1
|
Shang Y, Xue W, Kong J, Chen Y, Qiu X, An X, Li Y, Wang H, An J. Ultrafine black carbon caused mitochondrial oxidative stress, mitochondrial dysfunction and mitophagy in SH-SY5Y cells. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 813:151899. [PMID: 34838543 DOI: 10.1016/j.scitotenv.2021.151899] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 09/02/2021] [Accepted: 11/19/2021] [Indexed: 06/13/2023]
Abstract
Exposure to ambient ultrafine black carbon (uBC, with aerodynamic diameter less than 100 nm) is associated with many neurodegenerative diseases. Oxidative stress is the predominantly reported neurotoxic effects caused by uBC exposure. Mitochondrion is responsible for production of majority of ROS in cells and mitochondrial dysfunction is closely related to adverse nervous outcomes. Mitophagy is an important cellular process to eliminate dysfunctional or damaged mitochondria. However, the mechanisms that modulate mitophagy and mitochondrial dysfunction initiated by uBC remain to be elucidated. The purpose of this study was to investigate how mitochondrial oxidative stress regulated mitochondrial dysfunction and mitophagy in human neuroblastoma cell line (SH-SY5Y) after uBC treatment. RNA interference was further applied to explore the roles of mitophagy in mitochondrial dysfunction. We found uBC triggered cell apoptosis via ROS-mitochondrial apoptotic pathway. The uBC also caused serious mitochondrial damage and respiratory dysfunction, indicated by the abnormalities in mitochondrial division and fusion related proteins, decreased mitochondria number and ATP level. Increased PTEN induced putative kinase 1 (PINK1) and Parkin protein levels and the autolysosome numbers suggested uBC could promote Pink1/Parkin-dependent mitophagy process in SH-SY5Y cells. Mitophagy inhibition could reserve mitochondria number and ATP activity, but not fusion and division related protein levels in SH-SY5Y cells exposed to uBC. Administration of a mitochondria-targeted antioxidant (mitoquinone) significantly eliminated uBC caused apoptosis, mitochondrial dysfunction and mitophagy. Our data suggested mitochondrial oxidative stress regulated uBC induced mitochondrial dysfunction and PINK1/Parkin-dependent mitophagy. PINK1/Parkin-dependent mitophagy probably participated in regulating uBC caused mitochondrial dysfunction but not by controlling mitochondrial fusion and division related proteins. Our results may provide some new insights and evidences to understand the mechanisms of neurotoxicity induced by uBC.
Collapse
Affiliation(s)
- Yu Shang
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China; State Environmental Protection Key Laboratory of Formation and Prevention of Urban Air Pollution Complex, Shanghai Academy of Environment Sciences, Shanghai 200233, China
| | - Wanlei Xue
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Jiexing Kong
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Yingjun Chen
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
| | - Xinghua Qiu
- BIC-ESAT and SKL-ESPC, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Xingqin An
- State Key Laboratory of Severe Weather & Key Laboratory of Atmospheric Chemistry of CMA, Chinese Academy of Meteorological Sciences, Beijing 100081, China
| | - Yi Li
- State Key Laboratory of Severe Weather & Key Laboratory of Atmospheric Chemistry of CMA, Chinese Academy of Meteorological Sciences, Beijing 100081, China
| | - Hongli Wang
- State Environmental Protection Key Laboratory of Formation and Prevention of Urban Air Pollution Complex, Shanghai Academy of Environment Sciences, Shanghai 200233, China
| | - Jing An
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China.
| |
Collapse
|
2
|
Zhou L, Chang J, Zhao W, Gao Y. Proanthocyanidins regulate the Nrf2/ARE signaling pathway and protect neurons from cypermethrin-induced oxidative stress and apoptosis. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2021; 177:104898. [PMID: 34301360 DOI: 10.1016/j.pestbp.2021.104898] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 05/31/2021] [Accepted: 06/03/2021] [Indexed: 06/13/2023]
Abstract
Cypermethrin, a type II pyrethroid pesticide, is one of the most widely used pesticides in agricultural and in household settings. The toxic effects of cypermethrin are a matter of concern, as humans are almost inevitably exposed to it in daily life. It is an urgent problem to seek natural substances from plants that can eliminate or relieve the effects of pesticide residues on human health. Proanthocyanidins are the most potent antioxidants and free radical scavengers in natural plants, and are widely available in fruits, vegetables, and seeds. We found that proanthocyanidins (1, 2.5, and 5 μg/mL) can decrease ROS generation, relieve mitochondrial membrane potential loss, repair nuclear morphology, reduce cell apoptosis, and protect neurons from cypermethrin-induced oxidative insult. The protective mechanism exerted by proanthocyanidins against cypermethrin-induced neurotoxicity is negatively regulate rather than activate the Nrf2/ARE signaling pathway to maintain intracellular homeostasis.
Collapse
Affiliation(s)
- Lihua Zhou
- School of Public Health, Bengbu Medical College, Bengbu, Anhui 233030, China.
