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Puty B, Bittencourt LO, Lima LAO, Plaça JR, Dionizio A, Buzalaf MAR, Gomes BD, de Oliveira EHC, Lima RR. Unraveling molecular characteristic of fluoride neurotoxicity on U87 glial-like cells: insights from transcriptomic and proteomic approach. Front Cell Neurosci 2023; 17:1153198. [PMID: 37362003 PMCID: PMC10289037 DOI: 10.3389/fncel.2023.1153198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Accepted: 05/19/2023] [Indexed: 06/28/2023] Open
Abstract
The potential of fluoride (F) as a neurotoxicant in humans is still controversial in the literature. However, recent studies have raised the debate by showing different mechanism of F-induced neurotoxicity, as oxidative stress, energy metabolism and inflammation in the central nervous system (CNS). In the present study, we investigated the mechanistic action of two F concentration (0.095 and 0.22 μg/ml) on gene and protein profile network using a human glial cell in vitro model over 10 days of exposure. A total of 823 genes and 2,084 genes were modulated after exposure to 0.095 and 0.22 μg/ml F, respectively. Among them, 168 were found to be modulated by both concentrations. The number of changes in protein expression induced by F were 20 and 10, respectively. Gene ontology annotations showed that the main terms were related to cellular metabolism, protein modification and cell death regulation pathways, such as the MAP kinase (MAPK) cascade, in a concentration independent manner. Proteomics confirmed the changes in energy metabolism and also provided evidence of F-induced changes in cytoskeleton components of glial cells. Our results not only reveal that F has the potential to modulate gene and protein profiles in human U87 glial-like cells overexposed to F, but also identify a possible role of this ion in cytoskeleton disorganization.
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Affiliation(s)
- Bruna Puty
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém, Brazil
- Laboratory of Cell Culture and Cytogenetics, Environmental Section, Evandro Chagas Institute, Ananindeua, Brazil
| | - Leonardo Oliveira Bittencourt
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém, Brazil
| | - Leidiane Alencar Oliveira Lima
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém, Brazil
| | - Jéssica Rodrigues Plaça
- National Institute of Science and Technology in Stem Cell and Cell Therapy (INCT/CNPq) and Center for Cell-Based Therapy, Centro de Pesquisa, Inovacão e Desenvolvimento/Fundacão de Amparo á Pesuisa do Estado de São Paulo (CEPID/FAPESP), Ribeirão Preto, Brazil
| | - Aline Dionizio
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, Brazil
| | | | - Bruno Duarte Gomes
- Laboratory of Neurophysiology Eduardo Oswaldo Cruz, Institute of Biological Sciences, Federal University of Pará, Belém, Brazil
| | | | - Rafael Rodrigues Lima
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém, Brazil
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2
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Soto-Verdugo J, Siva-Parra J, Hernández-Kelly LC, Ortega A. Acute Manganese Exposure Modifies the Translation Machinery via PI3K/Akt Signaling in Glial Cells. ASN Neuro 2022; 14:17590914221131452. [PMID: 36203371 PMCID: PMC9551334 DOI: 10.1177/17590914221131452] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
SUMMARY STATEMENT We demonstrate herein that short-term exposure of radial glia cells to Manganese, a neurotoxic metal, induces an effect on protein synthesis, altering the protein repertoire of these cells.
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Affiliation(s)
| | | | | | - Arturo Ortega
- Arturo Ortega, Departamento de Toxicología,
Centro de Investigación y de Estudios Avanzados del Instituto Politécnico
Nacional, México City, México, 07360.
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3
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Ren C, Li HH, Zhang CY, Song XC. Effects of chronic fluorosis on the brain. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 244:114021. [PMID: 36049331 DOI: 10.1016/j.ecoenv.2022.114021] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 08/18/2022] [Accepted: 08/23/2022] [Indexed: 06/15/2023]
Abstract
This article reviews the effects of chronic fluorosis on the brain and possible mechanisms. We used PubMed, Medline and Cochraine databases to collect data on fluorosis, brain injury, and pathogenesis. A large number of in vivo and in vitro studies and epidemiological investigations have found that chronic fluorosis can cause brain damage, resulting in abnormal brain structure and brain function.Chronic fluorosis not only causes a decline in concentration, learning, and memory, but also has mental symptoms such as anxiety, tension, and depression. Several possible mechanisms that have been proposed: the oxidative stress and inflammation theory, neural cell apoptosis theory, neurotransmitter imbalance theory, as well as the doctrine of the interaction of fluorine with other elements. However, the specific mechanism of chronic fluorosis on brain damage is still unclear. Thus, a better understanding of the mechanisms via which chronic fluorosis causes brain damage is of great significance to protect the physical and mental health of people in developing countries, especially those living in the endemic areas of fluorosis. In brief, further investigation concerning the influence of fluoride on the brain should be conducted as the neural damage induced by it may bring about a huge problem in public health, especially considering growing environmental pollution.
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Affiliation(s)
- Chao Ren
- Department of Otorhinolaryngology Head and Neck Surgery, Yantai Yuhuangding Hospital, Qingdao University, Yantai, Shandong Province 264000, China; Shandong Provincial Clinical Research Center for Otorhinolaryngologic Diseases, Yantai, Shandong Province 264000, China; Shandong Provincial Innovation and Practice Base for Postdoctors, Yantai Yuhuangding Hospital, Yantai 264000, China; Department of Neurology, Yantai Yuhuangding Hospital, Qingdao University, Yantai, Shandong Province 264000, China.
| | - Hui-Hua Li
- Zhenjiang Mental Health Center, The Fifth People's Hospital of Zhenjiang City, Zhenjiang, Jiangsu Province 212000, China
| | - Cai-Yi Zhang
- Department of Psychiatry, Xuzhou Medical University Affiliated Xuzhou Oriental Hospital, No.379 Tongshan Road, Xuzhou, Jiangsu Province 221000, China; Department of Emergency psychology, Xuzhou Medical University, No.209 Tongshan Road, Xuzhou, Jiangsu Province 221000, China; Department of Emergency, Xuzhou Medical University Affiliate Hospital, No.99 Huaihai Road, Xuzhou, Jiangsu Province 221000, China
| | - Xi-Cheng Song
- Department of Otorhinolaryngology Head and Neck Surgery, Yantai Yuhuangding Hospital, Qingdao University, Yantai, Shandong Province 264000, China; Shandong Provincial Clinical Research Center for Otorhinolaryngologic Diseases, Yantai, Shandong Province 264000, China; Shandong Provincial Innovation and Practice Base for Postdoctors, Yantai Yuhuangding Hospital, Yantai 264000, China.
