scholarly journals Novel Associations of Nonstructural Loci with Paraoxonase Activity

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Ellen E. Quillen ◽  
David L. Rainwater ◽  
Thomas D. Dyer ◽  
Melanie A. Carless ◽  
Joanne E. Curran ◽  
...  

The high-density-lipoprotein-(HDL-) associated esterase paraoxonase 1 (PON1) is a likely contributor to the antioxidant and antiatherosclerotic capabilities of HDL. Two nonsynonymous mutations in the structural gene,PON1, have been associated with variation in activity levels, but substantial interindividual differences remain unexplained and are greatest for substrates other than the eponymous paraoxon. PON1 activity levels were measured for three substrates—organophosphate paraoxon, arylester phenyl acetate, and lactone dihydrocoumarin—in 767 Mexican American individuals from San Antonio, Texas. Genetic influences on activity levels for each substrate were evaluated by association with approximately one million single nucleotide polymorphism (SNPs) while conditioning onPON1genotypes. Significant associations were detected at five loci including regions on chromosomes 4 and 17 known to be associated with atherosclerosis and lipoprotein regulation and loci on chromosome 3 that regulate ubiquitous transcription factors. These loci explain 7.8% of variation in PON1 activity with lactone as a substrate, 5.6% with the arylester, and 3.0% with paraoxon. In light of the potential importance ofPON1in preventing cardiovascular disease/events, these novel loci merit further investigation.

Antioxidants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 899
Author(s):  
Jolanta Parada-Turska ◽  
Grażyna Wójcicka ◽  
Jerzy Beltowski

Paraoxonase 1 (PON1) is the high density lipoprotein-associated esterase which inhibits the development of atherosclerosis by metabolizing lipid peroxidation products as well as hydrolyzing proatherogenic metabolite of homocysteine (Hcy), Hcy thiolactone, which otherwise reacts with lysine groups of proteins, thus forming N-Hcy-protein in a process referred to as protein N-homocysteinylation. Rheumatoid arthritis (RA) is the chronic inflammatory autoimmune disease associated with increased risk of cardiovascular complications, but the underlying mechanisms are incompletely understood. We examined PON1 status and N-homocysteinylation of serum proteins in patients with RA. Blood was collected from 74 RA patients and 70 control subjects. PON1 activity was measured toward synthetic (paraoxon, phenyl acetate) and natural (Hcy thiolactone) substrates. PON1 protein concentration was measured by ELISA. Total Hcy as well as N-Hcy-protein were measured in serum as well. PON1 activity toward Hcy thiolactone was lower in RA patients than in control subjects which was accompanied by increased concentration of N-Hcy-protein despite normal total Hcy concentration. PON1 protein concentration was unchanged in the RA group, but the specific enzyme activity was reduced. When RA patients were categorized according to the DAS28-ESR score, PON1 concentration and enzymatic activity were lower whereas N-Hcy-protein was higher in those with high disease activity. PON1 activity and Hcy thiolactone were correlated with DAS28-ESR score and myeloperoxidase concentration. In conclusion, RA is associated with deficiency of PON1 activity and increased protein N-homocyseinylation which may contribute to accelerated development of cardiovascular diseases.


2019 ◽  
Vol 32 (4) ◽  
pp. 321-326
Author(s):  
Mukund Ramchandra Mogarekar ◽  
Mahendrakumar Gajanan Dhabe ◽  
Mayuri Madhukarrao Palmate

