The impact of common polymorphisms in CETP and ABCA1 genes with the risk of coronary artery disease in Saudi Arabians

The ABCA1 gene polymorphisms rs1800977 and rs2230806 are differentially associated with the risk for myocardial infarction in Slovenian subjects with type 2 diabetes mellitus

BACKGROUND

The adenosine triphosphate-binding cassette transporter A1 (ABCA1) is closely linked to various aspects of the regulation of whole-body cholesterol metabolism and atherosclerosis formation. The object of the study was to investigate the association between rs1800977 and rs2230806 polymorphisms in the ABCA1 gene and myocardial infarction (MI) in Slovenian subjects with type 2 diabetes mellitus (T2DM).

METHODS

1590 T2DM patients (484 subjects with MI and 1106 controls) were included in this retrospective cross-sectional case-control study. After genotyping, Pearson χ2 test was used to compare the distribution of genotypes and alleles among the two groups. Logistic regression analysis adjusted for several risk factors for MI was performed.

RESULTS

Genotype distribution showed significant association with MI in T2DM subjects for both selected polymorphisms in ABCA1 gene (p = 0.009 for rs2230806 and p = 0.042 for rs1800977). After applying corrections for confounding variables like age, waist circumference, diastolic blood pressure, serum high-density lipoprotein levels, gender and smoking several genetic models still showed significant associations with MI (dominant model for rs2230806 and dominant, overdominant and co-dominant for rs1800977).

CONCLUSION

Our study showed that presence of the T allele of the rs2230806 ABCA1 gene is associated with higher risk of MI, while the A allele of the rs1800977 conferred protection against MI in Slovenian T2DM subjects.

Association of the polymorphisms of the cholesteryl ester transfer protein gene with coronary artery disease: a meta-analysis

Aims

This meta-analysis aimed to assess the association of the polymorphisms of cholesterol ester transfer protein (CETP) rs708272 (G>A), rs5882 (G>A), rs1800775 (C>A), rs4783961 (G>A), rs247616 (C>T), rs5883 (C>T), rs1800776 (C>A), and rs1532624 (C>A) with coronary artery disease (CAD) and the related underlying mechanisms.

Methods

A comprehensive search was performed using five databases such as PubMed, EMBASE, Web of Science, Cochrane Library and Scopus to obtain the appropriate articles. The quality of the included studies was assessed by the Newcastle-Ottawa Scale. The statistical analysis of the data was performed using STATA 17.0 software. The association between CETP gene polymorphisms and risk of CAD was estimated using the pooled odds ratio (OR) and 95% confidence interval (95% CI). The association of CETP gene polymorphisms with lipids and with CETP levels was assessed using the pooled standardized mean difference and corresponding 95% CI. P < 0.05 was considered statistically significant.

Results

A total of 70 case-control studies with 30,619 cases and 31,836 controls from 46 articles were included. The results showed the CETP rs708272 polymorphism was significantly associated with a reduced risk of CAD under the allele model (OR = 0.846, P < 0.001), the dominant model (OR = 0.838, P < 0.001) and the recessive model (OR = 0.758, P < 0.001). AA genotype and GA genotype corresponded to higher high-density lipoprotein cholesterol (HDL-C) concentrations in the blood compared with GG genotype across the studied groups (all P < 0.05). The CETP rs5882 and rs1800775 polymorphisms were not significantly associated with CAD under the allele model (P = 0.802, P = 0.392), the dominant model (P = 0.556, P = 0.183) and the recessive model (P = 0.429, P = 0.551). Similarly, the other mentioned gene polymorphisms were not significantly associated with CAD under the three genetic models.

Conclusions

The CETP rs708272 polymorphism shows a significant association with CAD, and the carriers of the allele A are associated with a lower risk of CAD and higher HDL-C concentrations in the blood compared to the non-carriers. The CETP rs5882, rs1800775, rs4783961, rs247616, rs5883, rs1800776, and rs1532624 are not significantly associated with CAD.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023432865, identifier: CRD42023432865.

