201
|
Kirchner S, Kieu T, Chow C, Casey S, Blumberg B. Prenatal exposure to the environmental obesogen tributyltin predisposes multipotent stem cells to become adipocytes. Mol Endocrinol 2010; 24:526-39. [PMID: 20160124 PMCID: PMC2840805 DOI: 10.1210/me.2009-0261] [Citation(s) in RCA: 210] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2009] [Accepted: 12/30/2009] [Indexed: 01/12/2023] Open
Abstract
The environmental obesogen hypothesis proposes that pre- and postnatal exposure to environmental chemicals contributes to adipogenesis and the development of obesity. Tributyltin (TBT) is an agonist of both retinoid X receptor (RXR) and peroxisome proliferator-activated receptor gamma (PPARgamma). Activation of these receptors can elevate adipose mass in adult mice exposed to the chemical in utero. Here we show that TBT sensitizes human and mouse multipotent stromal stem cells derived from white adipose tissue [adipose-derived stromal stem cells (ADSCs)] to undergo adipogenesis. In vitro exposure to TBT, or the PPARgamma activator rosiglitazone increases adipogenesis, cellular lipid content, and expression of adipogenic genes. The adipogenic effects of TBT and rosiglitazone were blocked by the addition of PPARgamma antagonists, suggesting that activation of PPARgamma mediates the effect of both compounds on adipogenesis. ADSCs from mice exposed to TBT in utero showed increased adipogenic capacity and reduced osteogenic capacity with enhanced lipid accumulation in response to adipogenic induction. ADSCs retrieved from animals exposed to TBT in utero showed increased expression of PPARgamma target genes such as the early adipogenic differentiation gene marker fatty acid-binding protein 4 and hypomethylation of the promoter/enhancer region of the fatty acid-binding protein 4 locus. Hence, TBT alters the stem cell compartment by sensitizing multipotent stromal stem cells to differentiate into adipocytes, an effect that could likely increase adipose mass over time.
Collapse
Affiliation(s)
- Séverine Kirchner
- Department of Developmental and Cell Biology, 2011 Biological Sciences 3, University of California, Irvine, California 92697-2300, USA
| | | | | | | | | |
Collapse
|
202
|
Abstract
Male infertility, characterized by hypogonadism, decreased semen quality or ejaculatory dysfunction, accounts for approximately 20% of infertility cases. Obesity and metabolic dysfunction have been identified, among other causal factors, to contribute to male infertility. In the context of the Western world's 'obesity epidemic', this article discusses three main biological mechanisms linking obesity to impaired male reproductive function: hypogonadism, testicular heat stress/hypoxia-induced apoptosis and endocrine disruption by 'obesogens'. Among these, obesity-induced hypogonadism is undoubtedly the most clinically significant and is easily assessed. Rapidly expanding areas of research in this area include leptin modulation of kisspeptins and hypothalamic-pituitary-testicular hormone pathways, and roles of other adipocytokines in male infertility, as well as the impact of exposure to obesogens on the quality of semen.
Collapse
Affiliation(s)
- Karen P Phillips
- a Assistant Professor, Interdisciplinary School of Health Sciences, Faculty of Health Sciences, Principal Scientist, Institute of Population Health, University of Ottawa, 43 Templeton Street, Room 215, Ottawa, ON K1N 6N5, Canada.
| | - Nongnuj Tanphaichitr
- b Senior Scientist, Ottawa Hospital Research Institute, and Professor in Obstetrics and Gynecology, and Biochemistry/Microbiology/Immunology, University of Ottawa, 725 Parkdale Avenue, Ottawa, ON K1Y 4E9, Canada.
