胞浆内线粒体 DNA 在脂多糖诱导肺泡巨噬细胞炎症反应时的变化简

目的：观察胞浆内线粒体 DNA（mitochondrial DNA，mtDNA）在脂多糖（lipopolysaccharide，LPS）诱导的NR8383肺泡巨噬细胞炎症反应时的动态变化，以初步探讨胞浆内 mtDNA在肺泡巨噬细胞炎症反应中的作用。方法将体外培养的大鼠肺泡巨噬细胞（NR8383）用终浓度为1μg·mL-1的 LPS刺激0、3、6、12和24 h后收集细胞培养上清液及细胞，采用差速离心法分离胞浆中的mtDNA，实时荧光定量聚合酶链反应（real-time PCR）检测胞浆中mtDNA表达情况，采用酶联免疫吸附法（ELISA）检测细胞培养上清液中 IL-1β蛋白水平。结果 LPS刺激后3、6、12和24 h IL-1β及胞浆中mtDNA的含量均显著高于0 h组（P＜0．01）。结论 LPS刺激肺泡巨噬细胞后，胞浆中mtDNA含量升高，推测其可能参与了肺泡巨噬细胞的炎症反应。

Changes in Cytoplasmic Mitochondrial DNA in Lipopolysaccharide-induced Alveolar Macrophage Inflammatory Response

Objective To observe the dynamic changes in cytoplasmic mitochondrial DNA （mtDNA）in lipopolysaccharide （LPS）-induced alveolar macrophage inflammatory response,and to explore the role of mtDNA in alveolar macrophage inflammatory response.Methods Alveolar macrophages（NR8383）were stimulated with LPS（1μg·mL-1）in vitro.Culture supernatants and cells were collected after treatment for 0,3,6,12 and 24 hours,and cytoplasmic mtDNA was isolated by differential centrifugation.The expression of mtDNA was detected by real-time PCR, and the level of interleukin-1β（IL-1β）in the supernatants was measured by ELISA.Results The levels of IL-1βin supernatants and mtDNA in cytoplasm after LPS stimulation for 3,6,12 and 24 hours were significantly higher than those at the beginning of LPS stimulation （P＆lt;0.01）.Con-clusion The expression of mtDNA in the cytoplasm of alveolar macrophages increases after stim-ulation with LPS,suggesting that mtDNA may be involved in alveolar macrophage inflammatory response.