Roles of peripheral lipoproteins and cholesteryl ester transfer protein in the vascular contributions to cognitive impairment and dementia

This narrative review focuses on the role of cholesteryl ester transfer protein (CETP) and peripheral lipoproteins in the vascular contributions to cognitive impairment and dementia (VCID). Humans have a peripheral lipoprotein profile where low-density lipoproteins (LDL) represent the dominant lipoprotein fraction and high-density lipoproteins (HDL) represent a minor lipoprotein fraction. Elevated LDL-cholesterol (LDL-C) levels are well-established to cause cardiovascular disease and several LDL-C-lowering therapies are clinically available to manage this vascular risk factor. The efficacy of LDL-C-lowering therapies to reduce risk of all-cause dementia and AD is now important to address as recent studies demonstrate a role for LDL in Alzheimer's Disease (AD) as well as in all-cause dementia. The LDL:HDL ratio in humans is set mainly by CETP activity, which exchanges cholesteryl esters for triglycerides across lipoprotein fractions to raise LDL and lower HDL as CETP activity increases. Genetic and pharmacological studies support the hypothesis that CETP inhibition reduces cardiovascular risk by lowering LDL, which, by extension, may also lower VCID. Unlike humans, wild-type mice do not express catalytically active CETP and have HDL as their major lipoprotein fraction. As HDL has potent beneficial effects on endothelial cells, the naturally high HDL levels in mice protect them from vascular disorders, likely including VCID. Genetic restoration of CETP expression in mice to generate a more human-like lipid profile may increase the relevance of murine models for VCID studies. The therapeutic potential of existing and emerging LDL-lowering therapies for VCID will be discussed. Figure Legend. Cholesteryl Ester Transfer Protein in Alzheimer's Disease. CETP is mainly produced by the liver, and exchanges cholesteryl esters for triglycerides across lipoprotein fractions to raise circulating LDL and lower HDL as CETP activity increases. Low CETP activity is associated with better cardiovascular health, due to decreased LDL and increased HDL, which may also improve brain health. Although most peripheral lipoproteins cannot enter the brain parenchyma due to the BBB, it is increasingly appreciated that direct access to the vascular endothelium may enable peripheral lipoproteins to have indirect effects on brain health. Thus, lipoproteins may affect the cerebrovasculature from both sides of the BBB. Recent studies show an association between elevated plasma LDL, a well-known cardiovascular risk factor, and a higher risk of AD, and considerable evidence suggests that high HDL levels are associated with reduced CAA and lower neuroinflammation. Considering the potential detrimental role of LDL in AD and the importance of HDL's beneficial effects on endothelial cells, high CETP activity may lead to compromised BBB integrity, increased CAA deposits and greater neuroinflammation. Abbreviations: CETP - cholesteryl transfer ester protein; LDL - low-density lipoproteins; HDL - high-density lipoproteins; BBB - blood-brain barrier; CAA - cerebral amyloid angiopathy, SMC - smooth muscle cells, PVM - perivascular macrophages, RBC - red blood cells.

Rare Variants in Genes of the Cholesterol Pathway Are Present in 60% of Patients with Acute Myocardial Infarction

Acute myocardial infarction (AMI) is a pandemic in which conventional risk factors are inadequate to detect who is at risk early in the asymptomatic stage. Although gene variants in genes related to cholesterol, which may increase the risk of AMI, have been identified, no studies have systematically screened the genes involved in this pathway. In this study, we included 105 patients diagnosed with AMI with an elevation of the ST segment (STEMI) and treated with primary percutaneous coronary intervention (PPCI). Using next-generation sequencing, we examined the presence of rare variants in 40 genes proposed to be involved in lipid metabolism and we found that 60% of AMI patients had a rare variant in the genes involved in the cholesterol pathway. Our data show the importance of considering the wide scope of the cholesterol pathway in order to assess the genetic risk related to AMI.

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.

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.

Effects of ABCA1 gene polymorphisms on risk factors, susceptibility and severity of coronary artery disease

BACKGROUND

The relationships between the rs1800976, rs4149313 and rs2230806 polymorphisms in ATP binding cassette protein A1 and severity of coronary artery disease (CAD) remain unclear.

