A meta-analysis on relationship between paraoxonase 1 polymorphisms and atherosclerotic cardiovascular diseases

Association of paraoxonase-1 (Q192R) gene polymorphism with coronary artery spasm during cardiac catheterisation in Egyptians

BACKGROUND

Coronary artery spasm is among the etiology of myocardial infarction. Oxidative stress is involved in the pathogenesis of coronary artery spasm (CAS). Paraoxonase-1 (PON1) is an HDL-bound antioxidant enzyme that protects LDL from oxidative modification. Oxidative-stress-related genetic factors and certain polymorphisms in the paraoxonase 1 gene might influence the pathogenesis of CAS. We aimed to investigate the association between PON1 gene polymorphism and its enzymatic activity and coronary artery spasm during cardiac catheterization.

METHODS AND RESULTS

The study population was 150 patients who underwent elective coronary angiography. Subjects were genotyped to the Q192R polymorphism (rs662) on the PON1 gene by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), and PON1 activity was quantitatively analyzed by enzyme linked immunosorbent assay. Results showed that the subjects carrying the RR genotype and R allele were significantly more likely to develop coronary artery spasm (OR=4.2, 2.03, P< 0.006, P˂0.02, respectively). Moreover, serum PON1 levels were significantly decreased (P˂0.001) in the CAS group. RR genotype of PON1 Q192R polymorphism, Tc, LDLc, TG, catheter size, and paroxonase-1 serum level are independent predictors of coronary spasm.

CONCLUSION

We conclude that the PON1 (rs662) gene polymorphism is associated with CAS during cardiac catheterization in Egyptians. The PON1-192R allele and lower serum enzyme concentration may play an important role in coronary spasm.

Paraoxonase 1: evolution of the enzyme and of its role in protecting against atherosclerosis

PURPOSE OF REVIEW

To review the discoveries which led to the concept that serum paraoxonase 1 (PON1) is inversely related to atherosclerotic cardiovascular disease (ASCVD) incidence, how this association came to be regarded as causal and how such a role might have evolved.

RECENT FINDINGS

Animal models suggest a causal link between PON1 present on HDL and atherosclerosis. Serum PON1 activity predicts ASCVD with a similar reliability to HDL cholesterol, but at the extremes of high and low HDL cholesterol, there is discordance with PON1 being potentially more accurate. The paraoxonase gene family has its origins in the earliest life forms. Its greatest hydrolytic activity is towards lactones and organophosphates, both of which can be generated in the natural environment. It is active towards a wide range of substrates and thus its conservation may have resulted from improved survival of species facing a variety of evolutionary challenges.

SUMMARY

Protection against ASCVD is likely to be the consequence of some promiscuous activity of PON1, but nonetheless has the potential for exploitation to improve risk prediction and prevention of ASCVD.

PON1 rs662, rs854560 and TRIB1 rs17321515, rs2954029 Gene Polymorphisms Are Associated with Lipid Parameters in Patients with Unstable Angina

Acute coronary heart disease (CHD) is mainly caused by the rupture of an unstable atherosclerotic plaque. Many different factors can cause stenosis or even occlusion of the coronary artery lumen, such as vasculitis and platelet aggregation. Our study was performed to assess the association between PON1 rs662, rs854560 and TRIB1 rs17321515, rs2954029 polymorphisms and the risk of CHD, as well as the association between studied polymorphisms and selected clinical parameters affecting the risk of developing ischemic heart disease. A total of 232 patients with unstable angina were enrolled in this study. There were no statistically significant differences in the PON1 rs662, rs854560 and TRIB1 rs17321515, rs2954029 polymorphism distributions between the total study and control groups. Total cholesterol plasma levels were significantly higher in patients with the PON1 rs662 TT genotype compared to those with the CC+TC genotypes, as well as in patients with the PON1 rs854560 TT genotype compared to those with the AA+AT genotypes. LDL plasma levels were significantly increased in patients with the PON1 rs854560 TT genotype compared to those with the AA+AT genotypes. Plasma levels of HDL were significantly decreased in patients with the TRIB1 rs17321515 AA+AG genotypes compared to those with the GG genotype, as well as in patients with the TRIB1 rs2954029 AA+AT genotypes compared to those with the TT genotype. Our results suggest that the analysed polymorphisms are not risk factors for unstable angina in the Polish population. However, the results of this study indicate an association between the PON1 rs662, rs854560 and TRIB1 rs17321515, rs2954029 polymorphisms with lipid parameters in patients with coronary artery disease.

