Scavenger receptor class B type 1 gene rs5888 single nucleotide polymorphism and the risk of coronary artery disease and ischemic stroke: a case-control study

Role of APOC3 3238C/G, APOB 12669G/A and SCARB1 1050C/T polymorphisms, their expression in patients of HIV-associated lipodystrophy

Apolipoproteins and Scavenger Receptor Class B1 (SCARB1) proteins are involved in the etiology of HIV-associated lipodystrophy (HIVLD). APOC3 3238C/G, APOB 12669G/A and SCARB1 1050C/T polymorphisms were linked with increased level of APOB, TG, HDL-C and risk of cardiovascular diseases (CVDs). Hence, we evaluated the genetic variations of APOC3 3238C/G, APOB 12669G/A and SCARB1 1050C/T in 187 patients of HIV (64 with HIVLD, 123 without HIVLD) and 139 healthy controls using PCR-RFLP and expression by qPCR. The genotypes of SCARB1 1050 TT and APOB 12669AA showed a risk to severe HIVLD (P = 0.23, OR = 4.95; P = 0.16, OR = 2.02). The APOC3 3238 GG genotype was associated with a lesser risk of severe HIVLD (P = 0.07, OR = 0.22). The APOB 12669 GA genotype was associated with a greater risk of HIVLD severity in patients with impaired LDL, triglyceride (TG), and cholesterol levels (P = 0.34, OR = 4.13; P = 0.25, OR = 3.64; P = 0.26, OR = 5.47). Similarly, APOB 12669AA genotypes in the presence of impaired triglyceride levels displayed the susceptibility to severity of HIVLD (P = 0.77, OR = 2.91). APOB 12669 GA genotype along with impaired HDL and cholesterol levels indicated an increased risk for HIVLD acquisition among patients without HIVLD (P = 0.42, OR = 2.42; P = 0.26, OR = 2.27). In patients with and without HIVLD, APOC3 3238CG genotypes having impaired cholesterol and glucose levels had higher risk for severity and development of HIVLD (P = 0.13, OR = 2.84, P = 0.34, OR = 1.58; P = 0.71, OR = 1.86; P = 0.14, OR = 2.30). An increased expression of APOB and SCARB1 genes were observed in patients with HIVLD (+0.51 vs. -0.93; +4.78 vs. +3.29), and decreased expression of APOC3 gene was observed in patients with HIVLD (-0.35 vs. -1.65). In conclusion, the polymorphisms mentioned above were not associated with the modulation of HIVLD. However, in the presence of impaired triglyceride, HDL, cholesterol and glucose levels, APOB 12669AA and 12669 GA, APOC3 3238CG genotypes indicated a risk for the development and severity of HIVLD.

Scavenger receptor class B type I genetic variants associated with disease severity in chronic hepatitis C virus infection

Analysis of host genetic polymorphisms is an increasingly important tool for understanding and predicting pathogenesis and treatment response of viral diseases. The gene locus of scavenger receptor class B type I (SR-BI), encoding a cell entry factor and receptor for hepatitis C virus (HCV), contains several genetic polymorphisms. We applied a probe extension assay to determine the frequency of six single nucleotide polymorphisms (SNPs) within the SR-BI gene locus in 374 individuals with history of HCV infection. In addition, SR-BI messenger RNA (mRNA) levels were analyzed in liver biopsy specimens of chronically infected HCV subjects. The rs5888 variant allele T was present at a higher frequency in subjects with advanced fibrosis (χ² , p = 0.016) and after adjusting for age, duration of infection and alcohol intake as confounding factors. Haplotype analysis of SNP frequencies showed that a haplotype consisting of rs61932577 variant allele C and rs5888 variant allele T was associated with an increased risk of advanced liver fibrosis (defined by an Ishak score 4-6) (adjusted odds ratio 2.81; 95% confidence interval 1.06-7.46. p = 0.038). Carriers of the rs5888 variant allele T displayed reduced SR-BI mRNA expression in liver biopsy specimens. In conclusion the rs5888 polymorphism variant is associated with decreased SR-BI expression and an increased risk of development of advanced fibrosis in chronic HCV infection. These findings provide further evidence for a role of SR-BI in HCV pathogenesis and provides a genetic marker for prediction of those infected individuals at greater risk of developing severe disease.

Differential effects of hyperhomocysteinemia on the lipid profiles and lipid ratios between patients with and without coronary artery disease: A retrospective observational study

