Paraoxonase 2 is an ER chaperone that regulates the epithelial Na+ channel.

The mammalian paraoxonases (PONs) have been linked to protection against oxidative stress. However, the physiological roles of members in this family (PON1, PON2, and PON3) are still being characterized. PON2 and PON3 are expressed in the aldosterone-sensitive distal nephron of the kidney and have been shown to negatively regulate expression of the epithelial sodium channel (ENaC), a trimeric ion channel that orchestrates salt and water homeostasis. To date, the nature of this phenomenon has not been explored. Therefore, to investigate the mechanism by which PON2 regulates ENaC, we expressed PON2 along with the ENaC subunits in fisher rat thyroid (FRT) cells, a system that is amenable to biochemical analyses of ENaC assembly and trafficking. We found that PON2 primarily resides in the endoplasmic reticulum (ER) in FRT cells, and its expression reduces the abundance of each ENaC subunit, reflecting enhanced subunit turnover. In contrast, no effect on the levels of mRNAs encoding the ENaC subunits was evident. Inhibition of lysosome function with chloroquine or NH4Cl did not alter the inhibitory effect of PON2 on ENaC expression. In contrast, PON2 accelerates ENaC degradation in a proteasome-dependent manner and acts before ENaC subunit ubiquitination. As a result of enhanced ENaC subunit ubiquitination and degradation, both channel surface expression and ENaC-mediated Na+ transport in FRT cells were reduced by PON2. Together, our data suggest that PON2 functions as an ER chaperone to monitor ENaC biogenesis and redirects the channel for ER-associated degradation.

Dietary Avian Proteins Are Comparable to Soybean Proteins on the Atherosclerosis Development and Fatty Liver Disease in Apoe-Deficient Mice.

BACKGROUND AND AIM: The type and amount of dietary protein has become a topic of renewed interest in light of their involvement in metabolic diseases, atherosclerosis and thrombosis. However, little attention has been devoted to the effect of avian proteins despite their wide human consumption. The aim was to investigate the influence of chicken and turkey as sources of protein compared with that of soybean on atherosclerosis and fatty liver disease. METHODS AND RESULTS: To this purpose, male and female Apoe-deficient were fed purified Western diets differing in their protein sources for 12 weeks. After this period, blood, liver, aortic tree and heart base samples were taken for analyses of plasma lipids and atherosclerosis. Plasma triglycerides, non-esterified fatty acids, esterified cholesterol levels and radical oxygen species in lipoproteins changed depending on the diet and sex. Females consuming the turkey protein-containing diet showed decreased atherosclerotic foci, as evidenced by the en face atherosclerosis analyses. The presence of macrophages and smooth muscle cells in plaques were not modified, and no changes were observed in hepatic lipid droplets in the studied groups either. Paraoxonase activity was higher in the group consuming turkey protein without sex differences, but only in females, it was significantly associated with aortic lesion areas. CONCLUSIONS: Compared to soybean protein, the consumption of avian proteins depending on sex resulted in similar or lower atherosclerosis development and comparable hepatic steatosis.

Altered high-density lipoprotein composition and functions during severe COVID-19.

Coronavirus disease 2019 (COVID-19) pandemic is affecting millions of patients worldwide. The consequences of initial exposure to SARS-CoV-2 go beyond pulmonary damage, with a particular impact on lipid metabolism. Decreased levels in HDL-C were reported in COVID-19 patients. Since HDL particles display antioxidant, anti-inflammatory and potential anti-infectious properties, we aimed at characterizing HDL proteome and functionality during COVID-19 relative to healthy subjects. HDLs were isolated from plasma of 8 severe COVID-19 patients sampled at admission to intensive care unit (Day 1, D1) at D3 and D7, and from 16 sex- and age-matched healthy subjects. Proteomic analysis was performed by LC-MS/MS. The relative amounts of proteins identified in HDLs were compared between COVID-19 and controls. apolipoprotein A-I and paraoxonase 1 were confirmed by Western-blot analysis to be less abundant in COVID-19 versus controls, whereas serum amyloid A and alpha-1 antitrypsin were higher. HDLs from patients were less protective in endothelial cells stiumalted by TNFα (permeability, VE-cadherin disorganization and apoptosis). In these conditions, HDL inhibition of apoptosis was blunted in COVID-19 relative to controls. In conclusion, we show major changes in HDL proteome and decreased functionality in severe COVID-19 patients.

