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Hu Y, Zhang L, Tian C, Chen F, Li P, Zhang A, Wang W. Molecular crosstalk and putative mechanisms underlying mitochondrial quality control: The hidden link with methylmercury-induced cognitive impairment. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 278:116360. [PMID: 38678690 DOI: 10.1016/j.ecoenv.2024.116360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 04/04/2024] [Accepted: 04/19/2024] [Indexed: 05/01/2024]
Abstract
Methylmercury (MeHg) is a neurotoxin associated with foetal neurodevelopmental and adult cognitive deficits. Neurons are highly dependent on the tricarboxylic acid cycle and oxidative phosphorylation to produce ATP and meet their high energy demands. Therefore, mitochondrial quality control (MQC) is critical for neuronal homeostasis. While existing studies have generated a wealth of data on the toxicity of MeHg, the complex cascades and molecular pathways governing the mitochondrial network remain to be elucidated. Here, 0.6, 1.2 and 2.4 mg/kg body weight of MeHg were administered intragastrically to pregnant Sprague Dawley rats to model maternal MeHg exposure. The results of the in vivo study revealed that MeHg-treated rats tended to perform more directionless repetitive strategies in the Morris Water Maze and fewer target-orientation strategies than control offspring. Moreover, pathological injury and synaptic toxicity were observed in the hippocampus. Transmission electron microscopy (TEM) demonstrated that the autophagosomes encapsulated damaged mitochondria, while showing a typical mitochondrial fission phenotype, which was supported by the activation of PINK1-dependent key regulators of mitophagy. Moreover, there was upregulation of DRP1 and FIS1. Additionally, MeHg compensation promoted mitochondrial biogenesis, as evidenced by the activation of the mitochondrial PGC1-α-NRF1-TFAM signalling pathway. Notably, SIRT3/AMPK was activated by MeHg, and the expression and activity of p-AMPK, p-LKB1 and SIRT3 were consistently coordinated. Collectively, these findings provide new insights into the potential molecular mechanisms regulating MeHg-induced cognitive deficits through SIRT3/AMPK MQC network coordination.
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Affiliation(s)
- Yi Hu
- The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang 550025, China
| | - Li Zhang
- The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang 550025, China
| | - Changsong Tian
- The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang 550025, China
| | - Fang Chen
- The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang 550025, China
| | - Ping Li
- The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang 550025, China; State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Aihua Zhang
- The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang 550025, China; Collaborative Innovation Centre for Prevention and Control of Endemic and Ethnic Regional Diseases Co-constructed by the Province and Ministry, Guizhou Medical University, Guiyang 550025, China.
| | - Wenjuan Wang
- The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang 550025, China; Collaborative Innovation Centre for Prevention and Control of Endemic and Ethnic Regional Diseases Co-constructed by the Province and Ministry, Guizhou Medical University, Guiyang 550025, China.
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Yu G, Wu L, Su Q, Ji X, Zhou J, Wu S, Tang Y, Li H. Neurotoxic effects of heavy metal pollutants in the environment: Focusing on epigenetic mechanisms. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 345:123563. [PMID: 38355086 DOI: 10.1016/j.envpol.2024.123563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 02/04/2024] [Accepted: 02/11/2024] [Indexed: 02/16/2024]
Abstract
The pollution of heavy metals (HMs) in the environment is a significant global environmental issue, characterized by its extensive distribution, severe contamination, and profound ecological impacts. Excessive exposure to heavy metal pollutants can damage the nervous system. However, the mechanisms underlying the neurotoxicity of most heavy metals are not completely understood. Epigenetics is defined as a heritable change in gene function that can influence gene and subsequent protein expression levels without altering the DNA sequence. Growing evidence indicates that heavy metals can induce neurotoxic effects by triggering epigenetic changes and disrupting the epigenome. Compared with genetic changes, epigenetic alterations are more easily reversible. Epigenetic reprogramming techniques, drugs, and certain nutrients targeting specific epigenetic mechanisms involved in gene expression regulation are emerging as potential preventive or therapeutic tools for diseases. Therefore, this review provides a comprehensive overview of epigenetic modifications encompassing DNA/RNA methylation, histone modifications, and non-coding RNAs in the nervous system, elucidating their association with various heavy metal exposures. These primarily include manganese (Mn), mercury (Hg), lead (Pb), cobalt (Co), cadmium (Cd), nickel (Ni), sliver (Ag), toxic metalloids arsenic (As), and etc. The potential epigenetic mechanisms in the etiology, precision prevention, and target therapy of various neurodevelopmental disorders or different neurodegenerative diseases are emphasized. In addition, the current gaps in research and future areas of study are discussed. From a perspective on epigenetics, this review offers novel insights for prevention and treatment of neurotoxicity induced by heavy metal pollutants.
