Paraoxonase Arg 192 allele is an independent risk factor for three-vessel stenosis of coronary artery disease

Associação do Genótipo e Fenótipo da Paraoxonase-1 com Angiografia Positiva para Doença Arterial Coronariana

Fundamento

Tem sido demonstrado que um aumento dos níveis séricos de PON1 é protetor contra vários distúrbios. Foi relatado que vários polimorfismos de nucleotídeo único (SNPs, single nucleotide polymorphisms ) do gene PON1 estão associados a níveis e atividade de proteínas enzimáticas séricas.

Objetivos

Investigar a associação de SNPs do PON1 e atividade da paraoxonase sérica com a doença arterial coronariana (DAC).

Métodos

Foram estudados 601 pacientes não relacionados submetidos à angiografia coronária, incluindo aqueles com estenose >50% (N=266) e aqueles com estenose <30% (N=335). Os SNPs rs662 e rs840560 do gene da paraoxonase foram determinados utilizando o método ARMS-PCR e o SNP rs705379 foi genotipado utilizando análise de PCR-RFLP. A atividade da paraoxonase sérica foi medida utilizando paraoxon como substrato. O valor de p<0,05 foi considerado significante.

Resultados

A atividade da paraoxonase sérica não foi significativamente diferente entre os grupos de estudo. Após ajuste para idade, sexo, hipertensão, diabetes mellitus e dislipidemia, o genótipo GG e o modelo codominante de rs662 foram positivamente associados a uma angiografia positiva (respectivamente, OR = 2,424, IC 95% [1,123-5,233], p <0,05, OR = 1,663, IC 95% [1,086-2,547]). A atividade da paraoxonase sérica foi significativamente maior no alelo G e variante GG do polimorfismo rs662, alelo A e variante AA de rs854560 e alelo C e variante CC de rs705379. A análise de haplótipos mostrou que o haplótipo ATC foi significativamente mais prevalente no grupo com angiografia negativa. A análise entre os grupos indicou que o alelo A de rs662 foi significativamente associado à menor atividade da paraoxonase no grupo com angiografia positiva (p=0,019).

Conclusões

A presença do alelo G do polimorfismo de nucleotídeo único rs662 está independentemente associada ao aumento do risco de DAC.

Effect of Carotenoids on Paraoxonase-1 Activity and Gene Expression

Paraoxonase 1 (PON1) is an antioxidant enzyme attached to HDL with an anti-atherogenic potential. It protects LDL and HDL from lipid peroxidation. The enzyme is sensitive to various modulating factors, such as genetic polymorphisms as well as pharmacological, dietary (including carotenoids), and lifestyle interventions. Carotenoids are nutritional pigments with antioxidant activity. The aim of this review was to gather evidence on their effect on the modulation of PON1 activity and gene expression. Carotenoids administered as naturally occurring nutritional mixtures may present a synergistic beneficial effect on PON1 status. The effect of carotenoids on the enzyme depends on age, ethnicity, gender, diet, and PON1 genetic variation. Carotenoids, especially astaxanthin, β-carotene, and lycopene, increase PON1 activity. This effect may be explained by their ability to quench singlet oxygen and scavenge free radicals. β-carotene and lycopene were additionally shown to upregulate PON1 gene expression. The putative mechanisms of such regulation involve PON1 CpG-rich region methylation, Ca(2+)/calmodulin-dependent kinase II (CaMKKII) pathway induction, and upregulation via steroid regulatory element-binding protein-2 (SREBP-2). More detailed and extensive research on the mechanisms of PON1 modulation by carotenoids may lead to the development of new targeted therapies for cardiovascular diseases.

Risk Assessment Using the Association Between Renin-Angiotensin Genes Polymorphisms and Coronary Artery Disease

Coronary artery disease (CAD) is a multifactorial disease that involves genetic and environmental interaction. In addition to the well-known CAD risk factors, such as diabetes mellitus, hypertension, hyperlipidemia, and atherosclerosis, it has a genetic component that predisposes to its occurrence even in young people. One of the most commonly studied genes that increase the susceptibility to CAD is renin-angiotensin system (RAS) genes polymorphisms mainly angiotensin-converting enzyme gene (ACE) polymorphisms, angiotensinogen polymorphisms, angiotensin- II type 1 receptor gene polymorphisms, and many other genes. These genetic polymorphisms have a direct association with CAD development or indirect association through causing atherosclerosis and hypertension which, in turn, are complicated by CAD later on. The difference between genetic mutations and polymorphisms lies in the frequency of the abnormal genotype. If the frequency is 1% and more in the general population, it is called polymorphism and if it is less than 1%, then it is called a mutation.