Identification and characterization of sequence signatures in the Bacillus subtilis promoter Pylb for tuning promoter strength.

OBJECTIVE: To thoroughly characterize the Pylb promoter and identify the elements that affect the promoter activity. RESULT: The sequences flanking the - 35 and - 10 box of the Pylb promoter were divided into six segments, and six random-scanning mutant promoter libraries fused to an enhanced green fluorescent protein EGFP were made and analyzed by flow cytometry. Our results showed that the four nucleotides flanking the - 35 box could mostly influence the promoter activity, and this influence was related to the GC content. The promoters mutated in these regions were successfully used for expressing the gene ophc2 encoding organophosphorus hydrolase (OPHC2) and the gene katA encoding catalase (KatA). CONCLUSION: Our work identified and characterized the sequence signatures of the Pylb promoter that could tune the promoter strength, providing further information for the potential application of this promoter. Meanwhile, the sequence signatures have the potential to be used for tuning gene expression in enzyme production, metabolic engineering, and synthetic biology.

Effects of the storage of breast milk at different temperatures on total antioxidant capacity, total oxidant status, and paraoxonase-1 level.

Konak M, Minici M, Tarakçi N, Altunhan H, Toker A, Örs R. Effects of the storage of breast milk at different temperatures on total antioxidant capacity, total oxidant status, and paraoxonase-1 level. Turk J Pediatr 2019; 61: 1-6. Breast milk is a well-balanced ideal nutritional source with high bioavailability for infants. As being a fresh, biological and dynamic product, changes in the breast milk during these storage periods have been the subject of ongoing research. This study aims to evaluate total antioxidant capacity (TAC), total oxidant status (TOS), and paraoxonase-1 (PON-1) levels of fresh and freezestored breast milk. Ten cc of breast milk was obtained from the mothers as the days between 10 and 15 in the morning within a 1-hour period. TAC, TOS, and PON-1 levels were evaluated in the fresh breast milk. Collected breast milk samples were divided into two groups for storage at -20°C or -80°C. Stored samples were tested for TAC, TOS, and PON-1 levels after 72 hours. The highest TAC level was detected in fresh breast milk (p < 0.05). The TOS levels of fresh breast milk showed a statistically significant reduction in rate after storage. The TOS levels at -20°C and -80°C were significantly lower at -80°C (p < 0.05). Our study results show that oxidant and antioxidant activities are at the maximum level in the fresh breast milk. In terms of antioxidant status the effect of freezing temperatures hasn`t been determined. We conclude that it is more convenient to store the breast milk at -80°C than to store at -20°C in terms of preserving the storage TOS level.

Global plasma protein profiling reveals DCM characteristic protein signatures.

To identify potential biomarkers supporting better phenotyping and to improve understanding of the pathophysiology of dilated cardiomyopathy (DCM), this study comparatively analyzed plasma protein profiles of DCM patients and individuals with low normal and normal left ventricular ejection fraction (LVEF) by mass spectrometry. After plasma depletion using a MARS Hu-6 column, global proteome profiling was performed using a LTQ-Orbitrap Velos mass spectrometer. To compare and confirm results, two different discovery sets of samples were investigated. Differentially abundant proteins are involved in lipid metabolism, coagulation, and acute phase response. Serum paraoxonase 1 (PON1), cystatin C, lysozyme C, apolipoprotein A-II, and apolipoprotein M were validated by targeted protein analysis in a third independent patient cohort. Additionally, PON1 levels were also determined by an ELISA. These data highlight PON1 as a potential marker for differentiating DCM patients not only from patients with normal LVEF, but also from heart failure patients with preserved ejection fraction. The results highlight lipid metabolism and inflammation as the major pathways being altered in DCM patients in comparison to patients presenting with suspicious myocarditis to the hospital. SIGNIFICANCE: Several studies focused on the identification of heart failure (HF) associated protein signatures in blood plasma, but only few that are largely based on only small sample series considered specific HF pathologies. Therefore, we performed a comparative global blood plasma protein profiling of a larger sample of individuals with reduced left ventricular ejection fraction (LVEF) classified as dilated cardiomyopathy patients and individuals with normal LVEF but presenting with suspicious myocarditis. DCM patients displayed altered levels of proteins involved in lipid metabolism, coagulation, and acute phase response. The most reliable candidates, such as serum paraoxonase 1 (PON1), cystatin C, lysozyme C, apolipoprotein A-II, and apolipoprotein M were validated by targeted protein analysis in an independent patient cohort. PON1 levels were also determined by an ELISA. These data highlight PON1 as a potential marker for differentiating DCM patients not only from patients with normal LVEF, but also from heart failure patients with preserved ejection fraction.

