| 1. |
- Penell, Johanna, et al.
(författare)
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Persistent organic pollutants are related to the change in circulating lipid levels during a 5 year follow-up
- 2014
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Ingår i: Environmental Research. - : Elsevier BV. - 0013-9351 .- 1096-0953. ; 134, s. 190-197
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Tidskriftsartikel (refereegranskat)abstract
- When reporting circulating levels of persistent organic pollutants (POPs), usually lipid-normalized values are given. However, animal experiments and some human data indicate that exposure to POPs may change lipid values. The aim of the present study is to investigate if POP levels can predict future changes in levels of circulating lipids. In the population-based Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study, lipids were measured at age 70 and at age 75 in 598 subjects without lipid-lowering medication. Twenty-three different POPs, including 16 polychlorinated biphenyls (PCBs), five organochlorine pesticides, one dioxin (OCDD) and one flame retardant brominated compound (BDE47) were analyzed by high-resolution chromatography coupled to high-resolution mass spectrometry (HRGC/HRMS) at age 70. Strong relationships were seen among the baseline levels of the non-dioxin-like PCBs 194, 206 and 209 and the degree of increase in total serum cholesterol and LDL-cholesterol during the 5 year follow-up. These relationships were generally stronger when lipidnormalized levels were used compared to wet-weight based levels. On the contrary, for two of the pesticides, hexachlorobenzene and trans-nonachlordane, levels were inversely related to the change in LDL-cholesterol, with strongest associations found using wet-weight based levels. PCBs 194, 206 and 209 were inversely related to the change in HDL-cholesterol, in particular for wet-weight based levels. However, these relationships were only significant for wet-weight PCB 194 following adjustment for multiple testing. None of the POPs was related to the change in serum triglycerides. When investigating the association between the change in total serum cholesterol and LDL-cholesterol across different categories of change in BMI, we noted robust results especially in the group with stable BMI, suggesting that the observed relationships were not due to fluctuations in BMI over time. In conclusion, POPs are related to the change in lipids over time, especially LDL-cholesterol. This may explain why POP exposure previously has been linked to atherosclerosis and cardiovascular disease.
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| 2. |
- Sjöberg Lind, Ylva, et al.
(författare)
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Circulating levels of persistent organic pollutants (POPs) are associated with left ventricular systolic and diastolic dysfunction in the elderly
- 2013
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Ingår i: Environmental Research. - : Elsevier. - 0013-9351 .- 1096-0953. ; 123, s. 39-45
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND OBJECTIVE:Major risk factors for congestive heart failure (CHF) are myocardial infarction, hypertension, diabetes, atrial fibrillation, smoking, left ventricular hypertrophy (LVH) and obesity. However, since these risk factors only explain part of the risk of CHF, we investigated whether persistent organic pollutants (POPs) might also play a role.METHODS:In the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study, left ventricular ejection fraction, (EF), E/A-ratio and isovolumic relaxation time (IVRT), were determined by echocardiography and serum samples of 21 POPs were analyzed in serum measured by high-resolution chromatography coupled to high-resolution mass spectrometry (HRGC/HRMS) in 998 subjects all aged 70 years.RESULTS:In this cross-sectional analysis, high levels of several of the polychlorinated biphenyls (PCB congeners 99, 118, 105, 138, 153, and 180) and octachlorodibenzo-p-dioxin (OCDD) were significantly related to a decreased EF. Some POPs were also related to a decreased E/A-ratio (PCBs 206 and 209). All the results were adjusted for gender, hypertension, diabetes, smoking, LVH and BMI, and subjects with myocardial infarction or atrial fibrillation were excluded from the analysis.CONCLUSIONS:Circulating levels of POPs were related to impairments in both left ventricular systolic and diastolic function independently of major congestive heart failure risk factors, suggesting a possible role of POPs in heart failure.
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| 3. |
- Sjöberg Lind, Ylva, et al.
