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

Abstract

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 TNFα, IL-2, IL-4, IL-6, IL-10, and IFNγ 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, TNFα, and IL-10 was reduced by the secretome of MMSCs treated with valproic acid. The production of IL-2, IL-6, and TNFα 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 IFNγ, IL-1β, 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.