1
|
Wang X, Rowan-Carroll A, Meier MJ, Yauk CL, Wade MG, Robaire B, Hales BF. House dust-derived mixtures of organophosphate esters alter the phenotype, function, transcriptome, and lipidome of KGN human ovarian granulosa cells. Toxicol Sci 2024; 200:95-113. [PMID: 38603619 PMCID: PMC11199920 DOI: 10.1093/toxsci/kfae052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2024] Open
Abstract
Organophosphate esters (OPEs), used as flame retardants and plasticizers, are present ubiquitously in the environment. Previous studies suggest that exposure to OPEs is detrimental to female fertility in humans. However, no experimental information is available on the effects of OPE mixtures on ovarian granulosa cells, which play essential roles in female reproduction. We used high-content imaging to investigate the effects of environmentally relevant OPE mixtures on KGN human granulosa cell phenotypes. Perturbations to steroidogenesis were assessed using ELISA and qRT-PCR. A high-throughput transcriptomic approach, TempO-Seq, was used to identify transcriptional changes in a targeted panel of genes. Effects on lipid homeostasis were explored using a cholesterol assay and global lipidomic profiling. OPE mixtures altered multiple phenotypic features of KGN cells, with triaryl OPEs in the mixture showing higher potencies than other mixture components. The mixtures increased basal production of steroid hormones; this was mediated by significant changes in the expression of critical transcripts involved in steroidogenesis. Further, the total-OPE mixture disrupted cholesterol homeostasis and the composition of intracellular lipid droplets. Exposure to complex mixtures of OPEs, similar to those found in house dust, may adversely affect female reproductive health by altering a multitude of phenotypic and functional endpoints in granulosa cells. This study provides novel insights into the mechanisms of actions underlying the toxicity induced by OPEs and highlights the need to examine the effects of human relevant chemical mixtures.
Collapse
Affiliation(s)
- Xiaotong Wang
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Quebec, H3G 1Y6, Canada
| | - Andrea Rowan-Carroll
- Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario, K1A 0K9, Canada
| | - Matthew J Meier
- Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario, K1A 0K9, Canada
| | - Carole L Yauk
- Department of Biology, University of Ottawa, Ottawa, Ontario, K1N 9A7, Canada
| | - Michael G Wade
- Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario, K1A 0K9, Canada
| | - Bernard Robaire
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Quebec, H3G 1Y6, Canada
- Department of Obstetrics and Gynecology, McGill University, Montréal, Quebec, H3G 1Y6, Canada
| | - Barbara F Hales
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Quebec, H3G 1Y6, Canada
| |
Collapse
|
2
|
Zhou Y, Zhang L, Wang P, Li Q, Li J, Wang H, Gui Y, Liu Y, Sui X, Li J, Shi H, Zhang Y. Prenatal organophosphate esters exposure and neurodevelopment trajectory in infancy: Evidence from the Shanghai Maternal-Child Pairs Cohort. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 927:172366. [PMID: 38614325 DOI: 10.1016/j.scitotenv.2024.172366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 04/08/2024] [Accepted: 04/08/2024] [Indexed: 04/15/2024]
Abstract
BACKGROUND Concerns remain about the neurotoxic properties of the ubiquitous organophosphate esters (OPEs), the replacement of the toxicant polybrominated diphenyl ethers. OBJECTIVES We examined the associations of prenatal exposure to OPEs and their mixtures with early-life neurodevelopment trajectories. METHODS Totally 1276 mother-child pairs were recruited from the Shanghai Maternal-Child Pairs Cohort. A high-performance liquid chromatography-triple quadrupole mass spectrometer was used to measure the levels of 7 OPEs in cord serum. Ages and Stages Questionnaires was used to examine children's neuropsychological development at 2, 6, 12, and 24 months of age. Group-based trajectory models were applied to derive the neurodevelopmental trajectories. Multiple linear regression and logistic regression model were performed to assess the relationships between OPEs exposure and neurodevelopment and trajectories. Mixtures for widely detected OPEs (n = 4) were investigated using quantile-based g-computation. RESULTS Tributyl phosphate (TBP), tris (2-butoxy ethyl) phosphate (TBEP), tris(1,3-dichloro-2-propyl) phosphate (TDCPP), and 2-ethylhexyl diphenyl phosphate (EHDPP), had detection rates >50 %. TDCPP had the highest median concentration (1.02 μg/L) in cord serum. EHDPP concentrations were negatively associated with scores in most domains at 12 months of age, with effect values (β) ranging from -1.89 to -0.57. EHDPP could negatively affect the total ASQ (OR = 1.07, 95 % CI: 1, 1.15) and gross-motor (OR = 1.09, 95 % CI: 1.02, 1.17) trajectory in infancy. Joint exposure to OPEs was associated with decreased scores in the total ASQ, gross-motor, fine-motor and problem-solving domain of 12-month-old infants, with β ranging from -5.93 to -1.25. In addition, the qgcomp models indicated significant positive associations between the concentrations of OPEs mixtures and risks of the persistently low group of the total ASQ, gross-motor and fine-motor development in early childhood. The impact of OPEs was more pronounced in boys. DISCUSSION Our findings suggested OPEs, especially EHDPP, had a persistently negative effect on neurodevelopment during the first 2 years.
Collapse
Affiliation(s)
- Yuhan Zhou
- School of Exercise and Health, Shanghai University of Sport, Shanghai 200438, China; Key Lab of Health Technology Assessment, National Health Commission of the People's Republic of China, Fudan University, Shanghai 200032, China; Key Laboratory of Public Health Safety, Ministry of Education, School of Public Health, Fudan University, Shanghai 200032, China
| | - Liyi Zhang
- Key Lab of Health Technology Assessment, National Health Commission of the People's Republic of China, Fudan University, Shanghai 200032, China; Key Laboratory of Public Health Safety, Ministry of Education, School of Public Health, Fudan University, Shanghai 200032, China
| | - Pengpeng Wang
- Key Lab of Health Technology Assessment, National Health Commission of the People's Republic of China, Fudan University, Shanghai 200032, China; Key Laboratory of Public Health Safety, Ministry of Education, School of Public Health, Fudan University, Shanghai 200032, China
| | - Qiang Li
- Key Lab of Health Technology Assessment, National Health Commission of the People's Republic of China, Fudan University, Shanghai 200032, China; Putuo District Center for Disease Control & Prevention, Shanghai 200333, China
| | - Jinhong Li
- Key Lab of Health Technology Assessment, National Health Commission of the People's Republic of China, Fudan University, Shanghai 200032, China; Key Laboratory of Public Health Safety, Ministry of Education, School of Public Health, Fudan University, Shanghai 200032, China
| | - Hang Wang
- Key Lab of Health Technology Assessment, National Health Commission of the People's Republic of China, Fudan University, Shanghai 200032, China; Key Laboratory of Public Health Safety, Ministry of Education, School of Public Health, Fudan University, Shanghai 200032, China
| | - Yuyan Gui
- Key Lab of Health Technology Assessment, National Health Commission of the People's Republic of China, Fudan University, Shanghai 200032, China; Key Laboratory of Public Health Safety, Ministry of Education, School of Public Health, Fudan University, Shanghai 200032, China
| | - Yang Liu
- Key Lab of Health Technology Assessment, National Health Commission of the People's Republic of China, Fudan University, Shanghai 200032, China; Key Laboratory of Public Health Safety, Ministry of Education, School of Public Health, Fudan University, Shanghai 200032, China
| | - Xinyao Sui
- Key Lab of Health Technology Assessment, National Health Commission of the People's Republic of China, Fudan University, Shanghai 200032, China; Key Laboratory of Public Health Safety, Ministry of Education, School of Public Health, Fudan University, Shanghai 200032, China
| | - Jiufeng Li
- Key Lab of Health Technology Assessment, National Health Commission of the People's Republic of China, Fudan University, Shanghai 200032, China; Key Laboratory of Public Health Safety, Ministry of Education, School of Public Health, Fudan University, Shanghai 200032, China
| | - Huijing Shi
- Key Laboratory of Public Health Safety, Ministry of Education, Department of Maternal, Child and Adolescent Health, School of Public Health, Fudan University, Shanghai, China
| | - Yunhui Zhang
- Key Lab of Health Technology Assessment, National Health Commission of the People's Republic of China, Fudan University, Shanghai 200032, China; Key Laboratory of Public Health Safety, Ministry of Education, School of Public Health, Fudan University, Shanghai 200032, China.
| |
Collapse
|
3
|
Li Z, Hales BF, Robaire B. Impact of Exposure to a Mixture of Organophosphate Esters on Adrenal Cell Phenotype, Lipidome, and Function. Endocrinology 2024; 165:bqae024. [PMID: 38376928 PMCID: PMC10914377 DOI: 10.1210/endocr/bqae024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 02/13/2024] [Accepted: 02/16/2024] [Indexed: 02/21/2024]
Abstract
Organophosphate esters (OPEs) are used primarily as flame retardants and plasticizers. Previously, we reported that adrenal cells are important targets of individual OPEs. However, real-life exposures are to complex mixtures of these chemicals. To address this, we exposed H295R human adrenal cells to varying dilutions (1/1000K to 1/3K) of a Canadian household dust-based OPE mixture for 48 hours and evaluated effects on phenotypic, lipidomic, and functional parameters. Using a high-content screening approach, we assessed phenotypic markers at mixture concentrations at which there was greater than 70% cell survival; the most striking effect of the OPE mixture was a 2.5-fold increase in the total area of lipid droplets. We then determined the response of specific lipid species to OPE exposures with novel, nontargeted lipidomic analysis of isolated lipid droplets. These data revealed that house dust OPEs induced concentration-dependent alterations in the composition of lipid droplets, particularly affecting the triglyceride, diglyceride, phosphatidylcholine, and cholesterol ester subclasses. The steroid-producing function of adrenal cells in the presence or absence of a steroidogenic stimulus, forskolin, was determined. While the production of 17β-estradiol remained unaffected, a slight decrease in testosterone production was observed after stimulation. Conversely, a 2-fold increase in both basal and stimulated cortisol and aldosterone production was observed. Thus, exposure to a house dust-based mixture of OPEs exerts endocrine-disrupting effects on adrenal cells, highlighting the importance of assessing the effects of environmentally relevant mixtures.
Collapse
Affiliation(s)
- Zixuan Li
- Department of Pharmacology & Therapeutics, McGill University, Montreal, QC, H3G 1Y6, Canada
| | - Barbara F Hales
- Department of Pharmacology & Therapeutics, McGill University, Montreal, QC, H3G 1Y6, Canada
| | - Bernard Robaire
- Department of Pharmacology & Therapeutics, McGill University, Montreal, QC, H3G 1Y6, Canada
- Department of Obstetrics & Gynecology, McGill University, Montreal, QC, H3G 1Y6, Canada
| |
Collapse
|
4
|
Marinello WP, Gillera SEA, Huang L, Rollman J, Reif DM, Patisaul HB. Uncovering the common factors of chemical exposure and behavior: Evaluating behavioral effects across a testing battery using factor analysis. Neurotoxicology 2023; 99:264-273. [PMID: 37914043 PMCID: PMC11154886 DOI: 10.1016/j.neuro.2023.10.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 10/09/2023] [Accepted: 10/26/2023] [Indexed: 11/03/2023]
Abstract
Although specific environmental chemical exposures, including flame retardants, are known risk factors for neurodevelopmental disorders (NDDs), direct experimental evidence linking specific chemicals to NDDs is limited. Studies focusing on the mechanisms by which the social processing systems are vulnerable to chemical exposure are underrepresented in the literature, even though social impairments are defining characteristics of many NDDs. We have repeatedly demonstrated that exposure to Firemaster 550 (FM 550), a prevalent flame retardant mixture used in foam-based furniture and infant products, can adversely impact a variety of behavioral endpoints. Our recent work in prairie voles (Microtus ochrogaster), a prosocial animal model, demonstrated that perinatal exposure to FM 550 sex specifically impacts socioemotional behavior. Here, we utilized a factor analysis approach on a battery of behavioral data from our prior study to extract underlying factors that potentially explain patterns within the FM 550 behavior data. This approach identified which aspects of the behavioral battery are most robust and informative, an outcome critical for future study designs. Pearson's correlation identified behavioral endpoints associated with distance and stranger interactions that were highly correlated across 5 behavioral tests. Using these behavioral endpoints, exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) extracted 2 factors that could explain the data: Activity (distance traveled endpoints) and Sociability (time spent with a novel conspecific). Exposure to FM 550 significantly decreased Activity and decreased Sociability. This factor analysis approach to behavioral data offers the advantages of modeling numerous measured variables and simplifying the data set by presenting the data in terms of common, overarching factors in terms of behavioral function.
Collapse
Affiliation(s)
- William P Marinello
- Department of Biological Sciences, NC State University, Raleigh, NC 27695, USA
| | - Sagi Enicole A Gillera
- Department of Biological Sciences, NC State University, Raleigh, NC 27695, USA; ICF International Inc, Durham, NC 27713, USA
| | - Lynn Huang
- Department of Statistics, NC State University, Raleigh, NC 27695, USA
| | - John Rollman
- Department of Statistics, NC State University, Raleigh, NC 27695, USA
| | - David M Reif
- Bioinformatics Research Center, NC State University, Raleigh, NC 27695, USA
| | - Heather B Patisaul
- Department of Biological Sciences, NC State University, Raleigh, NC 27695, USA; Center for Human Health and the Environment, NC State University, Raleigh, NC 27695, USA.
| |
Collapse
|
5
|
Bommarito PA, Friedman A, Welch BM, Cantonwine DE, Ospina M, Calafat AM, Meeker JD, McElrath TF, Ferguson KK. Temporal trends and predictors of gestational exposure to organophosphate ester flame retardants and plasticizers. ENVIRONMENT INTERNATIONAL 2023; 180:108194. [PMID: 37708814 PMCID: PMC10591987 DOI: 10.1016/j.envint.2023.108194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 08/30/2023] [Accepted: 09/06/2023] [Indexed: 09/16/2023]
Abstract
BACKGROUND Organophosphate esters (OPEs), used as flame retardants and plasticizers, are chemicals of concern for maternal and infant health. Prior studies examining temporal trends and predictors of OPE exposure are primarily limited by small sample sizes. OBJECTIVES Characterize temporal trends and predictors of OPE exposure biomarkers. METHODS We determined urinary concentrations of eight biomarkers of OPE exposure at three timepoints during pregnancy for participants in the LIFECODES Fetal Growth Study (n = 900), a nested case-cohort recruited between 2007 and 2018. We examined biomarker concentrations, their variability during pregnancy, and temporal trends over the study period. In addition, we identified sociodemographic and pregnancy characteristics associated with biomarker concentrations. Analyses were conducted using both the within-subject pregnancy geometric means and biomarker concentrations measured at individual study visits. RESULTS Five OPE biomarkers were detected in at least 60% of the study participants. Biomarkers were not strongly correlated with one another and intraclass correlation coefficients, measuring within-subject variability during pregnancy, ranged from 0.27 to 0.51. Biomarkers exhibited varying temporal trends across study years. For example, bis(1-chloro-2-propyl) phosphate (BCIPP) increased monotonically, whereas bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) and diphenyl phosphate (DPHP), displayed non-monotonic trends with concentrations that peaked between 2011 and 2014. We observed associations between sociodemographic characteristics and OPE biomarkers. In general, concentrations of most OPE biomarkers were higher among participants from racial and ethnic minority populations, participants who were younger, had higher pre-pregnancy body mass index (BMI), and less than a college degree. We observed consistent results using either averaged or visit-specific biomarker concentrations. SIGNIFICANCE We observed widespread exposure to several OPEs and OPE biomarkers displayed varying temporal trends in pregnant people from 2007 to 2018. Concentrations of most OPE biomarkers varied according to sociodemographic factors, suggesting higher burdens of exposure among participants with higher pre-pregnancy BMI, those belonging to racial and ethnic minority populations, and lower educational attainment.
