1
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Kumar S, Shenoy S, Swamy RS, Ravichandiran V, Kumar N. Fluoride-Induced Mitochondrial Dysfunction and Approaches for Its Intervention. Biol Trace Elem Res 2024; 202:835-849. [PMID: 37300595 DOI: 10.1007/s12011-023-03720-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 05/28/2023] [Indexed: 06/12/2023]
Abstract
Fluoride is present everywhere in nature. The primary way that individuals are exposed to fluoride is by drinking water. It's interesting to note that while low fluoride levels are good for bone and tooth growth, prolonged fluoride exposure is bad for human health. Additionally, preclinical studies link oxidative stress, inflammation, and programmed cell death to fluoride toxicity. Moreover, mitochondria play a crucial role in the production of reactive oxygen species (ROS). On the other hand, little is known about fluoride's impact on mitophagy, biogenesis, and mitochondrial dynamics. These actions control the growth, composition, and organisation of mitochondria, and the purification of mitochondrial DNA helps to inhibit the production of reactive oxygen species and the release of cytochrome c, which enables cells to survive the effects of fluoride poisoning. In this review, we discuss the different pathways involved in mitochondrial toxicity and dysfunction induced by fluoride. For therapeutic approaches, we discussed different phytochemical and pharmacological agents which reduce the toxicity of fluoride via maintained by imbalanced cellular processes, mitochondrial dynamics, and scavenging the ROS.
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Affiliation(s)
- Sachindra Kumar
- National Institute of Pharmaceutical Education and Research, Hajipur, Industrial Area Hajipur, Vaishali, 844102, India
| | - Smita Shenoy
- Department of Pharmacology, Kasturba Medical College, Manipal, Manipal Academy of Higher Education (MAHE), Manipal, 576104, India
| | - Ravindra Shantakumar Swamy
- Division of Anatomy, Department of Basic Medical Sciences (DBMS), Manipal Academy of Higher Education (MAHE), Manipal, 576104, India
| | - V Ravichandiran
- National Institute of Pharmaceutical Education and Research, Hajipur, Industrial Area Hajipur, Vaishali, 844102, India
| | - Nitesh Kumar
- National Institute of Pharmaceutical Education and Research, Hajipur, Industrial Area Hajipur, Vaishali, 844102, India.
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2
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Elsayed SA, Saleh EE, Aboelnga MM, Toson EA. Experimental and computational studies of silver(I) dibenzoylmethane-based complexes, interaction with DNA/RNA/BSA biomolecules, and in vitro cytotoxic activity. J Inorg Biochem 2023; 241:112132. [PMID: 36701985 DOI: 10.1016/j.jinorgbio.2023.112132] [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: 11/16/2022] [Revised: 01/17/2023] [Accepted: 01/17/2023] [Indexed: 01/21/2023]
Abstract
Two silver(I) complexes of composition [Ag2(L)2] (1) and [Ag(L)(PPh3)2](2) (HL = dibenzoyl- methane, PPh3 = triphenylphosphine) were synthesized and characterized by elemental analysis, FTIR, NMR, XRPD, and UV-visible spectra. The molecular structures of the studied ligands and Ag(I) complexes have been characterized using Density Function Theory (DFT) calculations. This analysis has enabled us to determine the reactivity and the coordination site(s) for each ligand. Ag(I) ion is found to be coordinated with the ligand's oxygens in almost a linear fashion in complex (1), while in complex (2) it adopts a tetrahedral geometry. The interaction compounds with biomolecules; calf thymus (ct DNA), yeast-tRNA, and bovine serum albumin (BSA) were investigated using both absorption and fluorescence spectroscopy. The in vitro cytotoxic studies of the complexes against normal human lung fibroblast (WI38), cancerous breast (MDA-MB-231), mammary gland breast (MCF7), hepatocellular (HePG2), and prostate (PC3) cell lines indicated that the complexes are highly toxic to the cancer cells but less toxic towards the normal one when compared with the ligand. Flow cytometric results showed that complex (1) induced cell cycle arrest at the G2/M phase, and complex (2) at G2/M and S phases. Moreover, the results of apoptotic genes (caspase3 and p53) and anti-apoptotic (Bcl2) led us to suggest an apoptotic killing mechanism of cells rather than a necrotic one.
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Affiliation(s)
- Shadia A Elsayed
- Chemistry Department, Faculty of Science, Damietta University, New Damietta 34517, Egypt.
| | - Elham E Saleh
- Chemistry Department, Faculty of Science, Damietta University, New Damietta 34517, Egypt
| | - Mohamed M Aboelnga
- Chemistry Department, Faculty of Science, Damietta University, New Damietta 34517, Egypt
| | - Elshahat A Toson
- Chemistry Department, Faculty of Science, Damietta University, New Damietta 34517, Egypt
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3
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El-Bestawy EM, Tolba AM, Rashad WA. Morphological, ultrastructural, and biochemical changes induced by sodium fluoride in the tongue of adult male albino rat and the ameliorative effect of resveratrol. Anat Cell Biol 2022; 55:483-496. [PMID: 36168808 PMCID: PMC9747341 DOI: 10.5115/acb.22.088] [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] [Received: 04/17/2022] [Revised: 06/05/2022] [Accepted: 06/21/2022] [Indexed: 01/02/2023] Open
Abstract
Little knowledge is available about the effects of fluoride exposure on the tongue. This study evaluated the effects of sodium fluoride (NaF) on the tongue ultrastructure and detected the ameliorative effects of resveratrol. Forty adult albino rats were separated into 4 groups: the control group was given a balanced diet and purified water. The NaF treated group: received 10 mg/kg/d dissolved in 2.5 ml distilled water once daily for 30 days orally. The NaF+resveratrol group: received NaF 10 mg/kg/d orally together with resveratrol in a dose of 30 mg/kg daily for 30 days. The resveratrol group was subjected to resveratrol in a dose of 30 mg/kg/d by oral gavage for 30 days. Sections were stained with hematoxylin & eosin, and Masson's trichrome. Tumor necrosis factor α immunohistochemical study and electron microscopic examinations were done. The oxidative stress markers malondialdehyde, antioxidant reduced glutathione, and the total antioxidant capacity were measured. The NaF group revealed ulceration, necrotic muscle fibers, distorted papillae and a significant increase in malondialdehyde level, and a significant decrease in glutathione and the total antioxidant levels. In the NaF+resveratrol group, pathological changes were less, and the oxidant levels were decreased by the administration of resveratrol with NaF. In conclusion, NaF adversely affects the ultrastructure of the adult rat tongue and resveratrol can ameliorate this effect.
