APOA1 and APOB polymorphisms and apolipoprotein concentrations as biomarkers of risk in acute coronary syndrome: Relationship with lipid-lowering therapy effectiveness

Association of rs662799 and rs5070 genetic polymorphisms with hypertriglyceridemia and atherogenic dyslipidemia in pediatric patients in Southeast Mexico

BACKGROUND AND AIMS

Triglycerides are the initiators of the metabolic changes that lead to atherogenic dyslipidemia (AD). The APOA5 and APOA1 genes are involved in the response and metabolism of serum lipids and lipoproteins, where single nucleotide polymorphisms (SNP) rs662799 (promoter region) and rs5070 (intronic region) have been associated with the susceptibility to dyslipidemia. Until now, few studies evaluate the association of these polymorphisms with the presentation of hypertriglyceridemia and AD among Mexican children. Therefore, the objective was to determine the association between rs662799 and rs5070 with hypertriglyceridemia and AD in a pediatric population of southeastern Mexico.

MATERIALS AND METHODS

A case-control analysis was performed including 268 infants aged 2-16 years, anthropometric, clinical variables, and serum lipid profiles were analyzed. DNA was extracted from blood samples and genotyping of polymorphisms was executed with the TaqMan SNP genotyping assay. Allele and genotypic frequencies were calculated. For genetic association analysis, logistic regression models were fitted according to models of inheritance.

RESULTS

The SNP rs662799 (C) was significantly associated with hypertriglyceridemia in the overdominant model (OR=3.89, p=0.001) and AD in the dominant model (OR=4.01, p=0.001). The SNP rs5070 (T) has a protective effect against hypertriglyceridemia in the additive risk model (OR=0.68, p=0.03).

CONCLUSION

Polymorphism rs662799 was significantly associated with cases of hypertriglyceridemia and AD in minors in southeastern Mexico. On the other hand, rs5070 polymorphism was not associated with cases of hypertriglyceridemia or AD.

APOA1 mRNA and protein in kidney renal clear cell carcinoma correlate with the disease outcome

Renal cancer is one of the most common malignant tumors with high mortality, and kidney renal clear cell carcinoma (KIRC) is the most common type of renal cancer. We attempted to evaluate the clinical and prognostic significance of Apolipoprotein A1 (APOA1) mRNA and protein in KIRC patients. Clinical data along with RNA-sequencing data were downloaded from UCSC Xena. The Human Protein Atlas database was searched to reveal APOA1 protein expression profiles in KIRC and normal renal tissues. The TIMER database was applied to determine the correlations of APOA1 with immune cells and PD-1 and PD-L1 in KIRC. Ninety-one cases of KIRC patients and 93 healthy controls from our hospital were enrolled for clinical validation. Levels of APOA1 mRNA in KIRC tissues (N = 535) are not only lower than the levels in normal renal tissues (N = 117), but also in paired normal renal tissues (N = 72). High expression of APOA1 mRNA at the time of surgery was correlated with worse overall survival (OS) (HR 1.66; p = 0.037) and disease-free survival (DFS) (HR 1.65; p = 0.047), and APOA1 DNA methylation was linked to worse OS (HR 2.1; p = 0.001) rather than DFS (HR 1.12; p = 0.624) in KIRC patients. Concentrations of preoperative serum APOA1 protein were markedly decreased in KIRC patients compared to healthy controls (p < 0.01), and low levels of APOA1 protein predicted less favorable OS than those with high levels (HR = 2.84, p = 0.0407). APOA1 negatively correlated with various immune cell infiltrates and PD-L1 expression (r = − 0.283, p = 2.74e−11) according to the TIMER database. Low levels of APOA1 mRNA at the time of surgery predict favorable survival in KIRC patients. Our results provide insights to identify a novel prognostic index with great clinical utility.

Comparison of apolipoprotein-A1 levels between paroxysmal atrial fibrillation patients and healthy subjects

Introduction: Studies found that the inflammation plays a key role in the pathogenesis of paroxysmal atrial fibrillation (PAF). It is well-known that apolipoprotein-A1 (Apo-A1) demonstrates antiinflammatory and anti-oxidant properties in a healthy physiological system. In the present study, we aimed to determine whether there is any difference of Apo-A1 levels in patients with PAF and healthy subjects.