Collapse
Affiliation(s)
- P A Bommarito
- Epidemiology Branch, Division of Intramural Research, National Institute of Environmental Health Sciences, 111 T.W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | - A Friedman
- Epidemiology Branch, Division of Intramural Research, National Institute of Environmental Health Sciences, 111 T.W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | - B M Welch
- Epidemiology Branch, Division of Intramural Research, National Institute of Environmental Health Sciences, 111 T.W. Alexander Drive, Research Triangle Park, NC 27709, USA; School of Public Health, University of Nevada, Reno, Reno, NV, USA
| | - D E Cantonwine
- Division of Maternal-Fetal Medicine, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street Boston, MA 02115, USA
| | - M Ospina
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA
| | - A M Calafat
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA
| | - J D Meeker
- Department of Environmental Health, School of Public Health, University of Michigan, Ann Arbor, MI, USA
| | - T F McElrath
- Division of Maternal-Fetal Medicine, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street Boston, MA 02115, USA
| | - K K Ferguson
- Epidemiology Branch, Division of Intramural Research, National Institute of Environmental Health Sciences, 111 T.W. Alexander Drive, Research Triangle Park, NC 27709, USA.
| |
Collapse
|
6
|
Marinello WP, Gillera SEA, Han Y, Richardson JR, St Armour G, Horman BM, Patisaul HB. Gestational exposure to FireMaster® 550 (FM 550) disrupts the placenta-brain axis in a socially monogamous rodent species, the prairie vole (Microtus ochrogaster). Mol Cell Endocrinol 2023; 576:112041. [PMID: 37562579 PMCID: PMC10795011 DOI: 10.1016/j.mce.2023.112041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 07/26/2023] [Accepted: 08/06/2023] [Indexed: 08/12/2023]
Abstract
Gestational flame retardant (FR) exposure has been linked to heightened risk of neurodevelopmental disorders, but the mechanisms remain largely unknown. Historically, toxicologists have relied on traditional, inbred rodent models, yet those do not always best model human vulnerability or biological systems, especially social systems. Here we used prairie voles (Microtus ochrogaster), a monogamous and bi-parental rodent, leveraged for decades to decipher the underpinnings of social behaviors, to examine the impact of fetal FR exposure on gene targets in the mid-gestational placenta and fetal brain. We previously established gestational exposure to the commercial mixture Firemaster 550 (FM 550) impairs sociality, particularly in males. FM 550 exposure disrupted placental monoamine production, particularly serotonin, and genes required for axon guidance and cellular respiration in the fetal brains. Effects were dose and sex specific. These data provide insights on the mechanisms by which FRs impair neurodevelopment and later in life social behaviors.
Collapse
Affiliation(s)
- William P Marinello
- Department of Biological Sciences, NC State University, Raleigh, NC, 27695, USA
| | | | - Yoonhee Han
- Department of Environmental Health Sciences, Robert Stempel College of Public Health and Social Work, Florida International University, Miami, FL, 33199, USA
| | - Jason R Richardson
- Department of Environmental Health Sciences, Robert Stempel College of Public Health and Social Work, Florida International University, Miami, FL, 33199, USA
| | - Genevieve St Armour
- Department of Biological Sciences, NC State University, Raleigh, NC, 27695, USA
| | - Brian M Horman
- Department of Biological Sciences, NC State University, Raleigh, NC, 27695, USA
| | - Heather B Patisaul
- Department of Biological Sciences, NC State University, Raleigh, NC, 27695, USA; Center for Human Health and the Environment, NC State University, Raleigh, NC, 27695, USA.
| |
Collapse
|
7
|
Hernandez-Castro I, Eckel SP, Howe CG, Niu Z, Kannan K, Robinson M, Foley HB, Yang T, Vigil MJ, Chen X, Grubbs B, Lerner D, Lurvey N, Al-Marayati L, Habre R, Dunton GF, Farzan SF, Aung MT, Breton CV, Bastain TM. Prenatal exposures to organophosphate ester metabolite mixtures and children's neurobehavioral outcomes in the MADRES pregnancy cohort. Environ Health 2023; 22:66. [PMID: 37737180 PMCID: PMC10515433 DOI: 10.1186/s12940-023-01017-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 09/11/2023] [Indexed: 09/23/2023]
Abstract
BACKGROUND Evidence suggests organophosphate esters (OPEs) are neurotoxic; however, the epidemiological literature remains scarce. We investigated whether prenatal exposures to OPEs were associated with child neurobehavior in the MADRES cohort. METHODS We measured nine OPE metabolites in 204 maternal urine samples (gestational age at collection: 31.4 ± 1.8 weeks). Neurobehavior problems were assessed among 36-month-old children using the Child Behavior Checklist's (CBCL) three composite scales [internalizing, externalizing, and total problems]. We examined associations between tertiles of prenatal OPE metabolites (> 50% detection) and detect/non-detect categories (< 50% detection) and CBCL composite scales using linear regression and generalized additive models. We also examined mixtures for widely detected OPEs (n = 5) using Bayesian kernel machine regression. RESULTS Maternal participants with detectable versus non-detectable levels of bis(2-methylphenyl) phosphate (BMPP) had children with 42% (95% CI: 4%, 96%) higher externalizing, 45% (-2%, 114%) higher internalizing, and 35% (3%, 78%) higher total problems. Participants in the second versus first tertile of bis(butoxethyl) phosphate (BBOEP) had children with 43% (-1%, 109%) higher externalizing scores. Bis(1-chloro-2-propyl) phosphate (BCIPP) and child sex had a statistically significant interaction in internalizing (p = 0.02) and total problems (p = 0.03) models, with 120% (23%, 295%) and 57% (6%, 134%) higher scores in the third versus first BCIPP tertile among males. Among females, detectable vs non-detectable levels of prenatal BMPP were associated with 69% higher externalizing scores (5%, 170%) while the third versus first tertile of prenatal BBOEP was associated with 45% lower total problems (-68%, -6%). Although the metabolite mixture and each CBCL outcome had null associations, we observed marginal associations between di-n-butyl phosphate and di-isobutyl phosphate (DNBP + DIBP) and higher internalizing scores (0.15; 95% CrI: -0.02, 0.32), holding other metabolites at their median. CONCLUSIONS Our results generally suggest adverse and sex-specific effects of prenatal exposure to previously understudied OPEs on neurobehavioral outcomes in 36-month children, providing evidence of potential OPE neurotoxicity.
Collapse
Affiliation(s)
- Ixel Hernandez-Castro
- Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, 1845 N. Soto Street, Los Angeles, CA, USA
| | - Sandrah P Eckel
- Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, 1845 N. Soto Street, Los Angeles, CA, USA
| | - Caitlin G Howe
- Department of Epidemiology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Zhongzheng Niu
- Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, 1845 N. Soto Street, Los Angeles, CA, USA
| | | | - Morgan Robinson
- Wadsworth Center, New York State Department of Health, Albany, NY, USA
| | - Helen B Foley
- Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, 1845 N. Soto Street, Los Angeles, CA, USA
| | - Tingyu Yang
- Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, 1845 N. Soto Street, Los Angeles, CA, USA
| | - Mario J Vigil
- Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, 1845 N. Soto Street, Los Angeles, CA, USA
| | - Xinci Chen
- Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, 1845 N. Soto Street, Los Angeles, CA, USA
| | - Brendan Grubbs
- Department of Obstetrics and Gynecology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | | | | | - Laila Al-Marayati
- Department of Obstetrics and Gynecology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Rima Habre
- Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, 1845 N. Soto Street, Los Angeles, CA, USA
| | - Genevieve F Dunton
- Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, 1845 N. Soto Street, Los Angeles, CA, USA
- Department of Psychology, University of Southern California, Los Angeles, CA, USA
| | - Shohreh F Farzan
- Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, 1845 N. Soto Street, Los Angeles, CA, USA
| | - Max T Aung
- Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, 1845 N. Soto Street, Los Angeles, CA, USA
| | - Carrie V Breton
- Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, 1845 N. Soto Street, Los Angeles, CA, USA
| | - Theresa M Bastain
- Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, 1845 N. Soto Street, Los Angeles, CA, USA.
| |
Collapse
|
8
|
Newell AJ, Jima D, Reading B, Patisaul HB. Machine learning reveals common transcriptomic signatures across rat brain and placenta following developmental organophosphate ester exposure. Toxicol Sci 2023; 195:103-122. [PMID: 37399109 PMCID: PMC10695431 DOI: 10.1093/toxsci/kfad062] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2023] Open
Abstract
Toxicogenomics is a critical area of inquiry for hazard identification and to identify both mechanisms of action and potential markers of exposure to toxic compounds. However, data generated by these experiments are highly dimensional and present challenges to standard statistical approaches, requiring strict correction for multiple comparisons. This stringency often fails to detect meaningful changes to low expression genes and/or eliminate genes with small but consistent changes particularly in tissues where slight changes in expression can have important functional differences, such as brain. Machine learning offers an alternative analytical approach for "omics" data that effectively sidesteps the challenges of analyzing highly dimensional data. Using 3 rat RNA transcriptome sets, we utilized an ensemble machine learning approach to predict developmental exposure to a mixture of organophosphate esters (OPEs) in brain (newborn cortex and day 10 hippocampus) and late gestation placenta of male and female rats, and identified genes that informed predictor performance. OPE exposure had sex specific effects on hippocampal transcriptome, and significantly impacted genes associated with mitochondrial transcriptional regulation and cation transport in females, including voltage-gated potassium and calcium channels and subunits. To establish if this holds for other tissues, RNAseq data from cortex and placenta, both previously published and analyzed via a more traditional pipeline, were reanalyzed with the ensemble machine learning methodology. Significant enrichment for pathways of oxidative phosphorylation and electron transport chain was found, suggesting a transcriptomic signature of OPE exposure impacting mitochondrial metabolism across tissue types and developmental epoch. Here we show how machine learning can complement more traditional analytical approaches to identify vulnerable "signature" pathways disrupted by chemical exposures and biomarkers of exposure.
Collapse
Affiliation(s)
- Andrew J Newell
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - Dereje Jima
- Molecular Education, Technology, and Research Innovation Center, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - Benjamin Reading
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - Heather B Patisaul
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina 27695, USA
- Center for Human Health and the Environment, North Carolina State University, Raleigh, North Carolina 27695, USA
| |
Collapse
|
9
|
Schkoda S, Horman B, Witchey SK, Jansson A, Macari S, Patisaul HB. Skeletal effects following developmental flame-retardant exposure are specific to sex and chemical class in the adult Wistar rat. FRONTIERS IN TOXICOLOGY 2023; 5:1216388. [PMID: 37577032 PMCID: PMC10414991 DOI: 10.3389/ftox.2023.1216388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 06/22/2023] [Indexed: 08/15/2023] Open
Abstract
Introduction: Accumulating evidence reveals that endocrine disrupting chemicals (EDCs) can disrupt aspects of metabolic programming, suggesting that skeletal development may be at risk, a possibility that is rarely examined. The commercial flame retardant (FR) mixture, Firemaster 550 (FM 550), has repeatedly been shown to negatively influence metabolic programming, raising concerns that skeletal integrity may consequently be impaired. We have previously shown that gestational and lactational exposure to 1,000 µg FM 550 negatively affected sex-specific skeletal traits in male, but not female, rats assessed at 6 months of age. Whether this outcome is primarily driven by the brominated (BFR) or organophosphate ester (OPFR) portions of the mixture or the effects persist to older ages is unknown. Materials and methods: To address this, in the present study, dams were orally exposed throughout gestation and lactation to either 1,000 μg BFR, 1,000 µg OPFR, or 2,000 µg FM 550. Offspring (n = 8/sex/exposure) were weaned at PND 21 and assessed for femoral cortical and trabecular bone parameters at 8 months of age by high-resolution X-ray micro-computed tomography (micro-CT). Serum levels of serotonin, osteocalcin, alkaline phosphatase, and calcium were quantified. Results: FM 550 affected both sexes, but the females were more appreciably impacted by the OPFRs, while the males were more vulnerable to the BFRs. Conclusion: Although sex specificity was expected due to the sexual dimorphic nature of skeletal physiology, the mechanisms accounting for the male- and female-specific phenotypes remain to be determined. Future work aims to clarify these unresolved issues.
Collapse
Affiliation(s)
- Stacy Schkoda
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, United States
| | - Brian Horman
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, United States
| | - Shannah K. Witchey
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, United States
| | - Anton Jansson
- Analytical Instrumentation Facility, North Carolina State University, Raleigh, NC, United States
| | - Soraia Macari
- Department of Restorative Dentistry, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Heather B. Patisaul
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, United States
- Center for Human Health and the Environment, North Carolina State University, Raleigh, NC, United States
| |
Collapse
|
10
|
Yang R, Yang Y, Yang L, Chen H, Zhong W, Zhu L. First insight into the sex-dependent accumulation, tissue distribution and potential toxicities of 2-ethylhexyl diphenyl phosphate and its metabolites in adult zebrafish. JOURNAL OF HAZARDOUS MATERIALS 2023; 452:131299. [PMID: 37027911 DOI: 10.1016/j.jhazmat.2023.131299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 03/05/2023] [Accepted: 03/24/2023] [Indexed: 05/03/2023]
Abstract
The 2-ethylhexyl diphenyl phosphate (EHDPHP), a primary organophosphorus flame retardant used in various industrial products, is prone to biotransformation. However, there is a knowledge gap on the sex- and tissue-specific accumulation and potential toxicities of EHDPHP (M1) and its metabolites (M2-M16). In this study, adult zebrafish (Danio rerio) were exposed to EHDPHP (0, 5, 35 and 245 µg/L) for 21-day, which was followed by 7-day depuration. The bioconcentration factor (BCF) of EHDPHP in female zebrafish was 26.2 ± 7.7% lower than in males due to the lower uptake rate (ku) while higher depuration rate (kd) in the females. The regular ovulation and higher metabolic efficiency promoted elimination from female zebrafish, thus leading to much less (28-44%) accumulation of ∑(M1-M16) in female zebrafish. They exhibited the highest accumulation in the liver and intestine in both sexes, which might be regulated by tissue-specific transporters and histones evidenced by molecular docking results. Intestine microbiota analysis further revealed that female zebrafish were more susceptible to EHDPHP exposure, with more significant changes in phenotype number and KEGG pathways in female than male fish. Disease prediction results suggested that EHDPHP exposure might cause cancers, cardiovascular diseases as well as endocrine disorders in both sexes. These results provide a comprehensive understanding of the sex-dependent accumulation and toxicity of EHDPHP and its metabolites.
Collapse
Affiliation(s)
- Rongyan Yang
- Key Laboratory of Pollution Processes and Environmental Criteria of Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering of Nankai University, Tianjin 300350, China
| | - Yi Yang
- Key Laboratory of Pollution Processes and Environmental Criteria of Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering of Nankai University, Tianjin 300350, China
| | - Liping Yang
- Key Laboratory of Pollution Processes and Environmental Criteria of Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering of Nankai University, Tianjin 300350, China
| | - Hao Chen
- Key Laboratory of Pollution Processes and Environmental Criteria of Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering of Nankai University, Tianjin 300350, China
| | - Wenjue Zhong
- Key Laboratory of Pollution Processes and Environmental Criteria of Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering of Nankai University, Tianjin 300350, China.
| | - Lingyan Zhu
- Key Laboratory of Pollution Processes and Environmental Criteria of Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering of Nankai University, Tianjin 300350, China
| |
Collapse
|
11
|
Li Q, Lesseur C, Srirangam P, Kaur K, Hermetz K, Caudle WM, Fiedler N, Panuwet P, Prapamontol T, Naksen W, Suttiwan P, Baumert BO, Hao K, Barr DB, Marsit CJ, Chen J. Associations between prenatal organophosphate pesticide exposure and placental gene networks. ENVIRONMENTAL RESEARCH 2023; 224:115490. [PMID: 36828252 PMCID: PMC10054353 DOI: 10.1016/j.envres.2023.115490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 02/09/2023] [Accepted: 02/11/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND Exposure to organophosphate (OP) pesticides during pregnancy has been linked to deficiencies of neurobehavioral development in childhood; however, the molecular mechanisms underlying this association remain elusive. The placenta plays a crucial role in protecting the fetus from environmental insults and safeguarding proper fetal development including neurodevelopment. The aim of our study is to evaluate changes in the placental transcriptome associated with prenatal OP exposure. METHODS Pregnant farm workers from two agricultural districts in northern Thailand were recruited for the Study of Asian Women and Offspring's Development and Environmental Exposures (SAWASDEE) from 2017 to 2019. For 254 participants, we measured maternal urinary concentrations of six nonspecific dialkyl phosphates (DAP) metabolites in early, middle, and late pregnancy. In parallel, we profiled the term placental transcriptome from the same participants using RNA-Sequencing and performed Weighted Gene co-expression Network Analysis (WGCNA). Generalized linear regression modeling was used to examine associations of urinary OP metabolites and placental co-expression module eigenvalues. RESULTS We identified 21 gene co-expression modules in the placenta. From the six DAP metabolites assayed, diethylphosphate (DEP) and diethylthiophosphate (DETP) were detected in more than 70% of the urine samples. Significant associations between DEP at multiple time points and two specific placental gene modules were observed. The 'black' module, enriched in genes involved in epithelial-to-mesenchymal transition (EMT) and hypoxia, was negatively associated with DEP in early (p = 0.034), and late pregnancies (p = 0.016). The 'lightgreen' module, enriched in genes involved in myogenesis and EMT, was negatively associated with DEP in late pregnancy (p = 0.010). We observed 2 hub genes (CELSR1 and PYCR1) of the 'black' module to be negatively associated with DEP in early and late pregnancies. CONCLUSIONS Our results suggest that prenatal OP exposure may disrupt placental gene networks in a time-dependent manner. Such transcriptomic effects may lead to down-stream changes in placental function that ultimately affect the developing fetus.
