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Curi TZ, Passoni MT, Lima Tolouei SE, de Araújo Ramos AT, França de Almeira SC, Scinskas ABAF, Romano RM, de Oliveira JM, Spercoski KM, Carvalho Dos Santos A, Dalsenter PR, Koch HM, Martino-Andrade AJ. Reproductive toxicity following in utero and lactational exposure to a human-relevant phthalate mixture in rats. Toxicol Sci 2023; 197:1-15. [PMID: 37788136 DOI: 10.1093/toxsci/kfad102] [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: 10/05/2023] Open
Abstract
This rodent (Wistar rats) study examined reproductive effects of in utero/lactational exposure to a mixture of 6 antiandrogenic phthalates (PMix): diisobutyl phthalate, di-n-butyl phthalate, diisopentyl phthalate, butylbenzyl phthalate, di-2-ethylhexyl phthalate, and diisononyl phthalate. The PMix was defined based on exposure data from pregnant women in Brazil. Experimental groups were established by extrapolating the estimated human dose to rats (0.1 mg/kg/day), followed by up to 3 additional doses corresponding to 5, 1000, and 5000 times the starting rat dose: 0 (control), 0.1, 0.5, 100, and 500 mg/kg/day. The fetal experiment assessed gestational exposure effects on fetal gonads, whereas the postnatal experiment evaluated reproductive parameters in males and females after in utero and lactational exposure. Prenatal exposure decreased fetal testicular testosterone production at 0.5 and 500 mg/kg/day. PMix 500 also reduced mRNA expression of steroidogenesis-related genes, upregulated transcript expression of the retinoic acid-degrading enzyme Cyp26b1, and increased multinucleated gonocytes incidence in fetal testes. Postnatal assessment revealed antiandrogenic effects at the highest dose, including reduced anogenital distance, nipple retention, and decreased weight of reproductive organs. Early puberty onset (preputial separation) was observed at the lowest dose in males. In contrast, females did not show significant changes in fetal and adult endpoints. Overall, the PMix recapitulated early and late male rat phthalate syndrome phenotypes at the highest dose, but also induced some subtle changes at lower doses, which warrant confirmation and mechanistic assessments. Our data support the use of epidemiologically defined mixtures for exposure risk assessments over traditional toxicological approaches.
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Affiliation(s)
- Tatiana Zauer Curi
- Reproductive Toxicology Laboratory, Department of Pharmacology, Federal University of Paraná (UFPR), Curitiba, PR 81531-990, Brazil
| | - Marcella Tapias Passoni
- Reproductive Toxicology Laboratory, Department of Pharmacology, Federal University of Paraná (UFPR), Curitiba, PR 81531-990, Brazil
| | - Sara Emilia Lima Tolouei
- Reproductive Toxicology Laboratory, Department of Pharmacology, Federal University of Paraná (UFPR), Curitiba, PR 81531-990, Brazil
| | - Anderson Tadeu de Araújo Ramos
- Animal Endocrine and Reproductive Physiology Laboratory, Department of Physiology, Federal University of Paraná (UFPR), Curitiba, PR 81531-990, Brazil
| | - Samara Christina França de Almeira
- Animal Endocrine and Reproductive Physiology Laboratory, Department of Physiology, Federal University of Paraná (UFPR), Curitiba, PR 81531-990, Brazil
| | - Anna Beatriz Abreu Ferraz Scinskas
- Animal Endocrine and Reproductive Physiology Laboratory, Department of Physiology, Federal University of Paraná (UFPR), Curitiba, PR 81531-990, Brazil
| | - Renata Marino Romano
- Reproductive Toxicology Laboratory, Department of Pharmacy, State University of Centro-Oeste, Guarapuava, PR 85040-167, Brazil
| | - Jeane Maria de Oliveira
- Reproductive Toxicology Laboratory, Department of Pharmacy, State University of Centro-Oeste, Guarapuava, PR 85040-167, Brazil
| | | | - Ariany Carvalho Dos Santos
- Histopathology Laboratory, Department of Health Sciences, Federal University of Grande Dourados (UFGD), Dourados, MS 9804-970, Brazil
| | - Paulo Roberto Dalsenter
- Reproductive Toxicology Laboratory, Department of Pharmacology, Federal University of Paraná (UFPR), Curitiba, PR 81531-990, Brazil
| | - Holger Martin Koch
- Institute for Prevention and Occupational Medicine of the German Social Accident Insurance, Institute of the Ruhr-University-Bochum (IPA), Bochum 44789, Germany
| | - Anderson Joel Martino-Andrade
- Reproductive Toxicology Laboratory, Department of Pharmacology, Federal University of Paraná (UFPR), Curitiba, PR 81531-990, Brazil
- Animal Endocrine and Reproductive Physiology Laboratory, Department of Physiology, Federal University of Paraná (UFPR), Curitiba, PR 81531-990, Brazil
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Yin L, Hu C, Yu XJ. High-content analysis of testicular toxicity of BPA and its selected analogs in mouse spermatogonial, Sertoli cells, and Leydig cells revealed BPAF induced unique multinucleation phenotype associated with the increased DNA synthesis. Toxicol In Vitro 2023; 89:105589. [PMID: 36958674 PMCID: PMC10351343 DOI: 10.1016/j.tiv.2023.105589] [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: 11/10/2022] [Revised: 03/14/2023] [Accepted: 03/17/2023] [Indexed: 03/25/2023]
Abstract