This study aimed to investigate the differential effects of hyperhomocysteinemia (HHcy) on lipid profiles and lipid ratios between patients with coronary artery disease (CAD) and without CAD. The data of 872 CAD patients and 774 non-CAD controls were extracted from the information system of hospitalized patients. Serum homocysteine (Hcy), total cholesterol (TC), triglycerides (TGs), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein (Apo) AI, and ApoB concentrations were detected. HHcy was defined as a serum level of Hcy ≥ 15 μmol/L. The CAD patients had lower levels of HDL-C and ApoAI and higher levels of Hcy than the controls (P < .05). Serum TGs and HDL-C were negatively correlated with Hcy in controls. Serum HDL-C and ApoAI were negatively correlated with Hcy, and the ratios of TC/HDL-C, TG/HDL-C, LDL/HDL-C, and ApoB/ApoAI were positively correlated with Hcy in the CAD patients (P < .05). Although the trends for HHcy to decrease the lipid profiles were not different between the CAD and controls (Pinteraction > 0.05), CAD with HHcy had lower HDL-C and ApoAI levels than those of subjects with normal Hcy; controls with HHcy had lower TC, LDL-C, and ApoB levels than those of subjects with normal Hcy (P < .05). There were different HHcy trends affecting the ratios of TC/HDL-C and LDL/HDL-C between the CAD patients and controls (Pinteraction for TC/HDL-C = 0.025; Pinteraction for LDL/HDL-C = 0.033). CAD patients with HHcy had a higher ratio of TC/HDL-C (P = .022) and LDL/HDL-C (P = .045) than those of patients with normal Hcy, but in the controls, the subjects with HHcy exhibited a trend toward a decreased ratio of TC/HDL-C (P = .481) and LDL/HDL-C (P = .303). There were differential effects of HHcy on the lipid ratios between CAD and non-CAD patients. HHcy was related to higher ratios of TC/HDL-C and LDL/HDL-C in patients with CAD.

Association between a genetic variant in scavenger receptor class B type 1 and its role on codon usage bias with increased risk of developing coronary artery disease

OBJECTIVE

Coronary artery disease (CAD) as an important cause of morbidity and mortality globally. The scavenger receptor class B type 1 (SCARB1) plays an essential role in the reverse cholesterol transport. We have explored the association between a genetic variant, rs5888, in the SCARB1 gene with CAD and serum HDL-C levels.

METHODS

Patients were categorized into two groups' angiogram positive (>50% coronary stenosis) and angiogram negative (<50% coronary stenosis). Genotyping was carried out using polymerase chain reaction-amplification refractory mutation system. The association between the SNP rs5888 and serum HDL-C was analyzed using a logistic regression model.

RESULTS

The results showed that the subjects carrying a T allele was associated with a decreased serum HDL-C levels compared to the C allele in total population (p < 0.001). The risk of angiogram positivity in subjects carrying a T allele was 3.1-fold higher than for the control group (p < 0.001).

CONCLUSION

CVD patients carrying the T allele of rs5888 variant in the SCARB1 gene was associated with decreased serum level of HDL.

Associations between nine candidate genetic polymorphisms with coronary heart disease : A meta-analysis

BACKGROUND

The aim of this study was to obtain a more accurate assessment of the potential association between nine genetic polymorphisms and the risk of coronary heart disease (CHD).

METHODS

A literature search was performed in PubMed, Embase, OVID, Web of Science, Wanfang, and Chinese National Knowledge Infrastructure (CNKI) databases to identify eligible studies. We analyzed the odds ratios (OR) and 95% confidence intervals (CI) to assess the strength of the associations.

RESULTS

A significant association was found between the PON1 -108C/T polymorphism and CHD risk (TT vs. CC: OR = 1.67, 95% CI = 1.14-2.47, p = 0.009; CT vs. CC: OR = 1.47, 95% CI = 1.17-1.85, p = 0.001; [TT + CT] vs. CC: OR = 1.56, 95% CI = 1.18-2.06, p = 0.002; T allele vs. C allele: OR = 1.28, 95%CI = 1.06-1.54, p = 0.011). There was a significant association between the hOGG1 +1245C/G polymorphism and CHD (GG vs. CC: OR = 2.33, 95% CI: 1.19-4.56, p = 0.014; CG vs. CC: OR = 1.36, 95% CI: 1.01-1.83, p = 0.046; [GG + CG] vs. CC: OR = 1.46, 95% CI: 1.10-1.94, p = 0.010; GG vs. [CC+CG]: OR = 2.11, 95% CI: 1.08-4.10, p = 0.028; G allele vs. C allele: OR = 1.45, 95% CI: 1.14-1.84, p = 0.002). The results also showed a statistically significant association of the SCARB1 +1050C/T polymorphism with CHD (TT vs. CC: OR = 1.30, 95% CI = 1.04-1.62, p = 0.022). Meta-analyses of the other six polymorphisms suggested a lack of any association with CHD risk.

CONCLUSION

Our results show that the susceptibility to CHD was associated with three polymorphisms: PON1 -108C/T, hOGG1 +1245C/G, and SCARB1 +1050C/T.

Sex-Specific Influence of the SCARB1 Rs5888 SNP on the Serum Lipid Response to Atorvastatin in Patients with Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention

Background

Epidemiological studies have shown that there are sex differences in blood lipid levels and lipid responses to statins. Previous studies have shown that the rs5888 single nucleotide polymorphism (SNP) in the scavenger receptor class B type 1 (SCARB1) gene is associated with serum lipid levels in a sex-specific manner. The present study was undertaken to detect the sex-specific influence of the SCARB1 rs5888 SNP on the serum lipid response to atorvastatin in patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI).

Methods

A total of 158 unrelated ACS patients (108 males, 50 females) were enrolled, and all patients received atorvastatin 20 mg/daily after PCI. Genotyping of the rs5888 SNP was performed by polymerase chain reaction and direct sequencing. Serum lipid profiles were determined before treatment and after an average follow-up time of one year.

