Fluid shear stress induces differentiation of circulating phenotype endothelial progenitor cells

2012 ◽  
Vol 303 (6) ◽  
pp. C595-C606 ◽  
Author(s):  
Syotaro Obi ◽  
Haruchika Masuda ◽  
Tomoko Shizuno ◽  
Atsuko Sato ◽  
Kimiko Yamamoto ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Endothelial Cells ◽  
Shear Stress ◽  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Signal Transduction Pathway ◽  
Tube Formation ◽  
Tissue Fluid ◽  
Transduction Pathway ◽  
Endothelial Progenitor

Endothelial progenitor cells (EPCs) are mobilized from bone marrow to peripheral blood, and contribute to angiogenesis in tissue. In the process, EPCs are exposed to shear stress generated by blood flow and tissue fluid flow. Our previous study showed that shear stress induces differentiation of mature EPCs in adhesive phenotype into mature endothelial cells and, moreover, arterial endothelial cells. In this study we investigated whether immature EPCs in a circulating phenotype differentiate into mature EPCs in response to shear stress. When floating-circulating phenotype EPCs derived from ex vivo expanded human cord blood were exposed to controlled levels of shear stress in a flow-loading device, the bioactivities of adhesion, migration, proliferation, antiapoptosis, tube formation, and differentiated type of EPC colony formation increased. The surface protein expression rate of the endothelial markers VEGF receptor 1 (VEGF-R1) and -2 (VEGF-R2), VE-cadherin, Tie2, VCAM1, integrin αv/β3, and E-selectin increased in shear-stressed EPCs. The VEGF-R1, VEGF-R2, VE-cadherin, and Tie2 protein increases were dependent on the magnitude of shear stress. The mRNA levels of VEGF-R1, VEGF-R2, VE-cadherin, Tie2, endothelial nitric oxide synthase, matrix metalloproteinase 9, and VEGF increased in shear-stressed EPCs. Inhibitor analysis showed that the phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signal transduction pathway is a potent activator of adhesion, proliferation, tube formation, and differentiation in response to shear stress. Western blot analysis revealed that shear stress activated the VEGF-R2 phosphorylation in a ligand-independent manner. These results indicate that shear stress increases differentiation, adhesion, migration, proliferation, antiapoptosis, and vasculogenesis of circulating phenotype EPCs by activation of VEGF-R2 and the PI3K/Akt/mTOR signal transduction pathway.

Proliferation, differentiation, and tube formation by endothelial progenitor cells in response to shear stress

2003 ◽  
Vol 95 (5) ◽  
pp. 2081-2088 ◽  
Author(s):  
Kimiko Yamamoto ◽  
Tomono Takahashi ◽  
Takayuki Asahara ◽  
Norihiko Ohura ◽  
Takaaki Sokabe ◽  
...  
Keyword(s):  
Shear Stress ◽  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Peripheral Blood ◽  
Tube Formation ◽  
Target Tissue ◽  
Tissue Fluid ◽  
Vascular Endothelial ◽  
Endothelial Progenitor ◽  
Static Conditions

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.

Shear stress regulates inflammatory and thrombogenic gene transcripts in cultured human endothelial progenitor cells

2010 ◽  
Vol 104 (09) ◽  
pp. 582-591 ◽  
Author(s):  
Trine Lund ◽  
Stig Hermansen ◽  
Thomas Andreasen ◽  
Jan Olsen ◽  
Bjarne Østerud ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Mrna Expression ◽  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Mrna Levels ◽  
Endothelial Progenitor ◽  
Gene Transcripts ◽  
Nos Inhibitor