Bisphenol A is an endocrine disruptor that has been shown to have testicular toxicity in animal models. Its structural analog, including bisphenol S (BPS), bisphenol AF (BPAF), and tetrabromobisphenol A (TBBPA) have been introduced to the market as BPA alternatives. Previously, we developed high-content analysis (HCA) assays and applied machine learning to compare the testicular toxicity of BPA and its analogs in spermatogonial cells and testicular cell co-culture models. There are diverse cell populations in the testis to support spermatogenesis, but their cell type-specific toxicities are still not clear. The purpose of this study is to examine the selective toxicity of BPA, BPS), BPAF, and TBBPA on these testicular cells, including Sertoli cells, Leydig cells, and spermatogonia cells. We developed a high-content image-based single-cell analysis and measured a broad spectrum of adverse endpoints related to the development of reproductive toxicology, including cell number, nuclear morphology, DNA synthesis, cell cycle progression, early DNA damage response, cytoskeleton structure, DNA methylation status, and autophagy. We introduced an HCA index and spectrum to reveal multiple HCA parameters and observed distinct toxicity profiling of BPA and its analogs among three testicular types. The HCA spectrum shows the dynamic, chemical-specific, dose-dependent changes of each HCA parameter. Each chemical displayed a unique dose-dependent profile within each type of cell. All three types of cells showed the highest response to BPAF at 10 μM across all endpoints measured. BPAF targeted spermatogonial cell (C18) more significantly at 5 μM. BPS more likely targeted Sertoli cell (TM4) and Leydig cell (TM3) and less at spermatogonia cells. TBBPA targeted spermatogonia, Sertoli cells, and less at TM3 cells. BPA is mainly targeted at TM4, followed by TM3 cells, and less at spermatogonial cells. Most importantly, we observed that BPAF induced a dose-dependent increase in spermatogonia cells, not in Sertoli and Leydig cells. In summary, our current HCA assays revealed the cell-type-specific toxicities of BPA and its analogs in different testicular cells. Multinucleation induced by BPAF, along with increased DNA damage and synthesis at low doses, could possibly have a profound long-term effect on reproductive systems.
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Affiliation(s)
- Lei Yin
- ReproTox Biotech LLC, 800 Bradbury Dr. SE Science & Technology Park, Albuquerque, NM 87106, United States of America
| | - Chelin Hu
- College of Nursing School, University of New Mexico, Albuquerque, NM 87106, United States of America
| | - Xiaozhong John Yu
- College of Nursing School, University of New Mexico, Albuquerque, NM 87106, United States of America.
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Bello UM, Madekurozwa MC, Groenewald HB, Arukwe A, Aire TA. Changes in testicular histomorphometry and ultrastructure of Leydig cells in adult male Japanese quail exposed to di (n-butyl) phthalate (DBP) during the prepubertal period. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:55402-55413. [PMID: 36894732 PMCID: PMC10121545 DOI: 10.1007/s11356-023-25767-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 02/02/2023] [Indexed: 06/18/2023]
Abstract
Phthalate esters, such as di(n-butyl) phthalate, (DBP), are synthetic chemical pollutants commonly used as plasticizers in the manufacture of plastics. In the present study, we investigated the effects of DBP in the testes of adult male quails (Coturnix cortunix japonica) exposed by oral gavage to variable doses of DBP (0 [control], 1, 10, 50, 200, and 400 mg/kgbw-d), for 30 days during the prepubertal period, using histo-morphometric and ultrastructural techniques. Generally, significant decreases in seminiferous tubular diameter (STD) and epithelial height (SEH) were observed predominantly at the highest DBP doses (200 and 400 mg/kg), as compared to medium (50 mg/kg), and lowest doses (1 and 10 mg/kg) as well as the control group. Ultrastructurally, apparent dose-specific degenerative changes were observed in the Leydig cells. The lowest DBP doses (1 and 10 mg/kg) did not produce significant effects on Leydig cell ultrastructure, whereas, at the highest doses (200 and 400 mg/kg), the Leydig cells were remarkably conspicuous in the interstitium and appeared foamy. There was a preponderance of electron-lucent lipid droplets which crowded out the normal organelles of the cell, as well as increases in the number of dense bodies in the cytoplasm. The smooth endoplasmic reticulum (sER) was less obvious, compacted, and wedged between the abundant lipid droplets and mitochondria. Taken together, these findings indicate that pre-pubertal exposure of precocious quail birds to DBP, produced parameter-specific histometric tubular changes, as well as dose-dependent cyto-structural derangement of the Leydig cells; which consequently may lead to overt reproductive impairments in the adult bird in the environment.
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Affiliation(s)
- Umar M Bello
- Department of Anatomy and Physiology, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110, South Africa.
