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Priante G, Musacchio E, Pagnin E, Calò LA, Baggio B. Specific effect of arachidonic acid on inducible nitric oxide synthase mRNA expression in human osteoblastic cells. Clin Sci (Lond) 2005; 109:177-82. [PMID: 15801909 DOI: 10.1042/cs20040369] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A specific modulatory effect of PUFAs (polyunsaturated fatty acids) on gene expression of some cytokines involved in bone remodelling has been reported previously. In particular, although a direct action of AA (arachidonic acid) on bone cytokine gene expression has been shown in human osteoblastic cells, OA (oleic acid) and EPA (eicosapentaenoic acid) were ineffective. Since the NO (nitric oxide) system has also been shown to have an important modulatory activity on osteoblasts, osteoclasts and bone metabolism, in the present study we have investigated the effects of PUFAs on iNOS (inducible NO synthase) gene expression in a human osteoblast-like cell line. AA induced a significant increase in iNOS mRNA expression, whereas EPA and OA had no stimulatory effects but instead caused a significant inhibition of AA-induced iNOS gene expression. Blocking of the COX (cyclo-oxygenase) pathway did not inhibit AA-induced iNOS expression. AA action was inhibited instead by the addition of calphostin C and genistein, inhibitors of PKC (protein kinase C) and tyrosine kinases respectively. Experiments performed with specific anti-cytokine antibodies showed a significant decrease in iNOS expression in AA-treated osteoblastic cells, suggesting that both cytokine-dependent and -independent mechanisms account for the effects of AA on iNOS gene expression. In conclusion, our investigation clearly shows specific effects of PUFAs on iNOS expression in human osteoblast-like cells with a cytokine-dependent and -independent mechanism. These results might have clinical relevance and are of interest for understanding the reported beneficial effects of dietary PUFA manipulation on the prevention and/or treatment of primary and secondary bone disease.
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Affiliation(s)
- Giovanna Priante
- Department of Medical and Surgical Sciences, University of Padua, Padova, Italy
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Chen RM, Chen TL, Chiu WT, Chang CC. Molecular mechanism of nitric oxide-induced osteoblast apoptosis. J Orthop Res 2005; 23:462-8. [PMID: 15734263 DOI: 10.1016/j.orthres.2004.08.011] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/05/2004] [Indexed: 02/04/2023]
Abstract
Nitric oxide (NO) can regulate osteoblast activities. Our previous study showed that NO induced osteoblast apoptosis. This study was further aimed to evaluate the mechanism of NO-induced osteoblast apoptosis from the viewpoints of mitochondrial functions, intracellular oxidative stress, and the anti-apoptotic Bcl-2 protein using neonatal rat calvarial osteoblasts as the experimental model. Exposure of osteoblasts to sodium nitroprusside (SNP), an NO donor, significantly increased amounts of lactate dehydrogenase in the culture medium, and decreased cell viability in concentration- and time-dependent manners. Administration of SNP in osteoblasts time-dependently led to DNA fragmentation. The mitochondrial membrane potential was significantly reduced following SNP administration. SNP decreased complex I NADH dehydrogenase activity in a time-dependent manner. Levels of cellular adenosine triphosphate (ATP) were suppressed by SNP. In parallel with the mitochondrial dysfunction, SNP time-dependently increased levels of intracellular reactive oxygen species. Immunoblotting analysis revealed that SNP reduced Bcl-2 protein levels. Exposure to lipopolysaccharide (LPS) and IFN-gamma significant increased endogenous nitrite production. In parallel with the increase in endogenous NO, administration of LPS and IFN-gamma suppressed cell viability, mitochondrial membrane potential, and ATP synthesis. Results of this study show that NO released from SNP can induce osteoblast insults and apoptosis, and the mechanism may involve the modulation of mitochondrial functions, intracellular reactive oxygen species, and Bcl-2 protein.
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Affiliation(s)
- Ruei-Ming Chen
- Department of Anesthesiology, Wan-Fang Hospital, College of Medicine, Taipei Medical University, No. 111, Hsing-Lung Rd., Sec. 3, Taipei 116, Taiwan.
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Jung JY, Pashia ME, Nishimoto SY, Faddis BT, Chole RA. A possible role for nitric oxide in osteoclastogenesis associated with cholesteatoma. Otol Neurotol 2004; 25:661-8. [PMID: 15353992 DOI: 10.1097/00129492-200409000-00003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
HYPOTHESIS This study was designed to investigate the potential role of nitric oxide in cholesteatoma-induced bone resorption, in vitro and in vivo. BACKGROUND Cholesteatoma is a disease of inflammatory bone resorption in the middle ear leading to hearing loss and vestibular dysfunction. Inappropriate activation of osteoclasts causes the morbidity associated with this disease. Previous studies suggest nitric oxide may be an important mediator of osteoclast function. METHODS A murine model of cholesteatoma induced bone resorption was used to demonstrate nitric oxide synthase (NOS) gene expression and the effect of a NOS inhibitor. An in vitro osteoclast culture method was used to demonstrate the effect of nitric oxide on isolated osteoclasts. Osteoclast development was assayed by counting the number of mature osteoclasts; activity was assayed by measuring the amount of resorbed bone. RESULTS Quantitative reverse transcriptase-polymerase chain reaction results demonstrated the temporal expression of all three NOS isoforms in vivo. NOS I demonstrated very low levels of expressions throughout the duration of the study with no change in expression in response to keratin implant. Similarly, NOS III also demonstrated low levels of expression and no change in response to keratin. NOS II was highly upregulated in response to keratin throughout the duration of the study. In vitro, pharmacological nitric oxide donors--sodium nitroprusside and S-nitroso-N-acetyl-D,L-penicillamine--dose-dependently stimulated osteoclast resorption. Alone, interferon gamma (IFNgamma)--but not IL-1beta or TNFalpha--generated nitrite in vitro. A cytokine cocktail of IL-1beta, TNFalpha, and IFNgamma synergistically enhanced nitrite production. Nitrite production was blocked by the addition of aminoguanidine (AG), suggesting that AG-inhibited cytokine mediated nitrite production. However, in an in vivo model of cholesteatoma-induced bone resorption, the osteoclast response of AG-treated mice was not statistically different from untreated controls. CONCLUSIONS All three NOS isoforms were expressed in an in vivo model of cholesteatoma-induced bone resorption with significant upregulation of NOS II throughout the study. Exogenously administered nitric oxide dose-dependently enhanced osteoclast activation in vitro. The pro-inflammatory cytokines, IL-1beta, TNFalpha, and IFNgamma, synergistically induce nitrite production, which was abrogated by treatment with the nitric oxide synthase inhibitor, AG. Although AG suppresses nitrite production in vitro, treatment had no effect on osteoclast response in vivo, suggesting that the effects of inflammatory cytokines on osteoclast response were mediated through other pathways.
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Affiliation(s)
- Jae Y Jung
- Department of Otolaryngology, Washington University, St. Louis, Missouri 63110, USA
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Heng BC, Cao T, Stanton LW, Robson P, Olsen B. Strategies for directing the differentiation of stem cells into the osteogenic lineage in vitro. J Bone Miner Res 2004; 19:1379-94. [PMID: 15312238 DOI: 10.1359/jbmr.040714] [Citation(s) in RCA: 132] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2004] [Revised: 03/02/2004] [Accepted: 05/18/2004] [Indexed: 01/29/2023]
Abstract
A major area in regenerative medicine is the application of stem cells in bone reconstruction and bone tissue engineering. This will require well-defined and efficient protocols for directing the differentiation of stem cells into the osteogenic lineage, followed by their selective purification and proliferation in vitro. The development of such protocols would reduce the likelihood of spontaneous differentiation of stem cells into divergent lineages on transplantation, as well as reduce the risk of teratoma formation in the case of embryonic stem cells. Additionally, such protocols could provide useful in vitro models for studying osteogenesis and bone development, and facilitate the genetic manipulation of stem cells for therapeutic applications. The development of pharmokinetic and cytotoxicity/genotoxicity screening tests for bone-related biomaterials and drugs could also use protocols developed for the osteogenic differentiation of stem cells. This review critically examines the various strategies that could be used to direct the differentiation of stem cells into the osteogenic lineage in vitro.