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4
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Ning H, Li C, Yin Z, Hu D, Ge Y, Chen L. Fluoride exposure decreased neurite formation on cerebral cortical neurons of SD rats in vitro. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:50975-50982. [PMID: 33977427 DOI: 10.1007/s11356-021-13950-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 04/12/2021] [Indexed: 06/12/2023]
Abstract
Fluoride, a geochemical element, can damage the brain and result in dysfunction of the central nervous system. In recent years, fluoride-induced neurotoxicity has become one of research focuses of environmental toxicology. Our previous study showed that fluoride could induce the structural damages of the cerebral cortex and reduce the learning and memory abilities of mice offspring. However, the underlying mechanisms of these effects remain unclear. In this study, primary neurons were isolated from the cerebral cortices of postnatal 1-day SD rats. The primary cultured cerebral cortical neurons were adherent and the cellular network was obvious. Neurons were identified by Nissl's staining and were used for experiments. Different concentrations of sodium fluoride (0.5, 1.0, 1.5, 2.0 and 2.5 mM) were chosen to explore its toxic effects on neuron of SD rats in vitro. Results showed that neuronal morphology was obviously damaged in 2.0 and 2.5 mM, but was not adversely affected in 0.5 and 1 mM. Further studies revealed that the neurites of neuron were shrunken and even became fractured with the increase in NaF dose, which have been detected by scanning electron microscopy (SEM). Meanwhile, TEM showed marginated chromatin, widened nuclear gaps, damaged nuclei and swollen or even absent mitochondria in 1.5, 2 and 2.5 mM group. The cytoskeletal staining was consistent with the above results. The number of neurites of cerebral cortical neuron significantly decreased after fluoride exposure by immunofluorescent assay. In summary, high fluoride (1.5, 2 and 2.5 mM) concentrations exerted a significant toxic effect on the cellular morphologies and neural formation of primary cultured cortical neurons. These findings provide new insights into the roles of NaF in neuronal damage and can contribute to an improved understanding of fluoride-induced neurotoxicity.
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Affiliation(s)
- Hongmei Ning
- College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, China
| | - Chong Li
- College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, China
| | - Zhihong Yin
- College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, China
| | - Dongfang Hu
- College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, China
| | - Yaming Ge
- College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, China.
| | - Lingli Chen
- College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, China.
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Puty B, Bittencourt LO, Nogueira IC, Buzalaf MAR, Oliveira EH, Lima RR. Human cultured IMR-32 neuronal-like and U87 glial-like cells have different patterns of toxicity under fluoride exposure. PLoS One 2021; 16:e0251200. [PMID: 34138870 PMCID: PMC8211231 DOI: 10.1371/journal.pone.0251200] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 04/21/2021] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Fluoride (F) is a naturally exists in nature but several studies have indicated it as an environmental toxicant to all leaving beings. Human F exposure has increased over the years since this ion has been used by industry on foods, beverages, toothpastes and on water supply. Although F is safe at optimal concentrations in water supply, human exposure to high levels could trigger neurofunctional deficits. MATERIALS AND METHODS In this study, human glial-like (U87) and neuronal-like (IMR-32) cells lineages were used to access F toxicity and CNS cell sensibility on both cell facing the same protocol. Cells were exposed to F over 3, 5 and 10 days on two different F concentrations. Fluoride exposed cells were evaluated by standard toxicity assays to cell viability, apoptosis, necrosis and general cell metabolism. Oxidative stress parameters were evaluated by ATP and ROS levels, lipid peroxidation, GSH/GSSG ratio and comet assay. RESULTS No changes were observed in IMR-32 at any given time while after 10 days of exposure to 0.22μg/mL, U87 glial-like cells showed signs of toxicity such as decreased cell viability by necrosis while general cell metabolism was increased. Oxidative stress parameters were next evaluated only on U87 glial-like cells after 10 days of exposure. F induced a decrease on ATP levels while no changes were observed on reactive oxygen species and lipid peroxidation. GSH/GSSG ratio was decreased followed by DNA damage both on 0.22μg/mL F. CONCLUSIONS Our results suggest an important differential behavior of the distinct types of cells exposed to the different fluoride concentrations, pointing that the U87 glial-like cells as more susceptible to damage triggered by this ion.
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Affiliation(s)
- Bruna Puty
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém, Brazil
- Laboratory of Cell Culture and Cytogenetics, Environmental Section, Evandro Chagas Institute, Ananindeua, Brazil
| | - Leonardo Oliveira Bittencourt
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém, Brazil
| | - Iago Cesar Nogueira
- Laboratory of Cell Culture and Cytogenetics, Environmental Section, Evandro Chagas Institute, Ananindeua, Brazil
| | | | - Edivaldo Herculano Oliveira
- Laboratory of Cell Culture and Cytogenetics, Environmental Section, Evandro Chagas Institute, Ananindeua, Brazil
| | - Rafael Rodrigues Lima
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém, Brazil
- * E-mail:
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6
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Wang J, Yue B, Zhang X, Guo X, Sun Z, Niu R. Effect of exercise on microglial activation and transcriptome of hippocampus in fluorosis mice. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 760:143376. [PMID: 33172640 DOI: 10.1016/j.scitotenv.2020.143376] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 10/02/2020] [Accepted: 10/21/2020] [Indexed: 06/11/2023]
Abstract
Fluorosis is a widespread endemic disease. Reports have shown that high fluoride causes the dysfunction of central nervous system (CNS) in animals. The neurotoxicity of fluoride may be related to the activation of microglia. Moreover, numerous studies have found that exercise facilitates the plasticity of structure and function in CNS, partly owing to the regulation of microglia activation. The present study was conducted to explore the effect of exercise on the microglial activation of hippocampus in fluorosis mice. One hundred adult female Institute of Cancer Research (ICR) mice were randomly divided into 4 groups: control group (group C, distilled water by gavage); exercise group (group E, distilled water by gavage and treadmill exercise); fluoride group [group F, 24 mg/kg sodium fluoride (NaF) by gavage]; fluoride plus exercise group (group F + E, 24 mg/kg NaF by gavage and treadmill exercise). After 8 weeks, hippocampal morphological structure, microglial activation and RNA transcriptome of mice in each group were evaluated by hematoxylin and eosin (HE) staining, Nissl staining, immunohistochemistry (IHC), quantitative real time PCR (QRT-PCR) and transcriptome sequencing. We discovered that the number of M1-type microglia in fluorosis-mice hippocampus was significantly increased when compared to group C; group F + E showed a decrease in the number of M1-type microglia with the comparison to group F. In addition, the hippocampal transcriptome analysis showed that 576 differential expression genes (DEG) were confirmed in group F, compared to group C, and 670 DEG were differently expressed in group F + E when compared to group F. Gene Ontology (GO) analysis showed that changed genes were implicated in regulation of transcription, DNA-templated, integral component of membrane and adenosine triphosphate (ATP) binding. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of 670 DEG was helpful to find neuroactive ligand-receptor interaction pathway. In conclusion, these results indicate that treadmill running inhibits the excessive activation of microglia in hippocampus of the fluoride-toxic mice, accompanied with the alteration of neuroactive ligand-receptor interaction pathway.
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Affiliation(s)
- Jixiang Wang
- Shanxi Key Laboratory of Ecological Animal Science and Environmental Veterinary Medicine, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi 030801, China
| | - Baijuan Yue
- Shanxi Key Laboratory of Ecological Animal Science and Environmental Veterinary Medicine, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi 030801, China
| | - Xuhua Zhang
- Shanxi Key Laboratory of Ecological Animal Science and Environmental Veterinary Medicine, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi 030801, China
| | - Xin Guo
- Shanxi Key Laboratory of Ecological Animal Science and Environmental Veterinary Medicine, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi 030801, China
| | - Zilong Sun
- Shanxi Key Laboratory of Ecological Animal Science and Environmental Veterinary Medicine, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi 030801, China
| | - Ruiyan Niu
- Shanxi Key Laboratory of Ecological Animal Science and Environmental Veterinary Medicine, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi 030801, China.
