1
|
Wakui S, Sato D, Okayama Y, Kansaku N, Muto T. Prenatal exposure to di(n-butyl) phthalate delays the spermatogenic cycle in rats: Investigation using a BrdU-injection method. Reprod Toxicol 2022; 109:135-146. [PMID: 35032615 DOI: 10.1016/j.reprotox.2022.01.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 12/31/2021] [Accepted: 01/09/2022] [Indexed: 11/26/2022]
Abstract
Di(n-butyl) phthalate (DBP) esters are plasticizers that are used to provide transparency and flexibility in household plastic products but can easily leach out to contaminate organisms and the environment. We investigated whether prenatal DBP exposure affects spermatogenesis in rats. Pregnant Sprague-Dawley rats were injected with DBP 10, 50, and 100 mg/kg, or vehicle, administered intragastrically, on gestation days 12-21. At 9 or 17 weeks, 5-bromodeoxyuridine (BrdU) 50 mg/kg was injected intraperitoneally, and one testis was removed 3 h later. The remaining testis was excised 12.95 days + 3 h after the BrdU injection. Immunohistochemical analysis of BrdU was performed with periodic acid-Schiff and hematoxylin counterstaining for a quantitative analysis of the delay in one cycle of spermatogenesis. The DBP 100 mg group showed that the ratio of the appearance of seminiferous tubules in stages VII and VIII were significantly decreased, but those of stages IX and X were significantly increased compared to the Vehicle group. The reference value for the duration of spermatogenesis per cycle was set at 310.8 h. The DBP 100 mg group showed a significant delay in the duration of one cycle of spermatogenesis (16.95 h at puberty and 19.01 h at adulthood) compared with the Vehicle group. This study determined that F1-generation rats with prenatal DBP 100 mg exposure revealed significant accumulation of spermatogenic cells at stages IX to X in the second and third cycles, and the significant delay in the duration of spermatogenesis was more prominent at adulthood than in puberty.
Collapse
Affiliation(s)
- Shin Wakui
- Laboratory of Toxicology, Department of Animal Science and Biotechnology, Azabu University School of Veterinary Medicine, Kanagawa, 252-5201, Japan.
| | - Daisuke Sato
- Laboratory of Toxicology, Department of Animal Science and Biotechnology, Azabu University School of Veterinary Medicine, Kanagawa, 252-5201, Japan
| | - Yuya Okayama
- Laboratory of Toxicology, Department of Animal Science and Biotechnology, Azabu University School of Veterinary Medicine, Kanagawa, 252-5201, Japan
| | - Norio Kansaku
- Laboratory of Toxicology, Department of Animal Science and Biotechnology, Azabu University School of Veterinary Medicine, Kanagawa, 252-5201, Japan
| | - Tomoko Muto
- Laboratory of Toxicology, Department of Animal Science and Biotechnology, Azabu University School of Veterinary Medicine, Kanagawa, 252-5201, Japan
| |
Collapse
|
2
|
Ma T, Zhou Y, Xia Y, Jin H, Wang B, Wu J, Ding J, Wang J, Yang F, Han X, Li D. Environmentally relevant perinatal exposure to DBP disturbs testicular development and puberty onset in male mice. Toxicology 2021; 459:152860. [PMID: 34280466 DOI: 10.1016/j.tox.2021.152860] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 07/12/2021] [Accepted: 07/15/2021] [Indexed: 02/06/2023]
Abstract
Di-n-butyl phthalate (DBP) is considered as a potential modifier of puberty. However, different results indicate that DBP plays an accelerated, delayed, or neutral role in the initiation of puberty. Furthermore, whether the effect of DBP on puberty will disrupt the function of reproductive system in the adults is still ambiguous. Therefore, we aimed to investigate the effect of maternal exposure to DBP on the onset of puberty in male offspring mice and the subsequent changes in the development of reproductive system. Here, pregnant mice were treated with 0 (control), 50, 250, or 500 mg/kg/day DBP in 1 mL/kg corn oil administered daily by oral gavage from gestation day (GD) 12.5 to parturition. Compared with the control group, the 50 mg/kg/day DBP group accelerated puberty onset and testicular development were quite remarkable in male offspring mice during early puberty. Furthermore, in 22-day male offspring mice, 50 mg/kg/day DBP induced increased levels of gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone in serum, and promoted the expression of steroidogenesis-related genes in the testes. Testicular Leydig cells (LCs) were isolated from the testes of 3-week-old mice and treated with 0 (control), 0.1, 1 mM monobutyl phthalate (MBP, the active metabolite of DBP) for 24 h. Consistent with the in vivo results, the expression of steroidogenesis-related genes and testosterone production were increased in LCs following exposure to 0.1 mM MBP. In adulthood, testes of the male offspring mice exposed to all doses of DBP exhibited adverse morphology compared with the control group. These results demonstrated that maternal exposure to 50 mg/kg/day DBP induced earlier puberty and precocious development of the testis, and eventually damaged the reproductive system in the later life.
