Molecular genetics of atherosclerosis

Artificial intelligence-based preventive, personalized and precision medicine for cardiovascular disease/stroke risk assessment in rheumatoid arthritis patients: a narrative review

The challenges associated with diagnosing and treating cardiovascular disease (CVD)/Stroke in Rheumatoid arthritis (RA) arise from the delayed onset of symptoms. Existing clinical risk scores are inadequate in predicting cardiac events, and conventional risk factors alone do not accurately classify many individuals at risk. Several CVD biomarkers consider the multiple pathways involved in the development of atherosclerosis, which is the primary cause of CVD/Stroke in RA. To enhance the accuracy of CVD/Stroke risk assessment in the RA framework, a proposed approach involves combining genomic-based biomarkers (GBBM) derived from plasma and/or serum samples with innovative non-invasive radiomic-based biomarkers (RBBM), such as measurements of synovial fluid, plaque area, and plaque burden. This review presents two hypotheses: (i) RBBM and GBBM biomarkers exhibit a significant correlation and can precisely detect the severity of CVD/Stroke in RA patients. (ii) Artificial Intelligence (AI)-based preventive, precision, and personalized (aiP3) CVD/Stroke risk AtheroEdge™ model (AtheroPoint™, CA, USA) that utilizes deep learning (DL) to accurately classify the risk of CVD/stroke in RA framework. The authors conducted a comprehensive search using the PRISMA technique, identifying 153 studies that assessed the features/biomarkers of RBBM and GBBM for CVD/Stroke. The study demonstrates how DL models can be integrated into the AtheroEdge™-aiP3 framework to determine the risk of CVD/Stroke in RA patients. The findings of this review suggest that the combination of RBBM with GBBM introduces a new dimension to the assessment of CVD/Stroke risk in the RA framework. Synovial fluid levels that are higher than normal lead to an increase in the plaque burden. Additionally, the review provides recommendations for novel, unbiased, and pruned DL algorithms that can predict CVD/Stroke risk within a RA framework that is preventive, precise, and personalized.

Leveraging epigenomes and three-dimensional genome organization for interpreting regulatory variation

Understanding the impact of regulatory variants on complex phenotypes is a significant challenge because the genes and pathways that are targeted by such variants and the cell type context in which regulatory variants operate are typically unknown. Cell-type-specific long-range regulatory interactions that occur between a distal regulatory sequence and a gene offer a powerful framework for examining the impact of regulatory variants on complex phenotypes. However, high-resolution maps of such long-range interactions are available only for a handful of cell types. Furthermore, identifying specific gene subnetworks or pathways that are targeted by a set of variants is a significant challenge. We have developed L-HiC-Reg, a Random Forests regression method to predict high-resolution contact counts in new cell types, and a network-based framework to identify candidate cell-type-specific gene networks targeted by a set of variants from a genome-wide association study (GWAS). We applied our approach to predict interactions in 55 Roadmap Epigenomics Mapping Consortium cell types, which we used to interpret regulatory single nucleotide polymorphisms (SNPs) in the NHGRI-EBI GWAS catalogue. Using our approach, we performed an in-depth characterization of fifteen different phenotypes including schizophrenia, coronary artery disease (CAD) and Crohn's disease. We found differentially wired subnetworks consisting of known as well as novel gene targets of regulatory SNPs. Taken together, our compendium of interactions and the associated network-based analysis pipeline leverages long-range regulatory interactions to examine the context-specific impact of regulatory variation in complex phenotypes.

A multi-target protective effect of Danggui-Shaoyao-San on the vascular endothelium of atherosclerotic mice

BACKGROUND

Atherosclerosis (AS) is a chronic disease characterized by abnormal blood lipid metabolism, inflammation and vascular endothelial injury. Vascular endothelial injury is the initial stage during the occurrence of AS. However, the function and mechanism of anti-AS are not well characterized. Danggui-Shaoyao-San (DGSY) is a classic Traditional Chinese Medicine (TCM) prescription for the treatment of gynecological diseases, and has been widely used in the treatment of AS in recent years.

METHODS

ApoE^-/- atherosclerosis male mice were established by feeding with high-fat diet, and then randomly divided into three groups: Atherosclerosis group (AS), Danggui-Shaoyao-San group (DGSY), and Atorvastatin calcium group (X). The mice were administered with the drugs for 16 weeks. Pathological changes in aortic vessels were examined by staining with Oil red O, Masson and hematoxylin-eosin. In addition, blood lipids were analyzed. The level of IL-6 and IL-8 in aortic vessels were detected by ELISA and the expression of ICAM-1 and VCAM-1 in the aortic vascular endothelium were measured by Immunohistochemical. The mRNA expression of interα5β1/c-Abl/YAP in the aortic vessels were measured by Real-time quantitative PCR and location of expression was assessed by immunofluorescence.

RESULTS

DGSY can significantly reduce the content of TC,TG and LDL-C and increase the level of HDL-C in the serum, reduce the plaque area and inhibit the concentration of IL-6 and IL-8, down-regulate the expression of IVAM-1,VCAM-1 and interα5β1/ c-Abl/YAP in the aortic vessels.

CONCLUSIONS

Collectively, DGSY can alleviate vascular endothelium damage and delay the occurrence of AS, and the underlying mechanism may be related to the multi-target protective of DGSY.

There is urgent need to treat atherosclerotic cardiovascular disease risk earlier, more intensively, and with greater precision: A review of current practice and recommendations for improved effectiveness

Atherosclerotic cardiovascular disease (ASCVD) is epidemic throughout the world and is etiologic for such acute cardiovascular events as myocardial infarction, ischemic stroke, unstable angina, and death. ASCVD also impacts risk for dementia, chronic kidney disease peripheral arterial disease and mobility, impaired sexual response, and a host of other visceral impairments that adversely impact the quality and rate of progression of aging. The relationship between low-density lipoprotein cholesterol (LDL-C) and risk for ASCVD is one of the most highly established and investigated issues in the entirety of modern medicine. Elevated LDL-C is a necessary condition for atherogenesis induction. Basic scientific investigation, prospective longitudinal cohorts, and randomized clinical trials have all validated this association. Yet despite the enormous number of clinical trials which support the need for reducing the burden of atherogenic lipoprotein in blood, the percentage of high and very high-risk patients who achieve risk stratified LDL-C target reductions is low and has remained low for the last thirty years. Atherosclerosis is a preventable disease. As clinicians, the time has come for us to take primordial and primary prevention more serously. Despite a plethora of therapeutic approaches, the large majority of patients at risk for ASCVD are poorly or inadequately treated, leaving them vulnerable to disease progression, acute cardiovascular events, and poor aging due to loss of function in multiple visceral organs. Herein we discuss the need to greatly intensify efforts to reduce risk, decrease disease burden, and provide more comprehensive and earlier risk assessment to optimally prevent ASCVD and its complications. Evidence is presented to support that treatment should aim for far lower goals in cholesterol management, should take into account many more factors than commonly employed today and should begin significantly earlier in life.