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Affiliation(s)
- Boon Chin Heng
- Faculty of Dentistry, National University of Singapore, 119074 Singapore
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55
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Lane NE, Williams EN, Hung YY, Hochberg MC, Cummings SR, Nevitt MC. Association of nitrate use with risk of new radiographic features of hip osteoarthritis in elderly white women: The study of osteoporotic fractures. ACTA ACUST UNITED AC 2003; 49:752-8. [PMID: 14673960 DOI: 10.1002/art.11461] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE To examine the association between nitrate medication use and the development of new radiographic findings of hip osteoarthritis (OA) in elderly women. METHODS Pelvic radiographs were obtained at baseline and a mean of 8.3 years later in 5,987 women, age > or =65 years at the baseline examination of the Study of Osteoporotic Fractures. Atlas-standardized individual radiographic features (IRFs) of OA were assessed and minimal joint space was measured on paired films. New radiographic findings of hip OA were defined as the development in hips free of these findings at baseline: 1) joint space narrowing (JSN), which consisted of either a MJS < or =1.5 mm or an IRF score indicating lateral JSN > or =2 or medial JSN > or =3; 2) an IRF score for osteophytes of > or =2 in any location; or 3) a summary grade of 2 or more (at least 2 IRFs present). Nitrate use was recorded by interview at years 6 and 8. Logistic and linear regression analyses were performed to determine the association of nitrate use with new radiographic findings of hip OA, adjusting for age, weight, height, bone mineral density, and estrogen. RESULTS Compared with no reported use of nitrates, we found significant associations between use of nitrates at 1 clinic visit and new JSN (odds ratio [OR] 1.94, 95% confidence interval [95% CI] 1.18-3.17, P = 0.009), new osteophyte formation (OR 1.70, 95% CI 1.03-2.88, P = 0.04), and any new radiographic finding of hip OA or total hip arthroplasty for OA (OR 1.71, 95% CI 1.16-2.52, P = 0.007). Any nitrate use was associated with an increased risk of developing summary grade 3 or greater hip OA (OR 1.84, 95% CI 1.03-3.31, P = 0.041), but not with any other incident findings of OA. CONCLUSION Older women using nitrates may have an increased risk of developing new radiographic findings of hip OA.
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Affiliation(s)
- Nancy E Lane
- Division of Rheumatology, Department of Medicine, Box 0868, University of California at San Francisco, San Francisco, CA 94143, USA.
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Meinel L, Zoidis E, Zapf J, Hassa P, Hottiger MO, Auer JA, Schneider R, Gander B, Luginbuehl V, Bettschart-Wolfisberger R, Illi OE, Merkle HP, von Rechenberg B. Localized insulin-like growth factor I delivery to enhance new bone formation. Bone 2003; 33:660-72. [PMID: 14555272 DOI: 10.1016/s8756-3282(03)00207-2] [Citation(s) in RCA: 121] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Insulin-like growth factor I (IGF I) exerts an important role during skeletal growth and bone formation. Therefore, its localized delivery appears attractive for the treatment of bone defects. To prolong IGF I delivery, we entrapped the protein into biodegradable poly(lactide-co-glycolide) microspheres (PLGA MS) and evaluated the potential of this delivery system for new bone formation in two defect models of ovine long bones, i.e., a 8-mm methaphyseal drill hole and a 10-mm segmental tibia defect. Administration of 100 microg of IGF I in PLGA MS resulted in new bone formation within 3 weeks in the drill hole and bridging of the segmental defect within 8 weeks. The observed increase of 12% newly formed bone in the drill hole defect after 3 weeks was substantial, compared to the measured morphometric bone-to-total area ratio of 31% bone in normal cancellous bone. Bone regeneration was further explored by measuring gene expression of typical markers for local mediators and growth factors by real-time polymerase chain reaction. Inflammation was reduced in presence of IGF I and this in vivo observation was corroborated in vitro by quantifying gene expression of inflammatory proteins and by assessing the activation of the NF-kappaB pathway, playing an important role in the regulation of inflammation. Administration of the IGF I delivery system downregulated inflammatory marker gene expression at the site of bone injury, induced new bone formation and reduced bone resorption, and resulted in bridging of 10-mm segmental tibial defects within 8 weeks.
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Affiliation(s)
- Lorenz Meinel
- Institute of Pharmaceutical Sciences, Drug Formulation and Delivery Group, ETH Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
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57
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Jung JY, Lin AC, Ramos LM, Faddis BT, Chole RA. Nitric oxide synthase I mediates osteoclast activity in vitro and in vivo. J Cell Biochem 2003; 89:613-21. [PMID: 12761894 DOI: 10.1002/jcb.10527] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Bone resorption is responsible for the morbidity associated with a number of inflammatory diseases such as rheumatoid arthritis, orthopedic implant osteolysis, periodontitis and aural cholesteatoma. Previous studies have established nitric oxide (NO) as a potentially important mediator of bone resorption. NO is a unique intercellular and intracellular signaling molecule involved in many physiologic and pathologic pathways. NO is generated from L-arginine by the enzyme nitric oxide synthase (NOS). There are three known isoforms of NOS with distinct cellular distributions. In this study, we have used mice with targeted deletions in each of these isoforms to establish a role for these enzymes in the regulation of bone resorption in vivo and in vitro. In a murine model of particle induced osteolysis, NOS I-/- mice demonstrated a significantly reduced osteoclast response. In vitro, osteoclasts derived from NOS I-/- mice were larger than wild type controls but demonstrated decreased resorption. Although NOS I has been demonstrated in osteoblasts and osteocytes as a mediator of adaptive bone remodeling, it has not previously been identified in osteoclasts. These results demonstrate a critical role for NOS I in inflammatory bone resorption and osteoclast function in vitro.
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Affiliation(s)
- Jae Y Jung
- Department of Otolaryngology, Washington University, St Louis, Missouri 63110, USA
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58
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Reher P, Harris M, Whiteman M, Hai HK, Meghji S. Ultrasound stimulates nitric oxide and prostaglandin E2 production by human osteoblasts. Bone 2002; 31:236-41. [PMID: 12110440 DOI: 10.1016/s8756-3282(02)00789-5] [Citation(s) in RCA: 141] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We have previously shown that the therapeutic range of ultrasound heals osteoradionecrotic bone and induces bone formation in vitro. It is well established that nitric oxide (NO) and prostaglandins are crucial early mediators in mechanically induced bone formation. The therapeutic range of ultrasound may act in the same way; therefore, we have investigated the effect of the therapeutic range of ultrasound on NO induction and prostaglandin E(2) (PGE(2)) production in vitro. Two ultrasound machines were evaluated, "traditional" (1 MHz, pulsed 1:4, tested at four intensities) and a "long-wave" (45 kHz, continuous, also tested at four intensities) devices. Ultrasound was applied to human mandibular osteoblasts for 5 min, and incubated at 37 degrees C for up to 24 h. The control group (sham insonated) was treated in the same way. NO was determined by measuring the nitrite concentration in the culture media colorimetrically, and PGE(2) was assayed by radioimmunoassay. Ultrasound produced a significant increase in both induced nitrite and PGE(2) production. The NO synthesis appeared to be via inducible NO synthase (iNOS) on the basis of the time course and levels of nitrite obtained, although the inhibition of other NOS isoforms by aminoguanidine cannot be excluded. PGE(2) synthesis appeared to be via COX-2. With the 45 kHz machine, a significant increase in NO was achieved at three intensities, 5, 30, and 50 mW/cm(2). The 1 MHz machine stimulated the synthesis of both NO and PGE(2), but was significant at only one dose (0.1 W/cm(2(SAPA))). There was no difference between the two machines with regard to PGE(2) synthesis. The time-course experiment revealed peak production to be 12-18 h for both NO and PGE(2). The therapeutic range of ultrasound stimulates both NO and PGE(2) synthesis by human osteoblasts, and the 45 kHz machine appeared to be more effective than the traditional short-wave length. These results may reflect the healing effect of ultrasound on fractures and osteoradionecrosis.
