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Borgert CJ. Hypothesis-driven weight of evidence evaluation indicates styrene lacks endocrine disruption potential. Crit Rev Toxicol 2023:1-16. [PMID: 37216681 DOI: 10.1080/10408444.2022.2112652] [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: 03/28/2022] [Revised: 08/01/2022] [Accepted: 08/02/2022] [Indexed: 05/24/2023]
Abstract
Styrene is among the U.S. EPA's List 2 chemicals for Tier 1 endocrine screening subject to the agency's two-tiered Endocrine Disruptor Screening Program (EDSP). Both U.S. EPA and OECD guidelines require a Weight of Evidence (WoE) to evaluate a chemical's potential for disrupting the endocrine system. Styrene was evaluated for its potential to disrupt estrogen, androgen, thyroid, and steroidogenic (EATS) pathways using a rigorous WoE methodology that included problem formulation, systematic literature search and selection, data quality evaluation, relevance weighting of endpoint data, and application of specific interpretive criteria. Sufficient data were available to assess the endocrine disruptive potential of styrene based on endpoints that would respond to EATS modes of action in some Tier 1-type and many Tier 2-type reproductive, developmental, and repeat dose toxicity studies. Responses to styrene were inconsistent with patterns of responses expected for chemicals and hormones known to operate via EATS MoAs, and thus, styrene cannot be deemed an endocrine disruptor, a potential endocrine disruptor, or to exhibit endocrine disruptive properties. Because Tier 1 EDSP screening results would trigger Tier 2 studies, like those evaluated here, subjecting styrene to further endocrine screening would produce no additional useful information and would be unjustified from animal welfare perspectives.
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Affiliation(s)
- Christopher J Borgert
- Applied Pharmacology and Toxicology Inc, Gainesville, FL, USA
- Department of Physiological Sciences, University of Florida College of Veterinary Medicine, Gainesville, FL, USA
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2
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Biale G, La Nasa J, Mattonai M, Corti A, Castelvetro V, Modugno F. Seeping plastics: Potentially harmful molecular fragments leaching out from microplastics during accelerated ageing in seawater. WATER RESEARCH 2022; 219:118521. [PMID: 35526427 DOI: 10.1016/j.watres.2022.118521] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 04/21/2022] [Accepted: 04/26/2022] [Indexed: 06/14/2023]
Abstract
Microplastics are the particulate plastic debris found almost everywhere as environmental contaminants. They are not chemically stable persistent pollutants, but reactive materials. In fact, synthetic polymers exposed to the environment undergo chemical and physical degradation processes which lead not only to mechanical but also molecular fragmentation, releasing compounds that are potentially harmful for the environment and human health. We carried out accelerated photo-oxidative ageing of four reference microplastics (low- and high-density polyethylene, polypropylene, and polystyrene) directly in artificial seawater. We then made a characterization at the molecular level along with a quantification of the chemical species leached into water. Gas chromatography/mass spectrometry analyses performed after selective extraction and derivatization enabled us to identify more than 60 different compounds. Analysis of the leachates from the three polyolefins revealed that the main degradation products were mono- and dicarboxylic acids, along with linear and branched hydroxy acids. The highest amount of leached degradation species was observed for polystyrene, with benzoic acid and phenol derivatives as the most abundant, along with oligomeric styrene derivatives. The results from reference microplastics were then compared with those obtained by analyzing leachates in artificial seawater from aged plastic debris collected in a natural environment. The differences observed between the reference and the environmental plastic leachates mainly concerned the relative abundances of the chemical species detected, with the environmental samples showing higher amounts of dicarboxylic acids and oxidized species.
