Comparison of cell surface markers and inflammatory factor expression in M0, M1 and M2 macrophages. (a) Cell surface marker staining of F4/80 and CD206 expression in M0, M1 and M2 macrophages. RAW264.7 macrophages cultured in normal medium were defined as M0 with significant F4/80 and negative CD206 expression. RAW264.7 macrophages stimulated with LPS were defined as M1 with significant F4/80 and weak CD206 expression. RAW264.7 macrophages stimulated with LPS and co-cultured with MSCs in transwells were defined as M2 with significant expression of F4/80 and CD206. (b) ELISA showed that MSC treatment significantly decreased the levels of the pro-inflammatory cytokines TNF-α and IL-6 and increased the levels of the anti-inflammatory cytokine IL-10 in culture medium. *P <0.05 versus M0, #P <0.05 versus M2, n = 3. (c-d) MSCs increased the percentage of CD206+ IL-10+ cells in RAW264.7 macrophages after co-culture for 72 hours. #P <0.05 versus M0 or M1, n = 3. MSCs, mesenchymal stem cells.