Plasma Paraoxonase Research Articles

Paraoxonase-1 enzyme activity in rheumatoid arthritis patients: association with carotid intima-media thickness?

Objectives The aim was to find the relationship of biochemical determinants of paraoxonase-1 (PON1) enzyme activity with carotid intima-media thickness (IMT) as a surrogate marker of atherosclerotic cardiovascular (CV) disease risk in patients with rheumatoid arthritis (RA). Background There is strong correlation between patients with RA and CV morbidity and mortality that cannot be explained by traditional risk factors alone. And this could be due to abnormal function of high-density lipoproteins (HDL). HDL promotes cholesterol efflux, as well as protects low-density lipoprotein (LDL) against oxidation, and this ability has been referred to as an 'anti-inflammatory' function because the lipid oxidation products derived from LDL are highly proinflammatory. PON1 is an HDL-associated enzyme that promotes antioxidant and anti-inflammatory properties of HDL by preventing the formation of oxidized LDL and inactivating oxidized phospholipids. Patients and methods The authors conducted a case–control study, including 30 RA patients and 20 controls, enrolled in Menoufia, Egypt. B-mode Doppler ultrasound imaging to measure carotid IMT, C-reactive protein (CRP), erythrocyte sedimentation rate, lipid profile, and PON1 activity were measured. Results RA patients tended to be more dyslipidemic as evidenced by decreased HDL and increased total cholesterol, tryglycerides (TGD), and LDL, which showed increased carotid IMT and decreased PON1 activity than the control group. Patients with carotid plaque tended to be more dyslipidemic and plasma PON1 activity tended to be lower than in patients without carotid plaque. A significant correlation between plasma PON1 activity and systemic inflammation as measured by the erythrocyte sedimentation rate and hsCRP level was noted. Conclusion Our data suggest that the lower the activity of PON1, the higher the atherosclerotic CV disease risk in RA patients, as assessed by the presence of carotid plaque. There is a significant correlation between plasma PON1 activity and systemic inflammation in RA patients. Higher hsCRP levels were associated with lower PON1 activity.

Plasma paraoxonase1 activity in rats treated with monocrotophos: a study of the effect of duration of exposure.

We have earlier demonstrated the potential of monocrotophos (MCP), a highly toxic organophosphorus insecticide (OPI), to elicit insulin resistance in rats after chronic exposure. Given the understanding of role of paraoxonase1 (PON1) in OPI toxicity and diabetes pathology, this study was envisaged to understand the effect of duration of exposure to MCP on plasma PON1 activity in rats. Rats were administered MCP per os at 1/20 and 1/10th LD50 as daily doses for 180 days. Interim blood samples were collected at 15, 30, 45, 90 and 180 d for analysis of plasma parameters. Exposure to MCP for 45 resulted in persistent trend of hyperinsulinemia, while significant increase in fasting glucose levels was observed after 180 days. MCP caused suppression of plasma cholinesterase activity though the study period, albeit extent of inhibition was more severe during the early phase of the study. Exposure to MCP for 180 d resulted in hypertriglyceridemia and marginal decrease in HDL-C levels. MCP failed to modulate PON1 activity in plasma during the early phase of the study (up to 45 d). However, prolonged exposure resulted in significant increase in the plasma PON1 activity. This suggests that manifestation of insulin resistance in rats subjected to chronic exposure to MCP is associated with increase in PON1 activity. Our work provides rationale for studying whether the increase in PON1 activity observed in the present study serves to counter the deleterious effect of long term exposure to organophosphorus insecticides on metabolic homeostasis.

Identification of Major Esterase Involved in Hydrolysis of Soft Anticholinergic (2R3’R-SGM) Designed From Glycopyrrolate in Human and Rat Tissues

