The role of microRNAs in arterial remodelling

Injectable graphene oxide/hydrogel-based angiogenic gene delivery system for vasculogenesis and cardiac repair

The objective of this study was to develop an injectable and biocompatible hydrogel which can efficiently deliver a nanocomplex of graphene oxide (GO) and vascular endothelial growth factor-165 (VEGF) pro-angiogenic gene for myocardial therapy. For the study, an efficient nonviral gene delivery system using polyethylenimine (PEI) functionalized GO nanosheets (fGO) complexed with DNAVEGF was formulated and incorporated in the low-modulus methacrylated gelatin (GelMA) hydrogel to promote controlled and localized gene therapy. It was hypothesized that the fGOVEGF/GelMA nanocomposite hydrogels can efficiently transfect myocardial tissues and induce favorable therapeutic effects without invoking cytotoxic effects. To evaluate this hypothesis, a rat model with acute myocardial infarction was used, and the therapeutic hydrogels were injected intramyocardially in the peri-infarct regions. The secreted VEGF from in vitro transfected cardiomyocytes demonstrated profound mitotic activities on endothelial cells. A significant increase in myocardial capillary density at the injected peri-infarct region and reduction in scar area were noted in the infarcted hearts with fGOVEGF/GelMA treatment compared to infarcted hearts treated with untreated sham, GelMA and DNAVEGF/GelMA groups. Furthermore, the fGOVEGF/GelMA group showed significantly higher (p < 0.05, n = 7) cardiac performance in echocardiography compared to other groups, 14 days postinjection. In addition, no significant differences were noticed between GO/GelMA and non-GO groups in the serum cytokine levels and quantitative PCR based inflammatory microRNA (miRNA) marker expressions at the injected sites. Collectively, the current findings suggest the feasibility of a combined hydrogel-based gene therapy system for ischemic heart diseases using nonviral hybrid complex of fGO and DNA.

Exercise training in hypertension: Role of microRNAs

Hypertension is a complex disease that constitutes an important public health problem and demands many studies in order to understand the molecular mechanisms involving his pathophysiology. Therefore, an increasing number of studies have been conducted and new therapies are continually being discovered. In this context, exercise training has emerged as an important non-pharmacological therapy to treat hypertensive patients, minimizing the side effects of pharmacological therapies and frequently contributing to allow pharmacotherapy to be suspended. Several mechanisms have been associated with the pathogenesis of hypertension, such as hyperactivity of the sympathetic nervous system and renin-angiotensin aldosterone system, impaired endothelial nitric oxide production, increased oxygen-reactive species, vascular thickening and stiffening, cardiac hypertrophy, impaired angiogenesis, and sometimes genetic predisposition. With the advent of microRNAs (miRNAs), new insights have been added to the perspectives for the treatment of this disease, and exercise training has been shown to be able to modulate the miRNAs associated with it. Elucidation of the relationship between exercise training and miRNAs in the pathogenesis of hypertension is fundamental in order to understand how exercise modulates the cardiovascular system at genetic level. This can be promising even for the development of new drugs. This article is a review of how exercise training acts on hypertension by means of specific miRNAs in the heart, vascular system, and skeletal muscle.

Analysis of circulating microRNAs that are specifically increased in hyperlipidemic and/or hyperglycemic sera

MicroRNAs (miRNAs) are small non-coding RNA sequences that regulate gene expression post-transcriptionally by translation inhibition or mRNA degradation. The aim of the present study was to analyze serum miRNAs modulated by hyperlipidemia and/or hyperglycemia and to correlate them with biochemical parameters within lipid metabolism. Five selected circulating miRNAs (miR-125a-5p, miR-146a, miR-10a, miR-21 and miR-33a) were individually analyzed by TaqMan miRNA assays along with lipid and inflammation parameters in sera from 20 hyperlipidemic (HL) and/or hyperglycemic (HG) patients, and compared with data from five normolipidemic/normoglycemic subjects. Results showed: (1) the levels of all the analyzed circulating miRNA were increased in HL sera and correlated positively with sera's lipid and inflammatory parameters; (2) circulating miR-125a-5p and miR-146a levels were increased in HG and/or HL sera; (3) all selected miRNAs were detected in α-lipoprotein fraction from sera, and miR-33a was also present in β-lipoprotein fraction; (4) miRNA concentrations were increased in the α-lipoprotein fraction from HL sera. These data show a statistically significant correlation of the analyzed miRNA with increased lipids, specifically with α- and β-lipoproteins, and CRP and IL-1β levels in HL and/or HG sera, suggesting a contribution of these miRNAs to the atherosclerotic process.

