Common and Rare Genetic Variation in CCR2, CCR5, or CX3CR1 and Risk of Atherosclerotic Coronary Heart Disease and Glucometabolic Traits

The genetic correlation and causal association between key factors that influence vascular calcification and cardiovascular disease incidence

Background

Serum calcium (Ca), vitamin D (VD), and vitamin K (VK) levels are key determinants of vascular calcification, which itself impacts cardiovascular disease (CVD) risk. The specific relationships between the levels of these different compounds and particular forms of CVD, however, remain to be fully defined.

Objective

This study was designed to explore the associations between these serum levels and CVDs with the goal of identifying natural interventions capable of controlling vascular calcification and thereby protecting against CVD pathogenesis, extending the healthy lifespan of at-risk individuals.

Methods

Linkage disequilibrium score (LDSC) regression and a two-sample Mendelian randomization (MR) framework were leveraged to systematically examine the causal interplay between these serum levels and nine forms of CVD, as well as longevity through the use of large publically accessible Genome-Wide Association Studies (GWAS) datasets. The optimal concentrations of serum Ca and VD to lower CVD risk were examined through a restrictive cubic spline (RCS) approach.

Results

After Bonferroni correction, the positive genetic correlations were observed between serum Ca levels and myocardial infarction (MI) (p = 1.356E-04), as well as coronary artery disease (CAD) (p = 3.601E-04). Negative genetic correlations were detected between levels of VD and CAD (p = 0.035), while elevated VK1 concentrations were causally associated with heart failure (HF) [odds ratios (OR) per 1-standard deviation (SD) increase: 1.044], large artery stroke (LAS) (OR per 1-SD increase: 1.172), and all stroke (AS) (OR per 1-SD increase: 1.041). Higher serum Ca concentrations (OR per 1-SD increase: 0.865) and VD levels (OR per 1-SD increase: 0.777) were causally associated with reduced odds of longevity. These findings remained consistent in sensitivity analyses, and serum Ca and VD concentrations of 2.376 mmol/L and 46.8 nmol/L, respectively, were associated with a lower CVD risk (p < 0.001).

Conclusion

Our findings support a genetic correlation between serum Ca and VD and CVD risk, and a causal relationship between VK1 levels and CVD risk. The optimal serum Ca (2.376 mmol/L) and VD levels (46.8 nmol/L) can reduce cardiovascular risk.

South Asian ethnicity: What can we do to make this risk enhancer a risk equivalent?

South Asians account for around 25% of the global population and are the fastest-growing ethnicity in the US. This population has an increasing burden of atherosclerotic cardiovascular disease (ASCVD) which is also seen in the diaspora. Current risk prediction equations underestimate this risk and consider the South Asian ethnicity as a risk-enhancer among those with borderline-intermediate risk. In this review, we discuss why the South Asian population is at a higher risk of ASCVD and strategies to mitigate this increased risk.

A Common Variant at the 3'untranslated Region of the CCL7 Gene (rs17735770) Is Associated With Decreased Susceptibility to Coronary Heart Disease

Monocytes participate in the development of atherosclerosis through the action of cytokines and other inflammatory mediators. Among them, CCR2 and its ligands, CCL2 and CCL7 play an important role, so the main objective of this work was to determine whether genetic variants affecting their activity were associated with cardiovascular disease. A cohort of 519 patients that have suffered coronary events was analyzed under a propensity score-matching protocol selecting a homogeneous set of cases and controls, according to age, sex, smoking status, dyslipidemia, arterial hypertension and type 2 diabetes as risk factors. While dyslipidemia and arterial hypertension were more prevalent among patients with angina pectoris, current smoking status and elevated inflammatory markers, including total leukocyte and monocyte counts, were more likely associated with acute coronary events. Propensity score matching analysis, performed to eliminate the influence of these risk factors and highlight genetic modifiers, revealed that a single nucleotide variant, rs17735770 at the 3'untranslated region of the CCL7 gene transcript, was associated with decreased cardiovascular risk in a group represented mostly by men, with an average age of 57, and without significant differences in traditional risk factors. Furthermore, the presence of this variant altered the local mRNA structure encompassing a binding site for miR-23ab, resulting in increased translation of a reporter gene in a miR23 independent fashion. The rs17735770 genetic variant led to increased expression of CCL7, a potential antagonist of CCR2 at inflammatory sites, where it could play a meaningful role during the evolution of atherosclerosis.

