Role of Sost in Wnt signal pathway in osteoporosis rats and regulating effect of soybean isoflavones on Wnt signal pathway

Abstract

To explore the mechanism of soybean isoflavones (SI) on OVX-induced osteoporosis, we investigated the effect of SI on Wnt signaling that emerged as a novel key pathway for promoting bone formation. Results showed that SI decreased bone mineral elements loss, improved biomechanics parameters in OVX rats. Wnt3a activation can promote the dissociation of β-catenin complexes, release of β-catenin monomer and inhibition of β-catenin monomer degradation. SI decreased sost mRNA and sclerosteosis protein expression in a dose-dependent manner, and increased β-catenin proteins expression in femur of OVX rats. These data suggest that SI suppresses the canonical Wnt signal in OVX rats, partially through the enhancement of the dickkopf-1 production. OVX results in decreased estrogen level in rats. SI act as inhibitors of Wnt-mediated activation of by competitively binding to LRP5, and subsequently downregulating β-catenin gene.