ABSTRACT
[Objective] To investigate the mesenchymal stem cells (MSC) in treating acute lung injury (ALI) via ALI mouse model.[Methods] By monoclonal antibody Anti-GD2 of specific antigen ganglioside (GD2) only expressed on MSC as a carrier,new fluorescent molecule probe were synthesized through covalently coupling Anti-GD2 and fluorescent group CyDye mono-reactive NHS Esters (Cy7).Synthetic Anti-GD2-Cy7 and MSC were labeled by the specific binding of antigen and antibody in vitro.Total 84 balb/c male mice were selected and randomly selected 48 mice were divided into three groups:sham group (n =16),MSC+ ALI group (n =16),NS + ALI group (n =16).The lung histopathology and scores,lung W/D ratio and permeability of lung microvasculature were examined at 24 h,48 h after ALI mouse model.Other 36 mice were randomly divided into three groups:normal group (n =12),sham group(n =12),MSC +ALI group(n =12).Labeled MSC-GD2-Cy7 were transplanted into MSC+ALI group and sham group mice via tail vein injection.At 30 min,1 d,3 d,and 7 d post-MSC-GD2-Cy7 injection,the mice were sacrificed after anesthesia and then the lung was removed.Excised lung was detected on small animal fluorescent imager.[Results] Contrast to NS+ ALI group,the lung histopathology and scores,lung W/D ratio and permeability of lung microvasculature of MSC +ALI group were more greatly improved at both 24 h and 48 h.Fluorescent results showed that the signal intensity in thc lung of MSC +ALI group was significantly higher than that of sham group at each time point [(3.37 ± 0.02)× 10-4 vs (2.05 ± 0.04) × 10-4 scaled counts/s;(35.54 ± 0.47)× 10-4 vs (25.29 ± 1.48) × 10-4 scaled counts/s;(11.17 ± 0.75)×10-4 vs (6.09 ± 0.62)× 10-4 scaled counts/s;(3.10 ± 0.14) vs (0.00 ± 0.00)× 10-4 scaled counts/s;all P ＜ 0.05].[Conclusion] Our study showed that a proportion of cells migrated into normal and injured lungs 30 min after cell transplantation,and the cells started to recruit and largely gather in injured lungs at day 1 and persisted to day 7,these results suggest that MSC possess the ability to home into injured tissues.