Oscillatory Fluid Flow Affects the Osteogenic Differentiation of Human Bone Marrow Stromal Cells in a Primary Cilium Dependent Manner

Osteoporosis is a debilitating bone disease which occurs in part when bone marrow stromal cells (BMSCs) fail to produce sufficient numbers of osteoblasts to counteract bone resorption by osteoclasts. The majority of research to date has described chemically induced differentiation of BMSCs but a key regulator of stromal cell differentiation is physical loading. BMSCs experience both hydrostatic pressure and fluid flow within the marrow cavity and such modes of loading have been shown to significantly alter gene expression in vitro [1,2]. In particular, the effect of oscillatory fluid flow (OFF) induced shear stress results in the upregulation of osteogenic genes in preosteoblastic cells; however the effect of this mode of loading is not well characterized in human MSCs (hMSCs) [3].