Article

HUVEC ICAM-1 and VCAM-1 synthesis in response to potentially athero-prone and athero-protective mechanical and nicotine chemical stimuli.

National Centre for Biomedical Engineering Science, National University of Ireland Galway, Galway, Ireland.
Annals of Biomedical Engineering 02/2010; 38(5):1880-92. DOI: 10.1007/s10439-010-9959-8
Source: PubMed

ABSTRACT Previous mechano-transduction studies have investigated the endothelial cell (EC) morphological response to mechanical stimuli; generally consisting of a wall shear stress (WSS) and a cyclic tensile hoop strain (THS). More recent studies have investigated the EC biochemical response (intercellular adhesion molecule, ICAM-1, and vascular cellular adhesion molecule, VCAM-1, expression) to idealized mechanical stimuli. However, current literature is lacking in the area of EC biochemical response to combinations of physiological WSS and THS mechanical stimuli. The objective of this study is to investigate the EC response to physiological WSS and THS stimuli and to compare this response to that of ECs exposed to idealized steady WSS and cyclic THS of the same magnitudes. This study also investigated the EC response to a nicotine chemical stimulus combined with a suspected athero-prone physiological mechanical stimulus. A bioreactor was designed to apply a range of combinations of physiological WSS and THS waveforms. The bioreactor was calibrated and validated using computational fluid dynamics and video extensometry techniques. The bioreactor was used to investigated the biochemical response exhibited by human umbilical vein endothelial cells (HUVECs) exposed to physiological athero-protective (first bioreactor test case, pulsatile WSS combined with pulsatile THS) and athero-prone (second bioreactor test case, oscillating WSS combined with pulsatile THS) mechanical environments. The final testing environment (third bioreactor test case) combined a nicotine chemical stimulus with the mechanical stimuli of the second bioreactor test case. In first and second bioreactor test cases, the addition of a pulsatile THS to the WSS resulted in opposite trends of ICAM-1 down-regulation and up-regulation, respectively. This outcome suggests that the effect of the additional pulsatile THS depends on the state of the applied WSS waveform. Similarly, in first and second bioreactor test cases, the addition of a pulsatile THS to the WSS resulted in a VCAM-1 up-regulation. However, it has been previously shown that the addition of a cyclic THS to a high- or low-steady WSS resulted in a VCAM-1 down-regulation, indicating that the EC response to idealized mechanical stimuli (steady WSS and cyclic THS) is not comparable to physiological mechanical stimuli (unsteady WSS and pulsatile THS), even though in both situations the average magnitude of WSS and THS applied were similar. In third bioreactor test case, a nicotine chemical stimulus induced a substantial VCAM-1 up-regulation and a moderate ICAM-1 up-regulation. The addition of the mechanical stimuli of the second bioreactors test case resulted in a greater VCAM-1 up-regulation than what was expected, considering the observations of the previous second bioreactor test case alone. This study found that the EC biochemical response to physiological mechanical stimuli is not comparable to the previously observed EC response to idealized mechanical stimuli, even though in both environments the mechanical stimuli were of a similar magnitude. Also, the level of VCAM-1 expressed by the nicotine stimulated ECs showed an elevated level of sensitivity to the athero-prone mechanical stimuli.