Analysis of lncRNA-miRNA-mRNA expression pattern in heart tissue after total body radiation in a mouse model

Background

Radiation therapy is integral to effective thoracic cancer treatments, but its application is limited by sensitivity of critical organs such as the heart. The impacts of acute radiation-induced damage and its chronic effects on normal heart cells are highly relevant in radiotherapy with increasing lifespans of patients. Biomarkers for normal tissue damage after radiation exposure, whether accidental or therapeutic, are being studied as indicators of both acute and delayed effects. Recent research has highlighted the potential importance of RNAs, including messenger RNAs (mRNAs), microRNAs (miRNAs), and long non-coding RNAs (lncRNAs) as biomarkers to assess radiation damage. Understanding changes in mRNA and non-coding RNA expression will elucidate biological pathway changes after radiation.

Methods

To identify significant expression changes in mRNAs, lncRNAs, and miRNAs, we performed whole transcriptome microarray analysis of mouse heart tissue at 48 h after whole-body irradiation with 1, 2, 4, 8, and 12 Gray (Gy). We also validated changes in specific lncRNAs through RT-qPCR. Ingenuity Pathway Analysis (IPA) was used to identify pathways associated with gene expression changes.

Results

We observed sustained increases in lncRNAs and mRNAs, across all doses of radiation. Alas2, Aplnr, and Cxc3r1 were the most significantly downregulated mRNAs across all doses. Among the significantly upregulated mRNAs were cell-cycle arrest biomarkers Gdf15, Cdkn1a, and Ckap2. Additionally, IPA identified significant changes in gene expression relevant to senescence, apoptosis, hemoglobin synthesis, inflammation, and metabolism. LncRNAs Abhd11os, Pvt1, Trp53cor1, and Dino showed increased expression with increasing doses of radiation. We did not observe any miRNAs with sustained up- or downregulation across all doses, but miR-149-3p, miR-6538, miR-8101, miR-7118-5p, miR-211-3p, and miR-3960 were significantly upregulated after 12 Gy.

Conclusions

Radiation-induced RNA expression changes may be predictive of normal tissue toxicities and may indicate targetable pathways for radiation countermeasure development and improved radiotherapy treatment plans.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-02998-w.

Pathophysiological Mechanisms Underlying Excess Risk for Diabetes and Cardiovascular Disease in South Asians: The Perfect Storm

BACKGROUND

South Asians are at a significantly increased risk of type 2 diabetes (T2D) and cardiovascular disease (CVD), are diagnosed at relatively younger ages, and exhibit more severe disease phenotypes as compared with other ethnic groups. The pathophysiological mechanisms underlying T2D and CVD risk in South Asians are multifactorial and intricately related.

METHODS

A narrative review of the pathophysiology of excess risk of T2D and CVD in South Asians.

RESULTS

T2D and CVD have shared risk factors that encompass biological factors (early life influences, impaired glucose metabolism, and adverse body composition) as well as behavioral and environmental risk factors (diet, sedentary behavior, tobacco use, and social determinants of health). Genetics and epigenetics also play a role in explaining the increased risk of T2D and CVD among South Asians. Additionally, South Asians harbor several lipid abnormalities including high concentration of small-dense low-density lipoprotein (LDL) particles, elevated triglycerides, low high-density lipoprotein (HDL)- cholesterol levels, dysfunctional HDL particles, and elevated lipoprotein(a) that predispose them to CVD.

CONCLUSION

In this comprehensive review, we have discussed risk factors that provide insights into the pathophysiology of excess risk of T2D and CVD in South Asians.