The Role of Polyphenols in Modulating PON1 Activity Regarding Endothelial Dysfunction and Atherosclerosis

The incidence and prevalence of cardiovascular diseases are still rising. The principal mechanism that drives them is atherosclerosis, an affection given by dyslipidemia and a pro-inflammatory state. Paraoxonase enzymes have a protective role due to their ability to contribute to antioxidant and anti-inflammatory pathways, especially paraoxonase 1 (PON1). PON1 binds with HDL (high-density lipoprotein), and high serum levels lead to a protective state against dyslipidemia, cardiovascular diseases, diabetes, stroke, nonalcoholic fatty liver disease, and many others. Modulating PON1 expression might be a treatment objective with significant results in limiting the prevalence of atherosclerosis. Lifestyle including diet and exercise can raise its levels, and some beneficial plants have been found to influence PON1 levels; therefore, more studies on herbal components are needed. Our purpose is to highlight the principal roles of Praoxonase 1, its implications in dyslipidemia, cardiovascular diseases, stroke, and other diseases, and to emphasize plants that can modulate PON1 expression, targeting the potential of some flavonoids that could be introduced as supplements in our diet and to validate the hypothesis that flavonoids have any effects regarding PON1 function.

The association of the paraoxonase 1 Q192R polymorphism with coronary artery disease (CAD) and cardiometabolic risk factors in Iranian patients suspected of CAD

Introduction

The present study aimed to investigate the association of the paraoxonase 1 (PON1) Q192R polymorphism with coronary artery disease (CAD) and cardiometabolic risk factors in Iranian patients suspected of CAD.

Methods

This cross-sectional study was conducted on 428 patients undergoing angiography. The data related to demographic information and physical activity were collected by valid and reliable questionnaires. The PON-1 genotypes were detected by the polymerase chain reaction-restriction fragment length polymorphism (RFLP-PCR) technique. The Gensini and SYNTAX score, anthropometric measurements, and biochemical and clinical parameters were measured by standard protocols.

Results and discussion

Findings indicated that the odds of obesity was significantly higher in people with the RR genotype compared to the QQ genotype carriers (OR: 2.95 CI: 1.25-6.93, P = 0.014) and also odds of low high-density lipoprotein cholesterol (HDL-C) was marginally higher (OR: 2.31 CI: 0.97-5.49, P = 0.056). There was no significant association between other CAD risk factors with PON1 Q192R polymorphism (P > 0.05). Further analysis showed a significant interaction between sex and 192QR (P = 0.019) and 192 RR (P = 0.007) genotypes on body mass index (BMI). More specifically, the risk of obesity in men carrying the RR genotype was 3.38 times (OR: 3.38 CI: 1.08-10.58, P = 0.036). Also, a significant joint effect of the RR genotype and sex on HDL-C was seen (P = 0.003). The stratification based on sex showed that the risk of low HDL-C is significantly higher in women carrying the RR genotype (OR: 6.18 CI: 1.21-31.46, P = 0.028). A marginal sex-genotype interaction was also found in the risk of elevated alanine aminotransferase (ALT) (P = 0.057). In summary, the findings showed that the risk of obesity and low HDL-C was higher in people carrying the RR genotype. On the other hand, a Q192R polymorphism-sex interaction was observed on the risk of obesity, elevated ALT, and low HDL-C.

