Project description:We performed transcriptomic analysis of bone-marrow-derived macrophages (BMDMs, C57BL/6 mice) treated with extracellular vesicles (EVs) from A. flavus strain LD-F1 or LD-F1-b, with PBS-treated (phosphate buffer saline) cells as control.
Project description:Aflatoxins are toxic and carcinogenic secondary metabolites produced by the fungi Aspergillus flavus and A. parasiticus. In order to better understand the molecular mechanisms that regulate aflatoxin production, the biosynthesis of the toxin in A. flavus and A. parasticus grown in yeast extract sucrose media supplemented with 50 mM tryptophan (Trp) were examined. A. flavus grown in the presence of 50 mM tryptophan was found to have significantly reduced aflatoxin B1 and B2 biosynthesis, while A. parasiticus cultures had significantly increased B1 and G1 biosynthesis. Microarray analysis of RNA extracted from fungi grown under these conditions revealed seventy seven genes that are expressed significantly different between A. flavus and A. parasiticus, including the aflatoxin biosynthetic genes aflD (nor-1), aflE (norA), and aflO (omtB). It is clear that the regulatory mechanisms of aflatoxin biosynthesis in response to Trp in A. flavus and A. parasiticus are different. These candidate genes may serve as regulatory factors of aflatoxin biosynthesis. Keywords: Aflatoxin, Aspergillus, flavus, Amnio Acids, Tryptophan
Project description:RNA-seq was used to compare differential gene expressions for Aspergillus flavus wild type strain and ASPES transcription factor deletion strains.The goals of this study are to explore the aflatoxin regulation pathway in A. flavus.
Project description:Aspergillus flavus and A. parasiticus are two of the most important aflatoxin-producing species that contaminate agricultural commodities worldwide. Both species are heterothallic and undergo sexual reproduction in laboratory crosses. Here, we examine the possibility of interspecific matings between A. flavus and A. parasiticus. These species can be distinguished morphologically and genetically, as well as by their mycotoxin profiles. Aspergillus flavus produces both B aflatoxins and cyclopiazonic acid (CPA), B aflatoxins or CPA alone, or neither mycotoxin; Aspergillus parasiticus produces B and G aflatoxins or the aflatoxin precursor O-methylsterigmatocystin, but not CPA. Only four out of forty-five attempted interspecific crosses between compatible mating types of A. flavus and A. parasiticus were fertile and produced viable ascospores. Single ascospore strains from each cross were isolated and were shown to be recombinant hybrids using multilocus genotyping and array comparative genome hybridization. Conidia of parents and their hybrid progeny were haploid and predominantly monokaryons and dikaryons based on flow cytometry. Multilocus phylogenetic inference showed that experimental hybrid progeny were grouped with naturally occurring A. flavus L strain and A. parasiticus. Higher total aflatoxin concentrations in some F1 progeny strains compared to midpoint parent aflatoxin levels indicate synergism in aflatoxin production; moreover, three progeny strains synthesized G aflatoxins that were not produced by the parents, and there was evidence of putative allopolyploidization in one strain. These results suggest that hybridization is an important diversifying force resulting in the genesis of novel toxin profiles in these agriculturally important species.
Project description:Human bone marrow-derived MSCs were stimulated with Bronchoalveolar lavage fluid (BALF) from healthy individuals or patients with ARDS, Cystic Fibrosis, Cystic Fibrosis positive for Aspergillus or untreated untreated MSC. Extracellular vesicles were isolated from MSC conditioned medium following minimal experimental requirements for definition of extracellular vesicles and their functions: a position statement from the International Society for Extracellular Vesicles (J Extracell Vesicles. 2014 Dec 22:3:26913. doi: 10.3402/jev.v3.26913. eCollection 2014). In Phase 1 of this study, differential expression as well as discriminant analysis was used to identify 14 microRNAs that were differentially expressed in MSC-derived EVs from MSCs exposed to BALF from ARDS patients compared to healthy controls. The effect of EVs on cellular physiology and was demonstrated in vitro by demonstration that wwo miRNAs involved in regulation of the cystic fibrosis transmembrane conductance regulator (CFTR), miRNA-145-5p and miRNA-138-5p, were also significantly increased in ARDS BALF-exposed hMSCs EVs. Functionally, EVs from hMSCs exposed to either ARDS or HV BALF had differential on CFTR Cl- secretion by cultured primary human bronchial epithelial cells, an effect predicted to reduce mucociliary clearance.