Collapse
Affiliation(s)
- Tan Ma
- Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing, Jiangsu, 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, Jiangsu, 210093, China
| | - Yuan Zhou
- Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing, Jiangsu, 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, Jiangsu, 210093, China
| | - Yunhui Xia
- Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing, Jiangsu, 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, Jiangsu, 210093, China
| | - Haibo Jin
- Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing, Jiangsu, 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, Jiangsu, 210093, China
| | - Bo Wang
- Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing, Jiangsu, 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, Jiangsu, 210093, China; Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu Province, China
| | - Jiang Wu
- Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing, Jiangsu, 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, Jiangsu, 210093, China
| | - Jie Ding
- Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing, Jiangsu, 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, Jiangsu, 210093, China
| | - Junli Wang
- Center of Reproductive Medicine, Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, 533000, Guangxi, China
| | - Fenglian Yang
- School of Pharmacy, Youjiang Medical University for Nationalities, Baise, 533000, Guangxi, China
| | - Xiaodong Han
- Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing, Jiangsu, 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, Jiangsu, 210093, China
| | - Dongmei Li
- Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing, Jiangsu, 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, Jiangsu, 210093, China.
| |
Collapse
|
3
|
Scarano WR, Bedrat A, Alonso-Costa LG, Aquino AM, Fantinatti B, Justulin LA, Barbisan LF, Freire PP, Flaws JA, Bernardo L. Exposure to an environmentally relevant phthalate mixture during prostate development induces microRNA upregulation and transcriptome modulation in rats. Toxicol Sci 2019; 171:84-97. [PMID: 31199487 PMCID: PMC6736208 DOI: 10.1093/toxsci/kfz141] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 05/14/2019] [Accepted: 06/02/2019] [Indexed: 12/14/2022] Open
Abstract
Environmental exposure to phthalates during intrauterine development might increase susceptibility to neoplasms in reproductive organs such as the prostate. Although studies have suggested an increase in prostatic lesions in adult animals submitted to perinatal exposure to phthalates, the molecular pathways underlying these alterations remain unclear. Genome-wide levels of mRNAs and miRNAs were monitored with RNA-seq to determine if perinatal exposure to a phthalate mixture in pregnant rats is capable of modifying gene expression expression during prostate development of the filial generation. The mixture contains diethyl-phthalate, di-(2-ethylhexyl)-phthalate, dibutyl-phthalate, di-isononyl-phthalate, di-isobutyl-phthalate, and benzylbutyl-phthalate. Pregnant females were divided into 4 groups and orally dosed daily from GD10 to PND21 with corn oil (Control:C) or the phthalate mixture at three doses (20 μg/kg/d:T1; 200 μg/kg/d:T2; 200 mg/kg/d:T3). The phthalate mixture decreased anogenital distance, prostate weight and decreased testosterone level at the lowest exposure dose at PND22. The mixture also increased inflammatory foci and focal hyperplasia incidence at PND120. miR-184 was upregulated in all treated groups in relation to control and miR-141-3p was only upregulated at the lowest dose. In addition, 120 genes were deregulated at the lowest dose with several of these genes related to developmental, differentiation and oncogenesis. The data indicate that phthalate exposure at lower doses can cause greater gene expression modulation as well as other downstream phenotypes than exposure at higher doses. A significant fraction of the downregulated genes were predicted to be targets of miR-141-3p and miR-184, both of which were induced at the lower exposure doses.
