title: Histone deacetylase activity is decreased in peripheral blood monocytes in patients with COPD.
abstract: BACKGROUND
  Histone deacetylase (HDAC) is an enzyme that regulates chromatin structure and inflammatory gene expression. In patients with chronic obstructive pulmonary disease (COPD), while accumulating evidence indicates that the activity of HDAC is decreased in lung tissue alveolar macrophages, HDAC activity in peripheral inflammatory cells has not yet been evaluated in detail.
  
  
  METHODS
  HDAC activities in peripheral blood mononuclear cells (PBMC) were investigated in patients with stable COPD (n = 26), non-smoking controls (n = 13), and smoking controls (n = 10), respectively. HDAC activity was measured using an HDAC Activity/Inhibitor Screening Assay Kit. Serum interleukine-8 (CXCL8) levels were determined by ELISA techniques. Lung function test was carried out according to the ATS/ERS guidelines.
  
  
  RESULTS
  Compared with healthy non-smokers, HDAC activity in the PBMCs of COPD patients was decreased by 40% (13.06 ± 5.95 vs. 21.39 ± 4.92 (μM/μg), p < 0.001). In patients with COPD, HDAC activity was negatively correlated to smoke intensity (r = -0.867, p < 0.001). In COPD patients who had smoked for more than 40 pack-years, HDAC activity in PBMC was 40% lower than that in COPD patients who had smoked fewer than 40 pack-years.Moreover, serum CXCL8 levels in patients with COPD were significantly higher than that in controls and were negatively correlated to HDAC activities.
  
  
  CONCLUSIONS
  In patients with COPD, HDAC activity in the PBMCs is lower than that in healthy controls. The reduction of HDAC activity may be associated with smoking exposure through inflammatory pathways.
authors.affiliation: Department of Respiratory Medicine, ZhongNan Hospital of Wuhan University, Wuhan, Peoples Republic of China. chyw7758521@yahoo.com.
authors.forename: Yanwei
authors.initials: Y
authors.lastname: Chen
authors.forename: Ping
authors.initials: P
authors.lastname: Huang
authors.forename: Wen
authors.initials: W
authors.lastname: Ai
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Li
authors.forename: Wei
authors.initials: W
authors.lastname: Guo
authors.forename: Jingnong
authors.initials: J
authors.lastname: Zhang
authors.forename: Jiong
authors.initials: J
authors.lastname: Yang