Investigating the effect of intracameral cefuroxime on oxidative stress and apoptosis in the rat cornea / Investigando o efeito de cefuroxima intracameral sobre o estresse oxidativo e a apoptose na córnea de ratos

ABSTRACT PURPOSE: We examined the effect of intracameral administration of cefuroxime on oxidative stress and endothelial apoptosis in rat corneal tissue. METHODS: In total, 30 rats were divided into 3 groups of 10 rats each (intracameral administration of cefuroxime 0.1 mg/0.01 mL (cefuroxime group); intracameral administration of balanced salt solution 0.01 mL (control group); or absence of intracameral injection (sham group). Corneal endothelial apoptosis was assessed by immunohistochemical analysis using caspase-3 and caspase-8. Total oxidant status, total antioxidant status, oxidative stress index, and paraoxonase and arylesterase levels were examined in corneal endothelial tissue and serum. RESULTS: Paraoxonase levels in the serum were significantly different between the sham and cefuroxime groups (p=0.027). A significant difference was also observed in total oxidant status levels between the cefuroxime and balanced salt solution groups (p=0.023). In addition, there were significant differences in total antioxidant status levels in corneal tissue between the cefuroxime and sham groups (p<0.001) and between the cefuroxime and balanced salt solution groups (p<0.001). Furthermore, significant differences were also observed in oxidative stress index levels between the cefuroxime and balanced salt solution groups (p=0.001) and between the cefuroxime and sham groups (p=0.026). According to the immunohistochemical staining results, a significant association with caspase-3 activity existed between the cefuroxime and balanced salt solution groups (p=0.007), while no significant difference was found with caspase-8 activity (p=0.541). Caspase-3 activity exhibited a significant relationship between the sham and balanced salt solution groups (p=0.018), but no relationship was found with caspase-8 activity (p=0.623). CONCLUSION: Immunohistochemical examination revealed that intracameral cefuroxime increased apoptosis when compared to the sham and balanced salt solution groups. Moreover, intracameral cefuroxime increased oxidative stress in the cornea and simultaneously induced apoptosis.

RESUMO OBJETIVO: Examinamos o efeito da administração intracameral da cefuroxima sobre o estresse oxidativo e a apoptose endotelial no tecido corneano de ratos. MÉTODOS: No total, 30 ratos foram divididos em 3 grupos de 10 ratos cada (administração intracameral de cefuroxima 0,1 mg/0,01 mL (grupo cefuroxima), administração intracameral de solução salina balanceada 0,01 mL (grupo controle) ou ausência de injeção intracameral (grupo sham)). A apoptose endotelial da córnea foi avaliada por análise imuno-histoquimica usando caspase-3 e -8. O status oxidante total, o status antioxidante total, o índice de estresse oxidativo e os níveis de a paraoxonase e arilesterase foram investigados no tecido endotelial da córnea e no soro. RESULTADOS: Os níveis de paraoxonase no soro foram significativamente diferentes entre os grupos sham e cefuroxima (p=0,027). Foi também observada uma diferença significativa nos níveis de estado oxidante total entre os grupos cefuroxima e solução salina balanceada (p=0,023). Além disso, houve diferenças significativas nos níveis de status antioxidante total no tecido da córnea entre os grupos cefuroxima e sham (p<0,001) e entre os grupos cefuroxima e solução salina balanceada (p<0,001). Diferenças significativas também foram observadas nos níveis do índice de estresse oxidativo entre os grupos cefuroxima e solução salina balanceada (p=0,001) e entre os grupos cefuroxima e sham (p=0,026). De acordo com os resultados de coloração imuno-histoquimica, houve associação significativa com a atividade da caspase-3 entre os grupos cefuroxima e solução salina balanceada (p=0,007), enquanto não houve diferença significativa com a atividade da caspase-8 (p=0,541). A atividade da caspase-3 exibiu uma relação significativa entre os grupos sham e solução salina balanceada (p=0,018), mas nenhuma relação foi encontrada com a atividade da caspase-8 (p=0,623). CONCLUSÃO: O exame imuno-histoquímico revelou que a cefuroxima intracameral aumentou a apoptose quando comparada com os grupos sham e solução salina balanceada. Além disso, a cefuroxima intracameral aumentou o estresse oxidativo na córnea e induziu simultaneamente a apoptose.

