Association of single nucleotide polymorphisms in endothelin family genes with the progression of atherosclerosis in patients with essential hypertension

Endothelin-converting Enzyme-1b Genetic Variants Increase the Risk of Coronary Artery Ectasia

Coronary artery ectasia (CAE), defined as a 1.5-fold or greater enlargement of a coronary artery segment compared to the adjacent normal coronary artery, is frequently associated with atherosclerotic coronary artery disease (CAD). Membrane-bound endothelin converting enzyme-1 (ECE-1) is involved in the maturation process of the most potent vasoconstrictor ET-1. Polymorphisms in the endothelin (ET) gene family have been shown associated with the development of atherosclerosis. This study aims to investigate the effects of rs213045 and rs2038089 polymorphisms in the ECE-1 gene which have been previously shown to be associated with atherosclerosis and hypertension (HT), in CAE patients. Ninety-six CAE and 175 patients with normal coronary arteries were included in the study. ECE-1b gene variations rs213045 and rs2038089 were determined by real-time PCR. The frequencies of rs213045 C > A (C338A) CC genotype (60.4% vs. 35.4%, p < 0.001) and rs2038089 T > C T allele (64.58% vs. 35.42%, p = 0.017) were higher in the CAE group compared to the control group. The multivariate regression analysis showed that the ECE-1b rs213045 CC genotype (p = 0.001), rs2038089 T allele (p = 0.017), and hypercholesterolemia (HC) (p = 0.001) are risk factors for CAE. Moreover, in nondiabetic individuals of the CAE and control groups, it was observed that the rs213045 CC genotype (p < 0.001), and rs2038089 T allele (p = 0.003) were a risk factor for CAE, but this relationship was not found in the diabetic subgroups of the study groups (p > 0.05). These results show that ECE-1b polymorphisms may be associated with the risk of CAE and this relationship may change according to the presence of type II diabetes.

Matrix Gla protein polymorphism rs1800802 is associated with atheroma plaque progression and with cardiovascular events in a chronic kidney disease cohort

Background

Chronic kidney disease (CKD) is associated with increased atherosclerotic burden and higher risk for cardiovascular events (CVE). Atherosclerosis has a significant genetic component and, in CKD, it is influenced by mineral metabolism alterations. Therefore, genetic modifications of mineral metabolism-related proteins could affect atherosclerosis in CKD patients. In the present study we investigated the role of single nucleotide polymorphisms (SNPs) of the matrix gamma-carboxy glutamic acid protein (MGP) on atherosclerosis progression and CVE in a CKD cohort.

Methods

A total of 2187 CKD patients from the Observatorio Nacional de Aterosclerosis en Nefrologia (NEFRONA) study were genotyped for SNPs present in the matrix gamma-carboxy glutamic acid (Gla) protein (MGP) gene. Atheromatosis was detected by vascular ultrasound. Progression of atheromatosis, defined as an increase in territories with plaque, was assessed after 24 months. Patients were followed for 48 months for CVE. Association of SNPs with plaque progression was assessed by logistic regression and their capacity to predict CVE by Cox regression.

Results

Three SNPs of the MGP gene were analyzed. No association of the rs4236 or the rs1800801 SNPs was detected with any of the outcomes. However, patients homozygotes for the minor allele of the rs1800802 SNP showed higher adjusted risk for plaque progression [odds ratio 2.3 (95% confidence interval 1.06-4.9)] and higher risk of suffering a CVE [hazard ratio 2.16 (95% confidence interval 1.13-4.12)] compared with the rest of genotypes. No association of the SNP with total or dp-ucMGP levels was found in a subsample.

Conclusions

The rs1800802 polymorphism of MGP is associated with plaque progression and CVE in CKD patients.

Identification of the Transcription Factor ATF3 as a Direct and Indirect Regulator of the LDLR

Coronary artery disease (CAD) is a complex, multifactorial disease caused, in particular, by inflammation and cholesterol metabolism. At the molecular level, the role of tissue-specific signaling pathways leading to CAD is still largely unexplored. This study relied on two main resources: (1) genes with impact on atherosclerosis/CAD, and (2) liver-specific transcriptome analyses from human and mouse studies. The transcription factor activating transcription factor 3 (ATF3) was identified as a key regulator of a liver network relevant to atherosclerosis and linked to inflammation and cholesterol metabolism. ATF3 was predicted to be a direct and indirect (via MAF BZIP Transcription Factor F (MAFF)) regulator of low-density lipoprotein receptor (LDLR). Chromatin immunoprecipitation DNA sequencing (ChIP-seq) data from human liver cells revealed an ATF3 binding motif in the promoter regions of MAFF and LDLR. siRNA knockdown of ATF3 in human Hep3B liver cells significantly upregulated LDLR expression (p < 0.01). Inflammation induced by lipopolysaccharide (LPS) stimulation resulted in significant upregulation of ATF3 (p < 0.01) and subsequent downregulation of LDLR (p < 0.001). Liver-specific expression data from human CAD patients undergoing coronary artery bypass grafting (CABG) surgery (STARNET) and mouse models (HMDP) confirmed the regulatory role of ATF3 in the homeostasis of cholesterol metabolism. This study suggests that ATF3 might be a promising treatment candidate for lowering LDL cholesterol and reducing cardiovascular risk.

Cap analysis of gene expression reveals alternative promoter usage in a rat model of hypertension

The role of alternative promoter usage in tissue-specific gene expression has been well established; however, its role in complex diseases is poorly understood. We performed cap analysis of gene expression (CAGE) sequencing from the left ventricle of a rat model of hypertension, the spontaneously hypertensive rat (SHR), and a normotensive strain, Brown Norway to understand the role of alternative promoter usage in complex disease. We identified 26,560 CAGE-defined transcription start sites in the rat left ventricle, including 1,970 novel cardiac transcription start sites. We identified 28 genes with alternative promoter usage between SHR and Brown Norway, which could lead to protein isoforms differing at the amino terminus between two strains and 475 promoter switching events altering the length of the 5' UTR. We found that the shift in Insr promoter usage was significantly associated with insulin levels and blood pressure within a panel of HXB/BXH recombinant inbred rat strains, suggesting that hyperinsulinemia due to insulin resistance might lead to hypertension in SHR. Our study provides a preliminary evidence of alternative promoter usage in complex diseases.

