Transcriptome adaptation of group B Streptococcus to growth in human amniotic fluid
ABSTRACT: We have discovered that GBS significantly remodels its transcriptome in response to exposure to human amniotic fluid. A large number of the affected genes are of unknown function, which means that much remains to be learned about the full influence of amniotic fluid on GBS. The majority of the observed changes in transcripts affects genes involved in basic bacterial metabolism and is connected to AF composition and nutritional requirements of the bacterium. The observation that many genes encoding adhesions are down-regulated, and genes encoding known virulence factors such as a hemolysin and a potent IL-8 proteinase are up-regulated likely have consequences for the outcome of host-pathogen interactions. Overall design: Streptococcus agalactiae, serotype III strain NEM316 was grown in human amniotic fluid. Samples of bacteria were collected in mid log, late log and stationary growth phases and were used for RNA isolation for microarray analysis
Project description:We have discovered that GBS significantly remodels its transcriptome in response to exposure to human amniotic fluid. A large number of the affected genes are of unknown function, which means that much remains to be learned about the full influence of amniotic fluid on GBS. The majority of the observed changes in transcripts affects genes involved in basic bacterial metabolism and is connected to AF composition and nutritional requirements of the bacterium. The observation that many genes encoding adhesions are down-regulated, and genes encoding known virulence factors such as a hemolysin and a potent IL-8 proteinase are up-regulated likely have consequences for the outcome of host-pathogen interactions. Streptococcus agalactiae, serotype III strain NEM316 was grown in human amniotic fluid. Samples of bacteria were collected in mid log, late log and stationary growth phases and were used for RNA isolation for microarray analysis
Project description:Preterm birth is a leading cause of neonatal morbidity and mortality. Microbial infection and inflammation of the amniotic cavity are associated with the majority of early preterm births and thought to arise from ascension of bacteria from the lower genital tract. Group B Streptococci (GBS) are beta-hemolytic, gram-positive bacteria, which commonly colonize the vagina and have been recovered from the amniotic fluid in cases of preterm birth. Host immune defenses that are critical for prevention of microbial invasion of the amniotic cavity (MIAC) and preterm labor are not completely understood. We recently showed that increased expression of the hemolytic pigment promotes GBS penetration of human placenta ex vivo and hyperhemolytic/hyperpigmented GBS strains with mutations in the hemolysin repressor (CovR/CovS) can be isolated from women in preterm labor. To understand placental/ choriodecidual immune responses that are necessary to prevent MIAC and preterm labor, we utilized a unique chronically catheterized nonhuman primate model that closely emulates human pregnancy. We observed that preterm labor, MIAC, and fetal injury occurred significantly more frequently in pregnant nonhuman primates infected with hyperpigmented GBS (ΔcovR) despite the strong induction of proinflammatory responses in the chorioamnion. Placental histopathology revealed a systematic progression in development of chorioamnionitis in GBSΔcovR animals beginning with chorionic vasculitis and subsequently progressing to neutrophilic infiltration in the chorioamnion. Overall design: In this study, eleven chronically catheterized pregnant NHP (Macaca nemestrina) containing catheters surgically implanted via laparotomy into the maternal femoral vein, amniotic cavity, and choriodecidual interface in the lower uterine segment (between uterine muscle and fetal membranes, external to amniotic fluid) received one of two experimental treatments: i.e. choriodecidual inoculation of either GBS COH1ΔcovR (n=6; hyperpigmented strain) or GBS COH1ΔcovRΔcylE (n=6; isogenic, nonpigmented strain). Results obtained from these animals were compared to saline controls (n=5; choriodecidual and amniotic fluid saline inoculations) that were performed previously.
Project description:Microarray data comparison of amniocytes, amniotic fluid-iPSCs, and cardiomyocyte derivatives Overall design: Differentiated cardiomyocytes from amniotic fluid and dermal fibroblast controls
Project description:This SuperSeries is composed of the following subset Series: GSE30064: Cultured human amniotic fluid-derived mesenchymal stromal cells [PIQOR data] GSE30065: Cultured human amniotic fluid-derived mesenchymal stromal cells [miRXplore data] Refer to individual Series
Project description:The objective of this study was to identify the tissue expression patterns and biological pathways enriched in term amniotic fluid cell-free fetal RNA by comparing functional genomic analyses of term and second-trimester amniotic fluid supernatants. There were 2,871 significantly differentially regulated genes. In term amniotic fluid, tissue expression analysis showed enrichment of salivary gland, tracheal, and renal transcripts as compared with brain and embryonic neural cells in the second trimester. Functional analysis of genes upregulated at term revealed pathways that were highly specific for postnatal adaptation such as immune function, digestion, respiration, carbohydrate metabolism, and adipogenesis. Inflammation and prostaglandin synthesis, two key processes involved in normal labor, were also activated in term amniotic fluid. This was a prospective whole genome microarray study comparing eight amniotic fluid samples collected from eight women at term who underwent prelabor cesarean delivery and eight second-trimester amniotic fluid samples from routine amniocenteses. A functional annotation tool was used to compare tissue expression patterns in term and second-trimester samples. Pathways analysis software identified physiologic systems, molecular and cellular functions, and upstream regulators that were significantly overrepresented in term amniotic fluid.