| |
Collapse
|
203
|
Feige JN, Gerber A, Casals-Casas C, Yang Q, Winkler C, Bedu E, Bueno M, Gelman L, Auwerx J, Gonzalez FJ, Desvergne B. The pollutant diethylhexyl phthalate regulates hepatic energy metabolism via species-specific PPARalpha-dependent mechanisms. ENVIRONMENTAL HEALTH PERSPECTIVES 2010; 118:234-41. [PMID: 20123618 PMCID: PMC2831923 DOI: 10.1289/ehp.0901217] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2009] [Accepted: 10/08/2009] [Indexed: 05/21/2023]
Abstract
BACKGROUND The modulation of energetic homeostasis by pollutants has recently emerged as a potential contributor to the onset of metabolic disorders. Diethylhexyl phthalate (DEHP) is a widely used industrial plasticizer to which humans are widely exposed. Phthalates can activate the three peroxisome proliferator-activated receptor (PPAR) isotypes on cellular models and induce peroxisome proliferation in rodents. OBJECTIVES In this study, we aimed to evaluate the systemic and metabolic consequences of DEHP exposure that have remained so far unexplored and to characterize the underlying molecular mechanisms of action. METHODS As a proof of concept and mechanism, genetically engineered mouse models of PPARs were exposed to high doses of DEHP, followed by metabolic and molecular analyses. RESULTS DEHP-treated mice were protected from diet-induced obesity via PPARalpha-dependent activation of hepatic fatty acid catabolism, whereas the activity of neither PPARbeta nor PPARgamma was affected. However, the lean phenotype observed in response to DEHP in wild-type mice was surprisingly abolished in PPARalpha-humanized mice. These species differences are associated with a different pattern of coregulator recruitment. CONCLUSION These results demonstrate that DEHP exerts species-specific metabolic actions that rely to a large extent on PPARalpha signaling and highlight the metabolic importance of the species-specific activation of PPARalpha by xenobiotic compounds.
Collapse
Affiliation(s)
- Jérôme N. Feige
- Center for Integrative Genomics, National Research Center “Frontiers in Genetics,” University of Lausanne, Lausanne, Switzerland
| | - Alan Gerber
- Center for Integrative Genomics, National Research Center “Frontiers in Genetics,” University of Lausanne, Lausanne, Switzerland
| | - Cristina Casals-Casas
- Center for Integrative Genomics, National Research Center “Frontiers in Genetics,” University of Lausanne, Lausanne, Switzerland
| | - Qian Yang
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland, USA
| | - Carine Winkler
- Center for Integrative Genomics, National Research Center “Frontiers in Genetics,” University of Lausanne, Lausanne, Switzerland
| | - Elodie Bedu
- Center for Integrative Genomics, National Research Center “Frontiers in Genetics,” University of Lausanne, Lausanne, Switzerland
| | - Manuel Bueno
- Center for Integrative Genomics, National Research Center “Frontiers in Genetics,” University of Lausanne, Lausanne, Switzerland
| | - Laurent Gelman
- Center for Integrative Genomics, National Research Center “Frontiers in Genetics,” University of Lausanne, Lausanne, Switzerland
| | - Johan Auwerx
- Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Frank J. Gonzalez
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland, USA
| | - Béatrice Desvergne
- Center for Integrative Genomics, National Research Center “Frontiers in Genetics,” University of Lausanne, Lausanne, Switzerland
- Address correspondence to B. Desvergne, Center for Integrative Genomics, Le Génopode, Université de Lausanne, CH-1015 Lausanne, Switzerland. Telephone: 41-0-21-692-41-40. Fax: 41-0-21-692-41-15. E-mail:
| |
Collapse
|
204
|
Melzer D, Rice NE, Lewis C, Henley WE, Galloway TS. Association of urinary bisphenol a concentration with heart disease: evidence from NHANES 2003/06. PLoS One 2010; 5:e8673. [PMID: 20084273 PMCID: PMC2800195 DOI: 10.1371/journal.pone.0008673] [Citation(s) in RCA: 380] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2009] [Accepted: 12/03/2009] [Indexed: 11/30/2022] Open
Abstract
