The association between prenatal oxidative stress levels measured by isoprostanes and offspring neurodevelopmental outcomes at 36 months

Oxidative stress during pregnancy has been a mechanistic pathway implicated in autism development, yet few studies have examined this association directly. Here, we examined the association of prenatal levels of 8-iso-PGF2α, a widely used measure of oxidative stress, and several neurodevelopmental outcomes related to autism in children. Participants included 169 mother-child pairs from the Early Autism Risk Longitudinal Investigation (EARLI), which enrolled mothers who had an autistic child from a previous pregnancy and followed them through a subsequent pregnancy and until that child reached age 3 years. Maternal urine samples were collected during the second trimester of pregnancy and were later measured for levels of isoprostanes. Child neurodevelopmental assessments included the Mullen Scales of Early Learning (MSEL), the Social Responsiveness Scale (SRS), and the Vineland Adaptive Behavior Scale (VABS), and were conducted around 36 months of age. Primary analyses examined associations between interquartile range (IQR) increases in 8-iso-PGF2α levels, and total composite scores from each assessment using quantile regression. In adjusted analyses, we did not observe statistically significant associations, though estimates suggested modestly lower cognitive scores (β for MSEL = -3.68, 95% CI: -10.09, 2.70), and minor increases in autism-related trait scores (β for SRS T score = 1.68, 95% CI: -0.24, 3.60) with increasing 8-iso-PGF2α. These suggestive associations between decreased cognitive scores and increased autism-related traits with increasing prenatal oxidative stress point to the need for continued investigation in larger samples of the role of oxidative stress as a mechanistic pathway in autism and related neurodevelopmental outcomes.

Identification of novel F2-isoprostane metabolites by specific UDP-glucuronosyltransferases

UDP-glucuronosyltransferases (UGTs) catalyze the conjugation of glucuronic acid with endogenous and exogenous lipophilic small molecules to facilitate their inactivation and excretion from the body. This represents approximately 35 % of all phase II metabolic transformations. Fatty acids and their oxidized eicosanoid derivatives can be metabolized by UGTs. F2-isoprostanes (F2-IsoPs) are eicosanoids formed from the free radical oxidation of arachidonic acid. These molecules are potent vasoconstrictors and are widely used as biomarkers of endogenous oxidative damage. An increasing body of evidence demonstrates the efficacy of measuring the β-oxidation metabolites of F2-IsoPs rather than the unmetabolized F2-IsoPs to quantify oxidative damage in certain settings. Yet, the metabolism of F2-IsoPs is incompletely understood. This study sought to identify and characterize novel phase II metabolites of 15-F2t-IsoP and 5-epi-5-F2t-IsoP, two abundantly produced F2-IsoPs, in human liver microsomes (HLM). Utilizing liquid chromatography-mass spectrometry, we demonstrated that glucuronide conjugates are the major metabolites of these F2-IsoPs in HLM. Further, we showed that these molecules are metabolized by specific UGT isoforms. 15-F2t-IsoP is metabolized by UGT1A3, 1A9, and 2B7, while 5-epi-5-F2t-IsoP is metabolized by UGT1A7, 1A9, and 2B7. We identified, for the first time, the formation of intact glucuronide F2-IsoPs in human urine and showed that F2-IsoP glucuronidation is reduced in people supplemented with eicosapentaenoic and docosahexaenoic acids for 12 weeks. These studies demonstrate that endogenous F2-IsoP levels can be modified by factors other than redox mechanisms.

Omega-3 to omega-6 fatty acid oxidation ratio as a novel inflammation resolution marker for metabolic complications in obesity

BACKGROUND AND AIMS

The oxidative metabolism of polyunsaturated fatty acids (PUFAs) leads to bioactive isoprostanoids. The aim was to establish the associations of a complete urinary isoprostanoid profiling in a cohort study of carefully phenotyped obese subjects to determine possible potential differential implications for omega-6 PUFA- and omega-3 PUFA-derived isoprostanoids for obesity, metabolic indicators, and inflammation.

METHODS AND RESULTS

PUFA peroxidation compounds were determined in urine samples from obese human subjects (n = 46) by liquid chromatography coupled to tandem mass spectrometry. Increased omega-6 arachidonic acid (AA) oxidation, mainly represented by 5-F_2c isoprostane (5-F_2c-IsoP) and metabolites of 15-F_2t-IsoP, was associated with body mass index, glycated hemoglobin (HbA1c) and mean arterial blood pressure. In addition, we identified the omega-3 PUFA-derived urinary metabolites 14-F_4t-NeuroP from docosahexaenoic acid (DHA) and 5-F_3t-IsoP from eicosapentaenoic acid (EPA), which declined with age. The omega-3 to omega-6 oxidation ratio was a significant predictor of inflammation in obesity.

CONCLUSION

The findings point to full urinary isoprostanoid profiling as a more sensitive measure of PUFA oxidative stress in obesity-induced metabolic complications compared with individual isoprostanoid measures. Furthermore, the results suggest the balance between the omega-3 and omega-6 PUFA oxidation as determinative for the consequences of oxidative stress on inflammation in obesity.

Decreased oxidative stress and altered urinary oxylipidome by intravenous omega-3 fatty acid emulsion in a randomized controlled trial of older subjects hospitalized for COVID-19

Proinflammatory bioactive lipid mediators and oxidative stress are increased in coronavirus disease 2019 (COVID-19). The randomized controlled single-blind trial COVID-Omega-F showed that intravenous omega-3 polyunsaturated fatty acids (n-3 PUFA) shifted the plasma lipid signature of COVID-19 towards increased proresolving precursor levels and decreased leukotoxin diols, associated with a beneficial immunodulatory response. The present study aimed to determine the effects of n-3 PUFA on the urinary oxylipidome and oxidative stress in COVID-19. From the COVID-Omega-F trial, 20 patients hospitalized for COVID-19 had available serial urinary samples collected at baseline, after 24-48 h, and after completing 5 days treatment with one daily intravenous infusion (2 mL/kg) of either placebo (NaCl; n = 10) or a lipid emulsion containing 10 g of n-3 PUFA per 100 mL (n = 10). Urinary eicosanoids and isoprostanes were analyzed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Erythrocytes obtained at the different time-points from n = 10 patients (n = 5 placebo and n = 5 n-3 PUFA) were used for determination of reactive oxygen species. Intravenous n-3 PUFA emulsion administration altered eicosanoid metabolites towards decreased levels for mediators of inflammation and thrombosis, and increased levels of the endothelial function mediator prostacyclin. Furthermore, non-enzymatic metabolism was skewed towards n-3 PUFA-derived metabolites with potential anti-inflammatory and pro-resolving effects. The oxidative stress marker 15-F_2t-isoprostane was significantly lower in patients receiving n-3 PUFA treatment, who also exhibited significantly decreased erythrocyte oxidative stress compared with placebo-treated patients. These findings point to additional beneficial effects of intravenous n-3 PUFA emulsion treatment through a beneficial oxylipin profile and decreased oxidative stress in COVID-19.

Association between lipid peroxidation biomarkers and microRNA expression profiles

BACKGROUND

In-vitro and animal studies demonstrate that epigenetic regulation may play an important role in lipid peroxidation. No human study to date has directly evaluated microRNAs (miRNAs), as epigenetic modulators, in relation to systemic levels of lipid peroxidation.

OBJECTIVES

To evaluate associations between systemic levels of lipid peroxidation and miRNA expression profiles in women.

METHODS

Included in the analysis were 92 women aged 40-70 years, a subset of the Shanghai Women's Health Study (SWHS). Lipid peroxidation was assessed by urinary markers F₂-isoprostanes (F₂-IsoPs), the products of free radical-catalyzed peroxidation of arachidonic acid, and its major metabolite after β-oxidation, 2,3-dinor-5,6-dihydro-15-F_2t-IsoP (F₂-IsoP-M), with GC/NICI-MS assays. Expression levels of 798 miRNAs were quantified in peripheral plasma with NanoString nCounter assays. A multivariable linear regression model was used to examine the association between lipid peroxidation and miRNA expression.

RESULTS

After adjusting for potential confounders, 29 miRNAs and 213 miRNAs were associated with F₂-IsoPs and F₂-IsoP-M, respectively. When further controlling for multiple comparisons, none of these nominally significant associations with F₂-IsoPs was retained, whereas 71 of 213 miRNAs associated with F₂-IsoP-M remained. The predicted targets of the F₂-IsoP-M associated miRNAs were enriched for several lipid peroxidation-related processes such as PI3K/AKT, MAPK, FOXO and HIF-1 signaling pathways. Moreover, 10 miRNAs (miR-93-5p, miR-761, miR-301b-3p, miR-497-5p, miR-141-3p, miR-186-5p, miR-126-3p, miR-200b-3p, miR-520d-3p, and miR-363-3p) exhibited functional interactions with 50 unique mRNAs targets involved in the regulation of β-oxidation.

CONCLUSIONS

To our knowledge, this study, for the first time, provides human data suggesting that miRNA expression may be linked to lipid peroxidation products and their metabolism.

Nitric oxide-inhibited chloride transport in cortical thick ascending limbs is reversed by 8-iso-prostaglandin-F2α

Background

Salt reabsorption in the cortical thick ascending limb (cTAL) is regulated by opposing effects. Thus, while nitric oxide (NO) inhibits sodium chloride (NaCl) reabsorption, 8-iso-prostaglandin-F2α (8-iso-PGF2α) stimulates it. Their interaction, however, has not been evaluated in the cTAL. Because 8-iso-PGF2α has considerable stability while NO is a free radical with a short half-life, we hypothesized that, in the cTAL, the inhibition of NaCl absorption will be reversed by 8-iso-PGF2α.

Methods

Chloride absorption (JCl) was measured in isolated perfused cTALs. We also evaluated whether activation of protein kinase A (PKA) is required for this interaction. Since cyclic adenosine monophosphate (cAMP) is a major messenger for the 8-iso-PGF2α signaling cascade, and NO inhibits JCl by decreasing cAMP bioavailability, we measured 8-iso-PGF2α-stimulated cAMP in the presence of sodium nitroprusside (SNP).

