Decreased expression of the NF-kappa B family member RelB in lung fibroblasts from Smokers with and without COPD potentiates cigarette smoke-induced COX-2 expression

作者：Sheridan Jared A; Zago Michela; Nair Parameswaran; Li Pei Z; Bourbeau Jean; Tan Wan C; Hamid Qutayba; Eidelman David H; Benedetti Andrea L; Baglole Carolyn J^*

来源：Respiratory Research, 2015, 16(1): 54.

DOI：10.1186/s12931-015-0214-6

• Inflammation
• NF-kappa B
• miRNA
• COPD
• Cigarette smoke
• Lung

Background: Heightened inflammation, including expression of COX-2, is associated with COPD pathogenesis. RelB is an NF-kappa B family member that attenuates COX-2 in response to cigarette smoke by a mechanism that may involve the miRNA miR-146a. There is no information on the expression of RelB in COPD or if RelB prevents COX-2 expression through miR-146a.
Methods: RelB, Cox-2 and miR-146a levels were evaluated in lung fibroblasts and blood samples derived from non-smokers (Normal) and smokers (At Risk) with and without COPD by qRT-PCR. RelB and COX-2 protein levels were evaluated by western blot. Human lung fibroblasts from Normal subjects and smokers with and without COPD, along with RelB knock-down (siRNA) in Normal cells, were exposed to cigarette smoke extract (CSE) in vitro and COX-2 mRNA/protein and miR-146a levels assessed.
Results: Basal expression of RelB mRNA and protein were significantly lower in lung cells derived from smokers with and without COPD, the latter of which expressed more Cox-2 mRNA and protein in response to CSE. Knock-down of RelB in Normal fibroblasts increased Cox-2 mRNA and protein induction by CSE. Basal miR-146a levels were not different between the three groups, and only Normal fibroblasts increased miR-146a expression in response to smoke. There was a positive correlation between systemic RelB and Cox-2 mRNA levels and circulating miR-146a levels were higher only in GOLD stage I subjects.
Conclusions: Our data indicate that RelB attenuates COX-2 expression in lung structural cells, such that loss of pulmonary RelB may be an important determinant in the aberrant, heightened inflammation associated with COPD pathogenesis.

• 出版日期2015-5-6
• 单位McGill