- Laboratory of Cell Biology and Histology, Department of Veterinary Anatomy, Faculty of Veterinary Medicine, Ahmadu Bello University, Zaria, Nigeria.
| | - Mary-Cathrine Madekurozwa
- Department of Anatomy and Physiology, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110, South Africa
| | - Hermanus B Groenewald
- Department of Anatomy and Physiology, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110, South Africa
| | - Augustine Arukwe
- Department of Biology, Norwegian University of Science and Technology (NTNU), Høgskoleringen 5, 7491, Trondheim, Norway
| | - Tom A Aire
- Department of Anatomy, Physiology and Pharmacology, School of Veterinary Medicine, St. George's University, True-Blue, St. George's, Grenada
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Hu C, Hsiao ZH, Yin L, Yu X. The role of small GTPases in bisphenol AF-induced multinucleation in comparison with dibutyl phthalate in the male germ cells. Toxicol Sci 2023; 192:43-58. [PMID: 36625514 PMCID: PMC10025878 DOI: 10.1093/toxsci/kfad005] [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: 01/11/2023] Open
Abstract
The goal of this study is to examine bisphenol AF (BPAF)-induced multinucleation (MNC) in comparison with dibutyl phthalate (DBP), known to induce MNC in mouse gonocytes in vivo. We performed image-based single-cell high content analysis (HCA) in the mouse spermatogonia C18-4 cells treated with various concentrations of BPAF and DBP. BPAF as low as 5 µM was cytotoxic and resulted in 40% cell death of the C18-4 cells after 72 h. HCA revealed that 5 µM of BPAF significantly increased the number of MNC by an average of 3.6-fold. DBP did not induce MNC in the doses we tested. Cytokinesis is tightly regulated by various small GTPase-signaling pathways. We, therefore, tested 5 selective GTPase inhibitors and found that Y27632, a ROCK inhibitor, reduced the BPAF-induced MNC by nearly 30%. Inhibition of Cdc42 by ML141 conversely increased the number of BPAF-induced MNC. We performed a hierarchical cluster analysis of the HCA data and demonstrated that the cytoskeletal disruption by BPAF was reversely modified by Y27632. We found that mRNA expression of genes regulating Rho and Rac GTPase activities, p190RhoGap and MgcRacGap, was altered in BPAF-treated C18-4 cells in a time-dependent manner. Multinucleated gonocytes are often indicators of disease pathologies. Our results provided the first evidence of mechanisms of the dual toxicity by BPAF to male germ cells, which induces chromosome endoreplication without the coordinated cytokinetic cellular components. The unique genotoxic mechanism of forming multinucleated germ cells suggests a novel mode of action in the male repro-toxicity concern over the increasingly ubiquitous presence of BPA analogs.
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Affiliation(s)
- Chelin Hu
- University of New Mexico, Albuquerque, New Mexico 87131, USA
| | | | - Lei Yin
- ReproTox Biotech LLC, Albuquerque, New Mexico 87131, USA
| | - Xiaozhong Yu
- University of New Mexico, Albuquerque, New Mexico 87131, USA
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Alhasnani MA, Loeb S, Hall SJ, Caruolo Z, Simmonds F, Solano AE, Spade DJ. Interaction between mono-(2-ethylhexyl) phthalate and retinoic acid alters Sertoli cell development during fetal mouse testis cord morphogenesis. Curr Res Toxicol 2022; 3:100087. [PMID: 36189433 PMCID: PMC9520016 DOI: 10.1016/j.crtox.2022.100087] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 09/17/2022] [Accepted: 09/17/2022] [Indexed: 11/24/2022] Open
Abstract
Phthalic acid esters (phthalates) are a class of industrial chemicals that cause developmental and reproductive toxicity, but there are significant gaps in knowledge of phthalate toxicity mechanisms. There is evidence that phthalates disrupt retinoic acid signaling in the fetal testis, potentially disrupting control of spatial and temporal patterns of testis development. Our goal was to determine how a phthalate would interact with retinoic acid signaling during fetal mouse testis development. We hypothesized that mono-(2-ethylhexyl) phthalate (MEHP) would exacerbate the adverse effect of all-trans retinoic acid (ATRA) on seminiferous cord development in the mouse fetal testis. To test this hypothesis, gestational day (GD) 14 C57BL/6 mouse testes were isolated and cultured on media containing MEHP, ATRA, or a combination of both compounds. Cultured testes were collected for global transcriptome analysis after one day in culture and for histology and immunofluorescent analysis of Sertoli cell differentiation after three days in culture. ATRA disrupted seminiferous cord morphogenesis and induced aberrant FOXL2 expression. MEHP alone had no significant effect on cord development, but combined exposure to MEHP and ATRA increased the number of FOXL2-positive cells, reduced seminiferous cord number, and increased testosterone levels, beyond the effect of ATRA alone. In RNA-seq analysis, ATRA treatment and MEHP treatment resulted in differential expression of genes 510 and 134 genes, respectively, including 70 common differentially expressed genes (DEGs) between the two treatments, including genes with known roles in fetal testis development. MEHP DEGs included RAR target genes, genes involved in angiogenesis, and developmental patterning genes, including members of the homeobox superfamily. These results support the hypothesis that MEHP modulates retinoic acid signaling in the mouse fetal testis and provide insight into potential mechanisms by which phthalates disrupt seminiferous cord morphogenesis.
