42 research outputs found

    Inhibitory effects of agmatine on monoamine oxidase (MAO) activity: Reconciling the discrepancies

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    Abstract Agmatine has been functionally characterized as an important hormone and co-neurotransmitter in mammals. Given its ability in binding Imidazoline sites, a regolatory site of monoaminoxydase, it has been suggested to be involved in many neurological aspects. However, its inhibitory effect on this enzyme still remains an unanswered question. This present study is aimed to asses whether different experimental conditions could affect the agmatine action on monoaminoxydase activity. We demonstrate that the monoaminoxydase inhibition by agmatine is obtained under alkaline conditions and a long time of incubation. No inhibitiory action was found for shorter times of reaction at elevated pH, or at neutral condition and long time of incubation. No inhibition was also detected by substituting the monoamineoxydase substrate tyramine with kynuramine, however, while in these conditions a remarkable inhibition was shown by two aminoxydase inhibitors tranylcypromine and idazoxan. Herein, we discuss a mechanism model and the functional consequences of agmatine action on monoaminoxydase

    Nutraceutical prospective: The synergetic mechanism of action of inositols and resveratrol on metabolic syndrome

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    Abstract It has been known that inositols function as insulin second messengers and mediate different insulin-dependent processes and are a valid natural, non-pharmaceutical alternative to contrast insulin-resistance as well as associated metabolic syndrome in women with Polycystic ovarian disease (PCOS). Several studies also have shown positive effects of resveratrol in reducing glucose and lipid concentrations in patients. Recently, clinical evidence has proven that an D-chiro-inositol/resveratrol combination has a potential role to play in maintaining metabolic and endocrine health, however no large clinical trials have demonstrated the medical effectiveness of the combination, and the combined mode of action remains poorly discussed. Herein, we address the hypothesis of a synergistic mechanism adopted by D-chiro-inositol and resveratrol in reducing insulin resistance and hyperlipidemia and thus showing a greater therapeutic potential compared to treatment with inositol's alone

    TLR3 essentially promotes protective class I–restricted memory CD8+ T-cell responses to Aspergillus fumigatus in hematopoietic transplanted patients

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    Aspergillus fumigatus is a model fungal pathogen and a common cause of severe infections and diseases. CD8+ T cells are present in the human and murine T-cell repertoire to the fungus. However, CD8+ T-cell function in infection and the molecular mechanisms that control their priming and differentiation into effector and memory cells in vivo remain elusive. In the present study, we report that both CD4+ and CD8+ T cells mediate protective memory responses to the fungus contingent on the nature of the fungal vaccine. Mechanistically, class I MHC-restricted, CD8+ memory T cells were activated through TLR3 sensing of fungal RNA by cross-presenting dendritic cells. Genetic deficiency of TLR3 was associated with susceptibility to aspergillosis and concomitant failure to activate memory-protective CD8+ T cells both in mice and in patients receiving stem-cell transplantations. Therefore, TLR3 essentially promotes antifungal memory CD8+ T-cell responses and its deficiency is a novel susceptibility factor for aspergillosis in high-risk patients.These studies were supported by the Specific Targeted Research Project ALLFUN (FP7-HEALTH-2009 contract number 260338 to L.R.), by SYBARIS (FP7-HEALTH-2009 contract number 242220 to L.R.), and by the Italian Project AIDS 2010 by the Istituto Superiore di Sanita (contract number 40H40 to L.R.). A.C. and C.C. were supported by fellowships from Fundacao para a Ciencia e Tecnologia, Portugal (contracts SFRH/BPD/46292/2008 and SFRH/BD/65962/2009, respectively)

    From memory to antifungal vaccine design

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    Fungal infections and related diseases have a high morbidity and mortality rate. Human antifungal vaccines are therefore of great interest, however, their development is challenging. Major hurdles include fungal species-specific differences in pathogenic mechanisms and strategies to escape immune surveillance, as well as the fact that individuals susceptible to infection do not necessarily share the same risk factors. Progress in antifungal vaccines demands the integration of immunology with systems biology, immunogenetics and bioinformatics in the arena of both fungal and host biology. Bridging the fields of basic immunology and vaccine research is needed to create individualized host immune profiles that will direct the rational development of customized adjuvants and vaccines with a predicted efficacy in each target population.Specific Targeted Research Project “FUNMETA” (FP7− ERC−2009−293714 to R.L.

