1
|
Li CH, Shi YL, Li M, Guo LH, Cai YQ. Receptor-Bound Perfluoroalkyl Carboxylic Acids Dictate Their Activity on Human and Mouse Peroxisome Proliferator-Activated Receptor γ. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:9529-9536. [PMID: 32639727 DOI: 10.1021/acs.est.0c02386] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
In in vitro cell assays, nominal concentrations of a test chemical are most frequently used in the description of its dose-response curves. Although the biologically effective concentration (BEC) is considered as the most relevant dose metric, in practice, it is very difficult to measure. In this work, we attempted to determine the BEC of long-chain perfluoroalkyl carboxylic acids (PFCAs) in peroxisome proliferator-activated receptor γ (PPARγ) activity assays. In both adipogenesis and transcriptional activity assays with human and mouse cells, PPARγ activity of 7 PFCAs first increased and then decreased with their carbon chain length. The binding affinity of these PFCAs with the ligand-binding domain of PPARγ was measured by fluorescence competitive binding assay and showed very poor correlation with their receptor activity (r2 = 0.002-0.047). Internal concentrations of the PFCAs in the cells were measured by LC-MS/MS. Although their correlation with the receptor activity increased significantly, it is still low (r2 = 0.41-0.82). Using the binding affinity constant, internal concentration, and PPARγ concentration measured by immunoassays, concentrations of receptor-bound PFCAs in cells were calculated, which exhibited excellent correlation with PPARγ activity in both adipogenesis and transcriptional activity assays (r2 = 0.91-0.93). These results demonstrate that the concentration of receptor-bound PFCA is the BEC that dictates its activity on human and mouse PPARγ in cell assays. In the absence of any direct detection method, our approach can be used to calculate the target-site concentration of other ligands.
Collapse
Affiliation(s)
- Chuan-Hai Li
- State Key Laboratory of Environmental Chemistry and Eco-toxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085, China
- School of Public Health, Qingdao University, 308 Ningxia Street, Qingdao, Shandong 266071, China
| | - Ya-Li Shi
- State Key Laboratory of Environmental Chemistry and Eco-toxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085, China
| | - Minjie Li
- College of Quality & Safety Engineering, China Jiliang University, 258 Xueyuan Street, Hangzhou, Zhejiang 310018, China
| | - Liang-Hong Guo
- Institute of Environmental and Health Sciences, China Jiliang University, 168 Xueyuan Street, Hangzhou, Zhejiang 310018, China
- Institute of Environmental and Health, Jianghan University, Wuhan, Hubei 430056, China
| | - Ya-Qi Cai
- State Key Laboratory of Environmental Chemistry and Eco-toxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085, China
| |
Collapse
|
2
|
Xin Y, Wan B, Yang Y, Cui XJ, Xie YC, Guo LH. Perfluoroalkyl acid exposure induces protective mitochondrial and endoplasmic reticulum autophagy in lung cells. Arch Toxicol 2018; 92:3131-3147. [PMID: 30022264 DOI: 10.1007/s00204-018-2266-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 07/12/2018] [Indexed: 01/07/2023]
Abstract
Wide application of perfluoroalkyl acids (PFAAs) has raised great concerns on their side-effects on human health. PFAAs have been shown to accumulate mainly in the liver and cause hepatotoxicity. However, PFAAs can also deposit in lung tissues through air-borne particles and cause serious pulmonary toxicity. But the underlying mechanisms are still largely unknown. Autophagy is a type of programmed cell death parallel to necrosis and apoptosis, and may be involved in the lung toxicity of PFAAs. In this study, lung cancer cells, A549, were employed as the model to investigate the effects of three PFAAs with different carbon chain lengths on cell autophagy. Through Western blot analysis on LC3-I/II ratio of cells exposed to non-cytotoxic concentration (200 µM) and cytotoxic concentration (350 µM), we found concentration-dependent increase of autophagosomes in cells, which was further confirmed by TEM examination on ultra-thin section of cells and fluorescence imaging on autophagosomes in live cells. The abundance of p62 increased with the PFAAs concentration indicating the blockage of autophagy flux. Furthermore, we identified the mitochondrial autophagy (mitophagy) and endoplasmic reticulum autophagy (ER-phagy) morphologically as the major types of autophagy, suggesting the disruption on mitochondria and ERs. These organelle damages were confirmed by the overgeneration of ROS, hyperpolarization of mitochondrial membrane potential, as well as the up-regulation of ER-stress-related proteins, ATF4 and p-IRE1. Further analysis on the signaling pathways showed that PFAAs activated the MAPK pathways and inhibited the PI3K/Akt pathway, with potencies following the order of PFDA > PFNA > PFOA. Anti-oxidant (NAC) treatment did not rescue cells from death, indicating that oxidative stress is not the reason of cytotoxicity. Inhibition of autophagy by Atg5 siRNA and chloroquine even increased the toxicity of PFAAs, suggesting that PFAAs-autophagy was induced as the secondary effects of organelle damages and played a protective role during cell death.
