Asian Sand Dust Up-Regulates MUC4 Expression in Human Upper Airway Epithelial Cells

Ginsenoside Rb1 Attenuates TGF-β1-Induced MUC4/5AC Expression and Epithelial-Mesenchymal Transition in Human Airway Epithelial Cells

Background and Objectives Ginsenoside Rb1 is the main metabolite of Panax ginseng. It is known to have many beneficial properties including anti-inflammatory, antitumoral and antioxidant effects. However, the therapeutic effects of ginenoside Rb1 on inflammatory airway diseases have not been elucidated. Therefore, we investigated the effects of ginsenoside Rb1 on the TGF-β1-induced mucin gene expression and epithelial-mesenchymal transition (EMT) in human airway epithelial cells.Materials and Method We evaluated the effects of ginsenoside Rb1 on the changes of MUC4, MUC5AC, occludin, claudin 4, claudin 18, neural (N)-cadherin, and epithelial (E)-cadherin expression by TGF-β1 in NCI-H292 cells using reverse, real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and western blot.Results TGF-β1 significantly increased MUC4/5AC expression. Rb1 inhibited TGF-β1- induced MUC4/5AC expression. In addition, TGF-β1 significantly attenuated occludin, claudin 18, and E-cadherin expressions but induced claudin 4 and N-cadherin expressions. On the other hand, Rb1 reversed changes in the TGF-β1- mediated expressions of cell junction molecules.Conclusion These results suggest that ginsenoside Rb1 attenuates TGF-β1-induced MUC4/5AC expressions and EMT in the human airway epithelial cells. These findings are important data demonstrating the potential of ginsenoside Rb1 as a therapeutic agent for inflammatory airway diseases.

Asian Sand Dust Upregulates IL-6 and IL-8 via ROS, JNK, ERK, and CREB Signaling in Human Nasal Fibroblasts

Background

Asian sand dust (ASD) profoundly affects respiratory health by inducing inflammation and causing upper airway inflammatory diseases. Interleukin (IL)-6 and IL-8 are pro-inflammatory mediators that are involved in upper airway inflammatory diseases. However, the effect of ASD on the production of IL-6 and IL-8 in nasal fibroblasts has not been adequately studied. We investigated the effect of ASD on the induction of pro-inflammatory mediators and its underlying mechanisms in nasal fibroblasts.

Methods

Real-time cytotoxicity assays were used to determine the effect of ASD on the viability of fibroblasts. Enzyme-linked immunosorbent assays and real-time polymerase chain reactions were performed to determine whether ASD induced the expression of IL-6 and IL-8. Reactive oxygen species (ROS) were quantified using 2, 7-dichlorofluorescein-diacetate and MitoSOX Red. Induction of IL-6 and IL-8 signal transduction pathways by ASD was confirmed by Western blotting. Ex vivo culture of the inferior turbinate tissue was performed to confirm the effects of ASD.

Results

ASD upregulated ROS levels, and this in turn promoted IL-6 and IL-8 expression through the MAPK (JNK and ERK) and CREB signaling pathways in nasal fibroblasts. However, ASD did not induce phosphorylation of p38. Specific inhibitors of each pathway (ROS, JNK, ERK, and CREB inhibitors) suppressed ASD-induced IL-6 and IL-8 upregulation.

Conclusions

ASD induces pro-inflammatory mediators, and the increased levels of IL-6 and IL-8 might be associated with the pathogenesis of chronic rhinosinusitis.