Tackling Atherosclerosis via Selected Nutrition

The development and pathogenesis of atherosclerosis are significantly influenced by lifestyle, particularly nutrition. The modern level of science and technology development promote personalized nutrition as an efficient preventive measure against atherosclerosis. In this survey, the factors were revealed that contribute to the formation of an individual approach to nutrition: genetic characteristics, the state of the microbiota of the gastrointestinal tract (GIT) and environmental factors (diets, bioactive components, cardioprotectors, etc.). In the course of the work, it was found that in order to analyze the predisposition to atherosclerosis associated with nutrition, genetic features affecting the metabolism of nutrients are significant. The genetic features include the presence of single nucleotide polymorphisms (SNP) of genes and epigenetic factors. The influence of telomere length on the pathogenesis of atherosclerosis and circadian rhythms was also considered. Relatively new is the study of the relationship between chrono-nutrition and the development of metabolic diseases. That is, to obtain the relationship between nutrition and atherosclerosis, a large number of genetic markers should be considered. In this relation, the question arises: “How many genetic features need to be analyzed in order to form a personalized diet for the consumer?” Basically, companies engaged in nutrigenetic research and choosing a diet for the prevention of a number of metabolic diseases use SNP analysis of genes that accounts for lipid metabolism, vitamins, the body’s antioxidant defense system, taste characteristics, etc. There is no set number of genetic markers. The main diets effective against the development of atherosclerosis were considered, and the most popular were the ketogenic, Mediterranean, and DASH-diets. The advantage of these diets is the content of foods with a low amount of carbohydrates, a high amount of vegetables, fruits and berries, as well as foods rich in antioxidants. However, due to the restrictions associated with climatic, geographical, material features, these diets are not available for a number of consumers. The way out is the use of functional products, dietary supplements. In this approach, the promising biologically active substances (BAS) that exhibit anti-atherosclerotic potential are: baicalin, resveratrol, curcumin, quercetin and other plant metabolites. Among the substances, those of animal origin are popular: squalene, coenzyme Q10, omega-3. For the prevention of atherosclerosis through personalized nutrition, it is necessary to analyze the genetic characteristics (SNP) associated with the metabolism of nutrients, to assess the state of the microbiota of the GIT. Based on the data obtained and food preferences, as well as the individual capabilities of the consumer, the optimal diet can be selected. It is topical to exclude nutrients of which their excess consumption stimulates the occurrence and pathogenesis of atherosclerosis and to enrich the diet with functional foods (FF), BAS containing the necessary anti-atherosclerotic, and stimulating microbiota of the GIT nutrients. Personalized nutrition is a topical preventive measure and there are a number of problems hindering the active use of this approach among consumers. The key factors include weak evidence of the influence of a number of genetic features, the high cost of the approach, and difficulties in the interpretation of the results. Eliminating these deficiencies will contribute to the maintenance of a healthy state of the population through nutrition.

Interactive effects of interferon-gamma functional single nucleotid polymorphism (+874 T/A) with cardiovascular risk factors in coronary heart disease and early myocardial infarction risk

Atherosclerosis is an inflammatory disease characterized by extensive lipid accumulation in the artery wall. Throughout the atherosclerotic process, interferon-gamma (IFN-γ), which is an important pro-inflammatory cytokine, plays a central role in atherosclerotic plaque instability and the occurrence of myocardial infarction (MI). In this study, we aimed to investigate the relationship between IFN-γ +874 T/A (rs2430561) polymorphism and coronary heart disease (CHD) as well as its effects on MI and CHD. Three hundred and ninety patients with CHD (229 with MI, 161 without MI) and 233 healthy controls were screened by the amplification refractory mutation system (ARMS) PCR method for IFN-γ +874 T/A polymorphism. For MI risk, early adult age was important risk factors and the risk was increased with IFN-γ +874 T/A polymorphism. IFN-γ T allele was significantly increased in the CHD patients with age≤45 (p = 0.048) and patients with history of MI (p = 0.007). As IFN-γ is an inflammatory cytokine with an emerging role in the atherosclerotic process, it was suggested that inhibition of IFN-γ activity could be a therapeutic strategy to stabilize human atherosclerotic plaque. Our findings support the association between MI risk and IFN-γ +874 T/A polymorphism in the Turkish population, particularly by increasing the level of IFN-γ in young patients, thereby causing rupture of vulnerable plaques in atherosclerotic lesions. Identification of the IFN-γ +874 T/A gene variants as risk factors for early CHD and MI development may be a practical biomarker to guide the MI risk process and determine the ideal therapeutic approach.

Study of angiotensin-converting enzyme insertion/deletion polymorphism, enzyme activity and oxidized low density lipoprotein in Western Iranians with atherosclerosis: a case-control study

Background

It has been indicated that Angiotensin-Converting Enzyme Insertion/Deletion (ACE I/D) polymorphism (rs4646994) could be regarded as a genetic factor that raises the risk of CAD through its impact on the activity of Angiotensin-Converting Enzyme (ACE) and angiotensin II level. The present study seeks to examine the relationship between ACE I/D polymorphism with the risk of atherosclerosis. Moreover, its potential effects on ACE activity and oxLDL level are investigated.

Methods

In this study, 145 healthy individuals and 154 patients (143 males and 156 females) were selected among the subjects referred to Shahid Madani Hospital. Atherosclerosis was determined in all subjects with gold standard angiography. Blood samples were collected, used to isolate white blood cells (WBC) and serum separation. The DNA was extracted and the polymorphism was determined by polymerase chain reaction (PCR). The enzyme activity was measured using high-performance liquid chromatography (HPLC).