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7
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Abstract
Fluoride is essential for the development of teeth and bone but its excessive exposure causes reprotoxic effects. We have studied the graded effects of different doses of sodium fluoride (NaF) on 24 adult Wistar rats which were randomly divided into four groups (n = 6). All the rats were given normal diet prepared in our laboratory. Control (group I) rats were received vehicle only and treated rats (group II, III, and IV) were administered NaF orally at 10, 15, and 20 mg/kg/d doses, respectively, for 30 consecutive days. Gravimetric index of testis was decreased significantly in group III and IV rats but such changes were not observed in the accessory reproductive organs. Marked alterations in number, motility, viability, and plasma membrane functional integrity of caudal spermatozoa were noted in most of the treated groups. Noticeable alterations in testicular histoarchitecture were observed in group III and IV rats. Graded Changes of testicular redox homeostasis were noted by assessment of enzymatic (superoxide dismutase [SOD], catalase, glutathione s-transferase [GST], and glutathione peroxidase [GPx]) and nonenzymatic (malondialdehyde [MDA] and protein carbonyl [PC]) markers. Changes of testicular functional markers (acid phosphatase [ACP], alkaline phosphatase [ALP], and lactate dehydrogenase (LDH) activity) were noted in group III and IV rats. DNA fragmentation assay proved the possibility of DNA damage caused by oxidative stress, as evidenced by prominent trailing pattern of fragmented testicular genomic DNA from group III and IV rats. The study concludes that fluoride-mediated oxidative stress not only impedes the structural and functional facets of testis but also results in testicular DNA damage.
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Affiliation(s)
- Priyankar Pal
- Department of Life Sciences, Presidency University, Kolkata, India
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8
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Nadei OV, Khvorova IA, Agalakova NI. Cognitive Decline of Rats with Chronic Fluorosis Is Associated with Alterations in Hippocampal Calpain Signaling. Biol Trace Elem Res 2020; 197:495-506. [PMID: 31797207 DOI: 10.1007/s12011-019-01993-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 11/25/2019] [Indexed: 12/15/2022]
Abstract
The study was designed to evaluate an influence of excessive fluoride (F-) intake on cognitive capacities of adult rats and on proteins of memory-related calpain signaling in hippocampus. Control animals were given water with natural F- content of 0.4 ppm; rats from other groups consumed the same water supplemented with 5, 20, and 50 ppm F- (as NaF) for 12 months. The efficiency of learning and memory formation was evaluated by novel object recognition (NOR) and Morris water maze tests. The expression of enzymes of calpain-1 and calpain-2 signaling in hippocampus was detected by Western blotting. Excessive F- consumption had moderate impact on short-term memory, but impaired spatial learning and long-term memory of animals. Intoxication of rats with 5-50 ppm F- led to stimulation of calpain-1 in hippocampal cells and its translocation from cytosol to membranes, accompanied by activation of GTPase RhoA. Exposure to 20-50 ppm F- resulted in proteolytic cleavage of phosphatase PHLPP1 and increased expression of phospho-ERK1/2 kinase with insignificant decline of total ERK1/2 activity. In contrast, F- did not change the expression of calpain-2 and its substrates-phosphatase PTEN and kinase mTOR. However, F- intake led to downregulation of cAMP-response element binding protein (CREB) and brain-derived neurotrophic factor (BDNF). Thus, altered expression of calpain-1 and its downstream effectors at a background of stable activity of calpain-2 indicates overstimulation of signaling pathways of early LTP phase and disrupted link between early and late LTP phases, most probably due to altered activity of transcriptional and neurotrophic factors.
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Affiliation(s)
- Olga V Nadei
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 44 Thorez av., Saint Petersburg, Russia, 194223
| | - Irina A Khvorova
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 44 Thorez av., Saint Petersburg, Russia, 194223
| | - Natalia I Agalakova
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 44 Thorez av., Saint Petersburg, Russia, 194223.
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9
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García-López AL, Hernández-Castillo J, Hernández-Kelly LC, Olivares-Bañuelos TN, Ortega A. Fluoride Exposure Affects Glutamine Uptake in Müller Glia Cells. Neurotox Res 2020; 38:765-774. [PMID: 32734566 DOI: 10.1007/s12640-020-00263-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 07/21/2020] [Accepted: 07/27/2020] [Indexed: 02/06/2023]
Abstract
Fluoride, a pollutant present in contaminated ground water, oral care products, food, and pesticides, has deleterious effects in the structure and function of the central nervous system. Among the established neurological defects described in the exposed population, a reduced score in intelligence quotient tests in children of contaminated areas has gained attention over the past years. Maternal fluoride exposure during gestation decreases learning and memory abilities that correlate with a significant diminution of glutamate receptors expression. Since the involvement of glia cells in the maintenance and regulation of glutamatergic synapses is well-documented, in this contribution, we characterized the effect of fluoride exposure in the regulation of glia glutamine transporters. To this end, we used the Müller glia cell line, Mio-M1, and through the use of [3H]L-Glutamine uptake experiments and a Western blot approach, we demonstrate here the functional expression of system N of glutamine transporters, SNAT3 and SNAT5, in this model of human retina radial glia cells. Furthermore, these transporters interact with the glutamate transporter excitatory amino acid transporter 1, in an activity-dependent manner. Fluoride treatment reduces glutamine uptake and cell membrane [3H]glutamine surface binding, in good correlation with a decrease in SNAT3 and 5 protein levels. These results demonstrate that glia cells respond to the presence of fluoride reducing glutamine mobilization and by these means decreases glutamate turnover suggesting a disruption of glutamatergic transmission.
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Affiliation(s)
- Ana L García-López
- Laboratorio de Neurotoxicología, Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Av. Instituto Politécnico Nacional No. 2508, Col. San Pedro Zacatenco, Apartado Postal 14-740, 07360, Ciudad de México, Mexico
| | - Jeanett Hernández-Castillo
- Laboratorio de Neurotoxicología, Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Av. Instituto Politécnico Nacional No. 2508, Col. San Pedro Zacatenco, Apartado Postal 14-740, 07360, Ciudad de México, Mexico
| | - Luisa C Hernández-Kelly
- Laboratorio de Neurotoxicología, Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Av. Instituto Politécnico Nacional No. 2508, Col. San Pedro Zacatenco, Apartado Postal 14-740, 07360, Ciudad de México, Mexico
| | - Tatiana N Olivares-Bañuelos
- Instituto de Investigaciones Oceanológicas, Universidad Autónoma de Baja California, Ensenada, 22860, Baja California, Mexico
| | - Arturo Ortega
- Laboratorio de Neurotoxicología, Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Av. Instituto Politécnico Nacional No. 2508, Col. San Pedro Zacatenco, Apartado Postal 14-740, 07360, Ciudad de México, Mexico.
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10
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Guth S, Hüser S, Roth A, Degen G, Diel P, Edlund K, Eisenbrand G, Engel KH, Epe B, Grune T, Heinz V, Henle T, Humpf HU, Jäger H, Joost HG, Kulling SE, Lampen A, Mally A, Marchan R, Marko D, Mühle E, Nitsche MA, Röhrdanz E, Stadler R, van Thriel C, Vieths S, Vogel RF, Wascher E, Watzl C, Nöthlings U, Hengstler JG. Toxicity of fluoride: critical evaluation of evidence for human developmental neurotoxicity in epidemiological studies, animal experiments and in vitro analyses. Arch Toxicol 2020; 94:1375-1415. [PMID: 32382957 PMCID: PMC7261729 DOI: 10.1007/s00204-020-02725-2] [Citation(s) in RCA: 82] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 03/26/2020] [Indexed: 12/29/2022]
Abstract
Recently, epidemiological studies have suggested that fluoride is a human developmental neurotoxicant that reduces measures of intelligence in children, placing it into the same category as toxic metals (lead, methylmercury, arsenic) and polychlorinated biphenyls. If true, this assessment would be highly relevant considering the widespread fluoridation of drinking water and the worldwide use of fluoride in oral hygiene products such as toothpaste. To gain a deeper understanding of these assertions, we reviewed the levels of human exposure, as well as results from animal experiments, particularly focusing on developmental toxicity, and the molecular mechanisms by which fluoride can cause adverse effects. Moreover, in vitro studies investigating fluoride in neuronal cells and precursor/stem cells were analyzed, and 23 epidemiological studies published since 2012 were considered. The results show that the margin of exposure (MoE) between no observed adverse effect levels (NOAELs) in animal studies and the current adequate intake (AI) of fluoride (50 µg/kg b.w./day) in humans ranges between 50 and 210, depending on the specific animal experiment used as reference. Even for unusually high fluoride exposure levels, an MoE of at least ten was obtained. Furthermore, concentrations of fluoride in human plasma are much lower than fluoride concentrations, causing effects in cell cultures. In contrast, 21 of 23 recent epidemiological studies report an association between high fluoride exposure and reduced intelligence. The discrepancy between experimental and epidemiological evidence may be reconciled with deficiencies inherent in most of these epidemiological studies on a putative association between fluoride and intelligence, especially with respect to adequate consideration of potential confounding factors, e.g., socioeconomic status, residence, breast feeding, low birth weight, maternal intelligence, and exposure to other neurotoxic chemicals. In conclusion, based on the totality of currently available scientific evidence, the present review does not support the presumption that fluoride should be assessed as a human developmental neurotoxicant at the current exposure levels in Europe.