| | - Jianrong Chang
- Scientific Research Center, Bengbu Medical College, Bengbu, Anhui 233030, China
| | - Wenhong Zhao
- School of Public Health, Bengbu Medical College, Bengbu, Anhui 233030, China
| | - Yangli Gao
- School of Public Health, Bengbu Medical College, Bengbu, Anhui 233030, China
| |
Collapse
|
3
|
Wang XS, Tan X, Zhang Y, Hu XX, Shen C, Huang YY, Fu HL, Yu RH, He CT. The enantiomer-selective metabolism of hexabromocyclododecanes (HBCDs) by human HepG2 cells. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 768:144430. [PMID: 33736337 DOI: 10.1016/j.scitotenv.2020.144430] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 12/06/2020] [Accepted: 12/07/2020] [Indexed: 06/12/2023]
Abstract
Although hepatic metabolism of hexabromocyclododecanes (HBCDs) played critical roles in the selective bioaccumulation of HBCDs in humans, the hepatic metabolism patterns of its enantiomers remained ambiguous. Aiming to elucidate the mechanism on hepatic metabolism of hexabromocyclododecanes (HBCDs) enantiomers, the enantiomers ((+)-α-HBCD, (-)-α-HBCD, (+)-γ-HBCD, and (-)-γ-HBCD), the diastereoisomers (α-, β-, and γ-HBCDs) and the mixed of α- and γ-HBCDs were incubated with human HepG2 cell under different exposure levels in the present study. The clearance percentages ranked as γ-HBCD enantiomers >β-HBCD enantiomers >α-HBCD enantiomers at the same exposure levels. The clearance percentages of (+)- and (-)-α-HBCDs increased when cells were exposed to racemic α-HBCD and the mixture of racemic α- and γ-HBCDs (p < 0.05). (-)-γ-HBCD was more resistant to human hepatic metabolism than (+)-γ-HBCD, leading to the enantiomer fractions (EFs) of γ-HBCD lower than 0.50. (-)-α-HBCD was slightly more metabolized when independently exposed to α-HBCD, while (+)-α-HBCD was more preferentially metabolized after exposure to α- and γ-HBCD mixtures. Hydroxylation and debromination HBCD metabolites were identified. In addition, the different EFs of HBCDs in cells and mediums suggested the selective transfer of chiral HBCDs and HBCD metabolites through the cell membrane. This study provided new insight into the enantiomer-selective metabolism of HBCDs.
Collapse
Affiliation(s)
- Xue-Song Wang
- School of Agriculture, Sun Yat-sen University, Guangzhou 510275, China; Guangdong Provincial Key Laboratory of Emergency Test for Dangerous Chemicals, China National Analytical Center Guangzhou (Guangdong Institute of Analysis), Guangdong Academy of Sciences, 100 Xianlie Middle Road, Guangzhou 510070, China
| | - Xiao Tan
- School of Agriculture, Sun Yat-sen University, Guangzhou 510275, China
| | - Yan Zhang
- School of Life Science, Sun Yat-sen University, Guangzhou 510275, China
| | - Xia-Xin Hu
- School of Agriculture, Sun Yat-sen University, Guangzhou 510275, China
| | - Chuang Shen
- School of Safety and Environmental Engineering, Hunan Institute of Technology, Hengyang 421002, China
| | - Ying-Ying Huang
- School of Safety and Environmental Engineering, Hunan Institute of Technology, Hengyang 421002, China
| | - Hui-Ling Fu
- School of Safety and Environmental Engineering, Hunan Institute of Technology, Hengyang 421002, China
| | - Ruo-Han Yu
- School of Life Science, Sun Yat-sen University, Guangzhou 510275, China
| | - Chun-Tao He
- School of Agriculture, Sun Yat-sen University, Guangzhou 510275, China.
| |
Collapse
|
4
|
Schrenk D, Bignami M, Bodin L, Chipman JK, del Mazo J, Grasl‐Kraupp B, Hogstrand C, Hoogenboom L(R, Leblanc J, Nebbia CS, Nielsen E, Ntzani E, Petersen A, Sand S, Schwerdtle T, Wallace H, Benford D, Fürst P, Rose M, Ioannidou S, Nikolič M, Bordajandi LR, Vleminckx C. Update of the risk assessment of hexabromocyclododecanes (HBCDDs) in food. EFSA J 2021; 19:e06421. [PMID: 33732387 PMCID: PMC7938899 DOI: 10.2903/j.efsa.2021.6421] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The European Commission asked EFSA to update its 2011 risk assessment on hexabromocyclododecanes (HBCDDs) in food. HBCDDs, predominantly mixtures of the stereoisomers α-, β- and γ-HBCDD, were widely used additive flame retardants. Concern has been raised because of the occurrence of HBCDDs in the environment, food and in humans. Main targets for toxicity are neurodevelopment, the liver, thyroid hormone homeostasis and the reproductive and immune systems. The CONTAM Panel concluded that the neurodevelopmental effects on behaviour in mice can be considered the critical effects. Based on effects on spontaneous behaviour in mice, the Panel identified a lowest observed adverse effect level (LOAEL) of 0.9 mg/kg body weight (bw) as the Reference Point, corresponding to a body burden of 0.75 mg/kg bw. The chronic intake that would lead to the same body burden in humans was calculated to be 2.35 μg/kg bw per day. The derivation of a health-based guidance value (HBGV) was not considered appropriate. Instead, the margin of exposure (MOE) approach was applied to assess possible health concerns. Over 6,000 analytical results for HBCDDs in food were used to estimate the exposure across dietary surveys and age groups of the European population. The most important contributors to the chronic dietary LB exposure to HBCDDs were fish meat, eggs, livestock meat and poultry. The CONTAM Panel concluded that the resulting MOE values support the conclusion that current dietary exposure to HBCDDs across European countries does not raise a health concern. An exception is breastfed infants with high milk consumption, for which the lowest MOE values may raise a health concern.