The glycopyrrolate soft analog, SGM, designed to be easily hydrolyzed into the significantly less active zwitterionic metabolite, SGa, typifies soft drug that reduces systemic side effects (a problem often seen with traditional anticholinergics) following local administration. In this study, hydrolysis of 2R3’R-SGM, the highest pharmacologically active stereoisomer of SGM, was investigated in human and rat tissues. In both species, 2R3’R-SGM was metabolized to 2R3’R-SGa in plasma but was stable in liver and intestine. The half-life of 2R3’R-SGM was found to be 16.9 min and 9.8 min in human and rat plasma, respectively. The enzyme inhibition and stimulation experiments showed that plasma paraoxonase 1 (PON1) is responsible for the hydrolysis of 2R3’R-SGM in humans and rats. The PON1-mediated hydrolysis of 2R3’R-SGM was confirmed in the lipoprotein-rich fractions of human plasma. As PON1 is naturally attached to high-density lipoprotein, it might be absent in topical tissues where 2R3’R-SGM is applied, supporting its local stability and efficacy. The metabolic behavior of 2R3’R-SGM indicates that it is an ideal soft drug to be detoxified as soon as it moves into systemic circulation. Furthermore, the similarity of 2R3’R-SGM metabolism in humans and rats showed that the rat is a suitable animal for preclinical study.

Polymorphisms in the anti-oxidant paraoxonase-1 (PON1) gene associated with fertility of postpartum dairy cows

Paraoxonase 1 (PON1) is a negative acute phase plasma protein synthesized by the liver that has anti-oxidant activity. The aim of this study was to evaluate the association of single nucleotide polymorphisms (SNPs) in the PON1 promoter region with plasma PON1 activity and fertility in Holstein dairy cows. Sixty-eighty Holstein cows were used in this initial investigative study. Blood samples were collected weekly beginning 28 days prior to expected calving, twice weekly in week 1 and 2 postpartum, and then once weekly through 6 weeks postpartum for plasma PON1 activity analysis. Cows were synchronized for ovulation and timed AI at 63–70 DIM using an Ovsynch program. Pregnancy diagnosis was confirmed by rectal palpation and reproductive performance data was recorded until 210 DIM. DNA was extracted from blood of each cow and a fragment of proximal PON1 gene promoter was sequenced. Seven single nucleotide polymorphisms (SNPs) were identified in the promoter region of the PON1 gene at positions −22, −105, −176, −221, −392, −611 and −676, six of which were significantly associated with plasma PON1 activity level. The SNPs −221 and −392 were significantly associated with both plasma PON1 activity and the calving to conception interval (P < 0.05) with no significant effect on calving to first ovulation interval. In conclusion, the genotypes associated with higher plasma PON1 activity in SNP locations −221 and −392 were also associated with a reduced calving to conception interval in this study set of cows. These SNPs may provide novel genetic markers for improved fertility in future larger studies in dairy cows.

Abstract 16673: Exposure to Ambient Polycyclic Aromatic Hydrocarbons Results in Lipoxygenase Activation and Decreased Paraoxonase-1 Activity

Introduction: There is cumulative evidence in support of causal associations between exposure to air pollution, atherosclerosis and cardiovascular mortality. However, the mechanisms for responsible for those associations are not known. Animal studies have found that exposure to ambient particulate matter (PM) promotes lipoprotein oxidation, together with decreased paraoxonase 1 (PON-1) activity, and activation of 5- and 12/15-lipoxygenase pathways but evidence on human subjects is lacking. Hypothesis: Exposure to polycyclic aromatic hydrocarbon (PAHs), a group of airborne chemicals originated from combustion sources highly prevalent in ambient PM, inhibit PON-1 activity and induce oxidative stress. Methods: We recruited 26 healthy non-smoking young adults traveling from Los Angeles to Beijing in summer. Paired urine and plasma samples were collected before (LA 1 ), during (BJ) and after (LA 2 ) the travel. Urinary monohydroxylated metabolites of five PAHs (i.e. naphthalene, dibenzofuran, fluorene, phenanthrene and pyrene) were measured as indicators of PAHs exposure. We also assessed plasma levels of PON-1 enzymatic activities, 5-, 12- and 15- hydroxyeicosatetraenoic (HETE) acids as well as 9- and 13-hydroxyoctadecadienoic acid (HODE) acids, which are oxidative products of polyunsaturated arachidonic and linoleic acid. Data was analyzed by a mixed-effect model with random intercepts. Results: Four out of five PAHs metabolites (all except for naphthalene) were elevated by 1.6-9.0 folds ( p &lt;0.001) in BJ as compared with levels in LA 1 or LA 2 indicating increased exposure to PAHs in BJ. On the contrary, there was a significant decrease in plasma paraoxonase and arylesterase activities ( p&lt; 0.05) without changes in plasma PON-1 concentration, indicating functional alteration of PON-1. There was also a significant increase in plasma levels of all HETEs and HODEs ( p&lt; 0.05) indicating elevated oxidative stress. The increase in 5-, 12- and 15-HETEs observed in BJ remained statistically significant after normalization by arachidonic acid ( p&lt; 0.05), indicating activation of 5 and 12/15 lipoxygenases. In addition, there were strong associations ( p &lt;0.05) between changes in all PAHs (except naphthalene), with HETEs, HODEs and changes in PON-1-associated paraoxonase and arylesterase enzymatic activities, after adjusting city’s effects. Conclusion: PM promotes atherosclerosis likely by its high content in PAHs, and their concomitant pro-oxidative effects resulting in activation of lipoxygenases and inhibition of PON-1 activity.