(författare)
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Persistent organic pollutants and abnormal geometry of the left ventricle in the elderly
- 2013
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Ingår i: Journal of Hypertension. - : Lippincott Williams & Wilkins. - 0263-6352 .- 1473-5598. ; 31:8, s. 1547-1553
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Tidskriftsartikel (refereegranskat)abstract
- Background:Established risk factors for left ventricular hypertrophy (LVH) are hypertension, diabetes, and obesity. However, as these risk factors explain only part of the variation in left ventricular mass, we investigated whether persistent organic pollutants (POPs) might also play a role in LVH, because exposure to polychlorinated biphenyl 126 induced cardiac growth in rats.Methods:In the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS), left ventricular mass index (LVMI), relative wall thickness (RWT), and geometric groups of LVH, were determined by echocardiography and 21 POPs were measured by high-resolution chromatography coupled to high-resolution mass spectrometry (HRGC/HRMS) in 1016 individuals aged 70 years. All individuals with a history of myocardial infarction were excluded from analysis (n=72).Results:Several of the POPs were related to abnormal left ventricular geometry before adjustment for established risk factors, but lost in significance following adjustment. However, the pesticide hexachlorobenzene (HCB) levels were significantly related to RWT, and concentric left ventricular remodeling, also following adjustment for sex, blood pressure, antihypertensive treatment, diabetes, and BMI (Pandlt;0.0001).Conclusion:In this cross-sectional study, circulating levels of HCB were related to increased wall thickness of the left ventricle and concentric left ventricular remodeling, independently of LVH risk factors, suggesting a role of this environmental contaminant in abnormal growth of the left ventricle.
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| 7. |
- Brittebo, Eva, 1951-, et al.
(författare)
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Bioactivation and effects of environmental pollutants in human and rodent blood vessel endothelial cells
- 2012
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Ingår i: Organohalogen compound database (http://www.dioxin20xx.org/ohc_database_search.htm).
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Konferensbidrag (refereegranskat)abstract
- IntroductionRecent epidemiological studies reveal associations between exposure to environmental pollutants and cardiovascular disorders in humans. Elevated serum concentrations of polychlorinated biphenyls (PCBs) have for instance been associated with cardiovascular risk factors such as hypertension (1-3). Exposure to the carbonate plastic monomer bisphenol A (BPA) has been associated with an increased incidence of cardiovascular disease and atherogenic changes in the vascular wall (4-6). The contention that the human cardiovascular system is a sensitive target for toxic chemicals gain support from our earlier and recent experimental studies in rodents, birds and fish, as well as in cultured human primary endothelial cells. It is also compatible with earlier observations that certain polycyclic aromatic hydrocarbons (PAHs) are environmental carcinogens that may also contribute to atherosclerosis in mice and birds (7,8).In this presentation we will briefly discuss effects of Ah receptor (AhR) agonists (e.g. the coplanar PCB126 or BNF, ß-naphthoflavone) on the expression of cytochrome P450 (CYP)1 enzymes in various endothelia in rodents in vivo or ex vivo, as well as in cultured human umbilical vein endothelial cells (HUVEC). The CYP1-dependent bioactivation and irreversible binding of prototype polyaromatic hydrocarbons (PAH) and heterocyclic amines such as benzo(a)pyrene (BaP), 7,12-dimethyl- benz(a)anthracene (DMBA) and 3-amino-1,4-dimethyl-5H-pyrido- [4,3-b]indole (Trp-P1) in these endothelia will be reviewed. We will also report how PCB126 affects vasoactive factors in HUVEC, and how these effects are modulated by physiological 17ß-oestradiol concentrations. Some effects of PCB126, 1-nitropyrene (1-NP) and bisphenol A (BPA) on biomarkers for endothelial dysfunction, cell stress and DNA damage in HUVEC will finally be presented.Material and methodsHuman umbilical vein endothelial cells (HUVEC) were purchased from Science Cell Research laboratories, Carlsbad, CA. C57Bl mice and Wistar or Sprague Dawley rats were purchased from various suppliers. All animal experiments were approved by the Local Ethical Committee for Research on Animals in Uppsala and the studies followed the guidelines laid down by the Swedish and European Union legislation on animal experimentation. Rodents, tissue-slices and cultured cells were treated with model chemicals as previously described. Tape section and light microscopy autoradiographic imaging using 3H-labelled BaP, DMBA and Trp-P-1 and immunohistochemistry