Over-expression of nuclear factor-κB family genes and inflammatory molecules is related to chronic obstructive pulmonary disease

Background: Nuclear factor-kappa B (NF-kappa B) signaling plays essential roles in inflammatory responses. However, whether the expression levels of NF-kappa B family genes affect inflammatory responses is unclear. Moreover, little is known regarding the association between NF-kappa B family genes expression and the pathogenesis of chronic obstructive pulmonary disease (COPD). The present study was undertaken to assess the relationship between the expression levels of NF-kappa B family genes mRNA and of inflammatory markers relevant to COPD pathogenesis. Methods: A total of 186 unrelated patients with acute exacerbations of COPD and 180 healthy controls were recruited. Total RNA was extracted from the peripheral fasting blood of each subject using trizol reagent. The mRNA levels of NF-kappa B family genes (NF-kappa B1, NF-kappa B2 and c-REL) were measured by real-time quantitative polymerase chain reaction. The serum levels of cyclooxygenase-2 (COX-2), C-reactive protein, interleukin (IL)-1 beta, IL-6, IL-8, IL-12 and tumor necrosis factor-alpha were measured with enzyme-linked immunosorbent assay kits. Results: The relative mRNA levels of the NF-kappa B family genes and the levels of inflammatory molecules were significantly higher in the COPD group than in the control group after adjustment for smoking. The IL-1 beta, IL-8 and COX-2 levels were significantly lower in the NF-kappa B2 under-expression subgroup as compared to the NF-kappa B2 over-expression subgroup. The COX-2 level was significantly lower (P<0.05) in the c-REL under-expression subgroup as compared to the c-REL over-expression subgroup. Conclusion: NF-kappa B2 over-expression was associated with IL-1 beta, IL-8 and COX-2 levels, whereas c-REL over-expression was associated with COX-2 level. Over-expression of both NF-kappa B2 and c-REL was found to be related to COPD.