Paraoxonase Research Articles

In silico investigation of the interactions of certain drugs proposed for the treatment of Covid-19 with the paraoxonase-1

Coronavirus disease 2019 (Covid-19) has caused one of the biggest pandemics of modern times, infected over 240 million people and killed over 4.9 million people, and continues to do so. Although many drugs are widely recommended in the treatment of this disease, the interactions of these drugs with an anti-atherosclerotic enzyme, paraoxonase-1 (PON1), are not well known. In our study, we investigated the interactions of 18 different drugs, which are claimed to be effective against covid-19, with the PON1 enzyme and its genetics variants L55M and Q192R with molecular docking, molecular dynamics simulation and free energy calculation method MM/PBSA. We found that ruxolitinib, dexamethasone, colchicine; dexamethasone, sitagliptin, baricitinib and galidesivir, ruxolitinib, hydroxychloroquine were the most effective compounds in binding PON1-w, PON1L55M and PON1Q192R respectively. Mainly, sitagliptin, galidesivir and hydroxychloroquine have attracted attention by showing very high affinity (<-300 kJ/mol) according to the MM/PBSA method. We concluded that the drug interactions should be considered and more attention should be paid in the use of these drugs. Communicated by Ramaswamy H. Sarma

The Increase in Paraoxonase 1 Is Associated With Decrease in Left Ventricular Volume in Kidney Transplant Recipients.

Background: Patients on dialysis have impaired cardiac function, in part due to increased fluid volume and ventricular stress. Restored kidney function through transplantation reduces left ventricular volume in both systole and diastole. We previously reported that the decrease in NT-proB-type natriuretic peptide (NT-proBNP) was associated with a decrease in adiponectin. Paraoxonase 1 (PON1) has been inversely associated with cardiovascular outcomes. We now report the association of changes in PON1 with changes in left ventricular volume and left ventricular mass after kidney transplantation.Design: Patients on dialysis were assessed at baseline and 12 months after kidney transplantation (n = 38). A comparison group of patients on dialysis who were not expected to receive a transplant in the next 24 months were studied (n = 43) to determine if the change of PON1 with kidney transplantation achieved a significance greater than that due to biologic variation. Left ventricular volume and mass were determined by cardiac magnetic resonance imaging. PON1 was measured by arylesterase activity and by mass.Results: PON1 mass and activity were not different between the groups at baseline. Both PON1 mass and activity were increased post-kidney transplantation (p < 0.0001 for change). The change in PON1 mass (p = 0.0062) and PON1 arylesterase activity (p = 0.0254) were inversely correlated with the change in NT-proBNP for patients receiving a kidney transplant. However, only the change in the PON1 mass, and not the change in PON1 arylesterase, was inversely correlated with the change in left ventricular volume (ml/m2.7) (p = 0.0146 and 0.0114 for diastolic and systolic, respectively) and with the change in hemoglobin (p = 0.0042).Conclusion: Both PON1 mass and arylesterase activity are increased by kidney transplantation. The increase in PON1 mass is consistent with a novel relationship to the increase in hemoglobin and decrease in left ventricular volume and NT-proBNP seen when kidney function is restored.

L-Glutamine supplementation enhances glutathione peroxidase and paraoxonase-1 activities in HDL of exercising older individuals.

