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Mechanisms of Fluoride Toxicity: From Enzymes to Underlying Integrative Networks. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10207100] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Fluoride has been employed in laboratory investigations since the early 20th century. These studies opened the understanding of fluoride interventions to fundamental biological processes. Millions of people living in endemic fluorosis areas suffer from various pathological disturbances. The practice of community water fluoridation used prophylactically against dental caries increased concern of adverse fluoride effects. We assessed the publications on fluoride toxicity until June 2020. We present evidence that fluoride is an enzymatic poison, inducing oxidative stress, hormonal disruptions, and neurotoxicity. Fluoride in synergy with aluminum acts as a false signal in G protein cascades of hormonal and neuronal regulations in much lower concentrations than fluoride acting alone. Our review shows the impact of fluoride on human health. We suggest focusing the research on fluoride toxicity to the underlying integrative networks. Ignorance of the pluripotent toxic effects of fluoride might contribute to unexpected epidemics in the future.
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Pan Y, Li Z, Wang Y, Yan M, Wu J, Beharee RG, Yu J. Sodium fluoride regulates the osteo/odontogenic differentiation of stem cells from apical papilla by modulating autophagy. J Cell Physiol 2019; 234:16114-16124. [PMID: 30767218 DOI: 10.1002/jcp.28269] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 01/18/2019] [Accepted: 01/22/2019] [Indexed: 01/24/2023]
Abstract
Fluoride (sodium fluoride) is thought to be essential in the development of tooth, and research shows that fluoride can modulate the differentiation of dental stem cells. However, the effects of fluoride on the committed differentiation of stem cells from apical papilla (SCAPs) and the underlying mechanisms remain unclear. Here, SCAPs were isolated from healthy extracted human third molars with immature roots and then were cultured with NaF conditioned media. Cell Counting Kit-8, EdU staining, and flow cytometry were performed to detected the proliferation activity. Alkaline phosphatase (ALP) activity, Alizarin Red staining, Western blot assay, and real-time reverse-transcription polymerase chain reaction were applied to assess the osteo/odontogenic differentiation NaF-treated SCAPs. Western blot assay and transmission electron microscope were used to evaluate the autophagy involved in the differentiation of SCAPs. ALP activity, ALP protein, and messenger RNA (mRNA) expression showed that 0.5 mM was the optimal concentration for the induction of SCAPs by NaF. 0.5 mM NaF-treated SCAPs induced more mineralized nodules as compared with untreated cells. Moreover, the osteo/odontogenic markers (RUNX2, OSX, DSP, and OCN) in mRNA levels were upregulated while the protein levels of these markers increased considerably in 0.5 mM NaF-treated SCAPs. Furthermore, the autophagy-related proteins (LC3, ATG5, and Beclin1) increased in NaF-treated SCAPs, and the osteo/odontogenic makers significantly decreased while silencing ATG5 to block autophagy. In all, sodium fluoride can regulate the osteo/odontogenic differentiation of SCAPs by modulating autophagy.