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Affiliation(s)
- Guangxia Yu
- Key Lab of Environment and Health, School of Public Health, Fujian Medical University, Fuzhou 350122, China; Department of Preventive Medicine, School of Public Health, Fujian Medical University, Fuzhou 350122, China
| | - Lingyan Wu
- Key Lab of Environment and Health, School of Public Health, Fujian Medical University, Fuzhou 350122, China
| | - Qianqian Su
- Key Lab of Environment and Health, School of Public Health, Fujian Medical University, Fuzhou 350122, China
| | - Xianqi Ji
- Key Lab of Environment and Health, School of Public Health, Fujian Medical University, Fuzhou 350122, China
| | - Jinfu Zhou
- Key Lab of Environment and Health, School of Public Health, Fujian Medical University, Fuzhou 350122, China; Fujian Maternity and Child Hospital College of Clinical Medicine for Obstetrics & Gynecology and Pediatrics, Fujian Medical University, Fuzhou 350001, China
| | - Siying Wu
- Key Lab of Environment and Health, School of Public Health, Fujian Medical University, Fuzhou 350122, China; Department of Epidemiology and Health Statistics, School of Public Health, Fujian Medical University, Fuzhou 350122, China
| | - Ying Tang
- Fujian Center for Prevention and Control Occupational Diseases and Chemical Poisoning, Fuzhou 350125, China
| | - Huangyuan Li
- Key Lab of Environment and Health, School of Public Health, Fujian Medical University, Fuzhou 350122, China; Department of Preventive Medicine, School of Public Health, Fujian Medical University, Fuzhou 350122, China.
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Garofalo G, Nielsen T, Caito S. Expression Profiling of Adipogenic and Anti-Adipogenic MicroRNA Sequences following Methylmercury Exposure in Caenorhabditis elegans. TOXICS 2023; 11:934. [PMID: 37999587 PMCID: PMC10674990 DOI: 10.3390/toxics11110934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 11/08/2023] [Accepted: 11/15/2023] [Indexed: 11/25/2023]
Abstract
MicroRNA (miRNA) are important regulators of gene expression that respond not only to developmental and pathological cues, but also to environmental stimuli. Dyslipidemia is a hallmark of metabolic conditions and has been shown to significantly affect the expression of circulating miRNA sequences. Recently, our lab has shown that the environmental toxicant methylmercury (MeHg) causes dyslipidemia in the Caenorhabditis elegans model organism. While 10 and 20 μM MeHg increases the expression of adipogenic transcription factors and lipid-binding proteins in worms, there is limited information on how the toxicant affects the miRNA regulators of these genes. We hypothesized that MeHg would increase the expression of adipogenic miRNA sequences and/or decrease the expression of anti-adipogenic miRNA sequences. We further hypothesized that the target mRNA sequences for the miRNAs affected by MeHg would be consequently altered. We selected three potentially adipogenic (mir-34, mir-124, and mir-355) and three potentially anti-adipogenic (mir-240, mir-786, and let-7) miRNA sequences homologous to known human miRNA sequences altered in obesity, and quantified their levels 24 h and 48 h post MeHg treatment. At 24 h post exposure, MeHg significantly increased expression of both the adipogenic and anti-adipogenic miRNA sequences 1.5-3x above untreated control. By 48 h post exposure, only the adipogenic miRNA sequences were elevated, while the anti-adipogenic miRNA sequences were decreased by 50% compared to untreated control. These data suggest that there are developmental changes in miRNA expression over time following MeHg exposure. We next selected one target mRNA sequence for each miRNA sequence based on miRNA-mRNA relationships observed in humans. MeHg altered the gene expression of all the target genes assayed. Except for mir-34, all the tested miRNA-mRNA sequences showed a conserved relationship between nematode and humans. To determine whether the selected miRNA sequences were involved in lipid accumulation in response to MeHg, lipid storage was investigated in transgenic worm strains that lacked the specific miRNA strains. Of the six strains investigated, only the mir-124 and let-7 mutant worms had lipid storage levels that were statistically different from wild type, suggesting that these two sequences can be potential mediators of MeHg-induced lipid dysregulation.
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Affiliation(s)
| | | | - Samuel Caito
- Department of Pharmaceutical Sciences, Husson University School of Pharmacy, Bangor, ME 04401, USA
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Cediel-Ulloa A, Lindner S, Rüegg J, Broberg K. Epigenetics of methylmercury. Neurotoxicology 2023; 97:34-46. [PMID: 37164037 DOI: 10.1016/j.neuro.2023.05.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 05/03/2023] [Accepted: 05/05/2023] [Indexed: 05/12/2023]
Abstract
PURPOSE OF REVIEW Methylmercury (MeHg) is neurotoxic at high levels and particularly affects the developing brain. One proposed mechanism of MeHg neurotoxicity is alteration of the epigenetic programming. In this review, we summarise the experimental and epidemiological literature on MeHg-associated epigenetic changes. RECENT FINDINGS Experimental and epidemiological studies have identified changes in DNA methylation following in utero exposure to MeHg, and some of the changes appear to be persistent. A few studies have evaluated associations between MeHg-related changes in DNA methylation and neurodevelopmental outcomes. Experimental studies reveal changes in histone modifications after MeHg exposure, but we lack epidemiological studies supporting such changes in humans. Experimental and epidemiological studies have identified microRNA-related changes associated with MeHg; however, more research is needed to conclude if these changes lead to persistent and toxic effects. SUMMARY MeHg appears to interfere with epigenetic processes, potentially leading to persistent changes. However, observed associations of mercury with epigenetic changes are as of yet of unknown relevance to neurodevelopmental outcomes.