According to our findings, after thorough searching, which support the association of RAS genes polymorphisms with premature CAD, hypertension, hypertrophic cardiomyopathy, and atherosclerosis, we recommend additional studies in the form of clinical trials and meta-analyses aiming to create a specific diagnostic tool for CAD risk assessment and discovering the high-risk people as early as possible. Targeted gene therapy, being the future of medicine, needs to be taken into researchers' consideration. It can have promising results in these cases.

Paraoxonase 1 concerning dyslipidaemia, cardiovascular diseases, and mortality in haemodialysis patients

Paraoxonase 1 (PON1) is known for preventing atherosclerosis through lipid-modifying features, antioxidant activity, anti-inflammatory, anti-apoptosis, anti-thrombosis, and anti-adhesion properties. Uremic patients requiring haemodialysis (HD) are especially prone to atherosclerosis and its complications. We analysed the PON1 gene (PON1) polymorphisms and serum PON1 (paraoxonase) activity concerning dyslipidaemia and related cardiovascular diseases and mortality to show how they associate under uremic conditions modified by maintenance HD treatment. The rs662 AA + AG (OR 1.76, 95%CI 1.10-2.80, P = 0.018), rs854560 TT (OR 1.48, 95%CI 1.04-2.11, P = 0.031), and rs854560 AT + TT (OR 1.28, 95%CI 1.01-1.63, P = 0.040) contributed to the prevalence of atherogenic dyslipidaemia diagnosed by the triglyceride (TG)/HDL-cholesterol ratio ≥ 3.8. The normalized serum PON1 activity positively correlated with atherogenic dyslipidaemia (ẞ 0.67 ± 0.25, P = 0.008). The PON1 rs854560 allele T was involved in the higher prevalence of ischemic cerebral stroke (OR 1.38, 1.02-1.85, P = 0.034). The PON1 rs705379 TT genotype contributed to cardiovascular (HR 1.27, 95% CI 1.03-1.57, P = 0.025) and cardiac (HR 1.34, 95% CI 1.05-1.71, P = 0.018) mortality. All P-values were obtained in multiple regression analyses, including clinical variables. Multifaceted associations of PON1 with dyslipidaemia, ischemic cerebral stroke, and cardiovascular mortality in HD patients provide arguments for the consideration of PON1 and its protein product as therapeutic targets in the prevention of atherosclerosis and its complications in uremic patients.

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.

Kiwifruit Supplementation Increases the Activity of the Paraoxonase Enzyme and decreases Oxidized Low-Density Lipoprotein in High-Fat Diet Fed Hamsters

Background: It is shown that kiwifruit elevates serum high-density lipoprotein cholesterol (HDL-C) levels and exhibits beneficial effects on human health due to its antioxidant potential. Objectives: This study aimed to investigate the impact of kiwifruit on the activity of the paraoxonase 1 (PON1) enzyme, as a main antioxidant enzyme in HDL functionality, in a high-fat diet (HFD). Methods: To this end, 42 male Syrian hamsters were divided into 6 groups including hamsters receiving a normal diet (the control normal group), a regular diet supplemented with kiwifruit at two concentrations (i.e., 1.86 g/kg and 3.73 g/kg), a HFD comprised of 15% butterfat + 0.05% cholesterol (the control high-fat group), and a HFD supplemented with kiwifruit at two concentrations (i.e., 1.86 and 3.73 g/kg) for 8 weeks. Results: The results showed that supplementation of kiwifruit to the HFD increased the levels of HDL-C and remarkably reduced the concentrations of oxidized low-density lipoprotein (ox-LDL) and malondialdehyde (MDA) compared with the control-HF group. In addition, the paraoxonase activity of PON1 significantly increased in HFD supplemented with kiwifruit (1.86 g/kg), and finally, arylesterase (ARE) activity increased in all treated groups when compared with untreated groups. Conclusion: Our findings suggested that kiwifruit can improve the lipid profile and prevent oxidative stress-induced by lipid peroxidation in hamsters receiving HFD, thus increasing the ARE and paraoxonase activities of PON1.

