1
|
Griffin JA, Li X, Lehmler HJ, Holland EB. Predicted versus observed activity of PCB mixtures toward the ryanodine receptor. Neurotoxicology 2024; 100:25-34. [PMID: 38065417 PMCID: PMC10842331 DOI: 10.1016/j.neuro.2023.12.003] [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: 07/12/2023] [Revised: 11/15/2023] [Accepted: 12/04/2023] [Indexed: 12/19/2023]
Abstract
Non-dioxin-like polychlorinated biphenyls (NDL PCBs) alter the activity of the ryanodine receptor (RyR), and this activity is linked to developmental neurotoxicity. Most work to date has focused on the activity of single congeners rather than relevant mixtures. The current study assessed the RyR activity of single congeners or binary, tertiary, and complex PCB mixtures. Observed mixture activity was then compared to the expected activity calculated using the concentration addition (CA) model or a RyR-specific neurotoxic equivalency scheme (rNEQ). The predictions of the CA model were consistent with the observed activity of binary mixtures at the lower portion of the concentration-response curve, supporting the additivity of RyR1 active PCBs. Findings also show that minimally active congeners can compete for the RyR1 binding site, and congeners that do not activate the RyR1 do not interfere with the activity of a full agonist. Complex PCB mixtures that mimic PCB profiles detected in indoor air, fish tissue, and the serum of mothers and children activated the RyR1 and displayed similar efficacy and potency regardless of varying congener profiles. Neither the CA model nor the rNEQ perfectly predicted the observed activity of complex mixtures, but predictions were often within one magnitude of change from the observed response. Importantly, PCB mixtures approximating profiles found in environmental samples or human serum displayed RyR1 activity at concentrations reported in published research. The work presented will aid in the development of risk assessment platforms for NDL PCBs and similar compounds toward RyR1 activation and related neurotoxicity.
Collapse
Affiliation(s)
- Justin A Griffin
- Department of Biological Science, California State University of Long Beach, Long Beach, CA, USA
| | - Xueshu Li
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA, USA
| | - Hans-Joachim Lehmler
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA, USA
| | - Erika B Holland
- Department of Biological Science, California State University of Long Beach, Long Beach, CA, USA.
| |
Collapse
|
2
|
Griffin JA, Li X, Lehmler HJ, Holland EB. Predicted Versus Observed Activity of PCB Mixtures Toward the Ryanodine Receptor. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.22.554299. [PMID: 37662381 PMCID: PMC10473618 DOI: 10.1101/2023.08.22.554299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Non-dioxin-like polychlorinated biphenyls (NDL PCBs) alter the activity of the ryanodine receptor (RyR), and this activity is linked to developmental neurotoxicity. Most work to date has focused on the activity of single congeners rather than relevant mixtures. The current study assessed the RyR activity of single congeners or binary, tertiary, and complex PCB mixtures. Observed mixture activity was then compared to the expected activity calculated using the concentration addition (CA) model or a RyR-specific neurotoxic equivalency scheme (rNEQ). The predictions of the CA model were consistent with the observed activity of binary mixtures at the lower portion of the concentration-response curve, supporting the additivity of RyR1 active PCBs. Findings also show that minimally active congeners can compete for the RyR1 binding site, and congeners that do not activate the RyR1 do not interfere with the activity of a full agonist. Complex PCB mixtures that mimic PCB profiles detected in indoor air, fish tissue, and the serum of mothers and children activated the RyR1 and displayed similar efficacy and potency regardless of varying congener profiles. Neither the CA model nor the rNEQ perfectly predicted the observed activity of complex mixtures, but predictions were often within one magnitude of change from the observed response. Importantly, PCB mixtures approximating profiles found in environmental samples or human serum displayed RyR1 activity at concentrations reported in published research. The work presented will aid in the development of risk assessment platforms for NDL PCBs, and similar compounds, towards RyR1 activation and related neurotoxicity.
