An insight into the role of magnesium in the immunomodulatory properties of mesenchymal stem cells

Magnesium (Mg2+) is a mineral with the ability to influence cell proliferation and to modulate inflammatory/immune responses, due to its antiinflammatory properties. In addition, mesenchymal stem cells (MSCs) modulate the function of all major immune cell populations. Knowing that, the current work aimed to investigate the effects of Mg2+ enrichment, and its influence on the immunomodulatory capacity of MSCs. Murine C3H/10T1/2 MSCs were cultivated in media with different concentrations of Mg2+ (0, 1, 3 and 5 mM), in order to evaluate the effects of Mg2+ on MSC immunomodulatory properties, cell proliferation rates, expression of NFKB and STAT-3, production of IL-1 beta, IL-6, TGF-beta, IL-10, PGE2 and NO, and TRPM7 expression. The results showed that TRPM7 is expressed in MSCs, but Mg2+, in the way that cells were cultivated, did not affect TRPM7 expression. Additionally, there was no difference in the intracellular concentration of Mg2+. Mg2+, especially at 5 mM, raised proliferation rates of MSCs, and modulated immune responses by decreasing levels of IL-113 and IL-6, and by increasing levels of IL-10 and PGE2 in cells stimulated with LPS or TNF-alpha. In addition, MSC5 cultured in 5 mM Mg2+ expressed lower levels of pNFKB/NFKB and higher levels of pSTAT-3/STAT-3. Furthermore, conditioned media from MSC5 reduced lymphocyte and macrophage proliferation, but Mg2+ did not affect this parameter. In addition, conditioned media from MSCs cultured at 5 mM of Mg2+ modulated the production profile of cytokines, especially of IL-1 beta and IL-6 in macrophages. In conclusion, Mg2+ is able to modulate some immunoregulatory properties of MSCs. (C) 2018 Elsevier Inc. All rights reserved.