SummaryShear stress has an established effect on mature endothelial cells, but less is known about how shear stress regulates endothelial progenitor cells (EPCs). In vitro expanded EPCs isolated from adult human blood represent a novel tool in regenerative vessel therapy. However, in vitro culturing may generate cells with unfavourable properties. The aim of the present study was therefore to assess whether shear stress may influence the inflammatory and thrombotic phenotype of in vitro expanded EPCs. In late outgrowth EPCs, 6 hours of shear stress (6.0 dynes/ cm2) significantly reduced the mRNA levels of IL-8, COX2, and tissue factor (TF) compared to static controls. This was associated with a reduced TF activity. In contrast, mRNA expression of NOS3 was significantly increased following 6 and 24 hours of shear stress. In accordance with this, NOS3 protein expression was increased following 24 hours of shear stress. Overall stimulation with the proinflammatory mediator, TNFα, for the final 2 hours increased the mRNA expression of IL-6, IL-8, MCP-1, ICAM1, and TF. However exposure to 6 hours of shear stress significantly suppressed the inductory potential of TNFα to increase the mRNA levels of IL-6, IL-8, COX2, and TF. Additionally, TNFα increased TF activity approximately 10 times, an effect that was also significantly reduced by exposure to 6 and 24 hours of shear stress. The effect of shear on the gene levels of TF and NOS3 were not blocked by the NOS inhibitor L-NAME. These observations suggest that EPCs are capable of functionally responding to shear stress.

scholarly journals Exosomes secreted from osteocalcin-overexpressing endothelial progenitor cells promote endothelial cell angiogenesis

2019 ◽  
Vol 317 (5) ◽  
pp. C932-C941 ◽  
Author(s):  
Ming Yi ◽  
Ye Wu ◽  
Jun Long ◽  
Fei Liu ◽  
Zhi Liu ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Rat Aorta ◽  
Tube Formation ◽  
Endothelial Progenitor ◽  
And Migration ◽  
G Protein Coupled ◽  
Receptor Family ◽  
Proliferation And Migration

Exosome secretion is an important paracrine way of endothelial progenitor cells (EPCs) to modulate resident endothelial cells. The osteocalcin (OCN)-expressing EPCs have been found to be increased in cardiovascular disease patients and are considered to be involved in the process of coronary atherosclerosis. Since OCN has been proven to prevent endothelial dysfunction, this study aimed to evaluate the effect of exosomes derived from OCN-overexpressed EPCs on endothelial cells. Exosomes derived from EPCs (Exos) and OCN-overexpressed EPCs (OCN-Exos) were isolated and incubated with rat aorta endothelial cells (RAOECs) with or without the inhibition of OCN receptor G protein-coupled receptor family C group 6 member A (GPRC6A). The effects of exosomes on the proliferation activity of endothelial cells were evaluated by CCK-8 assay, and the migration of endothelial cells was detected by wound healing assay. A tube formation assay was used to test the influence of exosomes on the angiogenesis performance of endothelial cells. Here, we presented that OCN was packed into Exos and was able to be transferred to the RAOECs via exosome incorporation, which was increased in OCN-Exos groups. Compared with Exos, OCN-Exos had better efficiency in promoting RAOEC proliferation and migration and tube formation. The promoting effects were impeded after the inhibition of GPRC6A expression in RAOECs. These data suggest that exosomes from OCN-overexpressed EPCs have a beneficial regulating effect on endothelial cells, which involved enhanced OCN-GPRC6A signaling.

scholarly journals Shear Stress Triggers Angiogenesis of Late Endothelial Progenitor Cells via the PTEN/Akt/GTPCH/BH4 Pathway

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Shao-Hong Wu ◽  
Feng Zhang ◽  
Shun Yao ◽  
Lu Tang ◽  
Hai-Tao Zeng ◽  
...  
Keyword(s):  
Shear Stress ◽  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Limb Ischemia ◽  
Tube Formation ◽  
Laminar Shear Stress ◽  
Endothelial Progenitor ◽  
Tensin Homolog