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Affiliation(s)
- Emtethal M. El-Bestawy
- Department of Human Anatomy and Embryology, Faculty of Medicine, Zagazig University, Sharqia Governorate, Egypt
| | - Asmaa M. Tolba
- Department of Human Anatomy and Embryology, Faculty of Medicine, Zagazig University, Sharqia Governorate, Egypt,Corresponding author: Asmaa M. Tolba, Department of Human Anatomy and Embryology, Faculty of Medicine, Zagazig University, Sharqia Governorate 44519, Egypt, E-mail:
| | - Walaa A. Rashad
- Department of Human Anatomy and Embryology, Faculty of Medicine, Zagazig University, Sharqia Governorate, Egypt
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4
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Babu S, Manoharan S, Ottappilakkil H, Perumal E. Role of oxidative stress-mediated cell death and signaling pathways in experimental fluorosis. Chem Biol Interact 2022; 365:110106. [PMID: 35985521 DOI: 10.1016/j.cbi.2022.110106] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Revised: 08/06/2022] [Accepted: 08/08/2022] [Indexed: 11/03/2022]
Abstract
Free radicals and other oxidants have enticed the interest of researchers in the fields of biology and medicine, owing to their role in several pathophysiological conditions, including fluorosis (Fluoride toxicity). Radical species affect cellular biomolecules such as nucleic acids, proteins, and lipids, resulting in oxidative stress. Reactive oxygen species-mediated oxidative stress is a common denominator in fluoride toxicity. Fluorosis is a global health concern caused by excessive fluoride consumption over time. Fluoride alters the cellular redox homeostasis, and its toxicity leads to the activation of cell death mechanisms like apoptosis, autophagy, and necroptosis. Even though a surfeit of signaling pathways is involved in fluorosis, their toxicity mechanisms are not fully understood. Thus, this review aims to understand the role of reactive species in fluoride toxicity with an outlook on the effects of fluoride in vitro and in vivo models. Also, we emphasized the signal transduction pathways and the mechanism of cell death implicated in fluoride-induced oxidative stress.
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Affiliation(s)
- Srija Babu
- Molecular Toxicology Laboratory, Department of Biotechnology, Bharathiar University, Coimbatore, 641046, Tamil Nadu, India
| | - Suryaa Manoharan
- Molecular Toxicology Laboratory, Department of Biotechnology, Bharathiar University, Coimbatore, 641046, Tamil Nadu, India
| | - Harsheema Ottappilakkil
- Molecular Toxicology Laboratory, Department of Biotechnology, Bharathiar University, Coimbatore, 641046, Tamil Nadu, India
| | - Ekambaram Perumal
- Molecular Toxicology Laboratory, Department of Biotechnology, Bharathiar University, Coimbatore, 641046, Tamil Nadu, India.
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5
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Avila-Rojas SH, Aparicio-Trejo OE, Sanchez-Guerra MA, Barbier OC. Effects of fluoride exposure on mitochondrial function: Energy metabolism, dynamics, biogenesis and mitophagy. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2022; 94:103916. [PMID: 35738460 DOI: 10.1016/j.etap.2022.103916] [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: 01/07/2022] [Revised: 06/09/2022] [Accepted: 06/17/2022] [Indexed: 06/15/2023]
Abstract
Fluoride is ubiquitous in the environment. Furthermore, drinking water represents the main source of exposure to fluoride for humans. Interestingly, low fluoride concentrations have beneficial effects on bone and teeth development; however, chronic fluoride exposure has harmful effects on human health. Besides, preclinical studies associate fluoride toxicity with oxidative stress, inflammation, and apoptosis. On the other hand, it is well-known that mitochondria play a key role in reactive oxygen species production. By contrast, fluoride's effect on processes such as mitochondrial dynamics, biogenesis and mitophagy are little known. These processes modulate the size, content, and distribution of mitochondria and their depuration help to counter the reactive oxygen species production and cytochrome c release, thereby allowing cell survival. However, a maladaptive response could enhance fluoride-induced toxicity. The present review gives a brief account of fluoride-induced mitochondrial alterations on soft and hard tissues, including liver, reproductive organs, heart, brain, lung, kidney, bone, and tooth.
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Affiliation(s)
- Sabino Hazael Avila-Rojas
- Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional. Departamento de Toxicología (CINVESTAV-IPN), Av. IPN No. 2508 Col., San Pedro Zacatenco, México CP 07360, Mexico.
| | | | - Marco Antonio Sanchez-Guerra
- Department of Developmental Neurobiology, National Institute of Perinatology, Montes Urales 800, Lomas Virreyes, Mexico 1100, Mexico.
| | - Olivier Christophe Barbier
- Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional. Departamento de Toxicología (CINVESTAV-IPN), Av. IPN No. 2508 Col., San Pedro Zacatenco, México CP 07360, Mexico.
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Ramírez-Martínez CM, Trejo-Remigio DA, Jurado-Castañeda E, Alonso-Moctezuma A, Rivera-Reza DI, Leyva-Huerta ER, Portilla-Robertson J, Jacinto-Alemán LF. Multiple approaches to oral epithelial dysplasia degree analyses: a pilot study. Minerva Dent Oral Sci 2022; 71:59-65. [PMID: 34609112 DOI: 10.23736/s2724-6329.21.04538-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
BACKGROUND Oral epithelial dysplasia (OED) is the presence of cells of an abnormal type within a tissue, which may signify a stage preceding the development of cancer. Our aim was to determine the interrelation between the expression of multiple molecular markers and the histological features of oral dysplasia. METHODS Fifteen samples of OED (five for each severity degree) were analyzed through software assisted image cytometry nuclear morphology. p53 (wild-type and mutated form), Bax and Bcl2 expression was immunohistochemically determined, and the gene expression of MMP1, MMP2, MMP9 and hTERT was determined by RT-PCR. The mean, standard deviation, ANOVA and Fisher's Exact Test (P<0.05) were performed. RESULTS Our analysis indicated congruence between the software-assisted measurement of nuclear morphology and severity degree. Only five samples were positive to p53-mutated form; and Bax was more expressed than Bcl-2. hTERT expression was significantly expressed in relation to severity, and MMP1 was predominantly expressed, followed by MMP9 and MMP2. CONCLUSIONS Our results reinforce that software-assisted measurement is an alternative to severity degree determination. MMP1 is an important marker for severity dysplasia degree; however, the predominant expression of Bax over Bcl-2 suggests that this pro-apoptotic state could be used to minorize the progression, perhaps, as a future therapeutic target.