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Affiliation(s)
- P Reher
- Department of Oral and Maxillofacial Surgery, Eastman Dental Institute, London, UK
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59
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Chen RM, Liu HC, Lin YL, Jean WC, Chen JS, Wang JH. Nitric oxide induces osteoblast apoptosis through the de novo synthesis of Bax protein. J Orthop Res 2002; 20:295-302. [PMID: 11918309 DOI: 10.1016/s0736-0266(01)00086-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Nitric oxide (NO) plays a crucial role in the physiological and pathophysiological regulations of osteoblast functions. This study is designed to evaluate the toxic effects of NO released by sodium nitroprusside (SNP), an NO donor, on neonatal Wistar rat calvarial osteoblasts from the analyses of cell viability, alkaline phosphatase (ALP) activity, cell morphology, apoptotic cells, terminal deoxynucleotidyl transferase-mediated dUTP nick end-label (TUNEL) assay, DNA ladder, and immunocytochemistry and Western blot for proapoptotic Bax protein. SNP increased the levels of nitrite, an oxidative product of NO, in the culture medium of osteoblasts in concentration- and time-dependent manners, and altered cell morphologies to round and shrinkage shapes. Administration of osteoblasts with SNP resulted in concentration- and time-dependent decreases of cell viability and ALP activity. Analysis of apoptotic cells revealed that SNP increased the percentages of osteoblasts processing apoptosis. Analyses of TUNEL and DNA ladder showed that SNP caused DNA fragmentation. Pretreatment with cycloheximide, an inhibitor of protein synthesis, partially blocked SNP-induced osteoblast apoptosis. Imunocytochemical and immunoblotting analyses revealed that SNP increased Bax protein in osteoblasts. This study suggests that SNP could increase the levels of NO in osteoblasts, and cause osteoblast apoptosis possibly through the de novo synthesis of proapoptotic Bax protein.
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Affiliation(s)
- Ruei-Ming Chen
- Department of Anesthesiology, Taipei Medical College, Wan-Fang Hospital, Taiwan, ROC
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60
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Brogan JM, Jin K, Eiki K, Tuncay KOC. Localization of nitric oxide synthase in the periodontal tissues of orthodontically moved and stationary teeth. Prog Orthod 2002. [DOI: 10.1034/j.1600-9975.2002.00023.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Abstract
Mechanisms controlling the transition of a neural precursor cell from proliferation to differentiation during brain development determine the distinct anatomical features of the brain. Nitric oxide (NO) may mediate such a transition, because it can suppress DNA synthesis and cell proliferation. We cloned the gene encoding the neuronal isoform of Xenopus NO synthase (XNOS) and found that in the developing brain of Xenopus tadpoles, a zone of XNOS-expressing cells lies adjacent to the zone of dividing neuronal precursors. Exogenous NO, supplied to the tadpole brain in vivo, decreased the number of proliferating cells and the total number of cells in the optic tectum. Conversely, inhibition of NOS activity in vivo increased the number of proliferating cells and the total number of cells in the optic tectum. NOS inhibition yielded larger brains with grossly perturbed organization. Our results indicate that NO is an essential negative regulator of neuronal precursor proliferation during vertebrate brain development.
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62
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Varanasi SS, Datta HK. Southern analysis of mitochondrial DNA in cortical bone of elderly patients undergoing knee and hip arthroplasty. J Pathol 2001; 193:557-62. [PMID: 11276017 DOI: 10.1002/path.823] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The role of mitochondrial DNA deletions (dmtDNA) in involutional bone loss seen in elderly men and women has never been examined. The present investigation was carried out to determine the extent of dmtDNA in cortical bone of elderly patients undergoing knee and hip arthroplasties. The majority of earlier studies have employed the polymerase chain reaction (PCR) to detect and quantify dmtDNA in different body tissues. In the present study, Southern blotting was used to screen bone biopsies from 30 patients undergoing orthopaedic surgery (mean age+/-SD 67.5+/-9.6 years; range 49-87 years). The blotting of PvuII-digested genomic DNA, carried out using mtDNA probes covering the entire span of mtDNA, revealed high levels of deletions in six subjects (mean age+/-SD 63.0+/-10.1 years; range 49-78 years) and moderate to low levels of mutations in another 14 subjects (mean age+/-SD 64.9+/-8.9 years; range 53-87 years). The importance of this rather high prevalence of dmtDNA in the bone of the elderly is discussed in terms of possible involvement of increased production of oxygen-derived free radicals and oxidative stress, and its possible role in the accelerated bone loss leading to osteoporosis.
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Affiliation(s)
- S S Varanasi
- School of Clinical and Laboratory Sciences, Department of Clinical Biochemistry, The Medical School, University of Newcastle upon Tyne, Newcastle upon Tyne, NE2 4HH, UK
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63
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Abstract
OBJECTIVE To review current knowledge of the pathophysiology of otosclerosis and to review hypotheses for the amelioration of this disease. DATA SOURCES Review of the literature and experimental observations by the authors. CONCLUSIONS Otosclerosis is a localized disease of bone remodeling within the otic capsule of the human temporal bone. Unlike other similar bone diseases, it does not occur outside of the temporal bone. These lesions seem to begin by resorption of stable otic capsule bone in adults, followed by a reparative phase with bone deposition. There are clearly genetic factors that lead to this disease, but measles virus infection and autoimmunity also may play contributing roles. Surgical correction of the conductive hearing loss is highly effective, but nonsurgical intervention has not yet been shown to prevent or slow the disease. Of the factors that may inhibit this process, fluorides, cytokine inhibitors, and bisphosphonates, third-generation bisphosphonates appear to hold the most promise.
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Affiliation(s)
- R A Chole
- Department of Otolaryngology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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64
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Aguirre J, Buttery L, O'Shaughnessy M, Afzal F, Fernandez de Marticorena I, Hukkanen M, Huang P, MacIntyre I, Polak J. Endothelial nitric oxide synthase gene-deficient mice demonstrate marked retardation in postnatal bone formation, reduced bone volume, and defects in osteoblast maturation and activity. THE AMERICAN JOURNAL OF PATHOLOGY 2001; 158:247-57. [PMID: 11141498 PMCID: PMC1850250 DOI: 10.1016/s0002-9440(10)63963-6] [Citation(s) in RCA: 187] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/19/2000] [Indexed: 12/30/2022]
Abstract
Nitric oxide (NO) has been implicated in the local regulation of bone metabolism. However, the contribution made by specific NO synthase (NOS) enzymes is unclear. Here we show that endothelial NOS gene knockout mice (eNOS-/-) have marked abnormalities in bone formation. Histomorphometric analysis of eNOS-/- femurs showed bone volume and bone formation rate was reduced by up to 45% (P: < 0.01) and 52% (P: < 0.01), respectively. These abnormalities were prevalent in young (6 to 9 weeks old) adults but by 12 to 18 weeks bone phenotype was restored toward wild-type. Dual energy X-ray absorptiometry analysis confirmed the age-related bone abnormalities revealing significant reductions in femoral (P: < 0.05) and spinal bone mineral densities (P: < 0.01) at 8 weeks that were normalized at 12 weeks. Reduction in bone formation and volume was not related to increased osteoclast numbers or activity but rather to dysfunctional osteoblasts. Osteoblast numbers and mineralizing activity were reduced in eNOS-/- mice. In vitro, osteoblasts from calvarial explants showed retarded proliferation and differentiation (alkaline phosphatase activity and mineral deposition) that could be restored by exogenous administration of a NO donor. These cells were also unresponsive to 17ss-estradiol and had an attenuated chemotactic response to transforming growth factor-beta. In conclusion, eNOS is involved in the postnatal regulation of bone mass and lack of eNOS gene results in reduced bone formation and volume and this is related to impaired osteoblast function.