Background Bisphenol A (BPA) is a high production volume chemical widely used in food and drinks packaging. Associations have previously been reported between urinary BPA concentrations and heart disease, diabetes and liver enzymes in adult participants of the National Health and Nutrition Examination Survey (NHANES) 2003/04. We aimed to estimate associations between urinary BPA concentrations and health measures in NHANES 2005/06 and in data pooled across collection years. Methodology and Findings A cross-sectional analysis of NHANES: subjects were n = 1455 (2003/04) and n = 1493 (2005/06) adults aged 18–74 years, representative of the general adult population of the United States. Regression models were adjusted for age, sex, race/ethnicity, education, income, smoking, BMI, waist circumference, and urinary creatinine concentration. Main outcomes were reported diagnoses of heart attack, coronary heart disease, angina and diabetes and serum liver enzyme levels. Urinary BPA concentrations in 2005/06 (geometric mean 1.79 ng/ml, 95% CI: 1.64 to 1.96) were lower than in 2003/04 (2.49 ng/ml, CI: 2.20 to 2.83, difference p-value = 0.00002). Higher BPA concentrations were associated with coronary heart disease in 2005/06 (OR per z-score increase in BPA = 1.33, 95%CI: 1.01 to 1.75, p = 0.043) and in pooled data (OR = 1.42, CI: 1.17 to 1.72, p = 0.001). Associations with diabetes did not reach significance in 2005/06, but pooled estimates remained significant (OR = 1.24, CI: 1.10 to 1.40, p = 0.001). There was no overall association with gamma glutamyl transferase concentrations, but pooled associations with alkaline phosphatase and lactate dehydrogenase remained significant. Conclusions Higher BPA exposure, reflected in higher urinary concentrations of BPA, is consistently associated with reported heart disease in the general adult population of the USA. Studies to clarify the mechanisms of these associations are urgently needed.
Collapse
Affiliation(s)
- David Melzer
- Epidemiology and Public Health Group, Peninsula Medical School, University of Exeter, Exeter, United Kingdom.
| | | | | | | | | |
Collapse
|
205
|
Whyatt RM, Adibi JJ, Calafat AM, Camann DE, Rauh V, Bhat HK, Perera FP, Andrews H, Just AC, Hoepner L, Tang D, Hauser R. Prenatal di(2-ethylhexyl)phthalate exposure and length of gestation among an inner-city cohort. Pediatrics 2009; 124:e1213-20. [PMID: 19948620 PMCID: PMC3137456 DOI: 10.1542/peds.2009-0325] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE Our objective was to assess the relationship between di(2-ethylhexyl)phthalate (DEHP) exposure during pregnancy and gestational age at delivery among 311 African American or Dominican women from New York City. METHODS Forty-eight-hour personal air and/or spot urine samples were collected during the third trimester. DEHP levels were measured in air samples and 4 DEHP metabolite levels were measured in urine. Specific gravity was used to adjust for urinary dilution. Gestational age was abstracted from newborn medical records (n = 289) or calculated from the expected date of delivery (n = 42). Multivariate linear regression models controlled for potential confounders. RESULTS DEHP was detected in 100% of personal air samples (geometric mean: 0.20 microg/m(3) [95% confidence interval [CI]: 0.18-0.21 microg/m(3)]); natural logarithms of air concentrations were inversely but not significantly associated with gestational age. Two or more of the DEHP metabolites were detected in 100% of urine samples (geometric mean: 4.8-38.9 ng/mL [95% CI: 4.1-44.3 ng/mL]). Controlling for potential confounders, gestational age was shorter by 1.1 days (95% CI: 0.2-1.8 days) for each 1-logarithmic unit increase in specific gravity-adjusted mono(2-ethylhexyl)phthalate concentrations (P = .01) and averaged 5.0 days (95% CI: 2.1-8.0 days) less among subjects with the highest versus lowest quartile concentrations (P = .001). Results were similar and statistically significant for the other DEHP metabolites. CONCLUSIONS Prenatal DEHP exposure was associated with shorter gestation but, given inconsistencies with previous findings for other study populations, results should be interpreted with caution, and additional research is warranted.
