Paraoxonase 1 Q192R Research Articles

The Association of the Cholesterol Efflux Capacity with the Paraoxonase 1 Q192R Genotype and the Paraoxonase Activity.

Paraoxonase 1 (PON1) binds to high-density lipoprotein (HDL) and protects against atherosclerosis. However, the relationship between functional PON1 Q192R polymorphism, which is associated with the hydrolysis of paraoxon (POXase activity) and atherosclerotic cardiovascular disease (ASCVD), remains controversial. As the effect of PON1 Q192R polymorphism on the HDL function is unclear, we investigated the relationship between this polymorphism and the cholesterol efflux capacity (CEC), one of the biological functions of HDL, in association with the PON1 activity. The relationship between PON1 Q192R polymorphisms and CEC was investigated retrospectively in 150 subjects without ASCVD (50 with the PON1 Q/Q genotype, 50 with the Q/R genotype, and 50 with the R/R genotype) who participated in a health screening program. The POXase and arylesterase (AREase: hydrolysis of aromatic esters) activities were used as measures of the PON1 activity. The AREase activity was positively correlated with CEC independent of the HDL cholesterol levels. When stratified by the PON1 Q192R genotype, the POXase activity was also positively correlated with CEC independent of HDL cholesterol. PON1 Q192R R/R genotype carriers had a lower CEC than Q/Q or Q/R genotype carriers, despite having a higher POXase activity. Moreover, in a multiple regression analysis, the PON1 Q192R genotype was associated with the degree of CEC, independent of the HDL cholesterol and POXase activity. The PON1 Q192R R allele is associated with reduced CEC in Japanese people without ASCVD. Further studies on the impact of this association on the severity of atherosclerosis and ASCVD development are thus called for.

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.

PON1, APOE and SDF-1 Gene Polymorphisms and Risk of Retinal Vein Occlusion: A Case-Control Study.

Numerous studies have tried to evaluate the potential role of thrombophilia-related genes in retinal vein occlusion (RVO); however, there is limited research on genes related to different pathophysiological mechanisms involved in RVO. In view of the strong contribution of oxidative stress and inflammation to the pathogenesis of RVO, the purpose of the present study was to investigate the association of inflammation- and oxidative-stress-related polymorphisms from three different genes [apolipoprotein E (APOE), paraoxonase 1 (PON1) and stromal cell-derived factor 1 (SDF-1)] and the risk of RVO in a Greek population. Participants in this case-control study were 50 RVO patients (RVO group) and 50 healthy volunteers (control group). Blood samples were collected on EDTA tubes and genomic DNA was extracted. Genotyping of rs854560 (L55M) and rs662 (Q192R) for the PON1 gene, rs429358 and rs7412 for the APOE gene and rs1801157 [SDF1-3'G(801)A] for SDF-1 gene was performed using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Multiple genetic models (codominant, dominant, recessive, overdominant and log-additive) and haplotype analyses were performed using the SNPStats web tool to assess the correlation between the genetic polymorphisms and the risk of RVO. Binary logistic regression analysis was used for the association analysis between APOE gene variants and RVO. Given the multifactorial nature of the disease, our statistical analysis was adjusted for the most important systemic risk factors (age, hypertension and diabetes mellitus). The dominant genetic model for the PON1 Q192R single nucleotide polymorphism (SNP) of the association analysis revealed that there was a statistically significant difference between the RVO group and the control group. Specifically, after adjusting for age and hypertension, the PON1 192 R allele (QR + RR) was found to be associated with a statistically significantly higher risk of RVO compared to the QQ genotype (OR = 2.51; 95% CI = 1.02-6.14, p = 0.04). The statistically significant results were maintained after including diabetes in the multivariate model in addition to age and hypertension (OR = 2.83; 95% CI = 1.01-7.97, p = 0.042). No statistically significant association was revealed between the other studied polymorphisms and the risk of RVO. Haplotype analysis for PON1 SNPs, L55M and Q192R, revealed no statistically significant correlation. In conclusion, PON1 192 R allele carriers (QR + RR) were associated with a statistically significantly increased risk of RVO compared to the QQ homozygotes. These findings suggest that the R allele of the PON1 Q192R is likely to play a role as a risk factor for retinal vein occlusion.