Collapse
Affiliation(s)
- Justin A. Griffin
- Department of Biological Science, California State University of Long Beach, Long Beach California
| | - Xueshu Li
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, Iowa
| | - Hans-Joachim Lehmler
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, Iowa
| | - Erika B. Holland
- Department of Biological Science, California State University of Long Beach, Long Beach California
| |
Collapse
|
3
|
Bannavti MK, Jahnke JC, Marek RF, Just CL, Hornbuckle KC. Room-to-Room Variability of Airborne Polychlorinated Biphenyls in Schools and the Application of Air Sampling for Targeted Source Evaluation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:9460-9468. [PMID: 34033460 PMCID: PMC8427462 DOI: 10.1021/acs.est.0c08149] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Airborne polychlorinated biphenyl (PCB) concentrations are higher indoors than outdoors due to their historical use in building materials and their presence in modern paints and surface treatments. For some populations, including school children, PCB levels indoors result in inhalation exposures that may be greater than or equivalent to exposure through diet. In a school, PCB exposure may come from multiple sources. We hypothesized that there are both Aroclor and non-Aroclor sources within a single school and that PCB concentration and congener profiles differ among rooms within a single building. To evaluate this hypothesis and to identify potential localized sources, we measured airborne PCBs in nine rooms in a school. We found that schoolroom concentrations exceed outdoor air concentrations. Schoolroom concentrations and congener profiles also varied from one room to another. The concentrations were highest in the math room (35.75 ng m-3 ± 8.08) and lowest in the practice gym (1.54 ng m-3 ± 0.35). Rooms in the oldest wing of the building, originally constructed between 1920 and 1970, had the highest concentrations. The congener distribution patterns indicate historic use of Aroclor 1254 as well as modern sources of non-Aroclor congeners associated with paint pigments and surface coatings. Our findings suggest this noninvasive source identification method presents an opportunity for targeted source testing for more cost-effective prioritization of materials remediation in schools.
Collapse
Affiliation(s)
| | | | - Rachel F. Marek
- Department of Civil and Environmental Engineering, IIHR-Hydroscience & Engineering, University of Iowa, Iowa City, Iowa USA 52242
| | - Craig L. Just
- Department of Civil and Environmental Engineering, IIHR-Hydroscience & Engineering, University of Iowa, Iowa City, Iowa USA 52242
| | - Keri C. Hornbuckle
- Department of Civil and Environmental Engineering, IIHR-Hydroscience & Engineering, University of Iowa, Iowa City, Iowa USA 52242
| |
Collapse
|
4
|
Wang H, Adamcakova-Dodd A, Flor S, Gosse L, Klenov VE, Stolwijk JM, Lehmler HJ, Hornbuckle KC, Ludewig G, Robertson LW, Thorne PS. Comprehensive Subchronic Inhalation Toxicity Assessment of an Indoor School Air Mixture of PCBs. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:15976-15985. [PMID: 33256405 PMCID: PMC7879961 DOI: 10.1021/acs.est.0c04470] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Few in vivo inhalation studies have explored the toxicity of environmentally relevant mixtures of polychlorinated biphenyls (PCBs). The manufacture of industrial PCBs was banned in 1978, but PCBs continue to be formed in industrial and consumer products. Schools represent a significant source of airborne exposures to legacy and nonlegacy PCBs, placing children at risk. To evaluate the impact of these exposures, we generated an airborne mixture of PCBs, called the School Air Mixture (SAM), to match the profile of an older school from our adolescent cohort study. Female Sprague-Dawley rats were exposed either to SAM or filtered air in nose-only exposure systems, 4 h/day for 4 weeks. Congener-specific air and tissue PCB profiles were assessed using gas chromatography with tandem mass spectrometry (GC-MS/MS). PCB exposures recapitulated the target school air profile with a similarity coefficient, cos θ of 0.83. PCB inhalation yielded μg/g ∑209 PCB levels in tissues. Neurobehavioral testing demonstrated a modest effect on spatial learning and memory in SAM-exposed rats. PCB exposure induced oxidative stress in the liver and lungs, affected the maturational stages of hematopoietic stem cells, reduced telomerase activity in bone marrow cells, and altered the gut microbiota. This is the first study to emulate PCB exposures in a school and comprehensively evaluate toxicity.