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Affiliation(s)
- Carla M Ramírez-Martínez
- School of Dentistry, Postgraduate and Research Division, Department of Oral Medicine and Pathology, National Autonomous University of Mexico, Mexico City, Mexico
| | - David A Trejo-Remigio
- School of Dentistry, Postgraduate and Research Division, Department of Oral Medicine and Pathology, Laboratory of Cell Culture and Immunohistochemistry, National Autonomous University of Mexico, Mexico City, Mexico
| | - Emiliano Jurado-Castañeda
- School of Dentistry, Postgraduate and Research Division, Department of Oral Medicine and Pathology, Clinic of Oral Medicine, National Autonomous University of Mexico, Mexico City, Mexico
| | - Alejandro Alonso-Moctezuma
- School of Dentistry, Postgraduate and Research Division, Department of Oral and Maxillofacial Surgery Specialty, National Autonomous University of Mexico, Mexico City, Mexico
| | - Diana I Rivera-Reza
- School of Dentistry, Postgraduate and Research Division, Department of Oral Medicine and Pathology, National Autonomous University of Mexico, Mexico City, Mexico
| | - Elba R Leyva-Huerta
- School of Dentistry, Postgraduate and Research Division, Department of Oral Medicine and Pathology, National Autonomous University of Mexico, Mexico City, Mexico
| | - Javier Portilla-Robertson
- School of Dentistry, Postgraduate and Research Division, Department of Oral Medicine and Pathology, National Autonomous University of Mexico, Mexico City, Mexico
| | - Luis F Jacinto-Alemán
- School of Dentistry, Postgraduate and Research Division, Department of Oral Medicine and Pathology, National Autonomous University of Mexico, Mexico City, Mexico -
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7
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Halder D, Mallick A, Purkayastha P. DNA-flavonoid pH sensitive host-guest mechanism to sense fluoride ions and construction of molecular logic gates. J Photochem Photobiol A Chem 2022. [DOI: 10.1016/j.jphotochem.2022.113857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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8
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Zhou X, Chen Z, Zhong W, Yu R, He L. Effect of fluoride on PERK-Nrf2 signaling pathway in mouse ameloblasts. Hum Exp Toxicol 2019; 38:833-845. [PMID: 30977402 DOI: 10.1177/0960327119842273] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In the development of dental fluorosis, oxidative stress is considered as the key mechanism. Endoplasmic reticulum (ER) stress can induce oxidative stress and activate the important antioxidative factor nuclear factor erythroid 2-related factor 2 (Nrf2) in a PKR-like ER kinase (PERK)-dependent manner, but combining ER stress and oxidative stress, the role of PERK-Nrf2 signaling pathway involved in fluoride-regulated ameloblasts is not fully defined. Here, we studied the effect of fluoride on PERK-Nrf2 signaling pathway in mouse ameloblasts. We found that low-dose and continuous fluoride exposure increased binding immunoglobulin protein expression and activated PERK-activating transcription factor 4 signaling pathway. Meanwhile, the expression of Nrf2 and its target genes (glutamylcysteine synthetase and glutathione S-transferase-P1) enhanced following ER stress. Tunicamycin increased the expression of PERK, leading to Nrf2 nuclear import, and tauroursodeoxycholate suppressed Nrf2 activation through PERK during ER stress, indicating that PERK activation is required for Nrf2 nuclear entry. Furthermore, tert-butylhydroquinone triggered the overexpression of Nrf2 to reduce ER stress, but luteolin inhibited Nrf2 nuclear localization to elevate ER stress. In summary, this study proved that fluoride under certain dose can induce ER stress and promote Nrf2 nuclear import via PERK activation and suggested that antioxidation mechanism mediated by PERK-Nrf2 can alleviate fluoride-induced ER stress effectively.
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Affiliation(s)
- X Zhou
- 1 Department of Dental Medicine, The First Affiliated Hospital of Guangdong Pharmaceutical University, Guangzhou, China
- 2 Department of Occupational and Environmental Health, School of Public Health, Guangdong Pharmaceutical University, Guangzhou, China
- 3 Department of Occupational Health and Medicine, School of Public Health, Southern Medical University, Guangzhou, China
| | - Z Chen
- 2 Department of Occupational and Environmental Health, School of Public Health, Guangdong Pharmaceutical University, Guangzhou, China
| | - W Zhong
- 2 Department of Occupational and Environmental Health, School of Public Health, Guangdong Pharmaceutical University, Guangzhou, China
| | - R Yu
- 2 Department of Occupational and Environmental Health, School of Public Health, Guangdong Pharmaceutical University, Guangzhou, China
| | - L He
- 1 Department of Dental Medicine, The First Affiliated Hospital of Guangdong Pharmaceutical University, Guangzhou, China
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9
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Wei Q, Deng H, Cui H, Fang J, Zuo Z, Deng J, Li Y, Wang X, Zhao L. A mini review of fluoride-induced apoptotic pathways. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:33926-33935. [PMID: 30338467 DOI: 10.1007/s11356-018-3406-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 10/04/2018] [Indexed: 06/08/2023]
Abstract
Fluorine or fluoride can have toxic effects on bone tissue and soft tissue at high concentrations. These negative effects include but not limited to cytotoxicity, immunotoxicity, blood toxicity, and oxidative damage. Apoptosis plays an important role in fluoride-induced toxicity of kidney, liver, spleen, thymus, bursa of Fabricius, cecal tonsil, and cultured cells. Here, apoptosis activated by high level of fluoride has been systematically reviewed, focusing on three pathways: mitochondrion-mediated, endoplasmic reticulum (ER) stress-mediated, and death receptor-mediated pathways. However, very limited reports are focused on the death receptor-mediated apoptosis pathways in the fluoride-induced apoptosis. Therefore, understanding and discovery of more pathways and molecular mechanisms of fluoride-induced apoptosis may contribute to designing measures for preventing fluoride toxicity.
