Yeh Chih-Ching, Barr R Graham, Powell Charles A, Mesia-Vela Sonia, Wang Yuanjia, Hamade Nada K, Austin John H M, Santella Regina M
Department of Health Risk Management, China Medical University College of Public Health, Taichung, Taiwan.
Environ Res. 2008 Feb;106(2):219-25. doi: 10.1016/j.envres.2007.09.008. Epub 2007 Nov 9.
Cigarette smoking is a major source of oxidative stress. Protein carbonyls have been used as a biomarker of oxidative stress because of the relative stability of carbonylated proteins and the high protein concentration in blood. Increased levels of carbonyl groups have been found in serum proteins of smokers compared to nonsmokers. However, neither the dose effect of current cigarette smoke nor other predictors of oxidative stress have been studied. Hence, we used an Enzyme-Linked Immunosorbent Assay (ELISA) to evaluate plasma protein carbonyls in smokers recruited in the Early Lung Cancer Action Project (ELCAP) program. The lung cancer screening program enrolled current and former smokers age 60 years and over without a prior cancer diagnosis. A total of 542 participants (282 men and 260 women) completed a baseline questionnaire and provided blood samples for the biomarker study. Protein oxidation was measured by derivatization of the carbonyl groups with 2,4-dinitrophenylhydrazine (DNPH) and ELISA quantitation of the DNPH group. Current smoking status was confirmed with urinary cotinine. The mean (+/-S.D.) protein carbonyl level was 17.9+/-2.9 nmol carbonyl/ml plasma. Protein carbonyls did not differ significantly by gender. Carbonyl levels were higher among current than former smokers, but these differences did not attain statistical significance, nor did differences by urine cotinine levels, pack-years, pack/day among current smokers, and smoking duration. In a multiple regression analysis, higher protein carbonyl levels were independently associated with increasing age (0.59 nmol/ml increase per 10 years, 95% CI 0.14, 1.05, p=0.01), African-American vs. white race/ethnicity, (1.30 nmol/ml, 95% CI 0.4, 2.19, p=0.008), and lower educational attainment (0.75 nmol/ml, 95% CI 0.12, 1.38, p=0.02). Although we found no significant difference between current vs. past cigarette smoking and protein carbonyls in this older group of smokers, associations were found for age, ethnicity, and educational attainment. Our results indicate that the measurement of plasma carbonyls by this ELISA technique is still an easy and suitable method for studies of diseases related to oxidative stress.
吸烟是氧化应激的主要来源。由于羰基化蛋白质相对稳定且血液中蛋白质浓度较高，蛋白质羰基已被用作氧化应激的生物标志物。与不吸烟者相比，吸烟者血清蛋白中的羰基水平有所升高。然而，目前香烟烟雾的剂量效应以及氧化应激的其他预测因素均未得到研究。因此，我们使用酶联免疫吸附测定法（ELISA）来评估早期肺癌行动项目（ELCAP）中招募的吸烟者血浆中的蛋白质羰基。该肺癌筛查项目纳入了年龄在60岁及以上、既往未被诊断患有癌症的现吸烟者和既往吸烟者。共有542名参与者（282名男性和260名女性）完成了基线调查问卷并提供了用于生物标志物研究的血样。通过用2,4 -二硝基苯肼（DNPH）衍生羰基并对DNPH基团进行ELISA定量来测量蛋白质氧化。通过尿可替宁确认当前吸烟状态。蛋白质羰基的平均（±标准差）水平为17.9±2.9 nmol羰基/毫升血浆。蛋白质羰基在性别上无显著差异。现吸烟者的羰基水平高于既往吸烟者，但这些差异未达到统计学显著性，现吸烟者中尿可替宁水平、吸烟包年数、每日吸烟包数和吸烟持续时间之间的差异也未达到统计学显著性。在多元回归分析中，较高的蛋白质羰基水平与年龄增长（每10年增加0.59 nmol/毫升，95%置信区间0.14, 1.05，p = 0.01）、非裔美国人与白人种族/族裔（1.30 nmol/毫升，95%置信区间0.4, 2.19，p = 0.008）以及较低的教育程度（0.75 nmol/毫升，95%置信区间0.12, 1.38，p = 0.02）独立相关。尽管在这群老年吸烟者中，我们未发现当前吸烟与既往吸烟和蛋白质羰基之间存在显著差异，但发现了年龄、种族和教育程度之间的关联。我们的结果表明，通过这种ELISA技术测量血浆羰基仍然是研究与氧化应激相关疾病的一种简便且合适的方法。
