Genome-wide linkage analysis of cardiovascular disease biomarkers in a large, multigenerational family

Patients with Obstructive Sleep Apnea Have Altered Levels of Four Cytokines Associated with Cardiovascular and Kidney Disease, but Near Normal Levels with Airways Therapy

INTRODUCTION

Obstructive sleep apnea (OSA) results in chronic intermittent hypoxia leading to systemic inflammation, increases in pro-inflammatory cytokines TNF-Alpha and IL-6, and increased risk for a number of life threatening medical disorders such as cardiovascular and kidney disease.

METHODS

A BioPlex Array was used to examined the serum levels of four cytokines also expressed in endothelial cells and/or macrophages and associated with cardiovascular and kidney disease risk.

RESULTS

Relative to untreated OSA patients, airways treated OSA patients had a 5.4-fold higher median level of MMP2 (p = 9.1x10-11), a 1.4-fold higher level of TWEAK (p = 1.8x10-7), a 1.7-fold higher level of CD163 (p = 1.4x10-6), but a 2.0-fold lower level of MMP3 (p = 7.9x10-7). Airway treatment resulted in levels more similar to or indistinguishable from control subjects. Both t-SNE or UMAP analysis of the global structure of these multi-dimensional data revealed two data clusters, one populated primarily with data for controls and most airways treated OSA patients and a second populated primarily with data for OSA patients.

DISCUSSION

We discuss a concept in which the aberrant levels of these cytokines in untreated OSA patients may represent a chronic response after years of experiencing intermittent nightly hypoxia, which attenuated the acute response to hypoxia. A balanced therapeutic correction of the aberrant levels of these cytokines may limit the progression of CVD and kidney disease in OSA patients.

Variants in CDHR3, CACNAC1, and LTA Genes Predisposing Sensitivity and Response to Warfarin in Patients with Cardiovascular Disease

Introduction

Warfarin has been in use for more than 60 years; however, it has serious side effects including major bleeding. The high interpatient variability in the required dose impacts the sensitivity and responsiveness to warfarin in different patients. This study aims to assess the influence of CDHR3, CACNAC1, and LTA gene polymorphisms on the variability of warfarin dose requirements and susceptibility to coronary heart disease in the Jordanian population.

Methods

This study was conducted in the anti-coagulation clinic in Queen Alia Heart Institute in Amman, with 212 patients in total. Three SNPs were genotyped within CDHR3 (rs10270308), CACNAC1 (rs216013), and LTA (rs1041981) genes.

Results

Our findings revealed that patients with LTA polymorphism are more prone to warfarin sensitivity than others. Furthermore, carriers of the LTA polymorphism needed a lower initial dose of warfarin and are associated with less variation in doses required to achieve target INR.

Conclusion

The current study could help in understanding the role of genetic variability in warfarin dosing and matching patients to different treatment options. Clinical applications of these findings for warfarin treatment may also contribute to improving the efficacy and safety of warfarin treatment in Jordanian patients with cardiovascular disease.

The Relevance of Noncoding DNA Variations of Paraoxonase Gene Cluster in Atherosclerosis-Related Diseases

The human paraoxonase (PON) gene cluster is comprised of three contiguous genes (PON1, PON2 and PON3) of presumably common origin coding three lactonases of highly similar structure and substrate specificity. The catalytic activity of PON proteins is directed toward artificial organophosphates and in physiological conditions toward thiolactones and oxidized phospholipids. Consequently, PON enzymes are regarded as an effective defense against oxidative stress and, as a result, against atherosclerosis development. Additionally, both PON's serum activity and its concentration are influenced by several polymorphic variations in coding and noncoding DNA regions of the PON gene cluster remaining in linkage disequilibrium. Hence, the genetic polymorphism of the PON gene cluster may contribute to atherosclerotic process progression or deceleration. In this review the authors analyzed the relevance of noncoding DNA polymorphic variations of PON genes in atherosclerosis-related diseases involving coronary and peripheral artery disease, stroke, diabetes mellitus, dementia and renal disease and concluded that the effect of PON gene cluster' polymorphism has a considerable impact on the course and outcome in these conditions. The following PON genetic variations may serve as additional predictors of the risk of atherosclerosis in selected populations and individuals.

Genetic determinants of cardiometabolic risk factors in rural families in Brazil

OBJECTIVES

The purpose of this study was to estimate the heritability of genetic and environmental correlations between cardiometabolic risk factors in extended pedigrees.

METHODS

The Jequitinhonha Community Family Study Cohort (JCFSC) consists of individuals aged ≥18 years living in rural villages. Family pedigrees were constructed of the cohort. The following data were collected: demographic and socioeconomic status, lifestyle variables, anthropometrics, and lipid traits.

