The effect of thymic mesenchymal stromal cells on arginase activity and nitric oxide produced by mouse macrophages

Mesenchymal stromal cells (MSC) gained much attention due to their therapeutic properties, media­ted largely by anti-inflammatory action. We aimed to investigate the capacity of MSC obtained from young mice to modulate arginine metabolism of macrophages from old animals. Bone marrow cells obtained from young and aged mice were cocultivated with MSC in the presence of M-CSF. Nitric oxide production was analyzed in supernatants by Griess reaction, and arginase activity was measured in cell lysates. We have found that arginase activity was significantly lower in macrophages isolated from old mice as compared to young animals (P ˂ 0.05). Syngeneic MSC addition markedly stimulated arginase activity in macrophages from both young and aged mice (P ˂ 0.001), with greater effect in old animals. There were no significant differences in nitric oxide level between groups. In summary, there was more pronounced anti-inflammatory shift in macrophage metabolism in aged animals upon cocultivation with MSC