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The Interaction between Fluid Wall Shear Stress and Solid Circumferential Strain Affects Endothelial Gene Expression.

Amaya R, Pierides A, Tarbell JM - PLoS ONE (2015)

Bottom Line: Using a PCR array of 42 genes, we determined that BAECS exposed to non-reversing sinusoidal WSS (10±10 dyne/cm2) and CS (4 ± 4%) over a 7 hour testing period displayed 17 genes that were up regulated by SPA = -180 °, most of them pro-atherogenic, including NFκB and other NFκB target genes.The up regulation of NFκB p50/p105 and p65 by SPA =-180° was confirmed by Western blots and immunofluorescence staining demonstrating the nuclear translocation of NFκB p50/p105 and p65.These data suggest that asynchronous hemodynamics (SPA=-180 °) can elicit proatherogenic responses in endothelial cells compared to synchronous hemodynamics without shear stress reversal, indicating that SPA may be an important parameter characterizing arterial susceptibility to disease.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Engineering, City College of New York, City University of New York, New York, New York, 10031, United States of America.

ABSTRACT
Endothelial cells lining the walls of blood vessels are exposed simultaneously to wall shear stress (WSS) and circumferential stress (CS) that can be characterized by the temporal phase angle between WSS and CS (stress phase angle - SPA). Regions of the circulation with highly asynchronous hemodynamics (SPA close to -180°) such as coronary arteries are associated with the development of pathological conditions such as atherosclerosis and intimal hyperplasia whereas more synchronous regions (SPA closer to 0°) are spared of disease. The present study evaluates endothelial cell gene expression of 42 atherosclerosis-related genes under asynchronous hemodynamics (SPA=-180 °) and synchronous hemodynamics (SPA=0 °). This study used a novel bioreactor to investigate the cellular response of bovine aortic endothelial cells (BAECS) exposed to a combination of pulsatile WSS and CS at SPA=0 or SPA=-180. Using a PCR array of 42 genes, we determined that BAECS exposed to non-reversing sinusoidal WSS (10±10 dyne/cm2) and CS (4 ± 4%) over a 7 hour testing period displayed 17 genes that were up regulated by SPA = -180 °, most of them pro-atherogenic, including NFκB and other NFκB target genes. The up regulation of NFκB p50/p105 and p65 by SPA =-180° was confirmed by Western blots and immunofluorescence staining demonstrating the nuclear translocation of NFκB p50/p105 and p65. These data suggest that asynchronous hemodynamics (SPA=-180 °) can elicit proatherogenic responses in endothelial cells compared to synchronous hemodynamics without shear stress reversal, indicating that SPA may be an important parameter characterizing arterial susceptibility to disease.

No MeSH data available.


Related in: MedlinePlus

SPA modulates the protein expression levels of NFkB p105/p50 and NFkB p65 but does not affect CDH5.BAEC monolayer were exposed to WSS and CS with either SPA = 0 or SPA = -180 during 7 hours. Cell lysates from different samples (n = 6 each condition) were separated in gradient SDS-PAGE, and the proteins were transferred to nitrocellulose membranes. Nitrocellulose membranes were split into two parts for immunoblotting with NFKB p105/p50 or NFkB p65 using βactin as the endogenous control. Representative blots are shown in Fig 6. Samples were analysed by densitometry and normalized by the βactin control; then the relative protein expressions at SPA = -180 and SPA = 0 were compared. The bar graphs in (A) represent the quantification of 6 individual experiments (mean ± SEM). SPA = -180 increases the expression of NFκB p50 by 1.9 fold compared to SPA = 0 (p = 0.001) and the expression of NFκB p105 by 1.98 fold (p = 0.058). The bar in (B) suggest that SPA = -180 increase the expression of the transcriptional factor NFKB p65 (n = 8) by 1.98 fold (p = 0.002) (ANOVA, all p<0.05). SPA did not affect the CDH5 protein expression levels (n = 3 for each condition) (ANOVA p>0.05) as shown in panel B.
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pone.0129952.g006: SPA modulates the protein expression levels of NFkB p105/p50 and NFkB p65 but does not affect CDH5.BAEC monolayer were exposed to WSS and CS with either SPA = 0 or SPA = -180 during 7 hours. Cell lysates from different samples (n = 6 each condition) were separated in gradient SDS-PAGE, and the proteins were transferred to nitrocellulose membranes. Nitrocellulose membranes were split into two parts for immunoblotting with NFKB p105/p50 or NFkB p65 using βactin as the endogenous control. Representative blots are shown in Fig 6. Samples were analysed by densitometry and normalized by the βactin control; then the relative protein expressions at SPA = -180 and SPA = 0 were compared. The bar graphs in (A) represent the quantification of 6 individual experiments (mean ± SEM). SPA = -180 increases the expression of NFκB p50 by 1.9 fold compared to SPA = 0 (p = 0.001) and the expression of NFκB p105 by 1.98 fold (p = 0.058). The bar in (B) suggest that SPA = -180 increase the expression of the transcriptional factor NFKB p65 (n = 8) by 1.98 fold (p = 0.002) (ANOVA, all p<0.05). SPA did not affect the CDH5 protein expression levels (n = 3 for each condition) (ANOVA p>0.05) as shown in panel B.