Association between high systolic blood pressure and objective hearing impairment among Japanese adults: a facility-based retrospective cohort study

This retrospective longitudinal study examined the association between systolic blood pressure and hearing impairment among 13,187 Japanese individuals (men, 46.5%) aged 20-59 years. The systolic blood pressure of participants was categorized as <120, 120-129, 130-139, 140-149, 150-159, and ≥160 mmHg. Using pure-tone audiometry, hearing impairment at 1 and 4 kHz was defined as hearing thresholds in either ear >30 and >40 dB, respectively. We performed multivariable Cox proportional-hazards regression analysis to examine the association using two multiple-imputation methods (fully conditional specification and Markov chain Monte Carlo). There were 695 and 774 hearing-impairment cases at 1 and 4 kHz, respectively, during ~77,000 person-years of follow-up. Compared with the <120 mmHg group, the hazard ratios (95% confidence intervals) of hearing impairment for the 120-129, 130-139, 140-149, 150-159, and ≥160 mmHg groups after adjustment for age, sex, body mass index, high serum glucose, current smoking, and other potential confounders were 1.35 (1.12-1.63), 1.45 (1.13-1.86), 1.07 (0.73-1.58), 1.91 (1.18-3.07), and 1.81 (1.01-3.25), respectively, at 1 kHz using the first imputation method; 1.36 (1.13-1.63), 1.48 (1.17-1.86), 1.09 (0.76-1.58), 1.99 (1.29-3.06), and 1.92 (1.08-3.41), respectively, at 1 kHz using the second imputation method; 1.04 (0.86-1.24), 1.14 (0.91-1.43), 1.13 (0.83-1.54), 1.45 (0.96-2.19), and 1.35 (0.82-2.23), respectively, at 4 kHz using the first imputation method; and 1.03 (0.86-1.24), 1.17 (0.95-1.44), 1.15 (0.87-1.53), 1.54 (1.06-2.24), and 1.44 (0.88-2.35), respectively, at 4 kHz using the second imputation method. In conclusion, higher systolic blood pressure was associated with hearing impairment at 1 kHz. No clear association was observed at 4 kHz.

Association of Gene Polymorphisms of Some Endothelial Factors with Stent Reendothelization after Elective Coronary Artery Revascularization

Restenosis remains the main complication after percutaneous coronary interventions in patients with coronary heart disease. The causes of its development include, in particular, genetic factors. We studied polymorphic loci of genes encoding endothelin-1 (EDN1 rs5370), endothelin-1 receptor (EDNRA rs5333), endothelin-converting enzyme (ECE1 rs1076669), and endothelial NO synthase (eNOS rs1549758, eNOS rs1799983, and eNOS rs2070244) in the context of in-stent restenosis development. It was found that the analyzed polymorphisms of the endothelin system genes were more significant for patients aged ≥ 65 years, while the polymorphic loci of the endothelial NO synthase gene (eNOS rs1799983 and eNOS rs1549758) were predominantly associated with time of in-stent restenosis. The obtained results can be useful for comprehensive assessment of the restenosis risk factors and the choice of optimal treatment for patients with coronary heart disease before elective surgical intervention.

Genetic Polymorphisms in Sudden Sensorineural Hearing Loss: An Update

OBJECTIVE

To investigate the association between genetic polymorphisms and sudden sensorineural hearing loss (SSNHL). Most of the SSNHL cases still remain idiopathic, and several etiopathogenetic hypotheses, including a genetic predisposition, have been proposed.

METHODS

A literature review was conducted using different databases: Medline/PubMed, EMBASE, and CINAHL, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. All databases have been searched from May 2016 to April 2020.

RESULTS

Genetic susceptibility could represent a key element in the pathogenesis of SSNHL. A number of genetic polymorphisms related to (1) inner ear microvascular disease and endothelial dysfunction and (2) to inner ear oxidative stress and inflammation have been addressed in the current literature.

CONCLUSIONS

The potential identification of a genetic profile related to SSNHL could provide a more accurate prognostic evidence of idiopathic SSNHL (ISSNHL), offering to the patients not only early-prevention strategies but eventually information on various inheritance modalities.

Ancient genomes from present-day France unveil 7,000 years of its demographic history

Genomic studies conducted on ancient individuals across Europe have revealed how migrations have contributed to its present genetic landscape, but the territory of present-day France has yet to be connected to the broader European picture. We generated a large dataset comprising the complete mitochondrial genomes, Y-chromosome markers, and genotypes of a number of nuclear loci of interest of 243 individuals sampled across present-day France over a period spanning 7,000 y, complemented with a partially overlapping dataset of 58 low-coverage genomes. This panel provides a high-resolution transect of the dynamics of maternal and paternal lineages in France as well as of autosomal genotypes. Parental lineages and genomic data both revealed demographic patterns in France for the Neolithic and Bronze Age transitions consistent with neighboring regions, first with a migration wave of Anatolian farmers followed by varying degrees of admixture with autochthonous hunter-gatherers, and then substantial gene flow from individuals deriving part of their ancestry from the Pontic steppe at the onset of the Bronze Age. Our data have also highlighted the persistence of Magdalenian-associated ancestry in hunter-gatherer populations outside of Spain and thus provide arguments for an expansion of these populations at the end of the Paleolithic Period more northerly than what has been described so far. Finally, no major demographic changes were detected during the transition between the Bronze and Iron Ages.

Genetic Predictors of Knee Pain in Persons With Mild to Moderate Osteoarthritis

The purpose of this study was to examine genetic variability and knee pain in persons with osteoarthritis (OA). Seventy-five participants with medial compartment knee OA were recruited from a large Midwestern tertiary care center. Participants exhibited a mean age of 56.3 years; females comprised 61% of the sample. Measures of pain included subjective pain intensity at rest and with movement, cutaneous mechanical sensation and pain testing, heat pain threshold, and pressure pain threshold. Seventy-four participants were genotyped for 25 genetic variants across 15 candidate genes for central or peripheral pain pathways. Analysis suggests a role for four genes (EDNRA, COMT, BDRKB1, and IL1B) in several components of pain in persons with knee OA. The results from this study will help guide the development and evaluation of tailored strategies to decrease pain, improve function, and prevent the development of new chronic pain syndromes in older adults experiencing OA. [Research in Gerontological Nursing, xx(x), xx-xx.].