Circulating progenitor cells in hypertensive patients with different degrees of cardiovascular involvement

We investigated whether different degrees of hypertension-related cardiovascular involvement are associated with changes in circulating proangiogenic hematopoietic cell (PHC) numbers and/or phenotypes and/or in the PHC redox system in hypertensive individuals with isolated arterial stiffening (AS) hypertensives or with both carotid intima-media thickening and left ventricular hypertrophy (LVH) hypertensives. We also evaluated microRNA (miRs) 221 and 222 (miRs221/222) expression in CD34+ cells, the relationship between these miRs and cell number and reactive oxygen species (ROS) levels, and the expression of manganese superoxide dismutase (MnSOD), catalase (CAT) glutathione peroxidase type-1 (GPx-1) and gp91phox-containing nicotinamide-adenine-dinucleotide-phosphate-oxidase (NOX2). Proangiogenic hematopoietic cells (PHCs) from hypertensive patients and controls were isolated by flow cytometry. PHCs were higher in hypertensives than in controls but were lower in LVH than in AS hypertensives. In CD34+ cells from AS hypertensives, NOX2, MnSOD, CAT and GPx-1 were overexpressed; ROS, miRs and NOX2 were also increased and were associated with cell number. In LVH, we found an imbalance in the cell redox system; MnSOD showed the highest values, whereas CAT and GPx-1 were lower than in AS hypertensives. Intracellular ROS, miRs and NOX2 were higher and inversely associated with cell number. In AS hypertensives, the redox balance may sustain the increase in PHCs; by contrast, in hypertensives with more advanced lesions, redox imbalance may result in increased oxidative stress and cell reduction.

A miR-155-dependent microRNA hierarchy in dendritic cell maturation and macrophage activation

MicroRNAs (miRNAs) are small RNAs that play important regulatory roles in many cellular pathways. MiRNAs associate with members of the Argonaute protein family and bind to partially complementary sequences on mRNAs and induce translational repression or mRNA decay. Using deep sequencing and Northern blotting, we characterized miRNA expression in wild type and miR-155-deficient dendritic cells (DCs) and macrophages. Analysis of different stimuli (LPS, LDL, eLDL, oxLDL) reveals a direct influence of miR-155 on the expression levels of other miRNAs. For example, miR-455 is negatively regulated in miR-155-deficient cells possibly due to inhibition of the transcription factor C/EBPbeta by miR-155. Based on our comprehensive data sets, we propose a model of hierarchical miRNA expression dominated by miR-155 in DCs and macrophages.

Massive analysis of cDNA Ends (MACE) and miRNA expression profiling identifies proatherogenic pathways in chronic kidney disease

Epigenetic dysregulation contributes to the high cardiovascular disease burden in chronic kidney disease (CKD) patients. Although microRNAs (miRNAs) are central epigenetic regulators, which substantially affect the development and progression of cardiovascular disease (CVD), no data on miRNA dysregulation in CKD-associated CVD are available until now. We now performed high-throughput miRNA sequencing of peripheral blood mononuclear cells from ten clinically stable hemodialysis (HD) patients and ten healthy controls, which allowed us to identify 182 differentially expressed miRNAs (e.g., miR-21, miR-26b, miR-146b, miR-155). To test biological relevance, we aimed to connect miRNA dysregulation to differential gene expression. Genome-wide gene expression profiling by MACE (Massive Analysis of cDNA Ends) identified 80 genes to be differentially expressed between HD patients and controls, which could be linked to cardiovascular disease (e.g., KLF6, DUSP6, KLF4), to infection / immune disease (e.g., ZFP36, SOCS3, JUND), and to distinct proatherogenic pathways such as the Toll-like receptor signaling pathway (e.g., IL1B, MYD88, TICAM2), the MAPK signaling pathway (e.g., DUSP1, FOS, HSPA1A), and the chemokine signaling pathway (e.g., RHOA, PAK1, CXCL5). Formal interaction network analysis proved biological relevance of miRNA dysregulation, as 68 differentially expressed miRNAs could be connected to 47 reciprocally expressed target genes. Our study is the first comprehensive miRNA analysis in CKD that links dysregulated miRNA expression with differential expression of genes connected to inflammation and CVD. After recent animal data suggested that targeting miRNAs is beneficial in experimental CVD, our data may now spur further research in the field of CKD-associated human CVD.

