适当浓度的过氧化氢诱导人支气管上皮细胞发生钙振荡

包括过氧化氢（Hzoz）在内的活性氧通过引起细胞内钙的变化而造成细胞损伤。然而，不同浓度的H202可以导致细胞内不同的钙变化，并激活不同的信号通路。细胞内钙振荡是其中的一种钙信号变化形式，钙振荡可以调控转录因子NF—KB的活性。该研究探讨可以诱导支气管上皮细胞内钙振苏发生的H2o2浓度。体外培养人支气管上皮细胞，采取钙离子荧光探针Fura_2标记细胞。并使用离子成像系统，观测不同浓度的H：0：（0～1000μmol／L）作用下细胞内钙浓度的变化。结果发现，低于50μmol／L的H202仅仅引起“钙火花”；50～500μmol／L的H202导致细胞内钙振荡的发生；而1000μmol／L的H202引起细胞内持续的高钙；同时也证实150μmol／L的H202诱发明显的钙振荡，而钙振荡随后引起了NF—KB活性的升高。该研究提示，适当浓度的H：0：可以诱发支气管上皮细胞内钙振荡的发生，推测可能是活性氧导致慢性气道炎症损伤的一个机制。

Moderate Concentration of H202 Induced [Ca2＋]i Oscillation in Human Bronchial Epithelial Cells

Reactive oxygen species （ROS） including hydrogen peroxide （H202） can damage cells by inducing changes of cytosolic Ca2＋ （Ca2＋]0. However, different concentration of H202 induced different changes in Ca2＋]i which activated different signaling pathways. One type of Ca2＋]i changing is Ca2＋]i oscillation which can regulate the activity of NF-nB. The aim of this study is to get the concentrations of H202 which can induce Ca2＋]i oscillation in the bronchial epithelial cells. Human bronchial epithelial cells were cultured, and treated without or with different concentration of H202 （0-1 000 μmoFL）. Cytosolic Ca〉 concentration was detected by fluorescent Ca〉 indicator Fura-2. The results revealed that H202 concentrations 〈50 μmol/Ljust induced Ca2＋]i spark, 50-500 ~tmol/L induced Ca2＋]i oscil- lation, and 1 000 μmol/L induced constantly high level of Ca2＋]i. Moreover, the findings confirmed that 150 μmol/L H202 induced Ca2＋]i oscillation, and the Ca2＋]i oscillation induced increases of NF-ld3 activity. In conclusion, these data suggested that moderate concentration （50-500 μmol/L） of H202 can induce Ca2＋]i oscillation and NF-kB acti- vation in bronchial epithelial cells, which should be involved in ROS induced damage in chronic airway inflamma- tion.