus pyralis resulting in a bioluminescent phenotype. Because firefly luciferase is an enzyme and as such is prone to inactivation at elevated temperature, the first phase has consisted in evaluating in vitro the effect of temperature elevation (30, 40, 50, and 60 degrees C for 2 min) on bacteria bioluminescence. The second phase was performed in vivo. Two full-thickness circular, 14-mm diameter wounds (control and laser-irradiated) were induced on rats. Wound infection was carried out using a suspension (50 microl PBS) containing 5 x 10(7) cells of bioluminescent E. coli (10(9) cells/ml). Thirty minutes later, light irradiation was performed with an 810-nm diode laser (P = 10 W, psi = 1.4 cm, fluence: 130, 195, and 260 J/cm2). Temperature was measured within each wound with a noncontact infrared thermometer. Light emission of the bioluminescent bacteria was monitored in vivo by a bioluminescence imaging system before and at 4, 8, 24, and 48 h after laser irradiation. In vitro, bacteria bioluminescence is not affected when temperature is maintained at 50 degrees C for 2 min. In vivo, bioluminescence imaging showed that at 4 h, the viability of E. coli was reduced when compared to the control (CTRL) group (p < 0.01). This observation was confirmed at 8 h (p < 0.001), at 24 h (p < 0.001), and finally at 48 h (p < 0.001). Loss of viability of E. coli depends on laser fluence. At 48 h, bioluminescent bacteria were not detected (100% loss of viability) in the wound irradiated at 260 J/cm2. For this fluence, the temperature reached 45 degrees C at the end of the irradiation. This study confirms previous observations on the bactericidal effect of diode lasers. Because a progressive desiccation of the superficial dermis is usually observed when using laser irradiation, the hypothesis that laser irradiation dries out the wound making the wound an inhospitable place for bacteria is much more relevant than a direct effect of infrared light on chromophores inside bacteria. This is confirmed by the fact that in this latter case, one would expect an immediate drop in luminescence followed by an increase as the surviving bacteria started to divide and repopulate the wound. However, the exact mechanism deserves further studies. This study points out the advantage of using bioluminescence imaging to evaluate laser for the treatment of acute infections in vivo, nondestructively, and noninvasively.


Assuntos
Escherichia coli/efeitos da radiação , Terapia com Luz de Baixa Intensidade , Luciferases de Vaga-Lume/uso terapêutico , Substâncias Luminescentes/uso terapêutico , Pele/lesões , Infecção dos Ferimentos/radioterapia , Animais , Infecções por Escherichia coli/microbiologia , Luciferina de Vaga-Lumes , Masculino , Modelos Animais , Ratos , Ratos Sprague-Dawley , Pele/microbiologia , Pele/efeitos da radiação , Infecção dos Ferimentos/microbiologia
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