Results

The baseline serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and apolipoprotein (Apo)AI levels were higher in females than in males (P<0.05). After treatment with atorvastatin, serum TC, LDL-C, and ApoB were decreased, and ApoAI was increased (P<0.05). The effects of atorvastatin on serum lipid levels were different between males and females, and females had greater decreases in TC, LDL-C and ApoB levels than males (P<0.05). The genotypic frequencies of the rs5888 SNP were not different between males and females. The atorvastatin response was not associated with the rs5888 SNP in males (P > 0.05). Nonetheless, in female individuals carrying the rs5888 T-allele, we observed a greater reduction in TC, LDL-C, and ApoB levels after the use of 20 mg/day atorvastatin (P<0.05).

Conclusion

This study indicates that the SCARB1 rs5888 T-allele was associated with a greater reduction in serum TC, LDL-C, and ApoB after atorvastatin treatment in female patients with ACS undergoing PCI.

Integrated analysis of gene expression changes associated with coronary artery disease

BACKGROUND

This study investigated the pathways and genes involved in coronary artery disease (CAD) and the associated mechanisms.

METHODS

Two array data sets of GSE19339 and GSE56885 were downloaded. The limma package was used to analyze the differentially expressed genes (DEGs) in normal and CAD specimens. Examination of DEGs through Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment and Gene Ontology annotation was achieved by Database for Annotation, Visualization and Integrated Discovery (DAVID). The Cytoscape software facilitated the establishment of the protein-protein interaction (PPI) network and Molecular Complex Detection (MCODE) was performed for the significant modules.

RESULTS

We identified 413 DEGs (291 up-regulated and 122 down-regulated). Approximately 256 biological processes, only 1 cellular component, and 21 molecular functions were identified by GO analysis and 10 pathways were enriched by KEGG. Moreover, 264 protein pairs and 64 nodes were visualized by the PPI network. After the MCODE analysis, the top 4 high degree genes, including interleukin 1 beta (IL1B, degree = 29), intercellular adhesion molecule 1 (ICAM1, degree = 25), Jun proto-oncogene (JUN, degree = 23) and C-C motif chemokine ligand 2 (CCL2, degree = 20) had been identified to validate in RT-PCR and Cox proportional hazards regression between CAD and normals.

CONCLUSIONS

The relative expression of IL1B, ICAM1 and CCL2 was higher in CAD than in normal controls (P < 0.05-0.001), but only IL1B and CCL2 genes were confirmed after testing the gene expression in blood and/or analyzing in Cox proportional hazards regression (P < 0.05-0.001), and the proper mechanism may involve in the AGE-RAGE signaling pathway, fluid shear stress, the tumor necrosis factor (TNF) and cytokine-cytokine receptor interaction.

TIMD4 rs6882076 SNP Is Associated with Decreased Levels of Triglycerides and the Risk of Coronary Heart Disease and Ischemic Stroke

Background: The T-cell immunoglobulin and mucin domain 4 gene (TIMD4) rs6882076 single nucleotide polymorphism (SNP) has been associated with serum total cholesterol, low-density lipoprotein cholesterol and triglycerides (TG) levels, but the results are inconsistent. Moreover, little is known about such association in Chinese populations. The aim of this study was to detect the association of the TIMD4 rs6882076 SNP and serum lipid levels and the risk of coronary heart disease (CHD) and ischemic stroke (IS) in a Southern Chinese Han population. Methods: Genotypes of the TIMD4 rs6882076 SNP in 1765 unrelated subjects (CHD, 581; IS, 559 and healthy controls, 625) were determined by the Snapshot Technology. Results: The genotypic and allelic frequencies of the TIMD4 rs6882076 SNP were different between the CHD/IS patients and controls (P < 0.05 for all). The subjects with CT/TT genotypes were associated with decreased risk of CHD (P = 0.014 for CT/TT vs. CC genotypes, P = 0.010 for T vs. C alleles) and IS (P = 0.003 for CT/TT vs. CC genotypes; P = 0.016 for T vs. C alleles). The T allele carriers in healthy controls were also associated with decreased levels of serum TG. Conclusions: The results of the present study suggest that the TIMD4 rs6882076 SNP is associated with decreased risk of CHD and IS in our study population. It is likely to decrease the CHD and IS risk by reducing serum TG levels.

SCARB1 rs5888 gene polymorphisms in coronary heart disease: A systematic review and a meta-analysis

BACKGROUND

Studies have suggested that high-density lipoprotein (HDL) stimulates scavenger receptor class B type 1 (SR-B1) to promote hepatic uptake of cholesterol. SR-B1 is encoded by scavenger receptor class B member 1 (SCARB1) gene in human. A rare mutation in SCARB1 gene has been associated with coronary heart disease (CHD). A polymorphism rs5888 of SCARB1 gene has been linked to CHD risk in humans.

OBJECTIVES

The objective was to investigate the relationship between the SCARB1 gene polymorphism rs5888 and risk of CHD.

METHODS

We searched databases of case-control studies and cohort studies on rs5888 polymorphism of SCARB1 gene and risk of CHD. Two reviewers independently screened literature, extracted data, and estimated potential bias of included studies. The quality of the studies was evaluated by recommendation of Newcastle-Ottawa Scale (NOS). Meta-analysis was performed with Stata 12.0 software.

