Carry Hypoxia Induced Mitogenic Factor Bone Marrow Mesenchymal Stem Cells In Acute Lung Injury

ObjectiveAcute lung injury(ALI),with its high incidence rate and mortality,lacks specific treatment strategies currently.Lipopolysaccharide(LPS) plays important role in the pathogenesis of ALI.The research explored intervention roles of mesenchymal stem cells(MSC) in LPS-induced inflammatory lung injury and role of hypoxia-induced mitogenic factor(HIMF).As HIMF was an autocrine and paracrine cytokine,MSCs were designed as a vehicle carrying HIMF into the locus of lung injury to explore the roles of MSC and HIMF in the different period of acute lung injury.MethodsMSCs were successfully isolated from Balb/c mice,proliferated,subcultured and identified its phenotype and capacity to differentiate.After coculture with mouse lung epithelium 12(MLE12) under LPS exposure,the function of MSCs was observed.On the other hand,Lentiviral vector carrying HIMF was constructed and identified its efficiency in MSC transduction.In the animal model of ALI which LPS was inhaled,mice were administered with saline,MSC or MSC-HIMF.To evaluate its difference in ALI,several aspects were valued including W/D ratio,MPO activities, proinflammation and anti-inflammation cytokines,apoptosis index etc.Results1.MSCs were successfully isolated with high purity and were analyzed by FACS and multiple differentiation.2.Under inflammatory environment,MSCs played immunomodulation role with increased anti-inflammation cytokines expression.3.Inflammatory environment had no influence on MSC cycle,which was G0/G1 dominated.4.Lentivirus vector succeeded in transducing HIMF into MSC with steady HIMF expression.5.Pathological scores:MSC treatment can significantly alleviate lung damage compared with control,MSC-HIMF administration could not attenuate acute inflammatory reation,meanwhile it promoted chronic inflammation.6.Lung injury factors:compared with control,MSC treatment showed marked reduction in W/D ratio,MPO activities,proinflammation cytokines level and elevation in anti-inflammation cytokines;MSC-HIMF administration increased W/D ratio,MPO activities,upregulated proinflammation cytokines level until 14 days with high protein content in BALF.7.We speculated that MSC reduced lung injury by immunomodution of local immune state when observing reduced proinflammation cytokines level and increased anti-inflammation cytokines level in MSC treatment,and MSC can also exert its role by merging with injured lung cells or differentiating into lung cells.Conclusions1.MSC can be isolated and cultured for expansion in vitro;Lentivirus system is a proper way to carry exogenous gene.2.MSC intervention can significantly attenuate acute lung injury by immunomodution and reduce fibrosis process in certain extent.3.HIMF has proinflammatory effects in acute lung injury and promotes chronic inflammation.