Results

This study indicated that patients with atherosclerosis had higher levels of oxidized Low-Density Lipoprotein (oxLDL) and ACE activity (P < 0.05) as compared to controls. Although we found a significant association between ACE I/D polymorphism genotype and the allele with atherosclerosis in the male group, there were no association when the entire patient group was compared to the entire control group.

Conclusion

Our study revealed the ACE I/D polymorphism of the ACE gene may not be an independent risk factor in the development of atherosclerosis and evaluation of ACE activity level is more important in evaluating the risk of disease. The researchers found no relation between ACE I/D polymorphism and atherosclerosis and also between types of genotype, ACE activity, and OxLDL level.

Association study of CACNA1C polymorphisms with large artery atherosclerotic stroke in Chinese Han population

Aims Ischemic stroke (IS) is one of the most common diseases of neurology and the main cause of death and disability in Chinese population. CACNA1C was considered to be involved in the process of atherosclerosis, but there was little information about the association between genotypic polymorphisms of CACNA1C and ischemic stroke. Our study was designed to elucidate the relationship between four single-nucleotide polymorphisms (SNPs) variants in CACNA1C gene and the risk of large-artery atherosclerotic (LAA) stroke patients. Methods A total of 384 subjects were enrolled in this study, including 192 LAA stroke cases and 192 healthy controls. And four SNPs variants in CNCNA1C gene were genotyped using in-house developed multiplex tagged-amplicon deep sequencing (TAm-Seq). Statistical analysis were conducted using χ2 test and binary logistic regression analysis. Results We found one variant was significantly associated with LAA stroke in the allele models (rs10848683, p = 0.036, OR = 1.371, 95%CI: 1.021-1.841). And rs10848683 was also found to associate with LAA stroke under recessive model (p = 0.027, OR = 0.618, 95% CI: 0.403-0.947) after adjustment for gender and age. We also found that significant difference existed between haplotypes (rs229961-rs215976-rs216008-rs10848683) and LAA stroke (C-T-C-C, p = 0.017, OR = 2.265, 95%CI: 1.136-4.518; G-C-C-C, p = 0.046, OR = 1.891, 95% CI: 1.003-3.565; C-T-C-T, p = 0.001, OR = 0.256, 95%CI: 0.101-0.645). Conclusion The results suggested that there was a potential association between CNCNA1C gene and the risk factor of LAA stroke in Chinese Han population.

Stabilisation of atherosclerotic plaques

Plaque rupture and subsequent thrombotic occlusion of the coronary artery account for as many as three quarters of myocardial infarctions. The concept of plaque stabilisation emerged about 20 years ago to explain the discrepancy between the reduction of cardiovascular events in patients receiving lipid lowering therapy and the small decrease seen in angiographic evaluation of atherosclerosis. Since then, the concept of a vulnerable plaque has received a lot of attention in basic and clinical research leading to a better understanding of the pathophysiology of the vulnerable plaque and acute coronary syndromes. From pathological and clinical observations, plaques that have recently ruptured have thin fibrous caps, large lipid cores, exhibit outward remodelling and invasion by vasa vasorum. Ruptured plaques are also focally inflamed and this may be a common denominator of the other pathological features. Plaques with similar characteristics, but which have not yet ruptured, are believed to be vulnerable to rupture. Experimental studies strongly support the validity of anti-inflammatory approaches to promote plaque stability. Unfortunately, reliable non-invasive methods for imaging and detection of such plaques are not yet readily available. There is a strong biological basis and supportive clinical evidence that low-density lipoprotein lowering with statins is useful for the stabilisation of vulnerable plaques. There is also some clinical evidence for the usefulness of antiplatelet agents, beta blockers and renin-angiotensin-aldosterone system inhibitors for plaque stabilisation. Determining the causes of plaque rupture and designing diagnostics and interventions to prevent them are urgent priorities for current basic and clinical research in cardiovascular area.

POSSIBLE HYPOCHOLESTEROLEMIC EFFECT OF GINGER AND ROSEMARY OILS IN RATS

BACKGROUND

Hypercholesterolemia is a major risk factor for development of atherosclerosis. The present study was conducted to evaluate the potential effect of ginger oil alone or combined with rosemary oil as hypocholesterolemic agent in rats fed high fat diet.

MATERIALS AND METHODS

Healthy female albino rats (n=80) weighting about (150-180 g) were included in this study divided into two equal groups; Group (I): were fed on the basal diet. Group (I) were divided into 4 subgroups each 10: Group (Ia): negative control. Group (Ib): Rats received i.p 2.5 g/Kg b.w of ginger oil. Group (Ic): rats received i.p 2.5 g/Kg b.w of rosemary oil. Group (Id): Rats received i.p 5 g/Kg b.w mixture of ginger oil and rosemary oil (1:1). The second main groups; Group (II): high fat diet (HFD) were fed on the basal diet plus cholesterol (1%), bile salt (0.25%) and animal fat (15%) to induce hypercholesterolemia for six weeks. Group (II) was divided into 4subgroups: Group (IIa): HFD. Group (IIb): HFD were treated with i.p 2.5 g/Kg b.w ginger oil. Group (IIc): (n=10) HFD were treated with i.p 2.5 g/Kg b.w rosemary oil. Group (IId): (n=10) HFD were treated with i.p 5 g/Kg b.w mixture of oils.

RESULTS

It was found that HFD rats showed a significant elevation in glucose, total cholesterol, triglyceride, GOT, GPT, alkaline phosphatase and a reduction in serum HDL-c compared with negative control. Treatment with ginger oil, rosemary oil and their mixture modulated the elevation of these parameters. Histopathological examination of the liver tissue of HFD rats showed a lipid deposition and macrophage infiltration and stenosis of hepatic vein. Treatment with mixture oils preserves normal structure of liver.

CONCLUSION

It was concluded that, hypocholesterolemic effect was related to the active oil content as Rosemary oil contain - α-pinene, Camphor, cineole, borneol and Ginger oil contain Linalool, Terpineol, Borneol, Eucalyptol.

Association of CD147 genetic polymorphisms with carotid atherosclerotic plaques in a Han Chinese population with cerebral infarction

INTRODUCTION

Given the important role of CD147 in the development of atherosclerosis, we speculated that CD147 genetic polymorphisms might influence the formation of carotid atherosclerotic plaques. The study was to investigate the association between CD147 gene polymorphisms and susceptibility to carotid atherosclerotic plaques in individuals with cerebral infarction (CI).

