Genetics of Coronary Artery Disease McPherson, Ruth; Tybjaerg-Hansen, Anne
Circulation research,
2016-Feb-19, Volume:
118, Issue:
4
Journal Article
Peer reviewed
Genetic factors contribute importantly to the risk of coronary artery disease (CAD), and in the past decade, there has been major progress in this area. The tools applied include genome-wide ...association studies encompassing >200,000 individuals complemented by bioinformatic approaches, including 1000 Genomes imputation, expression quantitative trait locus analyses, and interrogation of Encyclopedia of DNA Elements, Roadmap, and other data sets. close to 60 common SNPs (minor allele frequency>0.05) associated with CAD risk and reaching genome-wide significance (P<5 × 10(-8)) have been identified. Furthermore, a total of 202 independent signals in 109 loci have achieved a false discovery rate (q<0.05) and together explain 28% of the estimated heritability of CAD. These data have been used successfully to create genetic risk scores that can improve risk prediction beyond conventional risk factors and identify those individuals who will benefit most from statin therapy. Such information also has important applications in clinical medicine and drug discovery by using a Mendelian randomization approach to interrogate the causal nature of many factors found to associate with CAD risk in epidemiological studies. In contrast to genome-wide association studies, whole-exome sequencing has provided valuable information directly relevant to genes with known roles in plasma lipoprotein metabolism but has, thus far, failed to identify other rare coding variants linked to CAD. Overall, recent studies have led to a broader understanding of the genetic architecture of CAD and demonstrate that it largely derives from the cumulative effect of multiple common risk alleles individually of small effect size rather than rare variants with large effects on CAD risk. Despite this success, there has been limited progress in understanding the function of the novel loci; the majority of which are in noncoding regions of the genome.
Abstract Since the publication of the 2012 guidelines new literature has emerged to inform decision-making. The 2016 guidelines primary panel selected a number of clinically relevant questions and ...has produced updated recommendations, on the basis of important new findings. In subjects with clinical atherosclerosis, abdominal aortic aneurysm, most subjects with diabetes or chronic kidney disease, and those with low-density lipoprotein cholesterol ≥ 5 mmol/L, statin therapy is recommended. For all others, there is an emphasis on risk assessment linked to lipid determination to optimize decision-making. We have recommended nonfasting lipid determination as a suitable alternative to fasting levels. Risk assessment and lipid determination should be considered in individuals older than 40 years of age or in those at increased risk regardless of age. Pharmacotherapy is generally not indicated for those at low Framingham Risk Score (FRS; <10%). A wider range of patients are now eligible for statin therapy in the FRS intermediate risk category (10%-19%) and in those with a high FRS (> 20%). Despite the controversy, we continue to advocate for low-density lipoprotein cholesterol targets for subjects who start therapy. Detailed recommendations are also presented for health behaviour modification that is indicated in all subjects. Finally, recommendation for the use of nonstatin medications is provided. Shared decision-making is vital because there are many areas in which clinical trials do not fully inform practice. The guidelines are meant to be a platform for meaningful conversation between patient and care provider so that individual decisions can be made for risk screening, assessment, and treatment.
Tribbles related homolog 1 (TRIB1) contributes to lipid and glucose homeostasis by facilitating the degradation of cognate cargos by the proteasome. In view of the key metabolic role of TRIB1 and the ...impact of proteasome inhibition on hepatic function, we continue our exploration of TRIB1 regulation in two commonly used human hepatocyte models, transformed cell lines HuH-7 and HepG2. In both models, proteasome inhibitors potently upregulated both endogenous and recombinant TRIB1 mRNA and protein levels. Increased transcript abundance was unaffected by MAPK inhibitors while ER stress was a weaker inducer. Suppressing proteasome function via PSMB3 silencing was sufficient to increase TRIB1 mRNA expression. ATF3 was required to sustain basal TRIB1 expression and support maximal induction. Despite increasing TRIB1 protein abundance and stabilizing bulk ubiquitylation, proteasome inhibition delayed but did not prevent TRIB1 loss upon translation block. Immunoprecipitation experiments indicated that TRIB1 was not ubiquitylated in response to proteasome inhibition. A control bona fide proteasome substrate revealed that high doses of proteasome inhibitors resulted in incomplete proteasome inhibition. Cytoplasm retained TRIB1 was unstable, suggesting that TRIB1 lability is regulated prior to its nuclear import. N-terminal deletion and substitutions were insufficient to stabilize TRIB1. These findings identify transcriptional regulation as a prominent mechanism increasing TRIB1 abundance in transformed hepatocyte cell lines in response to proteasome inhibition and provide evidence of an inhibitor resistant proteasome activity responsible for TRIB1 degradation.