Evaluation of single nucleotide polymorphisms in 6 candidate genes and carotid intima-media thickness in community-dwelling residents

Evidence suggests the existence of association between a large panel of modifiable biomarkers representing inflammation, coagulation, paraoxonase, and endothelial activation pathways and carotid atherosclerosis. Thus, this study investigated whether CRP, FGA, FGB, FGG, PON1, and EDNRA gene variants affected plasma hs-CRP, fibrinogen levels, and thickness of carotid intima media thickness (IMT). Nineteen single-nucleotide polymorphisms of CRP, FGA, FGB, FGG, PON1, and EDNRA genes were examined in 480 participants from 160 families. Carotid IMT was measured by ultrasound. Generalized linear models with generalized estimating equation were utilized to consider the dependence of subjects within families. In the recessive model, homozygotes for the minor alleles of rs1800789, rs1800790 and rs4220 SNPs in FGB gene indicated a reduced risk of IMT (Exp. β = 0.89, 0.89, 0.88), which remained significant after adjustment for confounding factors. Significant interaction effects between CRP SNP rs1130864 and rs3093059 and gender for IMT were observed with a significant association in men only. Men carrying minor-minor genotype of CRP SNP rs1130864 and rs3093059 had 0.70- and 0.78-fold lower IMT than men carrying minor-major/major-major genotype. We also observed that the interaction of CRP SNP rs1130864 and rs3093059 with obesity on IMT, hs-CRP and fibrinogen levels. These results support the hypothesis that inflammatory genes are involved in atherosclerosis, most likely via complex gene-gender and gene-obesity interactions.

Functional lncRNA-miRNA-mRNA networks in rabbit carotid atherosclerosis

Atherosclerosis is one of the most common clinical cardiovascular disorders. Accumulating evidence indicates that lncRNAs exert critical functions in atherosclerosis; however, their functional roles and regulatory mechanisms remain unclear. In this study, we induced atherosclerotic plaques in three rabbit carotid arteries through an atherogenic diet and balloon injury; three age-matched rabbits were fed normal chow and served as controls. We thoroughly investigated the RNA (mRNA, lncRNA and miRNA) expression profiles in atherosclerotic rabbit carotid models with deep RNA sequencing. We identified several significantly differentially expressed RNAs. The corresponding lncRNA-miRNA-mRNA network was constructed, and the significantly dysregulated network was selected. Furthermore, Gene Ontology and  Kyoto Encyclopedia of Genes and Genomes analyses indicated that the mRNAs in the network were involved in leukocyte activation, cell proliferation, cell adhesion molecules and cytokine-cytokine receptor interaction. After rigorous screening, we obtained a differentially expressed lncRNA-miRNA-mRNA interaction network associated with atherosclerosis. In the network, XLOC_054118 and XLOC_030217 upregulate the CHI3L1, SOAT, CTSB and CAPG genes by competitively binding to the miRNA ocu-miR-96-5p. XLOC_062719 and XLOC_063297 upregulate CTSS, CTSB and EDNRA genes by competitively binding to the miRNA ocu-miR-185-5p.

Effects of genotype on TENS effectiveness in controlling knee pain in persons with mild to moderate osteoarthritis

BACKGROUND

This study examined the extent to which genetic variability modifies Transcutaneous Electrical Nerve Stimulation (TENS) effectiveness in osteoarthritic knee pain.

METHODS

Seventy-five participants with knee osteoarthritis were randomly assigned to either: (a) High-frequency TENS, (b) Low-frequency TENS or (c) Transient Placebo TENS. Pain measures were collected pre- and post-treatment. Participants were genotyped on genes implicated in central or peripheral pain pathways: NGFB, NTRK1, EDNRA, EDNRB, EDN1, OPRM1, TAC1, TACR1, BDNF, BDKRB1, 5HTT, COMT, ESR2, IL6 and IL1B. Genetic association using linear regression modelling was performed separately for the transient placebo TENS subjects, and within the High-frequency TENS + Low-frequency TENS participants, including TENS level as a covariate.

RESULTS

In the placebo group, SNPs rs165599 (COMT) was significantly associated with an increased heat pain threshold (β = -1.87; p = .003) and rs6827096 (EDNRA) with an increased resting pain (β = 2.68; p = .001). Within the treatment groups, TENS effectiveness was reduced by the SNP rs6537485 (EDNRA) minor allele in relationship to mechanical sensation (β = 184.13; p = 5.5E-9). Individuals with the COMT rs4680 minor allele reported lowered pain at rest after TENS (β = -42.30; p = .001), with a higher magnitude of pain reduction (28 unit difference) in the low-frequency TENS group compared to the high-frequency TENS group (β = 28.37; p = .0004).

CONCLUSIONS

EDNRA and COMT are implicated in osteoarthritic knee pain and provide a basis for tailoring TENS interventions according to individual characteristics.

SIGNIFICANCE

Findings from this study demonstrate that genetic variation within the COMT and EDNRA genes influences the effectiveness of TENS, a non-pharmacologic pain-reduction intervention, in the context of osteoarthritic knee pain. Evidence such as this may contribute to risk models that provide a clinically useful tool for personalizing TENS interventions according to individual characteristics in order to best control pain and maximize functional status.

Associations of EDNRA and EDNRB Polymorphisms with Intracerebral Hemorrhage

OBJECTIVE

The most potent vasoconstrictor, endothelin-1 and its receptors, endothelin receptor A (EDNRA) and endothelin receptor B (EDNRB) are involved in hypertension. Hypertension is a major risk factor of intracerebral hemorrhage (ICH). Recent studies have demonstrated increased plasma endothelin-1 level in ICH patients and relationships between EDNRA and EDNRB genetic variants and ischemic stroke. The aim of the current study was to investigate whether EDNRA and EDNRB polymorphisms are associated with ICH by interacting with blood pressure levels.