MicroRNA-663 regulates human vascular smooth muscle cell phenotypic switch and vascular neointimal formation

RATIONALE

Abnormal phenotypic switch of vascular smooth muscle cell (VSMC) is a hallmark of vascular disorders such as atherosclerosis and restenosis after angioplasty. MicroRNAs (miRNAs) have emerged as important regulators for VSMC function, and we recently identified miR-663 as critical for controlling human aortic smooth muscle cell proliferation.

OBJECTIVE

To investigate whether miR-663 plays a role in human VSMC phenotypic switch and the development of neointima formation.

METHODS AND RESULTS

By using quantitative reverse-transcription polymerase chain reaction, we found that miR-663 was significantly downregulated in human aortic VSMCs on platelet-derived growth factor treatment, whereas expression was markedly increased during VSMC differentiation. Furthermore, we demonstrated that overexpression of miR-663 increased expression of VSMC differentiation marker genes, such as smooth muscle 22α, smooth muscle α-actin, calponin, and smooth muscle myosin heavy chain, and potently inhibited platelet-derived growth factor-induced VSMC proliferation and migration. We identified the transcription factor JunB and myosin light chain 9 as downstream targets of miR-663 in human VSMCs, because overexpression of miR-663 markedly inhibited expression of JunB and its downstream molecules, such as myosin light chain 9 and matrix metalloproteinase 9. Finally, we showed that adeno-miR-663 markedly suppressed the neointimal lesion formation by ≈50% in mice after vascular injury induced by carotid artery ligation, specifically via decreased JunB expression.

CONCLUSIONS

These results indicate that miR-663 is a novel modulator of human VSMC phenotypic switch by targeting JunB/myosin light chain 9 expression. These findings suggest that targeting miR-663 or its specific downstream targets in human VSMCs may represent an attractive approach for the treatment of proliferative vascular diseases.

MiR-146a as marker of senescence-associated pro-inflammatory status in cells involved in vascular remodelling

In order to identify new markers of vascular cell senescence with potential in vivo implications, primary cultured endothelial cells, including human umbilical vein endothelial cells (HUVECs), human aortic endothelial cells (HAECs), human coronary artery endothelial cells (HCAECs) and ex vivo circulating angiogenic cells (CACs), were analysed for microRNA (miR) expression. Among the 367 profiled miRs in HUVECs, miR-146a, miR-9, miR-204 and miR-367 showed the highest up-regulation in senescent cells. Their predicted target genes belong to nine common pathways, including Toll-like receptor signalling (TLR) that plays a pivotal role in inflammatory response, a key feature of senescence (inflammaging). MiR-146a was the most up-regulated miR in the validation analysis (>10-fold). Mimic and antagomir transfection confirmed TLR's IL-1 receptor-associated kinase (IRAK1) protein modulation in both young and senescent cells. Significant correlations were observed among miR-146a expression and β-galactosidase expression, telomere length and telomerase activity. MiR-146a hyper-expression was also validated in senescent HAECs (>4-fold) and HCAECs (>30-fold). We recently showed that CACs from patients with chronic heart failure (CHF) presented a distinguishing feature of senescence. Therefore, we also included miR-146a expression determination in CACs from 37 CHF patients and 35 healthy control subjects (CTR) for this study. Interestingly, a 1,000-fold increased expression of miR-146a was observed in CACs of CHF patients compared to CTR, along with decreased expression of IRAK1 protein. Moreover, significant correlations among miR-146a expression, telomere length and telomerase activity were observed. Overall, our findings indicate that miR-146a is a marker of a senescence-associated pro-inflammatory status in vascular remodelling cells.

