Transcription profiling of human blood outgrowth endothelial cells from patients with sickle cell anemia with predicted stroke risk
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ABSTRACT: Genetic differences in endothelial biology could underlie development of phenotypic heterogeneity amongst individuals afflicted with vascular diseases. We obtained BOEC (blood outgrowth endothelial cells) from 20 subjects with sickle cell anemia (age 4-19) shown to be either at-risk (n=11) or not-at-risk (n=9) for ischemic stroke due to, respectively, having or not having occlusive disease at the Circle of Willis (CoW). Gene expression profiling identified no significant single gene differences between the two groups, as expected. However, analysis of Biological Systems Scores, using gene sets that were pre-determined to survey each of nine biological systems, showed that only changes in inflammation signaling are characteristic of the at-risk subjects, as supported by multiple statistical approaches Experiment Overall Design: We obtained BOEC (blood outgrowth endothelial cells) from 20 subjects with sickle cell anemia (age 4-19) shown to be either at-risk (n=11) or not-at-risk (n=9) for ischemic stroke due to, respectively, having or not having occlusive disease at the Circle of Willis (CoW). To allow power calculations to be done, we performed microarray analysis on BOEC from 27 normal subjects of diverse ages. Gene expression profilings were obtained by using Affymetrix U133A chips
Project description:Genetic differences in endothelial biology could underlie development of phenotypic heterogeneity amongst individuals afflicted with vascular diseases. We obtained BOEC (blood outgrowth endothelial cells) from 20 subjects with sickle cell anemia (age 4-19) shown to be either at-risk (n=11) or not-at-risk (n=9) for ischemic stroke due to, respectively, having or not having occlusive disease at the Circle of Willis (CoW). Gene expression profiling identified no significant single gene differences between the two groups, as expected. However, analysis of Biological Systems Scores, using gene sets that were pre-determined to survey each of nine biological systems, showed that only changes in inflammation signaling are characteristic of the at-risk subjects, as supported by multiple statistical approaches Keywords: disease status analysis
Project description:Atrial fibrillation (AF) is a major risk factor for cardioembolic stroke. Anticoagulant drugs are effective in preventing AF-related stroke. However, the high frequency of anticoagulant-associated major bleeding is a major concern particularly when antiplatelet treatment is simultaneously administered. Here, microarray analysis in peripheral blood cells in eight patients with AF and stroke and eight AF subjects without stroke identified a stroke related gene expression pattern. HSPA1B, which encodes for heat-shock protein 70 kDa (Hsp70), was the most differentially expressed gene. This gene was downregulated in stroke subjects, a finding confirmed further in an independent AF cohort of 200 individuals. Hsp70 knock-out (KO) mice subjected to different thrombotic challenges developed thrombosis significantly earlier than their wild-type (WT) counterparts. In WT mice, Hsp70 inducers (TRC051384, or tubastatin A) delayed thrombus formation. Remarkably, Hsp70 inducers did not increase the bleeding risk even when aspirin was concomitantly administered. Hsp70 induction was associated with an increased vascular thrombomodulin expression, higher circulating levels of activated protein C (APC) upon thrombotic stimulus and increased protection against endothelial apoptosis. Thus, Hsp70 induction is a novel approach to delay thrombus formation with minimal bleeding risk, being especially promising in situations where there is a major bleeding hazard. Microarray analysis in peripheral blood cells includes eight patients with AF and stroke and eight AF subjects without stroke
Project description:Protein C (PC) deficiency increases the risk of venous thrombosis (VT) among members of Kindred Vermont II, but fails to fully account for the inheritance pattern. A genome scan of the pedigree supported the presence of a prothrombotic gene on chromosome 11q23 with weaker support on chromosomes 10p12 and 18p11.2-q11. Preliminary data from Affimetrix microarray expression analysis of Blood Outgrowth Endothelial Cells of 3 members of Kindred Vermont II compared to a well established normal control group indicated that IgsF4 was decreased in patients versus controls. In addition, both statistical and pathway analysis results suggested that these genes are associated protein C. Further studies indicated that Cell Adhesion Molecule 1 (CADM1), a member of the IgsF4 superfamily, may be associated with VT. Experiment Overall Design: We obtained BOEC (blood outgrowth endothelial cells) from 3 female kindred subjects (ages 56, 61, and 74) with Protein C Deficiency. We also performed microarray analysis on BOEC from 27 normal subjects of diverse ages.
Project description:Atrial fibrillation (AF) is a major risk factor for cardioembolic stroke. Anticoagulant drugs are effective in preventing AF-related stroke. However, the high frequency of anticoagulant-associated major bleeding is a major concern particularly when antiplatelet treatment is simultaneously administered. Here, microarray analysis in peripheral blood cells in eight patients with AF and stroke and eight AF subjects without stroke identified a stroke related gene expression pattern. HSPA1B, which encodes for heat-shock protein 70 kDa (Hsp70), was the most differentially expressed gene. This gene was downregulated in stroke subjects, a finding confirmed further in an independent AF cohort of 200 individuals. Hsp70 knock-out (KO) mice subjected to different thrombotic challenges developed thrombosis significantly earlier than their wild-type (WT) counterparts. In WT mice, Hsp70 inducers (TRC051384, or tubastatin A) delayed thrombus formation. Remarkably, Hsp70 inducers did not increase the bleeding risk even when aspirin was concomitantly administered. Hsp70 induction was associated with an increased vascular thrombomodulin expression, higher circulating levels of activated protein C (APC) upon thrombotic stimulus and increased protection against endothelial apoptosis. Thus, Hsp70 induction is a novel approach to delay thrombus formation with minimal bleeding risk, being especially promising in situations where there is a major bleeding hazard.