RESULTS

Seven studies including 6360 subjects (cases: 2456, controls: 3904) were included in the final data combination. Meta-analysis showed T allele had a lower risk of CHD as compared to C allele in allele model (T vs. C: OR = 0.87, 95% CI: 0.70 to 1.09, P = 0.229). Moreover, we found that T allele or TT/TC had a lower risk of CHD as compared to C/CC in male in allele model (T vs. C: OR = 0.79, 95% CI: 0.61 to 1.01). However, no significant association was observed in women in all allele models.

CONCLUSIONS

Our findings suggested that polymorphism rs5888 had negative association with CHD, especially in male. However, the conclusion needs further verification with high quality studies with larger sample size and rigorous designs.

SCARB1 Gene Polymorphisms and HDL Subfractions in Coronary Artery Disease

BACKGROUND/AIM

Cardiovascular diseases are a leading cause of mortality and morbidity worldwide. Polymorphisms in the SCARB1 gene are known to be related to plasma lipids.

PATIENTS AND METHODS

Real time-polymerase chain reaction (RT-PCR) was used for identification of SCARB1 polymorphisms and the Lipoprint Quantimetrix System was employed in identification of HDL subfractions.

RESULTS

According to allelic distribution, in both groups SCARB1 AA genotype led to a two-fold decrease in the risk of developing cardiovascular disease (p=0.04), while the GA genotype increased the risk two-fold (p=0.03). According to the HDL subfraction analysis results, the AA genotype had higher levels of big-sized HDL subfraction (p=0.02).

CONCLUSION

The SCARB1AA genotype decreased cardiovascular risk and carrying GA genotype and G allele increased the risk of CAD. AA genotype carriers had higher levels of big-sized HDL subfraction.

Association of the HNF1A polymorphisms and serum lipid traits, the risk of coronary artery disease and ischemic stroke

BACKGROUND

Hepatocyte nuclear factor-1α gene (HNF1A) single nucleotide polymorphisms (SNPs) have been associated with serum lipid traits in several previous genome-wide association studies. However, little is known about such associations in the Chinese populations. The present study aimed to determine the association of the HNF1A rs1169288, rs2259820, rs2464196 and rs2650000 SNPs and serum lipid traits, the risk of coronary artery disease (CAD) and ischemic stroke (IS).

METHODS

The genotypes of the four SNPs in 562 CAD and 521 IS patients, as well as 594 healthy controls, were detected using the Snapshot technology.

RESULTS

The genotype and allele distribution of the four SNPs was not different between controls and CAD or IS patients (p > 0.05 for all). rs1169288, rs2259820 and rs2464196 SNPs were significantly associated with serum lipid levels in both controls and CAD patients (p < 0.004-0.009). rs2259820 and rs2464196 SNPs were significantly associated with a lower risk of CAD [odds ratio (OR) = 0.64, 95% confidence interval (CI) = 0.44-0.91, p = 0.015 and OR =0.62, 95% CI = 0.43-0.89, p = 0.010, respectively]. Significant linkage disequilibrium was noted among the four SNPs (r²  > 0.5, D' > 0.8). The haplotype of rs1169288A-rs2259820C-rs2464196G-rs2650000A was associated with an increased risk of CAD (OR =1.95, 95% CI: 1.13-3.37, p = 0.015). Interactions of SNP-SNP (rs1169288-rs2464196-rs2650000) and haplotype-environment on the risk of CAD (A-C-G-A-smoking) or IS (A-C-G-A-sex and A-T-A-C-alcohol consumption) were also observed among these SNPs.

CONCLUSIONS

These findings suggest that the HNF1A polymorphisms may be the genetic risk factors for CAD and IS.

Association between the TIMD4-HAVCR1 variants and serum lipid levels, coronary heart disease and ischemic stroke risk and atorvastatin lipid-lowering efficacy

Little is known about the association of the TIMD4 (T-cell immunoglobulin and mucin domain 4 gene)-HAVCR1 (hepatitis A virus cellular receptor 1) variants and lipid metabolism, the risk of coronary heart disease (CHD) and ischemic stroke (IS). The present study aimed to determine the TIMD4-HAVCR1 variants, their haplotypes and gene–environment interactions on serum lipid levels, the risk of CHD and IS, and the lipid-lowering efficacy of atorvastatin in a southern Chinese Han population. Genotypes of three variants in 622 controls, 579 CHD, and 546 IS patients were determined by the Snapshot technology. Atorvastatin calcium tablet (20 mg/day) was given in 724 hyperlipidemic patients for 8 weeks after genotyping. The rs12522248 genotypic and allelic frequencies were different between controls and patients, and were associated with the risk of CHD and IS. The rs1501908G-rs12522248T-rs2036402T haplotype was associated with an increased risk of CHD; the G-C-T haplotype was associated with lower risk of CHD; and the C-C-C haplotype was associated with an increased risk of IS. Variants and their haplotypes in controls were associated with triglyceride (rs1501908), low-density lipoprotein cholesterol (LDL-C, rs1501908, G-T-T), high-density lipoprotein cholesterol (HDL-C, rs12522248, C-C-C) and the ratio of total cholesterol (TC) to HDL-C (C-C-C). Interactions of rs1501908- and rs2036402-alcohol (HDL-C); rs1501908- and rs12522248-high body mass index (hBMI, ≥24 kg/m²; TC); and TIMD4-HAVCR1 variants-atorvastatin on several lipid parameters were detected. Interactions of rs12522248TC/CC-hBMI, G-T-T-, and C-C-C-smoking on the risk of CHD; and C-C-C-smoking, C-C-C-, and G-C-T-hBMI on the risk of IS were also observed. These findings suggest that the TIMD4-HAVCR1 variants may be the genetic risk factors for CHD and IS.