Mentions: Asynchronous conditions increased the level of protein expression for NFκB p105, p50 and p65 compared to synchronous hemodynamics (Fig 6). These observations are consistent with the hypothesis that asynchronous hemodynamics is atheroprone and indirectly indicate EC under asynchronous hemodynamics initiate an inflammatory state. We found that asynchronous conditions significantly increased protein expression of NFκB p50 by 1.9 fold (p = 0.001) and NFκB p105 by 1.98 fold (p = 0.058) compared to SPA = 0° similarly, asynchronous hemodynamics increased the protein expression of NFκB p65 by 1.98 fold (p = 0.02) compared to SPA = 0°. SPA = 0° or SPA = -180° did not have any effect on the level of protein expression of CDH5 (p = 0.3).


The Interaction between Fluid Wall Shear Stress and Solid Circumferential Strain Affects Endothelial Gene Expression.

Amaya R, Pierides A, Tarbell JM - PLoS ONE (2015)

SPA modulates the protein expression levels of NFkB p105/p50 and NFkB p65 but does not affect CDH5.BAEC monolayer were exposed to WSS and CS with either SPA = 0 or SPA = -180 during 7 hours. Cell lysates from different samples (n = 6 each condition) were separated in gradient SDS-PAGE, and the proteins were transferred to nitrocellulose membranes. Nitrocellulose membranes were split into two parts for immunoblotting with NFKB p105/p50 or NFkB p65 using βactin as the endogenous control. Representative blots are shown in Fig 6. Samples were analysed by densitometry and normalized by the βactin control; then the relative protein expressions at SPA = -180 and SPA = 0 were compared. The bar graphs in (A) represent the quantification of 6 individual experiments (mean ± SEM). SPA = -180 increases the expression of NFκB p50 by 1.9 fold compared to SPA = 0 (p = 0.001) and the expression of NFκB p105 by 1.98 fold (p = 0.058). The bar in (B) suggest that SPA = -180 increase the expression of the transcriptional factor NFKB p65 (n = 8) by 1.98 fold (p = 0.002) (ANOVA, all p<0.05). SPA did not affect the CDH5 protein expression levels (n = 3 for each condition) (ANOVA p>0.05) as shown in panel B.
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pone.0129952.g006: SPA modulates the protein expression levels of NFkB p105/p50 and NFkB p65 but does not affect CDH5.BAEC monolayer were exposed to WSS and CS with either SPA = 0 or SPA = -180 during 7 hours. Cell lysates from different samples (n = 6 each condition) were separated in gradient SDS-PAGE, and the proteins were transferred to nitrocellulose membranes. Nitrocellulose membranes were split into two parts for immunoblotting with NFKB p105/p50 or NFkB p65 using βactin as the endogenous control. Representative blots are shown in Fig 6. Samples were analysed by densitometry and normalized by the βactin control; then the relative protein expressions at SPA = -180 and SPA = 0 were compared. The bar graphs in (A) represent the quantification of 6 individual experiments (mean ± SEM). SPA = -180 increases the expression of NFκB p50 by 1.9 fold compared to SPA = 0 (p = 0.001) and the expression of NFκB p105 by 1.98 fold (p = 0.058). The bar in (B) suggest that SPA = -180 increase the expression of the transcriptional factor NFKB p65 (n = 8) by 1.98 fold (p = 0.002) (ANOVA, all p<0.05). SPA did not affect the CDH5 protein expression levels (n = 3 for each condition) (ANOVA p>0.05) as shown in panel B.
Mentions: Asynchronous conditions increased the level of protein expression for NFκB p105, p50 and p65 compared to synchronous hemodynamics (Fig 6). These observations are consistent with the hypothesis that asynchronous hemodynamics is atheroprone and indirectly indicate EC under asynchronous hemodynamics initiate an inflammatory state. We found that asynchronous conditions significantly increased protein expression of NFκB p50 by 1.9 fold (p = 0.001) and NFκB p105 by 1.98 fold (p = 0.058) compared to SPA = 0° similarly, asynchronous hemodynamics increased the protein expression of NFκB p65 by 1.98 fold (p = 0.02) compared to SPA = 0°. SPA = 0° or SPA = -180° did not have any effect on the level of protein expression of CDH5 (p = 0.3).

