ATP-binding cassette transporter A1 (ABCA1) R219K (G1051A, rs2230806) polymorphism and serum high-density lipoprotein cholesterol levels in a large Japanese population: cross-sectional data from the Daiko Study

Identification of Important Genes Associated with the Development of Atherosclerosis

Atherosclerosis is one of the most important medical problems due to its prevalence and significant contribution to the structure of temporary and permanent disability and mortality. Atherosclerosis is a complex chain of events occurring in the vascular wall over many years. Disorders of lipid metabolism, inflammation, and impaired hemodynamics are important mechanisms of atherogenesis. A growing body of evidence strengthens the understanding of the role of genetic and epigenetic factors in individual predisposition and development of atherosclerosis and its clinical outcomes. In addition, hemodynamic changes, lipid metabolism abnormalities, and inflammation are closely related and have many overlapping links in regulation. A better study of these mechanisms may improve the quality of diagnosis and management of such patients.

Current Data and New Insights into the Genetic Factors of Atherogenic Dyslipidemia Associated with Metabolic Syndrome

Atherogenic dyslipidemia plays a critical role in the development of metabolic syndrome (MetS), being one of its major components, along with central obesity, insulin resistance, and hypertension. In recent years, the development of molecular genetics techniques and extended analysis at the genome or exome level has led to important progress in the identification of genetic factors (heritability) involved in lipid metabolism disorders associated with MetS. In this review, we have proposed to present the current knowledge related to the genetic etiology of atherogenic dyslipidemia, but also possible challenges for future studies. Data from the literature provided by candidate gene-based association studies or extended studies, such as genome-wide association studies (GWAS) and whole exome sequencing (WES,) have revealed that atherogenic dyslipidemia presents a marked genetic heterogeneity (monogenic or complex, multifactorial). Despite sustained efforts, many of the genetic factors still remain unidentified (missing heritability). In the future, the identification of new genes and the molecular mechanisms by which they intervene in lipid disorders will allow the development of innovative therapies that act on specific targets. In addition, the use of polygenic risk scores (PRS) or specific biomarkers to identify individuals at increased risk of atherogenic dyslipidemia and/or other components of MetS will allow effective preventive measures and personalized therapy.

Lipid-Related Genetic Variants for Personalized Dietary Interventions: A Systematic Review

Dyslipidemias are known risk factors for chronic diseases. Precision nutrition interventions are designed according to characteristics, such as diet, phenotype, and genotype. This systematic review aims to define a panel of genetic variants associated with lipid abnormalities that could be later used in nutrigenetic intervention studies. A systematic review is conducted following the PRISMA-P. Studies published from January 2010 to December 2020 in English language and humans are included from PubMed and ScienceDirect databases. Articles that demonstrate a strong association between polymorphisms (single nucleotide variation) of genes involved in lipid metabolism and increased risk for dyslipidemia are included. A total of 3031 articles are screened, but only 51 articles fulfill the inclusion criteria. The genes included are FABP2, MTTP related to CM synthesis and secretion; LPL, LIPC involved in triglyceride hydrolysis; CETP, APOA1, LCAT, ABCA1, and APOA5 related to lipoprotein metabolism, and APOE, LDLR, SCARB1, APOC3 involved in lipid clearance. In this systematic review, genetic variants related to chylomicron synthesis, triglyceride hydrolysis, lipoprotein metabolism, and lipid clearance demonstrate a strong association with lipid abnormalities, which can be used to design precision nutrition interventions that may help to prevent and treat dyslipidemia effectively.

Association Between ABCA1 R219K Variant and Alzheimer's Disease: An Updated Meta-Analysis and Systematic Review

BACKGROUND

Over a dozen studies have investigated the effect of the R219K variant in the ATP-binding cassette transporter A1 (ABCA1) gene on the risk of Alzheimer's disease (AD), but the results are conflicting.

OBJECTIVE

We performed a systematic review and meta-analysis to comprehensively assess the association between the ABCA1 R219K variant and the risk of AD.

METHODS

Studies included in the meta-analysis were obtained by searching PubMed, Web of Science and AlzGene. Review Manager 5.4 was used for meta-analysis. Both the odds ratio (OR) and its 95% confidence interval (CI) were used to evaluate the effect of ABCA1 R219K polymorphism on AD susceptibility. Heterogeneity between the included studies was assessed using I2 statistics and Cochran Qtest. Funnel plots were used to assess publication bias.