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Affiliation(s)
- J Aguirre
- Department of Histochemistry, Imperial College School of Medicine, Hammersmith Campus, London, United Kingdom
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Wimalawansa SJ. Nitroglycerin therapy is as efficacious as standard estrogen replacement therapy (Premarin) in prevention of oophorectomy-induced bone loss: a human pilot clinical study. J Bone Miner Res 2000; 15:2240-4. [PMID: 11092405 DOI: 10.1359/jbmr.2000.15.11.2240] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Nitric oxide (NO) is known to affect bone metabolism. Previous animal studies have shown that NO donor therapy can prevent ovariectomy (OVX)-induced as well as corticosteroid-induced bone loss. Therefore, we have carried out a 1-year human, randomized, controlled pilot clinical study to assess the efficacy of nitroglycerin (NG) in the prevention of estrogen-deficiency-induced bone loss in women. We observed that NG ointment, when applied to the skin once a day (within 4 weeks of undergoing oophorectomy), mimicked estrogen replacement therapy in prevention of bone loss. The primary outcome of bone mineral density (BMD) was not different in the two groups at the end of 1 year. Urinary N-telopeptide levels were significantly decreased after administration of either estrogen or NG. Although estrogen decreased serum osteocalcin and bone-specific alkaline phosphatase levels, NG therapy significantly increased these two markers of bone formation. Further, it was revealed that for up to 1 year, these doses of NG did not result in tachyphylaxis. This study showed for the first time that NG is as effective as estrogen in preventing bone loss in these surgically induced menopausal women. Additionally, the dose of NG used in this study was three to four times less than that generally used to affect cardiovascular homeostasis. Although in this randomized clinical study only a small number of patients was examined, data are encouraging. If these data hold true in large randomized, controlled clinical trials, then NG could emerge as an efficacious, cost-effective, affordable, safe, and convenient form of therapy (especially as an alternative therapy to hormone-replacement therapy [HRT]) for prevention of postmenopausal bone loss.
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Affiliation(s)
- S J Wimalawansa
- Department of Internal Medicine, University of Texas Medical Branch at Galveston 77555-1065, USA
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Zunic G, Pavlović R, Malicević Z, Savić V, Cernak I. Pulmonary blast injury increases nitric oxide production, disturbs arginine metabolism, and alters the plasma free amino acid pool in rabbits during the early posttraumatic period. Nitric Oxide 2000; 4:123-8. [PMID: 10835292 DOI: 10.1006/niox.2000.0276] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Plasma nitrate + nitrite (nitrates), as final NO products, and free amino acid pool (FAAP) characteristics, as indicators of protein/amino acid metabolism, were analyzed in the early (30 min) period following blast injury. The experiments were performed on 27 rabbits subjected to pulmonary blast injury (experimental group) or not exposed to overpressure (controls). We report that pulmonary blast injury (PBI) induces prompt NO overproduction within a very early period. Increased arginine utilization via NO synthase, presumably associated with its cleavage by arginase, leads to the depletion of the arginine level in arterial plasma 30 min following PBI. Impaired balance between arginine utilization and release/resynthesis from endogenous sources causes disturbed nutritional status and urea cycle activity. Early identification and appropriate management of the changes in amino acid metabolism should be included in the evaluation of patients with blast injury. Furthermore, the results suggest that depleted arterial levels of arginine and NO overproduction may be helpful in diagnosis and prognosis of blast injury.
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Affiliation(s)
- G Zunic
- Institute for Medical Research, Military Medical Academy, Belgrade, Yugoslavia
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67
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Collin-Osdoby P, Rothe L, Bekker S, Anderson F, Osdoby P. Decreased nitric oxide levels stimulate osteoclastogenesis and bone resorption both in vitro and in vivo on the chick chorioallantoic membrane in association with neoangiogenesis. J Bone Miner Res 2000; 15:474-88. [PMID: 10750562 DOI: 10.1359/jbmr.2000.15.3.474] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
High nitric oxide (NO) levels inhibit osteoclast (OC)-mediated bone resorption in vivo and in vitro, and nitrate donors protect against estrogen-deficient bone loss in postmenopausal women. Conversely, decreased NO production potentiates OC bone resorption in vitro and is associated with in vivo bone loss in rats and humans. Previously, we reported that bone sections from rats administered aminoguanidine (AG), a selective inhibitor of NO production via inducible NO synthase, exhibited both increased OC resorptive activity as well as greater numbers of OC. Here, we investigated further whether AG promoted osteoclastogenesis, in addition to stimulating mature OC function, using a modified in vivo chick chorioallantoic membrane (CAM) system and an in vitro chick bone marrow OC-like cell developmental model. AG, focally administered in small agarose plugs placed directly adjacent to a bone chip implanted on the CAM, dose-dependently elicited neoangiogenesis while stimulating the number, size, and bone pit resorptive activity of individual OC ectopically formed in vivo. In addition to enhancing OC precursor recruitment via neoangiogenesis, AG also exerted other vascular-independent effects on osteoclastogenesis. Thus, AG promoted the in vitro fusion and formation from bone marrow precursor cells of larger OC-like cells that contained more nuclei per cell and exhibited multiple OC differentiation markers. AG stimulated development was inversely correlated with declining medium nitrite levels. In contrast, three different NO donors each dose-dependently inhibited in vitro OC-like cell development while raising medium nitrite levels. Therefore, NO sensitively regulates OC-mediated bone resorption through affecting OC recruitment (angiogenesis), formation (fusion and differentiation), and bone resorptive activity in vitro and in vivo. Possibly, the stimulation of neoangiogenesis and OC-mediated bone remodeling via AG or other pro-angiogenic agents may find clinical applications in reconstructive surgery, fracture repair, or the treatment of avascular necrosis.
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Affiliation(s)
- P Collin-Osdoby
- Department of Biology, Washington University, St. Louis, Missouri 63130, USA
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68
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Calò L, Giannini S, Bonvicini P, Nobile M, Cantaro S, Plebani M, Semplicini A, D'Angelo A, Crepaldi G. Idiopathic hypercalciuria: O2(-)NO relationship and altered bone metabolism. J Endocrinol Invest 2000; 23:78-83. [PMID: 10800759 DOI: 10.1007/bf03343683] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The pathogenesis of idiopathic hypercalciuria (IH) has not been elucidated yet, but a correlation between IH and altered bone metabolism has been proposed. Since nitric oxide (NO) regulates osteoclasts' bone resorption, a possible role for NO can be suggested. In this study we evaluated iNOS gene expression by reverse transcription of mRNA from monocytes, followed by polymerase chain reaction in patients with IH subdivided into fasting (FH) and absorptive (AH) hypercalciuria. Since superoxide (O2-), which metabolizes NO, is overproduced by osteoclasts during bone resorption, peroxynitrite plasma level was evaluated as index of O2-. Vertebral BMD in IH as a whole group was lower vs controls (C) (Z score=-1.78+/-0.2 vs 0.51+/-0.25, p<0.001), but only FH patients showed a reduced bone density (2.13+/-0.18 vs 0.51+/-0.25, p<0.0001). PTH and calcitriol were not different. FH showed an increase in b-ALP vs AH and C (41.1+/-2.6 vs 30.1+/-3.9 vs 26.6+/-3.6 U/l p<0.02), and higher uHP, either on NCD (17.7+/-1.6 vs 11.4+/-1.3 mg/g uCr, p<0.04) or after LCD (26.7+/-2.5 vs 16.7+/-1.9, p<0.01). Cells from FH patients, but not from both AH patients and C, expressed iNOS. Peroxynitrite plasma level was elevated in FH (0.30+/-0.07) pmol/l while not detectable in AH and C. This study confirms an altered bone metabolism only in FH which shows an abnormal NO system. The increased iNOS gene expression in FH, in fact, points toward an altered NO system's activity downstream the generation of NO. A possible interaction of NO with O2-, which breaks down NO, and the role of this interaction in the pathophysiology of IH is discussed.
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Affiliation(s)
- L Calò
- Dipartimento di Scienze Mediche e Chirurgiche, Università di Padova ed Azienda Ospedaliera di Padova, Italy.