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Affiliation(s)
- Yin Pan
- Key Laboratory of Oral Diseases of Jiangsu Province, Institute of Stomatology, Nanjing Medical University, Nanjing, Jiangsu, China.,Department of Endodontics, School of Stomatology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Zehan Li
- Key Laboratory of Oral Diseases of Jiangsu Province, Institute of Stomatology, Nanjing Medical University, Nanjing, Jiangsu, China.,Department of Endodontics, School of Stomatology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Yanqiu Wang
- Key Laboratory of Oral Diseases of Jiangsu Province, Institute of Stomatology, Nanjing Medical University, Nanjing, Jiangsu, China.,Department of Endodontics, School of Stomatology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Ming Yan
- Key Laboratory of Oral Diseases of Jiangsu Province, Institute of Stomatology, Nanjing Medical University, Nanjing, Jiangsu, China.,Department of Endodontics, School of Stomatology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Jintao Wu
- Key Laboratory of Oral Diseases of Jiangsu Province, Institute of Stomatology, Nanjing Medical University, Nanjing, Jiangsu, China.,Department of Endodontics, School of Stomatology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Romila Gobin Beharee
- Key Laboratory of Oral Diseases of Jiangsu Province, Institute of Stomatology, Nanjing Medical University, Nanjing, Jiangsu, China.,Department of Endodontics, School of Stomatology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Jinhua Yu
- Key Laboratory of Oral Diseases of Jiangsu Province, Institute of Stomatology, Nanjing Medical University, Nanjing, Jiangsu, China.,Department of Endodontics, School of Stomatology, Nanjing Medical University, Nanjing, Jiangsu, China
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Wijekoon HMS, Bwalya EC, Fang J, Kim S, Hosoya K, Okumura M. Inhibitory effects of sodium pentosan polysulfate on formation and function of osteoclasts derived from canine bone marrow. BMC Vet Res 2018; 14:152. [PMID: 29720166 PMCID: PMC5930774 DOI: 10.1186/s12917-018-1466-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 04/20/2018] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Sodium pentosan polysulfate (NaPPS) was testified as a chondroprotective drug in with a detailed rationale of the disease-modifying activity. This study was undertaken to determine whether anti-osteoarthritis drug, NaPPS inhibited osteoclasts (OC) differentiation and function. Canine bone marrow mononuclear cells (n = 6) were differentiated to OC by maintaining with receptor activator of nuclear factor kappa B ligand (RANKL) and macrophage colony-stimulating factor (M-CSF) for up to 7 days with the treatment of NaPPS at concentration of 0, 0.2, 1 and 5 μg/mL. Differentiation and function of OC were accessed using tartrate-resistant acid phosphate (TRAP) staining and bone resorption assay, while monitoring actin ring formation. Invasion and colocalization patterns of fluorescence-labeled NaPPS with transcribed gene in OC were monitored. Gene expression of OC for cathepsin K (CTK), matrix metallopeptidase-9 (MMP-9), nuclear factor of activated T-cells cytoplasmic 1 (NFATc1), c-Fos, activator protein-1(AP-1) and carbonic anhydrase II was examined using real-time PCR. RESULTS Significant inhibition of OC differentiation was evident at NaPPS concentration of 1 and 5 μg/mL (p < 0.05). In the presence of 0.2 to 5 μg/mL NaPPS, bone resorption was attenuated (p < 0.05), while 1 and 5 μg/mL NaPPS achieved significant reduction of actin ring formation. Intriguingly, fluorescence-labeled NaPPS invaded in to cytoplasm and nucleus while colocalizing with actively transcribed gene. Gene expression of CTK, MMP-9 and NFATc1 were significantly inhibited at 1 and 5 μg/mL (p < 0.05) of NaPPS whereas inhibition of c-Fos and AP-1 was identified only at concentration of 5 μg/mL (p < 0.05). CONCLUSIONS Taken together, all the results suggest that NaPPS is a novel inhibitor of RANKL and M-CSF-induced CTK, MMP-9, NFATc1, c-Fos, AP-1 upregulation, OC differentiation and bone resorption which might be a beneficial for treatment of inflammatory joint diseases and other bone diseases associated with excessive bone resorption.
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Affiliation(s)
- H. M. Suranji Wijekoon
- Department of Veterinary Clinical Sciences, Laboratory of Veterinary Surgery, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, 060-0818 Japan
| | - Eugene C. Bwalya
- Department of Veterinary Clinical Sciences, Laboratory of Veterinary Surgery, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, 060-0818 Japan
| | - Jing Fang
- Department of Veterinary Clinical Sciences, Laboratory of Veterinary Surgery, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, 060-0818 Japan