METHODS

Five EDNRA and EDNRB polymorphisms were genotyped in this case-control study.

RESULTS

We identified that EDNRA rs5333 T allele might be a protective factor of ICH (adjusted odds ratio [OR] = 0.638, 95% CI: 0.417-0.977, P = 0.038), while EDNRB rs5351 A allele could be a risk factor of ICH (adjusted OR = 1.476, 95% CI: 1.042-2.089, P = 0.028). Moreover, we only found that the GG genotype of EDNRA rs5335 had higher diastolic blood pressure than the GC + CC genotypes in ICH patients (91.69 ± 18.77 vs. 84.71 ± 21.48, P = 0.004).

CONCLUSIONS

These findings support the important role of EDNRA and EDNRB polymorphisms in ICH, and suggest that they do not interact with blood pressure levels on altering ICH risk.

Positive Association between EDN1 rs5370 (Lys198Asn) Polymorphism and Large Artery Stroke in a Ukrainian Population

There are a lot of convincing evidences about the involvement of endothelin pathway proteins in the pathogenesis of atherosclerosis and its fatal complications. In this study, the analysis of a possible association between EDN1 rs5370 and EDNRA rs5335 gene polymorphisms and the risk of large artery stroke (LAS) in a Ukrainian population was conducted. 200 LAS patients and 200 unrelated controls were enrolled in a case-control study. The polymerase chain reaction-restriction fragment length polymorphism method (PCR-RFLP) was used for SNP genotyping. Our results revealed that EDN1 rs5370 polymorphism was associated with LAS development both before and after adjustment for atherosclerosis risk factors (sex, age, body mass index, arterial hypertension, type 2 diabetes mellitus, and smoking). The risk for a LAS incident in rs5370-T allele carriers was 1.6 times higher (CI = 1.066–2.403; P = 0.020) than in subjects with the GG genotype. No link between EDNRA rs5335 and LAS risk in a Ukrainian population was found. The present study indicated that EDN1 rs5370, but not EDNRA rs5335, can be the strong genetic predictor for LAS development in a Ukrainian population.

Endothelin-1 Gene Polymorphisms rs5370, rs1476046, and rs3087459 are not Associated with Diabetic Nephropathy in Caucasians with Type 2 Diabetes Mellitus

Background:Diabetic nephropathy (DN) is a major microvascular complication of type 2 diabetes mellitus (T2DM). Several lines of evidence implicate the endothelin (ET) system in the pathophysiology of DN. The aim of the present study was to analyze if genetic polymorphisms of the ET-1 (EDN1) gene affect susceptibility to DN in Caucasians with T2DM.

Materials and methods:The study population consisted of 651 Caucasian subjects with T2DM of more than 10 years’ duration: 276 patients with DN (cases) and 375 patients without evidence of DN (controls). Polymorphisms in ET-1 (EDN1) gene, rs5370, rs1476046, and rs3087459, were studied.

Results:Genotype distributions of the studied polymorphisms showed no significant difference between cases and controls.

Conclusions:We provide evidence that the rs5370, rs1476046, and rs3087459 polymorphisms ofEDN1gene are not risk factors for DN in Caucasians with T2DM.

Paleogenetic study on the 17th century Korean mummy with atherosclerotic cardiovascular disease

While atherosclerotic cardiovascular disease (ASCVD) is known to be common among modern people exposed to various risk factors, recent paleopathological studies have shown that it affected ancient populations much more frequently than expected. In 2010, we investigated a 17^th century Korean female mummy with presumptive ASCVD signs. Although the resulting report was a rare and invaluable conjecture on the disease status of an ancient East Asian population, the diagnosis had been based only on anatomical and radiological techniques, and so could not confirm the existence of ASCVD in the mummy. In the present study, we thus performed a paleogenetic analysis to supplement the previous conventional diagnosis of ASCVD. In aDNA extracted from the same Korean mummy, we identified the risk alleles of seven different SNPs (rs5351, rs10757274, rs2383206, rs2383207, rs10757278, rs4380028 and rs1333049) that had already been revealed to be the major risk loci of ASCVD in East Asian populations. The reliability of this study could be enhanced by cross-validation using two different analyses: Sanger and SNaPshot techniques. We were able to establish that the 17^th century Korean female had a strong genetic predisposition to increased risk of ASCVD. The current paleogenetic diagnosis, the first of its kind outside Europe, re-confirms its utility as an adjunct modality for confirmatory diagnosis of ancient ASCVD.

Genetic determinants of essential hypertension in the population of Tatars from Russia

OBJECTIVE

Systemic inflammation and impaired function of endothelium play an important role in the development of hypertension. Our study aimed to analyze an association between essential hypertension and polymorphic markers in candidate genes in the group of 530 Tatars from the Republic of Bashkortostan, Russia.

METHODS

The study group consisted of 216 male patients with essential hypertension (mean age 48.92 ± 8.8 years) and 314 healthy individuals of corresponding sex and age without history of cardiovascular disease. Association between studied polymorphisms and essential hypertension was analyzed using PLINK.

RESULTS

We detected an association between EDNRB rs5351, VEGFA -2549(18)I/D, and ADRB2 rs1042713 polymorphisms and essential hypertension in men of Tatar ethnic origin. EDNRB, VEGFA, and VCAM1 single-nucleotide polymorphisms were associated with SBP and DBP. However, only EDNRB rs5351 remained associated with hypertension after Bonferroni correction for multiple testing. A Markov chain Monte Carlo-based approach implemented in the APSampler program was used to analyze association of genotype and/or allele combinations with disease. The most influential in conferring risk of hypertension was EDNRBG/G+ADRB2A+VCAM1A combination (odds ratio = 4.15, PBonf = 5.43 × 10).

CONCLUSION

Our results suggest that rs5351 single-nucleotide polymorphism is a strong independent predictor of essential hypertension in men of Tatar ethnic origin.

Local Ancestry and Clinical Cardiovascular Events Among African Americans From the Atherosclerosis Risk in Communities Study

BACKGROUND

Local ancestry in relation to clinical cardiovascular events (CVEs) among African Americans can provide insight into their genetic susceptibility to the disease.