    Resveratrol-Based Multivitamin Supplement Increases Sperm Concentration and Motility in Idiopathic Male Infertility: A Pilot Clinical Study

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    Background. It is known that a multitude of factors may lead to male factor infertility, but still, in the majority of cases, the cause remains largely idiopathic, reflecting poor understanding of the basic process of spermatogenesis and the mechanisms involved. Resveratrol is a polyphenol compound that displays several cellular aspects mainly associated with SIRT1-pathway activation and promotion of mitochondrial enhancer activities. In several animal models, resveratrol has shown positive effects on mitochondria and membrane potential. This could explain effects on sperm concentration and motility. The aim of this study is to evaluate the effects on the semen parameters of GENANTE(R), a multivitamin supplement containing 150 mg of resveratrol/day, in patients with idiopathic infertility. Methods. This was a prospective single center clinical study. Twenty patients took a multivitamin supplement based on 150 mg of resveratrol (GENANTE(R)), in the form of an oral tablet every 12 h, and were followed up at 1, 3, and 6 months after treatment. Pre- and post-treatment evaluation included history, clinical examination, semen analysis, hormonal determinations, and scrotal and prostatic ultrasound. Results. Our preliminary pilot study demonstrated that the multivitamin supplement based on resveratrol improves sperm motility (48.3% +/- 13.8 vs. 59.0% +/- 12.8, p = 0.0001) and concentration (22.6 x 10(6)/m(L) +/- 9.5 vs. 25.7 x 10(6)/mL +/- 8.1, p = 0.0001) after 3 and 6 months of treatment in men with idiopathic infertility. Conclusion. Our data suggest that targeting the metabolic and energetic pathways involved in spermatogenesis and mitochondrial activity could lead to potential effects and counteract subfertility/infertility in men through a mitochondria dynamics mechanism. Trial registration number: ClinicalTrials.gov registration identifier: NCT03864198, registered on 1 January 2019

    Small Molecule CCR4 Antagonists Protect Mice from Aspergillus Infection and Allergy

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    International audienceThe ability to regulate the recruitment of immune cells makes chemokines and their receptors attractive drug targets in many inflammatory diseases. Based on its preferential expression on T helper type 2 (Th2) cells, CC chemokine receptor type 4 (CCR4) has been widely studied in the context of allergic diseases, but recent evidence on the expression of CCR4 in other cell types has considerably expanded the potential applications of CCR4 antagonism. However, the current number of approved indications, as well as the portfolio of CCR4-targeting drugs, are still limited. In the present study, we have assessed the potential therapeutic efficacy of a CCR4 small molecule antagonist, SP50, discovered via an in silico-based approach, against a variety of pre-clinical settings of infection with the fungus Aspergillus fumigatus. We show that SP50 efficiently worked as prophylactic vaccine adjuvant in immunocompetent mice, protected against invasive aspergillosis in immunosuppressed mice. Further, the CCR4 antagonist prevented allergic bronchopulmonary aspergillosis in susceptible mice, and in a murine model of cystic fibrosis, a genetic disorder characterized by chronic pulmonary inflammation and recurrent infections. In conclusion, our results extend the potential applications of CCR4 antagonism and prompt for the development of novel compounds with the potential to progress to clinical trials

    Distinct and complementary roles for Aspergillus fumigatus-specific Tr1 and Foxp3+Foxp3^+ regulatory T cells in humans and mice

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    Unlike induced Foxp3+Foxp3^+ regulatory T cells (Foxp3+Foxp3^+ iTregiT_{reg}) that have been shown to play an essential role in the development of protective immunity to the ubiquitous mold Aspergillus fumigatus, type-(1)-regulatory T cells (Tr1) cells have, thus far, not been implicated in this process. Here, we evaluated the role of Tr1 cells specific for an epitope derived from the cell wall glucanase Crf-1 of A. fumigatus (Crf-1/p41) in antifungal immunity. We identified Crf-1/p41-specific latent-associated peptide+peptide^+ Tr1 cells in healthy humans and mice after vaccination with Crf-1/p41+zymosan. These cells produced high amounts of interleukin (IL)-10 and suppressed the expansion of antigen-specific T cells in vitro and in vivo. In mice, in vivo differentiation of Tr1 cells was dependent on the presence of the aryl hydrocarbon receptor, c-Maf and IL-27. Moreover, in comparison to Tr1 cells, Foxp3+Foxp3^+ iTregiT_{reg} that recognize the same epitope were induced in an interferon gamma-type inflammatory environment and more potently suppressed innate immune cell activities. Overall, our data show that Tr1 cells are involved in the maintenance of antifungal immune homeostasis, and most likely play a distinct, yet complementary, role compared with Foxp3+Foxp3^+ iTregiT_{reg}
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