Project description:We compared multiple strains of lab trophozoites to recent clinical isolates. Clinical isolates were grown in xenic media, and maintained many characteristics of the cyst stage of devlopment Keywords: Stage conversion
Project description:Inosine monophosphate (IMP) plays a central role in intracellular purine metabolism. How IMP regulates inflammation induced by bacterial products or bacteria is unknown. In this study, we demonstrate that IMP fundamentally alters gene expression in the liver.To assess how IMP affects inflammatory cell activation in vivo, we subjected liver, the organ containing the highest numbers of macrophages in the body, to RNAseq analyses. High quality RNA was isolated from the livers of 3 vehicle- and 3 IMP-treated endotoxemic mice and submitted for RNAseq analysis. Our analysis identified 105 genes that were differentially expressed, determined by adjusted p values (42 downregulated, 63 upregulated; padj ≤ 0.05).
Project description:Pseudomonas aeruginosa (P. aeruginosa) lung infection is a significant cause of mortality in patients with cystic fibrosis (CF). Existing experimental data in our lab showed significantly different levels of virulence of "early" and "late" P. aeruginosa infection isolates in a C. elegans slow killing model. We wished to examine the expression profile of these isolates in order to explore genes that may be responsible for the observed differences. The expression profiles of two pairs of isolates (four isolates in total) were compared to each other using the Affymetrix P. aeruginosa PAO1 genome array, to gain insight into properties mediating virulence in these isolates. Data analysis was carried out using BIOCONDUCTOR software. Keywords: Comparative strain hybridization
2011-12-31 | GSE33275 | GEO
Project description:clinical IMP-producing Klebsiella spp. Isolates in China
Project description:Recent advancements in genome sequencing have facilitated accessing the natural genetic diversity of species, unveiling hidden genetic traits, clarifying gene functions, and the degree to which laboratory studies can be generalized. One notable discovery is the frequent (~20%) aneuploidy - an imbalance in chromosome copy numbers - in natural Saccharomyces cerevisiae (Sc) isolates, despite the significant fitness costs and transient nature reported for lab-engineered yeast aneuploids. To examine this discrepancy, we adapted a high-throughput proteomic platform to analyze the proteome of 800 diverse yeast isolates. Matching these proteomes to the natural isolates’ genomes, transcriptomes, as well as generating ubiquitinome and protein turnover data for selected isolates, we report that natural and lab-generated aneuploids differ specifically at the proteome. While lab-generated aneuploids attenuate specific proteins – mostly protein complex subunits – and do not alter the average gene dosage provided by chromosome duplications, in natural strains, 70% of proteins encoded on aneuploid chromosomes are attenuated, and protein levels are shifted towards the euploid state chromosome-wide. Our data links chromosome-wide dosage compensation in natural strains to i) genome-wide buffering of gene expression changes manifesting in trans on euploid chromosomes, ii) increased expression of structural components of the ubiquitin proteasome system, and iii) increased global rates of protein turnover. Our results encourage the exploitation of natural diversity of species to understand complex biological processes at the molecular level. This submission contains the raw files for the disomics lab engineered strains, the library used for the analysis and the corresponding DIA-NN report and associated files.
Project description:To identify factors and pathways regulated by IMP proteins and obtain leads to the mechanism behind the phenotypic changes, we compared the gene expression profiles of IMP siRNA treated cells with mock treated cells. Triplicate gene expression profiles were generated from both the IMP(1,3)A and IMP(1,3)B siRNA sets and were compared to the mock transfected cells. cRNA was hybridized to Affymetrix human U133A arrays.
Project description:Transcriptional profiling of NTG-treated E. coli imp fabI(G93V) cells compared to control cells (E. coli imp fabI(G93V) ) in the absence or presence of sub-lethal concentration of triclosan.
Project description:Background: Enterobacter cloacae complex (ECC) is a common opportunistic pathogen and is responsible for causing various infections in humans. Owing to its inducible chromosomal AmpC β-lactamase (AmpC), ECC is inherently resistant to the 1st- and 2nd- generation cephalosporins. However, whether β-lactams antibiotics enhance ECC resistance remains unclear. Results: In this study, we found that subinhibitory concentrations (SICs) of cefazolin (CFZ) and imipenem (IMP) can advance the expression of AmpC and enhance its resistance towards β-lactams through NagZ in Enterobacter cloacae (EC). Further, AmpC manifested a substantial upregulation in EC in response to SICs of CFZ and IMP. In nagZ knockout EC (ΔnagZ), the resistance to β-lactam antibiotics was rather weakened and the effect of CFZ and IMP on AmpC induction was completely abrogated. NagZ ectopic expression can rescue the induction effects of CFZ and IMP on AmpC and increase ΔnagZ resistance. More importantly, CFZ and IMP have the potential to induce the expression of AmpR's target genes in a NagZ-dependent manner. Conclusions: Our findings suggest that NagZ is a critical determinant for CFZ and IMP to promote AmpC expression and resistance and that CFZ and IMP should be used with caution since they may aggravate ECC resistance. At the same time, this study further improves our understanding of resistance mechanisms in ECC.
Project description:The numerous neurons and glia that form the brain originate from tightly controlled growth and division of neural stem cells, regulated systemically by known extrinsic signals. However, the intrinsic mechanisms that control the characteristic proliferation rates of individual neural stem cells are unknown. Here, we show that the size and division rates of Drosophila neural stem cells (neuroblasts) are controlled by the highly conserved RNA binding protein Imp (IGF2BP), via one of its top binding targets in the brain, myc mRNA. We show that Imp stabilises myc mRNA leading to increased Myc protein levels, larger neuroblasts, and faster division rates. Declining Imp levels throughout development limit myc mRNA stability to restrain neuroblast growth and division, while heterogeneous Imp expression correlates with myc mRNA stability between individual neuroblasts in the brain. We propose that Imp-dependent regulation of myc mRNA stability fine-tunes individual neural stem cell proliferation rates.
Project description:Adult stem cells support tissue homeostasis and repair throughout the life of an individual. However, numerous intrinsic and extrinsic changes occur with age that result in altered stem cell behavior and reduced tissue maintenance and regeneration. In the Drosophila testis, stem cells surround and contact the apical hub, a cluster of somatic cells that express the self-renewal factor Unpaired (Upd), which activates the JAK-STAT pathway in adjacent stem cells. However, aging results in a dramatic decrease in upd expression, with a concomitant loss of germline stem cells (GSCs). Here we present genetic and biochemical data to demonstrate that IGF-II mRNA binding protein (Imp) counteracts endogenous small interfering RNAs to stabilize upd RNA and contribute to maintenance of the niche. However, Imp expression decreases in hub cells of older males, similar to upd, which is due to targeting of Imp by the heterochronic microRNA let-7. Therefore, in the absence of Imp, upd mRNA becomes unprotected and susceptible to degradation. Understanding the mechanistic basis for aging-related changes in stem cell behavior will lead to the development of strategies to treat age-onset diseases and facilitate stem cell based therapies in older individuals.