Association of the TTC39B rs581080 SNP and serum lipid levels and the risk of coronary artery disease and ischemic stroke

The tetratricopeptide repeat domain protein 39B gene (TTC39B) single nucleotide polymorphism (SNP) of rs581080 has been associated with serum high-density lipoprotein cholesterol (HDL-C) levels. However, little is known about such association in the Chinese populations. The present study was performed to assess the association between the TTC39B rs581080 SNP and serum lipid levels and the risk of coronary artery disease (CAD) and ischemic stroke (IS) in the Guangxi Han population. Genotypes of the TTC39B rs581080 SNP in 1741 unrelated subjects (CAD, 578; IS, 537; and healthy controls; 624) were determined by the Snapshot Technology. The genotypic and allelic frequencies of the TTC39B rs581080 SNP were different between the CAD/IS patients and controls (P < 0.01 for all). The CG/GG genotypes and G allele were associated with an increased risk of CAD (P = 0.001 for CG/GG vs. CC, P = 0.003 for G vs. C) and IS (P = 0.002 for CG/GG vs. CC; P = 0.004 for G vs. C). The CG/GG genotypes in the healthy controls, but not in CAD or IS patients, were also associated with a decreased serum HDL-C concentration. These results suggest that the TTC39B rs581080 SNP is associated with the risk of CAD and IS in our study population. It is likely to increase the risk of CAD and IS by reducing serum HDL-C levels.

Association between single nucleotide polymorphism rs9534275 and the risk of coronary artery disease and ischemic stroke

BACKGROUND

The present study was to detect the association of single nucleotide polymorphism (SNP) in the breast susceptibility gene 2 (BRCA2) and the risk of coronary artery disease (CAD) and ischemic stroke (IS).

METHODS

Genotypes of the BRCA2 rs9534275 in 1822 unrelated subjects (CAD, 606; IS, 569; and healthy controls, 647) were determined by the polymerase chain reaction and restriction fragment length polymorphism and then confirmed by direct sequencing.

RESULTS

The genotypic and allelic frequencies of rs9534275 were significantly different between the CAD, IS patients and controls (P = 0.033 and P = 0.027; respectively). The GG, GT/GG genotypes and G allele were associated with an increased risk of CAD and IS (CAD: P = 0.005 for GG vs. TT, P = 0.004 for GT/GG vs. TT, P = 0.005 for G vs. T; IS: P = 0.003 for GG vs. TT, P = 0.005 for GT/GG vs. TT; P = 0.002 for G vs. T). The GG, GT and GT/GG genotypes in the CAD, but not in healthy controls and IS patients, were associated with an increased serum total cholesterol (TC) and apolipoprotein B (ApoB) concentration.

CONCLUSIONS

The present study shows that the G allele carriers of BRCA2 rs9534275 were associated with increased serum TC and ApoB levels in the CAD patients and increased risk of CAD and IS.

TRIAL REGISTRATION

Retrospectively registered.

The effect of MVK-MMAB variants, their haplotypes and G×E interactions on serum lipid levels and the risk of coronary heart disease and ischemic stroke

Aim

This study aimed to detect the association of the mevalonate kinase (MVK) and methylmalonic aciduria (cobalamin deficiency) cblB type (MMAB) gene variants, their haplotypes, and gene-environment (G×E) interactions on serum lipid levels and the risk of coronary heart disease (CHD) and ischemic stroke (IS) in a Chinese Han population.

Methods

Genotyping of the rs3759387, rs7134594, rs877710 and rs9593 SNPs in 846 CHD and 869 IS patients and 847 healthy controls was performed by PCR-RFLP and Sanger sequencing. Logistic regression and factor regression were used to investigate the association of 4 MVK-MMAB SNPs and serum lipid levels and the risk of CHD and IS.

Results

The genotypic and allelic frequencies of the rs3759387 and rs7134594 SNPs differed between controls and patients (P < 0.0125-0.001). The rs3759387 SNP was associated with the risk of CHD and IS in different genetic models. The A-T-G-A and C-T-C-T haplotypes were associated with increased risk of CHD. The haplotype of A-T-G-A was associated with an increased risk of IS, whereas the C-T-G-A haplotype was associated with a decreased risk of IS. Interactions of C-T-C-T-smoking or C-T-C-T-age on the risk of CHD, and A-T-G-A-hypertension or A-T-G-A-age on the risk of IS were also observed. The subjects with the rs3759387AA genotype in controls had lower high-density lipoprotein cholesterol (HDL-C) levels than did the subjects with AC/CC genotypes. Several SNPs interacted with alcohol consumption and cigarette smoking to increase serum HDL-C and apolipoprotein A1 levels, but they interacted with body mass index ≥ 24 kg/m² to decrease serum HDL-C and apolipoprotein A1 levels.