RESULTS

A total of 14 eligible studies involving 10084 subjects were retrieved from PubMed, Web of Science and AlzGene. Meta-analysis results showed that R219K polymorphism was significantly associated with a decreased risk of AD in Chinese under a recessive model (OR = 0.67; 95% CI = 0.51- 0.88; P = 0.004).

CONCLUSION

The present meta-analysis indicated that the KK genotype of R219K polymorphism may act as a protective factor for AD in the Chinese population. Additional studies with larger sample sizes are needed to further confirm this association.

Genetic and Epigenetic Regulation of Lipoxygenase Pathways and Reverse Cholesterol Transport in Atherogenesis

Atherosclerosis is one of the most important medical and social problems of modern society. Atherosclerosis causes a large number of hospitalizations, disability, and mortality. A considerable amount of evidence suggests that inflammation is one of the key links in the pathogenesis of atherosclerosis. Inflammation in the vascular wall has extensive cross-linkages with lipid metabolism, and lipid mediators act as a central link in the regulation of inflammation in the vascular wall. Data on the role of genetics and epigenetic factors in the development of atherosclerosis are of great interest. A growing body of evidence is strengthening the understanding of the significance of gene polymorphism, as well as gene expression dysregulation involved in cross-links between lipid metabolism and the innate immune system. A better understanding of the genetic basis and molecular mechanisms of disease pathogenesis is an important step towards solving the problems of its early diagnosis and treatment.

Role of ABCA1 in Cardiovascular Disease

Cholesterol homeostasis plays a significant role in cardiovascular disease. Previous studies have indicated that ATP-binding cassette transporter A1 (ABCA1) is one of the most important proteins that maintains cholesterol homeostasis. ABCA1 mediates nascent high-density lipoprotein biogenesis. Upon binding with apolipoprotein A-I, ABCA1 facilitates the efflux of excess intracellular cholesterol and phospholipids and controls the rate-limiting step of reverse cholesterol transport. In addition, ABCA1 interacts with the apolipoprotein receptor and suppresses inflammation through a series of signaling pathways. Thus, ABCA1 may prevent cardiovascular disease by inhibiting inflammation and maintaining lipid homeostasis. Several studies have indicated that post-transcriptional modifications play a critical role in the regulation of ABCA1 transportation and plasma membrane localization, which affects its biological function. Meanwhile, carriers of the loss-of-function ABCA1 gene are often accompanied by decreased expression of ABCA1 and an increased risk of cardiovascular diseases. We summarized the ABCA1 transcription regulation mechanism, mutations, post-translational modifications, and their roles in the development of dyslipidemia, atherosclerosis, ischemia/reperfusion, myocardial infarction, and coronary heart disease.

Etiologic Puzzle of Coronary Artery Disease: How Important Is Genetic Component?

In the modern era, coronary artery disease (CAD) has become the most common form of heart disease and, due to the severity of its clinical manifestations and its acute complications, is a major cause of morbidity and mortality worldwide. The phenotypic variability of CAD is correlated with the complex etiology, multifactorial (caused by the interaction of genetic and environmental factors) but also monogenic. The purpose of this review is to present the genetic factors involved in the etiology of CAD and their relationship to the pathogenic mechanisms of the disease. Method: we analyzed data from the literature, starting with candidate gene-based association studies, then continuing with extensive association studies such as Genome-Wide Association Studies (GWAS) and Whole Exome Sequencing (WES). The results of these studies revealed that the number of genetic factors involved in CAD etiology is impressive. The identification of new genetic factors through GWASs offers new perspectives on understanding the complex pathophysiological mechanisms that determine CAD. In conclusion, deciphering the genetic architecture of CAD by extended genomic analysis (GWAS/WES) will establish new therapeutic targets and lead to the development of new treatments. The identification of individuals at high risk for CAD using polygenic risk scores (PRS) will allow early prophylactic measures and personalized therapy to improve their prognosis.

