Angiotensin II acts through Rac1 to upregulate pendrin: role of NADPH oxidase.

Angiotensin II increases apical plasma membrane pendrin abundance and function. This study explored the role of the small GTPase Rac1 in the regulation of pendrin by angiotensin II. To do this, we generated intercalated cell (IC) Rac1 knockout mice and observed that IC Rac1 gene ablation reduced the relative abundance of pendrin in the apical region of intercalated cells in angiotensin II-treated mice but not vehicle-treated mice. Similarly, the Rac1 inhibitor EHT 1864 reduced apical pendrin abundance in angiotensin II-treated mice, through a mechanism that does not require aldosterone. This IC angiotensin II-Rac1 signaling cascade modulates pendrin subcellular distribution without significantly changing actin organization. However, NADPH oxidase inhibition with APX 115 reduced apical pendrin abundance in vivo in angiotensin II-treated mice. Moreover, superoxide dismutase mimetics reduced Cl- absorption in angiotensin II-treated cortical collecting ducts perfused in vitro. Since Rac1 is an NADPH subunit, Rac1 may modulate pendrin through NADPH oxidase-mediated reactive oxygen species production. Because pendrin gene ablation blunts the pressor response to angiotensin II, we asked if pendrin blunts the angiotensin II-induced increase in kidney superoxide. Although kidney superoxide was similar in vehicle-treated wild-type and pendrin knockout mice, it was lower in angiotensin II-treated pendrin-null kidneys than in wild-type kidneys. We conclude that angiotensin II acts through Rac1, independently of aldosterone, to increase apical pendrin abundance. Rac1 may stimulate pendrin, at least partly, through NADPH oxidase. This increase in pendrin abundance contributes to the increment in blood pressure and kidney superoxide content seen in angiotensin II-treated mice.NEW & NOTEWORTHY This study defines a new signaling mechanism by which angiotensin II modulates oxidative stress and blood pressure.

HIV-1 Tat and morphine interactions dynamically shift striatal monoamine levels and exploratory behaviors over time.

Despite the advent of combination anti-retroviral therapy (cART), nearly half of people infected with HIV treated with cART still exhibit HIV-associated neurocognitive disorders (HAND). HAND can be worsened by co-morbid opioid use disorder. The basal ganglia are particularly vulnerable to HIV-1 and exhibit higher viral loads and more severe pathology, which can be exacerbated by co-exposure to opioids. Evidence suggests that dopaminergic neurotransmission is disrupted by HIV exposure, however, little is known about whether co-exposure to opioids may alter neurotransmitter levels in the striatum and if this in turn influences behavior. Therefore, we assayed motor, anxiety-like, novelty-seeking, exploratory, and social behaviors, and levels of monoamines and their metabolites following 2 weeks and 2 months of Tat and/or morphine exposure in transgenic mice. Morphine decreased dopamine levels, but significantly elevated norepinephrine, the dopamine metabolites dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), and the serotonin metabolite 5-hydroxyindoleacetic acid, which typically correlated with increased locomotor behavior. The combination of Tat and morphine altered dopamine, DOPAC, and HVA concentrations differently depending on the neurotransmitter/metabolite and duration of exposure but did not affect the numbers of tyrosine hydroxylase-positive neurons in the mesencephalon. Tat exposure increased the latency to interact with novel conspecifics, but not other novel objects, suggesting the viral protein inhibits exploratory behavior initiation in a context-dependent manner. By contrast, and consistent with prior findings that opioid misuse can increase novelty-seeking behavior, morphine exposure increased the time spent exploring a novel environment. Finally, Tat and morphine interacted to affect locomotor activity in a time-dependent manner, while grip strength and rotarod performance were unaffected. Together, our results provide novel insight into the unique effects of HIV-1 Tat and morphine on monoamine neurochemistry that may underlie their divergent effects on motor and exploratory behavior.

Mixture effects of prenatal exposure to polybrominated diphenyl ethers on urinary oxidative stress biomarkers in the Chemicals in Our Bodies Cohort.

Polybrominated diphenyl ethers (PBDEs) exposure is associated with preterm birth. Laboratory studies suggest that PBDEs lead to elevated oxidative stress, a known contributor to preterm birth in epidemiologic studies. We hypothesized that elevated levels of PBDEs would be associated with increased oxidative stress during human pregnancy. Participants in this analysis were enrolled in the Chemicals in Our Bodies cohort and resided in the San Francisco Bay Area (N=201). Four PBDEs (BDE-47, -99, -100, -153) were measured in second trimester serum. Urinary oxidative stress biomarkers were measured at two timepoints (second and third trimester) and included 8-isoprostane-prostaglandin-F2α [8-iso-PGF2α], 2,3-dinor-5,6-dihydro-8-iso-PGF2α, 2,3-dinor-8-iso-PGF2α, and prostaglandin-F2α [PGF2α]. Associations between individual PBDEs and oxidative stress biomarkers (averaged and trimester specific) were examined using linear regression. Quantile g-computation and Bayesian kernel machine regression (BKMR) were used to assess cumulative effects of PBDEs. Quantile g-computation showed that higher concentrations of PBDEs were associated with increasing 8-iso-PGF2α, 2,3-dinor-8-iso-PGF2α, and PGF2α. Associations were greatest in magnitude for second trimester levels of 2,3-dinor-8-iso-PGF2α (mean change per quartile increase=0.25, 95% confidence interval=0.09, 0.41). Associations were similar using BKMR and linear regression. Our findings suggest that oxidative stress may be a plausible biological pathway by which PBDE exposure might lead to preterm birth.