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Affiliation(s)
- Qin Wei
- College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
| | - Huidan Deng
- College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
| | - Hengmin Cui
- College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China.
- Key Laboratory of Animal Diseases and Environmental Hazards of Sichuan Province, Sichuan Agriculture University, Wenjiang, Chengdu, 611130, Sichuan, China.
- Key Laboratory of Agricultural information engineering of Sichuan Province, Sichuan Agriculture University, Ya'an, 625014, Sichuan, China.
| | - Jing Fang
- College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Key Laboratory of Animal Diseases and Environmental Hazards of Sichuan Province, Sichuan Agriculture University, Wenjiang, Chengdu, 611130, Sichuan, China
| | - Zhicai Zuo
- College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Key Laboratory of Animal Diseases and Environmental Hazards of Sichuan Province, Sichuan Agriculture University, Wenjiang, Chengdu, 611130, Sichuan, China
| | - Junliang Deng
- College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Key Laboratory of Animal Diseases and Environmental Hazards of Sichuan Province, Sichuan Agriculture University, Wenjiang, Chengdu, 611130, Sichuan, China
| | - Yinglun Li
- College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Key Laboratory of Animal Diseases and Environmental Hazards of Sichuan Province, Sichuan Agriculture University, Wenjiang, Chengdu, 611130, Sichuan, China
| | - Xun Wang
- College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Key Laboratory of Animal Diseases and Environmental Hazards of Sichuan Province, Sichuan Agriculture University, Wenjiang, Chengdu, 611130, Sichuan, China
| | - Ling Zhao
- College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Key Laboratory of Animal Diseases and Environmental Hazards of Sichuan Province, Sichuan Agriculture University, Wenjiang, Chengdu, 611130, Sichuan, China
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10
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Ji M, Xiao L, Xu L, Huang S, Zhang D. How pH is regulated during amelogenesis in dental fluorosis. Exp Ther Med 2018; 16:3759-3765. [PMID: 30402142 DOI: 10.3892/etm.2018.6728] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 12/01/2017] [Indexed: 12/14/2022] Open
Abstract
Amelogenesis is a complicated process that concerns the interaction between growing hydroxyapatite crystals and extracellular proteins, which requires the tight regulation of pH. In dental fluorosis, the balance of pH regulation is broken, leading to abnormal mineralization. The current review focuses on the electrolyte transport processes associated with pH homeostasis, particularly regarding the changes in ion transporters that occur during amelogenesis, following exposure to excessive fluoride. Furthermore, the possible mechanism of fluorosis is discussed on the basis of acid hypothesis. There are two main methods by which F- accelerates crystal formation in ameloblasts. Firstly, it induces the release of protons, lowering the pH of the cell microenvironment. The decreased pH stimulates the upregulation of ion transporters, which attenuates further declines in the pH. Secondly, F- triggers an unknown signaling pathway, causing changes in the transcription of ion transporters and upregulating the expression of bicarbonate transporters. This results in the release of a large amount of bicarbonate from ameloblasts, which may neutralize the pH to form a microenvironment that favors crystal nucleation. The decreased pH stimulates the diffusion of F- into the cytoplasm of amelobalsts along the concentration gradient formed by the release of protons. The retention of F- causes a series of pathological changes, including oxidative and endoplasmic reticulum stress. If the buffering capacity of ameloblasts facing F- toxicity holds, normal mineralization occurs; however, if F- levels are high enough to overwhelm the buffering capacity of ameloblasts, abnormal mineralization occurs, leading to dental fluorosis.
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Affiliation(s)
- Mei Ji
- Department of Stomatology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
| | - Lili Xiao
- Department of Stomatology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
| | - Le Xu
- Department of Stomatology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
| | - Shengyun Huang
- Department of Stomatology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
| | - Dongsheng Zhang
- Department of Stomatology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
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11
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Li J, Zhao L, Zhao X, Wang P, Liu Y, Ruan J. Foxo1 Attenuates NaF-Induced Apoptosis of LS8 Cells through the JNK and Mitochondrial Pathways. Biol Trace Elem Res 2018; 181:104-111. [PMID: 28429284 DOI: 10.1007/s12011-017-1015-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Accepted: 04/04/2017] [Indexed: 12/21/2022]
Abstract
Fluoride-induced ameloblast apoptosis is a key event in dental fluorosis development. Forkhead box o1 (Foxo1) is a transcription factor involved in cell apoptosis. The present study aims to investigate the effect of Foxo1 on ameloblast apoptosis induced by fluoride in vitro and to explore its possible mechanism. Ameloblast-like cells (LS8 cells) were exposed to various concentrations of NaF for up to 48 h. Foxo1 activation was modulated using lentiviral vectors, and cell apoptosis was measured by flow cytometry. The expression levels of Foxo1, c-Jun N-terminal kinase (JNK), and some well-known regulators of the mitochondrial pathway of apoptosis (cytoplasmic cytochrome c, cleaved caspase-9, cleaved caspase-3, Bcl-2, and Bax) were detected by quantitative real-time PCR, western blot, and immunofluorescence assay. The results showed significantly decreased expression and increased phosphorylation of Foxo1 in NaF-treated LS8 cells. Further investigation revealed that forced Foxo1 activation with lentiviral vectors attenuated NaF-induced apoptosis of LS8 cells, markedly decreasing protein levels of cytoplasmic cytochrome c, cleaved caspase-9, and cleaved caspase-3 while increasing the Bcl-2/Bax ratio and JNK expression level. These findings suggest that Foxo1 attenuated NaF-induced apoptosis of LS8 cells via inhibiting the mitochondrial pathway and activating JNK.