Assessment of genetic polymorphism associated with ATP-binding cassette transporter A1 (ABCA1) gene and fluctuations in serum lipid profile levels in patients with coronary artery disease

Background

Coronary artery disease (CAD) is one of the common genetic and clinical risk factors associated with cardiovascular and multifactorial disorder. ATP-binding cassette transporter A1 (ABCA1) gene plays an important role in lipid metabolism and in multiple studies associated with CAD. However, more studies are needed to identify the exact role of single nucleotide polymorphisms which may cause CAD.

Objectives

The aim of this study is to investigate the genetic association of polymorphism g.1051G > A in the ABCA1 gene with CAD patients in the Saudi population.

Methods

We included 315 confirmed CAD cases, and 205 non-CAD or control subjects in this case-control study. DNA isolation was carried out for all registered participants and the polymorphism g.1051G > A was genotyped with Polymerase Chain Reaction followed by Restriction Fragment Length Polymorphism analysis with EcoNI restriction enzyme.

Results

Modifiable risk factors such as Body Mass Index, smoking and diabetes were strongly associated and non-modifiable risk factors such as hypertension (Systolic Blood Pressure and Diastolic Blood Pressure) and serum analysis such as Fasting Blood Glucose, Total cholesterol (TC), Triglyceride (TG) and LDL-c were significantly associated in CAD cases (p < 0.05). Allele (OR-1.73;95% CI:1.33–2.26; p = 0.0004), GA vs GG (OR-2.26; 95% CI: 1.53–3.35; p = 0.0003 and dominant inheritance pattern (OR-2.23; 95% CI:1.56–3.20; p = 0.00009 was strongly associated with CAD cases and control subjects. The frequency level of use of atorvastatin was significantly different among GG, GA and AA subjects. Additionally, TC and TG levels were influenced by the presence of g.1051G > A polymorphism.

Conclusion

The polymorphism g.1051G > A in the gene ABCA1 is closely associated with the existence of the CAD subjects. This polymorphism could also affect the serum levels of the lipid profile, suggesting a possible occurrence of CAD in the Saudi population.

Computational SNP Analysis and Molecular Simulation Revealed the Most Deleterious Missense Variants in the NBD1 Domain of Human ABCA1 Transporter

The ATP-binding cassette transporter A1 (ABCA1) is a membrane-bound exporter protein involved in regulating serum HDL level by exporting cholesterol and phospholipids to load up in lipid-poor ApoA-I and ApoE, which allows the formation of nascent HDL. Mutations in the ABCA1 gene, when presents in both alleles, disrupt the canonical function of ABCA1, which associates with many disorders related to lipid transport. Although many studies have reported the phenotypic effects of a large number of ABCA1 variants, the pathological effect of non-synonymous polymorphisms (nsSNPs) in ABCA1 remains elusive. Therefore, aiming at exploring the structural and functional consequences of nsSNPs in ABCA1, in this study, we employed an integrated computational approach consisting of nine well-known in silico tools to identify damaging SNPs and molecular dynamics (MD) simulation to get insights into the magnitudes of the damaging effects. In silico tools revealed four nsSNPs as being most deleterious, where the two SNPs (G1050V and S1067C) are identified as the highly conserved and functional disrupting mutations located in the NBD1 domain. MD simulation suggested that both SNPs, G1050V and S1067C, changed the overall structural flexibility and dynamics of NBD1, and induced substantial alteration in the structural organization of ATP binding site. Taken together, these findings direct future studies to get more insights into the role of these variants in the loss of the ABCA1 function.

The impact of ATP-binding cassette transporters on metabolic diseases

Currently, many people worldwide suffer from metabolic diseases caused by heredity and external factors, such as diet. One of the symptoms of metabolic diseases is abnormal lipid metabolism. ATP binding cassette (ABC) transporters are one of the largest transport protein superfamilies that exist in nearly all living organisms and are mainly located on lipid-processing cells. ABC transporters have been confirmed to be closely related to the pathogenesis of diseases such as metabolic diseases, cancer and Alzheimer's disease based on their transport abilities. Notably, the capability to transport lipids makes ABC transporters critical in metabolic diseases. In addition, gene polymorphism in ABC transporters has been reported to be a risk factor for metabolic diseases, and it has been reported that relevant miRNAs have significant roles in regulating ABC transporters. In this review, we integrate recent studies to examine the roles of ABC transporters in metabolic diseases and aim to build a network with ABC transporters as the core, linking their transport abilities with metabolic and other diseases.

