Fig. 1

MenSCs exert therapeutic effects mainly via following mechanisms: (1) differentiation into targeting cells, such as cartilaginous, adipocytic, osteogenic, cardiogenic, muscle, neurogenic, oocyte-like, iPSCs, myocytic, granulosa, and hepatic tissues; (2) immunomodulation interacting with various immune cells, such as inhibiting the proliferation of T lymphocyte cell (T cell), natural killer (NK) cell, and dendritic cell (DC), and promoting the production of regulatory B (Breg) cell; (3) paracrine effect secreting a variety of cytokines, such as VEGF, BDNF, NT-3, IL-4, TGF-β 2, EGF, PDGF, NO, HIF-1α, MMP-3, MMP-10, IL-6, MCP-1, HGF, IL-8, GRO, OPG, angiopoietin, elastin, thrombospondin-1, SDF-1, and IGF-1. MenSCs secrete these cytokines through the blood vein to give rise to inflammatory factors, and they interact with the immunomodulation. Similarly, some differential factors also released by paracrine effect through the blood vein to exert the role of differentiation; and (4) homing and engraftment targeting injured sites by some chemokine receptors (such as CXCR4). Green arrows mean positive role, Red T-shapes mean negative role