Oxidative stress is an important factor in the formation of atherosclerotic plaques. High-density lipoprotein (HDL) harbors paraoxonase-1 (PON-1) and glutathione peroxidase (GPx), key enzymes in the protection against the harmful effects of oxidative stress. Although exercise training can increase both HDL-c content and its antioxidant action, and glutamine (Gln) intake also promotes GPx-based defenses, the association between exercise training and Gln in the regulation of PON-1 activity was not explored. Therefore, the objective of this study was to investigate the effects of Gln supplementation on the redox balance and on the total HDL antioxidant capacity by evaluation of the activity of PON-1 and GPx enzymes in physically exercised elderly individuals compared to non-exercised ones. Fifty-one practitioners of a combined exercise training program (CET, age: 71.9±5.7years) and 32 non-practitioners (NP, age: 73±6.3years) participated in the study. CET and NP groups were separated into 2 subgroups according to the supplementation: Gln, 0.3g/kg/day + 10g maltodextrin (CET-Gln, n=26; and NP-Gln, n=16) or placebo, 10g maltodextrin (CET-PL, n=25; and NP-PL, n=16). Blood samples were drawn at baseline and after 30days after commencement of the supplementation for biochemical and enzyme activity analyses. Increased HDL-c, total peroxidase (PRx), and GPx activities were found in both CET-Gln and NP-Gln after the supplementation period, compared to baseline, in opposition to CET-PL and NP-PL groups. PON-1 activity increased only in CET-Gln. In both CET-Gln and NP-Gln groups, there was a reduction of the total peroxides/PRx, iron/PRx, and total peroxides/GPX ratios after supplementation. In CET-Gln, thiobarbituric acid-reactive substances (TBARS)/PRx and TBARS/GPx ratios were also lower after supplementation. CET-Gln and CET-PL subgroups had lower glycemia than NP-Gln and NP-PL, either at baseline or after the supplementation periods. The other parameters were unchanged after supplementation [total cholesterol, LDL-c, triglycerides, non-HDL cholesterol, total peroxides, TBARS, iron serum, Trolox-equivalent antioxidant capacity (TEAC), and uric acid]. Gln supplementation can increase glutathione peroxidase activity regardless the individuals were physically active or sedentary, but the PON-1 activity only increased in physically active individuals. These results show the potential of Gln supplementation in the maintenance of the vascular redox balance, with potential implications for atherogenesis protection.

Paraoxonase 1 and Chronic Obstructive Pulmonary Disease: A Meta-Analysis.

Oxidative stress is a driving factor in the pathophysiology of chronic obstructive pulmonary disease (COPD). While paraoxonase 1 (PON1) is an antioxidant enzyme and a potential biomarker of this disease, data regarding the status of PON-1 in COPD are inconclusive. In this regard, to shed light on this issue, we performed a meta-analysis of data on PON1 activity in COPD. Electronic databases (MEDLINE, Embase and CENTRAL) were searched for available studies on PON1 activity in patients with stable COPD published before October 2021. A meta-analysis was performed using random-effects models. Twelve studies (12 studies on paraoxonase and three on arylesterase) were identified. Patients with COPD had lower levels of paraoxonase activity (standard mean difference [SMD] −0.77, 95% confidence interval [CI] −1.35 to −0.18) and arylesterase activity (SMD −1.15, 95% CI −1.95 to −0.36) in comparison to healthy controls. In subgroup analyses, paraoxonase activity was lower in patients of studies as consisted of mainly non-severe COPD (SMD −1.42, 95% CI −2.04 to −0.79) and, by contrast, slightly higher in patients of studies including severe COPD (SMD 0.33, 95% CI 0.02 to 0.64) in comparison to healthy controls. Arylesterase activity showed a similar trend. Overall, PON1 activity was lower in patients with COPD, suggesting that PON1-related antioxidant defense is impaired in COPD. Future studies are warranted.

CRISPR/dCas9 Transcriptional Activation of Endogenous Apolipoprotein AI and Paraoxonase 1 in Enterocytes Alleviates Endothelial Cell Dysfunction

Atherosclerosis is the main cause of cardiovascular diseases with high prevalence worldwide. A promising therapeutic strategy to reverse atherosclerotic process is to improve the athero-protective potential of high-density lipoproteins (HDL). Since the small intestine is a source of HDL, we aimed to activate transcription of the endogenous HDL major proteins, apolipoprotein AI (ApoAI) and paraoxonase 1 (PON1), in enterocytes, and to evaluate their potential to correct the pro-inflammatory status of endothelial cells (EC). Caco-2 enterocytes were transfected with CRISPR activation plasmids targeting ApoAI or PON1, and their gene and protein expression were measured in cells and conditioned medium (CM). ATP binding cassette A1 and G8 transporters (ABCA1, ABCG8), scavenger receptor BI (SR-BI), and transcription regulators peroxisome proliferator-activated receptor γ (PPARγ), liver X receptors (LXRs), and sirtuin-1 (SIRT1) were assessed. Anti-inflammatory effects of CM from transfected enterocytes were estimated through its ability to inhibit tumor necrosis factor α (TNFα) activation of EC. Transcriptional activation of ApoAI or PON1 in enterocytes induces: (i) increase of their gene and protein expression, and secretion in CM; (ii) stimulation of ABCA1/G8 and SR-BI; (iii) upregulation of PPARγ, LXRs, and SIRT1. CM from transfected enterocytes attenuated the TNFα-induced inflammatory and oxidative stress in EC, by decreasing TNF receptor 1, monocyte chemoattractant protein-1, and p22phox. In conclusion, transcriptional activation of endogenous ApoAI or PON1 in enterocytes by CRISPR/dCas9 system is a realistic approach to stimulate biogenesis and function of major HDL proteins which can regulate cholesterol efflux transporters and reduce the inflammatory stress in activated EC.