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Key Words
- ATRA, All-trans retinoic acid. CAS # 302-79-4
- DMSO, dimethyl sulfoxide
- Fetal testis development
- GD, gestational day
- GO, Gene Ontology
- IPA, Ingenuity Pathway Analysis
- ITCN, Image-based Tool for Counting Nuclei
- MEHP, mono-(2-ethylheyxl) phthalate. CAS # 4376-20-9
- MNGs, multinucleated germ cells
- PVC, polyvinyl chloride
- Phthalate toxicity
- Retinoic acid
- Sertoli cell
- TDS, testicular dysgenesis syndrome
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Affiliation(s)
- Maha A. Alhasnani
- Department of Pathology and Laboratory Medicine, Brown University, Box G-E5, Providence, RI 02912, USA
| | - Skylar Loeb
- Department of Pathology and Laboratory Medicine, Brown University, Box G-E5, Providence, RI 02912, USA
| | - Susan J. Hall
- Department of Pathology and Laboratory Medicine, Brown University, Box G-E5, Providence, RI 02912, USA
| | - Zachary Caruolo
- Department of Pathology and Laboratory Medicine, Brown University, Box G-E5, Providence, RI 02912, USA
| | - Faith Simmonds
- Department of Pathology and Laboratory Medicine, Brown University, Box G-E5, Providence, RI 02912, USA
| | - Amanda E. Solano
- Department of Pathology and Laboratory Medicine, Brown University, Box G-E5, Providence, RI 02912, USA
| | - Daniel J. Spade
- Department of Pathology and Laboratory Medicine, Brown University, Box G-E5, Providence, RI 02912, USA
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Cargnelutti F, Di Nisio A, Pallotti F, Sabovic I, Spaziani M, Tarsitano MG, Paoli D, Foresta C. Effects of endocrine disruptors on fetal testis development, male puberty, and transition age. Endocrine 2021; 72:358-374. [PMID: 32757113 PMCID: PMC8128728 DOI: 10.1007/s12020-020-02436-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 07/23/2020] [Indexed: 10/24/2022]
Abstract
PURPOSE Endocrine disruptors (EDs) are exogenous substances able to impair endocrine system; consequently, they may cause numerous adverse effects. Over the last years, particular focus has been given to their harmful effects on reproductive system, but very little is known, especially in males. The aim of this review is to discuss the detrimental effects of EDs exposure on fetal testis development, male puberty, and transition age. METHODS A search for the existing literature focusing on the impact of EDs on fetal testis development, male puberty, andrological parameters (anogenital distance, penile length, and testicular volume), and testicular cancer with particular regard to pubertal age provided the most current information available for this review. Human evidence-based reports were given priority over animal and in vitro experimental results. Given the paucity of available articles on this subject, all resources were given careful consideration. RESULTS Information about the consequences associated with EDs exposure in the current literature is limited and often conflicting, due to the scarcity of human studies and their heterogeneity. CONCLUSIONS We conclude that current evidence does not clarify the impact of EDs on human male reproductive health, although severe harmful effects had been reported in animals. Despite controversial results, overall conclusion points toward a positive association between exposure to EDs and reproductive system damage. Further long-term studies performed on wide number of subjects are necessary in order to identify damaging compounds and remove them from the environment.
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Affiliation(s)
- Francesco Cargnelutti
- Laboratory of Seminology-Sperm Bank "Loredana Gandini", Department of Experimental Medicine, "Sapienza" University of Rome, Viale del Policlinico 155, 00161, Rome, Italy
| | - Andrea Di Nisio
- Department of Medicine, Operative Unit of Andrology and Medicine of Human Reproduction, University of Padova, Via Giustiniani, 2, 35128, Padua, Italy
| | - Francesco Pallotti
- Laboratory of Seminology-Sperm Bank "Loredana Gandini", Department of Experimental Medicine, "Sapienza" University of Rome, Viale del Policlinico 155, 00161, Rome, Italy
| | - Iva Sabovic
- Department of Medicine, Operative Unit of Andrology and Medicine of Human Reproduction, University of Padova, Via Giustiniani, 2, 35128, Padua, Italy
| | - Matteo Spaziani
- Department of Experimental Medicine, "Sapienza" University of Rome, Viale del Policlinico 155, 00161, Rome, Italy
| | - Maria Grazia Tarsitano
- Department of Experimental Medicine, "Sapienza" University of Rome, Viale del Policlinico 155, 00161, Rome, Italy
| | - Donatella Paoli
- Laboratory of Seminology-Sperm Bank "Loredana Gandini", Department of Experimental Medicine, "Sapienza" University of Rome, Viale del Policlinico 155, 00161, Rome, Italy.