32 - Hypobromous acid and loss of cardio-protective paraoxonase-1 activity from human plasma

Paraoxonase-1 (PON1) is a cardio-protective enzyme associated with plasma high-density lipoprotein (HDL). In this study we investigated effects of HOBr, a pro-inflammatory mediator, on plasma PON1 activity. In initial studies, HOBr or HOCl was added to 5-fold diluted human plasma and PON1 phosphotriesterase activity was assayed. Consistent with prior reports, addition of HOCl (2000 uM) to plasma caused loss of PON1 activity, which declined to 71 ± 3 % normal (P 0.05). In conclusion, our results demonstrate HOBr and brominated amines, such as taurine may be important mediators of PON1 activity during inflammation. Supported by Midwestern University.

Correlation of Paraoxonase-1 with the Severity of Crohn's Disease.

Diagnostics of Crohn’s disease (CD) requires noninvasive biomarkers facilitating early detection and differentiation of the disease. Therefore, in this study, we aimed to determine the relationship between paraoxonase-1 (PON-1), the severity of CD, oxidative stress, and inflammation in CD. The CD activity index was based on the current classification. Plasma PON-1 was measured in 47 patients with CD, and in 23 control volunteers. Using quantitative variables such as receiver operating characteristics (ROC) (area under the curve (AUC)), the diagnostic utility of PON-1 in differentiating the severity of CD was assessed. Circulating PON-1 was found to be decreased in the CD group compared to the control group (269.89 vs. 402.56 U/L, respectively), and it correlated well with the disease activity. PON-1 correlated positively with hemoglobin (Hb) (r = 0.539, p < 0.001), hematocrit (Ht) (r = 0.48, p < 0.001), total cholesterol (TC) (r = 0.343, p < 0.001), high density lipoprotein (HDL) (r = 0.536, p < 0.001), low density lipoprotein (LDL) (r = 0.54, p < 0.001), and triglyceride (TG) (r = 0.561, p < 0.001) and correlated negatively with white blood cell count (WBC) (r = −0.262, p = 0.029), platelet count (PLT) (r = −0.326, p = 0.006), C-reactive protein (CRP) (r = −0.61, p < 0.001), and malondialdehyde (MDA) (r = −0.924, p < 0.001). PON-1 as a marker for CD differentiation possessed a sensitivity and specificity of 93.62% and 91.30%, respectively. CD was found to be associated with the decrease in the levels of PON-1, which correlates well with activity of the disease and reflects the intensification of inflammation, as well as intensified lipid peroxidation. High sensitivity and specificity of PON-1 determines its selection as a good screening test for CD severity.

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 β-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.

Development of simultaneous quantification method of loteprednol etabonate (LE) and its acidic metabolites, and analysis of LE metabolism in rat

Loteprednol etabonate (LE) is a soft corticosteroid with two labile ester bonds at 17α- and 17β-positions. Its corticosteroidal activity disappears upon hydrolysis of either ester bond. Hydrolysis of both ester bonds produces the inactive metabolite, Δ1-cortienic acid (Δ1-CA).The simple high-performance liquid chromatography method using acetic acid gradient was developed for the simultaneous determination of LE and its acidic metabolites.LE was hydrolyzed in rat plasma with a half-life of 9 min. However, LE hydrolysis was undetectable in rat liver and intestine. LE hydrolysis in rat plasma was completely inhibited by paraoxon and bis(p-nitrophenyl) phosphate, thus identifying carboxylesterase as the LE hydrolase. Rat plasma carboxylesterase had a Km of 6.7 μM for LE.In contrast to the disappearance rate of LE in rat plasma, the formation rate of 17α-monoester and Δ1-CA was markedly low, and a main hydrolysate of LE was not detected in rat plasma.The metabolism of LE proceeded via different pathways in human and rat plasma. LE was slowly hydrolyzed by paraoxonase in human plasma to 17α-monoester with a half-life of 12 h, but by carboxylesterase in rat plasma to yield undetectable products, presumed to include the unstable 17β-monoester.