Collapse
Affiliation(s)
- Robin M. Whyatt
- Columbia Center for Children's Environmental Health, Mailman School of Public Health, Columbia University, New York, New York
| | - Jennifer J. Adibi
- Department of Obstetrics, Genecology and Reproductive Sciences, University of California, San Francisco, California
| | - Antonia M. Calafat
- National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia
| | | | - Virgina Rauh
- Columbia Center for Children's Environmental Health, Mailman School of Public Health, Columbia University, New York, New York
| | - Hari K. Bhat
- Columbia Center for Children's Environmental Health, Mailman School of Public Health, Columbia University, New York, New York
| | - Frederica P. Perera
- Columbia Center for Children's Environmental Health, Mailman School of Public Health, Columbia University, New York, New York
| | - Howard Andrews
- Columbia Center for Children's Environmental Health, Mailman School of Public Health, Columbia University, New York, New York
| | - Allan C. Just
- Columbia Center for Children's Environmental Health, Mailman School of Public Health, Columbia University, New York, New York
| | - Lori Hoepner
- Columbia Center for Children's Environmental Health, Mailman School of Public Health, Columbia University, New York, New York
| | - Deliang Tang
- Columbia Center for Children's Environmental Health, Mailman School of Public Health, Columbia University, New York, New York
| | - Russ Hauser
- Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts
| |
Collapse
|
206
|
Synergistic acceleration of thyroid hormone degradation by phenobarbital and the PPARα agonist WY14643 in rat hepatocytes. Toxicol Appl Pharmacol 2009; 240:99-107. [DOI: 10.1016/j.taap.2009.07.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2009] [Revised: 07/14/2009] [Accepted: 07/15/2009] [Indexed: 11/20/2022]
|
207
|
Cederroth CR, Nef S. Fetal programming of adult glucose homeostasis in mice. PLoS One 2009; 4:e7281. [PMID: 19789640 PMCID: PMC2748646 DOI: 10.1371/journal.pone.0007281] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2009] [Accepted: 09/08/2009] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Emerging evidence suggests that dietary soy and phytoestrogens can have beneficial effects on lipid and glucose metabolism. We have previously shown that male mice fed from conception to adulthood with a high soy-containing diet had reduced body weight, adiposity and a decrease in glucose intolerance, an early marker of insulin resistance and diabetes. OBJECTIVES The purpose of this study was to identify the precise periods of exposure during which phytoestrogens and dietary soy improve lipid and glucose metabolism. Since intrauterine position (IUP) has been shown to alter sensitivity to endocrine disruptors, we also investigated whether the combination of IUP and fetal exposure to dietary phytoestrogens could potentially affect adult metabolic parameters. METHODS Male outbred mice (CD-1) were allowed ad libitum access to either a high soy-containing diet or a soy-free diet either during gestation, lactation or after weaning. Adiposity and bone mass density was assessed by dual x-ray absorptiometry. Glucose tolerance was assessed by a glucose tolerance test. Blood pressure was examined by the tail-cuff system. RESULTS Here we show that metabolic improvements are dependent on precise windows of exposure during life. The beneficial effects of dietary soy and phytoestrogens on adiposity were apparent only in animals fed post-natally, while the improvements in glucose tolerance are restricted to animals with fetal exposure to soy. Interestingly, we observed that IUP influenced adult glucose tolerance, but not adiposity. Similar IUP trends were observed for other estrogen-related metabolic parameters such as blood pressure and bone mass density. CONCLUSION Our results suggest that IUP and fetal exposure to estrogenic environmental disrupting compounds, such as dietary phytoestrogens, could alter metabolic and cardiovascular parameters in adult individuals independently of adipose gain.