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69
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Laketić-Ljubojević I, Suva LJ, Maathuis FJ, Sanders D, Skerry TM. Functional characterization of N-methyl-D-aspartic acid-gated channels in bone cells. Bone 1999; 25:631-7. [PMID: 10593407 DOI: 10.1016/s8756-3282(99)00224-0] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Our recent identification of glutamate receptors in bone cells suggested a novel means of paracrine communication in the skeleton. To determine whether these receptors are functional, we investigated the effects of the excitatory amino acid, glutamate, and the pharmacological ligand, N-methyl-D-aspartic acid (NMDA), on glutamate-like receptors in the human osteoblastic cell lines MG63 and SaOS-2. Glutamate binds to osteoblasts, with a Kd of approximately 10(-4) mol/L and the NMDA receptor antagonist, D(L)-2-amino-5-phosphonovaleric acid (D-APV), inhibits binding. Using the patch-clamp technique, we measured whole-cell currents before and after addition of L-glutamate or NMDA and investigated the effects of the NMDA channel blockers, dizolcipine maleate (MK801), and Mg2+, and the competitive NMDA receptor antagonist, 3-((R)-2-carboxypiperazin-4-yl)-propyl-1-phosphoric acid (R-CPP), on agonist-induced currents. Both glutamate and NMDA induced significant increases in membrane currents. Application of Mg2+ (200 micromol/L) and MK801 (100 micromol/L) caused a significant decrease in inward currents elicited in response to agonist stimulation. The competitive NMDA receptor antagonist, R-CPP (100 micromol/L), also partially blocked the NMDA-induced currents in MG63 cells. This effect was reversed by addition of further NMDA (100 micromol/L). In Fura-2-loaded osteoblasts, glutamate induced elevation of intracellular free calcium, which was blocked by MK801. These results support the hypothesis that glutamate plays a role in bone cell signaling and suggest a possible role for glutamate agonists/antagonists in the treatment of bone diseases.
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70
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Hara F, Fukuda K, Ueno M, Hamanishi C, Tanaka S. Pertussis toxin-sensitive G proteins as mediators of stretch-induced decrease in nitric-oxide release of osteoblast-like cells. J Orthop Res 1999; 17:593-7. [PMID: 10459768 DOI: 10.1002/jor.1100170420] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Mechanical loading plays an important role in regulating bone remodeling, and nitric oxide may be one regulator of this process. To determine how mechanical stress modulates osteoblast function, we loaded cyclic tensile stretch on osteoblast-like cells and measured levels of nitric oxide in the medium. High frequency of stretch at any magnitude inhibited release of nitric oxide; however, low frequency of stretch enhanced its release from the static control. To examine the involvement of G protein (guanine nucleotide-binding regulatory protein) in stress-inhibited release of nitric oxide, we added pertussis toxin, a specific inhibitor of the Gi class, and found that it completely reversed the stress-inhibited release. These data support the idea that pertussis toxin-sensitive G protein is activated in the presence of cyclic tensile stretch.
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Affiliation(s)
- F Hara
- Department of Orthopaedic Surgery, Kinki University School of Medicine, Osaka-sayama, Osaka, Japan
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71
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Hukkanen MV, Platts LA, Fernandez De Marticorena I, O'Shaughnessy M, MacIntyre I, Polak JM. Developmental regulation of nitric oxide synthase expression in rat skeletal bone. J Bone Miner Res 1999; 14:868-77. [PMID: 10352094 DOI: 10.1359/jbmr.1999.14.6.868] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Nitric oxide (NO) has been implicated in bone growth and remodeling by studies showing that inhibition of NO-synthase (NOS) activity retards normal gain in bone mineral density both during skeletal development and after sexual maturity. In the present study, we aimed to assess the level of expression and cellular localization of the three NOS isoforms during skeletal bone development from neonatal to sexual maturity in female Wistar rats. Reverse transcription polymerase chain reaction (RT-PCR) was used to analyze the presence of NOS1 (neuronal), NOS2 (inducible), and NOS3 (endothelial) transcripts in femoral bone from neonatal, 4-, 8-, and 12-week-old rats. RT-PCR amplified NOS1, NOS2, and NOS3 transcripts of 472-, 807-, and 289-bp, respectively. There were no detectable differences in the levels of NOS1 mRNA between the groups; however, NOS2 mRNA was more abundant in the neonatal group compared with 4-, 8-, and 12-week groups. Expression of NOS1 protein could not be detected in bones by either Western blotting or immunocytochemistry in any of the age groups investigated. Western blots for NOS2 revealed expression in the neonatal group only and it was not detected in any of the older age groups. Immunostaining for NOS2 was also most evident in the neonatal group and was localized specifically to trabecular osteoblasts and osteoclasts. In all age groups studied, NOS3 mRNA and protein were found in bone-resorbing osteoclasts, cuboidal active osteoblasts, and osteocytes. Semiquantitative RT-PCR provided evidence of down-regulation of NOS3 transcripts during the skeletal development. This was confirmed using in situ hybridization, which showed higher expression in neonatal and 4-week groups than in other groups. Western blots and counting the ratio of trabecular osteoblasts that were NOS3 immunoreactive showed parallel down-regulation of NOS3 protein during skeletal development. Taken together, these data show that there is regulation of NOS2 and in particular NOS3 expression during skeletal development and this may be significant to trabecular bone growth and remodeling.
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Affiliation(s)
- M V Hukkanen
- Department of Histochemistry, Imperial College School of Medicine, Hammersmith Campus, London, United Kingdom
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72
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McAllister TN, Frangos JA. Steady and transient fluid shear stress stimulate NO release in osteoblasts through distinct biochemical pathways. J Bone Miner Res 1999; 14:930-6. [PMID: 10352101 DOI: 10.1359/jbmr.1999.14.6.930] [Citation(s) in RCA: 135] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Fluid flow has been shown to be a potent stimulus in osteoblasts and osteocytes and may therefore play an important role in load-induced bone remodeling. The objective of this study was to investigate the characteristics of flow-activated pathways. Previously we reported that fluid flow stimulates rapid and continuous release of nitric oxide (NO) in primary rat calvarial osteoblasts. Here we demonstrate that flow-induced NO release is mediated by shear stress and that this response is distinctly biphasic. Transients in shear stress associated with the onset of flow stimulated a burst in NO production (8.2 nmol/mg of protein/h), while steady flow stimulated sustained NO production (2.2 nmol/mg of protein/h). Both G-protein inhibition and calcium chelation abolished the burst phase but had no effect on sustained production. Activation of G-proteins stimulated dose-dependent NO release in static cultures of both calvarial osteoblasts and UMR-106 osteoblast-like cells. Pertussis toxin had no effect on NO release. Calcium ionophore stimulated low levels of NO production within 15 minutes but had no effect on sustained production. Taken together, these data suggest that fluid shear stress stimulates NO release by two distinct pathways: a G-protein and calcium-dependent phase sensitive to flow transients, and a G-protein and calcium-independent pathway stimulated by sustained flow.
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Affiliation(s)
- T N McAllister
- Department of Bioengineering, University of California-San Diego, La Jolla, California 92093, USA
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73
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Jamal SA, Browner WS, Bauer DC, Cummings SR. Intermittent use of nitrates increases bone mineral density: the study of osteoporotic fractures. J Bone Miner Res 1998; 13:1755-9. [PMID: 9797485 DOI: 10.1359/jbmr.1998.13.11.1755] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Nitric oxide slows bone remodeling and bone loss in animals. Because nitroglycerin and other nitrates increase nitric oxide levels, we hypothesized that nitrate use may be associated with greater bone mineral density (BMD) and decreased risk of fracture in humans. Further, intermittent nitrate use may be associated with greater benefits than daily nitrate use, which results in tachyphylaxis. We tested this hypothesis using data from the Study of Osteoporotic Fractures. We prospectively studied 6201 elderly women of whom 317 took nitrates on a daily basis and 74 used them intermittently. We measured BMD at the hip and the heel and adjusted all comparisons for multiple potential confounders. We found that women taking daily nitrates had slightly greater hip BMD (difference, 13%; 95% confidence interval [CI], 0.14-4.1%) but the same heel BMD (difference, 0%; 95% CI -2.6-2.6%) as nonusers. By contrast, women using nitrates intermittently had substantially greater hip (difference, 2.6%; 95% CI, 0.4-6.8%) and heel BMD (difference, 53%; 95% CI, 2.6-11%) than nonusers. This study suggests that the intermittent administration of nitrates may enhance BMD.