Óleo essencial de Aloysia triphylla é efetivo no transporte de tilápia do Nilo

Este estudo avaliou o uso do óleo essencial de Aloysia triphylla (OEAT) como redutor de estresse no transporte de tilápia do Nilo, Oreochromis niloticus. Juvenis foram transportados em carro por 8 h em sacos plásticos contendo água com 0 (controle), 20 ou 30 μL L-1 OEAT (em triplicata). Nós avaliamos qualidade da água, fluxos iônicos (Clâˆ"™, Na+ e K+), parí­¢metros plasmáticos (cortisol, glicose, lactato e paraoxonase) e taxa de ventilação (TV) de tilápia do Nilo. Nenhuma mortalidade ocorreu durante o transporte. Juvenis de tilápia do Nilo transportados com 20 ou 30 μL L-1 OEAT apresentaram menor pH da água do que o grupo controle e com 30 μL L-1 OEAT apresentaram menor condutividade, alcalinidade e fluxos de Clâˆ"™, Na+ e K+ da água comparado aos demais tratamentos. O OEAT não alterou ní­­veis de cortisol e paraoxonase do plasma, mas reduziu TV, e 30 μL L-1 OEAT reduziu os ní­­veis de glicose plasmática comparada ao grupo controle depois do transporte. O uso de 20 μL L-1 OEAT aumentou os ní­­veis plasmáticos de lactato comparado aos demais tratamentos. O uso de 30 μL L-1 OEAT para sedação em transporte de 8 h de tilápia do Nilo é recomendado por melhorar qualidade de água e reduzir perdas iônicas, ní­­veis plasmáticos de glicose e TV.

Effects of a 12-week aerobic exercise on markers of hypertension in men.

Introduction: This study was aimed at determining the effects of a 12-week aerobic exercise program on markers of hypertension in men. Methods: The study was of a semi-experimental design featuring repeated measurements. A total of 40 men (age range=37.9 ± 2.68) with primary hypertension were divided into two groups, namely, the exercise group (n=20) and the control group (n=20) (systolic blood pressure [SBP]: 140.531 ± 0.23, diastolic blood pressure [DBP]: 90.71 ± 0.05). The exercise group participated in a 12-week aerobic exercise program (55% to 70% of HRmax). Blood samples were taken from both groups at the baseline and at the 4th, 8th, and 12th weeks of the training program for the assessment of adiponectin, paraoxonase-1 (PON-1), and hydrogen peroxide (H2 O2 ) levels as the markers for investigation. A linear mixed model was also used to evaluate the association among the markers. Results: In the exercise group, exercise reduced the SBP and DBP at week 12 (P=0.031 and 0.023, respectively), and adiponectin increased at weeks 8 and 12 (P=0.014 and 0.001, respectively). The plasma PON-1 level showed a significant increase in all the three stages of measurement (P=0.007, 0.004, and 0.002 at weeks 4, 8, and 12, respectively), whereas the H2 O2 levels showed a significant decrease at weeks 8 and 12 (P=0.013 and 0.011, respectively). The control group exhibited significantly decreased PON-1 (P=0.003) and adiponectin (P=0.025) levels but significantly increased SBP at week 12 (P=0.032). Conclusion: The exercise-induced reduction of oxidative stress exerts a considerable effect on the reduction of blood pressure in hypertensive patients. According to our results increase in oxidative stress has the great impact on the of blood pressure.

Sympathomimetic Effects of Acute E-Cigarette Use: Role of Nicotine and Non-Nicotine Constituents.