Project description:Several are the inputs which are able to modulate mycotoxin synthesis. In particular, when a fungus receives an external stimulus reacts by activating, through a quite well-defined signal cascade, an evident switch in its lifestyle. This profound change is also due to the activation of global gene regulators and, in particular, of transcription factors able to switch on the mycotoxin gene clusters expression. Aflatoxins (AF) are harmful carcinogenic compounds produced mainly by Aspergillus flavus and A. parasiticus. AF are produced during the contamination of maize kernels into the field, even if their role in phyto-toxicity is not yet assessed. Nevertheless, AF biosynthesis is tightly regulated by host-derived signals. Recently, the nature of some of these signals have been elucidated. In particular, a role in susceptibility and resistance of maize to A. flavus contamination has been assigned to some plant oxylipins. These findings draw a scenario in which a complex interplay is under way between A. flavus and maize. For uncovering all the implications of this cross-talk we decide to follow a holistic approach. In particular, we designed experimental conditions aimed to mimic the different phases of A. flavus infection cycle on maize and then by performing a microarray analysis on the harvested mycelia. The microarray data set has been processed for performing the differential expression analysis of almost 14000 gene probes, the pathway analysis based on the gene ontology and inter pro annotations, the secondary metabolites cluster co-expression analysis and an identification of groups of co-expressed neighbor genes, possibly associated with production of secondary metabolites. Analysis of 12 microarrays monitoring gene expression of Aspergillus flavus over various growth conditions
Project description:Objective: Aspergillus flavus aflR, a gene encoding a Zn(II)2Cys6 DNA-binding domain, is an important transcriptional regulator of the aflatoxin biosynthesis gene cluster. Our previous results of GO analysis for the binding sites of AflR in A. flavus suggest that AflR may play an integrative regulatory role. This study aimed to investigate the integrative function of the aflR gene in A. flavus. Design: In this study, we used Aspergillus flavus NRRL3357 as a wild-type strain (WT) and constructed a knockout strain of A. flavus ΔaflR by homologous recombination. Based on the transcriptomics technology, we investigated the metabolic effects of aflR gene on growth, development and toxin synthesis of A. flavus, and discussed the overall regulation mechanism of aflR gene on A. flavus at the transcriptional level. Results: The disruption of aflR severely affected the aflatoxin biosynthetic pathway, resulting in a significant decrease in aflatoxin production. In addition, disrupted strains of the aflR gene produced relatively sparse conidia and a very small number of sclerotia. However, the biosynthesis of cyclopiazonic acid (CPA) was not affected by aflR gene disruption. Transcriptomic analysis of the ΔaflR strain grown on potato dextrose agar (PDA) plates at 0 h, 24 h, and 72 h showed that expression of clustering genes involved in the biosynthesis of aflatoxin was significantly down-regulated. Meanwhile, the ΔaflR strain showed significant expression differences in genes involved in spore germination, sclerotial development, and carbohydrate metabolism compared to the WT strain. Conclusions: The results showed that the A. flavus aflR gene also played a positive role in the growth and development of fungi.
Project description:Similar to bacterial proteins that are targeted to distinct macrophages organelles via extracellular vesicles, we propose that these vesicles also traffic small RNAs to modulate specific host factors. To test this, we aim to sequence extracellular vesicle derived sRNA, and whole bacterial small RNAs to determine selectivity, and to identify their bacterial and mammalian targets (Experimental Plan in Table-1). For this we will collect highly purified vesicles from N. gonorrhoeae (strain MS11A). We will also treat mouse derived primary macrophages with extracellular vesicles and compare their RNA response to untreated macrophages (Table-2). This will provide novel insights into how macrophages respond to N. gonorrhoeae infections. This data is part of a pre-publication release. For information on the proper use of pre-publication data shared by the Wellcome Trust Sanger Institute (including details of any publication moratoria), please see http://www.sanger.ac.uk/datasharing/
Project description:Background: There is some evidence demonstrating the effect of psychological interventions in improvements in health biological parameters. To best of our knowledge, no study had addressed the impact of any psychological intervention on extracellular vesicles. In addition, Mindfulness-Based Cognitive Therapy (MBCT) and Emotion Focused Therapy for Cancer Recovery (EFT-CR) in the group have never been explored regarding extracellular vesicles and the effectiveness of these was not compared yet.
Objectives:
1. To explore and compare the effect of MBCT and EFT-CR on biological parameters and psychological variables in distressed people who have had breast, prostate and colorectal cancer;
2. In addition, we will explore the acceptability through recruitment and retention rates of MBCT and EFT-CR in group and evaluate whether these interventions are appropriate for a larger clinical trial.
Methods: The design of this study is a parallel randomized controlled trial. Participants will be randomized into MBCT, EFT-CR or usual care. Outcome measures will be assessed before, at the end of the intervention (8 weeks) and follow-ups (24 and 52 weeks from the baseline moment).
Hypotheses: The researchers expected that both interventions will have an effect on extracellular vesicles and other study biomarkers as well as improvements in psychological outcomes, compared to treatment as usual (TAU) group. Regarding the comparative effectiveness, we did not have evidence to hypothesize which one of the interventions will be superior in both biological (extracellular vesicles) and psychological outcomes.
Contribution for practice: The results of this preliminary study would permit to know if there are benefits of these psychological interventions on changes in extracellular vesicles and on psychological outcomes related to health. In addition, this study will permit to determine the acceptability of conducting a larger randomized controlled trial.