Relationship Between Paraoxonase-1 Genotype and Activity, and Major Adverse Cardiovascular Events and Malignancies in Patients with Rheumatoid Arthritis Receiving Tofacitinib.

This post hoc analysis investigated the relationship between paraoxonase-1 (PON1) genotype and activity, and risk of major adverse cardiovascular events (MACE) and malignancies in tofacitinib rheumatoid arthritis (RA) clinical studies. Data were pooled from 9 phase II/III studies and the associated long-term extension studies (all completed by October 2017). PON1 activities in plasma were measured using paraoxon (paraoxonase activity), dihydrocoumarin (lactonase activity), and phenylacetate (arylesterase activity) as substrates. PON1 Q192R genotype effect on baseline PON1 activity was assessed using linear regression for each study, with fixed-effects meta-analysis across studies. MACE and malignancy risk by time-varying enzyme activity was determined using Cox proportional hazards regression. The analysis included 1,969 patients with RA. Compared with the QQ genotype, RR had a significant positive association with baseline paraoxonase activity and a significant negative association with baseline lactonase and arylesterase activity (all p < 0.001). Time-varying models demonstrated a significant association of increased paraoxonase activity over time with lower risk of MACE (p < 0.001) and malignancies (excluding non-melanoma skin cancer [NMSC]; p ≤ 0.05), even after controlling for risk factors identified in univariate analysis and RA disease activity. A similar trend was observed for lactonase and arylesterase for MACE. Higher paraoxonase activity over time was associated with significantly reduced risk of future MACE and malignancies (excluding NMSC), but not NMSC, in patients with RA receiving tofacitinib. Further investigation of PON1 as a novel functional lipid biomarker of MACE/malignancy risk in patients with RA is warranted.

Ailesel Koroner Arter Hastalığına Yatkınlıkta Güçlü Adaylar PON1, ITGB3 ve CYP3A4 Genlerinin Hastalıkla İlişkisi ve Haplotip Analizi

Objective: Genetic predisposition is very common among the patients with coronary artery disease (CAD), a complex and multifactorial disease. Our objective was to determine the possible association between the most remarkable functional variants in the paraoxonase 1(PON1), cytochrome P450 3A4 (CYP3A4), integrin subunit beta 3 (ITGB3) genes and familial CAD. Materials and Methods: We included 117 patients diagnosed with familial CAD and 99 healthy subjects with no family history of CAD. PON1 Q192R, PON1 L55M, CYP3A4*1G and ITGB3 L33P single nucleotide polymorphisms were genotyped using the Sequenom MassARRAY system. Results: Comparison of genotype and allele frequencies in inheritance models of polymorphisms between the patient and control groups did not reveal any significant findings related to CAD. Stratified analysis by gender did also not display any association both in females and males. There was no significant difference in the frequencies of the haplotypes of the PON1 Q192R and L55M polymorphisms between the groups. Conclusions: Our findings confirmed previous studies that did not consider PON1, CYP3A4 and ITGB3 genes as risk loci. The fact that our study was conducted only in patients with familial CAD shows the originality and importance of our results.

In Mild and Moderate Acute Ischemic Stroke, Increased Lipid Peroxidation and Lowered Antioxidant Defenses Are Strongly Associated with Disabilities and Final Stroke Core Volume.