| | - Carlo Foresta
- Department of Medicine, Operative Unit of Andrology and Medicine of Human Reproduction, University of Padova, Via Giustiniani, 2, 35128, Padua, Italy
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Bell S, Zsom A, Conley J, Spade D. Automated identification of multinucleated germ cells with U-Net. PLoS One 2020; 15:e0229967. [PMID: 32645012 PMCID: PMC7347116 DOI: 10.1371/journal.pone.0229967] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 05/29/2020] [Indexed: 11/30/2022] Open
Abstract
Phthalic acid esters (phthalates) are male reproductive toxicants, which exert their most potent toxicity during fetal development. In the fetal rat, exposure to phthalates reduces testosterone biosynthesis, alters the development of seminiferous cords and other male reproductive tissues, and induces the formation of abnormal multinucleated germ cells (MNGs). Identification of MNGs is a time-intensive process, and it requires specialized training to identify MNGs in histological sections. As a result, MNGs are not routinely quantified in phthalate toxicity experiments. In order to speed up and standardize this process, we have developed an improved method for automated detection of MNGs. Using hand-labeled histological section images with human-identified MNGs, we trained a convolutional neural network with a U-Net architecture to identify MNGs on unlabeled images. With unseen hand-labeled images not used in model training, we assessed the performance of the model, using five different configurations of the data. On average, the model reached near human accuracy, and in the best model, it exceeded it. The use of automated image analysis will allow data on this histopathological endpoint to be more readily collected for analysis of phthalate toxicity. Our trained model application code is available for download at github.com/brown-ccv/mngcount.
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Affiliation(s)
- Samuel Bell
- Brown University, Providence, RI, United States of America
- Planetary Science Institute, Tucson, AZ, United States of America
- * E-mail:
| | - Andras Zsom
- Brown University, Providence, RI, United States of America
| | - Justin Conley
- U.S. Environmental Protection Agency/ORD/CPHEA/PHITD/RDTB, Research Triangle Park, NC, United States of America
| | - Daniel Spade
- Brown University, Providence, RI, United States of America
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Spade DJ, Hall SJ, Wortzel JD, Reyes G, Boekelheide K. All-trans Retinoic Acid Disrupts Development in Ex Vivo Cultured Fetal Rat Testes. II: Modulation of Mono-(2-ethylhexyl) Phthalate Toxicity. Toxicol Sci 2020; 168:149-159. [PMID: 30476341 DOI: 10.1093/toxsci/kfy283] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Humans are universally exposed to low levels of phthalate esters (phthalates), which are used to plasticize polyvinyl chloride. Phthalates exert adverse effects on the development of seminiferous cords in the fetal testis through unknown toxicity pathways. To investigate the hypothesis that phthalates alter seminiferous cord development by disrupting retinoic acid (RA) signaling in the fetal testis, gestational day 15 fetal rat testes were exposed for 1-3 days to 10-6 M all-trans retinoic acid (ATRA) alone or in combination with 10-6-10-4 M mono-(2-ethylhexyl) phthalate (MEHP) in ex vivo culture. As previously reported, exogenous ATRA reduced seminiferous cord number. This effect was attenuated in a concentration-dependent fashion by MEHP co-exposure. ATRA and MEHP-exposed testes were depleted of DDX4-positive germ cells but not Sertoli cells. MEHP alone enhanced the expression of the RA receptor target Rbp1 and the ovary development-associated genes Wnt4 and Nr0b1, and suppressed expression of the Leydig cell marker, Star, and the germ cell markers, Ddx4 and Pou5f1. In co-exposures, MEHP predominantly enhanced the gene expression effects of ATRA, but the Wnt4 and Nr0b1 concentration-responses were nonlinear. Similarly, ATRA increased the number of cells expressing the granulosa cell marker FOXL2 in testis cultures, but this induction was attenuated by addition of MEHP. These results indicate that MEHP can both enhance and inhibit actions of ATRA during fetal testis development and provide evidence that RA signaling is a target for phthalate toxicity in the fetal testis.
