FIG. 4.

Effect of the PGE₂ content in MSC-conditioned culture media on macrophage switch from M1 to M2 profile. Flow-cytometric analysis of BM-macrophages cultured for 3 days in: control standard medium (α-MEM); MSC-conditioned medium (SF); MSC-conditioned medium supplemented with the COX-2 specific inhibitor NS-398 (NS-398); conditioned medium derived from IL-1α stimulated MSCs (IL-1); conditioned medium derived from IL-1α stimulated MSCs and supplemented with NS-398 (IL-1 + NS-398); and (IL-1 + NS-398) conditioned medium supplemented with different concentrations of PGE₂ (1, 15, and 100 nM) (IL-1 + NS-398 + PGE₂ 1 nM, IL-1 + NS-398 + PGE₂ 15 nM, IL-1 + NS-398 + PGE₂ 100 nM, respectively). CD206 was selected as marker of M2 macrophages. The black line represents the expression of the specific marker on tested cell populations. The gray line indicates nonreactive immunoglobulin of the same isotype, which was included as a negative control. Presented data refer to one representative experiment.