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Affiliation(s)
- S A Jamal
- The Department of Epidemiology and Biostatistics, University of California, San Francisco, USA
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74
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Cipolletta C, Jouzeau JY, Gegout-Pottie P, Presle N, Bordji K, Netter P, Terlain B. Modulation of IL-1-induced cartilage injury by NO synthase inhibitors: a comparative study with rat chondrocytes and cartilage entities. Br J Pharmacol 1998; 124:1719-27. [PMID: 9756389 PMCID: PMC1565565 DOI: 10.1038/sj.bjp.0702005] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Nitric oxide (NO) is produced in diseased joints and may be a key mediator of IL-1 effects on cartilage. Therefore, we compared the potency of new [aminoguanidine (AG), S-methylisothiourea (SMT), S-aminoethylisothiourea (AETU)] and classical [Nomega-monomethyl-L-arginine (L-NMMA), Nomega-nitro-L-arginine methyl ester (L-NAME)] NO synthase (NOS) inhibitors on the inhibitory effect of recombinant human interleukin-1beta (rhIL-1beta) on rat cartilage anabolism. Three different culture systems were used: (1) isolated chondrocytes encapsulated in alginate beads; (2) patellae and (3) femoral head caps. Chondrocyte beads and cartilage entities were incubated in vitro for 48 h in the presence of rhIL-1beta with a daily change of incubation medium to obtain optimal responses on proteoglycan synthesis and NO production. Proteoglycan synthesis was assessed by incorporation of radiolabelled sodium sulphate [Na2(35)SO4] and NO production by cumulated nitrite release during the period of study. Chondrocytes and patellae, as well as femoral head caps, responded concentration-dependently to IL-1beta challenge (0 to 250 U ml(-1) and 0 to 15 U ml(-1) respectively) by a large increase in nitrite level and a marked suppression of proteoglycan synthesis. Above these concentrations of IL-1beta (2500 U ml(-1) and 30 U ml(-1) respectively), proteoglycan synthesis plateaued whereas nitrite release still increased thus suggesting different concentration-response curves. When studying the effect of NOS inhibitors (1 to 1000 microM) on NO production by cartilage cells stimulated with IL-1beta (25 U ml(-1) or 5 U ml(-1)), we observed that: (i) their ability to reduce nitrite level decreased from chondrocytes to cartilage samples, except for L-NMMA and AETU; (ii) they could be roughly classified in the following rank order of potency: AETU > L-NMMA > or = SMT > or = AG > or = L-NAME and (iii) AETU was cytotoxic when used in the millimolar range. When studying the effect of NOS inhibitors on proteoglycan synthesis by cartilage cells treated with IL-1beta, we observed that: (i) they had more marked effects on proteoglycan synthesis in chondrocytes than in cartilage samples; (ii) they could be roughly classified in the following rank order of potency: L-NAME > or = L-NMMA > > AG > SMT > > AETU and (iii) potentiation of the IL-1 effect by AETU was consistent with cytotoxicity in the millimolar range. D-isomers of L-arginine analog inhibitors (1000 microM) were unable to correct nitrite levels or proteoglycan synthesis in IL-1beta treated cells. L-arginine (5000 microM) tended to reverse the correcting effect of L-NMMA (1000 microM) on proteoglycan synthesis, thus suggesting a NO-related chondroprotective effect. However, data with L-NAME and SMT argued against a general inverse relationship between nitrite level and proteoglycan synthesis. Dexamethasone (0.1 to 100 microM) (i) failed to inhibit NO production in femoral head caps and chondrocytes beads whilst reducing it in patellae (50%) and (ii) did not affect or worsened the inhibitory effect of IL-1beta on proteoglycan synthesis. Such results suggested a corticosteroid-resistance of rat chondrocyte iNOS. Data from patellae supported a possible contribution of subchondral bone in NO production. In conclusion, our results suggest that (i) NO may account only partially for the suppressive effects of IL-1beta on proteoglycan synthesis, particularly in cartilage samples; (ii) the chondroprotective potency of NOS inhibitors can not be extrapolated from their effects on NO production by joint-derived cells and (iii) L-arginine analog inhibitors are more promising than S-substituted isothioureas for putative therapeutical uses.
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Affiliation(s)
- C Cipolletta
- Laboratoire de Pharmacologie et UMR CNRS-UHP 7561, Physiopathologie et Pharmacologie Articulaires, Faculté de Médecine, Université Henri Poincaré-Nancy I, Vandoeuvre-lès-Nancy, France
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75
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Pearson ML, Goodman SB, Huie P, Sibley RK. Inducible nitric oxide synthase messenger RNA levels in hip periprosthetic tissue: a preliminary study. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 1998; 40:419-24. [PMID: 9570074 DOI: 10.1002/(sici)1097-4636(19980605)40:3<419::aid-jbm12>3.0.co;2-e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Nitric oxide (NO) is a ubiquitous molecule that has been associated with inflammation, arthritis, autoimmune disease, bone resorption, and other biological processes. Elucidating the role of NO at the bone-implant interface may further our understanding of the biological processes of osseointegration, loosening, and osteolysis. This study demonstrates the use of a molecular biological technique to investigate the possible role of NO in prosthetic loosening and periprosthetic bone resorption following total hip arthroplasty. Periprosthetic tissue from 12 patients undergoing revision hip arthroplasty was harvested and total ribonucleic acid (RNA) was extracted. In six of the 12 patients, multiple samples from different anatomic locations along the same interface were studied. To estimate the amount of NO present in the tissues in vivo, the level of inducible NO synthase (iNOS) messenger RNA (mRNA) was determined using a ribonuclease (RNase) protection assay. Inducible NOS mRNA was detected in every tissue sample: there was no correlation between iNOS mRNA levels and clinical loosening or osteolysis. Analysis of multiple tissue samples from the same prosthetic component revealed that the levels of iNOS mRNA vary greatly, confirming the heterogeneous nature of the interface.
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Affiliation(s)
- M L Pearson
- Division of Orthopaedic Surgery, Stanford University Medical Center, California 94305, USA
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76
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Ellis G, Adatia I, Yazdanpanah M, Makela SK. Nitrite and nitrate analyses: a clinical biochemistry perspective. Clin Biochem 1998; 31:195-220. [PMID: 9646943 DOI: 10.1016/s0009-9120(98)00015-0] [Citation(s) in RCA: 176] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
OBJECTIVE To review the assays available for measurement of nitrite and nitrate ions in body fluids and their clinical applications. DESIGN AND METHODS Literature searches were done of Medline and Current Contents to November 1997. RESULTS The influence of dietary nitrite and nitrate on the concentrations of these ions in various body fluids is reviewed. An overview is presented of the metabolism of nitric oxide (which is converted to nitrite and nitrate). Methods for measurement of the ions are reviewed. Reference values are summarized and the changes reported in various clinical conditions. These include: infection, gastroenterological conditions, hypertension, renal and cardiac disease, inflammatory diseases, transplant rejection, diseases of the central nervous system, and others. Possible effects of environmental nitrite and nitrate on disease incidence are reviewed. CONCLUSIONS Most studies of changes in human disease have been descriptive. Diagnostic utility is limited because the concentrations in a significant proportion of affected individuals overlap with those in controls. Changes in concentration may also be caused by diet, outside the clinical investigational setting. The role of nitrite and nitrate assays (alongside direct measurements of nitric oxide in breath) may be restricted to the monitoring of disease progression, or response to therapy in individual patients or subgroups. Associations between disease incidence and drinking water nitrate content are controversial (except for methemoglobinemia in infants).
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Affiliation(s)
- G Ellis
- Department of Laboratory Medicine and Pathobiology, University of Toronto, ON, Canada
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77
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Mancini L, Moradi-Bidhendi N, Brandi ML, MacIntyre I. Nitric oxide superoxide and peroxynitrite modulate osteoclast activity. Biochem Biophys Res Commun 1998; 243:785-90. [PMID: 9501002 DOI: 10.1006/bbrc.1998.8175] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The gas radical, nitric oxide (NO), is a key signalling molecule in the cardiovascular, nervous and immune systems. Recently it has been found that it is produced by both the osteoblast and osteoclast and that it has major effects in producing osteoclast detachment and exerting a tonic inhibition of bone resorption. This detaching effect is mediated by a rapid increase in cGMP following calcium-triggered e-NOS activation during normal bone resorption. This effect is not reproduced in vitro by 8-bromo-cGMP but is seen with the newer rapidly permeant 8-pCPT-cGMP. However the inhibition of bone resorption by SIN-1 in vitro is not mediated solely by cGMP but depends on other factors still unidentified. Superoxide anions alone produces both osteoclast detachment and inhibition of resorption. Both of these actions may be mediated at least in part by peroxynitrite which has the same effect as NO alone on osteoclast detachment.