MirSNPs in clopidogrel metabolism genes predict cardiovascular disease risk: a case-control study and meta-analysis

Aim: The present study was conducted to decipher the inter-relationship of SNPs and miRNAs involved in pharmacogenomics of clopidogrel on predisposition to cardiovascular diseases (CVDs). Materials & methods: A case-control study was conducted on 410 cases and 386 controls to analyze the association of 13 mirSNPs on CVDs risk. Genotyping was performed by tetra-primer amplification refractory mutation system PCR and validated using Sanger DNA sequencing. miRNA expression analysis was performed using TaqMan assays. A meta-analysis was performed for PON1 rs662 with coronary artery disease. Results & conclusion: PON1 rs662, PON1 rs3917577, CYP3A5 rs15524, COL4A1 rs874204 and PTGIR rs1126510 polymorphisms showed association with CVDs. The miRNA hsa-miR-224-5p showed differential expression in the PON1 rs3917577 GG genotype. The meta-analysis showed the population-specific impact of PON1 rs662 on South Asian and Middle East populations.

Application of Genome-Wide Association Studies in Coronary Artery Disease

Coronary artery disease (CAD) is a complex disease caused by the combination of environmental and genetic factors. It is one of the leading causes of death and disability in the world. Much research has been focussed on CAD genetic mechanism. In recent years, genome-wide association study (GWAS) has developed rapidly around the world. Medical researchers around the world have successfully discovered a series of CAD genetic susceptibility genes or susceptible loci using medical research strategies, leading CAD research toward a new stage. This paper briefly summarizes the important progress made by GWAS for CAD in the world in recent years, and then analyzes the challenges faced by GWAS at this stage and the development trend of future research, to promote the transformation of genetic research results into clinical practice and provide guidance for further exploration of the genetic mechanism of CAD.

Paraoxonase 1 and atherosclerosis-related diseases

A direct and an indirect relationship between paraoxonase 1 (PON1) and atherosclerosis exists. Given PON1's physical location within high-density lipoprotein (HDL) particles and its recognized enzyme activity, it is certainly reasonable to suggest that PON1 facilitates the antiatherogenic nature of HDL particles. PON1 also plays a role in regulating reverse cholesterol transport, antioxidative, anti-inflammatory, antiapoptotic, vasodilative, and antithrombotic activities and several endothelial cell functions. HDL dysfunctionality is a more recent issue and seems to be centered on pathological conditions affecting HDL structure and size profiles. This review is focused on the role of PON1 status in different atherosclerosis-related diseases that we have studied over the last twenty years (coronary heart disease, acute ischemic stroke, diabetes mellitus type 2, end-stage renal disease, chronic obstructive pulmonary disease, and sarcoidosis) with the aim to determine the true value of PON1 as a biomarker. The role of PON1 in cancer is also covered, as risk factors and mechanisms underlying both atherosclerosis and cancer share common features.

Q192R polymorphism in the PON1 gene and familial hypercholesterolemia in a Saudi population

BACKGROUND

Familial hypercholesterolemia (FH) is an autosomal dominant condition characterized by abnormal levels of low-density lipoprotein (LDL) in the blood. FH is a risk factor for atherosclerosis and cardiovascular disease. The relationship between the paraoxonase 1 (PON1) gene, atherosclerosis and coronary artery disease has not been studied in Saudi patients.

OBJECTIVE

To investigate the genetic associations of the Q192R polymorphism in the PON1 gene with FH in Saudi patients.

DESIGN

Case-control study.

SETTING

Tertiary care center, Riyadh.

METHODS

Two hundred Saudi patients were enrolled in this study, including 100 patients with FH and 100 healthy controls, during the period from January 2012 to March 2013. Serum was separated from coagulated blood (3 mL) and used for analysis of lipid profiles. Genomic DNA was isolated from anticoagulant-treated blood (2 mL). Genotyping for the Q192R polymorphism was performed by polymerase chain reaction-restriction fragment length polymorphism analysis, followed by 3% agarose gel electrophoresis.