Results

Basal JCl was 274 ± 85 pmol/min/mm. The NO donor, SNP (10-6 M), decreased JCl by 41% (333.5 ± 35.2 pmol/min/mm vs. 195.9 ± 26.1 pmol/min/mm), while 8-iso-PGF2α (100 μM) increased JCl to 315 ± 46 pmol/min/mm (p < 0.01), reversing the effects of the NO donor. While SNP inhibited JCl, 8-iso-PGF2α failed to increase JCl in the presence of H89. Basal cAMP was 56.3 ± 13.1 fmol/min/mm, that in the presence of the NO donor was 57.8 ± 6.1 fmol/min/mm, and that with 8-iso-PGF2α increased it to 92.1 ± 2.9 fmol/min/mm (n = 10, p < 0.04).

Conclusion

We concluded that 1) NO-induced inhibition of JCl in the cTAL can be reversed by 8-iso-PGF2α, 2) 8-iso-PGF2α and NO interaction requires PKA to control JCl in this nephron segment, and 3) in the presence of NO, 8-iso-PGF2α continues to stimulate JCl because NO cannot reverse 8-iso-PGF2α-stimulated cAMP level.

Elevated 8-isoprostane concentration is associated with thromboembolic events in patients with atrial fibrillation

BACKGROUND

Enhanced oxidative stress occurs in atrial fibrillation (AF), however its impact on the efficacy and safety of anticoagulation is unknown. We sought to evaluate whether 8-isoprostaglandin F2 (8-isoprostane) levels are associated with clinical outcomes in anticoagulated AF patients.

METHODS

In a study involving 243 AF patients (median age 69 years), we measured serum 8-isoprostane, along with prothrombotic markers, including plasma fibrin clot permeability, clot lysis time (CLT), endogenous thrombin potential (ETP), von Willebrand factor (VWF), and fibrinolytic proteins. Ischemic cerebrovascular events, major bleeding, and death were recorded during a median follow-up of 53 months while on anticoagulation, largely on non-vitamin K antagonist oral anticoagulants (NOACs).

RESULTS

Increased 8-isoprostane levels were observed in women, in patients with arterial hypertension, and those with paroxysmal or persistent AF. Patients with 8-isoprostane levels ≥559 pg/mL (the top quartile) compared with those with 8-isoprostane <250 pg/mL (the bottom quartile) had higher fibrinogen, lower VWF, higher plasminogen activator inhibitor 1, along with lower fibrin clot permeability with no difference in CHA₂DS₂-VASc score, CLT or ETP. Patients who experienced thromboembolic events (n = 20, 1.9%/year) had 48.6% higher 8-isoprostane concentrations compared to the remainder (P <0.01). Levels of 8-isoprostane >459 pg/mL based on the optimal cut-off value were associated with thromboembolic events during follow-up (hazard ratio 2.87, 95% confidence interval 1.17-7.03, P = 0.02). There were no associations between 8-isoprostane and major bleeding (2.0%/year) or all-cause mortality (1.9%/year).

CONCLUSIONS

Increased 8-isoprostane levels partly through altered fibrin clot structure are associated with thromboembolic events despite anticoagulant therapy in AF patients.

Isofurans and Isoprostanes as Potential Markers of Delayed Cerebral Ischemia Following Aneurysmal Subarachnoid Hemorrhage: A Prospective Observational Study

BACKGROUND

F2-Isoprostanes (F2-IsoPs) and Isofurans (IsoF), specific markers of lipid peroxidation in vivo, have been reported to be elevated and have prognostic implications following subarachnoid hemorrhage (SAH). Platelet activation and vasoconstriction are attributed to these compounds. Elevated IsoF to F2-IsoPs ratios have been proposed as in vivo biomarkers of mitochondrial dysfunction. In this pilot study, we examined their performance as specific biomarkers for delayed cerebral ischemia (DCI) development following SAH.

METHODS

Eighteen patients with SAH and six controls with normal neuroimaging and cerebrospinal fluid (CSF) analysis results underwent CSF sampling and abstraction of clinical, demographic, and laboratory data. Samples (two) of CSF were collected on day 1 and once on days 5-8 post bleed. F2-IsoP and IsoF assays were performed by gas chromatography/mass spectroscopy methods. Levels are expressed in median (interquartile range) for nonnormally distributed data. Repeated sample measurements were compared using the Wilcoxon signed-rank test, whereas the Mann-Whitney U-test was used for other nonnormally distributed data.

RESULTS

Mean age was 61 ± 15.7 (SAH cases) versus 48 ± 10 (controls) years, and 80% of patients with SAH were women. Median Hunt and Hess score was 3 (2-4), and modified Fisher scale was 3 (3-4). Thirty nine percent of patients developed DCI. F2-IsoP were significantly higher in SAH cases than in controls [47.5 (30.2-53.5) vs. 26.0 (21.2-34.5) pg/mL]. No significant differences were observed in patients with or without DCI [41 (33.5-52) vs. 44 (28.5-55.5) pg/mL]. IsoF were elevated in the second CSF sample in nine patients but were undetectable in the remainder cases and all controls. Patients who developed DCI had significantly higher IsoF than those who did not [57 (34-72) vs. 0 (0-34) pg/mL]. Patients who met criteria for DCI had a significantly higher IsoF to F2IsoPs ratio on the late CSF sample [1.03 (1-1.38) vs. 0 (0-0.52)].

CONCLUSIONS

Preliminary findings from this study suggest that IsoF may represent a specific biomarker predicting DCI following SAH. Future studies to further explore the value of IsoF as biomarkers of secondary brain injury following SAH seem warranted.

Serum 8-isoprostane levels in patients with resistant oral lichen planus before and after treatment with lycopene: a randomized clinical trial

Background

Oral lichen planus is an autoimmune disease in which topical steroids are the first line of treatment. The adverse effects of systemic corticosteroids prescribed for resistant oral lichen planus cases advocate alternative modalities. Lycopene is an antioxidant with a wide range of beneficial properties. This trial aimed to evaluate the effect of pure lycopene as compared to systemic corticosteroids (Prednisolone) on the symptoms, signs and oxidative stress in patients with erosive oral lichen planus recalcitrant to topical steroids.

Methods

Twenty patients were randomly divided into the test (lycopene) and control (corticosteroids) groups. Numeric rating scale and Escudier et al. (Br J Dermatol 4:765–770, 2007. 10.1111/j.1365-2133.2007.08106.x) lesion scores were assessed at baseline and weeks 4 and 8 from baseline. Serum levels of 8-isoprostane were measured in all patients at baseline and at the end of treatment (week 8).

Results

There was a significant reduction in signs and symptoms after the end of treatment in each group. However, no significant difference was found between the lycopene and the corticosteroids group. Moreover, a significant reduction in 8-isoprostane levels was observed in the lycopene group from baseline and as compared to the control group.

Conclusions

Based on the study results, lycopene is a safe and effective therapeutic modality for resistant oral lichen planus. 8-isoprostane is a biomarker of lipid peroxidation that can be reduced by lycopene.

Trial registration ID: PACTR202003484099670. 'Retrospectively registered on 11/3/2020'.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-01711-z.

Isoprostanes in wastewater as biomarkers of oxidative stress during COVID-19 pandemic

Isoprostanes are the potential biomarkers of endogenous human metabolism and proven clinically to provide the quantitative measure of systematic oxidative injury. An ultra-performance liquid chromatography-tandem mass spectrometric analytical method capable of determining four biomarkers of oxidative stress (8-iso-PGF2α, 2,3-dinor-iPF2α-III, PGE2, and 5-iPF2α-VI) in wastewater was developed and validated. Isoprostanes were quantified in the range of 31.1-1270 ng/L in raw wastewater samples in two communities in western Kentucky and Tennessee during the first four months of the COVID-19 pandemic. Consistent detection of PGE2 and 5-iPF2α-VI in wastewater suggested that PGE2 and 5-iPF2α-VI can be a reliable biomarker of community oxidative anxiety. The higher 4-month average mass load of isoprostanes [(ranged from 22.9 mg/d/1000 people to 807 mg/d/1000 people] may be attributed to the elevated community level oxidative anxiety owing COVID-19 uncertainties. The average mass loads of PGE2 and 5-iPF2α-VI in a community were significantly increased (two-tailed p < 0.001) from the first month of COVID-19 pandemic to the second month; however, significantly decreased (two-tailed p < 0.001) in the third month. Wastewater-based-epidemiological determination of isoprostanes can be a near-real-time and cost-effective approach of a trend in community depression. This is the first report of the quantification of PGE2 and 5-iPF2α-VI in wastewater and estimation of the community level oxidative anxiety.

Tomato powder is more effective than lycopene to alleviate exercise-induced lipid peroxidation in well-trained male athletes: randomized, double-blinded cross-over study

Background

Consumption of nutritional supplements to optimize recovery is gaining popularity among athletes. Tomatoes contain micronutrients and various bioactive components with antioxidant properties. Many of the health benefits of tomatoes have been attributed to lycopene encouraging athletes to consume pure lycopene supplements. The aim of this study was to compare the effect of tomato powder and lycopene supplement on lipid peroxidation induced by exhaustive exercise in well-trained male athletes.

Methods

Eleven well-trained male athletes participated in a randomized, double-blinded, crossover study. Each subject underwent three exhaustive exercise tests after 1-week supplementation of tomato powder (each serving contained 30 mg lycopene, 5.38 mg beta-carotene, 22.32 mg phytoene, 9.84 mg phytofluene), manufactured lycopene supplement (30 mg lycopene), or placebo. Three blood samples (baseline, post-ingestion and post-exercise) were collected to assess total anti-oxidant capacity (TAC) and variables of lipid peroxidation including malondialdehyde (MDA) and 8-isoprostane. Data were analyzed using repeated-measures of ANOVA at P < 0.05.

Results

Tomato powder enhanced total antioxidant capacity (12% increase, P = 0.04). Exhaustive exercise, regardless of supplement/ placebo, elevated MDA and 8-isoprostane levels (P < 0.001). The elevation of 8–isoprostane following exhaustive exercise was lower in the tomato powder treatment compared to the placebo (9% versus 24%, p = 0.01). Furthermore, following exhaustive exercise MDA elevated to a lower extent in tomatoe powder treatment compared to the placebo (20% versus 51%, p = 0.009). However, such differences were not indicated between lycopene and placebo treatments (p > 0.05).

Conclusion

Beneficial effects of tomato powder on antioxidant capacity and exercise-induced lipid peroxidation may be brought about by a synergistic interaction of lycopene with other bioactive nutrients rather than single lycopene.