METHODS

Four hundred and forty-two patients with CAD and 217 CAD-free subjects were enrolled in this study. The rs1800976, rs4149313 and rs2230806 polymorphisms were genotyped by PCR-RFLP. Severity of CAD was evaluated by Gensini score system, number of stenotic coronary vessels and extent of coronary stenosis.

RESULTS

C allele of the rs1800976 polymorphism, G allele of the rs4149313 polymorphism and A allele of the rs2230806 polymorphism were found to be risk alleles for CAD (p<0.05 for all). In patients with CAD, C allele of the rs1800976 polymorphism was associated with high levels of hypersensitive C reactive protein (hs-CRP) and cystatin c (CysC), and its frequency increased with percentiles of Gensini score, number of stenotic coronary vessels and extent of coronary stenosis (p<0.05 for all). The subjects with GA genotype of the rs4149313 polymorphism had higher levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), apolipoprotein B and hs-CRP than those with AA genotype (p<0.05 for all). The subjects with AA genotype of the rs2230806 polymorphism had higher levels of TC, LDL-C and uric acid than those with GA genotype (p<0.05 for all). No associations between the rs4149313 or rs2230806 polymorphism and severity of CAD were detected.

CONCLUSIONS

The rs1800976 polymorphism is significantly associated with the occurrence and severity of CAD, which is possibly mediated by hs-CRP and CysC.

Association of rs2230806 in ABCA1 with coronary artery disease: An updated meta-analysis based on 43 research studies

BACKGROUND

As a key gene in the reverse transport pathway of cholesterol, ABCA1 (ATP-binding cassette transporter A1) plays an important role in the pathogenesis of coronary artery disease (CAD). In the ABCA1, rs2230806 is the most widely studied polymorphism and its role has been controversial.

METHODS

We performed an updated meta-analysis by searching online electronic databases using the PubMed, Web of Science, Embase, Cochrane Library, EMBASE, Google Scholar, China National Knowledge Infrastructure, and Wan Fang databases before June 28, 2019. STATA12.0 software was used to perform a series of analyses on the data, including genetic effect model, heterogeneity, sensitivity, and publication bias analysis.

RESULTS

Based on our inclusion and exclusion criteria, finally 43 articles including a total of 34,348 subjects (14,085 CAD cases and 20,263 healthy controls) were investigated. Results showed that carrying the K allele in rs223086 in the overall population significantly reduced the risk of CAD (OR = 0.745, 95% CI = 0.687-0.809, P < .001). After the ethnicity stratification analysis, the above phenomenon was found to be significant in Asian populations (OR = 0.686, 95% CI = 0.633-0.744, P < .001), marginally significant in Caucasians (OR = 0.887, 95% CI = 0.786-1.001, P = .051), and not significant in other populations (OR = 0.851, 95% CI = 0.558-1.297, P = .452). Further stratified according to the sample size in the Asian and Caucasian populations, in the Asian the K allele is more protective in small samples than large samples; however, in the Caucasian small samples carrying the K allele play a protective role while large samples are negative. In addition, according to the source of the control population and the geographical location in China, the results showed that rs2230806 was significantly associated with CAD in any group. Five genetic models (allelic, recessive, dominant, homozygote, and heterozygote) were analyzed in the above analysis.

CONCLUSION

The K allele of rs2230806 was significantly associated with decreased risk of CAD, especially in Asian populations and small sample Caucasians.

Cholesteryl ester transfer protein: the physiological and molecular characteristics in the pathogenesis of atherosclerosis and Alzheimer’s disease