Project description:The Circle of Willis (CoW), the ring of arteries at the base of the brain, links the intracerebral arteries to one another to maintain adequate cerebral perfusion. The CoW proteome is affected in cerebrovascular and neurodegenerative diseases, but changes related to aging have not been described. Here, we report on a quantitative proteomics analysis comparing the CoW from five young (two-three-month-old) and five aged (18–20-month-old) mice.
Project description:Ischemic Stroke (IS) is one of the most impairing complications of sickle cell anemia (SCA), responsible for 20% of mortality in patients. Rheological alterations, adhesive properties of sickle reticulocytes, leukocyte adhesion, inflammation and endothelial dysfunction are related to the vasculopathy observed prior to ischemic events. The role of the vascular endothelium in this complex cascade of mechanisms is emphasized, as well as in the process of ischemia-induced repair and neovascularization. The aim of the present study was to perform a comparative transcriptomic analysis of endothelial colony-forming cells (ECFCs) from SCA patients with and without IS. Next, to gain further insights of the biological relevance of differentially expressed genes (DEGs), functional enrichment analysis, protein-protein interaction network (PPI) construction and in silico prediction of regulatory factors were performed. Among the 2,469 DEGs, genes related to cell proliferation (AKT1, E2F1, CDCA5, EGFL7), migration (AKT1, HRAS), angiogenesis (AKT1, EGFL7) and defense response pathways (HRAS, IRF3, TGFB1), important endothelial cell molecular mechanisms in post ischemia repair were identified. Despite the severity of IS in SCA, widely accepted molecular targets are still lacking, especially related to stroke outcome. Thus, these exploratory results may contribute to a better understanding of the role of endothelial cells in SCA ischemic stroke recovery, and promote new insights to further studies on therapeutic strategies for this severe complication.
Project description:Obesity is well recognized as a risk factor for coronary heart disease and mortality. The relationship between abdominal obesity and ischemic stroke remains less clear. Previous publication showed the obesity is an independent, potent risk factor for ischemic stroke in all race-ethnic groups. It is a stronger risk factor than BMI and has a greater effect among younger persons. The goal of this experiment was to compare genome wide enrichment of H3K9ac histone mark profile of white blood cells of healthy controls, patients with obesity and/or stroke in order to understand the histone modifications differences behind the different phenotypes. There were 3 subjects in each group.
Project description:Background: African Americans (AA) have increased burdens of cardiovascular disease and cancer compared to Caucasian Americans (CA). This study addresses the possibility that genetic differences affecting the biology of the vascular endothelium could be a factor contributing to this health disparity. Methods: From self-identified, healthy, 20-29 year old AA (n=21) and CA (n=17), we established cultures of blood outgrowth endothelial cells (BOEC) and applied microarray profiling. BOEC have never been exposed to in vivo influences, and their gene expression reflects culture conditions (meticulously controlled) and donor genetics. Analysis used two distinct approaches. Significance Analysis of Microarray, a FDR-based test, identified significant differential expression of single genes. Gene Set Enrichment Analysis examined expression of pre-determined gene sets that survey each of nine biological systems relevant to endothelial cell biology. Results: At the highly stringent threshold of FDR=0, we identified 31 single genes that were differentially expressed, 4 higher and 27 lower in AA. “PSPH” exhibited the greatest fold-change (AA>CA), but this was entirely accounted for by a homolog (PSPHL) hidden within the PSPH probe set. Among other significantly different genes were: for AA>CA, SOS1, AMFR, FGFR3; and for AA<CA, ARVCF, BIN3, EIF4B. Many more (221 transcripts for 204 genes) were differentially expressed at the more customary, less stringent threshold of FDR<.05. Using the biological systems approach, we identified shear response biology as being significantly altered for AA versus CA. It detected an apparent tonic increase of expression (AA>CA) for 46/157 genes within that system. Conclusions: The most significant single gene changes detected for AA involved genes having substantial, known roles in endothelial biology. Biological systems analysis suggested that shear stress response, a critical regulator of endothelial function and vascular homeostasis, may be different between AA and CA. These results potentially have direct implications for the role of endothelial cells in both vascular disease (e.g., hypertension and stroke) and cancer (via angiogenesis). The present findings are consistent with our overarching hypothesis that genetic influences stemming from ancestral continent-of-origin could impact upon endothelial cell biology and thereby contribute to disparity of vascular-related disease burden amongst AA. From self-identified, healthy, 20-29 year old AA (n=21) and CA (n=17), we established cultures of blood outgrowth endothelial cells (BOEC) and applied microarray profiling. BOEC have never been exposed to in vivo influences, and their gene expression reflects culture conditions (meticulously controlled) and donor genetics. Analysis used two distinct approaches. Significance Analysis of Microarray, a FDR-based test, identified significant differential expression of single genes. Gene Set Enrichment Analysis examined expression of pre-determined gene sets that survey each of nine biological systems relevant to endothelial cell biology.