Collapse
|
5
|
Dai W, Tang T, Dai Z, Shi D, Mo L, Zhang Y. Probing the Mechanism of Hepatotoxicity of Hexabromocyclododecanes through Toxicological Network Analysis. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:15235-15245. [PMID: 33190479 DOI: 10.1021/acs.est.0c03998] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The prediction and mechanism analysis of hepatotoxicity of contaminants, because of their various phenotypes and complex mechanisms, is still a key problem in environmental research. We applied a toxicological network analysis method to predict the hepatotoxicity of three hexabromocyclododecane (HBCD) diastereoisomers (α-HBCD, β-HBCD, and γ-HBCD) and explore their potential mechanisms. First, we collected the hepatotoxicity related genes and found that those genes were significantly localized in the human interactome. Therefore, these genes form a disease module of hepatotoxicity. We also collected targets of α-, β-, and γ-HBCD and found that their targets overlap with the hepatotoxicity disease module. Then, we trained a model to predict hepatotoxicity of three HBCD diastereoisomers based on the relationship between the hepatotoxicity disease module and targets of compounds. We found that 593 genes were significantly located in the hepatotoxicity disease module (Z = 11.9, p < 0.001) involved in oxidative stress, cellular immunity, and proliferation, and the accuracy of hepatotoxicity prediction of HBCD was 0.7095 ± 0.0193 and the recall score was 0.8355 ± 0.0352. HBCD mainly affects the core disease module genes to mediate the adenosine monophosphate-activated kinase, p38MAPK, PI3K/Akt, and TNFα pathways to regulate the immune reaction and inflammation. HBCD also induces the secretion of IL6 and STAT3 to lead hepatotoxicity by regulating NR3C1. This approach is transferable to other toxicity research studies of environmental pollutants.
Collapse
Affiliation(s)
- Weina Dai
- Chongqing Research Center for Pharmaceutical Engineering, College of Pharmacy, Chongqing Medical University, Chongqing 400016, China
| | - Tiantian Tang
- Chongqing Research Center for Pharmaceutical Engineering, College of Pharmacy, Chongqing Medical University, Chongqing 400016, China
| | - Zhenghua Dai
- Chongqing Research Center for Pharmaceutical Engineering, College of Pharmacy, Chongqing Medical University, Chongqing 400016, China
- Chongqing Academy of Metrology and Quality Inspection, Chongqing 401123, China
| | - Da Shi
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California 92093, United States
| | - Lingyun Mo
- The Guangxi Key Laboratory of Theory and Technology for Environmental Pollution Control, College of Environmental Science and Engineering, Guilin University of Technology, Guilin 541004, China
- Technical Innovation Center for Mine Geological Environment Restoration Engineering in Shishan Area of South China, Ministry of Natural Resources, Nanning 530028, China
| | - Yonghong Zhang
- Chongqing Research Center for Pharmaceutical Engineering, College of Pharmacy, Chongqing Medical University, Chongqing 400016, China
| |
Collapse
|
6
|
Jin Y, Shang Y, Zhang D, An J, Pan D. Hexabromocyclododecanes promoted autophagy through the PI3K/Akt/mTOR pathway in L02 cells. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2019; 244:77-82. [PMID: 31108313 DOI: 10.1016/j.jenvman.2019.05.031] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 04/22/2019] [Accepted: 05/06/2019] [Indexed: 06/09/2023]
Abstract
As additive brominated flame retardants, hexabromocyclododecanes (HBCDs) are being widely used in diverse artificial materials and products, including thermal insulation building materials, housings of electronic equipment, and upholstery textiles. Toxicology studies have shown that HBCDs exposure are closely related to hepatotoxicity and liver diseases. The present study is designed to explore how HBCDs affect cell apoptosis and autophagy process in a human hepatocyte cell line (L02) and to reveal the underline molecular mechanisms. Firstly, HBCDs could elevate the apoptosis rate of L02 cells dose-dependently. Three apoptosis related proteins (apoptotic protease activating factor 1 (Apaf-1), cysteinyl aspartate specific proteinase 3 (caspase-3) and cysteinyl aspartate specific proteinase 9 (caspase-9)) were observed to be up-regulated using western blotting method. Autophagy process was also started by HBCDs in L02 cells as indicated by the increased expressions of LC3-phosphatidylethanolamine conjugate (LC3-II) and other autophagic protein markers (Beclin-1, autophagy related protein 3 (Atg3), autophagy related protein 5 (Atg5), autophagy related protein 7 (Atg7) and autophagy related protein 16L1(Atg16L1)). The results of the green fluorescent protein (GFP)-microtubule-associated protein 1 light chain 3 (LC3) intracellular localization and fluorescence intensity further evidenced the activation of autophagy in L02 cells after treated with HBCDs. In addition, phosphatidylinositide 3-kinases/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway was activated in L02 cells by HBCDs, suggested by the increased expressions of related proteins. The inhibitors of PI3K (LY294002), DNA-activated protein kinase catalytic subunit (DNA-PKcs) (NU7441), Akt (MK2206), and mTOR (KU0063794) could obviously reduce the autophagic proteins prompted by HBCDs. The fluorescence intensities of GFP-LC3 transfected L02 cells were also decreased significantly after the application of these inhibitors. These results indicated that PI3K/Akt/mTOR pathway was participated in regulating autophagy process promoted by HBCDs. In above, HBCDs could induce mitochondrial-dependent apoptosis and autophagy in L02 cells, which was modulated by PI3K/Akt/mTOR pathway.