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Affiliation(s)
- Greta Biale
- Department of Chemistry and Industrial Chemistry, University of Pisa, Pisa, Italy
| | - Jacopo La Nasa
- Department of Chemistry and Industrial Chemistry, University of Pisa, Pisa, Italy; National Interuniversity Consortium of Materials Science and Technology (INSTM), Florence, Italy.
| | - Marco Mattonai
- Department of Chemistry and Industrial Chemistry, University of Pisa, Pisa, Italy
| | - Andrea Corti
- Department of Chemistry and Industrial Chemistry, University of Pisa, Pisa, Italy; CISUP Center for the Integration of Scientific Instruments of the University of Pisa, Pisa, Italy
| | - Valter Castelvetro
- Department of Chemistry and Industrial Chemistry, University of Pisa, Pisa, Italy; CISUP Center for the Integration of Scientific Instruments of the University of Pisa, Pisa, Italy
| | - Francesca Modugno
- Department of Chemistry and Industrial Chemistry, University of Pisa, Pisa, Italy; CISUP Center for the Integration of Scientific Instruments of the University of Pisa, Pisa, Italy
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Prichystalova R, Caron-Beaudoin E, Richardson L, Dirkx E, Amadou A, Zavodna T, Cihak R, Cogliano V, Hynes J, Pelland-St-Pierre L, Verner MA, van Tongeren M, Ho V. An approach to classifying occupational exposures to endocrine disrupting chemicals by sex hormone function using an expert judgment process. JOURNAL OF EXPOSURE SCIENCE & ENVIRONMENTAL EPIDEMIOLOGY 2021; 31:753-768. [PMID: 32704083 DOI: 10.1038/s41370-020-0253-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 06/29/2020] [Accepted: 07/15/2020] [Indexed: 06/11/2023]
Abstract
Endocrine disrupting chemicals (EDCs) are exogenous substances that interfere with the endocrine system and cause adverse effects. We aimed to classify the effects of 24 known EDCs, prevalent in certain occupations, according to four modes of action (estrogenic, antiestrogenic, androgenic, and/or antiandrogenic). A literature search, stratified into four types of literature was conducted (namely: national and international agency reports; review articles; primary studies; ToxCastTM). The state of the evidence of each EDC on sex hormone function was summarized and reviewed by an expert panel. For each mode of action, the experts evaluated the likelihood of endocrine disruption in five categories: "No", "Unlikely", "Possibly", "Probably", and "Yes". Seven agents were categorized as "Yes," or having strong evidence for their effects on sex hormone function (antiandrogenic: lead, arsenic, butylbenzyl phthalate, dibutyl phthalate, dicyclohexyl phthalate; estrogenic: nonylphenol, bisphenol A). Nine agents were categorized as "Probable," or having probable evidence (antiandrogenic: bis(2-ethylhexyl)phthalate, nonylphenol, toluene, bisphenol A, diisononyl phthalate; androgenic: cadmium; estrogenic: copper, cadmium and; anti-estrogenic: lead). Two agents (arsenic, polychlorinated biphenyls) had opposing conclusions supporting both "probably" estrogenic and antiestrogenic effects. This synthesis will allow researchers to evaluate the health effects of selected EDCs with an added level of precision related to the mode of action.
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Affiliation(s)
- R Prichystalova
- Faculty of Safety Engineering, Technical University of Ostrava, Ostrava, Czech Republic
| | - E Caron-Beaudoin
- Department of Occupational and Environmental Health, Université de Montréal, Montréal, QC, Canada
| | - L Richardson
- Centre de recherche du CHUM (CRCHUM), Montréal, QC, Canada
| | - E Dirkx
- Centre de recherche du CHUM (CRCHUM), Montréal, QC, Canada
| | - A Amadou
- Département Prévention Cancer Environnement, Centre Léon Bérard, Lyon, France
- Inserm UA 08 Radiations: Défense, Santé, Environement, Lyon, France
| | - T Zavodna
- Institute of Experimental Medicine of the CAS, Prague, Czech Republic
| | - R Cihak
- Výzkumný ústav organických syntéz a.s., Centre for Ecology, Toxicology and Analytics, Rybitví, Czech Republic
| | - V Cogliano
- National Center for Environmental Health Hazard Assessment, US Environmental Protection Agency, Washington, DC, USA
| | - J Hynes
- JH Tox Consulting, Maastricht, Netherlands
| | - L Pelland-St-Pierre
- Department of Social and Preventive Medicine, Université de Montréal, Montréal, QC, Canada
| | - M A Verner
- Department of Occupational and Environmental Health, Université de Montréal, Montréal, QC, Canada
- Centre de recherche en santé publique (CReSP), Université de Montréal, Montréal, QC, Canada
| | - M van Tongeren
- Faculty of Science and Engineering, Division of Population Health, Health Services Research & Primary Care, University of Manchester, Manchester, UK
| | - V Ho
- Centre de recherche du CHUM (CRCHUM), Montréal, QC, Canada.
