Project description:In the social amoebae (Dictyostelia) quorum sensing system mediates aggregation of single cells into multicellular aggregates by chemotactic movement towards gradients of diffusible molecules known as acrasins. The acrasin of P. violaceum is the unusual dipeptide N-propionyl-gamma-L-glutamyl-L-ornithine-delta-lactam-ethylester, known as glorin. Phylogenetic analysis has indicated that P. violaceum is more related to the most derived group 4 dictyostelids than to the ancient group 2 polysphondylids such as P. pallidum. Nevertheless it has been reported that P. pallidum cells respond to glorin in chemotaxis assays. This has led to the assumption that glorin-based communication may be the most ancient form of intercellular communication that Dictyostelia invented to organize early steps of multicellular development. In this study we show that glorin mediates rapid changes in gene expression at the transition from vegetative growth to aggregation, apparently without pronounced cross-talk with the cyclic AMP-based communication system that coordinates post-aggregation events in this species. We describe glorin-mediated changes in gene expression in the social amoeba Polysphondylium pallidum at the transition from unicellular growth to multicellular development. Comparison of gene expression in growing cells versus cells starving for 2 or 3 hours in the presence or absence of glorin.
Project description:In the social amoebae (Dictyostelia) quorum sensing system mediates aggregation of single cells into multicellular aggregates by chemotactic movement towards gradients of diffusible molecules known as acrasins. The acrasin of P. violaceum is the unusual dipeptide N-propionyl-gamma-L-glutamyl-L-ornithine-delta-lactam-ethylester, known as glorin. Phylogenetic analysis has indicated that P. violaceum is more related to the most derived group 4 dictyostelids than to the ancient group 2 polysphondylids such as P. pallidum. Nevertheless it has been reported that P. pallidum cells respond to glorin in chemotaxis assays. This has led to the assumption that glorin-based communication may be the most ancient form of intercellular communication that Dictyostelia invented to organize early steps of multicellular development. In this study we show that glorin mediates rapid changes in gene expression at the transition from vegetative growth to aggregation, apparently without pronounced cross-talk with the cyclic AMP-based communication system that coordinates post-aggregation events in this species. We describe glorin-mediated changes in gene expression in the social amoeba Polysphondylium pallidum at the transition from unicellular growth to multicellular development.
Project description:Treponema pallidum subspecies pallidum (T. pallidum) infection induces significant immune responses, resulting in tissue damage. Gene expression plays an essential role in regulating the progression of syphilis infection. However, little is known about the regulatory role of miRNAs in the immune response to T. pallidum infection. Here, we analyze the differential expression of miRNAs in peripheral blood mononuclear cells (PBMCs) between secondary syphilis (SS) patients and healthy controls and study the correlation between miRNAs expression and clinical features with bioinformatics.
Project description:We use ChIP-seq targeting histone 3 lysine 27-acetylation (H3K27ac) to identify putative enhancer sites genome-wide in the ventral pallidum cortex of adult prairie voles
2018-01-31 | GSE85826 | GEO
Project description:Complete Genome Sequences of Two Treponema pallidum subsp. pallidum specimens from Canadian Patients
Project description:Syphilis, caused by Treponema pallidum subsp. pallidum, is an urgent global public health threat. Syphilis vaccine development has been impeded by limited understanding of the molecular mechanisms that enable T. pallidum to establish and maintain infection. The vascular endothelium is critical for T. pallidum attachment, dissemination, and host immune response initiation; however, the molecular details of T. pallidum-endothelial interactions are incompletely understood. To enhance understanding, we performed time-course transcriptomic profiling on T. pallidum-exposed brain microvascular endothelial cells. These analyses showed T. pallidum exposure alters pathways related to extracellular matrix, growth factors, integrins, and Rho GTPases. The induced transcriptional response was consistent with endothelial to mesenchymal transition, a key process involved in fetal development and vascular dysfunction. This study provides a comprehensive understanding of the molecular response of endothelial cells to T. pallidum and identifies the host pathways that may cause syphilis disease symptoms, information that could aid syphilis vaccine design.
Project description:Treponema pallidum ssp. pallidum, the causative agent of syphilis, can now be cultured continuously in vitro utilizing a tissue culture system, and the multiplication rates are similar to those obtained in experimental infection of rabbits. In this study, the RNA transcript profiles of the T. pallidum Nichols during in vitro culture and rabbit infection were compared to examine whether gene expression patterns differed in these two environments. To this end, RNA preparations were converted to cDNA and subjected to RNA-seq using high throughput Illumina sequencing; reverse transcriptase quantitative PCR was also performed on selected genes for validation of results. The transcript profiles in the in vivo and in vitro environments were remarkably similar, exhibiting a high degree of concordance overall. However, transcript levels of 94 genes (9%) out of the 1,063 predicted genes in the T. pallidum genome were significantly different during rabbit infection versus in vitro culture, varying by up to 8-fold in the two environments. Genes that exhibited significantly higher transcript levels during rabbit infection included those encoding multiple ribosomal proteins, several prominent membrane proteins, glycolysis-associated enzymes, replication initiator DnaA, rubredoxin, thioredoxin, two putative regulatory proteins, and proteins associated with solute transport. In vitro cultured T. pallidum had higher transcript levels of DNA repair proteins, cofactor synthesis enzymes, and several hypothetical proteins. The overall concordance of the transcript profiles may indicate that these environments are highly similar in terms of their effects on T. pallidum physiology and growth, and may also reflect a relatively low level of transcriptional regulation in this reduced genome organism.
Project description:The experiment was performed with the intention of collecting transcriptomic data from isolated cell types (spore, stalk and vegetative cells) in Dictyostelium lacteum as well as from cysts in Polyshpondlyium pallidum. By combining these data with similar cell-type specific RNA-Seq data from other organisms, and by examining the expression patterns of transcription factor genes, we tried to characterize how gene regulation for cell differentiation evolved in Dictyostelia. Specifically ,we dissociated and collected spore and stalk from the fruiting bodies of D. lacteum at 24 hours of development. We also collected exponentially growing vegetative cells of D. lacteum. For collecting P. pallidum cyst samples, cells were induced to encyst with sorbitol, and samples were collected at 0, 8, 16, and 24 h of incubation. RNA was extracted using the RNeasy kit (QIAGEN), and cDNA libraries were made using the Illumina TruSeq kit. The Illumina sequencing platforms (NextSeq500 for D. lacteum samples, and Hi-seq 2000 for P. pallidum samples) were used for sequencing.