| | - Sangho Kim
- Department of Veterinary Clinical Sciences, Laboratory of Veterinary Surgery, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, 060-0818 Japan
| | - Kenji Hosoya
- Department of Veterinary Clinical Sciences, Laboratory of Veterinary Surgery, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, 060-0818 Japan
| | - Masahiro Okumura
- Department of Veterinary Clinical Sciences, Laboratory of Veterinary Surgery, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, 060-0818 Japan
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High-Dose Fluoride Impairs the Properties of Human Embryonic Stem Cells via JNK Signaling. PLoS One 2016; 11:e0148819. [PMID: 26859149 PMCID: PMC4747557 DOI: 10.1371/journal.pone.0148819] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 01/22/2016] [Indexed: 02/02/2023] Open
Abstract
Fluoride is a ubiquitous natural substance that is often used in dental products to prevent dental caries. The biphasic actions of fluoride imply that excessive systemic exposure to fluoride can cause harmful effects on embryonic development in both animal models and humans. However, insufficient information is available on the effects of fluoride on human embryonic stem cells (hESCs), which is a novel in vitro humanized model for analyzing the embryotoxicities of chemical compounds. Therefore, we investigated the effects of sodium fluoride (NaF) on the proliferation, differentiation and viability of H9 hESCs. For the first time, we showed that 1 mM NaF did not significantly affect the proliferation of hESCs but did disturb the gene expression patterns of hESCs during embryoid body (EB) differentiation. Higher doses of NaF (2 mM and above) markedly decreased the viability and proliferation of hESCs. The mode and underlying mechanism of high-dose NaF-induced cell death were further investigated by assessing the sub-cellular morphology, mitochondrial membrane potential (MMP), caspase activities, cellular reactive oxygen species (ROS) levels and activation of mitogen-activated protein kinases (MAPKs). High-dose NaF caused the death of hESCs via apoptosis in a caspase-mediated but ROS-independent pathway, coupled with an increase in the phospho-c-Jun N-terminal kinase (p-JNK) levels. Pretreatment with a p-JNK-specific inhibitor (SP600125) could effectively protect hESCs from NaF-induced cell death in a concentration- and time-dependent manner. These findings suggest that NaF might interfere with early human embryogenesis by disturbing the specification of the three germ layers as well as osteogenic lineage commitment and that high-dose NaF could cause apoptosis through a JNK-dependent pathway in hESCs.
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Bhawal UK, Lee HJ, Arikawa K, Shimosaka M, Suzuki M, Toyama T, Sato T, Kawamata R, Taguchi C, Hamada N, Nasu I, Arakawa H, Shibutani K. Micromolar sodium fluoride mediates anti-osteoclastogenesis in Porphyromonas gingivalis-induced alveolar bone loss. Int J Oral Sci 2015; 7:242-9. [PMID: 26674426 PMCID: PMC5153593 DOI: 10.1038/ijos.2015.28] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/01/2015] [Indexed: 11/15/2022] Open
Abstract
Osteoclasts are bone-specific multinucleated cells generated by the differentiation of monocyte/macrophage lineage precursors. Regulation of osteoclast differentiation is considered an effective therapeutic approach to the treatment of bone-lytic diseases. Periodontitis is an inflammatory disease characterized by extensive bone resorption. In this study, we investigated the effects of sodium fluoride (NaF) on osteoclastogenesis induced by Porphyromonas gingivalis, an important colonizer of the oral cavity that has been implicated in periodontitis. NaF strongly inhibited the P. gingivalis-induced alveolar bone loss. That effect was accompanied by decreased levels of cathepsin K, interleukin (IL)-1β, matrix metalloproteinase 9 (MMP9), and tartrate-resistant acid phosphatase, which were up-regulated during P. gingivalis-induced osteoclastogenesis. Consistent with the in vivo anti-osteoclastogenic effect, NaF inhibited osteoclast formation caused by the differentiation factor RANKL (receptor activator of nuclear factor κB ligand) and macrophage colony-stimulating factor (M-CSF). The RANKL-stimulated induction of the transcription factor nuclear factor of activated T cells (NFAT) c1 was also abrogated by NaF. Taken together, our data demonstrate that NaF inhibits RANKL-induced osteoclastogenesis by reducing the induction of NFATc1, ultimately leading to the suppressed expression of cathepsin K and MMP9. The in vivo effect of NaF on the inhibition of P. gingivalis-induced osteoclastogenesis strengthens the potential usefulness of NaF for treating periodontal diseases.