Conclusion

Several MVK-MMAB variants, especially the rs3759387 SNP, 4 main haplotypes, and G×E interactions were associated with serum lipid levels and the risk of CHD and IS in a Chinese Han population.

Genetic determinants of inherited susceptibility to hypercholesterolemia - a comprehensive literature review

Hypercholesterolemia is a strong determinant of mortality and morbidity associated with cardiovascular diseases and a major contributor to the global disease burden. Mutations in four genes (LDLR, APOB, PCSK9 and LDLRAP1) account for the majority of cases with familial hypercholesterolemia. However, a substantial proportion of adults with hypercholesterolemia do not have a mutation in any of these four genes. This indicates the probability of having other genes with a causative or contributory role in the pathogenesis of hypercholesterolemia and suggests a polygenic inheritance of this condition. Here in, we review the recent evidence of association of the genetic variants with hypercholesterolemia and the three lipid traits; total cholesterol (TC), HDL-cholesterol (HDL-C) and LDL-cholesterol (LDL-C), their biological pathways and the associated pathogenetic mechanisms. Nearly 80 genes involved in lipid metabolism (encoding structural components of lipoproteins, lipoprotein receptors and related proteins, enzymes, lipid transporters, lipid transfer proteins, and activators or inhibitors of protein function and gene transcription) with single nucleotide variants (SNVs) that are recognized to be associated with hypercholesterolemia and serum lipid traits in genome-wide association studies and candidate gene studies were identified. In addition, genome-wide association studies in different populations have identified SNVs associated with TC, HDL-C and LDL-C in nearly 120 genes within or in the vicinity of the genes that are not known to be involved in lipid metabolism. Over 90% of the SNVs in both these groups are located outside the coding regions of the genes. These findings indicates that there might be a considerable number of unrecognized processes and mechanisms of lipid homeostasis, which when disrupted, would lead to hypercholesterolemia. Knowledge of these molecular pathways will enable the discovery of novel treatment and preventive methods as well as identify the biochemical and molecular markers for the risk prediction and early detection of this common, yet potentially debilitating condition.

Influence of SCARB1 gene SNPs on serum lipid levels and susceptibility to coronary heart disease and cerebral infarction in a Chinese population

The SCARB1 gene encodes human scavenger receptor class B type I (SR-BI), the primary receptor for high-density lipoprotein (HDL)- cholesteryl ester uptake, and polymorphisms in this gene may influence SR-BI protein expression and serum lipid levels, modulating susceptibility to coronary heart disease (CHD) and cerebral infarction (CI). Therefore, we investigated the association between singlenucleotide polymorphisms (SNPs) in the SCARB1 gene and serum lipid levels as well as risk of CHD and CI in the Chinese Han population. Genotypes in 295 CHD patients, 302 CI patients and 312 healthy controls matched for age and gender were determined by high-resolution melting (HRM). Among the 5 SNPs investigated in this study, rs10846744 and rs2278986 were significantly associated with CHD risk. The frequency of the C allele for rs10846744 and that of the T allele for rs2278986 appeared to be significantly increased in the CHD group (OR: 1.416, 95%CI: 1.128-1.778, P=0.0058 and OR: 1.681, 95%CI: 1.327-2.130, P<0.0001, respectively). CHD patients with genotypes CC and CG for rs10846744 had a higher HDL-c level than those with genotype GG, and CHD patients with genotypes CC and CT for the rs2278986 SNP had a higher HDL-c level compared to those with the TT allele. The other 3 SNPs, rs5888, rs10744182 and rs838893, showed no significant association with serum lipid levels and CHD or CI risk in the Chinese population. The CCCTT and CCTTC haplotypes of rs5888, rs10846744, rs10744182, rs2278986 and rs838893 appear to significantly increase CHD risk, whereas the CGTTC, CCTCT and TGCTC haplotypes appear to significantly reduce risk. Overall, the CCTTC and TGTTC haplotypes acted as a significant risk for CI, with the CGCTC and CCCCT haplotypes conferring significantly reduced risk. These results suggest that SCARB1 gene polymorphisms may contribute to genetic susceptibility to CHD; in particular, the C allele of rs10846744 and the C allele of rs2278986 may serve as risk and protective factors for CHD, respectively.

MADD-FOLH1 Polymorphisms and Their Haplotypes with Serum Lipid Levels and the Risk of Coronary Heart Disease and Ischemic Stroke in a Chinese Han Population

This study aimed to detect the association of the MADD-FOLH1 single nucleotide polymorphisms (SNPs) and their haplotypes with the risk of coronary heart disease (CHD) and ischemic stroke (IS) in a Chinese Han population. Six SNPs of rs7395662, rs326214, rs326217, rs1051006, rs3736101, and rs7120118 were genotyped in 584 CHD and 555 IS patients, and 596 healthy controls. The genotypic and allelic frequencies of the rs7395662 SNP were different between controls and patients, and the genotypes of the rs7395662 SNP were associated with the risk of CHD and IS in different genetic models. Six main haplotypes among the rs1051006, rs326214, rs326217, rs3736101, and rs7120118 SNPs were detected in our study population, the haplotypes of G-G-T-G-C and G-A-T-G-T were associated with an increased risk of CHD and IS, respectively. The subjects with rs7395662GG genotype in controls had higher triglyceride (TG) and lower high-density lipoprotein cholesterol (HDL-C) levels than the subjects with AA/AG genotypes. Several SNPs interacted with alcohol consumption to influence serum TG (rs326214, rs326217, and rs7120118) and HDL-C (rs7395662) levels. The SNP of rs3736101 interacted with cigarette smoking to modify serum HDL-C levels. The SNP of rs1051006 interacted with body mass index ≥24 kg/m² to modulate serum low-density lipoprotein cholesterol levels. The interactions of several haplotypes and alcohol consumption on the risk of CHD and IS were also observed.