was performed as previously described (9-19). Precision-cut tissue slices for in vitro autoradiography were prepared as described in (14) and the slices were incubated with various 3H-labelled chemicals. HUVEC were exposed to various compounds and the detection of biomarkers of endothelial dysfunction, DNA damage were performed as described (20-22). Finally, female Fischer rats were exposed to BPA (0.025, 0.25 and 2.5 mg/l) and fructose (50 g/l) in the drinking water from 5 to 15 weeks of age to mimic human exposure (unpublished data).Results and discussionCo-localization of CYP1A1 expression and BaP, DMBA and Trp-P-1 adduct formation in endothelial linings As demonstrated by immunohistochemistry, a high CYP1A immunoreactivity occurred in capillaries of the heart, skeletal muscle, uterus and in blood-brain interfaces such as the leptomeninges and plexus choroideus, whereas no expression was observed for instance in cerebral capillary endothelial cells of mice treated with AhR agonists (9-11). No, or very low constitutive immunoreactivities were observed in these endothelia in vehicle-treated animals. No basal or induced CYP1B1 expression was observed in endothelial cells, while a weak CYP1B1 immunostaining was detected in the muscle layer of small arteries. It should be noted that in subcellular preparations of whole organs, e.g. heart and brain, the CYP1A1 in endothelial cells is diluted due to cells that do not express high levels of CYP1A1, for examples myocytes or neurons, in excess. A cell-specific metabolism in endothelial cells may therefore remain undetected due to the presence of metabolically inactive cells. In order to detect minor sites of bioactivation such as endothelial linings we employed light microscopic autoradiographic imaging to examine the bioactivation and subsequent irreversible binding of the radiolabelled prototype toxicants in tissues of animals pretreated with AhR-agonists. As determined by light microscopic autoradiography of AhR-agonist-treated mice exposed to 3H-labelled BaP, DMBA or Trp-P-1 and birds exposed to 3H-Trp-P-1 a significant accumulation of non-extractable radioactivity occurred in endothelial linings (9-18). The bound radioactivity occurred in the nuclei and the perinuclear cytoplasm, suggesting that the autoradiograms depict both DNA- and protein-bound adducts. Since the binding sites of 3H-labelled BaP, DMBA or Trp-P-1 corresponded with the sites of CYP1A1 induction, we concluded that rodents express a constitutively low but highly inducible and functional CYP1A1 in endothelial cells. The binding of reactive metabolites in endothelial cells exceeded the binding in all other cell types in AhR-agonist treated mice and was abolished by pretreatment with the CYP1A1 inhibitor ellipticine, supporting a CYP1A1-catalysed metabolic activation in situ to a reactive species (9, 10,12). These findings imply that there is a preferential CYP1A1-catalysed formation of reactive metabolites from all three carcinogens in endothelial cells expressing high CYP1A1 levels. Interestingly, however, carcinogenesis in endothelial cells is a relative rare finding, suggesting that degenerative lesions and cell death may be more prevalent responses to metabolism-activated carcinogens/mutagens in these cells. Experiments with 3H-DMBA and 3H-Trp-P-1 in HUVEC confirmed that AhR-agonists induced an increased bioactivation, suggesting that also human endothelial cells should be targets for toxicity of reactive intermediates formed from CYP1A1- activated carcinogens/mutagens (17-18). This conclusion is supported by immunohistochemical studies on the heavily vascularized human endometrium demonstrating an expression of CYP1A1 and CYP1B1 protein in and around human endometrial blood vessels, although a large interindividualvariation was observed (19). None of the endometrial biopsy samples displayed vascular expression of CYP2A6, CYP2B6, CYP2C8/2C9/2C19, CYP2D6, or CYP3A4/5 protein.Effects of PCB 126, 1-NP, and BPA on biomarkers of endothelial dysfunction and cell stress in endothelial cells In vitro studies demonstrated that PCB126 increased the levels of vasoconstriction factors and decreased the levels of vasodilating factors in cultured HUVEC in a fashion that is characteristic for endothelial dysfunction related to human hypertension. The study showed that the co-planar PCB126 induced expression of the endothelium-derived vasoconstriction factor COX-2 and stimulated formation of the vasoconstrictor prostaglandin PGF2 via the AhR in HUVEC (20). COX-2 is known to play a role in hypertension by catalysing the formation of vasoconstriction prostaglandins and by stimulating reactive oxygen species (ROS) production. Further studies demonstrated that PCB126 increased the production of the vasoconstriction prostaglandin PGF2 and ROS in HUVEC. The relationship between increased ROS production and human hypertension is well established, ROS promotes vasoconstriction by stimulating the production of vasoconstriction