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Duffel MW, Lehmler HJ. Complex roles for sulfation in the toxicities of polychlorinated biphenyls. Crit Rev Toxicol 2024; 54:92-122. [PMID: 38363552 PMCID: PMC11067068 DOI: 10.1080/10408444.2024.2311270] [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: 12/29/2023] [Accepted: 01/23/2024] [Indexed: 02/17/2024]
Abstract
Polychlorinated biphenyls (PCBs) are persistent organic toxicants derived from legacy pollution sources and their formation as inadvertent byproducts of some current manufacturing processes. Metabolism of PCBs is often a critical component in their toxicity, and relevant metabolic pathways usually include their initial oxidation to form hydroxylated polychlorinated biphenyls (OH-PCBs). Subsequent sulfation of OH-PCBs was originally thought to be primarily a means of detoxication; however, there is strong evidence that it may also contribute to toxicities associated with PCBs and OH-PCBs. These contributions include either the direct interaction of PCB sulfates with receptors or their serving as a localized precursor for OH-PCBs. The formation of PCB sulfates is catalyzed by cytosolic sulfotransferases, and, when transported into the serum, these metabolites may be retained, taken up by other tissues, and subjected to hydrolysis catalyzed by intracellular sulfatase(s) to regenerate OH-PCBs. Dynamic cycling between PCB sulfates and OH-PCBs may lead to further metabolic activation of the resulting OH-PCBs. Ultimate toxic endpoints of such processes may include endocrine disruption, neurotoxicities, and many others that are associated with exposures to PCBs and OH-PCBs. This review highlights the current understanding of the complex roles that PCB sulfates can have in the toxicities of PCBs and OH-PCBs and research on the varied mechanisms that control these roles.
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Affiliation(s)
- Michael W. Duffel
- Department of Pharmaceutical Sciences & Experimental Therapeutics, College of Pharmacy, The University of Iowa, Iowa City, Iowa, 52242, United States
| | - Hans-Joachim Lehmler
- Department of Occupational and Environmental Health, College of Public Health, The University of Iowa, Iowa City, Iowa, 52242, United States
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Xu Y, Peng T, Zhou Q, Zhu J, Liao G, Zou F, Meng X. Evaluation of the oxidative toxicity induced by lead, manganese, and cadmium using genetically modified nrf2a-mutant zebrafish. Comp Biochem Physiol C Toxicol Pharmacol 2023; 266:109550. [PMID: 36717045 DOI: 10.1016/j.cbpc.2023.109550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 01/03/2023] [Accepted: 01/15/2023] [Indexed: 01/30/2023]
Abstract
Heavy metal pollution has become a serious environmental concern and a threat to public health. Three of the most common heavy metals are cadmium (Cd), lead (Pb), and manganese (Mn). Nuclear factor erythroid 2-related factor 2 (Nrf2) is an important transcription factor activated in the response to oxidative stress. In this study, mutant zebrafish with an nrf2a deletion of 7 bp were constructed by the CRISPR/Cas9 system to investigate the oxidative toxicity of these three heavy metals. The results of general toxicity tests showed that Pb exposure did not cause significant damage to mutant zebrafish compared with wild-type (WT) zebrafish. However, high Mn exposure increased mortality and malformation rates in mutant zebrafish. Of concern, Cd exposure caused significant toxic damage, including increased mortality and malformation rates, apoptosis of brain neurons, and severe locomotor behavior aberration in mutant zebrafish. The results of qRT-PCR indicated that Cd exposure could induce the activation of genes related to oxidative stress resistance in WT zebrafish, while the expression of these genes was inhibited in mutant zebrafish. This study showed that of the three heavy metals, Cd had the strongest oxidative toxicity, Mn had medium toxicity, and Pb had the weakest toxicity.
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Affiliation(s)
- Yongjie Xu
- Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China
| | - Tao Peng
- Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China
| | - Qin Zhou
- Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China
| | - Jiawei Zhu
- Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China
| | - Gengze Liao
- Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China
| | - Fei Zou
- Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China.
| | - Xiaojing Meng
- Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China.
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