The rs5888 single nucleotide polymorphism in scavenger receptor class B type 1 (SCARB1) gene and the risk of premature coronary artery disease: a case-control study

Background

Several single nucleotide polymorphisms (SNPs) in lipid transport genes have been shown to be associated with premature coronary artery disease (PCAD). The scavenger receptor BI (SCARB1) is a key component of the reverse cholesterol transport and lipid metabolism. We aimed to examine the relationship between the rs5888 SNP within SCARB1and the risk of angiographically determined PCAD.

Methods

We used an age cut-off of 55 years for women and 45 years for men to define PCAD. Five-hundred and five patients with newly diagnosed angiographically documented PCAD (≥50 % luminal stenosis of any coronary vessel) as case group compared with 546 controls (subjects with no luminal stenosis at coronary arteries). The severity of CAD was determined by vessel score as well as Gensini score. A real-time polymerase chain reaction (PCR) and High Resolution Melting (HRM) analysis was used to distinguish between genotypes.

Results

T allele as compared to C allele was associated with increased odds of PCAD in total population (adjusted OR = 1.3, 95 % CI = 1.0 to 1.5; p = 0.020), and in women (adjusted OR = 1.3, 95 % CI = 1.0 to 1.8; p = 0.037), but not in men (adjusted OR = 1.2, 95 % CI = 0.9 to 1.5; p = 0.311). There was also no significant association between the examined polymorphism and the severity of CAD in whole or in men or women subgroups.

Conclusions

Our findings suggest that the SNP (rs5888) within SCARB1 is independently associated with PCAD in a sex-dependent manner.

Association of variants in CELSR2-PSRC1-SORT1 with risk of serum lipid traits, coronary artery disease and ischemic stroke

Recent genome-wide association studies (GWAS) have identified genetic variants associated with coronary artery disease (CAD), ischemic stroke (IS) and serum lipid traits in different ethnic groups. Some loci were found to affect the risk of CAD and IS. However, there were no data in the southern Chinese populations. Our study was to assess the association of CELSR2-PSRC1-SORT1 rs599839, rs464218 and rs6698443 SNPs and serum lipid levels and the risk of CAD and IS. The genotypes of 3 SNPs were detected in 561 CAD and 527 IS patients, and in 590 healthy controls. The genotypic and allelic frequencies of the rs599839 SNP were different between the controls and IS patients (P < 0.05). The minor G alleles of rs599839 and rs464218 SNPs were associated with higher high-density lipoprotein cholesterol concentrations in CAD and IS patients (P < 0.05); respectively. No association was found between the SNPs of rs599839, rs464218 and rs6698843 at the CELSR2-PSRC1-SORT1 and the risk of CAD or IS. These results will be replicated in the other Chinese populations.

Association of polymorphisms in the MAFB gene and the risk of coronary artery disease and ischemic stroke: a case-control study

BACKGROUND

The v-maf avian musculoaponeurotic fibrosarcoma oncogene homolog B gene (MAFB) has been associated with serum lipid levels in the Eurpean population, but little is known about such association in the Chinese population or in atherosclerosis-related patients. Therefore, the purpose of the present study was to assess the association of the single nucleotide polymorphisms (SNPs) in the MAFB and serum lipid levels and the risk of coronary artery disease (CAD) and ischemic stroke (IS) in the Chinese population.

METHODS

A total of 1,065 unrelated patients (CAD, 525 and IS, 540) and 539 healthy controls were recruited in this study. Genotypes of the MAFB rs2902940 and rs6102059 SNPs were determined by the Snapshot technology platform.

RESULTS

The rs2902940AA genotype was associated with an increased risk of CAD (adjusted OR = 1.63, 95% CI = 1.07-2.48, P = 0.023) and IS (adjusted OR = 1.69, 95% CI = 1.09-2.61, P = 0.017). The rs2902940GA/AA genotypes were also associated with an increased risk of CAD (adjusted OR = 1.56, 95% CI = 1.04-2.32, P = 0.030 for GA/AA vs. GG) and IS (adjusted OR = 1.72, 95% CI = 1.14-2.60, P = 0.010 for GA/AA vs. GG). Significant interactions were observed only in those with higher body mass index (BMI), hypertension and diabetes (P < 0.05). The subjects with rs2902940GA/AA genotypes in controls had lower serum ApoAI levels than the subjects with GG genotype (P = 0.024).

CONCLUSIONS

The rs2902940A allele carriers in the MAFB conferred a decreased serum ApoAI level in controls and an increased risk of CAD and IS. The rs2902940GA/AA genotypes interacted with higher BMI, hypertension and diabetes to contribute the risk of CAD and IS.