Intermittent energy restriction inhibits tumor growth and enhances paclitaxel response in a transgenic mouse model of endometrial cancer.

OBJECTIVE: Overweight/obesity is the strongest risk factor for endometrial cancer (EC), and weight management can reduce that risk and improve survival. We aimed to establish the differential benefits of intermittent energy restriction (IER) and low-fat diet (LFD), alone and in combination with paclitaxel, to reverse the procancer effects of high-fat diet (HFD)-induced obesity in a mouse model of EC. METHODS: Lkb1fl/flp53fl/fl mice were fed HFD or LFD to generate obese and lean phenotypes, respectively. Obese mice were maintained on a HFD or switched to a LFD (HFD-LFD) or IER (HFD-IER). Ten weeks after induction of endometrial cancer, mice in each group received paclitaxel or placebo for 4 weeks. Body and tumor weights; tumoral transcriptomic, metabolomic and oxylipin profiles; and serum metabolic hormones and chemocytokines were assessed. RESULTS: HFD-IER and HFD-LFD, relative to HFD, reduced body weight; reversed obesity-induced alterations in serum insulin, leptin and inflammatory factors; and decreased tumor incidence and mass, often to levels emulating those associated with continuous LFD. Concurrent paclitaxel, versus placebo, enhanced tumor suppression in each group, with greatest benefit in HFD-IER. The diets produced distinct tumoral gene expression and metabolic profiles, with HFD-IER associated with a more favorable (antitumor) metabolic and inflammatory environment. CONCLUSION: In Lkb1fl/flp53fl/fl mice, IER is generally more effective than LFD in promoting weight loss, inhibiting obesity-related endometrial tumor growth (particularly in combination with paclitaxel), and reversing detrimental obesity-related metabolic effects. These findings lay the foundation for further investigations of IER as an EC prevention and treatment strategies in overweight/obesity women.

Association between healthy dietary patterns and markers of oxidative stress in the Sister Study.

PURPOSE: We assessed the cross-sectional association between healthy dietary patterns [alternate Mediterranean diet (aMED), Dietary Approaches to Stop Hypertension (DASH), alternative Healthy Eating Index (aHEI), and Healthy Eating Index 2015 (HEI-2015)] and urinary biomarkers of oxidative stress. METHODS: Between 2003 and 2009, the Sister Study enrolled 50,884 breast cancer-free US women aged 35 to 74 (non-Hispanic White, 83.7%). Data were analyzed for 844 premenopausal and 454 postmenopausal women who had urine samples analyzed for F2-isoprostanes and non-missing covariate data. Food frequency questionnaire responses were used to calculate dietary pattern scores. Concentrations of 8-iso-prostaglandin F2α (8-iso-PGF2α) and its metabolite (8-iso-PGF2α-M) were measured in urine samples by GC/MS for premenopausal women and LC/MS for postmenopausal women. Multivariable linear regression models were used to estimate associations between aMED, DASH, aHEI, and HEI-2015 and urinary F2-isoprostanes by menopausal status. Effect modification by sociodemographic, lifestyle, and clinical characteristics was also evaluated. RESULTS: Among premenopausal women, the four dietary indices were inversely associated with 8-iso-PGF2α (aMED ßQ4vsQ1: - 0.17, 95% CI - 0.27, - 0.08; DASH ßQ4vsQ1: - 0.18, 95% CI - 0.28, - 0.08; aHEI ßQ4vsQ1: - 0.20, 95% CI - 0.30, - 0.10; HEI-2015 ßQ4vsQ1: - 0.19, 95% CI - 0.29, - 0.10). In contrast, inverse associations with 8-iso-PGF2α-M were found for the continuous aMED, aHEI, and HEI-2015. Associations between dietary indices and 8-iso-PGF2α were generally stronger among younger women, women with lower income, and women with higher BMI. Similar results were observed among postmenopausal women, though only the continuous DASH and aHEI models were statistically significant. CONCLUSION: Healthy dietary patterns were associated with lower levels of oxidative stress.

Association between F2-Isoprostane Metabolites and Weight Change in Older Women: A Longitudinal Analysis.

