Modulation of Murine Macrophage TLR7/8-Mediated Cytokine Expression by Mesenchymal Stem Cell-Conditioned Medium
Figure 5
ERK signaling is partially responsible for the modulated expression of IL-10, but not that of TNF-α or IL-6, in BMDMs preincubated in MSC-conditioned medium followed by R848 stimulation. (a) BMDMs were preincubated in MSC-conditioned medium or control medium with or without a cocktail consisting of an EP2 antagonist (AH6809, 10 μM) and an EP4 antagonist (GW 627368X, 10 μM). DMSO was used as a vehicle. After 1 h, R848 (TLR7/8 ligand, 10 μg/mL) was added, and BMDMs were incubated for an additional 0.5 h. The p-ERK level was determined by immunoblotting. Beta-actin was used as a loading control. Results are representative of 3 independent experiments. (b–d) BMDMs were preincubated in MSC-conditioned medium or control medium with or without MEK/ERK inhibitor (U-0126, 10 μM). DMSO was used as the vehicle. After 1 h, R848 (TLR7/8 ligand, 10 μg/mL) was added, and BMDMs were incubated for an additional 24 h. The levels of TNF-α (a), IL-6 (c), and IL-10 (d) were determined using ELISA. and , compared to the control medium group. , compared to the R848-stimulated cells (without MEK/ERK inhibitor). Data are expressed as the mean ± SEM. in each group. Results are representative of 3 independent experiments.