In acute ischemic stroke (AIS), there are no data on whether oxidative stress biomarkers have effects above and beyond known risk factors and measurements of stroke volume. This study was conducted in 122 mild-moderate AIS patients and 40 controls and assessed the modified ranking scale (mRS) at baseline, and 3 and 6 months later. We measured lipid hydroperoxides (LOOH), malondialdehyde (MDA), advanced oxidation protein products, paraoxonase 1 (PON1) activities and PON1 Q192R genotypes, high density lipoprotein cholesterol (HDL), sulfhydryl (-SH) groups), and diffusion-weighted imaging (DWI) stroke volume and fluid-attenuated inversion recovery (FLAIR) signal intensity. We found that (a) AIS is characterized by lower chloromethyl acetate CMPAase PON1 activity, HDL and -SH groups and increased LOOH and neurotoxicity (a composite of LOOH, inflammatory markers and glycated hemoglobin); (b) oxidative and antioxidant biomarkers strongly and independently predict mRS scores 3 and 6 months later, DWI stroke volume and FLAIR signal intensity; and (c) the PON1 Q192R variant has multiple effects on stroke outcomes that are mediated by its effects on antioxidant defenses and lipid peroxidation. Lipid peroxidation and lowered -SH and PON1-HDL activity are drug targets to prevent AIS and consequent neurodegenerative processes and increased oxidative reperfusion mediators due to ischemia-reperfusion injury.

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

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. 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. 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.

Suppressed paraoxonase-1 activity associates with elevated oxylipins and the presence of small airways disease in patients with rheumatoid arthritis

BackgroundRheumatoid arthritis (RA)-associated lung disease (LD) associates with significantly increased morbidity and mortality. Although oxidative stress plays an important role in the inflammatory responses in other forms of lung disease, minimal work has evaluated its role in RA-LD. The current work examines the relationship between the anti-oxidant HDL-associated enzyme paraoxonase-1 (PON1), the PON1 Q192R polymorphism, and a targeted oxylipin panel with RA-LD.MethodsThis study was conducted as a retrospective chart review of a longitudinal single-center cohort of 250 RA patients. CT scans of the chest were reviewed by the interpreting radiologist and classified as small airways disease (SAD), interstitial lung disease (ILD), and bronchiectasis. PON1 activity was measured by its lactonase, arylesterase, and paraoxonase functions. The PON1 Q192R polymorphism and a targeted lipidomics panel were performed as previously reported.Results43.2% of the 250 RA patient cohort (n = 108) had available CT scans, including 48 patients (44.4%) with SAD, 27 patients (25.0%) with bronchiectasis, and 16 patients (14.8%) with ILD. Patients with SAD had significantly lower baseline PON1 activity by its arylesterase, and lactonase functions, as well as higher 15-HETE, LTB4, and PGE2 levels compared to those without SAD. These predictors of SAD remained significant after multivariate analysis including known risk factors for RA-LD. Suppressed PON1 activity also correlated with higher levels of 15-HETE and 12-HETE.ConclusionIn a single-center RA cohort, suppressed baseline PON1 activity and elevation in the oxylipins 15-HETE, LTB4, and PGE2 predicted the presence of RA-SAD in longitudinal follow-up.Key Points• Small airways disease (SAD) was present in 44.4% of this rheumatoid arthritis (RA) cohort.• Patients with SAD had significantly lower baseline PON1 activity, as well as higher levels of the oxylipins 15-HETE, LTB4, and PGE2 levels compared to those without SAD.• Further work is warranted to confirm these findings and further define the role of PON1 and lipid oxidation in RA lung disease.

Deficit schizophrenia and its features are associated with PON1 Q192R genotypes and lowered paraoxonase 1 (PON1) enzymatic activity: effects on bacterial translocation - Corrigendum.

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Evaluation of a Gene–Environment Interaction of PON1 and Low-Level Nerve Agent Exposure with Gulf War Illness: A Prevalence Case–Control Study Drawn from the U.S. Military Health Survey’s National Population Sample

