Department of Respiratory Medicine, Affiliated Hospital of Nantong University, Nantong 226001, China.
J Thorac Dis. 2014 Jun;6(6):649-55. doi: 10.3978/j.issn.2072-1439.2014.06.26.
Plasma levels of endothelial microparticles (EMPs), small membrane vesicles, shed from activated or apoptotic endothelial cells are elevated in patients with COPD and in smokers with normal lung function. Whether plasma EMPs levels are elevated in a rat exposed in cigarette smoke, whether the elevated EMPs derived from pulmonary endothelial cell apoptosis, and the relationship between EMP and lung function are obscure.
All 60 wister rats were divided into six groups, three groups of ten rats were exposed to cigarette smoke of ten non-filter cigarettes per day, 5 days a week, using a standard smoking machine (Beijing BeiLanBo Company, China) for a period of 2, 4 and 6 months (n=10, respectively). Age-matched three control groups were sham-smoked. Pulmonary function parameters, including the ratio of forced expiratory volume in 0.3 second over forced vital capacity (FEV0.3/FVC) and dynamic compliance (Cdyn), were tested at the end of each period (2, 4, 6 months). Blood samples were collected and platelet-free plasma was isolated. Then CD42b-/CD31+ EMPs were analysed by flow cytometry. In parallel, lungs were removed and Colocalization with terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL), Hoeschts and CD31 was performed to evaluate pulmonary capillaries-specific apoptosis and identify the origins of the EMPs.
At 2, 4 and 6 months, in comparison with control groups, rats in cigarette smoke exposed groups had a significant increase in CD42b-/CD31+ EMPs (P<0.001, P<0.001, P<0.001, respectively), and Pulmonary function indicated that FEV0.3/FVC (P<0.05, P<0.01, P<0.01, respectively) and Cdyn (P<0.01, P<0.001, P<0.001 respectively) decreased. At the same time, CD42b-/CD31+ EMP counts were negatively correlated with Cdyn (P<0.05). Moreover, in vivo, TUNEL-positive cells co-localized with CD31 in whole lung tissue demonstrated a sequence of apoptosis signal in the cigarette smoke exposed groups.
CD42b-/CD31+ EMPs may be a potential biomarker for indicating the severity of impairment of pulmonary function in the rats exposed cigarette smoke. The increased EMPs may derive from pulmonary capillaries-specific apoptosis.
在 COPD 患者和肺功能正常的吸烟者中，内皮细胞释放的小膜囊泡即内皮细胞微颗粒（EMPs）的血浆水平升高。在暴露于香烟烟雾的大鼠中，血浆 EMPs 水平是否升高，升高的 EMPs 是否来自肺内皮细胞凋亡，以及 EMP 与肺功能之间的关系尚不清楚。
将 60 只 Wistar 大鼠分为 6 组，每组 10 只，每天暴露于 10 支无过滤香烟的香烟烟雾中，每周 5 天，使用标准吸烟机（中国北京北蓝波公司）持续 2、4 和 6 个月（n=10，分别）。年龄匹配的 3 个对照组进行假吸烟。在每个时期（2、4、6 个月）结束时测试肺功能参数，包括 0.3 秒用力呼气量与用力肺活量之比（FEV0.3/FVC）和动态顺应性（Cdyn）。收集血液样本并分离血小板自由血浆。然后通过流式细胞术分析 CD42b-/CD31+EMPs。同时，进行末端脱氧核苷酸转移酶介导的 dUTP 缺口末端标记（TUNEL）、Hoeschts 和 CD31 共定位，以评估肺毛细血管特异性凋亡并确定 EMPs 的来源。
与对照组相比，在 2、4 和 6 个月时，香烟烟雾暴露组大鼠的 CD42b-/CD31+EMPs 显著增加（P<0.001，P<0.001，P<0.001，分别），并且肺功能表明 FEV0.3/FVC（P<0.05，P<0.01，P<0.01，分别）和 Cdyn（P<0.01，P<0.001，P<0.001，分别）降低。同时，CD42b-/CD31+EMPs 计数与 Cdyn 呈负相关（P<0.05）。此外，体内 TUNEL 阳性细胞与全肺组织中的 CD31 共定位表明香烟烟雾暴露组中存在凋亡信号的顺序。
CD42b-/CD31+EMPs 可能是指示香烟烟雾暴露大鼠肺功能严重受损的潜在生物标志物。增加的 EMPs 可能来自肺毛细血管特异性凋亡。