The 2021 guidelines primary panel selected clinically relevant questions and produced updated recommendations, on the basis of important new findings that have emerged since the 2016 guidelines. In ...patients with clinical atherosclerosis, abdominal aortic aneurysm, most patients with diabetes or chronic kidney disease, and those with low-density lipoprotein cholesterol ≥ 5 mmol/L, statin therapy continues to be recommended. We have introduced the concept of lipid/lipoprotein treatment thresholds for intensifying lipid-lowering therapy with nonstatin agents, and have identified the secondary prevention patients who have been shown to derive the largest benefit from intensification of therapy with these agents. For all other patients, we emphasize risk assessment linked to lipid/lipoprotein evaluation to optimize clinical decision-making. Lipoprotein(a) measurement is now recommended once in a patient's lifetime, as part of initial lipid screening to assess cardiovascular risk. For any patient with triglycerides ˃ 1.5 mmol/L, either non-high-density lipoprotein cholesterol or apolipoprotein B are the preferred lipid parameter for screening, rather than low-density lipoprotein cholesterol. We provide updated recommendations regarding the role of coronary artery calcium scoring as a clinical decision tool to aid the decision to initiate statin therapy. There are new recommendations on the preventative care of women with hypertensive disorders of pregnancy. Health behaviour modification, including regular exercise and a heart-healthy diet, remain the cornerstone of cardiovascular disease prevention. These guidelines are intended to provide a platform for meaningful conversation and shared-decision making between patient and care provider, so that individual decisions can be made for risk screening, assessment, and treatment.
Le panel principal responsable des lignes directrices 2021 a sélectionné des éléments cliniquement pertinents et a soumis des recommandations actualisées, basées sur de nouvelles découvertes d'importance apparues depuis les lignes directrices de 2016. Ainsi, le traitement par statine reste recommandé pour les patients atteints d'athérosclérose clinique, d'anévrisme de l'aorte abdominale, pour la plupart des patients diabétiques ou atteints d'insuffisance rénale chronique, et chez ceux dont le cholestérol à lipoprotéines de basse densité est ≥ 5 mmol/l. Nous avons introduit la notion de seuils pour le traitement des lipides/lipoprotéines afin d'intensifier le traitement hypolipidémiant avec des agents non-statiniques, et nous avons identifié les patients en prévention secondaire distingués comme ayant tirer le plus grand bénéfice de l'intensification du traitement avec ces agents. Pour tous les autres patients, nous mettons l'accent sur l'appréciation du risque par le biais de l'évaluation des lipides/lipoprotéines afin d'optimiser la prise de décision clinique. Le dosage de la lipoprotéine (a) est maintenant recommandé une fois dans la vie d'un patient, dans le cadre du dépistage initial des lipides pour évaluer le risque cardiovasculaire. Pour tout patient présentant des taux de triglycérides ˃ 1,5 mmol/l, l'apolipoprotéine B ou le cholestérol lié aux lipoprotéines autres que celles de haute densité sont les indices lipidiques à privilégier pour le dépistage, plutôt que le cholestérol à lipoprotéines de basse densité. Nous proposons des recommandations actualisées concernant le rôle du score calcique des artères coronaires en tant qu'outil de décision clinique pour aider à la décision d'administrer un traitement par statine. Il existe de nouvelles recommandations concernant les soins préventifs des femmes souffrant de troubles hypertensifs de la grossesse. Le changement de comportement en matière de santé, incluant l'exercice physique régulier et une alimentation saine pour le coeur, reste la pierre angulaire de la prévention des maladies cardiovasculaires. Ces lignes directrices visent à fournir une plateforme pour une discussion constructive et une prise de décision partagée entre le patient et le prestataire de soins, afin que des décisions individuelles puissent être prises pour le dépistage, l'évaluation et le traitement des risques.
Abstract Many developments have occurred since the publication of the widely-used 2009 Canadian Cardiovascular Society (CCS) Dyslipidemia guidelines. Here, we present an updated version of the ...guidelines, incorporating new recommendations based on recent findings and harmonizing CCS guidelines with those from other Societies. The G rading of R ecommendations A ssessment, D evelopment and E valuation (GRADE) system was used, per present standards of the CCS. The total cardiovascular disease Framingham Risk Score (FRS), modified for a family history of premature coronary disease, is recommended for risk assessment. Low-density lipoprotein cholesterol remains the primary target of therapy. However, non-high density lipoprotein cholesterol has been added to apolipoprotein B as an alternate target. There is an increased emphasis on treatment of higher risk patients, including those with chronic kidney disease and high risk hypertension. The primary panel has recommended a judicious use of secondary testing for subjects in whom the need for statin therapy is unclear. Expanded information on health behaviours is presented and is the backbone of risk reduction in all subjects. Finally, a systematic approach to statin intolerance is advocated to maximize appropriate use of lipid-lowering therapy. This document presents the recommendations and principal conclusions of this process. Along with associated Supplementary Material that can be accessed online, this document will be part of a program of knowledge translation. The goal is to increase the appropriate use of evidence-based cardiovascular disease event risk assessment in the management of dyslipidemia as a fundamental means of reducing global risk in the Canadian population.
An early poster child for the success of genome-wide association studies, the chromosome 9p21.3 locus is robustly linked to early atherosclerosis, abdominal aortic aneurysm, and intracranial aneurysm ...(1). ...although putative binding sites for IFN regulatory factors 3/7 binding sites are present in the CAD risk region, reporter assays failed to demonstrate enhancer activity in the basal or TLR-stimulated state.