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Affiliation(s)
- Juedan Li
- Clinical Research Center of Shaanxi Province for Dental and Maxillofacial Diseases, Department of Preventive Dentistry, College of Stomatology, Xi'an Jiaotong University, 98 XiWu Road, Xi'an, Shaanxi, 710004, People's Republic of China
| | - Lin Zhao
- Clinical Research Center of Shaanxi Province for Dental and Maxillofacial Diseases, Department of Preventive Dentistry, College of Stomatology, Xi'an Jiaotong University, 98 XiWu Road, Xi'an, Shaanxi, 710004, People's Republic of China
- Department of Oral Pathology, College of Stomatology, Ningxia Medical University, 1160 Shengli Street, Yinchuan, 750021, People's Republic of China
| | - Xiaomeng Zhao
- Clinical Research Center of Shaanxi Province for Dental and Maxillofacial Diseases, Department of Preventive Dentistry, College of Stomatology, Xi'an Jiaotong University, 98 XiWu Road, Xi'an, Shaanxi, 710004, People's Republic of China
| | - Peng Wang
- Clinical Research Center of Shaanxi Province for Dental and Maxillofacial Diseases, Department of Preventive Dentistry, College of Stomatology, Xi'an Jiaotong University, 98 XiWu Road, Xi'an, Shaanxi, 710004, People's Republic of China
| | - Yan Liu
- Clinical Research Center of Shaanxi Province for Dental and Maxillofacial Diseases, Department of Preventive Dentistry, College of Stomatology, Xi'an Jiaotong University, 98 XiWu Road, Xi'an, Shaanxi, 710004, People's Republic of China
| | - Jianping Ruan
- Clinical Research Center of Shaanxi Province for Dental and Maxillofacial Diseases, Department of Preventive Dentistry, College of Stomatology, Xi'an Jiaotong University, 98 XiWu Road, Xi'an, Shaanxi, 710004, People's Republic of China.
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12
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Li W, Jiang B, Cao X, Xie Y, Huang T. Protective effect of lycopene on fluoride-induced ameloblasts apoptosis and dental fluorosis through oxidative stress-mediated Caspase pathways. Chem Biol Interact 2017; 261:27-34. [DOI: 10.1016/j.cbi.2016.11.021] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 09/24/2016] [Accepted: 11/17/2016] [Indexed: 01/03/2023]
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13
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Wang L, Zhu Y, Wang D. High-Dose Fluoride Induces Apoptosis and Inhibits Ameloblastin Secretion in Primary Rat Ameloblast. Biol Trace Elem Res 2016; 174:402-409. [PMID: 27193486 DOI: 10.1007/s12011-016-0738-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2016] [Accepted: 05/09/2016] [Indexed: 12/13/2022]
Abstract
The objectives of this study are to establish the in vitro culture system for rat primary ameloblast and to investigate the effects of fluoride on cell viability, apoptosis, and ameloblastin (AMBN) secretion of primary rat ameloblast in vitro. Ameloblast was isolated from the tooth germ of the maxillomandibular molar and cultured in vitro. Cells were treated with NaF at 0.4, 0.8, 1.6, 3.2, and 6.4 mM for 24, 48, and 72 h, respectively. Cell viability was measured by MTT assay and apoptosis was tested by flow cytometry. The activation of Fas ligand (FasL)/Fas pathway was detected using immunoblotting for FasL, Fas, cleaved caspase-8, cleaved caspase-3, and cleaved PARP. Secretion of AMBN in culture medium was measured using ELISA. Primary rat ameloblast was successfully isolated and cultured. The effects of low-dose fluoride on cell viability were bi-phasic, while high-dose fluoride resulted in decreased cell viability uniformly. Fluoride induced ameloblast apoptosis via activation of FasL/Fas signaling pathway and diminished secretion of AMBN by ameloblast. Fluoride could decrease ameloblast viability, induce ameloblast apoptosis via activating FasL/Fas signaling pathway, and reduce AMBN secretion.
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Affiliation(s)
- Lin Wang
- Department of Stomatology, Xi'an Medical University, No. 1, XinWang Road, WeiYang District, Xi'an, 710021, China.
| | - Yong Zhu
- Department of Stomatology, Xi'an Medical University, No. 1, XinWang Road, WeiYang District, Xi'an, 710021, China
| | - Danyang Wang
- Department of Stomatology, Xi'an Medical University, No. 1, XinWang Road, WeiYang District, Xi'an, 710021, China
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Singh R, Banerjee C, Ray A, Rajamani P, Mazumder S. Fluoride-induced headkidney macrophage cell apoptosis involves activation of the CaMKII g-ERK 1/2-caspase-8 axis: the role of superoxide in initiating the apoptotic cascade. Toxicol Res (Camb) 2016; 5:1477-1489. [PMID: 30090451 DOI: 10.1039/c6tx00206d] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 07/22/2016] [Indexed: 11/21/2022] Open
Abstract
Fluoride is known to induce apoptosis though the mechanisms remain obscure. The aim of the present study was to understand the underlying molecular mechanisms of fluoride-induced apoptosis using fish headkidney macrophages (HKMs). Exposure to fluoride triggered HKM cell apoptosis as evidenced by Hoechst 333432 and AnnexinV-propidium iodide staining, the presence of an internucleosomal DNA ladder and the comet assay. Our results suggest the influx of extra-cellular Ca2+ to be an initial event in fluoride-induced HKM cell apoptosis. We observed persistently elevated levels of superoxide anions and our inhibitor studies with EGTA suggested the primal role of the Ca2+ flux in triggering superoxide production in fluoride-exposed HKM cells. Fluoride exposure led to elevated levels of Ca2+/CaM dependent protein kinase II gamma (CaMKIIg) and pre-treatment with the inhibitor KN-93 but not its inactive structural analogue KN-92 reduced the number of apoptotic cells establishing the pro-apoptotic role of CaMKIIg in fluoride-induced HKM cell apoptosis. We report that the sustained superoxide generation is primarily responsible for the increased CaMKIIg levels observed in fluoride-exposed HKM cells. Our inhibitor studies further implicated CaMKIIg in the activation of extracellular signal-regulated kinases 1 and 2 (ERK 1/2) culminating in caspase-8/caspase-3 mediated apoptosis of HKM cells. We conclude that fluoride-induced apoptosis is largely dependent on Ca2+ induced superoxide generation leading to elevation in CaMKIIg which in turn induces the phosphorylation of ERK 1/2 and downstream activation of extrinsic caspase cascade in HKM cells.
