Objective To investigate the therapeutic effect of SPK1 gene transfected adipose derived mesenchymal stem cells(ADMSC)on experimental autoimmune encephalomyelitis mice and the effect on T helper cell 17(Th17)/regulatory T(Treg) cells balance. Methods EAE was induced by myelin oligodendrocyte glycoprotein 35-55 in mice.Totally 44 mice were randomly divided into four groups:normal control group(NC group),model group(EAE group),ADMSC group,and ADMSC-SPK1 group.Forty days after injection,the pathological changes of brain and spinal cord,Th17/Treg-related inflammatory markers in brain tissue,expressions of interleukin-17A(IL-17A)and forkhead box protein p3(Foxp3)in brain and spinal cord tissue,and flow cytometric results of spleen immune cells were detected. Results Forty days after the injection,serious inflammatory cell infiltration and demyelination occurred in the brain and spinal cord of EAE group,whereas demyelination and axonal injury were improved in ADMSC group and ADMSC-SPK1 group.Compared with EAE group,the ADMSC group and ADMSC-SPK1 group had significantly improved levels of IL-17A(Z=1.021,P=0.017;Z=1.193, P=0.009)and tumor necrosis factor-α(TNF-α)(Z=2.540,P=0.004; Z=3.005, P=0.006).The expression level of IL-17A in mouse brain and spinal cord tissues was significantly reduced in the ADMSC group(t=10.323,P=0.013;t=7.422,P=0.008),and it was significantly lower in the ADMSC-SPK1 group than in the ADMSC group (t=14.244, P=0.017; t=16.865,P=0.006).The expression level of Foxp3 in the ADMSC group was significantly increased(t=14.544, P=0.008;t=9.420,P=0.002),and it was significantly higher in the ADMSC-SPK1 group than ADMSC group(t=9.654,P=0.005; t=11.535, P=0.009).The proportion of IL-17+IFN-γ+T cells in spleen decreased in ADMSC-SPK1 group,while that of CD25+Foxp3+Treg cells increased. Conclusions ADMSC transfected with SPK1 has an ideal therapeutic effect on EAE mice,and the effect is superior to ADMSC without SPK1 transfection.The mechanism may be that ADMSC-SPK1 can markedly reduce the Th17/Treg cell ratio and decrease the release of related inflammatory cytokines in EAE mice.
Keywords: T helper cell 17/regulatory T cells balance; adipose derived mesenchymal stem cells; experimental autoimmune encephalomyelitis; multiple sclerosis; sphingosine kinase 1 gene transfection.