prostaglandins and by reducing bioavailability of the vasorelaxing factor NO. Indeed, exposure to PCB126 slightly reduced the production of NO in HUVEC. Furthermore, the PCB126-induced mRNA expressions of CYP1A1, CYP1B1 and COX-2 in HUVEC were enhanced in the presence of physiological levels of 17- estradiol. This suggests that increased levels of oestrogen stimulate AhR-dependent transcription of genes previously associated with endothelial dysfunction and hypertension.In another study we have examined the effects of a nitrated PAH, 1-nitropyrene, that is abundant in diesel exhausts (21). The results revealed that 1-NP induced DNA damage, increased levels of ROS and increased protein expression of the endoplasmic reticulum stress chaperone GRP78 in cultured HUVEC. Induction of CYP1A1 by PCB126 as well as inhibition of nitroreductive metabolism by dicoumarol attenuated the induction of DNA damage, intracellular ROS levels and GRP78 expression. This suggests that the effects of 1-NP on HUVEC were mediated by metabolites mainly formed at nitroreduction and not by CYP1-dependent bioactivation to reactive intermediates.Recent in vitro studies demonstrated that bisphenol A increased the mRNA expression of genes that regulate vasoconstriction and angiogenesis in HUVEC (eNOS, VEGF, VEGFR2, connexin 43 and ACE1) and in human cardiomyocytes (eNOS and ACE1) (22). The results also showed that BPA increased the expression of P-eNOS(ser1177) and the production of NO in HUVEC. NO is the main effector molecule in angiogenesis downstream of VEGF. Based on the findings that BPA increase the expression of proangiogenic factors we investigated whether BPA could stimulate in vitro angiogenesis in HUVEC using the endothelial tube formation assay. The results demonstrated that BPA increased HUVEC tube formation suggesting that BPA can act directly on the endothelium and stimulate angiogenesis. Long-term exposure in rats revealed that environmentally relevant levels of BPA, increased the cardiac mRNA expression of genes that regulate vasoconstriction and angiogenesis. Ten weeks exposure of rats from preadolescence to adulthood to BPA in the drinking water increased theexpression of eNOS, VEGF, VEGFR2 and ACE1 in the heart. Taken together, the genes that were upregulated in rat cardiac tissues in vivo were also upregulated in human endothelial cells and cardiomyocytes in vitro. The heart is a heavily vascularized t
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| 8. |
- Hong, N-S, et al.
(författare)
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The association between obesity and mortality in the elderly differs by serum concentrations of persistent organic pollutants : a possible explanation for the obesity paradox
- 2011
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Ingår i: International Journal of Obesity. - : Springer Science and Business Media LLC. - 0307-0565 .- 1476-5497. ; 36:9, s. 1170-1175
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Numerous studies have documented an obesity paradox in which the overweight and obese elderly have a better prognosis than those with ideal body weight. Good prognosis among the overweight or obese elderly may reflect the relative safety of storing the harmful lipophilic chemicals, known as persistent organic pollutants (POPs), in adipose tissue rather than in other critical organs. Therefore, we hypothesized lower mortality among the obese elderly with a higher body burden of POPs, but this pattern may not exist among the obese elderly with a lower body burden of POPs.PARTICIPANTS: Using the National Health and Nutrition Examination Survey (NHANES) 1999-2004 study with a mean 4.2-year follow-up, we tested whether the association between fat mass and total mortality in 635 (652 for organochlorine pesticides) elderly participants aged >= 70 years differed depending on serum concentrations of 23 POPs.RESULTS: There were statistically significant interactions between fat mass and POPs in predicting total mortality. In those with low POP concentrations, there was no obesity paradox; mortality increased with fat mass (hazard ratios about 2-3 in the highest vs lowest quintile of fat mass). However, consistent with an obesity paradox, these patterns completely disappeared in those with high POP concentrations. Compared with the lowest quintile of fat mass, statistically significantly lower mortality was observed in the elderly in the third to fifth quintiles of fat mass. In the case of polychlorinated biphenyls, the mortality in the highest quintile of fat mass was only one-fifth of that in the lowest quintile.CONCLUSION: These findings are consistent with our hypothesis that adipose tissue provides relatively safe storage of toxic lipophilic chemicals, a phenomenon that could explain the obesity paradox. Although weight loss may be beneficial among the obese elderly with low POP concentrations, weight loss in the obese elderly with higher serum concentrations of POPs may carry some risk.