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Affiliation(s)
- Andrea Cediel-Ulloa
- Department of Organism Biology, Uppsala University, Kåbovägen 4, 752 36 Uppsala, Sweden
| | - Sabrina Lindner
- Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, Lund, Sweden
| | - Joëlle Rüegg
- Department of Organism Biology, Uppsala University, Kåbovägen 4, 752 36 Uppsala, Sweden
| | - Karin Broberg
- Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, Lund, Sweden; Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
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Bose R, Spulber S, Ceccatelli S. The Threat Posed by Environmental Contaminants on Neurodevelopment: What Can We Learn from Neural Stem Cells? Int J Mol Sci 2023; 24:ijms24054338. [PMID: 36901772 PMCID: PMC10002364 DOI: 10.3390/ijms24054338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 02/03/2023] [Accepted: 02/17/2023] [Indexed: 02/24/2023] Open
Abstract
Exposure to chemicals may pose a greater risk to vulnerable groups, including pregnant women, fetuses, and children, that may lead to diseases linked to the toxicants' target organs. Among chemical contaminants, methylmercury (MeHg), present in aquatic food, is one of the most harmful to the developing nervous system depending on time and level of exposure. Moreover, certain man-made PFAS, such as PFOS and PFOA, used in commercial and industrial products including liquid repellants for paper, packaging, textile, leather, and carpets, are developmental neurotoxicants. There is vast knowledge about the detrimental neurotoxic effects induced by high levels of exposure to these chemicals. Less is known about the consequences that low-level exposures may have on neurodevelopment, although an increasing number of studies link neurotoxic chemical exposures to neurodevelopmental disorders. Still, the mechanisms of toxicity are not identified. Here we review in vitro mechanistic studies using neural stem cells (NSCs) from rodents and humans to dissect the cellular and molecular processes changed by exposure to environmentally relevant levels of MeHg or PFOS/PFOA. All studies show that even low concentrations dysregulate critical neurodevelopmental steps supporting the idea that neurotoxic chemicals may play a role in the onset of neurodevelopmental disorders.
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Liu M, Liu X, Pan M, Zhang Y, Tang X, Liu W, Zhao M, Ma J, Zhou N, Jiang Y, Wang W, Liu M. Characterization and microRNA Expression Analysis of Serum-Derived Extracellular Vesicles in Severe Liver Injury from Chronic HBV Infection. Life (Basel) 2023; 13:life13020347. [PMID: 36836704 PMCID: PMC9967308 DOI: 10.3390/life13020347] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 01/20/2023] [Accepted: 01/25/2023] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Extracellular vesicle (EV) microRNAs have been documented in several studies to have significantly different expressions in hepatitis B virus (HBV)-related liver diseases, such as hepatocellular carcinoma (HCC). The current work aimed to observe the characteristics of EVs and EV miRNA expressions in patients with severe liver injury chronic hepatitis B (CHB) and patients with HBV-associated decompensated cirrhosis (DeCi). METHODS The characterization of the EVs in the serum was carried out for three different groups, namely, patients with severe liver injury-CHB, patients with DeCi, and healthy controls. EV miRNAs were analyzed using miRNA-seq and RT-qPCR arrays. Additionally, we assessed the predictive and observational values of the miRNAs with significant differential expressions in serum EVs. RESULTS Patients with severe liver injury-CHB had the highest EV concentrations when compared to the normal controls (NCs) and patients with DeCi (p < 0.001). The miRNA-seq of the NC and severe liver injury-CHB groups identified 268 differentially expressed miRNAs (|FC| > 2, p < 0.05). In this case, 15 miRNAs were verified using RT-qPCR, and it was found that novel-miR-172-5p and miR-1285-5p in the severe liver injury-CHB group showed marked downregulation in comparison to the NC group (p < 0.001). Furthermore, compared with the NC group, three EV miRNAs (novel-miR-172-5p, miR-1285-5p, and miR-335-5p) in the DeCi group showed various degrees of downregulated expression. However, when comparing the DeCi group with the severe liver injury-CHB group, only the expression of miR-335-5p in the DeCi group decreased significantly (p < 0.05). For the severe liver injury-CHB and DeCi groups, the addition of miR-335-5p improved the predictive accuracy of the serological levels, while miR-335-5p was significantly correlated with ALT, AST, AST/ALT, GGT, and AFP. Conclusions: The patients with severe liver injury-CHB had the highest number of EVs. The combination of novel-miR-172-5p and miR-1285-5p in serum EVs helped in predicting the progression of the NCs to severe liver injury-CHB, while the addition of EV miR-335-5p improved the serological accuracy of predicting the progression of severe liver injury-CHB to DeCi.