METHODS

Eight SNPs in the regulatory and coding regions of the CD147 gene were examined using polymerase chain reaction-ligase detection reaction (PCR-LDR) in DNA samples from 732 Chinese patients with CI, divided into a carotid plaque group (n=475) and a non-carotid plaque group (n=257).

RESULTS

Significant differences were found in the genotypes and allele frequencies of the rs4919862 SNP between the carotid plaque and non-carotid plaque groups of CI patients (P<0.05), while the frequencies of the C allele and the CC genotype in the non-carotid plaque group were significantly lower than those in the carotid plaque group, and the frequencies of the T allele in the non-carotid plaque group were significantly higher than those in the carotid plaque group (P<0.05). In addition, there was strong linkage disequilibrium among the rs4919862, rs8637 and rs8259 sites. In a haplotype analysis, the occurrence rate of the haplotype GATGCAGC was 2.095 times higher in the carotid plaque group than in the non-carotid plaque group (P<0.05).

CONCLUSION

These results showed that the rs4919862 SNP of CD147 was closely associated with carotid atherosclerotic plaques formation. Thus, polymorphisms of the CD147 gene may be related to the tendency for carotid atherosclerotic plaques.

Atherosclerotic and thrombotic genetic and environmental determinants in Egyptian coronary artery disease patients: a pilot study

BACKGROUND

Coronary artery disease (CAD) is the leading cause of morbidity and mortality worldwide. Multiple genetic variants in combination with various environmental risk factors have been implicated. This study aimed to investigate the association of twelve thrombotic and atherosclerotic gene variants in combination with other environmental risk factors with CAD risk in a preliminary sample of Egyptian CAD patients.

METHODS

Twenty three consecutive CAD patients undergoing diagnostic coronary angiography and 34 unrelated controls, have been enrolled in the study. Genotyping was based on polymerase chain reaction and reverse multiplex hybridization. Five genetic association models were tested. Data distribution and variance homogeneity have been checked by Shapiro-Wilk test and Levene test, respectively; then the appropriate comparison test was applied. Spearman's rank correlation coefficient was used for correlation analysis and logistic regression has been performed to adjust for significant risk factors. Clustering the study participants according to gene-gene and gene-environment interaction has been done by Detrended Correspondence Analysis (DCA).

RESULTS

The univariate analysis indicated that the five variants; rs1800595 (FVR2; factor 5), rs1801133 (MTHFR; 5,10-methylenetetrahydrofolate reductase), rs5918 (HPA-1; human platelet antigen 1), rs1799752 (ACE; angiotensin-converting enzyme), and rs7412 and rs429358 (ApoE; apolipoprotein E) were significantly associated with CAD susceptibility under different genetic models. Multivariate analysis revealed clustering of the study population into three patient groups (P) and one control group. FVR2 was the most variant associated with CAD patients, combined with the factor V Leiden (FVL) variant in P1 cluster and with both ACE and MTHFR 667C > T in P2. Whereas, P3 was mostly affected by both MTHFR 667C > T and FXIII (factor 13) V89L mutations. When combined with traditional risk factors, P1 was mostly affected by dyslipidemia, smoking and hypertension, while P2 was mostly affected by their fasting blood sugar levels and ApoE variant.

CONCLUSIONS

Taken together, these preliminary results could have predictive value to be applied in refining a risk profile for our CAD patients, in order to implement early preventive interventions including specific antithrombotic therapy. Further large scale and follow-up studies are highly recommended to confirm the study findings.

Association of Angiotensin-Converting Enzyme Genotype, Insertion/Deletion Polymorphism and Saphenous Vein Graft Atherosclerosis in Iranian Patients

OBJECTIVE

The aim of this study was to evaluate possible interactions among Angiotensin-I converting enzyme genotype, insertion/deletion polymorphism and atherosclerosis of vein grafts in Iranian patients, and characterize their clinical and demographic profile.

METHODS

In this cross-sectional study, patients who underwent coronary artery bypass graft surgery more than five years ago, were included for angiographic analysis. Atherosclerosis was determined by quantitative angiography and adjusted Gensini score. The gene angiotensin converting enzyme I/D polymorphism was detected by polymerase chain reaction.

RESULTS

A total of 102 patients participated in this study. Eighty-four patients were male. The frequency distribution of DD, ID and II polymorphism were 23.6%, 62.7% and 13.7% respectively. There were no differences among genotypic groups in age, sex, number of risk factors, number of vein grafts and months since bypass surgery. According to adjusted Gensini score [0.18±0.12 (II) vs. 0.11±0.09 (ID) and 0.1±0.09 (DD) P=0.021] the II genotype was associated with severity of vein graft atherosclerosis.

CONCLUSION

Although there are conflicting results about gene angiotensin converting enzyme I/D polymorphism and the degree of venous bypass graft degeneration, this study suggests an association between ACE genotype II and atherosclerosis of saphenous vein grafts, however, large samples considering clinical, demographic and ethnic profile are necessary to confirm these results.

Polymorphisms in IL-10 and INF-γ genes are associated with early atherosclerosis in coronary but not in carotid arteries: A study of 122 autopsy cases of young adults

Atherosclerosis is a complex disease, involving both genetic and environmental factors. However, the influence of genetic variations on its early development remains unclear. This study examined the association of 12 different polymorphisms with atherosclerosis severity in anterior descending coronary (DA, n = 103) and carotid arteries (CA, n = 66) of autopsied young adults (< 30 years old). Histological sections (H-E) were classified according to the American Heart Association. Polymorphisms in ACE, TNF-α (− 308G/A and − 238 G/A), IFN-γ (+ 874 A/T), MMP-9 (− 1562 C/T), IL-10 (− 1082 A/G and − 819 C/T), NOS3 (894 G/T), ApoA1 (rs964184), ApoE (E2E3E4 isoforms), and TGF-β (codons 25 and 10) genes were genotyped by gel electrophoresis or automatic DNA sequencing. Firearm projectile or car accident was the main cause of death, and no information about classical risk factors was available. Histological analysis showed high prevalence of type III atherosclerotic lesions in both DA (69%) and CA (39%) arteries, while severe type IV and V lesions were observed in 14% (DA) and 33% (CA). Allele frequencies and genotype distributions were determined. Among the polymorphisms studied, IFN-γ and IL-10 (− 1082 A/G) were related to atherosclerosis severity in DA artery. No association between genotypes and lesion severity was found in CA. In conclusion, we observed that the high prevalence of early atherosclerosis in young adults is associated with IFN-γ (p < 0.001) and IL-10 (p = 0.013) genotypes. This association is blood vessel dependent. Our findings suggest that the vascular system presents site specialization, and specific genetic variations may provide future biomarkers for early disease identification.

