Intervention mechanisms of mesenchymal stem cells in juvenile mice model of acute lung injury induced by lipopolysaccharide / 中国小儿急救医学

ABSTRACT

Objective To explore the changes in expression levels of nuclear factor(NF)-κB,tumor necrosis factor(TNF)-e in the lungs of juvenile mice with acute lung injury(ALI) induced by lipopolysaccharide(LPS).And observe the repair of lung damage after intervening with exogenous mesenchymal stem cells(MSCs).Methods Thirty male juvenile C57 mice were randomly divided into the control group,the ALI group,and the ALI + MSCs group by the random number table method.Mice from each group were euthanized at 12 h and 48 h.The ALI model of juvenile mice was established by intraperitoneal injection of LPS 10 mg/kg.MSCs from mice bone marrow were isolated,cultured and amplified in vitro,and the MSCs (1 × 106/ml) 0.1 ml were given to mice via caudal vein.MSCs marker were identificated by flow cytometry.Pathomorphological changes of mice lung were observed under light microscope after Hematoxylin-Eosin staining.The protein expression changes of NF-κB,TNF-α were observed using immunohistochemistry.Resu]ts Compared with the control group,the protein expression levels of NF-κB,TNF-α were significantly higher at 12 h and 48 h in the lungs of the ALI group(P ＜ 0.05).While those in ALI + MSCs group were markedly lower at these time points than the ALI group [NF-κB12 h(0.181 ± 0.008) OD vs (0.203 ±0.008) OD,48 h(0.197 ± 0.002) OD vs (0.210 ± 0.005) OD; TNF-α12 h(0.185 ± 0.004) OD vs (0.201 ± 0.011) OD,48 h(0.185 ± 0.002) OD vs (0.215 ± 0.009) OD] (P ＜ 0.05).Histopathological evalution showed that typical pathological inflammation lesions in the lung were observed in ALI group,including alveolar congestion,hemorrhage,edema,infiltration of neutrophils in the airspace or vessel wall,thickness of the alveolar wall;pathological changes were relieved obviously in ALI + MSCs group.Conclusion The expression of NF-κB and TNF-α are increased in lung tissues in the juvenile mice model of ALI induced by LPS.MSCs can alleviate injury degree of ALI induced by LPS in mice,the mechanism of action may correlate with decreasing NF-κB and TNF-α content in lung tissue.