Collapse
Affiliation(s)
- Yingying Jin
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China
| | - Yu Shang
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China
| | - Dongping Zhang
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China
| | - Jing An
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China
| | - Dongyan Pan
- Department of Ophthalmology, Changhai Hospital, Second Military Medical University, Shanghai, 200433, China.
| |
Collapse
|
7
|
Farmahin R, Gannon AM, Gagné R, Rowan-Carroll A, Kuo B, Williams A, Curran I, Yauk CL. Hepatic transcriptional dose-response analysis of male and female Fischer rats exposed to hexabromocyclododecane. Food Chem Toxicol 2018; 133:110262. [PMID: 30594549 DOI: 10.1016/j.fct.2018.12.032] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 12/13/2018] [Accepted: 12/20/2018] [Indexed: 12/14/2022]
Abstract
Hexabromocyclododecane (HBCD) is a brominated flame retardant found in the environment and human tissues. The toxicological effects of HBCD exposure are not clearly understood. We employed whole-genome RNA-sequencing on liver samples from male and female Fischer rats exposed to 0, 250, 1250, and 5000 mg technical mixture of HBCD/kg diet for 28 days to gain further insight into HBCD toxicity. HBCD altered 428 and 250 gene transcripts in males and females, respectively, which were involved in metabolism of xenobiotics, oxidative stress, immune response, metabolism of glucose and lipids, circadian regulation, cell cycle, fibrotic activity, and hormonal balance. Signature analysis supported that HBCD operates through the constitutive androstane and pregnane X receptors. The median transcriptomic benchmark dose (BMD) for the lowest statistically significant pathway was within 1.5-fold of the BMD for increased liver weight, while the BMD for the lowest pathway with at least three modeled genes (minimum 5% of pathway) was similar to the lowest apical endpoint BMD. The results show how transcriptional analyses can inform mechanisms underlying chemical toxicity and the doses at which potentially adverse effects occur. This experiment is part of a larger study exploring the use of toxicogenomics and high-throughput screening for human health risk assessment.
Collapse
Affiliation(s)
- Reza Farmahin
- Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Anne Marie Gannon
- Regulatory Toxicology Research Division, Health Products and Food Branch, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Rémi Gagné
- Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Andrea Rowan-Carroll
- Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Byron Kuo
- Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Andrew Williams
- Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Ivan Curran
- Regulatory Toxicology Research Division, Health Products and Food Branch, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Carole L Yauk
- Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, ON, K1A 0K9, Canada.
| |
Collapse
|
8
|
Li Y, Li S, Xie X, Xiu H, Liu X, Shao J, Zhang X. Neuroprotection by Taurine on HBCD-Induced Apoptosis in PC12 Cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 975 Pt 1:95-106. [PMID: 28849447 DOI: 10.1007/978-94-024-1079-2_9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Hexabromocyclododecane (HBCD) is a widely used brominated flame retardant (BFR). Because of their presence in human issues, including brain tissue, concern has been raised on their possible neurotoxicity. Presently, we explored the neuroprotection of taurine against HBCD-induced apoptotic damages in PC12 cells. Cells were pre-treated with taurine before HBCD exposure and the viability was assayed via the methyl-thiazolyl-tetrazolium (MTT) method. Apoptotic features were observed with Hoechst 33342 staining. Apoptotic ratio was measured using flow cytometry with Annexin V-FITC coupled propidium iodide (PI) double staining. The changes in the levels of Bcl-2 and Bax proteins were quantitated by the western blot. The activity of caspase-3 was tested and the results revealed that presence of HBCD decreased cell survival and led to apoptosis in the tested cells. Further, exposure of HBCD reduced protein expression of Bcl-2, increased expression in Bax protein and activity of caspase-3. Taurine attenuated HBCD-induced cell viability loss and cell apoptosis. Moreover, taurine significantly prevented from reducing Bcl-2 protein expression and elevating Bax protein expression and caspase-3 activity induced by HBCD. These results demonstrated that taurine can alleviate HBCD-induced apoptosis by altering Bcl-2 expression and Bax protein and Caspase-3 activity in PC12.
Collapse
Affiliation(s)
- Yachen Li
- School of Public Health, Dalian Medical University, No. 9 Western Section of Lushun South Road, Dalian, 116044, China.
| | - Shuangyue Li
- School of Public Health, Dalian Medical University, No. 9 Western Section of Lushun South Road, Dalian, 116044, China
| | - Xizhe Xie
- College of Veterinary Medicine, Jilin University, Changchun, China
| | - Hang Xiu
- The First Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Xiaohui Liu
- School of Public Health, Dalian Medical University, No. 9 Western Section of Lushun South Road, Dalian, 116044, China
| | - Jing Shao
- School of Public Health, Dalian Medical University, No. 9 Western Section of Lushun South Road, Dalian, 116044, China
| | - Xiuli Zhang
- School of Pharmaceutical Sciences, Binzhou Medical University, Yantai, 264003, China.
| |
Collapse
|
9
|
Steves AN, Bradner JM, Fowler KL, Clarkson-Townsend D, Gill BJ, Turry AC, Caudle WM, Miller GW, Chan AWS, Easley CA. Ubiquitous Flame-Retardant Toxicants Impair Spermatogenesis in a Human Stem Cell Model. iScience 2018; 3:161-176. [PMID: 29901031 PMCID: PMC5994764 DOI: 10.1016/j.isci.2018.04.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 03/27/2018] [Accepted: 04/05/2018] [Indexed: 01/08/2023] Open
Abstract
Sperm counts have rapidly declined in Western males over the past four decades. This rapid decline remains largely unexplained, but exposure to environmental toxicants provides one potential explanation for this decline. Flame retardants are highly prevalent and persistent in the environment, but many have not been assessed for their effects on human spermatogenesis. Using a human stem cell-based model of spermatogenesis, we evaluated two major flame retardants, hexabromocyclododecane (HBCDD) and tetrabromobisphenol A (TBBPA), under acute conditions simulating occupational-level exposures. Here we show that HBCDD and TBBPA are human male reproductive toxicants in vitro. Although these toxicants do not specifically affect the survival of haploid spermatids, they affect spermatogonia and primary spermatocytes through mitochondrial membrane potential perturbation and reactive oxygen species generation, ultimately causing apoptosis. Taken together, these results show that HBCDD and TBBPA affect human spermatogenesis in vitro and potentially implicate this highly prevalent class of toxicants in the decline of Western males' sperm counts.