Abstract Background Approximately 7% of American adults have severe hypercholesterolemia (untreated low-density lipoprotein LDL cholesterol ≥190 mg/dl), which may be due to familial ...hypercholesterolemia (FH). Lifelong LDL cholesterol elevations in FH mutation carriers may confer coronary artery disease (CAD) risk beyond that captured by a single LDL cholesterol measurement. Objectives This study assessed the prevalence of an FH mutation among those with severe hypercholesterolemia and determined whether CAD risk varies according to mutation status beyond the observed LDL cholesterol level. Methods Three genes causative for FH ( LDLR , APOB , and PCSK9 ) were sequenced in 26,025 participants from 7 case-control studies (5,540 CAD case subjects, 8,577 CAD-free control subjects) and 5 prospective cohort studies (11,908 participants). FH mutations included loss-of-function variants in LDLR , missense mutations in LDLR predicted to be damaging, and variants linked to FH in ClinVar, a clinical genetics database. Results Among 20,485 CAD-free control and prospective cohort participants, 1,386 (6.7%) had LDL cholesterol ≥190 mg/dl; of these, only 24 (1.7%) carried an FH mutation. Within any stratum of observed LDL cholesterol, risk of CAD was higher among FH mutation carriers than noncarriers. Compared with a reference group with LDL cholesterol <130 mg/dl and no mutation, participants with LDL cholesterol ≥190 mg/dl and no FH mutation had a 6-fold higher risk for CAD (odds ratio: 6.0; 95% confidence interval: 5.2 to 6.9), whereas those with both LDL cholesterol ≥190 mg/dl and an FH mutation demonstrated a 22-fold increased risk (odds ratio: 22.3; 95% confidence interval: 10.7 to 53.2). In an analysis of participants with serial lipid measurements over many years, FH mutation carriers had higher cumulative exposure to LDL cholesterol than noncarriers. Conclusions Among participants with LDL cholesterol ≥190 mg/dl, gene sequencing identified an FH mutation in <2%. However, for any observed LDL cholesterol, FH mutation carriers had substantially increased risk for CAD.
To identify genetic variants that have a regulatory impact on circulating microRNAs (miRNAs) and to connect genetic risk to blood traits/biomarkers through the circulating miRNAs.
Leveraging ...miRNA-Seq data and the 1000 Genomes imputed genotypes, we carried out genome-wide association analysis for SNPs that regulate the expression of circulating miRNAs in a sample of 710 unrelated subjects of European ancestry. Wherever possible, we used data from the Framingham and the Geuvadis studies to replicate our findings. We found at least one genome-wide significant (P < 5e-8) miRNA-eQTL (mirQTL) for 143 circulating miRNAs. Overall each mirQTL explained a small portion (<1%) of variation in miRNA levels; however, we identified a few mirQTLs that explained 4% to 20% of variation in miRNA levels in plasma. Unlike trans-mirQTLs (P = 0.7), cis-mirQTLs tend to be also associated with their counterpart mature miRNAs (P < 0.0001), this suggests trans-mirQTLs exert their effect through processes that affect the stability of mature miRNAs; whereas, cis-mirQTLs mainly regulate the expression of primary-miRNAs. Next, we used the identified mirQTLs to investigate the links between circulating miRNAs with blood traits/biomarkers through Mendelian randomization analysis. We found miR-1908-5p plays an important role in regulating low-density lipoprotein (LDL), total cholesterol (TC), fasting glucose, HbA1c, and several lipid-metabolites in blood, whereas, miR-10b-5p mediates the trans-regulatory effect of the ABO locus on several blood proteins, coronary artery disease, and TC. Moreover, we demonstrated that a higher plasma level of miR-199a is causally associated with lower levels of LDL and TC. Finally, we found miR-143-3p and miR-145-5p are functionally related and mediate the effect of ZFPM2 on a number of its protein targets in blood including VEGFA, SERPINE1, and PDGFs.
This study identifies SNPs that have a regulatory impact on circulating miRNAs, and underlines the role of several circulating miRNAs in mediating the effect of a number of GWAS loci on cardiometabolic phenotypes.
During obesity, macrophage accumulation in adipose tissue propagates the chronic inflammation and insulin resistance associated with type 2 diabetes. The factors, however, that regulate the accrual ...of macrophages in adipose tissue are not well understood. Here we show that the neuroimmune guidance cue netrin-1 is highly expressed in obese but not lean adipose tissue of humans and mice, where it directs the retention of macrophages. Netrin-1, whose expression is induced in macrophages by the saturated fatty acid palmitate, acts via its receptor Unc5b to block their migration. In a mouse model of diet-induced obesity, we show that adipose tissue macrophages exhibit reduced migratory capacity, which can be restored by blocking netrin-1. Furthermore, hematopoietic deletion of Ntn1 facilitates adipose tissue macrophage emigration, reduces inflammation and improves insulin sensitivity. Collectively, these findings identify netrin-1 as a macrophage retention signal in adipose tissue during obesity that promotes chronic inflammation and insulin resistance.
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