Evolutionary history of disease-susceptibility loci identified in longitudinal exome-wide association studies

Background

Our longitudinal exome‐wide association studies previously detected various genetic determinants of complex disorders using ~26,000 single‐nucleotide polymorphisms (SNPs) that passed quality control and longitudinal medical examination data (mean follow‐up period, 5 years) in 4884–6022 Japanese subjects. We found that allele frequencies of several identified SNPs were remarkably different among four ethnic groups. Elucidating the evolutionary history of disease‐susceptibility loci may help us uncover the pathogenesis of the related complex disorders.

Methods

In the present study, we conducted evolutionary analyses such as extended haplotype homozygosity, focusing on genomic regions containing disease‐susceptibility loci and based on genotyping data of our previous studies and datasets from the 1000 Genomes Project.

Results

Our evolutionary analyses suggest that derived alleles of rs78338345 of GGA3, rs7656604 at 4q13.3, rs34902660 of SLC17A3, and six SNPs closely located at 12q24.1 associated with type 2 diabetes mellitus, obesity, dyslipidemia, and three complex disorders (hypertension, hyperuricemia, and dyslipidemia), respectively, rapidly expanded after the human dispersion from Africa (Out‐of‐Africa). Allele frequencies of GGA3 and six SNPs at 12q24.1 appeared to have remarkably changed in East Asians, whereas the derived alleles of rs34902660 of SLC17A3 and rs7656604 at 4q13.3 might have spread across Japanese and non‐Africans, respectively, although we cannot completely exclude the possibility that allele frequencies of disease‐associated loci may be affected by demographic events.

Conclusion

Our findings indicate that derived allele frequencies of nine disease‐associated SNPs (rs78338345 of GGA3, rs7656604 at 4q13.3, rs34902660 of SLC17A3, and six SNPs at 12q24.1) identified in the longitudinal exome‐wide association studies largely increased in non‐Africans after Out‐of‐Africa.

Low quality cardiovascular care is important coronary risk factor in India

Global Burden of Disease study has reported that cardiovascular and ischemic heart disease (IHD) mortality has increased by 34% in last 25 years in India. It has also been reported that despite having lower coronary risk factors compared to developed countries, incident cardiovascular mortality, cardiovascular events and case-fatality are greater in India. Reasons for the increasing trends and high mortality have not been studied. There is evidence that social determinants of IHD risk factors are widely prevalent and increasing. Epidemiological studies have reported low control rates of hypertension, hypercholesterolemia, diabetes and smoking/tobacco. Registries have reported greater mortality of acute coronary syndrome in India compared to developed countries. Secondary prevention therapies have significant gaps. Low quality cardiovascular care is an important risk factor in India. Package of interventions focusing on fiscal, intersectoral and public health measures, improvement of health services at community, primary and secondary healthcare levels and appropriate referral systems to specialized hospitals is urgently required.

Acute consumption of Andalusian aged wine and gin decreases the expression of genes related to atherosclerosis in men with high cardiovascular risk: Randomized intervention trial

BACKGROUND

Atherosclerosis is an inflammatory disease. Previous studies have suggested the beneficial effects of moderate consumption of alcoholic beverages on reducing cardiovascular risk (CVR). The aim of this study was to evaluate the effects of acute consumption of Andalusian aged wine (AAW) and gin by analyzing the expression of genes related to the appearance and progression of atherosclerosis in men with high CVR.

METHODS

We performed an open, randomized, controlled, crossover trial including 41 men with high CVR between 55 and 80 years age, who received a single dose of AAW or gin (0.5 g ethanol/kg). The expression of 10 genes related to atherosclerosis was determined by RT-PCR at baseline and 4 h after the intervention.

RESULTS

Gene expression analysis 4 h after consumption of each alcoholic beverage showed a significant decrease in Toll-like receptors 4 and 6 (TLR4, TLR6) and Caspase-1 (p < 0.05 all). Additionally, TLR2, Interleukin-1 receptor, chemokine receptor 3 and inflammasome expression decreased after AAW intake (p < 0.05, all) while only chemokine receptor 5 decreased after gin consumption (p = 0.039).