INTRODUCTION: Theoretically, some metabolic traits may predispose older individuals to weight loss during aging, leading to increased all-cause mortality and many serious health issues. Biomarkers to robustly predict progressive weight loss during aging are, however, lacking. We prospectively assessed if urinary levels of F2-isoprostanes and their peroxisomal ß-oxidation metabolite, 2,3-dinor-5,6-dihydro-15-F2t-isoprostane (F2-IsoP-M), were associated with subsequent weight loss in middle-aged and older women. METHODS: Included in the analysis were 2,066 women aged 40-70 years, a subset of a prospective cohort study. F2-isoprostanes (F2-IsoPs) and its ß-oxidation metabolite, F2-IsoP-M, were measured in urine using gas chromatography-mass spectrometry. Measurements of anthropometry and exposures to major determinants of body weight were performed at baseline and repeated thrice over 15-year follow-up. The longitudinal associations of F2-IsoP-M and the F2-IsoP-M to its parent compound, F2-IsoP, ratio (MPR) with repeatedly measured weight changes were examined using linear mixed-effect models. RESULTS: After adjusting for time-varying covariates: energy intake, physical activity, and comorbidity index, among others, levels of F2-IsoP-M and the MPR were both inversely associated with percentage of weight change. Weight in the highest quartile of these two biomarkers was 1.33% (95% CI = -2.41, -0.24) and 1.09% (95% CI = -2.16, -0.02) lower than those in the lowest quartile group, with p for trend of 0.01 and 0.03, respectively. The inverse association was consistently seen across follow-up periods, although appearing stronger with prolonged follow-up. There was no association between the parent compound, F2-IsoPs, and weight change. CONCLUSION: This study demonstrates the first piece of evidence to associate F2-IsoP metabolism, peroxisomal ß-oxidation, with weight loss in older women. Further investigations into the role of lipid peroxidation and peroxisomal ß-oxidation in weight change among older individuals are warranted.

Associations between oxidative stress biomarkers during pregnancy and infant cognition at 7.5 months.

Oxidative stress has been identified as an important biological pathway leading to neurodevelopmental delay. However, studies assessing the effects of oxidative stress on cognitive outcomes during infancy, a critical period of neurodevelopment, are limited. Our analysis included a subset of those enrolled in the Illinois Kids Development Study (N = 144). Four oxidative stress biomarkers (8-isoprostane-PGF2α , 2,3-dinor-5,6-dihydro-8-iso-PGF2α , 2,3-dinor-8-iso-PGF2α , and prostaglandin-F2α ) were measured in second and third trimesters urine and were averaged. Infant cognition was measured using a visual recognition memory task consisting of five blocks, each with one familiarization trial (two identical stimuli) and two test trials (one familiar and one novel stimulus). Outcomes measured included average run duration (a measure of information processing speed), novelty preference (a measure of recognition memory), time to reach familiarization, and shift rate (measures of attention). Linear regression was used to estimate associations between individual oxidative stress biomarkers and each outcome. Increasing 8-isoprostane-PGF2α , 2,3-dinor-8-iso-PGF2α , and prostaglandin-F2α were associated with a decrease in novelty preference (ß = -0.02, 95% confidence interval [CI] = -0.03, 0.00; ß = -0.02, 95% CI = -0.04, 0.00; ß = -0.01, 95% CI = -0.02, 0.00, respectively), as well as a modest increase in shift rate. These findings suggest that oxidative stress may be associated with poorer recognition memory in early infancy.

Dietary Inflammatory Potential and the Risk of Serrated and Adenomatous Colorectal Polyps.

Studies of dietary inflammation potential and risks of colorectal cancer precursors are limited, particularly for sessile serrated lesions (SSLs). This study examines the association using the energy-adjusted dietary inflammatory index (E-DIITM), a measure of anti- and/or pro-inflammatory diet, in a large US colonoscopy-based case-control study of 3246 controls, 1530 adenoma cases, 472 hyperplastic polyp cases, and 180 SSL cases. Odds ratios (ORs) and 95% confidence intervals (CIs) were derived from logistic regression models. Analyses were stratified by participant characteristics, and urinary prostaglandin E2 metabolite (PGE-M) and high-sensitivity plasma C-reactive protein (hs-CRP) levels, inflammation biomarkers. Highest E-DII™ intake was associated with significantly increased risks of colorectal adenomas (OR 1.36, 95% CI 1.11, 1.67), and hyperplastic polyps (OR 1.43, 95% CI 1.06, 1.98), compared with participants consuming the lowest E-DII™ quartile. A similar, but non-significant, increased risk was also observed for SSLs (OR 1.41, 95% CI 0.82, 2.41). The positive association was stronger in females (pinteraction <0.001), normal weight individuals (ptrend 0.01), and in individuals with lower inflammatory biomarkers (ptrend 0.02 and 0.01 for PGE-M and hs-CRP, respectively). A high E-DII™ is associated with colorectal polyp risk, therefore promoting an anti-inflammatory diet may aid in preventing colorectal polyps.

Urinary oxidative stress biomarkers are associated with preterm birth: an Environmental Influences on Child Health Outcomes program study.