Collapse
Affiliation(s)
- Qian Li
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Corina Lesseur
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Pranathi Srirangam
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Barnard College, New York, NY, USA
| | - Kirtan Kaur
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Karen Hermetz
- Gangarosa Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - W Michael Caudle
- Gangarosa Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Nancy Fiedler
- Environmental and Occupational Health Sciences Institute, Rutgers School of Public Health, Piscataway, NJ, USA
| | - Parinya Panuwet
- Gangarosa Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Tippawan Prapamontol
- Research Institute for Health Sciences, Chiang Mai University, Chiang Mai, Thailand
| | - Warangkana Naksen
- Faculty of Public Health, Chiang Mai University, Chiang Mai, Thailand
| | - Panrapee Suttiwan
- Psychology Center of Life-span Development and Intergeneration (LIFE Di), Faculty of Psychology, Chulalongkorn University, Bangkok, Thailand
| | - Brittney O Baumert
- Department of Population and Public Health Science, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90032, USA
| | - Ke Hao
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Dana Boyd Barr
- Gangarosa Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Carmen J Marsit
- Gangarosa Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Jia Chen
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| |
Collapse
|
12
|
Li Y, Wang X, Zhu Q, Xu Y, Fu Q, Wang T, Liao C, Jiang G. Organophosphate Flame Retardants in Pregnant Women: Sources, Occurrence, and Potential Risks to Pregnancy Outcomes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:7109-7128. [PMID: 37079500 DOI: 10.1021/acs.est.2c06503] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Organophosphate flame retardants (OPFRs) are found in various environmental matrixes and human samples. Exposure to OPFRs during gestation may interfere with pregnancy, for example, inducing maternal oxidative stress and maternal hypertension during pregnancy, interfering maternal and fetal thyroid hormone secretion and fetal neurodevelopment, and causing fetal metabolic abnormalities. However, the consequences of OPFR exposure on pregnant women, impact on mother-to-child transmission of OPFRs, and harmful effects on fetal and pregnancy outcomes have not been evaluated. This review describes the exposure to OPFRs in pregnant women worldwide, based on metabolites of OPFRs (mOPs) in urine for prenatal exposure and OPFRs in breast milk for postnatal exposure. Predictors of maternal exposure to OPFRs and variability of mOPs in urine have been discussed. Mother-to-child transmission pathways of OPFRs have been scrutinized, considering the levels of OPFRs and their metabolites in amniotic fluid, placenta, deciduae, chorionic villi, and cord blood. The results showed that bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) and diphenyl phosphate (DPHP) were the two predominant mOPs in urine, with detection frequencies of >90%. The estimated daily intake (EDIM) indicates low risk when infants are exposed to OPFRs from breast milk. Furthermore, higher exposure levels of OPFRs in pregnant women may increase the risk of adverse pregnancy outcomes and influence the developmental behavior of infants. This review summarizes the knowledge gaps of OPFRs in pregnant women and highlights the crucial steps for assessing health risks in susceptible populations, such as pregnant women and fetuses.
Collapse
Affiliation(s)
- Yongting Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xin Wang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qingqing Zhu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yaqian Xu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou Zhejiang, 310024, China
| | - Qiuguo Fu
- Department of Analytical Chemistry, Helmholtz Centre for Environmental Research (UFZ), Permoserstraße 15, 04318 Leipzig, Germany
| | - Thanh Wang
- Man-Technology-Environment (MTM) Research Centre, Örebro University, Örebro 701 82, Sweden
| | - Chunyang Liao
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou Zhejiang, 310024, China
- Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, Institute of Environment and Health, Jianghan University, Wuhan, Hubei 430056, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guibin Jiang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou Zhejiang, 310024, China
- Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, Institute of Environment and Health, Jianghan University, Wuhan, Hubei 430056, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| |
Collapse
|
13
|
Gan H, Zhang Y, Wang YF, Tao FB, Gao H. Relationships of prenatal organophosphate ester exposure with pregnancy and birth outcomes: A systematic scoping review of epidemiological studies. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 252:114642. [PMID: 36791503 DOI: 10.1016/j.ecoenv.2023.114642] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 01/31/2023] [Accepted: 02/09/2023] [Indexed: 06/18/2023]
Abstract
Exposure to organophosphate esters (OPEs) during pregnancy has been suggested to be associated with adverse pregnancy and birth outcomes. However, relevant investigations are scarce, and the findings are inconsistent. We aimed to conduct a scoping review to provide an overview of these associations. Electronic databases, including MEDLINE (through PubMed), Web of Science, and CNKI (China National Knowledge Infrastructure), were searched from inception to March 2022 and updated in July 2022. A total of 8 studies (1860 participants) were included. Limited evidence indicates that OPE exposure during pregnancy may be negatively associated with both maternal and neonatal triiodothyronine and tetraiodothyronine concentrations but positively associated with thyroid-stimulating hormone concentrations. OPE exposure during pregnancy may be associated with lower insulin concentrations. OPE exposure during pregnancy was associated with gestational age in a sex-specific manner. Intrauterine OPE exposure might increase the risk of preterm birth in female infants but decrease the risk of preterm birth in male infants. Prenatal OPE exposure might be associated with an increased risk of low birth weight. The current scoping review suggests that OPE exposure during pregnancy may disturb pregnancy and birth health, including adverse thyroid function and birth size. Because of the limited evidence obtained for most associations, additional studies followed by a traditional systematic review are needed to confirm these findings.
Collapse
Affiliation(s)
- Hong Gan
- Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, Hefei 230032, Anhui, China; Department of Pediatrics, The First Affiliated Hospital of Anhui Medical University, Hefei 230022, Anhui, China
| | - Yi Zhang
- Key Laboratory of Population Health Across Life Cycle, Anhui Medical University, Ministry of Education of the People's Republic of China, No. 81 Meishan Road, Hefei 230032, Anhui, China; Department of Endocrinology, The First Affiliated Hospital of Anhui Medical University, Hefei 230022, Anhui, China
| | - Ya-Fei Wang
- Nursing Department, Anhui Medical College, Hefei 230601, Anhui, China
| | - Fang-Biao Tao
- Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, Hefei 230032, Anhui, China; Key Laboratory of Population Health Across Life Cycle, Anhui Medical University, Ministry of Education of the People's Republic of China, No. 81 Meishan Road, Hefei 230032, Anhui, China.
| | - Hui Gao
- Department of Pediatrics, The First Affiliated Hospital of Anhui Medical University, Hefei 230022, Anhui, China; Key Laboratory of Population Health Across Life Cycle, Anhui Medical University, Ministry of Education of the People's Republic of China, No. 81 Meishan Road, Hefei 230032, Anhui, China.
| |
Collapse
|
14
|
Newell AJ, Kapps VA, Cai Y, Rai MR, St. Armour G, Horman BM, Rock KD, Witchey SK, Greenbaum A, Patisaul HB. Maternal organophosphate flame retardant exposure alters the developing mesencephalic dopamine system in fetal rat. Toxicol Sci 2023; 191:357-373. [PMID: 36562574 PMCID: PMC9936211 DOI: 10.1093/toxsci/kfac137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Organophosphate flame retardants (OPFRs) have become the predominant substitution for legacy brominated flame retardants but there is concern about their potential developmental neurotoxicity (DNT). OPFRs readily dissociate from the fireproofed substrate to the environment, and they (or their metabolites) have been detected in diverse matrices including air, water, soil, and biota, including human urine and breastmilk. Given this ubiquitous contamination, it becomes increasingly important to understand the potential effects of OPFRs on the developing nervous system. We have previously shown that maternal exposure to OPFRs results in neuroendocrine disruption, alterations to developmental metabolism of serotonin (5-HT) and axonal extension in male fetal rats, and potentiates adult anxiety-like behaviors. The development of the serotonin and dopamine systems occur in parallel and interact, therefore, we first sought to enhance our prior 5-HT work by first examining the ascending 5-HT system on embryonic day 14 using whole mount clearing of fetal heads and 3-dimensional (3D) brain imaging. We also investigated the effects of maternal OPFR exposure on the development of the mesocortical dopamine system in the same animals through 2-dimensional and 3D analysis following immunohistochemistry for tyrosine hydroxylase (TH). Maternal OPFR exposure induced morphological changes to the putative ventral tegmental area and substantia nigra in both sexes and reduced the overall volume of this structure in males, whereas 5-HT nuclei were unchanged. Additionally, dopaminergic axogenesis was disrupted in OPFR exposed animals, as the dorsoventral spread of ventral telencephalic TH afferents were greater at embryonic day 14, while sparing 5-HT fibers. These results indicate maternal exposure to OPFRs alters the development trajectory of the embryonic dopaminergic system and adds to growing evidence of OPFR DNT.
Collapse
Affiliation(s)
- Andrew J Newell
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - Victoria A Kapps
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - Yuheng Cai
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Raleigh, North Carolina 27606, USA
- Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina 27606, USA
| | - Mani Ratnam Rai
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Raleigh, North Carolina 27606, USA
- Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina 27606, USA
| | - Genevieve St. Armour
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - Brian M Horman
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - Kylie D Rock
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - Shannah K Witchey
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - Alon Greenbaum
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Raleigh, North Carolina 27606, USA
- Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina 27606, USA
| | - Heather B Patisaul
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina 27695, USA
- Center for Human Health and the Environment, North Carolina State University, Raleigh, North Carolina 27695, USA
| |
Collapse
|
15
|
Hawkey AB, Evans J, Holloway ZR, Pippen E, Jarrett O, Kenou B, Slotkin TA, Seidler FJ, Levin ED. Developmental exposure to the flame retardant, triphenyl phosphate, causes long-lasting neurobehavioral and neurochemical dysfunction. Birth Defects Res 2023; 115:357-370. [PMID: 36369782 DOI: 10.1002/bdr2.2125] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 09/07/2022] [Accepted: 10/26/2022] [Indexed: 11/13/2022]
Abstract
BACKGROUND Human exposures to organophosphate flame retardants result from their use as additives in numerous consumer products. These agents are replacements for brominated flame retardants but have not yet faced similar scrutiny for developmental neurotoxicity. We examined a representative organophosphate flame retardant, triphenyl phosphate (TPP) and its potential effects on behavioral development and dopaminergic function. METHODS Female Sprague-Dawley rats were given low doses of TPP (16 or 32 mg kg-1 day-1 ) via subcutaneous osmotic minipumps, begun preconception and continued into the early postnatal period. Offspring were administered a battery of behavioral tests from adolescence into adulthood, and littermates were used to evaluate dopaminergic synaptic function. RESULTS Offspring with TPP exposures showed increased latency to begin eating in the novelty-suppressed feeding test, impaired object recognition memory, impaired choice accuracy in the visual signal detection test, and sex-selective effects on locomotor activity in adolescence (males) but not adulthood. Male, but not female, offspring showed marked increases in dopamine utilization in the striatum, evidenced by an increase in the ratio of the primary dopamine metabolite (3,4-dihydroxyphenylacetic acid) relative to dopamine levels. CONCLUSIONS These results indicate that TPP has adverse effects that are similar in some respects to those of organophosphate pesticides, which were restricted because of their developmental neurotoxicity.
Collapse
Affiliation(s)
- Andrew B Hawkey
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, North Carolina, USA
| | - Janequia Evans
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, North Carolina, USA
| | - Zade R Holloway
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, North Carolina, USA
| | - Erica Pippen
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, North Carolina, USA
| | - Olivia Jarrett
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, North Carolina, USA
| | - Bruny Kenou
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, North Carolina, USA
| | - Theodore A Slotkin
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Frederic J Seidler
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Edward D Levin
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, North Carolina, USA.,Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina, USA
| |
Collapse
|
16
|
Yan Y, Guo F, Liu K, Ding R, Wang Y. The effect of endocrine-disrupting chemicals on placental development. Front Endocrinol (Lausanne) 2023; 14:1059854. [PMID: 36896182 PMCID: PMC9989293 DOI: 10.3389/fendo.2023.1059854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Accepted: 02/03/2023] [Indexed: 02/25/2023] Open
Abstract
Endocrine-disrupting chemicals (EDCs) or endocrine disruptors are substances that are either naturally occurring or artificial and are released into the natural environment. Humans are exposed to EDCs through ingestion, inhalation, and skin contact. Many everyday household items, such as plastic bottles and containers, the liners of metal food cans, detergents, flame retardants, food, gadgets, cosmetics, and pesticides, contain endocrine disruptors. Each hormone has a unique chemical makeup and structural attributes. The way that endocrine hormones connect to receptors is described as a "lock and key" mechanism, with each hormone serving as the key (lock). This mechanism is enabled by the complementary shape of receptors to their hormone, which allows the hormone to activate the receptors. EDCs are described as exogenous chemicals or compounds that have a negative impact on organisms' health by interacting with the functioning of the endocrine system. EDCs are associated with cancer, cardiovascular risk, behavioural disorders, autoimmune abnormalities, and reproductive disorders. EDCs exposure in humans is highly harmful during critical life stages. Nonetheless, the effect of EDCs on the placenta is often underestimated. The placenta is especially sensitive to EDCs due to its abundance of hormone receptors. In this review, we evaluated the most recent data on the effects of EDCs on placental development and function, including heavy metals, plasticizers, pesticides, flame retardants, UV filters and preservatives. The EDCs under evaluation have evidence from human biomonitoring and are found in nature. Additionally, this study indicates important knowledge gaps that will direct future research on the topic.
Collapse
Affiliation(s)
- Yan Yan
- Department of Endocrinology, The Second Hospital of Jilin University, Changchun, China
| | - Fengjun Guo
- Department of Obstetrics and Gynecology, The Second Hospital of Jilin University, Changchun, China
| | - Kexin Liu
- Department of Gastrointestinal Colorectal Surgery, China-Japan Union Hospital of Jilin University, Changchun, China
| | - Rixin Ding
- Department of Cardiovascular Medicine, Changchun Central Hospital, Changchun, China
| | - Yichao Wang
- Department of Obstetrics and Gynecology, The Second Hospital of Jilin University, Changchun, China
- *Correspondence: Yichao Wang,
| |
Collapse
|
17
|
Witchey SK, Doyle MG, Fredenburg JD, St Armour G, Horman B, Odenkirk MT, Aylor DL, Baker ES, Patisaul HB. Impacts of Gestational FireMaster 550 Exposure on the Neonatal Cortex Are Sex Specific and Largely Attributable to the Organophosphate Esters. Neuroendocrinology 2022; 113:1262-1282. [PMID: 36075192 PMCID: PMC9992460 DOI: 10.1159/000526959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 08/24/2022] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Flame retardants (FRs) are common bodily and environmental pollutants, creating concern about their potential toxicity. We and others have found that the commercial mixture FireMaster® 550 (FM 550) or its individual brominated (BFR) and organophosphate ester (OPFR) components are potential developmental neurotoxicants. Using Wistar rats, we previously reported that developmental exposure to FM 550 or its component classes produced sex- and compound-specific effects on adult socioemotional behaviors. The underlying mechanisms driving the behavioral phenotypes are unknown. METHODS To further mechanistic understanding, here we conducted transcriptomics in parallel with a novel lipidomics approach using cortical tissues from newborn siblings of the rats in the published behavioral study. Inclusion of lipid composition is significant because it is rarely examined in developmental neurotoxicity studies. Pups were gestationally exposed via oral dosing to the dam to FM 550 or the BFR or OPFR components at environmentally relevant doses. RESULTS The neonatal cortex was highly sexually dimorphic in lipid and transcriptome composition, and males were more significantly impacted by FR exposure. Multiple adverse modes of action for the BFRs and OPFRs on neurodevelopment were identified, with the OPFRs being more disruptive than the BFRs via multiple mechanisms including dysregulation of mitochondrial function and disruption of cholinergic and glutamatergic systems. Disrupted mitochondrial function by environmental factors has been linked to a higher risk of autism spectrum disorders and neurodegenerative disorders. Impacted lipid classes included ceramides, sphingomyelins, and triacylglycerides. Robust ceramide upregulation in the OPFR females could suggest a heightened risk of brain metabolic disease. CONCLUSIONS This study reveals multiple mechanisms by which the components of a common FR mixture are developmentally neurotoxic and that the OPFRs may be the compounds of greatest concern.