Cholesteryl ester transfer protein (CETP) is involved in reverse cholesterol transport, mediates the exchange of cholesteryl esters for triglycerides between high-density lipoproteinsand low-density lipoproteins/very low-density lipoproteins. Lipid transfer mechanism by CETP is unknown. Two main models have been proposed for the mechanism of action of CETP: shuttle and tunnel mechanisms. The variants of CETP gene affect activity and level of protein, thus they are associated with lipid profile and risk of many diseases. Some clinical studies reported that polymorphisms of CETP, including TaqIB and I405V, are associated with risk of atherosclerosis and/or Alzheimer’s disease. CETP plays important role an in the metabolism of cholesterol, thus is correlated with pathomechanism of coronary artery disease. Inhibition of CETP can be an effective strategy to improve the lipid profile and reduce risk of cardiovascular diseases. Therefore, new therapeutic strategies to reduce activity of CETP or decrease its level are developed. Effectiveness of following pharmacological methods of modulation of CETP activity was studied: anti-CETP vaccines, antisense oligonucleotide and small molecule inhibitors of CETP. This article presents an overview of the literature on the correlation between cardiovascular diseases and CETP protein/CETP gene. Furthermore, it discusses the impact of CETP on pathogenesis of Alzheimer’s disease.

Relationship between CETP gene polymorphisms with coronary artery disease in Polish population

The cholesteryl ester transfer protein (CETP) gene encodes a hydrophobic glycoprotein that plays a crucial role in the reverse transport of cholesterol. The aim of the present study was to determine whether CETP polymorphisms (rs1532624, rs247616 and rs708272) are associated with coronary artery disease (CAD) in a Polish population. Serum lipid levels and single nucleotide polymorphisms of CETP genes were determined in 494 subjects: 248 patients with premature CAD and 246 blood donors as controls. Selected polymorphisms were examined using TaqMan PCR analysis. We found that CAD risk was significantly higher for CC homozygotes and C allele carriers of the rs247616 polymorphism than for carriers with the T allele (OR 1.89, 95% CI 1.29–2.76, p = 0.001 and OR 1.51, 95% CI 1.14–1.99, p = 0.003) and likewise for the CC genotype of the rs1532624 polymorphism than for those with the A allele (OR 1.59, 95% CI 1.05–2.40, p = 0.026). Moreover, T allele carriers of the rs708272 polymorphism had significantly higher total cholesterol levels compared to CC homozygotes (p < 0.05) in the healthy controls. We also observed an allelic pattern, C_(rs2477616)C_(rs708272)C_(rs1532624), which increased susceptibility to CAD by 43% (OR = 1.43, 95% CI 1.10–1.85, p = 0.006). In conclusion, the rs247616 and rs1532624 polymorphisms of CETP may modulate the risk of CAD in Polish population.

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.

Associations of Cholesteryl Ester Transfer Protein TaqIB Polymorphism with the Composite Ischemic Cardiovascular Disease Risk and HDL-C Concentrations: A Meta-Analysis

BACKGROUND

Previous studies have evaluated the associations between the cholesteryl ester transfer protein (CETP) TaqIB polymorphism (rs708272), the risk of developing composite ischemic cardiovascular disease (CVD) and the concentration of high-density lipoprotein cholesterol (HDL-C), but results remain controversial. The objective of this study was to investigate whether a relationship exists between these factors.

METHODS

We conducted a meta-analysis of available studies to clarify the associations of the CETP TaqIB polymorphism with HDL-C concentration and the composite ischemic CVD risk in both Asians and Caucasians. All statistical analyses were done with Stata 12.0.

RESULTS

Through utilization of the Cochrane Library, Embase, PubMed, Web of Science, Springer, China Science and Technology Journal Database, China National Knowledge Infrastructure, Google Scholar, and Baidu Library, a total of 45 studies from 44 papers with 20,866 cases and 21,298 controls were combined showing a significant association between the CETP TaqIB variant and composite ischemic CVD risk. Carriers of allele TaqIB-B1 were found to have a higher risk of composite ischemic CVD than non-carriers: OR = 1.15, 95% CI = 1.09-1.21, p < 0.001. Meanwhile, 28 studies with 23,959 subjects were included in the association between the CETP TaqIB polymorphism and the concentration of HDL-C. RESULTS suggested that carriers of the B1B1 genotype had lower concentrations of HDL-C than those of the B2B2 genotype: SMD = 0.50, 95% CI = 0.36-0.65, p < 0.001.

CONCLUSIONS

The synthesis of available evidence demonstrates that the CETP TaqIB polymorphism protects against composite ischemic CVD risk and is associated with a higher HDL-C concentration in both Asians and Caucasians.