Project description:Oral infection of mice with Salmonella Typhimurium leads to rapid changes in small intestinal TCRgd IEL behavior. How these changes are induced is currently unknown. By analyzing the transcriptome of TCRgd and intestinal epithelial cells in the steady state and after infection, we find a potential role for epithelial cell MYD88 expression in regulating the IEL response. By additionally analyzing the transcriptome of epithelial cell-specific, conditional Myd88 knockout animals after Salmonella infection, we address the role of epithelial cell Myd88 signaling in regulating the IEL and EC response to Salmonella infection.
Project description:The GeneChip Porcine Genome Array was used to identify the transcriptional response upon Salmonella typhimurium infection in three porcine intestinal sections (jejumun, ileum and colon) along a time course of 1,2 and 6 days post infection. The objetives in this study were i) characterize transcriptional changes upon S. typhimurium infection in the intestinal mucosa; ii) identify differences among porcine intestinal sections in inmune resposes against S. typhimurium; iii) identify change that could be associated to salmonellosis pathogenesis and symtomatology; and finally, iv) identify transcriptional changes that could be induced by S. typhimurium in order to get bacterial survival and successful colonization.
Project description:This study reports on infection-inducible miRNAs in zebrafish. Using a custom-designed microarray platform for miRNA expression we found that miRNAs of the miR-21, miR-29, and miR-146 families were commonly induced by infection of zebrafish embryos with Salmonella typhimurium and by infection of adult fish with Mycobacterium marinum.
Project description:The potential for commensal microorganisms indigenous to a host (the microbiome or microbiota) to alter infection outcome by influencing host-pathogen interplay is largely unknown. We used a multi-omics systems approach, incorporating proteomics, metabolomics, glycomics, and metagenomics, to explore the molecular interplay between the murine host, the pathogen Salmonella enterica serovar Typhimurium (S. Typhimurium), and commensal gut microorganisms during intestinal infection with S. Typhimurium. We find proteomic evidence that S. Typhimurium thrives within the infected 129/SvJ mouse gut without antibiotic pre-treatment, inducing inflammation and disrupting the intestinal microbiome (e.g., suppressing Bacteroidetes and Firmicutes while promoting growth of Salmonella and Enterococcus). Alteration of the host microbiome population structure was highly correlated with gut environmental changes, including the accumulation of metabolites normally consumed by commensal microbiota. Finally, the less characterized phase of S. Typhimuriums lifecycle was investigated, and both proteomic and glycomic evidence suggests S. Typhimurium may take advantage of increased fucose moieties to metabolize fucose while growing in the gut. The application of multiple omics measurements to Salmonella-induced intestinal inflammation provides insights into complex molecular strategies employed during pathogenesis between host, pathogen, and the microbiome.
Project description:Visual cortical circuits show profound plasticity during early life and are later stabilized by molecular "brakes" limiting excessive circuit rewiring beyond a critical period. How the appearance of these factors is coordinated during the transition from development to adulthood remains unknown. We analyzed the role of miR-29a, a miRNA targeting factors involved in several important pathways for plasticity such as extracellular matrix and chromatin regulation. We found that visual cortical miR-29a expression in the visual cortex dramatically increases with age, but it is not experience-dependent. Precocious high levels of miR-29a induced by targeted intracortical injections of a miR-29a mimic blocked ocular dominance plasticity and caused an early appearance of perineuronal nets. Conversely, inhibition of miR-29a in adult mice using LNA antagomirs activated ocular dominance plasticity, reduced perineuronal net intensity and number, and changed their chemical composition restoring permissive low chondroitin 4-O-sulfation levels characteristic of juvenile mice. Activated adult plasticity had the typical functional and proteomic signature of juvenile plasticity. Transcriptomic and proteomic studies indicated that miR-29a manipulation regulates the expression of plasticity factors acting at different cellular levels, from chromatin regulation to synaptic organization and extracellular matrix remodeling. Intriguingly, the projection of miR-29a regulated gene dataset onto cell-specific transcriptomes revealed that parvalbumin-positive interneurons and oligodendrocytes were the most affected cells. Overall, miR29a is a master regulator of the age-dependent plasticity brakes promoting stability of visual cortical circuits.
Project description:Visual cortical circuits show profound plasticity during early life and are later stabilized by molecular "brakes" limiting excessive circuit rewiring beyond a critical period. How the appearance of these factors is coordinated during the transition from development to adulthood remains unknown. We analyzed the role of miR-29a, a miRNA targeting factors involved in several important pathways for plasticity such as extracellular matrix and chromatin regulation. We found that visual cortical miR-29a expression in the visual cortex dramatically increases with age, but it is not experience-dependent. Precocious high levels of miR-29a induced by targeted intracortical injections of a miR-29a mimic blocked ocular dominance plasticity and caused an early appearance of perineuronal nets. Conversely, inhibition of miR-29a in adult mice using LNA antagomirs activated ocular dominance plasticity, reduced perineuronal net intensity and number, and changed their chemical composition restoring permissive low chondroitin 4-O-sulfation levels characteristic of juvenile mice. Activated adult plasticity had the typical functional and proteomic signature of juvenile plasticity. Transcriptomic and proteomic studies indicated that miR-29a manipulation regulates the expression of plasticity factors acting at different cellular levels, from chromatin regulation to synaptic organization and extracellular matrix remodeling. Intriguingly, the projection of miR-29a regulated gene dataset onto cell-specific transcriptomes revealed that parvalbumin-positive interneurons and oligodendrocytes were the most affected cells. Overall, miR29a is a master regulator of the age-dependent plasticity brakes promoting stability of visual cortical circuits.
Project description:The GeneChip Porcine Genome Array was used to identify the transcriptional response upon Salmonella typhimurium infection in three porcine intestinal sections (jejumun, ileum and colon) along a time course of 1,2 and 6 days post infection. The objetives in this study were i) characterize transcriptional changes upon S. typhimurium infection in the intestinal mucosa; ii) identify differences among porcine intestinal sections in inmune resposes against S. typhimurium; iii) identify change that could be associated to salmonellosis pathogenesis and symtomatology; and finally, iv) identify transcriptional changes that could be induced by S. typhimurium in order to get bacterial survival and successful colonization. Sixteen male and female crossbreeds weaned piglets, approximately 4 weeks of age, were used in this study. Before infection, faecal samples from each animal were analyzed to confirm that piglets were free of Salmonella. Pigs were housed in an environmentally controlled isolation facility at 25ºC and under constant light with ad libitum access to feed and water. After an acclimation period of 5 days, pigs were challenged orally with 108 cfu of Salmonella enterica serovar Typhimurium phagetype DT104 (n=12), whereas the control group (n=4) received sterile medium orally. The four non-infected control pigs were necropsied two hours prior to experimental infection. Four randomly chosen infected pigs were necropsied at 1 day post infection (dpi), 2 dpi and 6 dpi, respectively. Faecal swabs, blood and tissues samples were aseptically collected. Ileum was collected, sectioned in pieces of around 10 cm and immediately frozen in liquid nitrogen for mucosa isolation and RNA purification. To ensure the inoculated pigs were infected, faecal samples were cultured and checked for positive Salmonellae organism Four reps per treatment and tissue group except 'Ileum 1dpi' has only 3 replicates.