Collapse
Affiliation(s)
- Wellerson R Scarano
- São Paulo State University (UNESP), Institute of Biosciences, Department of Morphology, Botucatu, SP, Brazil.,Harvard T. H. Chan School of Public Health, Department of Environmental Health & Molecular and Integrative Physiological Sciences Program, Boston, MA, USA
| | - Amina Bedrat
- Harvard T. H. Chan School of Public Health, Department of Environmental Health & Molecular and Integrative Physiological Sciences Program, Boston, MA, USA
| | - Luiz G Alonso-Costa
- São Paulo State University (UNESP), Institute of Biosciences, Department of Morphology, Botucatu, SP, Brazil
| | - Ariana M Aquino
- São Paulo State University (UNESP), Institute of Biosciences, Department of Morphology, Botucatu, SP, Brazil
| | - Bruno Fantinatti
- São Paulo State University (UNESP), Institute of Biosciences, Department of Morphology, Botucatu, SP, Brazil
| | - Luis A Justulin
- São Paulo State University (UNESP), Institute of Biosciences, Department of Morphology, Botucatu, SP, Brazil
| | - Luis F Barbisan
- São Paulo State University (UNESP), Institute of Biosciences, Department of Morphology, Botucatu, SP, Brazil
| | - Paula P Freire
- São Paulo State University (UNESP), Institute of Biosciences, Department of Morphology, Botucatu, SP, Brazil
| | - Jodi A Flaws
- Department of Comparative Biosciences, University of Illinois at Urbana-Champaign, IL
| | - Lemos Bernardo
- Harvard T. H. Chan School of Public Health, Department of Environmental Health & Molecular and Integrative Physiological Sciences Program, Boston, MA, USA
| |
Collapse
|
4
|
Shin N, Cuenca L, Karthikraj R, Kannan K, Colaiácovo MP. Assessing effects of germline exposure to environmental toxicants by high-throughput screening in C. elegans. PLoS Genet 2019; 15:e1007975. [PMID: 30763314 PMCID: PMC6375566 DOI: 10.1371/journal.pgen.1007975] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 01/19/2019] [Indexed: 02/07/2023] Open
Abstract
Chemicals that are highly prevalent in our environment, such as phthalates and pesticides, have been linked to problems associated with reproductive health. However, rapid assessment of their impact on reproductive health and understanding how they cause such deleterious effects, remain challenging due to their fast-growing numbers and the limitations of various current toxicity assessment model systems. Here, we performed a high-throughput screen in C. elegans to identify chemicals inducing aneuploidy as a result of impaired germline function. We screened 46 chemicals that are widely present in our environment, but for which effects in the germline remain poorly understood. These included pesticides, phthalates, and chemicals used in hydraulic fracturing and crude oil processing. Of the 46 chemicals tested, 41% exhibited levels of aneuploidy higher than those detected for bisphenol A (BPA), an endocrine disruptor shown to affect meiosis, at concentrations correlating well with mammalian reproductive endpoints. We further examined three candidates eliciting aneuploidy: dibutyl phthalate (DBP), a likely endocrine disruptor and frequently used plasticizer, and the pesticides 2-(thiocyanomethylthio) benzothiazole (TCMTB) and permethrin. Exposure to these chemicals resulted in increased embryonic lethality, elevated DNA double-strand break (DSB) formation, activation of p53/CEP-1-dependent germ cell apoptosis, chromosomal abnormalities in oocytes at diakinesis, impaired chromosome segregation during early embryogenesis, and germline-specific alterations in gene expression. This study indicates that this high-throughput screening system is highly reliable for the identification of environmental chemicals inducing aneuploidy, and provides new insights into the impact of exposure to three widely used chemicals on meiosis and germline function. The ever-increasing number of new chemicals introduced into our environment poses a significant problem for risk assessment. In addition, assessing the direct impact of toxicants on human meiosis remains challenging. We