Enrichment of alpha-linolenic acid in rodent diet reduced oxidative stress and inflammation during myocardial infarction

Myocardial infarction (MI) is an irreversible event caused by cardiac ischemia and may be fatal. Studies reported that increased intake of n-3 polyunsaturated fatty acids (PUFA) namely, eicosapentaenoic acid and docosahexaenoic acid reduce the risk of cardiovascular disease and lower the incidence of MI. Nonetheless, the cardioprotective effect of plant n-3-PUFA such as α-linolenic acid (ALA) in the diet is not conclusive. In this study, Sprague Dawley rats were supplemented with isocaloric diets enriched with ALA rich flaxseed (FS) and flaxseed oil (FSO), and normal chow (Control) for 4 weeks. MI was induced by isoproterenol (ISO) injection. Results showed that all ALA-enriched diets displayed cardioprotection against MI. The heart to body weight ratio, plasma LDH activity and plasma cTnI were reduced compared to ISO and was prominent in FS diet. ALA and EPA were up-regulated in both tissues and plasma by ALA-diets compared to Control and remained higher than ISO groups. Notably, LOX-mediated HETEs decreased whereas LOX-mediated HDHAs were elevated in both tissues and plasma of ALA-enriched diets compared to ISO. In addition, non-enzymatic oxidized products from arachidonic acid including 15-F_2t-IsoP were reduced in both tissues and plasma of MI rats supplemented with ALA-enriched diets while those from n-3 PUFAs including F₄-NeuroPs, PhytoPs and PhytoFs were elevated compared to control. ALA-enriched diets particularly flaxseed reduced gene expressions of inflammatory cytokines namely IL-1β, IL-6 and TNFα and prevented the down regulation of antioxidant catalase in the heart tissues. In conclusion ALA-enriched diets potentially exerted cardioprotection through the regulation of anti-inflammatory and anti-oxidative mediators from n-3 PUFA autooxidation.

Semen Biochemical Components in Varicocele, Leukocytospermia, and Idiopathic Infertility

The evaluation of the seminal plasma plays a relevant role in the definition of male infertility and in assisted reproduction outcomes; for this reason, it would be recommended to find biochemical markers able to characterize sperm pathology. In this study, 53 infertile patients (grouped by the presence leukocytospermia, idiopathic infertility, or varicocele) and 10 fertile men were selected. Spermiogram was performed by light microscopy, and sperm ultrastructure was evaluated by transmission electron microscopy (TEM) mathematically elaborated. Testosterone (TESTO), estradiol (E2), ferritin (FERR), iron (Fe), transferrin (TRSF), triglycerides (TRG), cholesterol (CHOL), and isoprostanes (F₂-IsoPs) were detected in seminal plasma. Sperm characteristics and biochemical components were correlated by Spearman’s rank correlation coefficient in the whole population and in each group. The levels of TESTO and E2 were positively correlated with sperm quality in particular, and E2 was correlated with fertility index expressing the number of sperm free of ultrastructural defects evaluated by TEM. On the contrary, the indices of iron metabolism (FERR, Fe, and TRSF) were positively associated with low sperm quality and sperm necrosis, particularly in leukocytospermia and varicocele groups, pathologies in which an inflammatory status and oxidative stress condition are present. The study of the seminal plasma composition deserves attention because the levels of the various components seem to be associated with specific reproductive pathologies.

Measurement of Enzymatic and Nonenzymatic Polyunsaturated Fatty Acid Oxidation Products in Plasma and Urine of Macular Degeneration Using LC-QTOF-MS/MS

Oxidized polyunsaturated fatty acids (PUFA) are associated to pathogenesis of diseases including cardiovascular and neurodegeneration. The novel products are not only biomarkers but also lipid mediators in gene regulation and signaling pathways. Herein, simultaneous quantitation of 28 products derived from nonenzymatic and enzymatic oxidation of PUFA i.e. 5-, 15-F_2t -isoprostanes, 7-, 17-F_2t -dihomo-isoprostanes, 7-, 17-F_2t -dihomo-isofurans, 5-, 8-, 18-F_3t -isoprostanes, 4-, 10-, 13-, 14-, 20-F_4t -neuroprostanes, 5-, 8-, 9-, 11-,12-, 15-, 20-HETE, 4-, 7-, 11-, 14-, 17-HDHA, RvE1, and NPD1 using LC-(ESI)-QTOF-MS/MS was developed. These products were measurable in a single sample and the analytical time was relative short (~15 min). Furthermore, we showed that the use of internal standards is a requisite to normalize matrix effects and preparation loss for the quantitation. Validation assays indicated the method to be robust for plasma and mid-stream urine sample analysis in particular from those of age-related macular degeneration subjects, where the accuracy of quantitation displayed good repeatability.

Relevance of seminal F2-dihomo-IsoPs, F2-IsoPs and F4-NeuroPs in idiopathic infertility and varicocele

The aim of this paper was to investigate the relevance of isoprostanoids i.e., F₂-isoprostanes (F₂-IsoPs), F₄-neuroprostanes (F₄-NeuroPs) and F₂-dihomo-isoprostanes (F₂-dihomo-IsoPs) in semen quality. Isoprostanoid levels were detected in semen of fertile and infertile men with varicocele or idiopathic infertility. Semen quality was assessed by light microscopy and transmission electron microscopy; the relationships between isoprostanes and semen parameters were also explored. F₂-IsoPs levels were significantly different in the varicocele group compared to idiopathic infertile group and fertile men (P < 0.01 and P < 0.001 respectively). Moreover, F₂-dihomo-IsoP values were significantly higher in varicocele group respect to fertile men (P < 0.05). No significant statistical differences were found regarding F₄-NeuroP concentrations. In the whole population, F₂-IsoPs positively correlated with F₂-dihomo-IsoPs and both isoprostanoids showed a positive correlation with immaturity and a negative correlation with sperm motility. F₂-IsoP levels were positively correlated with the percentage of immaturity in infertile varicocele groups (P < 0.01) whereas a significant relationship between F₄-NeuroP values and the percentage of sperm necrosis was shown in idiopathic infertility group (P < 0.01). A significant negative correlation of F₄-NeuroPs with sperm morphology was detected in infertile varicocele subjects (P < 0.05). This study suggests that isoprostanoid semen levels appear to be associated with male infertility being related to the sperm quality and confirming the important role of fatty acids profiling in human sperm maturation.

Saliva as a non-invasive tool for monitoring oxidative stress in swimmers athletes performing a VO2max cycle ergometer test

Biomarkers of oxidative stress are generally measured in blood and its derivatives. However, the invasiveness of blood collection makes the monitoring of such chemicals during exercise not feasible. Saliva analysis is an interesting approach in sport medicine because the collection procedure is easy-to-use and does not require specially-trained personnel. These features guarantee the collection of multiple samples from the same subject in a short span of time, thus allowing the monitoring of the subject before, during and after physical tests, training or competitions. The aim of this work was to evaluate the possibility of following the changes in the concentration of some oxidative stress markers in saliva samples taken over time by athletes under exercise. To this purpose, ketones (i.e. acetone, 2-butanone and 2-pentanone), aldehydes (i.e. propanal, butanal, and hexanal), α,β-unsaturated aldehydes (i.e. acrolein and methacrolein) and di-carbonyls (i.e. glyoxal and methylglyoxal) were derivatized with 2,4-dinitrophenylhydrazine, and determined by ultra-high performance liquid chromatography coupled to diode array detector. Prostaglandin E₂, F₂/E₂-isoprostanes, F₂-dihomo-isoprostanes, F₄-neuroprostanes, and F₂-dihomo-isofuranes were also determined by a reliable analytical procedure that combines micro-extraction by packed sorbent and ultra-high performance liquid chromatography-electrospray ionization tandem mass spectrometry. Overall the validation process showed that the methods have limits of detection in the range of units of ppb for carbonyls and tens to hundreds of ppt for isoprostanes and prostanoids, very good quantitative recoveries (90-110%) and intra- and inter-day precision lower than 15%. The proof of applicability of the proposed analytical approach was investigated by monitoring the selected markers of oxidative stress in ten swimmers performing a VO_2max cycle ergo meter test. The results highlighted a clear increase of salivary by-products of oxidative stress during exercise, whereas a sharp decrease, approaching baseline values, of these compounds was observed in the recovery phase. This study opens up a new approach in the evaluation of oxidative stress and its relation to aerobic activity.

20-hydroxyeicosatetraenoic acid alters endothelial cell barrier integrity independent of oxidative stress and cell death

Unregulated inflammation during bovine mastitis is characterized by severe mammary tissue damage with systemic involvement. Vascular dysfunction underlies tissue pathology because of concurrent oxidative stress mediated by several inflammatory mediators. We recently demonstrated increased production of 20-hydroxyeicosatetraenoic acid (20-HETE), a cytochrome P450-derived (CYP) oxylipid that correlated with oxidative stress during severe bovine coliform mastitis. The hypothesis for this study was that 20-HETE-induced oxidative stress disrupts barrier function of endothelial cells. Primary endothelial cells from the bovine aorta were utilized to investigate the effects of 20-HETE on barrier integrity in an in-vitro model of oxidative stress. The effects of various antioxidants on modulating the 20-HETE barrier integrity effects also were investigated. Our results showed that 20-HETE decreased endothelial barrier integrity, which was associated with increased reactive metabolite production and decreased total glutathione. The antioxidant, vitamin E, partially delayed the loss of endothelial resistance upon exposure to 20-HETE but did not prevent complete loss of barrier integrity. The decrease in barrier resistance due to 20-HETE was neither associated with oxidative stress as assessed by oxidative protein or lipid damage nor endothelial cell apoptosis; however, selenium supplementation conferred resistance to loss of barrier integrity suggesting a role for shifts in redox status. Specific mechanisms by which 20-HETE alters vascular barrier integrity require further investigation to identify targets for therapy during inflammatory conditions with enhanced CYP450 activity.