A Case-Control Study on the Oxidative Status in Women with Polycystic Ovary Syndrome Treated with Clomiphene Citrate.

BACKGROUND Polycystic ovary syndrome (PCOS) is associated with infertility or subfertility due to impaired ovulation. Clomiphene citrate is a first-line treatment option for the induction of ovulation in women with PCOS. The study aimed to compare markers of oxidative stress or the total oxidative status (TOS), total antioxidant status (TAS), and levels of paraoxonase-1 (PON-1) before and after day 21 of the menstrual cycle in women with PCOS treated with clomiphene citrate to induce ovulation. MATERIAL AND METHODS The study included 75 women who were divided into a control group (n=25) that included healthy untreated women, untreated women with PCOS (n=24) who had spontaneous ovulation, and women with PCOS who were treated with clomiphene citrate for subfertility or infertility (n=26) (the PCOS-CC group). The study group was treated for five days with clomiphene citrate (50 mg/day). Peripheral venous blood was sampled on day 3 and day 21 of the menstrual cycle from women in all three groups, and TAS, TOS, and PON-1 levels were measured. RESULTS In all three groups, TAS and PON levels were significantly reduced and TOS values were significantly increased on day 21 of the menstrual cycle. Comparison of TAS, TOS, and PON-1 levels between the three study groups on day 3 and day 21 of the menstrual cycle showed no significant difference (p=0.600, p=0.223, p=0.956, respectively). CONCLUSIONS This study showed that spontaneous ovulation occurs in association with an oxidative state in healthy women and women with PCOS, and women with PCOS following treatment with clomiphene citrate.

Investigating the effect of intracameral cefuroxime on oxidative stress and apoptosis in the rat cornea.

PURPOSE: We examined the effect of intracameral administration of cefuroxime on oxidative stress and endothelial apoptosis in rat corneal tissue. METHODS: In total, 30 rats were divided into 3 groups of 10 rats each (intracameral administration of cefuroxime 0.1 mg/0.01 mL (cefuroxime group); intracameral administration of balanced salt solution 0.01 mL (control group); or absence of intracameral injection (sham group). Corneal endothelial apoptosis was assessed by immunohistochemical analysis using caspase-3 and caspase-8. Total oxidant status, total antioxidant status, oxidative stress index, and paraoxonase and arylesterase levels were examined in corneal endothelial tissue and serum. RESULTS: Paraoxonase levels in the serum were significantly different between the sham and cefuroxime groups (p=0.027). A significant difference was also observed in total oxidant status levels between the cefuroxime and balanced salt solution groups (p=0.023). In addition, there were significant differences in total antioxidant status levels in corneal tissue between the cefuroxime and sham groups (p<0.001) and between the cefuroxime and balanced salt solution groups (p<0.001). Furthermore, significant differences were also observed in oxidative stress index levels between the cefuroxime and balanced salt solution groups (p=0.001) and between the cefuroxime and sham groups (p=0.026). According to the immunohistochemical staining results, a significant association with caspase-3 activity existed between the cefuroxime and balanced salt solution groups (p=0.007), while no significant difference was found with caspase-8 activity (p=0.541). Caspase-3 activity exhibited a significant relationship between the sham and balanced salt solution groups (p=0.018), but no relationship was found with caspase-8 activity (p=0.623). CONCLUSION: Immunohistochemical examination revealed that intracameral cefuroxime increased apoptosis when compared to the sham and balanced salt solution groups. Moreover, intracameral cefuroxime increased oxidative stress in the cornea and simultaneously induced apoptosis.