Project description:Amniotic fluid is critical for the development of foetus, which provides the appropriate conditions for foetus growth. Besides its presumed traditional roles of providing movement place and protecting from crushing, amniotic fluid is considered to have more important roles in the nervous development of foetus respecting nervous related compositions and close contact with the skin of foetus. Peripheral nervous sensory system is the feeling basis for the body with neuritis anchoring on the surface of skin. The effect of amniotic fluid on the development of peripheral sensory nervous system is unknown. To disclose the relationship between amniotic fluid and peripheral sensory nervous system, we profiled microRNAs dynamic expression in amniotic fluid during the stages of E13, E15 and E17. The cluster analysis results showed that there were significantly two different expression profiles of microRNAs during this development stage. The followed informatics analysis results showed that these two groups of microRNAs synergistically regulate the axon guidance process. Axon tracing by fluorogold and co-labelled immunofluorescence results indicated that there was a direct interaction between amniotic fluid and peripheral sensory nervous system in axon guidance. Taken together, our work is helpful to understand the development of peripheral sensory nervous system of foetus. Overall design: In this study, microRNAs in amniotic fluid cells were harvested at the stages of E13, E15 and E17 mice, then microRNAs expression profiles were performed on miRCURY microarrays. The following bioinformatics analysis, qRT-PCR and axon tracing results showed that there is a close relationship between microRNAs of amniotic fluid and the development of peripheral sensory nervous system.
Project description:Mesenchymal stromal cells (MSC) are currently being evaluated in numerous preclinical and clinical cell-based therapy studies. Furthermore, there is an increasing interest in exploring alternative uses of these cells in disease modelling, pharmaceutical screening and regenerative medicine by applying reprogramming technologies. However, the limited availability of MSCs from various sources, restricts their use. Term amniotic fluid has been proposed as an alternative source of MSCs. Previously, only low volumes of term fluid and its cellular constituents have been collected, and current knowledge of the MSCs derived from this fluid is limited. In this study, we collected amniotic fluid at term using a novel collection system and evaluated amniotic fluid MSC content and their characteristics, including their feasibility to undergo cellular reprogramming. Overall design: Two replicates of cord blood endothelium are compared to two replicates of amniotic fluid cells
Project description:Amniotic fluid stem cells (AFSCs) are of interest in regenerative medicine as a non-controversial and potentially 'abundant' source of stem cells. Progress has been made in understanding amniotic fluid stem cell biology, and amniotic fluid-derived cells have been induced to form neurons, osteoblasts, muscle cells, and others. Our study evaluates change in the genome-wide expression profile of amniotic fluid stem cells during in-vitro culture, using Affymetrix U133 Plus 2.0 microarray chips. We found that only 3.08% of gene probes were differentially expressed from early to late passage of AFSC culture. The differentially expressed genes were related to biological processes or cellular function - including transcription factors, protein kinases, and cytokines/growth factors. Other gene-sets of interest were oncogenes and tumor suppressor genes, which were a very small number of genes. We further analyzed the gene sets of interest using NIH DAVID and GSEA bioinformatics databases for gene annotations analysis. Applying false discovery rate correction, there was no significant difference in the genome-wide expression profiling between early and late passage. AFSCs maintain their genome-wide expression profile during in-vitro culture. Amniotic fluid-derived c-kit-positive cells were maintained in stem cell culture and genome-wide expression changes were studied and compared between early passage and late passage in culture.
Project description:Streptococcus agalactiae (Group B Streptococcus, GBS) can colonize the human vaginal tract leading to both superficial and serious infections in adults and neonates. To study bacterial colonization of the reproductive tract in a mammalian system, we employed a murine vaginal carriage model. Using RNASeq, the transcriptome of GBS growing in vivo during vaginal carriage was determined. Over one-quarter of the genes in GBS were found to be differentially regulated during in vivo colonization as compared to laboratory cultures. A two-component system (TCS) homologous to the staphylococcal virulence regulator SaeRS was identified as being up-regulated in vivo. One of the SaeRS targets, pbsP, a proposed GBS vaccine candidate, was shown to be important for colonization of the vaginal tract. A component of vaginal lavage fluid acted as a signal to turn on pbsP expression via SaeRS. These data demonstrate the ability to quantify RNA expression directly from the murine vaginal tract and identify novel genes involved in vaginal colonization by GBS. They also provide more information about the regulation of an important virulence and colonization factor of GBS, pbsP, by the TCS SaeRS. Overall design: RNASeq data from WT and mutant GBS samples taken from liquid culture or the murine vaginal tract