Exposure to airborne fine particulate matter is associated with impaired endothelial function and biomarkers of oxidative stress and inflammation

Epidemiological evidence suggests that exposure to air pollution is a leading risk factor for cardiovascular disease (CVD). However, there is little direct evidence linking exposure to vascular dysfunction. We conducted a cross-sectional study of 100 participants, recruited from the University of Louisville Clinics. Endothelial function was assessed by calculating the reactive hyperemia index (RHI). Oxidative stress was indexed by measuring urinary levels of isoprostanes (n = 91). Inflammatory biomarkers were measured in the plasma (n = 80). Daily average PM_2.5 levels were obtained from regional monitoring stations. Adjusted associations between PM_2.5 levels and measured outcomes were tested using generalized linear models. The average age of participants was 48 years (44% male, 62% white); 52% had a diagnosis of hypertension, and 44% had type-2 diabetes. A 12.4% decrease in RHI was associated with 10 μg/m³ increase in PM_2.5 (95% CI: 21.0, -2.7). The F-2 isoprostane metabolite showed a positive association of 28.4% (95% CI: 2.7, 60.3) per 10 μg/m³ increase in PM_2.5. Positive associations were observed with angiopoietin 1 (17.4%; 95% CI: 2.8, 33.8), vascular endothelial growth factor (10.4%; 95% CI: 0.6, 21.0), placental growth factor (31.7%; 95% CI: 12.2, 54.5), intracellular adhesion molecule-1 (24.6%; 95% CI: 1.6, 52.8), and matrix metalloproteinase-9 (30.3%; 95% CI: 8.0, 57.5) per 10 μg/m³ increase in PM_2.5. Additionally, a 10 μg/m³ increase in PM_2.5 was associated with 15.9% decrease in vascular cell adhesion molecule-1 (95% CI: 28.3, -1.3). These findings suggest that exposure to PM_2.5 is associated with impaired vascular function, which may result from oxidative stress and inflammation, thereby leading to a pro-atherogenic state.

Repeated measures of urinary oxidative stress biomarkers and preterm birth in Puerto Rico

BACKGROUND

Preterm birth (PTB; gestational age <37 weeks), the leading cause of infant morbidity and mortality worldwide, is of particular concern in Puerto Rico. Rates of PTB in Puerto Rico peaked at 20% in 2006, which are historically some of the highest in the world. Oxidative stress and inflammation have been implicated as contributors to adverse birth outcomes, including PTB, and these associations have not been explored in Puerto Rico. Our objective was to examine associations between urinary oxidative stress biomarkers and PTB in the Puerto Rico Testsite for Exploring Contamination Threats (PROTECT) pregnancy cohort (N = 469).

METHODS

8-iso-prostaglandin F2α (8-iso-PGF2α), its primary metabolite, and prostaglandin F2α (PGF2α) were included as biomarkers of oxidative stress or inflammation. Biomarkers were measured in urine samples collected at up to 3 timepoints across pregnancy (mean 18, 24, 28 weeks gestation). We quantified the proportion of 8-iso-PGF2α originating from oxidative stress and inflammation pathways with a formula based on the ratio of 8-iso-PGF2α to PGF2α. Logistic regression models were used to calculate adjusted odds ratios (OR) for associations between average biomarker concentrations from each woman (visits 1-3) and PTB. Associations between biomarker concentrations at each study visit and PTB were analyzed in separate models.

RESULTS

Averaged levels of 8-iso-PGF2α, its primary metabolite, and PGF2α were associated with increased odds of PTB (OR = 1.64, 95% confidence interval [CI] = 1.07-2.54; OR = 1.79, 95% CI = 1.14-2.84; OR = 1.98, 95% CI = 1.32-3.02, respectively). Odds ratios for PTB were greater in magnitude in association with oxidative stress biomarkers measured later in pregnancy. The fraction of 8-iso-PGF2α derived from inflammation was associated with PTB (OR = 1.73, 95% CI = 1.09, 2.93), while the fraction of 8-iso-PGF2α derived from oxidative stress was not associated with PTB (OR = 1.17, 95% CI = 0.90, 1.54).

CONCLUSIONS

Our results suggest that oxidative stress and inflammation, as measured by these biomarkers, may be important contributors to PTB. Further research is needed to improve our understanding of the role these biomarkers may play in the causal pathway between environmental factors and PTB.

Urinary oxylipin signature as biomarkers to monitor the allograft function during the first six months post-renal transplantation

Oxylipins such as isoprostanes (IsoPs), prostaglandins (PGs) and thromboxanes (TXs) are lipid mediators derived from the oxidation of polyunsaturated fatty acids, which regulate the magnitude of oxidative stress and inflammation processes and play an important role in pathophysiological processes in the kidney. A total of 36 oxylipins were analyzed by UHPLC-QqQ-MS/MS in the urine of 41 renal recipients from cadaveric donors of the Nephrology Unit of the University Hospital Virgen de la Arrixaca during the first six months after renal transplantation, in order to investigate several candidate oxylipins as more accurate and predictive biomarkers in renal transplantation than classical biological variables. A decrease in nine PGs, mostly from the AA-D pathway (p < 0.05) and one IsoP: 15-keto-15-F_2t-IsoP (p < 0.001) was observed. Moreover, two PGs (2,3-dinor-11β-PGF_2α and 17-trans-PGF_3α) increased between five days and six months after renal transplantation (p < 0.05). In addition, when kidney function improved, a positive correlation between oxylipin levels and the excretion of urine proteins was observed. These results suggest that oxylipins could be useful markers for monitoring renal function in the post-renal transplantation period. These findings could be of utility not only for the development of strategies for long-term preservation of graft function, but also for innovative and alternative therapies -using oxylipins as predictive markers-to avoid organ rejection.

Increase in omega-6 and decrease in omega-3 polyunsaturated fatty acid oxidation elevates the risk of exudative AMD development in adults with Chinese diet

Appropriate diet is essential for the regulation of age-related macular degeneration (AMD). In particular the type of dietary polyunsaturated fatty acids (PUFA) and poor antioxidant status including carotenoid levels concomitantly contribute to AMD risk. Build-up of oxidative stress in AMD induces PUFA oxidation, and a mix of lipid oxidation products (LOPs) are generated. However, LOPs are not comprehensively evaluated in AMD. LOPs are considered biomarkers of oxidative stress but also contributes to inflammatory response. In this cross-sectional case-control study, plasma omega-6/omega-3 PUFA ratios and antioxidant status (glutathione, superoxide dismutase and catalase), and plasma and urinary LOPs (41 types) were determined to evaluate its odds-ratio in the risk of developing exudative AMD (n = 99) compared to age-gender-matched healthy controls (n = 198) in adults with Chinese diet. The odds ratio of developing exudative AMD increased with LOPs from omega-6 PUFA and decreased from those of omega-3 PUFA. These observations were associated with a high plasma omega-6/omega-3 PUFA ratio and low carotenoid levels. In short, poor PUFA and antioxidant status increased the production of omega-6 PUFA LOPs such as dihomo-isoprostane and dihomo-isofuran, and lowered omega-3 PUFA LOPs such as neuroprostanes due to the high omega-6/omega-3 PUFA ratios; they were also correlated to the risk of AMD development. These findings indicate the generation of specific LOPs is associated with the development of exudative AMD.

Associations between socioeconomic status, psychosocial stress, and urinary levels of 8-iso-prostaglandin-F2α during pregnancy in Puerto Rico

BACKGROUND

Lower socioeconomic status (SES) and psychosocial stress during pregnancy have been associated with adverse birth outcomes. While hypothalamic-pituitary-axis activation is thought to be the primary driver, oxidative stress may also be involved mechanistically. We used data from the Puerto Rico Testsite for Exploring Contamination Threats (PROTECT) cohort (N=476) to examine associations between self-reported psychosocial stress measures, SES indicators, and urinary oxidative stress biomarker concentrations, hypothesizing that women with lower SES and increased psychosocial stress would have elevated oxidative stress biomarkers.

METHODS

Maternal age, education, marital status, insurance status, alcohol use and smoking status were obtained via self-reported questionnaires and were used as indicators of SES. Perceived stress, depression, negative life experiences, neighborhood perceptions, and social support were self-reported in questionnaires administered during pregnancy. Responses were grouped into tertiles for analysis, where the highest tertile corresponded to highest level of psychosocial stress. Urinary concentrations of 8-iso-prostaglandin F2α (8-iso-PGF2α) and its primary metabolite were measured at three study visits (median 18, 24, 28 weeks gestation) and averaged to reflect oxidative stress across pregnancy. Linear models were used to examine associations between SES indicators, tertiles of psychosocial stress and oxidative stress biomarkers.

RESULTS

Average levels of 8-iso-PGF2α and the 8-iso-PGF2α metabolite were higher among pregnant women who were younger, who had public compared to private insurance, and who were unemployed compared to employed. However, no associations were observed between psychosocial stress measures and biomarker concentrations in adjusted analyses.

CONCLUSIONS

Psychosocial stress during pregnancy, as indicated by self-reported questionnaire measures, was not associated with biomarkers of oxidative stress in the PROTECT study. However, results suggest that these biomarkers are elevated among women of lower SES, which is typically associated with stress. Notably, compared to other populations, self-reported psychosocial stress measures were lower in PROTECT compared to other populations.

Biomarkers of oxidative stress in the fetus and in the newborn

The dynamic field of perinatology entails ever-increasing search for molecular mechanisms of neonatal diseases, especially in the domain of fetal growth and neurodevelopmental outcome. There is an urgent need for new molecular biomarkers, to early identify newborn at high risk for developing diseases and to provide new treatment targets. The interest in biomarkers of oxidative stress in perinatal period have begun to grow in the last century, when it was evidenced the importance of the free radicals generation underlying the various disease conditions. To date, interesting researches have been carried out, representing milestones for implementation of oxidative stress biomarkers in perinatal medicine. Use of a panel of "oxidative stress biomarkers", particularly non protein bound iron, advanced oxidative protein products and isoprostanes, may provide valuable information regarding functional pathways underlying free radical mediated diseases of newborns and their early identification and prevention. Here, we will review recent advances and the current knowledge on the application of biomarkers of oxidative stress in neonatal/perinatal medicine including novel biomarker discovery, defining yet unrecognized biologic therapeutic targets, and linking of oxidative stress biomarkers to relevant standard indices and long-term outcomes.