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Affiliation(s)
- Daniel J Spade
- Department of Pathology and Laboratory Medicine, Brown University, Providence, Rhode Island 02912
| | - Susan J Hall
- Department of Pathology and Laboratory Medicine, Brown University, Providence, Rhode Island 02912
| | - Jeremy D Wortzel
- Department of Pathology and Laboratory Medicine, Brown University, Providence, Rhode Island 02912
| | - Gerardo Reyes
- Department of Pathology and Laboratory Medicine, Brown University, Providence, Rhode Island 02912.,Division of Natural Sciences, College of Mount Saint Vincent, Riverdale, New York 10471
| | - Kim Boekelheide
- Department of Pathology and Laboratory Medicine, Brown University, Providence, Rhode Island 02912
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9
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Yin L, Siracusa JS, Measel E, Guan X, Edenfield C, Liang S, Yu X. High-Content Image-Based Single-Cell Phenotypic Analysis for the Testicular Toxicity Prediction Induced by Bisphenol A and Its Analogs Bisphenol S, Bisphenol AF, and Tetrabromobisphenol A in a Three-Dimensional Testicular Cell Co-culture Model. Toxicol Sci 2020; 173:313-335. [PMID: 31750923 PMCID: PMC6986343 DOI: 10.1093/toxsci/kfz233] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Emerging data indicate that structural analogs of bisphenol A (BPA) such as bisphenol S (BPS), tetrabromobisphenol A (TBBPA), and bisphenol AF (BPAF) have been introduced into the market as substitutes for BPA. Our previous study compared in vitro testicular toxicity using murine C18-4 spermatogonial cells and found that BPAF and TBBPA exhibited higher spermatogonial toxicities as compared with BPA and BPS. Recently, we developed a novel in vitro three-dimensional (3D) testicular cell co-culture model, enabling the classification of reproductive toxic substances. In this study, we applied the testicular cell co-culture model and employed a high-content image (HCA)-based single-cell analysis to further compare the testicular toxicities of BPA and its analogs. We also developed a machine learning (ML)-based HCA pipeline to examine the complex phenotypic changes associated with testicular toxicities. We found dose- and time-dependent changes in a wide spectrum of adverse endpoints, including nuclear morphology, DNA synthesis, DNA damage, and cytoskeletal structure in a single-cell-based analysis. The co-cultured testicular cells were more sensitive than the C18 spermatogonial cells in response to BPA and its analogs. Unlike conventional population-averaged assays, single-cell-based assays not only showed the levels of the averaged population, but also revealed changes in the sub-population. Machine learning-based phenotypic analysis revealed that treatment of BPA and its analogs resulted in the loss of spatial cytoskeletal structure, and an accumulation of M phase cells in a dose- and time-dependent manner. Furthermore, treatment of BPAF-induced multinucleated cells, which were associated with altered DNA damage response and impaired cellular F-actin filaments. Overall, we demonstrated a new and effective means to evaluate multiple toxic endpoints in the testicular co-culture model through the combination of ML and high-content image-based single-cell analysis. This approach provided an in-depth analysis of the multi-dimensional HCA data and provided an unbiased quantitative analysis of the phenotypes of interest.
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Affiliation(s)
- Lei Yin
- ReproTox Biotech LLC, Athens, Georgia 30602
| | - Jacob Steven Siracusa
- Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, Georgia
| | - Emily Measel
- Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, Georgia
| | | | - Clayton Edenfield
- Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, Georgia
| | - Shenxuan Liang
- Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, Georgia
| | - Xiaozhong Yu
- Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, Georgia
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Baken KA, Lambrechts N, Remy S, Mustieles V, Rodríguez-Carrillo A, Neophytou CM, Olea N, Schoeters G. A strategy to validate a selection of human effect biomarkers using adverse outcome pathways: Proof of concept for phthalates and reproductive effects. ENVIRONMENTAL RESEARCH 2019; 175:235-256. [PMID: 31146096 DOI: 10.1016/j.envres.2019.05.013] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 05/09/2019] [Accepted: 05/10/2019] [Indexed: 05/21/2023]
Abstract
Human biomonitoring measures the concentrations of environmental chemicals or their metabolites in body fluids or tissues. Complementing exposure biomarkers with mechanistically based effect biomarkers may further elucidate causal pathways between chemical exposure and adverse health outcomes. We combined information on effect biomarkers previously implemented in human observational studies with mechanisms of action reported in experimental studies and with information from published Adverse Outcome Pathways (AOPs), focusing on adverse reproductive effects of phthalate exposure. Phthalates constitute a group of chemicals that are ubiquitous in consumer products and have been related to a wide range of adverse health effects. As a result of a comprehensive literature search, we present an overview of effect biomarkers for reproductive toxicity that are substantiated by mechanistic information. The activation of several receptors, such as PPARα, PPARγ, and GR, may initiate events leading to impaired male and female fertility as well as other adverse effects of phthalate exposure. Therefore, these receptors appear as promising targets for the development of novel effect biomarkers. The proposed strategy connects the fields of epidemiology and toxicology and may strengthen the weight of evidence in observational studies that link chemical exposures to health outcomes.
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Affiliation(s)
- Kirsten A Baken
- Unit Health, Flemish Institute for Technological Research (VITO NV), Mol, Belgium.
