title: Proliferation, differentiation, and tube formation by endothelial progenitor cells in response to shear stress.
abstract: Endothelial progenitor cells (EPCs), circulating in peripheral blood, migrate toward target tissue, differentiate, and contribute to the formation of new vessels. In this study, we report that shear stress generated by blood flow or tissue fluid flow can accelerate the proliferation, differentiation, and capillary-like tube formation of EPCs. When EPCs cultured from human peripheral blood were subjected to laminar shear stress, the cells elongated and oriented their long axes in the direction of flow. The cell density of the EPCs exposed to shear stress was higher, and a larger percentage of these cells were in the G2-M phase of the cell cycle, compared with EPCs cultured under static conditions. Shear stress markedly increased the EPC expression of two vascular endothelial growth factor receptors, kinase insert domain-containing receptor and fms-like tyrosine kinase-1, and an intercellular adhesion molecule, vascular endothelial-cadherin, at both the protein and mRNA levels. Assays for tube formation in the collagen gels showed that the shear-stressed EPCs formed tubelike structures and developed an extensive tubular network significantly faster than the static controls. These findings suggest that EPCs are sensitive to shear stress and that their vasculogenic activities may be modulated by shear stress.
authors.affiliation: Department of Biomedical Engineering, Graduate School of Medicine, University of Tokyo, 113-0033 Tokyo, Japan. k-yamamoto@umin.ac.jp
authors.forename: Kimiko
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Tomono
authors.initials: T
authors.lastname: Takahashi
authors.forename: Takayuki
authors.initials: T
authors.lastname: Asahara
authors.forename: Norihiko
authors.initials: N
authors.lastname: Ohura
authors.forename: Takaaki
authors.initials: T
authors.lastname: Sokabe
authors.forename: Akira
authors.initials: A
authors.lastname: Kamiya
authors.forename: Joji
authors.initials: J
authors.lastname: Ando
mesh_terms: D015703:Antigens, CD; D015415:Biomarkers; D015820:Cadherins / Q000235:genetics; D002454:Cell Differentiation / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D003094:Collagen; D004730:Endothelium, Vascular / Q000166:cytology* / Q000502:physiology*; D016326:Extracellular Matrix Proteins / Q000235:genetics; D005782:Gels; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000166:cytology; D018919:Neovascularization, Physiologic / Q000502:physiology*; D012333:RNA, Messenger / Q000032:analysis; D013234:Stem Cells / Q000166:cytology* / Q000502:physiology*; D013314:Stress, Mechanical; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000235:genetics; D000099152:Cadherin 5
chemical_list: D015703:Antigens, CD; D015415:Biomarkers; D015820:Cadherins; D003094:Collagen; D016326:Extracellular Matrix Proteins; D005782:Gels; D012333:RNA, Messenger; D040301:Vascular Endothelial Growth Factor Receptor-2; D000099152:Cadherin 5