Recent findings demonstrated the importance of microRNAs (miRNAs) in the vasculature and the orchestration of lipid metabolism and glucose homeostasis. MiRNA networks represent an additional layer of ...regulation for gene expression that absorbs perturbations and ensures the robustness of biological systems. This function is very elegantly demonstrated in cholesterol metabolism where miRNAs reducing cellular cholesterol export are embedded in the very same genes that increase cholesterol synthesis. Often their alteration does not affect normal development but changes under stress conditions and in disease. A detailed understanding of the molecular and cellular mechanisms of miRNA-mediated effects on metabolism and vascular pathophysiology could pave the way for the development of novel diagnostic markers and therapeutic approaches. In the first part of this review, we summarize the role of miRNAs in vascular and metabolic diseases and explore potential confounding effects by platelet miRNAs in preclinical models of cardiovascular disease. In the second part, we discuss experimental strategies for miRNA target identification and the challenges in attributing miRNA effects to specific cell types and single targets.
MicroRNAs in Cardiovascular Disease Barwari, Temo, MD; Joshi, Abhishek, BA, BMBCh; Mayr, Manuel, MD, PhD
Journal of the American College of Cardiology,
12/2016, Letnik:
68, Številka:
23
Journal Article
Recenzirano
Odprti dostop
Abstract Micro-ribonucleic acids (miRNAs) are in the spotlight as post-transcriptional regulators of gene expression. More than 1,000 miRNAs are encoded in the human genome. In this review, we ...provide an introduction to miRNA biology and research methodology, and highlight advances in cardiovascular research to date. This includes the potential of miRNAs as therapeutic targets in cardiac and vascular disease, and their use as novel biomarkers. Although some miRNA therapies are already undergoing clinical evaluation, we stress the importance of integrating current knowledge of miRNA biology into a systemic context. Discovery studies focus on miRNA effects within one specific organ, whereas the expression of most miRNAs is not restricted to a single tissue. Because most miRNA-based therapies act systemically, this may preclude widespread clinical use. The development of more targeted interventions will bolster well-informed clinical applications, increasing the chances of success and minimizing the risk of setbacks for miRNA-based therapeutics.
MicroRNAs (miRNAs) have been implicated in the epigenetic regulation of key metabolic, inflammatory, and antiangiogenic pathways in type 2 diabetes (DM) and may contribute to common disease ...complications.
In this study, we explore plasma miRNA profiles in patients with DM.
Total RNA was extracted from plasma samples of the prospective population-based Bruneck study. A total of 13 candidate miRNAs identified by microarray screening and miRNA network inference were quantified by quantitative PCR in all diabetic patients of the Bruneck study and age- and sex-matched controls (1995 evaluation, n=80 each). Quantitative PCR assessment revealed lower plasma levels of miR-20b, miR-21, miR-24, miR-15a, miR-126, miR-191, miR-197, miR-223, miR-320, and miR-486 in prevalent DM, but a modest increase of miR-28-3p. Findings emerged as robust in multivariable analysis and were independent of the standardization procedure applied. For endothelial miR-126, results were confirmed in the entire Bruneck cohort (n=822) in univariate (odds ratio 95% confidence interval, 0.38 0.26 to 0.55; P=2.72 × 10(-7)) and multivariate analyses (0.57 0.37 to 0.86; P=0.0082). Importantly, reduced miR-15a, miR-29b, miR-126, miR-223, and elevated miR-28-3p levels antedated the manifestation of disease. Most differences in miRNA levels were replicated in plasma obtained from hyperglycemic Lep(ob) mice. High glucose concentrations reduced the miR-126 content of endothelial apoptotic bodies. Similarly in patients with DM, the reduction of miR-126 was confined to circulating vesicles in plasma.
We reveal a plasma miRNA signature for DM that includes loss of endothelial miR-126. These findings might explain the impaired peripheral angiogenic signaling in patients with DM.