| | - Nathalie Lambrechts
- Unit Health, Flemish Institute for Technological Research (VITO NV), Mol, Belgium
| | - Sylvie Remy
- Unit Health, Flemish Institute for Technological Research (VITO NV), Mol, Belgium; Department of Epidemiology and Social Medicine, University of Antwerp, Antwerp, Belgium
| | - Vicente Mustieles
- Biosanitary Research Institute of Granada (ibs.GRANADA), University Hospitals of Granada, Granada, Spain; Center for Biomedical Research (CIBM), University of Granada, Granada, Spain; Consortium for Biomedical Research in Epidemiology & Public Health (CIBERESP), Spain
| | | | - Christiana M Neophytou
- Department of Biological Sciences, School of Pure and Applied Sciences, University of Cyprus, Nicosia, Cyprus
| | - Nicolas Olea
- Biosanitary Research Institute of Granada (ibs.GRANADA), University Hospitals of Granada, Granada, Spain; Center for Biomedical Research (CIBM), University of Granada, Granada, Spain; Consortium for Biomedical Research in Epidemiology & Public Health (CIBERESP), Spain
| | - Greet Schoeters
- Unit Health, Flemish Institute for Technological Research (VITO NV), Mol, Belgium; Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium; Department of Environmental Medicine, Institute of Public Health, University of Southern Denmark, Odense, Denmark
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11
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Rashad MM, Galal MK, EL-Behairy AM, Gouda EM, Moussa SZ. Maternal exposure to di-n-butyl phthalate induces alterations of c-Myc gene, some apoptotic and growth related genes in pups’ testes. Toxicol Ind Health 2018; 34:744-752. [DOI: 10.1177/0748233718791623] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The aim of this study was to investigate the effects of maternal exposure to di-( n-butyl) phthalate (DBP) on testicular development and function in pre-pubertal and post-pubertal male rat offspring. Fourteen pregnant female rats were equally divided into two groups: a control group and a DBP-treated group. During gestation day (GD) 12 to postnatal day (PND) 14, the control group was administered 1 ml/day corn oil, and the DBP-treated group was administered DBP 500 mg/kg/day by oral gavage. On PND 25 (pre-puberty) and PND 60 (post-puberty), blood for serum and the testes were collected from five male offspring of each group. To determine the relationship between the methylation state of the c-Myc promoter and the expression of the c-Myc gene, some apoptotic-related genes, such as p53 and Bax, the anti-apoptotic Bcl-2 gene, and some growth arrest-related genes, such as BRD7 and GAS1, were examined. Compared with the control ( p < 0.05), at pre-puberty, DBP induces c-Myc hyper-methylation with significant downregulation for c-Myc, p53, Bax genes, and significant upregulation for Bcl-2, BRD7, and GAS1, while at post puberty, the methylation state and expression of c-Myc and apoptosis-related genes returned to control levels in the same sequence with the fold change in the expression of BRD7 and GAS1 genes. These findings suggest that DBP induced a transient pre-pubertal increase in c-Myc promoter methylation that may be associated with disruption of both apoptotic and growth mechanisms in the testes.
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Affiliation(s)
- Maha M Rashad
- Biochemistry Department, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt
| | - Mona K Galal
- Biochemistry Department, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt
| | - Adel M EL-Behairy
- Biochemistry Department, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt
| | - Eman M Gouda
- Biochemistry Department, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt
| | - Said Z Moussa
- Biochemistry Department, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt
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12
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Validation of an automated counting procedure for phthalate-induced testicular multinucleated germ cells. Toxicol Lett 2018; 290:55-61. [PMID: 29571896 DOI: 10.1016/j.toxlet.2018.03.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 03/06/2018] [Accepted: 03/18/2018] [Indexed: 12/12/2022]
Abstract
In utero exposure to certain phthalate esters results in testicular toxicity, characterized at the tissue level by induction of multinucleated germ cells (MNGs) in rat, mouse, and human fetal testis. Phthalate exposures also result in a decrease in testicular testosterone in rats. The anti-androgenic effects of phthalates have been more thoroughly quantified than testicular pathology due to the significant time requirement associated with manual counting of MNGs on histological sections. An automated counting method was developed in ImageJ to quantify MNGs in digital images of hematoxylin-stained rat fetal testis tissue sections. Timed pregnant Sprague Dawley rats were exposed by daily oral gavage from gestation day 17 to 21 with one of eight phthalate test compounds or corn oil vehicle. Both the manual counting method and the automated image analysis method identified di-n-butyl phthalate, butyl benzyl phthalate, dipentyl phthalate, and di-(2-ethylhexyl) phthalate as positive for induction of MNGs. Dimethyl phthalate, diethyl phthalate, the brominated phthalate di-(2-ethylhexyl) tetrabromophthalate, and dioctyl terephthalate were negative. The correlation between automated and manual scoring metrics was high (r = 0.923). Results of MNG analysis were consistent with these compounds' anti-androgenic activities, which were confirmed in an ex vivo testosterone production assay. In conclusion, we have developed a reliable image analysis method that can be used to facilitate dose-response studies for the reproducible induction of MNGs by in utero phthalate exposure.
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13
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Xenotransplantation as a model for human testicular development. Differentiation 2017; 97:44-53. [DOI: 10.1016/j.diff.2017.09.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 08/08/2017] [Accepted: 09/05/2017] [Indexed: 11/20/2022]
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14
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Dai MS, Hall SJ, Vantangoli Policelli MM, Boekelheide K, Spade DJ. Spontaneous testicular atrophy occurs despite normal spermatogonial proliferation in a Tp53 knockout rat. Andrology 2017; 5:1141-1152. [PMID: 28834365 DOI: 10.1111/andr.12409] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 06/12/2017] [Accepted: 06/27/2017] [Indexed: 12/19/2022]
Abstract
The tumor suppressor protein p53 (TP53) has many functions in cell cycle regulation, apoptosis, and DNA damage repair and is also involved in spermatogenesis in the mouse. To evaluate the role of p53 in spermatogenesis in the rat, we characterized testis biology in adult males of a novel p53 knockout rat (SD-Tp53tm1sage ). p53 knockout rats exhibited variable levels of testicular atrophy, including significantly decreased testis weights, atrophic seminiferous tubules, decreased seminiferous tubule diameter, and elevated spermatocyte TUNEL labeling rates, indicating a dysfunction in spermatogenesis. Phosphorylated histone H2AX protein levels and distribution were similar in the non-atrophic seminiferous tubules of both genotypes, showing evidence of pre-synaptic DNA double-strand breaks in leptotene and zygotene spermatocytes, preceding cell death in p53 knockout rat testes. Quantification of the spermatogonial stem cell (SSC) proliferation rate with bromodeoxyuridine (BrdU) labeling, in addition to staining with the undifferentiated type A spermatogonial marker GDNF family receptor alpha-1 (GFRA1), indicated that the undifferentiated spermatogonial population was normal in p53 knockout rats. Following exposure to 0.5 or 5 Gy X-ray, p53 knockout rats exhibited no germ cell apoptotic response beyond their unirradiated phenotype, while germ cell death in wild-type rat testes was elevated to a level similar to the unexposed p53 knockout rats. This study indicates that seminiferous tubule atrophy occurs following spontaneous, elevated levels of spermatocyte death in the p53 knockout rat. This phenomenon is variable across individual rats. These results indicate a critical role for p53 in rat germ cell survival and spermatogenesis.