Collapse
Affiliation(s)
- Alyse N Steves
- Genetics and Molecular Biology Program, Laney Graduate School, Emory University, Atlanta, GA 30322, USA
| | - Joshua M Bradner
- Department of Environmental Health Science, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
| | - Kristen L Fowler
- Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, GA 30602, USA; Regenerative Bioscience Center, University of Georgia, Athens, GA 30602, USA
| | - Danielle Clarkson-Townsend
- Department of Environmental Health Science, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
| | - Brittany J Gill
- Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, GA 30602, USA; Regenerative Bioscience Center, University of Georgia, Athens, GA 30602, USA
| | - Adam C Turry
- Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, GA 30602, USA; Regenerative Bioscience Center, University of Georgia, Athens, GA 30602, USA
| | - W Michael Caudle
- Department of Environmental Health Science, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
| | - Gary W Miller
- Department of Environmental Health Science, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
| | - Anthony W S Chan
- Genetics and Molecular Biology Program, Laney Graduate School, Emory University, Atlanta, GA 30322, USA; Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, GA 30322, USA; Department of Human Genetics, Emory University, Atlanta, GA 30322, USA
| | - Charles A Easley
- Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, GA 30602, USA; Regenerative Bioscience Center, University of Georgia, Athens, GA 30602, USA; Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, GA 30322, USA.
| |
Collapse
|
10
|
Lu S, Tan Z, Jiang Y, Wu D, Zhang J, Zhou J, Lin X. Hexabromocyclododecanes in breast milk from residents in Shenzhen, China: Implications for infant exposure. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 622-623:1090-1097. [PMID: 29890578 DOI: 10.1016/j.scitotenv.2017.11.277] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 11/23/2017] [Accepted: 11/24/2017] [Indexed: 06/08/2023]
Abstract
Hexabromocyclododecanes (HBCDs) are widely used as flame retardants for various products and have become ubiquitous pollutants in environmental media. However, little is known about HBCD exposure for humans, especially in China. This study aimed to investigate the levels and profiles of hexabromocyclododecanes (HBCDs) in human breast milk and to estimate the daily HBCD intake for infants in Shenzhen, China. Levels of the HBCD diastereoisomers α-, β-, and γ-HBCD in 180 breast milk samples collected from primiparas in Shenzhen were measured. The concentrations of α-, β-, and γ-HBCD (ΣHBCDs) ranged within 0.103-15.1ng/g lipid and had a median of 1.82ng/g lipid. ΣHBCDs levels in milk in the present study are comparable to those in milk from other countries and regions but are markedly higher than those for most populations in other regions of China. Among the diastereoisomers, α-HBCD was predominant, accounting for 97.6% of the concentration of ΣHBCDs. The estimated daily intake of ΣHBCDs via breast milk for infants in Shenzhen ranged from 0.481 to 100ng/kgbw/day with a median of 8.40ng/kgbw/day, however, which was unlikely to raises a health concern based on the margin of exposure (MOE) approach. The duration of residence was found to have a significant positive correlation with the HBCD levels in the human breast milk (p<0.05). To our knowledge, this is the first report on HBCD levels in breast milk from Shenzhen residents.
Collapse
Affiliation(s)
- Shaoyou Lu
- POPs Lab, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China
| | - Zhen Tan
- Shenzhen Academy of Metrology & Quality Inspection, Shenzhen 518131, China
| | - Yousheng Jiang
- POPs Lab, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China
| | - Dongting Wu
- School of Medicine, Shenzhen University, Shenzhen, Guangdong 518060, China
| | - Jianqing Zhang
- POPs Lab, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China.
| | - Jian Zhou
- POPs Lab, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China
| | - Xiaoshi Lin
- POPs Lab, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China
| |
Collapse
|
11
|
Shi Y, Xu X, Chen J, Liang R, Zheng X, Shi Y, Wang Y. Antioxidant gene expression and metabolic responses of earthworms (Eisenia fetida) after exposure to various concentrations of hexabromocyclododecane. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 232:245-251. [PMID: 28951040 DOI: 10.1016/j.envpol.2017.09.039] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 08/28/2017] [Accepted: 09/09/2017] [Indexed: 06/07/2023]
Abstract
Hexabromocyclododecane (HBCD), a ubiquitous suspected contaminant, is one of the world's most prominent brominated flame retardants (BFRs). In the present study, earthworms (Eisenia fetida) were exposed to HBCD. The expression of selected antioxidant enzyme genes was measured, and the metabolic responses were assessed using nuclear magnetic resonance (NMR) to identify the molecular mechanism of the antioxidant stress reaction and the metabolic reactions of earthworms to HBCD. A significant up-regulation (p < 0.05) of superoxide dismutase (SOD) gene expression was detected, with the highest gene expression level of SOD appearing at a dose of 400 mg kg-1 dw (2.06-fold, p < 0.01). However, the glutathione transferase (GST) gene expression levels did not differ significantly (p > 0.05). Principal component analysis (PCA) of the metabolic responses showed that all groups could be clearly differentiated, and the highest concentration dose group was the most distant from the control group. Except for fumarate, the measured metabolites, which included adenosine triphosphate (ATP), valine, lysine, glycine, betaine and lactate, revealed significant (p < 0.05) increases after 14 days of exposure to HBCD. HBCD likely induces high levels of anaerobic respiration, which would result in high levels of ATP and lead to the disintegration of proteins into amino acids, including valine and lysine, to produce energy. The observed changes in osmotic pressure were indicative of damage to the membrane structure. Furthermore, this study showed that NMR-based metabolomics was a more sensitive tool than measuring the gene expression levels for elucidating the mode of toxicity of HBCD in earthworm exposure studies.
