Department of Anaesthesiology, Guangdong Medical College, Zhanjiang, China.
Clin Exp Pharmacol Physiol. 2012 May;39(5):447-53. doi: 10.1111/j.1440-1681.2012.05694.x.
Propofol (2,6-diisopropylphenol) is an anaesthetic agent with anti-oxidant properties. The aim of the present study was to determine whether propofol can protect pulmonary epithelial (A549) cells against lipopolysaccharide (LPS)-induced cell death and, if so, the mechanisms involved. The effects of LPS alone and in combination with propofol on A549 cell death were investigated. Cell viability was determined using the colourimetric 3-(4,5-dimethyl-2 thiazoyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Apoptotic A549 cells were detected by flow cytometry, as propidium iodide-negative and annexin-V-positive cells, and terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick end-labelling (TUNEL). Mitochondrial membrane potential (MMP), caspase 9 activity, Ca(2+) concentrations and reactive oxygen species (ROS) were analysed by immunofluorescent methods. Aconitase 2 (ACO2), microtubule-associated light chain 3 (LC3) and beclin-1 levels were evaluated using reverse transcription-polymerase chain reaction and/or western blot analysis. Exposure of A549 cells to 1-50 μg/mL LPS for 3-24 h resulted in the concentration- and time-dependent induction of cell death. Cell apoptosis accounted for approximately 77% of cell death induced by LPS. Propofol (5-150 μmol/L) concentration-dependently inhibited LPS-induced A549 cell death. This protective effect of propofol was accompanied by prevention of LPS-induced mitochondrial dysfunction (reductions in MMP, ACO2 expression and ATP) and was associated with the inhibition of LPS-induced activation of apoptotic signals (caspase 9 activity, ROS overproduction and Ca(2+) accumulation). In addition, propofol blocked LPS-induced overexpression of the autophagy-associated proteins LC3 and beclin-1. The data indicate that propofol protects A549 cells against LPS-induced apoptosis, and probably autophagy, by blocking LPS-induced activation of ROS/caspase 9 pathways and upregulation of LC3 and beclin-1, respectively.
异丙酚（2,6-二异丙基苯酚）是一种具有抗氧化特性的麻醉剂。本研究旨在确定异丙酚是否可以保护肺上皮（A549）细胞免受脂多糖（LPS）诱导的细胞死亡，如果可以，那么涉及的机制是什么。研究了 LPS 单独和与异丙酚联合作用对 A549 细胞死亡的影响。使用比色 3-（4,5-二甲基-2 噻唑基）-2,5-二苯基-2H-四唑溴盐（MTT）测定法测定细胞活力。通过流式细胞术检测凋亡的 A549 细胞，作为碘化丙啶阴性和膜联蛋白-V 阳性细胞，以及末端脱氧核苷酸转移酶介导的 dUTP-地高辛切口末端标记（TUNEL）。通过免疫荧光法分析线粒体膜电位（MMP）、半胱天冬酶 9 活性、Ca（2+）浓度和活性氧物种（ROS）。通过逆转录-聚合酶链反应和/或 Western blot 分析评估 2-烯醇化酶（ACO2）、微管相关轻链 3（LC3）和 beclin-1 水平。A549 细胞暴露于 1-50μg/mL LPS 3-24 h 导致细胞死亡的浓度和时间依赖性诱导。细胞凋亡约占 LPS 诱导的细胞死亡的 77%。异丙酚（5-150μmol/L）浓度依赖性抑制 LPS 诱导的 A549 细胞死亡。这种异丙酚的保护作用伴随着 LPS 诱导的线粒体功能障碍的预防（MMP、ACO2 表达和 ATP 减少），并与 LPS 诱导的凋亡信号激活的抑制相关（半胱天冬酶 9 活性、ROS 过度产生和 Ca（2+）积累）。此外，异丙酚阻断 LPS 诱导的自噬相关蛋白 LC3 和 beclin-1 的过表达。数据表明，异丙酚通过阻断 LPS 诱导的 ROS/半胱天冬酶 9 途径的激活和上调 LC3 和 beclin-1，分别阻止 LPS 诱导的 A549 细胞凋亡和可能的自噬。