Objectives This study sought to explore the association between baseline levels of microRNAs (miRNAs) (1995) and incident myocardial infarction (1995 to 2005) in the Bruneck cohort and determine ...their cellular origin. Background Circulating miRNAs are emerging as potential biomarkers. We previously identified an miRNA signature for type 2 diabetes in the general population. Methods A total of 19 candidate miRNAs were quantified by real-time polymerase chain reactions in 820 participants. Results In multivariable Cox regression analysis, 3 miRNAs were consistently and significantly related to incident myocardial infarction: miR-126 showed a positive association (multivariable hazard ratio: 2.69 95% confidence interval: 1.45 to 5.01, p = 0.002), whereas miR-223 and miR-197 were inversely associated with disease risk (multivariable hazard ratio: 0.47 95% confidence interval: 0.29 to 0.75, p = 0.002, and 0.56 95% confidence interval: 0.32 to 0.96, p = 0.036). To determine their cellular origin, healthy volunteers underwent limb ischemia-reperfusion generated by thigh cuff inflation, and plasma miRNA changes were analyzed at baseline, 10 min, 1 h, 5 h, 2 days, and 7 days. Computational analysis using the temporal clustering by affinity propagation algorithm identified 6 distinct miRNA clusters. One cluster included all miRNAs associated with the risk of future myocardial infarction. It was characterized by early (1 h) and sustained activation (7 days) post–ischemia-reperfusion injury and consisted of miRNAs predominantly expressed in platelets. Conclusions In subjects with subsequent myocardial infarction, differential co-expression patterns of circulating miRNAs occur around endothelium-enriched miR-126, with platelets being a major contributor to this miRNA signature.
The bulk of cardiovascular disease risk is not explained by traditional risk factors. Recent advances in mass spectrometry allow the identification and quantification of hundreds of lipid species. ...Molecular lipid profiling by mass spectrometry may improve cardiovascular risk prediction.
Lipids were extracted from 685 plasma samples of the prospective population-based Bruneck Study (baseline evaluation in 2000). One hundred thirty-five lipid species from 8 different lipid classes were profiled by shotgun lipidomics with the use of a triple-quadrupole mass spectrometer. Levels of individual species of cholesterol esters (CEs), lysophosphatidylcholines, phosphatidylcholines, phosphatidylethanolamines (PEs), sphingomyelins, and triacylglycerols (TAGs) were associated with cardiovascular disease over a 10-year observation period (2000-2010, 90 incident events). Among the lipid species with the strongest predictive value were TAGs and CEs with a low carbon number and double-bond content, including TAG(54:2) and CE(16:1), as well as PE(36:5) (P=5.1 × 10⁻⁷, 2.2 × 10⁻⁴, and 2.5 × 10⁻³, respectively). Consideration of these 3 lipid species on top of traditional risk factors resulted in improved risk discrimination and classification for cardiovascular disease (cross-validated ΔC index, 0.0210 95% confidence interval, 0.0010-0.0422; integrated discrimination improvement, 0.0212 95% confidence interval, 0.0031-0.0406; and continuous net reclassification index, 0.398 95% confidence interval, 0.175-0.619). A similar shift in the plasma fatty acid composition was associated with cardiovascular disease in the UK Twin Registry (n=1453, 45 cases).
This study applied mass spectrometry-based lipidomics profiling to population-based cohorts and identified molecular lipid signatures for cardiovascular disease. Molecular lipid species constitute promising new biomarkers that outperform the conventional biochemical measurements of lipid classes currently used in clinics.
Objectives This study sought to assess the long-term predictive value and net reclassification for risk of cardiovascular disease (CVD) of biomarkers reflecting oxidation-specific epitopes (OSEs). ...Background OSEs are immunogenic, proinflammatory, and proatherogenic. The long-term predictive value and net reclassification of OSEs for risk of CVD events are not known. Methods Oxidized phospholipids on apolipoprotein B-100 (OxPL/apoB) and immunoglobulin (Ig)-G (IgG) and IgM autoantibodies to malondialdehyde-modified, low-density lipoprotein (MDA-LDL) and copper-oxidized LDL (Cu-OxLDL) were measured in 765 subjects in 1995 and 656 subjects in 2000 in the Bruneck study, representing 45- to 84-year-old men and women from the general community. Results Over 15 years of follow-up, 138 subjects reached the primary endpoint of incident CVD (ischemic stroke, myocardial infarction, new-onset unstable angina, acute coronary interventions, and vascular death). In a multivariable Cox model, the highest tertile of OxPL/apoB was associated with higher risk of CVD (hazard ratio HR: 2.4; 95% confidence interval CI: 1.5 to 3.7) and stroke (HR: 3.6; 95% CI: 1.8 to 7.4) compared with the lowest tertile. IgG Cu-OxLDLs were associated with higher risk of CVD, whereas IgM MDA-LDLs were associated with lower risk. Using OxPL/apoB, IgG Cu-OxLDL, and IgM MDA-LDL variables, the area under the curve (AUC) for CVD risk prediction increased from 0.664 (95% CI: 0.629 to 0.697) to 0.705 (95% CI: 0.672 to 0.737) (p = 0.048). The net reclassification index (NRI) was 0.163 (p = 0.0044) and 0.332 (p < 0.0001) in all subjects (n = 765) and in subjects with intermediate risk (n = 305), respectively. Of 627 subjects who remained free of CVD, 108 were correctly reclassified to a lower risk category, and 83 were reclassified to a higher category (categories: 15-year risk <15%, 15% to 30%, >30%). Conclusions OSE biomarkers predict 15-year CVD and stroke outcomes and provide potential clinical utility by reclassifying a significant proportion of individuals into higher or lower risk categories after traditional risk assessment.
