RT Journal Article
SR Electronic
T1 Cigarette smoke modulates the PKAc-associated cross-coupling between NF-kB and glucocorticoid receptor in primary small airway epithelial cells
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP P3129
VO 42
IS Suppl 57
A1 Rosalia Gagliardo
A1 Mark Gjomarkaj
A1 Pascal Chanez
A1 Giulia Anzalone
A1 Angela Marina Montalbano
A1 Mirella Profita
YR 2013
UL http://erj.ersjournals.com/content/42/Suppl_57/P3129.abstract
AB Negative transcriptional regulation or cross-coupling between NF-kB and glucocorticoid receptor (GR) is proposed to play a regulatory role in human physiology and inflammatory diseases, such as Chronic Obstructive Pulmonary Disease. It has been shown that catalytic subunit of protein kinase A (PKAc) directly phosphorylates GR, activates GR-dependent DNA binding, and also associates with RelA in the cytoplasm promoting its phosphorylation in ser-276. We evaluated the effects of Cigarette Smoke Extract (CSE 10%), on PKAc-associated cross-coupling between NF-kB and glucocorticoid receptor in primary small airway epithelial cells (SAEC11566), using co-immunoprecipitation and Western Blot analysis.We show that PKAc associates with GR in a ligand-independent manner, and with RelA(p65) at baseline. In unstimulated SAEC, Fluticasone Propionate (FP) (0.1μM) increases GR/PKAc association, promoting GR phosphorylation and its nuclear translocation, depending on PKA signaling, since the use of H89 (20mM), a potent inhibitor of PKAc, significantly reduces the FP-induced GR activation. The stimulation of the cells with CSE attenuates, at cytosolic level, FP-induced GR cross-repression of NF-kB, promoting the association of PKAc with RelA(p65)/NF-kB, the p65 phosphorylation on ser-276 and its nuclear translocation.Our results localize the NF-kB and GR cross-coupling to the cytoplasm of SAEC and implicate PKAc-dependent signaling as a potential molecular interface in the negative regulation of anti-inflammatory GR activity in response to oxidative stress induced by cigarette smoke.