Paraoxonase 1 and atherosclerosis

Paraoxonase 1 (PON1), residing almost exclusively on HDL, was discovered because of its hydrolytic activity towards organophosphates. Subsequently, it was also found to hydrolyse a wide range of substrates, including lactones and lipid hydroperoxides. PON1 is critical for the capacity of HDL to protect LDL and outer cell membranes against harmful oxidative modification, but this activity depends on its location within the hydrophobic lipid domains of HDL. It does not prevent conjugated diene formation, but directs lipid peroxidation products derived from these to become harmless carboxylic acids rather than aldehydes which might adduct to apolipoprotein B. Serum PON1 is inversely related to the incidence of new atherosclerotic cardiovascular disease (ASCVD) events, particularly in diabetes and established ASCVD. Its serum activity is frequently discordant with that of HDL cholesterol. PON1 activity is diminished in dyslipidaemia, diabetes, and inflammatory disease. Polymorphisms, most notably Q192R, can affect activity towards some substrates, but not towards phenyl acetate. Gene ablation or over-expression of human PON1 in rodent models is associated with increased and decreased atherosclerosis susceptibility respectively. PON1 antioxidant activity is enhanced by apolipoprotein AI and lecithin:cholesterol acyl transferase and diminished by apolipoprotein AII, serum amyloid A, and myeloperoxidase. PON1 loses this activity when separated from its lipid environment. Information about its structure has been obtained from water soluble mutants created by directed evolution. Such recombinant PON1 may, however, lose the capacity to hydrolyse non-polar substrates. Whilst nutrition and pre-existing lipid modifying drugs can influence PON1 activity there is a cogent need for more specific PON1-raising medication to be developed.

Association of Paraoxonase-1 Genotype and Phenotype with Angiogram Positive Coronary Artery Disease

BACKGROUND

It has been shown that increased serum PON1 levels are protective against several disorders. Several single nucleotide polymorphisms (SNPs) of the PON1 gene have been reported to be associated with serum enzyme protein levels and activity.

OBJECTIVE

To investigate the association of SNPs of PON1 and serum paraoxonase activity with coronary artery disease (CAD).

METHODS

A total of 601 unrelated patients who underwent coronary angiography including those who had >50% stenosis (N=266) and those with <30% stenosis (N=335) were studied. The Paraoxonase gene rs662 and rs840560 SNPs were determined using the ARMS-PCR method and the rs705379 SNP was genotyped using PCR-RFLP analysis. Serum paraoxonase activity was measured using paraoxon as a substrate. A p value of p<0.05 was considered as significant.

RESULTS

Serum paraoxonase activity was not significantly different between the study groups. After adjustment for age, sex, hypertension, diabetes mellitus and dyslipidemia, the GG genotype and co-dominant model of rs662 was positively associated with a positive angiogram (respectively, OR=2.424, 95%CI [1.123-5.233], p<0.05, OR=1.663, 95%CI [1.086-2.547]). Serum paraoxonase activity was significantly higher in the G allele and GG variant of rs662, A allele and AA variant of rs854560 and C allele and CC variant of rs705379. The haplotype analysis has shown that the ATC haplotype was significantly more prevalent among the angiogram negative group. The analysis between groups indicated that the A allele of rs662 was significantly associated with lower paraoxonase activity in the positive angiogram group (p=0.019).

CONCLUSIONS

The presence of the G allele of the rs662 single nucleotide polymorphism is independently associated to increased risk of CAD.

Association of PON-1 polymorphism with susceptibility to and severity of ischemic stroke in the Chinese population

Aim: The authors aimed to investigate whether polymorphisms of PON-1 were associated with the susceptibility to and severity of ischemic stroke (IS). Methods: In this study, 302 IS patients and 303 healthy controls were enrolled. Polymorphisms rs854560 and rs854572 of PON-1 were detected using SNaPshot single-nucleotide polymorphism typing technology. Results: The rs854572 polymorphism of the PON-1 gene showed a significant correlation with IS, and its GG genotype reduced the risk of IS (recessive model, p = 0.001). The GG genotype was also associated with mild stroke (p = 0.032). No association was observed between rs854560 and IS. Conclusion: PON-1 rs854572 polymorphism was related to the risk of IS and could be a biomarker to access the severity of IS.