Nuclear reprogramming and its role in vascular smooth muscle cells

In general terms, "nuclear reprogramming" refers to a change in gene expression profile that results in a significant switch in cellular phenotype. Nuclear reprogramming was first addressed by pioneering studies of cell differentiation during embryonic development. In recent years, nuclear reprogramming has been studied in great detail in the context of experimentally controlled dedifferentiation and transdifferentiation of mammalian cells for therapeutic purposes. In this review, we present a perspective on nuclear reprogramming in the context of spontaneous, pathophysiological phenotypic switch of vascular cells occurring in the atherosclerotic lesion. In particular, we focus on the current knowledge of epigenetic mechanisms participating in the extraordinary flexibility of the gene expression profile of vascular smooth muscle cells and other cell types participating in atherogenesis. Understanding how epigenetic changes participate in vascular cell plasticity may lead to effective therapies based on the remodelling of the vascular architecture.

The vascular smooth muscle cell: a therapeutic target in Type 2 diabetes?

The rising epidemic of T2DM (Type 2 diabetes mellitus) worldwide is of significant concern. The inherently silent nature of the disease in its early stages precludes early detection; hence cardiovascular disease is often established by the time diabetes is diagnosed. This increased cardiovascular risk leads to significant morbidity and mortality in these individuals. Progressive development of complications as a result of previous exposure to metabolic disturbances appears to leave a long-lasting impression on cells of the vasculature that is not easily reversed and is termed 'metabolic memory'. SMCs (smooth muscle cells) of blood vessel walls, through their inherent ability to switch between a contractile quiescent phenotype and an active secretory state, maintain vascular homoeostasis in health and development. This plasticity also confers SMCs with the essential capacity to adapt and remodel in pathological states. Emerging clinical and experimental studies propose that SMCs in diabetes may be functionally impaired and thus contribute to the increased incidence of macrovascular complications. Although this idea has general support, the underlying molecular mechanisms are currently unknown and hence are the subject of intense research. The aim of the present review is to explore and evaluate the current literature relating to the problem of vascular disease in T2DM and to discuss the critical role of SMCs in vascular remodelling. Possibilities for therapeutic strategies specifically at the level of T2DM SMCs, including recent novel advances in the areas of microRNAs and epigenetics, will be evaluated. Since restoring glucose control in diabetic patients has limited effect in ameliorating their cardiovascular risk, discovering alternative strategies that restrict or reverse disease progression is vital. Current research in this area will be discussed.

MicroRNAs as biomarkers for ischemic heart disease

MicroRNAs (miRs) are short, noncoding RNAs that function as posttranscriptional inhibitors of mRNA translation to protein. They are essential for normal development and homeostasis. Dysregulated expression patterns both cause and result from disease states. Generally studied as intracellular mediators, miRs can be isolated from body fluids and exhibit remarkable stability to degradation. These features, in combination with their tissue specificity, make miRs attractive candidates as blood-derived biomarkers for coronary artery disease (CAD), the most frequent cause of death worldwide. The use of miRs as biomarkers in both symptomatic and asymptomatic CAD and the influence of conventional cardiovascular risk factors and CAD treatment on their circulating levels are the topics of this review. To conclude, it highlights the remaining hurdles to tackle before this promising application of miRs can enter into routine clinical practice.

Systems biology of the functional and dysfunctional endothelium

This review provides an overview of the effect of blood flow on endothelial cell (EC) signalling pathways, applying microarray technologies to cultured cells, and in vivo studies of normal and atherosclerotic animals. It is found that in cultured ECs, 5-10% of genes are up- or down-regulated in response to fluid flow, whereas only 3-6% of genes are regulated by varying levels of fluid flow. Of all genes, 90% are regulated by the steady part of fluid flow and 10% by pulsatile components. The associated gene profiles show high variability from experiment to experiment depending on experimental conditions, and importantly, the bioinformatical methods used to analyse the data. Despite this high variability, the current data sets can be summarized with the concept of endothelial priming. In this concept, fluid flows confer protection by an up-regulation of anti-atherogenic, anti-thrombotic, and anti-inflammatory gene signatures. Consequently, predilection sites of atherosclerosis, which are associated with low-shear stress, confer low protection for atherosclerosis and are, therefore, more sensitive to high cholesterol levels. Recent studies in intact non-atherosclerotic animals confirmed these in vitro studies, and suggest that a spatial component might be present. Despite the large variability, a few signalling pathways were consistently present in the majority of studies. These were the MAPK, the nuclear factor-κB, and the endothelial nitric oxide synthase-NO pathways.

