Vitamin D3 Modifies the Impacts of the Supernatants of Mesenchymal Stem Cells on Macrophages Functions

Recent documents indicate that mesenchymal stem cells (MSCs) express vitamin D3 receptors and communicate with other immunocytes. However, there is no information about the role of vitamin D3 on the crosstalk between MSCs and macrophages.
The present study was done to investigate the effects of the MSCs treated with 1α-25(OH)-vitamin D3 on the some of the macrophages functions.
In this experimental study, mesenchymal stem cells were isolated from bone marrow of Wistar male rats (8 - 10 weeks old) and pulsed with different concentration of vitamin D3 (0, 50, 100 and 200 nM) for 48 hours. After 24 hours, the supernatants of MSCs were collected and incubated overnight with macrophages. Next, vitality, neutral red uptake, phagocytic activity, respiratory burst, and killing activity of macrophages were evaluated. Data were analyzed using the one-way ANOVA through SPSS software version 20.
The supernatants of MSCs treated with vitamin D3 could significantly enhance the macrophage vitality and uptake of neutral red as well as phagocytic activity of macrophages. Supernatants of MSCs pulsed with vitamin D3 reduced tetradecanoylphorbol acetate induced respiratory burst of macrophages more profoundly than the supernatants of MSCs alone. Nevertheless, the killing activity of macrophages triggered by opsonized yeast didn’t show any significant effect by supernatants of MSCs pulsed with vitamin D3 compared to the supernatants of MSCs alone.
The supernatants of vitamin D3 treated MSCs potentiate the anti-inflammatory functions of MSCs- educated macrophages without any change in microbicidal potential of macrophages after challenge with opsonized pathogen cannot be altered.