title: 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.
authors.affiliation: Department of Pediatrics and Communicable Diseases, University of Michigan, 1150 W. Medical Center Dr., Room 3570, MSRBII, Box 5688, Ann Arbor, MI 48109-0688, USA.
authors.forename: Adam T
authors.initials: AT
authors.lastname: Comstock
authors.forename: Shyamala
authors.initials: S
authors.lastname: Ganesan
authors.forename: Asamanja
authors.initials: A
authors.lastname: Chattoraj
authors.forename: Andrea N
authors.initials: AN
authors.lastname: Faris
authors.forename: Benjamin L
authors.initials: BL
authors.lastname: Margolis
authors.forename: Marc B
authors.initials: MB
authors.lastname: Hershenson
authors.forename: Umadevi S
authors.initials: US
authors.lastname: Sajjan
mesh_terms: D001980:Bronchi / Q000378:metabolism* / Q000473:pathology* / Q000821:virology; D002461:Cell Line, Transformed; D002463:Cell Membrane Permeability / Q000187:drug effects / Q000502:physiology*; D016764:Cell Polarity; D004847:Epithelial Cells / Q000378:metabolism* / Q000382:microbiology / Q000473:pathology / Q000821:virology; D006193:Haemophilus influenzae / Q000502:physiology; D006367:HeLa Cells; D006801:Humans; D019255:NADPH Oxidases / Q000378:metabolism* / Q000494:pharmacology; D012229:Rhinovirus / Q000472:pathogenicity*; D014779:Virus Replication; D020830:rac1 GTP-Binding Protein / Q000235:genetics / Q000378:metabolism
chemical_list: D019255:NADPH Oxidases; D020830:rac1 GTP-Binding Protein