异丙酚对内毒素诱导小鼠RAW264．7巨噬细胞P2X7受体活化和IL-1β蛋白合成的影响

Effects of propofoi on P2X7 receptor activition and IL-1β production induced by endotoxin in murine RAW264.7 macrophages

目的探讨异丙酚对内毒素诱导小鼠RAW264．7巨噬细胞P2X受体活化和IL-1β蛋白合成的影响。方法RAW264．7巨噬细胞经1μmol／L亮蓝G（BBG）或1～100μmol／L异丙酚孵育20min，随后经1μg／mlLPS孵育4h，采用ELISA法测定IL-1β 的释放量，采用Westernblot法测定胞内IL-1β前体蛋白和成熟体蛋白含量，并计算异丙酚抑制IL-1β释放的半数有效浓度（IC50）。采用全细胞膜片钳记录模式，RAW264．7巨噬细胞经1 mmol／LATP孵育5s，以诱发P2墨受体门控离子通道电流，分别经1～1000μmol／L异丙酚孵育4min后记录电流峰值，计算异丙酚抑制P2墨受体门控离子通道电流峰值的IC50。结果异丙酚可抑制LPS诱导的IL-1β的释放，其IC50为（24±3）μmol／L。异丙酚可抑制p2X7受体门控离子通道电流峰值，其IC50为（334-5）μmol／L。LPS可上调胞内IL-1β前体蛋白表达（P〈0．01），而3～100μmol／L异丙酚可抑制LPS介导的胞内IL-1β前体蛋白表达上调。结论异丙酚抑制LPS诱导的小鼠RAW264．7巨噬细胞IL-1β的释放可能与抑制P2墨受体的活化和胞内IL-1β前体蛋白的合成有关。

Objective To investigate the effects of propofol on P2X7 receptor activition and IL-1β production induced by endotoxin in murine RAW264.7 macrophages. Methods RAW264.7 macrophages were treated with LPS （1μg/ml） for 4 h to induce the production and release of IL-1β, and pretreated with BBG （specific P2X7 receptor antagonist） 1μmo1/L or propofol 1-100 μmol/L for 20min before LPS stimulation, and IL-1β release was measured using ELISA kit. Whole-cell patch clamp technique was used to record the P2XT-gated currents induced by 1 mmol/L ATP, the cells were exposed to propofol with 1-1 000 μmol/L for 4 rain, and the ICs0 level of propofol was achieved. Western blot technique was used to measure the production of pro-IL-l~ protein and IL-1β protein intracellularly after LPS treatment for 4 h under different concentrations of propofol. Results IL-1β was released from RAW264.7 macrophages after LPS stimulation, which was decreased by propofol, and the IC50 level of propofol was （24 ± 3） μmol/L. P2XT-gated currents were inhibited by propofol, and the IC50 level was （33 ± 5 ） μmol/L. Pro-IL-1β protein intracellularly was up-regulated after LPS stimulation, and propofol with 3- 100μmol/L decreased the up-regulation of pro-lL-1β intracellularly induced by LPS. Conclusion Propofol could inhibit IL-1β release from RAW264.7 macrophages treated by LPS, which is mediated by inhibiting P2X7 receptor activition and decreasing the production of pro-IL-1β intracellularly.