Gene-Toxicant Interactions in Gulf War Illness: Differential Effects of the PON1 Genotype.

About 25–35% of United States veterans who fought in the 1990–1991 Gulf War report several moderate or severe chronic systemic symptoms, defined as Gulf War illness (GWI). Thirty years later, there is little consensus on the causes or biological underpinnings of GWI. The Gulf War Era Cohort and Biorepository (GWECB) was designed to investigate genetic and environmental associations with GWI and consists of 1343 veterans. We investigate candidate gene–toxicant interactions that may be associated with GWI based on prior associations found in human and animal model studies, focusing on SNPs in or near ACHE, BCHE, and PON1 genes to replicate results from prior studies. SOD1 was also considered as a candidate gene. CDC Severe GWI, the primary outcome, was observed in 26% of the 810 deployed veterans included in this study. The interaction between the candidate SNP rs662 and pyridostigmine bromide (PB) pills was found to be associated with CDC Severe GWI. Interactions between PB pill exposure and rs3917545, rs3917550, and rs2299255, all in high linkage disequilibrium in PON1, were also associated with respiratory symptoms. These SNPs could point toward biological pathways through which GWI may develop, which could lead to biomarkers to detect GWI or to better treatment options for veterans with GWI.

Abstract 13819: Circulating PON Lactonase Activity Predicts Major Adverse Cardiac Events in Subjects With Atherosclerotic Renal Artery Disease

Introduction: Decreased plasma lactonase activity, catalyzed by high-density lipoprotein (HDL)-associated paraoxonase (PON), is associated with increased oxidant stress and cardiovascular risk in settings such as coronary artery disease as well as some etiologies of chronic kidney disease (CKD). However, whether circulating PON lactonase activity predicts outcomes in atherosclerotic renal artery stenosis (ARAS) is unknown. We sought to determine the prognostic value of circulating PON lactonase activity in subjects with ARAS, particularly in relation to established risk factors. Methods/Results: PON lactonase activity was measured in plasma of subjects with ARAS and either systolic hypertension while taking ≥2 antihypertensive drugs or CKD (n=718) enrolled in the Cardiovascular Outcomes in Renal Atherosclerotic Lesions (CORAL) study as well as a cohort of apparently healthy, normotensive non-ARAS subjects (n=33). Participants with ARAS were prospectively followed for incident major adverse cardiac events (MACE, composite of cardiovascular death, nonfatal myocardial infarction, and stroke) over a median follow-up period of 43 months (interquartile range, 31 to 55). PON lactonase activity in ARAS subjects was significantly lower compared with that in non-ARAS control subjects [mean±SD, 2466±839 vs 3514±745 pmol/min/mL, P&lt;0.001]. Next, participants were dichotomized based on the baseline plasma levels of PON lactonase activity, into high (&gt; median) or low (≤ median) groups and were used to predict incident MACE at 3 years. Participants with lower PON lactonase activity had increased MACE at 3 years [67/359 (17%) vs 44/359 (12%), p&lt;0.05]. Lower circulating PON lactonase activity (hazard ratio 1.26, 95% CI 1.0 to 1.53, p=0.016) was a predictor of MACE. After adjusting for traditional risk factors and medication use, lower PON lactonase activity (hazard ratio 1.22, 95% CI 1.01 to 1.50, p=0.04) still conferred an increased risk of MACE. Conclusions: In patients with ARAS, decreased circulating PON lactonase activity, a measure of diminished antioxidant properties of HDL, predicts higher risk of incident long-term adverse cardiovascular events in multivariate models adjusting for established clinical and biochemical risk factors.