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Affiliation(s)
- Min Liu
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha 410078, China
| | - Xionghao Liu
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha 410078, China
- Hunan Key Laboratory of Basic and Applied Hematology, Central South University, Changsha 410078, China
- Hunan Key Laboratory of Animal Models for Human Diseases, Central South University, Changsha 410078, China
| | - Mengmeng Pan
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha 410078, China
| | - Yu Zhang
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha 410078, China
| | - Xiangling Tang
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha 410078, China
| | - Wanxi Liu
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha 410078, China
| | - Mingri Zhao
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha 410078, China
| | - Jing Ma
- Department of Infectious Disease, The Second Xiangya Hospital of Central South University, Changsha 410011, China
| | - Ning Zhou
- Department of Infectious Disease, The Second Xiangya Hospital of Central South University, Changsha 410011, China
| | - Yongfang Jiang
- Department of Infectious Disease, The Second Xiangya Hospital of Central South University, Changsha 410011, China
| | - Wenlong Wang
- Department of Infectious Disease, The Second Xiangya Hospital of Central South University, Changsha 410011, China
- Correspondence: (W.W.); (M.L.)
| | - Mujun Liu
- Hunan Key Laboratory of Basic and Applied Hematology, Central South University, Changsha 410078, China
- Hunan Key Laboratory of Animal Models for Human Diseases, Central South University, Changsha 410078, China
- Department of Cell Biology, School of Life Sciences, Central South University, Changsha 410013, China
- Correspondence: (W.W.); (M.L.)
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Ke T, Tinkov AA, Skalny AV, Santamaria A, Rocha JBT, Bowman AB, Chen W, Aschner M. Epigenetics and Methylmercury-Induced Neurotoxicity, Evidence from Experimental Studies. TOXICS 2023; 11:toxics11010072. [PMID: 36668798 PMCID: PMC9860901 DOI: 10.3390/toxics11010072] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/08/2023] [Accepted: 01/10/2023] [Indexed: 05/14/2023]
Abstract
MeHg is an environmental neurotoxin that can adversely affect the development of the nervous system. The molecular integrity of chromatin in the nucleus is an important target of MeHg. Low levels of MeHg trigger epigenetic mechanisms that may be involved in long-lasting and transgenerational neurotoxicity after exposure. Emerging evidence has shown that these mechanisms include histone modification, siRNA, and DNA methylation. The MeHg-induced inhibition of neurodifferentiation and neurogenesis are mechanistically associated with epigenetic alterations in critical genes, such as neurotrophin brain-derived neurotrophic factor (BDNF). Further, MeHg exposure has been shown to alter the activity and/or expression of the upstream regulators of chromatin structure, including histone deacetylases (HDACs) and DNA methyltransferase (DNMTs), which may trigger permanent alterations in histone modifications and DNA methylation. MeHg-exposure also alters several species of miRNA that are associated with neurodevelopment. Genetic studies in the C. elegans model of MeHg-induced toxicity proposes a potential interplay between exogenous RNAi and antioxidant defense. In this review, we discuss the molecular basis for MeHg exposure-induced alterations in chromatin structure and the roles of histone modifications, siRNA, and DNA methylation in MeHg-induced neurotoxic effects.
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Affiliation(s)
- Tao Ke
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Correspondence: (T.K.); (M.A.)
| | - Alexey A. Tinkov
- World-Class Research Center “Digital Biodesign and Personalized Healthcare”, IM Sechenov First Moscow State Medical University (Sechenov University), 119435 Moscow, Russia
- Laboratory of Ecobiomonitoring and Quality Control, Yaroslavl State University, 150003 Yaroslavl, Russia
- Department of Medical Elementology, RUDN University, 117198 Moscow, Russia
| | - Anatoly V. Skalny
- World-Class Research Center “Digital Biodesign and Personalized Healthcare”, IM Sechenov First Moscow State Medical University (Sechenov University), 119435 Moscow, Russia
- Department of Medical Elementology, RUDN University, 117198 Moscow, Russia
| | - Abel Santamaria
- Laboratorio de Aminoácidos Excitadores/Laboratorio de Neurofarmacología Molecular y Nanotecnología, Instituto Nacional de Neurología y Neurocirugía, Mexico City 14269, Mexico
| | - Joao B. T. Rocha
- Departamento de Bioquímica e Biologia Molecular, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria 97105-900, RS, Brazil
| | - Aaron B. Bowman
- School of Health Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Wen Chen
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Department of Toxicology, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Correspondence: (T.K.); (M.A.)