METHODS AND RESULTS

We examined local European ancestry (LEA) association with CVEs among 3000 African Americans from the Atherosclerosis Risk in Communities Study (ARIC). We estimated LEA using Local Ancestry Inference in adMixed Populations using Linkage Disequilibrium (LAMP-LD) and examined its association with myocardial infarction, stroke, coronary heart disease and its composite and cardiovascular disease composite using logistic regression. Genome-wide significance was achieved by 121 LEA regions in relation to myocardial infarction and 2 in relation to the cardiovascular disease composite. The LEA region downstream of 4q32.1 was significantly associated with 2 times higher odds of myocardial infarction (P=1.45×10^-6). The LEA region upstream of 6q11.1 was associated with 0.37 times lower odds of fatal coronary heart disease (P=7.34×10^-4), whereas the LEA region downstream of 21q21.1 was associated with 1.55 times higher odds of composite coronary heart disease (P=3.45×10^-4). Association of LEA with stroke was observed in the region upstream of 6p22.3 with a 1.57 times higher odds of stroke (P=9.69×10^-4). Likewise, the LEA region on 4q32.3 was associated with a 1.53 times higher odds of composite cardiovascular disease (P=3.04×10^-4). We also found 20 of the LEA regions at previously significant cardiovascular disease single-nucleotide polymorphisms to be associated with CVE in our study.

CONCLUSIONS

Future studies are needed to replicate and/or determine the causal variants driving our associations and explore clinical applications for those consistently associated with CVEs.

[Single nucleotide polymorphisms in genes of endothelin-1 and receptor A associated to cardiovascular in essential hypertension]

INTRODUCTION

The endothelin system, for its vasoconstrictor action, is related to the development of essential hypertension (HTAe). The polymorphism analysis of their genes represents a new approach to the study of this disease. We propose to analyze the interaction between stages of essential hypertension (HTAe) and risk factors with polymorphisms 138ex1 ins/del A gene endothelin-1 (ET-1) and H323H receptor gene A ET-1 (ETRA).

PATIENTS AND METHODS

We included 300 patients of both sexes, unrelated, who consecutively attended the clinic hypertension medical service. Each one underwent a complete physical examination, electrocardiogram, echocardiogram, and Rx thorax. The degree of severity of hypertension was determined in stages. The determination of polymorphisms was performed by amplification followed by cutting by specific restriction enzyme from DNA obtained from peripheral blood.

RESULTS

The 46% of patients had HTAe controlled, 17.6% had organ damage or cardiovascular, brain or kidney disease. It was observed that the 4A/4A carriers showed lower frequency of cardiovascular disease, kidney and brain (P<.032; 95% CI: 11.1-21.4). For H323H polymorphism, the evaluation by images showed a higher frequency of the dilations of left auricular (P=.02) and auricular fibrillation (P=.03) between the T/T carrier, a higher frequency of cardiomegaly was detected in C/C patients (P=.04).

CONCLUSION

The genotypes, 4A/4A of the ET-1 gene and the T/T from ETRA gene might be involved in worse outcome of cardiovascular damage. Their identification could help recognize subgroups of the hypertensive patients with different risk.

Impact of carotid atherosclerosis loci on cardiovascular events

BACKGROUND

Genome-wide association studies (GWAS) have identified six single-nucleotide polymorphisms (SNPs) related to carotid intima media thickness (cIMT) or plaque. However, whether these loci relate to other vascular diseases and subsequent vascular events is unclear.

METHODS AND RESULTS

We tested six SNPs (rs4888378, rs11781551, rs445925, rs6601530, rs17398575 and rs1878406) for association with subclinical atherosclerotic measures (cIMT, plaque presence and ankle-brachial index), as well as ischemic stroke, abdominal aortic aneurysm, peripheral or coronary artery disease (CAD) in the Second Manifestations of ARTerial disease (SMART) cohort. Four SNPs were associated with cIMT and two with plaque (p < 0.05). One SNP was also significantly associated to CAD (rs1878406, OR = 1.24, 95% CI = 1.08-1.42, p = 2 × 10(-3)). A genetic risk score (GRS) based on the cIMT-related SNPs was associated to increased risk of cIMT itself (p = 1 × 10(-3)), but not to other secondary outcomes or vascular events during follow-up (p = 0.86).

CONCLUSIONS

In addition to replicating previously published associations for cIMT, we confirmed a nominally significant effect between the GRS and cIMT.

Effect of SNP polymorphisms of EDN1, EDNRA, and EDNRB gene on ischemic stroke

The objective of this study is to investigate the association between SNP polymorphisms of endothelin-1 (EDN1) and endothelin receptor (EDNRA and EDNRB) gene and ischemic stroke (IS) in the Chinese Han population in northern. A case-control study was introduced. We genotyped eight SNPs (rs1800541, rs2070699, and rs5370 in EDN1 gene; rs1801708, rs5333, and rs5335 in EDNRA gene; and rs3818416 and rs5351 in EDNRB gene) and calculated their polymorphic distribution in control group, IS group, and the IS subgroups. In male population, EDN1 gene rs2070699 G allele increased the incidence risk to 1.78 times (P = 0.009; OR 1.78; 95 % CI 1.15-2.75) and the risk of morbidity of rs5370 T allele carrying increased to 1.49 times (P = 0.048; OR 1.49; 95 % CI 1.00-2.21). EDNRA gene mutation rs5335 homozygous CC morbidity risk was significantly lower (P = 0.016; OR 0.52; 95 % CI 0.31-0.88). In the female population, the mutant homozygous AA cancer risk was significantly higher than G allele carriers (P = 0.019; OR 2.65; 95 % CI 1.18-6.00) on EDNRA gene rs1801708. In EDN1 gene, T allele of rs5370 and G allele of rs2070699 may be IS incidence risk factors in Northern Han male population. A allele of rs1801708 in EDNRA gene can increase the risk of IS in Northern Han women population.