0 Bookmarks
 · 
197 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Atherosclerotic lesions occur non-randomly at vascular niches in bends and bifurcations where fluid flow can be characterized as "disturbed" (low shear stress with both forward and retrograde flow). Endothelial cells (ECs) at these locations experience significantly lower average shear stress without change in the levels of pressure or strain, which affects the local balance in mechanical stresses. Common in vitro models of atherosclerosis focus primarily on shear stress without accounting for pressure and strain loading. To overcome this limitation, we used our microfluidic endothelial cell culture model (ECCM) to achieve accurate replication of pressure, strain, and shear stress waveforms associated with both normal flow seen in straight sections of arteries and disturbed flow seen in the abdominal aorta in the infrarenal segment at the wall distal to the inferior mesenteric artery (IMA), which is associated with high incidence of atherosclerotic lesion formation. Human aortic endothelial cells (HAECs) were cultured within the ECCM under both normal and disturbed flow and evaluated for cell shape, cytoskeletal alignment, endothelial barrier function, and inflammation using immunofluorescence microscopy and flow cytometry. Results clearly demonstrate quantifiable differences between cells cultured under disturbed flow conditions, which are cuboidal with short and randomly oriented actin microfilaments and show intermittent expression of β-Catenin and cells cultured under normal flow. However, in the absence of pro-inflammatory stimulation, the levels of expression of activation markers: intra cellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), platelet endothelial cell adhesion molecule-1 (PECAM-1), and vascular endothelial cell growth factor - receptor 2 (VEGF-R2) known to be involved in the initiation of plaque formation were only slightly higher in HAECs cultured under disturbed flow in comparison to cells cultured under normal flow.
    Biomicrofluidics 09/2011; 5(3):32006-3200611. · 3.39 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The aim of the study was to estimate the effect of nornicotine on endothelial EA.hy926 cells in the context of its impact on cell-cell junctions. The objective of the study was to determine the relationship between junctional proteins and F-actin after treating the cells with nornicotine. After 24 h of cell exposure to 0.08, 0.12, and 0.16 ng/mL nornicotine, analysis was performed of cell death, cell migration, ultrastructure, and colocalization of beta-catenin/F-actin and zonula occludens (ZO)-1/F-actin. Our study did not reveal any alterations in EA.hy926 cell line survival following treatment with nornicotine. However, nornicotine exerted disparate effects on cell migration and led to changes in both the ultrastructure and organization of cell-cell junctional complexes and F-actin. Moreover, the cell migration observed in the experiments performed in the present work negatively correlated with the number of Weibel-Palade bodies seen through transmission electron microscopy (TEM). Moreover, the mechanism of cell migration promotion was VEGF-independent, and the decrease in the number of Weibel-Palade bodies resulted from nornicotine-induced F-actin depolymerization. In conclusion, the present study demonstrated that low concentrations of nornicotine do not affect cell survival, but promote cell movement and impair adherens junctions through changes in F-actin organization. Our results indicate for the first time the effect of nornicotine on endothelial EA.hy926 cells and suggest that nornicotine may induce transmigration pathways and, consequently, facilitate the transendothelial migration of monocytes associated with atherosclerosis.
    Folia Histochemica et Cytobiologica 11/2013; 51(3):179-92. · 1.10 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The present study aimed to determine whether curcumin isolated from the rhizome of Curcuma longa Linn could inhibit di-(2-ethylhexyl) phthalate (DEHP)-induced allergic inflammatory responses in human umbilical vein endothelial cells (HUVECs). We found that DEHP dose-dependently elevated adhesion molecule-1 (ICAM-1) protein level within 15-30 min, which was independent of de novo protein synthesis. And a late-phase induction of ICAM-1 was observed within 8 h treatment of DEHP via de novo protein synthesis through transcription and translation. DEHP also increased the expression of interleukin (IL)-8 in a time- and dose-dependent manner. Pretreatment with curcumin dose-dependently decreased DEHP-induced expression of ICAM-1 and IL-8 as well as phosphorylation of ERK1/2 and p38. Preincubation with ERK1/2 inhibitor (PD98059) or p38 inhibitor (SB203580) markedly blocked DEHP-stimulated activation of ICAM-1 and IL-8. We suggest that curcumin inhibits DEHP-induced expression of ICAM-1 and IL-8 through ERK and p38 MAPK signaling pathways in HUVECs and may contribute to ameliorate pathologies of DEHP-related allergic disorders.
    Inflammation 09/2011; 35(3):859-70. · 2.46 Impact Factor

Full-text

View
4 Downloads
Available from