Abstract 9976: New Risk Factors for Improved Identification of Coronary Artery Disease Risk in Type 2 Diabetes by Substituting Paraoxonase 1 Activity for HDL Cholesterol in Atherogenic Ratios

Introduction: HDL cholesterol (HDL-C) may not always represent the HDL function. This study was conducted to help predict the risk of coronary artery disease (CAD) in patients with type 2 diabetes (T2D) based on substituting paraoxonase 1 (PON1) as an important enzyme in HDL function for that of HDL-C in the atherogenic ratios LDL-C/HDL-C and log (TG/HDL-C). Methods: A total of 274 subjects undergoing diagnostic coronary angiography in this study; 92 without significant CAD and 182 with severe CAD. The hydrolysis rate of phenylacetate as a PON1 substrate was spectrophotometrically measured in kinetic mode. The area under the ROC curve (AUC) was calculated to quantify the overall discriminative capacity of the variables. Results: ROC analyses showed that LDL-C/PON1 (AUC=0.66, p=0.02) and log (TG/PON1) (AUC=0.65, p=0.019) had higher predictive powers compared with LDL-C/HDL-C (AUC=0.55, p=0.221) and log (TG/HDL-C) (AUC=0.57, p=0.121) for CAD characterization in T2D patients. Also, AUCs of LDL-C/PON1 (AUC=0.74, p=0.014) and log (TG/PON1) (AUC=0.67, p=0.057) were higher than those of LDL-C/HDL-C (AUC=0.51, p=0.469) and log (TG/HDL-C) (AUC=0.53, p=0.364) for predicting CAD in T2D patients with HbA1c ≥7%. The multiple regression analysis with adjustments for gender, age, BMI, duration of T2D, metformin and statin therapy indicated that LDL-C/PON1 [adjusted OR=1.1 (0.99,1.23), p=0.085] and log (TG/PON1) [adjusted OR=3.76 (0.94,14.89), p=0.058] were independently predictors of CAD in T2D patients. Conclusions: New cardiometabolic biomarkers using PON1 provide an incremental predictive value compared with those using HDL-C in identifying subjects at increased risk for CAD among patients with T2D and poor glycemic control. This study sought to exploit the lipoprotein-related biomarkers of CAD from a more effective perspective in T2D. Our findings may help develop clinically cost-effective and functional laboratory measurements to evaluate HDL function.

Establishment of a sandwich ELISA for bovine plasma PON-1 and its predictive capabilities for dairy cows with fatty liver

The aim of this study to improve the clinical diagnosis of fatty livers (FL) in dairy cows by using the paraoxonase-1 (PON-1) enzyme as a detection index. Prokaryotic expression technology was used to generate recombinant bovine PON-1 protein. Mice were immunized with this protein to generate hybridoma cells, stably secreting anti-PON-1. Cells were injected into the peritoneal cavity of mice, and ascites were purified to generate bovine PON-1 monoclonal antibody. Rabbits were then immunized with this antigen, and a polyclonal antibody against bovine PON-1 was obtained. Using monoclonal and polyclonal antibodies, a double-antibody sandwich ELISA for plasma PON-1 was constructed. Plasma samples were collected from healthy (n = 13) and FL (n = 13) cows, and plasma PON-1 levels were detected using the PON-1 ELISA. Receiver operating characteristic curve (ROC) analysis was used to analyze correlations between PON-1 levels and FL. Results showed that the ideal working concentration of the monoclonal antibody was 0.8 mg/mL, and the quantitative detection limit was 90 ng/mL. Plasma PON-1 levels were significantly lower in FL cows, when compared with healthy animals. It is concluded that PON-1 ELISA predicts risk factors for dairy cows with FL. PON-1 levels in plasma can be used as an early warning indicator for FL and concentration of 61.87 nmol/L was identified as warning index.

The effect of paraoxonase 1 (PON1) gene polymorphisms T(-107)C and L55M and diet composition on serum PON1 activity in women.