Proteomics-Based Approach to Identify Novel Blood Biomarker Candidates for Differentiating Intracerebral Hemorrhage From Ischemic Stroke-A Pilot Study

Background: A reliable distinction between ischemic stroke (IS) and intracerebral hemorrhage (ICH) is required for diagnosis-specific treatment and effective secondary prevention in patients with stroke. However, in resource-limited settings brain imaging, which is the current diagnostic gold standard for this purpose, is not always available in time. Hence, an easily accessible and broadly applicable blood biomarker-based diagnostic test differing stroke subtypes would be desirable. Using an explorative proteomics approach, this pilot study aimed to identify novel blood biomarker candidates for distinguishing IS from ICH.

Material and Methods: Plasma samples from patients with IS and ICH were drawn during hospitalization and were analyzed by using liquid chromatography/mass spectrometry. Proteins were identified using the human reference proteome database UniProtKB, and label-free quantification (LFQ) data were further analyzed using bioinformatic tools.

Results: Plasma specimens of three patients with IS and four patients with ICH with a median National Institute of Health Stroke Scale (NIHSS) of 12 [interquartile range (IQR) 10.5–18.5] as well as serum samples from two healthy volunteers were analyzed. Among 495 identified protein groups, a total of 368 protein groups exhibited enough data points to be entered into quantitative analysis. Of the remaining 22 top-listed proteins, a significant difference between IS and ICH was found for Carboxypeptidase N subunit 2 (CPN2), Coagulation factor XII (FXII), Plasminogen, Mannan-binding lectin serine protease 1, Serum amyloid P-component, Paraoxonase 1, Carbonic anhydrase 1, Fibulin-1, and Granulins.

Discussion: In this exploratory proteomics-based pilot study, nine candidate biomarkers for differentiation of IS and ICH were identified. The proteins belong to the immune system, the coagulation cascade, and the apoptosis system, respectively. Further investigations in larger cohorts of patients with stroke using additional biochemical analysis methods, such as ELISA or Western Blotting are now necessary to validate these markers, and to characterize diagnostic accuracy with regard to the development of a point-of-care-system for use in resource-limited areas.

The Relevance of Noncoding DNA Variations of Paraoxonase Gene Cluster in Atherosclerosis-Related Diseases

The human paraoxonase (PON) gene cluster is comprised of three contiguous genes (PON1, PON2 and PON3) of presumably common origin coding three lactonases of highly similar structure and substrate specificity. The catalytic activity of PON proteins is directed toward artificial organophosphates and in physiological conditions toward thiolactones and oxidized phospholipids. Consequently, PON enzymes are regarded as an effective defense against oxidative stress and, as a result, against atherosclerosis development. Additionally, both PON's serum activity and its concentration are influenced by several polymorphic variations in coding and noncoding DNA regions of the PON gene cluster remaining in linkage disequilibrium. Hence, the genetic polymorphism of the PON gene cluster may contribute to atherosclerotic process progression or deceleration. In this review the authors analyzed the relevance of noncoding DNA polymorphic variations of PON genes in atherosclerosis-related diseases involving coronary and peripheral artery disease, stroke, diabetes mellitus, dementia and renal disease and concluded that the effect of PON gene cluster' polymorphism has a considerable impact on the course and outcome in these conditions. The following PON genetic variations may serve as additional predictors of the risk of atherosclerosis in selected populations and individuals.

The Role of Paraoxonase 1 (PON1) Gene Polymorphisms in Coronary Artery Disease: A Systematic Review and Meta-Analysis

