Project description:Although unstable atherosclerosis in the carotid bifurcation is a significant etiology behind ischemic stroke, clinical imaging methods to distinguish stable from vulnerable lesions are lacking and selection of patients for stroke-preventive intervention still relies on surrogate variables with moderate predictive power, such as the degree of luminal narrowing. Here we combined clinical and diagnostic imaging information by comuted tomography to select patients with calcified plaques for large scale molecular analysis, in an effort to increase our understanding of the pathophysiology behind carotid plaque instability as related to patient- and plaque- phenotype.
Project description:Atherosclerotic plaque rupture is the etiology of ischemic stroke and myocardial infarction. Ribosome-depleted total RNA was sequenced from carotid plaques obtained from patients undergoing carotid endarterectomy with high-grade stenosis and either 1) a carotid-related ischemic cerebrovascular event within the previous 5 days ('recently ruptured,' n=6) or 2) an absence of a cerebrovascular event ('asymptomatic,' n=5). Examination of the differentially expressed genes supported the importance of inflammation and inhibition of proliferation and migration coupled with an increase in apoptosis. Thus, the transcriptome of recently ruptured plaques is enriched with transcripts associated with inflammation and fibrous cap thinning and support further examination of the role of B lymphocytes and interferons in atherosclerotic plaque rupture.
Project description:Protein profiles were determined from different distinct regions of human atherosclerotic plaques, including: internal control, fatty streak, plaque shoulder, plaque centre, and fibrous cap. Protein extracts from all 5 regions, from 3 men and 3 women, were separated by two-dimensional gel electrophoresis (in total 30 2-DE gels). Stained gels were matched by protein spot distribution, and a protein mapping was performed to identify as many protein spots as possible, by MALDI-TOF MS / peptide mass fingerprinting (Voyager DE Pro; Applied Biosystems). This resulted in the identification of 97 protein spots, corresponding to 52 unique protein by accession number. To expand on this nLC-MS/MS (Easy-nLC / LTQ Orbitrap Velos Pro; Thermo Fisher Scientific) experiments were run on additional carotid plaque samples from 10 men and 10 women, using three of the predefined regions; internal control, fatty streak, plaque core. MS/MS analysis resulted in the identification of over 1000 proteins. Human carotid atherosclerotic plaques (n = 26) were obtained from the Linköping Carotid Study, and all methods/protocols described herein have been approved by the local ethics committee (Linköping University Hospital, Linköping, Sweden). Written informed consent was also obtained from all patients.
Project description:A microarray analysis of advanced human atherosclerotic carotid artery plaques (equal or over 70% stenosis, NASCET criteria) from radiologically confirmed ipsilateral stroke patients (stroke-susceptible plaques, n=12) compared with carotid plaques collected from clinically asymptomatic patients with clear brain imaging (asymptomatic plaques, n=9) with equivalent conventional risk factors and severity of carotid stenosis.
Project description:Atherogenesis involves an interplay of inflammation, tissue remodeling and cellular transdifferentiation (CTD), making it especially difficult to precisely delineate its pathophysiology. Here we examine the single-cell transcriptome of entire calcified atherosclerotic core (AC) plaques and patient-matched proximal adjacent (PA) portions of carotid artery tissue from patients undergoing carotid endarterectomy. We use a novel tissue dissociation strategy, single-cell RNA sequencing, and systems-biology approaches to analyze the transcriptional profiles of six main cell populations and identify key gene drivers of pathogenic biological processes in vascular smooth muscle cells (VSMCs) and endothelial cells (ECs).
Project description:We compared gene expression profiles between asymptomatic and symptomatic atherosclerotic plaques from the same patient. This was accomplished by analyzing carotid plaques from four patients with bilateral high-grade carotid artery stenoses one being symptomatic (TIA or stroke) and the other asymptomatic.
