Relationship between p38MAPK signaling pathway and lipopolysaccharide-induced mitochondrial fission in alveolar epithelial cells: an in vitro experiment / 中华麻醉学杂志

ABSTRACT

Objective 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.