Increased isoprostanoid levels in brain from murine model of Krabbe disease - Relevance of isoprostanes, dihomo-isoprostanes and neuroprostanes to disease severity

Krabbe disease (KD) is a rare and devastating pediatric leukodystrophy caused by mutations in the galactocerebrosidase (GALC) gene. The disease leads to impaired myelin formation and extensive myelin damage in the brain. Oxidative stress is implicated in the pathogenesis of KD but insofar few information is available. The gray and white matter of the brain are rich in docosahexaenoic acid and adrenic acid respectively and under non-enzymatic oxidative stress, release isoprostanoids, i.e. F₄-neuroprostanes (F₄-NeuroPs) and F₂-dihomo-isoprostanes (F₂-dihomo-IsoPs). In this study, the formation of isoprostanoids in brain tissue was investigated in a well-established KD mouse model (twitcher) that recapitulates the human pathology. According to the genotype determinations, three groups of mice were selected: wild-type control mice (n = 13), heterozygotes mice (carriers of GALC mutations, n = 14) and homozygous twitcher mice (n = 13). Measurement of F₂-dihomo-IsoP and F₄-NeuroP levels were performed on whole brain tissue obtained at day 15 and day 35 of the life cycle. Brain isoprostanoid levels were significantly higher in the twitcher mice compared to the heterozygous and wild-type control mice. However, F₂-dihomo-IsoP and F₄-NeuroP levels did not differ in brain of day 15 compared to day 35 of the heterozygote mice. Interestingly, isoprostanoid levels were proportionally enhanced with disease severity (F₂-dihomo-IsoPs, rho = 0.54; F₄-NeuroPs, rho = 0.581; P values ≤ 0.05; n = 13). Our findings are the first to show the key role of polyunsaturated fatty acid oxidative damage to brain grey and white matter in the pathogenesis and progression of KD. This shed new insights on the biochemical indexes of KD progression, and potentially provide information for novel therapeutic targets.

Physical fitness is associated with prostaglandin F2α isomers during pregnancy

INTRODUCTION

Pregnancy and physical activity are associated with oxidative stress and immune changes. We hypothesized that pregnant women physically more active in early pregnancy will display a better oxidative stress management and inflammatory response later in pregnancy compared with less active pregnant women.

MATERIAL AND METHODS

Maternal physical activity using accelerometry monitors for 1 week and cardiorespiratory fitness (VO₂ at anaerobic threshold) were assessed at 14-18 weeks in 58 pregnant women. Plasma and erythrocytes membrane samples were obtained from maternal blood samples at 14-18 and 34-37 weeks of pregnancy. Pro-inflammatory prostaglandin (PG) F_2α and oxidative stress-derived F₂-isoprostanes were measured by high-performance liquid chromatography coupled to tandem mass spectrometry.

RESULTS

Higher physical activity levels at 14-18 weeks measured by mean counts per minute, >30 min/d of moderate to vigorous activity or >6500 steps/d at 14-18 weeks of pregnancy were associated with lower levels of total plasmatic PGF_2α later in pregnancy. Concentrations of 5 F₂-isomers in erythrocyte membranes in late pregnancy were significantly higher in the third (17.5-19.5 mL kg^-1 min^-1) and/or fourth (19.6-27.7 mL kg^-1 min^-1) quartiles of cardio-respiratory fitness compared to the first quartile (13.9-15.9 mL kg^-1 min^-1).

CONCLUSIONS

Overall, higher cardio-respiratory fitness in early pregnancy is associated with enhanced erythrocyte membranes oxidation at 34-37 weeks reflecting a higher oxygen transfer capacity. Also, the most active women experienced lower circulating levels of pro-inflammatory PGF_2α in plasma at 34-37 weeks, a marker associated with adverse antenatal inflammation-associated conditions. These results support the practice of physical activity by pregnant women.

Oxidative stress and abnormal bioactive lipids in early cystic fibrosis lung disease

BACKGROUND

Clinical data indicate that airway inflammation in children with cystic fibrosis (CF) arises early, is associated with structural lung damage, and predicts progression. In bronchoalveolar lavage fluid (BALF) from CFTR mutant mice, several aspects of lipid metabolism are abnormal that contributes to lung disease. We aimed to determine whether lipid pathway dysregulation is also observed in BALF from children with CF, to identify biomarkers of early lung disease and potential therapeutic targets.

METHODS

A comprehensive panel of lipids that included Sphingolipids, oxylipins, isoprostanes and lysolipids, all bioactive lipid species known to be involved in inflammation and tissue remodeling, were measured in BALF from children with CF (1-6 years, N = 33) and age-matched non-CF patients with unexplained inflammatory disease (N = 16) by HPLC-MS/MS. Lipid data were correlated with chest CT scores and BALF inflammation biomarkers.

RESULTS

The ratio of long chain to very long chain ceramide species (LCC/VLCC) and lysolipid levels were enhanced in CF compared to non-CF patients, despite comparable neutrophil counts and bacterial load. In CF patients both LCC/VLCC and lysolipid levels correlated with inflammation and chest CT scores. The ceramide precursors Sphingosine, Sphinganine, Sphingomyelin, correlated with inflammation, whilst the oxidative stress marker isoprostane correlated with inflammation and chest CT scores. No correlation between lipids and current bacterial infection in CF (N = 5) was observed.

CONCLUSIONS

Several lipid biomarkers of early CF lung disease were identified, which point toward potential disease monitoring and therapeutic approaches that can be used to complement CFTR modulators.

Urinary oxidative stress biomarkers and accelerated time to spontaneous delivery

BACKGROUND

Oxidative stress has been implicated in numerous birth outcomes, including spontaneous preterm birth. However, the relationship with presentation at delivery has been less well studied. We assessed the relationship between oxidative stress biomarkers and gestational duration with a focus on spontaneous presentation for delivery.

METHODS

Our sample included 740 women from a multi-center prospective cohort study, recruited from 2010 to 2012. Resultant measures of oxidative stress in pregnancy prostaglandin F_2α (PGF_2α), 8-iso-prostaglandin F_2α (8-iso-PGF_2α), and the primary 8-iso-PGF_2α metabolite were measured in third trimester urine samples. Information on presentation for delivery was abstracted from medical records. We examined associations with preterm birth using adjusted logistic models. Time to event (overall delivery and spontaneous delivery) was examined using adjusted accelerated failure time models.

RESULTS

The 8-iso-PGF_2α metabolite was associated with increased odds of overall preterm birth (OR: 1.44 [95% CI: 1.00, 2.06]), and the association with spontaneous preterm birth was similar in magnitude but not statistically significant (OR: 1.45 [95% CI: 0.96, 2.20]). We did not detect associations between other biomarkers and preterm birth, or between biomarkers and timing of overall or spontaneous delivery in accelerated failure time models.

CONCLUSIONS

Our data suggest that increased oxidative stress, as indicated by the 8-iso-PGF_2α metabolite, may be associated with preterm birth. In contrast to previous studies, associations were similar among individuals with spontaneous versus non-spontaneous presentation for delivery.

Isoprostanes as potential cerebral vasospasm biomarkers

Despite enormous progress in medicine, symptomatic cerebral vasospasm (CVS), remains an unexplained clinical problem, which leaves both physicians and patients helpless and relying on chance, due to the lack of specific marker indicative of imminent danger as well as the lack of specific treatment. In our opinion CVS occurrence depends on dynamic disbalance between free radicals' formation (oxidative stress) and antioxidant activity. Isoprostanes are products of free-radical peroxidation of polyunsaturated fatty acids, and seem to mark a promising path for the research aiming to unravel its possible mechanism. Not only are they the biomarkers of oxidative stress in vivo and in vitro, but also have manifold biological effects (including vasoactive, inflammatory and mitogenic) via activation of the thromboxane A2 receptor (TBXA2R), both in physiological and pathophysiological processes. This review addresses the importance of isoprostanes in CVS in quest of appropriate biomarkers.

Identification of biologically active δ-lactone eicosanoids as paraoxonase substrates

The mammalian paraoxonases (PONs 1, 2 and 3) are a family of esterases that are highly conserved within and between species. They exhibit antioxidant and anti-inflammatory activities. However, their physiological function(s) and native substrates are uncertain. Previous structure-activity relationship studies demonstrate that PONs have a high specificity for lipophilic lactones, suggesting that such compounds may be representative of native substrates. This report describes the ability of PONs to hydrolyze two bioactive δ-lactones derived from arachidonic acid, 5,6-dihydroxy-eicosatrienoic acid lactone (5,6-DHTL) and cyclo-epoxycyclopentenone (cyclo-EC). Both lactones were very efficiently hydrolyzed by purified PON3. PON1 efficiently hydrolyzed 5,6-DHTL, but with a specific activity about 15-fold lower than PON3. 5,6-DHTL was a poor substrate for PON2. Cyclo-EC was a poor substrate for PON1 and not hydrolyzed by PON2. Studies with the PON inhibitor EDTA and a serine esterase inhibitor indicated that the PONs are the main contributors to hydrolysis of the lactones in human and mouse liver homogenates. Studies with homogenates from PON3 knockout mouse livers indicated that >80% of the 5,6-DHTL and cyclo-EC lactonase activities were attributed to PON3. The findings provide further insight into the structural requirements for PONs substrates and support the hypothesis that PONs, particularly PON1 and PON3, evolved to hydrolyze and regulate a class of lactone lipid mediators derived from polyunsaturated fatty acids.

Synopsis of arachidonic acid metabolism: A review

Arachidonic acid (AA), a 20 carbon chain polyunsaturated fatty acid with 4 double bonds, is an integral constituent of biological cell membrane, conferring it with fluidity and flexibility. The four double bonds of AA predispose it to oxygenation that leads to a plethora of metabolites of considerable importance for the proper function of the immune system, promotion of allergies and inflammation, resolving of inflammation, mood, and appetite. The present review presents an illustrated synopsis of AA metabolism, corroborating the instrumental importance of AA derivatives for health and well-being. It provides a comprehensive outline on AA metabolic pathways, enzymes and signaling cascades, in order to develop new perspectives in disease treatment and diagnosis.

Biological activities of non-enzymatic oxygenated metabolites of polyunsaturated fatty acids (NEO-PUFAs) derived from EPA and DHA: New anti-arrhythmic compounds?

ω3 Polyunsaturated fatty acids (ω3 PUFAs) have several biological properties including anti-arrhythmic effects. However, there are some evidences that it is not solely ω3 PUFAs per se that are biologically active but the non-enzymatic oxygenated metabolites of polyunsaturated fatty acids (NEO-PUFAs) like isoprostanes and neuroprostanes. Recent question arises how these molecules take part in physiological homeostasis, show biological bioactivities and anti-inflammatory properties. Furthermore, they are involved in the circulations of childbirth, by inducing the closure of the ductus arteriosus. In addition, oxidative stress which can be beneficial for the heart in given environmental conditions such as the presence of ω3 PUFAs on the site of the stress and the signaling pathways involved are also explained in this review.