Collapse
Affiliation(s)
- Shannah K Witchey
- Department of Biological Sciences, NC State University, Raleigh, North Carolina, USA
| | - Michael G Doyle
- Department of Chemistry, NC State University, Raleigh, North Carolina, USA
| | - Jacob D Fredenburg
- Department of Biological Sciences, NC State University, Raleigh, North Carolina, USA
| | - Genevieve St Armour
- Department of Biological Sciences, NC State University, Raleigh, North Carolina, USA
| | - Brian Horman
- Department of Biological Sciences, NC State University, Raleigh, North Carolina, USA
| | - Melanie T Odenkirk
- Department of Chemistry, NC State University, Raleigh, North Carolina, USA
| | - David L Aylor
- Department of Biological Sciences, NC State University, Raleigh, North Carolina, USA
- Center for Human Health and the Environment, NC State University, Raleigh, North Carolina, USA
| | - Erin S Baker
- Department of Chemistry, NC State University, Raleigh, North Carolina, USA
| | - Heather B Patisaul
- Center for Human Health and the Environment, NC State University, Raleigh, North Carolina, USA
| |
Collapse
|
18
|
Marinello WP, Gillera SEA, Fanning MJ, Malinsky LB, Rhodes CL, Horman BM, Patisaul HB. Effects of developmental exposure to FireMaster® 550 (FM 550) on microglia density, reactivity and morphology in a prosocial animal model. Neurotoxicology 2022; 91:140-154. [PMID: 35526706 DOI: 10.1016/j.neuro.2022.04.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 04/29/2022] [Accepted: 04/29/2022] [Indexed: 11/20/2022]
Abstract
Microglia are known to shape brain sex differences critical for social and reproductive behaviors. Chemical exposures can disrupt brain sexual differentiation but there is limited data regarding how they may impact microglia distribution and function. We focused on the prevalent flame retardant mixture Firemaster 550 (FM 550) which is used in foam-based furniture and infant products including strollers and nursing pillows because it disrupts sexually dimorphic behaviors. We hypothesized early life FM 550 exposure would disrupt microglial distribution and reactivity in brain regions known to be highly sexually dimorphic or associated with social disorders in humans. We used prairie voles (Microtus ochrogaster) because they display spontaneous prosocial behaviors not seen in rats or mice and are thus a powerful model for studying chemical exposure-related impacts on social behaviors and their underlying neural systems. We have previously demonstrated that perinatal FM 550 exposure sex-specifically impacts socioemotional behaviors in prairie voles. We first established that, unlike in rats, the postnatal colonization of the prairie vole brain is not sexually dimorphic. Vole dams were then exposed to FM 550 (0, 500, 1000, 2000 µg/day) via subcutaneous injections through gestation, and pups were directly exposed beginning the day after birth until weaning. Adult offspring's brains were assessed for number and type (ramified, intermediate, ameboid) of microglia in the medial prefrontal cortex (mPFC), cerebellum (lobules VI-VII) and amygdala. Effects were sex- and dose-specific in the regions of interests. Overall, FM 550 exposure resulted in reduced numbers of microglia in most regions examined, with the 1000 µg FM 550 exposed males particularly affected. To further quantify differences in microglia morphology in the 1000 µg FM 550 group, Sholl and skeleton analysis were carried out on individual microglia. Microglia from control females had a more ramified phenotype compared to control males while 1000 µg FM 550-exposed males had decreased branching and ramification compared to same-sex controls. Future studies will examine the impact on the exposure to FM 550 on microglia during development given the critical role of these cells in shaping neural circuits.
Collapse
Affiliation(s)
- William P Marinello
- Department of Biological Sciences, NC State University, Raleigh, NC 27695, USA
| | | | - Marley J Fanning
- Department of Biological Sciences, NC State University, Raleigh, NC 27695, USA
| | - Lacey B Malinsky
- Department of Biological Sciences, NC State University, Raleigh, NC 27695, USA
| | - Cassie L Rhodes
- Department of Biological Sciences, NC State University, Raleigh, NC 27695, USA
| | - Brian M Horman
- Department of Biological Sciences, NC State University, Raleigh, NC 27695, USA
| | - Heather B Patisaul
- Department of Biological Sciences, NC State University, Raleigh, NC 27695, USA; Center for Human Health and the Environment, NC State University, Raleigh, NC 27695, USA.
| |
Collapse
|
19
|
A single-cell survey unveils cellular heterogeneity and sensitive responses in mouse cortices induced by oral exposure to triphenyl phosphate. Arch Toxicol 2022; 96:2545-2557. [PMID: 35752650 DOI: 10.1007/s00204-022-03301-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 04/07/2022] [Indexed: 11/02/2022]
Abstract
Triphenyl phosphate (TPhP) is a non-halogenated organophosphorus flame retardant, and there is a higher exposure risk in children. TPhP has been found to be neurotoxic upon developmental exposure, yet the specific mechanism remains unclear. To characterize the cellular responses underlying TPhP-induced developmental neurotoxicity, we administered TPhP (0.5, 5 or 50 mg/kg/day) to neonatal mice from postnatal day 10 (P10)-P70. A total of 17,229 cells and 26,338 genes were identified in cortical samples from control and low-dose (the internal doses of metabolite DPhP comparable to human exposure level) groups using single-cell RNA sequencing (scRNA-seq). TPhP exposure led to heterogeneous transcriptional alterations and intercellular crosstalk among neurons, neural stem/progenitor cells (NSPCs), endothelial cells, and immunocytes. Deprivation of NSPCs, loss of mature neurons, and concomitant neuroinflammation mediated by extrinsic and intrinsic immunocytes were found in TPhP-exposed cortices. In addition, we observed blood-brain barrier destruction prior to the anxiety/depression-like neurobehavioral changes. These results reveal the distinctive cellular processes in TPhP's neurodevelopmental toxicity and uncover that the impeded neurogenesis, disrupted vascular barrier, and concomitant neuroinflammation are the sensitive responses to TPhP exposure. Our study paves the way for the application of scRNA-seq in toxicity assessments for emerging neurotoxic pollutants.
Collapse
|
20
|
Individual and Combined Effects of Paternal Deprivation and Developmental Exposure to Firemaster 550 on Socio-Emotional Behavior in Prairie Voles. TOXICS 2022; 10:toxics10050268. [PMID: 35622681 PMCID: PMC9147230 DOI: 10.3390/toxics10050268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 05/11/2022] [Accepted: 05/12/2022] [Indexed: 12/05/2022]
Abstract
The prevalence of neurodevelopmental disorders (NDDs) is rapidly rising, suggesting a confluence of environmental factors that are likely contributing, including developmental exposure to environmental contaminants. Unfortunately, chemical exposures and social stressors frequently occur simultaneously in many communities, yet very few studies have sought to establish the combined effects on neurodevelopment or behavior. Social deficits are common to many NDDs, and we and others have shown that exposure to the chemical flame retardant mixture, Firemaster 550 (FM 550), or paternal deprivation impairs social behavior and neural function. Here, we used a spontaneously prosocial animal model, the prairie vole (Microtus ochrogaster), to explore the effects of perinatal chemical (FM 550) exposure alone or in combination with an early life stressor (paternal absence) on prosocial behavior. Dams were exposed to vehicle (sesame oil) or 1000 µg FM 550 orally via food treats from conception through weaning and the paternal absence groups were generated by removing the sires the day after birth. Adult offspring of both sexes were then subjected to open-field, sociability, and a partner preference test. Paternal deprivation (PD)-related effects included increased anxiety, decreased sociability, and impaired pair-bonding in both sexes. FM 550 effects include heightened anxiety and partner preference in females but reduced partner preference in males. The combination of FM 550 exposure and PD did not exacerbate any behaviors in either sex except for distance traveled by females in the partner preference test and, to a lesser extent, time spent with, and the number of visits to the non-social stimulus by males in the sociability test. FM 550 ameliorated the impacts of parental deprivation on partner preference behaviors in both sexes. This study is significant because it provides evidence that chemical and social stressors can have unique behavioral effects that differ by sex but may not produce worse outcomes in combination.
Collapse
|
21
|
Hawkey AB, Pippen E, Kenou B, Holloway Z, Slotkin TA, Seidler FJ, Levin ED. Persistent neurobehavioral and neurochemical anomalies in middle-aged rats after maternal diazinon exposure. Toxicology 2022; 472:153189. [PMID: 35452779 PMCID: PMC9655883 DOI: 10.1016/j.tox.2022.153189] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 04/13/2022] [Accepted: 04/15/2022] [Indexed: 11/17/2022]
Abstract
Diazinon is an organophosphate pesticide that has a history of wide use. Developmental exposures to organophosphates lead to neurobehavioral changes that emerge early in life and can persist into adulthood. However, preclinical studies have generally evaluated changes through young adulthood, whereas the persistence or progression of deficits into middle age remain poorly understood. The current study evaluated the effects of maternal diazinon exposure on behavior and neurochemistry in middle age, at 1 year postpartum, comparing the results to our previous studies of outcomes at adolescence and in young adulthood (4 months of age) (Hawkey 2020). Female rats received 0, 0.5 or 1.0 mg/kg/day of diazinon via osmotic minipump throughout gestation and into the postpartum period. The offspring were tested on a battery of locomotor, affective, and cognitive tests at young adulthood and during middle age. Some of the neurobehavioral consequences of developmental DZN seen during adolescence and young adulthood faded with continued aging, whereas other neurobehavioral effects emerged with aging. At middle age, the rats showed few locomotor effects, in contrast to the locomotor hyperactivity that had been observed in adolescence. Notably, though, DZN exposure during development impaired reference memory performance in middle-aged males, an effect that had not been seen in the younger animals. Likewise, middle-aged females exposed to DZN showed deficient attentional accuracy, an effect not seen in young adults. Across adulthood, the continued potential for behavioral defects was associated with altered dopaminergic function, characterized by enhanced dopamine utilization that was regionally-selective (striatum but not frontal/parietal cortex). This study shows that the neurobehavioral impairments from maternal low dose exposure to diazinon not only persist, but may continue to evolve as animals enter middle age.
Collapse
Affiliation(s)
- Andrew B Hawkey
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, USA
| | - Erica Pippen
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, USA
| | - Bruny Kenou
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, USA
| | - Zade Holloway
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, USA
| | - Theodore A Slotkin
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, USA
| | - Frederic J Seidler
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, USA
| | - Edward D Levin
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, USA.
| |
Collapse
|
22
|
Liu S, Song G, Li F, Li R, Chen X, Guo Y, Zhou F, Wang Q, Yang L, Zhou B. Bis (2-ethylhexyl)-2,3,4,5-tetrabromophthalate showed poor penetrability but increased the permeability of blood brain barrier: Evidences from in vitro and in vivo studies. JOURNAL OF HAZARDOUS MATERIALS 2022; 424:127386. [PMID: 34879576 DOI: 10.1016/j.jhazmat.2021.127386] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 09/27/2021] [Accepted: 09/27/2021] [Indexed: 06/13/2023]
Abstract
Bis(2ethylhexyl)-2,3,4,5-tetrabromophthalate (TBPH), a replacement for restricted flame retardants, has become ubiquitous in the environment. To reveal the neurotoxicity and underlying mechanism of TBPH, we first evaluated its penetrability through the blood-brain barrier (BBB) using hCMEC/D3 cells as in vitro model, and found TBPH had poor penetrability through BBB with a maximum Papp of 14.8 × 10-6 cms-1. Further study using transgenetic zebrafish (Tg flk1: EGFP) as in vivo model confirmed that TBPH could affect the BBB permeability, probably via affecting the transcription of genes encoding tight junction proteins. Finally, wild type zebrafish embryos/larvae were exposed to TBPH to evaluate the neurotoxicity. The neurodevelopment, neurotransmitters and locomotor activity of zebrafish larvae did not changed, which may be because TBPH can hardly cross the BBB to pose direct exposure to the central nervous system. However, the transcription of opsins genes and visual response to light stimulation in zebrafish larvae were inhibited, pointing to additional mechanism that may cause visual impairment indirectly. Above all, these results can help further understand the neurotoxicity and underlying mechanism by TBPH, and also pointed out potential risk of this chemical to aquatic organisms.
Collapse
Affiliation(s)
- Sitian Liu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Guili Song
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China
| | - Fan Li
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Ruiwen Li
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China; Ecological Environment Monitoring and Scientific Research Center, Changjiang River Basin Ecological Environment Administration, Ministry of Ecology and Environment, Wuhan 430014, PR China
| | - Xiangping Chen
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China
| | - Yongyong Guo
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China
| | - Fang Zhou
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China
| | - Qiangwei Wang
- Institute of Pesticide and Environmental Toxicology, Zhejiang University, Hangzhou 310058, PR China
| | - Lihua Yang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China.
| | - Bingsheng Zhou
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China
| |
Collapse
|
23
|
Bao Z, Jing Y. Brominated flame retardant TBPH induced oxidative damage and reduced the expression of memory-related proteins in mice, with no discernable impairment of learning and memory. Hum Exp Toxicol 2021; 40:S684-S692. [PMID: 34784780 DOI: 10.1177/09603271211058876] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Bis(2-ethylhexyl)-2,3,4,5-tetrabromophthalate (TBPH) is one of the new brominated flame retardants with adverse neurobehavioral potential. These flame retardants are often added to household furnishings where children would come into contact with them. This study explores whether oral exposure to TBPH for 28 days would impair neurobehavioral function in mice and the role of curcumin (CUR) in this process. CUR is a natural antioxidant and is thought to be of use in the treatment of neurological toxicity due to its neuroprotective effects. Learning and memory of mice exposed to TBPH was investigated using the Morris water maze. Levels of malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH) were determined to assess oxidative damage. Western blot was used to detect the expression of glucose-regulated protein 78-kDa (GRP78), PKR-like ER kinase (PERK), and C/EBP homologous protein (CHOP) in the hippocampus. End-point effects were evaluated through observing post-synaptic density protein-95 (PSD-95), brain-derived neurotrophic factor (BDNF), and phosphorylated cAMP response element binding protein (p-CREB). Although TBPH exposure alone does not impair learning and memory, oxidative stress markers and endoplasmic reticulum stress-associated proteins were adversely affected in exposed mice. TBPH could significantly decrease the levels of BDNF, p-CREB, and PSD-95 in the hippocampus, and these TBPH-induced neurotoxic effects were attenuated by CUR. These findings provide further understanding of the neurotoxic effects of TBPH and the protective effect of CUR on TBPH exposure.
Collapse
Affiliation(s)
- Zhang Bao
- Department of Emergency, 117732Affiliated Renhe Hospital of China Three Gorges University, Yichang, China
| | - Yin Jing
- Department of Anesthesiology, 117732Affiliated Renhe Hospital of China Three Gorges University, Yichang, China
| |
Collapse
|
24
|
Patisaul HB. REPRODUCTIVE TOXICOLOGY: Endocrine disruption and reproductive disorders: impacts on sexually dimorphic neuroendocrine pathways. Reproduction 2021; 162:F111-F130. [PMID: 33929341 PMCID: PMC8484365 DOI: 10.1530/rep-20-0596] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 04/30/2021] [Indexed: 11/08/2022]
Abstract
We are all living with hundreds of anthropogenic chemicals in our bodies every day, a situation that threatens the reproductive health of present and future generations. This review focuses on endocrine-disrupting compounds (EDCs), both naturally occurring and man-made, and summarizes how they interfere with the neuroendocrine system to adversely impact pregnancy outcomes, semen quality, age at puberty, and other aspects of human reproductive health. While obvious malformations of the genitals and other reproductive organs are a clear sign of adverse reproductive health outcomes and injury to brain sexual differentiation, the hypothalamic-pituitary-gonadal (HPG) axis can be much more difficult to discern, particularly in humans. It is well-established that, over the course of development, gonadal hormones shape the vertebrate brain such that sex-specific reproductive physiology and behaviors emerge. Decades of work in neuroendocrinology have elucidated many of the discrete and often very short developmental windows across pre- and postnatal development in which this occurs. This has allowed toxicologists to probe how EDC exposures in these critical windows can permanently alter the structure and function of the HPG axis. This review includes a discussion of key EDC principles including how latency between exposure and the emergence of consequential health effects can be long, along with a summary of the most common and less well-understood EDC modes of action. Extensive examples of how EDCs are impacting human reproductive health, and evidence that they have the potential for multi-generational physiological and behavioral effects are also provided.
Collapse
Affiliation(s)
- Heather B Patisaul
- Department of Biological Sciences, Center for Human Health and the Environment, North Carolina State University, Raleigh, North Carolina, USA
| |
Collapse
|
25
|
Patisaul HB, Behl M, Birnbaum LS, Blum A, Diamond ML, Rojello Fernández S, Hogberg HT, Kwiatkowski CF, Page JD, Soehl A, Stapleton HM. Beyond Cholinesterase Inhibition: Developmental Neurotoxicity of Organophosphate Ester Flame Retardants and Plasticizers. ENVIRONMENTAL HEALTH PERSPECTIVES 2021; 129:105001. [PMID: 34612677 PMCID: PMC8493874 DOI: 10.1289/ehp9285] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 07/02/2021] [Accepted: 08/11/2021] [Indexed: 05/26/2023]
Abstract
BACKGROUND To date, the toxicity of organophosphate esters has primarily been studied regarding their use as pesticides and their effects on the neurotransmitter acetylcholinesterase (AChE). Currently, flame retardants and plasticizers are the two largest market segments for organophosphate esters and they are found in a wide variety of products, including electronics, building materials, vehicles, furniture, car seats, plastics, and textiles. As a result, organophosphate esters and their metabolites are routinely found in human urine, blood, placental tissue, and breast milk across the globe. It has been asserted that their neurological effects are minimal given that they do not act on AChE in precisely the same way as organophosphate ester pesticides. OBJECTIVES This commentary describes research on the non-AChE neurodevelopmental toxicity of organophosphate esters used as flame retardants and plasticizers (OPEs). Studies in humans, mammalian, nonmammalian, and in vitro models are presented, and relevant neurodevelopmental pathways, including adverse outcome pathways, are described. By highlighting this scientific evidence, we hope to elevate the level of concern for widespread human exposure to these OPEs and to provide recommendations for how to better protect public health. DISCUSSION Collectively, the findings presented demonstrate that OPEs can alter neurodevelopmental processes by interfering with noncholinergic pathways at environmentally relevant doses. Application of a pathways framework indicates several specific mechanisms of action, including perturbation of glutamate and gamma-aminobutyric acid and disruption of the endocrine system. The effects may have implications for the development of cognitive and social skills in children. Our conclusion is that concern is warranted for the developmental neurotoxicity of OPE exposure. We thus describe important considerations for reducing harm and to provide recommendations for government and industry decision makers. https://doi.org/10.1289/EHP9285.