Abstract Background The study was done to assess high-density lipoprotein (HDL) functionality and to correlate this with paraoxonase 1 (PON1) activity in malnourished children. It aimed to find the effect of malnutrition on changes in PON1 activity, HDL functionality, lipid profile and lipid hydroperoxide formation. Methods This case control study included 30 malnourished children (up to age 5 years) and 30 healthy controls in the paediatric inpatient department of SRTR Government Medical College Ambajogai, India. Clinically diagnosed cases depending on anthropometric indices were selected. Serum PON1 activity by using phenyl acetate as a substrate, HDL functionality by haemin by its protection on H2O2 and haemin induced LDL oxidation, lipid profile by routine enzymatic methods and lipid hydroperoxide using the FOX2 assay were measured. Results Malnourished children had significantly decreased PON1 activity (106.6 ± 12.74** vs. 132.23 ± 28.49 IU/L), HDL functionality (116.55 ± 8** vs. 132.29 ± 10.9%), total cholesterol (TC) (102.5 ± 16** vs. 116.4 ± 12.65 mg/dL), HDL-cholesterol (C) (33.41 ± 9.74** vs. 40.55 ± 5.85 mg/dL) and reduced total protein level (5.56 ± 0.91* vs. 6.06 ± 1.055) higher triglycerides (TG) (146.76 ± 34.97* vs. 125.96 ± 17.21 mg/dL) level and total hydroperoxide (TPX) levels (5.568 ± 1.70** vs. 3.22 ± 1.52 μM/L). *p < 0.05 **p < 0.001. PON1 activity (r2 = 0.576) and TC (r2 = 0.567) shows significant positive correlation with HDL functionality. PON1 activity, HDL-C, HDL functionality and TPX shows independent contribution towards malnutrition in children in multivariate and univariate logistic regression. TC lost its significance in multivariate regression. Conclusions Malnutrition leads to decrease in HDL functionality and increase in hydroperoxide levels with a decrease in PON1 activity.


Reproduction ◽  
2017 ◽  
Vol 154 (3) ◽  
pp. 237-243 ◽  
Author(s):  
Isabel Barranco ◽  
Cristina Perez-Patiño ◽  
Asta Tvarijonaviciute ◽  
Inmaculada Parrilla ◽  
Alejandro Vicente-Carrillo ◽  
...  

The paraoxonase type 1 (PON1) is an enzyme with antioxidant properties recently identified in the seminal plasma (SP) of several species, including the porcine. The aims of the present study were to (1) describe the immunohistochemical localisation of PON1 in the genital organs of fertile boars and (2) evaluate the relationship among PON1 activity and high-density lipoprotein cholesterol (HDL-C) concentration in fluids of the boar genital organs. Immunohistochemical analysis demonstrated that PON1 was present in testis (specifically in Leydig cells, blood vessels, spermatogonia and elongated spermatids), epididymis (specifically in the cytoplasm of the principal epithelial cells, luminal secretion and in the surrounding smooth muscle) and the lining epithelia of the accessory sexual glands (cytoplasmic location in the prostate and membranous in the seminal vesicle and bulbourethral glands). The Western blotting analysis confirmed the presence of PON1 in all boar genital organs, showing in all of them a band of 51 kDa and an extra band of 45 kDa only in seminal vesicles. PON1 showed higher activity levels in epididymal fluid than those in SP of the entire ejaculate or of specific ejaculate portions. A highly positive relationship between PON1 activity and HDL-C concentration was found in all genital fluids. In sum, all boar genital organs contributing to sperm-accompanying fluid/s were able to express PON1, whose activity in these genital fluids is highly dependent on the variable HDL-C concentration present.


2018 ◽  
Vol 108 (6) ◽  
pp. 1283-1290 ◽  
Author(s):  
Eke G Gruppen ◽  
Stephan J L Bakker ◽  
Richard W James ◽  
Robin P F Dullaart