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Affiliation(s)
- Ujjal K Bhawal
- Department of Biochemistry and Molecular Biology, Nihon University School of Dentistry at Matsudo, Matsudo, Japan.,Research Institute of Oral Health, Nihon University School of Dentistry at Matsudo, Matsudo, Japan.,Department of Oral Health, Graduate School of Dentistry, Kanagawa Dental University, Yokosuka, Japan
| | - Hye-Jin Lee
- Department of Dental Hygiene, Howon University, Gunsan, Korea
| | - Kazumune Arikawa
- Research Institute of Oral Health, Nihon University School of Dentistry at Matsudo, Matsudo, Japan.,Department of Preventive and Public Oral Health, Nihon University School of Dentistry at Matsudo, Matsudo, Japan
| | - Michiharu Shimosaka
- Research Institute of Oral Health, Nihon University School of Dentistry at Matsudo, Matsudo, Japan.,Department of Anesthesiology, Nihon University School of Dentistry at Matsudo, Matsudo, Japan
| | - Masatoshi Suzuki
- Research Institute of Oral Health, Nihon University School of Dentistry at Matsudo, Matsudo, Japan.,Department of Anesthesiology, Nihon University School of Dentistry at Matsudo, Matsudo, Japan
| | - Toshizo Toyama
- Department of Infection Control, Division of Microbiology, Kanagawa Dental University, Yokosuka, Japan
| | - Takenori Sato
- Department of Infection Control, Division of Microbiology, Kanagawa Dental University, Yokosuka, Japan
| | - Ryota Kawamata
- Department of Radiopraxis Science, Kanagawa Dental University, Yokosuka, Japan
| | - Chieko Taguchi
- Research Institute of Oral Health, Nihon University School of Dentistry at Matsudo, Matsudo, Japan.,Department of Preventive and Public Oral Health, Nihon University School of Dentistry at Matsudo, Matsudo, Japan
| | - Nobushiro Hamada
- Department of Infection Control, Division of Microbiology, Kanagawa Dental University, Yokosuka, Japan
| | - Ikuo Nasu
- Research Institute of Oral Health, Nihon University School of Dentistry at Matsudo, Matsudo, Japan.,Department of Preventive and Public Oral Health, Nihon University School of Dentistry at Matsudo, Matsudo, Japan
| | - Hirohisa Arakawa
- Department of Oral Health, Graduate School of Dentistry, Kanagawa Dental University, Yokosuka, Japan
| | - Koh Shibutani
- Research Institute of Oral Health, Nihon University School of Dentistry at Matsudo, Matsudo, Japan.,Department of Preventive and Public Oral Health, Nihon University School of Dentistry at Matsudo, Matsudo, Japan
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Fu YX, Gu JH, Zhang YR, Tong XS, Zhao HY, Yuan Y, Liu XZ, Bian JC, Liu ZP. Inhibitory effects of osteoprotegerin on osteoclast formation and function under serum-free conditions. J Vet Sci 2013; 14:405-12. [PMID: 23820214 PMCID: PMC3885733 DOI: 10.4142/jvs.2013.14.4.405] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Accepted: 02/16/2013] [Indexed: 12/31/2022] Open
Abstract
The purpose of this study was to determine whether osteoprotegerin (OPG) could affect osteoclat differentiation and activation under serum-free conditions. Both duck embryo bone marrow cells and RAW264.7 cells were incubated with macrophage colony stimulatory factor (M-CSF) and receptor activator for nuclear factor κB ligand (RANKL) in serum-free medium to promote osteoclastogenesis. During cultivation, 0, 10, 20, 50, and 100 ng/mL OPG were added to various groups of cells. Osteoclast differentiation and activation were monitored via tartrate-resistant acid phosphatase (TRAP) staining, filamentous-actin rings analysis, and a bone resorption assay. Furthermore, the expression osteoclast-related genes, such as TRAP and receptor activator for nuclear factor κB (RANK), that was influenced by OPG in RAW264.7 cells was examined using real-time polymerase chain reaction. In summary, findings from the present study suggested that M-CSF with RANKL can promote osteoclast differentiation and activation, and enhance the expression of TRAP and RANK mRNA in osteoclasts. In contrast, OPG inhibited these activities under serum-free conditions.
