Jiao Zong-Xian, Ao Qi-Lin, Xiong Mi
Department of Pathology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
Sheng Li Xue Bao. 2006 Jun 25;58(3):244-54.
Cigarette smoke extract (CSE) contains abundant oxidants and free radicals. Oxidative stress caused by cigarette smoking results in the destruction of the alveolar cell walls and emphysema. However, there exists discrepancy about how CSE works in the process. In the present study, we observed the effect of CSE on the cell growth of type II alveolar epithelial cell-derived A549 cell line, and provided molecular understanding of this effect. The MTT assay results showed that CSE decreased the cell viability of A549 cells in a dose- and time-dependent manner, and cell cycle was arrested in G(1)/S phase. Furthermore, CSE-induced apoptosis of A549 cells was verified by Hoechst 33258 staining, electron microscopy in morphology, and the appearance of DNA fragmentation and annexin V-FITC/propidium iodide (PI) staining assay at molecular level. It was found that CSE treatment resulted in the upregulation of Fas/APO-1 receptor and activation of caspase-3. CSE also initiated accumulation of intracellular reactive oxygen species, which was detected by laser confocal microscopy. Taken together, CSE could inhibit the cell growth and induce apoptosis of A549 cells through Fas receptor pathway. Oxidative stress caused by CSE may be the radical factor leading to apoptosis as well as cell growth inhibition in alveolar epithelial cells.
香烟烟雾提取物（CSE）含有大量氧化剂和自由基。吸烟引起的氧化应激会导致肺泡细胞壁破坏和肺气肿。然而，关于CSE在此过程中的作用方式存在差异。在本研究中，我们观察了CSE对II型肺泡上皮细胞来源的A549细胞系细胞生长的影响，并对这种影响提供了分子层面的理解。MTT检测结果表明，CSE以剂量和时间依赖性方式降低A549细胞的活力，细胞周期停滞在G(1)/S期。此外，通过Hoechst 33258染色、形态学电子显微镜检查以及分子水平上DNA片段化和膜联蛋白V-异硫氰酸荧光素/碘化丙啶（PI）染色检测验证了CSE诱导的A549细胞凋亡。发现CSE处理导致Fas/APO-1受体上调和caspase-3激活。CSE还引发细胞内活性氧的积累，这通过激光共聚焦显微镜检测到。综上所述，CSE可通过Fas受体途径抑制A549细胞的生长并诱导其凋亡。CSE引起的氧化应激可能是导致肺泡上皮细胞凋亡以及细胞生长抑制的关键因素。
