Dataset Information

TcdB of Clostridioides difficile mediates necrosis in epithelial cells and is depend on RAS

ABSTRACT: A Clostridioides difficile infection (CDI) is the most common nosocomial infection worldwide. The main virulence factors are TcdA and TcdB, which inhibit small Rho-GTPases. Inhibition of small Rho-GTPases leads to the so-called cytopathic effect, a reorganization of the actin cytoskeleton, an impairment of the colon epithelium barrier function, and inflammation. Additionally, TcdB induces a necrotic cell death termed pyknosis in vitro independently from its glucosyltransferas-es characterized by chromatin condensation and ROS production. To understand the underlying mechanism of this pyknotic effect, we conducted a large-scale phosphoproteomic study. We in-cluded the analysis of alterations in the phosphoproteome after treatment with TcdA, that was investigated for the first time. TcdA exhibit no glucosyltransferase-independent effect and was, thus, a good control to elucidate the underlying mechanism of the glucosyltransferase inde-pendent effect of TcdB. We found RAS to be a central upstream regulator for the glucosyltrans-ferase independent effect of TcdB. Inhibition of RAS leads to a 68% reduction in necrosis. Further analysis revealed apolipoprotein C-III (APOC3) as a possible crucial factor of CDI induced in-flammation in vivo.

INSTRUMENT(S): Orbitrap Fusion Lumos

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Epithelial Cell, Cell Culture

SUBMITTER: Florian Stieglitz

LAB HEAD: Andreas Pich

PROVIDER: PXD031726 | Pride | 2022-05-19

REPOSITORIES: Pride

ACCESS DATA

Publications

TcdB of Clostridioides difficile Mediates RAS-Dependent Necrosis in Epithelial Cells.

Stieglitz Florian F Gerhard Ralf R Hönig Rabea R Giehl Klaudia K Pich Andreas A

International journal of molecular sciences 20220412 8

A Clostridioides difficile infection (CDI) is the most common nosocomial infection worldwide. The main virulence factors of pathogenic C. difficile are TcdA and TcdB, which inhibit small Rho-GTPases. The inhibition of small Rho-GTPases leads to the so-called cytopathic effect, a reorganization of the actin cytoskeleton, an impairment of the colon epithelium barrier function and inflammation. Additionally, TcdB induces a necrotic cell death termed pyknosis in vitro independently fro ...[more]

PMID: 35457076

Similar Datasets

Project description:Abstract: RAS-like (RAL) GTPases function in Wnt signalling-dependent intestinal stem cell proliferation and regeneration. Whether RAL proteins work as canonical RAS effectors in the intestine, and the mechanisms of how they contribute to tumorigenesis remain unclear. Here, we show that RAL GTPases are necessary and sufficient to activate EGFR/MAPK signalling in the intestine. We identify non-canonical roles of RAL GTPases not as RAS effectors, but rather by acting upstream of RAS activation via induction of EGFR internalisation . Knocking down Drosophila RalA from intestinal stem and progenitor cells leads to increased levels of plasma membrane-associated EGFR and decreased MAPK pathway activation. Importantly, in addition to impacting stem cell proliferation and damage-induced intestinal regeneration, this function of RAL GTPases drives EGFR-dependent tumorigenic growth in the intestine and in human mammary epithelium. Altogether, our results reveal previously unrecognised cellular and molecular contexts where RAL GTPases become essential mediators of EGFR-driven tissue homeostasis and malignant transformation. Results: RalA is required within ISCs to induce midgut adult midgut regeneration following damage by oral infection with Erwinia carotovora carotovora 15 (Ecc15) (Johansson et al., 2019). To achieve a global view of intestinal pathways affected by RalA, we performed a transcriptomic analysis by RNAseq of whole midguts from vehicle treated (Mock) or damaged (Ecc15 fed) control animals or following RalA knockdown in intestinal stem and progenitor cells using the escargot-gal4 driver (ISC/EB>) (Micchelli and Perrimon, 2006). Consistent with its effect on ISC proliferation (Johansson et al., 2019), RalA knockdown significantly impaired damage-induced upregulation of cell cycle genes in the midgut. Additionally, levels of multiple transcriptional targets of the EGFR/MAPK pathway (Golembo et al., 1996; Hsu et al., 2001; Jin et al., 2015; Meng and Biteau, 2015), such as argos (aos), rhomboid (rho), Sox21a and string (stg) were increased following Ecc15 infection in control midguts. The upregulation of these target genes was significantly impaired upon RalA knockdown.

Dataset Information

TcdB of Clostridioides difficile mediates necrosis in epithelial cells and is depend on RAS

Publications

TcdB of <i>Clostridioides difficile</i> Mediates RAS-Dependent Necrosis in Epithelial Cells.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure