Regulation of Rac1 and Reactive Oxygen Species Production in Response to Infection of Gastrointestinal Epithelia

Generation of reactive oxygen species (ROS) during infection is an immediate host defense leading to microbial killing. APE1 is a multifunctional protein induced by ROS and after induction, protects against ROS-mediated DNA damage. Rac1 and NAPDH oxidase (Nox1) are important contributors of ROS gene...

Full description

Saved in:

Bibliographic Details
Published in:	PLoS pathogens 2016-01, Vol.12 (1), p.e1005382-e1005382
Main Authors:	den Hartog, Gerco, Chattopadhyay, Ranajoy, Ablack, Amber, Hall, Emily H, Butcher, Lindsay D, Bhattacharyya, Asima, Eckmann, Lars, Harris, Paul R, Das, Soumita, Ernst, Peter B, Crowe, Sheila E
Format:	Article
Language:	eng
Subjects:	Bacterial infections Blotting, Western Cancer Cell Line Deoxyribonucleic acid DNA DNA damage DNA-(Apurinic or Apyrimidinic Site) Lyase - metabolism Epithelial cells Experiments Fluorescent Antibody Technique Funding Gastric Mucosa - immunology Gastric Mucosa - metabolism Gastric Mucosa - microbiology Gastrointestinal diseases Health aspects Helicobacter Infections - immunology Helicobacter Infections - metabolism Humans Immunoprecipitation Infections Intestinal Mucosa - immunology Intestinal Mucosa - metabolism Intestinal Mucosa - microbiology Microscopy Microscopy, Confocal Oxidative stress Oxygen Pathogens Physiological aspects Physiology Proteins rac1 GTP-Binding Protein - immunology rac1 GTP-Binding Protein - metabolism Reactive oxygen species Reactive Oxygen Species - immunology Reactive Oxygen Species - metabolism Real-Time Polymerase Chain Reaction Salmonella Infections - immunology Salmonella Infections - metabolism Ulcers
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	Generation of reactive oxygen species (ROS) during infection is an immediate host defense leading to microbial killing. APE1 is a multifunctional protein induced by ROS and after induction, protects against ROS-mediated DNA damage. Rac1 and NAPDH oxidase (Nox1) are important contributors of ROS generation following infection and associated with gastrointestinal epithelial injury. The purpose of this study was to determine if APE1 regulates the function of Rac1 and Nox1 during oxidative stress. Gastric or colonic epithelial cells (wild-type or with suppressed APE1) were infected with Helicobacter pylori or Salmonella enterica and assessed for Rac1 and NADPH oxidase-dependent superoxide production. Rac1 and APE1 interactions were measured by co-immunoprecipitation, confocal microscopy and proximity ligation assay (PLA) in cell lines or in biopsy specimens. Significantly greater levels of ROS were produced by APE1-deficient human gastric and colonic cell lines and primary gastric epithelial cells compared to control cells after infection with either gastric or enteric pathogens. H. pylori activated Rac1 and Nox1 in all cell types, but activation was higher in APE1 suppressed cells. APE1 overexpression decreased H. pylori-induced ROS generation, Rac1 activation, and Nox1 expression. We determined that the effects of APE1 were mediated through its N-terminal lysine residues interacting with Rac1, leading to inhibition of Nox1 expression and ROS generation. APE1 is a negative regulator of oxidative stress in the gastrointestinal epithelium during bacterial infection by modulating Rac1 and Nox1. Our results implicate APE1 in novel molecular interactions that regulate early stress responses elicited by microbial infections.
ISSN:	1553-7374 1553-7366 1553-7374