Platelets are essential mediators of physiological hemostasis and pathological thrombosis. Currently available tests and markers of platelet activation did not prove successful in guiding treatment ...decisions for patients with cardiovascular disease, justifying further research into novel markers of platelet reactivity. Platelets contain a variety of microRNAs (miRNAs) and are a major contributor to the extracellular circulating miRNA pool. Levels of platelet-derived miRNAs in the circulation have been associated with different measures of platelet activation as well as antiplatelet therapy and have therefore been implied as potential new markers of platelet reactivity. In contrast to the ex vivo assessment of platelet reactivity by current platelet function tests, miRNA measurements may enable assessment of platelet reactivity in vivo. It remains to be seen however, whether miRNAs may aid clinical diagnostics. Major limitations in the platelet miRNA research field remain the susceptibility to preanalytical variation, non-standardized sample preparation and data normalization that hampers inter-study comparisons. In this review, we provide an overview of the literature on circulating miRNAs as biomarkers of platelet activation, highlighting the underlying biology, the application in patients with cardiovascular disease and antiplatelet therapy and elaborating on technical limitations regarding their quantification in the circulation.
Providing therapies tailored to each patient is the vision of precision medicine, enabled by the increasing ability to capture extensive data about individual patients. In this position paper, we ...argue that the second enabling pillar towards this vision is the increasing power of computers and algorithms to learn, reason, and build the 'digital twin' of a patient. Computational models are boosting the capacity to draw diagnosis and prognosis, and future treatments will be tailored not only to current health status and data, but also to an accurate projection of the pathways to restore health by model predictions. The early steps of the digital twin in the area of cardiovascular medicine are reviewed in this article, together with a discussion of the challenges and opportunities ahead. We emphasize the synergies between mechanistic and statistical models in accelerating cardiovascular research and enabling the vision of precision medicine.
Atherosclerosis is initiated by the retention of lipoproteins on proteoglycans in the arterial intima. However, the mechanisms leading to proteoglycan accumulation and lipoprotein retention are ...poorly understood. In this study, we set out to investigate the role of ADAMTS-5 (a disintegrin and metalloprotease with thrombospondin motifs-5) in the vasculature. ADAMTS-5 was markedly reduced in atherosclerotic aortas of apolipoprotein E-null (apoE−/−) mice. The reduction of ADAMTS-5 was accompanied by accumulation of biglycan and versican, the major lipoprotein-binding proteoglycans, in atherosclerosis. ADAMTS-5 activity induced the release of ADAMTS-specific versican (DPEAAE441) and aggrecan (374ALGS) fragments as well as biglycan and link protein from the aortic wall. Fibroblast growth factor 2 (FGF-2) inhibited ADAMTS-5 expression in isolated aortic smooth muscle cells and blocked the spontaneous release of ADAMTS-generated versican and aggrecan fragments from aortic explants. In aortas of ADAMTS-5-deficient mice, DPEAAE441 versican neoepitopes were not detectable. Instead, biglycan levels were increased, highlighting the role of ADAMTS-5 in the catabolism of vascular proteoglycans. Importantly, ADAMTS-5 proteolytic activity reduced the LDL binding ability of biglycan and released LDL from human aortic lesions. This study provides the first evidence implicating ADAMTS-5 in the regulation of proteoglycan turnover and lipoprotein retention in atherosclerosis.
In atherosclerosis, proteoglycan accumulation results in increased lipoprotein retention.
ADAMTS-5 is reduced in aortas of apolipoprotein E-null mice. ADAMTS-5 deficiency impairs processing of vascular proteoglycans, and ADAMTS-5 activity affects proteoglycan-mediated lipoprotein retention.
ADAMTS-5 regulates vascular proteoglycan catabolism and alters lipoprotein retention.
This is the first study implicating ADAMTS-5 proteolytic activity in atherosclerosis.
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