BACKGROUND: Preterm birth is the leading cause of infant morbidity and mortality worldwide. Elevated levels of oxidative stress have been associated with an increased risk of delivering before term. However, most studies testing this hypothesis have been conducted in racially and demographically homogenous study populations, which do not reflect the diversity within the United States. OBJECTIVE: We leveraged 4 cohorts participating in the Environmental Influences on Child Health Outcomes Program to conduct the largest study to date examining biomarkers of oxidative stress and preterm birth (N=1916). Furthermore, we hypothesized that elevated oxidative stress would be associated with higher odds of preterm birth, particularly preterm birth of spontaneous origin. STUDY DESIGN: This study was a pooled analysis and meta-analysis of 4 birth cohorts spanning multiple geographic regions in the mainland United States and Puerto Rico (208 preterm births and 1708 full-term births). Of note, 8-iso-prostaglandin-F2α, 2,3-dinor-5,6-dihydro-8-iso-prostaglandin-F2α (F2-IsoP-M; the major 8-iso-prostaglandin-F2α metabolite), and prostaglandin-F2α were measured in urine samples obtained during the second and third trimesters of pregnancy. Logistic regression was used to calculate adjusted odds ratios and 95% confidence intervals for the associations between averaged biomarker concentrations for each participant and all preterm births, spontaneous preterm births, nonspontaneous preterm births (births of medically indicated or unknown origin), and categories of preterm birth (early, moderate, and late). Individual oxidative stress biomarkers were examined in separate models. RESULTS: Approximately 11% of our analytical sample was born before term. Relative to full-term births, an interquartile range increase in averaged concentrations of F2-IsoP-M was associated with higher odds of all preterm births (odds ratio, 1.29; 95% confidence interval, 1.11-1.51), with a stronger association observed for spontaneous preterm birth (odds ratio, 1.47; 95% confidence interval, 1.16-1.90). An interquartile range increase in averaged concentrations of 8-iso-prostaglandin-F2α was similarly associated with higher odds of all preterm births (odds ratio, 1.19; 95% confidence interval, 0.94-1.50). The results from our meta-analysis were similar to those from the pooled combined cohort analysis. CONCLUSION: Here, oxidative stress, as measured by 8-iso-prostaglandin-F2α, F2-IsoP-M, and prostaglandin-F2α in urine, was associated with increased odds of preterm birth, particularly preterm birth of spontaneous origin and delivery before 34 completed weeks of gestation.

Mediator production and severity of aspirin-induced respiratory reactions: Impact of sampling site and body mass index.

BACKGROUND: Patients with aspirin-exacerbated respiratory disease can experience severe reactions during aspirin challenge that are associated with high levels of mast cell mediators. The tissue source and clinical factors contributing to systemic mediator levels are unknown. OBJECTIVE: We sought to determine the concordance between respiratory tract and systemic inflammatory mediator levels and identify clinical factors associated with these mediators. METHODS: We performed an oral aspirin challenge in 30 subjects with aspirin-exacerbated respiratory disease. Respiratory symptoms and function, nasal mucosal fluid, blood, and urine were collected at baseline, at the onset of a respiratory reaction, and over a 3-hour observation period. Changes in nasal and systemic mediator levels were compared. RESULTS: Neither tryptase nor leukotriene E4 levels in nasal fluid correlated with serum tryptase or urinary leukotriene E4 levels at baseline or during reactions. We observed no association between the baseline or aspirin-induced change in nasal versus urinary leukotriene E4 and serum tryptase levels. Body mass index inversely correlated with baseline and aspirin-induced urinary leukotriene E4, prostaglandin D2 metabolite, and serum tryptase levels, as well as with aspirin-induced symptoms and respiratory function, but not with nasal mediators. CONCLUSIONS: The levels of nasal and systemic aspirin-induced mast cell products are discordant in aspirin-exacerbated respiratory disease. Systemically detected levels are likely derived from mast cells outside of the sinonasal cavity and do not accurately reflect upper respiratory tract production. Increased body mass index decreases systemic mast cell mediator production and reaction severity, supporting a contribution of metabolic regulation in aspirin-induced systemic reactions.

Enhanced parasympathetic cholinergic activity with galantamine inhibited lipid-induced oxidative stress in obese African Americans.

BACKGROUND: African Americans (AAs) are disproportionately affected by cardiovascular disease (CVD), they are 20% more likely to die from CVD than whites, chronic exposure to inflammation and oxidative stress contributes to CVD. In previous studies, enhancing parasympathetic cholinergic activity has been shown to decrease inflammation. Considering that AAs have decreased parasympathetic activity compared to whites, we hypothesize that stimulating it with a central acetylcholinesterase (AChE) inhibitor, galantamine, would prevent lipid-induced oxidative stress. OBJECTIVE: To test the hypothesis that acute dose of galantamine, an AChE inhibitor, decreases lipid-induced oxidative stress in obese AAs. METHODS: Proof-of-concept, double-blind, randomized, placebo-controlled, crossover study that tested the effect of a single dose of 16 mg of galantamine versus placebo on lipid-induced oxidative stress in obese AAs. Subjects were studied on two separate days, one week apart. In each study day, 16 mg or matching placebo was administered before 20% intralipids infusion at doses of 0.8 mL/m2/min with heparin at doses of 200 U/h for 4 h. Outcomes were assessed at baseline, 2 and 4 h during the infusion. MAIN OUTCOME MEASURES: Changes in F2-isoprostane (F2-IsoPs), marker of oxidative stress, measured in peripheral blood mononuclear cells (PBMC) and in plasma at baseline, 2, and 4-h post-lipid infusion. Secondary outcomes include changes in inflammatory cytokines (IL-6, TNF alpha). RESULTS: A total of 32 obese AA women were screened and fourteen completed the study (age 37.8 ± 10.70 years old, BMI 38.7 ± 3.40 kg/m2). Compared to placebo, 16 mg of galantamine significantly inhibited the increase in F2-IsoPs in PBMC (0.007 ± 0.008 vs. - 0.002 ± 0.006 ng/sample, P = 0.016), and plasma (0.01 ± 0.02 vs. - 0.003 ± 0.01 ng/mL, P = 0.023). Galantamine also decreased IL-6 (11.4 ± 18.45 vs. 7.7 ± 15.10 pg/mL, P = 0.021) and TNFα levels (18.6 ± 16.33 vs. 12.9 ± 6.16 pg/mL, P = 0.021, 4-h post lipid infusion) compared with placebo. These changes were associated with an increased plasma acetylcholine levels induced by galantamine (50.5 ± 10.49 vs. 43.6 ± 13.38 during placebo pg/uL, P = 0.025). CONCLUSIONS: In this pilot, proof-of-concept study, enhancing parasympathetic nervous system (PNS) cholinergic activity with galantamine inhibited lipid-induced oxidative stress and inflammation induced by lipid infusion in obese AAs. TRIAL REGISTRATION: ClinicalTrials.gov identifiers NCT02365285.