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Twelve SNPs were associated with atherosclerosis severity in autopsied young adults.

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We found high prevalence of type III lesions in coronary and carotid arteries.

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Even severe lesions (types IV and V) were found in DA (14%) and CA (33%) arteries.

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Lesion severity was associated with IL-10 and IFN-γ genotype.

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The association was observed only in coronary, but not in carotid artery.

Endothelial progenitor cells induce transplant arteriosclerosis via VEGFR-1/2 activity

BACKGROUND

Acute rejection (AR) after organ transplantation results in transplant arteriosclerosis (TA). Endothelial progenitor cells (EPCs) are involved in tissue repair and blood vessel formation but are suspected to be a cause of TA.

METHODS

In this study, we introduced a syngeneic and allogeneic abdominal aortic transplant model with C57BL/6 and BALB/c mice. Syngeneic and allogeneic grafts were histopathologically analyzed after transplantation. Bone marrow-derived EPCs were injected into transplant model animals to observe their distribution and temporal concentration changes. Changes of vascular endothelial growth factor receptor 1 (VEGFR-1), phosphorylated VEGFR-1 (pVEGFR-1), VEGFR-2, pVEGFR-2, protein kinase B (Akt), pAkt, extracellular signal-regulated kinase 1 (Erk1), pErk1 levels in EPCs upon VEGF165 and the VEGFR inhibitor Vandetanib exposure were analyzed in vitro with western blotting.

RESULTS

In the allogeneic transplant group, two weeks after transplantation, formations of new intima layers could be observed, and its proliferation gradually increased to four and six weeks post-transplantation (p < 0.05), accompanied by significant arterial stenoses. Exogenous EPCs mainly localized to the damaged sites of the transplant arteries. In vivo, Vandetanib caused a significant dose dependent decrease of transplant hyperplasia (p < 0.05) and inhibited VEGF related proliferation, migration and adhesion of EPCs.

CONCLUSION

Vandetanib treatment can reduce arteriosclerosis induced by abdominal aorta transplantation by blocking VEGFRs in EPCs.

HIV-infection, atherosclerosis and the inflammatory pathway: candidate gene study in a Spanish HIV-infected population

Background

Higher prevalence of atherosclerosis and higher cardiovascular risk is observed in HIV-infected individuals. The biological mechanisms underlying these processes are unclear. Several studies have implicated genetic variants in the inflammatory genes in cardiovascular disease and in HIV natural course infection.

Methods & Findings

In this study we have tested the possible association between genetic variants in several inflammatory genes and asymptomatic cardiovascular disease measured by carotid intima media thickness (cIMT) and atherosclerotic plaque presence as dependent variables in 213 HIV-infected individuals. A total of 101 genetic variants in 25 candidate genes have been genotyped. Results were analyzed using Plink and SPSS statistical packages. We have found several polymorphisms in the genes ALOX5 (rs2115819 p = 0.009), ALOX5AP (rs9578196 p = 0.007; rs4769873 p = 0.004 and rs9315051 p = 0.0004), CX3CL1 (rs4151117 p = 0.040 and rs614230 p = 0.015) and CCL5 (rs3817655 p = 0.018 and rs2107538 p = 0.018) associated with atherosclerotic plaque. cIMT mean has been associated with CRP (1130864 p = 0.0003 and rs1800947 p = 0.008), IL1RN (rs380092 p = 0.002) and ALOX5AP (rs3885907 p = 0.02) genetic variants.

Conclusions

In this study we have found modest associations between genetic variants in several inflammatory genes and atherosclerotic plaque or cIMT. Nevertheless, our study adds evidence to the association between inflammatory pathway genetic variants and the atherosclerotic disease in HIV-infected individuals.

Cav1.2, cell proliferation, and new target in atherosclerosis

Ca_v1.2 calcium channels are the principal proteins involved in electrical, mechanical, and/or signaling functions of the cell. Ca_v1.2 couples membrane depolarization to the transient increase in intracellular Ca²⁺ concentration that is a trigger for muscle contraction and CREB-dependent transcriptional activation. The CACNA1C gene coding for the Ca_v1.2 pore-forming α_1C subunit is subject to extensive alternative splicing. This review is the first attempt to follow the association between cell proliferation, Ca_v1.2 expression and splice variation, and atherosclerosis. Based on insights into the association between the atherosclerosis-induced molecular remodeling of Ca_v1.2, proliferation of vascular smooth muscle cells, and CREB-dependent transcriptional signaling, this review will give a perspective outlook for the use of the CACNA1C exon skipping as a new potential gene therapy approach to atherosclerosis.

Connexins in atherosclerosis

Atherosclerosis, a chronic inflammatory disease of the vessel wall, involves multiple cell types of different origins, and complex interactions and signaling pathways between them. Autocrine and paracrine communication pathways provided by cytokines, chemokines, growth factors and lipid mediators are central to atherogenesis. However, it is becoming increasingly recognized that a more direct communication through both hemichannels and gap junction channels formed by connexins also plays an important role in atherosclerosis development. Three main connexins are expressed in cells involved in atherosclerosis: Cx37, Cx40 and Cx43. Cx37 is found in endothelial cells, monocytes/macrophages and platelets, Cx40 is predominantly an endothelial connexin, and Cx43 is found in a large variety of cells such as smooth muscle cells, resident and circulating leukocytes (neutrophils, dendritic cells, lymphocytes, activated macrophages, mast cells) and some endothelial cells. Here, we will systematically review the expression and function of connexins in cells and processes underlying atherosclerosis. This article is part of a Special Issue entitled: The Communicating junctions, roles and dysfunctions.

