| Objective: Acute lung injury and acute respiratory distress syndrome(ALI/ARDS)is leading causes of the high morbidity and mortality in clinical patients.We are looking for the new therapeutic methods because of the lack of effective treatments.Recent studies have identified human umbilical cord mesenchymal stem cells(h UC-MSCs)can play an important role in the treatment of ALI/ARDS.Sphingosine-1-phosphate(S1P)can significantly reduce LPS-induced lung edema and inflammatory lung injury by enhancing lung endothelial cell integrity.FTY720 as S1 P analog is a chemical composition after modification,also is S1P1 agonist with immunosuppressive effect.Several studies have demonstrated that S1P1 agonist can offer therapeutic potential in murine models of lung injury.Therefore,it is speculated that h UC-MSCs may regulate the S1 P metabolism and function in the injury lung through improving the endothelial barrier and play the therapeutic role.The aim of this study was to assess the therapy effects of combination with h UC-MSCs and FTY720 in murine model of acute lung injury induced by lipopolysaccharide,to enhance therapeutic effect,and reduce the lack of their effective treatments,meanwhile preliminarily elucidate the therapeutic mechanism.Methods: The eight-week-old female C57BL/6 mice were randomly divided into 5 groups: the normal group,the LPS group,the h UC-MSCs group,the FTY720 group and the h UC-MSCs ﹢ FTY720 group.The acute lung injury model was induced by intratracheal instillation of lipopolysaccharide(LPS).When the success of mouse model of acute lung injury was induced,the mice in transplantation group were administrated h UC-MSCs(2×105 cells)through the tail vein at time points of 24 h,while the FTY720 group were intraperitoneally injected FTY720.We observed that the histopathology(HE staining)and histologic scores,wet-to-dry weight ratio,Micro-CT examination,and total protein in the bronchoalveolar lavage fluid(BALF),as well as protein levels of interleukin(IL)-12p70,IL-10,IL-6,tumor necrosis factor-α(TNF-α),MCP-1,interferon-γ(IFN)-γ were evaluated on 48 h and 7d post-injury,and survival rate was analyzed for 48 h post-injury.While lung total protein extracts of the lung injury model were analyzed by two-dimensional polypropylene gel electrophoresis(2DE),then analyzed the comparison of electropherogram,found out the differential expression of protein spots and observed differential expression proteins in LPS-induced lung.Results:1.The results of pulmonary injury score and Micro-CT examination suggested that mouse model of LPS-induced acute lung injury was successfully built.2.This study revealed that the three treatment groups all increased survival rate and attenuated lung injuries in ALI mice,as evidenced by decreased injury scores,wet-to-dry weight ratio,total protein in the BAL,protein levels of IL-6,TNF-α and MCP-1 in BAL;The best was h UC-MSCs in combination with FTY720 treatment compared with h UC-MSCs alone or FTY720 group,but the reduction of survival rate and wet-to-dry weight ratio was not statistically significant compared with h UC-MSCs or FTY720 alone group.3.The results of 2DE indicated the lung total proteins in injury lung were more than the normal group.There were 21 differential expression proteins in the 100±2 protein points,the peroxiredoxin-6 was identified with LC-MS/MS and bioinformatics database of which was differential expression proteins,and the expression changing of this protein may be involved in the acute lung injury.Conclusions: ALI model could be established after intratracheal instillation of lipopolysaccharide;The combination therapy with h UC-MSCs and FTY720 can attenuate LPS-induced ALI with significant interaction between the two than h UC-MSCs or FTY720 alone;The results of 2DE showed the peroxiredoxin-6 was found upward-expressed in the injury lung.It is expected that combination therapy with h UC-MSCs and FTY720 could be best therapeutic strategies for ALI compared to h UC-MSCs or FTY720 alone,while the mechanism was still needed to be well studied. |
PDF Full Text Request