BackgroundChronic electronic (e) cigarette users have increased resting cardiac sympathetic nerve activity and increased susceptibility to oxidative stress. The purpose of the present study is to determine the role of nicotine versus non‐nicotine constituents in e‐cigarette emissions in causing these pathologies in otherwise healthy humans.Methods and ResultsThirty‐three healthy volunteers who were not current e‐cigarette or tobacco cigarette smokers were studied. On different days, each participant used an e‐cigarette with nicotine, an e‐cigarette without nicotine, or a sham control. Cardiac sympathetic nerve activity was determined by heart rate variability, and susceptibility to oxidative stress was determined by plasma paraoxonase activity. Following exposure to the e‐cigarette with nicotine, but not to the e‐cigarette without nicotine or the sham control, there was a significant and marked shift in cardiac sympathovagal balance towards sympathetic predominance. The decrease in high‐frequency component and the increases in the low‐frequency component and the low‐frequency to high‐frequency ratio were significantly greater following exposure to the e‐cigarette with nicotine compared with exposure to the e‐cigarette without nicotine or to sham control. Oxidative stress, as estimated by plasma paraoxonase, did not increase following any of the 3 exposures.ConclusionsThe acute sympathomimetic effect of e‐cigarettes is attributable to the inhaled nicotine, not to non‐nicotine constituents in e‐cigarette aerosol, recapitulating the same heart rate variability pattern associated with increased cardiac risk in multiple populations with and without known cardiac disease. Evidence of oxidative stress, as estimated by plasma paraoxonase activity, was not uncovered following acute e‐cigarette exposure.

Differences in liver functionality indexes in peripartal dairy cows fed rumen-protected methionine or choline are associated with performance, oxidative stress status, and plasma amino acid profiles.

The liver functionality index (LFI) represents an assessment of transition cow metabolic health by measuring changes in biomarkers associated with liver plasma protein synthesis (albumin), lipoprotein synthesis (cholesterol), and heme catabolism (bilirubin). The present analysis was conducted to determine the role of peripartal rumen-protected Met or choline (CHOL) supplementation on LFI groupings, and to assess relationships with performance, inflammation, oxidative stress status, and plasma AA profiles. A cohort of 40 multiparous Holstein cows that were part of a randomized complete block design with 2 × 2 factorial arrangement of Met (Smartamine M, Adisseo NA, Alpharetta, GA) and CHOL (ReaShure, Balchem Inc., New Hampton, NY) level (with or without) were used. From -21 d to calving, cows received the same close-up diet and were assigned randomly to each treatment. From calving to 30 d, cows were on the same postpartal diet and continued to receive the same treatments until 30 d. Addition of Met was adjusted daily at 0.08% dry matter of diet and CHOL was fed at 60 g/cow per day. Liver (-10, 7, 20, and 30 d) and blood (-10, 4, 8, 20, and 30 d) samples were harvested for biomarker analyses. Cows were ranked retrospectively and assigned to low (LLFI, LFI <0) and high (HLFI, LFI >0) LFI groups regardless of Met or CHOL supplementation. Compared with cows in LLFI, close-up and lactation DMI, milk yield, milk fat yield, and milk protein yield were greater in HLFI cows. As expected, cows in LLFI had lower plasma cholesterol and albumin but greater bilirubin concentrations around parturition. Plasma haptoglobin concentration was also lower in HLFI cows, but plasma paraoxonase and hepatic total and reduced hepatic glutathione concentrations were greater. Although higher concentrations of His, Met, and Trp, as well as a tendency for greater Ile, were observed in HLFI cows, overall essential AA concentrations did not differ with LFI status. In contrast, overall concentrations of nonessential AA were greater in HLFI cows due to greater circulating concentrations of Ala, Asn, Gln, Pro, and Ser. Similarly, overall concentrations of total AA and total sulfur-containing compounds were greater in cows with HLFI. Feeding Met compared with CHOL led to a tendency for more cows classified as HLFI. Overall, results support the broader application of the LFI in the management of transition cows. In that context, the fact that precalving concentrations of compounds such as reduced glutathione, total sulfur-containing compounds, Met, Tau, and homocysteine differed between HLFI and LLFI independent of Met or CHOL feeding also underscores their potential for monitoring cows that might be at a greater risk of developing health problems after calving. Further studies on the applicability of these biomarkers to monitor transition success appears warranted.

Uterine and systemic inflammation influences ovarian follicular function in postpartum dairy cows.