Collapse
Affiliation(s)
- Christopher R. Cederroth
- Department of Genetic Medicine and Development, University of Geneva Medical School, Geneva, Switzerland
| | - Serge Nef
- Department of Genetic Medicine and Development, University of Geneva Medical School, Geneva, Switzerland
| |
Collapse
|
208
|
Teuten EL, Saquing JM, Knappe DRU, Barlaz MA, Jonsson S, Björn A, Rowland SJ, Thompson RC, Galloway TS, Yamashita R, Ochi D, Watanuki Y, Moore C, Viet PH, Tana TS, Prudente M, Boonyatumanond R, Zakaria MP, Akkhavong K, Ogata Y, Hirai H, Iwasa S, Mizukawa K, Hagino Y, Imamura A, Saha M, Takada H. Transport and release of chemicals from plastics to the environment and to wildlife. Philos Trans R Soc Lond B Biol Sci 2009; 364:2027-45. [PMID: 19528054 DOI: 10.1098/rstb.2008.0284] [Citation(s) in RCA: 1403] [Impact Index Per Article: 93.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Plastics debris in the marine environment, including resin pellets, fragments and microscopic plastic fragments, contain organic contaminants, including polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons, petroleum hydrocarbons, organochlorine pesticides (2,2'-bis(p-chlorophenyl)-1,1,1-trichloroethane, hexachlorinated hexanes), polybrominated diphenylethers, alkylphenols and bisphenol A, at concentrations from sub ng g(-1) to microg g(-1). Some of these compounds are added during plastics manufacture, while others adsorb from the surrounding seawater. Concentrations of hydrophobic contaminants adsorbed on plastics showed distinct spatial variations reflecting global pollution patterns. Model calculations and experimental observations consistently show that polyethylene accumulates more organic contaminants than other plastics such as polypropylene and polyvinyl chloride. Both a mathematical model using equilibrium partitioning and experimental data have demonstrated the transfer of contaminants from plastic to organisms. A feeding experiment indicated that PCBs could transfer from contaminated plastics to streaked shearwater chicks. Plasticizers, other plastics additives and constitutional monomers also present potential threats in terrestrial environments because they can leach from waste disposal sites into groundwater and/or surface waters. Leaching and degradation of plasticizers and polymers are complex phenomena dependent on environmental conditions in the landfill and the chemical properties of each additive. Bisphenol A concentrations in leachates from municipal waste disposal sites in tropical Asia ranged from sub microg l(-1) to mg l(-1) and were correlated with the level of economic development.
Collapse
Affiliation(s)
- Emma L Teuten
- Marine Biology and Ecology Research Centre, Marine Institute University of Plymouth, Drake Circus, Plymouth, UK
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
209
|
Teuten EL, Saquing JM, Knappe DRU, Barlaz MA, Jonsson S, Björn A, Rowland SJ, Thompson RC, Galloway TS, Yamashita R, Ochi D, Watanuki Y, Moore C, Viet PH, Tana TS, Prudente M, Boonyatumanond R, Zakaria MP, Akkhavong K, Ogata Y, Hirai H, Iwasa S, Mizukawa K, Hagino Y, Imamura A, Saha M, Takada H. Transport and release of chemicals from plastics to the environment and to wildlife. Philos Trans R Soc Lond B Biol Sci 2009; 364:2027-2045. [PMID: 19528054 DOI: 10.1098/rstb.2008.0284.pmid:19528054;pmcid:pmc2873017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/21/2023] Open
Abstract
Plastics debris in the marine environment, including resin pellets, fragments and microscopic plastic fragments, contain organic contaminants, including polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons, petroleum hydrocarbons, organochlorine pesticides (2,2'-bis(p-chlorophenyl)-1,1,1-trichloroethane, hexachlorinated hexanes), polybrominated diphenylethers, alkylphenols and bisphenol A, at concentrations from sub ng g(-1) to microg g(-1). Some of these compounds are added during plastics manufacture, while others adsorb from the surrounding seawater. Concentrations of hydrophobic contaminants adsorbed on plastics showed distinct spatial variations reflecting global pollution patterns. Model calculations and experimental observations consistently show that polyethylene accumulates more organic contaminants than other plastics such as polypropylene and polyvinyl chloride. Both a mathematical model using equilibrium partitioning and experimental data have demonstrated the transfer of contaminants from plastic to organisms. A feeding experiment indicated that PCBs could transfer from contaminated plastics to streaked shearwater chicks. Plasticizers, other plastics additives and constitutional monomers also present potential threats in terrestrial environments because they can leach from waste disposal sites into groundwater and/or surface waters. Leaching and degradation of plasticizers and polymers are complex phenomena dependent on environmental conditions in the landfill and the chemical properties of each additive. Bisphenol A concentrations in leachates from municipal waste disposal sites in tropical Asia ranged from sub microg l(-1) to mg l(-1) and were correlated with the level of economic development.