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Affiliation(s)
- Rashmi Singh
- Immunobiology Laboratory , Department of Zoology , University of Delhi , Delhi 110 007 , India . ; ; Tel: +91-11-27667985
| | - Chaitali Banerjee
- Immunobiology Laboratory , Department of Zoology , University of Delhi , Delhi 110 007 , India . ; ; Tel: +91-11-27667985
| | - Atish Ray
- Immunobiology Laboratory , Department of Zoology , University of Delhi , Delhi 110 007 , India . ; ; Tel: +91-11-27667985
| | - Paulraj Rajamani
- School of Environmental Sciences , Jawaharlal Nehru University , Delhi , India
| | - Shibnath Mazumder
- Immunobiology Laboratory , Department of Zoology , University of Delhi , Delhi 110 007 , India . ; ; Tel: +91-11-27667985
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Suzuki M, Bartlett JD. Sirtuin1 and autophagy protect cells from fluoride-induced cell stress. Biochim Biophys Acta Mol Basis Dis 2013; 1842:245-55. [PMID: 24296261 DOI: 10.1016/j.bbadis.2013.11.023] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Revised: 11/12/2013] [Accepted: 11/25/2013] [Indexed: 12/11/2022]
Abstract
Sirtuin1 (SIRT1) is a nicotinamide adenine dinucleotide (NAD(+))-dependent deacetylase functioning in the regulation of metabolism, cell survival and organismal lifespan. Active SIRT1 regulates autophagy during cell stress, including calorie restriction, endoplasmic reticulum (ER) stress and oxidative stress. Previously, we reported that fluoride induces ER-stress in ameloblasts responsible for enamel formation, suggesting that ER-stress plays a role in dental fluorosis. However, the molecular mechanism of how cells respond to fluoride-induced cell stress is unclear. Here, we demonstrate that fluoride activates SIRT1 and initiates autophagy to protect cells from fluoride exposure. Fluoride treatment of ameloblast-derived cells (LS8) significantly increased Sirt1 expression and induced SIRT1 phosphorylation resulting in the augmentation of SIRT1 deacetylase activity. To demonstrate that fluoride exposure initiates autophagy, we characterized the expression of autophagy related genes (Atg); Atg5, Atg7 and Atg8/LC3 and showed that both their transcript and protein levels were significantly increased following fluoride treatment. To confirm that SIRT1 plays a protective role in fluoride toxicity, we used resveratrol (RES) to augment SIRT1 activity in fluoride treated LS8 cells. RES increased autophagy, inhibited apoptosis, and decreased fluoride cytotoxicity. Rats treated with fluoride (0, 50, 100 and 125ppm) in drinking water for 6weeks had significantly elevated expression levels of Sirt1, Atg5, Atg7 and Atg8/LC3 in their maturation stage enamel organs. Increased protein levels of p-SIRT1, ATG5 and ATG8/LC3 were present in fluoride-treated rat maturation stage ameloblasts. Therefore, the SIRT1/autophagy pathway may play a critical role as a protective response to help prevent dental fluorosis.
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Affiliation(s)
- Maiko Suzuki
- Department of Mineralized Tissue Biology, The Forsyth Institute, 245 First Street, Cambridge, MA 02142, USA; Harvard School of Dental Medicine, 188 Longwood Avenue, Boston, MA 02115, USA
| | - John D Bartlett
- Department of Mineralized Tissue Biology, The Forsyth Institute, 245 First Street, Cambridge, MA 02142, USA; Harvard School of Dental Medicine, 188 Longwood Avenue, Boston, MA 02115, USA.
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High amounts of fluoride induce apoptosis/cell death in matured ameloblast-like LS8 cells by downregulating Bcl-2. Arch Oral Biol 2013; 58:1165-73. [DOI: 10.1016/j.archoralbio.2013.03.016] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Revised: 01/23/2013] [Accepted: 03/20/2013] [Indexed: 01/24/2023]
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Li P, Xue Y, Zhang W, Teng F, Sun Y, Qu T, Chen X, Cheng X, Song B, Luo W, Yu Q. Sodium fluoride induces apoptosis in odontoblasts via a JNK-dependent mechanism. Toxicology 2013; 308:138-45. [PMID: 23578390 DOI: 10.1016/j.tox.2013.03.016] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Revised: 03/30/2013] [Accepted: 03/30/2013] [Indexed: 12/31/2022]
Abstract
Sodium fluoride (NaF) is widely used for the treatment of dental caries and dentin hypersensitivity. However, its pro-apoptotic effect on odontoblasts may lead to harmful side-effects. The purpose of this study was to evaluate the pro-apoptotic effects of NaF in odontoblasts and elucidate the possible underlying molecular mechanisms. NaF generated cytotoxic effects in odontoblast-lineage cell (OLC) in a dose- and time-dependent manner. Exposure of cells to 4mM NaF for 24h induced caspase-3 activation, ultrastructural alterations, and resulted in the translocation of Bax to the mitochondria and the release of cytochrome c from the mitochondrial inter-membrane space into the cytosol, indicating that fluoride-mediated apoptosis is mitochondria-dependent. Fluoride treatment also increased phosphorylation of JNK and ERK, but not p38, and apoptosis induced by fluoride was notably or partly suppressed by treatment with JNK or ERK inhibitors, respectively. Taken together, these findings suggest that NaF induces apoptosis in OLC odontoblasts through a JNK-dependent mitochondrial pathway.
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Affiliation(s)
- Peng Li
- Department of Operative Dentistry and Endodontics, School of Stomatology, Fourth Military Medical University, Xi'an 710032, PR China
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Fluorosis caused cellular apoptosis and oxidative stress of rat kidneys. Chem Res Chin Univ 2013. [DOI: 10.1007/s40242-013-2430-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Jacinto-Alemán LF, García-Carrancá A, Leyba-Huerta ER, Zenteno-Galindo E, Jiménez-Farfán MD, Hernández-Guerrero JC. erbB expression changes in ethanol and 7,12- dimethylbenz (a)anthracene-induced oral carcinogenesis. Med Oral Patol Oral Cir Bucal 2013; 18:e325-31. [PMID: 23229248 PMCID: PMC3613887 DOI: 10.4317/medoral.18068] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Accepted: 06/08/2012] [Indexed: 12/16/2022] Open
Abstract
OBJECTIVE [corrected] The aim of this study was to determine erbB expression in normal mucosa, oral dysplasia, and invasive carcinomas developed in the hamster's buccal pouch chemical carcinogenesis model. STUDY DESIGN Fifty Syrian golden hamsters were equally divided in five groups (A-E); two controls and three experimental group exposed to alcohol, DMBA, or both for 14 weeks. Number of tumors per cheek, volume, histological condition, erbB expression were determined and results were analyzed by the Mann-Whitney U and Dunn's test. RESULTS Control groups and those exposed to alcohol (A, B and C respectively) only presented clinical and histological normal mucosa; while those exposed to DMBA or DMBA plus alcohol (D and E groups) developed dysplasia and invasive carcinomas. erbB2, erbB3, and erbB4 increased their expression in alcohol-exposed mucosa, dysplasia, and invasive carcinomas. We observed a similar expression level for erbB2 in dysplasia and carcinomas; while, erbB3 and erbB4 were similar only in carcinomas. CONCLUSION The DMBA and alcohol can be considered as carcinogen and promoter for oral carcinogenesis. The erbB expression is different according to their histological condition, suggesting differential participation of the erbB family in oral carcinogenesis induced by alcohol and DMBA.