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Augustyniak J, Lipka G, Kozlowska H, Caloni F, Buzanska L. Oxygen as an important factor modulating in vitro MeHgCl toxicity associated with mitochondrial genes in hiPSCs. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 241:113737. [PMID: 35696963 DOI: 10.1016/j.ecoenv.2022.113737] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 05/29/2022] [Accepted: 05/31/2022] [Indexed: 06/15/2023]
Abstract
Mitochondria are energy factories of cells and important targets for methylmercury chloride (MgHgCl). Methylmercury (MeHg) is a well-known environmental toxicant that bioaccumulates in fish and shellfish. It readily crosses the placental barrier, making it a threat to correct fetal development. Despite being comprehensively investigated for years, this compound has not been assessed for its in vitro mitochondrial toxicity under different oxygen conditions. In this study, human induced pluripotent stem cells (hiPSCs) were used to evaluate the dependence of the expression of genes associated with pluripotency and mitochondria on atmospheric (21% O2) and low (5% O2) oxygen concentrations upon MeHgCl treatment. We showed that the toxicity of MeHgCl was strongly related to an increased mtDNA copy number and downregulation of the expression of an mtDNA replication and damage repair-associated gene POLG1 (Mitochondrial Polymerase Gamma Catalytic Subunit) in both tested oxygen conditions. In addition, the viability and mitochondrial membrane potential of hiPSCs were significantly lowered by MeHgCl regardless of the oxygen concentration. However, reactive oxygen species accumulation significantly increased only under atmospheric oxygen conditions; what was associated with increased expression of TFAM (Transcription Factor A, Mitochondrial) and NRF1 (Nuclear Respiratory Factor 1) and downregulation of PARK2 (Parkin RBR E3 Ubiquitin Protein Ligase). Taken together, our results demonstrated that MeHgCl could induce in vitro toxicity in hiPSCs through altering mitochondria-associated genes in an oxygen level-dependent manner. Thus, our work suggests that oxygen should be considered a factor was modulating the in vitro toxicity of environmental pollutants. Typical atmospheric conditions of in vitro culture significantly lower the predictive value of studies of such toxicity.
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Affiliation(s)
- J Augustyniak
- Department of Neurochemistry, Mossakowski Medical Research Institute Polish Academy of Sciences, Warsaw, Poland
| | - G Lipka
- Department of Stem Cell Bioengineering, Mossakowski Medical Research Institute Polish Academy of Sciences, Warsaw, Poland
| | - H Kozlowska
- Laboratory of Advanced Microscopy Technique, Mossakowski Medical Research Institute Polish Academy of Sciences, Warsaw, Poland
| | - F Caloni
- Department of Environmental Science and Policy (ESP), Università degli Studi di Milano, Milan, Italy
| | - L Buzanska
- Department of Stem Cell Bioengineering, Mossakowski Medical Research Institute Polish Academy of Sciences, Warsaw, Poland
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Pan J, Li X, Wei Y, Ni L, Xu B, Deng Y, Yang T, Liu W. Advances on the Influence of Methylmercury Exposure during Neurodevelopment. Chem Res Toxicol 2022; 35:43-58. [PMID: 34989572 DOI: 10.1021/acs.chemrestox.1c00255] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Mercury (Hg) is a toxic heavy-metal element, which can be enriched in fauna and flora and transformed into methylmercury (MeHg). MeHg is a widely distributed environmental pollutant that may be harmful to fish-eating populations through enrichment of aquatic food chains. The central nervous system is a primary target of MeHg. Embryos and infants are more sensitive to MeHg, and exposure to MeHg during gestational feeding can significantly impair the homeostasis of offspring, leading to long-term neurodevelopmental defects. At present, MeHg-induced neurodevelopmental toxicity has become a hotspot in the field of neurotoxicology, but its mechanisms are not fully understood. Some evidence point to oxidative damage, excitotoxicity, calcium ion imbalance, mitochondrial dysfunction, epigenetic changes, and other molecular mechanisms that play important roles in MeHg-induced neurodevelopmental toxicity. In this review, advances in the study of neurodevelopmental toxicity of MeHg exposure during pregnancy and the molecular mechanisms of related pathways are summarized, in order to provide more scientific basis for the study of neurodevelopmental toxicity of MeHg.
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Affiliation(s)
- Jingjing Pan
- Department of Environmental Health, School of Public Health, China Medical University, No.77 Puhe Road, Shenbei New District, Shenyang 110122, Liaoning China
| | - Xiaoyang Li
- Department of Environmental Health, School of Public Health, China Medical University, No.77 Puhe Road, Shenbei New District, Shenyang 110122, Liaoning China
| | - Yanfeng Wei
- Department of Environmental Health, School of Public Health, China Medical University, No.77 Puhe Road, Shenbei New District, Shenyang 110122, Liaoning China
| | - Linlin Ni
- Department of Environmental Health, School of Public Health, China Medical University, No.77 Puhe Road, Shenbei New District, Shenyang 110122, Liaoning China
| | - Bin Xu
- Department of Environmental Health, School of Public Health, China Medical University, No.77 Puhe Road, Shenbei New District, Shenyang 110122, Liaoning China
| | - Yu Deng
- Department of Environmental Health, School of Public Health, China Medical University, No.77 Puhe Road, Shenbei New District, Shenyang 110122, Liaoning China