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Affiliation(s)
- Ying-Xiao Fu
- College of Veterinary Medicine, Yangzhou University, and Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
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Karadeniz EI, Gonzales C, Nebioglu-Dalci O, Dwarte D, Turk T, Isci D, Sahin-Saglam AM, Alkis H, Elekdag-Turk S, Darendeliler MA. Physical properties of root cementum: Part 20. Effect of fluoride on orthodontically induced root resorption with light and heavy orthodontic forces for 4 weeks: A microcomputed tomography study. Am J Orthod Dentofacial Orthop 2011; 140:e199-210. [DOI: 10.1016/j.ajodo.2011.05.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2010] [Revised: 05/01/2011] [Accepted: 05/01/2011] [Indexed: 10/15/2022]
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Yan D, Willett TL, Gu XM, Martinez-Mier EA, Sardone L, McShane L, Grynpas M, Everett ET. Phenotypic variation of fluoride responses between inbred strains of mice. Cells Tissues Organs 2011; 194:261-7. [PMID: 21555858 DOI: 10.1159/000324224] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Excessive systemic exposure to fluoride (F) can lead to disturbances in bone homeostasis and dental enamel development. We have previously shown strain-specific responses to F in the development of dental fluorosis (DF) and in bone formation/mineralization. The current study was undertaken to further investigate F responsive variations in bone metabolism and to determine possible relationships with DF susceptibility. Seven-week-old male mice from FVB/NJ, C57BL/6J, C3H/HeJ, A/J, 129S1/SvImJ, AKR/J, DBA/2J, and BALB/cByJ inbred strains were exposed to NaF (0 or 50 ppm as F(-)) in drinking water for 60 days. Sera were collected for F, Ca, Mg, PO(4), iPTH, sRANKL, and ALP levels. Bone marrow cells were subjected to ex vivo cell culture for osteoclast potential and CFU colony assays (CFU-fibroblast, CFU-osteoblast, CFU-erythrocyte/granulocyte/macrophage/megakaryocyte, CFU-granulocyte/macrophage, CFU-macrophage, and CFU-granulocyte). Femurs and vertebrae were subjected to micro-CT analyses, biomechanical testing, and F, Mg, and Ca content assays. DF was evaluated using quantitative fluorescence and clinical criteria. Strain-specific responses to F were observed for DF, serum studies, ex vivo cell culture studies, and bone quality. Among the strains, there were no patterns or significant correlations between DF severity and the actions of F on bone homeostasis (serum studies, ex vivo assays, or bone quality parameters). The genetic background continues to play a role in the actions of F on tooth enamel development and bone homeostasis. F exposure led to variable phenotypic responses between strains involving dental enamel development and bone metabolism.
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Affiliation(s)
- Dong Yan
- Dental Research, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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Prystupa J. Fluorine—A current literature review. An NRC and ATSDR based review of safety standards for exposure to fluorine and fluorides. Toxicol Mech Methods 2011; 21:103-70. [DOI: 10.3109/15376516.2010.542931] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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10
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Everett ET. Fluoride's effects on the formation of teeth and bones, and the influence of genetics. J Dent Res 2010; 90:552-60. [PMID: 20929720 DOI: 10.1177/0022034510384626] [Citation(s) in RCA: 231] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Fluorides are present in the environment. Excessive systemic exposure to fluorides can lead to disturbances of bone homeostasis (skeletal fluorosis) and enamel development (dental/enamel fluorosis). The severity of dental fluorosis is also dependent upon fluoride dose and the timing and duration of fluoride exposure. Fluoride's actions on bone cells predominate as anabolic effects both in vitro and in vivo. More recently, fluoride has been shown to induce osteoclastogenesis in mice. Fluorides appear to mediate their actions through the MAPK signaling pathway and can lead to changes in gene expression, cell stress, and cell death. Different strains of inbred mice demonstrate differential physiological responses to ingested fluoride. Genetic studies in mice are capable of identifying and characterizing fluoride-responsive genetic variations. Ultimately, this can lead to the identification of at-risk human populations who are susceptible to the unwanted or potentially adverse effects of fluoride action and to the elucidation of fundamental mechanisms by which fluoride affects biomineralization.
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Affiliation(s)
- E T Everett
- Department of Pediatric Dentistry, School of Dentistry, University of North Carolina at Chapel Hill, 228 Brauer Hall, CB# 7450, Chapel Hill, NC 27599, USA.