CONCLUSION

The decrease in the expression of several genes related to the appearance and progression of atherosclerosis was greater after AAW than gin intake, suggesting that the phenolic content of AAW may play a protective role against atherosclerosis.

Serum of coronary atherosclerotic heart disease patients induces oxidative stress injury on endothelial cells

Endothelial cell (EC) dysfunction has a fundamental role in the development of atherosclerosis, which leads to myocardial infarction and stroke. The aim of this study is to investigate the effect of serum from patients with coronary atherosclerotic heart disease (CAD) on endothelial cells and investigate the possible mechanism underlying these effects. Serum from 35 patients with CAD and 35 healthy volunteers was collected. Human umbilical vein endothelial cell (HUVEC) proliferation and apoptosis were assessed by a CCK‑8 assay and a flow cytometry assay, respectively. The synthesis of nitric oxide (NO) and reactive oxygen species (ROS) was measured using the nitrate reduction method and DCFH2-DA staining, respectively. The proliferation of HUVECs was inhibited by treatment with serum from CAD patients (P<0.05). Suppression of HUVEC proliferation by CAD serum occurred in a concentration-dependent manner. The synthesis of NO was also reduced in the CAD serum-treated group. Furthermore, the serum from CAD patients increased both apoptosis and intracellular ROS production in HUVECs. Moreover, treatment with tempol antagonized CAD serum-meditated HUVEC injuries. Taken together, these results suggest that HUVEC injury via CAD serum treatment is mediated by ROS production. Tempol may partly reverse this effect by abolishing HUVEC apoptosis.

Six novel susceptibility loci for coronary artery disease and cerebral infarction identified by longitudinal exome-wide association studies in a Japanese population

Coronary artery disease (CAD) and cerebral infarction (CI) remain major causes of morbidity and mortality in humans. Recent genome-wide association studies have identified various genetic variants associated with these diseases. However, these studies were commonly conducted in a cross-sectional manner. Therefore, the present research performed longitudinal exome-wide association studies for CAD and CI using data on ~244,000 genotyped variants and the clinical data of 6,026 Japanese individuals who had attended annual health checkups for several years (mean followed-up period, 5±3 years). Following quality controls, the significance [false discovery rate (FDR) of <0.05] of association of the diseases with 24,651 single nucleotide polymorphisms (SNPs) in 5,989 individuals for three inheritance models was tested using the generalized estimating equation model. SNPs that reached statistical significance were further screened against a threshold of approxdf (a scale of small effective sample size) of >30. The longitudinal exome-wide association studies revealed that three SNPs [rs4606855 of ADGRE3 (P=2.5×10^-6; FDR=0.031; approxdf=71), rs3746414 of ZFP64 (P=5.9×10^-6; FDR=0.048; approxdf=93) and rs7132908 of FAIM2 (P<2.0×10^-16; FDR<4.9×10^-12; approxdf=65)] were significantly associated with the prevalence of CAD. A different set of three SNPs [rs6580741 of FAM186A (P<2.0×10^-16; FDR<4.9×10^-12; approxdf=48), rs1324015 of LINC00400 (P<2.0×10^-16; FDR<4.9×10^-12; approxdf=49) and rs884205 of TNFRSF11A (P<2.0×10^-16; FDR<4.9×10^-12; approxdf=32)] was significantly associated with CI. The comparison of disease incidence with these SNPs demonstrated that all the minor alleles were associated with decreased susceptibility to CAD or CI. In conclusion, six novel SNPs were identified as susceptibility loci for CAD (rs4606855 of ADGRE3, rs3746414 of ZFP64, and rs7132908 of FAIM2) or CI (rs6580741 of FAM186A, rs1324015 of LINC00400, and rs884205 of TNFRSF11A).