Background:Consensus on the etiology of 1991 Gulf War illness (GWI) has been limited by lack of objective individual-level environmental exposure information and assumed recall bias.Objectives:We investigated a prestated hypothesis of the association of GWI with a gene–environment (GxE) interaction of the paraoxonase-1 (PON1) Q192R polymorphism and low-level nerve agent exposure.Methods:A prevalence sample of 508 GWI cases and 508 nonpaired controls was drawn from the 8,020 participants in the U.S. Military Health Survey, a representative sample survey of military veterans who served during the Gulf War. The PON1 Q192R genotype was measured by real-time polymerase chain reaction (RT-PCR), and the serum Q and R isoenzyme activity levels were measured with PON1-specific substrates. Low-level nerve agent exposure was estimated by survey questions on having heard nerve agent alarms during deployment.Results:The GxE interaction of the Q192R genotype and hearing alarms was strongly associated with GWI on both the multiplicative [prevalence odds ratio (POR) of the ; 95% confidence interval (CI): 1.20, 9.72] and additive (synergy ; 95% CI: 1.82, 12.19) scales, adjusted for measured confounders. The Q192R genotype and the alarms variable were independent (adjusted POR in the ; 95% CI: 0.81, 1.73; ), and the associations of GWI with the number of R alleles and quartiles of Q isoenzyme were monotonic. The adjusted relative excess risk due to interaction (aRERI) was 7.69 (95% CI: 2.71, 19.13). Substituting Q isoenzyme activity for the genotype in the analyses corroborated the findings. Sensitivity analyses suggested that recall bias had forced the estimate of the GxE interaction toward the null and that unmeasured confounding is unlikely to account for the findings. We found a GxE interaction involving the Q-correlated PON1 diazoxonase activity and a weak possible GxE involving the Khamisiyah plume model, but none involving the PON1 R isoenzyme activity, arylesterase activity, paraoxonase activity, butyrylcholinesterase genotypes or enzyme activity, or pyridostigmine.Discussion:Given gene–environment independence and monotonicity, the unconfounded supports a mechanistic interaction. Together with the direct evidence of exposure to fallout from bombing of chemical weapon storage facilities and the extensive toxicologic evidence of biochemical protection from organophosphates by the Q isoenzyme, the findings provide strong evidence for an etiologic role of low-level nerve agent in GWI. https://doi.org/10.1289/EHP9009

DNA damage in a Chilean population exposed to pesticides and its association with PON1 (Q192R and L55M) susceptibility biomarker.

The active ingredients in pesticides are known to be genotoxic that can cause mutations, chromosomal aberrations, or other types of DNA damage. Early detection of genotoxicity reduces the risk of developing diseases such as cancer or suffering from reproductive disorders. In turn, the genotoxic risk depends on the intrinsic capability of the individual to metabolize and eliminate the xenobiotic from the organism. This study aimed to determine if two polymorphisms of paraoxonase-1 (PON1), which is involved in the metabolism of several organophosphate (OP) pesticides, are predictors of susceptibility to DNA damage in agricultural workers and inhabitants of rural areas chronically exposed to pesticides. A cross-sectional study was made considering three groups: agricultural workers (occupational exposure, OE, n= 85), rural inhabitants (environmental exposure, EE, n= 60), and an unexposed group conformed by people living far from agricultural areas (U, n= 33). The level of individual DNA damage was measured using the comet assay, and genotyping was done to determine the PON1 Q192R and L55M polymorphisms. Acetylcholinesterase and butyrilcholinesterase activities were also measured to determine exposure to OP. Individuals belonging to EE and OE groups displayed higher levels of DNA damage compared with U group (p< .001). OP exposure was the main predictor of genotoxicity (β=16.19; 95% CI: 1.85, 30.52), instead of PON1 polymorphisms (β=-12.20; 95% CI: -27.87, 3.48). These results confirm the genotoxic effects of pesticide exposure and suggest that the catalytic efficiency of PON1 to metabolize OP pesticides becomes negligible in individuals with a history of long-term environmental or occupational exposure to these substances.

Paraoxonase-1 Q192R Polymorphism and Lipid Peroxidation and Antioxidant Defense State in Russian Healthy Teenagers

Paraoxonase-1 Q192R Polymorphism and Lipid Peroxidation and Antioxidant Defense State in Russian Healthy Teenagers

Paraoxonase 1: Could it be important for asthma in children?