The microRNA-342-5p fosters inflammatory macrophage activation through an Akt1- and microRNA-155-dependent pathway during atherosclerosis

BACKGROUND

Atherosclerosis is a chronic inflammatory vascular disease driven by the subendothelial accumulation of macrophages. The mechanism regulating the inflammatory response in macrophages during atherogenesis remains unclear. Because microRNAs (miRNAs) play a crucial role in cellular signaling by posttranscriptional regulation of gene expression, we studied the miRNA expression profiles during the progression of atherosclerosis.

METHODS AND RESULTS

Using an miRNA real-time polymerase chain reaction array, we found that macrophage-derived miR-342-5p and miR-155 are selectively upregulated in early atherosclerotic lesions in Apoe(-/-) mice. miR-342-5p directly targets Akt1 through its 3'-untranslated region. Akt1 suppression by miR-342-5p induces proinflammatory mediators such as Nos2 and II6 in macrophages via the upregulation of miR-155. The local application of an miR-342-5p antagomir inhibits the development of atherosclerosis in partially ligated carotid arteries. In atherosclerotic lesions, the miR-342-5p antagomir upregulated Akt1 expression and suppressed the expression of miR-155 and Nos2. This reduced Nos2 expression was associated with a diminished generation of nitrotyrosine in the plaques. Furthermore, systemic treatment with an inhibitor of miR-342-5p reduced the progression of atherosclerosis in the aorta of Apoe(-/-) mice.

CONCLUSIONS

Macrophage-derived miR-342-5p promotes atherosclerosis and enhances the inflammatory stimulation of macrophages by suppressing the Akt1-mediated inhibition of miR-155 expression. Therefore, targeting miR-342-5p may offer a promising strategy to treat atherosclerotic vascular disease.

MicroRNA-1 prevents high-fat diet-induced endothelial permeability in apoE knock-out mice

The development of atherosclerosis (AS) is a multifactorial process in which elevated plasma cholesterol levels play a central role. As a new class of players involved in AS, the regulation and function of microRNAs (miR) in response to AS remain poorly understood. This study analyzed the effects of miR-1 (antagomir and mimic) on endothelial permeability and myosin light chain kinase (MLCK) expression and activity in the artery wall of apoE knock-out mice after feeding them a high-cholesterol diet. Further, we tested to determine whether that effects are involved in ERK phosphorylation. Here, we show that a high-cholesterol diet induces a significant decrease of miR-1 expression. Histopathologic examination demonstrated that miR-1 antagomir enhances endothelial permeability induced by high cholesterol and miR-1 mimic attenuated endothelial barrier dysfunction. Consistent with endothelial permeability, Western blotting, qPCR, and γ-³²P-ATP phosphate incorporation showed that MLCK expression and activity were further increased in miR-1 antagomir-treated mice and decreased in miR-1 mimic-treated mice compared with those of mice receiving control miR. Further mechanistic studies showed that high-cholesterol-induced extracellular signal regulated kinase (ERK) activation was enhanced by miR-1 antagomir and attenuated by miR-1 mimic. Collectively, those results indicate that miR-1 contributes to endothelial barrier function via mechanisms involving not only MLCK expression and activity but also ERK phosphorylation.

MicroRNA-126, -145, and -155: a therapeutic triad in atherosclerosis?

Atherosclerosis is a condition caused by lipid-induced inflammation of the vessel wall orchestrated by a complex interplay of various cell types, such as endothelial cells, smooth muscle cells, and macrophages. MicroRNAs (miRNAs) have emerged as key regulators of gene expression typically by repressing the target mRNA, which determines cell fate and function under homeostatic and disease conditions. Here, we outline the effects of miRNA-145, -126, and -155 in atherosclerosis in vivo. Downregulation of miR-145, which controls differentiation of smooth muscle cells, promotes lesion formation, whereas the endothelial cell-specific miRNA-126 signals the need for endothelial repair through its transfer from apoptotic endothelial cells in microvesicles. Elevated miR-155 levels are characteristic of proinflammatory macrophages and atherosclerotic lesions. However, the effects of miR-155 seem to be different in early and advanced atherosclerosis. The discovery of the role of these miRNAs in atherosclerosis sheds light on the current concepts of atherogenesis and may provide novel treatment options for cardiovascular diseases.

