Salidroside restores glucocorticoid sensitivity in chronic obstructive
pulmonary disease by activating Nrf2/HO-1 pathway
Abstract
Corticosteroid resistance is the essential obstacle for effective
treatment of chronic obstructive pulmonary disease (COPD). Oxidative
stress and persistent chronic inflammation caused by cigarette smoke are
likely to induce this corticosteroid insensitivity. Salidroside (Sal) is
a main ingredient of traditional Chinese medicine rhodiola, which has
the effects of anti-oxidation and anti-inflammatory. We aimed to
investigate the role of Sal in the corticosteroid sensitivity of COPD.
Collecting peripheral blood mononuclear cells (PBMC) from healthy
volunteers (HV) and patients with COPD, and human monocytic U937 cells
stimulated by normal culture and cigarette smoke extract (CSE),
corticosteroid sensitivity was determined as the dexamethasone
concentration causing 30% inhibition of tumor necrosis factor alpha
(TNF-α)-induced IL-8 production (Dex-IC 30) in these
cells. Compared with PBMC from HV and normally cultured U937, in PBMC
from COPD patients and U937 cells stimulated by CSE, the inhibitory
effect of dexamethasone on IL-8 was weakened and the levels of nuclear
factor erythroid 2‐related factor 2 (Nrf2) and histone deacetylase‐2
(HDAC2) was reduced. In conclusion, Sal restored dexamethasone
inhibition of IL‐8 production, accompanied by raising the expression of
Nrf2 and HDAC2 levels. Sal may upregulate HDAC2 expression by activating
the Nrf2/HO-1 signaling pathway, and then restore corticosteroid
sensitivity in COPD.