Common gene polymorphism in ATP-binding cassette transporter A1 and coronary artery disease: A genetic association study and a structural analysis

ATP-binding cassette transporter A1 (ABCA1) has a crucial role in removing intracellular cholesterol and plays a protective role against atherosclerosis. Therefore, genetic polymorphisms in this gene may alter the susceptibility to coronary artery disease (CAD). This study was aimed to examine the association of rs2230806 (c.1051 G > A; p.R219K) variation in the ABCA1 gene with CAD in a case-control design which was followed by a meta-analysis and in silico approach. In the case-control study, 300 subjects including 150 individuals with CAD and 150 healthy controls were recruited. The c.1051 G > A genotyping was done by polymerase chain reaction-restriction fragment length polymorphism method. In the meta-analysis, eligible studies were collected from PubMed, Google Scholar, and ScienceDirect databases and pooled odds ratio, heterogeneity, publication bias, and sensitivity analyses were carried. Finally, some bioinformatics tools were employed to assess the impacts of p.R219K variation on ABCA1 protein structure. Our case-control examination showed a statistically significant association between c.1051 G > A genetic polymorphism and CAD risk. In addition, the meta-analysis showed reliable significant associations between c.1051 G > A transition and risk of CAD in the Caucasian population. In silico analysis showed that the p.R219K substitution could alter the secondary structure, hydrophobicity pattern, and Ramachandran plot of ABCA1. These findings elucidate that the c.1051 G > A variation could be a genetic risk factor for CAD and it could be considered as a prognostic and predictive biomarker for susceptible individuals.

ABCA1 variants rs2230806 (R219K), rs4149313 (M8831I), and rs9282541 (R230C) are associated with susceptibility to coronary heart disease

BACKGROUND

To investigate the association between three single nucleotide polymorphisms (SNPs) of ABCA1 gene and susceptibility to coronary heart disease (CHD) in Chinese Han population.

METHODS

A total of 484 CHD patients and 488 controls were included in the study. Three SNPs rs2230806 (R219K), rs4149313 (M8831I), and rs9282541 (R230C) in ABCA1 gene were genotyped by SNaPshot.

RESULTS

Single nucleotide polymorphism rs1800977 was associated with susceptibility to CHD (AA vs GG, P = 0.013; A vs G, P = 0.029; recessive model, P = 0.020). Rs4149313 (AA vs GG, P = 0.010; recessive model, P = 0.011) and rs9282541 (T vs C, P = 0.029; dominant model, P = 0.039) were also risk factor for CHD.

CONCLUSION

This study suggests that three SNPs rs2230806, rs4149313, and rs9282541 in ABCA1 gene are significantly associated with susceptibility to CHD; further mechanism should be performed to be applied to drug research and development.

Associations of the ABCA1 gene polymorphisms with plasma lipid levels: A meta-analysis

BACKGROUND

Studies on the associations of the adenosine triphosphate-binding cassette transporter A1 gene (ABCA1) rs2230806, rs2230808, and rs2066714 polymorphisms with plasma lipid levels have reported apparently conflicting findings. This meta-analysis aimed to clarify the relationships between the 3 polymorphisms and fasting lipid levels.

METHODS

A comprehensive search of the literature was carried out by using the databases including Medline, Google Scholar, Web of Science, Embase, Cochrane Library, CNKI, Wanfang, and VIP. The studies that presented mean lipids and standard deviations or standard errors according to the rs2230806, rs2230808, and/or rs2066714 genotypes were examined and included. The random effects model was used. Standardized mean difference and 95% confidence interval were used to assess the differences in lipid levels between the genotypes. Heterogeneity among studies was tested by Cochran's χ-based Q-statistic, and Galbraith plots were used to detect the potential sources of heterogeneity. Publication bias was assessed by Begg's rank correlation test as well as funnel plots.

RESULTS

Sixty-two studies (48,452 subjects), 12 studies (9853 subjects) and 14 studies (10,727 subjects) were identified for the rs2230806, rs2230808, and rs2066714 polymorphisms, respectively. A dominant model was used for all the polymorphisms in this meta-analysis. The A allele carriers of the rs2230806 polymorphism had higher levels of high-density lipoprotein cholesterol (HDL-C) (P <.001), and lower levels of low-density lipoprotein cholesterol (LDL-C) (P =.03) and triglycerides (TG) (P <.01) than the non-carriers. The A allele carriers of the rs2230808 polymorphism had higher levels of total cholesterol (TC) (P <.001) than the non-carriers. The G allele carriers of the rs2066714 polymorphism had higher levels of TC (P <.01) and HDL-C (P = .02) than the non-carriers.