Polymorphic variation in choline transporter gene (CHT1) is associated with early, subclinical measures of carotid atherosclerosis in humans

Atherosclerosis is a heritable trait with little known about specific genetic influences on preclinical measures of plaque formation. Based on relations of parasympathetic-cholinergic function to atherosclerosis and to a choline transporter gene [CHT1 (G/T)] polymorphism, we investigated whether the same allelic variant predicts variation in carotid intima-media thickness (IMT) and plaque formation. Carotid IMT and plaque occurrence as well as genotyping for the CHT1 (G/T) variant were measured in a sample (N = 264) of generally healthy adults (age 30-55) of European ancestry. CHT1 GG homozygotes had greater IMT (P < 0.005) and plaque occurrence (P < 0.020) than T allele carriers. This is the first study showing polymorphic variation in the CHT1 gene to predict early, subclinical measures of carotid atherosclerosis which may aid in understanding cholinergic-vagal processes potentially underlying atherosclerotic risk.

The Use of High-Throughput Technologies to Investigate Vascular Inflammation and Atherosclerosis

The greatest challenge of scientific research is to understand the causes and consequences of disease. In recent years, great efforts have been devoted to unraveling the basic mechanisms of atherosclerosis (the underlying pathology of cardiovascular disease), which remains a major cause of morbidity and mortality worldwide. Because of the complex and multifactorial pathophysiology of cardiovascular disease, different research techniques have increasingly been combined to unravel genetic aspects, molecular pathways, and cellular functions involved in atherogenesis, vascular inflammation, and dyslipidemia to gain a multifaceted picture addressing this complexity. Thanks to the rapid evolution of high-throughput technologies, we are now able to generate large-scale data on the DNA, RNA, and protein levels. With the help of sophisticated computational tools, these data sets are integrated to enhance information extraction and are being increasingly used in a systems biology approach to model biological processes as interconnected and regulated networks. This review exemplifies the use of high-throughput technologies—such as genomics, transcriptomics, proteomics, and epigenomics—and systems biology to explore pathomechanisms of vascular inflammation and atherosclerosis.

Hypercholesterolemia promotes early renal dysfunction in apolipoprotein E-deficient mice

Background

Aging and dyslipidemia are processes which can lead to deleterious consequences to renal function. Therefore, the aim of this study was to determine the effects of both hypercholesterolemia and aging on renal function in mice.

Methods

Male hypercholesterolemic apolipoprotein E-deficient mice (ApoE, n = 13) and age-matched C57BL/6 control mice (C57, n = 15) were studied at 2 (young) and 8 (adult) month-old. At each time point, animals were placed in metabolic cages for 24 hours to urine volume and urinary creatinine quantification. Blood samples were collected for serum cholesterol, urea and creatinine measurements. Glomerular filtration rate (GFR) was estimated through creatinine clearance determination. Mesangial expansion was evaluated by Periodic Acid Schiff staining, renal fibrosis was determined through Masson's trichrome staining and neuronal nitric oxide synthase (nNOS) expression in the kidney was performed by Western Blotting. To statistical analysis two-way ANOVA followed by Fisher's post hoc test was used.

Results

Total plasma cholesterol was increased about 5-fold in ApoE mice at both time points compared to C57 animals. At 2-month-old, GFR was already markedly reduced in ApoE compared to C57 mice (187 ± 28 vs 358 ± 92 μL/min, p < 0.05). Adult C57 (-77%) and ApoE (-50%) mice also presented a significant reduction of GFR. In addition, serum urea was significantly increased in young ApoE animals compared to C57 mice (11 ± 1.3 vs 7 ± 0.9 mmol/L, p < 0.01). A significant mesangial expansion was observed at 2-month old ApoE mice compared to C57 mice (35 ± 0.6 vs 30 ± 0.9%, respectively, p < 0.05), which was aggravated at 8-month old animals (40 ± 3 and 35 ± 3%, respectively). Tubulointersticial fibrosis was augmented at both young (17 ± 2%, p < 0.05) and adult (20 ± 1%, p < 0.05) ApoE mice compared to respective C57 age controls (8 ± 1 and 12 ± 2%, respectively). The expression of nNOS was markedly reduced in a time-dependent manner in both strains.

Conclusions

These data show that both hypercholesterolemia and aging contribute to the loss of renal function in mice.

The association between variants on chromosome 9p21 and inflammatory biomarkers in ethnically diverse women with coronary heart disease: a pilot study

BACKGROUND

The most consistently replicated genetic variants associated with coronary heart disease (CHD) in populations of European descent have been found on chromosome 9p21. Yet there is little known about these associations in ethnic groups of African ancestry. These disease-associated variants are located in a genomic region of unknown function. The purpose of this exploratory study was to examine the allelic frequencies and haplotype structure of single nucleotide polymorphisms (SNPs) for Black and White women with CHD. The authors also sought to explore the relationship between these genetic variants and biomarkers of inflammation.

METHODS

Using polymerase chain reaction amplification, the authors genotyped 8 SNPs in a 58-kilobase region of chromosome 9p21 in a cohort of women with CHD (n = 91). The authors examined the interethnic relationship between the SNPs and four inflammatory biomarkers (C-reactive protein, intercellular adhesion molecule-1, interleukin-6, and tumor necrosis factor-alpha) using analysis of variance (ANOVA).

RESULTS

We found considerable interethnic allelic and haplotype diversity across the 9p21 locus, with only two SNPs in perfect linkage disequilibrium (LD) in both races. A pair of high- and low-risk haplotypes was most common in White women, while about 41% of Blacks carried the risk alleles for three of the eight SNPs the authors examined. The interethnic associations between the SNP genotypes and inflammatory markers were divergent in both direction and magnitude.

CONCLUSIONS

Our results lend support for the importance of ancestry-specific allelic context when examining variants on chromosome 9p21. Additional work is needed to elucidate the genetic contribution to inflammatory biomarkers for diverse racial groups.

Hypercholesterolemia-induced erectile dysfunction: endothelial nitric oxide synthase (eNOS) uncoupling in the mouse penis by NAD(P)H oxidase

INTRODUCTION

Hypercholesterolemia induces erectile dysfunction (ED) mostly by increasing oxidative stress and impairing endothelial function in the penis, but the mechanisms regulating reactive oxygen species (ROS) production in the penis are not understood.