The aim of this study was to evaluate the serum activity of PON1 in women according to SNPs L55M and T-107C and diet composition. Blood and serum samples from 26 women were used. DNA extraction, PCR and digestion with restriction enzymes of the PCR fragment were performed for genotyping the PON1 SNPs T-107C and L55M. Serum PON1 activity was measured in a single time point. Patients completed the semi-quantitative food frequency questionnaire and diet composition was estimated. Genotypic distribution for L55M SNP was 56% for the LL genotype, 32% for LM and 12% for MM; for the PON1 C(-107)T SNP it was 28% for the TT genotype, 41% for CT and 31% for CC. Individuals with C and L alleles had higher serum PON1 activity. Combining the two SNPs, we observed that individuals carrying the LL and CC genotypes had twice the activity of carriers of the TT and MM genotypes. Considering food intake, no significant difference was observed between genotypes and intake levels. PON1 T(-107)C and L55M SNPs exert a strong effect on serum PON1 activity in an additive manner and are more important than diet to predict serum PON1 activity.

Myeloperoxidase and Paraoxonase Activity in Acute Coronary Syndrome Patients

Background: Myeloperoxidase (MPO), an oxidative stress related enzyme is elevated in Coronary Artery Disease (CAD) and is involved in development of atherosclerotic plaque. Paraoxonase (PON) an enzyme protein associated with HDL serves as an antioxidant and plays an important role in preventing the formation of Oxidized LDL (OxLDL). This suggests a conflicting role of MPO and PON in development of cardiovascular disease and atherosclerosis.&#x0D; Aim: Present study was done to evaluate and compare MPO/PON ratio in Acute Coronary Syndrome (ACS) patients with controls. The study evaluates and compares the pro oxidant and pro inflammatory enzyme, MPO and anti-oxidant and anti-inflammatory enzyme, PON in ACS patients with controls. Oxidative marker, Malondialdehyde (MDA) and anti-oxidant marker, Reduced Glutathione (GSH) was assessed in ACS patients and compared with controls. An attempt was also made to correlate MPO/PON ratio to markers of oxidative stress (MDA and GSH).&#x0D; Methods: Cross-sectional study carried out in Dr. Somervell Memorial CSI Medical College, Trivandrum, Kerala, India.50 ACS patients from Cardiac Care Unit and 50 age and sex matched controls without CAD from Medical College Health Checkup was selected.&#x0D; Results: MPO and MPO/PON ratio were significantly high and PON was significantly lower in ACS patients compared to controls. Total cholesterol, Triglyceride, LDL, MDA were significantly high in ACS patients. Statistically significant positive correlation was observed between MPO/PON and MDA. Significant negative correlation was observed between MPO/PON and GSH.&#x0D; Conclusion: Myeloperoxidase and MPO/PON ratio was significantly high in ACS patients than controls. This is suggestive of the role of MPO in oxidative damage to lipoproteins in CAD patients. Prooxidant, Paraoxonase ,and antioxidant, GSH is lowered in ACS patients as a result of the increased oxidative stress. This study suggests that MPO/PON1 ratio can be used as a predictive marker of ACS.

Clusterin, paraoxonase 1, and myeloperoxidase alterations induce high-density lipoproteins dysfunction and contribute to peripheral artery disease; aggravation by type 2 diabetes mellitus.

Peripheral artery disease (PAD) is an atherosclerotic disorder affecting arteries of the lower limbs, the major risk factors including dyslipidemia and diabetes mellitus (DM). We aimed to identify alterations of the proteins in high-density lipoproteins (HDL) associated with HDL dysfunction in PAD patients. HDL2 and HDL3 were isolated from plasma of PAD patients with/without DM (PAD-DM/PAD) and healthy subjects (N). Apolipoprotein AI (ApoAI), ApoAII, ApoCIII, clusterin (CLU), paraoxonase 1 (PON1), myeloperoxidase (MPO), and ceruloplasmin (CP) were measured in HDL2 /HDL3 and plasma. Oxidation and glycation of the analyzed proteins were assessed as malondialdehyde-protein adducts (MDA) and advanced glycation end-products (AGE), respectively. The anti-inflammatory effect of HDL3 was estimated as its potential to reduce monocyte adhesion to tumor necrosis factor α-activated endothelial cells. We show that in PAD patients compared to N subjects: (i) HDL2 presented increased levels of MDA-PON1, AGE-PON1, AGE-ApoAI, ApoAII, ApoCIII, and CP levels, and decreased PON1 levels; (ii) HDL3 had increased levels of MDA- and AGE-CLU and -ApoAI, MDA-PON1, ApoCIII, CLU, MPO, CP, and reduced PON1 levels. All these alterations were exacerbated by DM. These changes were more pronounced in HDL3 , which had reduced anti-inflammatory potential in PAD and became pro-inflammatory in PAD-DM. In PAD patients' plasma, CLU levels and MPO specific activity increased, while PON1 specific activity decreased. In conclusion, HDL function is altered in PAD patients due to multiple modifications of associated proteins that are aggravated by DM. Plasma CLU, MPO, and PON1 could constitute indicators of HDL dysfunction and contribute to risk stratification in PAD patients.