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| 9. |
- Kumar, Jitender, et al.
(författare)
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Influence of persistent organic pollutants on oxidative stress in population-based samples
- 2014
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 114, s. 303-309
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Tidskriftsartikel (refereegranskat)abstract
- Persistent organic pollutants (POPs) are a large group of chemicals widely used and produced in various industrial applications. Many cell culture/animal studies have shown that POPs can induce oxidative stress. Since such data is lacking in humans, we conducted a large population-based study to analyze associations between POPs and oxidative stress markers. We measured following POPs; 16 polychlorinated biphenyls (PCBs), 5 organochlorine (OC) pesticides, octachlorinated dibenzo-p-dioxin, and polybrominated diphenyl ether 47, and oxidative stress markers; homocysteine, reduced [GSH] and oxidized glutathione [GSSG], glutathione ratio [GSSG/GSH], total glutathione, oxidized low-density lipoprotein [ox-LDL], ox-LDL antibodies, conjugated dienes, baseline conjugated dienes of LDL, and total anti-oxidative capacity in plasma samples collected from 992 70-year old individuals (50% women) from the population-based Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) cohort. Linear regression analyses were performed to study the associations between oxidative stress markers and summary measures of POPs including the total toxic equivalence (TEQ), sums of PCBs and BC pesticides (main exposures) while adjusting for potential confounders. In multivariable-adjusted analyses, sum of PCBs showed strong associations with ox-LDL (beta = 0.94; P = 2.9 * 10(-6)). Further, sum of PCBs showed association with glutathione-related markers (GSSG: beta = 0.01; P = 6.0 *10(-7); GSSG/GSH: beta = 0.002; P = 9.7 * 10(-10)), although in reverse direction. Other summary measures did not show any significant association with these markers. In our study of elderly individuals from the general population, we show that plasma levels of POPs are associated with markers of increased oxidative stress thereby suggesting that even low dose background exposure to POPs may be involved in oxidative stress. (C) 2014 Elsevier Ltd. All rights reserved.
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| 10. |
- Kumar, Jitender, et al.
(författare)
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Influence of persistent organic pollutants on the complement system in a population-based human sample
- 2014
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Ingår i: Environment International. - : Elsevier BV. - 0160-4120 .- 1873-6750. ; 71, s. 94-100
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Tidskriftsartikel (refereegranskat)abstract
- Background: Persistent organic pollutants (POPS) are toxic compounds generated through various industrial activities and have adverse effects on human health. Studies performed in cell cultures and animals have revealed that POPs can alter immune-system functioning. The complement system is part of innate immune system that helps to clear pathogens from the body. We performed a large-scale population-based study to find out associations between summary measures of different POPs and different complement system markers.Methods: In this cross-sectional study, 16 polychlorinated biphenyls (PCBs), 3 organochlorine (OC) pesticides, octachloro-p-dibenzodioxin, and 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) were analyzed for their association with levels of protein complement 3 (C3), 3a (C3a), 4 (C4) and C3a/C3 ratio. A total of 992 individuals (all aged 70 years, 50% females) were recruited from the Prospective Investigation of the Vasculature in Uppsala Seniors cohort. Regression analysis adjusting for a variety of confounders was performed to study the associations of different POP exposures (total toxic equivalency value or TEQ and sum of 16 PCBs) with protein complements.Results: The TEQ values were found to be positively associated with C3a (beta = 0.07, 95% CI = 0.017-0.131, p = 0.01) and C3a/C3 ratio (beta = 0.07, 95% Cl = 0.015-0.126, p = 0.01) taking possible confounders into account. The association observed was mainly driven by PCB-126.Conclusion: In this study involving 992 elderly individuals from the general population, we showed that POPs, mainly PCB-126, were associated with levels of complement system markers indicating that the association of these toxic compounds with downstream disease could be mediated by activation of immune system. (C) 2014 Elsevier Ltd. All rights reserved.
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