Collapse
Affiliation(s)
- Yan Xin
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, P.O. Box 2871, Beijing, 100085, People's Republic of China.,College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | - Bin Wan
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, P.O. Box 2871, Beijing, 100085, People's Republic of China. .,College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China.
| | - Yu Yang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, P.O. Box 2871, Beijing, 100085, People's Republic of China
| | - Xue-Jing Cui
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, P.O. Box 2871, Beijing, 100085, People's Republic of China.,College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | - Yi-Chun Xie
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, P.O. Box 2871, Beijing, 100085, People's Republic of China.,College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | - Liang-Hong Guo
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, P.O. Box 2871, Beijing, 100085, People's Republic of China. .,College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China. .,Institute of Environment and Health, Jianghan University, Wuhan, 430056, Hubei, People's Republic of China.
| |
Collapse
|
3
|
Cao H, Li X, Zhang W, Wang L, Pan Y, Zhou Z, Chen M, Zhang A, Liang Y, Song M. Anti-estrogenic activity of tris(2,3-dibromopropyl) isocyanurate through disruption of co-activator recruitment: experimental and computational studies. Arch Toxicol 2018; 92:1471-1482. [DOI: 10.1007/s00204-018-2159-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 01/17/2018] [Indexed: 12/21/2022]
|
4
|
Yu X, Nishimura F, Hidaka T. Effects of microbial activity on perfluorinated carboxylic acids (PFCAs) generation during aerobic biotransformation of fluorotelomer alcohols in activated sludge. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 610-611:776-785. [PMID: 28826115 DOI: 10.1016/j.scitotenv.2017.08.075] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 08/06/2017] [Accepted: 08/08/2017] [Indexed: 05/13/2023]
Abstract
Biotransformation of fluorotelomer alcohols (FTOHs) in wastewater treatment plants (WWTPs) can release toxic intermediates and perfluorinated carboxylic acids (PFCAs) to the aqueous environment. However, little information is known about the role of relevant microbial activity (i.e., autotrophs and/or heterotrophs) in biotransformation of FTOHs. Additionally, the dynamics of microbial community in sludge after exposure to FTOHs remain unclear. In the present research, using domestic and industrial WWTP sludge, we performed lab-scale batch experiments to characterize the FTOHs biodegradation property under aerobic condition. Both heterotrophs and the autotrophs were associated with FTOHs biotransformation. However, the microbial activity influenced PFCAs generation efficiency. Autotrophs based on ammonia oxidation (50mgN/L) resulted in more effective generation of PFCAs than heterotrophs based on glucose (200mgC/L) metabolism. Moreover, autotrophs generated more amounts of short-chain PFCAs (carbon number ≤7) than the heterotrophs. The ammonia monooxygenase (AMO) in ammonia oxidizing microorganisms (AOMs) are suggested as responsible for the enhanced generation of PFCAs during FTOHs biotransformation. In the sludge that had been exposed to poly- and perfluorinated alkyl substances in an industrial WWTP, Chlorobi was the predominant microorganisms (36.9%), followed by Proteobacteria (20.2%), Bacteroidetes (11.1%), Chloroflexi (6.2%), Crenarchaeota (5.6%), Planctomycetes (4.2%), and Acidobacteria (3.5%). In the present research, the dosed 8:2 FTOH (12.1mg/L) and its biotransformation products (intermediates and PFCAs) could force a shift in microbial community composition in the sludge. After 192h, Proteobacteria significantly increased and dominated. These results provide knowledge for comprehending the effects of microbial activity on FTOHs biodegradation and the information about interaction between microbial community and the exposure to FTOHs in activated sludge.
Collapse
Affiliation(s)
- Xiaolong Yu
- Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, C1, Kyoto daigaku-Katsura, Kyoto 615-8540, Japan.
| | - Fumitake Nishimura
- Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, C1, Kyoto daigaku-Katsura, Kyoto 615-8540, Japan
| | - Taira Hidaka
- Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, C1, Kyoto daigaku-Katsura, Kyoto 615-8540, Japan
| |
Collapse
|