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Affiliation(s)
- Matthew S Dai
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, USA
| | - Susan J Hall
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, USA
| | | | - Kim Boekelheide
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, USA
| | - Daniel J Spade
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, USA
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15
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Dekant W, Bridges J. Assessment of reproductive and developmental effects of DINP, DnHP and DCHP using quantitative weight of evidence. Regul Toxicol Pharmacol 2016; 81:397-406. [DOI: 10.1016/j.yrtph.2016.09.032] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 09/22/2016] [Accepted: 09/27/2016] [Indexed: 10/20/2022]
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Boisvert A, Jones S, Issop L, Erythropel HC, Papadopoulos V, Culty M. In vitro functional screening as a means to identify new plasticizers devoid of reproductive toxicity. ENVIRONMENTAL RESEARCH 2016; 150:496-512. [PMID: 27423704 DOI: 10.1016/j.envres.2016.06.033] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Revised: 06/19/2016] [Accepted: 06/20/2016] [Indexed: 06/06/2023]
Abstract
Plasticizers are indispensable additives providing flexibility and malleability to plastics. Among them, several phthalates, including di (2-ethylhexyl) phthalate (DEHP), have emerged as endocrine disruptors, leading to their restriction in consumer products and creating a need for new, safer plasticizers. The goal of this project was to use in vitro functional screening tools to select novel non-toxic plasticizers suitable for further in vivo evaluation. A panel of novel compounds with satisfactory plasticizer properties and biodegradability were tested, along with several commercial plasticizers, such as diisononyl-cyclohexane-1,2-dicarboxylate (DINCH®). MEHP, the monoester metabolite of DEHP was also included as reference compound. Because phthalates target mainly testicular function, including androgen production and spermatogenesis, we used the mouse MA-10 Leydig and C18-4 spermatogonial cell lines as surrogates to examine cell survival, proliferation, steroidogenesis and mitochondrial integrity. The most promising compounds were further assessed on organ cultures of rat fetal and neonatal testes, corresponding to sensitive developmental windows. Dose-response studies revealed the toxicity of most maleates and fumarates, while identifying several dibenzoate and succinate plasticizers as innocuous on Leydig and germ cells. Interestingly, DINCH®, a plasticizer marketed as a safe alternative to phthalates, exerted a biphasic effect on steroid production in MA-10 and fetal Leydig cells. MEHP was the only plasticizer inducing the formation of multinucleated germ cells (MNG) in organ culture. Overall, organ cultures corroborated the cell line data, identifying one dibenzoate and one succinate as the most promising candidates. The adoption of such collaborative approaches for developing new chemicals should help prevent the development of compounds potentially harmful to human health.
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Affiliation(s)
- Annie Boisvert
- The Research Institute of the McGill University Health Centre, McGill University, Montreal, Quebec, Canada H4A 3J1; Department of Medicine, McGill University, Montreal, Quebec, Canada H4A 3J1
| | - Steven Jones
- The Research Institute of the McGill University Health Centre, McGill University, Montreal, Quebec, Canada H4A 3J1; Department of Medicine, McGill University, Montreal, Quebec, Canada H4A 3J1
| | - Leeyah Issop
- The Research Institute of the McGill University Health Centre, McGill University, Montreal, Quebec, Canada H4A 3J1; Department of Medicine, McGill University, Montreal, Quebec, Canada H4A 3J1
| | - Hanno C Erythropel
- Department of Chemical Engineering, McGill University, Montreal, Quebec, Canada H4A 3J1
| | - Vassilios Papadopoulos
- The Research Institute of the McGill University Health Centre, McGill University, Montreal, Quebec, Canada H4A 3J1; Department of Medicine, McGill University, Montreal, Quebec, Canada H4A 3J1; Department of Pharmacology & Therapeutics, McGill University, Montreal, Quebec, Canada H4A 3J1
| | - Martine Culty
- The Research Institute of the McGill University Health Centre, McGill University, Montreal, Quebec, Canada H4A 3J1; Department of Medicine, McGill University, Montreal, Quebec, Canada H4A 3J1; Department of Pharmacology & Therapeutics, McGill University, Montreal, Quebec, Canada H4A 3J1.
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