The objective of this study was to determine the effects of uterine and systemic inflammatory responses to uterine bacterial contamination at calving in dairy cows on the growth and ovulatory outcomes of the first dominant follicle postpartum. Ovulatory capability of the first dominant follicle postpartum was predicted in 53 multiparous cows by using a combination of follicle growth characteristics and circulating estradiol concentrations. Endotoxin levels were assayed in follicular fluid samples that were aspirated the day after ovulatory outcome prediction. Plasma levels of haptoglobin, a proinflammatory acute phase protein, and paraoxonase, a negative acute phase protein were determined. Uterine bacteria and inflammation were evaluated in three uterine fluid samples from each cow collected on the day of calving, the day after follicle aspiration, and at 35 days postpartum. Cows that had a strong initial uterine inflammatory response (robust recruitment of polymorphonuclear leukocytes of ≥ 35% and cows with uterine pH < 8.5 on the day of calving) were more likely to have an ovulatory first dominant follicle. Follicular fluid endotoxin levels were higher in non-ovulatory cows compared with ovulatory cows. Endotoxin levels in circulation were not different between ovulatory groups but were higher prepartum than on day 7 and 14 postpartum. Systemic inflammation characterized by elevated haptoglobin concentrations was higher in non-ovulatory cows despite similar bacterial contamination and circulating endotoxin levels. Paraoxonase activity in follicular fluid was significantly associated with the paraoxonase activity in plasma, however, plasma paraoxonase concentrations were not different between non-ovulatory and ovulatory cows. Cows with a higher uterine bacterial load on the day of calving had slower ovarian follicle growth. In summary, a robust uterine inflammatory response on the day of calving was positively associated with ovarian function while elevated systemic inflammation during the early postpartum period was negatively associated with the ovulatory status of the first dominant follicle postpartum.

Plasma Metabolome, PON1 Status, Environmental Exposures and Childhood Autism

BackgroundFew studies have examined Autism Spectrum Disorder (ASD) and the interplay between genetics and environmental factors. The paraoxonase 1 (PON1) gene regulates the breakdown of organophosphate (OP) pesticides in the body and serves as an important antioxidant. PON1 levels may be affected by single nucleotide polymorphisms (SNPs), therefore individuals with certain PON1 SNPs plus environmental exposure during pregnancy may be at an increased risk for having a child with autism.ObjectiveThe objective of this study was to examine a possible gene‐environment interaction that focuses on prenatal environmental exposures and child metabolic vulnerability as a consequence of polymorphisms in the PON1 gene.MethodsAll children (n=400) in the present study including children with Autism Spectrum Disorder (ASD; n=200), and typically developed control children (TD; n=200) are part of a large ongoing population based case‐control CHARGE (CHildhood Autism Risk from Genetics and Environment) Study. Blood plasma metabolome profiles were obtained by Nuclear Magnetic Resonance (NMR) spectroscopy. Untargeted metabolomics analysis using Chemomx NMR Suite 8.1 was used to identify and quantify 69 metabolites in each sample including amino acids, organic acids, sugars and other compounds. The concentration of PON1 was determined by ELISA kits (Cloud‐Clone Corp), and paraoxonase activity was measured using commercially available assay kits (Molecular Probes Inc.). SNP data and environmental exposure data were previously collected in the CHARGE Study.ResultsChildren with ASD had higher levels of lactate, a metabolic waste product, and higher levels of the amino acids: alanine, serine, glycine, and tryptophan, consistent with mitochondrial dysfunction, and altered energy metabolism. In addition, ASD was associated with higher levels of uridine, a component of RNA previously reported to be inversely correlated with methylation capacity. Although we did not find a significant difference in the PON1 concentration and paraoxonase activity of children with ASD compared to controls, we did find that PON1 SNPs in coding and non‐coding regions significantly affected its plasma concentrations. Moreover, there were a disproportionate number of children with ASD and specific PON1 SNPs that correlated with maternal organophosphate exposures.ConclusionOur results add to the growing body of literature indicating autism is associated with an altered metabolic state compared to typically developed controls. These results suggest that maternal environmental exposures during pregnancy in combination with genetics may impact a child's metabolic outcome. Further studies are needed to understand how the metabolome affects neurodevelopmental outcome, or conversely if neurodevelopmental outcome affects the metabolome.Support or Funding InformationThis study was funded by the NIH 1P30 ESO23513‐01A1 pilot grant, the Administrative Supplement to the CHARGE Study R01 ES015359, and the USDA National Institute of Food and Agriculture Hatch Project 1005945.