Effect of two treatments on changes in serum acute phase protein concentrations in dogs with clinical leishmaniosis.

The objective of this study was to compare changes in serum concentrations of acute phase proteins (APPs) and paraoxanase (PON-1) in response to two treatments in dogs with leishmaniosis (CanL). For this purpose, 20 dogs with CanL were assigned to two treatment groups: antimonial plus allopurinol (Group G, n=12) and miltefosine plus allopurinol (Group M, n=8). Serum concentrations of PON-1 and APPs including C-reactive protein, haptoglobin (Hp), ferritin (Ft) and albumin were monitored over a period of 3 months after treatment. At the beginning of the study (day 0), most of the dogs had APP abnormalities. None of the variables differed significantly between groups in the first or subsequent visits. There was a significantly higher reduction in serum Ft in Group G than in Group M from day 0 to day 30 (P=0.0085), and also from day 0 to day 90 (P=0.0214). There was a higher increase in serum PON-1 in Group G than in than Group M from day 0 to day 30 (P=0.0039), and also from day 0 to day 90 (P=0.0404). This is the first report of APPs in dogs with natural clinical leishmaniosis treated with miltefosine. There was faster resolution of serum APP concentrations in dogs treated with antimonials (P<0.05).

Surface display of organophosphorus-degrading enzymes on the recombinant spore of Bacillus subtilis.

Organophosphorus-degrading enzymes show high hydrolysis efficiency and provide an environmentally friendly solution to the pollution of organophosphorus compound. However, poor enzyme stability and tedious purification process have limited practical applications. Spore-based display system can provide many advantages, such as safety, low cost, easy preparation and high resistance to harsh conditions. Recently, we have constituted the recombinant spore displaying organophosphorus hydrolase and organophosphorus acid anhydrolase. In the spore display systems, recombinant spores could be reliably produced and normal sporulation was not affected; the activities of recombinant spores were 15.81 and 10.67 U/mg spores (dry weight) respectively; furthermore, the recombinant spores exhibited significantly enhanced resistance to various harsh conditions compared to free-form enzymes. These results indicated that the spore display could contribute to the practical application of organophosphorus-degrading enzymes and provide a promising solution to bioremediation of organophosphorus compounds.

Why Should Psychiatrists and Neuroscientists Worry about Paraoxonase 1?

BACKGROUND: Nitro-oxidative stress (NOS) has been implicated in the pathophysiology of psychiatric disorders. The activity of the polymorphic antioxidant enzyme paraoxonase 1 (PON1) is altered in diseases where NOS is involved. PON1 activity may be estimated using different substrates some of which are influenced by PON1 polymorphisms. OBJECTIVES: 1) to review the association between PON1 activities and psychiatric diseases using a standardized PON1 substrate terminology in order to offer a state-of-the-art review; and 2) to review the efficacy of different strategies (nutrition, drugs, lifestyle) to enhance PON1 activities. METHODS: The PubMed database was searched using the terms paraoxonase 1 and psychiatric diseases. Moreover, the database was also searched for clinical trials investigating strategies to enhance PON1 activity. RESULTS: The studies support decreased PON1 activity as determined using phenylacetate (i.e., arylesterase or AREase) as a substrate, in depression, bipolar disorder, generalized anxiety disorder (GAD) and schizophrenia, especially in antipsychotic-free patients. PON1 activity as determined with paraoxon (i.e., POase activity) yields more controversial results, which can be explained by the lack of adjustment for the Q192R polymorphism. The few clinical trials investigating the influence of nutritional, lifestyle and drugs on PON1 activities in the general population suggest that some polyphenols, oleic acid, Mediterranean diet, no smoking, being physically active and statins may be effective strategies that increase PON1 activity. CONCLUSION: Lowered PON1 activities appear to be a key component in the ongoing NOS processes that accompany affective disorders, GAD and schizophrenia. Treatments increasing attenuated PON1 activity could possibly be new drug targets for treating these disorders.

Identification of Carboxylesterase, Butyrylcholinesterase, Acetylcholinesterase, Paraoxonase, and Albumin Pseudoesterase in Guinea Pig Plasma through Nondenaturing Gel Electrophoresis.

