The Exposure to Osteoarthritic Synovial Fluid Enhances the Immunomodulatory Profile of Adipose Mesenchymal Stem Cell Secretome

Figure 2

Conditioned medium of SF-exposed AMSCs reverts the M1 phenotype and promotes the polarization of macrophages into the M2 phenotype. Monocytes (M0) were differentiated into macrophages in the presence of GM-CSF (M1-like) or M-CSF (M2-like). The expression of CD80 ((a)1), HLA-DR ((b)1), Arginase I ((c)1), and CD163 ((d)1) was evaluated by flow cytometry. Conditioned medium of unstimulated (CM) or SF-exposed AMSCs (CM+SF) or synovial fluid only (SF) was added during M1-like differentiation. The expression levels of M1-like ((a)2 and (b)2) and M2-like markers ((c)2 and (d)2) are presented as fold increase compared to untreated M1-like cells. The secretion of TNF-α in M1-like macrophages treated with CM, CM+SF, and SF is expressed as fold increase with respect to the secretion of TNF-α in untreated M1-like cells. Data are shown as Difference with untreated cells (). Difference with untreated cells (). Difference with untreated cells ().

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