Inflammation: A Novel Therapeutic Target/Direction in Atherosclerosis

Over the past two decades, the viewpoint of atherosclerosis has been replaced gradually by a lipid-driven, chronic, low-grade inflammatory disease of the arterial wall. Current treatment of atherosclerosis is focused on limiting its risk factors, such as hyperlipidemia or hypertension. However, treatment targeting the inflammatory nature of atherosclerosis is still very limited and deserves further attention to fight atherosclerosis successfully. Here, we review the current development of inflammation and atherosclerosis to discuss novel insights and potential targets in atherosclerosis, and to address drug discovery based on anti-inflammatory strategy in atherosclerotic disease.

Synergistic Modulation of Inflammatory but not Metabolic Effects of High-Fat Feeding by CCR2 and CX3CR1

OBJECTIVE

The purpose of the study was to explore the impact of dual targeting of C-C motif chemokine receptor-2 (CCR2) and fractalkine receptor (CX3CR1) on the metabolic and inflammatory consequences of obesity induced by a high-fat diet (HFD).

METHODS

C57BL/6J wild-type, Cx3cr1^-/- , Ccr2^-/- , and Cx3cr1^-/- Ccr2^-/- double-knockout male and female mice were fed a 45% HFD for up to 25 weeks starting at 12 weeks of age.

RESULTS

All groups gained weight at a similar rate and developed a similar degree of adiposity, hyperglycemia, glucose intolerance, and impairment of insulin sensitivity in response to HFD. As expected, the circulating monocyte count was decreased in Ccr2^-/- and Cx3cr1^-/- Ccr2^-/- mice but not in Cx3cr1^-/- mice. Flow cytometric analysis of perigonadal adipose tissue of male, but not female, mice revealed trends to lower CD11c+MGL1- M1-like macrophages and higher CD11c-MGL1+ M2-like macrophages as a percentage of CD45+F4/80+CD11b+ macrophages in Cx3cr1^-/- Ccr2^-/- mice versus wild-type mice, suggesting reduced adipose tissue macrophage activation. In contrast, single knockout of Ccr2 or Cx3cr1 did not differ in their adipose macrophage phenotypes.

CONCLUSIONS

Although CCR2 and CX3CR1 may synergistically impact inflammatory phenotypes, their joint deficiency did not influence the metabolic effects of a 45% HFD-induced obesity in these model conditions.

[Gut microbiota and immune crosstalk in metabolic disease]

The aim of the review is to discuss about the role played by the defence crosstalk between the gut microbiota and the intestinal immune system, in the development of metabolic disease focusing on obesity and diabetes. Starting from physiological and pathological stand points and based on the latest published data, this review is addressing how the concept of the hologenome theory of evolution can drive the fate of metabolic disease. The notion of "metabolic infection" to explain the "metabolic inflammation" is discussed. This imply comments about the process of bacterial translocation and impaired intestinal immune defense against commensals. Eventually this review sets the soil for personalized medicine. The monthly increase in the number of publications on the gut microbiota to intestinal immune defense and the control of metabolism demonstrate the importance of this field of investigation. The notion of commensal as "self or non-self" has to be reevaluated in the light of the current data. Furthermore, data demonstrate the major role played by short chain fatty acids, secondary bile acids, LPS, peptidoglycans, indole derivatives, and other bacteria-related molecules on the shaping of cells involved in the intestinal protection against commensals is now becoming a central player in the incidence of metabolic diseases. The literature demonstrates that the onset of metabolic diseases and some specific co-morbidities can be explained by a gut microbiota to intestinal immune system crosstalk. Therefore, one should now consider this avenue of investigation as a putative source of biomarkers and therapeutic targets to personalize the treatment of metabolic disease and its co-morbidities. Gut microbiota is considered as a major regulator of metabolic disease. This reconciles the notion of metabolic inflammation and the epidemic development of the disease. In addition to evidence showing that a specific gut microbiota characterizes patients with obesity, type 2 diabetes, and hepatic steatosis, the mechanisms causal to the disease could be related to the translocation of microbiota from the gut to the tissues, which induces inflammation. The mechanisms regulating such a process are based on the crosstalk between the gut microbiota and the host immune system. The hologenome theory of evolution supports this concept and implies that therapeutic strategies aiming to control glycemia should take into account both the gut microbiota and the host immune system. This review discusses the latest evidence regarding the bidirectional impact of the gut microbiota on host immune system crosstalk for the control of metabolic disease, hyperglycemia, and obesity. To avoid redundancies with the literature, we will focus our attention on the intestinal immune system, identifying evidence for the generation of novel therapeutic strategies, which could be based on the control of the translocation of gut bacteria to tissues. Such novel strategies should hamper the role played by gut microbiota dysbiosis on the development of metabolic inflammation. Recent evidence in rodents allows us to conclude that an impaired intestinal immune system characterizes and could be causal in the development of metabolic disease. The fine understanding of the molecular mechanisms should allow for the development of a first line of treatment for metabolic disease and its co-morbidities.

