TABLE 2.
Shear stress-induced endothelial cell responses.
| EC Type | SS (dyn/cm2) | Exposure Time | EC response | Comments | References |
| Elongation | |||||
| HUVEC | 10 | 12 h | Elongation | Enhanced at 24 h | Steward et al. (2015) |
| HUVEC | 20 | 12 h | Elongation | Ohta et al. (2015) | |
| HAEC | 10 | Elongation | Mack et al. (2017) | ||
| 26 | |||||
| BAEC | 15.2 | 3 h | Elongation | Galbraith et al. (1998) | |
| BAEC | 30 | 24 h | Elongation | Levesque and Nerem (1985) | |
| Alignment | |||||
| HUVEC | 20 | 24 h | Alignment | Ohta et al. (2015) | |
| HMVEC | 9 | 21 h | Alignment | Non-oriented EC near the stagnation point and parallel to flow far from the center | Ostrowski et al. (2014) |
| 34 and 68 | Azimuthal EC orientation at radial distances and parallel to flow far from SS peak | ||||
| 210 | EC detachment near the flow orifice, and remaining EC with azimuthal orientation | ||||
| Impinging | Model of Impinging flow | ||||
| MAEC | 15 | 12 h | Alignment | Magid et al. (2003) | |
| PAEC | <12 | No alignment | Low effect on orientation | Dieterich et al. (2000) | |
| 68 | Alignment | Orientation within 10 min | |||
| Polarization (against flow unless indicated) | |||||
| HUVEC | 3 | 15 min | Polarization | ≈50% subconfluent EC polarized (lamellipodia in flow direction) | Wojciak-Stothard and Ridley (2003) |
| HUVEC | 20 | 4 h | Polarization | More than 60% of cells polarized | Franco et al. (2016) |
| HUVEC | Static and 4 | 24 h | Random orientation | Sonmez et al. (2020) | |
| 7.2 | 3 h | Polarization | Different time of exposure | ||
| 4.4, 18.6, and 40.2 | 24 h | Polarization | 95% polarized (against flow at higher SS values, 18.6 and 40.2) | ||
| HCAEC | 14 | 24 h | Polarization | 70–80% | Poduri et al. (2017) |
| Migration | |||||
| HUVEC | 7.5 | 24 h | Migration | Smooth migration and long distances with flow vs pulsatile flow or static | Blackman et al. (2002) |
| HMVEC | 9, 34, 68, and 210 Impinging flow | 21 h | Migration | Faster migration at higher flow up to 68 dyn/cm2. At 210 dyn/cm2, pushed outward and then adapt, change direction, and migrate upstream after ∼16.7 h | Ostrowski et al. (2014) |
| HCAEC | 35 | 72 h | Migration | Most migrating against the flow direction | Poduri et al. (2017) |
| Other cellular responses | |||||
| HUVEC | ≈0.5 + 4 Reciprocating | Round shape Random and short actin filaments at periphery Slow migration High permeability | Model of reciprocating flow | Chiu and Chien (2011) | |
| >10 Laminar | Alignment | Compared with the reciprocating flow model | |||
| Long and parallel stress fibers at center | |||||
| Fast migration | |||||
| Low permeability | |||||
| MAEC | ± 15 Reciprocating | 12 h | No alignment | Model of reciprocating flow | Magid et al. (2003) |
| BAEC | 0.5 ± 4 Reciprocating | Discontinuous VE-cadherin (similar to disturbed flow) | Model of reciprocating flow | Chien (2008) | |
| BAEC | 15.2 | 3 h | Thicker junctions | Galbraith et al. (1998) | |
| More stress fibers | |||||
| More apical F-actin | |||||
| 6 h | MTOC and nuclei reorganization | ||||
| RFPEC | 15 | 30 min | Filopodia protrusion | Zeng and Tarbell (2014) | |
| PAEC | 15 | 8 h | F-actin reorganization | Noria et al. (2004) | |
Representative selected reports showing endothelial cell responses to distinct shear stress values and patterns in vitro. Values of shear stress correspond to laminar flow unless otherwise indicated. ECs, endothelial cells; HUVEC, human umbilical vein ECs; HCAEC, human coronary artery ECs; MAEC, mouse aorta ECs; BAEC, bovine aorta ECs; RFPEC, rat fat pad ECs; PAEC, pig pulmonary artery ECs.