Project description:The Clostridioides difficile toxins TcdA and TcdB are responsible for diarrhea and colitis. The aim of this project was to explore the effects of the toxins on epithelial barrier function and the molecular mechanisms for diarrhea and inflammation. RNA-seq of toxin-treated intestinal cell monolayers was performed to describe the C. difficile-mediated effects. mRNA profiles from intestinale epithelial cells were generated by deep sequencing using Illumina NovaSeq 6000. This data provide the basis for subsequent upstream regulator analysis.
Project description:Time-resolve proximity proteomics of tight junction. To understand how the tight junction belt is assembled and positioned, we combined APEX2 proximity proteomics of the main junctional scaffold protein ZO-1 with a calcium switch tissue formation assay.This combination allowed us to synchronize the initiation of junction assembly in the entire tissue by the addition of calcium to the culture medium and quantify the time evolution of the junctional proteome during the assembly process using proximity proteomics.
Project description:Clostridioides difficile (C. difficile) toxins A (TcdA) and B (TcdB) cause antibiotic-associated colitis, increasing morbidity and mortality. Accurate in vitro models are necessary to detect early toxicity kinetics, investigate disease etiology, and develop preclinical models for new therapies. Properties of cancer cell lines and organoids inherently limit these efforts. We developed adult stem cell-derived monolayers of differentiated human colonic epithelium (hCE) with barrier function, investigated the impact of toxin application to apical/basal aspects of monolayers, and evaluated whether a leaky epithelial barrier enhances toxicity. Single-cell RNA-sequencing (scRNAseq) mapped C. difficile-relevant genes to human gut epithelial lineages. Transcriptomics informed timing of stem cell differentiation to achieve in vitro colonocyte maturation like that observed in vivo. Transepithelial electrical resistance (TEER) and fluorescent dextran permeability assays measured cytotoxicity as barrier loss post-toxin exposure. Leaky epithelial barriers were induced with diclofenac. scRNAseq demonstrated broad and variable toxin receptor expression across human gut lineages. Absorptive colonocytes displayed generally enhanced toxin receptor, Rho GTPase, and cell junction expression. 22-day differentiated Caco-2 cells remained immature whereas hCE monolayers were similar to mature colonocytes. hCE monolayers exhibited high barrier function after 1-day differentiation. Basal TcdA/B application to monolayers caused greater toxicity and apoptosis. Diclofenac induced leaky hCE monolayers and enhanced toxicity of apical TcdB exposure. Apical/basal toxicities are uncoupled with more rapid onset and increased magnitude of basal toxicity. Leaky paracellular junctions enhance toxicity of apical TcdB exposure. hCE monolayers represent a physiologically relevant and sensitive culture system to evaluate the impact of microbial toxins on gut epithelium.
Project description:Tight junction (TJ) proteins (Tjps), Tjp1 and Tjp2, are tight junction-associated scaffold proteins that bind to the transmembrane proteins of tight junctions and the underlying cytoskeleton. In this study, we first analyzed the tumorigenic characteristics of B16-F10 melanoma cells, including cell proliferation, migration, invasion, metastatic potential, and the expression patterns of related proteins, after the CRISPR-Cas9-mediated knockout (KO) of Tjp genes. The proliferation of Tjp1 and Tjp2 KO cells significantly increased in vitro. Other tumorigenic characteristics, including migration and invasion, were significantly enhanced in Tjp1 and Tjp2 KO cells.
Project description:The experiment intends to reveal the difference in gene expression profiles between the wild-type strain and the ∆cwp66 mutant of Clostridioides difficile. We first constructed the ∆cwp66 mutant, and the phenotypic changes of the ∆cwp66 mutant against the wild-type strain were studied. To further elucidate the mechanism of phenotypic changes of the ∆cwp66 mutant, RNA-sequencing experiments were carried out to reveal the underlying mechanism of phenotypic changes.
Project description:Epithelium barrier integrity is assumed at least in part by the presence of junctions between cells. Tight-junction formation may be necessary for Sertoli cells to cease dividing and to support germ cell development. Microarray analysis of P20 Cldn11 +/- and Cldn11-/- testes confirmed the impact od Cldn11 deficiency on cell cytoskeleton and junction-related genes. Keywords: transcriptomic analysis
Project description:The intestines house a diverse microbiota that must compete for nutrients to survive, but the specific limiting nutrients that control pathogen colonization are not clearly defined. Clostridioides difficile colonization typically requires prior disruption of the microbiota, suggesting that outcompeting commensals for resources is key in establishing C. difficile infection (CDI). The immune protein calprotectin (CP) is released into the gut lumen during CDI to chelate zinc (Zn) and other essential nutrient metals. Yet, the impact of Zn limitation on C. difficile colonization is unknown. To define C. difficile responses to Zn limitation, we performed RNA sequencing on C. difficile exposed to CP. In media with CP, C. difficile upregulated genes involved in metal homeostasis and amino acid metabolism.
Project description:Gene expression level of Clostridioides difficile (C. difficile) strain R20291 comparing control C. difficile carring pMTL84151 as vector plasmid with C. difficile conjugated with a pMTL84151-03890 gene. Goal was to determine the effects of 03890 gene conjugation on C. difficile strain R20291 gene expression.
Project description:Epithelium barrier integrity is assumed at least in part by the presence of junctions between cells. Tight-junction formation may be necessary for Sertoli cells to cease dividing and to support germ cell development. Microarray analysis of P20 Cldn11 +/- and Cldn11-/- testes confirmed the impact od Cldn11 deficiency on cell cytoskeleton and junction-related genes. Keywords: transcriptomic analysis Two-condition experiment: P20 Cldn11 +/- vs. P20 Cldn11 -/- testes. A pool of RNA from P20 Cldn11 +/- group was used as the reference group. Each P20 Cldn11 -/- was compared to reference group. Three biological replicates were processed in dye swap.