| | - Tianyao Yang
- Department of Environmental Health, School of Public Health, China Medical University, No.77 Puhe Road, Shenbei New District, Shenyang 110122, Liaoning China
| | - Wei Liu
- Department of Environmental Health, School of Public Health, China Medical University, No.77 Puhe Road, Shenbei New District, Shenyang 110122, Liaoning China
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10
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You D, Cohen JD, Pustovalova O, Lewis L, Shen L. OUP accepted manuscript. Toxicol Sci 2022; 186:221-241. [PMID: 35134991 PMCID: PMC8963304 DOI: 10.1093/toxsci/kfac011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
| | - Jennifer D Cohen
- Jennifer D. Cohen, Drug Safety Research & Evaluation, Takeda Development Center Americas, Inc., 9625 Towne Centre Drive, San Diego, CA 92121-1964, USA. E-mail:
| | | | - Lauren Lewis
- Drug Safety Research & Evaluation, Takeda Development Center Americas, Inc., Cambridge, Massachusetts 02139, USA
| | - Lei Shen
- Data Science Institute, Takeda Development Center Americas, Inc., Cambridge, Massachusetts 02139, USA
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11
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Nielsen T, Crawford N, Martell M, Khalil B, Imtiaz F, Newell-Caito JL, Caito S. MicroRNA Expression Influences Methylmercury-Induced Lipid Accumulation and Mitochondrial Toxicity in Caenorhabditis elegans. Chem Res Toxicol 2021; 35:77-88. [PMID: 34905692 DOI: 10.1021/acs.chemrestox.1c00306] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Metabolic effects of methylmercury (MeHg) are gaining wider attention. We have previously shown that MeHg causes lipid dysregulation in Caenorhabditis elegans (C. elegans), leading to altered gene expression, increased triglyceride levels and lipid storage, and altered feeding behaviors. Transcriptional regulators, such as transcription factors and microRNAs (miRNAs), have been shown to regulate lipid storage, serum triglycerides, and adipogenic gene expression in human and rodent models of metabolic diseases. As we recently investigated adipogenic transcription factors induced by MeHg, we were, therefore, interested in whether MeHg may also regulate miRNA sequences to cause metabolic dysfunction. Lipid dysregulation, as measured by triglyceride levels, lipid storage sites, and feeding behaviors, was assessed in wild-type (N2) worms and in transgenic worms that either were sensitive to miRNA expression or were unable to process miRNAs. Worms that were sensitive to the miRNA expression were protected from MeHg-induced lipid dysregulation. In contrast, the mutant worms that were unable to process miRNAs had exacerbated MeHg-induced lipid dysregulation. Concurrent with differential lipid homeostasis, miRNA-expression mutants had altered MeHg-induced mitochondrial toxicity as compared to N2, with the miRNA-sensitive mutants showing mitochondrial protection and the miRNA-processing mutants showing increased mitotoxicity. Taken together, our data demonstrate that the expression of miRNAs is an important determinant in MeHg toxicity and MeHg-induced metabolic dysfunction in C. elegans.
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Affiliation(s)
- Tyson Nielsen
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, Husson University, Bangor, Maine 04401, United States
| | - Nicole Crawford
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, Husson University, Bangor, Maine 04401, United States
| | - Megan Martell
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, Husson University, Bangor, Maine 04401, United States
| | - Belal Khalil
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, Husson University, Bangor, Maine 04401, United States
| | - Farooq Imtiaz
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, Husson University, Bangor, Maine 04401, United States
| | - Jennifer L Newell-Caito
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, Maine 04469, United States
| | - Samuel Caito
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, Husson University, Bangor, Maine 04401, United States
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12
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Zhang GQ, Wang SQ, Chen Y, Fu LY, Xu YN, Li L, Tao L, Shen XC. MicroRNAs Regulating Mitochondrial Function in Cardiac Diseases. Front Pharmacol 2021; 12:663322. [PMID: 34122082 PMCID: PMC8194257 DOI: 10.3389/fphar.2021.663322] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 04/23/2021] [Indexed: 12/21/2022] Open
Abstract
Mitochondria are the key organelles that supply cellular energy. As the most active organ in the body, the energy required to maintain the mechanical function of the heart requires a high quantity of high-quality mitochondria in cardiomyocytes. MicroRNAs (miRNAs) are single-stranded noncoding RNAs, approximately 22 nt in length, which play key roles in mediating post-transcriptional gene silencing. Numerous studies have confirmed that miRNAs can participate in the occurrence and development of cardiac diseases by regulating mitochondrial function-related genes and signaling pathways. Therefore, elucidating the crosstalk that occurs between miRNAs and mitochondria is important for the prevention and treatment of cardiac diseases. In this review, we discuss the biogenesis of miRNAs, the miRNA-mediated regulation of major genes involved in the maintenance of mitochondrial function, and the effects of miRNAs on mitochondrial function in cardiac diseases in order to provide a theoretical basis for the clinical prevention and treatment of cardiac disease and the development of new drugs.