Combining Urinary Biomarker Data From Studies With Different Measures of Urinary Dilution.

BACKGROUND: Guidance is lacking for how to combine urinary biomarker data across studies that use different measures of urinary dilution, that is, creatinine or specific gravity. METHODS: Among 741 pregnant participants from four sites of The Infant Development and Environment Study (TIDES) cohort, we assessed the relation of maternal urinary di-2-ethylhexyl phthalate (DEHP) concentrations with preterm birth. We compared scenarios in which all sites measured either urinary creatinine or specific gravity, or where measure of dilution differed by site. In addition to a scenario with no dilution adjustment, we applied and compared three dilution-adjustment approaches: a standard regression-based approach for creatinine, a standard approach for specific gravity (Boeniger method), and a more recently developed approach that has been applied to both (covariate-adjusted standardization method). For each scenario and dilution-adjustment method, we estimated the association between a doubling in the molar sum of DEHP (∑DEHP) and odds of preterm birth using logistic regression. RESULTS: All dilution-adjustment approaches yielded comparable associations (odds ratio [OR]) that were larger in magnitude than when we did not perform dilution adjustment. A doubling of ∑DEHP was associated with 9% greater odds of preterm birth (OR = 1.09, 95% confidence interval [CI] = 0.91, 1.30) when applying no dilution-adjustment method, whereas dilution-adjusted point estimates were higher, and similar across all scenarios and methods: 1.13-1.20 (regression-based), 1.15-1.18 (Boeniger), and 1.14-1.21 (covariate-adjusted standardization). CONCLUSIONS: In our applied example, we demonstrate that it is possible and straightforward to combine urinary biomarker data across studies when measures of dilution differ.

Amiodarone with or without N-Acetylcysteine for the Prevention of Atrial Fibrillation after Thoracic Surgery: A Double-blind, Randomized Trial.

BACKGROUND: Postoperative atrial fibrillation may identify patients at risk of subsequent atrial fibrillation, with its greater risk of stroke. This study hypothesized that N-acetylcysteine mitigates inflammation and oxidative stress to reduce the incidence of postoperative atrial fibrillation. METHODS: In this double-blind, placebo-controlled trial, patients at high risk of postoperative atrial fibrillation scheduled to undergo major thoracic surgery were randomized to N-acetylcysteine plus amiodarone or placebo plus amiodarone. On arrival to the postanesthesia care unit, N-acetylcysteine or placebo intravenous bolus (50 mg/kg) and then continuous infusion (100 mg/kg over the course of 48 h) was administered plus intravenous amiodarone (bolus of 150 mg and then continuous infusion of 2 g over the course of 48 h). The primary outcome was sustained atrial fibrillation longer than 30 s by telemetry (first 72 h) or symptoms requiring intervention and confirmed by electrocardiography within 7 days of surgery. Systemic markers of inflammation (interleukin-6, interleukin-8, tumor necrosis factor α, C-reactive protein) and oxidative stress (F2-isoprostane prostaglandin F2α; isofuran) were assessed immediately after surgery and on postoperative day 2. Patients were telephoned monthly to assess the occurrence of atrial fibrillation in the first year. RESULTS: Among 154 patients included, postoperative atrial fibrillation occurred in 15 of 78 who received N-acetylcysteine (19%) and 13 of 76 who received placebo (17%; odds ratio, 1.24; 95.1% CI, 0.53 to 2.88; P = 0.615). The trial was stopped at the interim analysis because of futility. Of the 28 patients with postoperative atrial fibrillation, 3 (11%) were discharged in atrial fibrillation. Regardless of treatment at 1 yr, 7 of 28 patients with postoperative atrial fibrillation (25%) had recurrent episodes of atrial fibrillation. Inflammatory and oxidative stress markers were similar between groups. CONCLUSIONS: Dual therapy comprising N-acetylcysteine plus amiodarone did not reduce the incidence of postoperative atrial fibrillation or markers of inflammation and oxidative stress early after major thoracic surgery, compared with amiodarone alone. Recurrent atrial fibrillation episodes are common among patients with postoperative atrial fibrillation within 1 yr of major thoracic surgery.

Association of dietary and plasma carotenoids with urinary F2-isoprostanes.