Collapse
Affiliation(s)
- Yajuan Shi
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Xiangbo Xu
- School of Environment & Natural Resources, Renmin University of China, Beijing 100872, China.
| | - Juan Chen
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ruoyu Liang
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaoqi Zheng
- School of Environment & Natural Resources, Renmin University of China, Beijing 100872, China
| | - Yajing Shi
- School of Biomedical and Chemical Engineering, Liaoning Institute of Science and Technology, Benxi 117004, China
| | - Yurong Wang
- School of Biomedical and Chemical Engineering, Liaoning Institute of Science and Technology, Benxi 117004, China
| |
Collapse
|
12
|
Liu Y, Chen Y, Du WT, Wu XX, Dong FX, Qu XB, Fan HB, Yao RQ. GluR3B Ab's induced oligodendrocyte precursor cells excitotoxicity via mitochondrial dysfunction. Brain Res Bull 2017; 130:60-66. [PMID: 28063880 DOI: 10.1016/j.brainresbull.2016.12.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 12/28/2016] [Indexed: 11/28/2022]
Abstract
Studies have indicated that glutamate receptor subunit 3 peptide B antibodies (GluR3B Ab's) by directing against a-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid subtype glutamate receptors (AMPARs) subunit 3 (GluR3B) was involved in the hippocampal neuron damage in the pathogenesis of epilepsy. Glutamate accumulation is critical for oligodendrocyte precursors (OPCs) excitotoxic injury. However, remarkably little is known about whether GluR3B Ab's causes OPCs excitotoxicity, and the underlying mechanisms remain unclear. In this study, we found that the survival rate of OPCs decreased, apoptosis increased and the release of LDH increased with GluR3B Ab's treatment. GluR3B Ab's enhanced the level of intracellular Ca2+ and reactive oxygen species (ROS), caused mitochondrial potential collapse measured by JC-1 and promoted mitochondrial cytochrome C release. AMPARs antagonist NBQX reversed OPCs apoptosis caused by GluR3B Ab's. Taken together, these data suggests that AMPAR was involved in GluR3B Ab's-induced OPCs toxicity by mitochondrial dysfunction. The study revealed a new mechanism for OPCs excitotoxicity in many central nervous system diseases such as epilepsy.
Collapse
Affiliation(s)
- Yi Liu
- Department of Cell Biology and Neurobiology, Laboratory of Neurobiology, Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, 209 Tongshan Road, Xuzhou 221004, PR China
| | - Yan Chen
- Department of Cell Biology and Neurobiology, Laboratory of Neurobiology, Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, 209 Tongshan Road, Xuzhou 221004, PR China
| | - Wan Tong Du
- Department of Cell Biology and Neurobiology, Laboratory of Neurobiology, Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, 209 Tongshan Road, Xuzhou 221004, PR China
| | - Xiu Xiang Wu
- Department of Cell Biology and Neurobiology, Laboratory of Neurobiology, Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, 209 Tongshan Road, Xuzhou 221004, PR China
| | - Fu Xing Dong
- Department of Cell Biology and Neurobiology, Laboratory of Neurobiology, Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, 209 Tongshan Road, Xuzhou 221004, PR China
| | - Xue Bin Qu
- Department of Cell Biology and Neurobiology, Laboratory of Neurobiology, Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, 209 Tongshan Road, Xuzhou 221004, PR China
| | - Hong Bin Fan
- Department of Neurology, Affiliated Hospital of Xuzhou Medical University, 99 West Huaihai Road, Xuzhou, 221002, Jiangsu, PR China.
| | - Rui Qin Yao
- Department of Cell Biology and Neurobiology, Laboratory of Neurobiology, Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, 209 Tongshan Road, Xuzhou 221004, PR China.
| |
Collapse
|
13
|
Feng J, Zhang XL, Li YY, Cui YY, Chen YH. Pinus massoniana Bark Extract: Structure-Activity Relationship and Biomedical Potentials. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2016; 44:1559-1577. [PMID: 27852122 DOI: 10.1142/s0192415x16500877] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/02/2023]
Abstract
Proanthocyanidins (PAs) belong to the condensed tannin subfamily of natural flavonoids. Recent studies have shown that the main bioactive compounds of Pinus massoniana bark extract (PMBE) are PAs, especially the proanthocyanidins B series, which play important roles in cell cycle arrest, apoptosis induction and migration inhibition of cancer cells in vivo and in vitro. PA-Bs are mixtures of oligomers and polymers composed of flavan-3-ol, and the relationship between their structure and corresponding biomedical potentials is summarized in this paper. The hydroxyl at certain positions or the linkage between different carbon atoms of different rings determines or affects their anti-oxidant and free radical scavenging bioactivities. The degree of polymerization and the water solubility of the reaction system also influence their biomedical potential. Taken together, PMBE has a promising future in clinical drug development as a candidate anticancer drug and as a food additive to prevent tumorigenesis. We hope this review will encourage interested researchers to conduct further preclinical and clinical studies to evaluate the anticancer activities of PMBE, its active constituents and their derivatives.
