Rhinovirus-Induced Barrier Dysfunction in Polarized Airway Epithelial Cells Is Mediated by NADPH Oxidase 1

Abstract

Previously, we showed that rhinovirus (RV), which is responsible for the majority of common colds, disrupts airway epithelial barrier function, as evidenced by reduced transepithelial resistance (R T ), dissociation of zona occludins 1 (ZO-1) from the tight junction complex, and bacterial transmigration across polarized cells. We also showed that RV replication is required for barrier function disruption. However, the underlying biochemical mechanisms are not known. In the present study, we found that a double-stranded RNA (dsRNA) mimetic, poly(I:C), induced tight junction breakdown and facilitated bacterial transmigration across polarized airway epithelial cells, similar to the case with RV. We also found that RV and poly(I:C) each stimulated Rac1 activation, reactive oxygen species (ROS) generation, and Rac1-dependent NADPH oxidase 1 (NOX1) activity. Inhibitors of Rac1 (NSC23766), NOX (diphenylene iodonium), and NOX1 (small interfering RNA [siRNA]) each blocked the disruptive effects of RV and poly(I:C) on R T , as well as the dissociation of ZO-1 and occludin from the tight junction complex. Finally, we found that Toll-like receptor 3 (TLR3) is not required for either poly(I:C)-or RV-induced reductions in R T . Based on these results, we concluded that Rac1-dependent NOX1 activity is required for RV-or poly(I:C)-induced ROS generation, which in turn disrupts the barrier function of polarized airway epithelia. Furthermore, these data suggest that dsRNA generated during RV replication is sufficient to disrupt barrier function.

IFNβ/TNFα synergism induces a non-canonical STAT2/IRF9-dependent pathway triggering a novel DUOX2 NADPH Oxidase-mediated airway antiviral response

“…Our observation that DUOX2/ DUOXA2 were induced following SeV infection in three different AEC models, A549, ALI-Calu-3 and NHBEs, adds to the picture of the previously reported RV-induced DUOX2/DUOXA2 expression in primary AECs [6,[30][31][32]. Importantly, SeV is a member of the Paramyxoviridae family of negative sense single-stranded RNA (ssRNA) viruses, whereas RV belongs to the Picornaviridae family containing positive sense ssRNA viruses.…”

Staphylococcus aureus colonization and non-influenza respiratory viruses: Interactions and synergism mechanisms

“…Its integrity is regulated in large part by tight junctions of epithelial cells [76], which is a complex of several internal and membrane proteins including occludin and zona occludens (ZO) proteins [77]. Rhinovirus infection disrupts the barrier function of the airway epithelium through the dissociation of ZO-1 and occludin from the tight junction complex [78]. Rhinovirus infection has been shown to induce oxidative stress in respiratory epithelial cells by generating reactive oxygen species (ROS) [79].…”

“…Rhinovirus infection has been shown to induce oxidative stress in respiratory epithelial cells by generating reactive oxygen species (ROS) [79]. ROS generation is induced by double-strands of viral RNA (dsRNA) that appear transiently during rhinovirus replication, and is produced by NADPH oxidase [78]. In non-phagocytic cells, ROS act as a molecular switch to stimulate pro-inflammatory responses [80].…”

“…In non-phagocytic cells, ROS act as a molecular switch to stimulate pro-inflammatory responses [80]. Nevertheless, ROS generation disrupts the barrier function of rhinovirus-infected cells [78]. Thus, a perturbation of the tight junction barrier function increases paracellular permeability, facilitates translocation of pathogens and their soluble products, and exposes basolateral receptors.…”

Respiratory Viral Infections and Subversion of Cellular Antioxidant Defenses

“…In regard to other respiratory viruses, rhinovirus infection has been associated with superoxide and hydrogen peroxide production through NOX1 [59] and influenza infection generates superoxide through NOX2 [60], as shown in Table 1.…”