AIMS

We evaluated whether hypercholesterolemia activates nicotinamide adenine dinucleotide phosphate (NAD[P]H) oxidase in the penis, providing an initial source of ROS to induce endothelial nitric oxide synthase (eNOS) uncoupling and endothelial dysfunction resulting in ED.

METHODS

Low-density-lipoprotein receptor (LDLR)-null mice were fed Western diet for 4 weeks to induce early-stage hyperlipidemia. Wild type (WT) mice fed regular chow served as controls. Mice received NAD(P)H oxidase inhibitor apocynin (10 mM in drinking water) or vehicle. Erectile function was assessed in response to cavernous nerve electrical stimulation. Markers of endothelial function (phospho [P]-vasodilator-stimulated-protein [VASP]-Ser-239), oxidative stress (4-hydroxy-2-nonenal [HNE]), sources of ROS (eNOS uncoupling and NAD[P]H oxidase subunits p67(phox) , p47(phox) , and gp91(phox) ), P-eNOS-Ser-1177, and eNOS were measured by Western blot in penes.

MAIN OUTCOME MEASURES

The main outcome measures are the molecular mechanisms of ROS generation and endothelial dysfunction in hypercholesterolemia-induced ED.

RESULTS

Erectile response was significantly (P<0.05) reduced in hypercholesterolemic LDLR-null mice compared with WT mice. Relative to WT mice, hypercholesterolemia increased (P<0.05) protein expressions of NAD(P)H oxidase subunits p67(phox) , p47(phox) and gp91(phox) , eNOS uncoupling, and 4-HNE-modified proteins, and reduced (P<0.05) P-VASP-Ser-239 expression in the penis. Apocynin treatment of LDLR-null mice preserved (P<0.05) maximal intracavernosal pressure, and reversed (P<0.05) the abnormalities in protein expressions of gp67(phox) and gp47(phox) , 4-HNE, P-VASP-Ser-239, and eNOS uncoupling in the penis. Apocynin treatment of WT mice did not affect any of these parameters. Protein expressions of P-eNOS-Ser-1177 and total eNOS were unaffected by hypercholesterolemia.

CONCLUSION

Activated NAD(P)H oxidase in the penis is an initial source of oxidative stress resulting in eNOS uncoupling, thus providing a mechanism of eNOS uncoupling and endothelial dysfunction in hypercholesterolemia-induced ED.

Cross-sectional study of risk factors for atherosclerosis in the Azorean population

BACKGROUND

Atherosclerosis-a major cause of vascular disease, including ischemic heart disease (IHD), is a pathology that has a two-fold higher mortality rate in the Azorean Islands compared to mainland Portugal.

AIM

This cross-sectional study investigated the role of genetic variation in the prevalence of atherosclerosis in this population.

SUBJECTS AND METHODS

A total of 305 individuals were characterized for polymorphisms in eight susceptibility genes for atherosclerosis: ACE, PAI1, NOS3, LTA, FGB, ITGB3, PON1 and APOE. Data were analysed with respect to phenotypic characteristics such as blood pressure, lipid profile, life-style risk factors and familial history of myocardial infarction.

RESULTS

In the total sample, frequencies for hypercholestrolemic, hypertensive and obese individuals were 63.6%, 39.3% and 23.3%, respectively. The genetic profile was similar to that observed in other European populations, namely in mainland Portugal. No over-representation of risk alleles was evidenced in this sample.

CONCLUSIONS

One has to consider the possibility of an important non-genetic influence on the high cholesterolemia present in the Azorean population. Since diet is the most important life-style risk factor for dyslipidemia, studies aiming to evaluate the dietary characteristics of this population and its impact on serum lipid levels will be of major importance.

Leptin receptor Lys109Arg and Gln223Arg polymorphisms are associated with early atherosclerosis

BACKGROUND

Leptin is a hormone expressed by the leptin gene, primarily in adipocytes, controlling food intake and energy expenditure. The effects of leptin are mediated by its receptor (LEPR) located in the central nervous system and other tissues, including adipocytes and endothelial cells. The aim of this study was to characterize two polymorphisms of LEPR, Lys109Arg (rs1137100) and Gln223Arg (rs1137101), as risk factors for early atherosclerosis. This connection has not been studied before.

METHODS

This study was performed in the randomly selected, middle-aged control subjects (n=526) from our well-defined OPERA (Oulu Project Elucidating Risk of Atherosclerosis) study. Analysis of covariance (ANCOVA) was performed to study the associations between genotypes, intima media thickness (IMT) measurements, and risk factors for atherosclerosis.

RESULTS

Subjects with the genotype Lys109Arg had the lowest body mass index (BMI) (P = 0.035), whereas Arg109Arg homozygotes had the highest total cholesterol (P=0.021) when adjusted for sex and age. Gln223Arg associated independently with systolic blood pressure (P=0.036). There were no differences in leptin concentrations between the genotypes. The adjusted (sex, age, BMI, smoking status, low-density lipoprotein cholesterol, systolic blood pressure, and fasting blood glucose) means for the IMT measurements were lowest in the Arg109 and Arg223 homozygotes (P=0.042 and P=0.041, ANCOVA, respectively).

CONCLUSIONS

The variations in the LEPR gene are independently associated with early atherosclerosis and some of its risk factors. These variations could possibly affect leptin signaling and thereby modify the effects of leptin on the atherosclerotic process.

Combined effect of inflammatory gene polymorphisms and the risk of ischemic stroke in a prospective cohort of subjects with type 2 diabetes: a Go-DARTS study

OBJECTIVE

We have previously observed that genetic profiles determined by the combination of five functionally significant single nucleotide polymorphisms (SNPs) (rs1800795, rs5498, rs5361, rs1024611, and rs679620) of genes encoding prototypical inflammatory molecules are associated with history of ischemic stroke. Here we tested the ability of this multigenic model to predict stroke risk in a large population-based prospective cohort of subjects with type 2 diabetes.

RESEARCH DESIGN AND METHODS

This study was conducted using a prospective cohort of individuals with type 2 diabetes participating in the Go-DARTS (Genetics of Diabetes Audit and Research in Tayside Scotland) study, which includes genetic and clinical information of patients with diabetes within the Tayside region of Scotland, U.K. The above-mentioned inflammatory SNPs were investigated in 2,182 Go-DARTS participants. We created an inflammatory risk score (IRS), ranging from 0 to 5, according to the number of "at-risk" genotypes concomitantly carried by a given individual. The primary outcome was the occurrence of fatal or nonfatal stroke of any kind. Mean follow-up time was 6.2 ± 1.1 years.