RESULTS

The JCFSC consists of 931 individuals distributed into 69 pedigrees with 4,907 members in total. The heritabilities were 0.47 for total cholesterol (TC), 0.44 for triglycerides (TG) and 0.42 for high-density lipoprotein cholesterol (HDLc), 0.49 for metabolic syndrome, approximately 0.60 for anthropometric traits and 0.30 for blood pressure/hypertension. Significant genetic correlations (ρg ) were found mainly between TG and TC (ρg  = 0.58) and hypertension and TG (ρg  = 0.52). Systolic blood pressure (SBP) was correlated with TG (ρg  = 0.39) and HDLc (ρg  = -0.30). Diastolic blood pressures correlated with TG (ρg =0.56) and TC (ρg =0.30). Genetic correlations were also found between anthropometric traits, including: body mass index (BMI) and TG (ρg =0.34), waist circumference (WC) and TG (ρg =0.42), and WC and HDLc (ρg =-0.33). Household effects were found for HDLc (c(2) = 0.19), SBP (c(2)  = 0.14) and Hypertension (c(2) = 0.14).

CONCLUSIONS

To some phenotypes, including lipids, hypertension, blood pressure, and anthropometric traits, genetic contribution is important in the determination of cardiometabolic risk factors. This study provides a foundation for future studies. These will mainly focus on rare variants that could describe the genetic mechanisms influencing cardiometabolic risk. Am. J. Hum. Biol. 28:619-626, 2016. © 2016 Wiley Periodicals, Inc.

Human paraoxonase-1 (PON1): Gene structure and expression, promiscuous activities and multiple physiological roles

Human PON1 is a HDL-associated lipolactonase capable of preventing LDL and cell membrane oxidation and is therefore considered to be atheroprotective. PON1 contributes to the antioxidative function of HDL and reductions in HDL-PON1 activity, prevalent in a wide variety of diseases with an inflammatory component, are believed to lead to dysfunctional HDL which can promote inflammation and atherosclerosis. However, PON1 is multifunctional and may contribute to other HDL functions such as in innate immunity, preventing infection by quorum sensing gram negative bacteria by destroying acyl lactone mediators of quorum sensing, and putative new roles in cancer development and the promotion of healthy ageing. In this review we explore the physiological roles of PON1 in disease development, as well as PON1 gene and protein structure, promiscuous activities and the roles of SNPs and ethnicity in determining PON1 activity.

Atherosclerosis in rheumatoid arthritis: is it all about inflammation?

Rheumatoid arthritis (RA) has long been associated with increased cardiovascular risk, but despite substantial improvements in disease management, mortality remains high. Atherosclerosis is more prevalent in RA than in the general population, and atherosclerotic lesions progress at a faster rate and might be more prone to rupture, causing clinical events. Cells and cytokines implicated in RA pathogenesis are also involved in the development and progression of atherosclerosis, which is generally recognized as an inflammatory condition. The two diseases also share genetic and environmental risk factors, which suggests that patients who develop RA might also be predisposed to developing cardiovascular disease. In RA, inflammation and atherosclerosis are closely linked. Inflammation mediates its effects on atherosclerosis both through modulation of traditional risk factors and by directly affecting the vessel wall. Treatments such as TNF inhibitors might have a beneficial effect on cardiovascular risk. However, whether this benefit is attributable to effective control of inflammation or whether targeting specific cytokines, implicated in atherosclerosis, provides additional risk reduction is unclear. Further knowledge of the predictors of cardiovascular risk, the effects of early control of inflammation and of drug-specific effects are likely to improve the recognition and management of cardiovascular risk in patients with RA.

PRIMUS: rapid reconstruction of pedigrees from genome-wide estimates of identity by descent

Understanding and correctly utilizing relatedness among samples is essential for genetic analysis; however, managing sample records and pedigrees can often be error prone and incomplete. Data sets ascertained by random sampling often harbor cryptic relatedness that can be leveraged in genetic analyses for maximizing power. We have developed a method that uses genome-wide estimates of pairwise identity by descent to identify families and quickly reconstruct and score all possible pedigrees that fit the genetic data by using up to third-degree relatives, and we have included it in the software package PRIMUS (Pedigree Reconstruction and Identification of the Maximally Unrelated Set). Here, we validate its performance on simulated, clinical, and HapMap pedigrees. Among these samples, we demonstrate that PRIMUS can verify reported pedigree structures and identify cryptic relationships. Finally, we show that PRIMUS reconstructed pedigrees, all of which were previously unknown, for 203 families from a cohort collected in Starr County, TX (1,890 samples).