(Study of the anti-inflammatory and immunotropic activity of the secretome from multipotent mesenchymal stromal cells induced by erythropoietin, valproic acid or dexamethasone in vitro)

The aim of this study was to evaluate the effect of treatment with valproic acid, erythropoietin, and dexamethasone on the anti-inflammatory and immunosuppressive activity of the secretome of adipose-derived multipotent mesenchymal stromal cells (MMSCs) in an in vitro experiment. Materials and methods. MMSCs were isolated from the fat of 6 healthy donors. The cells were grown in the culture up to passage 4. Then they were treated with valproic acid, erythropoietin or dexamethasone for 3 hours, washed from preparations, and incubated in a serum-free medium for 48 hours. Some of the cells were not treated with preparations. Supernatants from the cell cultures were concentrated by ultrafiltration, and protein standardization was performed using a nanophotometer. Then the supernatants were sterilized and added to mononuclear cells from peripheral blood of 8 healthy donors. The mononuclear cells were isolated by Ficoll density gradient centrifugation according to the standard protocol. Concentrations of TNF alpha, IL-2, IL-4, IL-6, IL-10, and IFN gamma cytokines in 24-hour cultures and IL-9, IL-10, IL-17A, and IL-21 cytokines in 48-hour cultures were determined using multiplex analysis. Results. The production of IL-2, IL-6, TNF alpha, and IL-10 was reduced by the secretome of MMSCs treated with valproic acid. The production of IL-2, IL-6, and TNF alpha decreased during incubation of the mononuclear cells with the secretome of MMSCs treated with erythropoietin. The secretome of dexamethasone-treated MMSCs suppressed the production of IFN gamma, IL-1 beta, IL-1ra, IL-2, IL-6, IL-9, IL-10, and IL-17A. No statistically significant differences were revealed in the production of IL-4, IL-5, IL-9, and IL-21. Conclusion. Among the studied inducers, dexamethasone enhanced the anti-inflammatory and immunosuppressive activity of MMSCs the most, which was manifested through the effect of their supernatants on peripheral blood mononuclear cells.