Objective: The paraoxonase 1 (PON-1) enzyme is an important antioxidant. The balance between oxidative stress and antioxidant defense mechanisms is disturbed during asthma attacks. The activity of the PON-1 enzyme is related to PON-1 gene polymorphism. This study aimed to evaluate the activity of PON-1 enzyme and Q192R polymorphism in asthmatic children. Material and methods: During the 2013-2014 period, we performed a prospective study with 34 asthmatic (study group) and 34 healthy (control group) children. Serum PON-1 activity was evaluated in the study group at the onset of an asthma attack and at the end, and also in the control group. Q192R gene polymorphism of asthmatic children, which is known to affect the PON-1 enzyme activity was also investigated. Results: There was no significant difference in terms of serum PON-1 enzyme activity and PON-1 gene polymorphism between the asthmatic children and healthy controls. However, a significant increase was observed at the PON-1 enzyme activity of asthmatic children at the end of the asthma attack compared to its onset. Conclusion: The PON-1 enzyme activity and Q192R genetic polymorphism in asthmatic children are not different from those of healthy children, but PON-1 enzyme activity is higher at the end of an asthma attack compared to the onset. PON-1 enzyme, as a member of the antioxidant mechanism, may be important both in understanding the pathophysiology of asthma and in the development of new medications for asthma.

Abnormal paraoxonase-1 (PON1) enzyme activity in idiopathic inflammatory myopathies.

Patients with idiopathic inflammatory myopathies (IIM) have severe vascular involvement, which contributes to disease morbidity and mortality. Paraoxonase-1 (PON1) is a high-density lipoprotein (HDL) associated protein that protects the vascular endothelium from oxidative injury and damage. The current work assessed the functional and genetic determinants of PON1 activity in IIM patients. A total of 184 IIM patients and 112 healthy controls (HC) were included. PON1 enzyme activity was assessed by paraoxonase, arylesterase and lactonase assays, and the Q192R PON1 single nucleotide polymorphism (SNP) was analysed. Multivariate regression models examined associations of PON1 activity with IIM diagnosis and myositis disease outcomes. The arylesterase and lactonase activities of PON1 were significantly lower in IIM patients compared with HC. Higher myositis disease activity, the presence of severe IIM-associated interstitial lung disease (ILD), and the presence of MDA5 or anti-synthetase antibodies were significantly associated with lower PON1 activity. The PON1 Q192R polymorphism was strongly linked to the paraoxonase activity of PON1 in IIM, and patients with the PON1 QQ genotype had better IIM disease outcomes compared with patients with the QR or RR genotypes. The arylesterase and lactonase activities of PON1 are significantly impaired in IIM patients compared with HC, and inversely associate with IIM disease activity and the presence of severe ILD. The PON1 QQ genotype associates with more favourable disease outcomes in IIM patients. Large prospective studies are needed to further evaluate the role of PON1 and PON1 genetic polymorphisms in the development and propagation of IIM and IIM-ILD.

PON1 (Paraoxonase 1) Q192R Gene Polymorphism in Ischemic Stroke among North Indian Population.

Background:PON1 is an High Density Lipoprotein (HDL)-associated esterase. Two common polymorphisms in the PON1 gene, Q192R and L55M substitutions, determine the inter-individual variation in PON1 activity. The association of these polymorphisms with the risk of ischemic stroke remains controversial. In the present study, the role of PON1 Q192R gene polymorphism in ischemic stroke was studied in the Indian population.Design and Methods:In the present case-control study, the PON1 Q192R gene polymorphism was screened in ischemic stroke patients (n: 63) and age, sex-matched controls (n: 63) using thePolymerase Chain Reaction-Restriction Segment Length Polymorphism (PCR-RFLP) method.Results:The mean age of stroke presentation was 58.11 ± 15.4 years. A total of 17.4% cases presented with young stroke (<45 years age) and 9.52% cases were seen to have a recurrent stroke. The distribution of -192Q/R PON1 gene polymorphism was not seen to differ between cases and controls. The traditional stroke risk factors did not have any effect on the PON1 genotype expression. A multivariate logistic regression analysis was done in order to assess an independent association of age, gender, traditional stroke risk factors, and PON1 polymorphism with acute ischemic stroke. However, neither the RR genotype nor the presence of the R allele was associated with an increase in the risk of acute ischemic stroke (OR [RR genotype]-4.76, P value: 0.24, 95% CI: 0.3497–64.8531; OR [R allele]-0.94, P value: 0.90, 95% CI: 0.3516–2.4989).Conclusion:PON1 Q192R gene polymorphism is not associated with an increased risk of acute ischemic stroke in the North Indian population. Further studies with a larger sample size are needed before PON1 Q192R gene polymorphism can be considered as a genetic risk factor for ischemic stroke.