Collapse
Affiliation(s)
- Emma L Teuten
- Marine Biology and Ecology Research Centre, Marine Institute University of Plymouth, Drake Circus, Plymouth, UK
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
210
|
|
211
|
Abstract
Bisphenol A (BPA) is a component of polycarbonate and other plastics including resins that line food and beverage containers. BPA is known to leach from products in contact with food and drink, and is therefore thought to be routinely ingested. In a recent cross sectional study, BPA was detected in urine samples from 92.6% of the US population examined. The potential for BPA to influence body weight is suggested by in vitro studies demonstrating effects of BPA on adipocyte differentiation, lipid accumulation, glucose transport and adiponectin secretion. Data from in vivo studies have revealed dose-dependent and sex dependent effects on body weight in rodents exposed perinatally to BPA. The mechanisms through which perinatal BPA exposure acts to exert persistent effects on body weight and adiposity remain to be determined. Possible targets of BPA action are discussed.
Collapse
Affiliation(s)
- Beverly S Rubin
- Department of Anatomy and Cellular Biology, Tufts University School of Medicine, Boston, MA 02111, United States.
| | | |
Collapse
|
212
|
Abstract
The recent dramatic rise in obesity rates is an alarming global health trend that consumes an ever increasing portion of health care budgets in Western countries. The root cause of obesity is thought to be a prolonged positive energy balance. Hence, the major focus of preventative programs for obesity has been to target overeating and inadequate physical exercise. Recent research implicates environmental risk factors, including nutrient quality, stress, fetal environment and pharmaceutical or chemical exposure as relevant contributing influences. Evidence points to endocrine disrupting chemicals that interfere with the body's adipose tissue biology, endocrine hormone systems or central hypothalamic-pituitary-adrenal axis as suspects in derailing the homeostatic mechanisms important to weight control. This review highlights recent advances in our understanding of the molecular targets and mechanisms of action for these compounds and areas of future research needed to evaluate the significance of their contribution to obesity.
Collapse
Affiliation(s)
- Felix Grün
- Department of Developmental & Cell Biology, University of California Irvine, 92697-2300, USA
| | | |
Collapse
|
213
|
Abstract
Obesity and obesity-related disorders, such as type 2 diabetes, hypertension, and cardiovascular disease, are epidemic in Western countries, particularly the United States. The conventional wisdom holds that obesity is primarily the result of a positive energy balance, i.e. too many calories in and too few calories burned. Although it is self-evident that fat cannot be accumulated without a higher caloric intake than expenditure, recent research in a number of laboratories suggests the existence of chemicals that alter regulation of energy balance to favor weight gain and obesity. These obesogens derail the homeostatic mechanisms important for weight control, such that exposed individuals are predisposed to weight gain, despite normal diet and exercise. This review considers the evidence for obesogens, how they might act, and where future research is needed to clarify their relative contribution to the obesity epidemic.
Collapse
Affiliation(s)
- Felix Grün
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, California 92697-2300, USA
| | | |
Collapse
|
214
|
Eveillard A, Mselli-Lakhal L, Mogha A, Lasserre F, Polizzi A, Pascussi JM, Guillou H, Martin PGP, Pineau T. Di-(2-ethylhexyl)-phthalate (DEHP) activates the constitutive androstane receptor (CAR): a novel signalling pathway sensitive to phthalates. Biochem Pharmacol 2009; 77:1735-46. [PMID: 19428328 DOI: 10.1016/j.bcp.2009.02.023] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Revised: 02/25/2009] [Accepted: 02/25/2009] [Indexed: 12/27/2022]
Abstract
Di-(2-ethylhexyl)-phthalate (DEHP), a widely used plasticizer, is detected in consumer's body fluids. Contamination occurs through environmental and food chain sources. In mouse liver, DEHP activates the peroxisome proliferator-activated receptor alpha (PPARalpha) and regulates the expression of its target genes. Several in vitro investigations support the simultaneous recruitment of additional nuclear receptor pathways. We investigated, in vivo, the hepatic impact of low doses of DEHP on PPARalpha activation, and the putative activation of additional signalling pathways. Wild-type and PPARalpha-deficient mice were exposed to different doses of DEHP. Gene expression profiling delineated the role of PPARalpha and revealed a PPARalpha-independent regulation of several prototypic constitutive androstane receptor (CAR) target genes. Thus, we developed an original hepatic cell line expressing CAR to investigate its activation by DEHP. By means of a pharmacological inhibitor or CAR-targeting shRNAs, we established that CAR is required for the effect of DEHP on Cyp2b10, a recognized CAR target gene. Moreover, DEHP dose-dependently induced CYP2B6 in human primary hepatocyte cultures. This finding demonstrates that CAR also represents a transcriptional regulator sensitive to phthalates. CAR-mediated effects of DEHP provide a new rationale for most endpoints of phthalates toxicity described previously, including endocrine disruption, hepatocarcinogenesis and the metabolic syndrome.
