Integrin αv in the mechanical response of osteoblast lineage cells

Although osteoblast lineage cells, especially osteocytes, are thought to be a primary mechanosensory cell in bone, the identity of the mechano-receptor and downstream mechano-signaling pathways remain largely unknown. Here we show using osteoblastic cell model of mechanical stimulation with fluid shear stress that in the absence of integrin alpha v, phosphorylation of the Src substrate p130Cas and JNK was impaired, culminating in an inhibition of nuclear translocation of YAP/TAZ and subsequent transcriptional activation of target genes. Targeted deletion of the integrin otv in osteoblast lineage cells results in an attenuated response to mechanical loading in terms of Sost gene expression, indicative of a role for integrin alpha v in mechanoreception in vivo. Thus, integrin alpha v may be integral to a mechanosensing machinery in osteoblastic cells and involved in activation of a Src-JNK-YAP/TAZ pathway in response to mechanical stimulation. (c) 2014 Elsevier Inc. All rights reserved.