Effects of dry period length and dietary energy source on inflammatory biomarkers and oxidative stress in dairy cows

Negative energy balance in dairy cows in early lactation has been associated with increased inflammation and oxidative stress in these cows. The objective of this study was to evaluate the effects of dry period (DP) length and dietary energy source on inflammatory biomarkers and oxidative stress in dairy cows. Holstein-Friesian dairy cows (60 primiparous and 107 multiparous) were assigned randomly to a 3 × 2 factorial design with 3 DP length (0, 30, or 60 d) and 2 early lactation rations (glucogenic or lipogenic). Cows were fed a glucogenic or lipogenic ration from 10 d before the expected calving date. Blood was collected in wk -3, -2, -1, 1, 2, and 4 relative to calving. Dry period length affected inflammatory biomarkers and oxidative stress, especially in wk 1 and 2 after calving. Cows with a 0-d DP had higher levels of ceruloplasmin, cholesterol, and reactive oxygen metabolites, and they tended to have higher haptoglobin levels compared with cows with a 30- or 60-d DP. Cows with a 0-d DP had a lower plasma paraoxonase and bilirubin in the first 2 wk after calving and a lower liver functionality index compared with cows with a 60-d DP. Cows of parity >3 fed a glucogenic ration had higher cholesterol levels compared with cows of parity >3 fed a lipogenic ration. No interaction between DP length and ration was present for inflammatory biomarkers or oxidative stress variables. Plasma bilirubin levels for cows with a 0-d DP were negatively related to energy balance and metabolic status in these cows. Moreover, occurrence of clinical health problems (fever, mastitis, metritis, and retained placenta) was 41, 27, and 30% for cows with 0-, 30-, and 60-d DP, respectively. High levels of ceruloplasmin, cholesterol, and reactive oxygen metabolites in cows with 0-d DP were related to the occurrence of health problems in these cows. In conclusion, omitting the DP increased levels of ceruloplasmin, cholesterol, and reactive oxygen metabolites, and decreased levels of bilirubin and paraoxonase in plasma, independent of ration, compared with cows with a 60-d DP. These contrasting effects of DP length on inflammatory status could be explained in part by the improved energy balance and occurrence of health problems in these cows, but was not related to increased somatic cell count in cows with a 0-d DP. Cows with a 0-d DP had better energy balance, but also had higher levels of oxidative stress compared with cows with a 60-d DP. Moreover, occurrence of health problems did not differ between cows with different DP lengths.

Plasma Paraoxonase, Sphingosine-1-phosphate, Total Sialic Acid, and Heat Shock Protein-27 in the Liver of the Sheep Naturally Infected with Cysticercus Tenuicollis: Evidence on Pathological Changes.

The present study aimed to investigate whether sphingosine 1 phosphate (S1P), paraoxonase (PON), total sialic acid (TSA), and heat shock protein-27 (HSP27) are altered in the sheep during infection of the liver with Cysticercus tenuicollis. This study was conducted on40 healthy sheep and40 sheep with Cysticercus tenuicollis infection. The infected and non-infected animals were selected based on the observation of severe Cysticercus tenuicollis infection in the liver and absence of any hepatic cysts, respectively. All parameters were measured in serum and plasma. The results revealed a significant decrease (P&amp;lt;0.01) in PON, TSA, and albumin (Alb) in the infected group, compared with those in the healthy one. Furthermore, the infected sheep had a significant increase (P&amp;lt;0.01) in S1P, HSP-27, malondialdehyde (MDA), total bilirubin, and unconjugated bilirubin as compared with those in their non-infected counterparts. Moreover, no significant change was observed in total plasma protein level in the infected animals in comparison to that in the healthy ones. The low levels of TSA and Alb revealed liver damage in the infected sheep. Moreover, the PON reduction might have resulted from hepatic steatosis and MDA enhancement. Meanwhile, S1P elevation could be attributed to the activation of platelets. In addition, HSP-27 increase was ascribed to the disease-induced stress conditions.

Human paraoxonase 1 overexpression in mice stimulates HDL cholesterol efflux and reverse cholesterol transport.

