Vascular Gene Expression in Atherosclerotic Plaque-Prone Regions Analyzed by Representational Difference Analysis

Abstract

Objectives: Atherosclerotic plaques are known to develop and progress where the endothelium is subjected to turbulent blood flow. We have applied cDNA representational difference analysis (RDA) to study vascular gene expression in mouse aorta in a model for atherosclerosis. Methods:Gene expression profiles were investigated in plaque-prone and plaque-resistant localizations in the ascending aorta and arch in 8-week-old ApoE–/– and LDLR–/– mice. Total RNA was extracted and two rounds of subtraction were performed; the difference products were characterized in detail by shotgun cloning and analysis of more than 2,700 gene sequences. Results: The identified differentially expressed gene sequences include both genes with known involvement in vascular gene expression and genes previously not implicated in vascular processes. For example, CD36 and caveolin, previously reported for their participation in the progression of atherosclerosis, were found to have an increased expression in vessel localizations thought to be especially susceptible to plaque formation. Conclusions: This report provides new in vivo information of expressed genes that can be useful for further investigations of the molecular mechanisms in focal localization of atherosclerosis.

Transcription Profiles of Aortic Smooth Muscle Cells from Atherosclerosis-Prone and -Resistant Regions in Young Apolipoprotein E-Deficient Mice before Plaque Development

“…Borang et al [21] compared gene expression of vascular cells between an atherosclerosis-prone and an atherosclerosis-resistant region in 6- to 8-week-old apoE–/– and LDL receptor knockout mice using intact aortas. Because endothelial cells can mask genes that are over- or underexpressed by SMCs and vice versa [22], we removed the endothelial cells before RNA isolation.…”

Genome-Wide Expression Studies of Atherosclerosis

“…Comparison of our own data set (7 CCLs) 12 with 6 other murine atherosclerosis studies 11,15,24 yielded little information about the differential expression of CCLs (Table I). CCL2 levels were higher after murine cytomegalovirus infection of the aorta of apoE Ϫ/Ϫ mice, coinciding with an increase in atherosclerotic plaque area, 14 and were higher in ApoEϪ/Ϫ fed a high-fat diet compared with those on a chow diet, as well as compared with C57Bl/6 and C3H/HeJ mice.…”

“…11,15 Based on information obtained from GO and other databases, differentially expressed genes represented biological themes such as inflammation, 12,13 matrix degradation, 12,13 and ossification 13 (which is in agreement with our current knowledge that these processes have an important role in the development of this disease), but also less expected pathways such as carbohydrate metabolism. 13 Only one study used cDNA representational difference analysis (RDA) 24 to analyze the expression in the ascending aorta and arch in apoE Ϫ/Ϫ and LDLR Ϫ/Ϫ mice. This yielded mostly ESTs and uncharacterized genes.…”

Molecular diversity of cardiac endothelial cells in vitro and in vivo

“…In contrast, in straight parts of the vascular tree, blood flow is laminar, and amplitudes are dependent on the position in the vascular tree (e.g., arterial vs. venous). Shear stress has important effects on endothelial cell phenotype, function, and gene expression, and some types of shear stress are associated with endothelial pro-atherosclerotic responses and atherosclerotic lesions (4,10,14). Aside from biomechanical factors, endothelial diversity may also be explained by biochemical stimuli via local intercellular cross talk with neighboring cells through the release of diffusible mediators, which is tissue specific.…”