Bottom Line: Using a PCR array of 42 genes, we determined that BAECS exposed to non-reversing sinusoidal WSS (10±10 dyne/cm2) and CS (4 ± 4%) over a 7 hour testing period displayed 17 genes that were up regulated by SPA = -180 °, most of them pro-atherogenic, including NFκB and other NFκB target genes.The up regulation of NFκB p50/p105 and p65 by SPA =-180° was confirmed by Western blots and immunofluorescence staining demonstrating the nuclear translocation of NFκB p50/p105 and p65.These data suggest that asynchronous hemodynamics (SPA=-180 °) can elicit proatherogenic responses in endothelial cells compared to synchronous hemodynamics without shear stress reversal, indicating that SPA may be an important parameter characterizing arterial susceptibility to disease.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Engineering, City College of New York, City University of New York, New York, New York, 10031, United States of America.

ABSTRACT
Endothelial cells lining the walls of blood vessels are exposed simultaneously to wall shear stress (WSS) and circumferential stress (CS) that can be characterized by the temporal phase angle between WSS and CS (stress phase angle - SPA). Regions of the circulation with highly asynchronous hemodynamics (SPA close to -180°) such as coronary arteries are associated with the development of pathological conditions such as atherosclerosis and intimal hyperplasia whereas more synchronous regions (SPA closer to 0°) are spared of disease. The present study evaluates endothelial cell gene expression of 42 atherosclerosis-related genes under asynchronous hemodynamics (SPA=-180 °) and synchronous hemodynamics (SPA=0 °). This study used a novel bioreactor to investigate the cellular response of bovine aortic endothelial cells (BAECS) exposed to a combination of pulsatile WSS and CS at SPA=0 or SPA=-180. Using a PCR array of 42 genes, we determined that BAECS exposed to non-reversing sinusoidal WSS (10±10 dyne/cm2) and CS (4 ± 4%) over a 7 hour testing period displayed 17 genes that were up regulated by SPA = -180 °, most of them pro-atherogenic, including NFκB and other NFκB target genes. The up regulation of NFκB p50/p105 and p65 by SPA =-180° was confirmed by Western blots and immunofluorescence staining demonstrating the nuclear translocation of NFκB p50/p105 and p65. These data suggest that asynchronous hemodynamics (SPA=-180 °) can elicit proatherogenic responses in endothelial cells compared to synchronous hemodynamics without shear stress reversal, indicating that SPA may be an important parameter characterizing arterial susceptibility to disease.

No MeSH data available.


Related in: MedlinePlus