Collapse
Affiliation(s)
- Hui Wang
- Department of Occupational and Environmental Health, the University of Iowa, Iowa City, Iowa 52242, United States
| | - Andrea Adamcakova-Dodd
- Department of Occupational and Environmental Health, the University of Iowa, Iowa City, Iowa 52242, United States
| | - Susanne Flor
- Department of Occupational and Environmental Health, the University of Iowa, Iowa City, Iowa 52242, United States
| | - Laura Gosse
- Interdisciplinary Graduate Program in Human Toxicology, the University of Iowa, Iowa City, Iowa 52242, United States
| | - Violet E. Klenov
- Department of Obstetrics and Gynecology, the University of Iowa, Iowa City, Iowa 52242, United States
| | - Jeffrey M. Stolwijk
- Interdisciplinary Graduate Program in Human Toxicology, the University of Iowa, Iowa City, Iowa 52242, United States
| | - Hans-Joachim Lehmler
- Department of Occupational and Environmental Health, the University of Iowa, Iowa City, Iowa 52242, United States
- Interdisciplinary Graduate Program in Human Toxicology, the University of Iowa, Iowa City, Iowa 52242, United States
| | - Keri C. Hornbuckle
- Interdisciplinary Graduate Program in Human Toxicology, the University of Iowa, Iowa City, Iowa 52242, United States
- Department of Civil and Environmental Engineering, the University of Iowa, Iowa City, Iowa 52242, United States
| | - Gabriele Ludewig
- Department of Occupational and Environmental Health, the University of Iowa, Iowa City, Iowa 52242, United States
- Interdisciplinary Graduate Program in Human Toxicology, the University of Iowa, Iowa City, Iowa 52242, United States
| | - Larry W. Robertson
- Department of Occupational and Environmental Health, the University of Iowa, Iowa City, Iowa 52242, United States
- Interdisciplinary Graduate Program in Human Toxicology, the University of Iowa, Iowa City, Iowa 52242, United States
| | - Peter S. Thorne
- Department of Occupational and Environmental Health, the University of Iowa, Iowa City, Iowa 52242, United States
- Interdisciplinary Graduate Program in Human Toxicology, the University of Iowa, Iowa City, Iowa 52242, United States
| |
Collapse
|
5
|
Herkert NJ, Hornbuckle KC. Effects of room airflow on accurate determination of PUF-PAS sampling rates in the indoor environment. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2018; 20:757-766. [PMID: 29611590 PMCID: PMC5966328 DOI: 10.1039/c8em00082d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Accurate and precise interpretation of concentrations from polyurethane passive samplers (PUF-PAS) is important as more studies show elevated concentrations of PCBs and other semivolatile air toxics in indoor air of schools and homes. If sufficiently reliable, these samplers may be used to identify local sources and human health risks. Here we report indoor air sampling rates (Rs) for polychlorinated biphenyl congeners (PCBs) predicted for a frequently used double-dome and a half-dome PUF-PAS design. Both our experimentally calibrated (1.10 ± 0.23 m3 d-1) and modeled (1.08 ± 0.04 m3 d-1) Rs for the double-dome samplers compare well with literature reports for similar rooms. We determined that variability of wind speeds throughout the room significantly (P < 0.001) effected uptake rates. We examined this effect using computational fluid dynamics modeling and 3-D sonic anemometer measurements and found the airflow dynamics to have a significant but small impact on the precision of calculated airborne concentrations. The PUF-PAS concentration measurements were within 27% and 10% of the active sampling concentration measurements for the double-dome and half-dome designs, respectively. While the half-dome samplers produced more consistent concentration measurements, we find both designs to perform well indoors.
Collapse
Affiliation(s)
- Nicholas J Herkert
- Department of Civil & Environmental Engineering, IIHR-Hydroscience and Engineering, The University of Iowa, 4105 SC, Iowa City, IA 52242, USA.
| | | |
Collapse
|
6
|
Feng W, Zheng J, Robin G, Dong Y, Ichikawa M, Inoue Y, Mori T, Nakano T, Pessah IN. Enantioselectivity of 2,2',3,5',6-Pentachlorobiphenyl (PCB 95) Atropisomers toward Ryanodine Receptors (RyRs) and Their Influences on Hippocampal Neuronal Networks. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:14406-14416. [PMID: 29131945 PMCID: PMC6251309 DOI: 10.1021/acs.est.7b04446] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Nineteen ortho-substituted PCBs are chiral and found enantioselectively enriched in ecosystems. Their differential actions on biological targets are not understood. PCB 95 (2,2',3,5',6-pentachlorobiphenyl), a chiral PCB of current environmental relevance, is among the most potent toward modifying ryanodine receptors (RyR) function and Ca2+ signaling. PCB 95 enantiomers are separated and assigned aR- and aS-PCB 95 using three chiral-column HPLC and circular dichroism spectroscopy. Studies of RyR1-enriched microsomes show aR-PCB 95 with >4× greater potency (EC50 = 0.20 ± 0.05 μM), ∼ 1.3× higher efficacy (Bmax = 3.74 ± 0.07 μM) in [3H]Ryanodine-binding and >3× greater rates (R = 7.72 ± 0.31 nmol/sec/mg) of Ca2+ efflux compared with aS-PCB 95, whereas racemate has intermediate activity. aR-PCB 95 has modest selectivity for RyR2, and lower potency than racemate toward the RyR isoform mixture in brain membranes. Chronic exposure of hippocampal neuronal networks to nanomolar PCB 95 during a critical developmental period shows divergent influences on synchronous Ca2+ oscillation (SCO): rac-PCB 95 increasing and aR-PCB 95 decreasing SCO frequency at 50 nM, although the latter's effects are nonmonotonic at higher concentration. aS-PCB95 shows the greatest influence on inhibiting responses to 20 Hz electrical pulse trains. Considering persistence of PCB 95 in the environment, stereoselectivity toward RyRs and developing neuronal networks may clarify health risks associated with enantioisomeric enrichment of PCBs.
