Mesenchymal Stromal Cells Affect Disease Outcomes via Macrophage Polarization

Figure 1

Mechanisms of macrophage polarization induced by MSCs in disease amelioration. MSCs produce paracrine factors such as PGE2, TSG-6, IL-6, IDO, and TGF-β1 when stimulated by proinflammatory mediators (LPS and TNF-α). The paracrine factors promote M2 macrophage polarization, which leads to increased Th2 response (upregulation of Treg and tissue remodeling as well as immunosuppression). MSCs also facilitate the production of VEGF and angiopoietin-1 which enhance angiogenesis. The net effect is disease amelioration.