P. aeruginosa Lipopolysaccharide-Induced MUC5AC and CLCA3 Expression Is Partly through Duox1 In Vitro and In Vivo

Wen Li,Niya Zhou,Ce Chen,Fugui Yan,Huahao Shen,Jian-Dong Li,Yinfang Wu,Hongbin Zhou,Xiaoping Lin,Zhihua Chen,Brian J Knoll

doi:10.1371/journal.pone.0063945

Abstract

BackgroundWe have previously found that reactive oxygen species (ROS) are involved in Pseudomonas aeruginosa lipopolysaccharide (PA-LPS) induced MUC5AC in airway epithelial cells. Dual oxidase1 (Duox1), a member of NADPH oxidase(Nox), is known to be responsible for ROS production in respiratory tract epithelial cells. Our aim was to clarify whether Duox1 was also involved in the PA-LPS-induced MUC5AC and calcium dependent chloride channel 3(Clca3), another recognized marker of goblet cell hyperplasia and mucus hyper-production.Methods PA-LPS-induced Duox1 mRNA levels were examined in A549 cells, primary mouse tracheal epithelial cells (mTECS) and lung tissues of mice. Nox inhibitors diphenyleneiodonium chloride (DPI) and Duox1 siRNA were used to investigate whether Duox1 is involved in PA-LPS-induced MUC5AC and Clca3 expression both in vitro and in vivo.ResultsDuox1 is induced by PA-LPS in A549 cells, primary mTECs and lung tissues of mice. DPI significantly inhibited PA-LPS-induced up-regulation of Duox1, Muc5ac and Clca3 in primary mouse trachea epithelial cells and lung tissues of mice. Knockdown of Duox1 markedly inhibited PA-LPS-induced MUC5AC expression via a ROS-TGF-α cascade in A549 cells. Furthermore, DPI significantly inhibited PA-LPS-induced increases in inflammatory cells accumulated in mouse lungs.ConclusionsWe demonstrate for the first time that PA-LPS-induced MUC5AC and Clca3 expression is partly through Duox1, and provide supportive evidence for Duox1 as a potential target in treatments of mucin over-production diseases.

Highlights

Mucus hypersecretion is commonly observed in chronic inflammatory airway diseases such as asthma, chronic obstructive pulmonary disease, and cystic fibrosis
The two Dual oxidases (Duox) isoforms Dual oxidase1 (Duox1) and Duox2 have high structural similarity. While they were differentially regulated by a variety of pathways mediate Pseudomonas aeruginosa lipopolysaccharide (PA-LPS)-induced MUC5AC expression in NCI-H292 cells [18], we explored whether Duox1 controlls the production of reactive oxygen species (ROS) and TGF-a in airway epithelial cells
We investigated whether Duox1 is induced by Pseudomonas aeruginosa (PA)-LPS in A549 cells, primary mouse tracheal epithelial cells and lung tissues of mice respectively, and NADPH oxidase (Nox) inhibitors diphenyleneiodonium chloride (DPI) inhibits PA-LPS-induced Duox1, MUC5AC and Clca3 expression in vitro and in vivo

Summary

Introduction

Mucus hypersecretion is commonly observed in chronic inflammatory airway diseases such as asthma, chronic obstructive pulmonary disease, and cystic fibrosis. A number of in vitro and in vivo studies have been carried out to explore the signaling mechanisms underlying the regulation of MUC5AC expression induced by many different stimuli [5,6,7,8,9,10]. Pseudomonas aeruginosa (PA) infection is common in chronic inflammatory airway diseases [11], especially in cystic fibrosis. It has been previously shown that Pseudomonas aeruginosa lipopolysaccharide (PA-LPS) significantly up-regulates MUC5AC mucin expression in airway epithelial cells [12,13,14]. We have previously found that reactive oxygen species (ROS) are involved in Pseudomonas aeruginosa lipopolysaccharide (PA-LPS) induced MUC5AC in airway epithelial cells. Our aim was to clarify whether Duox was involved in the PA-LPS-induced MUC5AC and calcium dependent chloride channel 3(Clca3), another recognized marker of goblet cell hyperplasia and mucus hyper-production

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