Collapse
Affiliation(s)
- Alexandre Eveillard
- Laboratoire de Pharmacologie et Toxicologie, Institut National de la Recherche Agronomique, INRA UR66, Toulouse, France
| | | | | | | | | | | | | | | | | |
Collapse
|
215
|
Phenolics: occurrence and immunochemical detection in environment and food. Molecules 2009; 14:439-73. [PMID: 19158655 PMCID: PMC6253769 DOI: 10.3390/molecules14010439] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2008] [Revised: 01/06/2009] [Accepted: 01/12/2009] [Indexed: 11/24/2022] Open
Abstract
Phenolic compounds may be of natural or anthropogenic origin and be present in the environment as well as in food. They comprise a large and diverse group of compounds that may be either beneficial or harmful for consumers. In this review first a non-exhausting overview of interesting phenolics is given, in particular with regards to their presence in environment and food. For some of these compounds, beneficial, toxicological and/or optionally endocrine disrupting activities will be presented. Further, immunochemical detection and/or isolation methods developed will be discussed, including advantages and disadvantages thereof in comparison with conventional analytical methods such as HPLC, GC, MS. A short overview of new sensor-like methods will also be included for present and future application.
Collapse
|
216
|
Zhou C, Verma S, Blumberg B. The steroid and xenobiotic receptor (SXR), beyond xenobiotic metabolism. NUCLEAR RECEPTOR SIGNALING 2009; 7:e001. [PMID: 19240808 PMCID: PMC2646121 DOI: 10.1621/nrs.07001] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2008] [Accepted: 12/12/2008] [Indexed: 12/31/2022]
Abstract
The steroid and xenobiotic receptor (SXR) (also known as pregnane X receptor or PXR) is a nuclear hormone receptor activated by a diverse array of endogenous hormones, dietary steroids, pharmaceutical agents, and xenobiotic compounds. SXR has an enlarged, flexible, hydrophobic ligand binding domain (LBD) which is remarkably divergent across mammalian species and SXR exhibits considerable differences in its pharmacology among mammals. The broad response profile of SXR has led to the development of "the steroid and xenobiotic sensor hypothesis". SXR has been established as a xenobiotic sensor that coordinately regulates xenobiotic clearance in the liver and intestine via induction of genes involved in drug and xenobiotic metabolism. In the past few years, research has revealed new and mostly unsuspected roles for SXR in modulating inflammation, bone homeostasis, vitamin D metabolism, lipid homeostasis, energy homeostasis and cancer. The identification of SXR as a xenobiotic sensor has provided an important tool for studying new mechanisms through which diet, chemical exposure, and environment ultimately impact health and disease. The discovery and pharmacological development of new PXR modulators might represent an interesting and innovative therapeutic approach to combat various diseases.