MAIN OUTCOME MEASURE

The strength of association between the Q192R polymorphism and FH in the Saudi population.

RESULTS

We confirmed that QR versus QQ (odds ratio [OR]: 1.55; 95% confidence interval [CI]: 1.05-3.43; P=.03), QR+RR versus QQ (OR: 1.98; 95% CI: 1.13-3.49; P=.01), and R versus Q (OR: 1.68; 95% CI: 1.09- 2.59; P=.01) in the Q192R polymorphism were associated with FH in the Saudi population.

CONCLUSION

In conclusion, the Q192R polymorphism in the PON1 gene is associated with FH in the Saudi population. Our results confirmed that the R allele, QR, and dominant model genotypes were associated with FH.

LIMITATION

Only a single variant (Q192R) was analyzed, and the medical and family histories of the patients were not known.

Association between paraoxonase-1 gene Q192R and L55M polymorphisms in systemic lupus erythematosus (SLE) and anti-phospholipid syndrome (APS) in a population from Cairo of Egypt

Paraoxonase-1 (PON1) is involved in the oxidative stress process that cause tissue damage observed in systemic lupus erythematosus (SLE) and anti-phospholipid syndrome (APS). The aim of the present study was to investigate the association of PON1 Q192R and L55M polymorphisms with risk of SLE and associated APS among Egyptian sample. The study included 120 SLE patients (45 without APS and 75 with APS) and 120 healthy subjects. PON1 Q192R and L55M polymorphisms were genotyped by real-time PCR. No significant differences in Q192R genotypes or allele frequencies were found between patients and controls (p = 0.5 and 0.1, respectively). The frequency of the 55M allele was significantly higher in SLE patients than in controls (66.6 vs. 43.3%), while the 55L allele was more frequent in controls (56.6%) than in patients (33.3%) (p = 0.03). The LL genotype was more frequent in controls (21.6%) than in patients (10%) while M allele carrier genotypes (LM + MM) were more frequent among patients (90%) than controls (78.3%), p = 0.04. Also, the 55M allele was more frequent in APS patients (73.3%) than in patients without APS (55.6%), p = 0.004. M allele carrier genotypes (LM + MM) was significantly higher among APS patients (95.4%) than in non-APS patients (80%), p = 0.008. Our results indicated that the PON1 L55M polymorphism associated with SLE and associated APS in a population from Cairo of Egypt, while the Q192R polymorphism plays no role in disease susceptibility. A large scale study to assess PON1 polymorphisms, PON1 activity, and markers of oxidative stress interaction is needed to clarify the role of PON-1 polymorphisms in the pathogenesis of SLE and associated APS.

A Genetic Biomarker of Oxidative Stress, the Paraoxonase-1 Q192R Gene Variant, Associates with Cardiomyopathy in CKD: A Longitudinal Study

Background. Oxidative stress is a hallmark of CKD and this alteration is strongly implicated in LV hypertrophy and in LV dysfunction. Methods and Patients. We resorted to the strongest genetic biomarker of paraoxonase-1 (PON1) activity, the Q192R variant in the PON1 gene, to unbiasedly assess (Mendelian randomization) the cross-sectional and longitudinal association of this gene-variant with LV mass and function in 206 CKD patients with a 3-year follow-up. Results. The R allele of Q192R polymorphism associated with oxidative stress as assessed by plasma 8-isoPGF2α (P = 0.03) and was dose-dependently related in a direct fashion to LVMI (QQ: 131.4 ± 42.6 g/m(2); RQ: 147.7 ± 51.1 g/m(2); RR: 167.3 ± 41.9 g/m(2); P = 0.001) and in an inverse fashion to systolic function (LV Ejection Fraction) (QQ: 79 ± 12%; RQ: 69 ± 9%; RR: 65 ± 10% P = 0.002). On longitudinal observation, this gene variant associated with the evolution of the same echocardiographic indicators [LVMI: 13.40 g/m(2) per risk allele, P = 0.005; LVEF: -2.96% per risk allele, P = 0.001]. Multivariate analyses did not modify these associations. Conclusion. In CKD patients, the R allele of the Q192R variant in the PON1 gene is dose-dependently related to the severity of LVH and LV dysfunction and associates with the longitudinal evolution of these cardiac alterations. These results are compatible with the hypothesis that oxidative stress is implicated in cardiomyopathy in CKD patients.