Collapse
Affiliation(s)
- Jiao Feng
- ‡ Department of Regenerative Medicine, Tongji University School of Medicine, Shanghai 200092, P.R. China
| | - Xiao-Lu Zhang
- ‡ Department of Regenerative Medicine, Tongji University School of Medicine, Shanghai 200092, P.R. China
| | - Ying-Ya Li
- ‡ Department of Regenerative Medicine, Tongji University School of Medicine, Shanghai 200092, P.R. China
| | - Ying-Yu Cui
- * Key Laboratory of Arrhythmias, Ministry of Education (Tongji University), Shanghai 200120, P.R. China
- † Institute of Medical Genetics, Tongji University School of Medicine, Shanghai 200092, P.R. China
- ‡ Department of Regenerative Medicine, Tongji University School of Medicine, Shanghai 200092, P.R. China
| | - Yi-Han Chen
- * Key Laboratory of Arrhythmias, Ministry of Education (Tongji University), Shanghai 200120, P.R. China
- † Institute of Medical Genetics, Tongji University School of Medicine, Shanghai 200092, P.R. China
- § Department of Pathology and Pathophysiology, Tongji University School of Medicine, Shanghai 200092, P.R. China
- ¶ Department of Cardiology, East Hospital, Tongji University School of Medicine, Shanghai 200120, P.R. China
| |
Collapse
|
14
|
Wang F, Zhang H, Geng N, Zhang B, Ren X, Chen J. New Insights into the Cytotoxic Mechanism of Hexabromocyclododecane from a Metabolomic Approach. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:3145-3153. [PMID: 26876804 DOI: 10.1021/acs.est.5b03678] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The toxic effects of hexabromocyclododecane (HBCD) are complex, and the underlying toxicological mechanisms are still not completely understood. In this study, a pseudotargeted metabolomic approach based on the UHPLC/Q-Trap MS system was developed to assess the HBCD-intervention-related metabolic alteration in HepG2 cells. In addition, some physiologic indicators and relevant enzyme activities were measured. HBCD exposure obviously impaired metabolic homeostasis and induced oxidative stress, even at an environmentally relevant dose (0.05 mg/L). Metabolic profiling and multivariate analysis indicated that the main metabolic pathways perturbed by HBCD included amino acid metabolism, protein biosynthesis, fatty acid metabolism, and phospholipid metabolism. HBCD suppressed the cell uptake of amino acids, mainly through inhibition of the activity of membrane transport protein Na(+)/K(+)-ATPase. HBCD down-regulated glycolysis and β-oxidation of long-chain fatty acids, causing a large decrease of ATP production. As a result, the across-membrane transport of amino acids was further inhibited. Meanwhile, HBCD induced a significant increase of total phospholipids, mainly through the remodeling of phospholipids from the increased free fatty acids. The obtained metabolomic results also provided some new evidence and clues regarding the toxicological mechanisms of HBCD that contribute to obesity, diabetes, nervous system damage, and developmental disorders.
Collapse
Affiliation(s)
- Feidi Wang
- Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences , Dalian 116023, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Haijun Zhang
- Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences , Dalian 116023, China
| | - Ningbo Geng
- Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences , Dalian 116023, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Baoqin Zhang
- Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences , Dalian 116023, China
| | - Xiaoqian Ren
- Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences , Dalian 116023, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jiping Chen
- Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences , Dalian 116023, China
| |
Collapse
|
15
|
An J, Guo P, Shang Y, Zhong Y, Zhang X, Yu Y, Yu Z. The "adaptive responses" of low concentrations of HBCD in L02 cells and the underlying molecular mechanisms. CHEMOSPHERE 2016; 145:68-76. [PMID: 26688241 DOI: 10.1016/j.chemosphere.2015.11.071] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 11/18/2015] [Accepted: 11/19/2015] [Indexed: 06/05/2023]
Abstract
This study aimed to investigate the "adaptive responses" of hexabromocyclododecanes (HBCD) at environmentally relevant concentrations in human hepatocytes L02. L02 cells were pre-treated with low concentrations of HBCD (10(-13)-10(-11) M), followed by treatment with high concentrations of HBCD, α-hexachlorocyclohexane (α-HCH), polychlorinated biphenyls (PCBs), or polybrominated diphenyl ether-47 (BDE47). The results showed that the pre-treatment with low concentrations of HBCD induced "adaptive responses" to high concentrations of HBCD/α-HCH exposure (but not to PCBs and BDE47), as evidenced by attenuation of survival inhibition, reactive oxygen species (ROS) over-production, and deoxyribonucleic acid (DNA) damage induction. The "adaptive responses" induced by low concentrations of HBCD, which depended on the activation of the phosphatidylinositide 3-kinase/protein kinase B (PI3K/Akt) pathway, reduced the phosphorylation of adenosine monophosphate-activated kinase (AMPK) and enhanced the phosphorylation of p38 mitogen-activated protein kinases (p38 MAPK). The observations were further confirmed by the experiments with inhibitors. Moreover, the evaluation on the changes of metabolic enzymes revealed that HBCD and α-HCH shared a similar pattern of cytochrome P450 induction (CYP2B6), which was different from those of PCBs and BDE47 (CYP1A1 and CYP2B6). These results indicated that low concentrations of HBCD could induce "adaptive responses" to the subsequent treatment with high concentrations of HBCD/α-HCH in L02 cells, which was associated with the PI3K/Akt pathway, and AMPK and p38 MAPK signaling. The "adaptive responses" seemed to be dependent on the types of chemicals in terms of the metabolic patterns and chemical structures.
Collapse
Affiliation(s)
- Jing An
- Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, PR China.