PURPOSE: Carotenoids may protect against chronic diseases including cancer and cardiometabolic disease by mitigating oxidative stress and/or inflammation. We cross-sectionally evaluated associations between carotenoids and biomarkers of oxidative stress or inflammation. METHODS: From 2003 to 2009, the Sister Study enrolled 50,884 breast cancer-free US women aged 35-74. Post-menopausal participants (n = 512) were randomly sampled to measure carotenoids and biomarkers of oxidative stress. Dietary carotenoid consumption was assessed using a validated 110-item Block 1998 food frequency questionnaire; use of ß-carotene-containing supplements was also assessed. Plasma carotenoids were quantified, adjusting for batch. Urinary markers of lipid peroxidation, 8-iso-prostaglandin F2α (8-iso-PGF2α) and its metabolite (8-iso-PGF2α-M) were also measured. Since the biomarker 8-iso-PGF2α can reflect both oxidative stress and inflammation, we used a modeled 8-iso-PGF2α to prostaglandin F2α ratio approach to distinguish effects reflecting oxidative stress versus inflammation. Multivariable linear regression was used to assess the associations of dietary and plasma carotenoids with the estimated biomarker concentrations. RESULTS: Total plasma carotenoids were inversely associated with 8-iso-PGF2α-M concentrations (P for trend across quartiles = 0.009). Inverse trends associations were also seen for α-carotene and ß-carotene. In contrast, lutein/zeaxanthin showed associations with both 8-iso-PGF2α and 8-iso-PGF2α-M concentrations. The inverse association for total carotenoids appeared to be specific for oxidative stress (chemical 8-iso-PGF2α; Phighest vs. lowest quartile = 0.04 and P for trend across quartiles = 0.02). The pattern was similar for α-carotene. However, lutein/zeaxanthin tended to have a stronger association with enzymatic 8-iso-PGF2α, suggesting an additional anti-inflammatory effect. Supplemental ß-carotene was inversely associated with both 8-iso-PGF2α and 8-iso-PGF2α-M concentrations, as well as with both chemical and enzymatic 8-iso-PGF2α. Dietary carotenoids were not associated with either biomarker. CONCLUSION: Plasma carotenoids and supplemental ß-carotene were associated with lower concentrations of 8-iso-PGF2α metabolite. Plasma carotenoids associations may reflect antioxidant effects.

Associations between mixtures of urinary phthalate metabolite concentrations and oxidative stress biomarkers among couples undergoing fertility treatment.

Phthalate exposure has been associated with adverse reproductive outcomes and oxidative stress is a potential mechanism by which they act. However, few human studies have explored co-exposure confounding or joint effects. Furthermore, most studies examine associations between biomarkers of exposure and oxidative stress from the same urine sample. We investigated single-exposure, co-exposure-adjusted, and joint associations between phthalate metabolites and oxidative stress in the Environment and Reproductive Health (EARTH) study among couples undergoing fertility treatment. We examined cross-sectional associations in both women and men, and longitudinal associations in women. Urine was collected in the follicular phase (women only) and at the time of fertility procedure (women and men), and analyzed for 11 phthalate metabolites. Urine from the time of fertility procedure was analyzed for oxidative stress biomarkers, including free 8-iso-prostaglandin F2α (8-iso-PGF2α), its primary metabolite (2,3-dinor-5,6-dihydro-15-F2t-isoprostane [F2-IsoP-M]), and prostaglandin F2α (PGF2α). Linear mixed effects models were used to estimate single-exposure associations. Bayesian Kernel Machine Regression (BKMR) was used to adjust for co-exposures and to estimate joint effects. Among women, we observed positive associations between all phthalate metabolites and oxidative stress biomarkers in single-exposure models, but there was clear co-exposure confounding. For instance, in a single-exposure model, we estimated a 63% (95% confidence interval: 51, 77) increase in the 8-iso-PGF2α metabolite per interquartile range (IQR) difference in mono-n-butyl phthalate (MBP) versus a 34% (95% credible interval: 12, 60) increase in co-adjusted models. However, several phthalate metabolites remained associated with oxidative stress in co-exposure models, and the joint effects of all exposures were high (e.g., an 114% increase in the 8-iso-PGF2α metabolite per IQR difference in all exposures). Longitudinal results were also attenuated compared to cross-sectional results in women; however, the joint effect of all exposures and the 8-iso-PGF2α metabolite remained positive and statistically significant (11% increase per IQR difference in all exposures, 95% credible interval: 0.2, 23). In men, associations were generally less pronounced, although the joint effect of the mixture on 8-iso-PGF2α was above the null. Because oxidative stress is related to reproductive success among couples seeking fertility treatment, mitigating phthalate exposure should be considered as a potentially beneficial measure.

The association between urinary glyphosate and aminomethyl phosphonic acid with biomarkers of oxidative stress among pregnant women in the PROTECT birth cohort study.