Associations of EDNRA and EDN1 polymorphisms with carotid intima media thickness through interactions with gender, regular exercise, and obesity in subjects in Taiwan: Taichung Community Health Study (TCHS)

The aim of this study was to evaluate the interacted association between EDNRA and EDN1 polymorphisms and gender, regular exercise, and obesity status on carotid intima media thickness (IMT) in community- dwelling subjects of the Taichung Community Health Study. Five single-nucleotide polymorphisms (SNPs rs1395821, rs1878406, rs5333, rs1800541, and rs5370) of the EDNRA and EDN1 gene were examined in 480 participants from 160 families. The IMT protocol involves scanning the common carotid arteries (CCAs), the carotid bifurcations (bulb), and the origins (first 1 cm) of the internal carotid arteries (ICAs). Generalized linear models with a generalized estimating equation were employed to consider the dependence among family members. After multivariate adjustment, the effects of interactions between EDNRA and EDN1 gene with gender, obesity, and exercise were observed. For gene-gender interaction on CCA IMT, the adjusted mean for men carrying the GA/GG genotype of EDNRASNP rs1878406 was 1.18 times higher than that for men carrying the AA genotype (95% CI: 1.01, 1.37). As for bulb and ICA IMT, the adjusted mean values for women carrying the AC/AA genotype of EDN1 rs5370 was lower than those carrying the CC genotype: 0.89, [0.82, 0.98]; and 0.90 [0.83, 0.99], respectively. We did observe significant effects of EDNRA SNPs rs1395821 and rs5333 in individuals who regularly exercised. A significantly lower adjusted mean in CCA IMT for non-obese individuals carrying EDNRA SNP rs5333 was observed (0.92 [0.86, 0.99]) compared with non-obese individuals carrying the AA genotype. This study first reported significant interactions of EDNRA and EDN1 polymorphisms with gender, regular exercise, and obesity on carotid IMT in Han Chinese participants.

Polymorphisms in endothelin system genes, arsenic levels and obesity risk

BACKGROUND/OBJECTIVES

Obesity has been linked to morbidity and mortality through increased risk for many chronic diseases. Endothelin (EDN) system has been related to endothelial function but it can be involved in lipid metabolism regulation: Receptor type A (EDNRA) activates lipolysis in adipocytes, the two endothelin receptors mediate arsenic-stimulated adipocyte dysfunction, and endothelin system can regulate adiposity by modulating adiponectin activity in different situations and, therefore, influence obesity development. The aim of the present study was to analyze if single nucleotide polymorphisms (SNPs) in the EDN system could be associated with human obesity.

SUBJECTS/METHODS

We analyzed two samples of general-population-based studies from two different regions of Spain: the VALCAR Study, 468 subjects from the area of Valencia, and the Hortega Study, 1502 subjects from the area of Valladolid. Eighteen SNPs throughout five genes were analyzed using SNPlex.

RESULTS

We found associations for two polymorphisms of the EDNRB gene which codifies for EDN receptor type B. Genotypes AG and AA of the rs5351 were associated with a lower risk for obesity in the VALCAR sample (p=0.048, OR=0.63) and in the Hortega sample (p=0.001, OR=0.62). Moreover, in the rs3759475 polymorphism, genotypes CT and TT were also associated with lower risk for obesity in the Hortega sample (p=0.0037, OR=0.66) and in the VALCAR sample we found the same tendency (p=0.12, OR=0.70). Furthermore, upon studying the pooled population, we found a stronger association with obesity (p=0.0001, OR=0.61 and p=0.0008, OR=0.66 for rs5351 and rs3759475, respectively). Regarding plasma arsenic levels, we have found a positive association for the two SNPs studied with obesity risk in individuals with higher arsenic levels in plasma: rs5351 (p=0.0054, OR=0.51) and rs3759475 (p=0.009, OR=0.53).

CONCLUSIONS

Our results support the hypothesis that polymorphisms of the EDNRB gene may influence the susceptibility to obesity and can interact with plasma arsenic levels.

Genetic variance in nitric oxide synthase and endothelin genes among children with and without endothelial dysfunction

Background

The presence of endothelial dysfunction (ED) constitutes an early risk factor for cardiovascular disease (CVD) in children. Nitric oxide (NO) and endothelin (EDN) are generated in endothelial cells and are critical regulators of vascular function, with ED resulting from an imbalance between these two molecules. We hypothesized that genetic variants in NO synthase and EDN isoforms and its receptors (EDNRA and EDNRB) may account for a proportion of the risk for ED in developing children.

Methods

Consecutive children (ages 5–10 years) were prospectively recruited from the community. Time to peak post-occlusive reperfusion (Tmax) was considered as the indicator of either normal endothelial function (NEF; Tmax < 45 sec) or ED (Tmax ≥ 45 sec). Lipid profiles, high sensitivity C-reactive protein (hsCRP), fasting glucose and insulin were assayed using ELISA. Genomic DNA from peripheral blood was extracted and genotyped for NOS1 (209 SNPs), NOS2 (122 SNPs), NOS3 (50 SNPs), EDN1 (43 SNPs), EDN2 (48 SNPs), EDN3 (14 SNPs), EDNRA (27 SNPs), and EDNRB (23 SNPs) using a custom SNPs array. Linkage disequilibrium was analyzed using Haploview version 4.2 software.

Results

The relative frequencies of SNPs were evaluated in 122 children, 84 with NEF and 38 with ED. The frequencies of NOS1 (11 SNPs), and EDN1 (2 SNPs) were differentially distributed between NEF vs. ED, and no significant differences emerged for all other genes. Significant SNPs for NOS1 and EDN1 SNPs were further validated with RT-PCR.

Conclusions

Genetic variants in the NOS1 and EDN1 genes appear to account for important components of the variance in endothelial function, particularly when concurrent risk factors such as obesity exist. Thus, analysis of genotype-phenotype interactions in children at risk for ED will be critical for more accurate formulation of categorical CVD risk estimates.

Polymorphisms in nitric oxide synthase and endothelin genes among children with obstructive sleep apnea

Background

Obstructive sleep apnea (OSA) is associated with adverse and interdependent cognitive and cardiovascular consequences. Increasing evidence suggests that nitric oxide synthase (NOS) and endothelin family (EDN) genes underlie mechanistic aspects of OSA-associated morbidities. We aimed to identify single nucleotide polymorphisms (SNPs) in the NOS family (3 isoforms), and EDN family (3 isoforms) to identify potential associations of these SNPs in children with OSA.

