摘要目的 采用离体实验评价p38分裂原激活蛋白激酶(p38MAPK)信号通路与LPS致大鼠肺泡上皮细胞线粒体分裂的关系.方法 将传代培养的肺泡上皮细胞以2×105个/ml的密度铺于96孔板中,200 μl/孔,达到80％融合后,采用随机数字表法分为4组(n=10):对照组(C组)、LPS组、LPS+SB203580组(LPS+SB组)和LPS+二甲基亚砜组(LPS+DMSO组).LPS组给予LPS 10 μg/ml孵育24 h;LPS+SB组给予p38MAPK抑制剂SB203580 10 μmol(用二甲基亚砜溶解)孵育1h,再给予LPS 10 μg/ml孵育24 h;LPS+DMSO组给予等容量二甲基亚砜孵育1h,再给予LPS 10 μg/ml孵育24h.测定MDA含量和SOD活性,采用Western blot法测定磷酸化p38MAPK(p-p38MAPK)、血红素加氧酶-1(HO-1)、发动蛋白相关蛋白1(DRP1)和分裂相关蛋白1(FIS1)的表达水平.结果 与C组比较,LPS组、LPS+SB组和LPS+ DMSO组MDA含量升高,SOD活性降低,p-p38MAPK、HO-1、FIS1和DRP1表达上调(P＜0.05);与LPS组比较,LPS+SB组MDA含量升高,SOD活性降低,p-p38MAPK和HO-1表达下调,FIS1和DRP1表达上调(P＜O.05),LPS+ DMSO组上述指标差异无统计学意义(P＞0.05).结论 p38MAPK信号通路激活可上调HO-1表达,从而减轻LPS致大鼠肺泡上皮细胞线粒体分裂.

abstractsObjective To evaluate the relationship between p38 mitogen-activated protein kinase (p38MAPK) signaling pathway and lipopolysaccharide (LPS)-induced mitochondrial fission in alveolar epithelial cells using an in vitro experiment.Methods The cultured alveolar epithelial cells were subcultured and seeded in 96-well plates at the density of 2 × 105 cells/ml (200 μl/well).The cells were divided into 4 groups (n=10 each) when cell confluence reached 80％ using a random number table method:control group (group C),LPS group,LPS+SB203580 group (group LPS+SB) and LPS+dimethyl sulfoxide (DMSO) group.Cells were incubated with LPS 10 μg/ml for 24 h in group LPS.Cells were incubated with p38MAPK inhibitor SB203580 10 μmol (dissolved in DMSO) for 1 h and then with LPS 10 μg/ml for 24 h in group LPS+SB.Cells were incubated with the equal volume of DMSO for 1 h and then with LPS 10 μg/ml for 24 h in group LPS+DMSO.Malonaldehyde (MDA) content and superoxide dismutase (SOD) activity were measured.The expression of phosphorylated p38MAPK (p-p38MAPK),heme oxygenase-1 (HO-1),dynamin-related protein 1 (DRP1) and fission protein 1 (FIS1) was determined by Western blot.Results Compared with group C,the MDA content was significantly increased,the SOD activity was decreased,and the expression of p-p38MAPK,HO-1,FIS1 and DRP1 was up-regulated in LPS,LPS+SB and LPS+ DMSO groups (P＜0.05).Compared with group LPS,the MDA content was significantly increased,the SOD activity was decreased,the expression of p-p38MAPK and HO-1 was down-regulated,the expression of FIS1 and DRP1 was up-regulated in group LPS+SB (P＜0.05),and no significant change was found in the parameters mentioned above in group LPS+DMSO (P＞0.05).Conclusion The p38MAPK signaling pathway activation can up-regulate the expression of HO-1,thus reducing LPS-induced mitochondrial fission in alveolar epithelial cells.