Objective: To observe the expression of NF-kappa B activation and the effect of dexamethasone on the NF-kappa B activity in the human airway epithelial cell line 16HBE after TNF-alpha stimulation.
Methods: After 16HBE was treated with different concentration of TNF-alpha(10 U/ml, 100 U/ml, 1,000 U/ml) and dexamethasone (100 nmol/L), total RNA and cellular, nuclear protein were extracted at 1 hour, 2 hour, 4 hour, respectively. RT-PCR and electrophoresis mobility shift assay(EMSA) were used to detect the expression of IL-8 mRNA and NF-kappa B activation.
Results: The activity of NF-kappa B activation became stronger at 1 hour in the TNF-alpha stimulated group than the control, peaked at 2 hours and then decreased at 4 hours. Supershift assay confirmed that both p50 and p65 were components of active NF-kappa B. At the same time, IL-8 mRNA expression was elevated at 4 hours. After dexamethasone treatment, the expression of NF-kappa B activation and IL-8 mRNA became lower.
Conclusions: It is suggested that activated NF-kappa B played a key role in the inflammatory process of respiratory diseases through regulating the expression of some important factors (cytokines). Glucocorticoid inhibited the activation of NF-kappa B and showed antiinflammatory effect.