Methods

A pediatric community cohort (ages 5–10 years) enriched for snoring underwent overnight polysomnographic (NPSG) and a fasting morning blood draw. The diagnostic criteria for OSA were an obstructive apnea-hypopnea Index (AHI) >2/h total sleep time (TST), snoring during the night, and a nadir oxyhemoglobin saturation <92%. Control children were defined as non-snoring children with AHI <2/h TST (NOSA). Endothelial function was assessed using a modified post-occlusive hyperemic test. The time to peak reperfusion (Tmax) was considered as the indicator for normal endothelial function (NEF; Tmax<45 sec), or ED (Tmax≥45 sec). Genomic DNA from peripheral blood was extracted and allelic frequencies were assessed for, NOS1 (209 SNPs), NOS2 (122 SNPs), NOS3 (50 SNPs), EDN1 (43 SNPs), EDN2 (48 SNPs), EDN3 (14 SNPs), endothelin receptor A, EDNRA, (27 SNPs), and endothelin receptor B, EDNRB (23 SNPs) using a custom SNPs array. The relative frequencies of NOS-1,-2, and −3, and EDN-1,-2,-3,-EDNRA, and-EDNRB genotypes were evaluated in 608 subjects [128 with OSA, and 480 without OSA (NOSA)]. Furthermore, subjects with OSA were divided into 2 subgroups: OSA with normal endothelial function (OSA-NEF), and OSA with endothelial dysfunction (OSA-ED). Linkage disequilibrium was analyzed using Haploview version 4.2 software.

Results

For NOSA vs. OSA groups, 15 differentially distributed SNPs for NOS1 gene, and 1 SNP for NOS3 emerged, while 4 SNPs for EDN1 and 1 SNP for both EDN2 and EDN3 were identified. However, in the smaller sub-group for whom endothelial function was available, none of the significant SNPs was retained due to lack of statistical power.

Conclusions

Differences in the distribution of polymorphisms among NOS and EDN gene families suggest that these SNPs could play a contributory role in the pathophysiology and risk of OSA-induced cardiovascular morbidity. Thus, analysis of genotype-phenotype interactions in children with OSA may assist in the formulation of categorical risk estimates.

Current concepts in age-related hearing loss: epidemiology and mechanistic pathways

Age-related hearing loss (AHL), also known as presbycusis, is a universal feature of mammalian aging and is characterized by a decline of auditory function, such as increased hearing thresholds and poor frequency resolution. The primary pathology of AHL includes the hair cells, stria vascularis, and afferent spiral ganglion neurons as well as the central auditory pathways. A growing body of evidence in animal studies has suggested that cumulative effect of oxidative stress could induce damage to macromolecules such as mitochondrial DNA (mtDNA) and that the resulting accumulation of mtDNA mutations/deletions and decline of mitochondrial function play an important role in inducing apoptosis of the cochlear cells, thereby the development of AHL. Epidemiological studies have demonstrated four categories of risk factors of AHL in humans: cochlear aging, environment such as noise exposure, genetic predisposition, and health co-morbidities such as cigarette smoking and atherosclerosis. Genetic investigation has identified several putative associating genes, including those related to antioxidant defense and atherosclerosis. Exposure to noise is known to induce excess generation of reactive oxygen species (ROS) in the cochlea, and cumulative oxidative stress can be enhanced by relatively hypoxic situations resulting from the impaired homeostasis of cochlear blood supply due to atherosclerosis, which could be accelerated by genetic and co-morbidity factors. Antioxidant defense system may also be influenced by genetic backgrounds. These may explain the large variations of the onset and extent of AHL among elderly subjects. This article is part of a Special Issue entitled "Annual Reviews 2013".

New insights into the Tyrolean Iceman's origin and phenotype as inferred by whole-genome sequencing

The Tyrolean Iceman, a 5,300-year-old Copper age individual, was discovered in 1991 on the Tisenjoch Pass in the Italian part of the Ötztal Alps. Here we report the complete genome sequence of the Iceman and show 100% concordance between the previously reported mitochondrial genome sequence and the consensus sequence generated from our genomic data. We present indications for recent common ancestry between the Iceman and present-day inhabitants of the Tyrrhenian Sea, that the Iceman probably had brown eyes, belonged to blood group O and was lactose intolerant. His genetic predisposition shows an increased risk for coronary heart disease and may have contributed to the development of previously reported vascular calcifications. Sequences corresponding to ~60% of the genome of Borrelia burgdorferi are indicative of the earliest human case of infection with the pathogen for Lyme borreliosis.

Meta-analysis of genome-wide association studies from the CHARGE consortium identifies common variants associated with carotid intima media thickness and plaque

Carotid intima media thickness (cIMT) and plaque determined by ultrasonography are established measures of subclinical atherosclerosis that each predicts future cardiovascular disease events. We conducted a meta-analysis of genome-wide association data in 31,211 participants of European ancestry from nine large studies in the setting of the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) Consortium. We then sought additional evidence to support our findings among 11,273 individuals using data from seven additional studies. In the combined meta-analysis, we identified three genomic regions associated with common carotid intima media thickness and two different regions associated with the presence of carotid plaque (P < 5 × 10(-8)). The associated SNPs mapped in or near genes related to cellular signaling, lipid metabolism and blood pressure homeostasis, and two of the regions were associated with coronary artery disease (P < 0.006) in the Coronary Artery Disease Genome-Wide Replication and Meta-Analysis (CARDIoGRAM) consortium. Our findings may provide new insight into pathways leading to subclinical atherosclerosis and subsequent cardiovascular events.

Polymorphisms in the endothelin-1 and endothelin a receptor genes and survival in patients with locoregionally advanced nasopharyngeal carcinoma

PURPOSE

We aimed to investigate the prognostic role of endothelin-1 (EDN1) and endothelin A receptor (EDNRA) gene polymorphisms in patients with locoregionally advanced nasopharyngeal carcinoma (NPC).