Paraoxonase 1 (PON1) L55M and Q192R polymorphisms are not associated with chronic kidney disease in Thai individuals with type 2 diabetes.

Decreased paraoxonase 1 (PON1) activity and PON1 polymorphisms have been found to be associated with chronic kidney disease (CKD) in type 2 diabetes mellitus (T2DM). This study aimed to investigate the association of the PON1 L55M and Q192R polymorphisms with CKD in T2DM, as well as their relationship with PON1 activity. A total of 166 T2DM patients, including 83 CKD patients and 83 non-CKD patients, were recruited. Biochemical parameters and paraoxonase (PONase) and arylesterase (AREase) activities were measured. The PON1 L55M and Q192R polymorphisms were analysed by a polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) method. Data were analysed using the chi-square test, Student's t-test and logistic regression analysis. Total cholesterol, TGs, LDL-C and Cr were significantly higher in CKD patients than in non-CKD patients. In contrast, the estimated glomerular filtration rate (eGFR) and AREase activity were significantly lower in CKD patients than in non-CKD patients (P<.05). The genotype and allele frequencies of the PON1 L55M and Q192R polymorphisms were not significantly different between CKD and non-CKD patients. Multivariate logistic regression analysis showed no association between the PON1 L55M and Q192R polymorphisms and CKD in T2DM. In addition, among all patients, patients with the PON1 LM genotype had significantly lower PONase activity than those with the LL genotype (P<.05). Among all patients, CKD patients and non-CKD patients, those with the PON1 RR genotype had significantly higher PONase activity but lower AREase activity than patients with the QR and QQ genotypes (P<.05). PON1 activity was influenced by the PON1 L55M and Q192R polymorphisms. However, the PON1 L55M and Q192R polymorphisms may not be considered genetic biomarkers for CKD in T2DM.

Paraoxonase 1 Q192R (A/G) Gene Polymorphism as possible risk factor for coronary heart diseases among Egyptians. Case-control study

Background: Coronary heart disease (CHD) is the leading cause of morbidity and mortality worldwide. There are many risk factors for CHD but recently the role of oxidative stress in progression of atherosclerosis has been more recognized. Paraoxonase 1 (PON1) protects against oxidation of LDL and many polymorphisms in both of exons and promoter regions of (PON1) gene have been investigated for their association with CHD. The aim of the present study was to investigate the relation between CHD suceptibility and PON1 Q192R (A/G) gene polymorphism in a cohort of Egyptian individuals. Methods: The study included 100 subjects, 50 patients who admitted to cardiovascular department with established diagnosis of obstructive coronary artery disease by coronary angiography and 50 healthy participants. Genotyping of PON1 Q192R (A/G) was done, and then serum concentration of PON1 was assessed by ELISA after that by spectrophotometer. Results: Serum PON1 enzyme was lower in patients with CHD than in control group with a statistically significant difference p < 0.001. A statistically significant association was observed with AG and GG genotypes of PON1 gene with CHD with P= 0.003, OR=5.02(95% CI =1.66-15.26) and P= 0.038, OR= 9.4 (95% CI =1.07-82.5); respectively. The G allele of PON1 was higher in CHD patients than controls suggesting that this allele may demonstrate a susceptibility effect to CHD in our cohort with P<0.001, OR= 5.16 (95% CI = 2.1-12.5) Conclusion: The Q192R polymorphism in the PON1 gene may be a susceptibility gene associated with increased risk of CHD among Egyptians.