Expression of Paraoxonase-2 in Different Stages of Cutaneous T Cell Lymphoma: Is It a Potential Biomarker for Aggressiveness?

Introduction: Paraoxonase 2 (PON2) is an intracellular membrane protein that belong to the PON gene family. This enzyme exerting a crucial role against production of reactive oxygen species within mithochondrial respiratory chain. Some reports provided clinical evidence for a link between PON2 and different types of malignancies and recently a growing attention has been focused on exploring the role of PON2 in cancer. Moreover, in contrast to solid tumors, a low expression levels of PON2 protein were detected in hematological malignancies like acute myeloid leukemia and B-cell lymphomas. The aim of this study was to investigate the role of PON2 in the cutaneous T cells Lymphoma (CTCL).Methods: We performed an immunohistochemistry analysis of PON2 protein expression at various stages CTCL. We analyzed PON2 protein using skin biopsies from stage I (n= 3) and stage II (n= 6) Mycosis Fungoides (MF) and stage III/IV (n= 5) erythrodermic MF/Sézary Syndrome (SS) and control (n=6) tissues. Values were expressed as percentage of PON2-positive staining cells, whereas the intensity of PON2 positivity was semi-quantitatively scored from negative to -/+/+++. Subsequent statistical analysis was carried out to explore the existence of correlations between intra-tumor enzyme level and clinical-pathological features at diagnosis.Results: In our preliminary study, results showed PON2 down-expression in SS compared to controls. Among CTCL, we found significant differences in enzyme levels between MF and erythrodermic MF/SS; in fact, PON2 expression was higher in patients with not erythrodermic MF compared to patients with erythrodermic MF/SS. (Table I) Moreover, we found no significant differences in enzyme levels between MF patients and controls.Conclusion: Our study is the first to demonstrate downregulation of PON2 intra-tumoral in SS patients while protein levels were higher in stage I and II MF patients. These findings seem to suggest that PON2 expression levels could be negatively related with tumor aggressiveness in CTCL: an interesting phenomenon where PON2 is upregulated in the early stages and downregulated in the late stages of CTCL. Further, in vitro studies are needed to clarify the mechanism related to PON2 expression. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

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.

Serum Paroxonase 1 level may be an Indicator and Predictor of the Severity of Androgenetic Alopecia

Background:Androgenetic alopecia (AGA) is a common stressful form of hair loss caused by androgen excess, genetic factors, and exposure to oxidative stress (OS) with the formation of reactive oxygen species (ROS). Paraoxonase 1 (PON1) is an enzyme synthesized in the liver bound to high-density lipoproteins to prevent lipid peroxidation.Aim:The aim of our work is to estimate serum PON1 level in patients with AGA and correlate its levels with disease severity which may help in determining if there is a role of ROS in pathogenesis of AGA.Subjects and Methods:This study was carried out as a case and control on 40 patients with AGA (diagnosed by typical clinical and dermoscopic finding) versus 40 control subjects. Blood samples were taken from all subjects to assess serum PON1enzyme using enzyme-linked immunosorbent assay kits.Results:There was a significant decrease in serum PON1 concentration level in AGA patients in comparison to controls, in addition, there was a significant decrease correlated with AGA severity (P < 0,001). The study proved that PON1 is considered highly sensitive and specific for AGA cases and a good predictive factor of AGA in healthy subjects.Conclusion:This is the first study done to reveal that the level of PON1 significantly decreased in AGA patients, which may give additional proof that OS has role in the pathogenesis of AGA and hence may help in the management of AGA by adding antioxidants in treatment.

