Project description:The inflammatory response of preterm infants' intestine underlines its inability to respond to hemodynamic stress, microbes and nutrients. Recent evidence suggests that exogenous epidermal growth factor (EGF) exerts a therapeutic influence on neonatal enteropathies. However, the molecular mechanisms underlying the beneficial effects of EGF remain to be clarified. The purpose of this study was to evaluate the impact of EGF on the gene expression profiles of the developing human small and large intestine at mid-gestation in serum-free organ cultures using Illumina microarrays. Differential functional effects of EGF along the human fetal intestine [Illumina] Transcriptional profiling of small and large intestinal explants cultured in the absence (control) or in the presence of EGF (50 ng/mL).
Project description:The inflammatory response of preterm infants' intestine underlines its inability to respond to hemodynamic stress, microbes and nutrients. Recent evidence suggests that exogenous epidermal growth factor (EGF) exerts a therapeutic influence on neonatal enteropathies. However, the molecular mechanisms underlying the beneficial effects of EGF remain to be clarified. The purpose of this study was to evaluate the impact of EGF on the gene expression profiles of the developing human small and large intestine at mid-gestation in serum-free organ cultures using Illumina microarrays.
Project description:Regulated host cell death is part of a plant defense strategy against pathogens but it is also involved in accommodating certain beneficial root microbes. We have identified extracellular metabolites and intracellular metabolic signals that contribute to beneficial root fungal endophyte colonization, and uncovered a conserved cell death mechanism likely co-opted for establishing plant-endophyte symbiosis.
Project description:In order to understand the appropriate use of potentially beneficial Gram positive microbes through their introduction in the gut microbiome, it is necessary to understand the influence of individual bacteria on the host response system at a cellular level. In the present study we showed that lipopolysaccharide (LPS), flagellated Gram negative bacteria, potentially beneficial Gram positive bacteria and yeast interact differently with human intestinal enterocytes (IEC) with a custom-designed expression microarray evaluating 17 specific host-response pathways. Only, LPS and flagellated Gram negative bacteria induced inflammatory response, while a subset of Gram positive microbes had anti-inflammatory potential. The main outcome from the study was the differential regulation of the central MAPK signaling pathway by these Gram positive microbes versus commensal/pathogenic Gram negative bacteria. The microarray was efficient to highlight the impact of individual bacteria on IEC response, but q-RT-PCR validation demonstrated some underestimation for down regulated genes by the microarray. This Immune Array will allow us to better understand the mechanisms underlying pathogen-induced host immune responses, aid in the selection potentially probiotic microbes and perhaps select biomarkers for future clinical studies. In this study, human immune response was assessed by stimulating HT-29 intestinal epithelial cells (IEC) with different microorganisms (or LPS) individually. For each of the 12 different treatments, between 4 and 8 biological replicates were performed, analyzed with dye-swaps and hybridized against control or untreated cells. Genes that were showing a 1.3 mRNA transcript abundance fold change and a P-value below 0.05 were considered to be differentially expressed.
Project description:We hypothesize that the collection, pooling, pasteurization, and freezing storage of the DHM exerts chemical and biological changes besides depleting the beneficial microbes and inactivating bioactive components in MOM. In this report, we evaluated the effect of the pasteurization process of DHM on the miRNA content of MOM EVs and their impact on innate immune response in human cell lines.
Project description:In order to understand the appropriate use of potentially beneficial Gram positive microbes through their introduction in the gut microbiome, it is necessary to understand the influence of individual bacteria on the host response system at a cellular level. In the present study we showed that lipopolysaccharide (LPS), flagellated Gram negative bacteria, potentially beneficial Gram positive bacteria and yeast interact differently with human intestinal enterocytes (IEC) with a custom-designed expression microarray evaluating 17 specific host-response pathways. Only, LPS and flagellated Gram negative bacteria induced inflammatory response, while a subset of Gram positive microbes had anti-inflammatory potential. The main outcome from the study was the differential regulation of the central MAPK signaling pathway by these Gram positive microbes versus commensal/pathogenic Gram negative bacteria. The microarray was efficient to highlight the impact of individual bacteria on IEC response, but q-RT-PCR validation demonstrated some underestimation for down regulated genes by the microarray. This Immune Array will allow us to better understand the mechanisms underlying pathogen-induced host immune responses, aid in the selection potentially probiotic microbes and perhaps select biomarkers for future clinical studies.
Project description:Unlike pathogens that trigger plant defense responses, beneficial microbes are compatible with plants. One possible reason for the compatibility is that the microbial factors from beneficial microbes are inert in that they do not trigger plant defense responses. Little is known about the mechanisms underlying this seemingly inert relation. Here we report that Arabidopsis lacking the gene Growth-Promotion 1 (GP1) becomes defensive to microbial volatiles from Bacillus amyloliqueficiens strain GB03, a beneficial rhizobacterium. The gp1 mutant was isolated in a forward genetic screen for mutants that show defectiveness in GB03-triggered plant inducible vigor. GP1 encodes a stearoyl-ACP desaturase that catalyzes the desaturation of stearic acid (18:0) to oleic acid (18:1). Consistently, plant inducible vigor was also impaired by chemical enhancement of 18:1 catabolism, while genetic disruption of 18:1 catabolism largely restored the inducible vigor in gp1. When exposed to GB03-emitted microbial volatiles (GMVs), wild type plants showed transcriptional up-regulation of growth-promoting processes and down-regulation of defense responses; in contrast, the gp1 transcriptome displayed elevated defense responses when treated with GMVs. Meanwhile disruption of salicylic acid-mediated defense partially restored plant inducible vigor in gp1. Microbiota profiling revealed that GP1 dysfunction alters the assemblage of plant-associated rhizobacteria communities, including a reduction in the Bacillaceae family that is known to contain many beneficial rhizobacteria species. Consistently, gp1 mutants showed severely impaired root colonization of GB03. Our findings suggest that GP1 prevents the plant defense system from being mistakenly activated by non-pathogenic microbial factors, thereby allowing mutualistic association between the plant and beneficial microbes.
Project description:Microbes of the root-associated microbiome contribute to improve resilience and fitness of plants. In this study, the interaction between the salt stress tolerance-inducing beneficial bacterium Enterobacter sp. SA187 and Arabidopsis was investigated with a special focus on the plant immune system. Among the immune signalling mutants, the Lys-motif receptors LYK4 strongly affected the beneficial interaction. Overexpression of the chitin receptor components LYK4 compromised the beneficial effect of SA187 on Arabidopsis. Transcriptome analysis revealed that the role of LYK4 in immunity is intertwined with a function in remodeling defense responses. Overall, our data indicate that components of the plant immune system are key elements in mediating beneficial metabolite-induced plant abiotic stress tolerance.
Project description:High light stress in subtropical and tropical regions strongly limits agricultural production due to photo-oxidative damage, decreased growth and yield. Here, we investigated whether beneficial microbes can protect plants under high light stress. We show that Enterobacter sp. SA187 (SA187) assists Arabidopsis in maintaining growth under high light stress, reducing the accumulation of reactive oxygen species (ROS) and maintaining photosynthesis. Under high light stress, SA187 induces dynamic transcriptional changes related to a fortified iron metabolism and redox system in Arabidopsis. A genetic analysis shows that SA187-induced plant high light stress tolerance is mediated by ethylene signaling via the transcription factor EIN3 to enhance iron metabolism. In summary, we show that Arabidopsis interaction with SA187 results in sustained photosynthesis under high light stress suggesting that beneficial microbes could be effective and cheap means for enhancing high light stress tolerance in crops.