中文摘要：

目的：观察线粒体 DNA（mitochondrial DNA，mtDNA）刺激肺泡巨噬细胞后炎症因子的动态变化，探讨mtDNA 对肺泡巨噬细胞的致炎效应。方法取 SD大鼠肝脏组织用改良的碱变性法进行 mtDNA 的提取、纯化。将体外培养的大鼠肺泡巨噬细胞（NR8383）分为mtDNA组（5μg·mL-1，A组），mtDNA组（10μg·mL-1，B组），空白对照组（C组），分别在 A、B组中加入mtDNA 5μg·mL-1、10μg·mL-1，在0、3、6、12和24 h时相点收集各组细胞培养上清液，采用酶联免疫吸附法（ELISA）检测细胞培养上清液中肿瘤坏死因子-α（TNF-α）、白介素-1β（IL-1β）和 IL-6的表达水平。结果 A组和B组在3、6、12和24 h TNF-α、IL-1β和IL-6的表达量显著高于C组（P＜0．01），且在3、6、12和24 h 时B组的表达量高于 A组（P＜0．05）。结论 mtDNA 能够诱导肺泡巨噬细胞TNF-α、IL-1β和 IL-6等炎症因子的表达，且呈剂量依赖性，推测mtDNA 具有促炎作用。

英文摘要：

Obj ective To observe the dynamic changes in inflammatory cytokines in alveolar macro-phages stimulated by mitochondrial DNA（mtDNA）,and to explore the inflammatory effect of mtDNA on alveolar macrophages.Methods The mtDNA was extracted and purified from SD rat liver tissue using a modified alkaline denaturation method.The cultured alveolar macrophages（NR8383）were divided into three groups：group A（treatment with 5μg·mL-1 mtDNA）,group B（treatment with 10μg·mL-1 mtDNA）,and group C（control group）.Culture supernatant was collected after treatment for 0,3,6,12 and 24 hours,and levels of tumor necrosis factor-α（TNF-α）,interleukin-1β（IL-1β）and interleukin-6 （IL-6）were measured by ELISA.Results Compared with control group,mtDNA treatment significantly increased the expression of TNF-α,IL-1βand IL-6 in a dose-dependent manner after treatment for 3,6,12 and 24 hours （P〈0.01 or P〈0.05 ）.Conclusion The mtDNA can stimulate alveolar macrophages to produce TNF-α,IL-1βand IL-6 in a dose-dependent manner,suggesting that mtDNA has a proinflamma-tory effect on alveolar macrophages.