Figure 2.

Mechanisms of action of VitK2 in “bone and vascular cross-talk”. At vascular level, VitK2, acting as cofactor for the enzyme GGCX, triggers the conversion of undercarboxylated MGP (ucMGP) in active carboxylated MGP (cMGP). The active cMGP could directly inhibit ectopic Ca2+ precipitation, but also VSMCst trans-differentiation through BMP-2. VitK2 can also inhibit VSMCs apoptosis through the Gas6/ AxL/Akt anti-apoptotic pathway. In bone tissue, VitK2 could promote osteoblasts proliferation and activity through MGP and Wnt/β-catenin pathway, control of oxidative stress (Ox-S) imbalance, via SXR receptor, and the well-established GGCX-dependent pathway. VitK2 may also exert a control of osteoclasts activities through the inhibition of NF-kB.