Association between Paraoxonase 1 (PON1) Polymorphisms and the Risk of Acute Coronary Syndrome in a North African Population

The purpose of the present study was to investigate the distribution of PON1 Q192R and L55M polymorphisms and activities in a North African population and to determine their association with cardiovascular complications. The prevalence of the QQ, QR, RR, LL, LM, and MM genotypes in the study population was 55.4%, 34.09%, 9.83%, 41.97%, 48.20%, and 9.83% respectively. The Q, R, L, and M alleles had a gene frequency of 0.755, 0.245, 0.67, and 0.33, respectively. The PON1 192 RR genotype was significantly more prevalent among ACS patients than among healthy subjects. There was a 4.33-fold increase in the risk of ACS in subjects presenting the PON1 192 RR genotype compared to those with the QQ genotype (OR=4.33; 95% CI=1.27–17.7). There was a significantly different distribution of PON1 L55M in the ACS patient groups (UA, STEMI, NSTEMI). Moreover, individuals presenting the PON1 55MM genotype present a higher risk for ACS than those with LL genotype (OR=3.69; 95% CI=1.61–11.80). Paraoxonase activities were significantly lower in coronary patients than in healthy subjects. The decrease in PON1 activity was inversely correlated with the number of concomitant risk factors for CVD (r=0.57, p<0.0001). The results of the present study suggested that the PON1 R and M alleles may play a role in the pathogenesis of cardiac ischemia in our North African population and that a decrease in PON1 activity may be a valuable marker for monitoring the development of the atherosclerosis process and the associated cardiovascular complications.

Association between butyrylcholinesterase activity and phenotypes, paraoxonase192 rs662 gene polymorphism and their enzymatic activity with severity of rheumatoid arthritis: correlation with systemic inflammatory markers and oxidative stress, preliminary report

OBJECTIVES

Evidences indicate that oxidative stress and inflammation are important processes in the development of destructive synovial tissue in rheumatoid arthritis (RA). The two major bioscavenger enzymes that are associated with inflammation and oxidative stress are human-butyrylcholinesterase (BuChE) and paraoxonase-1 (PON-1). Thus, the objective of this study was to determine the relation of BuChE phenotypes and PON-1 Q192R polymorphism with inflammatory markers such as anti-cytroline circulated peptide (CCP)-antibodies, CRP, neopterin, DAS28-CRP in RA patients.

DESIGN AND METHODS

In this study, we examined association of BuChE-phenotypes and activity, PON192rs662 (Q192R) polymorphism and its arylesterase activity (ARE) with systemic-inflammatory-markers and oxidative stress. The present case-control study consisted of 419-RA patients and 398 gender-age-matched unrelated healthy controls from west population of Iran. PON192rs662 polymorphism was detected by real-time-PCR. BuChE phenotype, TAC level, serum BuChE and ARE activities were determined spectrophotometrically. Anti-CCP-antibody and CRP were measured by ELISA and neopterin level was detected by HPLC. We used the EULAR activity criteria to measure DAS28-CRP.

RESULTS

We found that PON-1-Q192R was associated with severity of RA [remission-to-low and moderate-to-high in dominant Q/Q+Q/R vs. R/R: OR=2.27, p<0.001; codominant Q/Q vs. R/R: OR=1.65, p<0.001 and Q/R vs. R/R: OR=2.12, p=0.003; recessive Q/Q vs. R/R+Q/R: OR=1.79, p=0.032; and allele Q vs. R: OR=1.68, p<0.001] and presence of anti-CCP-antibody (codominant model Q/Q vs. R/R: OR=1.28, p=0.042). The carriers of Q/Q genotype PON-1-Q192R and BuChE non-UU-phenotype had higher ARE activity, serum levels of neopterin, anti-CCP antibody titer and number of tender-joint and lower activity of BuChE and serum level of TAC than that of R/R genotype and BuChE-UU-phenotype.

