Table 2.
A Summary of Studies Characterizing How Fluid Shear Stress Affects Endothelial Outgrowth Cell Function and Response to Tumor Necrosis Factor α Treatment
| Flow conditions | Flow system | Substrate | Shear stress | TNF-α treatment | Results (described as flow treated EOCs compared to static unless stated otherwise) | Reference |
|---|---|---|---|---|---|---|
| Steady flow | Parallel plate | Fibronectin-coated Teflon A films spun-cast on glass | 15 dyn/cm2 for 24 or 28 h | N/A | Increased eNOS, TM, ICAM-1 gene expression | (58) |
| No significant difference in VCAM-1 or E-selectin gene expression | ||||||
| Fibrin-based scaffold | 15 dyn/cm2 for 24 h | 10 U/mL for 24 h | Increased NO production | (48) | ||
| Decreased platelet adhesion | ||||||
| Attenuated TNF-α-induced upregulation of VCAM-1 and ICAM-1 | ||||||
| Gelatin-coated plastic | 5 or 25 dyn/cm2 for 5 h | N/A | Decrease in VCAM-1 gene expression at 25 dyn/cm2 | (74) | ||
| No difference in vWF gene expression with either shear stress | ||||||
| Collagen I-coated glass | 15 dyn/cm2 for 24 h | N/A | Increased TM, eNOS, TFPI gene expression | (46) | ||
| Increased TM protein | ||||||
| Increased APC activity | ||||||
| No differences in TF gene or protein | ||||||
| Orbital rotator | Collagen-coated TCPS | 6.0 dyn/cm2 for 6 or 24 h | 110 U/mL for 2 h | Decreased TF and eNOS gene expression at 6 and 24 h | (76) | |
| Increased eNOS gene expression at 6 and 24 h following TNF-α treatment | ||||||
| Attenuated TNF-α induced TF activity at 6 and 24 h | ||||||
| Steady and oscillatory flow | Cone and plate | Collagen I-coated TCPS | 24 h treatment with steady shear of 10 dyn/cm2, or oscillatory shear of 0±10 dyn/cm2 | N/A | Oscillatory shear reduced eNOS and P-selectin genes vs. steady shear | (60) |
| Steady shear decreased monocyte adhesion vs. oscillatory | ||||||
| Steady shear increased TM, ePCR and CD39 genes vs. oscillatory shear | ||||||
| No significant difference in the gene or protein expression of E-selectin or VCAM-1 in oscillatory shear vs. steady shear | ||||||
| Steady, pulsatile, and oscillatory flow | Perfusion bioreactor | Fibronectin-coated Sylgard tubes | 24 h treatment with either low unidirectional shear of 0.3±0.1, pulsatile shear of 6±3 dyn/cm2; or oscillatory shear of 0.3±3 dyn/cm2 | N/A | Unidirectional increased TF gene expression | (78) |
| Pulsatile decreased tPA gene expression | ||||||
| Bidirectional increased TF, decreased tPA gene expression | ||||||
| No condition had an effect on VCAM-1 or E-selectin gene expression |
TNF-α, tumor necrosis factor α; N/A, not available; eNOS, endothelial nitric oxide synthase; TM, thrombomodulin; ICAM-1, intercellular adhesion molecule 1; VCAM-1, vascular cell adhesion molecule 1; vWF, von Willebrand factor; TFPI, tissue factor pathway inhibitor; APC, activated protein; TF, tissue factor; TCPS, tissue culture polystyrene; tPA, tissue plasminogen activator.