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Affiliation(s)
- Luis-Fernando Jacinto-Alemán
- Immunology Laboratory, Postgraduate and Research Division, Dental School, National Autonomous University of Mexico, Mexico, DF, Mexico
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Agalakova NI, Gusev GP. Molecular Mechanisms of Cytotoxicity and Apoptosis Induced by Inorganic Fluoride. ACTA ACUST UNITED AC 2012. [DOI: 10.5402/2012/403835] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Fluoride (F) is ubiquitous natural substance and widespread industrial pollutant. Although low fluoride concentrations are beneficial for normal tooth and bone development, acute or chronic exposure to high fluoride doses results in adverse health effects. The molecular mechanisms underlying fluoride toxicity are different by nature. Fluoride is able to stimulate G-proteins with subsequent activation of downstream signal transduction pathways such as PKA-, PKC-, PI3-kinase-, Ca2+-, and MAPK-dependent systems. G-protein-independent routes include tyrosine phosphorylation and protein phosphatase inhibition. Along with other toxic effects, fluoride was shown to induce oxidative stress leading to excessive generation of ROS, lipid peroxidation, decrease in the GSH/GSSH ratio, and alterations in activities of antioxidant enzymes, as well as to inhibit glycolysis thus causing the depletion of cellular ATP and disturbances in cellular metabolism. Fluoride triggers the disruption of mitochondria outer membrane and release of cytochrome c into cytosol, what activates caspases-9 and -3 (intrinsic) apoptotic pathway. Extrinsic (death receptor) Fas/FasL-caspase-8 and -3 pathway was also described to be implicated in fluoride-induced apoptosis. Fluoride decreases the ratio of antiapoptotic/proapoptotic Bcl-2 family proteins and upregulates the expression of p53 protein. Finally, fluoride changes the expression profile of apoptosis-related genes and causes endoplasmic reticulum stress leading to inhibition of protein synthesis.
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Affiliation(s)
- Natalia Ivanovna Agalakova
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 44 M. Thorez Avenue, Sankt-Petersburg 194223, Russia
| | - Gennadii Petrovich Gusev
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 44 M. Thorez Avenue, Sankt-Petersburg 194223, Russia
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Matalova E, Svandova E, Tucker AS. Apoptotic signaling in mouse odontogenesis. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2011; 16:60-70. [PMID: 22204278 DOI: 10.1089/omi.2011.0039] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Apoptosis is an important morphogenetic event in embryogenesis as well as during postnatal life. In the last 2 decades, apoptosis in tooth development (odontogenesis) has been investigated with gradually increasing focus on the mechanisms and signaling pathways involved. The molecular machinery responsible for apoptosis exhibits a high degree of conservation but also organ and tissue specific patterns. This review aims to discuss recent knowledge about apoptotic signaling networks during odontogenesis, concentrating on the mouse, which is often used as a model organism for human dentistry. Apoptosis accompanies the entire development of the tooth and corresponding remodeling of the surrounding bony tissue. It is most evident in its role in the elimination of signaling centers within developing teeth, removal of vestigal tooth germs, and in odontoblast and ameloblast organization during tooth mineralization. Dental apoptosis is caspase dependent and proceeds via mitochondrial mediated cell death with possible amplification by Fas-FasL signaling modulated by Bcl-2 family members.
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Affiliation(s)
- Eva Matalova
- Institute of Animal Physiology and Genetics, v.v.i., Academy of Sciences, Brno, Czech Republic.
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Leite MF, Ferreira NFD, Shitsuka CDWM, Lima AM, Masuyama MM, Sant'Anna GR, Yamaguti PM, Polotow TG, de Barros MP. Effect of topical application of fluoride gel NaF 2% on enzymatic and non-enzymatic antioxidant parameters of saliva. Arch Oral Biol 2011; 57:630-5. [PMID: 22196077 DOI: 10.1016/j.archoralbio.2011.10.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Revised: 09/23/2011] [Accepted: 10/30/2011] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The aim of the study was to evaluate the effect of topical fluoride gel NaF 2% application on antioxidant parameters of whole saliva from children. DESIGN The saliva mechanically stimulated with parafilm was collected from 25 children (6-12 years) attending the Clinic of Paediatric Dentistry of Universidade Cruzeiro do Sul, São Paulo, Brazil, before (control group) and immediately after application of neutral fluoride gel NaF 2% (fluoride-gel group), according to the Standards for Research Using Human Subjects, Resolution 196/96 of the USA National Health Council of 10/10/1996. Afterwards, pre-post ferric-reducing antioxidant power (FRAP), trolox-equivalent antioxidant capacity (TEAC), uric acid, reduced/oxidised glutathione content (GSH/GSSG) and total peroxidase activity (TPO) were evaluated in whole saliva of both groups. RESULTS All non-enzymatic antioxidant parameters were augmented by fluoride-gel NaF 2% application, whereas a notable reduction (31%) of peroxidase activity was concomitantly observed in the children's saliva (p ≤ 0.05). Nevertheless, the reducing power of saliva was kept unaltered under these circumstances (p ≤ 0.05). CONCLUSIONS Despite the reduced activity of peroxidase (an important antimicrobial and antioxidant enzyme), the topical fluoride gel NaF 2% favourably stimulated the release of non-enzymatic antioxidant components of saliva, sustaining the reducing power of saliva and the natural defences of the oral cavity.
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Affiliation(s)
- Mariana Ferreira Leite
- Pediatric Dentistry Ph.D. Program, Centro de Ciências Biológicas e da Saúde, Universidade Cruzeiro do Sul, ZIP 08060-070, São Paulo, Brazil.