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Affiliation(s)
- L Mancini
- William Harvey Research Institute, St. Bartholomew's and the Royal London School of Medicine and Dendistry, United Kingdom
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78
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The Osteoclast Molecular Phenotype. ACTA ACUST UNITED AC 1998. [DOI: 10.1016/s1569-2590(08)60128-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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79
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Kanematsu M, Ikeda K, Yamada Y. Interaction between nitric oxide synthase and cyclooxygenase pathways in osteoblastic MC3T3-E1 cells. J Bone Miner Res 1997; 12:1789-96. [PMID: 9383683 DOI: 10.1359/jbmr.1997.12.11.1789] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Interleukin 1 (IL-1) and tumor necrosis factor alpha (TNF-alpha) have been implicated in the pathogenesis of osteoporosis. These proinflammatory cytokines induce both cyclooxygenase (COX) and nitric oxide synthase (NOS) with the release of prostaglandin (PG) and NO, respectively. The present study was undertaken to examine the interaction between COX and NOS pathways and their role in the regulation of osteoblastic function in MC3T3-E1 cells. Addition of IL-1 alpha and TNF-alpha induced a marked increase in the production of both NO and PGE2. Reverse transcription-polymerase chain reaction analysis showed that the increase in NO production was preceded by the expression of inducible NOS mRNA. The temporal profile of PGE2 production revealed a biphasic pattern: the first small peak at 3 h was caused by de novo synthesis of PGE2 through inducible COX (COX-2) mRNA, while the subsequent progressive accumulation of PGE2 was mediated through the activation of COX pathway by NO since (1) aminoguanidine (AG), a selective inhibitor of inducible NOS, significantly suppressed the PGE2 production by IL-1 alpha and TNF-alpha, (2) NOC-18, an NO donor, reversed this suppression, and (3) NOC-18 increased PGE2 production by itself. The increase in NO production in response to IL-1 alpha and TNF-alpha was further stimulated by aspirin and inhibited by exogenous addition of PGE2, suggesting that PGE2 produced by the cytokines, in turn, negatively modulates NO production. IL-1 alpha and TNF-alpha inhibited alkaline phosphatase (ALP) activity, which was significantly reversed by AG. NOC-18 not only suppressed ALP activity by itself but also blocked the effect of AG, suggesting the role of NO in the inhibition of ALP activity. PGE2 decreased ALP activity, and the inhibitory effect of NOC-18 was attenuated in the presence of aspirin, suggesting the involvement of PGE2 in the negative modulation of ALP activity by NO. These results suggest that NO produced in response to proinflammatory cytokines participates in the modulation of ALP activity via the activation of COX pathway. The interaction between NO and the COX pathways may play an important role in the regulation of osteoblastic functions under physiologic as well as pathologic conditions.
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Affiliation(s)
- M Kanematsu
- Department of Geriatric Research, National Institute for Longevity Sciences, Aichi, Japan
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80
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Sunyer T, Rothe L, Kirsch D, Jiang X, Anderson F, Osdoby P, Collin-Osdoby P. Ca2+ or phorbol ester but not inflammatory stimuli elevate inducible nitric oxide synthase messenger ribonucleic acid and nitric oxide (NO) release in avian osteoclasts: autocrine NO mediates Ca2+-inhibited bone resorption. Endocrinology 1997; 138:2148-62. [PMID: 9112415 DOI: 10.1210/endo.138.5.5144] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Osteoclast bone resorption is essential for normal calcium homeostasis and is therefore tightly controlled by calciotropic hormones and local modulatory cytokines and factors. Among these is nitric oxide (NO), a multifunctional free radical that potently inhibits osteoclast bone resorption in vitro and in vivo. Previous findings led us to propose that NO might serve as an autocrine, as well as paracrine, regulator of osteoclast function. This premise was investigated using isolated bone-resorptive avian osteoclasts and focusing on the inducible isoform of NO synthase (iNOS) responsible for inflammatory stimulated high-level NO synthesis in other cells. Avian osteoclasts expressed both iNOS messenger RNA (mRNA) and protein. However, inflammatory cytokines that induce iNOS mRNA, protein, and NO in other cells did not do so in avian osteoclasts, consistent with the known role of inflammatory stimuli in promoting osteoclast resorption and localized bone loss. In searching for potential modulators of osteoclast iNOS, protein kinase C activation [by phorbol 12-myristate 13-acetate (PMA)] and intracellular Ca2+ rises (A23187) were each found to elevate osteoclast iNOS mRNA and protein levels, while increasing NO release and reducing osteoclast bone resorption. The iNOS selective inhibitor aminoguanidine suppressed stimulated osteoclast NO production elicited by either signal, but reversed only the resorption inhibition due to raised Ca2+. Thus, whereas additional inhibitory signals are presumably coproduced in osteoclasts treated with PMA, osteoclast iNOS-derived NO may act as an autocrine signal to mediate Ca2+-inhibited bone resorption. These findings document for the first time an iNOS whose mRNA levels are regulated by Ca2+ or PMA, but not inflammatory stimuli, and the autocrine production of NO as a Ca2+ sensing signal to suppress osteoclast bone resorption. The unusual regulation of osteoclast iNOS makes it a potentially attractive target for designing novel therapeutic agents to alleviate excessive bone loss.
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Affiliation(s)
- T Sunyer
- Department of Biology, Washington University, St. Louis, Missouri 63130, USA
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81
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Kuzin B, Roberts I, Peunova N, Enikolopov G. Nitric oxide regulates cell proliferation during Drosophila development. Cell 1996; 87:639-49. [PMID: 8929533 DOI: 10.1016/s0092-8674(00)81384-7] [Citation(s) in RCA: 184] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Cell division and subsequent programmed cell death in imaginal discs of Drosophila larvae determine the final size of organs and structures of the adult fly. We show here that nitric oxide (NO) is involved in controlling the size of body structures during Drosophila development. We have found that NO synthase (NOS) is expressed at high levels in developing imaginal discs. Inhibition of NOS in larvae causes hypertrophy of organs and their segments in adult flies, whereas ectopic expression of NOS in larvae has the opposite effect. Blocking apoptosis in eye imaginal discs unmasks surplus cell proliferation and results in an increase in the number of ommatidia and component cells of individual ommatidia. These results argue that NO acts as an antiproliferative agent during Drosophila development, controlling the balance between cell proliferation and cell differentiation.
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Affiliation(s)
- B Kuzin
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
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82
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Rogers MJ, Chilton KM, Coxon FP, Lawry J, Smith MO, Suri S, Russell RG. Bisphosphonates induce apoptosis in mouse macrophage-like cells in vitro by a nitric oxide-independent mechanism. J Bone Miner Res 1996; 11:1482-91. [PMID: 8889848 DOI: 10.1002/jbmr.5650111015] [Citation(s) in RCA: 149] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Bisphosphonates (BPs) are an important class of antiresorptive drugs used in the treatment of bone diseases, including osteoporosis. Although their mechanism of action has not been identified at the molecular level, there is substantial evidence that BPs can have a direct effect on osteoclasts by mechanisms that may lead to osteoclast cell death by apoptosis. BPs can also inhibit proliferation and cause cell death in macrophages in vitro. We have now shown that the toxic effect of BPs on macrophages is also due to the induction of apoptotic, rather than necrotic, cell death. Morphological and biochemical features that are definitive of apoptosis (chromatin condensation, nuclear fragmentation, and endonuclease-mediated internucleosomal cleavage of DNA) could be identified in mouse macrophage-like J774 and RAW264 cells, following treatment with 100 microM pamidronate, alendronate, and ibandronate for 24 h or more. Clodronate was much less potent, even at 2000 microM, while 2000 microM etidronate did not cause apoptosis. Apoptosis was not due to increased synthesis of nitric oxide and could not be prevented by inhibitors of nitric oxide synthases. Since macrophages, like osteoclasts, are particularly susceptible to BPs, these observations support the recent suggestion that the mechanism by which BPs inhibit bone resorption may involve osteoclast apoptosis. Furthermore, the macrophage-like cell lines used in this study may be a convenient model with which to identify the molecular mechanisms by which BPs promote apoptosis in osteoclasts. Induction of macrophage apoptosis by BPs in vivo may also account, at least in part, for the anti-inflammatory properties of BPs as well as the ability of BPs to cause an acute phase response.