Project description:In order to identify potential new biomarkers of atherosclerotic plaque composition we performed a large scale analysis of gene expression patterns in human atherosclerotic lesions. Whole genome expression analysis of 101 peripheral plaques identified a robust gene signature (1514 genes) dominated by inflammatory processes, and cholesterol metabolism and storage genes. Specific pathways enriched in this signature included activation of the Toll-like receptor signaling pathway, T-cell activation, cholesterol efflux, oxidative stress response, inflammatory cytokine production, vasoconstriction and lysosomal activity. Analysis of gene expression in plaque micro-dissected material revealed that the signature is strongly up-regulated in macrophage-rich regions and down-regulated in regions with high smooth muscle cell content. A smaller qPCR biomarker panel and inflammatory composite score (ICS) were developed to facilitate clinical translation of discoveries from gene expression profiling. We found that ICS correlates with histological features related to plaque vulnerability. In addition, ICS is able to separate groups of plaques obtained from symptomatic and asymptomatic patients undergoing carotid endarerectomy. In summary, we identified a robust mRNA biomarker panel associated with histo-pathological as well as clinical hallmarks of vulnerable atherosclerotic plaque. This panel may be used as a diagnostic and prognostic tool in clinical setting to evaluate novel anti-atherosclerotic therapies. 6 human carotid plaques were sectioned in 1 mm thick slices. Alternative slices were used for gene expression profiling in Affymetrix/Merck custom 1.0 arrays (GPL10687), or for immunohistochemistry studies (CD68, Actin)
Project description:In order to identify potential new biomarkers of atherosclerotic plaque composition we performed a large scale analysis of gene expression patterns in human atherosclerotic lesions. Whole genome expression analysis of 101 peripheral plaques identified a robust gene signature (1514 genes) dominated by inflammatory processes, and cholesterol metabolism and storage genes. Specific pathways enriched in this signature included activation of the Toll-like receptor signaling pathway, T-cell activation, cholesterol efflux, oxidative stress response, inflammatory cytokine production, vasoconstriction and lysosomal activity. Analysis of gene expression in plaque micro-dissected material revealed that the signature is strongly up-regulated in macrophage-rich regions and down-regulated in regions with high smooth muscle cell content. A smaller qPCR biomarker panel and inflammatory composite score (ICS) were developed to facilitate clinical translation of discoveries from gene expression profiling. We found that ICS correlates with histological features related to plaque vulnerability. In addition, ICS is able to separate groups of plaques obtained from symptomatic and asymptomatic patients undergoing carotid endarerectomy. In summary, we identified a robust mRNA biomarker panel associated with histo-pathological as well as clinical hallmarks of vulnerable atherosclerotic plaque. This panel may be used as a diagnostic and prognostic tool in clinical setting to evaluate novel anti-atherosclerotic therapies. Total RNA from peripheral plaque (n=101) profiled in the Merck/Agilent 44k v1.1 against a reference pool of total RNA from 7 carotid plaques.
Project description:Recent studies suggest the presence of both âclassically activatedâ M1 and âalternatively activatedâ M2 macrophages in human atherosclerotic tissue, yet due to the lack of validated markers the reported localization patterns of these macrophage phenotypes within plaques are ambiguous. In the present study, we searched for markers that indisputably can identify differentiated M1 and M2 macrophages independently of stimuli that affect the activation status of the two subpopulations. We used these validated markers to assess the presence of M1 and M2 macrophages in different zones of human carotid artery atherosclerotic plaques obtained from 12 patients. Using microarray and qPCR technology we show that the frequently used macrophage subpopulation markers MCP-1 and CD206 do not discriminate between M1 and M2 macrophages. However, we confirm the subtype specificity of the classical M2 marker CD163 and we report that the genes INHBA and DSP (both M1) and SEPP1 and MARCKS (both M2) are highly suitable for macrophage phenotyping. mRNA expression of the pan-macrophage marker CD68 in the shoulder zones of the plaques and in adjacent tissue segments correlated positively with mRNA expression levels of SEPP1, MARCKS and CD163 (r=0.86, 0.94 and 0.96, and r= 0.86, 0.98 and 0.69, respectively) but not with the expression of the M1 markers DSP and INHBA. In contrast, mRNA expression of CD68 in the core of the plaques correlated positively with expression of DSP and INHBA (r=0.73 and 0.49) but not with SEPP1, MARCKS and CD163. These findings suggest that M1 macrophages predominate in the core of human carotid atherosclerotic plaques while M2 macrophages prevail at the periphery of the plaque. Keywords: Expression profiling by array Monocytes from healthy volunteers were differentiated into M1 and M2 macrophages by incubation with granulocyte-macrophage colony-stimulating factor (GM-CSF) or macrophage colony-stimulating factor (M-CSF), respectively. After 5 days cells were exposed to oxidized LDL. Total RNA was isolated and subjected to gene expression profiling.