Essential role of microRNA-155 in regulating endothelium-dependent vasorelaxation by targeting endothelial nitric oxide synthase

Nitric oxide generated by endothelial nitric oxide synthase (eNOS) plays an important role in maintaining cardiovascular homeostasis. Under various pathological conditions, abnormal expression of eNOS contributes to endothelial dysfunction and the development of cardiovascular diseases. A variety of pathological stimuli has been reported to decrease eNOS expression mainly through decreasing eNOS mRNA stability by regulating the binding of several cytosolic proteins to the cis-acting sequences within eNOS mRNA 3' untranslated regions. However, the detailed mechanisms remain elusive. Because microRNAs inhibit gene expression through binding to the 3' untranslated regions of their target mRNAs, microRNAs may be the important posttranscriptional modulators of eNOS expression. Here, we provided evidence that eNOS is a direct target of miR-155. Overexpression of miR-155 decreased, whereas inhibition of miR-155 increased, eNOS expression and NO production in human umbilical vein endothelial cells and acetylcholine-induced endothelium-dependent vasorelaxation in human internal mammary arteries. Inflammatory cytokines including tumor necrosis factor-α increased miR-155 expression. Inhibition of miR-155 reversed tumor necrosis factor-α-induced downregulation of eNOS expression and impairment of endothelium-dependent vasorelaxation. Moreover, we observed that simvastatin attenuated tumor necrosis factor-α-induced upregulation of miR-155 and ameliorated the effects of tumor necrosis factor-α on eNOS expression and endothelium-dependent vasodilation. Simvastatin decreased miR-155 expression through interfering mevalonate-geranylgeranyl-pyrophosphate-RhoA signaling pathway. These findings indicated that miR-155 is an essential regulator of eNOS expression and endothelium-dependent vasorelaxation. Inhibition of miR-155 may be a new therapeutic approach to improve endothelial dysfunction during the development of cardiovascular diseases.

MicroRNA-155 promotes atherosclerosis by repressing Bcl6 in macrophages

Macrophages in atherosclerotic plaques drive inflammatory responses, degrade lipoproteins, and phagocytose dead cells. MicroRNAs (miRs) control the differentiation and activity of macrophages by regulating the signaling of key transcription factors. However, the functional role of macrophage-related miRs in the immune response during atherogenesis is unknown. Here, we report that miR-155 is specifically expressed in atherosclerotic plaques and proinflammatory macrophages, where it was induced by treatment with mildly oxidized LDL (moxLDL) and IFN-γ. Leukocyte-specific Mir155 deficiency reduced plaque size and number of lesional macrophages after partial carotid ligation in atherosclerotic (Apoe-/-) mice. In macrophages stimulated with moxLDL/IFN-γ in vitro, and in lesional macrophages, loss of Mir155 reduced the expression of the chemokine CCL2, which promotes the recruitment of monocytes to atherosclerotic plaques. Additionally, we found that miR-155 directly repressed expression of BCL6, a transcription factor that attenuates proinflammatory NF-κB signaling. Silencing of Bcl6 in mice harboring Mir155-/- macrophages enhanced plaque formation and CCL2 expression. Taken together, these data demonstrated that miR-155 plays a key role in atherogenic programming of macrophages to sustain and enhance vascular inflammation.

Roles of microRNAs in atherosclerosis and restenosis

Atherosclerosis is commonly appreciated to represent a chronic inflammatory response of the vascular wall, and its complications cause high mortality in patients. Angioplasty with stent replacement is commonly performed in patients with atherosclerotic disease. However, the restenosis usually has a high incidence rate in angioplasty patients. Although the pathophysiological mechanisms underlying atherosclerosis and restenosis have been well established, new signaling molecules that control the progress of these pathologies have continuously been discovered. MicroRNAs (miRs) have recently emerged as a novel class of gene regulators that work via transcriptional degradation and translational inhibition or activation. Over 30% of genes in the cell can be directly regulated by miRs. Thus, miRs are recognized as crucial regulators in normal development, physiology and pathogenesis. Alterations of miR expression profiles have been revealed in diverse vascular diseases. A variety of functions of vascular cells, such as cell differentiation, contraction, migration, proliferation and inflammation that are involved in angiogenesis, neointimal formation and lipid metabolism underlying various vascular diseases, have been found to be regulated by miRs. This review summarizes current research progress and knowledge on the roles of miRs in regulating vascular cell function in atherosclerosis and restenosis. These discoveries are expected to present opportunities for clinical diagnostic and therapeutic approaches in vascular diseases resulting from atherosclerosis and restenosis.