Collapse
Affiliation(s)
- Heather B. Patisaul
- College of Sciences, North Carolina State University, Raleigh, North Carolina, USA
| | - Mamta Behl
- National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, USA
- National Toxicology Program, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, USA
| | - Linda S. Birnbaum
- National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, USA
- National Toxicology Program, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, USA
- Nicholas School of the Environment, Duke University, Durham, North Carolina, USA
| | - Arlene Blum
- Green Science Policy Institute, Berkeley, California, USA
- Department of Chemistry, University of California, Berkeley, Berkeley, California, USA
| | | | | | - Helena T. Hogberg
- Center for Alternatives to Animal Testing, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Carol F. Kwiatkowski
- Green Science Policy Institute, Berkeley, California, USA
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, USA
| | - Jamie D. Page
- Cancer Prevention & Education Society, Meads House, Leighterton, Tetbury, Gloucestershire, UK
| | - Anna Soehl
- Green Science Policy Institute, Berkeley, California, USA
| | - Heather M. Stapleton
- Nicholas School of the Environment, Duke University, Durham, North Carolina, USA
| |
Collapse
|
26
|
Choi G, Keil AP, Richardson DB, Daniels JL, Hoffman K, Villanger GD, Sakhi AK, Thomsen C, Reichborn-Kjennerud T, Aase H, Engel SM. Pregnancy exposure to organophosphate esters and the risk of attention-deficit hyperactivity disorder in the Norwegian mother, father and child cohort study. ENVIRONMENT INTERNATIONAL 2021; 154:106549. [PMID: 33910116 PMCID: PMC8217330 DOI: 10.1016/j.envint.2021.106549] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 03/26/2021] [Accepted: 03/29/2021] [Indexed: 05/31/2023]
Abstract
BACKGROUND Organophosphate esters (OPEs) are a class of flame retardants in common use. OPEs can easily leach from materials, resulting in human exposure. Increasing concentrations have been reported in human populations over the past decade. Recent studies have linked prenatal OPE exposure to hyperactivity and attention problems in children. Such behaviors are often found among children with attention-deficit hyperactivity disorder (ADHD), however, no study has investigated OPEs in relation to clinically assessed ADHD. OBJECTIVE To evaluate prenatal exposure to OPEs as risk factors for clinically assessed ADHD using a case-cohort study nested within the Norwegian Mother, Father, and Child Cohort Study (MoBa). METHODS We included in the case group 295 ADHD cases obtained via linkage with the Norwegian Patient Registry, and the sub-cohort group 555 children sampled at baseline, irrespective of their ADHD case status. Prenatal concentrations of OPE metabolites were measured in maternal urine collected at 17 weeks of gestation, and included diphenyl phosphate (DPHP), di-n-butyl phosphate (DNBP), bis(2-butoxyethyl) hydrogen phosphate (BBOEP), and bis(1,3-dichloro-2-propyl) phosphate (BDCIPP). We estimated risk ratios and the corresponding 95% confidence intervals [95% CI] using logistic regression, adjusting for season of urine collection, child sex, birth year, and maternal depression, education, and sum of urinary di(2-ethylhexyl) phthalate metabolites (∑DEHP) concentration during pregnancy. To assess the overall impact of simultaneously decreasing exposure to all chemical constituents of an OPE-phthalate mixture, quantile based g-computation was implemented. The mixture constituents included OPE and phthalate metabolites commonly detected in our study. In all models, we considered effect measure modification by child sex and polymorphisms in genes encoding paraoxonase 1 (PON1) and cytochrome P450 (P450) enzymes. Mediation analysis was conducted using thyroid function biomarkers estimated from maternal blood collected at 17 weeks of gestation. RESULTS DPHP was detected in nearly all samples (97.2%), with a higher geometric mean among the case group (0.70 µg/L) as compared to the sub-cohort (0.52 µg/L). DNBP was commonly detected as well (93.8%), while BBOEP (52.9%) and BDCIPP (22.9%) were detected less frequently. A higher risk of ADHD was observed in children with greater than median exposure to DPHP during pregnancy (risk ratio: 1.38 [95% CI: 0.96, 1.99]), which was slightly higher among girls (2.04 [1.03, 4.02]) and children of mothers with PON1 Q192R genotype QR (1.69 [0.89, 3.19]) or PON1 Q192R genotype RR (4.59 [1.38, 15.29]). The relationship between DPHP and ADHD (total risk ratio: 1.34 [0.90, 2.02]) was partially mediated through total triiodothyronine to total thyroxine ratio (natural direct effect: 1.29 [0.87, 1.94]; natural indirect effect: 1.04 [1.00, 1.10]; 12.48% mediated). We also observed an elevated risk of ADHD in relation to BDCIPP detection during pregnancy (1.50 [0.98, 2.28]). We did not observe notable differences in ADHD by DNBP (0.88 [0.62, 1.26]) or BBOEP (1.03 [0.73, 1.46]) during pregnancy. Simultaneously decreasing all constituents of common-detect OPE-phthalate mixture, specifically DPHP, DNBP, and 6 phthalate metabolites, by a quartile resulted in an ADHD risk ratio of 0.68 [0.64, 0.72]. CONCLUSION Prenatal exposure to DPHP and BDCIPP may increase the risk of ADHD. For DPHP, we observed potential modification by child sex and maternal PON1 Q192R genotype and partial mediation through maternal thyroid hormone imbalance at 17 weeks gestation.
Collapse
Affiliation(s)
- Giehae Choi
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
| | - Alexander P Keil
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - David B Richardson
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Julie L Daniels
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Kate Hoffman
- Nicholas School of the Environment, Duke University, Durham, NC, USA
| | | | | | | | - Ted Reichborn-Kjennerud
- Norwegian Institute of Public Health, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Heidi Aase
- Norwegian Institute of Public Health, Oslo, Norway
| | - Stephanie M Engel
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| |
Collapse
|
27
|
Gillera SEA, Marinello WP, Cao KT, Horman BM, Stapleton HM, Patisaul HB. Sex-specific Disruption of the Prairie Vole Hypothalamus by Developmental Exposure to a Flame Retardant Mixture. Endocrinology 2021; 162:6285199. [PMID: 34038511 PMCID: PMC8571712 DOI: 10.1210/endocr/bqab100] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Indexed: 02/07/2023]
Abstract
Prevalence of neurodevelopmental disorders (NDDs) with social deficits is conspicuously rising, particularly in boys. Flame retardants (FRs) have long been associated with increased risk, and prior work by us and others in multiple species has shown that developmental exposure to the common FR mixture Firemaster 550 (FM 550) sex-specifically alters socioemotional behaviors including anxiety and pair bond formation. In rats, FRs have also been shown to impair aspects of osmoregulation. Because vasopressin (AVP) plays a role in both socioemotional behavior and osmotic balance we hypothesized that AVP and its related nonapeptide oxytocin (OT) would be vulnerable to developmental FM 550 exposure. We used the prairie vole (Microtus ochrogaste) to test this because it is spontaneously prosocial. Using siblings of prairie voles used in a prior study that assessed behavioral deficits resulting from developmental FM 550 exposure across 3 doses, here we tested the hypothesis that FM 550 sex-specifically alters AVP and OT neuronal populations in critical nuclei, such as the paraventricular nucleus (PVN), that coordinate those behaviors, as well as related dopaminergic (determined by tyrosine hydroxylase (TH) immunolabeling) populations. Exposed females had fewer AVP neurons in the anterior PVN and more A13 TH neurons in the zona incerta than controls. By contrast, in FM 550 males, A13 TH neuron numbers in the zona incerta were decreased but only in 1 dose group. These results expand on previous work showing evidence of endocrine disruption of OT/AVP pathways, including to subpopulations of PVN AVP neurons that coordinate osmoregulatory functions in the periphery.
Collapse
Affiliation(s)
| | - William P Marinello
- Department of Biological Sciences, NC State University, Raleigh, NC 27695, USA
| | - Kevin T Cao
- Department of Biological Sciences, NC State University, Raleigh, NC 27695, USA
| | - Brian M Horman
- Department of Biological Sciences, NC State University, Raleigh, NC 27695, USA
| | - Heather M Stapleton
- Nicholas School of the Environment, Levine Science Research Center, Duke University, Durham, NC 27710, USA
| | - Heather B Patisaul
- Department of Biological Sciences, NC State University, Raleigh, NC 27695, USA
- Center for Human Health and the Environment, NC State University, Raleigh NC 27695, USA
- Correspondence: Heather B Patisaul, Professor of Biological Sciences, NC State University, 127 David Clark Labs, Raleigh, NC 27695, USA. E-mail:
| |
Collapse
|
28
|
Krentzel AA, Kimble LC, Dorris DM, Horman BM, Meitzen J, Patisaul HB. FireMaster® 550 (FM 550) exposure during the perinatal period impacts partner preference behavior and nucleus accumbens core medium spiny neuron electrophysiology in adult male and female prairie voles, Microtus ochrogaster. Horm Behav 2021; 134:105019. [PMID: 34182292 PMCID: PMC8403633 DOI: 10.1016/j.yhbeh.2021.105019] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 05/27/2021] [Accepted: 06/11/2021] [Indexed: 11/23/2022]
Abstract
One of the most widely used flame retardant (FR) mixtures in household products is Firemaster 550 (FM 550). FM 550 leaches from items such as foam-based furniture and infant products, resulting in contamination of the household environment and biota. Previous studies indicate sex-specific behavioral deficits in rodents and zebrafish in response to developmental FM 550 exposure. These deficits include impacts on social and attachment behaviors in a prosocial rodent: the prairie vole (Microtus ochrogaster). The prairie vole is a laboratory-acclimated rodent that exhibits spontaneous attachment behaviors including pair bonding. Here we extend previous work by addressing how developmental exposure to FM 550 impacts pair bonding strength via an extended-time partner preference test, as well as neuron electrophysiological properties in a region implicated in pair bond behavior, the nucleus accumbens (NAcc) core. Dams were exposed to vehicle or 1000 μg of FM 550 via subcutaneous injections throughout gestation, and female and male pups were directly exposed beginning the day after birth until weaning. Pair bond behavior of adult female and male offspring was assessed using a three hour-long partner preference test. Afterwards, acute brain slices of the NAcc core were produced and medium spiny neuron electrophysiological attributes recorded via whole cell patch-clamp. Behavioral impacts were sex-specific. Partner preference behavior was increased in exposed females but decreased in exposed males. Electrophysiological impacts were similar between sexes and specific to attributes related to input resistance. Input resistance was decreased in neurons recorded from both sexes exposed to FM 550 compared to vehicle. This study supports the hypothesis that developmental exposure to FM 550 impacts attachment behaviors and demonstrates a novel FM 550 effect on neural electrophysiology.
Collapse
Affiliation(s)
- Amanda A Krentzel
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695, USA
| | - Laney C Kimble
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695, USA
| | - David M Dorris
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695, USA
| | - Brian M Horman
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695, USA
| | - John Meitzen
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695, USA; Center for Human Health and the Environment, North Carolina State University, Raleigh, NC 27695, USA; Comparative Medicine Institute, North Carolina State University, Raleigh, NC 27695, USA.
| | - Heather B Patisaul
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695, USA; Center for Human Health and the Environment, North Carolina State University, Raleigh, NC 27695, USA
| |
Collapse
|
29
|
Patisaul HB. Endocrine disrupting chemicals (EDCs) and the neuroendocrine system: Beyond estrogen, androgen, and thyroid. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2021; 92:101-150. [PMID: 34452685 DOI: 10.1016/bs.apha.2021.03.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Hundreds of anthropogenic chemicals occupy our bodies, a situation that threatens the health of present and future generations. This chapter focuses on endocrine disrupting compounds (EDCs), both naturally occurring and man-made, that affect the neuroendocrine system to adversely impact health, with an emphasis on reproductive and metabolic pathways. The neuroendocrine system is highly sexually dimorphic and essential for maintaining homeostasis and appropriately responding to the environment. Comprising both neural and endocrine components, the neuroendocrine system is hormone sensitive throughout life and touches every organ system in the body. The integrative nature of the neuroendocrine system means that EDCs can have multi-system effects. Additionally, because gonadal hormones are essential for the sex-specific organization of numerous neuroendocrine pathways, endocrine disruption of this programming can lead to permanent deficits. Included in this review is a brief history of the neuroendocrine disruption field and a thorough discussion of the most common and less well understood neuroendocrine disruption modes of action. Also provided are extensive examples of how EDCs are likely contributing to neuroendocrine disorders such as obesity, and evidence that they have the potential for multi-generational effects.
Collapse
Affiliation(s)
- Heather B Patisaul
- Department of Biological Sciences, Center for Human Health and the Environment, North Carolina State University, Raleigh, NC, United States.
| |
Collapse
|
30
|
Varshavsky JR, Robinson JF, Zhou Y, Puckett KA, Kwan E, Buarpung S, Aburajab R, Gaw SL, Sen S, Gao S, Smith SC, Park JS, Zakharevich I, Gerona RR, Fisher SJ, Woodruff TJ. Organophosphate Flame Retardants, Highly Fluorinated Chemicals, and Biomarkers of Placental Development and Disease During Mid-Gestation. Toxicol Sci 2021; 181:215-228. [PMID: 33677611 PMCID: PMC8163039 DOI: 10.1093/toxsci/kfab028] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Perfluoroalkyl and polyfluoroalkyl substances (PFASs) and organophosphate flame retardants (OPFRs) are chemicals that may contribute to placenta-mediated complications and adverse maternal-fetal health risks. Few studies have investigated these chemicals in relation to biomarkers of effect during pregnancy. We measured 12 PFASs and four urinary OPFR metabolites in 132 healthy pregnant women during mid-gestation and examined a subset with biomarkers of placental development and disease (n = 62). Molecular biomarkers included integrin alpha-1 (ITGA1), vascular endothelial-cadherin (CDH5), and matrix metalloproteinase-1 (MMP1). Morphological endpoints included potential indicators of placental stress and the extent of cytotrophoblast (CTB)-mediated uterine artery remodeling. Serum PFASs and urinary OPFR metabolites were detected in ∼50%-100% of samples. The most prevalent PFASs were perfluorononanoic acid (PFNA), perfluorooctanoic acid (PFOA), and perfluorooctane sulfonic acid (PFOS), with geometric mean (GM) levels of ∼1.3-2.8 (95% confidence limits from 1.2-3.1) ng/ml compared to ≤0.5 ng/ml for other PFASs. Diphenyl phosphate (DPhP) and bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) were the most prevalent OPFR metabolites, with GMs of 2.9 (95% CI: 2.5-3.4) and 3.6 (95% CI: 2.2-3.1) ng/ml, respectively, compared to <1 ng/ml for bis(2-chloroethyl) phosphate (BCEP) and bis(1-chloro-2-propyl) phosphate (BCIPP). We found inverse associations of PFASs or OPFRs with ITGA1 or CDH5 immunoreactivity and positive associations with indicators of placental stress in multiple basal plate regions, indicating these chemicals may contribute to abnormal placentation and future health risks. Associations with blood pressure and lipid concentrations warrant further examination. This is the first study of these chemicals with placental biomarkers measured directly in human tissues and suggests specific biomarkers are sensitive indicators of exposure during a vulnerable developmental period.
