Aim: To elucidate the location and effects of transcription factor-nuclear factor-kappaB (NF-kappaB) in lung tissues of rats with chronic obstructive pulmonary disease (COPD).
Methods: Fourteen male Wistar rats were randomly divided into COPD model and control groups equally. The COPD model was established by intratracheal instillation of lipopolysaccharide twice and exposure to cigarette smoke daily. We detected the NF-kappaB p65 protein in lung by immunohistochemical method, and the expression of NF-kappaB p65 mRNA in lung by in situ hybridization.
Results: Immunohistochemistry, the expression of NF-kappaB p65 protein in alveolar, bronchiolar epithelium and arteriolar endothelium was significantly higher in the COPD group (0.426 +/- 0.007, 0.434 +/- 0.012 and 0.313 +/- 0.007, respectively) than those of the control group (0.115 +/- 0.006, 0.116 +/- 0.005 and 0.095 +/- 0.007, respectively, all P < 0.01). In situ hybridization showed that the expressions of NF-kappaB p65 mRNA in alveolar epithelium (0.203 +/- 0.008), bronchiolar and arteriolar smooth muscle cell (0.208 + 0. 010 and 0.206 + 0.007) of rats in the COPD group were stronger than those in the control group (0.100 +/- 0.006, 0.102 +/- 0.002 and 0.103 +/- 0.003 respectively) by semiquantitative analysis (all P < 0.01).
Conclusion: The expression and nuclear translocation of NF-kappaB may be the basis event of gene expression of many cytokines and inflammatory mediators, which may positively regulate gene expression of many cytokines and inflammatory mediators in various cell lines.