The effects of polymorphisms in CYP2C19, ATP-binding cassette transporter B1, and paraoxonase-1 on clopidogrel treatment of Uygur patients following percutaneous coronary intervention.

Acute coronary syndrome (ACS) carries a high mortality in Uygur populations. Percutaneous coronary intervention (PCI) is a safe treatment for patients with ACS. Clopidogrel reduces the risk for recurrent cardiovascular events after PCI; however, its activity is influenced by cytochrome P450 (CYP450), ATP-binding cassette transporter B1 (ABCB1), and paraoxonase-1 (PON1). To assess the effects of genetic polymorphisms CYP2C19*2, *3, *17, ABCB1 C3435T, and PON1 Q192R along with clinical and demographic factors on variations in responses in Uygur patients following PCI. We enrolled 281 patients with PCI who were treated with clopidogrel and aspirin for at least 12months and recorded major adverse cardiovascular events (MACE) or bleeding within 1year. Approximately, 2mL of peripheral venous blood samples were used for genotype detection. Binary logistic regression with likelihood ratio forward stepwise analysis and redundancy analysis were carried out to identify factors associated with MACE. We analyzed risk factors including age, body mass index, smoking, hypertension, dyslipidemia, gender, alcohol consumption, diabetes mellitus, carriers of ABCB1 C3435T T allele, carriers of PON1 Q192R A allele, metabolizer phenotype of CYP2C19, number of targeted vessels, and number of stents. The CYP2C19 IMs (OR 3.546, 95% CI 1.972-6.375, P = 0.001), CYP2C19 PMs (OR 7.038, 95% CI 1.658-29.880, P = 0.008), and number of targeted vessels (OR 2.033, 95% CI 1.078-3.648, P = 0.026) were significantly associated with MACE. The CYP2C19 IMs, PMs, and the number of targeted vessels are essential factors associated with MACE risk in dual clopidogrel-treated Uygur population with ACS following PCI. These data provide valuable insights into the genetic polymorphisms affecting clopidogrel response among minority groups in China.

Paraoxonase 1, B Vitamins Supplementation, and Mild Cognitive Impairment.

Background:Identification of modifiable risk factors that affect cognitive decline is important for the development of preventive and treatment strategies. Status of paraoxonase 1 (PON1), a high-density lipoprotein-associated enzyme, may play a role in the development of neurological diseases, including Alzheimer’s disease.Objective:We tested a hypothesis that PON1 status predicts cognition in individuals with mild cognitive impairment (MCI).Methods:Individuals with MCI (n = 196, 76.8-years-old, 60% women) participating in a randomized, double-blind placebo-controlled trial (VITACOG) were assigned to receive a daily dose of folic acid (0.8 mg), vitamin B12 (0.5 mg) and B6 (20 mg) (n = 95) or placebo (n = 101) for 2 years. Cognition was analyzed by neuropsychological tests. Brain atrophy was quantified in a subset of participants (n = 168) by MRI. PON1 status, including PON1 Q192R genotype, was determined by quantifying enzymatic activity of PON1 using paraoxon and phenyl acetate as substrates.Results:In the placebo group, baseline phenylacetate hydrolase (PhAcase) activity of PON1 (but not paraoxonase activity or PON1 Q192R genotype) was significantly associated with global cognition (Mini-Mental State Examination, MMSE; Telephone Inventory for Cognitive Status-modified, TICS-m), verbal episodic memory (Hopkins Verbal Learning Test-revised: Total Recall, HVLT-TR; Delayed Recall, HVLT-DR), and attention/processing speed (Trail Making A and Symbol Digits Modalities Test, SDMT) at the end of study. In addition to PhAcase, baseline iron and triglycerides predicted MMSE, baseline fatty acids predicted SDMT, baseline anti-N-Hcy-protein autoantibodies predicted TICS-m, SDMT, Trail Making A, while BDNF V66M genotype predicted HVLT-TR and HVLT-DR scores at the end of study. B-vitamins abrogated associations of PON1 and other variables with cognition.Conclusion:PON1 is a new factor associated with impaired cognition that can be ameliorated by B-vitamins in individuals with MCI.