Although many studies have investigated the association of paraoxonase 1 (PON1) polymorphisms with coronary artery disease (CAD). However, the outcomes were not consistent and remain uncertain. Therefore, it is the need of the hour to analyze the available literature and evaluate the association of PON1 polymorphisms with the CAD. All the relevant studies published in the English language from January 1, 2000, up to September 20, 2020, were identified by searching through various electronic databases. The two researchers independently extracted the information. The data were analyzed by using the MetaGenyo program. The pooled odds ratio was used to find the associations between CAD and PON1 polymorphisms. In the final analysis, we include 10 studies regarding the association of PON1 polymorphisms (rs662 and rs854560) with CAD. Overall, the Q192R polymorphism increased the risk of CAD in the tested genetic models including the homozygote model: OR 1.35, CI 1.02-1.79; allelic model: OR 1.16, CI 1.00-1.33; dominant model: OR 1.25, CI 1.03-1.52. The L55M polymorphism does not significantly associated with CAD in all the tested genetic models including the homozygote model: OR 1.00 CI, 0.64-1.56; allelic model: OR 1.02, 95% CI 0.84-1.23; dominant model: OR 1.08, CI 0.89-1.31. Further analysis showed no publication bias exists in meta-analysis. Our findings suggested that rs662 in the coding region was significantly associated with the CAD however, rs854560 has no significant association with the disease. Nevertheless, in future, there is a need for more studies with a larger sample size which may provide a more definite conclusion.Study Registration: PROSPERO registration number CRD42020202278.

Genetic Variability of Antioxidative Mechanisms and Cardiotoxicity after Adjuvant Radiotherapy in HER2-Positive Breast Cancer Patients

Background

Breast cancer treatment is associated with the occurrence of various cardiac adverse events. One of the mechanisms associated with cardiotoxicity is oxidative stress, against which cells are protected by antioxidative enzymes. Genetic variability of antioxidative enzymes can affect enzyme activity or expression, which modifies the ability of cells to defend themselves against oxidative stress and could consequently contribute to the occurrence of treatment-related cardiotoxicity. Our aim was to evaluate the association of common polymorphisms in antioxidative genes with cardiotoxicity after adjuvant radiotherapy (RT) in HER2-positive breast cancer patients.

Methods

Our retrospective study included 101 HER2-positive early breast cancer patients who received trastuzumab and adjuvant RT. We isolated DNA from buccal swabs and used competitive allele-specific PCR for genotyping of PON1 rs854560 and rs662, GSTP1 rs1138272 and rs1695, SOD2 rs4880, CAT rs1001179, and HIF1 rs1154965 polymorphisms. N-terminal pro B-type natriuretic peptide (NT-proBNP), left ventricular ejection fraction, and NYHA class were used as markers of cardiotoxicity. We used logistic regression to evaluate the association of genetic factors with markers of cardiotoxicity.

Results

Carriers of at least one polymorphic PON1 rs854560 allele were less likely to have increased NT-proBNP (OR = 0.34; 95% CI = 0.15-0.79; P = 0.012), even after adjustment for age (OR = 0.35; 95% CI = 0.15-0.83; P = 0.017). Carriers of at least one polymorphic PON1 rs662 allele were more likely to have increased NT-proBNP (OR = 4.44; 95% CI = 1.85-10.66; P = 0.001), even after adjustment for age (OR = 5.41; 95% CI = 2.12-13.78; P < 0.001). GSTP1 rs1695 was also associated with decreased NT-proBNP in the multivariable analysis (P = 0.026), while CAT rs1001179 was associated with NYHA class in the univariable (P = 0.012) and multivariable analysis (P = 0.023).

Conclusion

In our study, polymorphisms PON1 rs662 and rs854560, CAT rs1001179, and GSTP1 rs1695 were significantly associated with the occurrence of cardiac adverse events after adjuvant RT and could serve as biomarkers contributing to treatment personalization.

Analysis of PON1 gene polymorphisms (rs662 and rs854560) and inflammatory markers in organophosphate pesticides exposed cohorts from two distinct populations

BACKGROUND AND OBJECTIVES

Organophosphate (OPs) anticholinesterases are one of the main groups of pesticides used in agriculture. Harmful effects of OPs on health have been attributed primarily for irreversible inhibition of acetylcholinesterase (AChE) at nerve synapse. However, studies have shown that inhibition of AChE alone cannot explain all the maladies encountered in prolonged exposure to OPs. Predisposition to population heterogeneity and irregularities in various biochemicals like paraoxonases and inflammatory biochemicals are the possible affects of OPs long term exposure that may lead to sequels of diseases and are less addressed in literature. The study was aimed to assess the cholinergic enzymes (AChE and BChE), PON1, and inflammatory markers (IL1β, IL6, TNFα, CRP, Apo AI, Apo B) and determine the toxicogenetics association of PON1 gene (rs 662 and rs 85456) to chronically OPs exposed groups from Pakistan and Cameroon.