Drugs to protect against nerve agent toxicity are tested in animals. The current preferred small animal model is guinea pigs because their plasma bioscavenging capacity resembles that of NHP. We stained nondenaturing polyacrylamide slab gels with a variety of substrates, inhibitors, and antibodies to identify the esterases in heparinized guinea pig plasma. An intense band of carboxylesterase activity migrated behind albumin. Minor carboxylesterase bands were revealed after background activity from paraoxonase was inhibited by using EDTA. The major butyrylcholinesterase band was a disulfide-linked dimer. Incubation with the antihuman butyrylcholinesterase antibody B2 18-5 shifted the butyrylcholinesterase dimer band to slower migrating complexes. Carboxylesterases were distinguished from butyrylcholinesterase by their sensitivity to inhibition by bis-p-nitrophenyl phosphate. Acetylcholinesterase tetramers formed a complex with the antihuman acetylcholinesterase antibody HR2. Organophosphorus toxicants including cresyl saligenin phosphate, dichlorvos, and chlorpyrifos oxon irreversibly inhibited the serine esterases but not paraoxonase. Albumin pseudoesterase activity was seen in gels stained with α- or ß-naphthyl acetate and fast blue RR. We conclude that guinea pig plasma has 2 types of carboxylesterase, butyrylcholinesterase dimers and 5 minor butyrylcholinesterase forms, a small amount of acetylcholinesterase tetramers, paraoxonase, and albumin pseudoesterase activity. A knockout mouse with no carboxylesterase activity in plasma is available and may prove to be a better model for studies of nerve agent toxicology than guinea pigs.

Substrates for Paraoxonase.

BACKGROUND: Paraoxonase (PON) is a family of calcium-dependent hydrolases, which is related to many diseases. Elucidation of PON physiological roles, active center and all applications in medical fields are dependent on its substrates. OBJECTIVE: The reports about PON substrates scattered in a long span of period are collected to afford clue for drug design, diagnosis of PON status and other academic purposes. METHOD: PON substrates from 133 references are classified and compared. Structurally, PON substrates are generally classified as organic phosphorous esters, lactones and arylesters. Some phosphoramidates, organophosphorous obidoximes, aryl carboxylic acid amides and special fatty alcohol esters as PON substrates are also included. RESULTS: The electron nature, steric hindrance and hydrophilicity of substrate substituents affecting the PON catalytic ability, binding ability and specificities are discussed. Drugs, prodrugs and naturally endogenous molecules in life processes activated or inactivate by PON are reviewed. Interestingly, some organophosphate and lactone substrates are preferably hydrolyzed by one of the PON1R192Q allozymes, and such a substrate is generally essential for differentiating the three PON1192R phenotypes by using a dual-substrate method. Intricately, some chiral substrates are hydrolyzed by PON stereoselectively. CONCLUSION: As more substrates are synthesized and characterized, more facts about PON structure and catalytic properties (including PON active center and catalytic mechanism) will be revealed, and therefore the use of PON as a drug target or as an accurate disease marker will be achieved.

Paraoxonase 1 (PON1) activity in serum, follicular fluid and seminal plasma of sheep.

This work aimed to describe the activity of paraoxonase 1 (PON1) in serum, follicular fluid and seminal plasma of sheep. Average serum PON1 activity was 286.8 ± 96.2 U/ml in females and 237.6 ± 18.9 U/ml in males. There was a positive correlation between PON1 activity in serum and follicular fluid in females, being twice higher in serum than in follicular fluid (148.8 ± 15.7 U/ml). PON1 activity in males' serum was 10-fold higher than in seminal plasma (21.18 ± 14.2 U/ml), and there was no correlation between PON1 activity in both compartments. Finally, this work suggests that PON1 activity of in sheep is higher compared to other mammalian species, and there is an association between PON1 in serum and follicular fluid only.

Effect of the Oxidant-Antioxidant System in Seminal Plasma on Varicocele and Idiopathic Infertility in Male Humans.

