title: Laminar shear stress delivers cell cycle arrest and anti-apoptosis to mesenchymal stem cells.
abstract: Biomechanical forces are emerging as critical regulators of cell function and fluid flow is a potent mechanical stimulus. Although the mechanisms of osteoblasts and osteocytes responding to fluid flow are being elucidated, little is known about how the osteoprogenitors, mesenchymal stem cells (MSCs), respond to fluid flow. Here, we examined the effects of laminar shear stress (LSS) on MSCs in vitro. MSCs from bone marrow of Sprague-Dawley rats were isolated, purified, and subjected to physiological levels of LSS. DNA synthesis and cell cycle were measured through [(3)H]thymidine and by flow cytometry, respectively, to detect the cellular proliferation. Annexin V immunostaining and Bcl-2/Bax mRNA expression were evaluated to determine the effect of LSS on MSCs apoptosis. Results showed that fluid shear stress caused a dose-related reduction of MSCs' proliferation rate with the majority of cells being arrested in the G(0) or G(1) phase. Moreover, it was found that physiological levels of LSS exerted a potent suppression effect on MSC apoptosis. In summary, these data revealed a critical role of LSS in maintaining the quiescence of MSCs.
authors.affiliation: Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Luo
authors.forename: Wei
authors.initials: W
authors.lastname: Xiong
authors.forename: Jun
authors.initials: J
authors.lastname: Zhou
authors.forename: Zhong
authors.initials: Z
authors.lastname: Fang
authors.forename: Wenjian
authors.initials: W
authors.lastname: Chen
authors.forename: Yubo
authors.initials: Y
authors.lastname: Fan
authors.forename: Feng
authors.initials: F
authors.lastname: Li
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D001854:Bone Marrow Cells / Q000166:cytology; D002453:Cell Cycle / Q000502:physiology*; D049109:Cell Proliferation; D002478:Cells, Cultured; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013314:Stress, Mechanical; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein