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Sowanou A, Meng X, Zhong N, Ma Y, Li A, Wang J, Li H, Pei J, Gao Y. Association Between Osteoarthritis and Water Fluoride Among Tongyu Residents, China, 2019: a Case-Control of Population-Based Study. Biol Trace Elem Res 2022; 200:3107-3116. [PMID: 34581970 DOI: 10.1007/s12011-021-02937-2] [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: 07/22/2021] [Accepted: 09/20/2021] [Indexed: 10/20/2022]
Abstract
Fluoride is an environmental chemical that has adverse effects on articular cartilage, probably increasing osteoarthritis (OA) risk. However, this association still needs more epidemiological evidence to clarify. The aim of this study was to determine the relationships between chronic fluoride exposure and OA risk among the residents living in Tongyu County, China, 2019, with a frequency-matched case-control study (186 OA patients and 186 healthy participants). The results showed that urinary fluoride (UF) (2.73 ± 1.18 mg/L) was significantly higher in OA patients compared to the controls (2.35 ± 1.24 mg/L) (p < 0.002). After adjustment, the odds ratios (ORs) with 95% confidence intervals (95% CIs) between the OA risk and fluoride were calculated by the unconditional logistic regression. In full sample analysis, a 1 mg/L increase in UF level was associated with a 27% higher risk of OA (1.06-1.52, p = 0.008), and 4th quarter's participants were associated with higher risk when compared to 1st quarter (OR: 2.46, 95% CI: 1.34-4.57, p = 0.003). In stratified analysis, compared to 1st quarter, 4th quarter's participants were 4 times more likely to have OA (1.86-8.82, p < 0.001) in the non-obese group and 7.7 times more likely to have OA (2.58-25.05, p < 0.001) among adults ≤ 60 years. In conclusion, excessive exposure of water fluoride may increase OA risk, and could have more impact on the specific population such as non-obese, and adult aged ≤ 60 years.
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Affiliation(s)
- Alphonse Sowanou
- Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province and Ministry of Health (23618504), Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, 150081, Heilongjiang Province, China
| | - Xinyue Meng
- Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province and Ministry of Health (23618504), Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, 150081, Heilongjiang Province, China
| | - Nan Zhong
- Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province and Ministry of Health (23618504), Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, 150081, Heilongjiang Province, China
| | - Yongzheng Ma
- Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province and Ministry of Health (23618504), Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, 150081, Heilongjiang Province, China
| | - Ailin Li
- Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province and Ministry of Health (23618504), Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, 150081, Heilongjiang Province, China
| | - Jian Wang
- Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province and Ministry of Health (23618504), Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, 150081, Heilongjiang Province, China
| | - Hanying Li
- Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province and Ministry of Health (23618504), Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, 150081, Heilongjiang Province, China
| | - Junrui Pei
- Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province and Ministry of Health (23618504), Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, 150081, Heilongjiang Province, China.
| | - Yanhui Gao
- Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province and Ministry of Health (23618504), Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, 150081, Heilongjiang Province, China.
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2
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Lu J, Hu D, Ma C, Shuai B. Advances in Our Understanding of the Mechanism of Action of Drugs (including Traditional Chinese Medicines) for the Intervention and Treatment of Osteoporosis. Front Pharmacol 2022; 13:938447. [PMID: 35774616 PMCID: PMC9237325 DOI: 10.3389/fphar.2022.938447] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Accepted: 05/23/2022] [Indexed: 12/12/2022] Open
Abstract
Osteoporosis (OP) is known as a silent disease in which the loss of bone mass and bone density does not cause obvious symptoms, resulting in insufficient treatment and preventive measures. The losses of bone mass and bone density become more severe over time and an only small percentage of patients are diagnosed when OP-related fractures occur. The high disability and mortality rates of OP-related fractures cause great psychological and physical damage and impose a heavy economic burden on individuals and society. Therefore, early intervention and treatment must be emphasized to achieve the overall goal of reducing the fracture risk. Anti-OP drugs are currently divided into three classes: antiresorptive agents, anabolic agents, and drugs with other mechanisms. In this review, research progress related to common anti-OP drugs in these three classes as well as targeted therapies is summarized to help researchers and clinicians understand their mechanisms of action and to promote pharmacological research and novel drug development.
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3
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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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Johnston NR, Strobel SA. Principles of fluoride toxicity and the cellular response: a review. Arch Toxicol 2020; 94:1051-1069. [PMID: 32152649 PMCID: PMC7230026 DOI: 10.1007/s00204-020-02687-5] [Citation(s) in RCA: 120] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 02/21/2020] [Indexed: 02/04/2023]
Abstract
Fluoride is ubiquitously present throughout the world. It is released from minerals, magmatic gas, and industrial processing, and travels in the atmosphere and water. Exposure to low concentrations of fluoride increases overall oral health. Consequently, many countries add fluoride to their public water supply at 0.7-1.5 ppm. Exposure to high concentrations of fluoride, such as in a laboratory setting often exceeding 100 ppm, results in a wide array of toxicity phenotypes. This includes oxidative stress, organelle damage, and apoptosis in single cells, and skeletal and soft tissue damage in multicellular organisms. The mechanism of fluoride toxicity can be broadly attributed to four mechanisms: inhibition of proteins, organelle disruption, altered pH, and electrolyte imbalance. Recently, there has been renewed concern in the public sector as to whether fluoride is safe at the current exposure levels. In this review, we will focus on the impact of fluoride at the chemical, cellular, and multisystem level, as well as how organisms defend against fluoride. We also address public concerns about fluoride toxicity, including whether fluoride has a significant effect on neurodegeneration, diabetes, and the endocrine system.
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Affiliation(s)
- Nichole R Johnston
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, 06520, USA
| | - Scott A Strobel
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, 06520, USA.
- Department of Chemistry, Yale University, New Haven, CT, 06520, USA.
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Wang J, Yang J, Cheng X, Yin F, Zhao Y, Zhu Y, Yan Z, Khodaei F, Ommati MM, Manthari RK, Wang J. Influence of Calcium Supplementation against Fluoride-Mediated Osteoblast Impairment in Vitro: Involvement of the Canonical Wnt/β-Catenin Signaling Pathway. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:10285-10295. [PMID: 31443611 DOI: 10.1021/acs.jafc.9b03835] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Fluoride (F) is capable of promoting abnormal proliferation and differentiation in primary cultured mouse osteoblasts (OB cells), although the underlying mechanism responsible remains rare. This study aimed to explore the roles of wingless and INT-1 (Wnt) signaling pathways and screen appropriate doses of calcium (Ca2+) to alleviate the sodium fluoride (NaF)-induced OB cell toxicity. For this, we evaluated the effect of dickkopf-related protein 1 (DKK1) and Ca2+ on mRNA levels of wingless/integrated 3a (Wnt3a), low-density lipoprotein receptor-related protein 5 (LRP5), dishevelled 1 (Dv1), glycogen synthase kinase 3β (GSK3β), β-catenin, lymphoid enhancer binding factor 1 (LEF1), and cellular myelocytomatosis oncogene (cMYC), as well as Ccnd1 (Cyclin D1) in OB cells challenged with 10-6 mol/L NaF for 24 h. The demonstrated data showed that F significantly increased the OB cell proliferation rate. Ectogenic 0.5 mg/L DKK1 significantly inhibited the proliferation of OB cells induced by F. The mRNA expression levels of Wnt3a, LRP5, Dv1, LEF1, β-catenin, cMYC, and Ccnd1 were significantly increased in the F group, while significantly decreased in the 10-6 mol/L NaF + 0.5 mg/L DKK1 (FY) group. The mRNA expression levels of Wnt3a, LRP5, β-catenin, and cMYC were significantly decreased in the 10-6 mol/L NaF + 2 mmol/L CaCl2 (F+CaII) group. The protein expression levels of Wnt3a, Cyclin D1, cMYC, and β-catenin were significantly increased in the F group, whereas they were decreased in the F+CaII group. However, the mRNA and protein expression levels of GSK3β were significantly decreased in the F group while significantly increased in the F+CaII group. In summary, F activated the canonical Wnt/β-catenin pathway and changed the related gene expression and β-catenin protein location in OB cells, promoting cell proliferation. Ca2+ supplementation (2 mmol/L) reversed the expression levels of genes and proteins related to the canonical Wnt/β-catenin pathway.
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Affiliation(s)
- Jinming Wang
- College of Animal Science and Veterinary Medicine , Shanxi Agricultural University , Taigu , 030801 Shanxi , P. R. China
- Shanxi Key Laboratory of Environmental Veterinary Medicine , Shanxi Agricultural University , Taigu , 030801 Shanxi , P. R. China
| | - Jiarong Yang
- College of Animal Science and Veterinary Medicine , Shanxi Agricultural University , Taigu , 030801 Shanxi , P. R. China
- Shanxi Key Laboratory of Environmental Veterinary Medicine , Shanxi Agricultural University , Taigu , 030801 Shanxi , P. R. China
| | - Xiaofang Cheng
- College of Arts and Sciences , Shanxi Agricultural University , Taigu , 030801 Shanxi , P. R. China
| | - Fengfeng Yin
- College of Animal Science and Veterinary Medicine , Shanxi Agricultural University , Taigu , 030801 Shanxi , P. R. China
- Shanxi Key Laboratory of Environmental Veterinary Medicine , Shanxi Agricultural University , Taigu , 030801 Shanxi , P. R. China
| | - Yangfei Zhao
- College of Animal Science and Veterinary Medicine , Shanxi Agricultural University , Taigu , 030801 Shanxi , P. R. China
- Shanxi Key Laboratory of Environmental Veterinary Medicine , Shanxi Agricultural University , Taigu , 030801 Shanxi , P. R. China
| | - Yaya Zhu
- College of Animal Science and Veterinary Medicine , Shanxi Agricultural University , Taigu , 030801 Shanxi , P. R. China
- Shanxi Key Laboratory of Environmental Veterinary Medicine , Shanxi Agricultural University , Taigu , 030801 Shanxi , P. R. China
| | - Zipeng Yan
- College of Animal Science and Veterinary Medicine , Shanxi Agricultural University , Taigu , 030801 Shanxi , P. R. China
- Shanxi Key Laboratory of Environmental Veterinary Medicine , Shanxi Agricultural University , Taigu , 030801 Shanxi , P. R. China
| | - Forouzan Khodaei
- College of Animal Science and Veterinary Medicine , Shanxi Agricultural University , Taigu , 030801 Shanxi , P. R. China
- Shanxi Key Laboratory of Environmental Veterinary Medicine , Shanxi Agricultural University , Taigu , 030801 Shanxi , P. R. China
| | - Mohammad Mehdi Ommati
- College of Life Sciences , Shanxi Agricultural University , Taigu , 030801 Shanxi , P. R. China
| | - Ram Kumar Manthari
- College of Animal Science and Veterinary Medicine , Shanxi Agricultural University , Taigu , 030801 Shanxi , P. R. China
- Shanxi Key Laboratory of Environmental Veterinary Medicine , Shanxi Agricultural University , Taigu , 030801 Shanxi , P. R. China
| | - Jundong Wang
- College of Animal Science and Veterinary Medicine , Shanxi Agricultural University , Taigu , 030801 Shanxi , P. R. China
- Shanxi Key Laboratory of Environmental Veterinary Medicine , Shanxi Agricultural University , Taigu , 030801 Shanxi , P. R. China
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Waugh DT. Fluoride Exposure Induces Inhibition of Sodium/Iodide Symporter (NIS) Contributing to Impaired Iodine Absorption and Iodine Deficiency: Molecular Mechanisms of Inhibition and Implications for Public Health. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:E1086. [PMID: 30917615 PMCID: PMC6466022 DOI: 10.3390/ijerph16061086] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 03/19/2019] [Accepted: 03/21/2019] [Indexed: 12/24/2022]
Abstract
The sodium iodide symporter (NIS) is the plasma membrane glycoprotein that mediates active iodide transport in the thyroid and other tissues, such as the salivary, gastric mucosa, rectal mucosa, bronchial mucosa, placenta and mammary glands. In the thyroid, NIS mediates the uptake and accumulation of iodine and its activity is crucial for the development of the central nervous system and disease prevention. Since the discovery of NIS in 1996, research has further shown that NIS functionality and iodine transport is dependent on the activity of the sodium potassium activated adenosine 5'-triphosphatase pump (Na+, K+-ATPase). In this article, I review the molecular mechanisms by which F inhibits NIS expression and functionality which in turn contributes to impaired iodide absorption, diminished iodide-concentrating ability and iodine deficiency disorders. I discuss how NIS expression and activity is inhibited by thyroglobulin (Tg), tumour necrosis factor alpha (TNF-α), transforming growth factor beta 1 (TGF-β1), interleukin 6 (IL-6) and Interleukin 1 beta (IL-1β), interferon-γ (IFN-γ), insulin like growth factor 1 (IGF-1) and phosphoinositide 3-kinase (PI3K) and how fluoride upregulates expression and activity of these biomarkers. I further describe the crucial role of prolactin and megalin in regulation of NIS expression and iodine homeostasis and the effect of fluoride in down regulating prolactin and megalin expression. Among many other issues, I discuss the potential conflict between public health policies such as water fluoridation and its contribution to iodine deficiency, neurodevelopmental and pathological disorders. Further studies are warranted to examine these associations.
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Affiliation(s)
- Declan Timothy Waugh
- EnviroManagement Services, 11 Riverview, Doherty's Rd, Bandon, Co. Cork, P72 YF10, Ireland.
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7
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Tan J, Zhao M, Wang J, Li Z, Liang L, Zhang L, Yuan Q, Tan W. Regulation of Protein Activity and Cellular Functions Mediated by Molecularly Evolved Nucleic Acids. Angew Chem Int Ed Engl 2019; 58:1621-1625. [PMID: 30556364 PMCID: PMC6442720 DOI: 10.1002/anie.201809010] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Revised: 11/07/2018] [Indexed: 01/05/2023]
Abstract
Regulation of protein activity is essential for revealing the molecular mechanisms of biological processes. DNA and RNA achieve many uniquely efficient functions, such as genetic expression and regulation. The chemical capability to synthesize artificial nucleotides can expand the chemical space of nucleic acid libraries and further increase the functional diversity of nucleic acids. Herein, a versatile method has been developed for modular expansion of the chemical space of nucleic acid libraries, thus enabling the generation of aptamers able to regulate protein activity. Specifically, an aptamer that targets integrin alpha3 was identified and this aptamer can inhibit cell adhesion and migration. Overall, this chemical-design-assisted in vitro selection approach enables the generation of functional nucleic acids for elucidating the molecular basis of biological activities and uncovering a novel basis for the rational design of new protein-inhibitor pharmaceuticals.
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Affiliation(s)
- Jie Tan
- Molecular Science and Biomedicine Laboratory (MBL), Institute of Chemical Biology and Nanomedicine, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, and Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082 China,
| | - Mengmeng Zhao
- Molecular Science and Biomedicine Laboratory (MBL), Institute of Chemical Biology and Nanomedicine, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, and Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082 China
| | - Jie Wang
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Zhihao Li
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Ling Liang
- Molecular Science and Biomedicine Laboratory (MBL), Institute of Chemical Biology and Nanomedicine, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, and Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082 China
| | - Liqin Zhang
- Department of Chemistry and Department of Physiology and Functional Genomics, Center for Research at the Bio/Nano Interface, Health Cancer Center, UF Genetics Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611-7200, United States
| | - Quan Yuan
- Molecular Science and Biomedicine Laboratory (MBL), Institute of Chemical Biology and Nanomedicine, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, and Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082 China,
| | - Weihong Tan
- Molecular Science and Biomedicine Laboratory (MBL), Institute of Chemical Biology and Nanomedicine, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, and Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082 China, Department of Chemistry and Department of Physiology and Functional Genomics, Center for Research at the Bio/Nano Interface, Health Cancer Center, UF Genetics Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611-7200, United States
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8
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Tan J, Zhao M, Wang J, Li Z, Liang L, Zhang L, Yuan Q, Tan W. Regulation of Protein Activity and Cellular Functions Mediated by Molecularly Evolved Nucleic Acids. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201809010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Jie Tan
- Molecular Science and Biomedicine Laboratory (MBL) Institute of Chemical Biology and Nanomedicine State Key Laboratory of Chemo/Biosensing and Chemometrics College of Chemistry and Chemical Engineering College of Biology Aptamer Engineering Center of Hunan Province Hunan University Changsha 410082 China
| | - Mengmeng Zhao
- Molecular Science and Biomedicine Laboratory (MBL) Institute of Chemical Biology and Nanomedicine State Key Laboratory of Chemo/Biosensing and Chemometrics College of Chemistry and Chemical Engineering College of Biology Aptamer Engineering Center of Hunan Province Hunan University Changsha 410082 China
| | - Jie Wang
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education) College of Chemistry and Molecular Sciences Wuhan University Wuhan 430072 China
| | - Zhihao Li
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education) College of Chemistry and Molecular Sciences Wuhan University Wuhan 430072 China
| | - Ling Liang
- Molecular Science and Biomedicine Laboratory (MBL) Institute of Chemical Biology and Nanomedicine State Key Laboratory of Chemo/Biosensing and Chemometrics College of Chemistry and Chemical Engineering College of Biology Aptamer Engineering Center of Hunan Province Hunan University Changsha 410082 China
| | - Liqin Zhang
- Department of Chemistry and Department of Physiology and Functional Genomics Center for Research at the Bio/Nano Interface Health Cancer Center UF Genetics Institute and McKnight Brain Institute University of Florida Gainesville FL 32611-7200 USA
| | - Quan Yuan
- Molecular Science and Biomedicine Laboratory (MBL) Institute of Chemical Biology and Nanomedicine State Key Laboratory of Chemo/Biosensing and Chemometrics College of Chemistry and Chemical Engineering College of Biology Aptamer Engineering Center of Hunan Province Hunan University Changsha 410082 China
| | - Weihong Tan
- Molecular Science and Biomedicine Laboratory (MBL) Institute of Chemical Biology and Nanomedicine State Key Laboratory of Chemo/Biosensing and Chemometrics College of Chemistry and Chemical Engineering College of Biology Aptamer Engineering Center of Hunan Province Hunan University Changsha 410082 China
- Department of Chemistry and Department of Physiology and Functional Genomics Center for Research at the Bio/Nano Interface Health Cancer Center UF Genetics Institute and McKnight Brain Institute University of Florida Gainesville FL 32611-7200 USA
- Institute of Molecular Medicine (IMM) Renji Hospital Shanghai Jiao Tong University School of Medicine College of Chemistry and Chemical Engineering Shanghai Jiao Tong University Shanghai China
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9
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Yildiz M, Oral B. The effect of pregnancy and lactation on bone mineral density in fluoride-exposed rats. Toxicol Ind Health 2016; 22:217-22. [PMID: 16898264 DOI: 10.1191/0748233706th258oa] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Fluoride increases metabolic turnover of the bone in favour of bone formation. Excessive intake of fluoride may lead to pathological changes in teeth and bones: dental and skeletal fluorosis. In this study, we investigated the effect of pregnancy and lactation on bone mineral density (BMD) in fluoride-exposed rats. Female Wistar rats were given commercially available spring water with 100 ppm fluoride (N-8), or without addition (N-8) for 18 weeks. At 16 weeks of age, four female rats and one male rat were kept in a cage for 5 days; all females were successfully impregnated. BMD was measured at 16 weeks of age, on the first day postpartum, and at the end of lactation. Spinal BMD was significantly higher in fluoride-exposed rats than control (P≤0.05), but there were no differences in femoral BMD (P-0.670). During pregnancy, spinal BMD and femoral BMD were not significantly changed in fluoride-exposed rats, whereas BMD of the spine was significantly decreased in the control rats (P-0.013), but not in the femur. During lactation, BMD was significantly decreased at the two regions compared to initial values (P≤0.05) in both groups. This study shows that pregnancy has no effect on bone, but lactation has a decreasing effect on BMD in fluoride-exposed rats.
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Affiliation(s)
- Mustafa Yildiz
- Department of Nuclear Medicine, School of Medicine, Süleyman Demirel University, Isparta, Turkey.
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10
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Brun LR, Brance ML, Lombarte M, Maher MC, Di Loreto VE, Rigalli A. Effects of Yerba Mate (IIex paraguariensis) on Histomorphometry, Biomechanics, and Densitometry on Bones in the Rat. Calcif Tissue Int 2015. [PMID: 26223790 DOI: 10.1007/s00223-015-0043-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Yerba mate (Ilex paraguariensis) is a xanthine-containing beverage, which is also rich in caffeine. Because caffeine has a negative impact on bone mineral density (BMD) mainly associated with low calcium (Ca) diets, there would be expected a negative effect of yerba mate on bone. In this study, Sprague-Dawley rats were used and randomly assigned into four groups (n = 6/group): Control + Ca 0.2 g %; Control + Ca 0.9 g %; Yerba + Ca 0.2 g %; Yerba + Ca 0.9 g %. At the end of the experiment, tibias and femurs were obtained for BMD, morphometric, histomorphometric, and biomechanical analyses. While there was no difference in bone parameters between rats with and without yerba mate consumption, a negative effect of low Ca diet was observed in BMD, morphometric, histomorphometric, and biomechanical results. Interaction between Ca content in the diet and yerba mate was only found in trabecular bone volume, which would indicate that the negative effect of low Ca intake on bone volume is reversed in part by yerba mate infusion. However, yerba mate was not able to reverse the negative effect of low Ca content on biomechanical properties and trabecular connectivity. In summary, at least in our study, yerba mate would not have a negative effect on bone and would be safe for the bone health of consumers.
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Affiliation(s)
- Lucas R Brun
- Bone Biology Laboratory, School of Medicine, Rosario National University, Rosario, Argentina.
- National Council of Scientific and Technical Research (CONICET), Buenos Aires, Argentina.
- Cátedra de Química Biológica, Facultad de Ciencias Médicas, Santa Fe 3100, (2000) Rosario, Argentina.
| | - María L Brance
- Bone Biology Laboratory, School of Medicine, Rosario National University, Rosario, Argentina
- National Council of Scientific and Technical Research (CONICET), Buenos Aires, Argentina
| | - Mercedes Lombarte
- Bone Biology Laboratory, School of Medicine, Rosario National University, Rosario, Argentina
- National Council of Scientific and Technical Research (CONICET), Buenos Aires, Argentina
| | - María Cielo Maher
- Bone Biology Laboratory, School of Medicine, Rosario National University, Rosario, Argentina
| | | | - Alfredo Rigalli
- Bone Biology Laboratory, School of Medicine, Rosario National University, Rosario, Argentina
- National Council of Scientific and Technical Research (CONICET), Buenos Aires, Argentina
- Rosario National University Research Council, Rosario, Argentina
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11
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Lee HJ, Arikawa K. Influence of Low Level Sodium Fluoride on Expression of IGF-1 and IGF-2 Protein in Experimental Type 2 Diabetes with Periodontitis Model. J HARD TISSUE BIOL 2015. [DOI: 10.2485/jhtb.24.319] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Hye-Jin Lee
- Department of Dental Hygiene, Howon University
| | - Kazumune Arikawa
- Department of Preventive and Public Oral Health, Nihon University School of Dentistry at Matsudo
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12
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Cohen E, Hsu RY, Evangelista P, Aaron R, Rubin LE. Rapid-Onset Diffuse Skeletal Fluorosis from Inhalant Abuse: A Case Report. JBJS Case Connect 2014; 4:e108. [PMID: 29252776 DOI: 10.2106/jbjs.cc.n.00085] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
CASE A thirty-year-old man presented with severely debilitating left hip pain and stiffness. Radiographs demonstrated diffuse osteosclerosis and heterotopic bone formation with near ankylosis of the left hip. The patient underwent successful joint-preserving surgery to restore hip range of motion. After disclosing a history of inhalant abuse, which was confirmed by elevated serum fluoride levels, he was diagnosed with diffuse skeletal fluorosis. CONCLUSIONS To the best of our knowledge, we present the first reported case of diffuse skeletal fluorosis caused by inhalant abuse of 1,1-difluoroethane. Skeletal fluorosis is uncommon in the United States but is important to consider in the differential diagnosis when a patient presents with otherwise unexplained joint pain and osteosclerosis.
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Affiliation(s)
- Eric Cohen
- Departments of Orthopedics (E.C., R.Y.H., R.A., and L.E.R.) and Diagnostic Imaging (P.E.), Brown Alpert Medical School/Rhode Island Hospital, 593 Eddy Street, Providence, RI 02903.
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Brance ML, Brun LR, Di Loreto VE, Lupo M, Rigalli A. Sequential treatment with monofluorophosphate and zoledronic acid in osteoporotic rats. Climacteric 2013; 17:478-85. [PMID: 24205901 DOI: 10.3109/13697137.2013.860117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE Osteoporosis is the consequence of an imbalance in bone remodeling caused by excessive resorption or inappropriate bone formation. This paper proposes a sequential treatment with monofluorophosphate (MFP) and zoledronic acid (Z), together with changes in the calcium content in the diet. METHOD Seven-week-old female Sprague Dawley rats were divided into five groups (n = 21 per group): (1) sham-operated rats (Sham); (2) ovariectomized (OVX) rats fed with a normal calcium diet (OVX); (3) OVX rats fed with a normal calcium diet and treated sequentially with monofluorophosphate and zoledronic acid (OVX.G1); (4) OVX rats sequentially fed with a low calcium diet and then a high calcium diet, without treatment (OVX.G2); (5): OVX rats fed with a low calcium diet and then a high calcium diet, treated sequentially with monofluorophosphate and zoledronic acid (OVX.G3). RESULTS After 150 days, the OVX.G3 group showed a similar bone volume to that of the Sham group due to an increase in trabecular number. Dual X-ray absorptiometry bone analysis showed an increase of 9.8% compared with OVX rats. Additionally, an increase in the fracture load at the cortical bone and higher fracture load, ultimate load and stiffness in the compression test were found. CONCLUSION The sequential treatment with monofluorophosphate and zoledronic acid increases trabecular bone mass, bone mineral density and bone strength.
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Affiliation(s)
- M L Brance
- * Bone Biology Laboratory, School of Medicine, Rosario National University , Rosario
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14
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Aguirre MC, Armendariz M, Lupo M, Rigalli A. Mathematical model for the homeostasis of alpha-macroglobulins in the rat. Math Biosci 2011; 234:17-24. [PMID: 21864541 DOI: 10.1016/j.mbs.2011.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2010] [Revised: 08/04/2011] [Accepted: 08/05/2011] [Indexed: 11/17/2022]
Abstract
Alpha-macroglobulins (AM) are proteins that inactivate proteinases. Sodium monofluorophosphate (MFP) binds to AM and transiently changes AM plasma levels. As a consequence MFP is useful to modify AM homeostasis. A mathematical model to study the homeostasis of AM is proposed in this paper. The model describes changes in plasma concentration of AM, MFP concentration in the gastrointestinal tract, MFP plasma concentration, plasma concentration of AMMFP and includes rate constants of the processes involved in AM homeostasis. Estimation of the rate constants values was achieved using experimental and mathematical resources. The homeostasis of AM after an oral dose of 80 μmol of MFP was analyzed with a simulation tool. Experimental conditions that modify the homeostasis of AM had been simulated and validated using specific drugs that change some parameter of the system. The mathematical model describes accurately the behavior of the biological model. The results allow concluding that the simplifications made did not underestimate the main processes involved in the homeostasis and, also that the assumptions made were correct.
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Affiliation(s)
- M C Aguirre
- Bone Biology Laboratory, Rosario National University, Argentina
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15
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Wu CC, Huang ST, Lin HC, Tseng TW, Rao QL, Chen MY. Expression of osteopontin and type I collagen of hFOB 1.19 cells on sintered fluoridated hydroxyapatite composite bone graft materials. IMPLANT DENT 2011; 19:487-97. [PMID: 21119353 DOI: 10.1097/id.0b013e3181f57525] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE The biological effect of fluoridated hydroxyapatite (FHA) graft materials has been attributed to their fluoride ion content; but, only few studies have been conducted to explore the osteoblastic cellular response to physicochemical characteristics of them. We hypothesized that the effect of varied sintered FHA composites on osteoblastic behavior would attribute certain specified physicochemical characteristics of apatites. MATERIALS Sintered FHA composites were prepared by sintering method with varied gravity percentages of calcium fluoride and hydroxyapatite. Scanning electron microscopic, x-ray diffraction, and Fourier-transform infrared analysis were recorded. The human fetal-osteoblast (hFOB 1.19) cells were seeded on the apatites and tissue culture plates. Responses to the apatites were assessed in terms of osteopontin (OPN) and type I collagen, COL I, gene differentiation. RESULTS We observed the calcined hydroxyapatite (OHAp), sintered F- OHAps, and hydroxy fluorapatites (OH-FAps) with different physicochemical characteristics. The x-ray diffraction analysis showed sintered apatites to be fluorapatites. Otherwise, Fourier-transform infrared spectral patterns could differentiate the sintered F-OHAps from OH-FAps by the existence of OH, OH···F, or OH···F···OH bands. With ≤ 1 wt% CaF2 added, sintered F-OHAp composites expressed both OH and OH···F bands. With >1 wt% CaF2 added, sintered OH-FAp composites expressed both OH···F and OH···F···OH bands. Sintered F-OHAp composites could enhance OPN and COL I gene expression after 6-day culture (P ≤ 0.05). Otherwise, sintered OH-FAp composites inhibited the expression. CONCLUSION The results revealed that sintered F-OHAp composites with both OH and OH···F bands were bioactive bone graft materials.
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Affiliation(s)
- Cheng-Chei Wu
- College of Dental Science, Kaohsiung Medical University, Kaohsiung, Taiwan, Republic of China
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16
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Protein phosphatases: possible bisphosphonate binding sites mediating stimulation of osteoblast proliferation. Arch Biochem Biophys 2010; 507:248-53. [PMID: 21167123 DOI: 10.1016/j.abb.2010.12.013] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2010] [Revised: 12/09/2010] [Accepted: 12/10/2010] [Indexed: 11/24/2022]
Abstract
We investigated the existence of a bisphosphonate (BP) target site in osteoblasts. Binding assays using [³H]-olpadronate ([³H]OPD) in whole cells showed the presence of specific, saturable and high affinity binding for OPD (K(d)=1.39 ± 0.33 μM) in osteoblasts. [³H]OPD was displaced from its binding site by micromolar concentrations of lidadronate, alendronate and etidronate (K(d)=1.42 ± 0.15 μM, 2.00 ± 0.2 μM and 2.4 ± 0.4 μM, respectively), and by millimolar concentrations of the non-permeant protein phosphatase (PP) substrates p-nitrophenylphosphate and α-naphtylphosphate. PP inhibitors orthovanadate, NaF or vpb(bipy) did not displace [³H]OPD. As expected, specific OPD binding was detected in the plasma membrane of ROS 17/2.8 cells, although significant BP binding was also found intracellularly. Moreover, OPD increased DNA synthesis in these cells with a temporal profile similar to the protein tyrosine phosphatase (PTP) inhibitors, Na₃VO₄ and vpb(bipy); but different from a general PP inhibitor (NaF). The stimulatory effect of OPD and PTP inhibitors on osteoblast proliferation was inhibited by the protein tyrosine kinase inhibitors genistein and geldanamycin. These results provide new evidence on the existence of a BP target in osteoblastic cells, presumably a PTP, which may be involved in the stimulatory action of BPs on osteoblast proliferation.
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Brun L, Pera L, Rigalli A. Bone morphometry and differences in bone fluorine containing compounds in rats treated with NaF and MFP. Biomed Pharmacother 2010; 64:1-6. [DOI: 10.1016/j.biopha.2008.10.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2008] [Accepted: 10/21/2008] [Indexed: 10/20/2022] Open
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Affiliation(s)
- J H Beattie
- Division of Biochemical Sciences, Rowett Research Institute, Bucksburn, Aberdeen
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19
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Ruppel ME, Miller LM, Burr DB. The effect of the microscopic and nanoscale structure on bone fragility. Osteoporos Int 2008; 19:1251-65. [PMID: 18317862 DOI: 10.1007/s00198-008-0579-1] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2007] [Accepted: 01/25/2008] [Indexed: 12/20/2022]
Abstract
Bone mineral density is the gold-standard for assessing bone quantity and diagnosing osteoporosis. Although bone mineral density measurements assess the quantity of bone, the quality of the tissue is an important predictor of fragility. Understanding the macro- and nanoscale properties of bone is critical to understanding bone fragility in osteoporosis. Osteoporosis is a disease that affects more than 75 million people worldwide. The gold standard for osteoporosis prognosis, bone mineral density, primarily measures the quantity of bone in the skeleton, overlooking more subtle aspects of bone's properties. Bone quality, a measure of bone's architecture, geometry and material properties, is evaluated via mechanical, structural and chemical testing. Although decreased BMD indicates tissue fragility at the clinical level, changes in the substructure of bone can help indicate how bone quality is altered in osteoporosis. Additionally, mechanical properties which can quantify fragility, or bone's inability to resist fracture, can be changed due to alterations in bone architecture and composition. Recent studies have focused on examination of bone on the nanoscale, suggesting the importance of understanding the interactions of the mineral crystals and collagen fibrils and how they can alter bone quality. It is therefore important to understand alterations in bone that occur at the macro-, micro- and nanoscopic levels to determine what parameters contribute to decreased bone quality in diseased tissue.
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Affiliation(s)
- M E Ruppel
- Department of Biomedical Engineering, State University of New York-Stony Brook, Stony Brook, NY 11794, USA
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20
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Simić P, Giljević Z, Simunić V, Vukicević S, Korsić M. Treatment of Osteoporosis. Arh Hig Rada Toksikol 2007; 58:55-71. [PMID: 17424786 DOI: 10.2478/v10004-007-0009-3] [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: 11/20/2022] Open
Abstract
Liječenje OsteoporozeOsteoporoza je jedna od najčešćih metaboličkih bolesti i zahvaća 8 % do 10 % stanovništva. Budući da je prijelom najteža posljedica osteoporoze, vrlo je važno otkriti bolesnike koji imaju rizik nastanka prijeloma, dati im farmakološku terapiju i savjetovati im promjenu načina života. Nekoliko je lijekova pokazalo sposobnost smanjenja broja prijeloma kralježnice i/ili perifernog skeleta u bolesnika s osteoporozom. Antiresorptivni su lijekovi temelj terapije, ali su i anabolički lijekovi odnedavno proširili mogućnosti liječenja. Antiresorptivni lijekovi, estrogeni, selektivni modulatori estrogenskih receptora, bisfosfonati i kalcitonin, djeluju tako da smanjuju koštanu pregradnju. Paratireoidni hormon potiče novo stvaranje kosti popravljajući arhitekturu i gustoću kosti. Stroncijev ranelat smanjuje rizik osteoporotičnih prijeloma djelujući na oboje - smanjenje razgradnje i povećanje izgradnje kosti. Druga potencijalna liječenja osteoporoze također su opisana u ovome članku.
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Affiliation(s)
- Petra Simić
- Medicinski fakultet Sveucilista u Zagrebu, Klinika za internu medicinu Klinickog bolnickog centra Zagreb, Hrvatska
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22
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Tamer MN, Kale Köroğlu B, Arslan C, Akdoğan M, Köroğlu M, Cam H, Yildiz M. Osteosclerosis due to endemic fluorosis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2007; 373:43-8. [PMID: 17182085 DOI: 10.1016/j.scitotenv.2006.10.051] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2006] [Revised: 10/17/2006] [Accepted: 10/24/2006] [Indexed: 05/13/2023]
Abstract
Endemic water borne fluorosis is a public health problem in Isparta, a city located in southern Turkey. In order to investigate the association between osteosclerosis and fluorosis, we retrospectively screened the results of lumbar spine and femur neck bone mineral density (BMD) of 1500 patients who were examined before, for any reason in between 2001-2003. Sixty nine patients (67 females and 2 males, mean age 52.6+/-10.2) with vertebra T-scores>or=+2 were found only except a patient with osteoid osteoma in the femur neck (femur T-score+6.64). Thirty-four of the patients could be reexamined with lateral vertebra BMD and investigated for fluorosis and the other etiologic causes of osteosclerosis. Of 34 patients, 14 had either mottled tooth enamel or urine fluoride level greater than 1.5 mg/l. Other etiologic causes were hypothyroidism (2), hypoparathyroidism (1), history of lumbar fracture (1), use of retinoids (1), vitamin D (7), oral calcium preparations (9), and bisphosphanates (3). Lateral lumbar vertebral T-score was greater than+2 in 12 patients (35.3%). Femur T-score was greater than+2 in 7 patients (20.6%). Fourteen patients (41.2%) had lateral vertebral or femur T-score>or=+2. Five (35.7%) of these patients had signs of fluorosis, as discussed before. Mean body mass index of individuals with fluorosis was 36.4+/-7.9 and this result was significantly higher than other osteosclerotic subjects (31.6+/-4.4). In conclusion we believe that approximately one third of the osteosclerosis in our region was due to endemic skeletal fluorosis and obesity may enhance this osteosclerotic type bone changes in endemic fluorosis.
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Affiliation(s)
- Mehmet Numan Tamer
- Süleyman Demirel University Medical School, Endocrinology and Metabolism Department, Isparta, Turkey.
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23
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Ellingsen JE, Thomsen P, Lyngstadaas SP. Advances in dental implant materials and tissue regeneration. Periodontol 2000 2006; 41:136-56. [PMID: 16686931 DOI: 10.1111/j.1600-0757.2006.00175.x] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Jan Eirik Ellingsen
- Oral Research Laboratory and Department of Prosthetic Dentistry, Institute of Clinical Dentistry, Dental Faculty, University of Oslo, Oslo, Norway
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24
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Schiller KR, Mauro LJ. Tyrosine phosphatases as regulators of skeletal development and metabolism. J Cell Biochem 2005; 96:262-77. [PMID: 16052478 DOI: 10.1002/jcb.20515] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The protein tyrosine kinases (PTK) and the protein tyrosine phosphatases (PTPs) are enzymes which play an integral role in tyrosine phosphorylation-dependent signaling cascades. By catalyzing the phosphorylation and dephosphorylation of cellular proteins, these enzymes direct the steady-state levels of specific phosphoproteins and ultimately dictate the functional state of all cells. The importance of this type of signaling in the skeleton is accepted but poorly understood. The contribution of the PTKs to signaling events in bone has been well studied but, in contrast, the regulation by PTPs is poorly defined. The recent identification of 107 genes within the human genome which encode members of the PTP superfamily emphasizes the need to consider the importance of these proteins in skeletal tissue. In this prospective, we will summarize the present state of our knowledge regarding the function of this enzyme superfamily, illustrating its relevance to the development and maintenance of the skeleton and highlighting future directions that should improve our understanding of these critical signaling molecules.
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Affiliation(s)
- Katherine R Schiller
- Department of Animal Science, Physiology & Growth Division, University of Minnesota, Minnesota 55108, USA
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25
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Lau KHW, Baylink DJ. Osteoblastic tartrate-resistant acid phosphatase: its potential role in the molecular mechanism of osteogenic action of fluoride. J Bone Miner Res 2003; 18:1897-900. [PMID: 14584902 DOI: 10.1359/jbmr.2003.18.10.1897] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Although type 5 TRACP is recognized as a histochemical and biochemical marker of osteoclasts, there is evidence that bone forming cells, osteoblasts, and osteocytes also express a type 5 TRACP. Accordingly, an osteoblastic type 5 TRACP has been purified from human osteoblasts and from bovine cortical bone matrices. Comparison of biochemical properties of osteoblastic type 5 TRACP with those of osteoclastic type 5 TRACP suggests that osteoblastic type 5 TRACP is a different isoenzyme from osteoclastic type 5 TRACP. Two properties of osteoblastic type 5 TRACP may be relevant to its physiological functions: (1) it acts as a protein-tyrosine phosphatase (protein tyrosine phosphorylation) under physiologically relevant conditions, and (2) it is sensitive to inhibition by clinically relevant concentrations of fluoride. Because fluoride is a stimulator of osteoblastic proliferation and differentiation and a potent osteogenic agent and because protein tyrosine phosphorylation plays an important regulatory role in cell proliferation and differentiation, these unique properties and other evidence summarized in this review led to the proposal that the osteogenic action of fluoride is mediated, at least in part, by the fluoride-mediated inhibition of osteoblastic type 5 TRACP/protein tyrosine phosphorylation, which leads to a stimulation of osteoblast proliferation and differentiation, and subsequently, an increase in bone formation.
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Affiliation(s)
- K-H William Lau
- Musculoskeletal Disease Center, Jerry L. Pettis Memorial VA Medical Center, Loma Linda, California 92357, USA
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26
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Oguro A, Kawase T, Orikasa M. NaF induces early differentiation of murine bone marrow cells along the granulocytic pathway but not the monocytic or preosteoclastic pathway in vitro. In Vitro Cell Dev Biol Anim 2003; 39:243-8. [PMID: 12880368 DOI: 10.1290/1543-706x(2003)039<0243:niedom>2.0.co;2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2003] [Revised: 07/17/2003] [Accepted: 07/24/2003] [Indexed: 11/11/2022]
Abstract
The stimulatory effects of sodium fluoride (NaF) on bone formation have been explained solely by its activation of osteoblasts. However, whether and how NaF acts on the osteoclast lineage is poorly understood. We previously found that NaF differentiates HL-60 cells to granulocytic cells. To further test this action, we have employed here primary cultures of progenitor cells derived from murine bone marrow. NaF at subtoxic concentrations (<0.5 mM) significantly up-regulated activities of several intracellular enzymes (lactate dehydrogenase, beta-glucuronidase, acid phosphatase), cellular reduction of nitroblue tetrazolium, and nitric oxide (NO) production; which are all accepted as general differentiation markers. NaF (<0.5 mM) also up-regulated granulocyte-specific markers (chloroacetate esterase, cell surface antigens [Mac-1, Gr-1]) but not any of the monocyte-specific markers (nonspecific esterase, cell surface antigens [F4/80, MOMA-2]). Although other general differentiation markers (phagocytosis, adhesion, appearance, nuclear:cytoplasmic ratio) were not appreciably influenced by NaF, essentially in support of our previous data from HL-60 cells, the present findings suggest that NaF induces early differentiation of bone marrow hemopoietic progenitor cells along the granulocytic pathway but not the monocytic pathway that is linked to osteoclast formation. Therefore, in addition to its potent stimulatory effects on osteoblastic bone formation, NaF applied to patients with osteoporosis could be expected to indirectly reduce osteoclastic bone resorption.
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27
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Abstract
PURPOSE The effects of menopause on bone mineral density (BMD) in women with endemic fluorosis were investigated. MATERIALS AND METHODS Eighty healthy Turkish women who lived in and around the city of Isparta were selected randomly and enrolled in this study. They were separated into four groups: group 1, 20 premenopausal women with regular menstrual cycles and endemic fluorosis; group 2, 20 postmenopausal women with endemic fluorosis; group 3, 20 premenopausal normal women constituting one control group; and group 4, 20 postmenopausal normal women constituting the other control group. Bone mineral density was measured in the lumbar spine and proximal femur using dual-energy x-ray absorptiometry. RESULTS In the premenopausal group, BMD values of vertebrae L2-L4 and Ward's triangle in women with endemic fluorosis were significantly greater than the respective values in women without endemic fluorosis (P = 0.024, P = 0.036). There were no differences between the groups in BMD values of the femoral neck (P = 0.156) and intertrochanteric area (P = 0.076). The BMD values of vertebrae L2-L4, the femoral neck, intertrochanteric area, and Ward's triangle in the postmenopausal women with endemic fluorosis were significantly greater than those of postmenopausal women without endemic fluorosis (P < 0.001, P = 0.015, P = 0.002, and P < 0.001, respectively). The BMD values of vertebrae L2-L4, the femoral neck, intertrochanteric area, and Ward's triangle in the premenopausal women with endemic fluorosis were significantly greater than those of postmenopausal women with endemic fluorosis (P = 0.010, P = 0.002, P = 0.004, and P = 0.010, respectively). The BMD values of the sites noted for the premenopausal controls were significantly greater than those of postmenopausal controls (P < 0.001, P < 0.001, P < 0.001, and P < 0.001, respectively). CONCLUSIONS Postmenopausal BMD values in both endemic fluorosis and controls were significantly less than premenopausal BMD values. Although the differences were less prominent in women with endemic fluorosis, menopause is still the major determinant of BMD in the spine and femur.
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Affiliation(s)
- Mustafa Yildiz
- Department of Nuclear Medicine, Süleyman Demirel University, School of Medicine, Isparta, Turkey.
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28
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Lau KHW, Goodwin C, Arias M, Mohan S, Baylink DJ. Bone cell mitogenic action of fluoroaluminate and aluminum fluoride but not that of sodium fluoride involves upregulation of the insulin-like growth factor system. Bone 2002; 30:705-11. [PMID: 11996908 DOI: 10.1016/s8756-3282(02)00671-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The fluoroaluminate (AlF(4)(-)) ion and sodium fluoride (NaF) have previously been shown to be bone cell mitogens. This study sought to determine whether the bone cell mitogenic action of AlF(4)(-) and/or NaF would involve the insulin-like growth factor (IGF) regulatory system. We evaluated the effect of mitogenic doses of AlF(4)(-) and NaF on the mRNA levels and the protein level (in conditioned media [CM]) of several components of the IGF system (i.e., IGF-2, IGF binding protein [IGFBP]-4, and IGFBP-5) in human TE85 osteosarcoma cells. Aluminum fluoride (AlF(3)) was included for comparison. NaF, AlF(3), and AlF(4)(-), each at 50-100 micromol/L, increased [3H]thymidine incorporation in TE85 cells. Mitogenic concentrations of AlF(3) and AlF(4)(-): (1) increased the mRNA (up to twofold after 24 h treatment) and protein (in CM) levels (up to 2.5-fold after 48 h treatment) of IGF-2; (2) increased the mRNA level (twofold) and the protein level in CM (up to threefold) of stimulatory IGFBP-5; and (3) either reduced slightly or had no effect on the mRNA and protein (in CM) levels of the inhibitory IGFBP-4. Conversely, mitogenic concentrations of NaF had no significant effects on the protein (in CM) or mRNA level of IGF-2, IGFBP-4, or IGFBP-5. The addition of an inhibitory concentration of IGFBP-4 completely abolished the bone cell mitogenic activity of AlF(3) and AlF(4)(-) but not that of NaF. The findings of this study provide strong evidence that the bone cell mitogenic activity of AlF(4)(-) and AlF(3), but not that of NaF, is mediated by the upregulation of the IGF regulatory system.
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Affiliation(s)
- K-H William Lau
- Musculoskeletal Disease Center (151), Jerry L. Pettis Memorial VA Medical Center, 11201 Benton Street, Loma Linda, CA 92357, USA.
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29
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Abstract
Osteoporosis is a condition of increasing importance and prevalence in all parts of the world and particularly in Asia. Recent advances have led to the introduction of effective drugs that decrease bone resorption and stabilize bone mass. However, these drugs have been identified by serendipity rather than rational drug design and are not ideal because of limited bioavailability, mode of administration, or other unwanted effects. There is still a place for even more suitable and effective resorption inhibitors than those currently available. The more compelling need in this field is an acceptable drug that is anabolic for bone, that safely and acceptably increases bone mass and improves the disturbances in bone microarchitecture that characterize established and advanced osteoporosis. Possible approaches to identifying more effective resorption inhibitors and new anabolic agents are discussed.
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Affiliation(s)
- Gregory R Mundy
- Department of Medicine/Endocrinology, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, Texas 78229-3900, USA.
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30
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Rodríguez JP, Rosselot G. Sodium fluoride induces changes on proteoglycans synthesized by avian osteoblasts in culture. J Cell Biochem 2002; 83:607-16. [PMID: 11746504 DOI: 10.1002/jcb.1255] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The results reported here show that sodium fluoride (NaF) at low concentration (up to 10 microM) increased four times the proliferation rate of avian osteoblasts in culture. Also NaF increases, in a concentration dependent manner, 10 times the alkaline phosphatase activity. However, NaF decreased the incorporation of 35S-sulfate into proteoglycans (PGs) synthesized by osteoblasts (60-65%). Also, we observed that PGs synthesized in the presence of NaF (50 microM) exhibited a higher sensitivity to chondroitinase ABC than PGs synthesized by osteoblasts in the absence of NaF, suggesting an increase in the chondroitin sulfate moieties associated with the core protein of PGs. The modification of glycosaminoglycan (GAG) chains composition was evidenced also by change in the mean charge density of the PGs observed by ion exchange chromatography. Since the ratio of 35SO4/3H-glucosamine incorporated into PGs was similar in the presence and in the absence of NaF (8.2 and 7, respectively), it is not possible to explain differences in mean charge density by changes in the sulfation extent of PGs. No differences were observed in the hydrodynamic size of PG synthesized in the presence of NaF, nor in the hydrodynamic size of the GAG chains. According to these results, we speculate that the stimulatory effect of fluoride on bone mineralization may be mediated, in part, by the changes in the rate of synthesis or in the structural characteristics of bone PGs. The changes produced by fluoride in PGs suggest that these molecules play an inhibitory role in the bone mineralization process.
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Affiliation(s)
- J P Rodríguez
- Laboratorios de Biología Celular y de Biología Molecular, INTA, Universidad de Chile, Casilla 138-11, Santiago, Chile.
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Hashimoto H, Lau KH. Differential effects of bacterial toxins on mitogenic actions of sodium fluoride and those of aluminum fluoride in human TE85 osteosarcoma cells. Mol Cell Biochem 2001; 228:91-8. [PMID: 11855746 DOI: 10.1023/a:1013320625846] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
This study compared the effects of cholera toxin (CTX) and pertussis toxin (PTX) on the actions of sodium fluoride (NaF) and those of aluminum fluoride (AlF3) on cell proliferation and differentiation, as well as tyrosine phosphorylation level of mitogen activated protein kinase (MAPK) in human bone cells. NaF and AlF3 each significantly stimulated the proliferation of human TE85 osteosarcoma cells, increased cellular alkaline phosphatase (ALP) activity, and increased MAPK tyrosine phosphorylation level. CTX completely blocked the bone cell anabolic activities of both NaF and AlF3. While PTX (2 ng/ml) inhibited the bone cell actions of NaF, it had no significant effect on those of AlF3. Both CTX and PTX completely blocked the stimulatory action of AlF3 on MAPK tyrosine phosphorylation, but neither toxin had an effect on the action of NaF on MAPK tyrosine phosphorylation. In conclusion, PTX and CTX had contrasting effects on the anabolic bone cell actions of NaF and AlF3 actions. These findings argue against the hypothesis that the osteogenic activity of NaF is mediated via the formation of AlF3 in human TE85 osteosarcoma cells.
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Affiliation(s)
- H Hashimoto
- Department of Medicine, Loma Linda University, Jerry L. Pettis Memorial VA Medical Center, CA 92357, USA
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32
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Affiliation(s)
- G R Mundy
- University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, Texas 78284-7877, USA.
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33
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Abstract
Osteoporosis is a complex, multi-factorial condition characterized by reduced bone mass and impaired micro-architectural structure, leading to an increased susceptibility to fractures. Although most of the bone strength (including bone mass and quality) is genetically determined, many other factors (nutritional, environmental and life-style) also influence bone. Nutrition is important modifiable factor in the development and maintenance of bone mass and the prevention and treatment of osteoporosis. Approximately 80-90% of bone mineral content is comprised of calcium and phosphorus. Other dietary components, such as protein, magnesium, zinc, copper, iron, fluoride, vitamins D, A, C, and K are required for normal bone metabolism, while other ingested compounds not usually categorized as nutrients (e.g. caffeine, alcohol, phytoestrogens) may also impact bone health. Unraveling the interaction between different factors; nutritional, environmental, life style, and heredity help us to understand the complexity of the development of osteoporosis and subsequent fractures. This paper reviews the role of dietary components on bone health throughout different stages of life. Each nutrient is discussed separately, however the fact that many nutrients are co-dependent and simultaneously interact with genetic and environmental factors should not be neglected. The complexity of the interactions is probably the reason why there are controversial or inconsistent findings regarding the contribution of a single or a group of nutrients in bone health.
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Affiliation(s)
- J Z Ilich
- University of Connecticut, School of Allied Health, Storrs 06269, USA.
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Gitomer WL, Sakhaee K, Pak CY. A comparison of fluoride bioavailability from a sustained-release NaF preparation (Neosten) and other fluoride preparations. J Clin Pharmacol 2000; 40:138-41. [PMID: 10664919 DOI: 10.1177/00912700022008784] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Twelve normal subjects completed a crossover study with sustained-release sodium fluoride (Neosten, 11.3 mg F), monofluorophosphate (MFP, 10 mg F), and plain sodium fluoride (P-NaF, 11.3 mg F). After each preparation was given with 400 mg calcium, serum fluoride (Fser) was measured for 24 hours, and pharmacokinetic data were calculated. Fluoride absorption in the Neosten group, as measured by change in the area under the curve (delta AUC) of Fser, was less than 33% of that in the MFP and P-NaF treated groups. Both peak Fser (Cmax) and peak-basal variation in the Neosten group were 25% that found in the other groups. t1/2 was nearly twofold greater after Neosten. MFP and P-NaF showed greater bioavailability than Neosten and much higher Cmax that exceeded the toxic threshold of Fser (190 ng/ml). These findings could explain the ineffectiveness of MFP and P-NaF observed in recent clinical trials.
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Affiliation(s)
- W L Gitomer
- Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center at Dallas 75235-8885, USA
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35
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Kawase T, Orikasa M, Oguro A, Burns DM. Possible regulation of epidermal growth factor-receptor tyrosine autophosphorylation by calcium and G proteins in chemically permeabilized rat UMR106 cells. Arch Oral Biol 1999; 44:157-71. [PMID: 10206334 DOI: 10.1016/s0003-9969(98)00105-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
A model using chemically permeabilized cells was developed to examine mechanisms that regulate protein tyrosine phosphorylation in osteoblastic cells. Using either permeabilized UMR106 osteoblastic or A431 (reference) cells, epidermal growth factor (EGF)-induced cellular tyrosine phosphorylation, and whether there are previously unrecognized interactions between this transduction pathway and Ca2+- or G protein-dependent signalling pathways, were investigated. Both permeabilized cell types, when maintained in non-supplemented cytoplasmic substitution solution (basic CSS), responded to EGF (1-100 ng/ml) with dose-dependent increases in tyrosine phosphorylation. A complex and time-dependent pattern of phosphotyrosine-containing proteins resulted, but the profile of tyrosine phosphorylated proteins was appreciably less complex than in intact cells. Supplementation of basic CSS with MgATP restored the normal complexity of the profiles for EGF-induced tyrosine phosphorylation proteins in both permeabilized cell lines and produced a more sustained accumulation of phosphoprotein products in A431 cells. Adding Ca2+ (< or = 10(-6) M), with or without exogenous MgATP, dose-dependently attenuated EGF-induced tyrosine phosphorylation of EGF receptors (EGFR) and other substrates in UMR106 cells, but was less effective in A431 cells. In both cell types, genistein, an inhibitor of tyrosine kinases, was more effective in attenuating EGF-induced receptor tyrosine phosphorylation in permeabilized cells. Similarly, orthovanadate, an inhibitor of protein tyrosine phosphatases, stimulated the accumulation of phosphoprotein products more effectively in permeabilized cells. Thus, the permeabilization preserves many features of intact cells while facilitating manipulation of intracellular conditions. NaF reproducibly produced a significant vanadate-like action in permeabilized cells that was somewhat stronger than its effect on intact cells. In contrast, the well-known inhibition of tyrosine phosphorylation by phorbol 12-myristate 13-acetate (PMA) was less effective in permeabilized cells than in intact cells; these actions of PMA were Ca2+-dependent. In addition, guanylyl-imidodiphosphate (Gpp(NH)p) attenuated tyrosine phosphorylation in UMR106 cells, and this effect was specifically blocked by guanosine 5'-O-(2-thiodiphosphate) (GDPbetas). These results strongly suggest that there is crosstalk between EGFR-activated tyrosine phosphorylation/dephosphorylation pathways and both Ca2+- and G protein-mediated pathways in UMR106 cells, revealing a previously unrecognized modulation of EGF signalling in osteoblast-like cells that contrasts with the simpler regulatory mechanisms found in A431 cells.
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Affiliation(s)
- T Kawase
- Department of Pharmacology, Niigata University School of Dentistry, Japan.
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36
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37
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Abstract
Fluoride is an effective anabolic agent to increase spinal bone density by increasing bone formation, and at therapeutically relevant (i.e., micromolar) concentrations, it stimulates bone cell proliferation and activities in vitro and in vivo. However, the fluoride therapy of osteoporosis has been controversial, in large part because of a lack of consistent antifracture efficacy. However, information regarding the molecular mechanism of action of fluoride may improve its optimum and correct usage and may disclose potential targets for the development of new second generation drugs that might have a better efficacy and safety profile. Accordingly, this review will address the molecular mechanisms of the osteogenic action of fluoride. In this regard, we and other workers have proposed two competing models, both of which involve the mitogen activated protein kinase (MAPK) mitogenic signal transduction pathway. Our model involves a fluoride inhibition of a unique fluoride-sensitive phosphotyrosine phosphatase (PTP) in osteoblasts, which results in a sustained increase in the tyrosine phosphorylation level of the key signaling proteins of the MAPK mitogenic transduction pathway, leading to the potentiation of the bone cell proliferation initiated by growth factors. The competing model proposes that fluoride acts in coordination with aluminum to form fluoroaluminate, which activates a pertussis toxin-sensitive Gi/o protein on bone cell membrane, leading to an activation of cellular protein tyrosine kinases (PTKs), which in turn leads to increases in the tyrosine phosphorylation of signaling proteins of the MAPK mitogenic signal transduction pathway, ultimately leading to a stimulation of cell proliferation. A benefit of our model, but not the other model, is that it accounts for all the unique properties of the osteogenic action of fluoride. These include the low effective fluoride dose, the skeletal tissue specificity, the requirement of PTK-activating growth factors, the sensitivity to changes in medium phosphate concentration, the preference for undifferentiated osteoblasts, and the involvement of the MAPK. Unlike fluoride, the mitogenic action of fluoroaluminate is not specific for skeletal cells. Moreover, the mitogenic action of fluoroaluminate shows several important, different characteristics than that of fluoride. Thus, it is likely that our model of a fluoride-sensitive PTP represents the actual molecular mechanism of the osteogenic action of fluoride.
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Affiliation(s)
- K H Lau
- Musculoskeletal Disease Center, Jerry L. Pettis Memorial V.A. Medical Center, Department of Medicine, Loma Linda University, California 92357, USA
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38
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Waddington RJ, Langley MS. Structural analysis of proteoglycans synthesized by mineralizing bone cells in vitro in the presence of fluoride. Matrix Biol 1998; 17:255-68. [PMID: 9749942 DOI: 10.1016/s0945-053x(98)90079-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
This study investigated the biochemical structure of proteoglycans synthesized during matrix maturation by mineralizing bone cells in vitro, in the presence and absence of fluoride. Bone cells were obtained from rat femur washes and cultured in alpha MEM media supplemented with fetal calf serum, ascorbic acid, beta-glycerophosphate and dexamethasone. Cells were characterized as osteoblast-like by the expression of alkaline phosphatase activity and the synthesis of collagen type I and osteocalcin. Fluoride, present in the culture media at concentrations of 10(-5) M or 10(-7) M, had negligible effect on cell viability. However, calcium deposition was increased in cell cultures incubated in the presence of fluoride. Proteoglycans were extracted from the extracellular matrix with 4 M guanidinium chloride and purified by anion exchange chromatography. Biochemical analysis identified the presence of the small leucine rich proteoglycan, decorin and biglycan, in addition to degradation products relating to the larger chondroitin sulphate protoeglycan, versican. Fluoride had little effect on the size or amino acid composition of the protein core, but resulted in significant alterations to the GAG chains, including a dramatic reduction in chain length, reduction in sulphation and decrease in the proportion of dermatan sulphate compared to chondroitin sulphate. The influence of fluoride on proteoglycan structure synthesized by mineralizing bone cells provides valuable information, indicating specific roles for dermatan sulphate and chondroitin sulphate proteoglycans. The results suggested that fluoride affected the post-translational assembly of the GAG chains which may be an influential factor in the mineralization process.
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Affiliation(s)
- R J Waddington
- Department of Basic Dental Science, Dental School, Heath Park, Cardiff, United Kingdom
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39
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Affiliation(s)
- J Caverzasio
- WHO Collaborating Center for Osteoporosis and Bone Diseases, Department of Internal Medicine, University Hospital, Geneva, Switzerland.
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40
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Abstract
Osteoporosis defined as low bone mass and increased susceptibility to fracture is a reflection of the sum of peak bone mass and any bone that has been lost once peak mass has been attained. Several strategies have been applied to optimize peak bone mass and to prevent bone loss. Fluoride has greatest potential as a therapy for osteoporosis once bone has been lost. It has been demonstrated both experimentally and clinically to stimulate bone formation directly and to increase bone mass in patients who already have osteoporosis. Several bone formation/stimulation therapies are under development, and some of these have reached the stage of clinical trial. None of these therapies has been as extensively studied as fluoride, and none is sufficiently advanced in development to be clinically available in the next 3 to 5 years. Fluoride therapy for osteoporosis is already performed in many countries, and approval for use in osteoporosis in the United States is pending. The first clinical trials of NaF therapy for osteoporosis were reported by Rich and Ensinck in 1961. Since then, hundreds of reports on the successes and failures of fluoride therapy have appeared in the literature. At first glance, it seems disappointing and inexplicable that, after 40 years of research, fluoride is still considered an experimental drug in the United States. One plausible explanation is that much of the early research on this drug was suboptimal, including the author's contributions. Fluoride as a naturally occurring element is difficult to patent, and this has kept major pharmaceutical companies from investing heavily in fluoride therapy despite its obvious potential. As a result, pharmacologic and pharmacokinetics studies of fluoride are limited in scope, as are phase I and phase II human toxicology and dose-finding studies. Most early studies of large doses of plain NaF were unable to demonstrate a consistent effect on fracture rate despite a consistent and dramatic effect on bone density. Once this became obvious and as new technologies for measuring bone density became available, it became equally clear that future clinical trials would have to be performed using different formulations of fluoride and lower doses. This approach has not resulted in uniformly positive clinical trials, and one must look elsewhere for answers. The most compelling explanation is that the trials have included patients with different severity of disease, suggesting that there is point in the bone loss spectrum at which even a potent bone-stimulating agent such as fluoride is ineffective. This possibility should provoke a reappraisal of the earlier negative studies: was the failure a result of the drug or of patient selection? The answer to this question is crucial, because these failures have cast a long shadow over the safety of fluoride and are contributing more to the absence of this drug from the pharmacopoeia than any other factor.
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Affiliation(s)
- M Kleerekoper
- Department of Internal Medicine, Wayne State University School of Medicine, Detroit, Michigan, USA
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41
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Jeschke M, Standke GJ, Scaronuscarona M. Fluoroaluminate induces activation and association of Src and Pyk2 tyrosine kinases in osteoblastic MC3T3-E1 cells. J Biol Chem 1998; 273:11354-61. [PMID: 9556630 DOI: 10.1074/jbc.273.18.11354] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Fluoride is known to increase bone mass in vivo, probably through stimulation of osteoblast proliferation; however, the mechanisms of fluoroaluminate action in osteoblasts have not yet been elucidated. We have previously shown that in osteoblastic MC3T3-E1 cells, fluoroaluminate stimulates G protein-mediated protein tyrosine phosphorylation (Scaronuscarona, M., Standke, G. J. R., Jeschke, M., and Rohner, D. (1997) Biochem. Biophys. Res. Commun. 235, 680-684). Although the Ser/Thr kinases Erk1, Erk2, and p70(S6K) were activated in response to fluoroaluminate, the identity of fluoroaluminate-activated tyrosine kinase(s) remained elusive. In this study, we show that in MC3T3-E1 cells, fluoroaluminate induces a 110-kDa tyrosine-phosphorylated protein that we identify as Pyk2, a cytoplasmic tyrosine kinase related to Fak (focal adhesion kinase). The tyrosine phosphorylation of Pyk2 increased in a dose- and time-dependent manner. The autophosphorylation activity of Pyk2 increased 3-fold and reached its maximum within 10 min of fluoroaluminate treatment. Fluoroaluminate also induced activation of Src and the association of Pyk2 with Src. The phosphorylation of Src-associated Pyk2 increased >20-fold in in vitro kinase assays, suggesting that Pyk2 is phosphorylated by Src. Although MC3T3-E1 cells express much more Fak than Pyk2, Src preferentially associated with Pyk2. In vitro, Pyk2 bound to the Src SH2 domain, suggesting that this interaction mediates the Src-Pyk2 association in cells. These data indicate that osteoblastic cells express Pyk2, which is tyrosine-phosphorylated and activated in response to G protein activation by fluoroaluminate, and that the mechanism of Pyk2 activation most likely involves Src. Thus, Src and Pyk2 are tyrosine kinases involved in G protein-mediated tyrosine phosphorylation in osteoblastic cells and may be important for the osteogenic action of fluoroaluminate.
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Affiliation(s)
- M Jeschke
- Research Bone Metabolism, Novartis Pharma AG, CH-4002 Basel, Switzerland
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42
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Ammann P, Rizzoli R, Caverzasio J, Bonjour JP. Fluoride potentiates the osteogenic effects of IGF-I in aged ovariectomized rats. Bone 1998; 22:39-43. [PMID: 9437512 DOI: 10.1016/s8756-3282(97)00206-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The molecular mechanisms whereby fluoride stimulates osteogenic cell proliferation are not clearly established. However, fluoride has been shown to enhance the protein tyrosine phosphorylation of various constituents of intracellular signaling cascades in osteoblastic cells following stimulation of growth factor receptors such as the insulin-like growth factor-I (IGF-I) receptor. Such in vitro findings provided the rationale for testing whether the administration of fluoride could enhance IGF-I effects on bone mass in vivo. Adult ovariectomized osteopenic rats were treated with sodium fluoride at a dose of 6 mg/kg per day in drinking water for 8 weeks in association with IGF-I either at a dose of 2 mg/kg per day, which is capable of increasing bone mass, or at a lower dose without detectable skeletal effects. Bone mineral density (BMD) and content (BMC) were evaluated by dual-energy X-ray absorptiometry at the levels of the lumbar spine and proximal, midshaft, and total tibia before and after 8 weeks of treatment. During this period, fluoride alone did not significantly influence BMD/BMC at any skeletal site. However, it potentiated the effect of the higher dose of IGF-I on bone mass at the level of the proximal tibia. When administered in combination with the lower dose of IGF-I, which per se did not modify bone mass, it appeared to sensitize tibial bone to the effects of IGF-I. These changes were associated with a concomitant increase in osteocalcin, taken as a reflection of bone formation. These results indicate that fluoride could potentiate the osteogenic effects of IGF-I on bone in adult ovariectomized rats.
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Affiliation(s)
- P Ammann
- WHO Collaborating Center for Osteoporosis and Bone Diseases, Department of Internal Medicine, University Hospital, Geneva, Switzerland
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43
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Caverzasio J, Palmer G, Suzuki A, Bonjour JP. Mechanism of the mitogenic effect of fluoride on osteoblast-like cells: evidences for a G protein-dependent tyrosine phosphorylation process. J Bone Miner Res 1997; 12:1975-83. [PMID: 9421230 DOI: 10.1359/jbmr.1997.12.12.1975] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Recent results indicate that a fluoroalumino complex (AlFx) is probably the molecule responsible for the mitogenic effect of fluoride in MC3T3-E1 osteoblast-like cells. Initial analysis suggested that a tyrosine phosphorylation (tyr phos) process similar to that induced by thrombin and activation of the p42 MAP kinase (ERK 2) mediate this cellular response. In the present study, the signaling mechanism activated by AlFx was further investigated. The results indicated that AlFx dose-dependently enhanced the tyr phos of the cell adhesion proteins FAK and paxillin, as well as of the adaptor molecules p46shc, p52shc, and p66shc and their association with GRB2. Pretreatment of MC3T3-E1 cells with cytochalasin D completely prevented FAK and paxillin tyr phos without any alteration in the tyr phos of Shc proteins and activation of ERK2 induced by AlFx. This observation suggests that in confluent MC3T3-E1 cells, there is no link between the activation of FAK induced by AlFx and the stimulation of ERK2. Pretreatment of the cells with pertussis toxin inhibited Shc phosphorylation, activation of ERK2, and markedly reduced cell replication induced by AlFx. This toxin also significantly reduced the stimulation of Pi transport activity induced by AlFx in these cells. Alteration in tyr phos induced by AlFx was not associated with any detectable inhibition of tyrosine phosphatase activity in MC3T3-E1 cell homogenates, suggesting that enhanced tyr phos induced by AlFx probably resulted from activation of a tyrosine kinase. In conclusion, the results of this study suggest that the mitogenic effect of fluoride in MC3T3-E1 osteoblast-like cells is mediated by the activation of a pertussis toxin-sensitive Gi/o protein and suggest an important role for these heterotrimeric G proteins in controlling the growth and differentiation of bone-forming cells.
