Effect of Yes Associated Protein on Osteogenic/Adipogenic Differentiation of Bone Marrow Mesenchymal Stem Cells Under Oxidative Stress

Abstract

Oxidative stress affects bone marrow mesenchymal stem cells (BMSCs). YAP is an effector in Hippo signaling, but its’ role in BMSCs osteogenesis/adipogenesis under oxidative stress has not been reported. Mice BMSCs were isolated and assigned into 3 groups, normal control group; oxidative stress group; and YAP group (transfected with YAP plasmid) followed by analysis of YAP expression by Real time PCR. After 14 days of osteogenesis or adipogenic induction, RUNX2, OPN, FABP4 and PPARγ2 mRNA level was measured along with ROS and SOD activities, ALP activity and Wnt5 expression by western blot. Under oxidative stress, YAP expression significantly decreased, RUNX2 and OPN mRNA expression decreased, ROS expression increased, SOD activity decreased, FABP4 and PPARγ2 protein expression increased, ALP activity and Wnt5 expression decreased (P <0.05). YAP plasmid transfection could significantly up-regulate YAP, RUNX2 and OPN mRNA level, decrease ROS, increase SOD and ALP activity, reduce FABP4 and PPARγ2 mRNA expression and increase Wnt5 expression (P <0.05). YAP level in BMSCs is decreased under oxidative stress. Up-regulating YAP can improve the redox balance, promote BMSCs osteogenic differentiation under oxidative stress and inhibit their differentiation to adipocytes.