Collapse
Affiliation(s)
- Julia R Varshavsky
- Program on Reproductive Health and the Environment, University of California, San Francisco (UCSF), San Francisco, California 94158
- Center for Reproductive Sciences and Department of Obstetrics, Gynecology & Reproductive Sciences, University of California, San Francisco (UCSF), San Francisco, California 94158
| | - Joshua F Robinson
- Program on Reproductive Health and the Environment, University of California, San Francisco (UCSF), San Francisco, California 94158
- Center for Reproductive Sciences and Department of Obstetrics, Gynecology & Reproductive Sciences, University of California, San Francisco (UCSF), San Francisco, California 94158
| | - Yan Zhou
- Center for Reproductive Sciences and Department of Obstetrics, Gynecology & Reproductive Sciences, University of California, San Francisco (UCSF), San Francisco, California 94158
| | - Kenisha A Puckett
- Center for Reproductive Sciences and Department of Obstetrics, Gynecology & Reproductive Sciences, University of California, San Francisco (UCSF), San Francisco, California 94158
| | - Elaine Kwan
- Center for Reproductive Sciences and Department of Obstetrics, Gynecology & Reproductive Sciences, University of California, San Francisco (UCSF), San Francisco, California 94158
| | - Sirirak Buarpung
- Center for Reproductive Sciences and Department of Obstetrics, Gynecology & Reproductive Sciences, University of California, San Francisco (UCSF), San Francisco, California 94158
| | - Rayyan Aburajab
- Center for Reproductive Sciences and Department of Obstetrics, Gynecology & Reproductive Sciences, University of California, San Francisco (UCSF), San Francisco, California 94158
| | - Stephanie L Gaw
- Center for Reproductive Sciences and Department of Obstetrics, Gynecology & Reproductive Sciences, University of California, San Francisco (UCSF), San Francisco, California 94158
| | - Saunak Sen
- Department of Preventive Medicine, University of Tennessee Health Science Center, Memphis, Tennessee 38163
| | | | - Sabrina Crispo Smith
- Environmental Chemistry Laboratory, Department of Toxic Substances Control, California Environmental Protection Agency, Berkeley, California 94710
| | - June-Soo Park
- Environmental Chemistry Laboratory, Department of Toxic Substances Control, California Environmental Protection Agency, Berkeley, California 94710
| | - Igor Zakharevich
- Center for Reproductive Sciences and Department of Obstetrics, Gynecology & Reproductive Sciences, University of California, San Francisco (UCSF), San Francisco, California 94158
| | - Roy R Gerona
- Center for Reproductive Sciences and Department of Obstetrics, Gynecology & Reproductive Sciences, University of California, San Francisco (UCSF), San Francisco, California 94158
| | - Susan J Fisher
- Center for Reproductive Sciences and Department of Obstetrics, Gynecology & Reproductive Sciences, University of California, San Francisco (UCSF), San Francisco, California 94158
| | - Tracey J Woodruff
- Program on Reproductive Health and the Environment, University of California, San Francisco (UCSF), San Francisco, California 94158
- Center for Reproductive Sciences and Department of Obstetrics, Gynecology & Reproductive Sciences, University of California, San Francisco (UCSF), San Francisco, California 94158
| |
Collapse
|
31
|
Liu W, Luo D, Xia W, Tao Y, Wang L, Yu M, Hu L, Zhou A, Covaci A, Lin C, Xu S, Mei S, Li Y. Prenatal exposure to halogenated, aryl, and alkyl organophosphate esters and child neurodevelopment at two years of age. JOURNAL OF HAZARDOUS MATERIALS 2021; 408:124856. [PMID: 33383451 DOI: 10.1016/j.jhazmat.2020.124856] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 12/11/2020] [Accepted: 12/12/2020] [Indexed: 06/12/2023]
Abstract
Neurotoxicity of organophosphate esters (OPEs) has been reported in toxicological studies, but epidemiological findings are limited. We aimed to assess the associations between prenatal OPE exposures and children's neurodevelopment at 2 years old. We measured urinary concentrations of OPEs collected in the first and third trimester from 184 pregnant women in Wuhan, China. Childhood neurodevelopment was assessed using the Chinese revision of Bayley Scale of Infant Development. A two-fold increase in the average of bis (1,3-dichloro-2-propyl) phosphate (BDCIPP) was associated with 3.50 decrease in Psychomotor Development Index (PDI) score (95%CI: -5.86, -1.14) and 5.75 decrease in Mental Development Index (MDI) score (95%CI: -8.94, -2.55). Average of the molar concentrations of chlorinated-alkyl OPEs (ΣCl-OPEs) during pregnancy was inversely associated with PDI [β = -3.24 (95%CI: -5.95, -0.53)] and MDI scores [β = -5.86 (95%CI: -9.52, -2.20)]. Prenatal concentrations of BDCIPP and ΣCl-OPEs were inversely associated with neurodevelopment scores in boys, but not in girls. Our study provides evidence that elevated prenatal exposure to chlorinated-alkyl OPEs especially BDCIPP might be inversely associated with childhood neurodevelopment, and the effect seems to be sex-specific.
Collapse
Affiliation(s)
- Wenyu Liu
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental Health (Incubation), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Dan Luo
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental Health (Incubation), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China; Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, China
| | - Wei Xia
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental Health (Incubation), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Yun Tao
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental Health (Incubation), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Limei Wang
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental Health (Incubation), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Meng Yu
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental Health (Incubation), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Liqin Hu
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental Health (Incubation), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Aifen Zhou
- Wuhan Maternal and Child Healthcare Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Adrian Covaci
- Toxicological Center, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - Chunye Lin
- State Key Laboratory of Water Environmental Simulation, School of Environment, Beijing Normal University, Beijing, China
| | - Shunqing Xu
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental Health (Incubation), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Surong Mei
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental Health (Incubation), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
| | - Yuanyuan Li
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental Health (Incubation), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
| |
Collapse
|
32
|
Dong L, Wang S, Qu J, You H, Liu D. New understanding of novel brominated flame retardants (NBFRs): Neuro(endocrine) toxicity. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 208:111570. [PMID: 33396099 DOI: 10.1016/j.ecoenv.2020.111570] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 10/22/2020] [Accepted: 10/25/2020] [Indexed: 06/12/2023]
Abstract
Traditional brominated flame retardants (BFRs) negatively affect the environment and human health, especially in the sensitive (developing) nervous system. Considering the physicochemical similarities between novel brominated flame retardants (NBFRs) and BFRs, more and more evidence reveals the neurotoxic effects of NBFRs. We reviewed the neuro(endocrine) toxic effects of NBFRs in vivo and in vitro and discussed their action mechanisms based on the available information. The neurotoxic potential of NBFRs has been demonstrated through direct neurotoxicity and disruption of the neuroendocrine system, with adverse effects on neurobehavioral and reproductive development. Mechanistic studies have shown that the impact of NBFRs is related to the complex interaction of neural and endocrine signals. From disrupting the gender differentiation of the brain, altering serum thyroid/sex hormone levels, gene/protein expression, and so on, to interfere with the feedback effect between different levels of the HPG/HPT axis. In this paper, the mechanism of neurotoxic effects of NBFRs is explored from a new perspective-neuro and endocrine interactions. Gaps in the toxicity data of NBFRs in the neuroendocrine system are supplemented and provide a broader dataset for a complete risk assessment.
Collapse
Affiliation(s)
- Liying Dong
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
| | - Shutao Wang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
| | - Jinze Qu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
| | - Hong You
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China; School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai 264209, China.
| | - Dongmei Liu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
| |
Collapse
|
33
|
Rosenmai AK, Winge SB, Möller M, Lundqvist J, Wedebye EB, Nikolov NG, Lilith Johansson HK, Vinggaard AM. Organophosphate ester flame retardants have antiandrogenic potential and affect other endocrine related endpoints in vitro and in silico. CHEMOSPHERE 2021; 263:127703. [PMID: 32854002 DOI: 10.1016/j.chemosphere.2020.127703] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 06/25/2020] [Accepted: 07/10/2020] [Indexed: 05/16/2023]
Abstract
Organophosphate ester flame retardants (OPFRs) are used to prevent ignition and spreading of fire. They are present in various human matrices suggesting adult, fetal, and neonate exposure. Endocrine related effects have been observed in vivo, but information at the molecular level is lacking for some OPFRs. Also, a better understanding of potential contribution from chemical substructures is needed. The aim of this study was to screen OPFRs for endocrine disruptive potential in vitro and in silico. We selected eleven substances to represent some OPFRs with 1) little information on endocrine activity and others to represent 2) varied chemical substructures. We used in vitro assays for androgen receptor (AR), aryl hydrocarbon receptor (AhR), and Nrf2 activity, effects on steroidogenesis, and transthyretin (TTR) binding, as well as in silico models covering estrogen, thyroid, and CYP3A4 induction related endpoints. Ten OPFRs affected AR and AhR activity, seven affected TTR binding, and five affected 17β-estradiol levels. Several substances had IC50-values below 10 μM and exhibited efficacious effects. These included TPHP, CDP, TMPP, TIPPP, and EHDPP for AR antagonism, suggesting that the degree of arylation and the size of the substance can play a role for the activity. Chlorinated OPFRs had low/no effect on TTR binding. No clear trend was observed for AhR and steroidogenesis, but all arylated OPFRs were predicted to have alert for estrogen receptor binding in an in silico model with metabolism simulator included. Collectively, our data suggest that OPFRs have endocrine disruptive potential warranting further studies to enable human risk assessment.
Collapse
Affiliation(s)
- Anna Kjerstine Rosenmai
- Division of Diet Disease Prevention and Toxicology, National Food Institute, Technical University of Denmark, 2800 Kgs, Lyngby, Denmark.
| | - Sofia Boeg Winge
- Division of Diet Disease Prevention and Toxicology, National Food Institute, Technical University of Denmark, 2800 Kgs, Lyngby, Denmark
| | - Morlin Möller
- Division of Diet Disease Prevention and Toxicology, National Food Institute, Technical University of Denmark, 2800 Kgs, Lyngby, Denmark
| | - Johan Lundqvist
- Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Box 7028, SE-750 07, Uppsala, Sweden
| | - Eva Bay Wedebye
- Division of Diet Disease Prevention and Toxicology, National Food Institute, Technical University of Denmark, 2800 Kgs, Lyngby, Denmark
| | - Nikolai Georgiev Nikolov
- Division of Diet Disease Prevention and Toxicology, National Food Institute, Technical University of Denmark, 2800 Kgs, Lyngby, Denmark
| | - Hanna Katarina Lilith Johansson
- Division of Diet Disease Prevention and Toxicology, National Food Institute, Technical University of Denmark, 2800 Kgs, Lyngby, Denmark
| | - Anne Marie Vinggaard
- Division of Diet Disease Prevention and Toxicology, National Food Institute, Technical University of Denmark, 2800 Kgs, Lyngby, Denmark
| |
Collapse
|
34
|
Walley SN, Krumm EA, Yasrebi A, Wiersielis KR, O'Leary S, Tillery T, Roepke TA. Maternal organophosphate flame-retardant exposure alters offspring feeding, locomotor and exploratory behaviors in a sexually-dimorphic manner in mice. J Appl Toxicol 2020; 41:442-457. [PMID: 33280148 DOI: 10.1002/jat.4056] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 07/31/2020] [Accepted: 08/13/2020] [Indexed: 12/27/2022]
Abstract
Increased usage of organophosphate flame retardants (OPFRs) has led to detectable levels in pregnant women and neonates, which is associated with negative neurological outcomes. Therefore, we investigated if maternal OPFR exposure altered adult offspring feeding, locomotor, and anxiety-like behaviors on a low-fat (LFD) or high-fat diet (HFD). Wild-type C57Bl/6J dams were orally dosed with vehicle (sesame oil) or an OPFR mixture (1 mg/kg combination each of tris(1,3-dichloro-2-propyl)phosphate, triphenyl phosphate and tricresyl phosphate) from gestation day 7 to postnatal day 14. After weaning, pups were fed either a LFD or HFD until 19 weeks of age. Locomotor and anxiety-like behaviors were evaluated with the open field test, elevated plus maze, and metabolic cages. Feeding behaviors and meal patterns were analyzed by a Biological Data Acquisition System. Anogenital distance was reduced in OPFR-exposed male pups, but no effect was detected on adult body weight. We observed interactions of OPFR exposure and HFD consumption on locomotor and anxiety-like behavior in males, suggesting an anxiogenic effect while reducing overall nighttime activity. We also observed an interaction of OPFR exposure and HFD on weekly food intake and feeding behaviors. OPFR-exposed males consumed more total HFD than oil-exposed males during the 72-hour trial. However, when arcuate gene expression was analyzed, OPFR exposure induced Agrp expression in females, which would suggest greater orexigenic tone. Collectively, the implications of our study are that the behavioral effects of OPFR exposure are modulated by adult HFD consumption, which may influence the metabolic and neurological consequences of maternal OPFR exposure.
Collapse
Affiliation(s)
- Sabrina N Walley
- Department of Animal Sciences, School of Environmental & Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, New Jersey.,Joint Graduate Program in Toxicology, Rutgers, The State University of New Jersey, Piscataway, New Jersey
| | - Elizabeth A Krumm
- Department of Animal Sciences, School of Environmental & Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, New Jersey.,Graduate Program in Endocrinology and Animal Biosciences, Rutgers, The State University of New Jersey, New Brunswick, New Jersey
| | - Ali Yasrebi
- Department of Animal Sciences, School of Environmental & Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, New Jersey.,Graduate Program in Endocrinology and Animal Biosciences, Rutgers, The State University of New Jersey, New Brunswick, New Jersey
| | - Kimberly R Wiersielis
- Department of Animal Sciences, School of Environmental & Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, New Jersey.,Joint Graduate Program in Toxicology, Rutgers, The State University of New Jersey, Piscataway, New Jersey
| | - Sarah O'Leary
- Department of Animal Sciences, School of Environmental & Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, New Jersey
| | - Taylor Tillery
- Department of Animal Sciences, School of Environmental & Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, New Jersey
| | - Troy A Roepke
- Department of Animal Sciences, School of Environmental & Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, New Jersey.,Joint Graduate Program in Toxicology, Rutgers, The State University of New Jersey, Piscataway, New Jersey.,Graduate Program in Endocrinology and Animal Biosciences, Rutgers, The State University of New Jersey, New Brunswick, New Jersey
| |
Collapse
|
35
|
Witchey SK, Al Samara L, Horman BM, Stapleton HM, Patisaul HB. Perinatal exposure to FireMaster® 550 (FM550), brominated or organophosphate flame retardants produces sex and compound specific effects on adult Wistar rat socioemotional behavior. Horm Behav 2020; 126:104853. [PMID: 32949556 PMCID: PMC7726037 DOI: 10.1016/j.yhbeh.2020.104853] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 08/31/2020] [Accepted: 09/10/2020] [Indexed: 12/11/2022]
Abstract
Firemaster 550 (FM550) is a flame retardant (FR) mixture that has become one of the most commonly used FRs in household items such as foam-based furniture and baby products. Because this mixture readily leaches from products, contamination of the environment and human tissues is widespread. Prior work by us and others has reported sex-specific behavioral deficits in rodents and zebrafish following early life exposure. In an effort to understand the mechanisms by which these behavioral effects occur, here we explored the effects of its constituents on behavioral outcomes previously shown to be altered by developmental FM550 exposure. The FM550 commercial mixture is composed of two brominated compounds (BFR) and two organophosphate compounds (OPFRs) at almost equivalent proportions. Both the BFR and the OPFR components are differentially metabolized and structurally distinct, but similar to known neurotoxicants. Here we examined adult Wistar rat offspring socioemotional behaviors following perinatal exposure (oral, to the dam) to vehicle, 2000 μg/day FM550, 1000 μg/day BFR or 1000 μg/day OPFR from gestation day 0 to weaning. Beginning on postnatal day 65 offspring from all groups were subjected to a series of behavioral tasks including open field, elevated plus maze, marble burying, social interaction tests, and running wheel. Effects were exposure-, sex- and task-specific, with BFR exposure resulting in the most consistent behavioral deficits. Overall, exposed females showed more deficits compared to males across all dose groups and tasks. These findings help elucidate how different classes of flame retardants, independently and as a mixture, contribute to sex-specific behavioral effects of exposure.
Collapse
Affiliation(s)
- Shannah K Witchey
- Department of Biological Sciences, NC State University, Raleigh, NC 27695, United States of America; Center for Human Health and the Environment, NC State University, Raleigh, NC 27695, United States of America
| | - Loujain Al Samara
- Department of Biological Sciences, NC State University, Raleigh, NC 27695, United States of America
| | - Brian M Horman
- Department of Biological Sciences, NC State University, Raleigh, NC 27695, United States of America
| | - Heather M Stapleton
- Nicholas School of the Environment, Levine Science Research Center, Duke University, Durham, NC 27710, United States of America
| | - Heather B Patisaul
- Department of Biological Sciences, NC State University, Raleigh, NC 27695, United States of America; Center for Human Health and the Environment, NC State University, Raleigh, NC 27695, United States of America.
| |
Collapse
|
36
|
Vail GM, Roepke TA. Organophosphate Flame Retardants Excite Arcuate Melanocortin Circuitry and Increase Neuronal Sensitivity to Ghrelin in Adult Mice. Endocrinology 2020; 161:5910086. [PMID: 32961558 PMCID: PMC7575050 DOI: 10.1210/endocr/bqaa168] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 09/17/2020] [Indexed: 12/28/2022]
Abstract
Organophosphate flame retardants (OPFRs) are a class of chemicals that have become near ubiquitous in the modern environment. While OPFRs provide valuable protection against flammability of household items, they are increasingly implicated as an endocrine disrupting chemical (EDC). We previously reported that exposure to a mixture of OPFRs causes sex-dependent disruptions of energy homeostasis through alterations in ingestive behavior and activity in adult mice. Because feeding behavior and energy expenditure are largely coordinated by the hypothalamus, we hypothesized that OPFR disruption of energy homeostasis may occur through EDC action on melanocortin circuitry within the arcuate nucleus. To this end, we exposed male and female transgenic mice expressing green fluorescent protein in either neuropeptide Y (NPY) or proopiomelanocortin (POMC) neurons to a common mixture of OPFRs (triphenyl phosphate, tricresyl phosphate, and tris(1,3-dichloro-2-propyl)phosphate; each 1 mg/kg bodyweight/day) for 4 weeks. We then electrophysiologically examined neuronal properties using whole-cell patch clamp technique. OPFR exposure depolarized the resting membrane of NPY neurons and dampened a hyperpolarizing K+ current known as the M-current within the same neurons from female mice. These neurons were further demonstrated to have increased sensitivity to ghrelin excitation, which more potently reduced the M-current in OPFR-exposed females. POMC neurons from female mice exhibited elevated baseline excitability and are indicated in receiving greater excitatory synaptic input when exposed to OPFRs. Together, these data support a sex-selective effect of OPFRs to increase neuronal output from the melanocortin circuitry governing feeding behavior and energy expenditure, and give reason for further examination of OPFR impact on human health.