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Affiliation(s)
- Sabine Guth
- Department of Toxicology, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany
| | - Stephanie Hüser
- Department of Toxicology, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany
| | - Angelika Roth
- Department of Toxicology, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany
| | - Gisela Degen
- Department of Toxicology, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany
| | - Patrick Diel
- Department of Molecular and Cellular Sports Medicine, Institute of Cardiovascular Research and Sports Medicine, German Sport University Cologne, Cologne, Germany
| | - Karolina Edlund
- Department of Toxicology, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany
| | | | - Karl-Heinz Engel
- Department of General Food Technology, School of Life Sciences, TU Munich, Freising, Germany
| | - Bernd Epe
- Institute of Pharmacy and Biochemistry, University of Mainz, Mainz, Germany
| | - Tilman Grune
- Department of Molecular Toxicology, German Institute of Human Nutrition (DIfE), Nuthetal, Germany
| | - Volker Heinz
- German Institute of Food Technologies (DIL), Quakenbrück, Germany
| | - Thomas Henle
- Department of Food Chemistry, TU Dresden, Dresden, Germany
| | - Hans-Ulrich Humpf
- Institute of Food Chemistry, Westfälische Wilhelms-Universität Münster, Münster, Germany
| | - Henry Jäger
- Institute of Food Technology, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria
| | - Hans-Georg Joost
- Department of Experimental Diabetology, German Institute of Human Nutrition (DIfE), Nuthetal, Germany
| | - Sabine E Kulling
- Department of Safety and Quality of Fruit and Vegetables, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Karlsruhe, Germany
| | - Alfonso Lampen
- Department of Food Safety, Bundesinstitut für Risikobewertung (BfR), Berlin, Germany
| | - Angela Mally
- Department of Toxicology, University of Würzburg, Würzburg, Germany
| | - Rosemarie Marchan
- Department of Toxicology, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany
| | - Doris Marko
- Department of Food Chemistry and Toxicology, Faculty of Chemistry, University of Vienna, Vienna, Austria
| | - Eva Mühle
- Department of Toxicology, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany
| | - Michael A Nitsche
- Department of Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany
- Department of Neurology, University Medical Hospital Bergmannsheil, Ruhr-University, Bochum, Germany
| | - Elke Röhrdanz
- Department of Experimental Pharmacology and Toxicology, Federal Institute for Drugs and Medical Devices (BfArM), Bonn, Germany
| | - Richard Stadler
- Institute of Food Safety and Analytic Sciences, Nestlé Research Centre, Lausanne, Switzerland
| | - Christoph van Thriel
- Department of Toxicology, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany
| | | | - Rudi F Vogel
- Lehrstuhl für Technische Mikrobiologie, TU Munich, Freising, Germany
| | - Edmund Wascher
- Department of Ergonomics, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany
| | - Carsten Watzl
- Department of Immunology, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany
| | - Ute Nöthlings
- Department of Nutrition and Food Sciences, Nutritional Epidemiology, Rheinische Friedrich-Wilhelms University Bonn, Bonn, Germany.
| | - Jan G Hengstler
- Department of Toxicology, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany.
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Abstract
Although actively disputed and questioned, it has been proposed that chronic exposure to inorganic fluoride (F-) is toxic for brain. The major question for this review was whether an excessive F- intake is causally related to adverse neurological and cognitive health conditions in human beings and animals. The paper systematically and critically summarizes the findings of the studies showing positive associations between F- intoxication and various intellectual defects, as well as of those which attempted to clarify the nature of F- neurotoxicity. Many works provide support for a link between pre- and postnatal F- exposure and structural and functional changes in the central nervous system responsible for neurological and cognitive disorders. The mechanisms suggested to underlie F- neurotoxicity include the disturbances in synaptic transmission and synaptic plasticity, premature death of neurons, altered activities of components of intracellular signaling cascades, impaired protein synthesis, deficit of neurotrophic and transcriptional factors, oxidative stress, metabolic changes, inflammatory processes. However, the majority of works have been performed on laboratory rodents using such F- doses which are never exist in the nature even in the regions of endemic fluorosis. Thus, this kind of treatment is hardly comparable with human exposure even taking into account the higher rate of F- clearance in animals. Of special importance are the data collected on humans chronically consuming excessive F- doses in the regions of endemic fluorosis or contacting with toxic F- compounds at industrial sites, but those works are scarce and often criticized due to low quality. New, expertly performed studies with repeated exposure assessment in independent populations are needed to prove an ability of F- to impair neurological and intellectual development of human beings and to understand the molecular mechanisms implicated in F--induced neurotoxicity.
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Affiliation(s)
- N I Agalakova
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, Saint-Petersburg, Russian Federation
| | - O V Nadei
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, Saint-Petersburg, Russian Federation
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12
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Rodríguez-Campuzano AG, Hernández-Kelly LC, Ortega A. Acute Exposure to SiO 2 Nanoparticles Affects Protein Synthesis in Bergmann Glia Cells. Neurotox Res 2019; 37:366-379. [PMID: 31292883 DOI: 10.1007/s12640-019-00084-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 06/04/2019] [Accepted: 06/26/2019] [Indexed: 10/26/2022]
Abstract
Attractive due to an alleged high biocompatibility, silica nanoparticles have been widely used in the field of nanomedicine; however, their proven capacity to induce the synthesis and release of pro-inflammatory cytokines in several cellular models has raised concern about their safety. Glutamate, the main excitatory amino acid transmitter triggers a wide variety of signal transduction cascades that regulate protein synthesis at transcriptional and translational levels. A stimulus-dependent dynamic change in the protein repertoire in neurons and glia cells is the molecular framework of higher brain functions. Within the cerebellum, Bergmann glia cells are the most abundant non-neuronal cells and span the entire molecular layer of the cerebellar cortex, wrapping the synapses in this structure. Taking into consideration the functional role of Bergmann glia in terms of the recycling of glutamate, lactate supply to neurons, and prevention of neurotoxic insults, we decided to investigate the possibility that silica nanoparticles affect Bergmann glia and by these means alter the major excitatory neurotransmitter system in the brain. To this end, we exposed cultured chick cerebellar Bergmann glia cells to silica nanoparticles and measured [35S]-methionine incorporation into newly synthesized polypeptides. Our results demonstrate that exposure of the cultured cells to silica nanoparticles exerts a time- and dose-dependent modulation of protein synthesis. Furthermore, altered patterns of eukaryotic initiation factor 2 alpha and eukaryotic elongation factor 2 phosphorylation were present upon nanoparticle exposure. These results demonstrate that glia cells respond to the presence of this nanomaterial modifying their proteome, presumably in an effort to overcome any plausible neurotoxic effect.
