Project description:The effect of hemodynamic shear stress on endothelial gene expression was investigated in the porcine iliac arteries. Computational fluid dynamics simulations identified three anatomical regions likely to experience high, medium, and low shear stress. The expression of genes in endothelial cells recovered from these regions were assessed using microarray. Keywords: shear stress, endothelial cell gene expression, in vivo 11 iliac arteries were obtained from 6 animals, total RNA were extracted from high, medium and low shear region. The expression profiles were compared with a reference RNA using dual channel arrays. Samples with low original RNA quality and low hybridization quality were not included.
Project description:The effect of hemodynamic shear stress on endothelial gene expression was investigated in the porcine iliac arteries. Computational fluid dynamics simulations identified three anatomical regions likely to experience high, medium, and low shear stress. The expression of genes in endothelial cells recovered from these regions were assessed using microarray. Keywords: shear stress, endothelial cell gene expression, in vivo
Project description:Phenotypic heterogeneity among arterial ECs is particularly relevant to atherosclerosis since the disease occurs predominantly in major arteries, which vary in their atherosusceptibility. To explore EC heterogeneity, we used DNA microarrays to compare gene expression profiles of freshly harvested porcine coronary and iliac artery ECs. We demonstrate that in vivo the endothelial transcriptional profile of a coronary artery (the right coronary artery) is intrinsically different from that of a major conduit vessel (the external iliac artery), and that this difference is consistent with former vessel being more prone to atherosclerosis. Keywords: coronary atherosclerosis, endothelial heterogeneity, microarray, gene expression Endothelial cells were freshly harvest from right coronary, left and right iliac arteries from four pigs. RNA were isolated and expression profiles were obtained using olig microarrays.
Project description:Endothelial cell (EC) sensing of fluid shear stress regulates atherosclerosis, a disease of arteries that causes heart attack and stroke. Atherosclerosis preferentially develops at regions of arteries exposed to low oscillatory shear stress (LOSS), whereas high shear regions are protected. We show using inducible EC-specific genetic deletion in hyperlipidaemic mice that the Notch ligands JAG1 and DLL4 have opposing roles in atherosclerosis. While endothelial Jag1 promoted atherosclerosis at sites of LOSS, endothelial Dll4 was atheroprotective. Analysis of porcine and murine arteries and cultured human coronary artery EC exposed to experimental flow revealed that JAG1 and its receptor NOTCH4 are strongly upregulated by LOSS. Functional studies in cultured cells and in mice with EC-specific deletion of Jag1 show that JAG1-NOTCH4 signalling drives vascular dysfunction by repressing endothelial repair. These data demonstrate a fundamental role for JAG1-NOTCH4 in sensing LOSS during disease, and suggest therapeutic targeting of this pathway to treat atherosclerosis.
Project description:Endothelial cell (EC) sensing of fluid shear stress regulates atherosclerosis, a disease of arteries that causes heart attack and stroke. Atherosclerosis preferentially develops at regions of arteries exposed to low oscillatory shear stress (LOSS), whereas high shear regions are protected. We show using inducible EC-specific genetic deletion in hyperlipidaemic mice that the Notch ligands JAG1 and DLL4 have opposing roles in atherosclerosis. While endothelial Jag1 promoted atherosclerosis at sites of LOSS, endothelial Dll4 was atheroprotective. Analysis of porcine and murine arteries and cultured human coronary artery EC exposed to experimental flow revealed that JAG1 and its receptor NOTCH4 are strongly upregulated by LOSS. Functional studies in cultured cells and in mice with EC-specific deletion of Jag1 show that JAG1-NOTCH4 signalling drives vascular dysfunction by repressing endothelial repair. These data demonstrate a fundamental role for JAG1-NOTCH4 in sensing LOSS during disease, and suggest therapeutic targeting of this pathway to treat atherosclerosis.
Project description:Phenotypic heterogeneity among arterial ECs is particularly relevant to atherosclerosis since the disease occurs predominantly in major arteries, which vary in their atherosusceptibility. To explore EC heterogeneity, we used DNA microarrays to compare gene expression profiles of freshly harvested porcine coronary and iliac artery ECs. We demonstrate that in vivo the endothelial transcriptional profile of a coronary artery (the right coronary artery) is intrinsically different from that of a major conduit vessel (the external iliac artery), and that this difference is consistent with former vessel being more prone to atherosclerosis. Keywords: coronary atherosclerosis, endothelial heterogeneity, microarray, gene expression
Project description:In this study, we characterized the adaptive response of arterial endothelial cells to acute increases in shear stress magnitude in well-defined in vitro settings. Porcine endothelial cells were preconditioned by a basal level shear stress of 15 ± 15 dynes/cm2 at 1 Hz for 24 hours, and an acute increase in shear stress magnitude (30 ± 15 dynes/cm2) was then applied. The transcriptomics studies using microarray identified genes that were sensitive to the elevated shear magnitude. A significant number of the identified genes in our study are previously unknown as sensitive to shear stress. Porcine endothelial cells were preconditioned by a basal level shear stress of 15 ± 15 dynes/cm2 at 1 Hz for 24 hours, and an acute increase in shear stress magnitude (30 ± 15 dynes/cm2) was then applied. Gene expression at multiple time points was measured using microarray.