Collapse
Affiliation(s)
- Gwyndolin M Vail
- Joint Graduate Program in Toxicology, Rutgers, The State University of New Jersey, Piscataway, New Jersey
| | - Troy A Roepke
- Joint Graduate Program in Toxicology, Rutgers, The State University of New Jersey, Piscataway, New Jersey
- Department of Animal Sciences, School of Environmental & Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, New Jersey
- Environmental and Occupational Health Science Institute, Rutgers, The State University of New Jersey, Piscataway, New Jersey
- Rutgers Center for Lipid Research, Center for Nutrition, Microbiome, and Health, and New Jersey Institute of Food, Nutrition, and Health, Rutgers, The State University of New Jersey, New Brunswick, New Jersey
| |
Collapse
|
37
|
Miller CK, Halbing AA, Patisaul HB, Meitzen J. Interactions of the estrous cycle, novelty, and light on female and male rat open field locomotor and anxiety-related behaviors. Physiol Behav 2020; 228:113203. [PMID: 33045240 DOI: 10.1016/j.physbeh.2020.113203] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 10/06/2020] [Accepted: 10/07/2020] [Indexed: 01/15/2023]
Abstract
Animal behavior can be modulated by multiple interacting factors. In rodents such as rats, these factors include, among others, the female estrous cycle, exposure to a novel environment, and light. Here, we used the open field test to disassociate differences in behavior resulting from each of these factors by testing the hypothesis that locomotor and anxiety-related behaviors differ between estrous cycle phases in female rats and that novelty and light exposure concurrently influence these behaviors in both female and male rats. Adult female rats were tested twice under red or white light in estrus and diestrus estrous cycle phases. Adult male rats were also tested twice under either red or white light. In females, an interaction between novelty and estrous cycle phase influenced locomotor and anxiety-related behaviors. In males, novelty influenced locomotor and anxiety-related behaviors differentially under red and white light. Light exposure increased anxiety-related behaviors in both males and females, but reduced locomotor behavior only in females. These findings reveal the complexities of behavioral testing and highlight the importance of factors such as the estrous cycle, novelty, and light exposure.
Collapse
Affiliation(s)
- Christiana K Miller
- Graduate Program in Biology, North Carolina State University, Raleigh, NC, United States; W.M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, NC, United States; Department of Biological Sciences, North Carolina State University, Raleigh, NC, United States.
| | - Amy A Halbing
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, United States
| | - Heather B Patisaul
- W.M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, NC, United States; Department of Biological Sciences, North Carolina State University, Raleigh, NC, United States; Center for Human Health and the Environment, North Carolina State University, Raleigh, NC, United States
| | - John Meitzen
- W.M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, NC, United States; Department of Biological Sciences, North Carolina State University, Raleigh, NC, United States; Center for Human Health and the Environment, North Carolina State University, Raleigh, NC, United States
| |
Collapse
|
38
|
Hammel SC, Zhang S, Lorenzo AM, Eichner B, Stapleton HM, Hoffman K. Young infants' exposure to organophosphate esters: Breast milk as a potential source of exposure. ENVIRONMENT INTERNATIONAL 2020; 143:106009. [PMID: 32771876 DOI: 10.1016/j.envint.2020.106009] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 07/20/2020] [Accepted: 07/21/2020] [Indexed: 06/11/2023]
Abstract
Organophosphate esters (OPEs) are applied as both flame retardants and plasticizers to a variety of consumer items such as home furnishings, construction materials, and children's products. While some assessments have characterized exposure among toddlers and young children, little is known about the OPE exposure among infants, who are a vulnerable population due to their rapid development. Here, we collected spot urine samples from 6-week-old (n = 100) and 12-month-old infants (n = 63), with about half of the infants evaluated at both ages (n = 52), to characterize OPE exposure and determine what factors contributed to higher exposures. Five of six OPE metabolites analyzed were detected frequently (>70%). Diphenyl phosphate was detected in every urine sample, while bis(2-chloro-isopropyl) phosphate (BCIPP) was the most abundant metabolite measured overall. Concentrations of bis(1-chloro-2-propyl) 1-hydroxy-2-propyl phosphate (BCIPHIPP) and BCIPP [i.e., metabolites of tris(2-chloro-isopropyl) phosphate (TCIPP)] were significantly greater among 6-week-old infants compared to 12-month-olds, while levels of other OPE metabolites were not statistically different in the first year of life. OPE metabolites were generally correlated with one another in samples collected at each age (rs = 0.25-0.75; p < 0.05), and except BCIPHIPP, concentrations of the same metabolite were correlated over time (rs = 0.41-0.53; p < 0.05). Breastfeeding at 6 weeks of age and owning a larger number of children's products were associated with increased concentrations of urinary BDCIPP. Infants who were currently receiving breast milk had higher levels of TCIPP metabolites; urinary BCIPP concentrations were 6.2 times higher in infants receiving breast milk at 6 weeks of age, and BCIPHIPP levels were 2.2 times higher for 12-month-old infants receiving breast milk (10β = 7.2; 95% CI: 1.6-32.1 and 10β = 3.2; 95% CI: 1.2-8.1, respectively). Differences in the predominant TCIPP metabolite associated with breastfeeding may suggest differences in metabolism with age. Cumulatively, our results suggest levels of OPE exposure may be higher for infants than other age groups, including toddlers and older children.
Collapse
Affiliation(s)
- Stephanie C Hammel
- Nicholas School of Environment, Duke University, Durham, NC, United States; Children's Health & Discovery Initiative, Duke School of Medicine, North Carolina, United States
| | - Sharon Zhang
- Nicholas School of Environment, Duke University, Durham, NC, United States
| | - Amelia M Lorenzo
- Nicholas School of Environment, Duke University, Durham, NC, United States
| | - Brian Eichner
- Department of Pediatrics, Duke University Medical Center, Durham, NC, United States
| | - Heather M Stapleton
- Nicholas School of Environment, Duke University, Durham, NC, United States; Children's Health & Discovery Initiative, Duke School of Medicine, North Carolina, United States
| | - Kate Hoffman
- Nicholas School of Environment, Duke University, Durham, NC, United States; Children's Health & Discovery Initiative, Duke School of Medicine, North Carolina, United States.
| |
Collapse
|
39
|
Walley SN, Krumm EA, Yasrebi A, Kwiecinski J, Wright V, Baker C, Roepke TA. Maternal organophosphate flame-retardant exposure alters offspring energy and glucose homeostasis in a sexually dimorphic manner in mice. J Appl Toxicol 2020; 41:572-586. [PMID: 32969501 DOI: 10.1002/jat.4066] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 08/19/2020] [Accepted: 08/19/2020] [Indexed: 12/22/2022]
Abstract
Persistent organic pollutants such as organophosphate flame retardants (OPFRs) can accumulate in the body and interact with nuclear receptors that control energy homeostasis. One sensitive window of exposure is during development, either in utero or neonatal. Therefore, we investigated if maternal exposure to a mixture of OPFRs alters metabolism on a low-fat diet (LFD) or a high-fat diet (HFD) in both male and female offspring. Wild-type C57Bl/6J dams were orally dosed with vehicle (sesame oil) or an OPFR mixture (1 mg/kg each of tris(1,3-dichloro-2-propyl)phosphate, triphenyl phosphate, and tricresyl phosphate) from gestation day 7 to postnatal day 14. After weaning, pups were fed LFD or HFD. To assess metabolism, we measured body weight and food intake weekly and determined body composition, metabolism, activity, and glucose homeostasis at 6 months of age. Although maternal OPFR exposure did not alter body weight or adiposity, OPFR exposure altered substrate utilization and energy expenditure depending on diet in both sexes. Systolic and diastolic blood pressure was increased by OPFR in male offspring. OPFR exposure interacted with HFD to increase fasting glucose in females and alter glucose and insulin tolerance in male offspring. Plasma leptin was reduced in male and female offspring when fed HFD, whereas liver expression of Pepck was increased in females and Esr1 (estrogen receptor α) was increased in both sex. The physiological implications indicate maternal exposure to OPFRs programs peripheral organs including the liver and adipose tissue, in a sex-dependent manner, thus changing the response to an obesogenic diet and altering adult offspring energy homeostasis.
Collapse
Affiliation(s)
- Sabrina N Walley
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA.,Joint Graduate Program in Toxicology, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
| | - Elizabeth A Krumm
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA.,Graduate Program in Endocrinology and Animal Biosciences, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA
| | - Ali Yasrebi
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA.,Graduate Program in Endocrinology and Animal Biosciences, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA
| | - Justine Kwiecinski
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA
| | - Victoria Wright
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA
| | - Chloe Baker
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA
| | - Troy A Roepke
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA.,Joint Graduate Program in Toxicology, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA.,Graduate Program in Endocrinology and Animal Biosciences, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA.,Environmental and Occupational Health Science Institute, Rutgers, The State University of New Jersey, 170 Frelinghuysen Road, Piscataway, NJ, USA.,Rutgers Center for Lipid Research, Center for Nutrition, Microbiome, and Health, and New Jersey Institute of Food, Nutrition, and Health, Rutgers, The State University of New Jersey, 61 Dudley Road, New Brunswick, NJ, USA
| |
Collapse
|
40
|
Arumugasaamy N, Rock KD, Kuo CY, Bale TL, Fisher JP. Microphysiological systems of the placental barrier. Adv Drug Deliv Rev 2020; 161-162:161-175. [PMID: 32858104 DOI: 10.1016/j.addr.2020.08.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 07/28/2020] [Accepted: 08/24/2020] [Indexed: 12/20/2022]
Abstract
Methods to evaluate maternal-fetal transport across the placental barrier have generally involved clinical observations after-the-fact, ex vivo perfused placenta studies, or in vitro Transwell assays. Given the ethical and technical limitations in these approaches, and the drive to understand fetal development through the lens of transport-induced injury, such as with the examples of thalidomide and Zika Virus, efforts to develop novel approaches to study these phenomena have expanded in recent years. Notably, within the past 10 years, placental barrier models have been developed using hydrogel, bioreactor, organ-on-a-chip, and bioprinting approaches. In this review, we discuss the biology of the placental barrier and endeavors to recapitulate this barrier in vitro using these approaches. We also provide analysis of current limitations to drug discovery in this context, and end with a future outlook.
Collapse
|
41
|
Gingrich J, Ticiani E, Veiga-Lopez A. Placenta Disrupted: Endocrine Disrupting Chemicals and Pregnancy. Trends Endocrinol Metab 2020; 31:508-524. [PMID: 32249015 PMCID: PMC7395962 DOI: 10.1016/j.tem.2020.03.003] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 02/19/2020] [Accepted: 03/06/2020] [Indexed: 01/06/2023]
Abstract
Endocrine disrupting chemicals (EDCs) are chemicals that can interfere with normal endocrine signals. Human exposure to EDCs is particularly concerning during vulnerable periods of life, such as pregnancy. However, often overlooked is the effect that EDCs may pose to the placenta. The abundance of hormone receptors makes the placenta highly sensitive to EDCs. We have reviewed the most recent advances in our understanding of EDC exposures on the development and function of the placenta such as steroidogenesis, spiral artery remodeling, drug-transporter expression, implantation and cellular invasion, fusion, and proliferation. EDCs reviewed include those ubiquitous in the environment with available human biomonitoring data. This review also identifies critical gaps in knowledge to drive future research in the field.
Collapse
Affiliation(s)
- Jeremy Gingrich
- Department of Animal Science, College of Agriculture and Natural Resources, Michigan State University, East Lansing, MI, USA; Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
| | - Elvis Ticiani
- Department of Animal Science, College of Agriculture and Natural Resources, Michigan State University, East Lansing, MI, USA
| | - Almudena Veiga-Lopez
- Department of Animal Science, College of Agriculture and Natural Resources, Michigan State University, East Lansing, MI, USA.
| |
Collapse
|
42
|
Rock KD, St Armour G, Horman B, Phillips A, Ruis M, Stewart AK, Jima D, Muddiman DC, Stapleton HM, Patisaul HB. Effects of Prenatal Exposure to a Mixture of Organophosphate Flame Retardants on Placental Gene Expression and Serotonergic Innervation in the Fetal Rat Brain. Toxicol Sci 2020; 176:203-223. [PMID: 32243540 PMCID: PMC7357193 DOI: 10.1093/toxsci/kfaa046] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
There is a growing need to understand the potential neurotoxicity of organophosphate flame retardants (OPFRs) and plasticizers because use and, consequently, human exposure, is rapidly expanding. We have previously shown in rats that developmental exposure to the commercial flame retardant mixture Firemaster 550 (FM 550), which contains OPFRs, results in sex-specific behavioral effects, and identified the placenta as a potential target of toxicity. The placenta is a critical coordinator of fetal growth and neurodevelopment, and a source of neurotransmitters for the developing brain. We have shown in rats and humans that flame retardants accumulate in placental tissue, and induce functional changes, including altered neurotransmitter production. Here, we sought to establish if OPFRs (triphenyl phosphate and a mixture of isopropylated triarylphosphate isomers) alter placental function and fetal forebrain development, with disruption of tryptophan metabolism as a primary pathway of interest. Wistar rat dams were orally exposed to OPFRs (0, 500, 1000, or 2000 μg/day) or a serotonin (5-HT) agonist 5-methoxytryptamine for 14 days during gestation and placenta and fetal forebrain tissues collected for analysis by transcriptomics and metabolomics. Relative abundance of genes responsible for the transport and synthesis of placental 5-HT were disrupted, and multiple neuroactive metabolites in the 5-HT and kynurenine metabolic pathways were upregulated. In addition, 5-HTergic projections were significantly longer in the fetal forebrains of exposed males. These findings suggest that OPFRs have the potential to impact the 5-HTergic system in the fetal forebrain by disrupting placental tryptophan metabolism.
Collapse
Affiliation(s)
- Kylie D Rock
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina 27619
| | - Genevieve St Armour
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina 27619
| | - Brian Horman
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina 27619
| | - Allison Phillips
- Nicholas School of the Environment, Duke University, Durham, North Carolina 27708
| | - Matthew Ruis
- Nicholas School of the Environment, Duke University, Durham, North Carolina 27708
| | - Allison K Stewart
- Molecular Education, Technology, and Research Innovation Center, North Carolina State University, Raleigh, North Carolina 27695
| | - Dereje Jima
- Center for Human Health and the Environment, North Carolina State University, Raleigh, North Carolina 27695
- Bioinformatics Research Center, North Carolina State University, Raleigh, North Carolina 27695
| | - David C Muddiman
- Molecular Education, Technology, and Research Innovation Center, North Carolina State University, Raleigh, North Carolina 27695
| | - Heather M Stapleton
- Nicholas School of the Environment, Duke University, Durham, North Carolina 27708
| | - Heather B Patisaul
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina 27619
- Center for Human Health and the Environment, North Carolina State University, Raleigh, North Carolina 27695
| |
Collapse
|
43
|
Vail GM, Walley SN, Yasrebi A, Maeng A, Conde KN, Roepke TA. The interactions of diet-induced obesity and organophosphate flame retardant exposure on energy homeostasis in adult male and female mice. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2020; 83:438-455. [PMID: 32546061 PMCID: PMC7337410 DOI: 10.1080/15287394.2020.1777235] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Previously, sex-dependent alterations in energy homeostasis were reported in adult mice fed a standard chow attributed to exposure to a mixture of organophosphate flame retardants (OPFRs) via estrogen receptors (ERα). In this study, adult male and female mice (C57BL/6J; Taconic) were treated with the same mixture of OPFRs (1 mg/kg each of tricresyl phosphate (TCP), triphenyl phosphate (TPP), and tris(1-3-dichloro-2propyl)phosphate (TDCPP)) for 7 weeks on a low-fat diet (LFD, 10% kcal fat) or a high fat (HFD, 45% kcal fat) in a diet-induced obesity model. Consistent with our previous observations, OPFRs altered weight gain in males, differentially with diet, while females remained unaffected. OPFR treatment also revealed sex-dependent perturbations in metabolic activity. During the night (approximately 0100-0400 hr), males exhibited elevated activity and oxygen consumption, while in females these parameters were decreased, irrespective of diet. OPFR disrupted feeding behavior and abolished diurnal water intake patterns in females while increasing nighttime fluid consumption in males. Despite no marked effect of OPFRs on glucose or insulin tolerance, OPFR treatment altered circulating insulin and leptin in females and ghrelin in males. Data indicate that adult OPFR exposure might influence, and perhaps exacerbate, the effects of diet-induced obesity in adult mice by altering activity, ingestive behavior, and metabolism.