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Affiliation(s)
- Ada G Rodríguez-Campuzano
- Laboratorio de Neurotoxicología, Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Av. Instituto Politécnico Nacional No. 2508, Col. San Pedro Zacatenco, Apartado Postal 14-740, 07000, Mexico City, Mexico
| | - Luisa C Hernández-Kelly
- Laboratorio de Neurotoxicología, Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Av. Instituto Politécnico Nacional No. 2508, Col. San Pedro Zacatenco, Apartado Postal 14-740, 07000, Mexico City, Mexico
| | - Arturo Ortega
- Laboratorio de Neurotoxicología, Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Av. Instituto Politécnico Nacional No. 2508, Col. San Pedro Zacatenco, Apartado Postal 14-740, 07000, Mexico City, Mexico.
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13
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Dec K, Łukomska A, Skonieczna-Żydecka K, Kolasa-Wołosiuk A, Tarnowski M, Baranowska-Bosiacka I, Gutowska I. Long-term exposure to fluoride as a factor promoting changes in the expression and activity of cyclooxygenases (COX1 and COX2) in various rat brain structures. Neurotoxicology 2019; 74:81-90. [PMID: 31175943 DOI: 10.1016/j.neuro.2019.06.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 06/03/2019] [Accepted: 06/03/2019] [Indexed: 12/16/2022]
Abstract
BACKGROUND Sixty percent of the mammalian brain is composed of lipids including arachidonic acid (AA). AA released from cell membranes is metabolised in the cyclooxygenase (COX) pathway to prostanoids - biologically active substances involved in the regulation of many processes including inflammation. It has been shown that long-term exposure to fluoride in pre and neonatal period is dangerous because this element is able to penetrate through the placenta and to cross the blood-brain barrier. Exposure to fluoride during the development affects metabolism and physiology of neurons and glia which results in the impairment of cognitive functions but the exact mechanisms of fluoride neurotoxicity are not clearly defined. OBJECTIVE The aim of this study was to determine whether exposure to fluoride during the development affects COXes activity and the synthesis of prostanoids. MATERIAL AND METHODS Pre- and postnatal toxicity model in Wistar rats was used. Experimental animals received 50 mg/L of NaF in drinking water ad libitum, while control animals received tap water. In cerebral cortex, hippocampus, cerebellum and striatum were measured fluoride concentration, COX1 and COX2 genes expression, immunolocalization of the enzymatic proteins and concentration of PGE2 and TXB2. RESULTS of this study showed statistically significant changes in the concentration of fluoride in brain structures between study group and control animals. Moreover, significant changes in the expression level of COX1 and COX2, and in the concentration of PGE2 and TXB2 were observed. CONCLUSION Exposure to fluoride in the prenatal and neonatal period result in the increase in COX2 activity and increase in PGE2 concentration in rats brain, which may lead to disturbances in central nervous system homeostasis..
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Affiliation(s)
- Karolina Dec
- The Department of Biochemistry and Human Nutrition, Pomeranian Medical University in Szczecin, Broniewskiego 24 Str., 70-460 Szczecin, Poland
| | - Agnieszka Łukomska
- The Department of Biochemistry and Human Nutrition, Pomeranian Medical University in Szczecin, Broniewskiego 24 Str., 70-460 Szczecin, Poland; Laboratory of Neuroplasticity, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland
| | - Karolina Skonieczna-Żydecka
- The Department of Biochemistry and Human Nutrition, Pomeranian Medical University in Szczecin, Broniewskiego 24 Str., 70-460 Szczecin, Poland
| | - Agnieszka Kolasa-Wołosiuk
- The Department of Histology and Embryology, Pomeranian Medical University in Szczecin, Powstańców Wlkp. 72 av., 70-111 Szczecin, Poland
| | - Maciej Tarnowski
- The Department of Physiology, Pomeranian Medical University in Szczecin, Powstańców Wlkp. 72 av., 70-111 Szczecin, Poland
| | - Irena Baranowska-Bosiacka
- The Department of Biochemistry, Pomeranian Medical University in Szczecin, Powstańców Wlkp. 72 av., 70-111 Szczecin, Poland
| | - Izabela Gutowska
- The Department of Biochemistry and Human Nutrition, Pomeranian Medical University in Szczecin, Broniewskiego 24 Str., 70-460 Szczecin, Poland.
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14
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Yu Q, Shao D, Zhang R, Ouyang W, Zhang Z. Effects of drinking water fluorosis on L-type calcium channel of hippocampal neurons in mice. CHEMOSPHERE 2019; 220:169-175. [PMID: 30583209 DOI: 10.1016/j.chemosphere.2018.12.078] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 11/19/2018] [Accepted: 12/10/2018] [Indexed: 06/09/2023]
Abstract
The study aimed to investigate the effects of drinking water fluorosis on L-type calcium channels (LTCCs) in mouse hippocampal neurons. A total of 60 newly weaned ICR male mice were randomly divided into control, low fluoride and high fluoride groups. After 3 and 6 months of exposure to fluoride, the patch clamp technique was used to detect the peak and relative values (I/Imax), steady-state activation curve ratio (G/Gmax), decay time constant, and tail current time constant of LTCCs currents in hippocampal CA1 region of mouse brain slices. Fluoride greatly reduced the serum and urinary calcium concentrations in mice, and the chronic fluorosis has a greater impact than subchronic fluorosis. The peak value of LTCCs current in pyramidal neurons of hippocampal CA1 area was significant and increased with the prolonged exposure time. The relative values of current and steady-state coefficients were changed greatly. The decay and tail current time increased significantly. High fluorine concentration indicates great peak value and open time of LTCCs opening. LTCCs are sensitive to fluoride exposure. The activation voltage of calcium channels induced by fluoride exposure is decreased, the opening time of calcium channels is prolonged, and the calcium influx per unit time increased, thereby overloading calcium concentration in neurons and this may be an explanation for intracellular calcium overload caused by fluoride. The imbalance of calcium metabolism caused by fluorosis may be a pathogenesis of brain injury induced by fluoride. Furthermore, the risk of brain damage from low-fluorine exposure cannot be ignored.
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Affiliation(s)
- Qiuli Yu
- College of Chemistry and Life Science, Zhejiang Normal University, Jinhua, 321004, PR China
| | - Dandan Shao
- College of Chemistry and Life Science, Zhejiang Normal University, Jinhua, 321004, PR China
| | - Rui Zhang
- College of Chemistry and Life Science, Zhejiang Normal University, Jinhua, 321004, PR China
| | - Wei Ouyang
- College of Sports and Health Science, Zhejiang Normal University, Jinhua, Zhejiang, 321004, PR China
| | - Zigui Zhang
- College of Xing Zhi, Zhejiang Normal University, Jinhua, Zhejiang, 321004, PR China.