Investigation of Inhibition of Busulfan (Chemotherapeutic Drug) on Human Serum Paraoxonase-1 (PON1)

Investigation of Inhibition of Busulfan (Chemotherapeutic Drug) on Human Serum Paraoxonase-1 (PON1)

Study of Correlation between the Paraoxonase 1 (PON1) Activity and Lipid Profile in Various Types of Coronary Heart Disease

Study of Correlation between the Paraoxonase 1 (PON1) Activity and Lipid Profile in Various Types of Coronary Heart Disease

Quorum quenching effect of recombinant Paraoxonase-1 enzyme against quorum sensing genes produced from Pseudomonas aeruginosa

Inhibition of quorum sensing (QS), also known as quorum quenching (QQ), is thought to provide means of fighting Pseudomonas aeruginosa infections, Paraoxonase-1 (PON1) enzymes has been selected as a candidate for inhibiting QS signaling activity of P. aeruginosa. This study was conducted to produce a recombinant human PON1 (hPON1) in a bacterial host and evaluate its QQ affect against QS genes produced from P. aeruginosa. Circulating lactonase activity of PON1 were measured in the 50 serum samples, the PON1 gene was amplified by using a NOVA Taq DNA polymerase. After RT-PCR, the purified restricted PCR product hPON1 gene was ligated into pETBlue-1 by utilizing Clonables™ 2× Ligation Premix. Transformation to Nova Blue Singles™ Competent Cells and Tuner (DE3) pLacI was done by using (heat shock) method and the expression of QS gene was measured by using KAPA SYBR FAST qPCR. Results revealed that hPON1 gene was successfully cloned in to pETBlue-1 and white colonies of Nova Blue E. coli recombinant and was observed in Luria-Bertani (LB) agar plates contain IPTG as an inducer and X-gal as an indicator, the relative gene expression data obtained showed loss of AHL concentration by about 14-fold reduction in lasI gene expression while lasR showed 3-fold reduction when compared to the untreated cells. The reduction in rhlI gene synthase following recombinant PON1 treatment by 6-fold while in rhIR gene synthase was 3- fold reduction when compared to the untreated cells. Our study showed that, in addition of being generally effective, hPON1 could be a suitable candidate as a QQ agent sufficient to inhibit the virulence factors produced by P. aeruginosa.

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.

Association of anti-oxidative capacity of HDL with subclinical atherosclerosis in subjects with and without non-alcoholic fatty liver disease

BackgroundNon-alcoholic fatty liver disease (NAFLD) patients are at a substantial risk for developing cardiovascular disease (CVD). High-density lipoprotein (HDL) is well known to have protective effects against the development of atherosclerotic CVD. One of the major antiatherogenic effects of HDL is its anti-oxidative function.ObjectivesThis study investigated the association of anti-oxidative capacity of HDL with subclinical atherosclerosis in NAFLD and non-NAFLD subjects.MethodsA total of 143 subjects including 51 NAFLD and 92 control subjects were included in this case–control study. HDL oxidative index (HOI) was determined spectrophotometrically using a cell-free method in the presence of a fluorescent substrate dichlorofluorescein diacetate (DCFDA). Paraoxonase 1 (PON1) activity, superoxide dismutase (SOD) activity, and malondialdehyde (MDA) plasma levels were assessed in both groups.ResultsThe NAFLD patients with impaired HDL anti-oxidative function (HOI ≥ 1) had higher MDA levels, aspartate amino transferase (AST), liver stiffness (LS), and carotid intima-media thickness (cIMT) values compared to the controls. HDL oxidative index (HOI) was positively correlated with MDA levels and cIMT and negatively correlated with SOD activity.ConclusionsHigher circulating levels of MDA were associated with the impaired anti-oxidative function of HDL in NAFLD. The impaired anti-oxidative capacity of HDL might be related to NAFLD severity and subclinical atherosclerosis in NAFLD patients.