Correlation between autophagy of peripheral blood mononuclear cells and clinical parameters in chronic obstructive pulmonary disease patients / 中国医师进修杂志

ABSTRACT

Objective Autophagy serves a role in the pathogenesis of chronic inflammatory diseases. The aim of the present study was to compare the autophagy levels of the peripheral blood mononuclear cells (PBMCs) in patients with chronic obstructive pulmonary disease (COPD) and healthy individuals and to assess the association between autophagy and the clinical parameters of COPD. Methods Samples of peripheral blood from 20 patients with stable COPD and 20 healthy controls were collected. PBMCs were harvested using Ficoll density gradient centrifugation. Levels of the autophagy-associated proteins ubiquitin-binding protein P62 (P62), microtubule-associated proteins 1A/1B light chain 3A (LC3 I/Ⅱ) and beclin-1 in PBMCs were detected by western blotting. Enzyme-linked immunosorbent assay kits were used to detect the serum concentrations of interleukin (IL)-6, IL-8 and tumor necrosis factor (TNF)-α. Results Western blotting demonstrated that the protein expression of P62 decreased (P62/GAPDH = 0.212 ± 0.089 vs. 0.378 ± 0.176,P = 0.001 1), but LC3 I/Ⅱ(4.94 ± 1.85 vs. 3.85 ± 1.06, P = 0.024 9) and beclin-1 (Beclin-1/GAPDH = 0.578 ± 0.126 vs. 0.149 ± 0.035, P<0.01) levels increased in patients with COPD compared with healthy controls. Serum levels of IL-6 [(11.96 ± 3.46) ng/L vs. (2.70 ± 1.72) ng/L, P < 0.01], IL-8[(20.38 ± 18.44) ng/L vs. (6.00 ± 4.08) ng/L, P=0.001 6] and TNF-α (29.50 ± 28.18 vs. 11.08 ± 12.07, P=0.010 6) increased in patients with COPD. The extent of PBMC autophagy was negatively correlated with FEV1% predicted, but positively correlated with levels of proinflammatory cytokines. The levels of autophagy in PBMCs in patients with COPD increased and were negatively correlated with FEV1% predicted and positively correlated with circulating levels of pro-inflammatory cytokines. Conclusions Autophagy may serve a role as a biomarker of the severity of COPD or as a therapeutic target for treatment of COPD.