Project description:We used zebrafish embryos as an in vivo system to investigate the role of the microRNA-146 family (consisting of 2 members miR-146a and miR-146b) in the innate immune response to S. typhimurium infection. To determine the role of miR-146 microRNAs in the response to S. typhimurium infection we used Illumina RNA sequencing to compare the mRNA expression profiles of control embryos versus embryos with knockdown of miR-146a and miR-146b. RNA sequencing analysis of miR-146 knockdown embryos showed no major effects on pro-inflammatory gene expression or on the expression of transcriptional regulators and signal transduction components of the immune response. In contrast, apoliprotein-mediated lipid transport emerged as an infection-inducible pathway under miR-146 knockdown conditions, suggesting a function of miR-146 in regulating lipid metabolism during inflammation.
Project description:We used zebrafish embryos as an in vivo system to investigate the role of the microRNA-146 family (consisting of 2 members miR-146a and miR-146b) in the innate immune response to S. typhimurium infection. To determine the role of miR-146 microRNAs in the response to S. typhimurium infection we used Illumina RNA sequencing to compare the mRNA expression profiles of control embryos versus embryos with knockdown of miR-146a and miR-146b. RNA sequencing analysis of miR-146 knockdown embryos showed no major effects on pro-inflammatory gene expression or on the expression of transcriptional regulators and signal transduction components of the immune response. In contrast, apoliprotein-mediated lipid transport emerged as an infection-inducible pathway under miR-146 knockdown conditions, suggesting a function of miR-146 in regulating lipid metabolism during inflammation. Embryos were injected at the one cell stage with a combination of two morpholinos targeting miR-146a and miR-146b, or with the standard control morpholino from GeneTools. Subsequently, at 28 hours post fertilzation (hpf) they were infected by injecting 200-250 colony forming units of S. typhimurium strain SL1027 into the caudal vein, or mock-injected with PBS. RNA was isolated at 8 hours post injection (hpi) for Illumina RNAseq analysis. Two independent experiments were performed for RNAseq analysis of biological duplicates.
Project description:Deficiency in the protein-tyrosine phosphatase SHP1/PTPN6 is linked with hematological malignancies and chronic inflammatory diseases. Here we exploited the embryonic and larval stages of zebrafish as an animal model to study ptpn6 function in the sole context of innate immunity. We show that ptpn6 knockdown induces a spontaneous inflammation-associated phenotype at the late larval stage, which was microbe-independent and enhanced instead of suppressed by glucocorticoids. When challenged with Salmonella typhimurium or Mycobacterium marinum at earlier stages of development, the innate immune system was hyperactivated to a contra-productive level that impaired the control of these pathogenic bacteria. These results demonstrate the crucial regulatory function of ptpn6 in preventing host-detrimental effects of inflammation by imposing a tight control over the level of innate immune response activation. This microarray study was designed to determine the effect of morpholino knockdown of the ptpn6 gene on the innate immune response of zebrafish embryos during infection with Salmonella typhimurium. Three independent infection experiments were performed using mixed egg clutches of wild type zebrafish, which were a cross of the AB and TL strains. Each experiment consisted of the following four treatment groups: (1) uninfected control embryos, (2) S. typhimurium-infected control embryos, (3) uninfected ptpn6 knockdown embryos, and (4) S. typhimurium-infected ptpn6 knockdown embryos. Knockdown of ptpn6 was performed by micro-injecting embryos at the 1-2 cell stage with the ptpn6 morpholino, and control embryos were mock-injected with buffer. Embryos were grown at 28.5M-bM-^@M-^S30M-BM-0C in egg water and manually dechorionated at 24 hours post fertilization (hpf). Subsequently, embryos were infected at 28 hpf by micro-injecting 200-250 colony forming units (CFU) of S. typhimurium SL1027 bacteria into the caudal vein, or were mock-injected with buffer as a control. After injections embryos were transferred into fresh egg water and incubated for 8 h at 28M-BM-0C. After the incubation period, pools of 15-20 embryos per treatment group were snap-frozen in liquid nitrogen and RNA was isolated for microarray analysis. All treatment groups were analyzed using a common reference approach.
Project description:Deficiency in hematopoietic phosphatase Ptpn6/Shp1 hyperactivates the innate immune system and impairs control of bacterial infections in zebrafish embryos