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15
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Dec K, Łukomska A, Baranowska-Bosiacka I, Pilutin A, Maciejewska D, Skonieczna-Żydecka K, Derkacz R, Goschorska M, Wąsik A, Rębacz-Maron E, Gutowska I. Pre-and postnatal exposition to fluorides induce changes in rats liver morphology by impairment of antioxidant defense mechanisms and COX induction. CHEMOSPHERE 2018; 211:112-119. [PMID: 30071422 DOI: 10.1016/j.chemosphere.2018.07.145] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 07/21/2018] [Accepted: 07/23/2018] [Indexed: 06/08/2023]
Abstract
INTRODUCTION Fluorides are common in the environment and are absorbed mostly in the stomach and gut, it can easily move through cell membranes and its accumulation can cause harmful effects in skeletal and soft tissues. One of the most important F- accumulation sites is the liver. The aim of this study was to determine whether F- can cause inflammation in rat liver by affecting the activity of antioxidant enzymes and changes in the synthesis of prostaglandin E2 (PGE2) and thromboxane B2 (TXB2). MATERIALS AND METHODS An in vivo model of prenatal and postnatal exposure to sodium fluoride (NaF) was used to carry out the experiment. Animals from control group received tap water to drink, while animals exposed to F- received drinking water containing NaF, 50 mg/L. In serum and liver we analyzed F- concentration, in liver - antioxidant enzymes activity, PGE2 and TXB2 concentration and immunolocalization of COX1 and COX2 proteins were measured. RESULTS We observed significant changes in F- concentration only in liver. The results of this study showed that F- affects antioxidant enzymes activity, COX2 protein expression and PGE2 synthesis in liver. Also, in some regions of the liver of rats exposed to F-, the hepatocytes were diffusely altered, with changes resembling microvesicular steatosis. CONCLUSION Chronic exposure to F- during development causes an accumulation of this element in the liver and changes in antioxidant enzymes activity and cyclooxygenase expression. Long term exposure to this element is toxic to the liver and can cause disturbances in its homeostasis.
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Affiliation(s)
- K Dec
- Department of Biochemistry and Human Nutrition, Pomeranian Medical University in Szczecin, Broniewskiego 24 Str., 70-460, Szczecin, Poland
| | - A Łukomska
- Department of Biochemistry, Pomeranian Medical University in Szczecin, Powstańców Wlkp. 72 av., 70-111, Szczecin, Poland
| | - I Baranowska-Bosiacka
- Department of Biochemistry, Pomeranian Medical University in Szczecin, Powstańców Wlkp. 72 av., 70-111, Szczecin, Poland
| | - A Pilutin
- Department of Histology and Embryology, Pomeranian Medical University in Szczecin, Powstańców Wlkp. 72 av., 70-111, Szczecin, Poland
| | - D Maciejewska
- Department of Biochemistry and Human Nutrition, Pomeranian Medical University in Szczecin, Broniewskiego 24 Str., 70-460, Szczecin, Poland
| | - K Skonieczna-Żydecka
- Department of Biochemistry and Human Nutrition, Pomeranian Medical University in Szczecin, Broniewskiego 24 Str., 70-460, Szczecin, Poland
| | - R Derkacz
- Department of Biochemistry and Human Nutrition, Pomeranian Medical University in Szczecin, Broniewskiego 24 Str., 70-460, Szczecin, Poland
| | - M Goschorska
- Department of Biochemistry, Pomeranian Medical University in Szczecin, Powstańców Wlkp. 72 av., 70-111, Szczecin, Poland
| | - A Wąsik
- Department of Neurochemistry, Institute of Pharmacology, Polish Akademy of Sciences, Smętna 12 Str, 31-343, Kraków, Poland
| | - E Rębacz-Maron
- University of Szczecin, Department of Vertebrate Zoology and Anthropology, Institute for Research on Biodiversity, Faculty of Biology, University of Szczecin, Wąska 13 St., 71-415, Szczecin, Poland
| | - I Gutowska
- Department of Biochemistry and Human Nutrition, Pomeranian Medical University in Szczecin, Broniewskiego 24 Str., 70-460, Szczecin, Poland.
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16
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Tan PP, Zhou BH, Zhao WP, Jia LS, Liu J, Wang HW. Mitochondria-Mediated Pathway Regulates C2C12 Cell Apoptosis Induced by Fluoride. Biol Trace Elem Res 2018; 185:440-447. [PMID: 29594946 DOI: 10.1007/s12011-018-1265-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 02/05/2018] [Indexed: 11/29/2022]
Abstract
This study was designed to investigate the mechanisms of excessive fluoride-induced apoptosis via mitochondria-mediated pathway in skeletal muscle cells (C2C12 cells). C2C12 cells were cultured with the fluoride concentrations (0, 1, and 2.5 mmol/L) for 48 h. The morphology and ultrastructural changes of C2C12 cells were observed using a light microscope and transmission electron microscope (TEM). The protein expression levels of apoptosis factors, including Bax, Bcl-2, cytochrome c (Cyt c), caspase-3, and caspase-9, were measured using real-time polymerase chain reaction (real-time PCR) and immunocytofluorescence. The morphology and ultrastructure of C2C12 cells were seriously damaged by fluoride at 1 and 2.5 mmol/L doses, including swollen mitochondria, vacuolization, ridge breakage, and disappearance of the nuclear membrane. Simultaneously, compared with the control group, the expression levels of Bax, Bcl-2, Cyt c, caspase-3, and caspase-9 were up-regulated after fluoride treatment. Excessive fluoride damages the ultrastructure in mitochondria, leading to the release of Cyt c from the mitochondria to cytoplasm in C2C12 cells; thereby, activated caspases cascade apoptosis process through a mitochondria-mediated pathway.
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Affiliation(s)
- Pan-Pan Tan
- Henan Provincial Open Laboratory of Key Disciplines, Environment and Animal Products Safety, College of Animal Science and Technology, Henan University of Science and Technology, Kaiyuan Avenue 263, Luoyang, 471000, Henan, People's Republic of China
| | - Bian-Hua Zhou
- Henan Provincial Open Laboratory of Key Disciplines, Environment and Animal Products Safety, College of Animal Science and Technology, Henan University of Science and Technology, Kaiyuan Avenue 263, Luoyang, 471000, Henan, People's Republic of China.
| | - Wen-Peng Zhao
- Henan Provincial Open Laboratory of Key Disciplines, Environment and Animal Products Safety, College of Animal Science and Technology, Henan University of Science and Technology, Kaiyuan Avenue 263, Luoyang, 471000, Henan, People's Republic of China
| | - Liu-Shu Jia
- Henan Provincial Open Laboratory of Key Disciplines, Environment and Animal Products Safety, College of Animal Science and Technology, Henan University of Science and Technology, Kaiyuan Avenue 263, Luoyang, 471000, Henan, People's Republic of China
| | - Jing Liu
- Henan Provincial Open Laboratory of Key Disciplines, Environment and Animal Products Safety, College of Animal Science and Technology, Henan University of Science and Technology, Kaiyuan Avenue 263, Luoyang, 471000, Henan, People's Republic of China
| | - Hong-Wei Wang
- Henan Provincial Open Laboratory of Key Disciplines, Environment and Animal Products Safety, College of Animal Science and Technology, Henan University of Science and Technology, Kaiyuan Avenue 263, Luoyang, 471000, Henan, People's Republic of China.