- Department of Social and Preventive Medicine, Université de Montréal, Montréal, QC, Canada.
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Moujahed S, Ruiz A, Hallegue D, Sakly M. Quercetin alleviates styrene oxide-induced cytotoxicity in cortical neurons in vitro via modulation of oxidative stress and apoptosis. Drug Chem Toxicol 2020; 45:1634-1643. [PMID: 33297769 DOI: 10.1080/01480545.2020.1851706] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Styrene 7,8-oxide (SO) is the principal metabolite of styrene, an industrial neurotoxic compound which causes various neurodegenerative disorders. The present study aimed to explore the mechanisms of SO cytotoxicity (0.5 - 4 mM) in primary cortical neurons and to evaluate the neuroprotective potential of quercetin (QUER). Our results showed that exposure to SO decreased viability of cortical neurons in a concentration-dependent manner. In the presence of QUER, cell viability was increased significantly. The neuroprotective effects of QUER were associated with the reduction of intracellular Reactive Oxygen Species (ROS), the decrease in calcium overload and the restoration of mitochondrial membrane depolarization caused by SO. Additionally, to evaluate neuronal death mechanisms triggered by SO, cells were incubated with Ac-DEVD-CHO, Calpeptin and Necrostatin-1, pharmacological inhibitors of caspase-3, calpains and necroptosis respectively. The data showed that the three inhibitors reduced cell death induced by SO and suggested the implication of apoptotic, necrotic and necroptotic pathways. However, western blot analysis showed that QUER attenuated the activation of caspase-3 but did not prevent calpain activity. Taken together, these data indicated that the cytotoxicity of SO was mediated by oxidative stress and apoptosis, necrosis and necroptosis mechanisms, while the neuroprotection provided by QUER against SO depended mainly on its anti-apoptotic activity.
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Affiliation(s)
- Sabrine Moujahed
- Faculty of Sciences of Bizerte, Laboratory of Integrative Physiology, University of Carthage, Jarzouna, Tunisia
| | - Asier Ruiz
- Faculty of Medicine and Nursing, Department of Neurosciences, University of the Basque Country, Vizcaya, Spain
| | - Dorsaf Hallegue
- Faculty of Sciences of Bizerte, Laboratory of Integrative Physiology, University of Carthage, Jarzouna, Tunisia
| | - Mohsen Sakly
- Faculty of Sciences of Bizerte, Laboratory of Integrative Physiology, University of Carthage, Jarzouna, Tunisia
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Migration of styrene monomer from polystyrene packaging materials into foods: Characterization and safety evaluation. Trends Food Sci Technol 2019. [DOI: 10.1016/j.tifs.2019.07.020] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Banton MI, Bus JS, Collins JJ, Delzell E, Gelbke HP, Kester JE, Moore MM, Waites R, Sarang SS. Evaluation of potential health effects associated with occupational and environmental exposure to styrene - an update. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2019; 22:1-130. [PMID: 31284836 DOI: 10.1080/10937404.2019.1633718] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The potential chronic health risks of occupational and environmental exposure to styrene were evaluated to update health hazard and exposure information developed since the Harvard Center for Risk Analysis risk assessment for styrene was performed in 2002. The updated hazard assessment of styrene's health effects indicates human cancers and ototoxicity remain potential concerns. However, mechanistic research on mouse lung tumors demonstrates these tumors are mouse-specific and of low relevance to human cancer risk. The updated toxicity database supports toxicity reference levels of 20 ppm (equates to 400 mg urinary metabolites mandelic acid + phenylglyoxylic acid/g creatinine) for worker inhalation exposure and 3.7 ppm and 2.5 mg/kg bw/day, respectively, for general population inhalation and oral exposure. No cancer risk value estimates are proposed given the established lack of relevance of mouse lung tumors and inconsistent epidemiology evidence. The updated exposure assessment supports inhalation and ingestion routes as important. The updated risk assessment found estimated risks within acceptable ranges for all age groups of the general population and workers with occupational exposures in non-fiber-reinforced polymer composites industries and fiber-reinforced polymer composites (FRP) workers using closed-mold operations or open-mold operations with respiratory protection. Only FRP workers using open-mold operations not using respiratory protection have risk exceedances for styrene and should be considered for risk management measures. In addition, given the reported interaction of styrene exposure with noise, noise reduction to sustain levels below 85 dB(A) needs be in place.