Collapse
Affiliation(s)
- Changcheng Zhou
- Laboratory of Biochemical Genetics and Metabolism, The Rockefeller University, New York, New York, USA.
| | | | | |
Collapse
|
217
|
Hong YC, Park EY, Park MS, Ko JA, Oh SY, Kim H, Lee KH, Leem JH, Ha EH. Community level exposure to chemicals and oxidative stress in adult population. Toxicol Lett 2009; 184:139-44. [DOI: 10.1016/j.toxlet.2008.11.001] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2008] [Revised: 10/31/2008] [Accepted: 11/03/2008] [Indexed: 10/21/2022]
|
218
|
|
219
|
Ropero AB, Alonso-Magdalena P, Quesada I, Nadal A. The role of estrogen receptors in the control of energy and glucose homeostasis. Steroids 2008; 73:874-9. [PMID: 18249429 DOI: 10.1016/j.steroids.2007.12.018] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2007] [Accepted: 12/18/2007] [Indexed: 10/22/2022]
Abstract
Estrogens have been related to energy balance and glucose metabolism for a long time; however, the mechanisms involved in their actions are now being unveiled. The development of ERalpha and ERbeta knockout mice has demonstrated the participation of these receptors in the regulation of many processes related to the control of energy homeostasis. These include food intake and energy expenditure, insulin sensitivity in the liver and muscle, adipocyte growth and its body distribution as well as the pancreatic beta-cell function. In addition, other membrane receptors unrelated to ERalpha and ERbeta function in key tissues involved in energy balance and glucose homeostasis, i.e. the islet of Langerhans and the hypothalamus. Along with naturally occurring estrogens, there are endocrine disrupters that act as environmental estrogens and can impair the physiological action of ERalpha, ERbeta and other membrane ERs. New research is revealing a link between environmental estrogenic pollutants and the metabolic syndrome.
Collapse
Affiliation(s)
- Ana B Ropero
- Instituto de Bioingeniería, Universidad Miguel Hernández de Elche, Elche 03202, Alicante, Spain
| | | | | | | |
Collapse
|
220
|
|
221
|
|
222
|
Boberg J, Metzdorff S, Wortziger R, Axelstad M, Brokken L, Vinggaard AM, Dalgaard M, Nellemann C. Impact of diisobutyl phthalate and other PPAR agonists on steroidogenesis and plasma insulin and leptin levels in fetal rats. Toxicology 2008; 250:75-81. [PMID: 18602967 DOI: 10.1016/j.tox.2008.05.020] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2008] [Revised: 05/19/2008] [Accepted: 05/30/2008] [Indexed: 10/21/2022]
Abstract
Endocrine disrupting chemicals can induce malformations and impairment of reproductive function in experimental animals and may have similar effects in humans. Recently, the environmental obesogen hypothesis was proposed, suggesting that environmental chemicals contribute to the development of obesity and insulin resistance. These effects could be related to chemical interaction with nuclear receptors such as the peroxisome proliferator activated receptors (PPARs). As several testosterone-reducing drugs are PPAR activators, we aimed to examine whether four PPAR agonists were able to affect fetal testosterone production and masculinization of rats. Additionally, we wished to examine whether these chemicals affected fetal plasma levels of insulin and leptin, which play important roles in the developmental programming of the metabolic system. Pregnant Wistar rats were exposed from gestation day (GD) 7-21 to diisobutyl phthalate (DiBP), butylparaben, perfluorooctanoate, or rosiglitazone (600, 100, 20, or 1 mg/kg bw/day, respectively). Endocrine endpoints were studied in offspring at GD 19 or 21. DiBP, butylparaben and rosiglitazone reduced plasma leptin levels in male and female offspring. DiBP and rosiglitazone additionally reduced fetal plasma insulin levels. In males, DiBP reduced anogenital distance, testosterone production and testicular expression of Insl-3 and genes related to steroidogenesis. PPARalpha mRNA levels were reduced by DiBP at GD 19 in testis and liver. In females, DiBP increased anogenital distance and increased ovarian aromatase mRNA levels. This study reveals new targets for phthalates and parabens in fetal male and female rats and contributes to the increasing concern about adverse effects of human exposure to these compounds.
Collapse
Affiliation(s)
- Julie Boberg
- National Food Institute, Technical University of Denmark, Mørkhøj Bygade 19, DK-2860 Søborg, Denmark.
| | | | | | | | | | | | | | | |
Collapse
|
223
|
Musani SK, Erickson S, Allison DB. Obesity--still highly heritable after all these years. Am J Clin Nutr 2008; 87:275-6. [PMID: 18258613 DOI: 10.1093/ajcn/87.2.275] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|