Proteomic Profiling of Human Plasma by iTRAQ Reveals Down-Regulation of ITI-HC3 and VDBP by Cigarette Smoking

Abstract

Biomarkers in noninvasive fluids indicative of cigarette smoke's effects are urgently needed. In this pilot study, we utilized the proteomic approach, isobaric Tags for Relative and Absolute Quantitation (iTRAQ), to identify differentially expressed plasma proteins in healthy cigarette smokers compared to healthy nonsmokers; select proteins were further confirmed by immunoblot analysis. Significant, differentially expressed proteins identified in the plasma separated subjects based on their condition as smokers or nonsmokers. Several of the proteins identified in this study are associated with immunity and inflammatory responses and have been shown to be associated with tobacco-related diseases, including chronic obstructive pulmonary disease (COPD) and lung cancer. Proteins up-regulated in smokers included complement component 8 polypeptide chains α, β, and γ, and mannose-binding protein C, and proteins down-regulated included inter-α-trypsin inhibitor heavy chain H3 (ITI-HC3) and vitamin D-binding protein (VDBP). In addition, gelsolin and vitronectin, known tissue leakage proteins, were up- and down-regulated, respectively. Our results demonstrate for the first time that chronic cigarette smoking can influence the expression profile of the human plasma proteome. Proteins identified in this pilot study may serve as candidate biomarkers of diseases resulting from exposure to cigarette smoke in future molecular epidemiological studies.

Proteomic profiling of human plasma identifies apolipoprotein E as being associated with smoking and a marker for squamous metaplasia of the lung

“…In spite of these successes, depth of proteomic analyzes are limited by the small number of high abundant plasma proteins. A previous experiment by Bortner et al [19] performed by the same institutional Proteomic Mass Spectrometry core laboratory, which utilized a similar amount of starting material, prefractionization procedure and instruments, and the same mass spectrometer, verified two smoking-associated biomarker (ITI-HC3 and VDBP) in plasma of smokers after depletion of 20 highly abundant plasma proteins. In this study we implemented a proteins enrichment method, ProteoMiner (BioRad), which can enhance the depth of the proteomic analysis [35,36].…”

“…Labeled peptides were analyzed by 2D-LC-MS/MS according to Bortner et al [19]. Briefly, peptides were prefractionated by strong cation exchange using a Waters 600E HPLC system.…”

Does urinary peptide content differ between COPD patients with and without inherited alpha1-antitrypsin deficiency?

“…32 Alterations in gelsolin expression have been associated with cigarette smoking and different pulmonary diseases such as fibrosis; however, little is known about the role of gelsolin in COPD. [32][33][34] Gelsolin activates PI3K/Akt pathway, 35 which regulates cell growth, proliferation, adhesion, migration and survival. Interestingly, it promotes the differentiation of alveolar epithelial type I and II cells from alveolar epithelial stem cells.…”

Application of ’omics technologies to biomarker discovery in inflammatory lung diseases

“…Consequently, gel-free approaches, such as the stable isotope labelling approach (iTRAQ, isobaric tags for relative and absolute quantitation), have been employed, an example being a study to identify biomarkers of smoking in human plasma samples [72]. Here, the authors increased proteome coverage through depletion of the top 14 most abundant proteins, identifying 113 low abundance proteins, 16 of which were differentially expressed between smokers and nonsmokers.…”