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Affiliation(s)
- M J Rogers
- Department of Human Metabolism and Clinical Biochemistry, University of Sheffield Medical School, United Kingdom
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83
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Fraser JH, Helfrich MH, Wallace HM, Ralston SH. Hydrogen peroxide, but not superoxide, stimulates bone resorption in mouse calvariae. Bone 1996; 19:223-6. [PMID: 8873962 DOI: 10.1016/8756-3282(96)00177-9] [Citation(s) in RCA: 101] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Reactive oxygen species such as superoxide and hydrogen peroxide have been implicated as regulatory factors in the control of osteoclastic bone resorption. While superoxide radicals have been suggested to be the main bone resorbing species in organ culture and in vivo, hydrogen peroxide (H2O2) has recently been shown to activate isolated osteoclasts in vitro. In this study, we investigated the effects of hydrogen peroxide and superoxide on bone resorption in mouse calvarial organ cultures. Hydrogen peroxide stimulated bone resorption in a concentration-dependent manner in calvarial organ cultures with a maximal effect at 1 mumol/L (45Ca release; treated/control = 1.6 +/- 0.07; p < 0.001 from control). Bone resorption induced by H2O2 was significantly inhibited by catalase to 1.2 +/- 0.05; p < 0.02. In contrast, the combination of xanthine and xanthine oxidase, which generates superoxide anions, failed to stimulate bone resorption, except in the presence of superoxide dismutase (SOD), which resulted in a modest increase in bone resorption to a treated/control ratio of 1.2 +/- 0.05; p < 0.02. Analysis of calvarial bones which were exposed to H2O2 showed a significant increase in osteoclast numbers suggesting that H2O2 may be capable of stimulating osteoclast formation in addition to enhancing activity of mature osteoclasts. Our data are consistent with previous work, which has shown that H2O2 is a bone resorbing factor with effects on both osteoclast formation and in activity of mature osteoclasts. The experiments with SOD further suggest that the enhancement of bone resorption previously noted with superoxide generating systems may be due in part to generation of H2O2.
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Affiliation(s)
- J H Fraser
- Department of Medicine & Therapeutics, University of Aberdeen Medical School, Foresterhill, UK
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84
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Sunyer T, Rothe L, Jiang X, Osdoby P, Collin-Osdoby P. Proinflammatory agents, IL-8 and IL-10, upregulate inducible nitric oxide synthase expression and nitric oxide production in avian osteoclast-like cells. J Cell Biochem 1996; 60:469-83. [PMID: 8707887 DOI: 10.1002/(sici)1097-4644(19960315)60:4<469::aid-jcb4>3.0.co;2-q] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Nitric oxide synthase (NOS) isoenzymes generate nitric oxide (NO), a sensitive multifunctional intercellular signal molecule. High NO levels are produced by an inducible NOS (iNOS) in activated macrophages in response to proinflammatory agents, many of which also regulate local bone metabolism. NO is a potent inhibitor of osteoclast bone resorption, whereas inhibitors of NOS promote bone resorption both in vitro and in vivo. The possibility that osteoclasts, like macrophages, express a regulated iNOS and produce NO as a potential autocrine signal following inflammatory stimulation was investigated in well-characterized avian marrow-derived osteoclast-like cells. NO production (reflected by medium nitrite levels) was markedly elevated in these cells by the proinflammatory agents lipopolysaccharide (LPS) and the synergistic action of IL-1 alpha, TNF alpha, and IFN gama. inhibitors of NOS activity (aminoguanidine, L-NAME) or iNOS induction (dexamethasone, TGF beta) reduced LPS-stimulated nitrite production. LPS also increased the NOS-associated diaphorase activity of these cells and their reactivity with anti-iNOS antibodies. RT-PCR cloning, using avian osteoclast-like cell RNA and human iNOS primers, yielded a novel 900 bp cDNA with high sequence homology (76%) to human, rat, and mouse iNOS genes. In probing osteoclast-like cell RNA with the PCR-derived iNOS cDNA, a 4.8 kb mRNA species was detected whose levels were greatly increased by LPS. Induction of iNOS mRNA by LPS, or by proinflammatory cytokines, occurred prior to the rise of medium nitrite in time course studies and was diminished by dexamethasone. Moreover, osteoclast-like cells demonstrated an upregulation of NO production and iNOS mRNA by IL-8 and IL-10, regulatory mechanism's not previously described. It is concluded that osteoclast-like cells express a novel iNOS that is upregulated by inflammatory mediators, leading to NO production. Therefore, NO may serve as both a paracrine and autocrine signal for modulating osteoclast bone resorption.
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Affiliation(s)
- T Sunyer
- Department of Biology, Washington University, St. Louis, Missouri 63130, USA
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85
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Abstract
Nitric oxide (NO), a mediator of cardiovascular homeostasis, neurotransmission, and immune function, has recently been found to have important effects in bone. Both constitutive and inducible forms of NO synthase are expressed by bone-derived cells, and cytokines such as interleukin-1 (IL-1), tumor necrosis factor (TNF), and interferon gamma (IFN-gamma), are potent stimulators of NO production. When combined with other cytokines, IFN-gamma markedly induces NO production, which suppresses osteoclast formation and activity of mature osteoclasts. This "superinduction" of NO is largely responsible for the selective inhibitory effect of IFN-gamma on cytokine-induced bone resorption. High concentrations of NO are also inhibitory for cells of the osteoblast lineage, and NO production appears to be partly responsible for the inhibitory effects of cytokines on osteoblast proliferation. At lower concentrations, however, NO has different effects. Moderate induction of NO potentiates bone resorption, and the constitutive production of NO at low concentrations promotes the proliferation of osteoblast-like cells and modulates osteoblast function. NO therefore appears to be an important regulatory molecule in bone with effects on cells of the osteoblast and osteoclast lineage and represents one of the molecules produced by osteoblasts which directly regulate osteoclastic activity. Stimulation of NO production in bone by proinflammatory cytokines raises the possibility that NO may be involved as a mediator of bone disease in conditions associated with cytokine activation, such as rheumatoid arthritis, tumor associated osteolysis, and postmenopausal osteoporosis.
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Affiliation(s)
- D M Evans
- Department of Medicine and Therapeutics, University of Aberdeen, Scotland, UK
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86
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Abstract
The hallmark of biological mineralization is the precise regulation of mineral deposition in space and time. The cells which produce mineralized tissues are themselves controlled by developmental programs and hormonal signals which result in regulation of gene expression and modulation of protein function. These signals are transduced into changes in enzyme levels and/or activity. Upon activation, cellular enzymes then act to synthesize the organic matrix and process it extracellularly, utilize metabolic energy to transport ions from the blood to the matrix, and to initiate the mineralization cascade. The first enzyme activity described in mineralizing tissues was alkaline phosphatase and it is still the best characterized enzyme in the mineralization process. Yet, important questions about the role of this protein remain unanswered, and it continues to occupy a central focus in mineralized tissue investigation. Other phosphatases, including protein tyrosine phosphatases are important in regulating tyrosine kinase mediated signals. Investigators have now begun to look closely at several groups of kinases which are also important for proper mineralization. As peptide hormones are important modulators of mineralized tissues, protein kinase A has always been presumed to play a key role in phosphorylating intracellular proteins. There is also considerable interest in protein kinase C, as well as tyrosine kinases in mineralized tissue signal transduction. Another group of kinases important in mineralized tissues are the enzymes which phosphorylate the matrix phosphoproteins. Of these, casein kinase II appears to be involved in intracellular and extracellular protein phosphorylation. Several enzymes present in the premineralized matrix are thought to be significant in triggering mineralization. Alkaline phosphatase may act at this level, but new data also suggests that metalloproteases and gelatinases, by modifying or digesting matrix components, may be important in the initiation of calcification.
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Affiliation(s)
- E E Golub
- Biochemistry Department, University of Pennsylvania, School of Dental Medicine, Philadelphia 19104-6003, USA.
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