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17
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Ge Y, Chen L, Yin Z, Song X, Ruan T, Hua L, Liu J, Wang J, Ning H. Fluoride-induced alterations of synapse-related proteins in the cerebral cortex of ICR offspring mouse brain. CHEMOSPHERE 2018; 201:874-883. [PMID: 29567471 DOI: 10.1016/j.chemosphere.2018.02.167] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 02/24/2018] [Accepted: 02/26/2018] [Indexed: 06/08/2023]
Abstract
Fluoride (F) exposure causes cognitive dysfunction in humans and animals. However, the precise molecular mechanisms by which fluoride exerts its neurotoxic effects are poorly understood. In this study, an animal model of fluoride exposure was created by providing ICR mice were treated with vehicle F at a dose of 0 (control group), 50 (low-fluoride group) or 100 mg/L (high-fluoride group) in water for one month. After the mice mated, parents and offspring were treated and maintained under these conditions. The cognitive abilities of the mice were examined using a Morris water maze test. Results indicated that fluoride exposure significantly prolonged the escape latency period and decreased the number of crossings in a particular zone. Histopathologic analysis revealed the shrinkage and fragmentation of glial cells in the fluoride-treated groups. Pyramidal cells in the cerebral cortices of fluoride-treated groups were fewer than those of the control group. The expression of microtubule-associated protein 2 (MAP2) and synaptic proteins of the cerebral cortex in mouse offspring was assayed using RT-PCR and Western blot. Fluoride exposure possibly induced a significantly decreased expression of MAP2, synaptophysin (SYP) and developmentally regulated brain protein (Dbn) at protein and mRNA levels. Glutamate receptor (N-methyl-d-aspartate receptor, NMDAR) was also expressed, and this finding was consistent with the reduced MAP2, SYP and Dbn expression. Therefore, fluoride-mediated reduction in cognitive dysfunction is likely caused by the disruption of the expression of these synapse-associated proteins, resulting in attenuated neuronal functioning.
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Affiliation(s)
- Yaming Ge
- College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, Henan, 453003, PR China
| | - Lingli Chen
- College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, Henan, 453003, PR China; Shanxi Key Laboratory of Ecological Animal Science and Environmental Medicine, Shanxi Agricultural University, Taigu, Shanxi, 030801, PR China
| | - Zhihong Yin
- College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, Henan, 453003, PR China
| | - Xiaochao Song
- College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, Henan, 453003, PR China
| | - Tao Ruan
- College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, 225009, PR China
| | - Liushuai Hua
- College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, Henan, 453003, PR China
| | - Junwei Liu
- College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, Henan, 453003, PR China
| | - Jundong Wang
- Shanxi Key Laboratory of Ecological Animal Science and Environmental Medicine, Shanxi Agricultural University, Taigu, Shanxi, 030801, PR China.
| | - Hongmei Ning
- College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, Henan, 453003, PR China; Shanxi Key Laboratory of Ecological Animal Science and Environmental Medicine, Shanxi Agricultural University, Taigu, Shanxi, 030801, PR China.
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18
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Song C, Zhao J, Fu B, Li D, Mao T, Peng W, Wu H, Zhang Y. Melatonin-mediated upregulation of Sirt3 attenuates sodium fluoride-induced hepatotoxicity by activating the MT1-PI3K/AKT-PGC-1α signaling pathway. Free Radic Biol Med 2017; 112:616-630. [PMID: 28912098 DOI: 10.1016/j.freeradbiomed.2017.09.005] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2017] [Revised: 08/28/2017] [Accepted: 09/08/2017] [Indexed: 02/06/2023]
Abstract
Mitochondrial reactive oxygen species (ROS) production has been implicated in the pathogenesis of fluoride toxicity in liver. Melatonin, an indolamine synthesized in the pineal gland, was previously shown to protect against sodium fluoride (NaF)-induced hepatotoxicity. This study investigated the protective effects of melatonin pretreatment on NaF-induced hepatotoxicity and elucidates the potential mechanism of melatonin-mediated protection. Reducing mitochondrial ROS by melatonin substantially attenuated NaF-induced NADPH oxidase 4 (Nox4) upregulation and cytotoxicity in L-02 cells. Melatonin exerted its hepatoprotective effects by upregulating Sirtuin 3 (Sirt3) expression level and its activity. Melatonin increased the activity of manganese superoxide dismutase (SOD2) by promoting Sirt3-mediated deacetylation and promoted SOD2 expression through Sirt3-regulated DNA-binding activity of forkhead box O3 (FoxO3a), thus inhibiting the production of mitochondrial ROS induced by NaF. Notably, increased peroxisome proliferator-activated receptor gamma coactivator 1α (PGC-1α) by melatonin activated the Sirt3 expression, which was regulated by an estrogen-related receptor (ERR) binding element (ERRE) mapped to Sirt3 promoter region. Analysis of the cell signaling pathway profiling systems and specific pathway inhibition indicated that melatonin enhances PGC-1α expression by activating the PI3K/AKT signaling pathway. Importantly, inhibition of melatonin receptor (MT)-1 blocked the melatonin-activated PI3K/AKT-PGC-1α-Sirt3 signaling. Mechanistic study revealed that the protective effects of melatonin were associated with down-regulation of JNK1/2 phosphorylation. Our findings provided a theoretical basis that melatonin mitigated NaF-induced hepatotoxicity, which, in part, was mediated through the activation of the Sirt3 pathway.
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Affiliation(s)
- Chao Song
- College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, China; Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Jiamin Zhao
- College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, China; Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Beibei Fu
- College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, China; Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Dan Li
- College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, China; Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Tingchao Mao
- College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, China; Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Wei Peng
- College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, China; Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Haibo Wu
- College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, China; Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A&F University, Yangling 712100, Shaanxi, China.
| | - Yong Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, China; Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A&F University, Yangling 712100, Shaanxi, China.
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19
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Zhao Y, Zhao J, Wang J, Wang J. Fluoride exposure changed the structure and the expressions of HSP related genes in testes of pubertal rats. CHEMOSPHERE 2017; 184:1080-1088. [PMID: 28672688 DOI: 10.1016/j.chemosphere.2017.06.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 06/07/2017] [Accepted: 06/08/2017] [Indexed: 06/07/2023]
Abstract
Previous studies have indicated that fluoride exposure damaged the male reproductive function; however, the cellular mechanism of fluoride-induced testicular toxicity is still unclear. In this study, twenty-two female pregnant Wistar rats were allotted randomly to two groups: control (deionized water) and sodium fluoride (NaF, contain F-: 67.86 mg/L) groups. After delivery, the dosage was continued for 15 weeks for puppies. Twelve rats in each group were tested at 6 and 9 (pubertal); 12 and 15 (mature) weeks of age. Our results suggested that organ coefficient of epididymis was significantly decreased in the mature (12 and 15 week-old) rats. Epididymal sperm abnormality and femur fluoride concentration were increased with the concomitant decrease in sperm motility and concentration in these experimental periods. Compared to the control, in the NaF group, the seminiferous tubules of each age were reduced in terms of diameter and thickness. The sperm cells were lost and shedding and finally disappeared after 9 weeks. mRNA and protein levels of HSP27 and 90 were decreased with a concomitant increase in HSP70 and HSF mRNA and protein levels in NaF exposed rats. The mRNA and protein levels of HSP27 and HSF (only mRNA) were significantly increased in NaF treated rats at 9 and 15 weeks of age, respectively. In summary, these results emphasize that NaF induces testicular and sperm abnormalities through the involvement of HSPs especially during the pubertal period.
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Affiliation(s)
- Yangfei Zhao
- Shanxi Key Laboratory of Environmental Veterinary Medicine, Shanxi Agricultural University, Jinzhong, Shanxi, China
| | - Jun Zhao
- Shanxi Key Laboratory of Environmental Veterinary Medicine, Shanxi Agricultural University, Jinzhong, Shanxi, China
| | - Jinming Wang
- Shanxi Key Laboratory of Environmental Veterinary Medicine, Shanxi Agricultural University, Jinzhong, Shanxi, China
| | - Jundong Wang
- Shanxi Key Laboratory of Environmental Veterinary Medicine, Shanxi Agricultural University, Jinzhong, Shanxi, China.
