title: Elevated plasma levels of pigment epithelium-derived factor correlated with inflammation and lung function in COPD patients.
abstract: BACKGROUND
  Pigment epithelium-derived factor (PEDF) is a 50 kD small secreting glycoprotein that participates in multiple physiological and pathological processes. Recent studies have reported that PEDF plays an important role in inflammatory responses in several diseases. However, the role of PEDF in the pathogenesis of chronic obstructive pulmonary disease (COPD) remains unclear.
  
  
  OBJECTIVE
  The aim of the present study is to explore the potential relationship between PEDF and COPD.
  
  
  METHODS
  We used differential proteomics - stable isotope labeling with amino acids in cell culture - to investigate protein expression profile changes in cigarette smoke extract-treated pulmonary cells and found that the neurotrophic and antiangiogenic protein PEDF was abnormally expressed. Furthermore, Western blotting was used to detect the expression of PEDF in the lung tissue of rats that were exposed to cigarette smoke. Eighty subjects between the ages of 40-90 years, including 20 healthy nonsmokers, ten smoking volunteers, and 50 COPD patients, were recruited from September 2012 until August 2013 in Sichuan Province, People's Republic of China. We measured the plasma PEDF concentration and classic proinflammatory cytokines by multiplex enzyme-linked immunosorbent assay. In addition, we performed a spirometry examination to diagnose COPD patients and we also analyzed the correlation between PEDF and lung function.
  
  
  RESULTS
  First, we found that the expression of PEDF in cigarette smoke extract-treated cells increased 16.2-fold when compared with the control group. Next, we confirmed that 4 weeks' exposure to cigarette smoke can upregulate PEDF levels in rat lung tissues. We also discovered that plasma PEDF in COPD patients was significantly increased when compared with either healthy nonsmoking or smoking subjects. Furthermore, circulating PEDF was correlated with inflammatory cytokine and blood neutrophil numbers, but it was reversely associated with a decline in forced expiratory volume in 1 second percent predicted.
  