NK cells of the oldest seniors represent constant and resistant to stimulation high expression of cellular protective proteins SIRT1 and HSP70

Background

Natural killer cells (NK cells) are cytotoxic lymphocytes of innate immunity that reveal some immunoregulatory properties, however, their role in the process of ageing is not completely understood. The study aimed to analyze the expression of proteins involved in cellular stress response: sirtuin 1 (SIRT1), heat shock protein 70 (HSP70) and manganese superoxide dismutase (SOD2) in human NK cells with reference to the process of ageing. Non-stimulated and stimulated with IL-2, LPS or PMA with ionomycin cells originated from peripheral blood samples of: seniors aged over 85 (‘the oldest’; n = 25; 88.5 ± 0.5 years, mean ± SEM), seniors aged under 85 (‘the old’; n = 30; 75.6 ± 0.9 years) and the young (n = 31; 20.9 ± 0.3 years). The relationships between the levels of expression of cellular protective proteins in the studied population were also analyzed. The concentrations of carbonyl groups and 8-isoprostanes, markers of oxidative stress, in both stimulated and non-stimulated cultured NK cells were measured to assess the level of the oxidative stress in the cells.

Results

The oldest seniors varied from the other age groups by significantly higher expression of SIRT1 and HSP70 both in non-stimulated and stimulated NK cells. These cells also appeared to be resistant to further stimulations with IL-2, LPS or PMA with ionomycin. Highly positive correlations between SIRT1 and intracellular HSP70 in both stimulated and non-stimulated NK cells were observed. SOD2 presented low expression in non-stimulated cells, whereas its sensitivity to stimulation increased with age of donors. High positive correlations between SOD2 and surface HSP70 were observed. We found that the markers of oxidative stress in NK cells did not change with ageing.

Conclusions

The oldest seniors revealed well developed adaptive stress response in NK cells with increased, constant levels of SIRT1 and intracellular HSP70. They presented also very high positive correlations between expression of these cellular protective proteins both in stimulated and non-stimulated cells. These phenomena may contribute to the long lifespan of this group of elderly. Interestingly, in NK cells SOD2 revealed a distinct role in cellular stress response since it showed sensitivity to stimulation increasing with age of participants. These observations provide novel data concerning the role of NK cells in the process of ageing.

LC-MS/MS Analysis of Lipid Oxidation Products in Blood and Tissue Samples

Oxygenated lipid products of non-cyclooxygenase derivatives, namely, prostanoids such as, isoprostanes and isofurans, are formed in vivo through lipid autoxidation. Insofar it has been marked as novel biomarkers of oxidative stress in the biological systems. Elevations of these oxidized products are associated with several diseases. This chapter describes the preparation and measurement of the products, including newly identified F₂-dihomo-isoprostanes and dihomo-isofurans, from plasma and tissue samples using the liquid chromatography-tandem mass spectrometry approach.

Isoprostanes as markers for muscle aging in older athletes

Introduction

Production of isoprostanes (IsoPs) is enhanced after acute, intense, and prolonged exercise, in untrained subjects. This effect is greater in older subjects. The present study aims to delineate the profile of acute-exercise-induced IsoPs levels in young and older endurance-trained subjects.

Methods

All included subjects were male, young (n = 6; 29 yrs ± 5.7) or older (n = 6; 63.7 yrs ± 2.3), and competitors. The kinetics of F₂-IsoPs in blood-sera was assessed at rest, for the maximal aerobic exercise power (MAP) corresponding to the cardio-respiratory fitness index and after a 30-min recovery period.

Results

No significant time effect on F₂-IsoPs kinetics was identified in young subjects. However, in older athletes, F₂-IsoPs blood-concentrations at the MAP were higher than at rest, whereas these blood-concentrations did not differ between rest and after the 30-min recovery period.

Conclusion

Because plasma glutathione (GSH) promotes the formation of some F₂-IsoPs, we suggest that the surprising decrease in F₂-IsoPs levels in older subjects would be caused by decreased GSH under major ROS production in older subjects. We argue that the assessment F₂-IsoPs in plasma as biomarkers of the aging process should be challenged by exercise to improve the assessment of the functional response against reactive oxygen species in older subjects.

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Acute exercise promotes an increase in F₂-IsoPs plasma level in older athletes.

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The F₂-IsoPs plasma level significantly decreased after recovery in older athletes.

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This kinetic of F₂-IsoPs could reflect a decrease of glutathione (GSH).

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Oxidative stress status determination should be challenged by exercise.

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Assessment of F₂-IsoPs plasma level should be paired to GSH assessment.

Oxidized LDL triggers changes in oxidative stress and inflammatory biomarkers in human macrophages

Oxidized low-density lipoprotein (oxLDL) is a well-recognized proatherogenic particle that functions in atherosclerosis. In this study, we established conditions to generate human oxLDL, characterized according to the grade of lipid and protein oxidation, particle size and oxylipin content. The induction effect of the cellular proatherogenic response was assessed in foam cells by using an oxLDL-macrophage interaction model. Uptake of oxLDL, reactive oxygen species production and expression of oxLDL receptors (CD36, SR-A and LOX-1) were significantly increased in THP-1 macrophages. Analyses of 35 oxylipins revealed that isoprostanes (IsoP) and prostaglandins (PGs) derived from the oxidation of arachidonic, dihomo gamma-linolenic and eicosapentaenoic acids were strongly and significantly induced in macrophages stimulated with oxLDL. Importantly, the main metabolites responsible for the THP1-macrophage response to oxLDL exposure were the oxidative stress markers 5-epi-5-F_2t-IsoP, 15-E_1t-IsoP, 8-F_3t-IsoP and 15-keto-15-F_2t-IsoP as well as inflammatory markers PGDM, 17-trans-PGF_3α, and 11β-PGF_2α, all of which are reported here, for the first time, to function in the interaction of oxLDL with THP-1 macrophages. By contrast, a salvage pathway mediated by anti-inflammatory PGs (PGE₁ and 17-trans-PGF_3α) was also identified, suggesting a response to oxLDL-induced injury. In conclusion, when THP-1 macrophages were treated with oxLDL, a specific induction of biomarkers related to oxidative stress and inflammation was triggered. This work contributes to our understanding of initial atherogenic events mediated by oxLDL-macrophage interactions and helps to generate new approaches for their modulation.

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OxLDL has a potent impact on the oxylipin profiles in THP-1 human macrophages.

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OxLDL induces biomarkers of oxidation and inflammation in THP-1 human macrophages.

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Human Macrophages produce anti-inflammatory prostaglandins after oxLDL exposure.

Replacement therapy with levothyroxine modulates platelet activation in recent-onset post-thyroidectomy subclinical hypothyroidism

BACKGROUND AND AIM

Subclinical hypothyroidism has been linked to increased risk of atherosclerotic disease. Soluble CD40 ligand (sCD40L), mainly derived from activated platelets, and the lipid peroxidation product 8-iso-prostaglandin F_2α (8-iso-PGF_2α) are known to play a relevant pathophysiological role in atherogenesis. In this study, we analyzed the relationship between thyroid hormones and circulating levels of sCD40L and 8-iso-PGF_2α in patient with recent-onset post-thyroidectomy subclinical hypothyroidism under replacement therapy.

METHODS AND RESULTS

Circulating levels of thyroid hormones, sCD40L, and 8-iso-PGF_2α were assessed in 40 recently thyroidectomized patients (33 females, mean age 52.0 ± 11.7 years) at baseline (5-7 day after surgery) and after 2 months under replacement therapy with levothyroxine (LT-4). At baseline, circulating levels of thyroid hormones were indicative of a subclinical hypothyroidism (TSH 7.7 ± 3.9 μU/mL, FT3 1.8 ± 0.6 pg/mL, and FT3 8.9 ± 3.0 pg/mL). Circulating levels of sCD40L and 8-iso-PGF_2α were directly correlated with each other (r = 0.360, p = 0.023) and with TSH levels (r = 0.322, p = 0.043 and r = 0.329 p = 0.038, respectively). After 2 months under the replacement therapy with LT-4 circulating levels of TSH (from 7.7 ± 3.9 to 2.7 ± 2.8 μU/mL, p < 0.0001), sCD40L (from 6.11 ± 2.41 to 2.43 ± 2.00 ng/mL, p < 0.0001) and 8-iso-PGF_2α (from 45.33 ± 6.94 to 40.36 ± 6.20, p < 0.0001) significantly decreased. Changes in circulating levels of sCD40L and 8-iso-PGF_2α were directly correlated with each other (r = 0.349 p = 0.028) and with changes in TSH levels (r = 0.367 p = 0.020 and r = 0.339 p = 0.032, respectively).

CONCLUSION

Our study suggests an influential role of TSH on proatherogenic activation of platelets, probably through enhanced lipid peroxidation. These findings could partially explain the increased susceptibility of patients with subclinical hypothyroidism to develop atherosclerotic disease.

4-hydroxynonenal protein adducts: Key mediator in Rett syndrome oxinflammation

In the last 15 years a strong correlation between oxidative stress (OxS) and Rett syndrome (RTT), a rare neurodevelopmental disorder known to be caused in 95% of the cases, by a mutation in the methyl-CpG-binding protein 2 (MECP2) gene, has been well documented. Here, we revised, summarized and discussed the current knowledge on the role of lipid peroxidation byproducts, with special emphasis on 4-hydroxynonenal (4HNE), in RTT pathophysiology. The posttranslational modifications of proteins via 4HNE, known as 4HNE protein adducts (4NHE-PAs), causing detrimental effects on protein functions, appear to contribute to the clinical severity of the syndrome, since their levels increase significantly during the subsequent 4 clinical stages, reaching the maximum degree at stage 4, represented by a late motor deterioration. In addition, 4HNE-PA are only partially removed due to the compromised functionality of the proteasome activity, contributing therefore to the cellular damage in RTT. All this will lead to a characteristic subclinical inflammation, defined "OxInflammation", derived by a positive feedback loop between OxS byproducts and inflammatory mediators that in a long run further aggravates the clinical features of RTT patients. Therefore, in a pathology completely orphan of any therapy, aiming 4HNE as a therapeutic target could represent a coadjuvant treatment with some beneficial impact in these patients.‬‬‬.

Isoprostanes, neuroprostanes and phytoprostanes: An overview of 25years of research in chemistry and biology

Since the beginning of the 1990's diverse types of metabolites originating from polyunsaturated fatty acids, formed under autooxidative conditions were discovered. Known as prostaglandin isomers (or isoprostanoids) originating from arachidonic acid, neuroprostanes from docosahexaenoic acid, and phytoprostanes from α-linolenic acid proved to be prevalent in biology. The syntheses of these compounds by organic chemists and the development of sophisticated mass spectrometry methods has boosted our understanding of the isoprostanoid biology. In recent years, it has become accepted that these molecules not only serve as markers of oxidative damage but also exhibit a wide range of bioactivities. In addition, isoprostanoids have emerged as indicators of oxidative stress in humans and their environment. This review explores in detail the isoprostanoid chemistry and biology that has been achieved in the past three decades.

