title: Chemotransport contributes to the effect of oscillatory fluid flow on human bone marrow stromal cell proliferation.
abstract: Mechanical loads produce a diverse set of biophysical signals that may regulate bone cell activity, but accumulating evidence suggests that interstitial fluid flow is the primary signal that bone cells perceive. Because we previously demonstrated that oscillatory fluid flow increases human bone marrow stromal cell proliferation, we investigated the contribution of fluid shear stress and chemotransport, two stimuli induced by interstitial fluid flow. Alterations in flow rate at a constant peak shear stress were associated with decreases in oscillatory fluid flow-induced marrow stromal cell proliferation, while variations in peak fluid shear stress had no significant effect. Modulation of marrow stromal cell proliferation by flow rate may be attributed to changes in the release of ATP and intracellular calcium signaling. We found that if the flow rate is decreased while maintaining a constant peak fluid shear stress, marrow stromal cells release less ATP into the extracellular environment. Moreover, as the flow rate decreased fewer cells respond to fluid flow with an increase in intracellular calcium concentration. These data suggest that chemotransport is a prerequisite for marrow stromal cells to respond to interstitial fluid flow.
authors.affiliation: Division of Musculoskeletal Sciences, Department of Orthopaedics and Rehabilitation, Pennsylvania State University College of Medicine, Milton S. Hershey Medical Center, Hershey, Pennsylvania 17033, USA.
authors.forename: Ryan C
authors.initials: RC
authors.lastname: Riddle
authors.forename: Karen R
authors.initials: KR
authors.lastname: Hippe
authors.forename: Henry J
authors.initials: HJ
authors.lastname: Donahue
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D001854:Bone Marrow Cells / Q000502:physiology*; D020013:Calcium Signaling / Q000502:physiology; D049109:Cell Proliferation; D002478:Cells, Cultured; D006801:Humans; D012212:Rheology
chemical_list: D000255:Adenosine Triphosphate