Collapse
Affiliation(s)
- Gwyndolin M. Vail
- Joint Graduate Program in Toxicology, Rutgers, The State University of New Jersey, Piscataway, NJ. USA
| | - Sabrina N. Walley
- Joint Graduate Program in Toxicology, Rutgers, The State University of New Jersey, Piscataway, NJ. USA
| | - Ali Yasrebi
- Department of Animal Sciences, School of Environmental & Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ. USA
| | - Angela Maeng
- Joint Graduate Program in Toxicology, Rutgers, The State University of New Jersey, Piscataway, NJ. USA
| | - Kristie N. Conde
- Graduate Program in Neuroscience, Rutgers, The State University of New Jersey, New Brunswick, NJ. USA
| | - Troy A. Roepke
- Joint Graduate Program in Toxicology, Rutgers, The State University of New Jersey, Piscataway, NJ. USA
- Department of Animal Sciences, School of Environmental & Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ. USA
- Graduate Program in Neuroscience, Rutgers, The State University of New Jersey, New Brunswick, NJ. USA
| |
Collapse
|
44
|
Wiersielis KR, Adams S, Yasrebi A, Conde K, Roepke TA. Maternal exposure to organophosphate flame retardants alters locomotor and anxiety-like behavior in male and female adult offspring. Horm Behav 2020; 122:104759. [PMID: 32320692 PMCID: PMC8530209 DOI: 10.1016/j.yhbeh.2020.104759] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 04/11/2020] [Accepted: 04/12/2020] [Indexed: 11/27/2022]
Abstract
Endocrine disrupting chemicals (EDCs) are chemicals found in our environment that interrupt typical endocrine function. Some flame retardants (FRs) are EDCs as shown in their interaction with steroid and nuclear receptors. Humans are consistently exposed to flame retardants as they are used in everyday items such as plastics, clothing, toys, and electronics. Polybrominated diphenyl ethers were used as the major FR until 2004, when they were replaced by organophosphate flame retardants (OPFRs). Previous research in rodent models utilizing a commercial flame retardant mixture containing OPFRs reported alterations in anxiety-like behavior in the elevated plus maze (EPM) for rodents perinatally exposed to OPFRs. In the present study we utilize wild-type mice maternally exposed (gestational day 7 to postnatal day 14) to either an OPFR mixture of tris(1,3-dichloro-2-propyl), triphenyl phosphate, and tricresyl phosphate or a sesame seed oil vehicle. These mice were evaluated for anxiety-like behavior in adulthood on the open field test (OFT) and the light/dark box (LDB) as well as the EPM. Outcomes from the OFT and LDB indicate that males and females maternally exposed to OPFRs exhibit altered locomotor activity. Results of the EPM were sex-specific as we did not observe an effect in females; however, effects in males differed depending on exposure condition. Males maternally exposed to OPFRs exhibited an anxiolytic-like phenotype in contrast to their vehicle counterparts. This effect in perinatally OPFR-exposed males was not due to alterations in locomotor activity. Our research illustrates that there are sex- and exposure-dependent effects of perinatal OPFR exposure on adult locomotor and anxiety-like behaviors in a mouse model.
Collapse
Affiliation(s)
- K R Wiersielis
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA; Joint Graduate Program in Toxicology, Rutgers, The State University of New Jersey, Piscataway, NJ, USA.
| | - S Adams
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA
| | - A Yasrebi
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA
| | - K Conde
- Graduate Program in Neuroscience, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA
| | - T A Roepke
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA; Joint Graduate Program in Toxicology, Rutgers, The State University of New Jersey, Piscataway, NJ, USA; Graduate Program in Neuroscience, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA
| |
Collapse
|
45
|
Organophosphate Esters: Are These Flame Retardants and Plasticizers Affecting Children's Health? Curr Environ Health Rep 2020; 6:201-213. [PMID: 31755035 DOI: 10.1007/s40572-019-00258-0] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
PURPOSE OF REVIEW Organophosphate esters (OPEs) are applied to a variety of consumer products, primarily as flame retardants and plasticizers. OPEs can leach out of products over time and are consequently prevalent in the environment and frequently detected in human biomonitoring studies. Exposure during pregnancy is of particular concern as OPEs have recently been detected in placental tissues, suggesting they may be transferred to the developing infant. Also, studies have now shown that children typically experience higher exposure to several OPEs compared with adults, indicating they may be disproportionately impacted by these compounds. This review summarizes the current literature on reproductive and child health outcomes of OPE exposures and highlights areas for future research. RECENT FINDINGS Experimental animal studies demonstrate potential for OPEs to adversely impact health, and a limited number of epidemiologic studies conducted in adult cohorts suggest that OPEs may interfere with the endocrine system. Neurodevelopment is perhaps the most well studied of children's health endpoints, and several studies indicate that prenatal and early life OPE exposures impact both cognitive and behavioral development. Associations have also been reported with reproductive outcomes (e.g., fertilization and pregnancy loss) and with the timing of parturition and preterm birth. Cross-sectional studies also demonstrate associations between OPEs and respiratory health outcomes, allergic disease, and measures of adiposity. An expanding body of research demonstrates that OPEs are associated with adverse reproductive health and birth outcomes, asthma and allergic disease, early growth and adiposity, and neurodevelopment. Still, additional research is urgently needed to elucidate the full impact of OPEs on children's health.
Collapse
|
46
|
Sex- and age-dependent effects of maternal organophosphate flame-retardant exposure on neonatal hypothalamic and hepatic gene expression. Reprod Toxicol 2020; 94:65-74. [PMID: 32360330 DOI: 10.1016/j.reprotox.2020.04.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 03/31/2020] [Accepted: 04/03/2020] [Indexed: 12/29/2022]
Abstract
After the phase-out of polybrominated diphenyl ethers, their replacement compounds, organophosphate flame retardants (OPFRs) became ubiquitous in home and work environments. OPFRs, which may act as endocrine disruptors, are detectable in human urine, breast milk, and blood samples collected from pregnant women. However, the effects of perinatal OPFR exposure on offspring homeostasis and gene expression remain largely underexplored. To address this knowledge gap, virgin female mice were mated and dosed with either a sesame oil vehicle or an OPFR mixture (tris(1,3-dichloro-2-propyl)phosphate, tricresyl phosphate, and triphenyl phosphate, 1 mg/kg each) from gestational day (GD) 7 to postnatal day (PND) 14. Hypothalamic and hepatic tissues were collected from one female and one male pup per litter on PND 0 and PND 14. Expression of genes involved in energy homeostasis, reproduction, glucose metabolism, and xenobiotic metabolism were analyzed using quantitative real-time PCR. In the mediobasal hypothalamus, OPFR increased Pdyn, Tac2, Esr1, and Pparg in PND 14 females. In the liver, OPFR increased Pparg and suppressed Insr, G6pc, and Fasn in PND 14 males and increased Esr1, Foxo1, Dgat2, Fasn, and Cyb2b10 in PND 14 females. We also observed striking sex differences in gene expression that were dependent on the age of the pup. Collectively, these data suggest that maternal OPFR exposure alters hypothalamic and hepatic development by influencing neonatal gene expression in a sex-dependent manner. The long-lasting consequences of these changes in expression may disrupt puberty, hormone sensitivity, and metabolism of glucose, fatty acids, and triglycerides in the maturing juvenile.
Collapse
|
47
|
Pace CL, Horman B, Patisaul H, Muddiman DC. Analysis of neurotransmitters in rat placenta exposed to flame retardants using IR-MALDESI mass spectrometry imaging. Anal Bioanal Chem 2020; 412:3745-3752. [PMID: 32300844 DOI: 10.1007/s00216-020-02626-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 03/21/2020] [Accepted: 03/27/2020] [Indexed: 01/12/2023]
Abstract
Chemical exposures can adversely impact fetal development. For many compounds, including common flame retardants, the mechanisms by which this occurs remain unclear, but emerging evidence suggests that disruption at the level of the placenta may play a role. Understanding how the placenta might be vulnerable to chemical exposures is challenging due to its complex structure. The primary objective of this study was to develop a method for detecting placental neurotransmitters and related metabolites without chemical derivatization so changes in the abundance and spatial distribution of neurotransmitters in rat placenta following chemical exposure could be determined using infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) mass spectrometry imaging. Without chemical derivatization, 49 neurotransmitters and their related metabolites were putatively identified in untreated rat placenta sections using mass measurement accuracy and spectral accuracy. A few neurotransmitters were less abundant in placentas that were exposed to various flame retardants and were further investigated by KEGG metabolic pathway analysis. Many of these downregulated neurotransmitters shared the same enzyme responsible for metabolism, aromaticl-amino acid decarboxylase, suggesting a mechanistic role. These data constitute a new approach that could help identify novel mechanisms of toxicity in complex tissues. Graphical abstract.
Collapse
Affiliation(s)
- Crystal L Pace
- FTMS Laboratory for Human Health Research, Department of Chemistry, North Carolina State University, Raleigh, NC, 27695, USA
| | - Brian Horman
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, 27695, USA
| | - Heather Patisaul
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, 27695, USA
- Center for Human Health and the Environment, North Carolina State University, Raleigh, NC, 27695, USA
| | - David C Muddiman
- FTMS Laboratory for Human Health Research, Department of Chemistry, North Carolina State University, Raleigh, NC, 27695, USA.
- Center for Human Health and the Environment, North Carolina State University, Raleigh, NC, 27695, USA.
- Molecular Education, Technology and Research Innovation Center (METRIC), North Carolina State University, Raleigh, NC, 27695, USA.
| |
Collapse
|
48
|
Developmental Exposure to the Flame Retardant Mixture Firemaster 550 Compromises Adult Bone Integrity in Male but not Female Rats. Int J Mol Sci 2020; 21:ijms21072553. [PMID: 32272586 PMCID: PMC7178223 DOI: 10.3390/ijms21072553] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 04/01/2020] [Accepted: 04/03/2020] [Indexed: 12/27/2022] Open
Abstract
Flame retardants (FRs) are used in a variety of common items from furniture to carpet to electronics to reduce flammability and combustion, but the potential toxicity of these compounds is raising health concerns globally. Organophosphate FRs (OPFRs) are becoming more prevalent as older, brominated FRs are phased out, but the toxicity of these compounds, and the FR mixtures that contain them, is poorly understood. Work in a variety of in vitro model systems has suggested that FRs may induce metabolic reprogramming such that bone density is compromised at the expense of increasing adiposity. To address this hypothesis, the present studies maternally exposed Wistar rat dams orally across gestation and lactation to 1000 µg daily of the FR mixture Firemaster 550 (FM 550) which contains a mixture of brominated FRs and OPFRs. At six months of age, the offspring of both sexes were examined for evidence of compromised bone composition. Bone density, composition, and marrow were all significantly affected, but only in males. The fact that the phenotype was observed months after exposure suggests that FM 550 altered some fundamental aspect of mesenchymal stem cell reprogramming. The severity of the phenotype and the human-relevance of the dose employed, affirm this is an adverse outcome meriting further exploration.
Collapse
|
49
|
Gaylord A, Osborne G, Ghassabian A, Malits J, Attina T, Trasande L. Trends in neurodevelopmental disability burden due to early life chemical exposure in the USA from 2001 to 2016: A population-based disease burden and cost analysis. Mol Cell Endocrinol 2020; 502:110666. [PMID: 31952890 PMCID: PMC7073246 DOI: 10.1016/j.mce.2019.110666] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 11/20/2019] [Accepted: 11/20/2019] [Indexed: 11/24/2022]
Abstract
Endocrine disrupting chemicals are known to cause neurodevelopmental toxicity through direct and indirect pathways. In this study we used data from the National Health and Nutrition Examination Surveys, along with known exposure-disease relationships, to quantify the intellectual disability burden attributable to in utero exposure to polybrominated diphenyl ethers (PBDEs), organophosphates, and methylmercury and early life exposure to lead. We also estimated the cost of the IQ points lost and cases of intellectual disability. PBDE exposure was the greatest contributor to intellectual disability burden, resulting in a total of 162 million IQ points lost and over 738,000 cases of intellectual disability. This was followed by lead, organophosphates, and methylmercury. From 2001 to 2016, IQ loss from PBDEs, methylmercury, and lead have decreased or remained stagnant. Organophosphate exposure measurements were only available up to 2008 but did show an increase in organophosphate-attributable IQ loss. Although most of these trends show benefit for children's neurodevelopmental health, they may also point towards the use of potentially harmful substitutions for chemicals that are being phased out.
Collapse
Affiliation(s)
- Abigail Gaylord
- Department of Population Health, New York University School of Medicine, New York, NY, USA
| | | | - Akhgar Ghassabian
- Department of Environmental Medicine, New York University School of Medicine, New York, NY, USA; Department of Pediatrics, NYU School of Medicine, New York, NY, USA
| | - Julia Malits
- Department of Environmental Medicine, New York University School of Medicine, New York, NY, USA
| | - Teresa Attina
- Department of Pediatrics, NYU School of Medicine, New York, NY, USA
| | - Leonardo Trasande
- Department of Population Health, New York University School of Medicine, New York, NY, USA; Department of Environmental Medicine, New York University School of Medicine, New York, NY, USA; Department of Pediatrics, NYU School of Medicine, New York, NY, USA; NYU Wagner School of Public Service, New York, NY, USA; NYU College of Global Public Health, New York, NY, USA.
| |
Collapse
|
50
|
Rock KD, Gillera SEA, Devarasetty P, Horman B, Knudsen G, Birnbaum LS, Fenton SE, Patisaul HB. Sex-specific behavioral effects following developmental exposure to tetrabromobisphenol A (TBBPA) in Wistar rats. Neurotoxicology 2019; 75:136-147. [PMID: 31541695 PMCID: PMC6935469 DOI: 10.1016/j.neuro.2019.09.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 08/07/2019] [Accepted: 09/02/2019] [Indexed: 12/25/2022]
Abstract
Tetrabromobisphenol A (TBBPA) has become a ubiquitous indoor contaminant due to its widespread use as an additive flame retardant in consumer products. Reported evidence of endocrine disruption and accumulation of TBBPA in brain tissue has raised concerns regarding its potential effects on neurodevelopment and behavior. The goal of the present study was to examine the impact of developmental TBBPA exposure, across a wide range of doses, on sexually dimorphic non-reproductive behaviors in male and female Wistar rats. We first ran a pilot study using a single TBBPA dose hypothesized to produce behavioral effects. Wistar rat dams were orally exposed using cookie treats to 0 or 0.1 mg TBBPA/kg bw daily from gestational day (GD) 9 to postnatal day (PND) 21 to assess offspring (both sexes) activity and anxiety-related behaviors. Significant effects were evident in females, with exposure increasing activity levels. Thus, this dose was used as the lowest TBBPA dose in a subsequent, larger study conducted as part of a comprehensive assessment of TBBPA toxicity. Animals were exposed to 0, 0.1, 25, or 250 mg TBBPA/kg bw daily by oral gavage starting on GD 6 through PND 90 (dosed dams GD 6 - PND 21, dosed offspring PND 22 - PND 90). Significant behavioral findings were observed for male offspring, with increased anxiety-like behavior as the primary phenotype. These findings demonstrate that exposure to environmental contaminants, like TBBPA, can have sex-specific effects on behavior highlighting the vulnerability of the developing brain.
Collapse
Affiliation(s)
- Kylie D Rock
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, 27695, USA
| | - Sagi Enicole A Gillera
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, 27695, USA; National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | - Pratyush Devarasetty
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, 27695, USA
| | - Brian Horman
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, 27695, USA
| | - Gabriel Knudsen
- Laboratory of Toxicokinetics, National Cancer Institute, Research Triangle Park, NC, 27709, USA
| | - Linda S Birnbaum
- Laboratory of Toxicokinetics, National Cancer Institute, Research Triangle Park, NC, 27709, USA
| | - Suzanne E Fenton
- National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | - Heather B Patisaul
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, 27695, USA; Center for Human Health and the Environment, North Carolina State University, Raleigh, NC, 27695, USA.
| |
Collapse
|