Human endometrial-derived mesenchymal stem cells suppress inflammation in the central nervous system of experimental autoimmune encephalomyelitis-induced mice

Abstract

ObjectiveTo evaluate the possible immunomodulatory effect of human endometrial-derived mesenchimal stem cells (hedMSCs) in the experimental autoimmune encephalomyelitis (EAE) mouse model.DesignExperimental EAE mouse model; inoculation of human hedMSCsMaterials and MethodsTwo distinct C57Bl/6 groups of mice were inoculated with PBS or 106 hedMSCs i.p. one day prior to immunization with 150 μg of MOG 35-55 emulsified in complete Freund Adjuvant (CFA). EAE scores were followed daily and at the peak of disease, mice were sacrificed, spleen and central nervous system (CNS) removed and mononuclear cells suspensions prepared. Cells were then plated and re-stimulated or not with MOG 35-55 for 24 hours plus Phorbol-Myristate-Acetate and Ionomycin in the presence of Brefeldin A for the last 3 hours. Supernatants were collected and cells submitted to intracellular flow cytometry staining protocols to evaluate the percentages of IFN-γ, IL-17, and TNF-α –secreting CD4+ cells. Statistical analysis was performed using one-way ANOVA followed by Tukey test.ResultsA significant decrease in the absolute numbers of inflammatory cells in the CNS of mice that previously received hedMSCs was observed. This was associated with a reduction in the percentage of both Th1 and Th17 cells. However, no difference in the percentage of CD4+TNF-α+ cells neither in spleen nor in the CNS was observed. Overall CNS inflammation was reduced, as demonstrated by histopathological analysis of spinal cords from hedMSCs treated group. Reduced inflammation culminated in a significant reduction of EAE scores.ConclusionOur results corroborate previous findings showing the immunomodulatory role of MSCs in vivo. It is noteworthy to mention the xenogenic nature of our work, as human cells were transferred into mice. Although the mechanisms are still to be confirmed, it is suitable that somehow hedMSCs suppress the commitment of pathogenic Th1 and Th17 cells in the periphery, which may also be associated with a reduced migration of these cells to the CNS. ObjectiveTo evaluate the possible immunomodulatory effect of human endometrial-derived mesenchimal stem cells (hedMSCs) in the experimental autoimmune encephalomyelitis (EAE) mouse model. To evaluate the possible immunomodulatory effect of human endometrial-derived mesenchimal stem cells (hedMSCs) in the experimental autoimmune encephalomyelitis (EAE) mouse model. DesignExperimental EAE mouse model; inoculation of human hedMSCs Experimental EAE mouse model; inoculation of human hedMSCs Materials and MethodsTwo distinct C57Bl/6 groups of mice were inoculated with PBS or 106 hedMSCs i.p. one day prior to immunization with 150 μg of MOG 35-55 emulsified in complete Freund Adjuvant (CFA). EAE scores were followed daily and at the peak of disease, mice were sacrificed, spleen and central nervous system (CNS) removed and mononuclear cells suspensions prepared. Cells were then plated and re-stimulated or not with MOG 35-55 for 24 hours plus Phorbol-Myristate-Acetate and Ionomycin in the presence of Brefeldin A for the last 3 hours. Supernatants were collected and cells submitted to intracellular flow cytometry staining protocols to evaluate the percentages of IFN-γ, IL-17, and TNF-α –secreting CD4+ cells. Statistical analysis was performed using one-way ANOVA followed by Tukey test. Two distinct C57Bl/6 groups of mice were inoculated with PBS or 106 hedMSCs i.p. one day prior to immunization with 150 μg of MOG 35-55 emulsified in complete Freund Adjuvant (CFA). EAE scores were followed daily and at the peak of disease, mice were sacrificed, spleen and central nervous system (CNS) removed and mononuclear cells suspensions prepared. Cells were then plated and re-stimulated or not with MOG 35-55 for 24 hours plus Phorbol-Myristate-Acetate and Ionomycin in the presence of Brefeldin A for the last 3 hours. Supernatants were collected and cells submitted to intracellular flow cytometry staining protocols to evaluate the percentages of IFN-γ, IL-17, and TNF-α –secreting CD4+ cells. Statistical analysis was performed using one-way ANOVA followed by Tukey test. ResultsA significant decrease in the absolute numbers of inflammatory cells in the CNS of mice that previously received hedMSCs was observed. This was associated with a reduction in the percentage of both Th1 and Th17 cells. However, no difference in the percentage of CD4+TNF-α+ cells neither in spleen nor in the CNS was observed. Overall CNS inflammation was reduced, as demonstrated by histopathological analysis of spinal cords from hedMSCs treated group. Reduced inflammation culminated in a significant reduction of EAE scores. A significant decrease in the absolute numbers of inflammatory cells in the CNS of mice that previously received hedMSCs was observed. This was associated with a reduction in the percentage of both Th1 and Th17 cells. However, no difference in the percentage of CD4+TNF-α+ cells neither in spleen nor in the CNS was observed. Overall CNS inflammation was reduced, as demonstrated by histopathological analysis of spinal cords from hedMSCs treated group. Reduced inflammation culminated in a significant reduction of EAE scores. ConclusionOur results corroborate previous findings showing the immunomodulatory role of MSCs in vivo. It is noteworthy to mention the xenogenic nature of our work, as human cells were transferred into mice. Although the mechanisms are still to be confirmed, it is suitable that somehow hedMSCs suppress the commitment of pathogenic Th1 and Th17 cells in the periphery, which may also be associated with a reduced migration of these cells to the CNS. Our results corroborate previous findings showing the immunomodulatory role of MSCs in vivo. It is noteworthy to mention the xenogenic nature of our work, as human cells were transferred into mice. Although the mechanisms are still to be confirmed, it is suitable that somehow hedMSCs suppress the commitment of pathogenic Th1 and Th17 cells in the periphery, which may also be associated with a reduced migration of these cells to the CNS.