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Ogita M, Ogita A, Usuki Y, Fujita KI, Tanaka T. Antimycin A-induced cell death depends on AIF translocation through NO production and PARP activation and is not involved in ROS generation, cytochrome c release and caspase-3 activation in HL-60 cells. J Antibiot (Tokyo) 2009; 62:145-52. [PMID: 19229286 DOI: 10.1038/ja.2009.2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A respiratory inhibitor, antimycin A (AA), induced an apoptotic-like cell death characterized by nuclear and DNA fragmentation in human leukemia HL-60 cells. This cell death was significantly restricted by a nitric oxide synthase (NOS) inhibitor, N(G)-monomethyl-L-arginine (L-NMMA), and a poly(ADP-ribose) polymerase (PARP) inhibitor, 5-aminoisoquinoline (AIQ). Indeed, NO production and PARP overactivation were detected in the cells treated with AA. On the one hand, L-NMMA partly eliminated NO production and on the other, AIQ and L-NMMA also restricted PARP activation. Excessive signals related to PARP overactivation induce the translocation of an apoptosis-inducing factor (AIF) from the mitochondria to the nuclei, resulting in DNA fragmentation. In AA-treated cells, the nuclear translocation of AIF occurred. This translocation was restricted by pretreatment with AIQ and L-NMMA. Although pretreatment with ascorbic acid eliminated the reactive oxygen species (ROS) generation induced by the blockade of complex III by AA, the pretreatment did not protect the cells from AA-induced cell death. Furthermore, cytochrome c release or caspase-3 activation was not observed in the cells treated with AA. These results suggest that AA-induced cell death does not depend on respiratory inhibition and the succeeding cascades, but on NO production, PARP overactivation and AIF translocation.
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Affiliation(s)
- Masaki Ogita
- Department of Biology and Geosciences, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka, Japan
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Yan D, Gurumurthy A, Wright M, Pfeiler TW, Loboa EG, Everett ET. Genetic background influences fluoride's effects on osteoclastogenesis. Bone 2007; 41:1036-44. [PMID: 17936699 PMCID: PMC2238641 DOI: 10.1016/j.bone.2007.07.018] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2007] [Revised: 07/26/2007] [Accepted: 07/28/2007] [Indexed: 11/21/2022]
Abstract
Excessive fluoride (F) can lead to abnormal bone biology. Numerous studies have focused on the anabolic action of F yet little is known regarding any action on osteoclastogenesis. Little is known regarding the influence of an individual's genetic background on the responses of bone cells to F. Four-week old C57BL/6J (B6) and C3H/HeJ (C3H) female mice were treated with NaF in the drinking water (0 ppm, 50 ppm and 100 ppm F ion) for 3 weeks. Bone marrow cells were harvested for osteoclastogenesis and hematopoietic colony-forming cell assays. Sera were analyzed for biochemical and bone markers. Femurs, tibiae, and lumbar vertebrae were subjected to microCT analysis. Tibiae and femurs were subjected to histology and biomechanical testing, respectively. The results demonstrated new actions of F on osteoclastogenesis and hematopoietic cell differentiation. Strain-specific responses were observed. The anabolic action of F was favored in B6 mice exhibiting dose-dependent increases in serum ALP activity (p<0.001); in proximal tibia trabecular and vertebral BMD (tibia at 50&100 ppm, p=0.001; vertebrae at 50 and 100 ppm, p=0.023&0.019, respectively); and decrease in intact PTH and sRANKL (p=0.045 and p<0.001, respectively). F treatment in B6 mice also resulted in increased numbers of CFU-GEMM colonies (p=0.025). Strain-specific accumulations in bone [F] were observed. For C3H mice, dose-dependent increases were observed in osteoclast potential (p<0.001), in situ trabecular osteoclast number (p=0.007), hematopoietic colony forming units (CFU-GEMM: p<0.001, CFU-GM: p=0.006, CFU-M: p<0.001), and serum markers for osteoclastogenesis (intact PTH: p=0.004, RANKL: p=0.022, TRAP5b: p<0.001). A concordant decrease in serum OPG (p=0.005) was also observed. Fluoride treatment had no significant effects on bone morphology, BMD, and serum PYD cross-links in C3H suggesting a lack of significant bone resorption. Mechanical properties were also unaltered in C3H. In conclusion, short term F treatment at physiological levels has strain-specific effects in mice. The expected anabolic effects were observed in B6 and novel actions hallmarked by enhanced osteoclastogenesis shifts in hematopoietic cell differentiation in the C3H strain.
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Affiliation(s)
- Dong Yan
- Dental Research, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
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