ABSTRACT Background Paraoxonase-1 (PON-1) is a high-density lipoprotein (HDL)-associated enzyme with antioxidative properties, which may protect against the development of cardiovascular disease. Alcohol consumption increases HDL cholesterol, but the extent to which alcohol consumption gives rise to higher serum PON-1 activity is uncertain. Objective In a population-based study, we determined the relation of serum PON-1 activity with alcohol consumption when taking account of HDL cholesterol and apolipoprotein A-I (apoA-I), its major apolipoprotein. Design A cross-sectional study was performed in 8224 participants of the Prevention of Renal and Vascular End-Stage Disease (PREVEND) cohort. Alcohol consumption was categorized as 1) no/rarely (25.3%); 2) 0.1–10 g/d (49.3%); 3) 10–30 g/d (20.1%); and 4) >30 g/d (5.2%) with 1 drink equivalent to 10 g alcohol. Serum PON-1 activity was measured as its arylesterase activity (phenyl acetate as substrate). Results Median serum PON-1 activity was 50.8, 53.1, 54.4, and 55.7 U/L in the 4 categories of alcohol consumption, respectively (P < 0.001). Its increase paralleled the increments in HDL cholesterol and apoA-I. Notably, there was no further increase in PON-1 activity, HDL cholesterol, and apoA-I when alcohol consumption was increased from 10–30 g/d to >30 g/d. Multivariable linear regression analysis demonstrated that PON-1 activity was related to alcohol consumption independently from clinical covariates, high sensitivity C-reactive protein, and lipid concentrations, including HDL cholesterol (P < 0.001 for each category of alcohol consumption with no alcohol consumption as the reference category). Notably, as inferred from standardized β-coefficients, there was no difference in PON-1 activity between 10–30 g alcohol/d and >30 g alcohol/d. Conclusions Alcohol consumption is associated with an increase in serum PON-1 activity, but its effect seems to reach a plateau with alcohol consumption of 10–30 g/d.


2021 ◽  
Vol 2 (03) ◽  
pp. 118-130
Author(s):  
Raghad Ali ◽  
Rayah Baban ◽  
Shatha Ali

Background: The role of paraoxonase 1 enzyme (PON1) and its single nucleotide polymorphisms (SNPs) in children with nephrotic syndrome (NS) has been reported previously in different ethnic and racial groups with divergent results. The human PON1 gene contains two coding region polymorphisms leading to two different PON1 isoforms. Objectives: The aim of the present study was to find out the association between the PON1 (Q192R and L55M) polymorphisms and their relation with serum PON1 activity as well as lipid profile tests (total cholesterol, TC; triglycerides, TG; high-density lipoprotein cholesterol, HDL-c; and low-density lipoprotein cholesterol, LDL-c) in children with NS. Methods: This study included a total of 80 participants (40 with NS in the age group of 2-14 years and 40 age and sex-matched healthy controls). The PON1 enzyme activity and lipid profile tests were measured in serum samples of all included participants. The PON1 genotype was determined by PCR-restriction enzyme fragment length polymorphism (PCR-RFLP) for both PON1 alleles (192 and 55) SNPs. Results: Our findings showed that the mean levels of lipid profile tests (TC, TG, LDL-c) were significantly increased in patients when compared with healthy controls (p<0.05), while the HDL-c concentration was significantly decreased in patients than that of controls. Also, the patients had significantly lower concentrations of PON1 when compared with the controls regardless of the genotype Q192R and L55M polymorphisms. Moreover, the homozygous RR genotype for PON1 SNP 192 and MM homozygous genotype for PON1 SNP 55 were significantly frequent in patients when compared with the controls. Conclusions: Our results support that the presence of the homozygous RR genotype for PON1 SNP 192 and MM homozygous genotype for PON1 SNP 55 were significantly higher in patients compared with the controls.


2007 ◽  
Vol 80 (6) ◽  
pp. 1014-1023 ◽  
Author(s):  
Chao Tian ◽  
David A. Hinds ◽  
Russell Shigeta ◽  
Sharon G. Adler ◽  
Annette Lee ◽  
...  

2019 ◽  
Vol 6 (4) ◽  
pp. 37 ◽  
Author(s):  
Ali Salami ◽  
Christy Costanian ◽  
Said El Shamieh

Many studies have assessed the implication of cluster of differentiation 14 (CD14) molecules and its single nucleotide polymorphism rs2569190A>G with different complex diseases, such as diabetes and cardiovascular diseases (CVDs). In this study, we investigated the association of rs2569190A>G in CD14 with cardiovascular disease risk factors (hypercholesterolemia and hypertension) in 460 individuals from the general Lebanese population (Middle Eastern multiethnic population). Using a multiple logistic regression model adjusted for six covariates (under additive and recessive assumptions), we found that the G allele of rs2569190 in CD14 was associated with increased levels of total cholesterol (OR = 3.10, p = 0.009), low-density lipoprotein cholesterol (OR = 3.87, p = 0.003), and decreased levels of high-density lipoprotein cholesterol (OR = 0.38, p = 0.001). In contrast, no significant relationship was found with hypertension. Thus, we concluded that rs2569190G in CD14 is associated with a higher risk of developing hypercholesterolemia.


