Mechanical loading induces HIF-1α expression in chondrocytes via YAP.

Abstract

To investigate the role of YAP in cyclic mechanical stress induced up-regulation of HIF-1α in rat cartilage chondrocytes. Our in vitro and in vivo experiments demonstrated that cyclic mechanical stress promoted HIF-1α and YAP proteins expression in a magnitude dependent manner. Cyclic mechanical stress at 4000μ strain exhibited most significant effect in promoting HIF-1α and YAP up-regulation. Activation of YAP using LPA significantly promoted HIF-1α stabilization and expression, while YAP siRNA treatment suppressed the up-regulation of HIF-1α induced by cyclic mechanical stress. Our results indicated that cyclic mechanical stress promoted HIF-1α stabilization and YAP is involved in mechanical stress induced HIF-1α up-regulation.