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Affiliation(s)
- Guang-Qiong Zhang
- The State Key Laboratory of Functions and Applications of Medicinal Plants, School of Pharmaceutical Sciences, Guizhou Medical University, Guizhou, China.,The High Efficacy Application of Natural Medicinal Resources Engineering Center of Guizhou Province, School of Pharmaceutical Sciences, Guizhou Medical University, Guizhou, China.,The Key Laboratory of Optimal Utilization of Natural Medicine Resources, School of Pharmaceutical Sciences, Guizhou Medical University, Guizhou, China
| | - Sheng-Quan Wang
- The State Key Laboratory of Functions and Applications of Medicinal Plants, School of Pharmaceutical Sciences, Guizhou Medical University, Guizhou, China.,The High Efficacy Application of Natural Medicinal Resources Engineering Center of Guizhou Province, School of Pharmaceutical Sciences, Guizhou Medical University, Guizhou, China.,The Key Laboratory of Optimal Utilization of Natural Medicine Resources, School of Pharmaceutical Sciences, Guizhou Medical University, Guizhou, China
| | - Yan Chen
- The State Key Laboratory of Functions and Applications of Medicinal Plants, School of Pharmaceutical Sciences, Guizhou Medical University, Guizhou, China.,The High Efficacy Application of Natural Medicinal Resources Engineering Center of Guizhou Province, School of Pharmaceutical Sciences, Guizhou Medical University, Guizhou, China.,The Key Laboratory of Optimal Utilization of Natural Medicine Resources, School of Pharmaceutical Sciences, Guizhou Medical University, Guizhou, China
| | - Ling-Yun Fu
- The State Key Laboratory of Functions and Applications of Medicinal Plants, School of Pharmaceutical Sciences, Guizhou Medical University, Guizhou, China.,The High Efficacy Application of Natural Medicinal Resources Engineering Center of Guizhou Province, School of Pharmaceutical Sciences, Guizhou Medical University, Guizhou, China.,The Key Laboratory of Optimal Utilization of Natural Medicine Resources, School of Pharmaceutical Sciences, Guizhou Medical University, Guizhou, China
| | - Yi-Ni Xu
- The State Key Laboratory of Functions and Applications of Medicinal Plants, School of Pharmaceutical Sciences, Guizhou Medical University, Guizhou, China.,The High Efficacy Application of Natural Medicinal Resources Engineering Center of Guizhou Province, School of Pharmaceutical Sciences, Guizhou Medical University, Guizhou, China.,The Key Laboratory of Optimal Utilization of Natural Medicine Resources, School of Pharmaceutical Sciences, Guizhou Medical University, Guizhou, China
| | - Ling Li
- The State Key Laboratory of Functions and Applications of Medicinal Plants, School of Pharmaceutical Sciences, Guizhou Medical University, Guizhou, China.,The High Efficacy Application of Natural Medicinal Resources Engineering Center of Guizhou Province, School of Pharmaceutical Sciences, Guizhou Medical University, Guizhou, China.,The Key Laboratory of Optimal Utilization of Natural Medicine Resources, School of Pharmaceutical Sciences, Guizhou Medical University, Guizhou, China
| | - Ling Tao
- The State Key Laboratory of Functions and Applications of Medicinal Plants, School of Pharmaceutical Sciences, Guizhou Medical University, Guizhou, China.,The High Efficacy Application of Natural Medicinal Resources Engineering Center of Guizhou Province, School of Pharmaceutical Sciences, Guizhou Medical University, Guizhou, China.,The Key Laboratory of Optimal Utilization of Natural Medicine Resources, School of Pharmaceutical Sciences, Guizhou Medical University, Guizhou, China
| | - Xiang-Chun Shen
- The State Key Laboratory of Functions and Applications of Medicinal Plants, School of Pharmaceutical Sciences, Guizhou Medical University, Guizhou, China.,The High Efficacy Application of Natural Medicinal Resources Engineering Center of Guizhou Province, School of Pharmaceutical Sciences, Guizhou Medical University, Guizhou, China.,The Key Laboratory of Optimal Utilization of Natural Medicine Resources, School of Pharmaceutical Sciences, Guizhou Medical University, Guizhou, China
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13
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Methylmercury Epigenetics. TOXICS 2019; 7:toxics7040056. [PMID: 31717489 PMCID: PMC6958348 DOI: 10.3390/toxics7040056] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 10/22/2019] [Accepted: 11/05/2019] [Indexed: 12/12/2022]
Abstract
Methylmercury (MeHg) has conventionally been investigated for effects on nervous system development. As such, epigenetic modifications have become an attractive mechanistic target, and research on MeHg and epigenetics has rapidly expanded in the past decade. Although, these inquiries are a recent advance in the field, much has been learned in regards to MeHg-induced epigenetic modifications, particularly in the brain. In vitro and in vivo controlled exposure studies illustrate that MeHg effects microRNA (miRNA) expression, histone modifications, and DNA methylation both globally and at individual genes. Moreover, some effects are transgenerationally inherited, as organisms not directly exposed to MeHg exhibited biological and behavioral alterations. miRNA expression generally appears to be downregulated consequent to exposure. Further, global histone acetylation also seems to be reduced, persist at distinct gene promoters, and is contemporaneous with enhanced histone methylation. Moreover, global DNA methylation appears to decrease in brain-derived tissues, but not in the liver; however, selected individual genes in the brain are hypermethylated. Human epidemiological studies have also identified hypo- or hypermethylated individual genes, which correlated with MeHg exposure in distinct populations. Intriguingly, several observed epigenetic modifications can be correlated with known mechanisms of MeHg toxicity. Despite this knowledge, however, the functional consequences of these modifications are not entirely evident. Additional research will be necessary to fully comprehend MeHg-induced epigenetic modifications and the impact on the toxic response.