2003 ◽  
Vol 375 (2) ◽  
pp. 275-285 ◽  
Author(s):  
S. Duy NGUYEN ◽  
Dai-Eun SOK

The effect of lipids on PON1 (paraoxonase 1), one of antioxidant proteins in high-density lipoprotein, was investigated in respect to inhibition, protection against oxidative inactivation, and stabilization. When the effect of lipids on the PON1 activity was examined, a remarkable inhibition was expressed by polyenoic fatty acids (C18:2–C20:5). Linoleic acid, the most potent (Ki, 3.8 μM), showed competitive inhibition. Next, various lipids were examined for prevention against the inactivation of PON1 by ascorbate/Cu2+, which caused a remarkable (≥90%) inactivation of PON1. Compared with saturated fatty acids (C6–C18), exhibiting a modest protection (9–40%), monoenoic acids (C16:1–C20:1) showed a greater maximal protective effect (Emax, 70–82%), with oleic acid being the most effective (EC50, 2.7 μM). In contrast, polyenoic acids showed no protection. Noteworthy, linoleic acid prohibited the protective action of oleic acid non-competitively. In the structure–activity relationship, a negatively charged group seems to be required for the protective action. Consistent with this, dioleoylphosphatidylglycerol, negatively charged, was more protective than dioleoylphosphatidylcholine. These data, together with requirement of Ca2+ (EC50, 0.6 μM) for the protective action, may support the existence of a specific site responsible for the protective action. A similar protective action of lipids was also observed in the inactivation of PON1 by ascorbate/Fe2+, peroxides or p-hydroxymercuribenzoate. Separately, PON1 was stabilized by oleic acid or oleoylated phospholipids, in combination with Ca2+, but not linoleic acid. These results suggest that in contrast to an adverse action of linoleic acid, monoenoic acids or their phospholipid derivatives play a beneficial role in protecting PON1 from oxidative inactivation as well as in stabilizing PON1.


2005 ◽  
Vol 109 (2) ◽  
pp. 189-197 ◽  
Author(s):  
Mike J. Sampson ◽  
Simon Braschi ◽  
Gavin Willis ◽  
Sian B. Astley

The HDL (high-density lipoprotein)-associated enzyme PON (paraoxonase)-1 protects LDL (low-density lipoprotein) from oxidative modification in vitro, although it is unknown if this anti-atherogenic action occurs in vivo. In a cross-sectional study of 58 Type II diabetic subjects and 50 controls, we examined the fasting plasma LDL basal conjugated diene concentration [a direct measurement of circulating oxLDL (oxidatively modified LDL)], lipoprotein particle size by NMR spectroscopy, PON-1 polymorphisms (coding region polymorphisms Q192R and L55M, and gene promoter polymorphisms −108C/T and −162G/A), PON activity (with paraoxon or phenyl acetate as the substrates) and dietary antioxidant intake. Plasma oxLDL concentrations were higher in Type II diabetic patients (males, P=0.048; females, P=0.009) and unrelated to NMR lipoprotein size, PON-1 polymorphisms or PON activity (with paraoxon as the substrate) in any group. In men with Type II diabetes, however, there was a direct relationship between oxLDL concentrations and PON activity (with phenyl acetate as the substrate; r=0.611, P=0.0001) and an atherogenic NMR lipid profile in those who were PON-1 55LL homozygotes. Circulating oxLDL concentrations in vivo were unrelated to PON-1 genotypes or activity, except in male Type II diabetics where there was a direct association between PON activity (with phenyl acetate as the substrate) and oxLDL levels. These in vivo data contrast with in vitro data, and may be due to confounding by dietary fat intake. Male Type II diabetic subjects with PON-1 55LL homozygosity have an atherogenic NMR lipid profile independent of LDL oxidation. These data do not support an in vivo action of PON on LDL oxidation.


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