successfully utilized a high-throughput platform in the nematode C. elegans, a genetically tractable model organism which shares a high degree of gene conservation with humans, to identify chemicals that affect the germline leading to aneuploidy. We assessed chemicals that are highly prevalent in the environment in worms carrying a fluorescent reporter construct allowing for the identification of X chromosome nondisjunction combined with a mutation increasing cuticle permeability for analysis of low doses of exposure. Follow up analysis of three chemicals: DBP, permethrin and TCMTB, further validated the use of this strategy. Exposure to these chemicals resulted in elevated levels of DNA double-strand breaks, activation of a DNA damage checkpoint, chromosome morphology defects in late meiotic prophase I as well as impaired early embryogenesis and germline-specific changes in gene expression. Our results support the use of this high-throughput screening system to identify environmental chemicals inducing aneuploidy, and provide new insights into the effects of exposure to DBP, permethrin, and TCMTB on meiosis and germline function.
Collapse
Affiliation(s)
- Nara Shin
- Department of Genetics, Harvard Medical School, Boston, MA, United States of America
| | - Luciann Cuenca
- Department of Genetics, Harvard Medical School, Boston, MA, United States of America
| | - Rajendiran Karthikraj
- Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, New York, United States of America
| | - Kurunthachalam Kannan
- Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, New York, United States of America
- Department of Environmental Health Sciences, School of Public Health, University at Albany, State University of New York, Albany, New York, United States of America
| | - Monica P. Colaiácovo
- Department of Genetics, Harvard Medical School, Boston, MA, United States of America
- * E-mail:
| |
Collapse
|
5
|
Perinatal exposures to phthalates and phthalate mixtures result in sex-specific effects on body weight, organ weights and intracisternal A-particle (IAP) DNA methylation in weanling mice. J Dev Orig Health Dis 2018; 10:176-187. [PMID: 29991372 DOI: 10.1017/s2040174418000430] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Developmental exposure to phthalates has been implicated as a risk for obesity; however, epidemiological studies have yielded conflicting results and mechanisms are poorly understood. An additional layer of complexity in epidemiological studies is that humans are exposed to mixtures of many different phthalates. Here, we utilize an established mouse model of perinatal exposure to investigate the effects of three phthalates, diethylhexyl phthalate (DEHP), diisononyl phthalate (DINP) and dibutyl phthalate (DBP), on body weight and organ weights in weanling mice. In addition to individual phthalate exposures, we employed two mixture exposures: DEHP+DINP and DEHP+DINP+DBP. Phthalates were administered through phytoestrogen-free chow at the following exposure levels: 25 mg DEHP/kg chow, 25 mg DBP/kg chow and 75 mg DINP/kg chow. The viable yellow agouti (A vy ) mouse strain, along with measurement of tail DNA methylation, was used as a biosensor to examine effects of phthalates and phthalate mixtures on the DNA methylome. We found that female and male mice perinatally exposed to DINP alone had increased body weights at postnatal day 21 (PND21), and that exposure to mixtures did not exaggerate these effects. Females exposed to DINP and DEHP+DINP had increased relative liver weights at PND21, and females exposed to a mixture of DEHP+DINP+DBP had increased relative gonadal fat weight. Phthalate-exposed A vy /a offspring exhibited altered coat color distributions and altered DNA methylation at intracisternal A-particles (IAPs), repetitive elements in the mouse genome. These findings provide evidence that developmental exposures to phthalates influence body weight and organ weight changes in early life, and are associated with altered DNA methylation at IAPs.
Collapse
|