Regulation of human placenta derived mesenchymal stem cells to expression of retinoid-related orphan receptor γt in lung tissue of capillary bronchitis rats caused by respiratory syncytial virus

Li Dezhi; Wu Fuling; Gao Meng; Li Yingying; Shi Tao; Han Tingting; Wang Haiying

doi:10.3760/cma.j.issn.1673-4777.2017.02.014

Abstract：Objective To study the regulation of human placenta derived mesenchymal stem cells (hpMSCs) and retinoid-related orphan receptor γt (RORγt) in lung tissue of capillary bronchitis rats caused by respiratory syncytial virus (RSV).Methods A total of SD 36 juvenile rats were randomly divided into normal group,RSV group and hpMSCs group,12 rats in each group.The RSV group and hpMSCs group had capillary bronchitis models induced by RSV;the hpMSCs group had stem cell transplantation therapy with hpMSCs injection after virus infection.The normal control group had no treatment.Lung histopathological changes were observed in 3 groups.Plasma levels of interleukin(IL)-17 and IL-23 were tested by enzyme linked immunosorbent assay.Expressions of RORγt in peripheral blood mononuclear cell (PBMC) and lung tissue were tested by real-time fluorescence quantitative polymerase chain reaction and western blotting method.Results The RSV group had lung interstitial hyperemia,edema,inflammatory cell infiltration,wide alveolar septa and bronchial collapse and deformation.The lung inflammatory manifestation in hpMSCs group was obviously ameliorated compared to that in RSV group.Levels of IL-17,IL-23 in RSV group were higher than those in normal control group[(56 ± 6) ng/L vs (27 ±4)ng/L,(61 ± 5)ng/L vs (19 ± 3)ng/L];levels of IL-17,IL-23 in hpMSCs goup were lower than that in RSV group [(30 ± 4) ng/L,(40 ± 6) ng/L];the differences were statistically significant (P ＜ 0.05).Expression levels of RORγt mRNA in PBMC and lung tissue in RSV group were higher than those in normal control group (PBMC:11.4 ± 1.1 vs 1.0 ± 0.0,lung tissue:8.1 ± 0.7 vs 1.0 ± 0.0);the levels of RORγt mRNA in PBMC and lung tissue in hpMSCs group (PBMC:4.4 ± 0.7,lung tissue:3.4 ± 0.5) were lower than those in RSV group;the expression level of RORγt protein in lung tissue in RSV group was higher than that in normal control group(1.26 ±0.12 vs 0.72 ±0.12);the level of RORγt protein in lung tissue in hpMSCs group(0.88 ±0.14) was lower than that in RSV group;the differences were statistically significant (P ＜ 0.05).Conclusion HpMSCs can downregulate expressions of RORγt and related cytokines in capillary bronchitis rats caused by RSV,which can reduce alleviating pulmonary inflammation.