Pregnancy exposure to organophosphate esters and the risk of attention-deficit hyperactivity disorder in the Norwegian mother, father and child cohort study

BackgroundOrganophosphate esters (OPEs) are a class of flame retardants in common use. OPEs can easily leach from materials, resulting in human exposure. Increasing concentrations have been reported in human populations over the past decade. Recent studies have linked prenatal OPE exposure to hyperactivity and attention problems in children. Such behaviors are often found among children with attention-deficit hyperactivity disorder (ADHD), however, no study has investigated OPEs in relation to clinically assessed ADHD. ObjectiveTo evaluate prenatal exposure to OPEs as risk factors for clinically assessed ADHD using a case-cohort study nested within the Norwegian Mother, Father, and Child Cohort Study (MoBa). MethodsWe included in the case group 295 ADHD cases obtained via linkage with the Norwegian Patient Registry, and the sub-cohort group 555 children sampled at baseline, irrespective of their ADHD case status. Prenatal concentrations of OPE metabolites were measured in maternal urine collected at 17 weeks of gestation, and included diphenyl phosphate (DPHP), di-n-butyl phosphate (DNBP), bis(2-butoxyethyl) hydrogen phosphate (BBOEP), and bis(1,3-dichloro-2-propyl) phosphate (BDCIPP). We estimated risk ratios and the corresponding 95% confidence intervals [95% CI] using logistic regression, adjusting for season of urine collection, child sex, birth year, and maternal depression, education, and sum of urinary di(2-ethylhexyl) phthalate metabolites (∑DEHP) concentration during pregnancy. To assess the overall impact of simultaneously decreasing exposure to all chemical constituents of an OPE-phthalate mixture, quantile based g-computation was implemented. The mixture constituents included OPE and phthalate metabolites commonly detected in our study. In all models, we considered effect measure modification by child sex and polymorphisms in genes encoding paraoxonase 1 (PON1) and cytochrome P450 (P450) enzymes. Mediation analysis was conducted using thyroid function biomarkers estimated from maternal blood collected at 17 weeks of gestation. ResultsDPHP was detected in nearly all samples (97.2%), with a higher geometric mean among the case group (0.70 µg/L) as compared to the sub-cohort (0.52 µg/L). DNBP was commonly detected as well (93.8%), while BBOEP (52.9%) and BDCIPP (22.9%) were detected less frequently. A higher risk of ADHD was observed in children with greater than median exposure to DPHP during pregnancy (risk ratio: 1.38 [95% CI: 0.96, 1.99]), which was slightly higher among girls (2.04 [1.03, 4.02]) and children of mothers with PON1 Q192R genotype QR (1.69 [0.89, 3.19]) or PON1 Q192R genotype RR (4.59 [1.38, 15.29]). The relationship between DPHP and ADHD (total risk ratio: 1.34 [0.90, 2.02]) was partially mediated through total triiodothyronine to total thyroxine ratio (natural direct effect: 1.29 [0.87, 1.94]; natural indirect effect: 1.04 [1.00, 1.10]; 12.48% mediated). We also observed an elevated risk of ADHD in relation to BDCIPP detection during pregnancy (1.50 [0.98, 2.28]). We did not observe notable differences in ADHD by DNBP (0.88 [0.62, 1.26]) or BBOEP (1.03 [0.73, 1.46]) during pregnancy. Simultaneously decreasing all constituents of common-detect OPE-phthalate mixture, specifically DPHP, DNBP, and 6 phthalate metabolites, by a quartile resulted in an ADHD risk ratio of 0.68 [0.64, 0.72]. ConclusionPrenatal exposure to DPHP and BDCIPP may increase the risk of ADHD. For DPHP, we observed potential modification by child sex and maternal PON1 Q192R genotype and partial mediation through maternal thyroid hormone imbalance at 17 weeks gestation.