Polymorphisms in the GCKR are associated with serum lipid traits, the risk of coronary artery disease and ischemic stroke

The present study was to determine the association of two single nucleotide polymorphisms (SNPs) in the glucokinase regulator gene (GCKR) and serum lipid levels, and the risk of coronary artery disease (CAD) and ischemic stroke (IS). Genotypes of the GCKR rs1260326 and rs8179206 in 1736 unrelated subjects (CAD, 584; IS, 555; and healthy controls; 597) were determined by the Snapshot technology platform. The genotypic and allelic frequencies of rs1260326 and rs8179206 were not different among the three groups (P > 0.05). The subjects with rs1260326TT genotype had higher serum low-density lipoprotein cholesterol (LDL-C) levels in controls, and higher triglyceride (TG) levels in CAD patients than the subjects with CC and CT genotypes after adjustment for age, sex, body mass index, blood pressure, alcohol consumption, and cigarette smoking (P < 0.05). The rs1260326TT genotype was also associated with decreased risk of IS in females (OR = 0.37, 95% CI: 0.18-0.76, P = 0.007). The present study shows that the GCKR rs1260326TT genotype is associated with high LDL-C in controls, high TG levels in CAD patients, and a decreased risk of IS in females.

Asparaginase treatment side-effects may be due to genes with homopolymeric Asn codons (Review-Hypothesis)

The present treatment of childhood T-cell leukemias involves the systemic administration of prokary-otic L-asparaginase (ASNase), which depletes plasma Asparagine (Asn) and inhibits protein synthesis. The mechanism of therapeutic action of ASNase is poorly understood, as are the etiologies of the side-effects incurred by treatment. Protein expression from genes bearing Asn homopolymeric coding regions (N-hCR) may be particularly susceptible to Asn level fluctuation. In mammals, N-hCR are rare, short and conserved. In humans, misfunctions of genes encoding N-hCR are associated with a cluster of disorders that mimic ASNase therapy side-effects which include impaired glycemic control, dislipidemia, pancreatitis, compromised vascular integrity, and neurological dysfunction. This paper proposes that dysregulation of Asn homeostasis, potentially even by ASNase produced by the microbiome, may contribute to several clinically important syndromes by altering expression of N-hCR bearing genes. By altering amino acid abundance and modulating ribosome translocation rates at codon repeats, the microbiomic environment may contribute to genome decoding and to shaping the proteome. We suggest that impaired translation at poly Asn codons elevates diabetes risk and severity.

Association of two polymorphisms in the FADS1/FADS2 gene cluster and the risk of coronary artery disease and ischemic stroke

Little is known about the association of the FADS1/FADS2 SNPs and serum lipid levels and the risk of coronary artery disease (CAD) and ischemic stroke (IS) in the Chinese southern population. The present study aimed to determine such association in the Chinese southern population. A total of 1,669 unrelated subjects (CAD, 534; IS, 553; and healthy controls, 582) were recruited in the study. Genotypes of the FADS1 rs174546 SNP and the FADS2 rs174601 SNP were determined by the SNaPshot Multiplex Kit. The T allele and TT genotype frequencies of the two SNPs were predominant in our study population. The T alleles were associated with increased risk of CAD and IS. Correspondingly, the C alleles were associated with reduced risk of CAD and IS. Haplotype analyses showed that the haplotype of T-T (rs174546-rs174601) was associated with an increased risk for IS, and the haplotype of C-C (rs174546-rs174601) was associated with a reduced risk for CAD and IS. The two SNPs were likely to influence serum lipid levels. The T allele carriers of the two SNPs and rs174601 TT genotype were associated with decreased serum HDL-C and ApoAI levels in the patient groups and with an increased risk of CAD and IS. The present study suggests that the FADS1 rs174546 SNP and the FADS2 rs174601 SNP are associated with the risk of CAD and IS, and are likely to influence serum lipid levels. However, further functional studies are needed to clarify how the two SNPs actually affect serum lipid levels and the risk of CAD and IS.

Association between single nucleotide polymorphism rs1044925 and the risk of coronary artery disease and ischemic stroke

The present study was performed to clarify the association between the acyl-CoA:cholesterol acyltransferase-1 (ACAT-1) single nucleotide polymorphism (SNP) rs1044925 and the risk of coronary artery disease (CAD) and ischemic stroke (IS) in the Guangxi Han population. Polymerase chain reaction and restriction fragment length polymorphism was performed to determine the genotypes of the ACAT-1 SNP rs1044925 in 1730 unrelated subjects (CAD, 587; IS, 555; and healthy controls; 588). The genotypic and allelic frequencies of rs1044925 were significantly different between the CAD patients and controls (p = 0.015) and borderline different between the IS patients and controls (p = 0.05). The AC/CC genotypes and C allele were associated with a decreased risk of CAD and IS (CAD: p = 0.014 for AC/CC vs. AA, p = 0.022 for C vs. A; IS: p = 0.014 for AC/CC vs. AA; p = 0.017 for C vs. A). The AC/CC genotypes in the healthy controls, but not in CAD or IS patients, were associated with an increased serum high-density lipoprotein cholesterol (HDL-C) concentration. The present study shows that the C allele carriers of ACAT-1 rs1044925 were associated with an increased serum HDL-C level in the healthy controls and decreased risk in CAD and IS patients.