| | - Panpan Guo
- Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, PR China
| | - Yu Shang
- Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, PR China
| | - Yufang Zhong
- Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, PR China
| | - Xinyu Zhang
- Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, PR China
| | - Yingxin Yu
- Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, PR China
| | - Zhiqiang Yu
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, PR China
| |
Collapse
|
16
|
Transcriptomic and metabolomic approaches to investigate the molecular responses of human cell lines exposed to the flame retardant hexabromocyclododecane (HBCD). Toxicol In Vitro 2015; 29:2116-23. [DOI: 10.1016/j.tiv.2015.08.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 08/05/2015] [Accepted: 08/26/2015] [Indexed: 02/02/2023]
|
17
|
Genskow KR, Bradner JM, Hossain MM, Richardson JR, Caudle WM. Selective damage to dopaminergic transporters following exposure to the brominated flame retardant, HBCDD. Neurotoxicol Teratol 2015; 52:162-9. [PMID: 26073293 DOI: 10.1016/j.ntt.2015.06.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Revised: 06/05/2015] [Accepted: 06/09/2015] [Indexed: 12/01/2022]
Abstract
Over the last several decades, the use of halogenated organic compounds has become the cause of environmental and human health concerns. Of particular notoriety has been the establishment of the neurotoxicity of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). The subsequent banning of PBDEs has led to greatly increased use of 1,2,5,6,9,10-hexabromocyclododecane (HBCDD, also known as HBCD) as a flame retardant in consumer products. The physiochemical similarities between HBCDD and PBDEs suggest that HBCDD may also be neurotoxic to the dopamine system, which is specifically damaged in Parkinson disease (PD). The purpose of this study was to assess the neurotoxicity of HBCDD on the nigrostriatal dopamine system using an in vitro and in vivo approach. We demonstrate that exposure to HBCDD (0-25 μM) for 24 h causes significant cell death in the SK-N-SH catecholaminergic cell line, as well as reductions in the growth and viability of TH+ primary cultured neurons at lower concentrations (0-10 μM) after 72 h of treatment. Assessment of the in vivo neurotoxicity of HBCDD (25 mg/kg for 30 days) resulted in significant reductions in the expression of the striatal dopamine transporter and vesicular monoamine transporter 2, both of which are integral in mediating dopamine homeostasis and neurotransmission in the dopamine circuit. However, no changes were seen in the expression of tyrosine hydroxylase in the dopamine terminal, or striatal levels of dopamine. To date, these are the first data to demonstrate that exposure to HBCDD disrupts the nigrostriatal dopamine system. Given these results and the ubiquitous nature of HBCDD in the environment, its possible role as an environmental risk factor for PD should be further investigated.
Collapse
Affiliation(s)
- Kelly R Genskow
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322-3090, USA
| | - Joshua M Bradner
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322-3090, USA; Center for Neurodegenerative Disease, School of Medicine, Emory University, Atlanta, GA 30322-3090, USA
| | - Muhammad M Hossain
- Department of Environmental and Occupational Medicine, Robert Wood Johnson Medical School Piscataway, NJ 08854, USA
| | - Jason R Richardson
- Department of Environmental and Occupational Medicine, Robert Wood Johnson Medical School Piscataway, NJ 08854, USA
| | - W Michael Caudle
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322-3090, USA; Center for Neurodegenerative Disease, School of Medicine, Emory University, Atlanta, GA 30322-3090, USA.
| |
Collapse
|
18
|
Fa S, Pogrmic-Majkic K, Samardzija D, Hrubik J, Glisic B, Kovacevic R, Andric N. HBCDD-induced sustained reduction in mitochondrial membrane potential, ATP and steroidogenesis in peripubertal rat Leydig cells. Toxicol Appl Pharmacol 2014; 282:20-9. [PMID: 25447410 DOI: 10.1016/j.taap.2014.11.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Revised: 10/14/2014] [Accepted: 11/02/2014] [Indexed: 12/01/2022]
Abstract
Hexabromocyclododecane (HBCDD), a brominated flame retardant added to various consumer products, is a ubiquitous environmental contaminant. We have previously shown that 6-hour exposure to HBCDD disturbs basal and human chorionic gonadotropin (hCG)-induced steroidogenesis in rat Leydig cells. Reduction in mitochondrial membrane potential (ΔΨm) and cAMP production was also observed. Here, we further expanded research on the effect of HBCDD on Leydig cells by using a prolonged exposure scenario. Cells were incubated in the presence of HBCDD during 24h and then treated with HBCDD+hCG for additional 2h. Results showed that HBCDD caused a sustained reduction in ATP level after 24h of exposure, which persisted after additional 2-hour treatment with HBCDD+hCG. cAMP and androgen accumulations measured after 2h of HBCDD+hCG treatment were also inhibited. Real-time PCR analysis showed significant inhibition in the expression of genes for steroidogenic enzymes, luteinizing hormone receptor, regulatory and transport proteins, and several transcription factors under both treatment conditions. Western blot analysis revealed a decreased level of 30kDa steroidogenic acute regulatory protein (StAR) after HBCDD+hCG treatment. In addition, HBCDD decreased the conversion of 22-OH cholesterol to pregnenolone and androstenedione to testosterone, indicating loss of the activity of cytochrome P450C11A1 (CYP11A1) and 17β-hydroxysteroid dehydrogenase (HSD17β). Cell survival was not affected, as confirmed by cytotoxicity and trypan blue tests or DNA fragmentation analysis. In summary, our data showed that HBCDD inhibits ATP supply, most likely through a decrease in ΔΨm, and targets multiple sites in the steroidogenic pathway in Leydig cells.
Collapse
Affiliation(s)
- Svetlana Fa
- Molecular and Reproductive Toxicology Unit, Laboratory for Ecotoxicology, Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, 21000 Novi Sad, Serbia
| | - Kristina Pogrmic-Majkic
- Molecular and Reproductive Toxicology Unit, Laboratory for Ecotoxicology, Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, 21000 Novi Sad, Serbia
| | - Dragana Samardzija
- Molecular and Reproductive Toxicology Unit, Laboratory for Ecotoxicology, Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, 21000 Novi Sad, Serbia
| | - Jelena Hrubik
- Molecular and Reproductive Toxicology Unit, Laboratory for Ecotoxicology, Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, 21000 Novi Sad, Serbia
| | - Branka Glisic
- Molecular and Reproductive Toxicology Unit, Laboratory for Ecotoxicology, Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, 21000 Novi Sad, Serbia
| | - Radmila Kovacevic
- Molecular and Reproductive Toxicology Unit, Laboratory for Ecotoxicology, Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, 21000 Novi Sad, Serbia
| | - Nebojsa Andric
- Molecular and Reproductive Toxicology Unit, Laboratory for Ecotoxicology, Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, 21000 Novi Sad, Serbia.
| |
Collapse
|