EXPERIMENTAL DESIGN

Two hundred three consecutive patients with locoregionally advanced NPC were enrolled. Seven potentially functional polymorphisms in the EDN1 and EDNRA genes were determined by ligase detection reaction-PCR method from prospectively collected blood samples. The influence of the genetic polymorphisms on patient overall survival (OS) was analyzed using Cox proportional hazards model, Kaplan-Meier method, and the log-rank test.

RESULTS

The 5-year OS in patients with EDNRA/H323H TT, TC, and CC genotypes were 81.3%, 62.1%, and 75.0%, respectively (P = 0.004). Patients carrying the heterozygous (TC) or homozygous variant (CC) genotype in EDNRA/H323H were combined for analysis, which revealed that the 5-year OS in patients with TC/CC genotypes was significantly lower than those with the wild-type TT genotype (63.2% vs. 81.3%; P = 0.002). Multivariate analysis showed that EDNRA/H323H polymorphism (HR: 1.95; 95% CI: 1.18-3.23; P = 0.009) and N classification (HR: 1.35; 95% CI: 1.03-1.79; P = 0.03) were independent significant prognostic factors for OS in patients with locoregionally advanced NPC. In contrast, the EDN1 polymorphisms revealed no prognostic value.

CONCLUSIONS

The EDNRA/H323H polymorphism was a novel and independent prognostic marker for patients with locoregionally advanced NPC. The analysis of EDNRA/H323H polymorphism may help identify patient subgroups at high risk for poor disease outcome.

Systematic polymorphism discovery after genome-wide identification of potential susceptibility loci in a hereditary rodent model of human hypertension

Genetic strategies such as linkage analysis and quantitative trait locus (QTL) mapping have identified a multitude of loci implicated in the pathogenesis of hypertension in the spontaneously hypertensive rat (SHR). While several candidate genetic regions have been identified in the SHR and its control, the Wistar-Kyoto rat (WKY), systematic follow-up of candidate identification with polymorphism discovery has not been widespread. In the current report, we develop a data-mining strategy to identify candidate genes for hypertension in the SHR, and then sequence each gene in the SHR and WKY strains. We integrate blood pressure QTL data, microarray data and data-mining methods. First, we determined the set of genes differentially expressed in SHR and WKY adrenal glands. Next, the chromosomal position of all differentially expressed genes was compared with peak marker position of all reported SHR blood pressure QTLs. We also identified the set of differentially expressed genes with the most extreme fold-change. Finally, the QTL positional candidates and the genes with extreme differential expression were proposed as candidate genes if they had biologically plausible roles in hypertensive pathology. We identified seven candidate genes that merit resequencing (catechol-O-methyltransferase [Comt], chromogranin A [Chga], dopamine beta-hydroxylase [Dbh], electron transferring flavoprotein dehydrogenase [Etfdh], endothelin receptor type B [Ednrb], neuropeptide Y [Npy] and phenylethanolamine-N-methyltransferase [Pnmt]), and then discovered polymorphism in four of these seven candidate genes. Chga is proposed as the strongest candidate for additional functional investigation. Our method for candidate gene identification is portable and can be applied to microarray data from any tissue, in any disease model with a QTL database.

Polymorphisms of EDNRB, ATG, and ACE genes in salt-sensitive hypertension

Almost 50% of hypertensive individuals manifest blood pressure changes in response to salt depletion or repletion and are termed "salt sensitive" (SS). Blunted activity of the endothelin (ET) system and the renin-angiotensin-aldosterone system (RAAS) have been reported as possible mechanisms contributing to salt sensitivity. Data are available that endothelin receptor subtype B (ETBR)-deficient rats develop salt-sensitive hypertension when fed a high-salt diet. Whether the ETBR gene (EDNRB) is involved in genetic predisposition to human salt-sensitive hypertension has not been studied so far. We screened EDNRB in 104 hypertensive patients (49 salt sensitive and 55 salt resistant) and 110 normotensive controls. No new sequence variation was found, but genotype distribution of the common polymorphism G1065A revealed that the AA + GA genotypes were significantly more frequent in salt-resistant than in salt-sensitive individuals (p = 0.007), suggesting a protective role for the A allele. We also screened angiotensinogen gene AGT M235T and angiotensin-converting enzyme insertion/deletion polymorphism ACE I/D and found an association between TT genotype and hypertension. A possible synergistic effect to salt-sensitive hypertension was found by combining EDNRB GG with ACE DD/ID genotypes. In conclusion, our data confirm the role of ET system and RAAS in salt-sensitive hypertension.

Associations of hypertension and its complications with variations in the xanthine dehydrogenase gene

Hyperuricemia and oxidative stress participate in the pathophysiology of hypertension and its complications. Xanthine dehydrogenase (XDH) produces urate and, in its oxidase isoform, reactive oxygen species. Here we have studied whether or not the genetic variations in XDH could be implicated in hypertension and its complications. By sequencing the promoter region and all exons of XDH in 48 subjects, we identified three missense mutations (G172R, A932T, N1109T) in a heterozygous state in addition to 34 variations, including 15 common single nucleotide polymorphisms (SNPs). The three missense mutations and eight common SNPs (11488C>G, 37387A>G, 44408A>G, 46774G>A, 47686C>T, 49245A>T, 66292C>G, and 69901A>C) were genotyped in 953 hypertensive Japanese subjects and in 1,818 subjects from a general Japanese population. Four hypertensive patients with rare missense mutations (G172R or N1109T) in homozygous form had severe hypertension. Multivariate logistic regression analysis showed a significant association of three SNPs with hypertension in men: 47686C>T (exon 22, odds ratio [OR]: 1.52, p = 0.047) and 69901A>C (intron 31, OR: 3.14, p = 0.039) in the recessive model, and 67873A>C (N1109T) (exon 31, OR: 1.84, p = 0.018) in the dominant model. After full adjustment for all confounding factors, only one polymorphism (69901A>C) was found to be associated with carotid atherosclerosis in the dominant model (p = 0.028). Multiple logistic regression analysis showed that one SNP (66292C>G) was significantly associated with chronic kidney disease (CKD: estimated creatinine clearance < 60 ml/min) in the recessive model (p = 0.0006). Our results suggest that genetic variations in XDH contribute partly to hypertension and its complications, including atherosclerosis and CKD.