Background. Shear stress is an effective modulator of endothelial progenitor cells (EPCs) and has been suggested to play an important role in angiogenesis. The phosphatase and tensin homolog (PTEN)/Akt and guanosine triphosphate cyclohydrolase (GTPCH)/tetrahydrobiopterin (BH4) pathways regulate the function of early EPCs. However, the role of these pathways in the shear stress-induced angiogenesis of late EPCs remains poorly understood. Therefore, we aim to investigate whether shear stress could upregulate the angiogenesis capacity of late EPCs and to further explore the possible underlying mechanisms. Methods. Late EPCs were subjected to laminar shear stress (LSS), and their in vitro migration, proliferation, and tube formation capacity were determined. In addition, the in vivo angiogenesis capacity was explored, along with the expression of molecules involved in the PTEN/Akt and GTPCH/BH4 pathways. Results. LSS elevated the in vitro activities of late EPCs, which were accompanied by downregulated PTEN expression, accelerated Akt phosphorylation, and GTPCH/BH4 pathway activation (all P<0.05). Following Akt inhibition, LSS-induced upregulated GTPCH expression, BH4, and NO level of EPCs were suppressed. LSS significantly improved the migration, proliferation, and tube formation ability (15 dyn/cm2 LSS vs. stationary: 72.2±5.5 vs. 47.3±7.3, 0.517±0.05 vs. 0.367±0.038, and 1.664±0.315 vs. 1±0, respectively; all P<0.05) along with the in vivo angiogenesis capacity of late EPCs, contributing to the recovery of limb ischemia. These effects were also blocked by Akt inhibition or GTPCH knockdown (P<0.05, respectively). Conclusions. This study provides the first evidence that shear stress triggers angiogenesis in late EPCs via the PTEN/Akt/GTPCH/BH4 pathway, providing a potential nonpharmacologic therapeutic strategy for promoting angiogenesis in ischemia-related diseases.

Fluid shear stress induces arterial differentiation of endothelial progenitor cells

2009 ◽  
Vol 106 (1) ◽  
pp. 203-211 ◽  
Author(s):  
Syotaro Obi ◽  
Kimiko Yamamoto ◽  
Nobutaka Shimizu ◽  
Shinichiro Kumagaya ◽  
Tomomi Masumura ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Endothelial Cell ◽  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Peripheral Blood ◽  
Consensus Sequence ◽  
Mrna Levels ◽  
Endothelial Progenitor ◽  
Cell Markers

Endothelial progenitor cells (EPCs) are mobilized from bone marrow to peripheral blood and contribute to angiogenesis in tissues. In the process, EPCs are exposed to the shear stress generated by blood flow and tissue fluid flow. Our previous study showed that shear stress promotes differentiation of EPCs into mature endothelial cells. In this study, we investigated whether EPCs differentiate into arterial or venous endothelial cells in response to shear stress. When cultured EPCs derived from human peripheral blood were exposed to controlled levels of shear stress in a flow-loading device, the mRNA levels of the arterial endothelial cell markers ephrinB2, Notch1/3, Hey1/2, and activin receptor-like kinase 1 increased, but the mRNA levels of the venous endothelial cell markers EphB4 and neuropilin-2 decreased. Both the ephrinB2 increase and the EphB4 decrease were shear stress dependent rather than shear rate dependent. EphrinB2 protein was increased in shear-stressed EPCs, and the increase in ephrinB2 expression was due to activated transcription and not mRNA stabilization. Deletion analysis of the ephrinB2 promoter indicated that the cis-element (shear stress response element) is present within 106 bp 5′ upstream from the transcription initiation site. This region contains the Sp1 consensus sequence, and a mutation in its sequence decreased the basal level of transcription and abolished shear stress-induced ephrinB2 transcription. Electrophoretic mobility shift assays and chromatin immunoprecipitation assays showed that shear stress markedly increased binding of Sp1 to its consensus sequence. These results indicate that shear stress induces differentiation of EPCs into arterial endothelial cells by increasing ephrinB2 expression in EPCs through Sp1 activation.

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