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Affiliation(s)
- M I Banton
- a Gorge View Consulting LLC , Hood River , OR , USA
| | - J S Bus
- b Health Sciences , Exponent , Midland , MI , USA
| | - J J Collins
- c Health Sciences , Saginaw Valley State University , Saginaw , MI , USA
| | - E Delzell
- d Private consultant , Birmingham , AL , USA
| | | | - J E Kester
- f Kester Consulting LLC , Wentzville , MO , USA
| | | | - R Waites
- h Sabic , Innovative Plastics US LLC , Mount Vernon , IN , USA
| | - S S Sarang
- i Shell Health , Shell International , Houston , TX , USA
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Arab MR, Mirzaei R, Aval FS. The Protective Effects of Gadolinum Chloride on Pneumotoxic Effects of Styrene in Rat. CELL JOURNAL 2015; 17:422-8. [PMID: 26464813 PMCID: PMC4601862 DOI: 10.22074/cellj.2015.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Accepted: 09/23/2014] [Indexed: 11/11/2022]
Abstract
Objective The aim of the present study was to evaluate the protective effects of gadoli-
num on pneumotoxic effects of styrene in rats as an experimental model.
Materials and Methods In this experimental study a total number of 40 adult male Sprague
Dawley rats that weighed 200 ± 13 g were randomly divided into five groups: i. styrene (St,
N=10), ii. styrene+gadolinium chloride (GdCl3, N=10), iii. control (N=10), iv. GdCl3 (N=5) and v.
normal saline (Nor.Sal, as a solvent of GdCl3, N=5). Normal saline, as a sham control group,
was otherwise treated identically. Rats from the experimental groups were exposed to St in an
exposure chamber for 6 days/week, 4 hours/day for up to 3 weeks. At the end of the experi-
ment, rats from all groups were killed by deep anesthesia. Their lungs were removed, then
fixed in formalin and weighed. Tissue samples were processed routinely and sections stained
by the hematoxylin and eosin (H&E) and periodic acid Schiff (PAS) methods. We measured
the thicknesses of the respiratory epithelia and interalveolar septa. Obtained data were ana-
lyzed by ANOVA, the Tukey test and the paired t test.
Results Shedding of apical cytoplasm in the bronchiole was a prominent feature of the
St group. PAS staining revealed histochemical changes in goblet cells in the epithelium
of the St group. While there were no significant changes in lung weights and respiratory
epithelial thicknesses between all studied groups, statistical analysis showed a significant
alteration in the thickness of interalveolar septa in the St and St+GdCl3 group compared
to the control groups (P<0.001).
Conclusion Styrene induced structural and histochemical changes in bronchiole,
interalveolar septa and alveolar organization in the rats’ lungs. Gadolinium appeared
to partially reduce the toxic effects of styrene on the lungs.