The Risk of Oxygen during Cardiac Surgery (ROCS) trial: study protocol for a randomized clinical trial

Background

Anesthesiologists administer excess supplemental oxygen (hyper-oxygenation) to patients during surgery to avoid hypoxia. Hyper-oxygenation, however, may increase the generation of reactive oxygen species and cause oxidative damage. In cardiac surgery, increased oxidative damage has been associated with postoperative kidney and brain injury. We hypothesize that maintenance of normoxia during cardiac surgery (physiologic oxygenation) decreases kidney injury and oxidative damage compared to hyper-oxygenation.

Methods/design

The Risk of Oxygen during Cardiac Surgery (ROCS) trial will randomly assign 200 cardiac surgery patients to receive physiologic oxygenation, defined as the lowest fraction of inspired oxygen (FIO₂) necessary to maintain an arterial hemoglobin saturation of 95 to 97%, or hyper-oxygenation (FIO₂ = 1.0) during surgery. The primary clinical endpoint is serum creatinine change from baseline to postoperative day 2, and the primary mechanism endpoint is change in plasma concentrations of F₂-isoprostanes and isofurans. Secondary endpoints include superoxide production, clinical delirium, myocardial injury, and length of stay. An endothelial function substudy will examine the effects of oxygen treatment and oxidative stress on endothelial function, measured using flow mediated dilation, peripheral arterial tonometry, and wire tension myography of epicardial fat arterioles.

Discussion

The ROCS trial will test the hypothesis that intraoperative physiologic oxygenation decreases oxidative damage and organ injury compared to hyper-oxygenation in patients undergoing cardiac surgery.

Trial registration

ClinicalTrials.gov, ID: NCT02361944. Registered on the 30th of January 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2021-5) contains supplementary material, which is available to authorized users.

Comprehensive metabolomics identified lipid peroxidation as a prominent feature in human plasma of patients with coronary heart diseases

Coronary heart disease (CHD) is a complex human disease associated with inflammation and oxidative stress. The underlying mechanisms and diagnostic biomarkers for the different types of CHD remain poorly defined. Metabolomics has been increasingly recognized as an enabling technique with the potential to identify key metabolomic features in an attempt to understand the pathophysiology and differentiate different stages of CHD. We performed comprehensive metabolomic analysis in human plasma from 28 human subjects with stable angina (SA), myocardial infarction (MI), and healthy control (HC). Subsequent analysis demonstrated a uniquely altered metabolic profile in these CHD: a total of 18, 37 and 36 differential metabolites were identified to distinguish SA from HC, MI from SA, and MI from HC groups respectively. Among these metabolites, glycerophospholipid (GPL) metabolism emerged as the most significantly disturbed pathway. Next, we used a targeted metabolomic approach to systematically analyze GPL, oxidized phospholipid (oxPL), and downstream metabolites derived from polyunsaturated fatty acids (PUFAs), such as arachidonic acid and linoleic acid. Surprisingly, lipids associated with lipid peroxidation (LPO) pathways including oxidized PL and isoprostanes, isomers of prostaglandins, were significantly elevated in plasma of MI patients comparing to HC and SA, consistent with the notion that oxidative stress-induced LPO is a prominent feature in CHD. Our studies using the state-of-the-art metabolomics help to understand the underlying biological mechanisms involved in the pathogenesis of CHD; LPO metabolites may serve as potential biomarkers to differentiation MI from SA and HC.

Increased static and decreased capacity oxidation-reduction potentials in plasma are predictive of metabolic syndrome

Electric conductivity in plasma is the balance between oxidized and reduced molecules (static Oxidation-Reduction Potential, sORP) and the amount of readily oxidizable molecules (capacity ORP, cORP). Adults with metabolic syndrome (MetS) have increased inflammation, dyslipidemia and oxidative stress; therefore, participants with MetS were hypothesized to have higher plasma sORP and lower cORP than those measures in healthy adults. Heparin-anticoagulated plasma from healthy and age- and gender-matched individuals with MetS (BMI: 22.6±0.7 vs. 37.7±3.0 kg/m², respectively) was collected in the fasting state at 0, 24, 48, and 72 h during each of four separate interventions in a clinical trial. At baseline, plasma sORP was 12.4% higher (P=0.007), while cORP values were less than half (41.1%, P=0.001) in those with MetS compared with healthy participants. An sORP >140 mV detected MetS with 90% sensitivity and 80% specificity, while a cORP <0.50 μC detected MetS with 80% sensitivity and 100% specificity. sORP and cORP values in participants with MetS compared with healthy adults were linked to differences in waist circumference and BMI; in plasma markers of dyslipidemia (triglycerides, HDL-cholesterol, and oxidized LDL-cholesterol) and inflammation (C-reactive protein, IL-10); as well as with urinary markers of lipid peroxidation (e.g., 2,3-dinor-5,6-dihydro-8-iso-PGF_2α; 2,3-dinor-8-iso-PGF_2α). Higher sORP values are a robust indicator of metabolic stress, while lower cORP values act as an indicator of decreased metabolic resilience.

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Metabolic syndrome (MetS) adults have increased inflammation and oxidative stress.

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Plasma static (sORP) and capacity oxidation-reduction potentials (cORP) are easily measured.

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MetS sORP and cORP were linked to dyslipidemia, inflammation and oxidative damage.

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Higher sORP indicates stress; lower cORP indicates decreased resilience.

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sORP >140.0 mV or cORP <0.50 μC predicted MetS.

Assessment of Isoprostanes in Human Plasma: Technical Considerations and the Use of Mass Spectrometry

Oxygenated lipid mediators released from non-enzymatic peroxidation of polyunsaturated fatty acids (PUFA) are known to have functional roles in humans. Notably, among these lipid mediators, isoprostanes molecules are robust biomarkers of oxidative stress but those from n-3 PUFA are also bioactive molecules. In order to identify and assess the isoprostanes, the use of mass spectrometry (MS) for analysis is preferable and has been used for over two decades. Gas chromatography (GC) is commonly coupled to the MS to separate the derivatized isoprostanes of interest in biological samples. In order to increase the accuracy of the analytical performance, GC-MS/MS was also applied. Lately, MS or MS/MS has been coupled with high-performance liquid chromatography to assess multiple isoprostane molecules in a single biological sample without derivatization process. However, there are limitations for the use of LC-MS/MS in the measurement of plasma isoprostanes, which will be discussed in this review.

A case of contagious toxicity? Isoprostanes as potential emerging contaminants of concern

Isoprostanes are useful biomarkers of human and animal health, being representative of oxidative stress processes, and having biological impacts associated with toxicity and disease. Isoprostanes are also chemically stable, a property facilitating population-level health assessments through wastewater sampling. However, as biologically-active entities, the presence of isoprostanes in domestic effluents could have toxic impacts on biota in receiving environments. As such it is proposed that isoprostanes are emerging organic contaminants of particular concern. Fish and aquatic invertebrates may be affected by the presence of isoprostanes in wastewaters through mechanisms such as reproductive impairment, cardiovascular disturbance and/or oxidative stress. This would represent a unique scenario of "contagious" toxicity, whereby human health has a direct toxicological consequence on aquatic animal health.

Preliminary case control study to establish the correlation between novel peroxidation biomarkers in cord serum and the severity of hypoxic ischemic encephalopathy

BACKGROUND

Hypoxic-ischemic encephalopathy (HIE) has deleterious neurological consequences. To identify patients at risk of neuronal damage deserving implementation of neuroprotective strategies clinicians have relied on prenatal sentinel events, postnatal clinical assessment (Apgar score), and blood gas analysis. This feasibility study aimed to assess if lipid peroxidation byproducts associated with neuronal damage correlated with cord blood metabolic acidemia in patients with HIE.

POPULATION AND METHODS

This is a case/control study in which cases were newborn infants with severe acidemia (pH<7.00; base excess ≥12mmol/L) while control babies exhibited normal gases (pH=7.20-7.40; base excess=-4 to +4mmol/L) in the first cord blood analysis performed immediately after birth. Concomitantly, lipid peroxidation byproducts were determined using ultra performance liquid chromatography coupled to mass spectrometry in the same cord blood sample.

RESULTS

A total of 19 controls and 20 cases were recruited. No differences in gestational characteristics were present. However, cases exhibited profound metabolic alterations as compared to controls (Cases vs.

CONTROL

pH=6.90±0.1 vs. 7.33±0.03; base excess=-15±3 vs. -1±2mmol/L), 85% were admitted to the NICU, and 50% developed symptoms of HIE. 8-iso-15(R)-PGF2α (P=0.01) and total isoprostanes (P=0.045) presented statistically significant differences between cases and control groups and correlated with level of HIE.

CONCLUSIONS

The 8-iso-15(R)-PGF2α and isoprostanes reflecting oxidative damage are significantly increased in severe postnatal acidemia. Follow up studies with adequate power are necessary to confirm if these biomarkers measured in cord blood serum could be predictive of neonatal encephalopathy.

Prenatal exposure to the organophosphate insecticide chlorpyrifos enhances brain oxidative stress and prostaglandin E2 synthesis in a mouse model of idiopathic autism

BACKGROUND

Autism spectrum disorders (ASD) are emerging as polygenic and multifactorial disorders in which complex interactions between defective genes and early exposure to environmental stressors impact on the correct neurodevelopment and brain processes. Organophosphate insecticides, among which chlorpyrifos (CPF), are widely diffused environmental toxicants associated with neurobehavioral deficits and increased risk of ASD occurrence in children. Oxidative stress and dysregulated immune responses are implicated in both organophosphate neurodevelopmental effects and ASD etiopathogenesis. BTBR T+tf/J mice, a well-studied model of idiopathic autism, show several behavioral and immunological alterations found in ASD children, and we recently showed that CPF gestational exposure strengthened some of these autistic-like traits. In the present study, we aimed at investigating whether the behavioral effects of gestational CPF administration are associated with brain increased oxidative stress and altered lipid mediator profile.

METHODS

Brain levels of F2-isoprostanes (15-F2t-IsoP), as index of in vivo oxidative stress, and prostaglandin E2 (PGE2), a major arachidonic acid metabolite released by immune cells and by specific glutamatergic neuron populations mainly in cortex and hippocampus, were assessed by specific enzyme-immuno assays in brain homogenates from BTBR T+tf/J and C57Bl6/J mice, exposed during gestation to either vehicle or CPF. Measures were performed in mice of both sexes, at different postnatal stages (PNDs 1, 21, and 70).