BACKGROUND: Glyphosate is a widely used herbicide in global agriculture. Glyphosate and its primary environmental degradate, aminomethyl phosphonic acid (AMPA), have been shown to disrupt endocrine function and induce oxidative stress in in vitro and animal studies. To our knowledge, these relationships have not been previously characterized in epidemiological settings. Elevated urinary levels of glyphosate and AMPA may be indicative of health effects caused by previous exposure via multiple mechanisms including oxidative stress. METHODS: Glyphosate and AMPA were measured in 347 urine samples collected between 16 and 20 weeks gestation and 24-28 weeks gestation from pregnant women in the PROTECT birth cohort. Urinary biomarkers of oxidative stress, comprising 8-isoprostane-prostaglandin-F2α (8-iso-PGF2α), its metabolite 2,3-dinor-5,6-dihydro-15-F2 t-isoprostane (8-isoprostane metabolite) and prostaglandin-F2α (PGF2α), were also measured. Linear mixed effect models assessed the association between exposures and oxidative stress adjusting for maternal age, smoking status, alcohol consumption, household income and specific gravity. Potential nonlinear trends were also assessed using tertiles of glyphosate and AMPA exposure levels. RESULTS: No significant differences in exposure or oxidative stress biomarker concentrations were observed between study visits. An interquartile range (IQR) increase in AMPA was associated with 9.5% (95% CI: 0.5-19.3%) higher 8-iso-PGF2α metabolite concentrations. Significant linear trends were also identified when examining tertiles of exposure variables. Compared to the lowest exposure group, the second and third tertiles of AMPA were significantly associated with 12.8% (0.6-26.5%) and 15.2% (1.8-30.3%) higher 8-isoprostane metabolite, respectively. An IQR increase in glyphosate was suggestively associated with 4.7% (-0.9 to 10.7%) higher 8-iso-PGF2α. CONCLUSIONS: Urinary concentrations of the main environmental degradate of glyphosate, AMPA, were associated with higher levels of certain oxidative stress biomarkers. Associations with glyphosate reflected similar trends, although findings were not as strong. Additional research is required to better characterize the association between glyphosate exposure and biomarkers of oxidative stress, as well as potential downstream health consequences.

Inflammatory heterogeneity in aspirin-exacerbated respiratory disease.

BACKGROUND: Aspirin-exacerbated respiratory disease (AERD) is a mechanistically distinct subtype of chronic rhinosinusitis with nasal polyps (CRSwNP). Although frequently associated with type 2 inflammation, literature characterizing the milieu of inflammatory cytokines and lipid mediators in AERD has been conflicting. OBJECTIVE: We sought to identify differences in the upper airway inflammatory signature between CRSwNP and AERD and determine whether endotypic subtypes of AERD may exist. METHODS: Levels of 7 cytokines representative of type 1, type 2, and type 3 inflammation, and 21 lipid mediators were measured in nasal mucus from 109 patients with CRSwNP, 30 patients with AERD, and 64 non-CRS controls. Differences in inflammatory mediators were identified between groups, and patterns of inflammation among patients with AERD were determined by hierarchical cluster analysis. RESULTS: AERD could be distinguished from CRSwNP by profound elevations in IL-5, IL-6, IL-13, and IFN-γ; however, significant heterogeneity existed between patients. Hierarchical cluster analysis identified 3 inflammatory subendotypes of AERD characterized by (1) low inflammatory burden, (2) high type 2 cytokines, and (3) comparatively low type 2 cytokines and high levels of type 1 and type 3 cytokines. Several lipid mediators were associated with asthma and sinonasal disease severity; however, lipid mediators showed less variability than cytokines. CONCLUSIONS: AERD is associated with elevations in type 2 cytokines (IL-5 and IL-13) and the type 1 cytokine, IFN-γ. Among patients with AERD, the inflammatory signature is heterogeneous, supporting subendotypes of the disease. Variability in AERD immune signatures should be further clarified because this may predict clinical response to biologic medications that target type 2 inflammation.

Naproxen chemoprevention promotes immune activation in Lynch syndrome colorectal mucosa.

OBJECTIVE: Patients with Lynch syndrome (LS) are at markedly increased risk for colorectal cancer. It is being increasingly recognised that the immune system plays an essential role in LS tumour development, thus making an ideal target for cancer prevention. Our objective was to evaluate the safety, assess the activity and discover novel molecular pathways involved in the activity of naproxen as primary and secondary chemoprevention in patients with LS. DESIGN: We conducted a Phase Ib, placebo-controlled, randomised clinical trial of two dose levels of naproxen sodium (440 and 220 mg) administered daily for 6 months to 80 participants with LS, and a co-clinical trial using a genetically engineered mouse model of LS and patient-derived organoids (PDOs). RESULTS: Overall, the total number of adverse events was not different across treatment arms with excellent tolerance of the intervention. The level of prostaglandin E2 in the colorectal mucosa was significantly decreased after treatment with naproxen when compared with placebo. Naproxen activated different resident immune cell types without any increase in lymphoid cellularity, and changed the expression patterns of the intestinal crypt towards epithelial differentiation and stem cell regulation. Naproxen demonstrated robust chemopreventive activity in a mouse co-clinical trial and gene expression profiles induced by naproxen in humans showed perfect discrimination of mice specimens with LS and PDOs treated with naproxen and control. CONCLUSIONS: Naproxen is a promising strategy for immune interception in LS. We have discovered naproxen-induced gene expression profiles for their potential use as predictive biomarkers of drug activity. TRIAL REGISTRATION NUMBER: gov Identifier: NCT02052908.

The prostaglandin pathway is activated in patients who fail medical therapy for benign prostatic hyperplasia with lower urinary tract symptoms.