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Affiliation(s)
- Mohammad Reza Arab
- Cell and Molecular Research Center, Department of Anatomical Sciences, Faculty of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran
| | - Ramazan Mirzaei
- Health Promotion Research Center, Faculty of Health, Zahedan University of Medical Sciences, Zahedan, Iran
| | - Fereydoon Sargolzaei Aval
- Cell and Molecular Research Center, Department of Anatomical Sciences, Faculty of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran
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Gelbke HP, Banton M, Leibold E, Pemberton M, Samson SL. A critical review finds styrene lacks direct endocrine disruptor activity. Crit Rev Toxicol 2015; 45:727-64. [PMID: 26406562 DOI: 10.3109/10408444.2015.1064091] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The European Commission lists styrene (S) as an endocrine disruptor based primarily on reports of increased prolactin (PRL) levels in S-exposed workers. The US Environmental Protection Agency included S in its list of chemicals to be tested for endocrine activity. Therefore, the database of S for potential endocrine activity is assessed. In vitro and in vivo screening studies, as well as non-guideline and guideline investigations in experimental animals indicate that S is not associated with (anti)estrogenic, (anti)androgenic, or thyroid-modulating activity or with an endocrine activity that may be relevant for the environment. Studies in exposed workers have suggested elevated PRL levels that have been further examined in a series of human and animal investigations. While there is only one definitively known physiological function of PRL, namely stimulation of milk production, many normal stress situations may lead to elevations without any chemical exposure. Animal studies on various aspects of dopamine (DA), the PRL-regulating neurotransmitter, in the central nervous system did not give mechanistic explanations on how S may affect PRL levels. Overall, a neuroendocrine disruption of PRL regulation cannot be deduced from a large experimental database. The effects in workers could not consistently be reproduced in experimental animals and the findings in humans represented acute reversible effects clearly below clinical and pathological levels. Therefore, unspecific acute workplace-related stress is proposed as an alternative mode of action for elevated PRL levels in workers.
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Affiliation(s)
| | - Marcy Banton
- b Lyondell Chemical Company , Houston, Texas , USA
| | | | | | - Susan Leanne Samson
- e Division of Endocrinology, Department of Medicine , Baylor College of Medicine , Houston, Texas , USA
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Xu C, Liu Q, Liu H, Héroux P, Zhang Q, Jiang ZY, Gu A. Low Serum Testosterone Levels Are Associated with Elevated Urinary Mandelic Acid, and Strontium Levels in Adult Men According to the US 2011-2012 National Health and Nutrition Examination Survey. PLoS One 2015; 10:e0127451. [PMID: 25996772 PMCID: PMC4440739 DOI: 10.1371/journal.pone.0127451] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 04/15/2015] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Little is known regarding the effects of environmental exposure of chemicals on androgenic system in the general population. We studied 5,107 subjects included in the National Health and Nutrition Examination Survey (2011-2012). METHODS Urinary, serum, and blood levels of 15 subclasses comprising 110 individual chemicals were analyzed for their association with serum testosterone levels. The subjects were divided into high and low testosterone groups according to the median testosterone concentration (374.51 ng/dL). Odds ratios (ORs) of individual chemicals in association with testosterone were estimated using logistic regression after adjusting for age, ethnicity, cotinine, body mass index, creatinine, alcohol, and the poverty income ratio. RESULTS Adjusted ORs for the highest versus lowest quartiles of exposure were 2.12 (95% CI: 1.07, 4.21; Ptrend = 0.044), 1.84 (95% CI: 1.02, 3.34; Ptrend = 0.018) for the association between urinary mandelic acid, and strontium quartiles with low testosterone concentrations in adult men, respectively. However, no association was observed for the remaining chemicals with testosterone. CONCLUSIONS The National Health and Nutrition Examination Survey data suggest that elevations in urinary mandelic acid, and strontium levels are negatively related to low serum testosterone levels in adult men.