Methods: In this prospective cohort study, we enrolled a total of 35 PAF patients and 34 comparable healthy participants. Apo-A1 levels were measured from each subject using an immunophelometric method. All enrolled subjects were followed-up for one year during the study period. Results: Serum high-sensitivity C-reactive protein (hs-CRP) levels were statistically higher in PAF patients compared to healthy subjects (1.54±1.99 vs. 1.06±2.01, P = 0.016, respectively). Of note, patients with PAF had lower Apo-A1 levels (1.84±0.74 vs. 2.55±0.44, P = 0.001, respectively). There was no statistical difference between the groups in terms of apolipoprotein-B levels (1.08±0.36 vs. 0.99±0.38, P = 0.339, respectively). We did not find any correlation between Apo-A1 levels and PAF attacks in the study.

Conclusion: The main finding of this study was that Apo-A1 levels were significantly lower in PAF patients compared to healthy participants. Based on our results, we considered that Apo-A1 may have a key role in the pathogenesis of PAF.

The APOB rs693 polymorphism impacts the lipid profile of Brazilian older adults

The apolipoprotein B (APOB) gene contains several polymorphic sites described as risk modifiers for cardiovascular events. The objective of this study was to verify the association of the classic APOB Xba I polymorphism (rs693) with atherosclerotic risk factors in a segment of the Brazilian elderly population considering their usual dietary intake. Clinical and biochemical characteristics as well as total caloric and fat intake data were determined from 644 elderly individuals. Polymorphism analysis was performed by conventional polymerase chain reaction followed by enzyme restriction. Statistical analyses compared measures and proportions according to different APOB genotypic combinations. Statistically significant association was found between Xba I polymorphism and serum LDL, total cholesterol, and total lipid levels, with important elevations among T homozygotes compared to the other genotypes. There was homogeneity in all other parameters analyzed (including intake pattern), with a tendency for reduced levels of circulating apolipoprotein B among TT individuals. Our results pointed out that genetic variation in APOB affected the lipemic profile of elderly individuals in a context not biased by diet, generating a pattern suggestive of secretory disorder of lipoprotein particles, with possible implication in atherosclerotic risk.

Association of the APOA1 rs964184 SNP and serum lipid traits in the Chinese Maonan and Han populations

BACKGROUND

Maonan nationality belongs to a mountain ethnic minority in China. Little is known about the association of apolipoprotein A1 gene (APOA1) rs964184 single nucleotide polymorphism (SNP) and serum lipid levels in this population. The aim of this study was to detect the association of the APOA1 rs964184 SNP and several environmental factors with serum lipid profiles in the Chinese Maonan and Han populations.

METHODS

Genotypes of the APOA1 rs964184 SNP in 867 individuals of Maonan nationality and 820 participants of Han nationality were determined by polymerase chain reaction and restriction fragment length polymorphism, combined with gel electrophoresis, and confirmed by direct sequencing.

RESULTS

The frequencies of CC, CG and GG genotypes of the APOA1 rs964184 SNP were 68.86, 29.18 and 1.96% in the Maonan population, and 63.78, 30.85 and 5.37% in the Han population (P < 0.001). The frequency of the G allele was 16.55% in Maonan and 20.79% in Han (P < 0.001). The G allele carriers had lower high-density lipoprotein cholesterol (HDL-C) levels in Maonan and higher triglyceride (TG) levels in Han peoples than the G allele non-carriers. Subgroup analyses showed that the G allele carriers had lower HDL-C levels in both Maonan males and females; and lower apolipoprotein (Apo) A1 levels and the ApoA1/ApoB ratio in Han males than the G allele non-carriers. Serum lipid parameters in the two ethnic groups were also associated with several environmental factors.

CONCLUSIONS

The present study reveals that there may be a racial/ethnic- and/or gender-specific association between the APOA1 rs964184 SNP and serum lipid parameters in our study populations.

TRIAL REGISTRATION

Retrospectively registered.