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Affiliation(s)
- J Caverzasio
- Department of Medicine, University Hospital of Geneva, Switzerland
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44
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45
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Wu LW, Yoon HK, Baylink DJ, Graves LM, Lau KH. Fluoride at mitogenic doses induces a sustained activation of p44mapk, but not p42mapk, in human TE85 osteosarcoma cells. J Clin Endocrinol Metab 1997; 82:1126-35. [PMID: 9100584 DOI: 10.1210/jcem.82.4.3886] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Fluoride, at micromolar concentrations, stimulates bone cell proliferation in vitro. In this study, we sought to test whether fluoride at mitogenic doses increases the tyrosyl phosphorylation level and specific activity of a mitogen-activated protein kinase (MAPK) in human TE85 osteosarcoma cells. Analysis by immunoprecipitation with antiphosphotyrosine antibody followed by Western analysis using an anti-pan extracellular signal-regulated kinase antibody revealed that fluoride at the optimal mitogenic dose (i.e. 100 mumol/L) induced a time-dependent increase in the steady state tyrosyl phosphorylation level of p44mapk, but not p42mapk, with the maximal increase (4- to 13-fold) after 1-3 h fluoride treatment. The effect was sustained in that a 9-fold increase was seen after 12 h of the fluoride treatment. The sustained nature of the effect is consistent with an inhibition of dephosphorylation rather than a direct stimulation of phosphorylation. The fluoride effect on the tyrosyl phosphorylation level of p44mapk was dose dependent, with the optimal dose being 100 mumol/L fluoride. The mitogenic dose of fluoride also increased the specific activity and the in-gel kinase activity of p44mapk, but not that of p42mapk, in a time-dependent manner similar to the effect on the p44mapk tyrosyl phosphorylation level. Fluoride at the same micromolar doses did not increase cell proliferation, tyrosyl phosphorylation, or specific activity of any MAPK in human skin foreskin fibroblasts, which are fluoride-nonresponsive cells. Consistent with the interpretation that the effect of fluoride on the steady state tyrosyl phosphorylation level of p44mapk is a consequence of an inhibition of a phosphotyrosyl phosphatase (PTP), mitogenic doses of orthovanadate, a bone cell mitogen and a PTP inhibitor, also increased the steady state tyrosyl phosphorylation level of p44mapk, but not p42mapk, in a time-dependent sustained manner similar to that observed with fluoride. Together, these findings support the concept that inhibition of a PTP activity in bone cells could lead to an activation of MAPK activity.
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Affiliation(s)
- L W Wu
- Department of Medicine, Loma Linda University, California, USA
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46
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Sustained-Release Sodium Fluoride in the Management of Established Postmenopausal Osteoporosis. Am J Med Sci 1997. [DOI: 10.1016/s0002-9629(15)40038-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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47
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Pak CY, Sakhaee K, Rubin CD, Zerwekh JE. Sustained-release sodium fluoride in the management of established postmenopausal osteoporosis. Am J Med Sci 1997; 313:23-32. [PMID: 9001163 DOI: 10.1097/00000441-199701000-00005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- C Y Pak
- Center for Mineral Metabolism & Clinical Research, University of Texas Southwestern Medical Center, Dallas 75235-8885, USA
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48
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Abstract
Sodium fluoride (NaF) is known to stimulate osteoblastic bone formation, but little attention has been given to the possibility that NaF also affects bone resorption and the differentiation of osteoclastic progenitor cells. When human promyelocytic HL-60 cells were treated with NaF (0.5 mM, 0-4 days), cell proliferation was inhibited, and the addition of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) (10nM, 0-4 days) augmented this antiproliferative effect. NaF increased cellular reduction of nitroblue tetrazolium (NBT), and this effect was strongly augmented by 1,25(OH)2D3. In addition, NaF produced marked changes in cellular morphology, increased cellular adhesion to plastic, reduced the nuclear/cytoplasmic ratio, and increased cellular expression of chloroacetate esterase, but failed to alter cellular nonspecific esterase activity. Furthermore, NaF increased expression of CD11b and CD66b, and this stimulation was enhanced by adding 1,25(OH)2D3. The sum of these changes in classical promyelocytic cellular indices suggest: (1) that NaF stimulates the early stages of HL-60 differentiation toward a granulocyte-like cell and (2) that 1,25(OH)2D3 promotes these actions of NaF. Additional experiments aimed at further understanding the NaF-induced conversion of HL-60 cells identified further changes. NaF also increased cellular production of prostaglandin E2 (PGE2) and nitric oxide (NO) and induced expression of inducible nitric oxide synthase (iNOS); 1,25(OH)2D3 once again augmented these NaF-induced effects. Similarly, NaF stimulated the production of interleukin 1 alpha (IL-1 alpha), IL-6, and tumor necrosis factor-alpha, and 1,25(OH)2D3 again strongly enhanced these effects. Indomethacin completely blocked stimulation of NBT reduction, NO production, and iNOS expression induced by NaF plus 1,25(OH)2D3; adding exogenous PGE2 (0.1-10 ng/ml) to these indomethacin-blocked cultures dose-dependently restored NO production. These additional findings together with the observed slow onset (24-48 h) of NaF and 1,25(OH)2D3 interaction strongly suggest that 1,25(OH)2D3 acts as a cofactor with NaF primarily through interaction with an endogenous NaF-induced cyclo-oxygenase product(s), quite possibly PGE2 itself. Such a mechanism for NaF and 1,25(OH)2D3 interaction would be strongly analogous to the interaction we have recently demonstrated between 1,25(OH)2D3 and PGE1 on the differentiation of HL-60 cells.
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Affiliation(s)
- T Kawase
- Department of Pharmacology, Niigata University School of Dentistry, Japan
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49
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Imai T, Burgener D, Zhen X, Benjour JP, Caverzasio J. Aluminum potentiates P(i) transport stimulation induced by fluoride in osteoblast-like cells. THE AMERICAN JOURNAL OF PHYSIOLOGY 1996; 271:E694-701. [PMID: 8897857 DOI: 10.1152/ajpendo.1996.271.4.e694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The effect of aluminum (AI) on inorganic phosphate (P(i)) transport stimulation induced by fluoride (F) was investigated in MC3T3-E1 osteoblast-like cells. Al potentiated the increase in P(i) transport activity induced by F in a dose- and time-dependent manner. Results obtained with deferoxamine mesylate, an Al chelator, suggest that a fluoroalumino complex is probably the active F molecule responsible for the change in P(i) transport observed in this study. The signaling pathway responsible for the stimulation of P(i) transport by F+Al likely involves a tyrosine phosphorylation process but neither a protein kinase C nor a mitogen-activated protein kinase pathway. As previously found in UMR-106 cells for F alone, F+Al potentiated the change in P(i) transport induced by fetal calf serum. A similar interaction was found between F+Al and thrombin acting through a G protein-coupled receptor. These observations are compatible with the hypothesis that F+Al could interact with G protein-coupled receptors associated with a signaling tyrosine phosphorylation process involved in the regulation of P(i), transport in osteoblast-like cells.
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Affiliation(s)
- T Imai
- Department of Medicine, University Hospital of Geneva, Switzerland
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50
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Caverzasio J, Imai T, Ammann P, Burgener D, Bonjour JP. Aluminum potentiates the effect of fluoride on tyrosine phosphorylation and osteoblast replication in vitro and bone mass in vivo. J Bone Miner Res 1996; 11:46-55. [PMID: 8770696 DOI: 10.1002/jbmr.5650110108] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Osteosclerosis in workers exposed to fluoride (F) and aluminum (Al) (industrial fluorosis) led to the use of F as a treatment to increase bone mass in osteoporosis patients. Because the influence of traces of Al on the effects of F on bone formation is heretofore unknown, we have investigated this issue both in vitro and in vivo. We have found that minute amounts of Al (< or = 10(-5) M) potentiate the effects of F in vitro such that osteoblast proliferation increased by 15 +/- 2.7% at 50 microM (p < 0.001) and by 117.6 +/- 5.1% at 750 microM (p < 0.001), concentrations of F with no mitogenic effect alone. F + Al time-dependently modulated a growth factor signaling pathway(s) associated with enhanced tyrosine phosphorylation (TyrP) of several proteins (p90 [2.9x], p77 [4.9x], p68 [9.6x], and mitogen activated protein kinases [3x]). TyrP was only slightly or not at all changed by F and Al alone, respectively. The effects of F + Al on TyrP and cell proliferation were markedly reduced by 100 microM tyrphostin-51, a tyrosine kinase inhibitor. Protein kinase A (PKA) and protein kinase C (PKC) pathways were not involved in this response. In vivo, F + Al administered for 8 months, at doses that had no effect when the minerals were administered individually, significantly enhanced proximal tibia bone mineral density (BMD) by 6.3 +/- 1% compared with initial values and by 2-fold compared with control ovariectomized rats (p < 0.0001). These effects are consistent with a crucial role of Al in osteosclerosis observed in industrial fluorosis. The results suggest that the combination of F + Al modulates a growth factor-dependent TyrP pathway enhancing mitogen-activated protein kinase and osteoblastic proliferation and bone mass.
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Affiliation(s)
- J Caverzasio
- Department of Medicine, University Hospital of Geneva, Switzerland
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