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Affiliation(s)
- Cheng Xu
- State Key Laboratory of Reproductive Medicine, Institute of Toxicology, Nanjing Medical University, Nanjing, China
- Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Qian Liu
- State Key Laboratory of Reproductive Medicine, Institute of Toxicology, Nanjing Medical University, Nanjing, China
- Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Hui Liu
- State Key Laboratory of Reproductive Medicine, Institute of Toxicology, Nanjing Medical University, Nanjing, China
- Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Paul Héroux
- InVitroPlus Laboratory, Department of Surgery, Royal Victoria Hospital, Montreal, QC, Canada
- Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, QC, Canada
| | - Qunwei Zhang
- Department of Environmental and Occupational Health Sciences, School of Public Health and Information Health Sciences, University of Louisville, Louisville, KY, 40292, United States of America
| | - Zhao-Yan Jiang
- Department of Surgery, Ruijin Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, China
- * E-mail: (AG); (ZYJ)
| | - Aihua Gu
- State Key Laboratory of Reproductive Medicine, Institute of Toxicology, Nanjing Medical University, Nanjing, China
- Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China
- * E-mail: (AG); (ZYJ)
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Zhang S, Li W, Zhu C, Wang X, Li Z, Zhang J, Zhao J, Hu J, Li T, Zhang Y. Sertoli cell-specific expression of metastasis-associated protein 2 (MTA2) is required for transcriptional regulation of the follicle-stimulating hormone receptor (FSHR) gene during spermatogenesis. J Biol Chem 2012; 287:40471-83. [PMID: 23086931 DOI: 10.1074/jbc.m112.383802] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND Desensitization of FSH response by down-regulation of FSHR transcription is critical for FSH action. RESULTS Chromatin modifier MTA2 participates in the down-regulation of FSHR transcription. CONCLUSION The FSH/Ar/MTA2 cascade may serve as an indispensable negative feedback mechanism to modulate FSH transduction events in Sertoli cells. SIGNIFICANCE Our findings provide new insights into mechanisms by which FSH is deregulated in male infertile patients. The effect of follicle-stimulating hormone (FSH) on spermatogenesis is modulated at a fundamental level by controlling the number of competent receptors present at the surface of Sertoli cells (SCs). One underlying mechanism is the down-regulation of the expression levels of the FSH receptor (FSHR) gene after exposure to FSH. Here we report that metastasis-associated protein 2 (MTA2), a component of histone deacetylase and nucleosome-remodeling complexes, as a gene product induced directly by testosterone or indirectly by FSH, is exclusively expressed in SCs. Stimulation of SCs with FSH is accompanied by up-regulation of MTA2 expression and enhancement of deacetylase activity. This effect requires the integrity of functional androgen receptor. Furthermore, MTA2 is a potent corepressor of FSHR transcription, because it can recruit histone deacetylase-1 onto the FSHR promoter and participates in the down-regulation of FSHR expression upon FSH treatment. Abolishment of endogenous MTA2 by siRNA treatment disrupted the desensitization of the FSH response and thereafter impaired the FSH-dependent secretory function of SCs. From a clinical standpoint, deregulated expression of MTA2 in SCs of human pathological testes negatively correlates to the deregulated level of serum FSH. Overall, our present results provide the first evidence that the FSH/androgen receptor/MTA2 cascade may serve as an indispensable negative feedback mechanism to modulate the transduction events of SCs in response to FSH. These data also underscore an unexpected reproductive facet of MTA2, which may operate as a novel integrator linking synergistic actions of FSH and androgen signaling in SCs.
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Affiliation(s)
- Shun Zhang
- Department of Human Anatomy, Histology, and Embryology, Fourth Military Medical University, Xi'an 710032, China
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Chaari N, Kacem M, Marchaoui I, Kochtali I, Akrout M. Troubles de la fonction sexuelle et hormonale liés à l’exposition professionnelle aux solvants. ARCH MAL PROF ENVIRO 2009. [DOI: 10.1016/j.admp.2009.04.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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