BACKGROUND: The aim of this study was to investigate seminal oxidant-antioxidant activity in idiopathic and varicocele infertility in men. METHODS: Total anti-oxidant capacity (TAC), total oxidant status (TOS), paraoxonase (PON1), aryl esterase (ARE), and total thiol levels (TTL) were measured in seminal plasma with an autoanalyzer. The TOS/TAC ratio was determined as the oxidative stress index (OSI). A histopathological evaluation of the sperm was performed in the andrology laboratory of the hospital. Number, motility, morphology, volume, pH, and leukocytes were evaluated in all samples according to World Health Organization criteria. The three study groups were as follows: G1, males with idiopathic infertility; G2, males with varicocele infertility; and G3, normal healthy males (had fathered a child in the last 2 years). Each group was composed of 36 men (age, 25 - 40 years). The Rel Assay Diagnostics kit was used to determine the levels of the parameters. The study was conducted according to the principles of the declaration of Helsinki and was approved by Sakarya University Medicine Faculty Ethic Committee (e.n: 16214662/050.01.04/07). Statistical significance was assumed if p < 0.05. All statistical evaluations were performed using SPSS (version 20.0 for Windows; SPSS, Inc., Chicago, IL, USA). RESULTS: No differences were detected between the mean values of antioxidant parameters among the three groups (Kruskal-Wallis test). The p-values of the test parameters (TAC, TOS, PON1, ARE, TTL, OSI) are respectively: 0.494, 0.548, 0.068, 0.151, 0.202, 0.873. The antioxidant parameters of all subjects were compared using the MannWhitney U-test in both groups as fertile (G3) and infertile (G1 + G2). The PON1 levels in infertile subjects were significantly higher than those in fertile subjects. There was a statistically significant difference (p = 0.042). The other antioxidant parameters had no statistically significant difference (p > 0.05). The ARE was not performed in group 3 (control) due to a methodological problem. CONCLUSIONS: PON1 levels in infertile subjects were significantly higher than those of fertile subjects.

Assessment of the relationship between serum paraoxonase activity and epicardial adipose tissue in hemodialysis patients.

PURPOSE: Paraoxonase-1 (PON-1) is a high-density lipoprotein-associated (HDL) enzyme, which has been shown to reduce susceptibility to low-density lipoprotein (LDL) peroxidation. Epicardial adipose tissue (EAT) is a marker of atherosclerosis. The aim of this study was to determine the relationship between PON-1 activity and EAT in hemodialysis (HD) patients. METHODS: This is a cross-sectional study conducted on 72 (43 males) HD patients with end-stage renal disease. Serum levels for lipid profiles, C-reactive protein, calcium, phosphate, and parathyroid hormone were measured. PON-1 activity was also measured and compared to the rate of enzymatic hydrolysis of paraoxon to p-nitrophenol. Echocardiography was used to measure EAT thickness (EATT). The correlation between PON-1 and EATT was assessed, while independent predictors of EATT in HD patients were similarly assessed using multivariate regression analysis. RESULTS: There was a significant low mean value of PON-1 activity in HD patients compared with the control group (82.1 ± 31.6 vs. 164.3 ± 61.5 U/l, p = 0.0001) and significant high mean value of EATT in HD patients, compared with controls (6.2 ± 1.7 vs. 3.9 ± 1.1 mm, p = 0.0001). In addition, there was a significant negative correlation between PON-1 activity and EATT (r = -0.484, p = 0.0001) and a significant positive correlation between PON-1 activity and HDL-C (r = 0.417, p = 0.0003). PON-1, total cholesterol, triglycerides, LDL, HDL, age, and body mass index were found to be independent predictors of EATT. CONCLUSION: Our study demonstrated that PON-1 activity was significantly lower in HD patients compared with healthy controls and that PON-1 activity was inversely correlated with EATT in this population.