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Szczepański M, Kamianowska M, Kamianowski G. Effects of fluorides on apoptosis and activation of human umbilical vein endothelial cells. Oral Dis 2011; 18:280-4. [PMID: 22093110 DOI: 10.1111/j.1601-0825.2011.01873.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To determine the effects of fluorides on endothelial functioning. MATERIALS AND METHODS We analyzed expressions of adhesion molecules, ICAM-1 and ICAM-3, and annexin V, on the surface of human umbilical vein endothelial cells (HUVECs) exposed to various concentrations of NaF and SnF(2) . We compared the effects of fluoride-induced changes with those obtained when stimulating HUVECs with TNF-α and verified whether N-acetyl cysteine (NAC), well-known antioxidant, can prevent both fluoride- and TNF-α-induced alterations. RESULTS The expressions of annexin V and ICAM-1 increased significantly after adding NaF (5.0 or 7.5mM) or Sn(2) F (0.5 or 0.75mM) to the culture medium. Pre-incubating HUVECs with NAC prevented the effects induced by 5.0 mM of NaF and 0.5 mM of Sn(2) F. Only the highest concentration of NaF (7.5mM) triggered the expression of ICAM-3. The expressions of all three molecules increased significantly upon stimulating the cultures with TNF-α (20ng ml(-1) ); these changes were not reversed by pre-incubation with NAC. CONCLUSIONS Fluorides induce oxidative stress, resulting in apoptosis and activation of HUVECs, manifested by an elevated expression of ICAM-1. The oxidative stress resulting from a stimulation by the highest NaF concentration triggers ICAM-3 expression on the HUVECs' surface.
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Affiliation(s)
- M Szczepański
- Department of Neonatology and Intensive Neonatal Care Unit, Medical University of Bialystok, Bialystok, Poland.
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Liu YJ, Guan ZZ, Gao Q, Pei JJ. Increased level of apoptosis in rat brains and SH-SY5Y cells exposed to excessive fluoride--a mechanism connected with activating JNK phosphorylation. Toxicol Lett 2011; 204:183-9. [PMID: 21565259 DOI: 10.1016/j.toxlet.2011.04.030] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Revised: 04/25/2011] [Accepted: 04/25/2011] [Indexed: 11/30/2022]
Abstract
In order to reveal the mechanism of the brain injury induced by chronic fluorosis, the levels of apoptosis and c-Jun N-terminal kinases (JNK) in brains of rats and SH-SY5Y cells exposed to different concentrations of sodium fluoride (NaF) were detected. The dental fluorosis and fluoride contents in blood, urine and bones of rats were measured to evaluate the exhibition of fluorosis. The apoptotic death rate was measured by flow cytometry and the expression of JNK at protein level by Western blotting. The results showed that as compared with controls, the apoptotic death rate was obviously increased in brains of the rats exposed to high-fluoride (50ppm) for 6 months with a concentration dependent manner, but no significant change for 3 months. In SH-SY5Y cells treated with high concentration (50ppm) of fluoride, the increased apoptotic death rate was obviously observed as compared to controls. In addition, the expressions of phospho-JNK at protein level were raised by 20.5% and 107.6%, respectively, in brains of the rats exposed to low-fluoride (5ppm) and high-fluoride for 6 months; while no significant changes were found between the rats exposed to fluoride and the controls for 3 months. The protein level of phospho-JNK was also increased in SH-SY5Y cells exposed to high-fluoride. There were no changes of total-JNK both in the rats and in the SH-SY5Y cells exposed to excessive fluoride as compared to controls. When SH-SY5Y cells were singly treated with SP600125, an inhibitor of phospho-JNK, the decreased expression of phospho-JNK, but no apoptosis, was detected. Interestingly, after JNK phosphorylation in the cultured cells was inhibited by SP600125, the treatment with high-fluoride did not induce the increase of apoptosis. In addition, there was a positive correlation between the expression of phospho-JNK and the apoptotic death rate in rat brains or SH-SY5Y cells treated with high-fluoride. The results indicated that exposure to excessive fluoride resulted in the increase of apoptosis in rat brains and SH-SY5Y cells, in which one of the mechanisms might be activating JNK phosphorylation.
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Affiliation(s)
- Yan-Jie Liu
- Pathological Department of the Affiliated Hospital, Guiyang Medical University, Guiyang 550004, PR China
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Pawłowska-Góral K, Pilawa B. Detection of free radicals formed by in vitro metabolism of fluoride using EPR spectroscopy. Toxicol In Vitro 2011; 25:1269-73. [PMID: 21514375 DOI: 10.1016/j.tiv.2011.04.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Revised: 03/07/2011] [Accepted: 04/04/2011] [Indexed: 11/15/2022]
Abstract
In many parts of the globe, where water contains large amount of fluoride, fluorosis is a serious public health problem. It is accompanied by many changes, not only in the bones, but practically in all organs of the body. Since it was discovered that oxidation stress, together with the peroxidation of lipids which accompanies it, results in many diseases, research has been carried out on this aspect of fluorosis. The findings, however, are incomplete and divergent. The aim of our study was to determine the presence of free radicals in hepatocytes exposed to fluoride in concentrations which do not lead to changes in the concentrations of calcium and magnesium ions. Free radical properties of hepatocytes incubated with fluoride were studied by an X-band electron paramagnetic resonance (EPR) spectroscopy. Hepatocytes are paramagnetic and broad unsymmetrical EPR spectra were obtained for them. Oxygen free radicals with g-factor of 2.0032 exist in hepatocytes. The effect of fluoride concentration and the time of incubation on free radicals amount in cells were examined. The amount of free radicals in hepatocytes increases with the increase of fluoride concentration for all the incubation times (10, 30, and 60 min). The amount of free radicals in hepatocytes decreases with the increase of time of incubation for all the used fluoride concentrations (0.002, 0.082, and 0.164 mmol/l). EPR spectra of the studied cells are homogeneously broadened. Continuous microwave saturation of EPR lines indicates that slow spin-lattice relaxation processes exist in the studied cells. Strong dipolar interactions responsible for the broadening (ΔB(pp): 1.45-1.87 mT) of the EPR spectra exist in the hepatocytes.
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Affiliation(s)
- Katarzyna Pawłowska-Góral
- Department of Food and Nutrition, School of Pharmacy and Laboratory Medicine, Medical University of Silesia in Katowice, Jedności 8, 41-200 Sosnowiec, Poland.
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