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Dec K, Łukomska A, Maciejewska D, Jakubczyk K, Baranowska-Bosiacka I, Chlubek D, Wąsik A, Gutowska I. The Influence of Fluorine on the Disturbances of Homeostasis in the Central Nervous System. Biol Trace Elem Res 2017; 177:224-234. [PMID: 27787813 PMCID: PMC5418325 DOI: 10.1007/s12011-016-0871-4] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 10/11/2016] [Indexed: 01/21/2023]
Abstract
Fluorides occur naturally in the environment, the daily exposure of human organism to fluorine mainly depends on the intake of this element with drinking water and it is connected with the geographical region. In some countries, we can observe the endemic fluorosis-the damage of hard and soft tissues caused by the excessive intake of fluorine. Recent studies showed that fluorine is toxic to the central nervous system (CNS). There are several known mechanisms which lead to structural brain damage caused by the excessive intake of fluorine. This element is able to cross the blood-brain barrier, and it accumulates in neurons affecting cytological changes, cell activity and ion transport (e.g. chlorine transport). Additionally, fluorine changes the concentration of non-enzymatic advanced glycation end products (AGEs), the metabolism of neurotransmitters (influencing mainly glutamatergic neurotransmission) and the energy metabolism of neurons by the impaired glucose transporter-GLUT1. It can also change activity and lead to dysfunction of important proteins which are part of the respiratory chain. Fluorine also affects oxidative stress, glial activation and inflammation in the CNS which leads to neurodegeneration. All of those changes lead to abnormal cell differentiation and the activation of apoptosis through the changes in the expression of neural cell adhesion molecules (NCAM), glial fibrillary acidic protein (GFAP), brain-derived neurotrophic factor (BDNF) and MAP kinases. Excessive exposure to this element can cause harmful effects such as permanent damage of all brain structures, impaired learning ability, memory dysfunction and behavioural problems. This paper provides an overview of the fluoride neurotoxicity in juveniles and adults.
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Affiliation(s)
- K Dec
- Department of Biochemistry and Human Nutrition, Pomeranian Medical University in Szczecin, Broniewskiego street 24, 70-406, Szczecin, Poland
| | - A Łukomska
- Department of Biochemistry and Human Nutrition, Pomeranian Medical University in Szczecin, Broniewskiego street 24, 70-406, Szczecin, Poland
| | - D Maciejewska
- Department of Biochemistry and Human Nutrition, Pomeranian Medical University in Szczecin, Broniewskiego street 24, 70-406, Szczecin, Poland
| | - K Jakubczyk
- Department of Biochemistry and Human Nutrition, Pomeranian Medical University in Szczecin, Broniewskiego street 24, 70-406, Szczecin, Poland
| | - I Baranowska-Bosiacka
- Department of Biochemistry, Pomeranian Medical University in Szczecin, Powstańców Wlkp. 72 av., 71-111, Szczecin, Poland
| | - D Chlubek
- Department of Biochemistry, Pomeranian Medical University in Szczecin, Powstańców Wlkp. 72 av., 71-111, Szczecin, Poland
| | - A Wąsik
- Institute of Pharmacology, Polish Academy of Sciences, Department of Neurochemistry, Smętna street 12, 31-343, Kraków, Poland
| | - I Gutowska
- Department of Biochemistry and Human Nutrition, Pomeranian Medical University in Szczecin, Broniewskiego street 24, 70-406, Szczecin, Poland.
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Escobar-García D, Mejía-Saavedra J, Jarquín-Yáñez L, Molina-Frechero N, Pozos-Guillén A. Collagenase 1A2 (COL1A2) gene A/C polymorphism in relation to severity of dental fluorosis. Community Dent Oral Epidemiol 2015; 44:162-8. [DOI: 10.1111/cdoe.12201] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 10/09/2015] [Indexed: 01/11/2023]
Affiliation(s)
- Diana Escobar-García
- Laboratorio de Ciencias Básicas; Facultad de Estomatología; Universidad Autónoma de San Luis Potosí; San Luis Potosí México
| | - Jesús Mejía-Saavedra
- Centro de Investigación Aplicada en Ambiente y Salud (CIACYT-Facultad de Medicina) Universidad Autónoma de San Luis Potosí; San Luis Potosí México
| | - Lizet Jarquín-Yáñez
- Centro de Investigación Aplicada en Ambiente y Salud (CIACYT-Facultad de Medicina) Universidad Autónoma de San Luis Potosí; San Luis Potosí México
| | - Nelly Molina-Frechero
- División de Ciencias Biológicas y de la Salud; Universidad Autónoma Metropolitana; México D.F. México
| | - Amaury Pozos-Guillén
- Laboratorio de Ciencias Básicas; Facultad de Estomatología; Universidad Autónoma de San Luis Potosí; San Luis Potosí México
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Yan N, Liu Y, Liu S, Cao S, Wang F, Wang Z, Xi S. Fluoride-Induced Neuron Apoptosis and Expressions of Inflammatory Factors by Activating Microglia in Rat Brain. Mol Neurobiol 2015; 53:4449-60. [DOI: 10.1007/s12035-015-9380-2] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2015] [Accepted: 07/27/2015] [Indexed: 12/21/2022]
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Akinrinade ID, Memudu AE, Ogundele OM. Fluoride and aluminium disturb neuronal morphology, transport functions, cholinesterase, lysosomal and cell cycle activities. ACTA ACUST UNITED AC 2015; 22:105-15. [PMID: 25863844 DOI: 10.1016/j.pathophys.2015.03.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Revised: 03/12/2015] [Accepted: 03/25/2015] [Indexed: 02/05/2023]
Abstract
UNLABELLED Fluoride and aluminium have been reported to cause severe alterations in the brain. However, their exact mechanisms of neurotoxic activities remain unknown. AIM This study was designed to investigate the role of fluoride and aluminium in neuronal transport, lysosomal, cell cycle protein and acetylcholinesterase activities. METHOD Adult Wistar rats were given low and high doses of fluoride, aluminium and a combination of both with the control group receiving distilled water for 30 days. Blood sera and brain homogenates were quantified for alkaline phosphatase (biomarker for neuronal transport) activities. Brain sections were stained with cresyl fast violet to detect neuronal cell damage. Histochemical demonstration of acetylcholinesterase (AChE) activity and the immunohistochemical detection of cell cycle protein (anti-cyclin D) and lysosomal protein (anti-cathepsin D) were done using the antigen retrieval method. RESULT Results showed severe histomorphologic alterations, dysregulation of membrane transport activities, inhibition of AChE activities and increased expression of lysosomal and cell cycle proteins. CONCLUSION These findings confirm that excessive fluoride and aluminium intake induces the progression of cell death which inhibit AChE activities and trigger the release of lysosomal and cell cycle proteins.
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Affiliation(s)
- Ibukun Dorcas Akinrinade
- Department of Anatomy, College of Health Sciences, Bingham University, P.M.B. 005, New Karu 961106, Nasarawa State, Nigeria.
| | - Adejoke Elizabeth Memudu
- Department of Anatomy, College of Health Sciences, Bingham University, P.M.B. 005, New Karu 961106, Nasarawa State, Nigeria.
| | - Olalekan Michael Ogundele
- Neural Systems Lab, Department of Comparative Biomedical Sciences, Louisiana State University, Baten Rouge 70802, LA, USA.
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Akinrinade ID, Memudu AE, Ogundele OM, Ajetunmobi OI. Interplay of glia activation and oxidative stress formation in fluoride and aluminium exposure. PATHOPHYSIOLOGY 2015; 22:39-48. [DOI: 10.1016/j.pathophys.2014.12.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 11/25/2014] [Accepted: 12/03/2014] [Indexed: 01/24/2023] Open
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