Association between paraoxonase 1 (PON1) enzyme activity, PON1 C(−107)T polymorphism, nutritional status, and lipid profile in children

BACKGROUND: Paraoxonase 1 (PON1) is an enzyme that possesses anti-atherogenic and anti-inflammatory properties with serum levels determined by genetic and exogenous factors. Lower serum PON1 arylesterase activity is associated to metabolic alterations related to childhood overweight and onset and/or development of diabetes and CVD later in life. However, data on the relationship between genetic PON1 polymorphisms and nutritional status as well as lipid profile in children are limited. To investigate the distribution of the C(−107)T PON1 gene polymorphism and its relation with serum PON1 enzyme activity, nutritional status and lipid profile in children. METHODS: A cross-sectional study was performed including 73 children aged 5 to 7 years who attended public pediatric clinics. PON1 C(−107)T, arylesterase activity, body mass index for the age, and serum lipid profile were evaluated. RESULTS: PON1 activity was higher in overweight children compared to the normal weight ones (p= 0.02). The genotypic frequency did not differ between the two groups (p> 0.05). Carriers of CC genotype had higher enzyme activity than T allele carriers, and this difference was greater among normal weight children. HDL levels were higher among normal weight children carrying CC genotype, compared to those carrying the T allele (p< 0.01).CONCLUSION: The PON1 C(−107)T polymorphism is associated with higher serum enzyme activity in children, as observed previously in adults. In addition, this polymorphism also shows association to higher high density lipoprotein (HDL) levels and serum PON1 arylesterase activity in the normal weight children studied.

[Oxidative stress and semen parameters in the serum and seminal plasma of infertile men with chronic viral hepatitis].

OBJECTIVE: To investigate the malondialdehyde (MDA) level and paraoxonase-1 (PON-1) activity in the serum and seminal plasma of infertile men with chronic viral hepatitis and their influence on the semen parameters of the patients. METHODS: We collected serum and semen samples from 42 infertile men, 45 infertile males with chronic viral hepatitis, and 50 healthy fertile men as controls. We measured the MDA level in the serum and seminal plasma by spectrophotometry, detected the PON-1 activity by spectrophotometry, and determined the sperm DNA fragmentation index (DFI) by acridine orange fluorescence staining. RESULTS: The MDA level was significantly higher but the PON-1 activity remarkably lower in the serum and seminal plasma of the infertile males with chronic viral hepatitis than in the healthy controls and infertile patients (P <0.01 or P <0.05). Total sperm motility and sperm survival rate were significantly lower while the sperm DFI markedly higher in the former than in the latter two groups (P <0.01 or P <0.05). No statistically significant difference was found among the three groups in sperm concentration (P >0.05). The WBC counts in the semen of the infertile and infertile with chronic viral hepatitis groups were significantly higher than that in the health controls (P <0.05). The MDA level and PON-1 activity in the seminal plasma were positively correlated with those in the serum in the infertile males with chronic viral hepatitis (r=0.57 or 0.48, P <0.01). CONCLUSION: Virus-induced chronic active hepatitis enhances oxidative stress in the reproductive system, aggravates sperm damage, and affects sperm quality parameters.

Measurement of activity and concentration of paraoxonase 1 (PON-1) in seminal plasma and identification of PON-2 in the sperm of boar ejaculates.

This study revealed and characterised the presence of the antioxidant enzymes paraoxonase (PON) type 1 (PON-1, extracellular) and type 2 (PON-2, intracellular) in boar semen. To evaluate PON-1, an entire ejaculate from each of ten boars was collected and the seminal plasma was harvested after double centrifugation (1,500g for 10 min). Seminal plasma was analysed for concentration as well as enzymatic activity of PON-1 and total cholesterol levels. Seminal-plasma PON-1 concentration ranged from 0.961 to 1.670 ng/ml while its enzymatic activity ranged from 0.056 to 0.400 IU/ml, which represent individual variance. Seminal-plasma PON-1 concentration and enzymatic activity were negatively correlated (r = -0.763; P < 0.01). The activity of seminal-plasma PON-1 negatively correlated with ejaculate volume (r = -0.726, P < 0.05), but positively correlated with sperm concentration (r = 0.654, P < 0.05). Total seminal-plasma cholesterol concentration positively correlated with PON-1 activity (r = 0.773; P < 0.01), but negatively correlated with PON-1 concentration (r = -0.709; P < 0.05). The presence of intracellular PON-2 was determined via immunocytochemistry in spermatozoa derived from artificial insemination. PON-2 localised to the post-acrosomal area of the sperm head and principal piece of the tail in membrane-intact spermatozoa. In summary, PON is present in boar semen, with PON-1 at low levels in seminal plasma and PON-2 within the spermatozoa. Further studies are needed to characterise the relationship between antioxidant PONs with sperm and other seminal-plasma parameters.