MATERIALS AND METHODS

AChE, BChE and PON1 were measured by colorimetric method using spectrophotometry. Inflammatory markers were determined by Elisa assay. PCR-restriction fragment length polymorphism (PCR-RFLP) using salting out method was employed for SNP genotyping.

RESULTS

The results revealed the significant (p ≤ 0.05) inhibition of cholinergic enzymes PON 1 was found to be 6.91 ng/mL±1.03 and 2.84 ng/mL±1.40 (mean ± SD) in Pakistan and Cameroon groups respectively. IL6, TNFα, CRP were increased and Apo AI was less while Apo B was increased in OP exposed groups in both population groups. SNPs analysis of PON1 showed significant differences in allelic and genotype frequencies of OPs exposed and non-exposed groups.

CONCLUSIONS

PON1 was noticeably less in Cameroonian than Pakistani, albeit both groups have significant decrease in PON1 actity. In addition, the study concludes that OPs induce low grade inflammation, an aetiology of many diseases. Selected PON1 SNPs analysis showed a significant toxicogenetics association with OPs exposure marker enzymes. The results of this study may help in regulation of usage of OPs anticholinesterases in different populations. The study will further open new avenues in toxicogenetic and exploration of SNPs based strategies on organophosphate intoxication.

Association of Genes Related to Oxidative Stress with the Extent of Coronary Atherosclerosis

Oxidative stress is believed to play a critical role in atherosclerosis initiation and progression. In line with this, in a group of 1099 subjects, we determined eight single nucleotide polymorphisms (SNPs) related to oxidative stress (PON1 c.575A>G, MPO c.−463G>A, SOD2 c.47T>C, GCLM c.−590C>T, NOS3 c.894G>T, NOS3 c.−786T>C, CYBA c.214C>T, and CYBA c.−932A>G) and assessed the extent of atherosclerosis in coronary arteries based on Gensini score. An increased risk of having a Gensini score in the higher half of the distribution was observed for the PON1 c.575G allele (odds ratio (OR) = 1.27, 95% confidence interval (CI): 1.004–1.617, p = 0.046). Next, the genetic risk score (GRS) for the additive effect of the total number of pro-oxidative alleles was assessed. We noted an increase in the risk of having a Gensini score above the median with the maximum number of risk alleles (OR = 2.47, 95% CI: 1.19–5.23, p = 0.014). A univariate Spearman’s test revealed significant correlation between the total number of pro-oxidant alleles (GRS) and the Gensini score (ρ = 0.068, p = 0.03). In conclusion, the PON1 c.575A>G variant and the high number of risk alleles (GRS) were independent risk factors for a high Gensini score. We suggest, however, that GRS might occur as a more valuable component in adding a predictive value to the genetic background of atherosclerosis.

Q192R polymorphism in the PON1 gene and nasal polyp in a Turkish population

The pathogenesis of nasal polyps is not completely understood. Oxidative damage contributes to polyp formation in the nasal mucosa. The paraoxonase 1 (PON1) enzyme is an important liver enzyme with high antioxidant activity. In this study, we investigated the correlation between Q192R genotypic polymorphism of the PON1 enzyme and nasal-polyp disease. The study examined 62 nasal-polyp patients and 88 controls. PON1 Q192R polymorphism was determined using polymerase chain reaction-restriction fragment length polymorphism. The genotype distribution of the PON1 gene was significantly different between nasal-polyp patients (QQ = 69.35%, QR = 25.81%, RR = 4.83%) and healthy controls (QQ = 52.27%, QR = 44.31%, RR = 3.40%). Our results suggest that the PON1 QQ genotype (odds ratio [OR] = 2.066, P = .036) is associated with a higher risk of developing the nasal-polyp disease while QR genotype (OR = 0.437, P = .021) showed a lower risk.