ABSTRACT
Objective To explore the effects of mesenchymal stem cells ( MSC ) treatment on platelet counts in mice with immune-mediated thrombocytopenia ( ITP) and the possible mechanism .Meth-ods ITP was induced by daily intraperitoneal injection of anti-platelet membrane CD 41 antibody (MWReg30) into BALB/c mice.The mice were then divided into experiment and control groups with 20 mice in each.Each mouse in experimental group was injected with 2×107 mesenchymal stem cells (MSC) through the tail vein .The numbers of blood platelets in mice from two groups were counted on days 5, 7 and 14 after MSC injection .Reverse transcriptase polymerase chain reaction ( RT-PCR) was performed to meas-ure T-bet and GATA-3 gene expression in peripheral blood mononuclear cells ( PBMCs ) at mRNA level on day 14.The levels of IFN-γ, IL-2, IL-4 and IL-10 in serum were detected by ELISA .Results The platelet counts in experimental group were significantly higher than those in control group on days 7 and 14 after MSC injection [(588.0±81.6)×109/L and (623.0±78.9) ×109/L vs.(317.0±90.1) ×109/L and (288.0± 87.8)×109/L ] (P<0.05).On day 14 after MSC injection, the T-bet expression at mRNA level in PBMCs from mice in experimental group was significantly lower than that in control group [(0.04±0.03) vs.(0.27 ±0.05)] (P<0.05), while the GATA-3 expression at mRNA level was higher than those in control group [ (0.14±0.04) vs.(0.07±0.05)] (P<0.05).Compared with control group, the concentrations of Th1 type cytokines such as IFN-γand IL-2 were remarkably down-regulated in experimental group [(3.1±1.7) pg/ml and (3.2±2.1) pg/ml vs.(10.3±4.8) pg/ml and (16.3±5.7) pg/ml](P<0.05), while the con-centrations of Th2 type cytokines such as IL-4 and IL-10 were up-regulated in experimental group [(88.6± 15.2) pg/ml and (38.3±11.8) pg/ml vs.(32.7±5.7) pg/ml and (22.1±3.4) pg/ml ] (P<0.05). Conclusion MSC treatment can effectively increase platelet counts in mice with immune-mediated thrombo-cytopenia, which may be associated with the suppression of Th 1-dominant response mediated by abnormal ex-pression of T-bet and GATA-3.
ABSTRACT
AIM:The aim of this study is to investigate the relationship between the ratio of transcription factors T-bet/GATA-3 in peripheral blood mononuclear cells(PBMCs)and the imbalance of Th1/Th2 cytokines from patients with asthma,and to examine whether and how CpG ODN intervention would restore the imbalanced Th1/Th2 profile in asthma patients.METHODS:Three groups of subjects with asthma(asthma group),chronic obstructive pulmonary disease(COPD group),and normal controls(control group)were included in this study.T-bet,GATA-3 and TLR9 mRNA levels were measured by reverse transcription-polymerase chain reaction(RT-PCR).Th1 cytokine IFN-? and Th2 cytokines IL-4,IL-5 and IL-13 were measured by enzyme-linked immunoabsorbent assay(ELISA)in asthma group.Cultured PBMCs from asthma patients with CpG ODN incubation were collected for measuring T-bet,GATA-3 mRNA and TLR9 mRNA.RESULTS:The ratio of T-bet/GATA-3 in asthma group was significantly lower than that in the COPD group and control group.The serum levels of IL-4,IL-5 and IL-13 had positive correlation with the ratio of T-bet/GATA-3 in asthmatic patients,and the lower serum level of IFN-? had negative correlation with the ratio.The TLR9 mRNA expression in asthma was significantly attenuated than that in COPD group and control group.Consequently,the ratio of T-bet/GATA-3 in CpG group was significantly enhanced than that in control group.CONCLUSION:These results indicate that the ratio of T-bet/GATA-3 in asthma is decreased and could represent the imbalance of Th1/Th2 cells.CpG ODN influences the ratio of T-bet/GATA-3,upregulating the T-bet mRNA expression and downregulating the GATA-3 mRNA expression,which is able to reverse the imbalance of Th1/Th2 cells.CpG-ODN may be a promising therapeutic target for asthma.