Collapse
Affiliation(s)
- Wei Feng
- Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, California United States
| | - Jing Zheng
- Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, California United States
- Jiangsu Provincial Key Laboratory for TCM Evaluation and Translational Development, China Pharmaceutical University, Nanjing, China
| | - Gaëlle Robin
- Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, California United States
| | - Yao Dong
- Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, California United States
| | - Makoto Ichikawa
- Graduate School of Engineering, Osaka University, Osaka, Japan
| | - Yoshihisa Inoue
- Graduate School of Engineering, Osaka University, Osaka, Japan
| | - Tadashi Mori
- Graduate School of Engineering, Osaka University, Osaka, Japan
| | - Takeshi Nakano
- Research Center for Environmental Preservation, Osaka University, Osaka, Japan
| | - Isaac N. Pessah
- Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, California United States
- Corresponding Author Phone: +1-(530)-752-6696;
| |
Collapse
|
7
|
Marek RF, Thorne PS, Herkert NJ, Awad AM, Hornbuckle KC. Airborne PCBs and OH-PCBs Inside and Outside Urban and Rural U.S. Schools. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:7853-7860. [PMID: 28656752 PMCID: PMC5777175 DOI: 10.1021/acs.est.7b01910] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
PCBs appear in school air because many school buildings were built when PCBs were still intentionally added to building materials and because PCBs are also present through inadvertent production in modern pigment. This is of concern because children are especially vulnerable to the toxic effects of PCBs. Here we report indoor and outdoor air concentrations of PCBs and OH-PCBs from two rural schools and four urban schools, the latter near a PCB-contaminated waterway of Lake Michigan in the United States. Samples (n = 108) were collected as in/out pairs using polyurethane foam passive air samplers (PUF-PAS) from January 2012 to November 2015. Samples were analyzed using GC/MS-MS for all 209 PCBs and 72 OH-PCBs. Concentrations inside schools were 1-2 orders of magnitude higher than outdoors and ranged from 0.5 to 194 ng/m3 (PCBs) and from 4 to 665 pg/m3 (OH-PCBs). Congener profiles were similar within each sampling location across season but different between schools and indicated the sources as Aroclors from building materials and individual PCBs associated with modern pigment. This study is the first cohort-specific analysis to show that some children's PCB inhalation exposure may be equal to or higher than their exposure through diet.
Collapse
Affiliation(s)
- Rachel F. Marek
- IIHR-Hydroscience and Engineering, The University of Iowa, Iowa City IA (USA) 52242
- Corresponding authors’ contact information: Rachel F. Marek: 103 S. Capitol St., 4105 SC, Iowa City, IA 52242, , (319) 335-5585, FAX (319) 335-5660; Keri C. Hornbuckle: 103 S. Capitol St., 4105 SC, Iowa City, IA 52242, ; (319) 384-0789, FAX: (319) 335-5660; Peter S. Thorne: 105 River St., S341A CPHB, Iowa City, IA 52242, , (319) 335-4216, FAX: (319) 384-4138
| | - Peter S. Thorne
- Department of Occupational and Environmental Health, The University of Iowa, Iowa City IA (USA) 52242
- Corresponding authors’ contact information: Rachel F. Marek: 103 S. Capitol St., 4105 SC, Iowa City, IA 52242, , (319) 335-5585, FAX (319) 335-5660; Keri C. Hornbuckle: 103 S. Capitol St., 4105 SC, Iowa City, IA 52242, ; (319) 384-0789, FAX: (319) 335-5660; Peter S. Thorne: 105 River St., S341A CPHB, Iowa City, IA 52242, , (319) 335-4216, FAX: (319) 384-4138
| | - Nicholas J. Herkert
- IIHR-Hydroscience and Engineering, The University of Iowa, Iowa City IA (USA) 52242
- Department of Civil & Environmental Engineering, The University of Iowa, Iowa City IA (USA) 52242
| | - Andrew M. Awad
- IIHR-Hydroscience and Engineering, The University of Iowa, Iowa City IA (USA) 52242
| | - Keri C. Hornbuckle
- IIHR-Hydroscience and Engineering, The University of Iowa, Iowa City IA (USA) 52242
- Department of Civil & Environmental Engineering, The University of Iowa, Iowa City IA (USA) 52242
- Corresponding authors’ contact information: Rachel F. Marek: 103 S. Capitol St., 4105 SC, Iowa City, IA 52242, , (319) 335-5585, FAX (319) 335-5660; Keri C. Hornbuckle: 103 S. Capitol St., 4105 SC, Iowa City, IA 52242, ; (319) 384-0789, FAX: (319) 335-5660; Peter S. Thorne: 105 River St., S341A CPHB, Iowa City, IA 52242, , (319) 335-4216, FAX: (319) 384-4138
| |
Collapse
|