BACKGROUND: Little is known about how benign prostatic hyperplasia (BPH) develops and why patients respond differently to medical therapy designed to reduce lower urinary tract symptoms (LUTS). The Medical Therapy of Prostatic Symptoms (MTOPS) trial randomized men with symptoms of BPH and followed response to medical therapy for up to 6 years. Treatment with a 5α-reductase inhibitor (5ARI) or an alpha-adrenergic receptor antagonist (α-blocker) reduced the risk of clinical progression, while men treated with combination therapy showed a 66% decrease in risk of progressive disease. However, medical therapies for BPH/LUTS are not effective in many patients. The reasons for nonresponse or loss of therapeutic response in the remaining patients over time are unknown. A better understanding of why patients fail to respond to medical therapy may have a major impact on developing new approaches for the medical treatment of BPH/LUTS. Prostaglandins (PG) act on G-protein-coupled receptors (GPCRs), where PGE2 and PGF2 elicit smooth muscle contraction. Therefore, we measured PG levels in the prostate tissue of BPH/LUTS patients to assess the possibility that this signaling pathway might explain the failure of medical therapy in BPH/LUTS patients. METHOD: Surgical BPH (S-BPH) was defined as benign prostatic tissue collected from the transition zone (TZ) of patients who failed medical therapy and underwent surgical intervention to relieve LUTS. Control tissue was termed Incidental BPH (I-BPH). I-BPH was TZ obtained from men undergoing radical prostatectomy for low-volume, low-grade prostatic adenocarcinoma (PCa, Gleason score ≤ 7) confined to the peripheral zone. All TZ tissue was confirmed to be cancer-free. S-BPH patients divided into four subgroups: patients on α-blockers alone, 5ARI alone, combination therapy (α-blockers plus 5ARI), or no medical therapy (none) before surgical resection. I-BPH tissue was subgrouped by prior therapy (either on α-blockers or without prior medical therapy before prostatectomy). We measured prostatic tissue levels of prostaglandins (PGF2α , PGI2 , PGE2 , PGD2 , and TxA2 ), quantitative polymerase chain reaction levels of mRNAs encoding enzymes within the PG synthesis pathway, cellular distribution of COX1 (PTGS1) and COX2 (PTGS2), and tested the ability of PGs to contract bladder smooth muscle in an in vitro assay. RESULTS: All PGs were significantly elevated in TZ tissues from S-BPH patients (n = 36) compared to I-BPH patients (n = 15), regardless of the treatment subgroups. In S-BPH versus I-BPH, mRNA for PG synthetic enzymes COX1 and COX2 were significantly elevated. In addition, mRNA for enzymes that convert the precursor PGH2 to metabolite PGs were variable: PTGIS (which generates PGI2 ) and PTGDS (PGD2 ) were significantly elevated; nonsignificant increases were observed for PTGES (PGE2 ), AKR1C3 (PGF2α ), and TBxAS1 (TxA2 ). Within the I-BPH group, men responding to α-blockers for symptoms of BPH but requiring prostatectomy for PCa did not show elevated levels of COX1, COX2, or PGs. By immunohistochemistry, COX1 was predominantly observed in the prostatic stroma while COX2 was present in scattered luminal cells of isolated prostatic glands in S-BPH. PGE2 and PGF2α induced contraction of bladder smooth muscle in an in vitro assay. Furthermore, using the smooth muscle assay, we demonstrated that α-blockers that inhibit alpha-adrenergic receptors do not appear to inhibit PG stimulation of GPCRs in bladder muscle. Only patients who required surgery to relieve BPH/LUTS symptoms showed significantly increased tissue levels of PGs and the PG synthetic enzymes. CONCLUSIONS: Treatment of BPH/LUTS by inhibition of alpha-adrenergic receptors with pharmaceutical α-blockers or inhibiting androgenesis with 5ARI may fail because of elevated paracrine signaling by prostatic PGs that can cause smooth muscle contraction. In contrast to patients who fail medical therapy for BPH/LUTS, control I-BPH patients do not show the same evidence of elevated PG pathway signaling. Elevation of the PG pathway may explain, in part, why the risk of clinical progression in the MTOPS study was only reduced by 34% with α-blocker treatment.

Identification of a homozygous recessive variant in PTGS1 resulting in a congenital aspirin-like defect in platelet function.

We have identified a rare missense variant on chromosome 9, position 125145990 (GRCh37), in exon 8 in PTGS1 (the gene encoding cyclo-oxygenase 1, COX-1, the target of anti-thrombotic aspirin therapy). We report that in the homozygous state within a large consanguineous family this variant is associated with a bleeding phenotype and alterations in platelet reactivity and eicosanoid production. Western blotting and confocal imaging demonstrated that COX-1 was absent in the platelets of three family members homozygous for the PTGS1 variant but present in their leukocytes. Platelet reactivity, as assessed by aggregometry, lumi-aggregometry and flow cytometry, was impaired in homozygous family members, as were platelet adhesion and spreading. The productions of COX-derived eicosanoids by stimulated platelets were greatly reduced but there were no changes in the levels of urinary metabolites of COX-derived eicosanoids. The proband exhibited additional defects in platelet aggregation and spreading which may explain why her bleeding phenotype was slightly more severe than those of other homozygous affected relatives. This is the first demonstration in humans of the specific loss of platelet COX-1 activity and provides insight into its consequences for platelet function and eicosanoid metabolism. Notably despite the absence of thromboxane A2 (TXA2) formation by platelets, urinary TXA2 metabolites were in the normal range indicating these cannot be assumed as markers of in vivo platelet function. Results from this study are important benchmarks for the effects of aspirin upon platelet COX-1, platelet function and eicosanoid production as they define selective platelet COX-1 ablation within humans.