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14
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Fritsche E, Barenys M, Klose J, Masjosthusmann S, Nimtz L, Schmuck M, Wuttke S, Tigges J. Current Availability of Stem Cell-Based In Vitro Methods for Developmental Neurotoxicity (DNT) Testing. Toxicol Sci 2019; 165:21-30. [PMID: 29982830 DOI: 10.1093/toxsci/kfy178] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
There is evidence that chemical exposure during development can cause irreversible impairments of the human developing nervous system. Therefore, testing compounds for their developmentally neurotoxic potential has high priority for different stakeholders: academia, industry, and regulatory bodies. Due to the resource-intensity of current developmental neurotoxicity (DNT) in vivo guidelines, alternative methods that are scientifically valid and have a high predictivity for humans are especially desired by regulators. Here, we review availability of stem-/progenitor cell-based in vitro methods for DNT evaluation that is based on the concept of neurodevelopmental process assessment. These test methods are assembled into a DNT in vitro testing battery. Gaps in this testing battery addressing research needs are also pointed out.
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Affiliation(s)
| | - Marta Barenys
- IUF - Leibniz Research Institute for Environmental Medicine 40225, Düsseldorf, Germany
| | - Jördis Klose
- IUF - Leibniz Research Institute for Environmental Medicine 40225, Düsseldorf, Germany
| | - Stefan Masjosthusmann
- IUF - Leibniz Research Institute for Environmental Medicine 40225, Düsseldorf, Germany
| | - Laura Nimtz
- IUF - Leibniz Research Institute for Environmental Medicine 40225, Düsseldorf, Germany
| | - Martin Schmuck
- IUF - Leibniz Research Institute for Environmental Medicine 40225, Düsseldorf, Germany
| | - Saskia Wuttke
- IUF - Leibniz Research Institute for Environmental Medicine 40225, Düsseldorf, Germany
| | - Julia Tigges
- IUF - Leibniz Research Institute for Environmental Medicine 40225, Düsseldorf, Germany
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15
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Guida N, Valsecchi V, Laudati G, Serani A, Mascolo L, Molinaro P, Montuori P, Di Renzo G, Canzoniero LM, Formisano L. The miR206-JunD Circuit Mediates the Neurotoxic Effect of Methylmercury in Cortical Neurons. Toxicol Sci 2019. [PMID: 29522201 DOI: 10.1093/toxsci/kfy051] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Methylmercury (MeHg) causes neuronal death through different pathways. Particularly, we found that in cortical neurons it increased the expression of Repressor Element-1 Silencing Transcription Factor (REST), histone deacetylase (HDAC)4, Specificity Protein (Sp)1, Sp4, and reduced the levels of brain-derived neurotrophic factor (BDNF). Herein, in rat cortical neurons we investigated whether microRNA (miR)206 can modulate MeHg-induced cell death by regulating REST/HDAC4/Sp1/Sp4/BDNF axis. MeHg (1 µM) reduced miR206 expression after both 12 and 24 h and miR206 transfection prevented MeHg-induced neuronal death. Furthermore, miR206 reverted MeHg-induced REST and Sp4 increase and BDNF reduction at gene and protein level, and reverted HDAC4 protein increase, but not HDAC4 mRNA upregulation. Moreover, since no miR206 seed sequences were identified in the 3'-untranslated regions (3'-UTRs) of REST and SP4, we investigated the role of JunD, that presents a consensus motif on REST, Sp4, and BDNF promoters. Indeed, MeHg increased JunD mRNA and protein levels, and JunD knockdown counteracted MeHg-induced REST, Sp4 increase, but not BDNF reduction. Furthermore, we identified a miR206 binding site in the 3'-UTR of JunD mRNA (miR206/JunD) and mutagenesis of miR206/JunD site reverted JunD luciferase activity reduction induced by miR206. Finally, miR206 prevented MeHg-increased JunD binding to REST and Sp4 promoters, and MeHg-reduced BDNF expression was determined by the increase of HDAC4 binding on BDNF promoter IV. Collectively, these results suggest that miR206 downregulation induced by MeHg exposure determines an upregulation of HDAC4, that in turn downregulated BDNF, and the activation of JunD that, by binding REST and Sp4 gene promoters, increased their expression.
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Affiliation(s)
| | - Valeria Valsecchi
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, "Federico II" University of Naples, 80131 Naples, Italy
| | - Giusy Laudati
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, "Federico II" University of Naples, 80131 Naples, Italy.,Division of Pharmacology, Department of Science and Technology, University of Sannio, 82100 Benevento, Italy
| | - Angelo Serani
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, "Federico II" University of Naples, 80131 Naples, Italy
| | - Luigi Mascolo
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, "Federico II" University of Naples, 80131 Naples, Italy
| | - Pasquale Molinaro
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, "Federico II" University of Naples, 80131 Naples, Italy
| | - Paolo Montuori
- Department of Preventive Medical Sciences, University Federico II, 80131 Naples, Italy
| | - Gianfranco Di Renzo
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, "Federico II" University of Naples, 80131 Naples, Italy
| | - Lorella M Canzoniero
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, "Federico II" University of Naples, 80131 Naples, Italy.,Division of Pharmacology, Department of Science and Technology, University of Sannio, 82100 Benevento, Italy
| | - Luigi Formisano
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, "Federico II" University of Naples, 80131 Naples, Italy.,Division of Pharmacology, Department of Science and Technology, University of Sannio, 82100 Benevento, Italy
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