  
  CONCLUSIONS
  Our findings provide a novel link between PEDF and COPD. Elevated PEDF levels may be involved in promoting the development of COPD by performing proinflammatory functions.
authors.affiliation: Division of Pulmonary Diseases, State Key Laboratory of Biotherapy of China, West China Hospital, West China School of Medicine, Sichuan University, Chengdu, Sichuan, People's Republic of China ; Department of Respiratory Medicine, West China Hospital, West China School of Medicine, Sichuan University, Chengdu, Sichuan, People's Republic of China ; Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
authors.forename: Xiaoou
authors.initials: X
authors.lastname: Li
authors.affiliation: Division of Pulmonary Diseases, State Key Laboratory of Biotherapy of China, West China Hospital, West China School of Medicine, Sichuan University, Chengdu, Sichuan, People's Republic of China ; Department of Respiratory Medicine, West China Hospital, West China School of Medicine, Sichuan University, Chengdu, Sichuan, People's Republic of China.
authors.forename: Tao
authors.initials: T
authors.lastname: Wang
authors.affiliation: Division of Pulmonary Diseases, State Key Laboratory of Biotherapy of China, West China Hospital, West China School of Medicine, Sichuan University, Chengdu, Sichuan, People's Republic of China ; Department of Respiratory Medicine, West China Hospital, West China School of Medicine, Sichuan University, Chengdu, Sichuan, People's Republic of China.
authors.forename: Ting
authors.initials: T
authors.lastname: Yang
authors.affiliation: Division of Pulmonary Diseases, State Key Laboratory of Biotherapy of China, West China Hospital, West China School of Medicine, Sichuan University, Chengdu, Sichuan, People's Republic of China ; Department of Respiratory Medicine, West China Hospital, West China School of Medicine, Sichuan University, Chengdu, Sichuan, People's Republic of China.
authors.forename: Yongchun
authors.initials: Y
authors.lastname: Shen
authors.affiliation: Division of Pulmonary Diseases, State Key Laboratory of Biotherapy of China, West China Hospital, West China School of Medicine, Sichuan University, Chengdu, Sichuan, People's Republic of China ; Department of Respiratory Medicine, West China Hospital, West China School of Medicine, Sichuan University, Chengdu, Sichuan, People's Republic of China.
authors.forename: Jing
authors.initials: J
authors.lastname: An
authors.affiliation: Division of Pulmonary Diseases, State Key Laboratory of Biotherapy of China, West China Hospital, West China School of Medicine, Sichuan University, Chengdu, Sichuan, People's Republic of China ; Department of Respiratory Medicine, West China Hospital, West China School of Medicine, Sichuan University, Chengdu, Sichuan, People's Republic of China.
authors.forename: Lian
authors.initials: L
authors.lastname: Liu
authors.affiliation: Division of Pulmonary Diseases, State Key Laboratory of Biotherapy of China, West China Hospital, West China School of Medicine, Sichuan University, Chengdu, Sichuan, People's Republic of China ; Department of Respiratory Medicine, West China Hospital, West China School of Medicine, Sichuan University, Chengdu, Sichuan, People's Republic of China.
authors.forename: Jiajia
authors.initials: J
authors.lastname: Dong
authors.affiliation: Division of Pulmonary Diseases, State Key Laboratory of Biotherapy of China, West China Hospital, West China School of Medicine, Sichuan University, Chengdu, Sichuan, People's Republic of China ; Department of Respiratory Medicine, West China Hospital, West China School of Medicine, Sichuan University, Chengdu, Sichuan, People's Republic of China.
authors.forename: Lingli
authors.initials: L
authors.lastname: Guo
authors.affiliation: Division of Pulmonary Diseases, State Key Laboratory of Biotherapy of China, West China Hospital, West China School of Medicine, Sichuan University, Chengdu, Sichuan, People's Republic of China ; Department of Respiratory Medicine, West China Hospital, West China School of Medicine, Sichuan University, Chengdu, Sichuan, People's Republic of China.
authors.forename: Diandian
authors.initials: D
authors.lastname: Li
authors.affiliation: Division of Pulmonary Diseases, State Key Laboratory of Biotherapy of China, West China Hospital, West China School of Medicine, Sichuan University, Chengdu, Sichuan, People's Republic of China ; Department of Respiratory Medicine, West China Hospital, West China School of Medicine, Sichuan University, Chengdu, Sichuan, People's Republic of China.
authors.forename: Xue
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Division of Pulmonary Diseases, State Key Laboratory of Biotherapy of China, West China Hospital, West China School of Medicine, Sichuan University, Chengdu, Sichuan, People's Republic of China ; Department of Respiratory Medicine, West China Hospital, West China School of Medicine, Sichuan University, Chengdu, Sichuan, People's Republic of China.
authors.forename: Lei
authors.initials: L
authors.lastname: Chen
authors.affiliation: Division of Pulmonary Diseases, State Key Laboratory of Biotherapy of China, West China Hospital, West China School of Medicine, Sichuan University, Chengdu, Sichuan, People's Republic of China ; Department of Respiratory Medicine, West China Hospital, West China School of Medicine, Sichuan University, Chengdu, Sichuan, People's Republic of China.
authors.forename: Dan
authors.initials: D
authors.lastname: Xu
authors.affiliation: Division of Pulmonary Diseases, State Key Laboratory of Biotherapy of China, West China Hospital, West China School of Medicine, Sichuan University, Chengdu, Sichuan, People's Republic of China ; Department of Respiratory Medicine, West China Hospital, West China School of Medicine, Sichuan University, Chengdu, Sichuan, People's Republic of China.
authors.forename: Fuqiang
authors.initials: F
authors.lastname: Wen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D016022:Case-Control Studies; D002478:Cells, Cultured; D016207:Cytokines / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D004847:Epithelial Cells / Q000276:immunology / Q000378:metabolism*; D005136:Eye Proteins / Q000097:blood*; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000097:blood*; D008168:Lung / Q000276:immunology / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009414:Nerve Growth Factors / Q000097:blood*; D011014:Pneumonia / Q000097:blood* / Q000175:diagnosis / Q000276:immunology / Q000503:physiopathology; D040901:Proteomics / Q000379:methods; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood* / Q000175:diagnosis / Q000276:immunology / Q000503:physiopathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D015843:Serpins / Q000097:blood*; D012906:Smoke / Q000009:adverse effects; D012907:Smoking / Q000009:adverse effects; D015854:Up-Regulation; D000099174:Pigment Epithelium-Derived Factor
chemical_list: D016207:Cytokines; D005136:Eye Proteins; D018836:Inflammation Mediators; D009414:Nerve Growth Factors; D015843:Serpins; D012906:Smoke; D000099174:Pigment Epithelium-Derived Factor
keywords: chronic obstructive pulmonary disease; cigarette smoke; inflammation; pigment epithelium-derived factor
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