CONCLUSIONS

The current findings demonstrate for the first time that there is a link between systemic inflammatory markers, oxidative stress, the PON192rs662-Q allele and BuChE-non-UU-phenotype and their corresponding enzymatic activity which may be considered as a risk factor for the severity of RA for a population in Iran.

Paraoxonase (PON)1 Q192R functional genotypes and PON1 Q192R genotype by smoking interactions are risk factors for the metabolic syndrome, but not overweight or obesity

Background The metabolic syndrome (MetS) is a complex of multiple risk factors that contribute to the onset of cardiovascular disorder, including lowered levels of high-density lipoprotein (HDL) and abdominal obesity. Smoking, mood disorders, and oxidative stress are associated with the MetS. Paraoxonase (PON)1 is an antioxidant bound to HDL, that is under genetic control by functional polymorphisms in the PON1 Q192R coding sequence. Aims and methods This study aimed to delineate the associations of the MetS with plasma PON1 activity, PON1 Q192R genotypes, smoking, and mood disorders (major depression and bipolar disorder), while adjusting for HDL cholesterol, body mass index, age, gender, and sociodemographic data. We measured plasma PON1 activity and serum HDL cholesterol and determined PON1 Q192R genotypes through functional analysis in 335 subjects, consisting of 97 with and 238 without MetS. The severity of nicotine dependence was measured using the Fagerström Nicotine Dependence Scale. Results PON1 Q192R functional genotypes and PON1 Q192R genotypes by smoking interactions were associated with the MetS. The QQ and QR genotypes were protective against MetS while smoking increased metabolic risk in QQ carriers only. There were no significant associations between PON1 Q192R genotypes and smoking by genotype interactions and obesity or overweight, while body mass index significantly increased MetS risk. Smoking and especially severe nicotine dependence are significantly associated with the MetS although these effects were no longer significant after considering the effects of the smoking by PON1 Q192R genotype interaction. The MetS was not associated with mood disorders, major depression or bipolar disorder. Discussion PON1 Q192R genotypes and genotypes by smoking interactions are risk factors for the MetS that together with lowered HDL and increased body mass and age contribute to the MetS.

Synergistic effects of BuChE non-UU phenotype and paraoxonase (PON1) 55 M allele on the risk of systemic lupus erythematosus: influence on lipid and lipoprotein metabolism and oxidative stress, preliminary report

There is some evidence indicating lipid peroxidation can affect progression of atherosclerosis, cardiovascular diseases (CVDs) and glomerulonephritis in systemic lupus erythematosus (SLE) patients. Human butyrylcholinesterase (BuChE) and paraoxonase-1 (PON1) are two major bioscavenger enzymes that are associated with inflammation, oxidative stress and lipid metabolism. Hyperlipidemia, increase in lipid oxidation reactions and defects in antioxidant status may lead to increased oxidative stress and high frequency of CVDs in SLE. It has also been suggested that deficiency in the function of the antioxidant system and an increase in reactive oxygen release (ROS) may play an important role in the pathogenesis of SLE. This study is the first investigation to examine the association of BuChE phenotypes, PON1 (L55M; PON-55-M) polymorphism, the levels of malondialdehyde (MDA), neopterin, lipid-lipoprotein and activities of BuChE and arylesterase activity (ARE) of PON with severity of SLE.

The present case-control study consisted of 109 SLE patients and 101 gender- and age-matched, unrelated healthy control subjects from the population of west Iran. We found that the PON-55-M allele and BuChE non-UU act synergistically to increase the risk of SLE by 2.5 times (1.03–6.7, p = 0.044). There was a significant negative correlation between severity of SLE with serum BuChE activity ( R = −0.31, p < 0.001) and positive correlation with serum neopterin level. The SLE patients with the PON-55-M (M/L + M/M) allele or with BuChE non-UU phenotype had significantly lower serum ARE and BuChE activities than those with PON-55-L/L or BuChE-UU phenotypes, respectively. In addition, their serum levels of MDA, neopterin and LDL-C were significantly elevated, suggesting that these individuals are more susceptible to CVD. However, further studies are needed to shed more light on the contribution of the M allele of PON1 and non-UU phenotypes of BuChE in the development of SLE in different ethnicities.