Utilizing nutritional genomics to tailor diets for the prevention of cardiovascular disease: a guide for upcoming studies and implementations

INTRODUCTION

Personalized diets based on an individual's genome to optimize the success of dietary intervention and reduce genetic cardiovascular disease (CVD) risk, is one of the challenges most frequently discussed in the scientific community. Areas covered: The authors gathered literature-based evidence on nutritional genomics and CVD phenotypes, our own results and research experience to provide a critical overview of the current situation of using nutritional genomics to tailor diets for CVD prevention and to propose guidelines for future studies and implementations. Expert commentary: Hundreds of studies on gene-diet interactions determining CVD intermediate (plasma lipids, hypertension, etc.) and final phenotypes (stroke, etc.) have furnished top-level scientific evidence for claiming that the genetic effect in cardiovascular risk is not deterministic, but can be modified by diet. However, despite the many results obtained, there are still gaps in practically applying a personalized diet design to specific genotypes. Hence, a better systemization and methodological improvement of new studies is required to obtain top-level evidence that will allow their application in the future precision nutrition/medicine. The authors propose several recommendations for tackling new approaches and applications.

Emerging role of chemokine CC motif ligand 4 related mechanisms in diabetes mellitus and cardiovascular disease: friends or foes?

Chemokines are critical components in pathology. The roles of chemokine CC motif ligand 4 (CCL4) and its receptor are associated with diabetes mellitus (DM) and atherosclerosis cardiovascular diseases. However, due to the complexity of these diseases, the specific effects of CCL4 remain unclear, although recent reports have suggested that multiple pathways are related to CCL4. In this review, we provide an overview of the role and potential mechanisms of CCL4 and one of its major receptors, fifth CC chemokine receptor (CCR5), in DM and cardiovascular diseases. CCL4-related mechanisms, including CCL4 and CCR5, might provide potential therapeutic targets in DM and/or atherosclerosis cardiovascular diseases.

Gut microbiota and immune crosstalk in metabolic disease

Background

Gut microbiota is considered as a major regulator of metabolic disease. This reconciles the notion of metabolic inflammation and the epidemic development of the disease. In addition to evidence showing that a specific gut microbiota characterizes patients with obesity, type 2 diabetes, and hepatic steatosis, the mechanisms causal to the disease could be related to the translocation of microbiota from the gut to the tissues, inducing inflammation. The mechanisms regulating such a process are based on the crosstalk between the gut microbiota and the host immune system. The hologenome theory of evolution supports this concept and implies that therapeutic strategies aiming to control glycemia should take into account both the gut microbiota and the host immune system.

Scope of review

This review discusses the latest evidence regarding the bidirectional impact of the gut microbiota on host immune system crosstalk for the control of metabolic disease, hyperglycemia, and obesity. To avoid redundancies with the literature, we will focus our attention on the intestinal immune system, identifying evidence for the generation of novel therapeutic strategies, which could be based on the control of the translocation of gut bacteria to tissues. Such novel strategies should hamper the role played by gut microbiota dysbiosis on the development of metabolic inflammation.

Major conclusions

Recent evidence in rodents allows us to conclude that an impaired intestinal immune system characterizes and could be causal in the development of metabolic disease. The fine understanding of the molecular mechanisms should allow for the development of a first line of treatment for metabolic disease and its co-morbidities.

This article is part of a special issue on microbiota.