CONCLUSION

The ABCA1 rs2230806, rs2230808, and rs2066714 polymorphisms are significantly associated with plasma lipid levels in the present meta-analysis.

Association Study of the ATP - Binding Cassette Transporter A1 (ABCA1) Rs2230806 Genetic Variation with Lipid Profile and Coronary Artery Disease Risk in an Iranian Population

BACKGROUND:

ATP - binding cassette transporter A1 (ABCA1) plays essential roles in the biogenesis of high -density lipoprotein - cholesterol. Variations in the ABCA1 gene may influence the risk of coronary artery disease (CAD).

AIM:

Present study aimed to investigate the association of rs2230806 (R219K) polymorphism of ABCA1 gene with the development and severity of CAD in an Iranian population.

MATERIALS AND METHODS:

Our study population consisted of 100 patients with angiographically confirmed CAD and 100 controls. The genotyping of R219K mutation of ABCA1 gene was determined by PCR - RFLP method. Lipid profile was determined using routine colourimetric assays. Statistical analysis was done by SPSS - 16.

RESULTS:

The genotypic (P = 0.024) and allelic (P = 0.001) distribution of the ABCA1 R219K polymorphism were significantly different between the two groups. In a univariate analysis (with genotype RR as the reference), the RK genotype (OR = 0.46, 95%CI = 0.25-0.86, P = 0.020) and KK genotype (OR = 0.27, 95%CI = 0.11 – 0.66, P = 0.005) was significantly associated with a decreased risk of CAD. A multiple logistic regression analysis revealed that smoking (0.008), diabetes (P = 0.023), triglyceride (P = 0.001), HDL - cholesterol (P = 0.002) and ABCA1 KK genotype (P = 0.009) were significantly and independently associated with the risk of CAD. The association between different genotypes of R219K polymorphism with lipid profile was not significant in both groups (P > 0.05). The R219K polymorphism was significantly associated with severity of CAD (P < 0.05).

CONCLUSION:

The carriage of K allele of ABCA1 R219K polymorphism has a protective effect on CAD risk and correlates with a decreased severity of CAD. This protective effect seems to be mediated independently of plasma lipid levels.

Correlation Between ABCA1 Gene Polymorphism and aopA-I and HDL-C in Abdominal Aortic Aneurysm

BACKGROUND

As the most common type of aneurysm, abdominal aortic aneurysm (AAA) has an unfavorable prognosis due to the high frequency of rupture. Studies have indicated a close relationship between the pathogenesis and progression of AAA and abnormal serum lipid levels. ATP-binding cassette transport protein A1 (ABCA1) is a cell-surface protein facilitating cellular efflux of cholesterol. The single-nucleotide polymorphism (SNP) of ABCA1 gene has been suggested to be correlated with abnormal metabolism of lipids. Therefore, this study aimed to investigate the relationship between ABCA1 polymorphism and apoA-I and HDL-C in an attempt to elucidate its correlation with AAA occurrence.

MATERIAL/METHODS

We included 126 AAA patients and 119 healthy controls in this study. PCR and restriction fragment length polymorphism (RFLP) were used to detect the SNP pattern of ABCA1 gene at locus rs2230806 from both AAA patients and healthy controls. The distribution pattern and correlation with apoA-I and HDL-C was analyzed.

RESULTS

The distribution of KK/RR genotype of ABCA1 gene had significant difference between disease and control group, with lower rates of RR genotype and R allele in the disease group (p<0.05). Levels of apoA-I and HDL-C, but not triglyceride and LDL-C levels, in AAA patients who carried R allele in ABCA1 gene (including RR and RK genotypes) were higher than in non-carriers (p<0.05). The R allele of ABCA1 gene was shown to be related with the occurrence of AAA (p<0.05).

CONCLUSIONS

Polymorphism of ABCA1 gene is correlated with AAA occurrence, possibly via the regulation of serum lipid metabolism by R allele.