Paraoxonase 1 (PON1) 55 polymorphism, lipid profiles and psoriasis

BACKGROUND

Paraoxonase 1 (PON1) is a serum high-density lipoprotein-bound enzyme with antioxidant function. It hydrolyses lipid peroxides, protecting low-density lipoproteins from oxidative modifications. Patients with psoriasis are at greater risk of oxidative stress, which is associated with abnormal plasma lipid metabolism.

OBJECTIVES

In this study, association of the PON1 55 M allele with serum arylesterase (ARE) activity, malondialdehyde (MDA), lipid profiles and psoriasis was investigated.

METHODS

The present case-control study consisted of 100 patients with psoriasis with and without cardiovascular diseases (mean age 35·3 years) and 100 sex- and age-matched unrelated healthy controls (mean age 35·7 years) from the population of western Iran. The PON1 55 Met>Leu polymorphism was detected by polymerase chain reaction-restriction fragment length polymorphism. Serum ARE activity, MDA, and lipid and apolipoprotein levels were determined spectrophotometrically, by high-performance liquid chromatography and by enzyme assay, respectively.

RESULTS

The presence of the PON1 55 M allele was found to be associated with psoriasis (odds ratio = 1·96, P = 0·017). The patients with psoriasis with the PON1 M (M/L + M/M) allele had higher MDA levels (4·12 ± 0·88 vs. 2·24 ± 0·55 μmol L(-1) , P < 0·001), apolipoprotein B (APOB)/APOA1 ratio (0·91 ± 0·66 vs. 0·66 ± 0·35, P = 0·004), APOB (111 ± 38·7 vs. 88·3 ± 22·5 mg mL(-1) , P = 0·001) and lipoprotein(a) [LP(a)] (21·9 ± 18·4 vs. 15·8 ± 16·6 mg mL(-1) , P = 0·034), but lower ARE activity (39·6 ± 11 vs. 45·9 ± 11·8 U mL(-1) , P = 0·031) than the control subjects. ARE activity showed a significant positive correlation with APOA1 and a negative correlation with MDA concentration in patients with psoriasis.

CONCLUSIONS

The PON1 55 M allele is a risk factor for psoriasis. Carriers of this allele have high levels of MDA, APOB and LP(a), a high APOB/APOA1 ratio and low ARE activity. These results indicate that oxidative stress, impairment of the antioxidant system and abnormal lipid metabolism may play a role in the pathogenesis and progression of psoriasis and its related complications. These data suggest that patients with psoriasis are more susceptible to vascular diseases.

Association between paraoxonase-1 gene polymorphisms and risk of metabolic syndrome

Paraoxonase-1 (PON1), a high-density lipoprotein (HDL) associated enzyme, is involved in the metabolism and detoxification of insecticides and pesticides. Three polymorphisms within the PON1 gene affect the enzyme activity. Two of these (L55M and Q192R) are located at the coding region and the third (-107C/T) is in promoter region. We performed a case-control study in order to elucidate the possible contribution of variability within PON1 at three mentioned positions to the risk of MS in a South-East Iranian population. DNA was isolated from peripheral blood of patients (N = 119) with MS and healthy controls (N = 201). Allelic polymorphisms at positions Q192R, L55M and -107C/T in the PON1 gene were studied by Amplification Refractory Mutation System (ARMS)-PCR. It was observed that genotypes RR and QR + RR of Q192R locus significantly increased the risk of MS (OR = 2; 95% CI: 1.17-3.40, P = 0.0001 and OR = 1.62; 95% CI: 1.0-2.63; P = 0.05, respectively). The risk in patients with MM and LM + MM genotypes at the L55M locus was marginal (OR = 1.33; 95% CI: 0.68-1.85; P = 0.34 and OR = 1.12; 95% CI: 0.68-1.85; P = 0.73 respectively). The CC genotype at -107C/T locus also increased the risk of metabolic syndrome, but was not significant. This association was somewhat stronger when combined genotypes at Q192R and L55M loci were analyzed (OR = 3.30; 95% CI: 1.34-8.24; P = 0.007). Our results, in this first study, provide evidence for association of PON1 gene polymorphisms with the risk for metabolic syndrome.