RESULTS

At birth, BTBR T+tf/J mice exhibited higher baseline 15-F2t-IsoP levels as compared to C57Bl6/J mice, suggestive of greater oxidative stress processes. Gestational treatment with CPF-enhanced 15-F2t-IsoP and PGE2 levels in strain- and age-dependent manner, with 15-F2t-IsoP increased in BTBR T+tf/J mice at PNDs 1 and 21, and PGE2 elevated in BTBR T+tf/J mice at PNDs 21 and 70. At PND 21, CPF effects were sex-dependent being the increase of the two metabolites mainly associated with male mice. CPF treatment also induced a reduction of somatic growth, which reached statistical significance at PND 21.

CONCLUSIONS

These findings indicate that the autistic-like BTBR T+tf/J strain is highly vulnerable to environmental stressors during gestational period. The results further support the hypothesis that oxidative stress might be the link between environmental neurotoxicants such as CPF and ASD. The increased levels of oxidative stress during early postnatal life could result in delayed and long-lasting alterations in specific pathways relevant to ASD, of which PGE2 signaling represents an important one.

Effect of long-term vitamin E and selenium supplementation on urine F2-isoprostanes, a biomarker of oxidative stress

BACKGROUND

Cigarette smoking generates reactive oxidant species and contributes to systemic oxidative stress, which plays a role in the pathophysiology of chronic diseases. Nutrients with antioxidant properties, including vitamin E and selenium, are proposed to reduce systemic oxidative burden and thus to mitigate the negative health effects of reactive oxidant species.

OBJECTIVE

Our objective was to determine whether long-term supplementation with vitamin E and/or selenium reduces oxidative stress in smokers, as measured by urine 8-iso-prostaglandin F2-alpha (8-iso-PGF2α).

DESIGN

We measured urine 8-iso-PGF2α with competitive enzyme linked immunoassay (ELISA) in 312 male current smokers after 36 months of intervention in a randomized placebo-controlled trial of vitamin E (400IU/d all rac-α-tocopheryl acetate) and/or selenium (200µg/d L-selenomethionine). We used linear regression to estimate the effect of intervention on urine 8-iso-PGF2α, with adjustments for age and race.

RESULTS

Compared to placebo, vitamin E alone lowered urine 8-iso-PGF2α by 21% (p=0.02); there was no effect of combined vitamin E and selenium (intervention arm lower by 9%; p=0.37) or selenium alone (intervention arm higher by 8%; p=0.52).

CONCLUSIONS

Long-term vitamin E supplementation decreases urine 8-iso-PGF2α among male cigarette smokers, but we observed little to no evidence for an effect of selenium supplementation, alone or combined with vitamin E.

Simultaneous quantitative profiling of 20 isoprostanoids from omega-3 and omega-6 polyunsaturated fatty acids by LC-MS/MS in various biological samples

Isoprostanoids are a group of non-enzymatic oxygenated metabolites of polyunsaturated fatty acids. It belongs to oxylipins group, which are important lipid mediators in biological processes, such as tissue repair, blood clotting, blood vessel permeability, inflammation and immunity regulation. Recently, isoprostanoids from eicosapentaenoic, docosahexaenoic, adrenic and α-linolenic namely F3-isoprostanes, F4-neuroprostanes, F2-dihomo-isoprostanes and F1-phytoprostanes, respectively have attracted attention because of their putative contribution to health. Since isoprostanoids are derived from different substrate of PUFAs and can have similar or opposing biological consequences, a total isoprostanoids profile is essential to understand the overall effect in the testing model. However, the concentration of most isoprostanoids range from picogram to nanogram, therefore a sensitive method to quantify 20 isoprostanoids simultaneously was formulated and measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The lipid portion from various biological samples was extracted prior to LC-MS/MS evaluation. For all the isoprostanoids LOD and LOQ, and the method was validated on plasma samples for matrix effect, yield of extraction and reproducibility were determined. The methodology was further tested for the isoprostanoids profiles in brain and liver of LDLR(-/-) mice with and without docosahexaenoic acid (DHA) supplementation. Our analysis showed similar levels of total F2-isoprostanes and F4-neuroprostanes in the liver and brain of non-supplemented LDLR(-/-) mice. The distribution of different F2-isoprostane isomers varied between tissues but not for F4-neuroprostanes which were predominated by the 4(RS)-4-F4t-neuroprostane isomer. DHA supplementation to LDLR(-/-) mice concomitantly increased total F4-neuroprostanes levels compared to F2-isoprostanes but this effect was more pronounced in the liver than brain.

n-3 Fatty acids regulate the inflammatory-state related genes in the lung epithelial cells exposed to polycyclic aromatic hydrocarbons

BACKGROUND

Chronic airway inflammation is coordinated by a complex of inflammatory mediators, including eicosanoids. The aim of this study was to evaluate the impact of polycyclic aromatic hydrocarbons (PAHs) on the human lung epithelial carcinoma A549 cells supplemented with docosahexaenoic (DHA) and eicosapentaenoic (EPA) acids.

METHODS

We analyzed the influence of DHA, EPA and/or benzo(a)pyrene (BaP), chrysene (Chr), fluoranthene (Flu) and benzo(a)anthracene (Baa) treatment on the fatty acids (FAs) profile and the formation of isoprostanes. We studied the cyclooxygenase-2, FP-receptor, peroxisome proliferator-activated receptors PPARδ and PPARγ, transcription factor NF-кB p50 and p65 expression by Western blot, phospholipase A2 (cPLA2) activity, as well as aryl hydrocarbon receptor (AHR), cytochrome P450 (CYP1A1), phospholipase A2 (PLA2G4A) and prostaglandin synthase 2 (PTGS2) gene expression by qRT-PCR.

RESULTS

DHA or EPA supplementation and BaP or Baa treatment resulted in a higher level of PGF3α. COX-2 expression was decreased while PPARδ expression and cPLA2 activity was increased after fatty acid supplementation and PAHs treatment. DHA and EPA up-regulated AHR and PLA2G4A genes.

CONCLUSIONS

Supplementation with n-3 FAs resulted in changes of inflammatory-state related genes in the lung epithelial cells exposed to PAHs. The altered profile of lipid mediators from n-3 FA as well as repression of the COX-2 protein by n-3 PUFAs in A549 cells incubated with PAHs suggests anti-inflammatory and pro-resolving properties of DHA and EPA. It remains to be shown whether these pleiotropic and protective actions of n-3 FAs contribute to fish oil's therapeutic effect in asthma.

Plasma F2-isoprostane class VI isomers at 12-18 weeks of pregnancy are associated with later occurrence of preeclampsia

Preeclampsia (PE) has long been associated with early oxidative stress, although the symptoms occur later in pregnancy. We have hypothesized that the oxidative stress in PE, as characterized by the presence of F2-isoprostane (F2-isoP) isomers in late pregnancy, should already be present in plasma at the first regular visit of the obstetrical follow-up. There are 64 possible isomers of F2-isoPs derived from the oxidation of arachidonic acid (AA), but only one of these isomers has been investigated so far in PE, the classical 8-iso-PGF2α. Here, we have investigated two regioisomers of class III (8-iso-15(R)-PGF2α and 8-iso-PGF2α) and a mix of two isomers of class VI ((±)5-iPF2α-VI) in plasma samples collected prospectively at 12-18 weeks from normotensive controls (n = 60) and pregnant mothers who developed PE later in pregnancy (n = 33). The plasma samples were subjected to alkaline hydrolysis followed by liquid-liquid extraction to extract total F2-isoPs for later quantification by HPLC-MS/MS. The F2-isoPs were normalized to either plasma volume or polyunsaturated fatty acid (PUFA) levels measured by GC-FID in plasma phospholipids. Early in pregnancy, only the class VI F2-isoP isomers were found at concentrations significantly higher in women developing PE later in pregnancy (+13%; p = 0.0074). Normalization of F2-isoPs to their substrate, AA, or the omega-3 to omega-6 ratio improved the predictability of PE as determined by receiver operating characteristic (from area under the curve of 0.67 to 0.68 and 0.70 respectively). Interestingly, omega-3 fatty acids were 25% higher in the control group than in the PE group (P = 0.0225). Omega-6 PUFAs correlated with F2-Isop isomers only in cases of PE (r > 0.377; P >0.03, Spearman correlation). In sum, this study indicates that specific isomers of class VI are significant predictors of PE. This work also suggests that F2-isoP isomers are not all generated and eliminated to the same extent and are influenced by the PUFA composition of plasma phospholipids.

Aspirin provocation increases 8-iso-PGE2 in exhaled breath condensate of aspirin-hypersensitive asthmatics

BACKGROUND

Isoprostanes are bioactive compounds formed by non-enzymatic oxidation of polyunsaturated fatty acids, mostly arachidonic, and markers of free radical generation during inflammation. In aspirin exacerbated respiratory disease (AERD), asthmatic symptoms are precipitated by ingestion of non-steroid anti-inflammatory drugs capable for pharmacologic inhibition of cyclooxygenase-1 isoenzyme. We investigated whether aspirin-provoked bronchoconstriction is accompanied by changes of isoprostanes in exhaled breath condensate (EBC).

METHODS

EBC was collected from 28 AERD subjects and 25 aspirin-tolerant asthmatics before and after inhalatory aspirin challenge. Concentrations of 8-iso-PGF2α, 8-iso-PGE2, and prostaglandin E2 were measured using gas chromatography/mass spectrometry. Leukotriene E4 was measured by immunoassay in urine samples collected before and after the challenge.

RESULTS

Before the challenge, exhaled 8-iso-PGF2α, 8-iso-PGE2, and PGE2 levels did not differ between the study groups. 8-iso-PGE2 level increased in AERD group only (p=0.014) as a result of the aspirin challenge. Urinary LTE4 was elevated in AERD, both in baseline and post-challenge samples. Post-challenge airways 8-iso-PGE2 correlated positively with urinary LTE4 level (p=0.046), whereas it correlated negatively with the provocative dose of aspirin (p=0.027).

CONCLUSION

A significant increase of exhaled 8-iso-PGE2 after inhalatory challenge with aspirin was selective and not present for the other isoprostane measured. This is a novel finding in AERD, suggesting that inhibition of cyclooxygenase may elicit 8-iso-PGE2 production in a specific mechanism, contributing to bronchoconstriction and systemic overproduction of cysteinyl leukotrienes.