This study was aimed to investigate the effect of human PON1 overexpression in mice on cholesterol efflux and reverse cholesterol transport. PON1 overexpression in PON1-Tg mice induced a significant 3-fold (p<0.0001) increase in plasma paraoxonase activity and a significant ~30% (p<0.0001) increase in the capacity of HDL to mediate cholesterol efflux from J774 macrophages compared to wild-type mice. It also caused a significant 4-fold increase (p<0.0001) in the capacity of macrophages to transfer cholesterol to apoA-1, a significant 2-fold (p<0.0003) increase in ABCA1 mRNA and protein expression, and a significant increase in the expression of PPARγ (p<0.0003 and p<0.04, respectively) and LXRα (p<0.0001 and p<0.01, respectively) mRNA and protein compared to macrophages from wild-type mice. Moreover, transfection of J774 macrophages with human PON1 also increased ABCA1, PPARγ and LXRα protein expression and stimulates macrophages cholesterol efflux to apo A1. In vivo measurements showed that the overexpression of PON1 significantly increases the fecal elimination of macrophage-derived cholesterol in PON1-Tg mice. Overall, our results suggested that the overexpression of PON1 in mice may contribute to the regulation of the cholesterol homeostasis by improving the capacity of HDL to mediate cholesterol efflux and by stimulating reverse cholesterol transport.

Predictive Value of Plasma Parameters in the Risk of Postpartum Ketosis in Dairy Cows.

IntroductionThe predictive value of selected parameters in the risk of ketosis and fatty liver in dairy cows was determined.Material and MethodsIn total, 21 control and 17 ketotic Holstein Friesian cows with a β-hydroxybutyrate (BHBA) concentration of 1.20 mmol/L as a cut-off point were selected. The risk prediction thresholds for ketosis were determined by receiver operating characteristic (ROC) curve analysis.ResultsIn the ketosis group, paraoxonase-1 (PON-1) activity and concentration of PON-1 and glucose (GLU) were decreased, and aminotransferase (AST) activity as well as BHBA and non-esterified fatty acid (NEFA) contents were increased. The plasma activity and concentration of PON-1 were significantly positively correlated with the level of plasma GLU. The plasma activity and concentration of PON-1 were significantly negatively correlated with the levels of AST and BHBA. According to ROC curve analysis, warning indexes of ketosis were: plasma PON-1 concentration of 46.79 nmol/L, GLU concentration of 3.04 mmol/L, AST concentration of 100 U/L, and NEFA concentration of 0.82 mmol/L.ConclusionThis study showed that the levels of PON-1, GLU, AST, and NEFA could be used as indicators to predict the risk of ketosis in dairy cows.

Mercury, eicosapentanoic acid and docosahexaenoic acid demonstrate limited effect on plasma paraoxonase-1 activity and blood pressure among avid seafood consumers in the Long Island Study of Seafood Consumption, NY, USA.

Moderate fish consumption is recommended for prevention of coronary heart disease (CHD) as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) have known beneficial effects on risk factors such as reducing blood pressure (BP) and increasing paraoxonase-1 (PON-1) activity. However concomitant methylmercury (MeHg) exposure from fish consumption may mitigate these benefits and the net effect on BP and PON-1 activity has not been extensively studied in western populations consuming diverse seafood types. We studied the correlation between EPA, DHA and Hg levels with BP and PON-1 activity in a population of avid seafood consumers. Two hundred and eighty-eight avid seafood consumers from Long Island, NY had blood samples drawn for total blood mercury (THg), plasma EPA and DHA levels, and plasma PON-1 activity. Average systolic blood pressure (SBP), diastolic blood pressure (DBP) and pulse pressure (PP) were measured. Subjects' mean EPA+DHA was 4.9% total fatty acids, mean THg was 7.6mcg/L. Mean SBP was 122.5mmHg, mean DBP 70.3mmHg, mean PP 52.2mmHg and mean PON-1 activity 421.2U/L. THg was not associated with any of the BP measures in adjusted linear regression models; EPA+DHA was significantly inversely associated with PP (p=0.02). THg was associated with a significant increase in PON-1 activity (p=0.04), while EPA+DHA was associated with a significant decrease in PON-1 activity (p=0.007); although the size of the effects was small. Our findings suggest blood THg and serum DHA+EPA levels have limited relationship to BP and PON-1 activity, and may not be important modulators of these known CHD risk factors in this population of avid seafood consumers.