RESULTS

The incidence of stroke increased according to the IRS. The IRS was significantly and independently associated with increased stroke risk after adjustment for other conventional risk factors (hazard ratio 1.34 [95% CI 1.1-1.7]; P = 0.009). The highest hazard ratio for stroke was found in subjects concomitantly carrying > 3 proinflammatory variations and in subjects without previous cardiovascular diseases.

CONCLUSIONS

This large prospective cohort study provides evidence that SNPs of genes encoding prototypical inflammatory molecules may be used to create multigenic models that predict stroke risk in subjects with type 2 diabetes.

Translating genomic analyses into improved management of coronary artery disease

Human genetic variation can modulate pathophysiologic processes that alter susceptibility to complex disease. Recent genomic analyses have sought to identify how common genetic variation alters susceptibility to coronary artery disease (CAD). From genome-wide association studies (GWAS), common genetic variants in several novel chromosomal loci have been associated with CAD. GWAS identified the 9p21 locus as the strongest independent genetic CAD risk factor, along with 11 additional loci that harbor common genetic variants associated with increased CAD risk. A thorough understanding of human genetic variation and genomic analyses will be crucial to understand how GWAS-identified loci increase susceptibility to CAD. This article outlines the relevance of genetic variation in the elucidation of novel CAD risk factors and the clinical utility of genetic variants in the management and treatment of CAD.

Genetic variants promoting smooth muscle cell proliferation can result in diffuse and diverse vascular diseases: evidence for a hyperplastic vasculomyopathy

Genetic predisposition to early onset of occlusive vascular diseases, including coronary artery disease, ischemic stroke, and Moyamoya disease, may represent varying presentations of a common underlying dysregulation of vascular smooth muscle cell proliferation. We discuss mutations in two genes, NF1 and ACTA2, which predispose affected individuals to diffuse and diverse vascular diseases. These patients show evidence of diffuse occlusive disease in multiple arterial beds or even develop seemingly diverse arterial pathologies, ranging from occlusions to arterial aneurysms. We also present the current evidence that both NF1 and ACTA2 mutations promote increased smooth muscle cell proliferation in vitro and in vivo, which leads us to propose that these diffuse and diverse vascular diseases are the outward signs of a more fundamental disease: a hyperplastic vasculomyopathy. We suggest that the concept of a hyperplastic vasculomyopathy offers a new approach not only to identifying mutated genes that lead to vascular diseases but also to counseling and possibly treating patients harboring such mutations. In other words, this framework may offer the opportunity to therapeutically target the inappropriate smooth muscle cell behavior that predisposes to a variety of vascular diseases throughout the arterial system.

Role of somatic mutations in vascular disease formation

Coronary artery disease, cerebrovascular disease, pulmonary artery hypertension and Alzheimer's disease all lead to substantial morbidity and mortality, and we currently lack effective treatments for these vascular diseases. Since the discovery, decades ago, that atherosclerotic lesions display clonal growth, atherosclerosis and other vascular diseases have been postulated to be neoplastic processes, arising through a series of critical somatic mutations. There is conflicting evidence supporting this but studies of DNA damage and mutagenesis, both genomic and mitochondrial, in atherosclerotic and vascular lesions, have yielded evidence that somatic mutations are involved in atherogenesis and vascular disease development. The roles of mitochondrial DNA damage, oxidative stress and signaling by members of the TGF-beta receptor family are implicated. With the increasing convenience and cost-effectiveness of genome sequencing, it is feasible to continue to seek specific genetic targets in the pathogenesis of these devastating diseases, with the hope of developing personalized genomic medicine in the future.

Expression of cytokine genes in the aorta is altered by the deficiency in MCP-1: effect of a high-fat, high-cholesterol diet

BACKGROUND

Monocyte chemoattractant protein-1 (MCP-1) facilitates the recruitment of monocytes/macrophages into vascular intima, and it is probably involved in the regulation of other signaling pathways relevant to the pathogenesis of arteriosclerosis and metabolic disturbances. However, chemokines are redundant. Consequently, the protective effect of MCP-1 deficiency may be mediated by changes in other cytokine signals.

METHODS AND RESULTS

Changes in the pattern of gene expression in the aorta were evaluated in LDLr(-/-) and MCP-1(-/-) LDLr(-/-) mice fed either chow or Western-style diet. Functional analyses were used to characterize the pathways affected and to identify biological processes in which MCP-1 may play an additional role. Some data also suggest that MCP-5 may act as a surrogate for MCP-1 deletion. Arteriosclerosis lesion and plaque composition are associated with enrichment in the cytokine-cytokine receptor interaction pathway.

CONCLUSIONS

There is a complex network of interactions linking MCP-1 and other cytokines. The lack of MCP-1 limits the aortic response to atherogenic stimuli, but does not completely protect against neointima formation. Activation of alternative inflammatory pathways in the vascular wall in response to MCP-1 deficiency should be considered to fully understand the actual role of this chemokine.

Predictive genetic testing for coronary artery disease

Coronary artery disease (CAD) is an inflammatory-metabolic disease in which atherosclerotic plaques cause stenosis of the coronary arteries, leading to acute clinical complications such as myocardial infarction. Since CAD is a multifactorial, polygenic disease with a substantial environmental component, individual risk prediction and stratification is often difficult. Recent technological advances have resulted in substantial progress elucidating the impact of common genetic variation on CAD progression. The discovery of common genetic variants, including the chromosome 9p21.3 locus as the strongest and most highly replicated independent genetic CAD risk factor, has stimulated interest in genetic testing for CAD-associated risk variants. The ultimate goal of genotype-based CAD risk prediction is to improve upon the discrimination and stratification offered by conventional risk factors alone. Genotype-based CAD risk prediction may eventually have clinical utility, but not without intrinsic complexities. Are genotype variables superior predictors of risk compared to a family history of CAD? Is a 10-year risk prediction window ambitious enough for the predictive power of genotype data? This review will outline the current state of genotype-based CAD risk prediction and highlight challenging issues integral to the successful implementation of genetic testing for CAD.